all features in gsm ran sw g10b

Title

Sub Title

Document Name

Rev PA1

Title

© Ericsson AB 2015All rights reserved. The information in this document is the property of Ericsson. Except as specifically authorized in writing by Ericsson, the receiver of this document shall keep the information contained herein confidential and shall protect the same in whole or in part from disclosure and dissemination to third parties. Disclosure and disseminations to the receiver's employees shall only be made on a strict need to know basis. The information in this document is subject to change without notice and Ericsson assumes no responsibility for factual inaccuracies or typographical errors.

Rev PA1 2014-12-11 Ericsson AB 2014 2 (716)Commercial in confidence

Title

Contents

Table of contents need to be updated (Contents → Create Table of Contents → Choose heading level 1.1 and press OK)


Title

1 Features Introduced in 09A or Earlier - BASIC FEATURES


Title

1.1 2048 WCDMA Neighbor Cells

Feature Identity: FAJ 121 617/1, Rev. A

Feature Type: Basic in G10B

Technology: GSM

1.1.1 Attention

Commercial attention

Not applicable

Dependencies

No internal technical dependencies have been defined for this Feature

1.1.2 Summary

The feature makes it possible to define up to 2048 WCDMA neighbor cells per BSC. This is useful in areas with small WCDMA cell sizes compared to the GSM cell sizes.

1.1.3 Benefits

The feature gives the following benefits:

Flexibility in radio network planning as all WCDMA cells also in densely planned WCDMA networks can be defined as neighbour cells.

Better quality in the WCDMA network as MSs will enter the best cell.

MSs can move from GSM to WCDMA when anywhere within the WCDMA coverage area.


Title

1.1.4 Description

The increased number of WCDMA neighbor cells makes it possible to have all WCDMA cells within the coverage area of a BSS as neighbors to the BSS. It will therefore be possible to have a defined WCDMA neighbor cell in all areas with WCDMA coverage. Furthermore, it gives the flexibility to define neighbor cell relationships to the most likely and best suited WCDMA cells to hand over to, which improves the quality in the WCDMA network.

The feature increases the maximum number of external WCDMA neighbor cells that can be defined in the BSC from 512 to 2048. Cell relationships between these cells and the GSM cells can be defined.

The total number of cell relationships that can be defined between the GSM cells and the WCDMA cells is increased from 8192 to 16384 per BSC. These relationships specify the possible targets and rules for handover from GSM to WCDMA (from a GSM cell, to a WCDMA cell).

The maximum number of WCDMA neighbors that can be defined for a GSM cell is still 64.


Title

1.2 Active BA-list Recording



Technology: GSM

1.2.1 Attention


Not applicable

Dependencies


1.2.2 Summary

This feature supports the operator in finding the most appropriate set of neighbor cell relations within one BSC when adding new cells, or optimizing the neighbor cell relations in the radio network. It also supports the operator in the task of finding the best location for micro cells.

1.2.3 Benefits

Decreases the operation and maintenance cost for the operator by facilitating optimization of the neighboring cell relations for a cell.

Increases radio network quality and decreases dropped call rate by providing support in detection of omitted neighboring cell relations.

Increasing radio network quality by providing support with removal of neighboring cell relations seldom used, which will increase the accuracy of the measurements reports sent by the mobile to the BSC (which is important in dense radio networks).

Decrease the operation and maintenance cost by facilitating the process of finding the best locations for micro cells.


Title

Assure the value of investment by allowing the operator to know the traffic in a micro cell before the installation.

1.2.4 Description

It is important in a network to specify an adequate number of neighboring cells (n-cells) in the BCCH allocation (BA) list in the system information. Too many n-cells in the BA-list will cause the mobiles to give less accurate measurement reports to be used by the Locating algorithm in order to improve the quality of the network. Too few n-cells will have a negative impact on the quality in the network which may lead to bad speech quality and increased dropped calls.

Up to 64 recordings are possible, but a cell can only be defined in one recording at a time. It is possible to define one, several, or all cells in a recording.

The operator specifies what type of recording is to be made for all cells in the recording. The alternatives are:

Only defined neighboring cells are to be recorded.

Only undefined neighboring cells are to be recorded, test frequencies are specified.

Both defined and undefined neighboring cells are to be recorded, test frequencies are specified.

An undefined neighboring cell is a cell that has not been defined as a neighboring cell to another cell. Thus, handover cannot be done between the cells. The test frequencies may be the BCCH frequency of the neighbor cells neighbor.

It is also possible for the operator to control when a neighbor cell or test frequency is to be recorded by specifying an absolute and/or relative signal strength compared to the own cell. This gives the operator the possibility to only record the occurrences which fulfils the operators quality levels of when a cell shall be regarded as a neighbor cell.

The BSC starts the recording by including the frequencies (temporarily, only in alternative 2 and 3) to be evaluated in the BA-list of the cells specified. The BSC measures how often the cells are perceived as a neighbor cell by the mobiles.

In order to keep the number of frequencies in the BA list as low as possible, only an operator specified number of test frequencies will be added in the BA-list. If there exists more test frequencies, the BSC will automatically add those test frequencies after a defined time and remove already tested frequencies. This is continued repeatedly during the recording period.


Title

The recording output contains the following information in order to rank the cell and the n-cells to that cell, and is provided for all cells in the recording.

For the serving cell:

The average signal strength.

The total number of received measurement reports.

The total number of received measurement reports with undefined neighboring cells.

For each reported combination of frequency and BSIC in the received measurement reports:

How many times a combination occurred.

The average signal strength.

How many times the combination was reported as strongest, second strongest, etc.

The average signal strength when a combination was strongest, second strongest etc.

How often the combination occurred with a signal strength higher than or equal to the serving cell plus the defined relative signal strength.

How often the combination occurred with a signal strength higher than or equal to the defined absolute signal strength.

How often the combination occurred as the only neighboring cell.

After the recording has ended, the BSC saves the results of the recording in a file for further processing or the result can be obtained in an alphanumeric form. The reports can be transferred to OSS for further evaluation and graphical presentation. With the information, the operator will be able to optimize the BA-list for all cells in the recording.

After the recording the BA-list will contain the neighboring cells specified before the recording started and all test frequencies are removed from the BA-list.

Active BA-list Recording together with a BCCH test transmitter (for example the TEMS transmitter), makes up part of the OSS feature Traffic Estimation Tool. The Traffic Estimation Tools makes it possible to measures the traffic in a potential micro cell site before the deployment.


Title

The test transmitter is placed at the potential site location. By including the BCCH-frequency of the test transmitter in the BA-list for the cells close to the transmitter, mobiles within the coverage area of the transmitter will include its BSIC, frequency and signal strength in the measurement report.

By defining an absolute signal strength and by recording how often the combination occurred with a signal strength higher than or equal to the defined absolute signal strength, it is possible to determine the traffic the cell would have carried being a real micro cell. By evaluating different site locations the best alternative could be chosen.

Further more, knowing the amount of traffic that the micro cell will carry before the deployment, it is possible - in advance - to assure that the micro cell yields enough traffic to justify the investment.

1.2.5 Enhancement

Not applicable


Title

1.3 Advanced Frequency Handling



Technology: GSM

1.3.1 Attention


Not applicable

Dependencies


1.3.2 Summary

This feature optimizes GPRS/EGPRS services as well as SDCCH configurations when frequencies are spread over a larger spectrum or when many frequencies are used within a cell.

This enables 1/1 frequency reuse in large spectrum allocations as well as optimized frequency handling when the feature FAJ 122 085 Multi Band Cell is used.

1.3.3 Benefits

The benefits of this feature are the following:

Many frequencies, up to 128, can be allocated in a cell.

Large frequency bands can be used for 1/1 configurations.

More than 16 frequencies can be used in a frequency hopping multi band cell.


Title

1.3.4 Description

The maximum number of frequencies per cell is increased to up to 128 frequencies. This makes it possible to use 1/1 frequency reuse in large spectrums. In many cases, especially when frequency hopping is used, it is also a prerequisite to be able to deploy the feature FAJ 122 085 Multi Band Cell. For example the feature is needed when more than 16 frequencies is wanted in a frequency hopping multi band cell.

The main obstacle to enable more frequencies in a cell has been that allocation of SDCCH, as it is defined in the GSM Standards, is done using the old phase 1 method. This leads to a number of frequency band dependent restrictions regarding the number and range of frequencies that can be used in a frequency hopping cell. By restricting SDCCH to be configured only in channel groups with frequencies that can fit into the formats used for SDCCH allocation it is possible to circumvent the restrictions, thereby enabling more frequencies in a cell. For allocation of TCH this is not a problem since frequency allocation can be done according to the phase 2 method, where only the frequencies in the used channel group needs to be specified.

To be consistent with the increased number of frequencies per cell, new frequency formats for allocation of GPRS/EGPRS channels have also been implemented.


Title

1.4 Advanced Single Slot Allocation



Technology: GSM

1.4.1 Attention


Not applicable

Dependencies


1.4.2 Summary

TCH allocation has been significantly expanded by enhancing the existing quality based strategy and introducing new strategies for multislot and MAIO (Mobile Allocation Index Offset) considerations.

This makes it possible to adjust the TCH allocation according to the preferred traffic mix in the radio network.

1.4.3 Benefits

The Advanced Single Slot Allocation feature offers the following benefits:

The flexibility to choose channel allocation strategy that best suits the desired traffic mix.

High channel quality as well as decreased interference is achieved when allocation of channels is done with quality consideration.

Minimized co-channel and adjacent channel interference is achieved when allocation of channels is done with MAIO consideration.


Title

Higher data throughput for multislot CS and PS connections is achieved since the new strategy for allocation of channels with multislot consideration will increase the probability of having consecutive timeslots available.

1.4.4 Description

It is possible to choose between three different strategies (quality, multislot and MAIO consideration) for allocation of single slot TCH connections depending on the preferred traffic mix in the radio network.

The TCH allocation strategy with quality consideration is based on channel quality data provided by the feature FAJ 122 909 Idle Channel Measurement. It prioritize channels with low interference levels and it is recommended to be used when the channel quality is considered the most important criteria at channel allocation. In case idle channel measurement is not activated the strategy will instead give preference to channels hopping over as many frequencies as possible.

TCH allocation with multislot consideration leaves as many idle channels as possible for multislot calls and will therefore increase the probability of having consecutive channels available for incoming multislot traffic. The multislot strategy enhances allocation of multiple timeslots for both circuit switched data and packet switched data calls.

The TCH allocation strategy with MAIO consideration is to be used when it is of outmost importance to minimize the interference from co-channels and adjacent channels within and between cells. This applies to networks using synthesized frequency hopping and fractional load planning (FLP 1/1 and 1/3) with high fractional loads. The MAIO strategy gives preference to channels with MAIO that minimizes interference. The amount of interference that is generated by a channel with a certain MAIO is determined by the MAIO planning. In order to set MAIO to other values than the default setting the feature FAJ 122 870 Flexible MAIO Management is needed.

The choice of strategy is made per channel group. If more than one strategy is configured in a cell, channels with quality strategy will be allocated first, second are channels with MAIO strategy and last comes channels with multislot strategy.


Title

1.5 Alarm Co-ordination



Technology: GSM

1.5.1 Attention


Not applicable

Dependencies


1.5.2 Summary

This feature will reduce the amount of BTS-related alarms in the BSC.

It will be possible to set the allowed filter time that should pass before an alarm is triggered. The purpose is to let the fault situation stabilise, avoiding unnecessary alarms to be triggered. After the fault situation has stabilised the faults will be input to the alarm co-ordination procedure.

The feature will allow the operator to co-ordinate alarms, received from a transceiver group, such that only one alarm is presented for that specific transceiver group. The presented alarm will always be the one having the highest severity level.

1.5.3 Benefits

This feature will be possible to reduce the volume of alarms without reducing the amount of available information.


Title

The timing window allows reducing the amount of alarms that gives no real information to the operator. The fault situation will then stabilise before an alarm is triggered. The real fault may be received before or after the reception of intermittent alarms. This feature also makes is possible to adapt alarm sensitivity functions to the operator"s situation, for example, transmission network characteristics.

In addition, this feature will allow for alarm co-ordination on a transceiver group level, that is, if this feature is enabled, only one alarm per transceiver group will be received. The alarm with the highest severity level will always be shown.

It will also be possible to print all outstanding hidden alarms.

1.5.4 Description

It will be possible to set a filter time window intended to reduce triggering intermittent alarms.

The filter time window can be set by command per transceiver group. The filtering time is set per transceiver group, which makes it, for example, possible to have different alarm filtering times on transceiver groups with bad transmission quality on the Abis compared to transceiver groups with good transmission quality on the Abis.

After the alarm filtering, the alarms will be input to the alarm co-ordination procedure.

When a transceiver group is defined, it will have the alarm co-ordination on transceiver group switched off as a default. The alarm co-ordination can be set on or off. If the alarm co-ordination is switched on, the hidden alarms can be printed for one or more defined managed objects.


Title

1.6 Alarm Suppression



Technology: GSM

1.6.1 Attention


Not applicable

Dependencies


1.6.2 Summary

This feature will suppress alarms, originated from a certain source, from being shown to the operator.

1.6.3 Benefits

If it is known that faults from a specific source do not correspond to a real fault, it is possible to suppress the alarms originated from this source.

1.6.4 Description

The alarm suppression can be requested on a per transceiver group basis in following alarm situations:

On TGC fault (all faults on a transceiver group)

Permanent fault

Local maintenance terminal intervention

Class 1 fault


Title

Operation and maintenance fault

TS synchronisation fault

Class 2 fault

Local mode

Loop test fail.

The above specification means that alarm situations associated with the above faults can be suppressed. It is also possible to suppress all alarms originated from a specific transceiver group.


Title

1.7 Assignment to Another Cell



Technology: GSM

1.7.1 Attention


Not applicable

Dependencies


1.7.2 Summary

This feature provides the possibility to assign a Traffic Channel (TCH) in a cell other than the one currently serving the connection, to an MS during call set-up. There are two possible reasons for making this assignment:

Congestion in the cell to which the MS made the access.

The locating function identifies another cell as a better cell.

1.7.3 Benefits

There is a higher probability of success at the first call set-up attempt when the current cell is congested, since free TCH"s in surrounding cells can be used. The benefit for the end-user is therefore increased availability of the network.

Another benefit for the operator is that this feature makes dimensioning of the network more resistant to temporary, local traffic peaks.

In addition, this feature ensures that the MS will be assigned to the cell with the best radio network quality.


Title

1.7.4 Description

At call set-up, the MS is communicating with the system on a Stand alone Dedicated Control Channel (SDCCH) for a short period of time. After that, a TCH is assigned to the MS.

If the feature is not implemented, the call set-up is terminated if there is no free TCH in the cell to which the MS belongs. The subscriber has to make a new attempt. A second attempt may be equally unsuccessful if there are still no free TCH"s in the cell. The situation is not improved until a TCH becomes available, or the MS moves to another cell having free TCH"s. When this feature is introduced, a TCH with less signal strength in a nearby cell can be chosen if the current cell is congested, or if the nearby cell has a better quality.

Care must be taken not to disrupt the interference situation in the network by letting MS"s be assigned to any possible surrounding cell. The locating function makes an evaluation of the possible candidates, and selects the next cell in the candidate list.

It can happen that the locating algorithm makes a different choice of the best cell than the idle mode cell selection algorithm in the MS. The reason might be that conditions have changed, or that the cell selection algorithm in the MS has not made the correct choice, as perceived by the locating algorithm. When introducing the feature, an operator does not have to pay attention to this difference: the choice made by the locating algorithm is valid and provides the basis for assignment to a neighbouring cell. Thus a possible source of disturbances is eliminated.


Title

1.8 Automatic Reconfiguration of BCCH and SDCCH



Technology: GSM

1.8.1 Attention


Not applicable

Dependencies


1.8.2 Summary

Broadcast Control Channel (BCCH) and Stand alone Dedicated Control Channel (SDCCH) will automatically be reconfigured in the event of a BTS fault and subsequent loss of the physical channel.

The BCCH and SDCCH logical channels will be transferred to another transceiver within the same Transceiver Group.

1.8.3 Benefits

System availability is increased. This feature ensures that the signalling capability between the MS and the network is always supported by the network.

The priorities made by this feature will ensure that the best possible reconfiguration result is obtained

1.8.4 Description

A configuration specification is created from the input given by the operating staff. It is matched with available BTS equipment, and then the BTS equipment is configured accordingly.


Title

Once the equipment has been set up to match the configuration specification, the system will attempt to maintain this. If equipment that is being used becomes unavailable, an attempt will be made to replace it with available equipment. The BCCH and SDCCH are the highest prioritized channels when re-configuring.

An example would be if the TX (Transmitter) carrying the BCCH channel becomes faulty. In that case any TX that is free or only carrying traffic channels may be taken, thereby connecting the BCCH in preference.


Title

1.9 Automatic Reconfiguration of TRAUs (Transcoders)



Technology: GSM

1.9.1 Attention


Not applicable

Dependencies


1.9.2 Summary

If Transcoder Rate Adaptation equipment fails, it will automatically be replaced with fault free equipment, if available.

1.9.3 Benefits

High transcoding reliability gives increased system availability. The benefit of this for the end user is less probability of call congestion.

1.9.4 Description

The TRA codes and decodes the information sent to and received from a mobile station. With this feature a fault in TRA equipment with a TRX connection leads to an automatic change to fault free equipment. If no such equipment exists, the equipment will be replaced when some becomes available.

This feature is valid when a semi-permanent TRA-TRX connection is used.


Title

1.10 AXE Hardware Inventory in BSC



Technology: GSM

1.10.1 Attention


Not applicable

Dependencies


1.10.2 Summary

The AXE hardware inventory feature provides a function that automatically keeps track of all installed boards and their inventory information.

1.10.3 Benefits

An exchange consists of several components that constitute a large portion of an operator's investment in a GSM network. The management of all the individual components at repair, replacements, upgrades, extensions, etc. contributes to a substantial part of the costs to operate the network.

One important mechanism to get control of the investment and the subsequent management costs is a well functioning Facility management. A cornerstone in a facility management process is a good inventory system especially for the type of equipment that is handled a lot and represents a substantial value.

Until now these types of systems require a lot of manual work. Each board or replaceable unit is individually marked with a label describing the unit including a unique serial number. The information is available both as text and in bar code form. The bar code makes it possible to faster and more accurately input the data in an inventory system but it is still a mainly manual process that is very slow and costly and the information easily deteriorate over time.


Title

The Hardware Inventory function in AXE provides a function that automatically keeps track of all installed boards and their inventory information. It makes it possible for the operator to create an automated facility management process that eliminates the expensive costs for manual inventory of equipment. The main benefits are:

Better control over the installed hardware With the hardware inventory function it is possible, at any time, to get a complete view of the hardware installed in the switch

Reduced manual work There is no longer any need to send personnel to site for inventory. Also the preparation time when making updates to a site can be reduced

Better board localization The position of each board (X,Y and Z) can be entered into the system, thus making it possible to exactly locate each board in the switch

1.10.4 Description

The Hardware Inventory can be described as composed of five areas:

'

The boards with their individual PROM containing the Hardware identification

The Hardware circuitry and low level software (SW) that reads the PROM

The central software in the switch that gathers the information read from the hardware and adds information about location of the boards

The Hardware Inventory Manager that stores all the data in a database and assists in providing the information about where the boards are located. This part of the inventory is provided by OSS and is not a part of this feature.

The Hardware Inventory Tool which makes it possible to check the hardware from a PC, locally at site. This functionality is provided in the WinFIOL and Tools software.

HARDWARE IDENTIFICATION

The HW identification consists of the following information:

Product Name

Product Number

Product Revision


Title

Serial Number

Production Week

The information is available on all boards built according to the BYB 501 building practice except the IOG HW (IOG 20 B, C and M). The information is written into a PROM on the board at the production process. It is the bar code information on the labels on the board that is read by a scanner and written into the PROM to assure data consistency.

THE HARDWARE CIRCUITRY

The process to read the information varies depending on the architecture of the different parts of the system. Two different sources for hardware information exists:

Central Processor

APZ 212 25 and APZ 212 30 has their own internal mechanisms to read the PROM on the boards in the CPG.

RP controlled equipment

The majority of the HW in a switch is controlled via RP's. In the BYB 501 building practice the subracks are equipped with RP's that connects the equipment to the serial RP-bus. These RP's can via a Maintenance bus in the back plane of the subrack read the PROM of the individual boards. This design makes it possible to read the information on a board without any support from the board itself. This means that the hardware inventory information can be read from a board irrespectively if the board is blocked, faulty, in operation or even without power.

One RP is reading the information from half of the boards in the subrack and the other from the other half. The maintenance bus is not duplicated so if one RP is faulty then its half of the boards can not be read. But the information about the faulty RP can be read since that is read by the other RP in the subrack.

The RP's are continuously scanning the Maintenance bus to detect any changes of the hardware.

CENTRAL SOFTWARE

The software in the central processor gathers information from the two sources and stores the information in DBS tables.

The hardware identification information is supplemented with information about the physical position of the board in the subrack in accordance with the information on the ruler printed on the front of the subrack.


Title

For RP controlled equipment the type of subrack is added by the operator as part of the hardware installation process.

The operator can also add information about the magazine position in the exchange as an X, Y and Z co-ordinate. This will enable the Hardware Inventory function to provide exact position information about each individual board in a complete 3-dimensional view of the switch.


Title

1.11 Back-up in Main Store



Technology: GSM

1.11.1 Attention


Not applicable

Dependencies


1.11.2 Summary

BSC data can be backed up in Main Store. This feature reduces the time that certain functions and commands are blocked during output of complete system backup copy and during the automatic output of data dump (DS dump).

1.11.3 Benefits

The main benefit for the operator is reduced Operation and Maintenance costs. During output of the system backup copy and Data Store dump, certain commands are blocked. This feature reduces the time when the commands are blocked. The time required for reloading will also be considerably reduced

in most cases.

1.11.4 Description

With this feature, whole or parts of the system backup copy can be stored in the main store.

If the Data Store dump is stored, a function is obtained where the blocking times for certain functions and commands is greatly reduced.


Title

If a complete system backup copy is stored, the system backup copy will be loaded from the main store in case of reloading. The reloading time will be considerably reduced.

When dumping to an external file medium the reloading is first dumped to the main store. Thereafter a low priority job is started that copies the reloading information to the reloading file.

Archiving software and data is necessary to ensure system security. Depending on operator choice, a number of software versions can be stored. Back-up copies of data are kept in the support processor to be reloaded in case of an exchange reload. Time schedules for making back-up copies can be specified.

Log files log all main events taking place in the time period between back-ups. At system reload, the logged information is added to the reload information.

The system backup copy contains system reloading information and is stored on an external file medium such as magnetic tape, optical disc, or hard disc. The system backup copy comprises, the Program Store (PS)/Reference Store (RS) dump and the small and large data dump.

The data dump is a copy of certain variables in the data store.


Title

1.12 Battery Test



Technology: GSM

1.12.1 Attention


Not applicable

Dependencies


1.12.2 Summary

Battery test functionality reduces maintenance cost, environmental impact and improves in service performance (ISP). This is achieved by introducing test of battery backup time and optimized battery charging.

1.12.3 Benefits

Battery Test offers improvements in three areas:

Reduced maintenance costs

Reduced environmental impact

Improved ISP


Title

1.12.4 Description

The battery backup time is tested (on cyclic basis) and if the measured time is less than an operator configured expected battery backup time an alarm is generated. This reduces the operator's maintenance costs, avoids unnecessary replacements of batteries (saves money and is good from an environmental point of view) and gives the operator the ability to replace the batteries before they are in too bad condition, rather than finding out that a RBS runs out of service due to bad batteries or changed load conditions.

Charging of the batteries is improved to support FVLA, VRLA, Na/MeCL and NiMeH battery types. The new charging algorithms will optimize the charging depending on the battery type. This means that the RBS will have full battery backup faster after a power outage. The battery life will also increase since the probability of a discharge with a not fully charged battery is decreased.

The feature is available for the following RBS 2000 macro configurations:

single cabinet

master + extension with separated or shared batteries

sites with several RBS 2000 sharing one battery (set)

The Power Supply Unit (PSU) must be either PSU 230 or PSU AC and batteries must support more than 0,2 hours of backup time.


Title

1.13 BSC IP connectivity

Feature Identity: FAJ 121 665/2, Rev. B


Technology: GSM

1.13.1 Attention


Not applicable

Dependencies

Hardware impacts and dependencies

Either BSC LAN Switch (Summit 48si) or NWI-E (Network Interface Ethernet) are required.

Internal product impacts and dependencies

Not Applicable

Other node impacts and dependencies

Not Applicable

Terminal impacts and dependencies

Not Applicable

1.13.2 Summary

The BSC IP Connectivity feature provides a well-defined IP over Ethernet interface for the BSC. It enables the operator to connect the BSC to IP infrastructure on the site using one of several supported L2 and L3 solutions.


Title

1.13.3 Benefits

The main benefits are:

A single IP / Ethernet interface to the BSC

A documented and verified IP over Ethernet interface

Hi availability

IP security

1.13.4 Description

The central part of the IP-connectivity feature is a Layer 3 Ethernet switch integrated with the BSC and set up in 1+1 configuration for redundancy. Both Summit48si (BSC LAN Switch) and Network Interface Ethernet (NWI-E) are supported.

A configuration script facilitates the creation of a correct switch configuration. With a set of parameters, the configuration can be adapted to the specific requirements of the operator, such as:

Port/physical separation

VLAN tagging

L2 topology

VRRP

BFD (only on NWI-E)

IP subnets

Next hop gateway

An Access Control List (ACL) can be configured to protect the BSC from IP access from other IP subnets than those explicitly permitted.

1.13.5 Enhancement

Enhancements in GSM RAN software G13B:


Title

BFD is supported on NWI-E

Up to four external ports are supported

The L2 topology can be chosen per traffic type


Title

1.14 BSC Supervision Functions



Technology: GSM

1.14.1 Attention


Not applicable

Dependencies


1.14.2 Summary

This feature contains of a number of BSC supervision functions. Examples of supervision functions provided by this feature are:

Blocking supervision of devices in the BSC

Supervision of logical channels availability

Seizure supervision in the BSC

Software file congestion supervision

The supervision functions will issue alarms if the supervised devices are acting abnormal.

1.14.3 Benefits

This feature enables the operator to continuously supervise the BSC. If a problem occurs it will be easy to detect and localise. The feature will thus increase the quality of the radio network.


Title

1.14.4 Description

Blocking supervision of devices in the BSC.

This function checks that the number of blocked devices per device owning block does not exceed a pre-set limit value. An alarm is issued when a limit value is reached. The blocking supervision is issued per device group. A group of devices are all devices belonging to a device owning block.

Blocking supervision includes devices towards the MSC and in the transcoder.

Supervision of logical channels availability.

This function checks that the number of available Logical Channels (LCH) per cell or subcell does not fall below a pre-set limit value. If the limit is exceeded an alarm is issued.

The function is connected per one type of LCH and per cell or subcell.

Logical channel (LCH) is a name used in common for Stand alone Dedicated Control Channel (SDCCH), Traffic Channel (TCH), Broadcast Control Channel (BCCH) or Cell Broadcast Channel (CBCH).

Seizure supervision in the BSC.

The purpose of this function is to point out those devices in the BSC, that have an interface towards the MSC, which are continuously busy or never used during the supervision period. An alarm is issued if a supervised device is continuously busy or never used during the supervision period.

The function also supervises dedicated channels to detect if they too are continuously busy or never used during the supervision period. It is possible to decide if supervision should take place for not used channels only, continuously busy channels or both. Dedicated channels here are Stand alone Control Channels (SCCH) and Traffic Channels (TCH).

Software file congestion supervision

This function enables the exchange personnel to detect incorrectly dimensioned software files in traffic blocks that cause congestion and loss of calls.

A congestion event is an event that is encountered when an attempt to seize a file individual fails because there are no idle individuals.

The function comprises a facility for storing congestion events in a log list and an optional issuing of an alarm when the first congestion event occurs.


Title

1.14.5 Enhancement

In the previous release, the function Co-ordination of Alarms in the BSC was included in this feature. In this release it has been enhanced. The enhancement is covered by two new features in this release : NF 195.1 Alarm Coordination and NF 197.1 Alarm Suppression.


Title

1.15 BSS 06A SW Upgrade

Feature Identity: FAP 131 280/1, Rev. B


Technology: GSM

1.15.1 Attention


Not applicable

Dependencies

Minimum release level on nodes interfacing BSS 06A is MSC R10, MSS 3.0, SGSN 5.5, CGSN R3 and SMPC 6.0.Minimum release level on OSS-RC is R3.1.

1.15.2 Summary

The functionality in BSS 06A SW Upgrade provides a number of mutually independent benefits:

Support for PGW HW in BSC, used for the optional features Abis Optimization and Abis over IP

Support for PSTU HW, which provides the IP/Ethernet interface in the RBS for Abis over IP

NC2 provides a platform for advanced Packet Data traffic control features. Features based on NC2 may be designed to optimize resource utilisation, service availability and quality of packet based services in GSM/WCDMA and GSM only networks.

Extended Dynamic Allocation for DTM multi slot classes optimizes the throughput uplink vs downlink based on traffic need for the packet data part of DTM.

In BSS 06A the following optional features are enhanced: FAJ 121 25, Tandem Free Operation and FAJ 122 433, Efficient Priority Handling.


Title

1.15.3 Benefits

-

1.15.4 Description

1.15.4.1 Technical Description

1.15.4.1.1 Supported 3GPP standard

BSS 06A SW Upgrade supports 3GPP R6/Sep 2005 (GERAN meeting #26).

1.15.4.1.2 BSS Support for PGW (Packet GateWay) HW

BSS 06A SW Upgrade introduces support for PGW. PGW is needed for the optional features FAJ 121 997, Abis Optimization and FAJ 121 998, Abis over IP. Feature Descriptions for Abis Optimization and Abis over IP and BSC HW Product Package Descriptions provide more details.

1.15.4.1.3 BSS Support for PSTU HW

BSS 06A SW Upgrade introduces support for PSTU HW. The PSTU HW provides the IP/Ethernet interface for RBS 2308. Feature Description for Abis over IP and RBS product descriptions provide more details.

1.15.4.1.4 NC2 (Network Control Mode 2) – based on 3GPP R6

When the terminal is in NC2 mode, the network controls the cell re-selection decisions. The terminal sends measurement reports to the system, and the system decides on cell reselections and orders the terminal to do the reselections.

NC2 can be used as basis for implementing advanced PS locating features in GSM/WCDMA as well as GSM only networks. These features could be used for for example cell reselection decisions based on requested service and network load, in order to optimize resource utilization, service quality and availability.

In BSS 06A the optional feature FAJ 122 601 “Optimized throughput at GSM to WCDMA Cell Change” is based on NC2.


Title

1.15.4.1.5 Extended Dynamic Allocation (EDA) support for DTM – based on 3GPP R6

EDA support for DTM enables dynamic time slot allocation between up- and downlink for the packet data part of DTM. EDA will then prioritize up vs downlink based on in which direction the best throughput is needed.

In BSS 06A the optional feature FAJ 122 615 “DTM class 11; Two Packet Data Time Slots in Uplink” is based on EDA for DTM and support for additional DTM multi slot classes in coming releases will also be using this capability.


Title

1.16 BSS 06B SW Upgrade



Technology: GSM

1.16.1 Attention


Not applicable

Dependencies

BSC HW Impact: BSS 06B does not support BYB 202 or mixed BYB 202/BYB 501 nodes (valid already in BSS 06A).BTS HW Impact: NoneDependencies to other network elements:Minimum release level on nodes interfacing BSS 06B is MSC R11, MSS R3.0, SGSN R6, CGSN R4 and SMPC 7.0.Minimum release level on OSS-RC is R4.1.

1.16.2 Summary

The functionality in BSS 06B SW Upgrade provides a number of mutually independent benefits:

Support for functionality in 3GPP R6 up to GERAN meeting #28 (January 2006)

Support for new BSC HW:

The doubled capacity of the latest generation of Transcoder HW, TRA R7, reduces footprint and power consumption of a given BSC/TRC configuration.

SLI boards for SIGTRAN Support in BSC

BSC IP Connectivity Enhancements:

O&M Traffic Prioritization for improved quality of service with BSC IP Connectivity


Title

Extended support for IP network optimization with support for RMON Statistics in BSC LAN Switch

Performance Management enhancements:

Performance management support for SAIC (Single Antenna Interference Cancellation) capable mobiles

Improved statistics for GPRS/EGPRS; radio environment quality, number of active users, cell reselection performance

Statistics for Intra cell handovers when Half-Rate is used

O&M Support for Abis over IP:

Software and Hardware Management, Configuration Management and Fault Management are introduced to support Abis over IP networks

3GPP Compliance for re-distribution of users in MSC In Pool

General System Improvements:

Improved fault detection of Abis and Ater interface devices by monitoring call drops on device level

Improved GPRS/EGPRS service availability through load regulation of internal statistics

In BSS 06B the following optional features are enhanced: FAJ 121 50 Real Time Event Data, FAJ 122 072 Operation and Maintenance Terminal, FAJ 122 345 Remote Operation and Maintenance Terminal and FAJ 121 618 Remote OMT over IP.

1.16.3 Benefits

-


Title

1.16.4 Description



All interfaces are updated to support 3GPP/GSM Release 6/GERAN meeting #28 (January 2006).

1.16.4.1.2 Support for new BSC HW

1.16.4.1.2.1 Transcoder HW (TRA R7)

TRA R7 represents the next step in the enhancements of the speech-processing platform. TRA R7 doubles the processing capacity compared to TRA R6B, which means support for 384 channels per board. This capacity is valid for all codec types and also when Tandem Free Operation (TFO) is used.

TRA R7 uses low voltage technology, which reduces the power consumption per TRA channel. These capabilities reduce the footprint and power consumption for a given BSC/TRC configuration.

1.16.4.1.2.2 SLI (Signalling terminal for IP) HW

Support for SLI HW is introduced BSC. SLI is the signaling terminal for IP Signaling Transport and required for the optional feature “SIGTRAN Support in BSC”.

1.16.4.1.3 BSC IP Connectivity Enhancements

1.16.4.1.3.1 Traffic Prioritization of O&M Traffic

This functionality applies to the BSC LAN Switch and makes traffic separation and O&M traffic prioritization possible. It is possible to differ between two types of traffic; traffic related to file transfers using FTP/SFTP/TFTP or proprietary file transfer protocols and traffic related to command and alarm handling. The BSC LAN switches acts on QoS parameters (like DSCP=DiffServ Code Point) set by other IP hosts in the network.

This functionality provides improved QoS support and reduces latency of real-time sessions like MML commands will be reduced.


Title

1.16.4.1.3.2 Support for RMON (Remote Network MONitoring) Statistics

This function makes it possible for OSS to capture performance data from the BSC LAN Switch using RMON. Extending performance measurement using RMON statistics simplifies the work with network optimization. RMON is developed by IETF, launched 1993 and evolved from SNMP.

1.16.4.1.4 Performance Management Enhancements

1.16.4.1.4.1 SAIC statistics

Performance management support specifically for SAIC (Single Antenna Interference Cancellation) mobiles is introduced making it possible to compare performance between SAIC and non-SAIC mobiles.

New counters are introduced to calculate the penetration level of SAIC capable MSs in the network.

1.16.4.1.4.2 New radio link bit rate counters

New counters are introduced to improve the monitoring of the radio environment quality. The new counters only consider radio blocks sent with an optimal coding scheme. By not including coding scheme ramp-up and ramp-down periods a more accurate measurement of the radio quality is obtained.

Two counters for acknowledged downlink data for GPRS and EGPRS mode TBF is introduced.

1.16.4.1.4.3 User session counters for GPRS

New traffic load counters are introduced, periodically showing active users that transferred any payload data uplink or downlink data the last second. GMM/SM signaling is not included and DTM, non-DTM, EGPRS and GPRS connections are treated separately.

1.16.4.1.4.4 Counters for UL TBF release due to cell reselection

Two new counters are implemented (one for the whole cell and one for the overlaid subcell), which counts uplink TBF releases due to successful cell reselections. This is done in order not to count a successful cell reselection as lost radio contact.


Title

1.16.4.1.4.5 Intra cell handover counters at HR packing

Two new counters to count the number of intra cell handovers caused by HR packing are introduced.

1.16.4.1.5 O&M Support for Abis over IP

To support definition of a new TG for Abis over IP and to migrate a TG from TDM mode or Abis Optimization to Abis over IP updates have been made to existing management applications in OSS-RC R4.

1.16.4.1.5.1 Configuration Management of STN (Site Transport Node for RBS)

Configuration control flow is handled via Bulk operations i.e. download, activate and upload.

1.16.4.1.5.2 Fault Management of STN (Site Transport Node for RBS)

The alarms and stateless events are generated from the STN/BTS and are transferred via SNMP.

A Heartbeat event is generated by the STN to the OSS according to a predefined time when no alarm/event have been generated.

1.16.4.1.5.3 Software and Hardware Management of STN(Site Transport Node for RBS)

Software- and hardware management are integrated into Software Management Organizer (SMO) in OSS-RC R4.

1.16.4.1.5.4 3GPP Compliance for re-distribution of users in MSC In Pool

The CAP parameter range has been changed from 1-255 to 0-255. The CAP parameter defines the capacity of the MSC relative the other MSCs connected to the BSC. The BSC will distribute subscribers to the MSCs based on their relative CAP values. MSC selection does not distribute new subscribers towards MSC nodes with CAP = 0.


Title

1.16.4.1.6 General System Improvements

1.16.4.1.6.1 Improved Supervision of Abis and Ater devices

This functionality improves the detection of faulty devices connected to the Abis and Ater paths. An alarm is generated if a certain percentage of the calls for a Abis or Ater line interface device ends with a drop. The drop level (in percentage) for when the alarm shall be raised is configurable.

It is also possible to define which action to be taken on the suspected faulty device: “Do nothing”, “Use the device only if there are no others available” or “Take the device out of operation”.

1.16.4.1.6.2 Load Regulation of GPH Internal Statistics

This functionality does a load regulation of the printout of GPH Internal Statistics to ensure that RPP restarts due to processor overload or lack of memory does not occur. This guarantees that GPRS/EGPRS traffic is not affected by the printouts and the service availability is thus improved.


Title




Technology: GSM

1.17.1 Attention


Not applicable

Dependencies

BSC HW Impact:BSS 07A does not support BYB 202 or mixed BYB 202/BYB 501 nodes (valid already in BSS 06A).APZ 212 20/25 is not supported.BTS HW Impact: NoneDependencies to other network elements:Minimum release level on nodes interfacing BSS 07A is MSC R11, MSS R3.0, SGSN R6, CGSN R4 and SMPC R8.Minimum release level on OSS-RC is R5.0.

1.17.2 Summary

The functionality in BSS 07A SW Upgrade provides a number of mutually independent benefits:

Support for functionality in 3GPP R6 up to GERAN meeting #31 (September 2006)

Packet Gateway load distribution, supporting PGW redundancy and load distribution over several Packet Gateways.

Encryption Algorithm Interworking, making it possible to have several algorithms active at the same time.

Antenna System Monitoring, giving the possibility to remotely detect antenna malfunction.

Enhanced Maintenance Logging, extending the trouble shooting capabilities.


Title

Improved EGPRS/GPRS performance:

Preserved MS battery with Extended Uplink, decreasing the MS battery consumption.

Pre-emptive re-transmissions in downlink, decreasing the latency especially under bad radio conditions.

EDA optimized TBF reservations, increasing the throughput for EDA capable MSs.

Improved TBF setup procedures, improving the setup success rate especially under bad radio conditions.

In BSS 07A the following optional features are enhanced: FAJ 121 997 Abis Optimization and FAJ 121 618 Remote OMT over IP.

1.17.3 Benefits

-

1.17.4 Description



All interfaces are updated to support 3GPP/GSM Release 6/GERAN meeting #31 (September 2006).

1.17.4.1.2 Packet Gateway (PGW) load distribution

To prevent overloading of individual PGWs, this feature monitors and, when necessary, distributes the CPU- and traffic load over available PGWs.

The feature detects PGWs considered to be highly loaded. The handling of one or more Super Channel Groups (SCGRs) is then scheduled to be moved to one or several PGWs with spare capacity so that the work load per PGW-RP is lowered to a desired level. For CPU- and traffic load being very high, these peaks are handled immediately. It is also possible to initiate the load redistribution manually.


Title

With PGW Load Distribution, PGW redundancy is introduced, i.e. if one PGW becomes faulty, the system will redistribute the Super Channel Groups belonging to this PGW onto other PGWs.

1.17.4.1.3 Encryption Algorithm Interworking

The handling of encryption algorithms is enhanced so that several algorithms can be active at the same time in a BSC.

At call set up and handover, the best possible algorithm is selected based on the capability of the BTS and the MS as well as information about encryption configuration in the MSC and BSC. This means that the encryption algorithm can be changed during call setup and handover, for example if one cell has A5/1 capable transceivers and the other cell has A5/2 only transceivers.

At algorithm selection A5/1 has highest priority followed by A5/2 and then A5/0 (no encryption). If the feature FAJ 121 0182, A5/3 Ciphering Algorithm is used, the A5/3 algorithm has highest priority.

Algorithms that are not to be used can be turned off. For example, A5/2 can be turned off to comply with the GSM Association phase out directive.

The improvements allow for operators with a mix of A5/1 and A5/2 only transceivers in their network, to directly start to introduce enhanced security without having to wait for a complete HW change out.

1.17.4.1.4 Antenna System Monitoring (ASM)

Antenna System Monitor provides supervision of the antenna system.

It monitors the difference in received signal strength on different RX paths belonging to the same TRX and by the result judge any malfunction on the antenna system.

ASM can be used where the TX and the RX are connected to the same antenna element. If RX is configured to No Diversity, ASM will not work.

The limits for RX imbalance (SSRxA-SSRxB) difference criterion is possible to change via the OMT in local or connected state and via the Remote OMT. An alarm will be issued when the calculated RX imbalance is greater than the threshold set for the RX imbalance.


Title

1.17.4.1.5 Enhanced Maintenance Logging

The feature is used for trouble shooting in the BSC and is referred to in The Data Collection Guideline. It has in 07A been enhanced to cover more areas in the BSC.

1.17.4.1.6 Improved EGPRS/GPRS performance

1.17.4.1.6.1 Preserved MS battery with Extended Uplink

Today's terminals are required to send dummy data on uplink as a response to a USF (Uplink Scheduling by the network) when no other data is to be transmitted (empty data buffers). This consumes battery in the terminal and creates interference in the uplink spectrum. The dummy data are frequently sent when the terminal operate in Extended UL TBF mode, especially in combination with the feature Persistent Uplink Scheduling which schedules the terminal frequently.

3GPP Rel-6 has introduced an option for the terminal not to respond to uplink scheduling with dummy data, unless the terminal has data to send. This will lead to 10-40% reduced battery consumption during the data transfer.

BSS 07A introduce support for this 3GPP option, which also require terminal support.

1.17.4.1.6.2 Pre-emptive re-transmissions in downlink

The BSS will re-send data blocks in downlink before a response (Ack/Nack) has been received from the terminal. This means that data blocks are re-transmitted before the network knows if the block has been lost or not. The benefit is that the terminal will receive lost blocks faster since it does not have to wait for a full Ack/Nack period. The second "blind" re-transmission will more or less guarantee that the block will go through (in normal radio conditions).

Example of benefits:

Ping time (32 bytes): will decrease with ~15% (R4 MS) and ~8% (R99 MS) at C/I <= 10 dB

Web/WAP/MMS: will be faster at bad radio conditions

Push to talk over Cellular (PoC): will have better service quality

The pre-emptive retransmissions are only performed when there are no other data to send on the PDCH(s), meaning that the feature do not impact any other services or users negatively.


Title

1.17.4.1.6.3 EDA optimized TBF reservations

The throughput for terminals using EDA (Extended Dynamic Allocation) is improved by more optimal channel allocation. Extended Dynamic Allocation is used for terminals with high uplink bit rate, typically allocating four uplink timeslots. When such terminals are multiplexed with single slot users (typically users performing periodic routing area update) the bit rate may be negatively impacted. In BSS 07A the channel allocation is improved so that the single slot user does not negatively interfere with the EDA user.

In addition, the time to enter EDA mode (e.g. when the user start sending data on uplink) is reduced from three to one second.

This feature increase FTP uplink bit rate during EDA mode with:

10-20% in live network

30% when multiplexed with GMM/SM TBFs

5% when alone (quicker EDA ramp-up)

1.17.4.1.6.4 Improved TBF setup procedures

The success rate of UL TBF establishments is increased under bad radio conditions thanks to an improved TBF setup procedure.


Title




Technology: GSM

1.18.1 Attention


Not applicable

Dependencies

BSC HW Impact:BSS 07B does not support BYB 202 or mixed BYB 202/BYB 501 nodes (valid already in BSS 06A).APZ 212 20/25 is not supported.BTS HW Impact:RBS 6000 configurations are supported.Dependencies to other network elementsMinimum release level on nodes interfacing BSS 07B is MSC R12.1, MSS R4.1, SGSN R7, CGSN R4 and SMPC R8.Minimum release level on OSS-RC is R5.2.

1.18.2 Summary

The BSS 07B SW Upgrade provides a number of mutually independent benefits:

Support for functionality in 3GPP R6 up to GERAN meeting January 2007

Counters have been enhanced and added to improve the ability to observe user and system behavior more accurately

Significantly increased consistency for cell configuration data

More reliable and informative RBS HW consistency check

Support for new BSC HW:

Reduced footprint, where the smallest configuration will only require 2 cabinets.

Less HW components, reducing installation time and spare part handling.


Title

HW prepared for future function growth without capacity degradation including inbuilt IP connectivity.

From BSS 07B and onwards the following optional feature is a basic feature:

FAJ 121 375, GPRS/EGPRS End-user Performance

In BSS 07B the following optional features are enhanced:

FAJ 122 437, A-bis Interface over Satellite

FAJ 121 997, Abis over IP

FAJ 121 846, Abis triggered HR allocation

FAJ 121 361, Dynamic FR/HR Adaptation

FAJ 121 582, Dynamic Half Rate Allocation

FAJ 122 625, Enhanced Handover Success Rate

FAJ 121 0100, Network Analyzer Interface,

FAJ 121 846, Real Time Event Data

1.18.3 Benefits

-

1.18.4 Description



All interfaces are updated to support 3GPP/GSM Release 6/January 2007.

1.18.4.1.2 FAJ 121 375, GPRS/EGPRS End-user Performance

This previously optional feature has been made basic. There is no change to the functionality. For technical description please see the document 1/221 04-FGB 101 125 GSM BSS Optional Features document.


Title

To use the feature it needs to be activated in the same way as for an optional feature.

1.18.4.1.3 Statistics Enhancements

The evaluation of DTX usage on the uplink is enhanced to provide better accuracy in FER statistics. DTX is now never assumed unless DTX signaling is explicitly detected. This results in fewer measurement reports being excluded from FER calculations when DTX is used at bad radio conditions.

New FER and RxQual monitors are provided in RPMO and EBS. The monitors are calculated over a configurable number (2-40) of measurement reports. A sliding window mechanism is used, meaning that a new value is calculated at reception of every new valid measurement report. For the FER monitor, measurement reports where DTX has been used are excluded. The FER monitor requires the feature FAJ 121 821 Enhanced Measurement Reporting.

A new counter is provided that monitors if FER is above a threshold when subscribers terminate a call. The purpose is to capture how often subscribers disconnect calls due to poor speech quality. The feature FAJ 121 821 Enhanced Measurement Reporting is required.

A new counter to monitor the penetration of SAIC (Single Antenna Interference Rejection) capable terminals using half rate channels is introduced.

The ability to observe Downlink TBF establishments has been improved. STS statistics have been updated to better reflect end-user impact of unsuccessful TBF establishment. A new counter is added to count the amount of buffer discards during the TBF establishment phase, which reflect the situations where the end-user is impacted due to loss of data. The existing counter for TBF establishment failures could show relatively high values, for example due to the functionality loss-free preemption, without any significant impact to the end-user.

In addition, a large share of TBF establishment failure case relates to the reason that the MS do not answer to a Downlink TBF setup request from the network. This case is now covered by a new counter.

1.18.4.1.4 OSS-BSC Interface for Cell Configuration Data

A new interface between OSS-RC and the BSC for sending cell configuration data is introduced. Compared to the existing MML printout based interface, it is much more efficient since it is a binary file interface where only changed data is included. The data is automatically sent from the BSC to CDM (Configuration Data Mart) database in OSS-RC when any changes occur, ensuring that OSS-RC is always up to date with a maximum five minute delay. The CNA application in OSS-RC can then access this data in CDM whenever needed.


Title

Compared to the current adjust procedure performed once a day (night) by CNA, the consistency of the cell configuration data used and displayed by CNA is significantly increased.

1.18.4.1.5 Improved RBS HW Consistency Check

The OMT functions Check IDB, Display Detected HW Information and Install IDB have been improved to make HW and IDB comparison more reliable by reducing dependency to product numbers. Information is now also presented for checks were no inconsistencies were found.

1.18.4.1.6 Support for new BSC HW

1.18.4.1.6.1 APZ 212 55

The new eGEM based CP reduces the foot-print.

1.18.4.1.6.2 APG 43

The new eGEM based I/O reduces foot-print.

1.18.4.1.6.3 GPHB

The eGEM based GPHB provides the GPH application with 4 times the capacity compare to RPP. It can handle 256 EGPRS TS or 512 GPRS TS.

1.18.4.1.6.4 TRHB

The eGEM based TRHB provides the TRH with 8 times the capacity compare to RPG-3. It can handle 256 TRXs.

1.18.4.1.6.5 STEB

New eGEM based HW for SS7 NB signaling and HSL Applications is provided. One STEB provides all SS7 signaling capacity needed for any BSC configuration and removes the need of GDM-H magazines for signaling.

1.18.4.1.6.6 GARP2 (PGW)

eGEM based HW for the PGW application. One board handles up to 200 TRXs.


Title

1.18.4.1.6.7 NWI-E

Plug in HW for the Ethernet interface, a DataCom cabinet is not needed.


Title




Technology: GSM

1.19.1 Attention


Not applicable

Dependencies

BSC HW Impact:- Support for APZ 212 55 and APG 43- No support for APZ 212 20, APZ 212 25 nor for IOG20.- Not supported BSC HW must be replaced before upgrading to BSC 08A. - BSC HW upgrade paths from APZ 212 20/25 + IOG20 to APZ 212 55 + APG43 exists in 06B- BSC IO swap from APZ 212 30 + IOG20 to APZ 212 30 + APG40 exists in 06A, 06B and 07A. BTS HW Impact:RBS 6000 configurations are supported.Dependencies to other network elementsMinimum release level on nodes interfacing BSS 08A is:- MSC R12.1, MSS 4.1- SGSN R7, CGSN R4 - SMPC 8.0Minimum release level on OSS-RC is R6.0.

1.19.2 Summary

The improvement area “BSS SW Upgrade and Update Improvements” gives the following benefits:

BSC Upgrade can be performed within one maintenance window

Support for upgrading at least three BSCs in parallel for all operators

Reliable and predictable SW load between OSS-RC and BSC in transmission networks with narrow bandwidth and/or link breaks

With the increased reliability, manageability and efficiency cost and lead-time for upgrading and updating a complete BSS network is reduced.


Title

1.19.3 Benefits

-

1.19.4 Description



BSS 08A supports 3GPP Rel-7.

1.19.4.1.2 BSS SW Upgrade and Update Improvements

1.19.4.1.2.1 Robust File Transfer between OSS-RC and BSC

In order to better handle SW upgrades and updates, where sometimes large amounts of data need to be transmitted over unreliable and bandwidth-limited transmission links, the BSC supports the new capabilities of the corresponding OSS-RC release.

OSS-RC (SMO application) uses new clients for FTP and SFTP that supports transfer resume.

The BSC APG IIS FTP Server and the BSC APG F-Secure SFTP server supports transfer resume.

A file transfer from OSS-RC to BSC or vice versa, will automatically be resumed without data loss after a temporarily broken connection

1.19.4.1.2.2 Three BSC Upgrades in Parallel

To create better means for an operator to perform several upgrades in parallel (per person) the OSS-RC tool is SMO is used, which provides superior overview compared to OPS. The upgrade and update processes are aligned.

The workload per BSC is reduced by minimizing the need for manual interaction. All pop-up questions are removed, except the ones that are related to failure messages or confirmation to proceed to a next phase with reduced functionality or redundancy. The operator may also be prompted to resolve a situation not possible to resolve in SW. Manual status analysis is removed.


Title

At least three BSC upgrades in parallel are possible for non-skilled operators. Skill and experience will set the upper limit for BSC upgrades in parallel.

BSC Upgrade within one Maintenance Window

A number of improvements are done to secure that a BSC upgrade - including CP, APG and fallback - can be done within one maintenance window (5 hours):

ASSAR: Automated Switch Status Analysis Report - Analysis script that reports only ”Abnormal status” instead of doing a manual analysis of a long printout list. This Makes it easier to see if the upgrade has succeeded or not.

Script Optimizations are done to increase the level of automation and provide more intelligent fault handling.

Recommendations are provided on what should be performed outside a maintenance window.

Pre-loading of RP reduces the freeze time during the upgrade restart. ISP (In Service performance) is improved by decreasing the System Down Time.

1.19.4.1.2.3 Additional improvements for BSC Update

Improvements that simplify the handling of correction packages, thereby reducing work and cost for implementing release updates:

Optimized package download handling Ericsson to customer and OSS-RC to BSC

Improved BSC update documentation, aligned with upgrade documentation

Improved RP loading robustness

Improved use of MISSRA marker (revision check of HW and SW)

On the fly help in pop-up windows

Continuous work to improve procedures


Title


Feature Identity: FAP 131 304/1, Rev. A


Technology: GSM

1.20.1 Attention


Not applicable

Dependencies

BSC HW Impact:- Support for APZ 212 55 and APG 43- No support for APZ 212 20, APZ 212 25 nor for IOG20.- Not supported BSC HW must be replaced before upgrading to BSC 08B. - BSC HW upgrade paths from APZ 212 20/25 + IOG20 to APZ 212 55 + APG43 exists in 06B- BSC IO swap from APZ 212 30 + IOG20 to APZ 212 30 + APG40 exists in 06A, 06B and 07A. BTS HW Impact:RBS 6000 configurations are supported.Dependencies to other network elementsMinimum release level on nodes interfacing BSS 08B is: - MSC R12.1, MSS 4.1,- SGSN R8, CGSN R4, - SMPC 8.0.Minimum release level on OSS-RC is R6.2.

1.20.2 Summary

The improvement area “BSS SW Upgrade and Update Improvements” gives the following benefits:

Faster upgrade to new SW level

Faster time to market with new features

Only one night for BSC upgrades

Estimated to give customer internal project savings of additional 5 kSEK/BSC (vs. BSS 08A)

8000 BSCs * 5 kSEK/BSC = 40 MSEK savings/year globally


Title

Decreased cost for services (similar savings as customer internal savings)

Improved documentation

Simplified and more reliable BSC updates

1.20.3 Benefits

-

1.20.4 Description



BSS 08B supports 3GPP Rel-7.

1.20.4.1.2 BSS SW Upgrade and Update Improvements

Robustness

Automated Cell recovery

Automated procedures (example: block/deblock of RBS) that reduce the time required for the Maintenance Window at BSC upgrade, enabling more upgrades in parallel

Stability

Reduce Manual Interpretation

ASSAR (Automated Switch Status Analysis Report) reduce critical upgrade time, supporting a number of additional commands compared with BSS 08A

Reduce Upgrade/Update Time

Support of 5 parallel upgrades/updates

Improvement from 3 parallel in BSS 08A, verification activity


Title


Feature Identity: FAP 131 314/1, Rev. A


Technology: GSM

1.21.1 Attention


Not applicable

Dependencies

BSC HW Impact: NoneBTS HW Impact:RBS 6000 configurations are supported.Dependencies to other network elementsMinimum release level on nodes interfacing BSS 09A is:- MSC R12.1- MSS 4.1- SGSN R8- CGSN R4 - MPS 9.0Minimum release level on OSS-RC is R7.0

1.21.2 Summary

The improvements specific to BSS 09A with significant benefit for the operator are:

Reduced time and complexity for SW upgrades including correction packages.

Improved ability to dimension the Gb capacity according to actual need.

Improved latency and coding scheme selection for EDGE thanks to improvements of the RLC/MAC protocol.

Reduced time and complexity in OSS to keep the information in CNA up to date.

In BSS 09A the following optional features are enhanced:

FAJ 123 145 EDGE Reduced Latency (Fast ACK/NACK)

FAJ 121 988 Abis over IP


Title

FAJ 123 142 Abis Local Connectivity - Satellite

FAJ 123 159 Abis Local Connectivity - Terrestrial

FAJ 122 072 Operation and Maintenance Terminal (OMT)

FAJ 122 345 Remote OMT

FAJ 121 618 Remote OMT over IP

FAJ 123 146 Support for 4000 TRXs per BSC (enhancement available at BSS G10B release date)

1.21.3 Benefits

-

1.21.4 Description



BSS 09A supports 3GPP Rel-7.

1.21.4.1.2 Reduced time and complexity for SW upgrades

The upgrade scripts and the correction packages for the BSS 09A release and onwards allow for upgrades to include correction packages.

The total time for SW upgrades including correction packages will therefore be reduced. This means that the extra Maintenance Window for update usually can be removed.

The risk to re-introduce errors that are already corrected in the “from-level”, but not yet included in the “to-level” is minimized. Customers can go directly to the latest correction package, without performing an extra update, thereby reducing cost in terms of time and money.


Title

1.21.4.1.3 Gb capacity monitoring

Counters are introduced that enable monitoring of Gb utilization. An alarm will be triggered when load is close to, or has reached, the configured Gb capacity (valid for both Gb/FR and Gb/IP).

1.21.4.1.4 Faster RLC/MAC

The RLC/MAC protocol layer in the Packet Control Unit (PCU) is improved. A tighter coupling between the two layers enables quicker reaction of scheduling and coding scheme selection. This gives improved latency, better resource utilization when multiplexing several users, less use of dummy blocks and a more optimal coding scheme selection.

1.21.4.1.5 BSC-OSS Interface for Cell Configuration Data

The interface between the BSC and OSS-RC for sending BSS configuration data to OSS-RC is enhanced. Support for additional data used by the CNA application in OSS-RC is added. With this enhancement all data in CNA is kept up to date without using the time consuming adjust procedure in OSS-RC.

Configuration data used by the CNA application is automatically sent from the BSC to the Configuration Data Mart (CDM) database in OSS-RC when any changes occur. This ensures that OSS-RC is always up to date with a maximum delay of roughly five minutes. The CNA application can then access this data in CDM whenever needed. Compared to the current adjust procedure performed once a day (night), the consistency of the cell configuration data is significantly increased.


Title

1.22 BSS Connectivity Test



Technology: GSM

1.22.1 Attention


Not applicable

Dependencies


1.22.2 Summary

This feature allows testing of transmission paths between the logical TRC and BTS, in both directions.

All paths are tested automatically at system start. Paths are also continuously supervised during transmission, that is for both idle and active channels.

1.22.3 Benefits

This feature benefits the operator in that they can reduce the risk of putting a faulty BTS or BSC/TRC into service. At installation of a BTS, all speech connections are automatically tested before installation personnel leave the site.

Connectivity tests can also be carried out while the system is in operation. This reduces the risk of end-users experiencing fault situations or a decrease in service quality. A unit will not be used by the system unless it has been registered free of faults.


Title

1.22.4 Description

In RBS 200 and RBS 2000, all speech paths from a BTS to a BSC/TRC are automatically tested when new units are put into service.

In both RBS 200 and RBS 2000, all idle speech paths from a BSC/TRC to a BTS are automatically

tested. For an RBS 200, a local BSC terminal at the BTS site can be used to initiate this test.

During BSS operation, all transmission links (Abis paths) are continually supervised in both directions. The operator is informed about fault events, for example loss of synchronisation. This makes it possible for corrective action to be taken quickly.

Synchronisation between the TRC and the IWU (a part of the MSC) is also supervised.


Title

1.23 BSS R10 GPRS/EGPRS Improvements



Technology: GSM

1.23.1 Attention


Not applicable

Dependencies


1.23.2 Summary

To improve the packet data system the following GPRS/EGPRS improvements are introduced:

Increased RPP capacity for EDGE

Detect and Release Hanging PDCHs and TBFs in PCU

Gb Link Recovery

PCU Configuration (Single/Multiple RP environment)

RRGBP Improvements

More GPRS/EGPRS Counters

1.23.3 Benefits

The BSS R10 GPRS/EGPRS improvements have the following benefits:

Improved performance for packet switched services.

Reduced need for RPP HW


Title

More PDCH's available for multislot users as well as more on-demand PDCH's being returned to the CS domain.

Improves robustness and stability of the BSS.

Improved ISP.

Avoiding capacity losses.

Flexible, faster, less processor consuming and more user-friendly printout command for checking the status of the GB interface.

Improved end to end performance management tools for packet data services.

Improved ability to monitor performance of the GPRS/EGPRS functionality in BSS.

1.23.4 Description

Increased RPP capacity for EDGE - The capacity of the RPP boards when supporting EGPRS has been significantly enhanced in BSS R10. The number of supported EDGE TS (E-PDCH) is now 64 per RPP board compared to the previous 56. This has been made possible by better utilization of the DSP capacity of the RPP boards. This is almost a 15% improvement in supported number of EDGE capable timeslots and will consequently reduce the need for RPP HW in an EDGE enabled network correspondingly. The same improvement is also valid for GPRS channels supporting CS3/CS4 (G-PDCHs).The number of basic GPRS channels (B-PDCHs) supported remains at 150 PDCHs per RPP.

Detect and Release Hanging PDCHs and TBFs in PCU - If a TBF (Temporary Block Flow) is occupied without any ongoing activity for a while, this can be classified as a 'hanging TBF'. The result is that PDCHs are not only busy by 'hanging TBFs' but more severely, will not be returned to CS traffic. The existing 'auto release' of hanging TBFs is improved and expanded to detect more cases and more RP modules.

Detecting more hanging TBF cases in more RP modules improves the robustness and stability of the BSS. The effect is that more PDCH's are available for multislot users and more on-demand PDCH's are returned to the CS domain. This also leads to significantly improved end-user performance, both for data and speech connections. This can be compared to Forlopp Audit time-out in CP environment.

Gb Link Recovery - The current implementation of Gb recovery is improved so that a lost Gb link (an NSVC) is recovered immediately and while the Gb link is still 'missing' an attempt is made to restore new Gb links. This avoids the Gb bandwidth to stay reduced a long period of time.


Title

The improvement will give a better behavior so the Gb links can be dimensioned based on the real utilization but still having a proper behavior after faults. This leads to improved end-user performance, both for data and speech and ultimately to significantly improved ISP figures for the BSS.

PCU Configuration (Single/Multiple RP environment) - The current way to select Single or Multiple RP environment of the PCU is automatic. However, there is a risk when automatically trying to determine if a PCU is Single or Multiple environment that potentially could lead to reductions in GPRS capacity. A more direct and secure way is implemented by adding two new commands and removing the automatic detection. A command to set the PCU configuration and another to print the PCU configuration is introduced. When the fault occurs, the PCU will run in 1 RPP mode and will not be expanded.

The risk of a GPRS/EGPRS capacity loss that could occur when the fault within the automatic detection of 'type of environment' happens is thus eliminated.

RRGBP Improvements - A new optional parameter is introduced in command RRGBP. The enhanced RRGBP printout command is more flexible, faster, less processor consuming and more user-friendly when only checking the status of the Gb interface. With the parameter it is possible to determine whether the cell information should be omitted or not in the printout.

More GPRS/EGPRS Counters - A whole range of new counters is introduced in BSS R10 to improve the performance management possibility of the GPRS/EGPRS service. It is based on the Ericsson concept of a layered structure which provides both top level counters as well as more detailed, lower level counters.

The following list summarizes the areas where additional counters are introduced:

Top level counters:

New downlink availability counters

New uplink availability counters

Improved IP throughput counters (weighted by data volume)

2nd level counters:

New counters for multi-slot utilization (allow a graphical distribution to be shown)

New counters to monitor impacts of users mobility

New counters to give a distribution of the GSL device usage in the PCU

New counters to give a distribution of the RPP load within the PCU


Title

Improved counters for radio link quality (weighted by data volume)

Improvements to GPRS/EGPRS traffic load counters

Counters to support new features:

Counters for the feature FAJ 121 375, GPRS/EGPRS end-user performance.

Extensive range of new counters for the feature FAJ 121 360, Streaming.


Title

1.24 BSS R10 System Improvements



Technology: GSM

1.24.1 Attention


Not applicable

Dependencies


1.24.2 Summary

To improve the BSS system characteristics, the following new functions are implemented:

Load Regulated CS paging via PCU

Adapt default values to recommended values for T3105. This improves both the handover success rate and downlink speech quality

Improved Emergency Call Handling

Enhanced RX Performance

Extended Fault Reporting for RBS 2202/2102/2101/2302/2301/2401

IDB and HW Consistency Check for RBS 2206/2106/2308

1.24.3 Benefits

The benefits of the system improvements in BSS R10 are:

O&M improvements


Title

Improved system robustness

Improved emergency call handling

Improved ISP (In Service Performance)

1.24.4 Description

Prior to BSS R10, CS Paging via the PCU is not load regulated to protect the BSC CP from overload and can in some severe cases lead to a Complete Exchange Failure (CEF). When a CS Paging was sent via the PCU (and on PACCH or PPCH), the MS responded with a CHANNEL REQUIRED (Paging Response) via the TRH. The TRH was only load regulating the paging response with the TRH-CP window. These calls were getting the highest priority and suppressed all other calls, even the emergency calls. This was not a problem if the GPRS traffic stay below 5-10% or Gs interface was not used. Note that CS paging via PCU that are sent on the normal PCH (then via the CP) is already load regulated.

Load regulation will be introduced in order to reduce the amount of CS paging via PCU in case of BSC CP overload. This means circuit switched mobile terminated calls will have the same overload behavior regardless if paging is received on the A or the Gb interface.

Load Regulating CS paging via PCU will help avoiding CEF's and significantly improve the ISP figures.

TIMER3105 indicates the time between repetition of physical information messages during the handover procedure. The change of the default value for T3105 will improve downlink speech quality as well as the handover success rate.

To increase the possibility to make emergency calls at SDCCH congestion this improvement is needed. The solution is to reserve the last SDCCH channel for emergency calls for 1 minute in case a random access with establishment cause 'emergency call' is received. In this situation, when the last channel is reserved for emergency accesses, then the traffic level for adaptive configuration of logical channels is compensated so that the reserved channel is not counted as idle.

The RX performance will be improved by approximately 1 dB for 8-PSK (EDGE). This is accomplished by new receiver algorithms and leads to improved data throughput and coverage.

Extended Fault Reporting will now also be available for RBS 2202/2102/2101/2302/2301/2401. This increases the number of fault types that can be reported over Abis by the BTS to the BSC which results in a higher fault localization capability. This increases the efficiency of BTS site visits which gives a decreased O & M cost as well as decreased downtime.


Title

The RBS HW configuration is described by the IDB (configuration file) that is installed by a field technician during RBS installation. If the field technician installs an IDB that is inconsistent with the actual HW configuration, the result is a RBS that might not function properly. With IDB and HW consistency check, the OMT will retrieve configuration information from the RBS in order to make a consistency check before installation of the IDB is performed. If an inconsistency is detected, a warning is issued which reduces the possibility of handling mistakes. When the warning is issued, the field technician can either abort the installation and correct the mistake or continue with the installation if the inconsistency was intended . The second scenario might occur when the installed IDB describes a future expansion possibility and the intention is to prepare the RBS for that future expansion.

1.24.4.1.1 Miscellaneous

Implemented in: BSC, BTS


Title




Technology: GSM

1.25.1 Attention


Not applicable

Dependencies


1.25.2 Summary

The handling of multislot PDCH allocation has been improved to improve channel utilization and reduce RPP load. The performance monitoring of GPRS/EGPRS is also improved.

The counters described in this feature are only the counters introduced for GPRS/EGPRS in general. In addition to these, there are also counters added specifically for some new features in order to give relevant support for optimization and performance management for these features.

1.25.3 Benefits


Improved channel utilization and reduced RPP load.

Improved ability to monitor performance of the GPRS/EGPRS functionality in BSS.

Improved ability to monitor the end to end performance of packet data users in BSS.


Title

Improved performance as optimization efforts can be directed to the most relevant areas for the end user.

1.25.4 Description

The channel allocation of PDCHs is improved to only allocate as many new PDCHs as is needed to support the requested multislot class of the MS. This means that over-allocation of PDCHs is not performed, which was the case before. The new allocation strategy is valid at reservation, upgrading and re-reservation of individual MSs. When new PDCHs are allocated due to load on existing PDCHs (TBFLIMIT threshold is exceeded) then only the number of new PDCHs needed to fall below the threshold plus one extra is allocated.

A whole range of new counters is introduced in BSS R11 to improve the performance management possibility of the GPRS/EGPRS service. It is based on the Ericsson concept of a layered structure which provides both top level counters as well as more detailed, lower level counters.

The following list summarizes the areas where additional counters are introduced:

Top level counters:

New counters for GPRS availability per cell. When the volume of data transferred in a cell is zero the counter can be used to check if the cell has been unavailable for GPRS

New counters for IP latency (round trip time in the BSS) for small IP packets per cell.

New counters for total LLC data volume (including GMM/SM signalling) per cell.

2nd level counters:

New counters added so that all abnormally released uplink TBFs per cell are counted.

New counters added to allow direct calculation of the average radio link bitrates per PDCH for CS1 to CS4 and EGPRS transfers on the downlink per cell.

Improvements to the downlink multi-slot utilization counters per cell. The average number of maximum reservable timeslots is counted separately for Basic mode TBF, GPRS mode TBF and EGPRS mode TBF. It allows for example the average IP throughput for EGPRS mode TBFs to be compared directly with the average number of reservable timeslots for EGPRS mode TBFs.

New counters for uplink multi-slot utilization per cell.


Title

New traffic load scanning counters per cell. The average number of simultaneous TBFs is counted separately for GPRS capable MSs and EGPRS capable MSs (in addition to the existing counters which are classified per TBF mode). It allows for example the average number of simultaneous EGPRS mode TBFs to be compared with the average number of simultaneous TBFs for EGPRS capable MSs.

Additional PS counter

The peak number of allocated PDCH per cell counter modified to give the peak during an entire STS measurement period.


Implemented in BSC.


Title




Technology: GSM

1.26.1 Attention


Not applicable

Dependencies


1.26.2 Summary


RPP HW Supervision

Frame Number Based Timers in the BSC

Improved LAPD handling

Change of Block Categories

GPRS/EGPRS Availability Monitoring

Mean Holding Time of TRA Improvements

1.26.3 Benefits

The Benefits of the system improvements in BSS R11 are:

More efficient trouble shooting of RPP HW

Improved GPRS performance


Title

Increased signalling capacity from the BTS, decreased peak load and decreased dropped calls.

Improved ISP

Identification of faulty GPRS/EGPRS cells

Improved identification of faulty TRA

1.26.4 Description

RPP HW Supervision

Adding a periodic test of the group switch interface from the RPP will provide better and faster error detection of the RPP HW.

In order to guarantee properly working data-links for all RPPs an APT maintained HW supervision is provided for all serial port units used by the on-board device processors of each RPP. This is accomplished by running a periodic group switch loop-back test.

Frame Number Based Timers in the BSC

Since the round trip time for messages varies a lot in different networks it is difficult to establish an exact value for a timer that needs to be coordinated between the MS and the PCU.

With frame number based timers the PCU indicates in what frame number a message is received from the MS. That is, when the timer in the MS starts. This frame number is then used by the PCU to calculate which frame number that is the last (or first) frame number that can be used to make sure that a message will reach the MS before (or after) the timer in the MS expires.

This will optimize the timing of messages between the MS and the PCU, and under certain conditions will the delays be shorter compared to without this function.

Improved LAPD handling

Every information frame sent from the BSC requires that an acknowledgement is sent back to the BSC. In this new implementation the acknowledgement is sent back to the BSC together with other frames, which enables an increase of the signaling capacity from the RBS.


Title

An SDCCH/8 will generate 8 MR's (Measurement Results) for every 470 ms TDMA multi-frame. Today the SDCCH/8 MR's are sent on RSL at the same time as payload signaling. In the new implementation the peak load is decreased as the MR's are sent on RSL during periods when no payload signaling is sent.

When the system (link) becomes overloaded, the system will start to throw frames away (MR frames as well as other signaling frames). By throwing frames in a more controlled way during peak load, every 8th or 4th MR dependent on link load, the dropped call rate can be decreased.

Change of Block Categories

In order to improve ISP some SW blocks in the BSC have got their block categories downgraded from 2 to 1 or 0. Block category 2 handles more critical functions than 0 and 1. The typical action will be an immediate small system restart if a fault occurs in blocks with category 2.

GPRS/EGPRS Availability Monitoring

This procedure identifies cells with no packet switced traffic during the last five minutes and then tries to induce packet switched traffic in these cells. If the attempts to induce traffic fail and at the same time other GPRS traffic volume counters suggest that there has been no GPRS traffic in the cell, the cell is suspected faulty.

Mean Holding Time of TRA Improvements

Depending on the value of a new BSC parameter the Mean Holding Time function will take different actions while monitoring the mean holding time for the transcoder resources. An alarm may be raised and the TRA may be taken out of service based on the call drop rate compared to the value of the parameter.


Implemented in RBS and BSC.


Title




Technology: GSM

1.27.1 Attention


Not applicable

Dependencies


1.27.2 Summary

Several system improvements for GPRS/EGPRS are introduced in BSS R12. These changes allow for better Temporary Block Flow (TBF) handling, reduced RPP load and an improved performance management. Shorter access times for real time services and better handling of E-GSM band are also part of the system improvements.

1.27.3 Benefits


Easier to switch between GPRS and EGPRS mode making end-to-end performance better

Shorter access times for the initial set-up of GPRS/EGPRS sessions improving performance for real time services

Better channel utilization as better granularity in the decision to allocate new PDCHs

Improved channel reservation for GPRS/EGPRS resulting in better PDCH utilization and end-to-end performance


Title

Improved ability to monitor performance of GPRS/EGPRS

Better support for GPRS/EGPRS in E-GSM band

1.27.4 Description

TBF mode switch

To ensure best possible performance for end users this feature provides the ability to change TBF mode between GPRS and EGPRS. Since there is no support for changing mode of an ongoing TBF in the 3GPP specifications the way to change TBF mode is to release both UL and DL TBFs connected to the MS in question and set it up again using the new TBF mode. As a result of this a short interruption in the data flow will occur but as the new TBF is better suited to take care of the user the end-to-end performance is improved. MSs having only an UL TBF or TBFs belonging to DTM connections are not considered.

Note that this functionality removes the necessity to have an EGPRS capable dedicated PDCH in cells in order to use EGPRS mode during the lifetime of a TBF. This is particularly useful in combination with FAJ 122 450, Flexible Abis.

Faster TBF setup

The initial (first) GPRS/EGPRS access is improved by triggering the TBF downlink setup earlier in the process. The functionality builds upon the Early setup of DL TBF functionality (FAJ 121 375, GPRS/EGPRS End-user Performance). The effect is a reduction in "first Ping" times with up to 120 ms. From an end-user perspective it creates better perception for real-time services like push-to-talk and gaming.

Better granularity in TBF sharing parameter

By allocating new PDCHs only when the number of TBFs on existing PDCHs exceeds the operator set limit, new PDCHs allocated in vain is avoided. The granularity of the configuration parameter is improved making it possible for the operator to have more exact control of the TBF sharing factor.

Improved PDCH utilization and reduced RPP load

When on-demand or semi-dedicated PDCHs no longer carry any traffic, a timer (PILTIMER) is started in order to delay the release of the PDCH in case new traffic will arrive. An idle PDCH uses RPP resources even though there is no traffic on it. Several changes have been made to this timer in R12.

The default value for this timer is changed to 10 seconds. Using shorter timer value reduces the RPP load significantly.


Title

The timer is no longer restarted for idle PDCHs every time a TBF is setup just for signaling on a few of the available PDCHs (PSET). This avoids having several idle PDCHs consuming RPP resources when for instance only Cell Updates or Routing Area Updates are taking place. The result is reduced RPP load.

The timer is no longer restarted for idle PDCHs every time an existing TBF on some of the PDCHs available (PSET) is upgraded with more timeslots. The result is reduced RPP load.

Improved performance management

New counters are introduced to improve the performance management possibility of the GPRS/EGPRS service. The counters listed are only the general counters not linked to a specific R12 feature.

New throughput counters based on MS GPRS/EGPRS capability

Counter for Immediate Assignment messages discarded due to congestion on AGCH (both CS and PS Immediate Assignments)

Packet Flow Context's (PFCs) with lower priority are excluded from the cell level throughput counters for users that run several parallel PFCs

Counter for number of UL TBFs where the MS turned up on the PDCH, separate for DTM and non DTM connections

Improvements to the GPRS availability measure, a new peg counter for five minute periods the cell is suspected to be unavailable

Traffic load counters reflecting active TBF time (when data is transferred or in the downlink buffer), counters for number PDCHs and number TBFs per PDCH separately for E-, G- and B-PDCHs, uplink and downlink

Counter for total number versus used RLC blocks Uplink and Downlink

Better support for GPRS/EGPRS in E-GSM band

Operators that are using the Extendend GSM 900 band (P+G1) and have the BCCH defined in the P-band can still use the G1 frequencies for GPRS/EGPRS. This is possible as an existing parameter (MBCRAC) is extended with one additional value to indicate that not only the BCCH band but also the corresponding sub-frequency band is considered in the channel allocation algorithm.

With this improvement a very flexible an efficient use of the Extended GSM band is possible to achieve.


Title


Implemented in BSC.


Title




Technology: GSM

1.28.1 Attention


Not applicable

Dependencies


1.28.2 Summary


Improved RBS Fault Filtering

RBS External function change improvements

RBS Internal function change improvements

1.28.3 Benefits

The Benefits of the system improvements in BSS R12 are:

Removal of redundant alarms from remote transcoder lost will reduce number of faults

Faster RBS function change

Improved ISP


Title

1.28.4 Description

Improved RBS Fault Filtering

The improved RBS fault filtering reduces the number of 'Remote Transcoder Lost' fault reports generated by RBS and thus received at the BSC/OSS. The reduction is accomplished by abstracting the 'Remote Transcoder Lost' fault report from TS to TRXC level. This implies that the number of fault reports is reduced with a factor up to 8 at total link failure. For individual faults the number of fault reports will still be the same compared with today's implementation.

Faster External RBS Function Change

The time to execute External Function Change initiated by the BSC has been reduced with 13 minutes with RBS 2x06/2x07 by optimizing the downloaded files which is a redcution of 40% compared to earlier releases.

Faster Internal RBS Function Change

The time to execute Internal function change initiated by the RBS has been reduced with 40 - 151 seconds on sTRU's on RBS 2x02 and up to 106 seconds on a full RBS 2x06 by optimizing the Internal Function Change process which is a reduction of about 50% compared to earlier releases.


Title

1.29 BSS R9.0 System Improvements



Technology: GSM

1.29.1 Attention


Not applicable

Dependencies


1.29.2 Summary


Group Switch (GS) Loop Handling

SRS congestion supervision

TRH overload protection

Temporary increase of O & M priority at recovery

Larger window size on LAPD

Paging CCCH Overload Handling

STS Alarm for approaching counter limit

CP load regulation for CS and PS traffic

1.29.3 Benefits

The benefits of the system improvements in R9.0 are:


Title


Improved In Service Performance (ISP)

O&M improvements

Increased capacity

1.29.4 Description

The GS Loop handling is used to synchronize the TSs towards the BTS when transcoders are configured in pool and to check that the link is operating between the TS and the BSC GS. The new implementation of GS loop handling will result in a more robust BSS system. Blocked TSs in the BTS, due to unnecessary TS synchronization faults, are avoided. The TS synchronization fault alarm (also called "LMO 2000" fault) will now appear more precisely.

SRS congestion supervision provide the operator with the possibility to get a warning (alarm) when there is a risk for SRS congestion and an alarm when SRS congestion has occurred. This gives better fault localization and a basis for planning SRS extension. This function is supported by all GS variants.

TRH overload protection protects the TRHs from massive signaling from the BTSs. The signaling flow from the BTS is regulated by sending Receiver Not Ready (RNR) messages to the BTS. This will reduce the number of restarts in the BSC (both RP and CP restarts).

Temporary increase of O & M priority at recovery improves the recovery time during high CP load situations. This is achieved by prioritizing radio network recovery over traffic execution. The maximum percentage of CP utilization for radio network recovery is set per BSC. Emergency calls will always have higher priority. No faster recovery will be obtained at low CP load situations.

With Larger window size on LAPD, the window size is increased from 2 to 4. This increases the throughput of the LAPD Downlink. The Larger window size on LAPD can be used both concentrated and non-concentrated links.

Paging CCCH Overload Handling introduces an algorithm that limits the queue time in the paging groups to maximum 5 seconds for each paging. Also at queue congestion the oldest pagings are discarded. This makes the average queuing time less during CCCH overload situations. This feature will make it safe to run on high CCCH load and CCCH overload will be handled in a good way. With this feature many paging groups can be defined without having to risk poor paging performance at CCCH overload.


Title

STS Alarm for approaching counter limit introduces an alarm to indicate when the limit for the maximum number of counters that can be retrieved from the CP is reached.

CP load regulation for CS and PS traffic introduces new counters in the CP load control function that indicates traffic types. This gives better statistics.


Implemented in BSC and BTS.


Title

1.30 BSS R9.1 System Improvements



Technology: GSM

1.30.1 Attention


Not applicable

Dependencies


1.30.2 Summary

To improve the BSS system the following new functions are implemented:

Extended Fault Reporting

Support for increased number of RPPs per PCU

System Voltage Control

Battery Control

Enhanced RX Performance

Enhanced Synchronization


Title

1.30.3 Benefits

Reduced O & M cost

Reduced downtime

Increased PCU capacity

Improved indoor coverage

Increased MS battery lifetime

Need for less TX power from the MS leading to less uplink interference

Improved speech quality and capacity

Better throughput for data transmission uplink

Reduced RBS start up time due to reduced time to establish synchronism.

Improved robustness to synchronization reference disturbances. (Jitter, wander and intermittent breaks.)

Improved attenuation of synchronization reference disturbances. (Jitter and wander.)

Increased holdover time for some types of synchronization reference disturbances. (Jitter, wander and intermittent breaks.)

1.30.4 Description

The Extended Fault Reporting mechanism over Abis from a BTS to a BSC will be improved by increasing the number of fault types that can be reported. This results in that a high fault localization capability can be maintained even when new BTS products and antenna near products are introduced. Fewer and more effective BTS site visits are achieved with a high fault localization capability. Decreased O & M cost and downtime.

The Support for increased number of RPPs per PCU increases the system limit from 16 to 64 RPPs per PCU. This makes it possible to handle high GPRS/EDGE traffic volumes. Please note that it is 64 RPP boards per PCU and not per BSC, which implies that additional RPP boards can be used for High Speed Signaling Link (HSL).


Title

The System Voltage Control Feature makes it possible to change the system voltage via the OMT or Remote OMT. The RBS power supply (PSU) will charge the batteries with the system voltage that is specified. Changes from the default value can be made at installation of the RBS or later when the RBS is in operation, without restarting the RBS.

The Battery Control feature makes it possible to change the battery disconnect and reconnect voltages, temperature alarm limits and charging control mode (temperature compensated or fixed voltage). Support for fixed voltage charging that is introduced as part of this feature is the charging method that is recommended for some battery types. The parameters are changed via OMT or Remote OMT. Changes from the default values can be made at installation of the RBS or later when the RBS is in operation, without restarting the RBS.

The Enhanced RX Performance improves the receiver performance for RBS 2206/2106 by a new equalizer. The equalizer is used to estimate and calculate the most probable bit sequence transmitted from the mobile station, i.e. the content in the transmitted signal. By using improved baseband algorithms in the equalizer the BTS receiver performance is improved compared to RBS 2202/2102. Both the receiver sensitivity and interference suppression capability is improved. These improvements can be used by the operator either to improve speech quality or to increase capacity in the networks due to better spectrum utilization.

The synchronization function is needed to achieve air time-slot synchronization according to GSM standards. A regulator algorithm is used to synchronize the RBS to a long-term stable synchronization reference extracted from the transmission network. Disturbances in the transmission network introduce disturbances to the synchronization reference. An enhanced regulator algorithm in the RBS software gives improvements in robustness and performance to RBS functions that benefit from an accurate perception of time and frequency.


The improvement "Support for increased number of RPPs per PCU" is implemented in BSC.

The other improvements are implemented in BSC and BTS.


Title

1.31 BTS - Short Time to Operation



Technology: GSM

1.31.1 Attention


Not applicable

Dependencies


1.31.2 Summary

The feature "BTS - Short Time to Operation" speeds up the O & M operations in the total BSS system. The improvement will radically decrease the time to bring a BTS into operation. Therefore the BTS can be operational earlier and thus can increase the operators revenue.

1.31.3 Benefits

Following benefits are attained when bringing BTSs into operation either as a result of network extension or normal manual O & M:

Significantly better operation handling

Reduced execution time

Benefits reached in other situations are:

Saved time in areas such as the split of a BSC

Faster normal handling of the BSC


Title

1.31.4 Description

The feature is intended to be used by OSS to speed up the O & M operations in the total BSS system.

Load Interruption can be decreased, since loading of the MO twice today is reduced to only once in some situations.

The operator can choose if to automatically produce printouts and automatically perform TS Loop tests when bringing a BTS to operation. This will save execution time and operation handling will be improved.

The improvements will be visible to the operator using MML commands as well as using OSS (dependent on OSS implementation).


Implemented in BSC and OSS.


Title

1.32 BTS Backwards compatibility



Technology: GSM

1.32.1 Attention


Not applicable

Dependencies


1.32.2 Summary

The BTS will adapt and act with respect to the Abis interface and the functionality, according to the BSS release running on the BSC. The BTS will be able to adapt to both the latest and one previous BSC release.

1.32.3 Benefits

To always be sure that the latest SW is in place in the BTS's. The BTS may therefore already be SW prepared for R8 even if the BSC is on R7.

A consistent network, release wise, can be achieved when the BTS's are upgraded first. The network keeps workin

1.32.4 Description

Description of function

The BSC can already handle BTS's of the latest and one previous BSS release. It is possible to have BTS's of two different releases connected to one BSC, e.g. if the operator wants to upgrade the network stepwise.


Title

Analogous to this, the BTS will now be able to adapt to both the latest and one previous BSC release. The BTS will adapt and act with respect to the Abis interface and the functionality, according to the BSS release running on the BSC.

The BSC will basically "ask" the BTS which releases (or rather IWD versions) it supports and then select the one to be used and then inform the BTS about the selection. This "negotiation" of IWD version will occur between the BSC and the BTS whenever the BTS software changes. It must however also be performed whenever the BSC software is changed, i.e. at a BSC Function Change, or when it is uncertain whether a BSC change has occurred, i.e. at a large restart with reload.

This feature is valid for RBS 2000.


Title

1.33 Call Path Tracing in BSC



Technology: GSM

1.33.1 Attention


Not applicable

Dependencies


1.33.2 Summary

This feature traces and identifies all the devices, both hardware and software, and channels used in a connection between the BSC and a MS. The result is presented in a printout showing the actual connection.

1.33.3 Benefits

The Call Path Tracing feature lets the operator by command have a picture of a connection. This is a help at operation and it simplifies maintenance. Thus O & M costs can be decreased.

A connection can be investigated for suspect behavior. This allows potential problems to be identified and solved at an early stage.

1.33.4 Description

Call Path Tracing performs tracing of all significant blocks in the BSC participating in a connection and traces both the speech and signaling connections. The tracing function is able to handle connections during handover, set-up and disconnection. Signaling connections towards MSC are not traced.


Title

The tracing starts from a given device (hardware unit), Logical Channel Signaling Individual (LCSI), Traffic Channel (TCH) or Stand Alone Dedicated Signaling Channel (SDCCH). The result is a snap shot picture of a connection through the BSC in the form of a list of devices. For some of the devices miscellaneous information is given.

The tracing is static, that is the result show the state at one instant.

1.33.5 Enhancement

Tracing is also supported for subrate switching. It is possible to trace several connections if tracing is started on a device that is used for subrate switching.


Title

1.34 Cell Relocation Support Between BSCs



Technology: GSM

1.34.1 Attention


Not applicable

Dependencies


1.34.2 Summary

This feature supports the operator in the time consuming work of relocating cells and RBS"s between BSC"s.

1.34.3 Benefits

Reduced operation and maintenance costs by facilitating relocation of cells and RBS"s between BSC"s. An example can be introduction of new BSS network topologies such as BSC"s without transcoders.

Reduced downtime by faster relocation of cells and RBS"s between BSC"s.

1.34.4 Description

At relocation of cells between BSC"s, a number of data must be redefined for the target cell in the target BSC and removed from the original cell in the original BSC. Especially when relocating a border cell that is defined in both BSC"s, the cell can not have the same name in both BSC"s.


Title

This feature provides means to temporarily define cells and cell data in the target BSC. When the cell has been reallocated to the target BSC, the change of the cell name to the origin name used in the origin BSC is possible in order to have consistency of the cell.

At relocation of a cell and the RBS, the BSC makes a conditional load of the software in the RBS. New software is loaded in the RBS only if the software is of a wrong version. This reduces the downtime when relocating cells and RBS"s between BSC"s.


Title

1.35 Cell Traffic Recording



Technology: GSM

1.35.1 Attention


Not applicable

Dependencies


1.35.2 Summary

Cell Traffic Recording provides an efficient tool for in depth analysis of the radio path. The feature can be used for observation of live traffic and to provide statistical measurements.

The main difference between Cell Traffic Recording and Mobile Traffic Recording is that in Mobile Traffic Recording it is the operator in the MSC that decides which MS"s to record. In Cell Traffic Recording any MS fulfilling a cell triggering criteria is followed.

Up to 16 simultaneous recordings are allowed. A file output is made to the hard disc in the BSC. To make the file readable it must be processed in the OSS.

1.35.3 Benefits

The Cell Traffic Recording feature is an important tool to optimize the radio network .

The operator can monitor whether radio resources are being efficiently used. For example, the operator can check the data which is the basis for handover decisions. This enables the identification of parameter settings that should be adjusted.


Title

A cell with poor traffic performance can be investigated. This allows potential problems to be identified and solved at an early stage.

For example, after a cell re-configuration, the Cell Traffic Recording feature enables the operator to immediately check the radio network performance. This is to ensure that the network quality expected by the end user is maintained at its high level or preferably increased.

Cell traffic data can be compiled for statistical purposes. This can be analyzed and the results used as an input to network planning/optimization activities.

1.35.4 Description

The Cell Traffic Recording feature registers traffic events and measurement data for a radio path.

Two types of recordings can be specified, either recording of event data or recording of both event data and measurement data.

Event data contains information about type of event, connection reference and time when it occurred. Examples of recording events are: cell access, establishment indication, assignment command, assignment complete, assignment failure, various types of handover messages, various types of connection release messages, clear command, SAPI related messages, etc.

Measurement data can also be recorded. Measurement data is sent by the BTS and MS to the BSC. It contains measurement reports specified in the GSM specifications. A timing window specifies the time when measurement data is recorded which is defined by the operator (2-30 seconds). This is the data that is used as the basis for handover decisions.

Recording on a cell can be initiated either from the BSC or from the OSS. The recording starts when a triggering event takes place. Triggering events can be cell access, connection release, handover and trace invocation.

Event data is recorded, that is for events related to the specific connection. The events are classified according to the following categories:

Messages sent on Abis interface

Messages received on Abis interface

Messages sent on A interface

Messages received on A interface

Internal messages.


Title

Results from the Cell Traffic recording are given either as printouts at the BSC or as a file output that has to be post processed in OSS.

Cell Traffic Recording is active for one cell at a time in the BSC. Up to 16 simultaneous recordings are allowed and all of the recordings can be with measurement data.

1.35.5 Enhancement

The enhancements are:

Support of the new GSM Phase 2 message BSS INVOKE TRACE which is handled in parallel with the Ericsson proprietary message TRACE INVOCATION. This makes it possible to trace between other vendors MSC"s and Ericsson BSC"s.

Increased flexibility in defining the recording area. Recording of mobiles starts in one cell and the mobiles may be recorded in the starting cell only, in the starting cell and its neighboring cells or in the BSC.

More efficient file output to the IOG which gives higher output capacity thus decreases the possibility of interrupted recordings.

Time stamping in deci-seconds instead of seconds gives more accurate resolution.


Title

1.36 Channel Administration



Technology: GSM

1.36.1 Attention


Not applicable

Dependencies


1.36.2 Summary

The feature Channel Administration processes the allocation of radio resources within cells. The operator is provided with possibilities to control the logical rules for selection of resources in a cell for each specific traffic situation that demands resources. In addition to a default setting, the operator may choose amongst seven different allocation strategies in the form of Channel Allocation Profiles (CHAP) that a cell can be connected to.

1.36.3 Benefits

Flexibility by controlling the allocation strategy in cells, depending on traffic demand.

Better utilisation of traffic features like Immediate Assignment on TCH and.

Differential Channel Allocation.

Choice of detail level can be made from one BSC down to individual cells

A basic default strategy is delivered with the system.


Title

1.36.4 Description

Each Channel Allocation Profile (CHAP) specifies the behavior in all possible traffic situations defined. Each cell is connected to a CHAP, either by default or by operator command. The CHAP defines the resource allocation strategy for this cell.

Every CHAP contains different selection types. A selection type is defined as a unique traffic situation and is a combination of:

Traffic case (immediate assignment based on establishment cause), (assignment to serving/better/worse cell), (intercell handover), (intracell handover), (subcell change)

Subcell preferred (overlaid, underlaid/normal, extended range)

Channel mode (speech/data, signaling only)

TCH rate.

Each selection type in the CHAP is connected to a resource type priority list. A resource type priority list is defined as an ordered list of resource types. A resource type is a combination of:

Channel type (SDCCH, TCH/F, TCH/H)

Subcell (Underlaid/normal, overlaid).

At channel allocation in a cell the following will occur:

Find the CHAP defined by the operator for this cell.

Depending on the traffic case, the selection type is found.

The selection type defines which resource type priority list is used.

The resource type priority list defines the resource type.

The resource type defines the channel to allocate.

Failure at allocation will enable an attempt to allocate the next resource type defined in the resource type priority list.


Title

1.37 Channel Event Recording



Technology: GSM

1.37.1 Attention


Not applicable

Dependencies


1.37.2 Summary

The feature Channel Event Recording makes it possible to monitor the behavior of the channels in a cell during a time period defined by the operator. The recordings provide the operator with information needed when other features are to be optimized.

1.37.3 Benefits

The Channel Event Recording feature gives the information needed to optimise the features Idle Channel Measurement, Channel Administration and Differential Channel Allocation.

For example, when the optional feature Differential Channel Allocation is used some channels are just allowed to be used by high priority subscribers. With the Channel Event Recording feature the operator can get information about how frequently these channels are allocated/(used). The results may show that the operator can make one of these channels available for subscribers with lower priority and still have enough capacity for high priority subscribers. In this way the Channel Event Recording will help the operator to maximize the capacity of the radio network.


Title

Any adjustments needed concerning a specific channel are quickly identified. This improves the radio network availability.

1.37.4 Description

The feature Channel Event Recording provides the facility to record the changing of interference level on idle traffic channels. The operator will be able to monitor the channel status by obtaining recorded data for channel events. This feature can also be used to evaluate the features Idle Channel Measurement, Channel Administration and Differential Channel Allocation.

Channel events are allocation, creation, deletion, blocking, deblocking, releasing of a channel, and when the interference level is changed for a channel.

Channel Event Recording is initiated for a specified cell by command. In the command , cell designation and the duration time of the recording are given. The duration time can be set between one minute and ten hours. When the feature is initiated the state of all channels in the cell will be recorded immediately, including all parameters describing the channel. Subsequently a recording will start when a channel event occurs.

If an allocation event occurs following parameters will be recorded:

Channel individual

Time

Channel allocation profile

Selection type

Priority level

Resource type(s)

Channel allocation result (s).

At termination of Channel Event Recording an administrative record is stored, which includes information about recorded channel events.

The recorded data is collected and stored on a binary coded file. Post processing of the file is therefore necessary in order to make the recording function useful.

Channel Event Recording can be active for 16 cells simultaneously in the BSC.


Title

1.37.5 Enhancement

The feature now includes recording of the events locking and unlocking of a channel.


Title

1.38 Combined Control Channels



Technology: GSM

1.38.1 Attention


Not applicable

Dependencies


1.38.2 Summary

Four individual Stand Alone Dedicated Control Channels (SDCCH) are configured on one TDMA time slot, instead of the conventional eight SDCCHs. This makes it possible to combine all control channels necessary for call set up and to place them in one TDMA time slot.

This feature is related to NF 220.3 Supported Combination of Channel Types per TRX.

1.38.3 Benefits

The feature provides a capacity improvement in low traffic cells; that is, cells with one or two transceivers. It gives the operator the opportunity to use one time slot for both SDCCH and BCCH + CCCH signaling, and the other available timeslots for Traffic Channels. This enables the operator to increase capacity, for example, in rural areas.

If the feature is not included, the operator has to configure one separate time slot for BCCH + CCCH, and another time slot for SDCCH/8 (8 SDCCH on one TDMA time slot). The feature also provides an increased flexibility in the number of SDCCHs that can be allocated to one cell: the dimensioning of SDCCHs can be made in one group of four


Title

for one time slot in the cell, instead of one group of eight.

The table below shows an example of the traffic increase when this feature is included. A grade of service of 2% has been used for the calculation.

No. Of TRX"s Traffic capacity

Traffic capacity

SDCCH/4

SDCCH/4

not used

is used

Increase

1

6 TCH/2.3 E 7 TCH / 2.9 E 26 %

2

14 TCH/8.2 E 15 TCH / 9.0 E 10 %

1.38.4 Description

Four individual SDCCHs are configured on one TDMA time slot together with BCCH and CCCH in order to provide channel combination v) of GSM T.S. 05.02, section 6.4. The configuration is made by operator command and is an alternative to the configuration of eight SDCCHs on a single TDMA time slot.


Title

1.39 Data Channels



Technology: GSM

1.39.1 Attention


Not applicable

Dependencies


1.39.2 Summary

Data Channels are used by tele services and bearer services.

1.39.3 Benefits

Data services such as fax and data transmission can be provided for end users.

1.39.4 Description

This feature supports the following data channels:

TCH/F9.6 transparent and non-transparent

TCH/F4.8 transparent

TCH/F2.4 transparent

Data rates 0.3, 1.2, 1.2/0.075 and 2.4 for transparent data services are mapped on TCH/F2.4. The remaining data rates 4.8 and 9.6 kbit/s are mapped on TCH/F4.8 and TCH/F9.6, respectively.


Title

All data rates for non-transparent data services are mapped on TCH/F9.6.

In the non-transparent type of data service there is a Radio Link Protocol (RLP) between the MS for error detection and the re-transmission of data. Discontinuous Transmission (DTX) uplink is applied in the non-transparent service of this feature, but DTX for transparent data is undefined.


Title

1.40 Differential Channel Allocation



Technology: GSM

1.40.1 Attention


Not applicable

Dependencies


1.40.2 Summary

The feature Differential Channel Allocation enables the operator to regulate the allocation of radio resources within a cell depending on the priority specified for a subscriber. This allows different grades of service to be offered to different groups of subscribers.

The priority of the subscribers is received by the BSC in the information element "priority" provided by the MSC over the A-interface.

1.40.3 Benefits

This feature allows an operator to maximize revenue through subscriber differentiation. For example, if an operator offers a low price rate, then the number of call attempts will increase. With this feature the operator can ensure that certain subscribers, for example business users, are given priority access. This will ensure that revenue from those subscribers paying higher rates is not lost.


Title

Before operators implement this feature, they can activate the recording of statistics, for example, on who has tried to access the cell, whether the attempt was successful or not, and which channels were used. The operator can use this as input to optimizing the channel reservation strategy and to deciding how the service should be differentiated for each subscriber category. (See NF180.1 Channel Event Recording.)

With this feature, the operator may alternatively choose to prioritize access to the network rather than offering different grades of service. For example, channels could be reserved only to be used at assignment or handover.

1.40.4 Description

This feature lets operators flexibly differentiate between different subscriber categories in their network. This is controlled by specifying a number of channels that cannot be allocated for connections with a certain priority level.

The operator can define up to 32 priority profiles in the BSC, where each priority profile contains 16 priority levels. For each priority level in a priority profile the percentage of inaccessible channels and the probability of failure is specified. The priority profile is then connected to a resource type in a specific cell. A resource type is a combination of channel type (TCH, SDCCH) and subcell (overlaid, underlaid/normal).

At allocation of a channel in a cell for a connection with a specific priority level, the following rules apply:

If the number of idle channels of a certain resource type is equal to or less than the number of inaccessible channels specified for the priority level, then the allocation fails.

If the number of idle channels of a certain resource type is greater by two than the number of inaccessible channels specified for the priority level, then the allocation will succeed.

If the number of idle channels of a certain resource type is one greater than the number of inaccessible channels specified for the priority level, then the allocation will fail with the specified probability.

Differentiation will occur at assignment. The differentiation will also be possible to activate at Intra BSC Handover per BSC.

It is possible to reserve channels that are only to be used at assignment or handover. This is of benefit to operators who wish to prioritize access to the network. It is also possible to give emergency calls higher priority than ordinary calls by specifying a unique priority level for such calls.


Title


Title

1.41 Diversity



Technology: GSM

1.41.1 Attention


Not applicable

Dependencies


1.41.2 Summary

Diversity is achieved by having two antennas independently receive the same signal. This improves the signal quality and diminishes the effects of fading.

(Read also: Diversity Supervision, NF 301.1)

1.41.3 Benefits

The main benefit of this feature is that it reduces the effects of interference due to Rayleigh fading. This contributes to a more reliable and cost efficient network.

The coverage can be increased since the radio reception is improved.

Less interference means better speech quality and fewer lost calls.

Reduced interference could allow increased capacity if the frequency re-use distance can be reduced due to less interference.


Title

1.41.4 Description

Rayleigh fading occurs when the signal from the MS takes more than one path to the antenna. The signal is then received from a lot of different directions from which it has bounced. The received signal is the sum of many identical signals which differs only in phase. When the signals are added, the sum might unfortunately turn out to be close to zero.

Diversity is a way to solve the fading problem. Two antennas receive the same signal and each signal is independently influenced by fading. The risk of both being affected by a deep fading dip at the same time is small. From the two signals, an equalizer creates a signal that has a better quality than either of the two original ones.

At 900 MHz it is possible to gain about 3-5 dB with a distance of 5 to 6 meters between the antennas. At 1800 MHz the distance between the antennas can be shortened.


Title

1.42 Double BCCH Allocation (BA) Lists



Technology: GSM

1.42.1 Attention


Not applicable

Dependencies


1.42.2 Summary

-

1.42.3 Benefits

This feature allows a short active mode BA list and a long idle mode BA list.

A short active mode list, including real neighbors but excluding the home cell, gives improved measurement accuracy for an MS. This will give more time for measurements when the number of candidates are reduced to only those defined as real neighbors by the locating algorithm. Thus the active mode list should include only BCCH frequencies of real neighbors to the cell where the MS is presently situated.

Better measurements achieve better handover performance, and this is the main benefit of the shorter active mode BA list.


Title

A long idle mode list will mean that the time for establishing contact with the network after an MS is switched on will be reduced. This is true if the MS stores the BA list when the MS is turned off. The longer the list in idle mode the better, and therefore, this list should include many possible BCCH frequencies. Availability of frequencies will reduce the reconnection time on power on and it will also give a higher probability to keep roaming mobiles in the network after power off/power on.

The MS receives the measurement frequencies in system information messages from the BSC.

1.42.4 Description

The BA list tells the MS on which frequencies it should do BCCH measurements.

The Double BA Lists feature allows defining different BA lists per cell for MS's in idle mode and MS's in active mode.

The flexibility for operator handling of the radio network is increased. Examples of applications enhancing the accuracy of MS downlink measurements in MS active mode, would be shortening the time for access to the network after MS power on and allowing a wider idle mode BA list to be used for cells that are new in the network, and where the best BA list is not yet completely known to cell planning.

In idle mode, it is best for the MS to have a fairly large BA list, as this will minimize the time needed to access the network when the MS is on. In active mode, it is of interest to have as few frequencies in the BA list as possible, as the number of measurement frequencies is inversely related to the accuracy of the MS measurement result.

Idle and active BA lists can be defined per cell. It is possible to have up to 32 BCCH frequencies in a BA list. The feature also allows a "smooth" update when changing the BA list.


Title

1.43 Dynamic Allocation of Transcoder Resources



Technology: GSM

1.43.1 Attention


Not applicable

Dependencies


1.43.2 Summary

Within the new BSS system architecture, that is TRA in Pool, different types of transcoders will be located in pools. This lets network operators allocate the required transcoder resources for FR, HR, EFR, AMR, AMR HR and possible new future codec types, on a per call basis.

Introducing this architecture will result in less transcoder hardware being needed. In addition, with this architecture the introduction of new speech codec types will be easier and more cost efficient.

1.43.3 Benefits

The main benefit of this feature is the reduction in the amount of transcoder hardware required. Approximately 50% less is needed compared to what is required with today's semi-permanent configuration. This is due to the fact that the operator can dimension transcoder requirements based on actual traffic demand instead of allocating the trancoder resources semi-permanently.

Another benefit is that the multiple codec support allows introducing of new codec types based on demand in phase with mobile station penetration.


Title

1.43.4 Description

A transcoder pool is a resource pool containing a number of identical transcoder resources. From a transcoder pool it is possible to select resources on a per call basis. These pools can contain different transcoder types supporting different codec types.

To handle these pools in an efficient way the transcoder part of BSC will be logically separated from the rest of the BSC.

To be able to support this feature, subrate switching at 8 or 16 kit/s will be required. This means that the Group Switch Subsystem (GSS) hardware must be upgraded.


Title

1.44 Easy Handling of Managed Objects



Technology: GSM

1.44.1 Attention


Not applicable

Dependencies


1.44.2 Summary

The feature "Easy Handling of Managed Objects" (MOs) simplifies usage and allows easier Operation and Maintenance (O & M). The handling of MOs (managed object) will be considerably easier and faster for the operator. This by handling subordinate MOs in commands.

1.44.3 Benefits

This feature improves the efficiency of O & M work with MML commands and OSS.

1.44.4 Description

The feature is intended to be used by OSS to speed up the O & M operations in the total BSS system. The operator using MML commands as well as using OSS (dependent on OSS implementation) will experience easier and faster handling of MOs.

Today when equipment is to be taken into or out of service each MO must be mentioned in the commands and in a certain order.


Title

This feature makes it possible to handle MO and its subordinate MOs with only one command. MOs supported are: TG (Transceiver Group), CF/TGC (Central Function/Transceiver Group Control) or TRXC (Transceiver Controller) and all its subordinate MOs. The events supported are taking these MOs into/out of service and deblocking/blocking. This feature is invoked by adding a parameter to existing commands. The function of these commands is unchanged from today if the parameter is left out.


Implemented in: BSC


Title

1.45 Enhanced BTS Program & Load of RBS 2000



Technology: GSM

1.45.1 Attention


Not applicable

Dependencies


1.45.2 Summary

This feature changes the BTS program load procedures and makes the interface more efficient and flexible to be able to support future BTS products.

1.45.3 Benefits

It will be possible to abort an ongoing program load without causing any traffic disturbances.

The BTS's will be able to handle larger files and more files in a file package, i.e. more functionality, without prolonging the installation and recovery it.

1.45.4 Description

Functional description:

The future BTS products (RBS 2000) will be built on a common platform. In order to prepare for the introduction of products based on a common platform this feature is introduced. It will mean changes to the mechanism for offering and downloading files to the BTS.


Title

This involves distributing software to all future BTS products in a single (much larger) file package (now with up to 64 files). When all the files in the package are offered to any one BTS, it will select only those files for download that are necessary for its specific configuration.

In order to do this, the first file that is downloaded from the BSC to the BTS will be a special file describing the whole software package to the BTS, while from the BSC's perspective it appears as a normal loadable file. The BTS will use the information in this particular file to send a response message to the BSC specifying all the files that is required by the BTS. The BSC will then start downloading the files requested by the BTS.


Title

1.46 Extended Call Release Reporting



Technology: GSM

1.46.1 Attention


Not applicable

Dependencies


1.46.2 Summary

Extended Call Release Reporting makes additional call drop information available to the MSC. The MSC can transfer this information to the billing system where it can be used to enhance subscriber satisfaction.

1.46.3 Benefits

Makes it possible for the MSC to provide more detailed information regarding dropped calls to the billing system. This information can then be used to increase subscriber satisfaction by for example providing better fault information and/or reduced tariffs.

1.46.4 Description

Internally in the BSC there are detailed information regarding why a certain call was dropped. This information has so far only been available to the operator for statistical purposes. With the Extended Call Release Reporting feature the information will also be reported to the MSC.


Title

The MSC can in turn transfer this information to the billing system for further handling. In the billing system the data can be used to increase subscriber satisfaction, for example better fault information can be provided to subscribers or tariffs can be reduced.


Implemented in: BSC


Title

1.47 Extended RBS Holdover Time



Technology: GSM

1.47.1 Attention


Not applicable

Dependencies


1.47.2 Summary

The RBS holdover time at loss of synchronization is increased from one hour up to approximately 24 hours. This will give operator more time to repair faults before RBS availability is impacted, thereby improving in service performance.

1.47.3 Benefits

Extended RBS Holdover Time have the following benefits:

Better in service performance (ISP), as the RBS can provide service for a longer time after loss of synchronization.

Easier planning of RBS maintenance, since repairs does not have to be performed immediately.


Title

1.47.4 Description

The RBS holdover time (i.e. the time from loss of synchronization until the RBS is taken out of service) is extended by compensating for the temperature variation in the DXU/IXU. This makes it possible to increase the holdover time from one hour up to approximately 24 hours for a DXU/IXU that is configured as Master or Stand-alone. The exact holdover time is dependent on the temperature variation in the cabinet during the holdover period. The remaining holdover time estimated by the RBS can be monitored with the OMT.

For a DXU/IXU that is configured as Slave, two holdover modes are used. If the transceivers connected to a slave DXU/IXU constitutes whole cells or sectors the full holdover time can be used, i.e. up to 24 hours. When the transceivers connected to a slave DXU/IXU only makes up part of the transceivers in a cell, the current holdover time for slave DXU/IXU of 2 minutes shall be used. The reason for this is the high requirements on synchronization between transceivers within a cell. The configuration of whether transceivers connected to a slave DXU/IXU is whole cells or only part of a cell is performed with the OMT.

The extended holdover time can only be supported on RBSs equipped with DXU-21/IXU-21. This is because it is the only DXU/IXU that contains a temperature sensor.


Implemented in: RBS


Title

1.48 External Alarm Connection and Presentation Locally at Site



Technology: GSM

1.48.1 Attention


Not applicable

Dependencies


1.48.2 Summary

This feature enables external alarms at the RBS's to be presented both at the BSC site and at the RBS site.

1.48.3 Benefits

The main benefit of this feature is that is reduces the cost of operation and maintenance for the operator.

1.48.4 Description

External alarms can be connected to the BSC via the RBS 2000 transmission interface. These alarms can be presented both at the BSC site and at the RBS site.

External alarms originate from a source defined by the customer. Types of alarms could be for example, fire, or burglary supervision alarms. Parameters are initially defined manually at RBS installation, using a local Operation and Maintenance Terminal. An alarm printout is issued when an alarm is reported.


Title

Note that external alarms are not part of RBS equipment. The number of external alarms which can be connected to an RBS depends on the RBS configuration. For example, up to 16 can be connected to RBS 2102 and RBS 2202.


Title

1.49 Flexible Alarm Classification



Technology: GSM

1.49.1 Attention


Not applicable

Dependencies


1.49.2 Summary

This feature enables the operator to customize the priority of BTS alarms to their special situation. The alarm class level (indicating the priority) can be set either higher or lower than the default settings.

1.49.3 Benefits

The possibility to set the alarm classes according to the operator needs in order to adapt the system to their existing alarm handling process. This enables a quality and resource efficient process.

The possibility to assign the highest priority alarm class to BTS alarms allows the operator to take prompt actions to repair the BTS while it is still running. This will reduce or even prevent the downtime. - The operator can give important BTS's a higher prioritized alarm.


Title

1.49.4 Description

Description, function: A BTS condition indicates either a fault or a consequence of a fault from an entity in the BTS. Some BTS conditions have specific alarm slogans, some have not (they are then grouped together with other BTS conditions and the group have a specific alarm slogan). There are two levels of the alarm classification: the alarm slogan classification and the BTS condition classification. The alarm slogan classification gives the operator the possibility to specify the alarm class (severity) of one or more defined alarm slogans, which then overrides the default alarm class. The operator also has the possibility to specify 'no alarm' for one or more defined alarm slogans, which will then mask out the corresponding alarms. The BTS condition classification makes it possible to define an alarm class for each BTS condition. This classification will override the one specified for the associated alarm slogan. Four alarm slogans (BTS internal, BTS external, Operator Condition and mains failure) replace two existing alarm slogans (Class 1 fault, class 2 fault), as these two have explicit relative priorities which might not apply once the operator has defined a new alarm classification.

Description, use:

An operator which uses an alternative alarm prioritization than the default, uses this feature to change alarm classification data in a controlled way. To get an overview of the changes that has been made, each alarm slogan with the associated default alarm class and any operator specified alarm class can be printed. The new alarm slogans will make it easier for the operator to get a clear view of the fault situation.


Title

1.50 Flexible Channel Allocation



Technology: GSM

1.50.1 Attention


Not applicable

Dependencies


1.50.2 Summary

This feature enables the operator to choose whether the idle TCH's on the BCCH frequency should be allocated first or last. This possibility is mainly supposed to be used in radio networks where the BCCH frequency is non-hopping. As the BCCH frequency always is transmitted, it can be advantageous to allocate the TCH's on this frequency first to avoid C/I interference.

1.50.3 Benefits

If the idle TCH's on the BCCH frequency are allocated first it is possible to reduce the C/I interference in the radio network, and thereby increase the network quality.

Flexible Channel Allocation also offers decision flexibility to the operator. It is now possible to allocate TCH's according to the operator's own needs.

The end-user will recognize a speech quality improvement due to the possibility to decrease the C/I interference in the radio network


Title

1.50.4 Description

In radio networks where the BCCH frequency is non-hopping it can be advantageous to allocate idle TCH's on this frequency first. The reason is to reduce the C/I interference in the radio network and thereby increase the network quality. By transmitting with as few frequencies as possible a reduction of the C/I interference can be obtained. This reduction can clearly be reached in cells with few TRX's, as frequency hopping is usually not used during these circumstances. Flexible Channel Allocation enables the operator to choose whether the idle TCH's in the BCCH frequency should be allocated first or last.

Flexible Channel Allocation is interesting to use where the BCCH frequency is non-hopping. The feature can therefore be used in non-hopping, and in both non-hopping and frequency hopping cells (that is, the BCCH frequency is non-hopping and other frequencies are hopping).


Implemented in: BSC

1.50.5 Enhancement

Simplified configuration of how to use the TCH's on the BCCH carrier. The usage of these TCH's was before configured separately for circuit switched (CS) services (CHALLOC) and packet switched (PS) data (PDCHALLOC), which could lead to conflicting settings. Now the configuration is combined into one parameter, which means that it is easier to improve performance.

Increased flexibility when configuring the channel allocation behavior. Now usage of the TCH's on the BCCH carrier for CS services (CHALLOC) can be configured on cell level. This means that flexibility is increased both when matching the channel allocation behavior to the cell configuration and when matching the CS service to the PS data behavior.

Increased flexibility when configuring the coexistence of CS services and PS services in a cell. The operator can configure if CS services or PS data shall have priority in situations when there is a conflict between them. A conflict can arise because when PDCH's are allocated on a carrier all remaining timeslots on that carrier are marked as preferred for PS data. This means that these timeslots should only be used by CS services as a last resort when all other channels are busy. The preference marking of channels for PS data sometimes clashes with the CS service (CHALLOC) configuration. The operator can now decide how these situations shall be resolved.


Title

1.51 Flexible SDCCH Allocation



Technology: GSM

1.51.1 Attention


Not applicable

Dependencies


1.51.2 Summary

Flexible SDCCH Allocation provides increased flexibility to allocate SDCCH where it is most suitable depending on the traffic in the cell. The feature makes it possible to maintain SDCCH capacity while avoiding allocation of SDCCH on certain transceivers, for example EDGE or CS3/CS4 enabled transceivers.

1.51.3 Benefits

Flexible SDCCH Allocation has the following benefits:

Allows dimensioning and configuration of SDCCH channels in a cell according to the traffic.

Maintained SDCCH capacity, even though some transceivers in a cell is not preferred to be used for SDCCH.


Title

1.51.4 Description

Flexible SDCCH Allocation provides flexibility when allocating SDCCH in a cell, allowing configuration of SDCCH on the most suitable carrier. Therefore up to eight SDCCH/8 timeslots can be allocated on any carrier in the air-interface and not just on the BCCH carrier.

The load generated by a SDCCH/8 timeslot is much higher than a traffic channel, and allocating multiple SDCCH/8 on a transceiver, can impact the BSC hardware dimensioning. In order to control the impact and even avoid it when the additional flexibility is not needed, it is possible to set the number of SDCCH/8 timeslots that a transceiver is allowed to handle. The maximum number of SDCCH/8 that can be configured on a transceiver is four.

In the radio base station there is not a one-to-one relation between a transceiver and what is transmitted on the air-interface (carrier). In order to optimize the hardware and A-bis link utilization, the BSC will automatically spread the SDCCH/8 between all possible transceivers to distribute the load. The inter-transceiver bus (also used for baseband frequency hopping) is used to put the information onto the correct carrier. The consequence of this is that if, for example eight SDCCH/8 timeslots is required on a carrier, then at least two transceivers carrying four SDCCH/8 each is needed.

Note that Flexible SDCCH Allocation does not increase the total number of SDCCH that can be configured in a cell, instead it enhances the flexibility of where to put them. If additional SDCCH capacity is required then the feature FAJ 121 355 Increased SDCCH Capacity should be used.

One example when multiple SDCCH on a transceiver is needed is when EDGE and/or CS3/CS4 is introduced. Since it is not desired to allocate SDCCH on EDGE or CS3/CS4 enabled transceivers, other transceivers might have to handle multiple SDCCH/8 instead in order to maintain SDCCH capacity. Another example is when the feature FAJ 122 085 Multi Band Cell is used. If support for single band terminals is required, then SDCCH cannot be allocated to the non-BCCH frequency band. For similar reasons the possibility to forbid allocation of SDCCH in certain channel groups is also introduced.

Multiple SDCCH/8 per transceiver is also needed when the feature FAJ 121 355 Increased SDCCH Capacity is used.


Implemented in: BSC


Title

1.52 Frequency Hopping on 32 Frequencies



Technology: GSM

1.52.1 Attention


Not applicable

Dependencies


1.52.2 Summary

This feature makes it possible to frequency hop on up to 32 frequencies when synthesized frequency hopping is used. This will both simplify frequency planning and increase radio network capacity.

1.52.3 Benefits

The following benefits can be identified:

Higher capacity due to increased hopping gain

Easier frequency planning since fewer channel groups are needed. In most cases all hopping frequencies can be allocated in the same channel group.

1.52.4 Description

This feature gives the possibility to assign up to 32 frequencies to a channel group when synthesized frequency hopping is used, as compared to 16 previously.


Title

Frequency hopping on 32 frequencies is useful when synthesized frequency hopping is utilized, since more frequencies than transceivers are allocated to a channel group. In many FLP networks there are around 20 frequencies available for frequency hopping in a cell, and in these networks this feature will greatly simplify frequency planning since it will not be necessary to split the frequencies between two channel groups. Avoiding this split will also increase capacity since the frequency hopping gain is improved.

In one channel group, only transceivers that belongs to the same transceiver group (TG) can be connected. When baseband frequency hopping is used it is the number of transceivers in a channel group that determines how many frequencies that it is possible to assign to a channel group.


Implemented in the BSC.


Title

1.53 GPRS/EGPRS End-user Performance



Technology: GSM

1.53.1 Attention


Not applicable

Dependencies


1.53.2 Summary

The feature GPRS/EGPRS End-user Performance will improve the performance of packet switched services in all networks as throughput, capacity and quality of the system is optimized. An increased data rate of up to 30% can be achieved. This, together with better planning flexibility and advanced traffic steering possibilities, ensures a significant boost of the GPRS/EGPRS end-user performance.

This is possible as the amount of data overhead is minimized, packet switched services is introduced in overlaid subcells, cell re-selection functionality is improved and GPRS/EGPRS resources are used in a more efficient way.

1.53.3 Benefits

The major benefits of this feature are:

Improved end-user throughput (with up to 30%), due to reduced signaling and dynamic uplink/downlink resource handling


Title

Improved configuration flexibility as packet switched services is supported together with the features FAJ 121 53 BCCH in Overlaid Subcell and FAJ 122 085 Multiband Cell regardless of in which subcell or frequency band the BCCH is allocated.

The number of cell reselections can be reduced to avoid unnecessary interruptions in the packet data flow as GPRS/EGPRS Cell reselection parameters can be set separately to the circuit switched cell plan. This makes it possible to modify and adapt a packet switched cell plan to GPRS/EGPRS specific conditions.

Increased capacity as the average load of neighboring cells can be balanced.

1.53.4 Description

The feature GPRS/EGPRS End-user Performance improves the performance of packet switched services as an increased data rate of up to 30% can be achieved. This, together with better planning flexibility and advanced traffic steering possibilities, ensures a significant boost of the GPRS/EGPRS end-user performance.

The feature will increase the end-user performance for various services like FTP download, web browsing and streaming by introducing functionality that reduces the signaling load. By delaying the release of a downlink TBF (Temporary Block Flow) a TBF is kept alive longer which reduces frequent TBF set-ups/releases. With this, the throughput for bursty traffic such as web browsing and e-mails etc is improved significantly.

The handling of uplink and downlink resources is further optimized as the TBFs are changed in accordance with the application needs. This means that if the main direction of application transfer is in the uplink, then this feature will dynamically downgrade the downlink TBF to fewer timeslots and upgrade the uplink TBF to more timeslots. A GPRS/EGPRS terminal can thus use an optimal amount of timeslots based on which link that is momentarily used.

Functionality expanding reservations and moving TBFs to channels corresponding to the need is also added. This is required to optimize the TBFs when longer TBF lifetimes exist and a more dynamic resource handling is introduced. When upgrading a TBF, PDCHs are added to the reservation without moving the TBF from its current PDCHs. By allowing a TBF to be upgraded, a TBF running on fewer PDCHs than requested can get more PDCHs added as they become available. However, an existing TBF may also be moved to channels that better correspond to the requirements of the TBF. This may occur if e.g. many TBFs are sharing the same channels or a TBF running on a different PDCH type than requested. This will improve PDCH utilization, since the traffic load within the cell is more evenly distributed.


Title

To further improve latency in the system a faster set-up mechanism of downlink TBFs is introduced. The downlink TBF set-up is triggered by information in the uplink TBF. The uplink TBF is also kept alive longer allowing for more data to be sent without setting up new TBFs. This Extended uplink TBF mode functionality complements the functionality to keep downlink TBFs alive longer. However, as a standard change is required only terminals compliant to the release 4 of the GERAN specifications will be able to take advantage of this mechanism. The functionality will however improve the throughput significantly due to the reduced delays in the uplink (i.e. the delay introduced by uplink TCP acknowledgments are reduced).

Higher cell planning flexibility is introduced as it will be possible to choose where in a cell (having a subcell structure) to allocate dedicated PDCHs. By allowing GPRS/EGPRS to be used in an overlaid subcell, the GPRS/EGPRS channels can be placed on the BCCH in the same subcell using the feature FAJ 121 53 BCCH in Overlaid Subcell.

A cell border offset, HCS (Hierarchical Cell Structures) functionality and separate BCCH Allocation (BA) list for GPRS/EGPRS is also added. The separate layer parameters, HCS thresholds and BA list used for GPRS/EGPRS makes it possible to e.g. promote cells more suitable for GPRS/EGPRS (e.g. cells capable of EGPRS). This means that a specific GPRS/EGPRS cell plan can be achieved. To be able to take advantage of these parameters a Master PDCH needs to be defined in the cell.


Title

1.54 GSM Phase 2 Support



Technology: GSM

1.54.1 Attention


Not applicable

Dependencies


1.54.2 Summary

This feature is required to add the GSM Phase 2 unique features in the BSS. The feature makes the traffic functions in the BSS in compliance with the GSM Phase 2 technical specifications for the air-interface (04.08), the A-interface (08.08) and the Abis-interface (08.58).

The CME 20 R5 network is fully backwards compatible; that is, it will handle GSM Phase 1 MS's as well as the GSM Phase 2 MS's.

The feature introduces new information elements in existing messages and adds new messages on the BSS interfaces. The feature thereby provides support for new features in the system that takes advantage of these additions.

The handling of the terrestrial resources between the BSC and the MSC is improved as part of the GSM Phase 2 upgrade of the A-interface.


Title

1.54.3 Benefits

With this feature the operator gets a mobile system with new messages over the BSS interfaces in accordance with the GSM Phase 2 standard. This feature therefore provides support for new features (like System Information GSM Phase 2, and Support of A5/2 ciphering algorithm) that can take advantage of these additions.

The handling of the terrestrial resources between the BSC and MSC can be improved, as this feature can detect attempts on faulty administrative proceedings. Such attempts could be call setup, or blocking/unblocking of devices, etc.

The BSC can check how the BTS is configured, which prevents GSM Phase 2 messages to be sent to a BTS that cannot handle these messages.

1.54.4 Description

This feature is required in order to add the GSM Phase 2 unique features in the BSS. The feature covers the following traffic handling cases:

Skip indicator: The skip indicator is forming a part of the new "header" on the air interface messages for radio resource and mobility management. The skip indicator controls which messages should be accepted.

Classmark: The new format for the Signalling Information Element (IE) classmark is accepted. For example, the classmark IE contains information on the encryption capabilities of the MS and whether the MS has a GSM Phase 2 status.

Encryption: the new requirement for multiple ciphering algorithms. The encryption alternatives that can be supported are A5/1, A5/2, and "no encryption".

Immediate assignment: two new formats are implemented as well as a layer 3 message.

Paging: the new information element "Channel Needed", in the A-interface message PAGING, will be accepted by the BSC and thereafter sent towards the BTS.

Handling terrestrial resources towards MSC:

The new message UNEQUIPPED CIRCUIT.

This message is sent to the MSC if one, or more, unknown circuit identity codes are received over the A-interface. If the message is received from the MSC, the indicated circuit will be brought out of service in the BSC.


Title

New handling at reception of BLOCKING/UNBLOCKING ACKNOWLEDGE

when the device is blocked/unblocked. The update deals with abnormal conditions in the process of blocking and unblocking circuits between the MSC and BSC.

New handling at reception of BLOCKING/UNBLOCKING ACKNOWLEDGE

The GSM Phase 2 Support feature can also make out if the BTS is configured to support phase 1, phase 2, or both phase 1 and phase 2 messages. The check that can be performed by the BSC prevents faulty messages from being sent to the BTS's.


Title

1.55 Handling of External RBS Hardware



Technology: GSM

1.55.1 Attention


Not applicable

Dependencies


1.55.2 Summary

This feature improves the supervision for external RBS hardware like antenna related equipment.

1.55.3 Benefits

Decreased operation and maintenance cost for the operator by increased fault localization capabilities of external RBS hardware like boosters or active antennas.

Improved quality and reduced cell down time because of improved fault handling of external hardware.

1.55.4 Description

Sophisticated external antenna related hardware is foreseen to become more important in the future. In order to provide sophisticated fault management of such hardware within BSS the RBS external alarm interface is used to report and supervise alarms.


Title

The RBS external alarm interface is mapped towards a managed object in the BSC. When a fault is detected on RBS external hardware the fault is reported on the managed object the external hardware was mapped on. The BSC will act on the fault by issuing an alarm to the operator and/or block the managed object depending if the fault is considered as impacting functionality.

Boosters or active antennas are mapped on the managed objects TX or RX. If a fault report is reported on these managed objects this indicates to the operator that the performance is reduced on either coverage or sensitivity thus decreasing the radio network quality.


Title

1.56 Handling of RBS Capabilities



Technology: GSM

1.56.1 Attention


Not applicable

Dependencies


1.56.2 Summary

This feature assists the operator in verifying that the specified parameters at cell configuration are consistent with the capabilities of the associated RBS. If inconsistent parameters are specified, which if used leads to that an RBS will not function, the BSC will clearly indicate the inconsistency to the operator.

1.56.3 Benefits

Improved overview, easier and faster handling of a BSS network with different RBS capabilities. This information can be used when configuring the RBS's.

Increased network quality and reduced down time because of fewer parameter errors at configuration.

Reduced operation and maintenance cost due to easier detection of inconsistencies between parameters given in commands, and capabilities of the installed hardware reduce the risk for faulty configuration of RBS's.


Title

1.56.4 Description

In the future it is foreseen that the number of RBS's variants with different capabilities will increase. This is due to the introduction of new RBS hardware and the support of external RBS hardware such as boosters and active antennas which will change the capabilities of the RBS's.

Information about RBS capabilities (configuration capacity and limitations if any for both hardware and software), such as parameter ranges and supported functions are available in the RBS's.

The RBS capabilities information is made available for use in BSC. As soon as a change in capabilities occurs in an RBS this is reported to the BSC. The BSC requests the new capability information over Abis from the RBS. The RBS capabilities information may be printed for a specific RBS hardware to be used for overviewing the RBS hardware or at configuration of an RBS.

Examples of RBS capabilities are:

Output power supported

Frequencies supported

Combiner type available

The RBS capabilities information may be used when configuring different types of RBS's with different capabilities.

If a mismatch between the capabilities of the RBS and the operator defined parameters occurs during configuration a fault alarm will be given. In the BSC, it will be possible to log and print the configuration rejection causes given by the RBS.


Title

1.57 Handling of Synchronization Reference



Technology: GSM

1.57.1 Attention


Not applicable

Dependencies


1.57.2 Summary

This feature provides the operator with the possibility to order the RBS to either use the internal synchronization reference if it exists, or extract the synchronization reference from the transmission network.

1.57.3 Benefits

Decreased operation and maintenance cost because no manual calibration is needed at site if the transmission network fulfils the GSM/GSM specifications.

Higher system availability because switching of the synchronization source at transmission network problems or failure of the internal oscillator hardware can be made remotely.

Reduced down time because manual calibration can be done without taking the RBS out of service.


Title

1.57.4 Description

GSM/GSM specifications require that the RF carrier shall have an absolute accuracy of 0.05 ppm. In order to fulfill this requirement all RBS's within a network with lower transmission accuracy than required may be equipped with internal high quality long-term stable reference synchronization oscillators.

For RBS's with internal reference oscillator synchronization source can be either: - The transmission network or - The internal high quality long-term stable reference synchronization oscillator.

In most transmission networks the quality fulfils the GSM/GSM specifications, that is fulfilling STRANTUM 2 quality. In these transmission networks it will be possible to switch off the built in reference oscillators, if such exist in the RBS, from the BSC thus avoiding time and cost consuming manual calibration in the RBS.

Manual calibration would otherwise be required approximately every third year.

If manual calibration is required this can be done during day time because the RBS can be calibrated without impacts on the traffic service.


Title

1.58 Handover in BSS



Technology: GSM

1.58.1 Attention


Not applicable

Dependencies


1.58.2 Summary

Handover is the procedure which takes place when an MS connection is moved to another channel in the same cell or a neighboring cell. This is done to ensure that a call always uses a channel with an acceptable quality.

1.58.3 Benefits

In CME 20/CMS 40 Handover is supported in all important scenarios.

The fast switching in the BSC ensures smooth handover. This means that speech quality will be maintained even during handover so that the user does not perceive an interruption during the call.

1.58.4 Description

The Handover procedure is initiated by the reception of a list of candidate cells in preferred order from the function Locating (Feature NF 259.4).

Handover can take place between traffic channels belonging to:

Different MSC/VLR (and different BSC's)


Title

Different BSC's (Inter BSC Handover)

Different cells within a BSC (Intra BSC Handover)

The same cell (Intra cell Handover, NF 290.1).

See also:

Handover of Traffic at Channel Blocking, NF 181.1 Handover on SDCCH, NF 289.1 Hierarchical Cell Structures, NF 914.1.

1.58.5 Enhancement

Supports handover between half rate, full rate, and enhanced full rate channels.


Title

1.59 Handover of Traffic at Channel Blocking



Technology: GSM

1.59.1 Attention


Not applicable

Dependencies


1.59.2 Summary

The feature Handover of traffic at Channel Blocking tries to initiate a handover of a mobile in order to save the call, if possible. This occurs in different situations where a channel and corresponding hardware are blocked.

1.59.3 Benefits

For the operator this feature:

Increases customer satisfaction and revenue

Increases the quality of the system

Decreases loss of service thus increases the system availability

Decreases the system load since no new call set-up is needed.

For the end user this feature increases the perceived network quality.


Title

1.59.4 Description

This feature makes it possible to handover traffic at channel blocking if possible.

The channel blocking can be initiated by different administrative changes from the operator such as manual blocking of equipment and changing of software versions in the BTS. The channel blocking can also occur automatically at reconfiguration of equipment.

At channel blocking the BSC will try to handover calls depending on what type of event that initiated the channel blocking. At function change handover out from the cell will be initiated. At manual blocking of equipment and reconfiguration either inter cell handover or intra cell handover will be initiated, depending on the situation.


Title

1.60 High Speed Signaling Link



Technology: GSM

1.60.1 Attention


Not applicable

Dependencies


1.60.2 Summary

The feature "High Speed Signaling Link" increases the C7 signaling capacity for the A interface and A-ter interface, from 64 kbit/s to 2 Mbit/s per link.

1.60.3 Benefits

The feature "High Speed Signaling Link " increases the capacity for high capacity BSC nodes by resolving C7 signaling bottlenecks.

1.60.4 Description

This feature increases the C7 signaling capacity for the ETSI standard for the A interface and A-ter interface (BSC-TRC), from 64 kbit/s to 2 Mbit/s per link.

The possibility of using a maximum of 16 signaling links of 64 kbit/s each from a BSC for the A interface and A-ter interface, is a bottleneck for high capacity BSC nodes.

The following variants are supported:

IT-U with HSL Q.2210


Title

IT-U with HSL Q.703

IT-U with HSL Q.2210 and HSL Q.703

MPT (china) with HSL Q.2210

MPT (china) with HSL Q.703

MPT (china) with HSL Q.2210 and HSL Q.703


Implemented in: BSC

1.60.5 Enhancement

Enhancements in BSS R10:

High Speed Signaling link is supported for the ANSI standard as well.

The ANSI implementation complies to the following standards:

GR-2878-CORE (12/99), T1.637 (07/94), T1.635 (=01/94), TR-NWT-001112 (06/93), GR-1113-CORE (07/94), T1.645 (01/95), T1.652 (03/96)


Title

1.61 Immediate Assignment on TCH



Technology: GSM

1.61.1 Attention


Not applicable

Dependencies


1.61.2 Summary

Immediate Assignment on TCH provides new alternatives for resource allocation strategies at call set-up. This will give more efficient use of installed resources in the cells of the radio network, easier dimensioning of cell configuration, and shorter call set-up times. This is done by making more efficient use of mobile provided information at initial access. The mobile information is used to select the final required resource type at an earlier time in the call set-up chain of events. Both GSM phase 1 and phase 2 mobiles are handled, each to the best effect as regards the mobiles possibilities to provide resource information.

There is also an overflow mechanism, so that TCH channels can be allowed to be used if there is temporary congestion on the SDCCH resources. This will reduce blocking.

1.61.3 Benefits

Increased utilisation of cell resources.

Increased flexibility in configuring cell resources.

Reduced call set-up time.


Title

1.61.4 Description

Immediate Assignment on TCH gives the operator the possibility to define the channel allocation strategy at the immediate assignment procedure. This feature makes it possible to have faster call set up times for speech and data connections. It also allows for setting of allocation alternatives between SDCCH and TCH if blocking should occur on either resource type.

When the feature TCH immediate assign is active, the priority order between assignment of a SDCCH or a TCH at Immediate assignment can be defined in the feature Channel administration, which will give the possibility to decide whether an alternative allocation is allowed.

Some examples of possible strategies that can be chosen are:

Immediate assignment is made either on SDCCH or on TCH, depending on the information provided by the mobile at initial access.

Immediate assignment on TCH will be done only in situations of congestion on the SDCCH. This will give a greater flexibility in configuring cell resources for SDCCH traffic.

Different immediate strategy can be chosen for different cells. This can be defined by combining Immediate Assignment on TCH strategy with the proper definition of parameters in the feature Channel Administration.


Title

1.62 Improved BSC-OSS Interworking



Technology: GSM

1.62.1 Attention


Not applicable

Dependencies


1.62.2 Summary

This feature improves and speeds up the transferring of data from BSC to OSS.

1.62.3 Benefits

File transfer instead of alphanumeric printouts reduces the data transferring time between BSC and OSS.

File transfer instead of alphanumeric printouts reduces the load in the BSC and IOG thus leading to improved performance.

Possibility to only fetch changed data reduces the total time of an adjust thus decreases the operation and maintenance cost.

1.62.4 Description

In order to make an adjust in previous releases the OSS has to issue a number of printout commands to the BSC and then store the data in OSS for usage by the operator. The adjust is needed in OSS to get the database consistent with the data in the BSC that contains the network configuration.


Title

This feature will make it possible to get all data in a file format that is faster and increases performance at adjusts. The data that can be collected is the BTS configuration data.

The operator initiates the adjust by entering the type of data requested in OSS. It is possible to specify for what objects to collect data from and the type of data to fetch. The objects to collect data for can be Cells, TG's, EMG's or all objects. The following data is available:

Cell

Cell channel group data

Cell status

TG

MO data

MO status

MO configuration data

MO fault information

MO hopping data

MO capability information

TG to channel group data

EMG

Line terminal data

LAPD concentration data

Semipermanent path data

It is also possible to specify what type of data to fetch for the objects and the data types are:

Definition data which is set by commands

Dynamic data is all data changed automatically to reflect the status such as fault data.

BTS HW description data.


Title

It is possible to specify to get all data changed from a certain time. The BSC keeps track of all changes of BTS data by time stamping all objects that have been changed. This option is used in order to do adjust with short intervals that reduces the need of a full adjust.


Title

1.63 Improved Configuration of BTSs



Technology: GSM

1.63.1 Attention


Not applicable

Dependencies


1.63.2 Summary

This feature will be used to take full advantage of the BSC's powerful processor when configuring BTSs.

1.63.3 Benefits

The available processor capacity varies over time depending on the traffic situation in the network. At night when the traffic is low, the processor can to a great extent be used for capacity demanding tasks such as configuration of BTSs. During peak hours, the processor capacity needed for traffic increases, giving less capacity over for BTS configurations.

By an adaptive regulation of the processor capacity, the traffic handling can proceed without disturbances, while at the same time the BTS configurations can be handled at a maximum speed.

As a result of this, the recovery time after communication failure will decrease.

1.63.4 Description

One of the most capacity demanding tasks in a BSS system is to configure BTSs.


Title

It was previously not possible to adaptively use the available processor capacity for configuration of the BTSs. The processor will have varying traffic load, giving a negatively correlated availability of processor capacity for BTS configurations.

This function allows for optimal usage of the powerful processor at all times for the capacity demanding task of configuring BTSs.

Each APZ processor can process a certain number of jobs per second. An algorithm will be run every second to compare the real capacity load with the permitted capacity load to use for BTS configurations.

The real processor capacity load is continually measured. If the real processor load is below the permitted capacity load, the number of parallel BTS configurations jobs is increased, resulting in a new and higher permitted capacity load allowed for BTS configurations.

When the real processor load is above the permitted capacity load, specified by the operator for BTS configurations, the number of parallel BTS configuration jobs is decreased, resulting in a new and lower usage of the processor capacity for BTS configurations.

The effect of this is an adaptive usage of the processor load. The number of parallel BTS configurations will be modified according to the real processor load at all times.

1.63.5 Enhancement

In previous releases it was possible to use up to 80 % of the processor power for configuration tasks. In this release it is possible to use up to 90 % of the processor power for configuration tasks.

When expanding the cell with a transceiver the configuration will not start until the transmitter is tuned thus reducing the downtime in the cell with the transmitter tuning time (approximately 20 seconds).

The configuration time for a RBS is also reduced due to more efficient configuration algorithm and the improvements above. The BSC is creating/deleting a Basic Physical Channel (BPC) which corresponds to a time slot at a rate of 4 BPCs/second (load and processor dependant). As an example to expand a three TRX frequency hopping cell (with no traffic) to four TRXs will take approximately:

Deletion of 24 BPCs = 6 seconds

Creation of 32 BPCs = 8 seconds

Total time = 14 seconds


Title

In previous releases = 40 seconds

Time when less than 50% of the capacity in the cell is available = 7 seconds

Time when no capacity in the cell is available < 1 second.


Title

1.64 Improved Handling of Emergency Calls in RBS



Technology: GSM

1.64.1 Attention


Not applicable

Dependencies


1.64.2 Summary

This feature provides higher priority to emergency accesses in the RBS over normal accesses.

1.64.3 Benefits

Emergency calls will become prioritized and handled before normal calls in the RBS thus, providing higher possibility of successful emergency calls.

1.64.4 Description

A new handling of emergency accesses in the RBS will treat and provide faster service to emergency calls.

When an emergency access is received in the RBS it will become prioritized and handled before all normal accesses. The RBS will forward the emergency access to the BSC before the normal accesses thus providing emergency calls higher priority and faster handling.


Title

1.65 Improved RBS 200 Software Download



Technology: GSM

1.65.1 Attention


Not applicable

Dependencies


1.65.2 Summary

The purpose of the feature is to improve the handling of the BTS software in the BSS.

1.65.3 Benefits

The benefit from this feature is lowered system maintenance costs. Today the BSC staff must have knowledge of the correspondence between a BTS software package and the type of signaling processing cards used in the BTS; that is, if SPU cards or SPP cards are used in the BTS or not. This feature allows for using only one file package towards RBS 200 and one (different) file package towards RBS 2000.

This feature will minimize the risk of human error when downloading software.

1.65.4 Description

The BSS will be able to handle a BTS software file package with more files than is required for the intended BTS type; that is, RBS 200 or RBS 2000. Each file package may contain files for both SPU and SPP signaling cards.


Title


Title

1.66 Increased Capacity on Abis



Technology: GSM

1.66.1 Attention


Not applicable

Dependencies


1.66.2 Summary

The feature "Increased Capacity on Abis" increases transmission capacity between BSC and BTS. By supporting 4 PCM per RBS2000 instead of 2 it is possible to double the capacity on Abis. This improves throughput of high capacity traffic e.g. EGPRS.

1.66.3 Benefits

This feature has the following benefits:

Double the capacity on Abis

Support of high capacity EGPRS traffic

1.66.4 Description

This feature increases the total bandwidth to a TG (Transceiver Group), from 2 to 4 PCMs. It is used to support high capacity EGPRS traffic.


Title

One 64 kbps PCM channel per Radio time slot is required to support all EGPRS MCSs (Modulation and Coding Scheme). The existing DXU supports 2 PCM connections, which can be a limiting capacity factor for high EGPRS traffic on classic STM.

With the introduction of the new high capacity BTS platform, DXU21 in RBS 2000, 4 PCM inlets to the DXU is offered and a doubled transmission capacity can be achieved on the Abis interface.

The two additional inlets, will be handled in the same way as the existing PCM inlets. (One PCM consists of 32*64 kbps channels where every 64 kbps PCM channel is divided into 16 kbps sub-channels.)


Implemented in: BSC


Title

1.67 Increased number of neighbouring cells



Technology: GSM

1.67.1 Attention


Not applicable

Dependencies


1.67.2 Summary

The maximum number of neighboring cell relations in one BSC is increased from 4096 to 8192. A BSC with maximum (512) number of cells defined can with this increase use 16 instead 8 neighboring cells per cell.

1.67.3 Benefits

For operators with dual band networks and/or Hierarchical Cell Structures (HCS) it may be necessary to have more than 8 neighboring cells per cell.

1.67.4 Description

Not applicable


Title

1.68 Increased Paging Capacity



Technology: GSM

1.68.1 Attention


Not applicable

Dependencies


1.68.2 Summary

This feature increases the Paging capacity by improving the internal handling of the Paging procedure within the BSC.

1.68.3 Benefits

Increased paging capacity with at least 50% in the BSC thus reducing the risk of paging congestion. By increasing the paging capacity in the BSC the load of paging in the MSC will also decrease.

Increased flexibility in definition of location areas because of increased paging capacity.

1.68.4 Description

The internal handling of the Paging procedure within the BSC is changed. Restructuring of the paging software and optimized usage of the internal RP bus increases the paging capacity in the BSC.


Title

1.68.5 Enhancement

The feature is enhanced with overload protection in the TRH in order to make full use of the capacity of APZ 212 20 and APZ 212 30. Also, the possibility to manually restrict the number of handled PAGING messages per second is added. This is useful in special configurations, e.g. LAPD Multiplexing in order to avoid congestion on the LAPD link.


Title

1.69 Initiation Handling of Cells



Technology: GSM

1.69.1 Attention


Not applicable

Dependencies


1.69.2 Summary

This feature gives the network operator support for configuring cells and for setting or changing the maximum transmitting power for a cell. This feature is needed for initial configuration of cells. It is also used when a network is being expanded or when cell planning is being optimized.

1.69.3 Benefits

The main benefit of this support for initial cell configuration and cell re-configuration is that it contributes to cost-efficient Operation and Maintenance.

It lets the operator create tailor made cells for an optimized network, for example to tailor the coverage of a cell. Operation and maintenance costs are minimized since the operator can easily expand or reduce cell coverage by adjusting BTS output power levels without incurring the cost of visiting BTS sites. To achieve the same result by tilting the antenna requires a site visit.


Title

This feature can also be used to force a more efficient use of network resources. For example, in a city area a particular cell may be continually loaded with traffic while a neighboring cell is under utilized. With this feature, the output power of the busy cell can easily be reduced. This will force more handovers to the neighboring cell and thereby ensure a more even distribution of traffic between cells. Transmitting power may be changed without disturbing traffic.

The operator is given more support when bringing new cells into service with better information flow regarding missing parameters if cell activations fail.

This feature also provides support for automatic re-configuration. If BTS equipment is taken out of operation, for example, if a transceiver becomes faulty, this feature will try to use un-configured BTS equipment if it is available. Otherwise, it will attempt to take equipment from lower priority channels and be configured to use that equipment.

1.69.4 Description

This feature provides support for administration of cell description data and administration of cell configuration data. Cell description data consists of data which defines the cell structure and essential cell data which can only be changed when the cell is not in operation. Up to 15 parameters can be set.

For the administration of cell description data in the BSC, the operator can, for example:

Define/delete cells

Change/print cell description data

Print location area data

Define/delete subcells

Change Training Sequence Code (TSC) for a subcell

Print TSC values for cells and subcells

Define/delete channel groups

Change channel groups between subcells

Print channel groups for cells and subcells

Change cell state (between active and halted)

Print cell state.


Title

For the administration of cell configuration data, the operator can carry out the following :

Change/print transmission power data for a cell or subcell

Add/remove frequencies to a cell or channel group

Change/print frequency hopping data for a cell or channel group

Change/print SDCCH data

Change/print Basic Physical Channel data for a cell or channel group

Change/print Discontinuous Transmission downlink status for a cell

Print managed object instances of BTS Configuration data.

Three different frequency hopping configurations are supported: baseband, synthesiser and mixed hopping.

1.69.5 Enhancement

The enhancement provides improved information to the operator regarding missing parameters if cell activation fails. A printout including the names of the missing parameters will be given.

Cell configuration and reconfiguration is improved. It will be possible to change transmitting power while the cell is in operation (active state).

It will be possible to add/delete frequencies while the cell is in operation if frequency hopping is not used.


Title

1.70 Local Synchronization Reference



Technology: GSM

1.70.1 Attention


Not applicable

Dependencies


1.70.2 Summary

This feature provides an additional synchronization reference in the RBS. It can be used instead of an external synchronization reference to secure accurate synchronization.

1.70.3 Benefits

The benefit of this feature is that it supports high network quality. With the Local Synchronization Reference a high quality connection to the MS is secured. The operator does not have to rely on the transport network providing a reliable synchronization reference.

This feature is especially valuable in cases where a leased line network is used.

1.70.4 Description

An accurate synchronization function is required to synchronize the RBS internally. This is needed to achieve air timeslot synchronization, according to the standards. The air interface specification has to be fulfilled.


Title

Short-term stability of the timing is achieved by the RBS itself, but for long-term stability of the RBS an external synchronization reference or this feature is needed. These two possible sources for synchronization are handled in the same way by the RBS.

If an external reference is used, then it is taken from the transport network interface. If the quality of the (leased) line network is poor, the external reference is not reliable. In this case, a reliable reference can be assured by using this feature.

The two main criteria used to determine the quality of the network are:

Long term frequency stability

Jitter and wander characteristics.

The Local Synchronization Reference is implemented in both HW and SW. The HW consists of an accurate local oscillator clock in the RBS.


Title

1.71 Locating



Technology: GSM

1.71.1 Attention


Not applicable

Dependencies


1.71.2 Summary

The locating feature provides the basis for handover decisions.

It can be controlled via parameters, and works out the cell selection for active MS's.

Locating serves as a basis for other radio network features in the Ericsson GSM system; such as, hierarchical cell structures, overlaid/underlaid subcells, intra-cell handover, assignment to another cell and cell load sharing.

1.71.3 Benefits

The locating feature enables an operator to offer call continuity to end-users, thus preventing dropped calls and an associated revenue loss. It enables good signal quality to be maintained throughout a call, even if the MS moves about a large area.

With the Ericsson locating algorithm it is possible to take both uplink and downlink conditions into consideration in the cell evaluation process, which in addition to other features of the Ericsson solution makes it superior to the locating algorithm specified in the GSM recommendations.


Title

Locating also offers an opportunity to minimize the total interference (C/I) in the network by allowing for the optimum selection of the best radio link between the MS and the base station. Less interference means higher speech quality, decreased number of lost calls, and increased capacity.

The Ericsson locating feature offers flexibility to the operator as parameters can be set to optimize the locating function in various environments, and for various uses. For example, it is possible to adjust cell size in a controlled way. This supports more flexible cell planning.

The end-user will experience a high level of service quality, that is, good speech quality and few call dropouts.

1.71.4 Description

The locating algorithm works out the basis for handover decisions, that is, the cell selection for active MS's.

A good locating algorithm is important to the MS in order to:

Ensure good signal quality and call continuity for individual MS's

Determine the cell size to minimize total interference (C/I) in the network.

The input to the locating algorithm is measurement reports from the BTS and the MS. These reports are sent every 480 ms. The reports contain measurement information on signal strength and signal quality both uplink and downlink. They also contain timing advance measurements and information on signal strength of the neighboring cells. On the basis of these reports the BSC decides if a handover is necessary and also to which cell the handover will be made.

In order to add flexibility to the averaging process of the measurement values, five different filter alternatives are available. The handover decision is then presented in the output from the algorithm which contains a list of cell candidates the MS can be handed over to.

Reasons for handover to another cell are:

Field strength relations between the current carrier and the neighboring cells' carriers (the cell with the highest signal strength or the lowest path loss is selected)

Signal quality (when the bit error rate is too high, a handover is suggested)

Timing advance (as the MS moves to the cell border, the locating algorithm proposes a handover when the timing advance threshold value is exceeded).


Title

Other radio network features.

The locating algorithm takes both the downlink and the uplink conditions (such as uplink and downlink path loss or expected received signal level) into account in the cell evaluation process.

By using measurement comparisons to neighboring cells, instead of fixed handover thresholds, the handover borders will be more precise, regardless of which direction the MS is moving. In addition, a hysteresis function guards against fluctuating handovers.

The hysteresis can be adjusted to suit network needs and is adjustable on a per cell to neighboring cell relation. To allow for changing the sizes of cells, offsets can be applied that moves the handover boundary between cells. The offset is adjustable on a per cell to neighboring cell relation. Up to 64 neighboring cells are handled in the Locating feature.

The locating algorithm proposes an urgent handover if bad signal quality, or excessive timing advance, is measured. However, for handover prompted by bad signal quality, an extra signal strength check is performed to ensure that the candidate cell is not too far from the serving cell. The purpose of this check is to prevent excessive interference.

The locating feature makes it possible to use penalty handling for both intra and inter BSC handovers. Handover penalties are used to prevent immediate handovers back to cells that were abandoned due to poor radio link quality (interference, time dispersion, etc.) when the new cell is providing a lower signal level than the cell abandoned. The timing advance penalty handling prevents "ping pong" handovers between sector cells due to excessive timing advance.

The locating feature works with other radio network features, such as:

Assignment to another cell

Hierarchical cell structures (the different levels in the network are taken into consideration in the evaluation process).

Overlaid/Underlaid subcells (handover/assignment to overlaid subcells is supported)

Intra-cell handover (handover can be performed both on TCH and SDCCH)

Extended range cell.

Cell load sharing.


Title


Implemented in: BSC

1.71.5 Enhancement

Not applicable


Title

1.72 Loss Free Pre-emption



Technology: GSM

1.72.1 Attention


Not applicable

Dependencies


1.72.2 Summary

Loss Free Pre-emption improves the performance of GPRS/EGPRS applications at times of high traffic load. It enables an aggressive pre-emption strategy for on-demand PDCHs to be used thus optimizing channel utilization.

1.72.3 Benefits


End-to-end performance of TCP based applications at times of high traffic load is improved.

Channel utilization is improved as on-demand channels can be used to a larger degree

Easier to balance the trade off between CS and PS services using both on-demand and semi-dedicated/dedicated channels.

Enables high performance of Dual Transfer Mode


Title

1.72.4 Description

Loss Free Pre-emption improves the end-to-end performance of TCP based applications at times of high load in the cell. It prevents TCP time-outs that could happen when a downlink TBF cannot be established or is released before the data transfer has been completed. This avoids the long interruptions in the data flow that otherwise would occur when for instance CS calls preempts on-demand channels with ongoing TBFs.

When the setup of a downlink TBF fails or an ongoing TBF has to be released, without the feature, all the LLC-PDUs (Logical Link Control - Packet Data Units) that have been received and queued in the PCU buffer are discarded and the SGSN is informed. The PCU can then only try to set up the downlink TBF again once a new LLC-PDU towards the same MS is received from the SGSN. The discarded LLC PDUs will only be retransmitted once the TCP server realizes that IP packets have been lost and re-sends them. This can lead to long interrupts in the data transfer, and also time-out in the TCP server.

With Loss Free Pre-emption the queued LLC-PDUs are instead kept in the PCU buffer, and attempts are made to re-establish the downlink TBF at certain intervals.

Loss Free Pre-emption keeps the buffer in the PCU and attempts to re-establish the downlink TBF for the following cases:

Failed downlink TBF setup due to no PDCH available.

Released TBF due to pre-emption.

Released TBF due to other channel related causes such as GSL device fault or blocking of BPC.

Released TBF due to DTM setup (see FAJ 121 611, Dual Transfer Mode).

Note that for DTM, which actively will release an ongoing TBF to be able to receive an incoming page and then enter Dual Transfer Mode, Loss Free Pre-emption is a necessity. Without it DTM users would suffer from very long PS delays in the transition between the different modes.

Loss Free Pre-emption allows a very aggressive pre-emption strategy for on-demand PDCHs to be used especially in cells with semi-dedicated or dedicated channels to fall back onto (see FAJ 121 607, Semi-Dedicated PDCH). This efficiently improves the channel utilization while keeping the end-user performance on a high level.


Title


Implemented in BSC.


Title

1.73 Loudness Adjustment in TRAU



Technology: GSM

1.73.1 Attention


Not applicable

Dependencies


1.73.2 Summary

The purpose of this feature is to enable adjustment of uplink and downlink line levels.

1.73.3 Benefits

The main benefit is that the operator can adjust the loudness of a line. A loudness adjustment may help to improve the speech quality for end users.

1.73.4 Description

This feature allows uplink and downlink line levels to be adjusted independently of each other by means of operator command in the BSC.

The line level is a value of the loudness, that is the strength of the speech. For example, if the loudness of the speech coming from outside the BSC is too low, this feature enables the operator to adjust the loudness so that the speech will have a suitable strength when it reaches the mobile station.

Adjustments are made per BSC and the range is -12 dB to 12 dB in steps of 1 dB.


Title


Title

1.74 Managed Object Recovery



Technology: GSM

1.74.1 Attention


Not applicable

Dependencies


1.74.2 Summary

This feature speeds up the Managed Object (MO) recovery of the RBS's in BSS after Abis transmission link breaks, both microwave and PCM link breaks, restarts in the BSC, and at RBS maintenance. TRXC, TX, RX, TS in the RBS are examples of Managed Objects (MOs).

1.74.3 Benefits

Reduced down time by reducing the MO recovery time after Abis transmission link breaks.

More fault tolerant system by improved handling of unstable links.

Reduced down time in the BSC by since the time for a large restart in the radio network is decreased.

Improved availability in the radio network due to decreased recovery time of the MOs in the RBS's during maintenance actions.


Title

1.74.4 Description

The handling of the MO's is improved in the areas of recovery after Abis transmission link breaks, restarts and maintenance of MOs in the RBS.

Improved handling of MOs in the BSC will make the BSC more robust in handling different fault situations in the transmission network, radio network or in the RBS's. The main improvements are:

The BSC will avoid reconfiguration of MOs in the RBS's unless a mismatch exists between the actual configuration in the RBS and the wanted configuration in BSC during restarts, BTS program load and function change, or after Abis transmission link breaks (thus reducing the down time).

A Change in the procedure of handling MO's by not using auto disabling of them at restarts makes the handling faster.

Detecting and keeping fault information about link breaks in order to avoid acting until the links are stable gives accurate recovery.

1.74.5 Enhancement

Handling at large restart is improved in order to avoid auto disabling of managed object in the BTS. This makes the MO's available for traffic immediately after the restart and reducing the total downtime for large restart even further. The large restart time decreases to less than half of what it was in R7.


Title

1.75 Manual Access Control



Technology: GSM

1.75.1 Attention


Not applicable

Dependencies


1.75.2 Summary

Sixteen Access Control Classes

(ACC) are defined by GSM. Each mobile station is assigned an ACC and this is stored in the Subscriber Identity Module (SIM). This feature enables the operator to bar mobiles with a certain ACC from a particular cell.

1.75.3 Benefits

This feature enables the operator to apply end user segmentation and thereby increase revenue.

By using the Manual Access Control feature it is possible to define cells which are only accessible for prioritized groups. For example, in areas of high traffic an extra cell may be provided to increase capacity. However, only those users with prioritized access may be handed over to this cell when additional capacity is needed. Those users who want guaranteed service availability at peak times can therefore be charged a premium price by the operator. With this strategy the operator can increase revenue.


Title

1.75.4 Description

System information messages are continuously sent by the BTS to all MS"s in a cell. One purpose of these messages is to give the MS"s information about how they should access the system.

The Access Control Class is included in the system information message. There are sixteen ACCs defined by GSM, each class is represented by one bit. If a bit is set to 1 it indicates that the class is barred for access. Each mobile belongs to an ACC and the ACC is stored in the Subscriber Identity Module in the MS.

The Manual Access Control feature enables the operator to prohibit classes from getting access to a certain cell. This is done by changing the contents of the system information message for a BTS remotely from BSC. For example, if the operator defines the Access Control Class number 5 to be barred for a certain BTS, all mobiles belonging to ACC number 5 will not have access to that cell.


Title

1.76 Mega BSC - 2000 TRXs



Technology: GSM

1.76.1 Attention


Not applicable

Dependencies


1.76.2 Summary

This feature increases the maximum number of supported TRXs to 2048 in a BSC or BSC/TRC. The Mega BSC feature will reduce the operators Capex and Opex by e.g. fewer sites and simplified network growth.

1.76.3 Benefits

The main benefit with a Mega BSC is the possibility to have fewer BSCs in high traffic capacity areas. Fewer BSCs and BSC splits gives the following benefits:

Capex savings due to reduced number of BSCs needed.

More cost effective upgrade of BSCs in operation.

Operation and maintenance savings due to fewer nodes.

Reduced signalling and load.

Improved GPRS/EGPRS performance due to fewer inter BSC cell reselections.


Title

1.76.4 Description

The Mega BSC - 2000 TRXs feature increases the maximum number of supported TRXs from 1020 to 2048. The maximum number of Channel Groups are increased to 2048 to match the maximum number TRXs.

The possibility to build larger BSCs and BSC/TRCs means that savings can be done due to that fewer nodes can be used. Network roll-out will be easier and existing growing networks can be expanded with fewer BSC splits.

SW upgrades will be more cost effective since fewer nodes needs to be updated. Operation and maintenance costs will also be reduced due to fewer nodes to manage and visit for maintenance reasons.

The reduced number of nodes will also lead to reduced signaling and load on the BSCs due to reduced number of Inter-BSC handovers and cell reselections.

New product packages are defined for new nodes and for expansions of existing nodes. New nodes can be ordered in a number of capacity steps up to the maximum configuration that supports 2048 TRXs. Expansions packages for both existing BYB501 and existing AXE810 nodes are provided. Existing BYB501 nodes needs to be expanded using the NNRP-4 Group Switch conversion HW and process.

The traffic capacity in TRC is increased from 8000 to 12000 Erlang.

High Speed Signaling Link is required to support the increased signaling, unless the BSC/TRC is connected to a Pool of MSCs. If MSC in Pool is used the signaling load will be divided on several A-interfaces.


Implemented in BSC.


Title

1.77 Mix of ETC-Types in BSC



Technology: GSM

1.77.1 Attention


Not applicable

Dependencies


1.77.2 Summary

The feature provides the possibility to use ETC-types for 1.5 Mbit/s (T1), 2Mbit/s (E1) and 155 Mb/s link (STM-1) in the same BSC. Thus providing the operator with an easier access to a SDH transmission network and the possibility to build even more flexible transmission solutions.

1.77.3 Benefits

Usage of mixed ETC-types will give increased flexibility and lower costs since the use of ETC-155 will reduce the amount of cables and hardware considerably.

Decreased cables and hardware needed between BSC and MSC or Between BSC and Cross-connector when using ETC-155 will save space and costs.

Higher MTBF since there are less cables and connectors that can cause faults

Possibility to Mix 2 Mbit/s and 1.5 Mbit/s transmission in countries where both standards are used (both T1, E1 and STM-1 can be used simultaneously)


Title

1.77.4 Description

The Feature Mix of ETC-types gives support to use more than one ETC-type simultaneously in the same BSC. A new ETC type ETC-155 is introduced with this feature. The operator can get a very flexible transmission solution since he can use ETC-155 where the capacity need is high and E1 or T1 where the need is lower. By using a ETC-155 between an MSC and a BSC instead of 2 Mbit/s one cable will replace approximately 63 Cables and one ETC-155 board will replace 63 2-Mbit/s ETC boards.

On some market, mainly south East Asia both 1.5 Mbit/s ETC's and 2 Mbit/s ETC's are used in the same country. This feature gives the operators the possibility to use both types in the same BSC together with the ETC-155 if needed.

The ETC-155 is also important for the future since introduction of EDGE and GPRS CS-3 and 4 will require higher transmission capacity.


Title

1.78 MNC Expansion



Technology: GSM

1.78.1 Attention


Not applicable

Dependencies


1.78.2 Summary

The Public Land Mobile Network (PLMN) identity is comprised of the Mobile Country Code (MCC) together with the Mobile Network Code (MNC).

In the U.S. the requirement is that the MNC should consist of three digits and that is the main purpose of this feature.

1.78.3 Benefits

The main benefit of this feature is to provide operators with the possibility of using three digits for the MNC.

The MNC parameter is used in the international Mobile Subscriber Identity (IMSI) as well as in Cell Global Identity (CGI) and Location Area Identity (LAI).

1.78.4 Description

The MNC is used in the following cases in the BSC:

At call definition


Title

At assembling of system information

During paging of mobiles

At CGI translation during Inter BSC Handover

When informing the MSC in which cell the mobile is located

At printout of CGI and LAI

In Cell and Mobile Traffic Recording

The MCC is limited to 3 digits, and currently there are 7 values of MCC assigned to the U.S. by the ITU.

GSM specification 04.08, chapter 10.5.1.3 specifies that the MNC should contain 1-2 digits (value range 01-99). There are therefore 693 possible combinations of MCC and MNC (that is 693 possible PLMN values), using a 2-digit MNC.

Since there are 2,074 PCS licenses available in the US, there is a possibility that more than 693 PLMN values are required.

Expansion of the MNC identity from 2 to 3 digits for all country code increases the possible combinations to 6,993, which is sufficient. The feature lets the MNC expand by three digits in the BSS.


Title

1.79 Mobile Traffic Recording



Technology: GSM

1.79.1 Attention


Not applicable

Dependencies


1.79.2 Summary

Mobile Traffic Recording (MTR) allows the operator to order recording of selected MSs (identified by their IMSIs) which are followed through the radio network. The operator can send out a test mobile or record live traffic to investigate the performance of the network in a certain area or for certain events. The recordings are initiated from the MSC.

The main difference between Cell Traffic Recording and Mobile Traffic Recording is that in Mobile Traffic Recording, it is the operator in the MSC that decides which MSs to record, while in Cell Traffic Recording, any MS fulfilling certain triggering events is followed.

Up to 16 simultaneous recordings are allowed.

A file output is made to a hard disc in the BSC. To make the file readable it must be post processed in the OSS.


Title

1.79.3 Benefits

With this feature the operator can monitor and even increase the performance of the network. For example, the operator can check the data that is used to make handover decisions. This will help the operator to identify parameters that need adjusting thereby leading to increased performance.

In particular, after changes or extensions have been made to the network, the network performance can be immediately checked. This can be done by recording a test mobile or an ordinary mobile in the radio network.

Any adjustments needed are quickly identified. If a customer is complaining, the MTR feature enables the operator to track the MS and analyze the problem. This ensures that the network quality experienced by end users is maximized.

Possibility to track and act on stolen mobiles will help the operator to minimize the fraud within his network.

1.79.4 Description

Mobile Traffic Recording is a feature for recording event data produced in the BSC, and for recording of measurement data from the BTS and the MS.

Initiation and specification of the recordings takes place via the A-interface message TRACE INVOCATION which is sent by the MSC/VLR for each MS connection. The message contains a specification of recording type, type of output device, and recording reference.

Event data is related to a specific connection. The events are classified according to the following categories:

Messages sent on the Abis interface

Messages received on the Abis interface

Messages sent on the A interface

Messages received on the A interface

Internal messages

Examples are: establishment indication, assignment command, assignment complete, assignment failure, various types of handover messages, channel rate, speech coding version, various types of connection release messages, clear command, SAPI related messages, etc. These are recorded together with a recording reference, date, and time.


Title

Measurement data can also be recorded. Measurement data is sent by the BTS and MS to the BSC and contains the measurement report as stated in the GSM specifications. This is the data that is used as the basis for handover decisions.

Measurement data will be collected continuously as opposed to Cell Traffic Recording where measurement data is recorded according to a time window prior to and after certain events.

Up to 16 simultaneous recordings are allowed. Out of these a maximum of 4 recordings with both event and measurement data are possible. The remaining recordings are with event data only.

1.79.5 Enhancement

The enhancements are:

Support of the new GSM Phase 2 message MSC INVOKE TRACE which is handled in parallel with the Ericsson proprietary message TRACE INVOCATION. This makes it possible to trace between other vendors MSCs and Ericsson BSCs.

More efficient file output to the IOG which gives higher output capacity thus decreases the possibility of interrupted recordings.

Time stamping in deci-seconds instead of seconds gives more accurate resolution.


Title

1.80 MSC-BSC Traffic Load Regulation



Technology: GSM

1.80.1 Attention


Not applicable

Dependencies


1.80.2 Summary

MSC-BSC Traffic load regulation regulates the traffic between MSC and BSC at overload situations.

1.80.3 Benefits


Improved In Service Performance (ISP)

1.80.4 Description

With MSC-BSC Traffic load regulation, an overloaded MSC will inform the connected BSC(s) about the overload situation. The BSC will then stop sending new traffic requests to the MSC. This will minimize the impacts in the GSM network due to overload situations in the MSC and thereby avoid severe GSM network failures.


Title


Implemented in BSC


Title

1.81 Multidrop at RBS 2000 (Macro)



Technology: GSM

1.81.1 Attention


Not applicable

Dependencies


1.81.2 Summary

The feature Multi Drop at RBS 2000 (Macro), makes it possible to interconnect several RBS's (RBS 2101, RBS 2102, RBS 2103 and RBS 2202) to a single PCM transmission link.

1.81.3 Benefits

The main benefit of this feature is that it supports cost-efficient usage of the transmission links between the BSC and the RBS's. Re-configuration of the cascaded RBS's can be carried out at the BSC.

A number of flexible configurations are supported. These will enable the operator to reduce transmission costs and cabling costs.

At least five RBS 2000s can be cascaded together so that they share the same E1 transmission link. The assumption is that each RBS in the chain has two TRX's. If this feature is combined with NF 89.1 LAPD Multiplexing, RBS 2000, then the number of TRX's or RBS's in the chain could be increased. No additional cross-connect equipment is needed. For T1, at least 4 RBS's can be cascaded.


Title

With this feature, other types of traffic can be transparently transported through the RBS. All time slots on the 2 or 1.5 Mbit/s link which are not meant to be dropped at a certain RBS will be transported through the RBS without interruption.

This feature allows RBS's for different systems (GSM 900, 1800 and 1900) located at the same site, to share the same transmission link to the BSC.

1.81.4 Description

With Multi Drop functionality, up to five, two TRU RBS's can be interconnected. If the Multi Drop functionality is combined with LAPD Multiplexing or LAPD Concentrating more than five, two TRU RBS's can be interconnected. The maximum distance between the RBS's is approximately 200-400 meters. Both the maximum number of interconnected RBS's and the maximum distance is dependent of the Abis (logical interface between the BSC and the RBS) distance from the BSC to the first RBS, cable type used, etc.

Multi drop connected RBS's are connected so that each RBS uses its port A (on the DXU) towards the BSC and port B (on the DXU) towards the next RBS. That RBS (downstream to the first one) is connected in the same way with port A towards the previous RBS (and indirectly the BSC) and port B towards the next RBS etc.

The Multi Drop functionality is activated during installation by using the Operation and Maintenance Terminal (CME 20 R6.1/CMS 40 R3). Configuration can also be carried out at the BSC using Remote OMT. The current models of the DXU (BOE 602 02/01 and BOE 602 02/02) support the Multi Drop functionality. No additional hardware is required (except) the cables between the RBS's.

Supported transmission interfaces:

G.703 ( E1, 2 Mbit/s):

75 ohm (coaxial)

120 ohm (twisted pair)

T1.403 (T1, 1.5 Mbit/s):


If one of the multi dropped DXU's is faulty, all downstream RBS's (including the faulty one) could be taken out of traffic. However, the DXU is very reliable so it is very unlikely that this limitation will have any practical impact on the system reliability.


Title

Re-setting the faulty RBS and the downstream RBS's takes a few seconds. If re-setting is successful (no major faults) then the multidropped RBS's are brought back into service.


Title

1.82 Multidrop at RBS 2301 (Micro)



Technology: GSM

1.82.1 Attention


Not applicable

Dependencies


1.82.2 Summary

This feature allows RBS 2301s to be cascaded together so that they can share a PCM transmission link.

1.82.3 Benefits

The main benefit of this feature is that it supports cost-efficient usage of the transmission links between the BSC and the RBS's. Re-configuration of the cascaded RBS's can be carried out at the BSC.

A number of flexible configurations are supported. These will enable the operator to reduce transmission costs and cabling costs.

At least five RBS 2301s can be cascaded together so that they share the same E1 transmission link. The assumption is that each RBS in the chain has two TRX's. If this feature is combined with NF 89.1 LAPD Multiplexing, RBS 2000, then the number of TRX's or RBS's in the chain could be increased. No additional cross-connect equipment is needed. For T1, at least four RBS 2301s can be cascaded.

Robustness is ensured. Even if an RBS becomes faulty, transmission through the cascade continues.


Title

With this feature, other types of traffic can be transparently transported through the RBS. All time slots on the 2 or 1.5 Mbit/s link will be transported through the RBS without interruption.

This feature allows RBS 2301s for different systems (GSM 900, 1800 and 1900) located at the same site, to share the same transmission link to the BSC.

RBS 2301 is protected against lightning.

1.82.4 Description

The RBS 2301 can be configured for multidrop mode using the Operation and Maintenance Terminal (OMT). This configuration can also be carried out at the BSC using Remote OMT.

Supported transmission interfaces:

G.703 ( E1, 2 Mbit/s):

75 ohm (coaxial)


T1.403 (T1, 1.5 Mbit/s):


When used in multidrop mode, the RBS's are connected so that each RBS uses its A port towards the BSC and B port towards the next RBS. Each connected RBS is connected in the same way with its A port towards the previous RBS (and implicitly the BSC) and B port towards the next RBS etc..

If one RBS 2301 in a multi-drop chain does not work, it is by-passed. It is recommended that the line-build is defined so that the RBS which does work has the signal strength to transmit to the next working RBS.


Title

1.83 Multiple Cells per TG



Technology: GSM

1.83.1 Attention


Not applicable

Dependencies


1.83.2 Summary

The BSC is enhanced to support multiple cells within a single Transceiver Group (TG). The feature is intended to be used in overlaid radio networks sharing physical components. The chosen implementation makes it possible for the operator to define transceivers dedicated to a specific cell or common to a number of cells. By using these options it is possible to share spare equipment between cells. It is even possible to use the spare equipment, intended to serve as stand by equipment for more than one cell, until the equipment is actually needed.

Standby equipment is equipment that is configured when other equipment carrying important logical channels are lost. Administration functions will be enhanced to permit operators to define such multiple cells (up to a certain limit) defined for the source system, after which attempts to define further cells will be rejected by an error message.

1.83.3 Benefits

Not applicable


Title

1.83.4 Description

Not applicable


Title

1.84 Optimized default allocation of MAIO



Technology: GSM

1.84.1 Attention


Not applicable

Dependencies


1.84.2 Summary

Wideband frequency hopping systems with Fractional Load planning offers an attractive combination of simplicity and good spectral efficiency, especially when only a limited spectrum is available. The Mobile Allocation Index Offset (MAIO) settings affects the interference and thereby spectrum efficiency and performance of such networks, and Optimized Default Allocation of MAIO provides a good default setting of MAIO values in a site, thereby reducing interference in Fractional Load planning systems, e.g. 1/3 or other tight planning schemes.

1.84.3 Benefits

Optimized Default Allocation of MAIO provides a good default setting of MAIO values in a site, thereby reducing adjacent channel interference in a Fractional Load planning system.

Optimized Default Allocation of MAIO allows adjacent channels to be allocated within a cell, thereby increasing the flexibility of the frequency planning.

Optimized Default Allocation of MAIO allows 1/3 frequency planning to be utilized without consideration of MAIO settings, thus reducing the effort for frequency planning.


Title

With fractional load planning methods, capacity in the network can be increased simply by adding additional TRX on existing sites, instead of taking other more costly measures, such as adding more cells to the network

By applying fractional load wide band frequency hopping methods the effort for cell planning is reduced significantly.

1.84.4 Description

Description of Functionality In many cases the choice of Mobile Allocation Index Offset (MAIO) scheme for the TRX's in a site does not matter. This is not the case in systems with wideband frequency hopping and Fractional Load Planning (FLP) though. The principle of FLP is that more frequencies are allocated to each cell than there are TRX's in the cell. By using synthesized frequency hopping, all TCH frequencies defined for a specific cell are included in the hopping sequence, but only as many frequencies as there are active TRX's in the cell are transmitted on at a given instance. The MAIO value determines where in a hopping sequence a new call connection shall start, and for FLP systems with 1/3 frequency reuse planning, adjacent channel interference will deteriorate performance of the network if the MAIO settings are not managed correctly. Please refer to ETSI GSM TS 05.02 for more details. With the feature Optimized Default Allocation of MAIO, a number of frequency reuse plans are supported by default MAIO allocations. For instance, several methods of fractional 1/3 reuse can be supported without manually setting the MAIO, thus minimizing the planning effort. One such example is a blocked 1/3 plan i.e. the frequencies are divided in three groups of consecutive frequencies. The Optimized Default Allocation of MAIO feature uses "even then odd" MAIO strategies. This means that first all even MAIO values for that cell are used in increasing order, followed by odd values in increasing order (e.g. if 5 TRX's were used in a cell with 7 frequencies, the order of MAIO allocation would be 0,2,4,6,1). This minimizes the adjacent channel interference within the cell in a blocked 1/3 plan. Description of Use In case of 1/3 reuse the frequencies are divided in three groups, one group per sector in a typical three sector site. With Optimized Default Allocation of MAIO, the operator assigns a default setting of MAIO values to each cell in the network, thereby reducing adjacent channel collisions within a site (co-channel interference is avoided by the grouping of frequencies). The frequencies for the BCCH are planned separately from the TCH frequencies. The reason for this is both that the BCCH requires a better quality and is therefore planned with a less tight reuse, and that the BCCH cannot be hopped on when synthesis frequency hopping is used, unless an extra TRU is added for so called BCCH zero filling.


Title

1.85 Overload Protection in TRH



Technology: GSM

1.85.1 Attention


Not applicable

Dependencies


1.85.2 Summary

This feature will avoid overloading of the CP (Central Processor) by prohibiting that too old 'channel requests' reach the CP. This protection handles overload situations caused by massive mobile originating call attempts.

1.85.3 Benefits

The main benefit is reduced downtime, due to

' Improved ISP (In Service Performance) in BSS by improving BSC availability

' Reduced processor load in the BSC, since 'channel request' messages that are too old are rejected

' Less restart problems, since old 'channel request' messages are deleted.

' Increased traffic handling (throughput) during overload situations


Title

1.85.4 Description

Description, function: The BSC must respond to a 'channel request' sent from a mobile within 250ms. If it does not respond within this time, the mobile sends a new 'channel request'. There is no possibility to relate a 'channel request' to a certain subscriber. If there are multiple messages sent from the same mobile to the BSC, each will be handled separately and multiple channels will be allocated and activated. As the mobile will respond to the first immediate assignment only, the others will time-out. This will lead to unnecessary processor load in the BSC. In this feature a communication window is introduced between the RP's and the CP. This window keeps track of the number of allowed outstanding 'channel requests' that are sent from the RP to the CP. If no reply is received from the CP, a timer gives a time-out and a 'reject' message is sent to the mobile. If the window is closed, i.e. no 'channel requests' can be sent to the CP, the 'channel requests' are kept in a queue. If the queue is full when a new 'channel request' arrives, a 'reject' message is sent to the mobile. 'Channel requests' that have been in the RP for

too long time are also rejected. There is also a throttling mechanism that limits the number of 'channel requests' sent from all RP's together. If the limit is reached a 'reject' message is sent to the mobile.

Description, use: This feature will improve the overload protection of the CP when it already is in an overloaded state. Sophisticated protection mechanisms are introduced to handle overload situations between the CP and the RP's caused by massive mobile originating call attempts.


Title

1.86 Paging



Technology: GSM

1.86.1 Attention


Not applicable

Dependencies


1.86.2 Summary

When an MS terminated call is to be set up, paging is the procedure that is used to search for the MS and to order it to initiate a connection.

1.86.3 Benefits

Paging makes it possible to set up MS terminated calls.

1.86.4 Description

Paging is the procedure to set up an MS terminated call. It is initiated when the BSC receives a paging message from the MSC or the SGSN with information on where to page the MS. The information from the MSC or the SGSN will determine if the paging shall be done in all cell in the BSC, the cells belonging to a certain Location Area or in just one cell.

If a Temporary Mobile Subscriber Identity (TMSI) is received, it is used by the BSC as MS identity in the paging procedure, otherwise International Mobile Subscriber Identity (IMSI) is used. As TMSI is shorter, it enables higher paging capacity. This means that up to 4 mobile stations can be paged in one paging message over the air-interface as compared to 2 if IMSI is used.


Title

The 22 latest received paging messages in the BSC are queued until they are handled. In order to protect system stability the BSC will discard paging messages in case the que is overflowing. If the number of discarded paging messages surpasses a threshold, alarms will be issued to notify maintenance staff.

In order to handle congestion on the paging channel in the air-interface, paging messages will also be queued in the BTS. To ensure maximum system performance paging messages will be discarded both if the que is overflowing and if they have been in the queue for too long.

The BTS supports re-transmission of paging messages over the air-interface. The IMSI and TMSI are stored for re-transmission and included in the next request if not enough IMSI and TMSI are found in the actual paging queue.

Extended Paging is supported which makes it possible to page the MS not only within its own paging group, but in other paging groups as well.


Implemented in: BSC, BTS

1.86.5 Enhancement

Not applicable


Title

1.87 PCCCH Capacity



Technology: GSM

1.87.1 Attention


Not applicable

Dependencies


1.87.2 Summary

By the introduction of a Master PDCH (MPDCH) the signaling load on the normal Common Control Channel (CCCH) is reduced as GPRS attached terminals will instead be using the Packet Common Control Channel (PCCCH). This features increases the paging capacity on the Packet Paging Channel (PPCH) and makes it possible to avoid congestion on the Packet Random Access Channel (PRACH).

PCCCH Capacity makes it possible to efficiently handle large amount of GPRS/EGPRS signaling making the transition to the MPDCH smooth.

1.87.3 Benefits


Increased paging capacity on the PPCH with up to four times.

Makes it possible to migrate to MPDCH and Network Operation Mode I.

Frees up capacity on the MPDCH that can be used for payload traffic thus improving the throughput on the MPDCH.


Title

Avoids congestion on the PRACH leading to an increased random access success rate.

1.87.4 Description

The PCCCH is used to carry assignment and paging messages for packet switched services on a Master PDCH (MPDCH). With the introduction of the MPDCH in the network the operator gets several benefits. One of these is an immediate off-load of the normal CCCH as GPRS attached users will instead be monitoring the PCCCH. If many terminals are GPRS attached in the network this puts high demand on the capacity of the PCCCH.

With the PCCCH Capacity feature a significant increase in capacity is achieved, which makes the introduction of MPDCH in the network smooth. The feature improves the capacity in mainly two areas:

Improved paging capacity on PPCH

Improved random access capacity on PRACH

Improved paging capacity on PPCH is achieved by packing up to four pages on each paging message over the air interface. This means not only that paging messages are used in a more efficient way but also that the throughput on the MPDCH is increased as more capacity is used to send data.

Packing of pages on PPCH is a necessity to avoid paging congestion at the introduction of an MPDCH together with Network Operation Mode I (using the Gs interface between SGSN and MSC) as even pages for speech calls are handled by the PPCH.

Improved random access capacity on PRACH is achieved as it is possible to reserve resources of the MPDCH used for Packet Channel Request messages. The operator can specify the number of block periods reserved for PRACH on the uplink of the MPDCH on a per cell basis.


Implemented in BSC.


Title

1.88 PCM-B Transmission Link



Technology: GSM

1.88.1 Attention


Not applicable

Dependencies


1.88.2 Summary

An additional PCM transmission link, that is a PCM-B link, will be required towards RBS 2000 in order to provide more flexibility when building a BSS network for larger sites.

This is to increase the capacity when there is a need to access more than 10 TRX"s in one base station.

It is important to note that for capacity reasons this feature is interesting to the U.S. market, where the number of 64 kbit/s time slots on one PCM link, T1(1.5 Mbit/s), is 24. Even with the LAPD concentration feature no more than 10 TRX"s can be supported by one T1 link.

1.88.3 Benefits

The operator will have the option to select either A and B links or one of these two for communication between BSC and RBS. This means that the operator can build more powerful sites in densely populated areas. In addition, the operator can choose to use this additional link for redundancy purposes.

With both these two options the operator will be able to build more flexible networks.


Title

1.88.4 Description

For each TRX we need two 64 kbit/s PCM TS"s for traffic and one 64 kbit/s PCM TS for signalling. This means that with one PCM transmission link, 32 or 24 64 kbit/s, we can support up to 10 TRX"s on 2 Mbit/s (E1), and up to 8 TRX"s on 1.5 Mbit/s (T1).

With an additional PCM link, that is a PCM-B, larger sites with more than 10/8 TRX"s could also be supported.

However to be able to support sites with 12 TRX"s, support for Multi-Cabinet configuration of RBS 2000 will also be required.


Title

1.89 PCU Load Control



Technology: GSM

1.89.1 Attention


Not applicable

Dependencies


1.89.2 Summary

The load of the PCU HW is increasing due to increasing GPRS/EGPRS traffic and new GPRS/EGPRS functionality. This feature implements PCU load control mechanisms to facilitate an optimal use of the PCU HW.

1.89.3 Benefits


Increased Service availability and more efficient RPP utilization.

Improved end-user experience due to less traffic disturbances.

1.89.4 Description

Increased service availability and improved end-user experience are achieved by introducing mechanisms in the RPP, which avoid disturbances in traffic throughput, or even restart of the RPP, at high CPU load. This is achieved by prioritizing between activities that are performed on the CPU, and by introducing several load thresholds at which different actions shall be performed in order to limit the load.


Title

Load Regulation

Ensures that important traffic functions have enough RPP CPU time by prioritizing these functions higher than less important activities.

Overload protection

The PCU Overload Protection mechanisms will handle all fast changes in RPPs CPU load or memory usage and make sure that the RPP will not restart due to high load. This is done by for example stopping operation and maintenance related functions and removing PDCH's until the load is on an acceptable level.

Load distribution

RPP Load Distribution handles all long-term changes in the RPPs CPU load by monitoring and comparing the load of each RPP within the whole PCU. Load can then be evened out by 'moving cells' between RPPs. Prior to BSS R12 cells where only moved when an RPP was faulty or lacked free GPH devices (interface to the Group Switch).


Implemented in BSC


Title

1.90 Processor and Exchange Load Measurements in BSC



Technology: GSM

1.90.1 Attention


Not applicable

Dependencies


1.90.2 Summary

This feature measures and supervises processor load and exchange input load. It also controls the processor load in order to prevent overload.

1.90.3 Benefits

With this feature the operator can have continuous information about the load data for each BSC. This provides a good overview of network performance. It can indicate possibilities for optimizing the network or give an early warning that the network needs to be expanded.

Measurements may indicate that the processor is heavily utilized at certain times during the day and less so at other times. With this information, the operator can take steps which will result in the traffic load being more evenly distributed over all the hours of the day. For example, different tariffs could be charged depending on time of day.

When subscriber density in an area increases, this will be reflected by an increasing load on the processor. This feature gives the operator the opportunity to take action in time, if necessary. For example, measurements may indicate that the operator will soon need to provide more capacity in the network.


Title

Load control maximizes system availability for the end user and minimizes the risk of losing calls at peak traffic times. This enhances the operator's reputation as the provider of a reliable and high quality network.

1.90.4 Description

Processor load is defined as the percentage of time that the processor spends executing tasks above a certain priority level. Exchange input load is the total number of calls offered to the exchange.

Load data can be obtained immediately on command. A printout is given containing for example average processor load, offered calls, and actual fetched calls.

A printout is also given when a significant change in the processor load or exchange input load occurs. The load data is compared to adjustable threshold values.

An alarm is generated if the load becomes too great for the exchange or the processor to handle.

To maintain a high flow of successfully handled calls during overload conditions, the accepted call intensity is regulated with regard to the load situation of the system. This prevents an extremely high offered call intensity from causing overload and system failure. The traffic process in normal situations is not affected.


Title

1.91 Radio Link Failure Supervision



Technology: GSM

1.91.1 Attention


Not applicable

Dependencies


1.91.2 Summary

The purpose of this feature is to supervise the radio connection between the Base Transceiver Station (BTS) and the Mobile Station (MS). If the radio connection does not fulfill operator defined criteria the link will be released.

1.91.3 Benefits

The main benefit of this feature for the operator is that it supports cost efficient use of radio network resources.

This feature enables the operator to set parameters that decide when the radio link is to be released.

1.91.4 Description

Radio Link Failure Supervision uses:

The Timing Advance information in the Measurement Reports

The Measurement Result messages


Title

The BSC receives the Measurement Result from the BTS containing BTS measurements and the Measurement Report. The Measurement Report is received in the BTS from the MS and it contains power and quality measurements of the radio connection.

Timing Advance is a value in the Measurement Result which tells how far from the BTS the MS is. When the Timing Advance reaches a certain limit the radio link between the BTS and the MS is released. The limit value is operator defined in the BSC.

A radio link counter in the BSC is set to a operator defined value. The counter is decreased by 1 if the Measurement Result is missing or if the BSC receives the Measurement Result without MS information. The counter is increased by 2 if the BSC receives the Measurement Result with MS information included. If the counter reaches 0, the radio link between the BTS and the MS is released. The maximum value of the counter is the operator defined value.

The feature is implemented as software in the BSC.


Title

1.92 RBS 200 Digital Path Supervision



Technology: GSM

1.92.1 Attention


Not applicable

Dependencies


1.92.2 Summary

This feature supports both fault and performance supervision of digital PCM links to the BSC or to the Transmission Remote Interface (TRI) in the RBS.

Faults in the transmission interface are detected and separated from faults in the RBS. A report is sent to the BSC.

1.92.3 Benefits

The benefit for the operator is that easier and faster transport network fault detection and localization is possible. This allows cost-efficient network operation and maintenance.

1.92.4 Description

The following faults are reported individually:

Loss Of incoming Signal (LOS)

Loss Of frame alignment (LOF)


Title

Alarm Indication Signal (AIS)

Remote Alarm Indication (RAI)

Consecutive Severely Errored Seconds (CSES) or Excessive bit error RATE (ERATE)

Unavailable state supervision (UAST)

Quality Supervision of each PCM path is performed. It covers supervision of:

Bit Fault Frequency (BFF)

Disturbance Frequency (DF)

Slip Frequency (SF)

Errored Seconds (ES)

Severely Errored Second (SES).

1.92.5 Enhancement

Not applicable


Title

1.93 RBS 2000 Digital Path Supervision



Technology: GSM

1.93.1 Attention


Not applicable

Dependencies


1.93.2 Summary

This feature provides fault supervision and quality supervision of the PCM path. Supervision is performed at the PCM interface in the RBS. The PCM interface, a transmission interface, is part of the Distribution Switch Unit (DXU).

Faults in the transmission interface are detected and separated from faults in the RBS. Reports are sent to the BSC.

If the RBS is connected to the BSC via an external transmission network such as a leased line network, then this feature only supervises the transmission path from the RBS to the external transmission equipment.

If there is a transparent transport network, for example a radio path between the BSC and BTS, then supervision is end-to-end.

This feature extends the support provided by the feature"NF 610.1 Supervision of Digital Paths Connected to the BTS".

1.93.3 Benefits

More information regarding PCM system performance is available, leading to faster and easier transport network fault detection and localization.


Title

In addition, service degradation will be detected by using the received performance measurements.

1.93.4 Description

The following faults are now reported individually:

Loss Of incoming Signal (LOS)

Loss Of Frame alignment (LOF)




Unavailable state supervision (UAST)

Quality Supervision of each PCM path is performed. It covers supervision of:



Slip Frequency (SF)


Severely Errored Second (SES)

Unavailable Seconds (UAS).

The network operator can set, by command, the frequency at which quality supervision reports should be sent to the BSC.

Control parameters for PCM fault management and PCM quality supervision can be set by command. The same type of functionality is also supported for the RBS 200.

PCM supervision, according to the standards, is supported on 2 Mbit/s PCM links with an interface according to ITU-T G.703, and on 1.5 Mbit/s ANSI DS1 PCM links. It should be observed that a Digital Path (DIP) fault cannot be reported if there is only one PCM link and this link is unavailable.

This feature is implemented in software in BSC and BTS.


Title


Title

1.94 RBS Battery Log



Technology: GSM

1.94.1 Attention


Not applicable

Dependencies


1.94.2 Summary

This feature gives information about the battery conditions. The information, which can be displayed in the Operation and Maintenance Terminal (OMT), Remote Operation and Maintenance Terminal (Remote OMT) or Remote OMT over IP, contains operating temperature, number of discharges and operating time, i.e. parameters that impact the battery life time.

1.94.3 Benefits

The RBS Battery Event Log has the following benefits:

The information in the event log can be used to plan for battery replacements and to identify batteries with poor quality.

The information in the Battery Event Log will make it possible to investigate the reason behind a faulty battery.

1.94.4 Description

This feature gives information about the battery conditions. The information can be fetched via OMT or remotely via Remote OMT or Remote OMT over IP.


Title

The RBS writes information to a battery log that is stored in the DXU memory. The following information is stored in the log:

Operating time within different temperature intervals

Number of discharges

Total operating time

The parameters above influence the expected life time of the battery.

The battery log is read using OMT, Remote OMT or Remote OMT over IP.


Implemented in RBS, OMT, Remote OMT and Remote OMT over IP.


Title

1.95 Re-Use of Frequencies within a Cell



Technology: GSM

1.95.1 Attention


Not applicable

Dependencies


1.95.2 Summary

This feature enables the use of the same frequencies in more than one channel group within a cell when synthesized frequency hopping is used. This makes it possible to build sites with the most cost optimal RBS hardware configurations without sacrificing spectrum efficiency.

1.95.3 Benefits

Re-Use of Frequencies within a Cell has the following benefits:

Build sites with the most cost optimal RBS hardware configurations, without impacting spectrum efficiency.

Expansions can be done without impacting existing RBS hardware, that is, no site downtime.


Title

1.95.4 Description

Re-Use of Frequencies within a Cell makes it possible to use the same frequencies in more than one channel group within a cell. A basic prerequisite for this is that synthesized frequency hopping is used in the cell. Interference is avoided by allocating different MAIO values to the transceivers in the same way as is done within a channel group, resulting in that a frequency is not used for more than one connection in a cell at any instant in time.

The feature allows all transceivers in a cell use all frequencies for hopping even though the transceivers have to be divided into two or more groups. The frequency hopping gain is thereby maintained and no loss of spectrum efficiency is experienced.

A situation when transceivers can be divided in to different groups for RBS 2000 is when transceiver belonging to multiple cells are controlled by one DXU, for instance a 4/4/4 configuration in one or two cabinets depending on which RBS that is used. This is the most cost efficient way of building this configuration, and when expanding the number of transceivers the recommended method is to add a new cabinet and use RBS 2000 Synchronization to connect the new cabinet. Thereby the new cabinet can be installed without affecting the existing equipment and site downtime can be kept to zero.

The same method and results also apply when expanding RBS 200 with RBS 2000, that is, no impact on spectrum efficiency and existing traffic.


Implemented in: BSC


Title

1.96 Reduction of BSC Restart Time



Technology: GSM

1.96.1 Attention


Not applicable

Dependencies


1.96.2 Summary

This feature significantly improves In Service Performance (ISP) due to reduced restart times.

1.96.3 Benefits

In Service Performance is improved by 40% for an average operator.

1.96.4 Description

The restart times for Small restart with complete RP restart and Large Restart with and without Radio Network Reconfiguration are reduced significantly. For the average network, the total ISP improvement corresponds to around 40%, however the actual restart times are dependant on both APZ type and how many transceivers the BSC supports.


Title

The reduced restart times are achieved by updating RPs in parallel at small restart with complete RP restart and at large restart with and without radio network reconfiguration. Restart of CCS-7 links is initiated immediately after a Large restart which implies that CCS-7 signaling links are available much earlier. These together with some other system improvements leads to significant reductions of restart times in the BSC. Both the CP restart time and the time to first and last call possible are reduced.


Implemented in: BSC


Title

1.97 Redundant Control of TRIs



Technology: GSM

1.97.1 Attention


Not applicable

Dependencies


1.97.2 Summary

The main task of this feature is to re-allocate signaling channels from a faulty PCM link to a redundant PCM link.

1.97.3 Benefits

This feature increases the reliability of the connection between the BTS and the BSC, hence it improves the radio network availability.

1.97.4 Description

The Transmission Radio Interface (TRI) is physically located in the BTS. It forms a digital cross connector function on a 64 kbit/s level. The TRI enables the BTS to be connected in series with other BTS"s

which is known as cascade-connected TRI"s. Speech and signaling channels between the BSC and other TRI"s are thus connected through the bypassed TRI. In this case two or more PCM links may be connected towards the BSC.


Title

If one of the PCM links fails the Redundant control of TRI"s feature blocks the faulty link. The feature will issue an alarm and reallocate the signaling channels to the redundant PCM link.


Title

1.98 Release of Sequential Events (FORLOPP)



Technology: GSM

1.98.1 Attention


Not applicable

Dependencies


1.98.2 Summary

At present when the APZ detects a processing fault in the system, its first action is to perform a selective or small system restart.

Most of the software faults found affect a very small proportion of processes in the system. It is possible to clear the process where the fault occurred and to allow the rest of the system to work normally.

At a Forlopp release, only the Forlopp indicated by the fault detecting function is affected; other functions in the system are not affected.

1.98.3 Benefits

The End-User

Reduced disturbances caused by software faults leads to higher availability for the end-users.

The Operator


Title

There will be an improvement in system performance. System downtime will be decreased when using the Forlopp concept compared to a non-forlopp adapted BSC system.

The operator will have the possibility to get a printout of processes that have been hanging for a pre-defined period of time. Also, the operator will have the possibility to order a release of the process(es).

Increased availability in the BSC thus reducing the maintenance cost.

1.98.4 Description

Software errors are detected by hardware, microprogram or supervisory programs. After a fault detection, the recovery takes place by means of a system restart or a Forlopp release.

"Forlopp" means a sequence of events or a process. Forlopp management enables a process to be identified and handled independently.

The software is divided into a forlopp-oriented part and a non forlopp-oriented part. If an error is detected in the forlopp-oriented part, a recovery by means of a Forlopp release is performed.

Errors in non forlopp-oriented parts normally lead to a system restart.

A "process" in AXE is a sequence of events created to perform a unique task. When the task, for example a call, has been completed, the process is terminated.

With Forlopp management a process such as a call process can be identified and handled separately. Data related to a process (Forlopp) is stored in one or several task individuals. Each task individual is marked with a unique Forlopp identity.

A Forlopp release implies that only the failed Forlopp is released and all other forlopps remain unaffected. When a Forlopp release is performed, all task individuals connected to this Forlopp will be informed about the fault situation by an abort signal.

Error information is preserved to enable an analysis of the reason for the error.

The system supervises the number of Forlopp releases. Too many within a given time interval will result in a system restart.

The time required for a Forlopp release is considerably shorter than that for a system restart. Traffic handling continues during a Forlopp release.

The Forlopp release function can be activated or deactivated by command.


Title

The traffic handling in the BSC is Forlopp adapted.

1.98.5 Enhancement

Configuration, command and printout (both alarm and command) handling are Forlopp adapted. This is estimated to lower the number of restarts in a BSC/TRC with approximately 40% thus improving the availability of the BSS.


Title

1.99 Remote Function Change



Technology: GSM

1.99.1 Attention


Not applicable

Dependencies


1.99.2 Summary

The remote function change feature introduces a radically new way to upgrade SW. Instead of sending a rollout team on-site to upgrade the SW by following an implementation procedure described on paper, the upgrade team can now sit at the central OMC and supervise the execution of a SW program that remotely upgrades the SW in the target exchange. Using OSS applications, an upgrade team can supervise the remote upgrade of up to approx. 30 exchanges during one maintenance window (i.e. during one night) from one OSS terminal. This results in a substantial increase in rollout speed over the traditional on-site upgrade procedure (approx. 2 nights per exchange). The ability to perform parallel SW upgrades from a central location, results in a faster time to market (TTM) for new subscriber features. At the same time O & M cost decreases by better utilization of upgrade experts, and highly reduced traveling costs.

1.99.3 Benefits

Revenue increased by

Highly reduced roll-out time results in that end users can start using and paying for new services faster

Decreased downtime which has a direct impact on the economical result


Title

Quality of service improved by

Decreased number of in-service disturbances due to human errors

O & M cost decreased by

Better utilization of system experts

Reduced employee overtime

Substantially reduced traveling costs

1.99.4 Description

The control of the upgrade process is performed using SW scripts. OSS plays a key role. The upgrade process is controlled and supervised from the OSS application Software Management Organizer (SMO). The SW scripts are executed on the OPS application. A third application, AXE Software Management Module (ASM), is used for file transfer from the OMC to the IOG.

The script driven upgrade process is summarized below

Health check to establish the stability of the exchange

SW download from the OMC to the local site (i.e. IOG)

Backup

SP upgrade(s)

CP upgrade (i.e. central and regional software)

Health check to validate the SW change

Confirmation

Backup

The scripts and the script driven process are released by the development organization, along with the system release at GA (General Availability).


Title

1.99.5 Enhancement

Up to approx. 30 Exchanges can be upgraded during one night. Usage of Automatic Correction Deployment achieved by specialized software scripts that require no human interaction results in more efficient use of the workforce. Higher security due to improved script fault handling


Title

1.100 Selective Restart



Technology: GSM

1.100.1 Attention


Not applicable

Dependencies


1.100.2 Summary

The feature selective restart increases the availability of the BSC by delaying some type of restarts. The restarts will be executed during a time specified by the operator, preferably during nights. This is done in order to minimize the effect on ongoing calls especially during busy hour, when a restart would cause revenue losses for the operator.

1.100.3 Benefits

Increased availability

Increased revenue

More fault tolerant system

1.100.4 Description

Not applicable


Title

1.101 Shorter Speech Interrupts at Handover



Technology: GSM

1.101.1 Attention


Not applicable

Dependencies


1.101.2 Summary

This feature will reduce the speech interrupt at handover within the same BSC, for both intracell and intercell handover. This reduction will improve the quality experienced by the end user.

1.101.3 Benefits

The feature will allow a significant reduction in the speech interrupt at handover within the same BSC. Customer feedback has been that the downlink speech interruption has been noticeable and annoying. These drawbacks have been addressed with this feature.

Reducing speech interruption becomes more important as the cell sizes get smaller, for example with microcells, and when functions like overlaid/underlaid cells are used more heavily, leading to more handovers per call.

The shorter speech interrupt is also important in positioning GSM against the CDMA (IS-95) system, which claims "seamless" or "soft handover" handover as a selling argument.


Title

1.101.4 Description

The downlink speech interrupt for intra BSC handovers, is approximately halved by this feature. This is done by distributing the downlink speech to both the old (present) channel and the new (target) channel during the handover process.

Two speech paths are established through the BSC during the handover. When the MS arrives on the new channel the speech is "already there", eliminating the need to wait for the speech path to be switched over, and the new transcoder to be ready to send the 20 ms speech frames towards the BTS. The old speech path is then disconnected after the MS has confirmed its presence on the new channel

1.101.5 Enhancement

The handover interruption in the uplink direction is reduced with approximately 30%. This improvement is achieved by optimize the time between the reception of the HANDOVER DETECTION and the actual switch. This time value can be changed in the parameter list.


Title

1.102 Software Load of RBS 200



Technology: GSM

1.102.1 Attention


Not applicable

Dependencies


1.102.2 Summary

The feature Software Load of RBS 200 allows the operator to order a parallel software download from the BSC to the RBS 200 over the Abis interface. The number of parallel transfers adapts to the available processor capacity.

1.102.3 Benefits

The overall benefit of this feature for the network operator is that operation costs will decrease.

1.102.4 Description

The software loading of RBS 200 can be handled in two ways and they are:

Function change, where all managed objects for a BTS logical model are loaded with a predefined software version.

Program load, where specific managed objects for a BTS logical model are loaded with a predefined software version. This makes it possible to have different software versions within a transceiver group.


Title

For each of the above ways the operator can order the loading as conditional or unconditional. At conditional loading the BSC will check what software version exists in the RBS 200 and only load the RBS 200 if the software is different from the software version specified by the operator. When unconditional software load is ordered the BSC will load the software version ordered by the operator without controlling the current software version.

The BSC will load the new software to the managed object TRXC in the RBS 200 and perform a logical load to the MOs subordinate to the TRXC.

The operator will be informed when the software loading have been completed for a managed object.

1.102.5 Enhancement

The enhancement is that this feature now allows software download to numerous transceiver groups in parallel. The time needed for the total BTS function change is reduced, thus reducing total downtime. Duration of function change is proportional to the number of parallel loadings. The previous version enables software download from the BSC to up to 4 TRXs in one transceiver group at the same time.

The number of parallel transfers adapts to the available processor capacity. With no traffic load, the possible number of parallel loads will approximately be:

8 TRXs (APZ 211 11)

12 TRXs (APZ 212 11).

It should be noted that the numbers above are associated with loading towards one transceiver.

If LAPD concentration is used, the number of parallel loadings will increase at the expense of longer loading to a specific receiver. The total loading time will, however, be the same.


Title

1.103 Software Load of RBS 2000



Technology: GSM

1.103.1 Attention


Not applicable

Dependencies


1.103.2 Summary

The feature Software Load of RBS 2000 allows the operator to order a parallel software download from the BSC to numerous transceiver groups over the Abis interface. The number of parallel transfers adapts to the available processor capacity.

1.103.3 Benefits

The overall benefit of this feature for the network operator is that operation costs will decrease.

1.103.4 Description

The software loading of RBS 2000 can be handled in two ways and they are:

Function change where all managed objects for the BTS logical model are loaded with a predefined software version.

Program load where specific managed objects for the BTS logical model are loaded with a predefined software version. This makes it possible to have different software versions within a transceiver group.


Title

For each of the above ways the operator can order the loading as conditional or unconditional. At conditional loading the BSC will check what software version exists in the RBS 2000 and only load the RBS 2000 if the software is different from the software version specified by the operator. When unconditional software load is ordered the BSC will load the software version ordered by the operator without controlling the current software version.

The BSC will load the new software to the managed object CF in the RBS 2000. The software loading will take place without affecting the traffic in the BTS. When the software has been loaded in the CF, internal loading will start in the RBS 2000 between the CF and the TRU"s without affecting traffic. When all TRU"s have been loaded with the new software, the BSC will order all TRU"s to swap to the new software.

The operator will be informed when the software loading has been completed for a managed object.

1.103.5 Enhancement

The enhancement is that this feature now allows software download to numerous transceiver groups in parallel. The time needed for the total BTS function change is reduced, thus reducing total downtime. Duration of function change is proportional to the number of parallel loadings. The previous version enables software download from the BSC to one transceiver group at a time.

Loading is performed towards the DXU, which handles the internal parallel loading towards all transceivers connected to the DXU.

The number of parallel transfers adapts to the available processor capacity. With no traffic load, the possible number of parallel loads will be approximately:

13 DXUs (APZ 211 11)

24 DXUs (APZ 212 11).

If LAPD concentration or LAPD multiplexing is used, the number of parallel loadings will increase at the expense of longer loading to a specific transceiver. The total loading time will, however, be the same.


Title

1.104 Standby Synchronization of the TRI



Technology: GSM

1.104.1 Attention


Not applicable

Dependencies


1.104.2 Summary

This feature increases the reliability of the TRI synchronization. The synchronization will be automatically selected from one of two PCM links (this requires of course a minimum 2 PCM links between BSC and BTS).

1.104.3 Benefits

With the Standby Synchronization of the TRI a high quality connection to the MS is secured, even if one of the two PCM links can not provide accurate synchronization.

1.104.4 Description

In digital mobile telephone systems there is a high requirement on the frequency accuracy for the air interface. In GSM this requirement is 0.05 ppm. To fulfill the requirement, the BTS must use a sufficiently stable synchronization source.


Title

During normal operation the Extension Module Time Switch Board (TSW) in the TRI constitutes the stable synchronization source. The TSW is phase locked to an incoming PCM link and can thereby provide a synchronization accuracy of 0.0001 - 0.00001 ppm to the radio equipment. However, if the PCM reference is lost, the TSW will run on an internal clock that is not as stable as required.


Title

1.105 Subscriber Identity Confidentiality, Use of TMSI



Technology: GSM

1.105.1 Attention


Not applicable

Dependencies


1.105.2 Summary

The provision of this function implies that the IMSI should not, as normally, be transmitted on the radio path in the paging message: nor any such information that allows an intruder to derive the IMSI. Instead of the IMSI, the Temporary Mobile Subscriber Identity (TMSI) is used. TMSI provides a high level of protection against tracing the subscriber location.

The TMSI is administered by MSC/VLR. The impact on the BSC is related to the paging function, where TMSI optionally can be used instead of IMSI. If TMSI is received, it is used as MS identity in the PAGING COMMAND. The paging function orders an MS to initiate a connection. And furthermore, as TMSI is shorter than IMSI, the paging capacity is increased.

1.105.3 Benefits

Not applicable

1.105.4 Description

Not applicable


Title

1.106 Supervision of Digital Paths Connected to the BTS



Technology: GSM

1.106.1 Attention


Not applicable

Dependencies


1.106.2 Summary

This feature provides fault supervision of PCM lines between the BSC and the BTS. Supervision is performed at the BTS end.

The supervision performed is very dependent on the actual configuration. If transport modules such as external digital cross connectors are configured, then a separate network management system is usually needed. In that case, only the connection between the transport module and the BTS is supervised (at the BTS) by this feature.

If there is a transparent transport network, for example a radio path between the BSC and BTS, then this feature provides end-to-end fault supervision.

1.106.3 Benefits

The benefit of this feature for the network operator is that it contributes to cost efficient network operation and maintenance. Faults on the transmission link which are detected by the BTS are reported to the BSC.


Title

1.106.4 Description

This feature describes the general functionality that the BTS provides independently of the HW configuration. The functionality is implemented in the Distribution Switch Unit (DXU), which is the T1/E1 interface in RBS 2000. The DXU supports the Extended Superframe format.

This feature includes detection of the following alarm signals:

Loss Of Signal (LOS)

Loss Of Frame alignment (LOF)




In the event of a fault situation, an alarm indication is sent to the BSC. The alarm indicates that a fault on the transmission path has occurred. The fault type is not stated.

Supervision of transmission quality performed by the DXU is HW prepared in CMS 40 R1 and can be SW upgraded.

This feature is implemented in software in BSC and BTS.


Title

1.107 Support for 8000 EGPRS Time Slots



Technology: GSM

1.107.1 Attention


Not applicable

Dependencies


1.107.2 Summary

The maximum capacity of a PCU is doubled from 64 to 128 RPPs, which support 8000 EGPRS Time Slots. This means that the EGPRS capacity is not a bottleneck in the BSC.

1.107.3 Benefits


The BSC and BSC/TRC are prepared for rapid growth of Packet Data traffic.

CAPEX and OPEX savings due to reduced number of BSCs needed.

1.107.4 Description

Raising the maximum number of RPPs from 64 to 128 will increase the maximum capacity of the PCU. This means that one BSC can support 8000 EDGE Time Slots, which corresponds to 50% of the Time Slots of a fully expanded BSC (2048 TRXs).


Title

The higher capacity means that operators can continue to expand an existing BSC with more than 64 RPPs instead of having to introduce a new BSC node due to increasing GPRS/EGPRS traffic. This will lead to lower CAPEX due to fewer investments in new nodes and lower OPEX since it is fewer nodes to operate.


Implemented in BSC.


Title

1.108 Support for New BTS



Technology: GSM

1.108.1 Attention


Not applicable

Dependencies


1.108.2 Summary

This feature will give the support for RBS 2000 in the BSC.

The main benefit compared to RBS 200 is that the installation test procedures will be much simpler. This will enable the BTS to be brought into service quicker by limiting the Coordination activities between the BTS installation personnel and the BSC operators.

Improved fault handling is also included in this feature implying a simplified procedure for replacing faulty units. The interface between the BSC and the BTS is based on the LAPD-protocol for all types of messages, thus eliminating proprietary STC-STR signaling.

1.108.3 Benefits

As this feature gives the necessary BSC support for RBS 2000 it implies the following benefits:

Low cost of ownership for the sites

Flexibility for different capacity needs


Title

Possibility to locate the RBS at a variety of sites

Possibility to achieve a rapid network roll out.

1.108.4 Description

This feature will allow for a much more simplified installation procedure compared to RBS 200.

In the BSC the operator sees the BTS as a number of so called Managed Objects (MOs). A MO is a logical representation of hardware units and software at the BTS site. Note that hardware could be shared between MOs. (The Transceiver Group is a special case, it does not have any own hardware or software but instead it consists of a set of MOs. In some cases the TG is equal to the cell, but in case of a multi cell cabinet, it consists of a level above the cell.)

A MO is said to be in Prepost Service (PPS) when it has been defined by the operator but is not in service. When a managed object is taken out of PPS it will be moved into service and this means that the communication over Abis between the BSC and BTS is established. For RBS 2000 the BSC will automatically start polling over the Abis interface when an object is taken out of PPS.

When the installation personnel switch over the BTS to remote control, the BSC will automatically establish contact with the MOs. When contact with the MOs is established, the BSC will make a number of tests of the MOs. During these tests it is seen by the installation personnel that the BSC is testing the MOs by the use of LED indicators in RBS 2000. After the tests have been performed it is indicated by LED indication that the BSC has taken control of the MO. When these procedures have been performed for all MOs the TG is automatically taken into operation if the cell parameters has been defined; that is, a deblocking and configuration of the equipment is automatically performed.

Compared to RBS 200, a more precise fault detection and localization will also be performed. This will be possible thanks to an internal RF test loop in the BTS. There will also be fewer replacement units in RBS 2000 compared to RBS 200.

External alarms, previously collected by the TRI, will be handled by a site-common function in RBS 2000 and will be transported using a LAPD protocol over the Abis interface to the BSC for action.


Title

1.109 Support for SMS Point-to-Point in BSS



Technology: GSM

1.109.1 Attention


Not applicable

Dependencies


1.109.2 Summary

This feature enables a Service Centre (SC) to submit a short message to a mobile station subscriber. (The BSS supports both directions.)

Short Message Service (SMS) is used for sending text messages to and from a mobile station. The maximum size of a short message is 160 alphanumerical characters. SMS makes use of a Service Centre (SC) which acts as a store-and-forward centre for messages.

This feature enables the short message to be sent either from a SC to a Mobile Station or from a Mobile Station to a SC.

1.109.3 Benefits

The main benefit of SMS for an end user is that availability increases. Messages can be received even during an ongoing call and stored in the mobile telephone. Messages can be received by other media, for example facsimile or electronic mail. The user can also take advantage of the attractive user interface in a laptop computer to compose and store messages.


Title

For the operator, this data service has a great market value. It will help the operator to increase revenue, to attract new subscribers, and to keep valuable business users from moving to a second operator.

Revenue can be increased through providing new services such as regular updates of data, or notification of events. Data updates could be, for example, of share price, currency exchange rate, or weather forecast. Examples of event notifications could be if a share price dropped below a certain threshold. Receiving a message will probably lead the user to making one or many calls and this will also result in increased revenue.

The operator could also use this service to advertise new subscription options to selected groups of subscribers. In addition, it could be used to remind individual subscribers about unpaid bills.

Another benefit is that with these new services, the operator can charge both the end user and the information provider who wants to use SMS P-P as a communication channel.

Providing SMS will certainly improve the image of the network. End users will perceive the operators network as an advanced network providing quality services. This is a benefit for an operator facing competition from a rival operator.

SMS P-P could also be used to differentiate an operator's services from those of competitors. Different subscriber groups could be targeted with different service packages.

1.109.4 Description

Support for SMS Point-to-Point in BSS handles the transfer of BSS transparent short messages. Service Access Point Identifier 3 (SAPI 3) is the connection that is used for SMS. This feature handles establishment and release of SAPI 3 connections in the BSC.

Two point-to-point services are defined; Mobile Originated (MO) and Mobile Terminated (MT).

When a short message is to be sent it is submitted to the Service Centre which delivers it to the Public Switched Telephone Network (PSTN) or to a Mobile Station (MS). A short message always has to originate or terminate in the GSM network.

Each short message is time-stamped by the SC when it is submitted. This time stamp is included in the short message on delivery to the recipient. The short message also includes a More-Message-to-Send flag, if there are more messages in the SC waiting to be delivered.


Title

The short message originator may be informed through notifications about successful or unsuccessful delivery of the message.

All messages and notifications are always safe stored on external media (disc storage) within the SC. Hence, the existence of a short message is guaranteed once it has been successfully submitted to the Service Centre.

If the MS is not reachable the short message is buffered in the SC. The service centre will regularly attempt to deliver the message.

When a mobile station becomes reachable an Alert message is sent to the SC. The SC then makes a new attempt to deliver buffered messages.

The Service Centre is interfaced towards the Gateway Mobile Switching Centre (GMSC) and all the SMS signalling and distribution down to MS is then done through the GMSC.

SMS messages and SMS delivery/failure reports use the Service Access Point Identifier (SAPI) 3 on the air interfaces. The channel used is Stand alone Dedicated Control Channel (SDCCH), or Slow Associated Control Channel (SACCH), associated with a Traffic Channel (TCH), depending on if a traffic channel is allocated or not.


Title

1.110 Support for Special Cell Configurations



Technology: GSM

1.110.1 Attention


Not applicable

Dependencies


1.110.2 Summary

This feature gives the operator the possibility to dedicate some specific TRX's/TRU's to one channel group within a subcell.

1.110.3 Benefits

Decreased infrastructure cost due to the possibility of dedicating TRX's/TRU's with external hardware like active antennas or boosters to a specific channel group. These TRX's/TRU's with higher output power may be used in increasing coverage. An example is to have these TRX's/TRU's supporting the underlaid cell in an overlaid/underlaid cell configuration.

Increased flexibility of handling dedicated hardware which diminishes the impacts caused by carrier spacing.

1.110.4 Description

It will be common to have HW with different capabilities belonging to the same RBS (TRX/TRU or CDU's). These different capabilities can be that some TRX/TRU's have higher output power, because of active antennas or different combiners, thus offering different radio coverage.


Title

In order to efficiently use this type of HW it is possible to connect dedicated TRX/TRU hardware to a channel group by operator command. By having this possibility the operator is able to control what RBS hardware will support a specific subcell.

The possibility of connecting dedicated TRX/TRU hardware to a dedicated channel group also helps the operator with handling the carrier spacing. In this case at least two channel groups are needed within a subcell with at least two combiners.


Title

1.111 Support of 1,020 TRXs in the BSC



Technology: GSM

1.111.1 Attention


Not applicable

Dependencies


1.111.2 Summary

This feature lets BSC's with the APZ 212 to support up to 1,020 TRX's.

Recommended use of this feature is in networks where most subscribers have a stationary behavior, or for coverage of rural areas.

1.111.3 Benefits

This feature reduces the infrastructure cost for an operator.

1.111.4 Description

The operator will be able to define up to 1,020 TRX's in the BSC by using ordinary operator commands.

The system limit of number of TG's, cells, and EMG's (TRI's, which counts for RBS 200 only) supported by the BSC will remain the same.

That is:

512 TG's


Title

512 cells

256 EMG's (TRI's)


Title

1.112 Support of A5/1 Ciphering Algorithm



Technology: GSM

1.112.1 Attention


Not applicable

Dependencies


1.112.2 Summary

The purpose of this feature is to pass cipher mode information from the MSC to the BTS and the MS. The A5/1 ciphering algorithm ensures the privacy of the user information (speech and data) as well as the user related signaling elements.

1.112.3 Benefits

This feature enables the operator to get all information sent over the air interface ciphered.

1.112.4 Description

The purpose of the Support of A5/1 Ciphering Algorithm feature is to pass cipher mode information from the MSC to the BTS and the MS.

The feature is initiated when the message CIPHER MODE COMMAND is received from the MSC.


Title

Before the ciphering procedure can start an authentication is made. The authentication procedure evaluates a ciphering key (Kc) which is one of the inputs in the encryption algorithm A5/1. The other input is the Time Division Multiple Access (TDMA) frame number.

The ciphering procedure operates in the following way. The message CIPHER MODE COMMAND together with Kc is sent to BTS from the MSC via the BSC.

The CIPHER MODE COMMAND message is then forwarded to the Mobile Station. The MS then encrypts the CIPHER MODE COMPLETE message using encryption algorithm A5/1. The encrypted message is then sent to the BTS. The BTS decrypts the CIPHER MODE COMPLETE message.

If the decryption is successful the message CIPHER MODE COMPLETED is sent to the MSC. After this procedure all information over the air interface will be ciphered.


Title

1.113 Support of A5/2 Ciphering Algorithm



Technology: GSM

1.113.1 Attention


Not applicable

Dependencies


1.113.2 Summary

The purpose of this feature is to pass cipher mode information from the MSC to the BTS and the MS. This feature supports the ciphering algorithm A5/2 that ensures the privacy of the user information.

The export restrictions on encryption algorithm A5/1 has forced the need of a new encryption algorithm. This feature supports the new encryption algorithm A5/2.

1.113.3 Benefits

With this feature the operator can ensure confidentiality during calls for all subscribers using a MS that supports A5/2.

This feature improves the image of the radio network and makes it more attractive for end users.

The benefit for the operator is that it could attract new subscribers from existing analogue mobile networks.


Title

1.113.4 Description

The purpose of the Support of A5/2 Ciphering Algorithm feature is to pass cipher mode information from the MSC to the BTS and the MS.

The feature is initiated when the message CIPHER MODE COMMAND is received from the MSC.

The A5/2 Cipher Algorithm is chosen by command in the BSC. All BTS's in the BSS area must have the Support of A5/2 Ciphering Algorithm feature.

Before the ciphering procedure can start an authentication is made. The authentication procedure evaluates a ciphering key (Kc) which is one of the inputs in the encryption algorithm A5/2. The other input is the Time Division Multiple Access (TDMA) frame number.

The ciphering procedure operates in the following way. The message CIPHER MODE COMMAND together with Kc is sent to BTS from the MSC via the BSC. The CIPHER MODE COMMAND message is then forwarded to the Mobile Station. The MS then encrypts the CIPHER MODE COMPLETE message using encryption algorithm A5. The encrypted message is then sent to the BTS. The BTS decrypts the CIPHER MODE COMPLETE message. If the decryption is successful the message CIPHER MODE COMPLETED is sent to the MSC. After this procedure all information over the air interface will be ciphered.


Title

1.114 Support of APZ 212 33C



Technology: GSM

1.114.1 Attention


Not applicable

Dependencies


1.114.2 Summary

APZ 212 33C is a compact powerful processor.

1.114.3 Benefits

The main benefits of APZ 212 33C are:

Enough capacity for all BSC applications today and in the future

Improved In Service Performance

Low cost of ownership due to compact footprint, low power consumption, high reliability and few spare parts

1.114.4 Description

APZ 212 33C is both compact and powerful at the same time. It is housed in one subrack and provides well enough capacity for all types of BSCs. A powerful APZ improves the In Service Performance due to shorter restart times and minimized the risk for overload.


Title

APZ 212 33C helps the operator to save O & M costs thanks to it's compact footprint and low power consumption. The high reliability combined with fewer board types results in lower costs for spare parts and site visits.

APZ 212 33C has high speed IPN communication (100 Mbit/s fast Ethernet) towards the IO system, resulting in decreased times for backup and reload from the IO system.


Implemented in: BSC


Title

1.115 Support of AXE 810 - APG40



Technology: GSM

1.115.1 Attention


Not applicable

Dependencies


1.115.2 Summary

The feature "Support of APG40" enables use of Ericsson´s new compact and powerful IO platform for BSC and BSC/TRC nodes.

Benefits with APG40 are related to high capacity TCP/IP communication including preparations to handle security management, according to standards. Another benefit is increased STS counter throughput for statistics from the radio network.

1.115.3 Benefits

The main benefits by using APG40 compared to IOG20 for BSC nodes are:

A platform for future applications

Increased processing capacity

Increased STS counter throughput from CP to IO

Use of standard TCP/IP communication which allows operator to use existing IP-networks

Up to ten times increased data throughput CP - IO


Title

1.115.4 Description

This feature enables use of APG40, Ericsson´s new compact and powerful IO platform for BSC and BSC/TRC nodes.

TCP/IP communication is used towards the operation and maintenance center (OMC) e.g. OSS. The communication between the CP and IO system is based on IPN (fast Ethernet communication 100 Mbit/s), resulting in decreased backup and reload time from the IO system.

Secure Shell (SSH) and Secure File Transfer protocol (SFTP) are supported.


Implemented in: BSC

1.115.5 Enhancement


All commands are stored in the security log

Faster function change of AP software

Throughput capacity: 1 million counters per 15 minutes


Title

1.116 Support of AXE 810 - APT 1.5



Technology: GSM

1.116.1 Attention


Not applicable

Dependencies


1.116.2 Summary

APT 1.5 is a new compact and high capacity component in the AXE 810 HW platform that will be used for all AXE based GSM nodes. BSC and BSC/TRC nodes based on AXE 810 - APT 1.5 AXE platform offers compact design, improved system performance, increased capacity and decreased cost of operation.

1.116.3 Benefits

BSC and BSC/TRC nodes based on APT 1.5 HW offers:

High capacity

Decreased Cost of Ownership

1.116.4 Description

AXE 810/APT 1.5 offers virtually unlimited subrate switch capacity, which enables higher traffic capacity in the BSC.


Title

AXE 810/APT 1.5 offers decreased Cost of Ownership, due to reduced footprint and power consumption. The new compact design will reduce cost both for site rental and installation.

The number of needed spare parts are reduced thanks to fewer board types and reduced failure rate. The reduced failure rate will also lead to fewer site visits.


Implemented in: BSC

1.116.5 Enhancement

The benefit is that BYB 501 based BSCs can be expanded with AXE 810 HW without having to convert the GS by using the NNRP-5 process.

NNRP-5 makes it possible to connect GEM based AXE810 HW, for example TRA R6, to a BYB501 (AXE 10) based GS. Please note that NNRP-5 is not a conversion of the GS and therefore the GS capacity can not be increased as with NNRP-4.


Title

1.117 Supported Combinations of Channel Types per TRX



Technology: GSM

1.117.1 Attention


Not applicable

Dependencies


1.117.2 Summary

The following combinations of channel types are supported by this feature:

BCCH

SDCCH/4

SDCCH/4_CBCH

SDCCH/8

SDCCH/8_CBCH

TCH/F

1.117.3 Benefits

Not applicable

1.117.4 Description

The BSC can handle:


Title

a mix of 512 BCCHs, SDCCH/4s and SDCCH/4_CBCHs

a mix of 1024 SDCCH/8s and SDCCH/8_CBCHs

8160 TCHs.

Up to 16 SDCCH including SDCCH/4 can be defined in a cell. A cell can have only one Cell Broadcast Channel (CBCH).

For a GSM 900 system, up to 32 frequencies can be assigned to an internal cell. If the system type is GSM1800 or 1900 up to 32 can be assigned to an internal cell if the range of the frequency channel numbers is less than 112. If it is greater than 112, the maximum number of frequencies which can be assigned is 18.

Up to 16 frequencies can be assigned to a channel group.

Up to 8 BPC can be assigned per frequency.

1.117.5 Enhancement

The number of SDCCH including SDCCH/4 which can be defined in a cell has increased from 4 to 16.


Title

1.118 Switch in RBS 200 (Transmission Radio Interface)



Technology: GSM

1.118.1 Attention


Not applicable

Dependencies


1.118.2 Summary

The Transmission Radio Interface (TRI) serves as a digital cross connector located in the RBS. It handles the connection between a Pulse Code Modulation (PCM) line and the radio Transceivers (TRX).

A TRI may be connected in series with other TRI"s. This makes it possible to configure advanced transmission system solutions like cascade or star networks.

The TRI enables RBS 200 to be remotely operated from the BSC.

1.118.3 Benefits

With cascade or star RBS configurations, transmission costs are reduced. Up to four RBS"s can share the same transmission path.

The ability to remotely operate the RBS"s from the BSC means a significant reduction in Operation and Maintenance costs. For example, having external alarms from the RBS"s sent to the BSC means that costly site visits can be avoided.


Title

1.118.4 Description

The TRI is physically located in the RBS. It consists of a switch, interfaces, and control equipment. Up to 10 PCM interfaces are supported.

TRI switches the 64 kbit/s time slots on a PCM line to the time slots directed to a radio transceiver, and vice versa. It is also possible to switch a PCM line to another PCM line.

A BSC I/O terminal can be connected to the TRI for remote access to the BSC. This makes it possible to enter commands and get output at the local site.

Up to 32 external alarms can be connected to the TRI and be translated into the same internal representation as for internal alarms. Thus the alarms can be displayed at the BSC. External alarms can be for example, fire, burglary or fan supervision alarms.


Title

1.119 Switch in RBS 2000 (DXU)



Technology: GSM

1.119.1 Attention


Not applicable

Dependencies


1.119.2 Summary

Radio Base Station (RBS) 2000 is equipped with a switch known as the Distribution Switch Unit (DXU). The DXU is the interface to the transmission network.

The DXU does not provide any drop-insert functions. Separate transport network equipment shall be used in this case.

The DXU is also used for collecting external alarms.

1.119.3 Benefits

DXU allows flexible allocation of timeslots to the TRX's. The benefit for the operator is increased capacity, since no separate 64 kbit/s channel is needed for control signaling. In addition, the need for hardware in the BSC to support a separate control signaling channel is removed.

By having a DXU, RBS 2000 is prepared for future advanced transmission system solutions. For example, only a software upgrade is needed in CME 20 R6.1/CMS 40 R3, to add multidrop support enabling cascading of RBS 2000s.


Title

The operator also has the freedom to define what alarms shall be connected to the RBS. Up to 16 different alarms can be supported.

1.119.4 Description

The DXU is located in the RBS 2000 and can be compared to the TRI in the RBS 200 family.

The DXU is controlled by the BSC and uses the LAPD protocols as signaling channels. The DXU does not need a dedicated signaling channel. Instead, the signaling channel is shared with the first TRX.

The DXU switches signaling information on the Abis to the correct CF link. It switches traffic and signaling on the Abis to the TRX. The switching rates are: 64/16 kbits/s.

Sensors for supervision and alarms for external equipment, fire, burglary, etc., can be connected to RBS 2000 via the DXU enabling such alarms to be presented both at the BSC site and at the BTS site.


Title

1.120 System Information, GSM Phase 2



Technology: GSM

1.120.1 Attention


Not applicable

Dependencies


1.120.2 Summary

This feature sends system information to the MS's in accordance with GSM Phase 2. With this feature the network operator can better control the selection of which cell the idle mode GSM Phase 2 MS should camp on.

New mandatory Information Elements (IE) in System Information are introduced as well as the new System Information messages SI 7 and SI 8. New parameters makes it possible to assign a priority to a cell which a GSM phase 2 MS can use at cell selection/reselection.

System Information makes it possible to better support GSM Phase 2 MS's in idle mode in networks with the feature Hierarchical Cell Structures.

1.120.3 Benefits

The operator can better use available capacity resources by exerting control over which cell the MS uses in idle mode and which cell the MS most likely initiates calls on.


Title

The benefits become more evident in a layered cell structure where the capacity will be in the micro or pico cell layer, but the access traffic will normally go to the higher layer due to power level differences. This feature makes it possible to shift a large part of the access traffic to the micro cell layer.

The end-user will notice improved service in terms of a higher Grade of Service (GOS); that is, less failed call attempts due to cell congestion by an optimized distribution of the access traffic among the cells.

1.120.4 Description

This feature sends the system information to the MS's in accordance with GSM Phase 2. It is possible, to a certain extent, to control which cells the MS will camp on, that is, listen to, in a layered cell structure (that is, micro and macro cell layers) and thereby obtain a better distribution of the access traffic between the layers. A similar functionality offered to MS's (in active mode) in the Hierarchical Cell Structures feature, can therefore be achieved in idle mode for all GSM Phase 2 MS's.

The new system information messages SI 7 and SI 8 are sent out on the BCCH towards all MS's camped on a certain cell. These messages contain information that all GSM Phase 2 MS's can take advantage of. The new parameters in these messages are:

Cell Bar Qualify (which is used to control the MS cell selection and reselection).

Cell Reselect Offset (which is a value used by the MS to apply a positive or a negative offset to the value of the locating algorithm, C2).

Temporary Offset (which is used by the MS as a part of the calculation of C2 for the cell reselection process. The parameter is used to apply a negative offset to C2 for the duration of penalty time).

Penalty Time (which defines the length of time for which the Temporary Offset is active).

All the parameters are changeable and can be printed by command. Transmitting SI 7 and SI 8 can be allowed or inhibited by command.

Through the locating algorithm criteria, C2, and the Temporary Offset and Penalty Time parameters, it is possible to let fast moving MS's to camp on a macro cell, or the cells providing the umbrella coverage, instead of camping on the micro cells. It is also possible to offset the power budget differences between macro and micro cells, by using the Call Reselect Offset parameter, to make it more probable that the MS's will camp on the microcells in idle mode.


Title

This feature prioritizes the different cells in the network, which means that the highest prioritized cells are selected first when the idle GSM Phase 2 MS wants a cell to camp on. The Call Bar Qualify parameter can be used to prioritize the selection of cells so that a low priority cell only can be selected by GSM Phase 2 MS's if no other higher prioritized cell is available.


Title

1.121 TMA Dual Alarm



Technology: GSM

1.121.1 Attention


Not applicable

Dependencies


1.121.2 Summary

This feature helps the operator to get better/earlier information about TMA (Tower Mounted Amplifier) faults.

1.121.3 Benefits

The operator will get more than one warning before a faulty TMA causes a traffic disturbing (class 1) fault. By reporting also TMA degradation (class 2 fault), the operator is given an indication of a faulty TMA as early as possible and it will enable the operator to better plan his maintenance tasks.

The down-time will be reduced since the operator gets an earlier warning.

1.121.4 Description

Description of function

The TMA's will be able to report faults in two levels:

The first level, degraded TMA (class 2 fault), indicates that one of the two parallel amplifier stages is broken, which means a reduced total gain.


Title

The second level, faulty TMA (class 1 fault), indicates that both stages are broken, which means that the TMA does not work at all.

Description of use A better interface is implemented between BTS and TMA, which allows reporting of reduced functionality as well as faulty equipment. Today the BTS software does not detect TMA degradation and no faults are indicated until it completely fails to work. This new feature allows the operators to better plan their maintenance operations.


Title

1.122 TRA in Pool Handling



Technology: GSM

1.122.1 Attention


Not applicable

Dependencies


1.122.2 Summary

This feature handles and administrates the transcoder in pool. This includes:

Administration of transcoder pools, that is creating, deleting, and changing pools

Printing of pool data (pool name, channel rate, required/active number of TRA resources in pool, active/available TRA resources in pool)

Handling of transcoder device redundancy, that is replacing faulty devices

Supervision of idle transcoder devices and supervision of transcoder resource mean holding time

Specific performance measurements for the transcoder in pool.

1.122.3 Benefits

It is possible to define, change, and print the contents of the different transcoder pools.


Title

The feature makes it possible to find transcoder device abnormalities in the transcoder pool, and gives warnings when running out of resources enabling early actions to secure correct dimensioning of the pool sizes. It is possible to print mean hold time supervision data, and idle level supervision data. This tells if the number of idle transcoder channels is near a critical limit. The operator will be informed by alarms when a critical limit is reached. It also gives information about the mean hold time for a transcoder channel.

Measurements are supported to further improve optimal dimensioning of the pool sizes.

Faulty transcoder resources in a pool will automatically be replaced by the system.

1.122.4 Description

A new codec type pool can be created. There can be only one pool of the same codec type. However, this pool can consist of different transcoder hardware: TRA R2, R3 and R4 transcoder devices can co-exist in the same pool. The maximum number of codec types which will be possible to support is 32. Today the 3 existing codec types are supported by the system. The number of transcoder channels in the pool is by default set to zero at creation of a new pool.

It is only possible to delete a pool when the number of transcoder channels is zero and the pool supervision is deactivated.

It is possible to change the number of transcoder channels of a given codec type. The wanted number overwrites the existing number. The requested number of transcoder resources are fetched in groups of 4/8 into the pool. This requires less signaling than if the resources were fetched one by one. If there are no transcoder resources left of the specified type, the seizing attempts will continue twice a minute until the wanted number is obtained. If the number of actual transcoder resources in the pool is greater than requested, the surplus will be released. The release will normally only be requested for transcoder channels not used for a call, implying that the operator has a choice to force release transcoder devices whether they are busy or not.

The least flexible transcoder devices will be allocated to a pool first, and the most flexible transcoder device will be released from a pool first.

In case of a hardware fault, the faulty transcoder resource is released from the pool and the corresponding pool individual is marked "not used" until a working transcoder resource is seized to replace the released one. If the transcoder channel is active, the transmission will be released before the transcoder device is marked as not used. If there is an idle transcoder channel, a replacement of the excluded transcoder device will be ordered.


Title

The following measurements are supported.

Transcoder pool dimensioning:

Active Transcoder Resources

Available Transcoder Resources

Idle Transcoder Resources

Transcoder Resources Allocation Attempts

Transcoder Resources Congestion

Transcoder Resources Congestion Time

Allocation Attempts for Non Existing Transcoder Resource

Data/fax transmission failure:

- V.110 Synchronization Failure

Active, available, and idle transcoder resources contain both scanning and accumulation counters. Scanning counters are incremented by one every time an accumulation counter is updated. Together the two counters may be used to get mean values.

Supervision of idle transcoder devices:

Supervising idle transcoder devices can be started and stopped. The transcoder pool device list consists of idle and busy transcoder channels. When initiated, the pool supervision feature checks the number of idle transcoder channel against a first alarm level limit every 30 seconds. Should the number of idle transcoder channels stay below the alarm limit for four consecutive readings, a serious alarm is issued. Should the number of idle transcoder channels go below the second alarm level limit for four consecutive readings, the serious alarm is replaced by a critical alarm. The number of idle transcoder channels must be above the first, or second, alarm level limit(s) for four consecutive readings in order to cease the alarm(s). A critical alarm may be replaced by a serious alarm.

The alarm classes and the limits for the idle supervision alarms can be changed if the default values are not required.

Idle level supervision data can be printed. The pool name is given and as a result the pool name, pool alarm threshold and supervision status is shown. Thresholds and defined alarm classes will be given as well.

Supervision of transcoder resource mean hold time:


Title

The supervision of transcoder resource mean hold time can be started or stopped. When initiated, the mean hold time for transcoder resources is checked during the traffic process. Every individual store the time in seconds when it was seized. It also stores a timer for a leaky bucket algorithm. When the device is released, the seized time is compared to a mean hold time limit.

It is possible to print mean hold time supervision data. This gives the settings (limits etc.) for each supervision case. There will be alarms giving the operator information when a critical limit is reached.


Title

1.123 TRA Software Handling



Technology: GSM

1.123.1 Attention


Not applicable

Dependencies


1.123.2 Summary

TRA software download enables download of software to transcoders.

It is possible for the operator to retrieve software release identification from transcoder units.

1.123.3 Benefits

This feature makes it easier for the operator to adapt transcoder pool sizes to changing traffic needs without the need to manipulate hardware, and without the need of visiting the Transcoder Rate adaptor Controller (TRC) site.

All transcoder types can handle different types of codecs by downloading different software.

The feature can be used to:

Load Device Processor Software Units (DSU"s) with enhanced or changed functionality

Correct faulty DSUs


Title

Convert equipment to support other types of codecs by loading a different DSU

Retrieve software release identification from transcoder units.

By not having this feature, major costs may incur in the event of PROM changes. Changes may be asked for due to different interpretations of the GSM specifications by Ericsson and mobile station manufacturers, functional additions, and error corrections.

1.123.4 Description

This feature allows an operator to manually order program loading of loadable transcoder devices.

TRA software information read provides the software release identification.


Title

1.124 Traffic and Event Measurements in BSC



Technology: GSM

1.124.1 Attention


Not applicable

Dependencies


1.124.2 Summary

This feature represents a measurement function for ordering and collecting measurements in the BSC, and is intended to be used for the continuous monitoring of the radio network. The function interworks with the Statistics and Traffic Measurements (STS) subsystem. Numerous counters defined in other parts of the BSC are read by STS. The STS functionality can be used for tailor-made reports. The output can also be transferred to OSS for post-processing.

1.124.3 Benefits

With this feature the operator can better control and supervise their radio network. The Traffic and Event Measurements in BSC feature makes it possible to investigate the network performance. The measurement output (like, traffic and dropped connection measurements) can be used to see how the radio network is experienced from an end-user point of view. This feature can also be used to discover and analyse problems in the radio network.

The performed measurements can serve as a support for different radio network decisions. Such decisions could, for instance, be: if the radio network needs to be expanded, or how to set the different network parameters (dimensioning).


Title

1.124.4 Description

This feature represents a measurement function for ordering and collecting measurements in the BSC. Measurements performed by this feature are, for example:

Traffic measurements on cell ( for CS and PS. Also, there are counters on call attempts, assignment attempt, congestion, traffic level, defined and available channels).

Dropped connections measurement (both for TCH and SDCCH. The cause for the dropped connection can be given).

Random access measurements (for example, there are counters that measure answer to paging and emergency call).

Handover measurements (there are, for instance, counters that measure different kinds of handovers, and reasons for handovers. Examples of different kinds of handover measurements are intra cell handover, handover to neighbor cell, and subcell change. Measurements on reasons for handover could be excessive timing advance, and bad uplink/downlink quality).

LAPD link measurements (the behavior of each LAPD link is continuously measured).

Additional counters are defined (apart from those exemplified above) to support the operator when monitoring different types of traffic, and to analyse various abnormal situations.

1.124.5 Enhancement

Speech Quality Statistics on full rate traffic channels with Good, Acceptable and Bad speech quality.

Hierarchical Cell Structure Statistics

Statistics on the performance of the HCS ranking

Load Regulation and Traffic & Processor Load Statistics

Statistics on the CS load and the CS load regulation of the BSC

Statistics on the PS load and the PS load regulation of the BSC

HSCSD Traffic Level Statistics

Statistics on the usage of traffic channels for HSCSD


Title

Dual Band MS Statistics

Statistics on the traffic level for dual band MS.

Random Access Channel Statistics

Statistics on call-setups rejected in the TRH

Handover Registrations between serving cell and an external neighbor

Statistics on handover attempts to a HCS prioritized external neighbor

Traffic Congestion Statistics

Statistics on radio resource congestion

GPRS Statistics

Statistics on discarded PCU frames

Statistics on CS Paging

Statistics on PS Paging

Statistics on allocated PDCH

Statistics on packet channel allocations

Statistics on packet data random access

Statistics on radio block messages

Statistics on retransmission of radio messages

Statistics on PCU load


Title

1.125 Traffic Channels Submultiplexing (3 PCM Time Slots per TRX)



Technology: GSM

1.125.1 Attention


Not applicable

Dependencies


1.125.2 Summary

By locating the transcoder in the BSC instead of in the BTS, it is possible to multiplex four full rate Traffic Channels (TCH) into only one 64 kbit/s channel in the transmission link between the BSC and the BTS.

1.125.3 Benefits

The main benefit of this feature is that it reduces the cost of transmitting speech and data between the BSC and the BTS.

It also increases the number of BTS"s that can use the same transmission link to the BSC.

1.125.4 Description

The Transcoder/Rate Adaptation (TRA) function in the BSC performs transcoding of speech information. Speech on the incoming 64 kbit/s circuits is transcoded to 16 kbit/s (13 kbit/s speech, 3 kbit/s for signaling) used towards the BTS"s, and vice versa.


Title

If the TRA is located in the BTS, the transmission to the BSC requires 64 kbit/s for each TCH. Having the TRA placed in the BSC instead, only 16 kbit/s is required per TCH. Thus four TCH"s can be multiplexed into one 64 kbit/s transmission channel.

One TRX therefore needs a total of three 64 kbit/s channels instead of nine that would be needed if the TRA was situated in the BSC. Two time slots carrying traffic and one carrying the LAPD signaling.


Title

1.126 Transceiver Tester (TRXT) Controlled by BSC



Technology: GSM

1.126.1 Attention


Not applicable

Dependencies


1.126.2 Summary

The Transceiver Tester (TRXT) feature provides the system with enhanced testing and supervision of the radio parts in the BTS. It increases the fault detection and fault localization capability of the BTS, both uplink and downlink. Transceiver tests are performed on Full Rate Traffic Channels only.

Testing can be initiated both automatically and manually.

1.126.3 Benefits

The main benefit of this feature is that it reduces the cost of operation and maintenance for the operator.

Channel availability can be maximized since faults in the BTS radio parts will automatically be reported to the operator for immediate correction.

The TRXT can be used remotely by O & M personnel at the BSC to verify that the radio connections in a cell are working correctly. Initial investigation of suspect connections can be done without having to visit the BTS site.


Title

The tests can be initiated at the BTS site, using the Local Maintenance Terminal. This enables installation personnel to check that equipment has been successfully installed before leaving the site. This keeps the number of site visits to install equipment to a minimum. Less site visits means lower O & M costs.

1.126.4 Description

The TRXT consists of software in the BSC that controls the function and software and hardware in the BTS that connects the transmitter and receiver parts of the transceiver.

There are three ways to initiate the transceiver tests:

Manually by an operator command (at the BSC or at the RBS site)

Periodic test according to a predefined schedule

Automatic supervision

With automatic supervision, tests are performed when certain criteria have not been met. For example, when no attempts have been made to assign a traffic channel during a certain time or, the ratio between unsuccessful and started attempts to assign a traffic channel exceeds a certain value.

When a transceiver test is initiated, a connection is established to the TRXT on an idle traffic channel using standard call establishment signaling. The BSC then evaluates the measurement reports including uplink and downlink information on both signal strength and quality.

To complete the test for the whole cell, a channel selection function is implemented in BSC to perform a systematic check of all idle channels in the cell. All uplink and downlink timeslots configured as TCH can be tested by the TRXT feature. BCCH and SDCCH are implicitly supervised by means of a successful test.

As a result of the complete test a printout will be given, including results of the performed tests. If any faulty channel is detected, an alarm is given at BSC and the printout will include information regarding faulty BTS equipment based on Transceiver Groups, TRX, and timeslot.

TRXT uses to a large extent the same hardware and software as in normal traffic handling. This enables cross-functional testing in the BTS, rather than tests of individual pieces of equipment on their own.


Title

1.126.5 Enhancement

The TRXT power level is made more flexible. It will be possible to set the maximum power capability for the TRXT to a value lower than the maximum MS power capability specified for the cell.

Improved initiation of periodic test. It will be possible to include one, several or all cells in the periodic test. Cells will not be included by default when TRXT equipment is defined.

The interval of the automatic supervision and the threshold for when a TRXT test is initiated will be possible to set by command.


Title

1.127 Transcoder Pool Handling



Technology: GSM

1.127.1 Attention


Not applicable

Dependencies


1.127.2 Summary

The feature "Transcoder Pool Handling" makes it possible to detect and find faulty transcoder resources in the transcoder pool. The system availability is improved. The feature includes testing and supervision of transcoder resources. The function also defines feature capabilities such as connection between TRA HW and particular features such as MCC and 14.4 kbit/s.

1.127.3 Benefits

This feature gives following benefits:

Increased system availability

Increased fault detection and fault localization capabilities


Title

1.127.4 Description

The feature enables supervision and testing of transcoder pool resources. This means that faulty transcoder devices can be detected and localized. This is achieved by the functions Mean Hold Time supervision and Mobile Traffic Recording. The system availability is improved by minimizing the risk for having faulty TRA devices in the pool, and an improved selection criteria for TRA resources. Feature capabilities are also defined such as connection between TRA HW and particular features such as MCC and 14.4 kbit/s. A new sub-pool structure is defined below the existing TRA pool structure. Different sub-pools may contain transcoders with different capabilities e.g a Full Rate TRA pool may contain two sub-pools; one with TRA devices supporting MCC and another sub-pool with TRA devices that doesn't support MCC. This may then be used by the system to prioritize so that speech calls have a higher probability, than data calls, to get a TRA device that supports MCC.


Implemented in: BSC


Title

1.128 TRC-BSC Overload Control



Technology: GSM

1.128.1 Attention


Not applicable

Dependencies


1.128.2 Summary

This feature provides means to detect an overload situation and introduces sophisticated protection mechanisms in the BSC/TRC in order to handle overload situations between different nodes (BSC/TRC, TRC and BSC) caused by massive accesses from mobiles.

1.128.3 Benefits

The overload control will reduce downtime thus increasing the availability of BSS.

Increased traffic handling (throughput) during overload situations.

Improved robustness during overload situations.

1.128.4 Description

At overload in the TRC the BSC's served by the TRC are ordered to reduce the traffic flow towards the TRC. This is done by imposing a limit on the number of outstanding requests from the BSC's for transcoder resources used during call set up.


Title

The maximum number of allowed outstanding requests, window size, in the BSC are dynamically regulated based on the responses received from the TRC for transcoder resources.

If an overload message is sent from the TRC and received in the BSC the window size for the maximum number of outstanding requests is reduced.

If the number of outstanding requests in the window size are below the limit new requests to the TRC for transcoder resources are allowed in the BSC. If the number of outstanding requests are equal to the window size the access is rejected in the BSC.


Title

1.129 TRH Load Distribution



Technology: GSM

1.129.1 Attention


Not applicable

Dependencies


1.129.2 Summary

The TRH (traffic) load distribution feature introduces a method for a more effective use of TRH's in the BSC. This is done by periodically (or by operator command) reallocating TRX's between TRH's based on the TRH max load, during a period defined by the operator.

1.129.3 Benefits

Reduced risk for TRH overload

TRH will have a more efficient hardware utilisation resulting in less TRH's being needed and therefore less space needed for TRH's in the BSC

The number of TRX's which a TRH can handle will be increased by at least 50%

1.129.4 Description

Without this feature, the maximum allowed load a TRH can cope with is 4 TRX's.


Title

This feature distributes the load from TRX's between available TRH's depending on the maximum load defined by the operator. When the TRH load is less than the one defined by the operator this feature will make it possible to add loads from more TRX's on this specific TRH, thus decreasing the number of needed TRH's.

If the TRH load has increased beyond the maximum load defined by the operator, this feature will reallocate one of the TRX's causing the overload to a TRH with available capacity to handle the load from the TRX.

The reallocation of load from TRX's between TRH's is executed at regular intervals and is operator controlled. Immediate rearrangement can be initiated by the operator if so wanted.

During reallocation of TRX's between TRH's, the traffic disturbance will be kept at a minimum.

Monitoring the TRH load will be possible for the operator, with detailed information like average, low, and high load per TRH. The actions taken by this function will also be logged as information for the operator.

Alarms will be sent during abnormal operation to notify the operator. This is vital when the available TRH's have no capacity left to handle more load from new or existing TRX's.


Title

1.130 TRH Load Regulation



Technology: GSM

1.130.1 Attention


Not applicable

Dependencies


1.130.2 Summary

The TRH Load Regulation (processor load) feature minimizes the risk of overloading the Regional Processor Device (RPD) when the RPD is used as Transceiver Handler (TRH).

1.130.3 Benefits

This feature increases the system performance.

The feature minimizes the risk of losing calls in busy areas. This increases the network quality perceived by the end-user.

1.130.4 Description

The object with the TRH Load Regulation feature is to automatically regulate the load of the Regional Processor Device (RPD) when the load of the RPD becomes critical.

All active mobile stations served by one BSC send a measurement report to the RPD twice every second. With data from this report the regional processor performs a locating calculation which evaluates a list of handover candidates.


Title

The regulation of the locating calculations will start with those mobiles which are least likely to be subject to handover. The result of the previous locating calculations is used to predict how far the mobile is from being subject to handover. When all the conditions for regulation are fulfilled, the RPD load is regulated. This is done by skipping the calculations for every second received measurement report regarding that mobile.

The load of the regional processor is measured by the AXE Control System (APZ). When the load increases above a certain threshold level, close to the regional processors maximum capacity, the regulation is activated.


Title

1.131 TRH Redundancy



Technology: GSM

1.131.1 Attention


Not applicable

Dependencies


1.131.2 Summary

The main purpose of this feature is to maintain a resource in the BSC for signaling between the BSC and the Transceivers (TRX"s) in the Base Transceiver Stations (BTS"s).

1.131.3 Benefits

This feature improves the availability of signaling links between the BSC and the BTS, hence increasing the radio network availability.

1.131.4 Description

A Transceiver Handler (TRH) is a functional concept consisting of hardware and software. The main task of the TRH is to maintain LAPD links between the BSC and the BTS. LAPD links are used to carry logical channels for the signaling between the BSC and BTS.

The TRH supervision detects TRH faults and will automatically block the faulty TRH. The THR Redundancy feature will than make a TRH changeover. TRH changeover is the process of moving all connections and links from a faulty TRH to other redundant TRH equipment.


Title

Traffic connections will survive a TRH changeover if they are in a stable state, i.e. no signaling procedures like assignment or handover are in progress.

Improved availability of signaling links between the BSC and the BTS by automatic TRH configuration and reconfiguration is introduced by this feature. Also, the possibility to install redundant TRH equipment is made available.


Title

1.132 TSC Set per Channel Group



Technology: GSM

1.132.1 Attention


Not applicable

Dependencies


1.132.2 Summary

The capability to optimize the training sequence per channel group will increase the interference suppression performance in the BTS.

1.132.3 Benefits

TSC Set per Channel Group enables increased radio network capacity and quality:

Enhanced performance when dedicated interference cancellation features like IRC is used.

Enhanced interference suppression performance for all BTS.

1.132.4 Description

This feature makes it possible to optimize TSC (Training Sequence Code) on a per channel group basis. TSC controls which training sequence that is transmitted on carriers connected to channel groups that does not contain the BCCH. In the channel group with the BCCH carrier the training sequence is instead defined by the BCC (Base station Color Code).


Title

The training sequence is used by the receiver in the TRX for synchronization and channel estimation and to distinguish between the wanted signal and interfering signals. TSC planning is especially important in synchronized radio networks when interference cancellation is used, for example with Interference Rejection Combining (IRC), or with Single Antenna Interference Cancellation (SAIC) techniques in terminals.

On the BCCH carrier the training sequence is also used to improve handover performance, since the terminals use it to distinguish between cells transmitting on the same BCCH frequency. In many cases the frequency reuse of the BCCH carrier is different from that of the other TCH carriers, which implies that they are most likely interfered by different neighbor cells. Therefore, the training sequence needs to be different as well in order to obtain the best radio network performance. By configuring TSC per channel group this can be achieved, and optimizing interference cancellation can be done independently from the task of optimizing handover performance.


Implemented in: BSC


Title

1.133 Undefined Neighbouring Cells Recording



Technology: GSM

1.133.1 Attention


Not applicable

Dependencies


1.133.2 Summary

This feature allows the signal strength of cells which have not been defined in the BSC as neighboring cells to be recorded.

1.133.3 Benefits

This feature helps the operator to maximize radio network quality. It could be used to check if there are cells suitable for handover which have not been defined as neighbor cell relations in the BSC.

1.133.4 Description

A Mobile Station within a cell sends a report to the BSC containing a list of neighboring cells and their signal strength. For each cell a number of neighboring cells are defined as handover candidates. What this feature does is keep a record of cells that are suitable for a handover but are not defined as neighboring cells in the BSC. This allows the operator to detect discrepancies between cell planning and MS measurements.


Title

The feature is initiated by commands, and can be initiated for one, many, all cells or all cells of a specified system type. A time schedule is given by command where recording periods are defined. During a recording period occurrences and BCCH signal strength of up to 32 undefined neighboring cells are recorded for the ordered cell(s). The results are presented in an alphanumeric printout. For each undefined neighboring cell the Base Transceiver Station Identity Code (BSIC) is also recorded.

1.133.5 Enhancement

In this version the feature can be initiated also for all cells of a specified system type.


Title

1.134 Year 2000 compliance



Technology: GSM

1.134.1 Attention


Not applicable

Dependencies


1.134.2 Summary

With the turn of the millennium it is expected that, mainly due to the fact that software commonly carries only the two lower digits for each year, that is xx in 19xx, and as a result, ignores century when manipulating dates,

problems will occur in existing implementations.

When software starts mixing dates in 19xx and 20xx ranges, the software may fail immediately, and without completing the operation, or the software may continue to produce erroneous output, which can remain unnoticed.

1.134.3 Benefits

This feature will guarantee operators a smooth and trouble free shift of the millennium. That is: - The APZ node will have no problems with the shift of the millennium. - The APT node will have no problems with the shift of the millennium. - RBS 2000 will have no problems with the shift of the millennium. - RBS 200 will have no problems with the shift of the millennium.


Title

1.134.4 Description

The BSC, the RBS 200 and the RBS 2000 will fulfill the BSI (British Standard Institute) definition of year 2000 compliance, that is:

Year 2000 conformity shall mean that neither performance nor functionality is affected by dates prior to, during, and after the year 2000. In particular:

No value for current date will cause interruption in operation. ' Date-based functionality must behave consistently for dates prior to, during and after year 2000.

In all interfaces and data storage, the century in any date must be specified either explicitly or by unambiguous algorithms or inferencing rules.

Year 2000 must be recognized as a leap year.

Analyses, corrections and verifications, carried out by normal testing procedure, in regards of node implications at the shift of the millennium have been performed in order guarantee a smooth and trouble free transaction.

When necessary, specific year 2000 problem oriented verifications have been defined and carried out.


Title

2 New Features in GSM RAN G10A - BASIC FEATURES


Title

2.1 BSS G10A SW Upgrade



Technology: GSM

2.1.1 Attention


Not applicable

Dependencies

BSC HW Impact:Introduction of GARP2 (AGW) supporting the feature A-interface over IP BTS HW Impact:RBS 6000 configurations are supported.Dependencies to other network elementsMinimum release level on nodes interfacing BSS G10A is:- MSC R12.1- MSS 4.1- SGSN R8- CGSN R4 - MPS 9.0Minimum release level on OSS-RC is R10.0

2.1.2 Summary

The improvements specific to BSS G10A with significant benefit for the operator are:

More robust Channel Event Recording (CER), Cell Traffic Recording (CTR) and Mobile Traffic Recording(MTR)

New alarms enhancing the supervision of BSC traffic performance

In BSS G10A the following optional features are enhanced:

FAJ 122 931 BTS Power Savings

FAJ 123 137 AMR Wideband

FAJ 121 055 Adaptive Multi Rate (AMR)

FAJ 121 358 AMR Half rate


Title

FAJ 121 0181 Real Time Trace

FAJ 121 57 GSM-UMTS Cell Reselection and Handover

FAJ 123 142 Abis Local Connectivity – Satellite

FAJ 123 159 Abis Local Connectivity – Terrestrial

FAJ 122 072 Operation and Maintenance Terminal

FAJ 122 345 Remote Operation and Maintenance Terminal


2.1.3 Benefits

-

2.1.4 Description



BSS G10A supports 3GPP Rel-7.

2.1.4.1.2 Channel Event Recording (CER), Cell Traffic Recording (CTR) and Mobile Traffic Recording (MTR)

This system improvement provides a more robust use of Channel Event Recording, Cell Traffic Recording and Mobile Traffic Recording when recording data is stored on the APG I/O system.

APG failovers will have minimal impact on the recording process.

2.1.4.1.3 New Alarms

This improvement monitors BSC traffic performance. The traffic level and performance is supervised and if a suspected faulty situation is found an alarm is raised. All alarms are informative alarms, i.e. not triggering any automatic action in the BSC.


Title

RF Performance: The BSC monitors the assignment and handover success rate per TRX, and when these are low, the new alarm slogan RF Performance is raised. The alarm indicates that the specified TRX or TG may work with degraded radio performance and need to be examined.

No Traffic: The traffic in the cell is monitored by two parallel supervisions. One that checks if there is no CS or PS traffic and one that checks if the number of call establishments has suddenly dropped to 0. If any of the supervisions suspects a fault the new alarm Cell RF Output Power Supervision will be raised with the reason No Traffic

Low DL Quality: The BSC monitors the RX quality statistics reported by the MSs on a channel group basis. If a channel group reports very low downlink quality and reasonably good uplink quality the new alarm Cell RF Output Power Supervision will be raised with the reason Low DL Quality. This may indicate a problem with one of the TRXs handling the channel group.


Title

3 New Features in GSM RAN G10B - BASIC FEATURES


Title

3.1 BSS G10B SW Upgrade



Technology: GSM

3.1.1 Attention


Not applicable

Dependencies

BSC HW Impact:TRI (used for RBS 200) is not supported.BTS HW Impact:RBS 6000 configurations are supported.RBS 200 is not supported by BSS G10B.Dependencies to other network elementsMinimum release level on nodes interfacing BSS G10B is:- MSC R12.1- MSS 4.1- SGSN 2008B- MPS 10.0- CGSN is not supported by BSS G10B, as it is a phased out product. Minimum release level on OSS-RC is R10.2. OSS 10.3 is required for OSS Forward Compatibility.

3.1.2 Summary

The improvements specific to BSS G10B with significant benefit for the operator are:

OSS Forward Compatibility - with OSS-RC 10.3 it is possible to upgrade the BSCs before upgrading OSS.

In BSS G10B the following optional features are enhanced:

FAJ 123 147 A over IP

FAJ 121 997 Abis Optimization

FAJ 121 998 Abis over IP

FAJ 122 072 Operation and Maintenance Terminal


Title

FAJ 122 345 Remote Operation and Maintenance Terminal


3.1.3 Benefits

-

3.1.4 Description



BSS G10B supports 3GPP Rel-8.

3.1.4.1.2 OSS Forward Compatibility

A BSC software upgrade can be performed before the OSS is upgraded. New BSS features are not supported by OSS-RC until OSS-RC has been upgraded.

This is valid for networks with OSS-RC 10.3 and later releases.

Example:

The network is at BSS G10B and OSS-RC 10.3. When upgrading to BSS G12A, the BSC can be upgraded to G12A before OSS is upgraded to OSS-RC 12.


Title

4 Features Introduced in 09A or Earlier - OPTIONAL FEATURES


Title

4.1 1.5 Mbit/s T1/DS1 Long Haul


Feature Type: Optional in G10B

Technology: GSM

4.1.1 Attention


Not applicable

Dependencies


4.1.2 Summary

T1/DS1 is a standard interface which offers multivendor compatibility at transmission level. Normally, 1.5 Mbit/s T1/DS1 is an indoor short-haul interface. This feature provides a long-haul interface which can be used outdoors.

4.1.3 Benefits

The benefit of this feature is that it allows more cost efficient transmission network configurations. The operator can extend transmission links without having to buy additional transmission equipment.

The operator is offered more flexibility when configuring the transmission network between RBS 2301s and the BSC. For example, for an indoor application, already installed four wire between the RBS's can be re-used.

The RBS can be placed up to 1,800 meters (depending on cable type) away from the transmission equipment. Of course, if repeaters are used, this distance can be extended. With short haul, the distance is up to 300 meters.

The DS1 Long Haul interface can also be placed outdoors as lightening protection is provided.


Title

4.1.4 Description

This feature provides support for Line build-Out (LBO). The output signal at each transmission interface is adapted to the line length of the next node using Line Build-Out according to ANSI T1.403.

In addition to the electrical characteristics specified in ANSI T1.403, an increased receiver sensitivity is supported. This higher receiver sensitivity allows T1/DS1 to be extended for use as a long haul interface. The dynamic range for the receiver is approximately 0 to -30 dB at 772 kHz (0 dB = 6.0 Volts peak to peak, 100 ohms twisted pair cables).


Title

4.2 14.4 kbit/s Circuit Switched Data



Technology: GSM

4.2.1 Attention


Not applicable

Dependencies


4.2.2 Summary

This feature will increase the data rate by 50% for transparent data in circuit switched data calls in a network, compared to the standard 9.6 rate. The increase is slightly less for non-transparent data.

The high increase is achieved by having a higher data rate per timeslot in all circuit switched data applications, both for single and multi timeslot configurations.

4.2.3 Benefits

The 14.4 kbit/s Circuit Switched Data feature will increase throughput on existing data services and shorten waiting time.

Higher data rate will boost the interest for new services, as the increased data rate gives better performance.

The network service capacity will increase as radio resources are used more efficiently.

Capacity savings due to that multi time slot applications will use less time slots for the same throughput. (An application running at 28.8 kbit/s now only needs two timeslots at 14.4 kbit/s instead of using up three timeslots at 9.6 kbit/s.)


Title

4.2.4 Description

As the data rate increase works with existing types of data transmission, single time slot and multi timeslot, the increase in throughput is available to all types of data services. On single timeslot transmissions the rate will increase from 9.6 kbit/s to 14.4 kbit/s for transparent data (and to 13 kbit/s for non-transparent data). In circuit switched multislot services, the maximum rate will thereby increase from 38.4 to 57.6 kbit/s on the radio interface. To achieve the higher rates a new channel coding, with less protection, is applied on the radio interface.

The 14.4 service is requested in the same way as a 9.6 connection, i.e. both network and mobile can request the service. The mobile must be capable of handling 14.4 and indicate it with Mobile station classmark to the network.

The feature will increase transmission speed for circuit switched data applications using one or more timeslots. It will also reduce the transmission time for file transfer.


Title

4.3 2048 Cells per BSC



Technology: GSM

4.3.1 Attention


Not applicable

Dependencies

Hardware impacts and dependencies Increasing the number of cells of a BSC might require memory expansion on APZ 212 30/3x.

Internal product impacts and dependencies Not Applicable

Other node impacts and dependencies Not Applicable

Terminal impacts and dependencies Not Applicable

4.3.2 Summary

With the doubling of the number of supported cells and improving related system limits the same BSC can support an increased number of RBSs.

4.3.3 Benefits

· The number of supported cells per BSC is increased to 2048.

· The number of TGs (Transceiver Groups, corresponding to RBS) per BSC is increased to 2048.


Title

· For the Enterprise/PICO segment the BSC node can be better utilized, supporting more PICO base-stations.

4.3.3.1.1.1 Operator Value

Cost of Ownership

The main benefit with 2048 Cell per BSC feature is the possibility to have fewer BSCs in high traffic capacity areas. This is especially relevant for the case where networks consist of micro- or PICO-cells where the average traffic per TRX and cell is lower than for the macro-cell case.

Fewer BSCs and BSC splits means:

· CAPEX savings due to reduced number of BSCs needed.

· More cost effective upgrade of BSCs in operation

· Operation and maintenance savings due to fewer nodes

· Reduced signaling and load

· Improved GPRS/EGPRS performance due to fewer inter BSC cell reselections

4.3.4 Description

The following system limits are increased. In the table comparison is made of the system limits possible to achieve between basic values, adding the feature FAJ 121 817 Support for 1024 cells in BSC and adding the 2048 Cells per BSC feature


Title

Note: TG (Transceiver Group) is in most cases the same as RBS, so the TG limit of 2048 is in most cases comparable with a RBS limit on 2048.


Title

4.4 4-Way Receiver Diversity



Technology: GSM

4.4.1 Attention


Not applicable

Dependencies


Supported for RBS 6000 and RBS 2000 equipped with either DRU or dTRU and CDU-G. Depending on the configuration additional CDU-G might be required.


Not Applicable


Not Applicable


Not Applicable

4.4.2 Summary

The feature 4-Way Receiver Diversity increases the receiver sensitivity by up to 5 dB compared to 2-way receiver diversity, thereby making it possible to achieve ubiquitous coverage with up to 35% fewer sites.


Title

4.4.3 Benefits

The increased receiver sensitivity offered by 4-Way Receiver Diversity has the following benefits:

Cost savings as fewer RBS sites are needed to cover a certain area.

Shorter time to launch a network because fewer sites are needed.

Better indoor coverage.

Compensate for MS with reduced output power.

4.4.4 Description

4-Way Receiver Diversity (4WRXD) increases the diversity gain by 3-5 dB compared to 2-way receiver diversity. For RBS 6000, either two (R)RUS or an AIR is required per cell to provide the 4 receive chains needed for 4WRXD. In RBS 2000 the functionality is supported on dTRU and DRU where the two receiver parts of the dTRU/DRU are working as one transceiver, this also means that the TRX capacity is reduced in half.

In order to provide the optimum coverage enhancement, improvements are needed for both uplink and downlink. For RBS 6000 a corresponding increase in output power per transceiver is recommended. While for RBS 2000 the feature FAJ 122 078 Transmitter Coherent Combing (TCC) the perfect companion for 4WRXD, since they both provide matching gains to the respective link and requires the use of a dTRU as one transceiver.

The uplink diversity gain provided by the feature corresponds to a decrease in the number of sites required to achieve ubiquitous coverage with up to 35%. This is directly translated into reduced cost since a large part of the radio network cost is tied to the number of sites.

Increased coverage of RBS sites is beneficial when rolling out a new network or covering new areas since services can be launched with fewer sites, that is earlier network launch. 4WRXD is also of interest for existing networks. For example, coverage gaps can be bridged using already available sites. Thus a cause for high drop-call rates and/or poor indoor coverage can be avoided without additional sites.


Title

It is possible to mix transceivers working in normal and 4WRXD mode within the same cell. Together with the feature FAJ 122 430 Dynamic Overlaid/Underlaid Subcells this gives a solution that offers both coverage and capacity at the same time. This is possible since with Dynamic OL/UL Subcells the cell is split into two subcells, where the underlaid subcell operates in 4WRXD (+TCC) mode while the overlaid subcell uses normal mode. Extra capacity is thereby efficiently added by transceivers allocated to the overlaid subcell.


Title

4.5 A, A-ter and Gb interfaces over satellite



Technology: GSM

4.5.1 Attention


Not applicable

Dependencies

Hardware impacts and dependenciesNot Applicable

Internal product impacts and dependenciesNot Applicable

Other node impacts and dependenciesNot Applicable

Terminal impacts and dependenciesNot Applicable

4.5.2 Summary

Satellite connections create longer delays than other types of transmission due to the long distances. This feature will allow for longer delays than specified in GSM and still maintain synchronization on the A, Ater and Gb interfaces and will enable the operator utilize satellites for the transmission between BSC - MSC, BSC - TRC and BSC - SGSN. In Ericsson's solution the "Abis" interface can also use satellites as transmission media.

4.5.3 Benefits

This feature will give the operator the following benefits:

Coverage in areas which not was feasible to cover before, such as remote areas like oil platforms, mining areas etc.


Title

Flexibility when competing with fixed line operators.

Very fast coverage. Implementing satellite connections will be faster than both PCM and microwave connections.

Possibility to provide temporary coverage for sport events etc. located outside the ordinary coverage areas.

4.5.4 Description

This feature offers satellite transmission on the interfaces between the BSC - MSC (the A interface), the BSC - TRC (the Ater interface) and the BSC - SGSN (the Gb interface).

Using satellite transmission gives about 250 ms delays due to the long distances. The GSM standard specifies shorter delays. This feature will allow for longer delays while maintaining the synchronization on the transmission link.

Depending on the transmission capacity is required 2 Mbit links or individual 64 kbit timeslots can be used. If the satellite station does not provide a proper interface, or if the same PCM link is shared, a cross connectors is required. DXX and DXC are cross connector families provided by Ericsson.


Title

4.6 A-bis interface over satellite



Technology: GSM

4.6.1 Attention


Not applicable

Dependencies

Hardware impacts and dependencies Not Applicable

Internal product impacts and dependencies Increased latency on Abis transport will decrease GPRS performance. Use of EDGE is recommended



4.6.2 Summary

Satellite connections create longer delays than other types of transmission due to the long distances between earth and the satellite. This feature will allow for longer delays than specified in GSM and still maintain synchronization on the Abis interface and will enable the operator to utilize satellites for the transmission between the BSC and RBS 2000 and RBS 6000. The feature supports both PS traffic as well as CS traffic to be transported over the satellite interface.

4.6.3 Benefits

Coverage in areas which not was feasible to cover before, such as remote areas like oil platforms, mining areas etc.


Title

Very fast coverage build out. Implementing a satellite connection will be faster than land based transmission, for example PCM and microwave connections.

Possibility to provide temporary coverage for sport events etc. located outside the ordinary coverage areas.

Support for wireless data services to the end-users (GPRS and EDGE) in remote areas.

4.6.3.1.1 Operator Value

4.6.3.1.1.1 Cost of Ownership

For remote areas, the satellite transmission has a reduced cost compared to terrestrial backhaul.

4.6.3.1.1.2 Increased Revenues

It is possible to increase revenues by covering areas not reachable by terrestrial backhaul.

4.6.4 Description

This feature offers satellite transmission on the interface between the BTS and the BSC (the Abis interface) for both CS and PS services.

Using satellite transmission introduces one way delay of 250 ms or longer due to the long distances. The GSM standard specifies shorter delays. Longer delays lead to interruptions of the LAPD link. This feature will allow for longer delays while maintaining the synchronization on the transmission link.

Depending on the required transmission capacity 2 Mbps links or individual 64 kbps timeslots can be used. If the satellite station does not provide a proper interface, or if several BTSs should share the same PCM link, a cross connectors is required. DXX and DXC are cross connector families provided by Ericsson. They are options well integrated in the RBS 2000 and RBS 6000.

The feature FAJ 123 174 Packet Abis over TDM can be used to reduce the required TDM transmission capacity over the satellite link. If the satellite backhaul is IP based, the feature FAJ 123 175 Packet Abis over IP shall be used.


Title

4.6.5 Enhancement

Enhancements in BSS 07B

Support for EDGE is introduced natively in this feature. This means that it is possible to provide packet data services over EDGE to the end users also for sites that are connected through a satellite backhaul. GPRS is supported as well, but due to limitations in the 3GPP standard, the performance may be low or unstable. The use of EDGE is therefore strongly recommended whenever possible.

The feature is also updated with new timers, enabling a total Abis round trip time of up to 1060 ms for both speech and data services. This is an enhancement from the previous maximum RTT of 540 ms.

Prior to BSS 07B the GPRS/EDGE support for Abis over satellite as well as the increased RTT is available as a market adaptation.


Title

4.7 A5/3 Ciphering Algorithm



Technology: GSM

4.7.1 Attention


Not applicable

Dependencies


The feature is supported for all RBS 6000, RBS 2000 with sTRU/dTRU and other RBS 2000 with similar or later HW platforms such as RBS 2308.


Not Applicable


Support is required in the MSC.


Support is required in the terminals.

4.7.2 Summary

The A5/3 Ciphering Algorithm feature introduces the 3GPP standardized A5/3 algorithm for encryption of voice calls in GSM. Using A5/3 reduces the risk for both eavesdropping and fraud.


Title

4.7.3 Benefits

A5/3 Ciphering Algorithm gives the following benefits:

Increased safety with stronger encryption compared to A5/1 and A5/2

Reduced risk for eavesdropping and fraud



By providing the safest possible network, subscribers do not move to other networks, hence churn is reduced.

Avoid compensation costs for subscribers subjected to fraud.

4.7.4 Description

The A5/3 ciphering algorithm for encryption of voice calls is introduced. The algorithm is implemented as standardized in 3GPP Release 6. It provides stronger encryption than the currently used encryption algorithms, i.e. 128 bit encryption strength compared to 64 bit with A5/1 and 40 bit with A5/2. This makes A5/3 much harder to break than the A5/1 and A5/2 algorithms.

The need to evolve the encryption capability in GSM is exemplified by the fact that the A5/2 algorithm has been broken. This means that with the appropriate equipment it is possible to both eavesdrop on and impersonate an MS capable of A5/2. GSM Association has therefore issued recommendations to phase out A5/2 from GSM networks.

A5/3 is supported on the sTRU/dTRU and other transceivers based on the same or later HW platforms. To ensure coexistence with TRXs not capable of A5/3, the encryption algorithm can change during a call, i.e. at call setup and handover when needed.

To ensure maximum use of A5/3 in cells with a mix of A5/3 capable and non capable transceivers, it is possible to prioritize allocation of calls made with A5/3 capable terminals to A5/3 capable transceivers.


Title

4.8 Abis Local Connectivity - Satellite



Technology: GSM

4.8.1 Attention


Not applicable

Dependencies


Not Applicable


FAJ 123 175 Packet Abis over IP is required.

In cells where Abis Local Connectivity - Satellite is activated the following optional features can't be used:

- FAJ 121 361 Dynamic FR/HR Adaptation

- FAJ 122 582 Dynamic Half Rate Allocation

- FAJ 121 846 Abis Triggered HR Allocation For other cells in the BSC the above features can be used


The following Market Adaptations (MA) needs to be ordered for the Ericsson MSC/MSS:

- ID: 105 65-0209/05468, Support for "Connected sub address" in CONNECT message


Title

- ID: 105 65-0209/06279, Lawful Intercept for Abis Local Connectivity Function (LCF) Similar functionality is required in other vendors CS core network for Abis Local Connectivity - Satellite to work.


Not Applicable

4.8.2 Summary

Abis Local Connectivity - Satellite saves satellite transmission costs by enabling the two call legs, within a BTS or cluster of BTS, to be connected at the STN

4.8.3 Benefits

By using Abis Local Connectivity - Satellite, Abis transmission bandwidth requirements can be reduced. The total reduction depends on the share of local calls made in the cluster of cells where the feature is activated. When Abis transmission is expensive, Abis Local Connectivity - Satellite together with Abis over IP, FAJ 121 998, will significantly reduce operators' OPEX and enable coverage expansion into new geographical areas.

Due to fewer transcoding steps and reduction of speech path delay the speech quality for locally switched calls will be improved. This will generally increase Minutes of Use, generating more revenues to the operator.


A BTS with classic TDM based transmission connected over satellite typically has a total cost of ownership that is some three times higher than a BTS connected by terrestrial transmission. Reducing this cost is among the top priorities for all operators. The bandwidth saving achieved with Abis Local Connectivity - Satellite, together with Ericsson Abis over IP, may lower the transmission cost for a BTS connected by satellite to a level, comparable to, and in some cases lower than a BTS connected by terrestrial transmission.

By deploying Abis Local Connectivity - Satellite in a cluster of cells the operator takes advantage of the fact that people tend to call people living or working close to them most frequently. Traffic measurements show that up to 70% of all calls made within a given geographical area can be local.

A nice side effect is that locally switched calls will benefit from improved speech quality as two out of four transcoding steps are eliminated and the speech path delay is reduced. This will make people call more often and also longer duration, generating new revenues to the operator.


Title

4.8.4 Description

Abis Local Connectivity - Satellite resides on the STN (Site Transport Node) function available on the SIU (Site Integration Unit) for the macro range of BTS and as an integral part of the RBS 2409. The feature supports the long delays inherent in satellite transmission.

Abis Local Connectivity - Satellite analyses the signaling between the mobile terminals and the network, and identifies and associates the two halves of a local call. Having done this, it returns the speech packages to the correct RBS traffic channel and so removes unnecessary speech load from 'upstream' transmission resources. Once the local connection is established, Abis Local Connectivity - Satellite monitors the mobility and keeps the call locally connected for as long both parties remain within the cluster of BTS that is served by the STN.

If one of the two terminals hand over to a cell not connected via the STN Abis Local Connectivity - Satellite releases the remaining leg to the normal path via BSC and MSS. This normal path via BSC and MSS is always setup for local calls and is ready to be used when required. Abis Local Connectivity - Satellite only removes the CS user-plane traffic for local calls from the Abis path between the BSC and the STN.

Abis Local Connectivity - Satellite is transparent to all services that are not local voice calls (non-local calls, SMS, GPRS/EDGE etc).

Abis Local Connectivity - Satellite requires both terminals in a local call to be within the same group of cells connected to the SIU.


Title

In order to identify which call legs that form a call Abis Local Connectivity - Satellite adds information to the call setup signaling. This addition is a standard Information Element, but it requires support from the CS core network (MSC/MSS) to be passed transparently through the network.

Abis Local Connectivity - Satellite is supported from OSS, both from a configuration and from a performance management point of view.

4.8.5 Enhancement

4.8.5.1.1 Enhancement in BSS G10A

The following improvements have been introduced:

The AMR codec is now supported for local calls

Flexible codec matching for local calls based on the terminal capabilities of both A and B parties

The features Dynamic FR/HR Adaptation, Dynamic Half Rate Allocation, and Abis Triggered HR Allocation are now supported for cells in which Abis Local Connectivity - Satellite is enabled

A configurable codec priority list for local call codec matching

Additional methods are introduced for identification of the call legs, facilitating the use of Abis Local Connectivity - Satellite with non-Ericsson core networks


Title

4.9 Abis Optimization



Technology: GSM

4.9.1 Attention


Not applicable

Dependencies


4.9.2 Summary

Abis Optimization reduces the effective bit rate on the Abis interface between the BSC and the RBS, thus reducing bandwidth requirements and saving transmission costs. To achieve this bit rate reduction optimization functions are used and a packet protocol is used over the traditional E1 or T1 circuits.

4.9.3 Benefits

The bit rate required on links between BSC and RBS is reduced.


4.9.3.1.1.1 Total Cost of Ownership

The feature offers the values of:

Reducing the leasing costs for Abis transmission

Avoiding re-dimensioning of transmission network at EDGE introduction and growth


Title

Reducing investments in transmission network at traffic growth

The operator can reduce the amount of transmission with 25-40% for an existing network, thereby saving leasing costs for existing sites.

Alternatively, the traffic volume can grow in the network without a need for additional transmission to the RBS sites. It would for example be feasible to increase the EGPRS traffic without upgrading the transmission network, or to create transmission capacity for a 3G deployment/growth.

4.9.4 Description

This feature introduces functions to only transfer bits holding information, but no stuffing bits normally used to achieve a constant bitrate on the Abis interface.

The BSS solution for Abis Optimization is based on that traffic and signaling on the Abis interface are sent on common Super Channels, using a packet protocol, instead of using dedicated timeslots on the TDM transmission. A Super Channel is built of one E1 or T1 link, or a fraction of one E1 or T1, where 64 kbit/s consecutive Abis timeslots are used.

Savings are made by for instance:

Reducing information sent during silent periods (DTX)

Reducing information sent in idle channels

Removal of padding for low MCSs for EGPRS channels

Removal of padding for low CSs for GPRS channels

Removal of padding for low voice codec rate for voice channels

Statistical multiplexing between cells

The bit rate saving achieved is dependent on traffic mix, voice activity factor, amount of half rate voice channels and RBS configuration. The exact saving has to be estimated per particular network. As an indication of the saving, for a 3*3 site with 60% half rate, with AMR, 4 EPDCHs per cell and 40% silent frames the saving can be expected to be 25-30% compared to a system running BSS R12. The saving compared to BSS R10 would be around twice as much.

The features FAJ 122 287 Discontinuous Transmission (DTX) Downlink and FAJ 122 256 Discontinuous Transmission (DTX) Uplink should be used in order to take advantage of silent periods in ongoing calls.


Title

The transport network is not affected. The same leased E1/T1 or microwave links can be used as today, with the same network architecture, but with narrower links. Abis Optimization assumes that time slot integrity is provided by the transport network.

The solution is based on an optimization function in the BSC and corresponding functionality in the RBS. The functionality is implemented in the packet gateway (PGW) in the BSC, whereas the functionality on the RBS side is running on the DXU/IXU and TRU.

The PGW is one or more devices in the BSC. The PGW handles speech, GPRS/EGPRS and signaling. The number of boards depends on the number of connected TRXs and the traffic mix. The same PGW can be used both for Abis Optimization and Abis over IP features.

The dimensioning of the Super Channels shall be done based on the actual traffic to be supported by an RBS (not the number of TRXs configured to carry traffic). A Super Channel serves one Transceiver Group (TG), and a TG can be served by up to four Super Channels. Optimization is done per TG.

When the load on a Super Channel has increased above an operator specified threshold the optional feature FAJ 121 846 Abis Triggered HR Allocation can be triggered to reduce the load on the Super Channel. If an overload situation still occurs, Abis Optimization throws away speech and CS&PS data as a first choice. Signaling frames are prioritized. In case transmission on a Super Channel is suffering from continuous overload, the BSC reduces the load by reducing the number of new connections. During the overload, no new allocation of PDCH channels, channels for DTM or channels for HSCSD is made.

For GPRS/EDGE traffic, the scheduling mechanism will adjust PS traffic to the available Abis bandwidth, ensuring best possible Abis utilization.


Title

The operator is informed about an Abis overload situation via an alarm. This alarm is triggered when the BSC or BTS has started to discard frames due to buffer overflow. The Super Channel is considered overloaded as long as new connections are rejected for the TG.

For dimensioning purposes, it is possible to print the load level per Super Channel. The load level is in percent of total available bandwidth and shows the load level in 5 second intervals the last minute. The operator can also use STS counters to monitor the utilization of the Abis links to each base station in order to determine when new Abis resources need to be added, or when resources can be removed.

See the Abis Optimization Dimensioning Guideline in CPI for help on how to dimension the Abis interface with Abis Optimization.

Separate PM counters for loss ratio and buffer delays on Uplink, Downlink, CS-frames and PS-frames are available. The measurements are performed end-to-end from PGW to TRX. These measurements can be used to judge transmission effects on radio KPI measurements. They also provide immediate information on whether a radio interface KPI change is related to the radio environment or transmission environment.

An adaptive regulation of PTA is available, providing long time stability for GPRS/EGPRS service if/when the Abis latency changes over time, e.g. due to varying traffic load. Introduction of adaptive timers is seamless since the function is by default turned off and can be enabled for TGs where the default PTA loaded value does not suffice to grant Packet Abis stability.

The possibility of setting the BTS buffer depth increases the possibility for fine tuning the network for different delay conditions. In good networks with low delay variation, the buffer depth could be set to a low value to obtain short roundtrip times and in networks with a varying delay variation, the buffer depth could be set to obtain maximum robustness and minimum packet loss.

4.9.5 Enhancement

An improved GPRS/EDGE scheduling mechanism is introduced. At high Abis load the PS scheduling align the amount of PS traffic with the available Abis bandwidth. This leads to increased utilization efficiency and PS performance when total Abis load is close to, or exceeds, available transport bandwidth.


Title

The improved scheduling enables larger PS timeslot allocations without the risk of Abis overload during voice busy hour. This leads to higher PS throughput outside voice busy hour and at the same time having high Abis utilization during voice busy hour.

Performance management related to Abis overload has been improved for better observability of Abis, for example how long time the link has been highly loaded.

Support for RBS 2x02 is added (BTS G11B is required). For configurations with only sTRUs in the tranceiver group, it is now possible to use Abis Optimization to a RBS 2x02. Configuration checks are added to ensure that no cTRUs are included in the TG when Abis Optimization is activated.


Title

4.10 Abis over IP



Technology: GSM

4.10.1 Attention


Not applicable

Dependencies


4.10.2 Summary

With the Abis over IP feature operators can use IP based transport networks to connect RBSs to the BSC, and in that way benefit from lower pricing of Ethernet services and efficient IP-based mobile backhaul technology.

4.10.3 Benefits

There are major benefits using Abis over IP. It gives the operator the opportunity to use lower priced IP/Ethernet services, compared to E1/T1 services, and by that provide cost efficient transmission to RBS sites. Providing Abis over IP also improves significant bandwidth savings in the parts of the transmission networks where a lot of site transmission are groomed, High-RAN (HRAN). The feature also opens up for transport sharing with WCDMA and integrated RBS site transport that not only introduce efficiency in bandwidth utilization but also reduced maintenance task for reconfigurations of capacity growth on the site.

The Ericsson Abis over IP solution has several advantages:

The load regulation function in Abis over IP is optimized for keeping the RAN KPIs intact during operation


Title

The Abis over IP feature uses an inbuilt function for synchronization of the RBS over a packet network. It uses the NTP or IEEE1588 protocol.

The Ericsson OSS-RC configuration application AIPCM implements powerful configuration rules that spans the combination of RAN parameters and parameters for the IP termination in the RBS and the BSC.


4.10.3.1.1.1 Total cost of ownership

This feature makes it possible to use the lowest priced transport service, leased lines or IP. IP based transport services in some cases offer significantly lower price with good quality of service. It may in many cases also be faster to get an xDSL line to an RBS site than to get an E1/T1. By using Abis over IP, micro-cells can be introduced quickly when demand is recognized.

In case the operator uses a self-built transport network, already today IP/Ethernet can be deployed as backhaul technology paving the way for fast WCDMA, HSPA and LTE introduction. Here savings can also be done in grooming and aggregation points in the transport network. In particular in High-RAN (HRAN) there are major benefits of using Abis IP as resources can be shared among all RBSs and traffic prioritization can used to ensure redundant transmission for critical traffic only.

Some operators have today already taken the decision to move from TDM based transmission to an All-IP infrastructure. Here Abis IP means that Ericsson GSM networks can easily support and benefit from this vision.

4.10.4 Description

Abis over IP uses IP transport between the RBS and the BSC. Ethernet is used as the physical interface, thereby opening up for connection to almost any IP based transport equipment, being xDSL, Metro-Ethernet, Satellite, Ethernet over MicroWave etc. A system overview is given in the picture below (dotted elliptical area not part of Abis over IP feature). The IP-termination is done in a packet gateway (PGW) in the BSC and on dedicated software in the RBS. The RBS needs to be equipped with an Ethernet interface. There are two options for this;

In the Pico RBS the necessary HW is integrated in the RBS.

The Micro, Macro and Main Remote RBSs require the SIU (Site integration Unit) mounted either in the RBS cabinet or in a 19" transmission cabinet outside the RBS.


Title

The Abis over IP feature builds on the same packet Abis technology as Abis Optimization. In Abis Opt the traffic and signaling channels are packed into one frame sent over an E1/T1 connection. Abis over IP bundles frames into common IP packages in order to keep the overhead down, thus reducing the bit rate. As bundling introduces a delay, it is possible to configure the maximum packet size and maximum waiting time (before sending a packet), thereby making this delay configurable. If lowest possible bit rate is important the Abis over IP feature should be combined with the optional feature Abis Optimization.

The quality of IP based transport networks may occasionally vary in available bandwidth, delay and delay variation, therefore mechanisms to handle high load and overload situations are included. If high load situations, when the traffic to a TG is higher than a configured threshold, are expected to occur frequently, the optional feature FAJ 121 846 Abis Triggered HR Allocation should be used in order to reduce the bit rate. When packets are discarded, new calls will be rejected.

For GPRS/EDGE traffic, the scheduling mechanism will adjust PS traffic to the available Abis bandwidth, ensuring best possible Abis utilization.

4.10.4.1.1.1 Traffic Prioritization

The Abis over IP feature uses DiffServ code points to give information to the transport network on how to prioritize packets during network overload. Traffic with the same priority is bundled into common IP packets in order to keep the IP overhead to a minimum. DiffServ values are configurable for each traffic type per Abis link. The traffic types are RSL (signaling), OML (O&M), Speech, CS data and GPRS/EGPRS. If the transport network supports packet prioritizing (not only transparency) based on DiffServ the RAN behavior during overload in transport network will be improved.

4.10.4.1.1.2 RBS synchronization

With the Abis over IP feature the RBS is synchronized from the in built synchronization source in the SIU or internally in the RBS2409. The SIU or RBS2409 receives timing information via the NTP protocol to calibrate the internal oscillator through time servers in the network. Both the RBS2409 and SIU have a built in long term stable oscillator calibrated from factory requiring very few NTP packets for long term adjustment. Thus the RBS can use both ADSL and Satellite backhaul without the need for additional synchronization (e.g. GPS).


Title

4.10.4.1.1.3 Security

It is assumed that the transport service over the IP network in normal case is reasonably secure. If that is not the case or if the operators security strategy mandates a fully secure connection the inbuilt IPSec termination in the Abis over IP feature can be used.

4.10.4.1.1.4 Multi-TG

The Multi-TG functionality supports several transceiver groups (and consequently several RBSs) being connected to one SIU. Thus not every RBS needs an SIU. This has several advantages. First the Multi-TG function enhances Abis Optimization by allowing the feature to operate across TGs and prioritize traffic types (e.g. voice having priority over data) also over several TGs. Secondly it removes the dependency between TG configurations and fixed resource allocations in the transport network. This means that an RBS with several TGs can be reconfigured from the OSS without any changes in the transport network. This is particularly useful when running a network with dual frequencies or having underutilized RBSs and wanting to re-dimension the transport to optimize backhaul capacity.

4.10.4.1.1.5 Adaptive timers for Packet Abis

An adaptive regulation of PTA is introduced, providing long time stability for GPRS/EGPRS service if/when the Abis latency changes over time. Typical scenarios where variable latency can occur are shared transport networks, xDSL, and satellite link start-up/tuning. By adaptive timers, the GPRS/EGPRS service will not be lost because the latency is suddenly changed. Introduction of adaptive timers is seamless since the function is by default turned off and can be enabled for TGs where the default PTA loaded value does not suffice to grant Packet Abis stability.

The possibility of setting the BTS buffer depth increases the possibility for fine tuning the network for different delay conditions. In good networks with low delay variation, the buffer depth could be set to a low value to obtain short roundtrip times and in networks with a varying delay variation, the buffer depth could be set to obtain maximum robustness and minimum packet loss.

4.10.5 Enhancement

An improved GPRS/EDGE scheduling mechanism is introduced. At high Abis load the PS scheduling align the amount of PS traffic with the available Abis bandwidth. This leads to increased utilization efficiency and PS performance when total Abis load is close to, or exceeds, available transport bandwidth.


Title

The improved scheduling enables larger PS timeslot allocations without the risk of Abis overload during voice busy hour. This leads to higher PS throughput outside voice busy hour and at the same time having high Abis utilization during voice busy hour. Apart from varying voice load, the available Abis bandwidth may also vary due to factors outside GSM, for example by changes to traffic level on a co-sited WCDMA or LTE RBSs.

Performance management related to Abis overload has been improved for better observability of Abis, for example how long time the link has been highly loaded.

Another enhancement is that robustness to short link breaks has been improved so that they do not trigger overload mechanisms on Abis. Short link brakes (<1 second) can occur for example at router failovers.

Support for RBS 2x02 is added (BTS G11B is required). For configurations with only sTRUs in the tranceiver group, it is now possible to use Abis over IP to a RBS 2x02. Configuration checks are added to ensure that no cTRUs are included in the TG when Abis over IP is activated.


Title

4.11 Abis Triggered HR Allocation



Technology: GSM

4.11.1 Attention


Not applicable

Dependencies

The following feature is always required:

GSM RAN SW: FAJ122315 - Half Rate Channels


Not Applicable


FAJ 122 315 Half Rate Channels is required.

FAJ 121 358 AMR Half Rate is needed in order to use the AMR half rate speech codec.

FAJ 123 174 Packet Abis over TDM or FAJ 123 175 Packet Abis over IP is required in order to utilize the freed transmission bandwidth for data traffic.

FAJ 122 450 Flexible Abis is also supported but not recommended since it is not as efficient as Packet Abis over TDM/IP.


Not Applicable



Title

Not Applicable

4.11.2 Summary

The feature reduces costs for Abis transmission and makes Abis resources available for EGPRS traffic by using Half Rate (HR) codecs for voice calls at traffic peaks. Abis Triggered HR Allocation allows for allocation of half rate channels, and change between full rate and half rate channels for ongoing calls, depending on the load on the Abis interface.

4.11.3 Benefits

Gives OPEX saving as the usage of Abis resources can be optimized

Makes Abis resources available for EGPRS traffic

Minimum impact on speech because half rate is only used at high Abis loads and if the radio link is good enough



Reduced OPEX and/or CAPEX due to less transmission needed.

4.11.4 Description

Abis Triggered HR Allocation makes it possible to allocate speech channels based on the Abis traffic load. At high traffic load, half rate capable terminals will be allocated half rate channels. For ongoing calls they may be moved from full rate to half rate channels. The change from full rate to half rate channels is initiated when Abis is approaching congestion. Abis resources are shared between cells served by a Transceiver Group (TG).

The following functions are included:

Allocation of half rate channels based on Abis resource situation

Move from full rate to half rate channels based on Abis resource situation


Title

Lack of Abis resources will trigger allocation of half rate channels at initiation of a new call or at handover. For FAJ 122 450 Flexible Abis, if the number of idle 16 kbps paths in the Abis pool falls below the threshold configured for the pool, idle full rate channels with dedicated Abis paths are selected for further full rate allocations in the cells served by the pool. If no such channels are available half rate channels are selected when full rate channels are requested. Lack of Abis resources will also initiate move from full rate channels to half rate channels.

A packing mechanism assures that 16 kbps paths are efficiently used for half rate (8 kbps) connections. When the number of available 16 kbps paths goes under a configured threshold half rate channels are packed on 16 kbps paths.

The same functions to minimize the speech quality impact are used as with FAJ 121 361 Dynamic FR/HR Adaptation and FAJ 122 582 Dynamic Half Rate Allocation. The function in itself goes a long way to accomplish this since half rate is only used when more capacity is needed. A radio link quality check is performed before a call is converted to half rate and the quality of the radio link is supervised continuously while a call is using a half rate channel. If the radio quality becomes poor the call is converted to full rate.

Abis Triggered HR Allocation can be used separately or at the same time as FAJ 121 361 Dynamic FR/HR Adaptation and FAJ 122 582 Dynamic Half Rate Allocation. When used together both the load in the cell and on the Abis interface are taken into consideration when channels are chosen.

The feature can also be used with FAJ 121 997 Abis Optimization and FAJ 121 998 Abis over IP, in addition to FAJ 122 450 Flexible Abis.

Mechanisms to minimize the speech quality impact are unaffected, but resource allocation is simpler and more efficient as the Super Channel is a common resource for all traffic channels, e.g. no packing of channels required.

4.11.5 Enhancement

4.11.5.1.1 Enhancements in BSS 07B

Two thresholds that prevent allocation of half rate channels if signal strength is too low are introduced. One threshold is used at call setup and the other at inter cell handover. If signal strength is below the thresholds, a full rate channel will be allocated regardless of the Abis load.

The benefits of these thresholds are increased speech quality and reduced drop call rate. Speech quality is improved since half rate is not used if the radio link is too poor. Drop call rate is reduced since a risky half rate to full rate channel intra cell handover performed on a bad radio channel can be avoided.


Title

Two Abis load thresholds, one for AMR capable terminals and one for non-AMR capable terminals, which governs rate adaptation from half rate to full rate, is introduced. After a traffic peak in a cell, when the Abis load in a cell decreases below the new thresholds, calls will be transferred from half rate to full rate channels.

This will further reduce the speech quality impact from using half rate. If there is sufficient free capacity in a cell there is no reason to use half rate.


Title

4.12 Adaptive Configuration of SDCCHs



Technology: GSM

4.12.1 Attention


Not applicable

Dependencies


Not Applicable


Not Applicable


Not Applicable


Not Applicable

4.12.2 Summary

This feature helps the operator to dimension the number of SDCCH channels and to use the radio resources in the most efficient way by adapting the number of SDCCHs according to the SDCCH and TCH load in the cells.


Title

4.12.3 Benefits

Increased operator revenue since automatic reconfiguration of SDCCH and TCH channels leads to more efficient usage of radio resources.

Increased operator revenues and better subscriber perceived quality by decreasing the risk of SDCCH congestion.

Reduced operation and maintenance costs by reducing the need of dimensioning, statistical analysis on the use of SDCCHs, as well as manual configurations of the number of SDCCHs.

4.12.4 Description

SDCCH usage is expected to show large statistical variations over short periods of time. At a certain point in time, a cell may be heavily loaded with SMS traffic and the next instant the need for TCH's is huge. In order to allocate the available time slot resources as efficiently as possible between SDCCHs and TCH's in a cell, time slots are automatically reconfigured from TCH to SDCCH and vice versa, as the need varies.

The number of SDCCHs defined by the operator is used as the minimum number of SDCCH channels in the cell. This means that the number of SDCCH channels should be under dimensioned when this feature is used.

The number of SDCCH channels is increased when the number of idle SDCCH channels has reached a threshold and there number of idle TCH is sufficient. Likewise, the number of SDCCH channels is decreased when there have been more than 8 idle SDCCH subchannels available in the cell for a certain time and there are more SDCCH channels in the cell than what is configured by the operator. The reconfiguration takes about two seconds.

4.12.5 Enhancement

The feature now takes SDCCHs configured in both subcells into account when overlaid/underlaid subcells is used. SDCCH channels can be added or removed from both subcells depending on the most appropriate location.


Title

4.13 Adaptive Multi Rate (AMR)



Technology: GSM

4.13.1 Attention


Not applicable

Dependencies


For BSCs with transcoders, TRA R5B or later is required.

Not supported on RBS 2301 prior to revision R6A.


Not Applicable


Support in core network is required.


Support in terminals is required.

4.13.2 Summary

AMR is a new speech codec type which adapts the speech codec bit-rate and channel coding according to the radio environment. AMR can be used to improve speech quality, increase radio network capacity or both. AMR is available for use in full rate channels (AMR FR).


Title

4.13.3 Benefits

AMR FR gives significantly better speech quality than Enhanced Full Rate (EFR) under severe radio conditions.

Up to doubled capacity with AMR FR, since the improved robustness makes it possible to add more transceivers and tighten the frequency reuse.



Reduced cost since fewer cells but with more capacity can provide the required network capacity.

4.13.3.1.1.2 Increased Revenue

AMR FR provides increased speech quality compared to EFR and standard full rate. Providing good speech quality makes subscribers call longer and more often.

4.13.4 Description

AMR is a speech codec type which consists of a number of different speech codec modes. These speech codec modes have different bit-rates for speech information and channel coding. By changing between these speech codec modes, i.e. adapting the speech codec and channels coding rates, according to the conditions of the radio environment significant performance improvements can be achieved compared to a fixed speech codec like EFR (Enhanced Full Rate).

Depending on measured C/I (channel quality) conditions, the best speech codec mode for the present conditions is chosen. At for example good radio conditions (high C/I), a codec mode with less channel coding and a higher speech coding bit-rate can be used. When C/I decrease, it is necessary to increase the channel coding.


Title

The possibility to increase/decrease the channel coding depending on C/I makes the channel more robust to bit errors. For example under poor radio conditions, the use of AMR in a full rate channel provides a much better speech quality than EFR. A more robust channel coding makes it possible to tighten the frequency planning and add more transceivers, and by that increase the capacity in the radio network. Simulations indicate that it could be possible to more than double speech traffic capacity in a network where only AMR FR is used. Hence, it is possible to use AMR to improve speech quality, increase radio network capacity or a combination of both. The trade off between speech quality and radio network capacity is determined by the frequency planning.

In theory the maximum cell coverage is determined by the robustness of the signaling, both for setting up and maintaining connections (CCCH, SDCCH, BCCH, SCH and SACCH). However it may sometimes be the case that speech quality provided by EFR becomes poor before the signaling controlling a connection fails. Thus the practical coverage, i.e. where it is possible to maintain a call with adequate speech quality, can be limited by the capability of the EFR speech codec. When AMR FR is used this changes; since AMR FR is much more robust it is possible to provide good speech quality all the way until the signaling gives up. In this respect, AMR FR provides better subscriber perceived coverage than any other speech codec.


Title

This feature enables basic AMR functions like adaptation between the different speech codec modes. It also includes the speech codecs and channel coding to use AMR in full rate channels (AMR FR). The speech codec bit-rate for the different codec modes is listed in the table.

Speech codec bit-rates defined for AMR FR:

In order to use AMR an Active Codec Set has to be defined. A codec set consists of a selection of up to 4 of the available codec modes. For each codec set there is an associated set of decision thresholds that determine which codec mode that should be used at a certain C/I. The codec mode changes are not audible and it is possible to change codec mode every second speech frame but only to the closest higher or lower codec mode in the codec set. Different codec modes can be used on the uplink and downlink (the codec set is the same). It is the receiving side (MS and BTS) that performs quality measurements on the incoming link to perform the codec mode adaptation.

There are three predefined codec sets that can be chosen as the Active Codec Set, i.e. the included codec modes and their associated threshold cannot be changed. These codec set are:

10.2, 6.7, 5.9 and 4.75

12.2, 7.95, 5.9 and 4.75

12.2, 7.4, 5.9, and 4.75


Title

In addition there are also two codec sets that can be configured by the operator. All important aspects of these codec sets can be changed, in other words, included codec modes, mode change thresholds, mode change threshold hysteresis and initial codec mode. This makes it possible to define a unique version of AMR Half Rate to optimize AMR Half Rate according to the current network characteristics.

The default setting of the operator configurable codec sets is the same as the predefined ones.

The third predefined codec set consisting of the codec modes: 12.2, 7.4, 5.9, and 4.75, enables maximum speech quality with tandem free operation (FAJ 121 50, Tandem Free Operation) between Full Rate AMR and Half Rate AMR as well as the use of Full Rate AMR on 8 kbps Abis (FAJ 121 827, Full Rate AMR on 8 kbps Abis). In both these cases the highest codec mode that can be used is the 7.4 kbps speech coder which is the highest mode that is possible in an 8 kbps Abis timeslot.

AMR is also standardized for use in UMTS systems, which enables full speech service transparency between an operator's 2G and 3G systems.

4.13.5 Enhancement

4.13.5.1.1 Enhancements in BSS G10A

The initial codec mode can be configured in the two operator configurable codec sets. This can increase speech quality since a higher codec mode can be used when changing channels.


Title

4.14 Advanced Handling of Fast Moving Mobiles



Technology: GSM

4.14.1 Attention


Not applicable

Dependencies


GSM RAN SW: FAJ122573 - Multi Layered HCS


Not Applicable


FAJ 122 573 Multi Layered HCS is required.


Not Applicable


Not Applicable

4.14.2 Summary

The feature provides means of handling fast moving mobiles or mobiles suffering bad quality caused by high inter cell handover intensity.


Title

4.14.3 Benefits

Reduced number of dropped calls by decreasing the number of handovers in the radio network will improve the end-user perceived quality.

Positive effect on the CP load in the BSC because of decreased number of handovers in the radio network.

Beneficial both for fast mobiles passing through microcell networks and for mobiles moving along a cell border.

4.14.4 Description

Fast moving mobiles will when moving in a microcell network require a large number of handovers, which may degrade the speech quality and increase the risk for dropped calls. Fast moving mobiles will also increase the load in the system because of the increased number of handovers.

Time dependent penalties in HCS, which makes microcells represented with a weaker signal strength than the actual during a fixed time interval after their appearance, will delay handover to them. For slow moving mobiles this will not generate any significant drawback, whereas fast mobiles in many situations may leave the microcell before the signal level penalty has expired, thereby preventing them to handover to an unsuitable cell layer.

To improve quality and reduce the number of handovers for fast moving mobiles in HCS, a new algorithm that counts the handover intensity is introduced per traffic connection. The algorithm measures the number of handovers performed during a pre-set time interval.

If, when a new handover is ordered, the handover intensity is higher than a fixed threshold, this feature is triggered. The handover candidates proposed by this feature are cells in a higher cell layer with the highest measured signal strength. When the algorithm has initiated a handover the handover intensity counter will be cleared and a new HCS locating evaluation started.


Title

4.15 AMR Half Rate



Technology: GSM

4.15.1 Attention


Not applicable

Dependencies




For BSCs with transcoders, TRA R5B or later is required.

Not supported on RBS 2301 prior to revision R6A.


FAJ 122 315 Half Rate Channels is required.






Title

4.15.2 Summary

The AMR Half Rate speech codec provides significantly better speech quality for half rate channels than the standard Half Rate codec. With AMR Half Rate, the use of half rate traffic channels becomes a more attractive solution to increase radio network capacity.

4.15.3 Benefits

Improved speech quality for half rate traffic channels.

Increased radio network capacity due to increased usage of half rate, which is possible because of the better speech quality.



Increased usage of half rate channels means that more traffic can be carried with fewer transceivers, which reduces both CAPEX and OPEX. For example a smaller BTS leads to reduced power consumption and reduced transmission.

Increased Revenue

AMR HR provides increased speech quality compared to standard half rate. Providing good speech quality makes subscribers call longer and more often.

4.15.4 Description

AMR Half Rate speech codec provides substantially better speech quality than the standard HR speech codec. This makes half rate an attractive alternative to increase the capacity in the radio network.

The basic functionality of the AMR Half Rate speech codec is the same as the AMR Full Rate speech codec, meaning that it consists of a number of different codec modes and the used mode will change during the call depending on the quality of the radio environment.

The use of half rate channels only applies to speech traffic and not to signaling or data (both circuit and packet switched data) transmissions which still uses normal full rate channels.

The speech codec bit-rate for the different codec modes that is defined for AMR Half Rate is listed in the table.


Title

Speech codec bit-rates defined for AMR HR:

The 7.95 kbps codec mode is not supported since it requires more than 8 kbps on the A-bis interface.

In order to use AMR Half Rate an Active Codec Set has to be selected. A codec set consists of a selection of up to 4 of the available codec modes. For each codec set there is an associated set of decision thresholds that determine which codec mode that should be used at a certain C/I. The codec mode changes are not audible and it is possible to change codec mode every second speech frame but only to the closest higher or lower codec mode in the codec set. Different codec modes can be used on the uplink and downlink (the codec set is the same).

There are two predefined codec sets that can be chosen as the Active Codec Set, i.e. the included codec modes and their associated threshold cannot be changed. These codec set are:

7.4, 6.7, 5.9 and 4.75

7.4, 5.9 and 4.75

In addition there are also two codec sets that can be configured by the operator. All important aspects of these codec sets can be changed, in other words, included codec modes, mode change thresholds, mode change threshold hysteresis and initial codec mode. This makes it possible to define a unique version of AMR Half Rate to optimize AMR Half Rate according to the current network characteristics.

The default setting of the operator configurable codec sets is the same as the predefined ones.


Title

It is recommended to use AMR Half Rate together with the features FAJ 121 361 Dynamic FR/HR Adaptation and FAJ 122 582 Dynamic HR Allocation to optimize the use of Half Rate.

4.15.5 Enhancement


The initial codec mode can now be configured in the two operator configurable codec sets. This can increase speech quality since a higher codec mode can be used when changing channels.


Title

4.16 AMR Power Control



Technology: GSM

4.16.1 Attention


Not applicable

Dependencies


Not Applicable


Dynamic MS Power Control and/or Dynamic BTS Power Control which are part of FAJ 121 0894 Radio Network Efficiency, are required for power regulation on the up and downlink respectively.

FAJ 121 055 Adaptive Multi Rate (AMR) is required in order to use the AMR full rate codec.

FAJ 121 358 AMR Half Rate is required in order to use the AMR half rate codec.


Not Applicable


Not Applicable


Title

4.16.2 Summary

The feature AMR power control is used to minimize the interference in the radio network by controlling the output power for terminals using the AMR speech codec separately. The result is a possibility to increase the radio network capacity as well as improve speech quality due to reduced interference.

4.16.3 Benefits

Increased capacity in networks with a mix of AMR and non-AMR capable handsets.

Enhanced speech quality for connections not using AMR full rate.

Optimized power consumption for AMR full rate compatible handsets.

4.16.4 Description

The feature AMR Power Control is used to minimize the interference in the radio network caused by terminals using AMR full rate. Since AMR full rate is a much more robust speech codec, it can provide the same speech quality as other speech codecs, but in a much more interfered environment. This means that the power used for a call with AMR full rate can be lower than for calls that are not using AMR full rate.

To be able to perform a separate power regulation for AMR full rate terminals, separate regulation targets are introduced for the uplink and downlink dynamic power control algorithms. Thereby the output power of both the terminal and the BTS can be further reduced for calls using the AMR full rate speech codec.

With AMR Power Control the interference level in a network with a mix of AMR full rate capable and non-AMR capable terminals can be lowered. Reduced interference produces an immediate improvement in speech quality for all calls, regardless of which speech codec that is used, but the effect is most noticeable for calls not using AMR full rate since they are not as robust. The interference reduction can also be used to increase radio network capacity by tightening the frequency reuse, leading to that additional transceivers can be installed in the cell.

Lower output power also reduces the power consumption for terminals using the AMR full rate speech codec.

AMR Power Control requires that the feature FAJ 122 260 Dynamic MS Power Control is activated for uplink power control and the feature FAJ 122 910 Dynamic BTS Power Control for downlink power control. Using the AMR full rate speech codec requires the feature FAJ 121 055 Adaptive Multi Rate (AMR).


Title

4.16.5 Enhancement

Separate regulation targets are introduced in the power control algorithm for calls using AMR half rate. This enables optimization of the power control algorithm specifically targeted for these calls.

Simulations indicate that separate power control regulation targets for EFR and AMR half rate compared to using common regulation targets, provides a radio network capacity gain of up to 20% in a network with a mix of EFR and AMR half rate calls.

AMR half rate has shown to be less robust than EFR, the enhancement makes it possible to increase speech quality for AMR half rate calls since they can now be allowed to use slightly higher output power than EFR calls.

Using the AMR half rate speech codec requires the feature FAJ 121 358 AMR Half Rate.


Title

4.17 AMR Radio Link Timers



Technology: GSM

4.17.1 Attention


Not applicable

Dependencies


4.17.2 Summary

AMR Radio Link Timers introduces separate radio link timers for calls using AMR. This will reduce the drop call rate for calls using the AMR full rate speech codec since calls can be kept longer.

4.17.3 Benefits

Reduced drop rate for calls using the AMR Full Rate speech codec since calls can be maintained longer.

Increased channel retainability.

Optimized channel utilization for all codec types.

Increased revenue, due to extended talk time.

4.17.4 Description

This feature makes it possible to configure separate radio link timers for calls using the AMR full rate and the AMR half rate speech codecs.


Title

Since the AMR full rate speech codec is more robust than the SACCH signaling, a higher value for the radio link timer is needed. Otherwise there is a high risk that a call with good speech quality is disconnected due to failing signaling, thereby increasing the drop call rate. A higher timer value for AMR full rate calls will increase call time, thereby allowing the subscriber to terminate the call normally.

On the other hand, if the timer value is increased for all speech codecs the consequence would be that for calls using less robust speech codecs, the channels would be held onto longer after a subscriber has disappeared which leads to decreased channel utilization. The call might be terminated by the caller due to too poor speech quality, but due to loss of signaling the system has not received the disconnection message.

The feature AMR Radio Link Timers is beneficial when there is a mix of AMR full rate and non AMR full rate calls in the network, since otherwise a common radio link timer value is sufficient.


Title

4.18 AMR Wide Band



Technology: GSM

4.18.1 Attention


Not applicable

Dependencies

The following features are always required:

M-MGw: FAJ1210163 - AMR-WB Speech

MSC-S: FAJ121727 - AMR-WB Speech


For BSCs with transcoders, TRA R6 or later is required.

Supported on RBS 6000 and RBS 2000 with sTRU/dTRU or similar TRU.


Not Applicable






Title

4.18.2 Summary

AMR-WB is a feature that attracts subscribers and incites them to make more and longer calls. This is possible since AMR-WB offers significantly enhanced speech quality.

4.18.3 Benefits

AMR-WB provides the following benefits:

Significantly improved speech quality



In a network with good speech quality, churn is reduced since fewer subscribers change to other networks.


Feedback from consumer trials indicates that good speech quality stimulates subscribers to make more and longer calls.

With AMR-WB the speech quality in mobile networks is better than in fixed networks. AMR-WB is therefore a means to move traffic from fixed networks to mobile networks.

4.18.4 Description

AMR Wide Band (AMR-WB) is a new speech codec that provides significantly improved speech quality. This is accomplished by using a speech bandwidth of 0.1 to 7 kHz compared to the traditional 0.3 to 3.4 kHz bandwidth used for the existing GSM codec's and in the fixed networks. By adding both low and high frequencies to the speech a much clearer and more pleasant sound is achieved.

Similar to the current narrow band AMR speech codec's FR AMR and HR AMR, AMR-WB consists of several codec modes where each is optimized for a certain radio link quality.

AMR-WB is implemented for the GSM Full Rate channel using GMSK modulation with three codec modes as defined in the 3GPP standards.


Title

The bit rates of the used codec modes are:

12.65 kbps

8.85 kbps

6.60 kbps

The AMR-WB codec offers similar robustness as FR-AMR, both from an interference and noise point of view. This means that AMR-WB provides roughly the same radio network coverage and capacity as FR-AMR.

Since there is no PCM encoding standard for AMR-WB, it must be sent digitally encoded throughout the network. A consequence of this is that all nodes involved in a call from one subscriber to another must have support for AMR-WB, this includes all MSs, RBSs, BSCs, MGWs and MSC servers.

If AMR-WB can not be established end to end the call is changed to use the next available full rate codec supported in the network. The reason for this is that when AMR-WB is only used by one party in a call the quality and robustness is not as good as for FR-AMR or EFR. Another reason is that AMR-WB requires more transcoder HW and if AMR-WB is not established end to end these resources are wasted.

The same AMR-WB is also standardized for WCDMA which means that service continuity for high quality calls between GSM and WCDMA is possible.

Due to the big difference in speech quality between AMR-WB and the half rate codecs it is possible to turn off the dynamic HR handling for calls using AMR-WB.

4.18.5 Enhancement


The codec mode thresholds, hysteresis and the initial codec mode can be configured by the operator. This increases flexibility and enables operators to tune the AMR-WB codec set.

Information is added in the feature FAJ 121 50, Real Time Event Data, that makes it possible to monitor if the AMR-WB codec is changed to a narrow band codec during a call.

The operator can configure priority between AMR-WB and EDGE for access to timeslots supporting both services. AMR-WB and EDGE have the same TRX HW requirements. The function gives operators the possibility to ensure maximum call set up success rate for AMR-WB in cells with few capable transceivers.


Title

AMR-WB is enabled on a channel group level instead of subcell level. This increases flexibility in cells where not all transceivers are capable of AMR-WB, since an underlaid/overlaid sub cell structure does not have to be implemented.


Title

4.19 Antenna Hopping



Technology: GSM

4.19.1 Attention


Not applicable

Dependencies


Supported for RBS 6000 with RUG, RBS 2000 with DRU/dTRU and RBS 2308. Filter combiners like for example CDU-F is not supported.


Not Applicable


Not Applicable


Not Applicable

4.19.2 Summary

Antenna Hopping increases the capacity of the radio network in systems which use few or no hopping frequencies. This is achieved by switching transmit antenna between bursts, which increases fading diversity.


Title

4.19.3 Benefits

Antenna Hopping offers increased radio network capacity with up to 30% in systems without frequency hopping or hopping over few frequencies.

Antenna Hopping increases speech quality on non-hopping traffic channels.

4.19.4 Description

Antenna Hopping increases the radio network capacity by introducing increased fading diversity. This is achieved by switching antenna between bursts, that is, bursts will be sent on alternating antennas.

Antenna hopping offers a gain of up to 3 dB in networks that does not use frequency hopping, but it can also be utilized together with frequency hopping. When combined with frequency hopping, antenna hopping gives up to 2 dB gain for channels hopping over few (< 9) frequencies.

The gain can be used to increase capacity by tightening the frequency reuse or just as a speech quality booster. For example antenna hopping can be used to tighten the BCCH frequency reuse in networks using FLP frequency planning. In those networks the BCCH in usually non-hopping which leaves the traffic channels on that carrier vulnerable to interference. Since antenna hopping will protect the traffic channels the BCCH frequencies can be planned according to the requirements of the more robust signaling channels instead.

At least two transmit antennas are required in a cell where antenna hopping shall be used.

Antenna hopping can not be combined with filter combiners since bursts are switched between different transceivers, which means that a transceiver will change frequency between different bursts.


Title

4.20 BTS Power Savings



Technology: GSM

4.20.1 Attention


Not applicable

Dependencies

Hardware impacts and dependencies The feature is supported on all RBS 2000, RBS 6000 (RUG), but not RBS 200.

Internal product impacts and dependencies The operator must decide whether to use BTS Power Savings or MCPA TX Power Savings for an MCPA RBS.



4.20.2 Summary

BTS Power Savings enables power savings in an entire network by simply switching on a feature.


Title

With this feature activated, the BTS power consumption is reduced when the traffic level in the cell is low enough. This is accomplished by disabling a number of TRXs that are NOT needed for carrying the traffic in the cell. At increasing traffic in a cell the TRXs will be put back in operation.

4.20.3 Benefits

The OPEX (in terms of electricity bills or in some cases fuel costs) is reduced by less power consumption of the BTS.

The installed battery backup will keep the BTS operational for longer times.

The need for cooling power is reduced since the amount of heat generated by the BTS is reduced.



For many GSM operators, the power consumption cost represents a large share of the OPEX. A reduction of the consumed power will directly affect the operator's OPEX.

The power savings result is in the range of 10 to 20 percent of the normally used BTS power.

A simplified operator business case can be based on the number of installed TRX:

As a rule of thumb, the yearly saving per TRX is around 100 kWh. The actual figure for an actual network is dependant on parameters like cell traffic profiles over 24h periods, number of TRX per cell and to some extent what RBS are deployed in the network

With an electricity cost of e.g. 0.15 € per kWh (country specific), the yearly saving will be 100 x 0.15 = 15 € per TRX. To get the network savings, we multiply this figure with the number of installed TRX.

Example: A customer has 50.000 TRX in the network (not counting TRXs carrying the BCCH). When the feature is switched on, the customer will see the result as a yearly saving of 50.000 x 15 € = 750.000 €.

Note that there will be additional savings in power consumption due to reduced cooling need and less loss in site power conversion. These savings are not considered in this simplified business case.


Title

In case of diesel (DG / Gen-set) operation, the savings will come from less fuel consumption and less transportation of fuel to the site.


At power outages, the increased battery times made possible by BTS Power Savings means that an increased number of calls can be billed.

4.20.4 Description

The feature reduces the BTS site power consumption without affecting traffic and network quality.

Thanks to efficient traffic and HW handling features, there will be no affect on the services. No extra effort from O&M people is needed.

The method used is to monitor the number of idle timeslots that are unused in a cell. If the number of timeslots that are unused in the cell are high enough (allowing for fluctuations over time) the feature will start to disable one or several TRXs.

The traffic residing on a TRX to be disabled will be moved to other TRXs. A guard time is applied between disabling of TRXs in order to avoid a too aggressive switch on/off.

As TRX units are put in hot stand-by mode (disabled), the power consumption is reduced.

When the traffic level in the cell increases and the amount of idle timeslots is below a threshold value (to secure call setup quality), a stand-by TRX is immediately put back in service.

The cases for both baseband hopping and synthesizer hopping cells are handled by the feature.

In a synthesizer hopping cell, removing a TRX will not change the hopping frequencies but in a baseband hopping cell disabling a TRX will reduce the number of frequencies (possible to use) in the cell. This would under normal circumstances cause some performance degradation in the cell; however, since the traffic is very low whenever the feature is active, this degradation is in reality not taking place.


Title

4.20.5 Enhancement

4.20.5.1.1 Enhancements in G10A

The TRX enabling algorithm in the feature is improved.

Better alarm handling for Cell Supervision of Logical Channels availability in conjunction with the use of the feature.

New STS counters are introduced to increase observability of the feature in terms of how many TRXs that have been disabled and enabled.

The printouts for BTS Power savings have been enhanced to include data on number of deactivated TRX per cell and BSC.

The flexibility of enabling/disabling priorities for the cell is improved.

The feature is supported also in Extended Range cells.


Title

4.21 Call Queuing



Technology: GSM

4.21.1 Attention


Not applicable

Dependencies


HLR: FAJ122637 - Enhanced Multi-level Precedence and Pre emption Service in HLR

MSC-S: FAJ122619 - Enhanced Multi-Level Precedence and Pre-emption


Not Applicable


Call Queuing and the feature FAJ 122 433 Efficient Priority Handling (i.e. preemption) are complimentary features and they are both part of the enhanced Multi-Level Precedence and Preemption (eMLPP) function standardized for GSM systems in 3GPP.


The features FAJ 122 619 Enhanced Multi-Level Precedence and Pre-emption in the MSC and FAJ 122 637 Enhanced Multi-level Precedence and Pre emption Service in HLR in the HLR are required.

If Wireless Priority Service is required then the feature FAJ 121 421 Wireless Priority Service - Full Operating Capability is also required in the MSC.


Title


Not Applicable

4.21.2 Summary

Call Queuing enables prioritization of subscribers when there is congestion in the radio network.

4.21.3 Benefits

Call Queuing have the following benefits:

Call Queuing makes it possible to provide enhanced network accessibility for prioritized subscribers during congestion.

Enables prioritization of subscribers without interrupting existing calls since queuing is used instead of preemption.

Traffic resources does not have to be reserved and capacity is not wasted when priority subscribers are not present.

A 40-80% traffic increase in Erlang per cell for cells with one or two transceivers.

4.21.4 Description

When Call Queuing is active subscribers are put in a queue, waiting for a traffic channel when there is congestion in a cell. The queue is sorted in order of priority, giving subscribers with higher priority access to traffic channels before lower prioritized subscribers. Compared to preemption where ordinary subscribers might be disconnected to make room for high priority subscribers, Call Queuing provides priority access without disrupting the service of ordinary subscribers. Another advantage of Call Queuing is that traffic channels do not have to be reserved, and capacity is not wasted when priority subscribers are not present.


Title

Call Queuing can be used to increase capacity in cells with one or two transceivers. Using the Erlang C formula one can see that a 40-80% traffic increase in Erlang per cell is possible with an average queue time that is approximately equal to the mean holding time. This is due to that when there is a queue in a cell, a channel can always be assigned to the next call immediately when it becomes idle, thereby maximizing the channel utilization. As the number of transceivers in a cell increases the capacity gain with Call Queuing decreases, which is why this way of using Call Queuing is only recommended for cells with one or two transceivers.

Since an SDCCH channel is occupied by each subscriber while they are being queued, it is important to dimension the SDCCH capacity and adjust the queue length for each cell so that SDCCH congestion is avoided. In case the queue is full, subscribers with higher priority will remove lower prioritized subscribers from the queue. The maximum queue time can also be configured, and subscribers that have been in the queue for too long will be removed and the call cleared.

In order to prevent that all available resources in a cell are occupied by high priority subscribers it is possible to limit the amount of traffic channels that they have priority to. When the threshold has been surpassed, priority subscribers and normal subscribers will have equal priority to the remaining traffic channels. This makes it possible to guarantee a certain network accessibility also for ordinary subscribers in congested situations.

Call Queuing is supported for mobile originating calls, mobile terminated calls and handover. It is possible to prioritize handover before set up of new calls. Call Queuing only applies to connections requiring a single timeslot, which means that non-transparent multislot data calls will only be allocated one timeslot initially, while transparent connections requesting multiple timeslots will be rejected.

Call Queuing and the feature FAJ 122 433 Efficient Priority Handling (preemption) are complimentary features and they are both part of the enhanced Multi-Level Precedence and Preemption (eMLPP) function defined for GSM systems.

The information whether queuing is is allowed for a call and the priority level of the subscriber is sent from the MSC to the BSC during the call set up.

Tthe feature Call Queuing is needed in GSM RAN to support Wireless Priority Service.


Title

4.21.5 Enhancement

The Call Queuing feature is enhanced with the possibility to configure the maximum queue time separately for each priority level. This allows operators to for example set a longer queue time for high priority subscribers which will increase their chances of getting access to the network. Another way to use this new functionality is to shorten the queue time for subscribers with lower priority, thereby reducing the load on the SDCCH, hence fewer SDCCH time slots are needed.


Title

4.22 Cell Load Sharing



Technology: GSM

4.22.1 Attention


Not applicable

Dependencies


Not Applicable


Not Applicable


Not Applicable


Not Applicable

4.22.2 Summary

The feature Cell Load Sharing introduces a way to distribute traffic during peaks or uneven distribution in a cell to surrounding cells. This increases the capacity in the cell without the need for installing more equipment and is done by initiating a handover to the surrounding cells.


Title

4.22.3 Benefits

Increased capacity

Increased subscriber quality, lower blocking

More efficient use of installed equipment

Cell planning flexibility

4.22.4 Description

By utilizing the parts of the handover hysteresis area between neighboring cells to execute network initiated handover, the traffic load on cells can be shifted and blocking probability in cells be lowered. The operator can either choose to see this as getting a cell network that is more robust to local traffic peaks in cells, or as getting higher capacity. This feature has no detrimental impact on planned C/I levels.

The Cell Load Sharing feature helps to distribute the traffic between neighboring cells within a BSC so that traffic load peaks are distributed over several cells. This is done in conjunction with the Locating feature, so that handover to a neighboring cell can be executed for some active calls where mobiles are situated within parts of the hysteresis area between cells. The benefits are lower blocking probability and increased channel utilization.

By setting the load sharing parameters it is possible to partition the traffic load between neighboring cells as long as there are enough mobiles situated in the hysteresis area. Some of the parameters that can be set are the hysteresis area reduction, lower level of idle traffic channels in a cell before initiating handover of channels to neighboring cells, and lower level of idle traffic channels in a cell before the cell can accept channels handed over by this feature.

Cell Load Sharing can only be active within one cell layer of the hierarchical cell structure and is performed for TCH channels.

Performance management statistics are provided so that it is possible to detect cells that regularly hand over channels to neighboring cells, and therefore may need additional traffic channel installation. Planning for the network is thus supported.


Title

4.23 Combined cell re-selection triggering GSM to WCDMA



Technology: GSM

4.23.1 Attention


Not applicable

Dependencies


4.23.2 Summary

Combined cell re-selection triggering GSM to WCDMA introduces network support for an improved GSM to WCDMA cell reselection algorithm, resulting in increased likelihood to be served in a WCDMA network if preferred.

4.23.3 Benefits

A more accurate steering of the terminals increases the likelihood to be served by the WCDMA network. This is applicable to the case when WCDMA is the preferred network, defined by the operator.

Combined cell re-selection triggering GSM to WCDMA improves the performance of GSM to WCDMA cell reselection (and hence improving the end user performance) by avoiding cell reselection to weak WCDMA cells. Cell re-selection to weak WCDMA cells increases the risk of not camping in a suitable cell and thereby being unable to establish services until another suitable cell has been found. Furthermore, the risk increases of introducing long interruption of ongoing packet transfer sessions until another suitable cell has been found.


Title

4.23.4 Description

The standard GSM to WCDMA cell reselection algorithm has proven to have weaknesses in the sense that cell reselection can be triggered to weak WCDMA cells causing problems for the terminals to reach the WCDMA cell on the uplink.

The improved GSM to WCDMA cell reselection algorithm (provided by the new feature - Combined cell re-selection triggering GSM to WCDMA) includes new criterias making sure that the terminal performs cell reselection to the most suitable WCDMA cell. This is achieved by avoiding cell reselection to weak WCDMA cells and hence the following behavior is avoided:

- For ongoing packet transfer sessions: avoid interruption time caused by cell reselection to weak WCDMA cells, unreachable for the MSs (resulting in that the MS returns to the original cell after the access attempt lost coverage).

- MSs in idle mode: avoid non-reachable MSs for the time periods when MSs are trying to access to weak cells.

This feature includes configuration support for the parameters controlling the improved cell reselection algorithm (FDD_RSCPmin and FDD_Qmin_Offset). The new parameters are broadcasted as system information on the broadcast channels BCCH and PBCCH.


Title

4.24 Combined handover triggering GSM to WCDMA



Technology: GSM

4.24.1 Attention


Not applicable

Dependencies


4.24.2 Summary

With a combined trigger for initiating handover from GSM to WCDMA, the quality evaluation of the target WCDMA cell is improved. This will result in higher amount of successful GSM to WCDMA CS handovers.

4.24.3 Benefits

This feature will give the operator the benefit of fewer dropped CS calls in the GSM to WCDMA direction thanks to better evaluation of the target cell quality.

Apart from the negative effect of the dropped call as such, end-users will also not be reachable or able to use the network while the terminal is trying to reconnect to a suitable cell after the lost call. Therefore an additional benefit of this feature is that the amount of users not being able to use the network will be reduced.


Title



The revenues are increased by less number of dropped calls, as well as the increased call minutes thanks to more users being reachable during the handover process.

4.24.4 Description

The 3GPP standardized GSM to WCDMA handover measurements has proven to have weaknesses in the sense that handover can be triggered to WCDMA cells with good downlink quality but where the uplink is too weak to be used by the user. This will lead to that the GSM network may handover calls from 2G to a 3G cell that is reported as good by the terminal, but once the user has been handed over the call is dropped. This case is specifically noticed for WCDMA cells with low load.

This feature introduce support for a improved mechanism available in 3GPP Rel-5, where measurements including both signal to noise ratio and signal strength is taken into account in the handover trigger, as opposed to only considering the signal to noise ratio.

This improved GSM to WCDMA handover trigger make sure that the handover is directed to the most suitable WCDMA cell. By avoiding handover to weak WCDMA cells the risk of dropped call is reduced. In addition the situation where the MS is unreachable for a period of time is avoided (during that the MS returns to the original cell/system after the failed handover).

The corresponding improvement for terminals in idle mode or involved in a PS session is supported by the feature FAJ 121 933, Combined cell re-selection triggering GSM to WCDMA.


Title

4.25 Competitor Coverage Recording



Technology: GSM

4.25.1 Attention


Not applicable

Dependencies



Other node impacts and dependencies The optional feature FAJ 121 1172 Competitor Coverage Evaluation Manager must be activated in OSS-RC.


4.25.2 Summary

Competitor Coverage Recording performs recordings on competitor GSM networks as well as the own GSM network. The recordings provide useful facts that enable the customer to compare coverage with the competitors

The customer will have a better ability to provide competitive services by improving radio coverage where it matters the most to the end-users, probably affecting churn figures in a positive direction.


Title

4.25.3 Benefits

Management level facts on competitive strength of their network are provided very quickly

Competitor recordings are easily repeated with minimum effort

Recordings are based on true end-user behavior, using real end-user traffic to gather data, instead of relying on drive routes

Recordings provide fundamental decision-making input for access network investment, based on the true competitive situation

The recorded data is an excellent starting point for optimization efforts using a top-down approach, focusing on areas where the competitive situation calls for tuning and optimization



Well focused coverage improvements will reduce churn (poor coverage is a prime reason for churn).

The functionality serves as input to decisions on coverage investments and CAPEX can be much more focused and lean.

Expansion, tuning and optimization of network coverage can be made in areas where it makes a real difference.

4.25.3.1.1.2 Increased revenues

Roaming subscribers will more frequently use the network in areas like airports and border areas if the competitive coverage is improved.

4.25.4 Description

In GSM there is a fundamental mechanism for measuring on other frequencies in order for handovers to work. In normal cases measurements are collected to be able to find the best candidate for handover.


Title

For the Competitor Coverage Recording feature, the BSC orders the terminals to measure on not only the frequencies of the "own" network, but also on frequencies in competitors' GSM networks. By using many terminals it is possible to measure on all frequencies, and thereby finding out the coverage level of the competitor networks.

In order not to affect the normal neighbor cell measurements, careful scheduling of measured frequencies is supported.

OSS-RC plays a significant role in the complete functionality. The definition of areas to compare can be selected freely; consisting of all cell in an area, cells along a certain route, cells of a certain type (e.g. indoor) or any grouping relevant to the operator. Also, the analysis of measurement data, for instance the calculations necessary to determine competitor coverage compared to the "own" network, is taking place in OSS-RC. OSS-RC generates four reports with different level of detail.


Title

4.26 Discontinuous Transmission (DTX) Downlink



Technology: GSM

4.26.1 Attention


Not applicable

Dependencies


4.26.2 Summary

DTX downlink makes it possible to switch off the transmission in the BTS to MS direction when there is a pause in the conversation.

The purpose of the function is to reduce downlink interference in the radio network and to decrease BTS power consumption.

4.26.3 Benefits

DTX downlink increases the quality of the radio network. It minimizes the period of time that a BTS transmitter is active. Thus, the interference caused by that transmitter to other co-channel cells is approximately halved.

As this feature decreases the interference level it also makes it possible to make a tighter frequency re-use pattern hence increasing the radio network capacity.

If the frequency re-use pattern is not changed, the decreasing interference level in the network will improve speech quality and thus minimize the risk of dropped calls.

The decreased power consumption of the BTS results in lower Operation and Maintenance costs.


Title

In addition, a BTS can operate on back-up batteries for a longer period.

4.26.4 Description

The purpose of this feature is to reduce the downlink interference caused by transmission from BTSs that use the same frequencies. This is just one of the BSS features that are aimed at improving the interference situation in the radio network. DTX downlink should be used together with DTX uplink and frequency hopping to achieve the highest resistance to interference.

The feature uses the Voice Activity Detection (VAD) mechanism defined in the GSM technical specification series 06. The VAD detects periods of silence, occurring during normal telephony conversation.

The silent periods are detected in the transcoding equipment in the BSC. During the periods of silence, the BTS transmitter could basically be switched off. However, it is active at certain instances in time to allow the MS to make the necessary measurements of signal level and transmission quality. Special information (Silence Descriptors, SID) is transmitted to the MS in order to allow it to generate a so called background comfort noise.

The DTX downlink feature is supported for the following channel types:

TCH speech, full rate

TCH data, 9.6 kbit/s, non-transparent


Title

4.27 Discontinuous Transmission (DTX) Uplink



Technology: GSM

4.27.1 Attention


Not applicable

Dependencies


4.27.2 Summary

This feature reduces costs for the end user. "Talk time" is practically doubled as a result of the lower MS power consumption.

DTX reduces the uplink interference caused by transmission from MSs that use the same frequency. This reduction of interference in the system enables a tighter frequency re-use pattern, hence increasing the radio network capacity.


4.27.3 Benefits

This feature reduces costs for the end user. "Talk time" is practically doubled as a result of the lower MS power consumption.

DTX reduces the uplink interference caused by transmission from MSs that use the same frequency. This reduction of interference in the system enables a tighter frequency re-use pattern, hence increasing the radio network capacity.


Title


4.27.4 Description

In order for this feature to work, all Transceivers (TRXs) in the BTS must have the Discontinuous Transmission (DTX) Uplink feature.

The feature uses the Voice Activity Detection (VAD) mechanism defined in the GSM technical specification series 06. The VAD detects periods of silence occurring during normal telephony conversation.

The silent periods are detected in the MS. During the periods of silence, the MS transmitter could basically be switched off. However, it is active at certain instances in time to allow the BTS to make the necessary measurements of signal level and transmission quality. Special information (Silence Descriptors, SID) is transmitted to the BTS in order to allow it to generate a so called background comfort noise.

The DTX uplink feature is just one of the features aimed at improving the interference situation in the radio network. DTX uplink should be used together with DTX downlink and frequency hopping to achieve the highest resistance to interference.

The DTX uplink feature is supported for the following channel types:

TCH speech, full rate

TCH data, 9.6 kbit/s, non-transparent


Title

4.28 DTM Class 11; Two Packed Data Timeslots in Uplink



Technology: GSM

4.28.1 Attention


Not applicable

Dependencies


GSM RAN SW: FAJ121611 - Dual Transfer Mode

4.28.2 Summary

This feature doubles the throughput in the uplink direction when using DTM.

DTM Class 11 in combination with the Dual Transfer Mode feature FAJ 121 611 enables concurrent end user applications that require higher bandwidths. One end user application requiring high bandwidth is streaming video concurrent with a voice call. One such application is the IMS based weShare application. The use of such end user applications is believed to increase the operator's revenue, both due to increased talk time and increased amount of data sent/received.

4.28.3 Benefits

DTM Class 11 enables two packet switched timeslots to be used in the uplink direction. Using EDGE and two packet data timeslots, up to 110 kbit /s can be obtained. Typically a video streaming application requires 64 kbit/s.


Title

DTM Class 11 (in combination with Dual Transfer Mode) is a fundamental enabler for streaming video type applications from the mobile (uplink) providing that EDGE is used.



The potential for the operator is to increase the revenue in the network based on that the minutes of use goes up for subscribers using a weShare type application. When sharing a video stream while talking, the talk time is extended. Below is an example operator business case:

4.28.4 Description


Title

DTM Class 11 enables the use of up to two PS timeslots in the uplink direction, providing a bandwidth of up to 110 kbit/s using EDGE. In combination with FAJ 121 611 Dual Transfer Mode, the BSC supports up to two PS timeslots in either uplink or downlink. The total number of timeslots used at any given time is 5 giving the following two cases:

The standardized Extended Dynamic Allocation functionality is used to dynamically allocate more timeslots in ether the uplink or the downlink direction based on traffic demand. Extended Dynamic Allocation for DTM is part of the BSS 06A SW Upgrade.

In order to have an easy to use service with good end user experience, an IMS based application is also recommended. The use case weShare requires that one party can send streaming video and the other party receive streaming video with sufficient quality. The combination of FAJ 121 611 Dual Transfer Mode and DTM class 11 (this feature), provides for up to 110 kbit /s in either uplink or downlink.


Title

4.29 Dual Transfer Mode



Technology: GSM

4.29.1 Attention


Not applicable

Dependencies


Internal product impacts and dependencies Either GPRS or EGPRS support is required

Other node impacts and dependencies DTM feature in MSC (FAJ 121 493) and SGSN (FAJ 121 565) are required for full DTM functionality

Terminal impacts and dependencies Terminal support for DTM is required

MSC-S: FAJ121493 - Dual Transfer Mode for GSM

SGSN-MME: FAJ121565 - Dual Transfer Mode

4.29.2 Summary

Dual Transfer Mode (DTM) enables a user to have a speech and a data connection ongoing simultaneously. This opens up the possibility for a wide range of services including interactive games, sending pictures and web browsing while maintaining an ongoing speech connection. In addition Dual Transfer Mode enable CS page to be reached by non-DTM capable terminals engaged in a PS transfer.


Title

4.29.3 Benefits

DTM provides the following benefits:

DTM enables simultaneous PS and CS services making it possible to both send and receive data while keeping a speech call ongoing.

DTM increases minutes of use as end users do not need to end a data session while engaging in speech calls or vice versa.

DTM is bringing true multimedia into GSM and can be used as an enabler for increasing operators market share as it can be marketed directly towards end users.

DTM is the foundation for many new services and applications that requires simultaneous speech and data connections.

DTM enables service continuity of simultaneous PS and CS services with WCDMA.

Improves accessibility as even non DTM capable terminals engaged in PS transfers can be reached by incoming CS pages in a cell with DTM enabled.

4.29.4 Description

4.29.4.1.1.1 General

In Dual Transfer Mode, the mobile station has a Circuit Switched (CS) connection to the network (used for transfer of speech) and has simultaneously allocated radio resources on one or more Packet Data Channels (PDCHs). The CS connection and the allocation of radio resources on PDCHs are coordinated by BSS to comply with the multislot class defined for the MS in DTM.

DTM is described in 3GPP Technical Specifications as a form of simplified class A operation for a MS. This feature is optional for the mobile station and the network. It is only applicable for an MS supporting GPRS or EGPRS.

DTM is not allowed in cells with an active queue (see FAJ 121 362, Call Queuing). DTM can be turned on and off on a per cell basis.

4.29.4.1.1.2 Paging Coordination, Mobility Management and Network Operation Mode

BSS coordinates mobile terminating calls by paging coordination functionality between CS and PS for DTM regardless of Network Operation Mode (NOM) setting.


Title

This means that for a MS in packet transfer mode the network sends paging messages directly to the MS on the Packet Associated Control Channel (PACCH). Hence, a user engaged in a packet data session will not miss CS pages regardless of NOM setting. Even a non-DTM capable MS benefits from this as it also will be reached by incoming CS pages if DTM is enabled in the cell. A DTM capable MS will furthermore benefit from being able to continue both connections simultaneously.

This paging coordination is available in the whole BSC area once the DTM feature is activated, meaning that all cells will have paging coordination regardless if DTM is enabled or not in the cell. Thanks to this the paging coordination is available also in cells where DTM can not be enabled (extended range and cells with call queuing).

A DTM capable MS engaged in a CS call will also not miss PS pages if DTM is supported. This is particularly important for services like Instant Talk (see FAJ 121 591, Instant Talk Performance).

When a DTM capable MS is in CS dedicated mode both cell update and routing area update can be performed on the CS signaling channels (FACCH or SDCCH) thus avoiding separate PDCHs to be set up. This reduces the load on PCU resources. For a DTM capable MS in idle mode the existing combined RA/LA update procedure is used for networks using NOM I. In NOM II and III a simultaneous RA and LA update procedure is instead used for DTM.


Title

Figure 1. The dual transfer mode is reach from the CS dedicated mode.

To enter the dual transfer mode the MS sets up PS resources by using the signaling resources from the already set up CS connection. As can be seen in figure 1, it is only possible to enter dual transfer mode by establishing a PS connection when a CS dedicated connection already is present. However, if the mobile is in packet transfer mode it needs to release the TBF, enter the CS dedicated mode before reestablishing the TBF again and enter dual transfer mode.

4.29.4.1.1.3 Locating

All locating evaluations for connections in dual transfer mode are done based on the CS part of the DTM connection. The serving cell is determined according to the normal handover procedure for CS mode of operation. At handover the PS resources are abandoned and the handover is done on the CS channel. The MS then enters dual transfer mode again in the new cell.

In general the present strategy for ordinary CS connections is followed with some exceptions/clarifications:

Cell Load Sharing (FAJ 122 911) will not move connections in DTM mode.

Dynamic Overlaid/Underlaid Subcell (FAJ 122 430) is impacted as the subcell load distribution function will not move connections in DTM mode. However, the coverage limiting thresholds such as distance to cell border, path loss and timing advance are followed also for DTM connections.

Multi Layered Hierarchical cell structure (FAJ 122 573) is followed also for DTM connections.

The Locating (FAJ 122 259) thresholds for bad quality urgency handover and Intra Cell Handover (FAJ 122 290) are followed also for DTM connections.

Dynamic Half Rate Allocation (FAJ 122 582) is not used for DTM connections and Dynamic FR/HR Adaptation (FAJ 121 361) will not change speech mode of connections in DTM mode


Title

4.29.4.1.1.4 DTM Multislot Classes

BSS supports all the new DTM multislot classes introduced: 5, 6, 9, 10 and 11. Multislot class 6 is treated as multislot class 5 and multislot classes 10 and 11 are treated as multislot class 9. With the optional feature “FAJ 122 615, DTM Class 11” activated multislot class 11 will be treated as class 11. DTM class 5 is mandatory for an MS supporting DTM. Other DTM classes as well as EGPRS are optional for the MS. The DTM solution in BSS supports all speech codecs defined.

Figure 2. Timeslot allocation of multislot classes 5 and 9. The speech (CS) part can also be allocated on the "right-hand" side of the data (PS) part

4.29.4.1.1.5 Channel Allocation

The main principle for DTM channel allocation is to prioritize the channels giving the best PS throughput considering the multislot class and GPRS/EGPRS capability in the preferred subcell.

When different allocation alternatives give the same PS throughput the operator is able to impact the DTM channel allocation. Either to enable the best possible speech quality by allocating the CS part as a full rate channel or enable better packing of DTM users by allocating the CS part as a half rate channel.

The PDCHs that are used by DTM connections might be completely new channels or already PS allocated channels (e.g. dedicated PDCHs). Already allocated PDCHs are preferred over new ones to maximize hardware utilization. The PDCHs can be allocated to DTM on either side of a CS channel, see figure 3. A DTM connection may share all PDCHs allocated with other users (TBFs).


Title

Figure 3. Possible timeslot allocation scenarios for DTM

The PS part of the connection is supporting Quality of Service as for normal GPRS/EGPRS connections. This means that no additional considerations are made for a DTM connection.

Different pre-emption strategies is possible to use for DTM, see FAJ 121 060, Flexible Priority Handling of Packet Data Channels.

4.29.5 Enhancement

4.29.5.1.1 Enhancement in BSS R12

DTM is aligned with FAJ 121 614 Flexible MPDCH Configuration. At DTM channel allocation, it is validated whether data is allowed or not on the Master PDCH. This improvement enhances the probability of successful DTM establishment.

At DTM channel allocation, resources in the current subcell are preferred to avoid sub cell changes. The end user will experience this as fewer PS application interrupts due to intra cell handover.

A new counter is introduced to improve performance management of DTM. New monitors and reports are introduced in FAJ 121 46 R-PMO.


Title

4.30 DXX support in RBS 2000



Technology: GSM

4.30.1 Attention


Not applicable

Dependencies


4.30.2 Summary

The DXX support is introduced into the RBS 2000 to improve the management of the Cellular transmission network. This feature will perform limited additional transmission management without using external transport modules. Both PCM-A and PCM-B are supported and the feature can work in cascaded chain mode.

The feature is used together with a DXX transport network. When the support function is used within the RBS, the RBS acts from a management point of view as a node in the DXX network.

4.30.3 Benefits

DXX support offers operators efficient transmission supervision between BSC/TRC and BTS, and between BTS's without additional nodes in the RBS site.

The RBS 2000 nodes will be visible in the DXX/NMS (the transmission network management centre), and the layer 1 transmission in the RBS will be supervised in terms of Fault and Performance management (FM and PM). The FM and PM provide early warnings in case of faults and degradation of the trunks, enabling the operator to take actions at an early stage.


Title

4.30.4 Description

The DXX support feature includes Transport Network O & M generic functions and DXX specific functions.

The Generic functions are:

Enabling and detection of Transport Network O & M protocol

Allocation of management time-slot for the Transport Network O & M protocol

The DXX specific functions are:

Node identity

Node access control

Node real time control

Current alarm report for transmission faults

Alarm history report for transmission faults

G.821 Performance reports for transmission line

Fault masks for transmission faults

Transmission interface Loop-back

Node inventory for transmission parameters

Generic functions:

The enabling function gives the operator from the OMT possibility to enable and disable the Transport Network O & M support feature. When the DXX support feature is enabled a protocol detection function works, detecting protocols on the TNOM management channel. If a protocol is recognized then the appropriate protocol is enabled within the RBS.

From OMT a 64 kbit/s time-slot is allocated to be used to transport the management protocol within the transmission network. The same time-slot (number) is used for PCM-A and PCM-B, but can be changed in a DXX node. One single time-slot is used for the whole network.

DXX specific functions:

The RBS is from OMT or NMS dedicated with a node identity number. The node ID is unique for each RBS and used for communication with the DXX network.


Title

The RBS supports a node access control that is used to limit access rights to the node from NMS, making it possible to set different privileges to different nodes.

The real time control function maintains the administration of Real time and Relative time clocks in the RBS. The clocks are used to make time-stamps in fault and performance reports to the NMS.

The Current alarm report function reports status and fault conditions related to the transmission interfaces in the RBS. The following conditions are supported:

RBS Flash faults

RBS reset

Los Of Signal (LOS)

Los Of Frame (LOF)

Alarm indication Signal (AIS)

Bit Error Rate > 1E-3 (ERATE)


G.821 limits event

G.821 unavailable state

Fault masks

Buffer slips

Status of CSU loops

The Alarm history report function reports the last 100 events (specified above) that has occurred in the RBS.

The G.821 performance reports function sends performance reports to DXX upon request. The statistics can be reported for current and previous 15 minutes and 24 hours intervals. The function also controls G.821 alarm limits. The following statistics are provided:

Total Time (TT)

Available Time (AT)

Severely Errored Seconds (SES)


Title


Degraded Minutes (DM)

Number of CRC errors from far end (CRCE)

Number of seconds when RAI has been received (RAI)

Number of Code Violations (CV)

Number of CRC block errors (CRC)

Number of faulty Frame Synchronisation Words (FSW)

Number of lost Frame Synchronisation (FS)

Number of RX Buffer slips (BUFIN)

An alarm is activated when at least one G.821 limit has been exceeded. Limits can be set for SES, ES, CRC-E and RAI.

Limited statistics is supported by endless counters. The following counters are supported:

Total time (TT)

Available time (AT)

Severely Errored Seconds (SES)


Degraded Minutes (DM)

It is within the RBS possible to set fault filters to inhibit alarm reporting to the management centre. The fault filters are of the type fault freezing or fault mask. The freezing, freeze the alarm status of the RBS. The fault mask, masks all transmission faults from one or both RBS interface or specific faults as RAI and AIS.

The Loop-back function controls line loops in the RBS interface PCM-A and PCM-B, to be used for test purposes. All time-slots except the management time-slot are looped back. The loops are controlled with a timer, possible to set in minute intervals.

The Node inventory makes it possible from DXX to maintain the RBS node inventory and setting of the transmission interface parameters. The parameters controlled from BSS cannot be modified from DXX.


Title


Title

4.31 Dynamic BTS Power Control



Technology: GSM

4.31.1 Attention


Not applicable

Dependencies


Not Applicable


Not Applicable


Not Applicable


Not Applicable

4.31.2 Summary

The feature Dynamic BTS Power Control allows the BSC to dynamically adjust the output power transmitted from the BTS for active TCH connections as specified by the operator.

The feature has the effect of lowering the total emitted radio output power of all BTS's in the radio network, thus lowering the level of total disturbance, which increases the C/I ratio in the radio network.


Title

4.31.3 Benefits

Increased performance, (less lost calls and handovers)

Increased quality, (higher speech quality for subscribers)

Increased capacity, (tighter frequency reuse in the network)

Together with other features such as Dynamic MS Power Control and Frequency Hopping this feature may be used for optimizing cell planning.

4.31.4 Description

The feature Dynamic BTS Power Control lets an operator dynamically adjust the output power transmitted from the BTS. The control algorithm uses the signal strength and quality information in the measurement reports received by the MS and the BTS which are reported to the BSC over the Abis interface.

The control algorithm in the BSC controls the BTS power by messages on the Abis interface.

If the feature is used together with the Frequency Hopping feature, further enhancement of the downlink disturbance is possible, depending on the cell planning used and the actual radio network environment. These features can be used to increase capacity by a shorter reuse distance in the frequency planning.

4.31.5 Enhancement

4.31.5.1.1.1 Enhancements in BSS R12:

The handling and configuration of the BTS dynamic power control algorithm is simplified. This is achieved by moving algorithm configuration not directly affecting the power regulation from subcell level to BSC level. For example filter parameters are common for the whole BSC.

Easier feature handling leads to reduced operation and maintenance cost as well as fewer configuration mistakes which in turn results in better radio network quality and higher capacity.


Title

When the feature FAJ 121 826 Enhanced Measurement Reporting (EMR) is used, EMR capable handsets reports BEP (Bit Error Probability) in the measurement reports for the downlink. Since BEP is using 5 bits instead of 3, it provides much better granularity than RXQUAL, especially at poor radio conditions. If BEP is available it is used in the power control algorithm instead of RXQUAL. This enables increased performance of the power control algorithm, particularly in low C/I environments.


Title

4.32 Dynamic FR/HR Adaptation



Technology: GSM

4.32.1 Attention


Not applicable

Dependencies




Not Applicable


FAJ 122 315 Half rate Channels is required.


Not Applicable


Not Applicable

4.32.2 Summary

Dynamic FR/HR Adaptation enables the system to automatically change channel rate due to traffic load and radio link quality for ongoing speech calls. This makes it possible to both increase capacity and maintain adequate speech quality.


Title

4.32.3 Benefits

Increased capacity due to the use of half rate channels when traffic load is high.

Minimized speech quality impact due to using half rate because:

Half rate channels only have to be used when the cell is close to congestion

AMR half rate capable terminals can use half rate first

Good speech quality for half rate channels, since they are only used if the radio link quality is good enough.



By using half rate to handle high traffic loads, fewer transceivers are needed in the network. Apart from the reduction in transceivers there are also many other cost savings that can be made due to this. For example lower power consumption, less transmission bandwidth, fewer spare parts and reduced operation and maintenance.

Minimizing the speech quality impact from half rate reduces churn.


Better quality leads to longer calls and the possibility to ensure a certain speech quality level when using half rate accomplishes this.

4.32.4 Description

Dynamic FR/HR Adaptation makes it possible to change between full rate and half rate channels for ongoing calls. The change from full rate to half rate channels is initiated when a cell is approaching congestion. Depending on the penetration of half rate capable terminals, a significant capacity increase can be achieved whenever the traffic situation demands it.


Title

Included in the feature are several functions to minimize the speech quality impact that is inherent with the use of half rate channels. Half rate is only used when more capacity is needed. A radio link quality check is performed before a call is converted to half rate, to ensure a good enough speech quality on the half rate channel. The quality of the radio link is supervised continuously while a call is using a half rate channel, and if the radio quality becomes poor, the call is converted to full rate. It is also the case that the AMR half rate speech codec provides better speech quality than the standard half rate speech codec. Due to this speech codec difference it is possible to initiate conversion of AMR half rate capable terminals first.

To ensure adequate flexibility it is possible to optimize all thresholds on cell level.

4.32.5 Enhancement

Two new traffic load thresholds are introduced, one for AMR capable terminals and one for non-AMR capable terminals. They control the change from half rate to full rate channels. After a traffic peak in a cell, when the traffic load in a cell decreases below the new thresholds, calls are transferred from half rate to full rate channels.

This further reduces the speech quality impact from using half rate.


Title

4.33 Dynamic Half Rate Allocation



Technology: GSM

4.33.1 Attention


Not applicable

Dependencies




Not Applicable


FAJ 122 315 Half rate Channels is required.


Not Applicable


Not Applicable


Title

4.33.2 Summary

This feature allows allocation of full rate or half rate channels according to the traffic situation in the cell for dual rate mobiles. Half rate channels are allocated when there is a risk for congestion in a cell, otherwise full rate channels are selected. This enables a capacity gain while minimizing the speech quality impacts of using half rate.

4.33.3 Benefits

Increased capacity through the use of half rate channels at high traffic loads.

Improved network quality since congestion is reduced.

Minimum impact on speech quality because half rate is only used at high traffic loads and when the radio link is good enough.

Better speech quality because dual rate mobiles are allocated full rate channels:

When there is no risk for congestion in a cell

When the radio link is poor

Reduced drop call rate since fewer intra cell handovers are performed on poor radio links.



By using half rate to handle high traffic loads, fewer transceivers are needed in the network. Apart from the reduction in transceivers there are also many other cost savings that can be made due to this. For example lower power consumption, less transmission bandwidth, fewer spare parts and reduced operation and maintenance.


Title

4.33.4 Description

Dynamic Half Rate Allocation makes it possible to allocate traffic channels for voice based on the traffic load in the cell. At high traffic loads half rate capable terminals are allocated half rate channels. Full rate channels are only used during low and normal traffic loads. The traffic load threshold is based on the percentage of idle traffic channels in each cell and can be configured per cell. Dynamic Half Rate Allocation is considered when a new channel is allocated, for example at call setup or handover.

The feature is designed as a cost efficient and easy way to avoid congestion during peak hours, without having to invest in additional transceivers. The impact on speech quality is kept as low as possible since half rate channels is only used when it is needed due to high traffic loads. Dynamic Half Rate Allocation is not recommended as a long term solution in networks experiencing severe capacity problems as speech quality will be impaired by the continuous use of half rate.

To ensure adequate flexibility it is possible to optimize all thresholds on cell level.

4.33.5 Enhancement

4.33.5.1.1.1 Enhancements in BSS 07B

Two thresholds that prevent allocation of half rate channels if signal strength is too low are introduced. One threshold is used at call setup and the other at inter cell handover. If signal strength is below the thresholds a full rate channel will be allocated regardless of the traffic load in the cell.

The benefits of these thresholds are increased speech quality and reduced drop call rate. Speech quality is improved since half rate can be avoided if the radio link is too poor. Drop call rate is reduced since a risky intra cell handover to change from a half rate to a full rate channel on a bad radio channel can be avoided.


Title

4.34 Dynamic MS Power Control



Technology: GSM

4.34.1 Attention


Not applicable

Dependencies


Not Applicable


Not Applicable


Not Applicable


Not Applicable

4.34.2 Summary

The feature has the effect of lowering the total emitted radio output power of all MSs in the radio network, thus lowering the level of total disturbance, which increases the C/I ratio in the radio network.

The feature Dynamic MS Power Control allows the BSC to dynamically adjust the output power transmitted from the MS as specified by the operator.


Title

4.34.3 Benefits

The operator benefits are:

Increased performance, (less lost calls and handovers)

Increased quality, (higher speech quality for subscribers)

Increased capacity (tighter frequency reuse in the network).

The subscriber benefit is decreased MS battery consumption.

Together with other features such as Dynamic BTS Power Control and Frequency Hopping this feature may be used for optimizing cell planning.

4.34.4 Description

The feature Dynamic MS Power Control lets an operator dynamically adjust the output power transmitted from the MS. The control algorithm uses the signal strength and quality information in the measurement reports received by the MS and the BTS which are reported to the BSC over the Abis interface.

The feature can be controlled per subcell by the operator. This allows the operator to control the feature by specifying one behavior for MS's in the overlaid cell and another behavior for MS's in the underlaid cell.

The functions in BTS for the feature Dynamic MS Power Control is to store the MS power level received from BSC and to include it in the downlink SACCH blocks.

The control algorithm in the BSC controls the MS power by messages in the air interface.

Initially, at call setup and immediately after a handover, the regulation can only be performed towards lower power values. On the other hand, the initial down regulation is very fast. This provides the protection against excessive multicoupler saturation.

If the feature is used together with the Frequency Hopping feature, further enhancement of the uplink disturbance is possible, depending on the cell planning used and the actual radio network environment.

These features can be used to increase speech quality and/or increase capacity by a shorter reuse distance in the frequency planning.


Title

4.34.5 Enhancement

4.34.5.1.1.1 Enhancements in BSS R10

A new algorithm has been introduced to improve stability, regulation speeds and the response to quality changes at high signal strength. This also improves interference resistance towards surrounding cells.

The improvements consist of:

Exponential signal strength and quality filters

Differentiated up- and down regulation speeds

New non-linear mapping between RXQUAL and C/I

Enhanced Quality compensation at high signal strength

This enables a more aggressive down-regulation of the MS output power, which lowers interference levels and thereby allow higher radio network capacity.


The handling and configuration of the MS dynamic power control algorithm is simplified. This is achieved by moving algorithm configuration not directly affecting the power regulation from subcell level to BSC level. For example filter parameters are common for the whole BSC.

Easier feature handling leads to reduced operation and maintenance cost as well as fewer configuration mistakes which in turn results in better radio network quality and higher capacity.

When the feature FAJ 121 826 Enhanced Measurement Reporting (EMR) is used, TRUs capable of reporting BEP (Bit Error Probability) does so in the uplink measurement reports. Since BEP is using 5 bits instead of 3, it provides much better granularity than RXQUAL, especially at poor radio conditions. If BEP is available it is used in the power control algorithm instead of RXQUAL. This enables increased performance of the power control algorithm, particularly in low C/I environments.


Title

4.35 Dynamic Overlaid/Underlaid Subcells



Technology: GSM

4.35.1 Attention


Not applicable

Dependencies


Not Applicable


Not Applicable


Not Applicable


Not Applicable

4.35.2 Summary

Dynamic Overlaid/Underlaid Subcells can be used to increase the traffic capacity in a cellular network without adding new sites. It provides a mechanism to cover for temporary peaks in the traffic load in a cell with retained interference level.


Title

4.35.3 Benefits

Radio network capacity is increased without decreasing the radio network quality. The variations in traffic load between cells during busy hour, especially in areas with temporary traffic peaks, allows for a tighter frequency reuse for the frequencies used in the overlaid subcells.

The costs for acquiring new sites and operation are decreased by decreasing/delaying the number of new sites needed.

4.35.4 Description

In Dynamic Overlaid/Underlaid Subcells the available channels in a cell are divided between an overlaid and an underlaid subcell. The underlaid subcell has the full set of control channels that is the Common Control Channels (CCCH) which includes the Broadcast Control Channel (BCCH).

The coverage area of the underlaid subcell is equal to that of the cell as a whole, but the coverage area of the overlaid subcell is less than that of the underlaid subcell. A capacity gain is obtained by using a tighter frequency reuse in the overlaid subcell compared to the underlaid subcell, and to make this possible the overlaid subcell must be restricted in size. Therefore, only mobiles with a downlink path loss less than a path loss threshold and a timing advance less than a timing advance threshold may use the traffic channels in the overlaid subcell.

There are two strategies for handling the traffic in Dynamic Overlaid/Underlaid Subcells, depending on if subcell load distribution is active or not in the cell. If subcell load distribution is not active the overlaid subcell is always used if an MS is within the coverage threshold and a channel is available. If subcell load distribution is active, the overlaid subcell is only used as a last resort when the traffic load in the underlaid subcell becomes too high. This together with the fact that load peaks appear relatively locally in the network make it possible to use an even tighter frequency reuse pattern for the overlaid subcells.

When subcell load distribution is active the traffic in the cell is distributed in the following way:

When the amount of idle TCH's in the underlaid subcell decreases below a parameter defined level, handover to overlaid subcell is initiated. The mobiles closest to the BTS, that is, with the lowest path loss, are always selected first for handover to overlaid subcell.

When the amount of idle TCH's in the underlaid subcell increases above another defined parameter level, that is, when the traffic level becomes low enough, handover back to the underlaid subcell is initiated. In this case, the mobiles with the highest path loss are selected first for handover to underlaid subcell.


Title

The number of idle TCH's in every cell is monitored periodically in the BSC and subcell load distribution is performed according to the operator settings.

The serving area of the overlaid subcell is kept in such a way that when a mobile is moving out from the overlaid subcell, restricted by a path loss threshold and a timing advance threshold, a handover to the underlaid subcell is initiated.

A direct handover to an overlaid subcell in a neighboring cell can only be performed if the neighbor is co-sited with the serving cell.

By combining Dynamic Overlaid/Underlaid Subcells with Fractional Load Planning significant capacity gains can be achieved.

4.35.5 Enhancement


The feature is enhanced so that subcell load distribution is now possible to initiate also in the overlaid subcell. The same criteria: path loss, DTCB and timing advance are used.

If either of the subcells is experiencing near congestion situations, traffic will be moved to the other subcell by performing handover of the most suitable connection.

The enhancement enables cells to handle traffic peaks and variation in a better way, which means more efficient use of the available capacity in the network and less end-user congestion.

In network situations where subcells are in use and the BCCH carrier needs extra protection FAJ 121 813 Tight BCCH Frequency Reuse is beneficial.

The enhancement also enables greater flexibility in how the features FAJ 122 085 Multi Band Cell and FAJ 122 582 Dynamic Half Rate Adaptation are used in the network.


Title

4.36 E911 U-TDOA Support in BSC



Technology: GSM

4.36.1 Attention


Not applicable

Dependencies


PDE and LMUs are required. Transmission links between PDE and LMU needs to be dedicated for LMU signaling. An LMU is installed and connected to the antenna system of each BTS with minor impact on uplink radio performance in the cell.


This feature supports emergency calls only.


The feature FAL104 3545 E911 U-TDOA Support in SMPC is required in the SMPC. It may be replaced with other vendors' standard compliant SMLC functionality.


Not Applicable


Title

4.36.2 Summary

The feature E911 U-TDOA Support will enable the integration of Uplink Time Difference of Arrival (U-TDOA) systems, with other methods such as Cell Global Identity/Timing Advance (CGI/TA) and Assisted GPS (AGPS). The Lb interface between Serving Mobile Positioning Centre (SMPC) and BSC is extended with U-TDOA specific messages. The Lbis interface between SMPC and Positioning Determination Entity (PDE) provides information to PDE about initial CGI/TA estimate and mobile channel and coding information.

Compared to Abis Monitoring solutions the operator now has a more robust and integrated solution.

4.36.3 Benefits

The major benefits of this feature are:

The Abis Monitoring Units are made obsolete, i.e. OPEX and CAPEX are reduced. More, the identity of the MS is now unambiguously defined.

U-TDOA becomes integrated and interworking with other standardized methods such as CGI/TA and AGPS.

4.36.4 Description

The feature E911 U-TDOA Support provides a standard compliant solution with Lb and Lbis signaling between BSS and PDE, see figure below.


Title

Figure: U-TDOA System Overview

The SMPC is responsible for initiating the positioning procedure. The positioning method is determined by the requested Quality of Service (accuracy and latency), and the methods supported by the MS and the system. If the requirement of accuracy is not fulfilled with CGI/TA, and time allows other methods may be attempted. With the E911 U-TDOA Support feature, the SMPC will initiate a U-TDOA positioning procedure if enabled and the MS is in an emergency call and A-GPS is not available. The SMPC offers added flexibility in how to prioritize between A-GPS and U-TDOA.

SMPC is also responsible for the delivering of CGI/TA estimate, channel and ciphering/encryption information to PDE. This can be used to decide which LMUs should measure on what channels.

If the PDE is not responding (on time) or when the positioning result is considered unreliable, SMPC will fall back to the CGI/TA estimate.

It is possible to per BSC and per SMPC turn on/off E911 U-TDOA Support. U-TDOA diagnostics are available in SMPC on cell level.

The SMPC is responsible to issue an alarm if loosing when the PDE contact is malfunctioning.


Title

4.37 ECGI Support in BSC



Technology: GSM

4.37.1 Attention


Not applicable

Dependencies


4.37.2 Summary

The feature ECGI Support in BSC enables the Enhanced CGI (ECGI) functionality in the Serving Mobile Positioning Centre (SMPC), providing up to 25% higher accuracy than CGI/TA in a typical network. The ECGI method uses signal strength measurements, in addition to CGI and TA, to estimate the position of the terminal

4.37.3 Benefits

The main benefits of ECGI are:

Improved accuracy up to 25% at positioning of any GSM terminal. This leads to approximately a 40% reduction of the size of the uncertainty area around the estimated position.

Improved overall perception of AGPS as ECGI is used as fallback if AGPS fails.

SMPC functionality is essentially self tuning and requires minimum operation and maintenance, as e.g. RF prediction and drive test data is not needed.


Title

4.37.4 Description

The feature ECGI Support in BSC provides the SMPC with signal strength information from the measurement reports, which are sent twice every second from the terminal. This information is sent over the Lb interface and is combined with the CGI and TA information to get an estimate of the position of the terminal.

ECGI is also used as fallback in case higher accuracy methods (AGPS) fails or are deemed unreliable. This means that the gap between expected (AGPS) accuracy and the fallback is reduced and the perception of AGPS will be higher.

The CGI/TA latitude-longitude estimate is always put in the middle of the TA arc, see figure below. The ECGI method moves the estimate within the TA arc, depending on the measurement reports from the serving and neighbor cells. The accuracy of this estimate is improved by up to 25% compared to CGI/TA. The uncertainty area describes (to a certain level of confidence) the possibility of terminals being somewhere else than at the latitude-longitude estimate. This area is approximately 40% smaller than the CGI/TA uncertainty area, still with the same confidence level.

Figure: Comparison between CGI/TA and ECGI accuracy


Title

For small cells (micro and pico), a possibility to always report the site coordinate is introduced.

The ECGI algorithm does not make use of prediction models or drive test data, and therefore requires minimum additional efforts to operate and maintain compared to CGI/TA. Only a few new (global) SMPC parameters are introduced.


Title

4.38 EDGE Evolution – Reduced Latency



Technology: GSM

4.38.1 Attention


Not applicable

Dependencies


Internal product impacts and dependencies 'FAJ 121 31, EGPRS' and either of 'FAJ 123 174, Packet Abis over TDM' or 'FAJ 123 175, Packet Abis over IP' are required

In order to achieve latency in the order of 80 ms and maximize usage of Reduced Latency, activation of the following sub-features from 'FAJ 123 161 EDGE Performance Package' are strongly recommended:

FAJ 121 375, GPRS/EGPRS End-user Performance

FAJ 121 604, Persistent Scheduling

FAJ 121 824, Application Aware Timeslot Allocation

FAJ 121 820, Single Phase Access for EGPRS.


Terminal impacts and dependencies Support of LATRED (3GPP Rel-7) in terminals is required. This includes either Reduced TTI (10ms) or Fast Ack/Nack reporting

GSM RAN SW: FAJ12131 - EGPRS


Title

4.38.2 Summary

EDGE Evolution - Reduced Latency gives large improvements in end-user performance by a Reduced Transmission Time Interval and an improved Ack/Nack procedure. The end-to-end Round Trip Time is dramatically reduced, which improves all applications. As an example, downloading of a web page or an email will be up to 30% faster.

4.38.3 Benefits

EDGE Evolution - Reduced Latency provides the following benefits:

Significant improvement in latency for terminals with support of Reduced Latency (referred to as LATRED in 3GPP Rel-7)

Approximately 80 ms end-to-end Round Trip Time for Ping, messaging and signaling

Improved end-user perception of applications such as web browsing and email with 20-30% faster download times

5% increased throughput thanks to reduced signaling overhead


4.38.3.1.1.1 Increased revenue

The feature increases operator revenue as higher performance leads to users being more willing to use packet data applications frequently.

EDGE Evolution - Reduced Latency gives operators a clear competitive advantage in media benchmark tests improving the packet data image of the operator.

4.38.4 Description

With FAJ 123 145, EDGE Evolution - Reduced Latency the end-user performance is significantly improved. The benefit is possible by a dramatic reduction in end-to-end Round Trip Time (RTT). This is accomplished by a Reduced Transmission Time Interval (TTI) of 10 ms and lead to an RTT of about 80 ms and 20% to 30% faster downloads for applications like Web browsing and E-mail. See Figure 1.


Title

With 10 ms TTI on the air interface (downlink and uplink), in average 5 ms less random queuing time (downlink and uplink) and at least 10 ms reduced transport time on the Abis interface (downlink and uplink) the end-to-end latency is reduced with in total 50-60 ms. The total RAN RTT is then reduced from about 100 ms to 40-50 ms as shown in Figure 2. This requires terminal support of Reduced Latency (referred to as LATRED in 3GPP Rel-7).


Title

With Basic TTI of 20 ms one Radio Block is transmitted as four normal bursts on four consecutive TDMA frames on a single Packet Data Channel (PDCH). The difference in Reduced TTI mode is that the four bursts are transmitted on two consecutive TDMA frames on two PDCHs that constitute a PDCH-pair. Abis Optimization or Abis over IP is required to support the new burst mapping on the PDCHs.

Shorter MS reaction time is also part of EDGE - Evolution Reduced Latency. With the combination of 10 ms TTI and Shorter MS reaction time it is possible to reduce latency at bad radio conditions.

It is possible to multiplex Basic TTI and Reduced TTI on the same timeslots and to dynamically change TTI mode for a single user. For transfers in Reduced TTI mode the 8-PSK modulation is used initially in order to maximize performance and efficiency.

Fast Ack/Nack reporting is also part of the reduced latency framework. With Fast Ack/Nack the Piggy-backed Ack/Nack (PAN) report is introduced. This report is sent as a part of user data blocks, as opposed to traditional Ack/Nack reports which are sent as separate control blocks.

The advantage is that Ack/Nack reports can be sent frequently without stealing bandwidth from user data. As an example, for a 5+1 TS allocation, the throughput will increase with 4-5% thanks to the reduced overhead from control packets.

When Piggy-backed Ack/Nack reports are sent as part of the user data, it is possible for the mobile to inform the PCU about lost packets immediately (Event based reporting) since there is no need to wait for the next scheduled Ack/Nack report. This will reduce latency when there are retransmissions.

In combination with Reduced TTI mode, Fast Ack/Nack reporting lead to a higher degree of 8-PSK usage. The reason for this is that control blocks (traditional Ack/Nack reports) are sent with GMSK modulated blocks.

All data applications will benefit from lower latency (see Figure 4) and new services can be supported. As an example EDGE Evolution - Reduced Latency offer better support of e-mail / VoIP services.


Title

4.38.5 Enhancement

4.38.5.1.1 Enhancement in BSS 09A

In BSS 09A the feature EDGE Evolution - Reduced Latency is enhanced with Fast Ack/Nack reporting which is also part of the reduced latency framework (referred to as LATRED in 3GPP Rel-7).


Title

4.39 EDGE Performance Package



Technology: GSM

4.39.1 Attention


Not applicable

Dependencies


Single Phase Access for EGPRS is not supported when BCCH/CCCH is placed on a classic TRU, RBS2301, RBS2302, RBS2401 or RBS 200


This feature replaces:- FAJ 121 822, Active Queue Management- FAJ 121 824, Application Aware Timeslot Allocation- FAJ 121 843, Channel Repacking- FAJ 122 649, EGPRS Prioritized over GPRS- FAJ 121 606, Extended Dynamic Allocation- FAJ 121 814, Five Downlink Time Slots- FAJ 121 816, Incremental Redundancy in Uplink- FAJ 121 359, Network Assisted Cell Change- FAJ 122 614, Optimized Throughput at Inter-BSC Cell Change- FAJ 121 604, Persistent Scheduling- FAJ 121 820, Single Phase Access for EGPRS- FAJ 121 825, GPRS/EGPRS Load Optimization. NOTE: These features are seen as "sub functions" to the optional feature.

Sub functions Single Phase Access for EGPRS and EGPRS Prioritized over GPRS, is only applicable for FAJ 121 31 EGPRS.

Other node impacts and dependencies FAJ 121 930, Inter-BSC NACC is required in SGSN in order to utilize Optimized Throughput at Inter-BSC Cell Change function. This feature supports RIM (RAN Information Message).

Terminal impacts and dependencies 3GPP Release 4 capable terminal required to support NACC (and inter-BSC NACC).


Title

Terminal supporting three or more uplink timeslots required to benefit from Extended Dynamic Allocation.

Terminal supporting 3GPP Release 5 Multislot Classes 30 to 33 is required to benefit from the Five Downlink Timeslots function.

GSM RAN SW: FAJ122572 - GPRS

4.39.2 Summary

This feature give significantly better end-user performance to EDGE users, the performance gain of this feature in an EDGE network can be similar to going from GPRS to EDGE. It consists of functionality improve throughput, reduce latency, improve mobility and makes the packet data service more stable and efficient.

EDGE Performance Package consists of a number of sub functions previously available as separate features.

4.39.3 Benefits

4.39.3.1.1 Benefits

Web download time reduced with 35%

Reduced system latency, from 390 down to 133 ms.

Increased bitrate from 236 to 296 kbps by supporting 5 downlink timeslots

Increased uplink bitrate from 118 to 236 kbps

Improved uplink capacity of 25% with Incremental Redundancy

Increased multislot utilization thanks to channel repacking

Reduced outage at cell-changes (Intra-BSC: 4 to 1 sec, Inter-BSC: 13 to 7 sec)

Increased cell capacity by prioritization of EDGE over GPRS users

Reduced access time to system by 300 ms

System throughput may increase with up to 60% in high load situations with GPRS/EGPRS Load Optimization.


Title



Increased packet data capacity in the BSS leads to that a given amount of equipment can handle more users, thus reducing total cost of ownership.


The improved end-user performance in terms of bitrate, latency and better mobility leads to increased usage of data services and therefore increased revenues. In addition, a better data service likely leads to a positive effect on the churn.

As an example, a fictive operator with 3 million subscribers has been used to calculate the increased revenues from more data services and a positive churn. It is assumed that EDGE Performance package leads to an increased growth in packet data usage and users, which increase revenues. In addition voice revenue is increased thanks to the increased amount of users on the voice service. Comparing that with needed investments on capacity expansion and EDGE Performance Package the payback time is less than two years in this example.


Title

4.39.4 Description

4.39.4.1.1.1 Sub function EGPRS Prioritized over GPRS

The operator can configure a weight priority for EDGE users compared to GPRS users. This weight is applied both to TBF reservation and to scheduling. For the scheduling the weight factor is applied both for downlink and uplink TBFs.

The weight factor is also applied when determining on what PDCHs the TBFs shall be reserved. The application of the weight factor in reservation leads to that the GPRS TBFs avoid using the EDGE PDCHs when there are active EDGE TBF(s) in the cell. To what degree is determined by the weight factor.

The below figure shows the total throughput, with and without the feature as well as the theoretical maximum, for different number of simultaneous CS full-rate calls (denoted "Erlang") in a 2 TRX cell, for 25% EDGE and 75% GPRS users.

As can be seen from the figure the throughput on a cell level is improved with more than 25% when CS Erlang is above 5 thanks to the EDGE prioritization.


Title

4.39.4.1.1.2 Sub function Network Assisted Cell Change

Network Assisted Cell Change (NACC) is a function which allows the BSS to assist a GPRS/EGPRS terminal upon cell reselection while in packet transfer mode. This significantly reduces the service outage time for a terminal supporting NACC. The service outage time is reduced for intra-BSC cell reselections, from approximately 4 seconds down to below 1 second (measured as application layer outage). Corresponding outage measured on radio link level is approximately 0.3 seconds.

The BSS will furthermore make an attempt to finish the transfer of the current data packet (LLC PDU) by delaying the cell change somewhat. Retransmissions of LLC PDUs are therefore avoided with the effect of the cell change on higher layers being minimized.

The NACC feature does not control the terminals choice of new cell but can assist the terminal once it has chosen what cell to go to. NACC is a feature introduced in 3GPP Release 4.

4.39.4.1.1.3 Sub function Optimized Throughput at Inter-BSC Cell Change

The function improves the end-user performance at inter-BSC cell changes as interruptions are reduced by using NACC also on BSC-external cell changes. The following are estimates:

For TCP applications interruptions are reduced from 13s to 10s (7s if Gs interface is used)

For UDP applications interruptions are reduced from: 6,5s to 4,5s (3s if Gs interface is used)

In order to provide system information for a BSC external cell using the 3GPP NACC procedures, system information are shared between the BSCs. This is done using the 3GPP Release 5 standardized RIM (RAN Information Message) procedures, which also involves SGSN.

The functionality mirrors the existing intra-BSC NACC to a large extent, but due to the change of BSC area the end-user impact is larger. This is because the content in the BSC buffer is discarded and the terminal needs to perform a Location Area and Routing Area Update in the new cell.

4.39.4.1.1.4 Sub function Application Aware Timeslot Allocation

Application Aware Timeslot Allocation introduces a neutral state in the timeslot allocation mechanism. This has benefits in situations where the traffic occurs in both directions, such as cached web pages.


Title

Single Phase Access for EGPRS and/or Extended Dynamic Allocation are recommended to be activated for the full benefit of Application Aware Timeslot Allocation.

- Application Aware Timeslot Allocation in combination with Single-Phase Access

If TBFs are started with the single-phase access procedure the full capabilities of the terminal is not known by the network. This leads to that only one uplink timeslot is initially allocated, which may have negative impact on application performance if the IP packets to send on uplink are large. With the function Application Aware Timeslot Allocation, the neutral state is reached quicker which improve application performance.

- Application Aware Timeslot Allocation in combination with Extended Dynamic Allocation

When Extended Dynamic Allocation is used, the timeslot allocation to the user is very uplink biased (e.g. 1 TS downlink, 4 TS uplink). For applications generating traffic in both up- and downlink, performance may be limited by the few downlink timeslots. Application Aware Timeslot Allocation improves this by the introduction of the neutral state, making it easier for the network to enter e.g. a 3+2 DL/UL timeslot allocation.

4.39.4.1.1.5 Sub function Channel Repacking

Channel Repacking improves the GPRS/EGPRS performance and channel utilization by moving calls that are blocking the use of multiple consecutive timeslots. The selection of a new channel for a call is made according to the channel allocation strategies configured in the cell (see feature FAJ 121 363, Advanced Single Slot Allocation for additional information).

Channel Repacking not only facilitates effortless expansion of PDCH sets, but is also ensuring that DTM is not unnecessarily cluttering them with left over CS connections. Furthermore it is very efficient at cleaning up fragmentation that often occurs after congestion.

Sub function Five Downlink Time Slots

This function increases the throughput with 25% by enabling 5 downlink timeslots instead of 4 in the downlink. This is achieved by supporting MS Multislot Class 30 - 33.

The radio link throughput is increased from 80 to 100 kbit/s for GPRS and from 236 to 296 kbit/s for EGPRS.


Title

The total number of used timeslots for Multislot Class 30- 33 is 6. This means that if 5 TS is used in the downlink direction, only one uplink timeslot can be used (Multislot Class 30). The table below describes the timeslot configuration possible for each Multislot Class.

4.39.4.1.1.6 Sub function Incremental Redundancy in Uplink

Incremental Redundancy (IR) improves system capacity (up to 25% for EGPRS) and throughput on the uplink for all EDGE capable MSs.

Incremental Redundancy in Uplink leads to improved quality for the end users, as well as improved system capacity since the users completes their transmissions quicker and leave room for other users. IR in Uplink complements the LQC algorithm by an improved decoding. When IR is used the LQC algorithm is more aggressive in its coding scheme selection. Retransmissions are performed with the same coding scheme that was used for the first transmission. The receiver then uses soft combining of the first block with the retransmission(s) until the block is successfully decoded. Since partially received data are not discarded the likelihood of successful decoding with IR increases, which results in usage of a higher coding scheme and fewer retransmissions. Higher coding scheme and fewer retransmissions is the same thing as higher radio link bitrate.

Incremental Redundancy is already available for the downlink in the feature FAJ 121 31 EGPRS.


Title

4.39.4.1.1.7 Sub function Single Phase Access for EGPRS

The function Single Phase Access for EGPRS reduce initial TBF setup time. The improved TBF setup time is beneficial for applications that start with small messages, e.g. TCP handshaking.

Benefits are visible at download and upload of small objects, e.g., for services like WAP and MMS. With Single Phase Access the time to establish a new TBF will be improved for EGPRS with approximately 300 milliseconds.

For cell-reselections, the application layer outage for a downlink transfer is improved thanks to the faster TBF establishment. For uplink transfer, the benefit depends on the size of IP packets since only one timeslot is used initially on uplink. It is only EGPRS capable terminals that support Single Phase Access, therefore an EGPRS capable MS is required.

Application Aware Timeslot Allocation is recommended for full benefit of Single Phase Access.

4.39.4.1.1.8 Sub function Persistent Scheduling

Persistent Scheduling gives a significant improvement to all applications available for GPRS/EGPRS. The improvement is possible by a dramatic reduction in the end to end Round Trip Time (RTT). Downloading a web page or an email will go up to 30% faster. End to end latency is reduced to below 150 milliseconds.

Persistent scheduling minimizes the delay in the communication between MS and BSC. It complements already existing functions like Delayed TBF release and Extended uplink TBF mode (see GPRS/EGPRS End-user Performance).

The feature improves RTT in two ways:

It reduces unnecessary waiting time for MS to BSC communication by constantly (persistently) "asking" the MS whether it has anything to send in the uplink.

It makes sure that whatever the MS needs to send in uplink can be sent using consecutive radio blocks directly. Without the feature, the BSS only schedules one radio block at a time.

Whenever a user starts to send or receive data (having a TBF), that user will get full access to the uplink resources of that channel according to normal principles. Persistent scheduling will only schedule non-active users as long as no other users on that channel have data to send on the uplink.


Title

4.39.4.1.1.9 Sub function Extended Dynamic Allocation

Extended Dynamic Allocation allows up to four timeslots to be assigned for a terminal in the uplink compared to two without. This significantly increases the uplink bitrate capability and translates directly to an improved end-user experience for uplink heavy applications, for example sending email with attachments, are used.

At the first PDCH reservation for a TBF the dynamic allocation method will be used. This allows for better terminal reservation flexibility among mobiles. The system will periodically check if the downlink or uplink should be upgraded based on the traffic load in each direction. If more than two uplink timeslots are required a change from dynamic allocation to extended dynamic allocation will occur.

4.39.4.1.1.10 Sub function Active Queue Management

Active Queue Management (AQM) in BSS improves the perceived performance for several end-to-end applications such as large emails, web browsing and file transfers. The perceived performance when running multiple applications at the same time is also greatly enhanced. This is possible due to a fast indirect feedback of the radio link data rate to the application server, allowing it to adjust its send rate to the actual data rate of the wireless link. Harmful effects like multiple IP packet losses and time-outs are avoided. AQM reports the radio link data rate to the TCP sender by discarding IP-packets in the BSC at well-defined times. Therefore this feature is generic and works with any TCP based application.

AQM maximizes the throughput of TCP-based applications, while also minimizing the amount of data buffered. The latter leads to quicker response and interaction during e.g. web browsing.

Figure 2 shows how AQM works. Packet drops before complete buffer fullness results in a fast retransmit by the TCP sender and a TCP window being halved.


Title

The improvement of the end-to-end performance will vary due to e.g. which application is used. For file transfers the throughput could be increased with up to 100% in cases when applications are used in interfered environments or when low coding schemes for GPRS or EDGE are used. The interactivity is improved for all cases but also here the improvements are largest for lower bitrates.

The normal BSSGP Flow Control function is made passive when AQM is active. This means that the rate of the data flow is not regulated from the SGSN, and all buffering is made in the BSC. There is no new support needed in SGSN due to AQM.

The BSC reports the amount of data discarded due to AQM per Packet Flow Context (PFC) and per MS to the SGSN.

4.39.4.1.1.11 Sub function GPRS/EGPRS Load Optimization

GPRS/EGPRS Load Optimization focuses the radio resources on MSs with high probability of correctly decoding the sent radio blocks to increase the effective throughput in the system. This leads to a significant improvement in user satisfaction in instances where high traffic load otherwise would degrade the service for all users.


Title

Figure 3 shows how two users in a cell with different radio quality are sharing the same radio resources (left figure). By putting user #1 into low scheduling mode (right figure), user #2 experiences a 100% increase in throughput. In this particular case the effective total throughput for this cell is increased from 25 kbps up to 40 kbps (a 60% increase). Once user #2 has finished with the packet transfer the user #1 will be scheduled as normal again. Checks are also done continuously to see whether the quality of user #1 has improved. In such case the two users are scheduled normally again.

A mobile is put into low scheduling mode when the radio link bitrate falls below a threshold that is configured by the operator per BSC. The radio link bitrate is calculated over a number of radio blocks to make sure that no temporary dips causes a user to be put into low scheduling mode.

If the feature FAJ 121 32 Quality of Service (QoS) and Scheduling is activated, GPRS/EGPRS Load Optimization only affects Interactive and Background users. An Interactive user in low scheduling mode still has absolute priority over a Background user in normal scheduling mode.


Title

4.40 Efficient Priority Handling



Technology: GSM

4.40.1 Attention


Not applicable

Dependencies





Not Applicable


Efficient Priority Handling and the feature FAJ 121 362 Call Queuing are complimentary features and they are both part of the enhanced Multi-Level Precedence and Preemption (eMLPP) function standardized for GSM systems in 3GPP.




Not Applicable


Title

4.40.2 Summary

This feature gives the operators the possibility to differentiate the grade of service based on subscriber priority. This is accomplished by allowing subscribers with higher priority to preempt subscribers with lower priority.

4.40.3 Benefits

Efficient Priority Handling provides the following benefits:

Offer increased grade of service to special user segments like for example: Public safety users like the police, fire brigade etc, VIP subscribers and other subscribers with premium subscriptions

Provide high priority to emergency calls

Traffic resources does not have to be reserved, and capacity is not wasted when priority subscribers are not present



Offering high priority subscribers a high grade of service can be accomplished without expensive over dimensioning of the radio network.


Attract new user segments like the police or fire brigade by offering increased grade of service.

Offer higher grade of service at a premium to high priority subscribers.

Attract new subscribers by providing increased security by giving high priority to emergency calls.

4.40.4 Description

Efficient Priority Handling provides increased accessibility for prioritized calls at call setup or handover when a cell is congested. This is accomplished by preempting other calls with lower priority.


Title

For each call, the BSC receives preemption related information from the MSC. The information tells if a connection is allowed to preempt other connections, if it can be preempted by other connections and its priority level.

When preemption is performed in a congested cell, a search is made for an ongoing call that can be preempted. When one is found a handover to another cell is initiated, and if the handover is successful the free traffic channel is given to the prioritized subscriber. If the handover fails, another search is made and a handover is initiated for that connection. If the second handover is also unsuccessful a new search is made but this time the found call is disconnected.

If so desired, the search for a connection that may be preempted can be limited to only include subscribers with a priority level lower than the subscriber initiating the preemption.

If a connection that can be preempted is not found, the call setup or handover procedure continues as usual according to the cell candidate list received from the locating function.

Preemption information is also sent by the MSC for all emergency calls. The handling of emergency calls is configured separately and is independent of each individual subscriber's priority level. Hence all subscribers can receive increased accessibility in emergency situations.

This feature can be activated separately or together with FAJ 121 362 Call Queuing and/or FAJ 122 923 Differential Channel Allocation offering enhanced possibilities of handling high priority subscribers and emergency calls.

Efficient Priority Handling and FAJ 121 362 Call Queuing are complimentary features and they are both part of the eMLPP (enhanced Multi-Level Precedence and Preemption) function standardized for GSM systems.

4.40.5 Enhancement

4.40.5.1.1 Enahcements in BSS 06A

The feature can take the subscriber priority level into account during the preemption procedure. It is possible to configure the feature so that a subscriber is only allowed to preempt other subscribers that have a lower priority level.

With the enhancement the feature handles all priority levels available in eMLPP and not just the priority differentiation possible with different pre-emption parameter settings. It is also easier to configure the desired preemption behavior.


Title

4.41 EGPRS



Technology: GSM

4.41.1 Attention


Not applicable

Dependencies

Hardware impacts and dependencies The feature requires EDGE dTRU, EDGE sTRU or RBS 2308. DXU-21 or IXU-21, or later is required for RBS2000



Terminal impacts and dependencies EDGE Capable terminals are required


4.41.2 Summary

Enhanced GPRS (EGPRS) is combining the GPRS functionality with the new standardized packet switched EDGE radio technology. EGPRS introduces a new high level modulation, called 8-PSK, as well as protocol enhancements for transmitting packets over the radio. The use of the new modulation and the protocol enhancements result in dramatically increased throughput and capacity gains enabling 3G services in existing GSM/GPRS networks.

4.41.3 Benefits

The feature has following benefits:


Title

The increased packet data throughput enables new 3G high-speed data services in existing GSM/GPRS networks.

EGPRS facilitates offering new applications which will generate revenue for the operator.

End-users will experience significantly increased data throughputs in comparison with using GPRS only.

EGPRS, a simple add on to existing GSM/GPRS networks, allows a short time to market with 3G services.

Capacity gains in the network allow operators to offer services to a larger subscriber base.

4.41.4 Description

The EGPRS feature introduces a new standardized modulation, standardized protocol enhancements as well as new functionality. The EGPRS modulation and coding schemes (MCS) are a mixture of GMSK and the new 8-PSK modulations (see table 1). Each of those MCSs with its different amounts of error correcting coding is aiming at a different radio environment. This allows a more precise adaptation to the actual radio environment. With reservation of up to eight timeslots per user together with the higher coding introduced, data rates in excess of 384 kbps (ITU definition of 3G) can be achieved.

9 new MCSs are introduced in EGPRS:


Title

Some of the EGPRS standardized enhancements are:

Re-segmentation and re-transmission of packets with another coding scheme. The EGPRS coding schemes are defined in three families A, B and C allowing packets to be re-transmitted with a coding scheme belonging to the same family. This means that re-segmentation can be done from e.g. MCS9 to MCS6 or from MCS6 to MCS3. The possibility of re-transmitting a packet that was not received correctly with a more robust MCS results in a dramatically increased overall throughput.

Fast and accurate link quality measurements available per radio allow more precise link adaptation. This is important in rapidly changing radio environments to guarantee the highest possible throughput.

Increased pool of packet addresses to minimize the risk of low throughput due to protocol stalling.

With EGPRS also the following functionality is introduced:

A Link Quality Control (LQC) mechanism which tries to achieve the highest possible throughput at a given radio environment by using the most appropriate MCS. It does this by combining Link Adaptation (LA) and Incremental Redundancy (IR) and due to the possibility of re-transmitting packets with another MCS (see above), LQC achieves extremely high throughputs. This combination of mechanisms significantly improves the performance compared to a pure LA solution. On the downlink full LQC support is provided (Incremental Redundancy and Link adaptation) while on the uplink only Link Adaptation is used.

Link Adaptation uses the radio link quality measured by the MS in downlink transfer to choose the most appropriate MCS to use for the next sequence of packets to be transmitted.

Incremental Redundancy uses another principle to optimize the throughput. Here very little coding is being used in the beginning without considering the actual radio link quality. When information is received incorrectly additional coding is being transmitted and then soft combined in the receiver with the previously received information. Soft combining increases the probability to decode the information. This procedure will be repeated until the information is successfully decoded. This means that no information about the radio link is necessary for incremental redundancy. For the mobile stations, incremental redundancy support is mandatory.


Title

EGPRS coding schemes enable data rates up to 59.2 kbps (MCS9) per time slot (TS). Corresponding to the increased data rates over the radio interface introduced by EGPRS, Abis transmission has to be increased to meet the high demands on the transmission side. The Channel allocation enhancements allow operators to define the amount of EGPRS capable TS by allocating the needed Abis transmission. This gives operators the flexibility of adding transmission and thereby enabling EGPRS TS when EGPRS traffic increases.

4.41.5 Enhancement


Based on live experience with EGPRS a more intelligent LQC algorithm is introduced. Block Error Rate (BLER) values are used in the enhanced LQC algorithm as a complement to the existing Bit Error Probability (BEP) values. The BLER value determines if the coding scheme proposed by algorithm based on BEP is the best or if it can be improved. This leads to an increased usage of the higher coding schemes (MCS7-9) even at lower C/I and therefore an improvement in throughput.

Throughput improvement of up to 60% is possible in certain radio environments for the mid-range C/Is (C/I 10dB to 20dB). This will significantly enhance the robustness of EGPRS and lead to an improved end-user experience for different applications.


Title

4.42 Enhanced AMR Coverage



Technology: GSM

4.42.1 Attention


Not applicable

Dependencies




Not Applicable


Not Applicable


Terminals with support for the 3GPP Rel-6 standardized function repeated SACCH is required.

4.42.2 Summary

Enhanced AMR Coverage increases the perceived coverage of FR AMR by up to 70%. It reduces the amount of dropped calls due to signaling failure in areas with poor coverage or high interference.


Title

4.42.3 Benefits

Reduced call drop rate

Up to 70% increased cell coverage for full rate AMR



Fewer sites can be used to cover a certain area.

Reduced call drop rate increases subscriber satisfaction and reduces churn.


Fewer dropped call leads to longer average call duration.

4.42.4 Description

Enhanced AMR Coverage increases the robustness of the SACCH signaling channel in order to avoid dropped calls in areas with poor coverage or high interference.

The feature provides the repeated SACCH function standardized for 3GPP Rel-6. Repeated SACCH means that the same message is sent twice over the SACCH. Significantly improved receiver performance in the terminal and the BTS is achieved by combining the two identical messages. This new transmission method for SACCH is valid for both up and downlink.

The enhanced robustness of SACCH signaling is especially valuable when using full rate AMR, since it matches the traffic channel robustness. A reduction in the drop call rate is expected for all speech codecs, however is should be greater for FR AMR

Simulations made during the standardization process indicate a SACCH robustness improvement in the range of ~5 dB. For calls using full rate AMR this corresponds to a cell coverage increase of up to 70%. Similar gains are expected in interference handling.

The repeat function is automatically activated when too many messages have been lost on SACCH. The up and downlink works independently of each other.


Title

4.43 Enhanced Full Rate (EFR)



Technology: GSM

4.43.1 Attention


Not applicable

Dependencies


Not Applicable


Not Applicable


Not Applicable


Terminals support is required.

4.43.2 Summary

Enhanced Full Rate (EFR) is a new speech codec that gives enhanced speech quality within the same bandwidth as is used for Full Rate traffic channels. The speech quality with EFR under good radio conditions is comparable to or better than ADPCM quality.

EFR is implemented in accordance with the ETSI GSM Phase 2+ standards.


Title

4.43.3 Benefits

EFR enables a speech quality in the GSM system that is comparable to or better than ADPCM speech quality.

The enhanced speech quality can be used as a service differentiator against other cellular operators networks.

The EFR speech quality enables GSM system operators to address new user segments and to compete with fixed wireline services. For example the private or the business market (wireless offices) can be targeted with the speech quality offered by EFR.

The EFR codec is more robust to background noise. To a certain extent, it performs better under poor radio conditions than the Full Rate codec. Also, it is less sensitive to bit errors on A-bis transmission links.

4.43.4 Description

The Enhanced Full Rate feature is based on a new speech codec and changes to the signaling protocols. These are implemented in accordance with the ETSI GSM phase 2+ standard. The EFR speech codec does not change the channel coding. It uses the same channel coding as for the full rate channel, but technological advances have improved speech encoding so that it gives better speech quality than the full rate codec.

The speech quality with EFR under good radio conditions is comparable to or better than ADPCM (32 kbit/s) quality. The speech quality enhancements provided by EFR will make it possible to offer new services like wireless office systems. EFR can also provide a competitive edge towards other operators.

The speech quality offered with EFR is as good as or better than the speech quality offered though the enhanced speech coder for the CDMA (IS-95) system. This allows operators to position their GSM system against the CDMA (IS-95) standard.

In the BSC, the transcoder pool architecture is mandatory for the introduction of EFR. The transcoder resource supporting the relevant speech codec, for example EFR will be selected on a per call basis depending on the MS capabilities. TRA R4 or later is required for support of EFR.

EFR is supported on both RBS 2000 and RBS 200.

EFR support is also required in the mobile stations.


Title


Title

4.44 Enhanced Handover Success Rate



Technology: GSM

4.44.1 Attention


Not applicable

Dependencies




Not Applicable


Not Applicable


The feature works with all terminals, however terminals with support for the 3GPP Rel-6 standardized function repeated FACCH have better performance.

4.44.2 Summary

Enhanced Handover Success Rate increases the number of successful handovers. This is accomplished by enhancing the handover procedure with the 3GPP standardized repeated FACCH function and automatic reestablishment on the original channel in case of failure.


Title

4.44.3 Benefits

Increased number of successful handovers due to a more robust signaling channel.

Reduced number of calls lost during handover due to automatic reestablishment on the original channel.



Reduced drop call rate increases subscriber satisfaction and reduces churn.


Fewer dropped call leads to longer average call duration.

4.44.4 Description

The feature Enhanced Handover Success Rate improves the handover procedure to reduce the risk of a lost call. Simulations for repeated FACCH presented in 3GPP during standardization indicates that an improvement in FACCH robustness of up to 2 dB is possible for non-adapted terminals, and up to 4 dB for terminals adapted to the repeated FACCH functionality.

The feature incorporates the repeated FACCH function standardized for 3GPP Rel-6. Repeated FACCH means that messages sent on FACCH like handover command is sent twice every time with a short time in between, instead of only once. This increases the chance of the terminal to hear and decode the information. New terminals adapted to this way of sending can combine the two transmissions to get even better performance.

During a handover the handover command sent up to thirty-four times at even intervals (much longer than the repeated FACCH repetitions) until the terminal shows up on the target channel. When using repeated FACCH each of these handover commands is sent twice, totaling sixty-eight instances of the message sent in all. In the Ericsson implementation the first five instances of handover command is sent in normal single message fashion. If the terminal still has not showed up on the target channel, the remaining twenty-nine handover commands are send using repeated FACCH.


Title

One reason for choosing this kind of implementation is to minimize the impact on speech quality. This is due to that the repeated message in repeated FACCH is sent using a burst that was intended to send speech information. This means that if repeated FACCH is always used there could some impact on speech quality. The other reason is to keep the handling of the feature as easy as possible, with only an on/off switch needed.

Data collected from live networks points to that 90-95% of all terminals hear one of the five first instances of the handover command. This means that for them there is no impact from repeated FACCH while the ones located in more difficult areas will automatically enjoy the benefits of a more robust signaling channel.

In case a terminal despite the improved message transmission still does not show up on the new channel, the system will automatically try to reestablish the call on the original channel. Data from networks indicate that in high capacity areas where there are high levels of interference, many handovers fail because the terminal never hears the handover command and can often be found on the old channel. In this way many terminals can be given a second chance at performing another handover which hopefully is more successful.

Trial results showed that around 30% of calls that would previously have been considered lost during handover were possible to reestablish on the original channel.

The improved handover procedure applies to all handovers, i.e. both intra-cell and inter-cell handovers.

4.44.5 Enhancement

4.44.5.1.1 Enhancements in 07B

All downlink messages on the FACCH are repeated. This is a standardized extension to the repeated FACCH function. It further reduces the chance of dropping a call due to high interference or poor coverage.


Title

4.45 Enhanced Measurement Reporting



Technology: GSM

4.45.1 Attention


Not applicable

Dependencies


RBS6000 and RBS2000 based on the dTRU, sTRU and similar HW platforms like for example RBS 2308/2309 provides full EMR support.

RBS2000 based on classic TRU and RBS 2301/2302/2401 have partial support for EMR. RXQUAL is reported instead of BEP for the uplink radio quality.

All RBS versions with support for EMR can forward EMR reports sent by EMR supporting terminals.


Not Applicable


Not Applicable


Support of EMR in the downlink requires MSs capable of EMR.


Title

4.45.2 Summary

Enhanced Measurement Reporting (EMR) standardized for GSM is supported. This enables enhanced supervision of speech quality and improved performance for algorithms such as dynamic power control that uses radio link quality as input.

4.45.3 Benefits

Enables enhanced speech quality monitoring.

Longer call times, caused by better speech quality which is a result of better monitoring capability.

Enhanced radio network capacity and quality due to improved performance of algorithms like power control, locating, intracell handover etc. that uses radio link quality information.

4.45.4 Description

The feature enables support for Enhanced Measurement Reporting (EMR), which makes it possible to both enhance supervision of speech quality using the feature FAJ 122 583 Speech Quality Supervision and improve the performance of radio network algorithms that uses radio link quality information such as dynamic power control.

EMR is a new measurement report containing additional data, of which BEP (Bit Error Probability) and the number of correctly received speech frames are the two most important ones.

Similar to RXQUAL, BEP is a measure for bit error rate, however BEP provides much better granularity (using 5 bits instead of 3), especially at poor radio conditions. This means that BEP has the potential to improve the performance of algorithms that relies on radio link quality information. To reap maximum benefit from BEP, all algorithms that previously used RXQUAL as a quality measure for the radio link, such as the power control and locating algorithms, are instead using BEP whenever it is available. Power control requires the features FAJ 122 910 Dynamic BTS Power Control for the downlink, and FAJ 122 260 Dynamic MS Power Control for the uplink.

The number of correctly received speech frames makes it possible to calculate the Frame Erasure Rate (FER), which is a much better measurement of speech quality than RXQUAL. This is because FER is a measurement of the speech codec performance while RXQUAL is a measurement of the radio link quality. Speech quality monitoring is provided by the feature FAJ 122 583 Speech Quality Supervision.


Title

The enhanced measurement reports are available for both the uplink and the downlink. For support of EMR in the downlink MSs capable of EMR are needed. For the uplink, RBSs based on the dTRU, sTRU and equivalent HW platform like for example RBS 2308/2309 is required for full support of EMR. RBS 2000 BTSs based on older transceivers, i.e. classic TRU and RBS 2301/2302/2401 supports EMR except the BEP measurement, only RXQUAL is reported instead. EMR on the uplink is reported for all MSs, even those that do not support EMR.

EMR is not supported at all on RBS 200.

Data available in the existing measurement reports, such as RXQUAL, RXLEV etc. are still be available for use in algorithms, statistics etc. that require them.

The enhanced measurement reports are available and visible in MTR (FAJ 122 299 Mobile Traffic Recording).


Title

4.46 Extended GSM Frequency Band support



Technology: GSM

4.46.1 Attention


Not applicable

Dependencies


4.46.2 Summary

This feature will allow the operator to expand the number of frequencies thus enabling higher radio network capacity in GSM 900 or better coverage for GSM 1800 operators.

4.46.3 Benefits

Higher radio network capacity for GSM 900 operators.

Better coverage and reduced investment for GSM 1800 operators

4.46.4 Description

The GSM specifications have specified an extension of the current GSM band. The Extended GSM band consists of the P-GSM and G1-GSM band.

The Primary (P) band consists of frequencies in the range of 890-915 MHz on the uplink and 935-960 MHz on the downlink which corresponds to the 'normal' GSM band.


Title

The G1 band consists of frequencies in the range of 880-890 MHz on the uplink and 925-935 MHz on the downlink which corresponds to the extension of the 'normal' GSM band.

An operator being granted frequencies in the G1 band will be able to use the new frequencies, depending if the operator is operating in GSM 900 or GSM 1800, in the same operating way. Naturally, careful planning must be done on how the new frequencies are best used in the current radio network.

It will be possible to mix P and G1 frequencies in the same cell and also define the BCCH on either a P or G1 frequency. However to avoid mistakes it will not be allowed to mix. P and G1 frequencies in channel group 0 (BCCH), since this will impact service for P band only mobiles, if the BCCH is defined on a P band frequency.

The BSC will allocate mobiles according to the mobile capabilities specified in Classmark Information. The BSC will prioritize G1 band channels higher than P band channels in a cell in order to allocate channels to mobiles in the most efficient way. Example, for a mobile that can handle both P and G1 band the BSC will give G1 band channels higher priority resulting in the mobile being allocated a channel on the G1 band. When Classmark Information is not known in the BSC, the BSC will allocate mobiles according to which band the BCCH frequency is specified on.

The best way to use G1 band for a GSM 900 operator it is to either define new cells with only G1 frequencies or to define a channel group in existing cells with only G1 frequencies. This is due to the large number of P band only mobiles.

The best way to use G1 band for a GSM 1800 operator it is to define new cells with only G1 frequencies.


Title

4.47 Extended Range Cell 121 km



Technology: GSM

4.47.1 Attention


Not applicable

Dependencies




Not Applicable


Not Applicable


Not Applicable

4.47.2 Summary

The purpose of the feature Extended Range Cell 121 km is to provide the possibility to carry traffic at a larger distance from the base station than the normal GSM range. It enables the operator to increase the maximum cell radius from 35 km to approximately 121 km.


Title

In sparsely populated areas such as deserts, coastal areas, maritime environments, etc. large cells can be valuable. Areas otherwise not economical to cover, like remote installations at sea or on land, are suitable for extended range coverage. The transmission loss over sea is normally less than over land, which makes use of larger cells natural for sea coverage.

4.47.3 Benefits

With this feature operators can increase their coverage area more cost efficiently. For example, instead of having three sites, each with two cells (that cover a radius of 35 km each) to provide coverage along a highway, the operator can achieve the same coverage by using one site with two extended range cells of 121 km. In this way the operator can significantly reduce his costs.

When implemented in existing cells, this feature will allow the coverage gaps in the existing network (gaps due to the 35 km range limitation) to be filled without adding new cells or sites.

This feature allows the operator to extend offshore coverage at sea, thus providing new business opportunities.

The benefit for the end-user is better coverage, particularly over water.

4.47.4 Description

The normal GSM range is restricted by a maximum delay for the signals between the MS and the BTS. The MS regularly receives information from the BTS enabling it to send successive bursts so that they will reach the BTS at the assigned time slot. This information is called Timing Advance (TA). The further away the mobile is from the base station, the larger the TA value is.

Extended range is obtained by allowing the BTS to receive the bursts later than during the time slot assigned to the MS. The time slot next to the one assigned to the MS is also used, that is two consecutive time slots are required for each channel in an extended cell. By using two timeslots for each channel the cell range can be increased from 35 km up to a maximum of 121 km.

In order to increase the traffic capacity in an extended range cell a TRX may be configured with a combined BCCH/SDCCH using the feature Combined Control Channels. In that case three traffic channels can be available on one TRX, instead of only two. If a second TRX is available, four additional traffic channels can be used.


Title

Another way to increase the capacity in an extended range cell is to combine it with Dynamic Overlaid/Underlaid Subcells. By using an overlaid/underlaid subcell structure the capacity capability of a normal cell is combined with the coverage capability of an extended range cell. It will be possible to cover medium and/or high capacity areas together with remote areas using one cell, thus decreasing TRX cost in the BTS. In this configuration the underlaid subcell is an extended range subcell with a coverage potential of up to 121 km and the overlaid subcell is a normal cell with a coverage area of up to 35 km.

Single slot packet data calls are supported in extended range cells. HSCSD calls using multiple timeslots in transparent mode will be disconnected when entering an extended range cell, while a HSCSD call in non-transparent mode will be downgraded to one timeslot.

Extended range cells up to 121 km is supported for RBS 2000 equipped with EDGE sTRU or any dTRU.

4.47.5 Enhancement

4.47.5.1.1 Enhancement in BSS R10

Extended range cells using RBS 200 with SPP boards is no longer supported.


Title

4.48 Fast Return to WCDMA after Call Release



Technology: GSM

4.48.1 Attention


Not applicable

Dependencies


GSM RAN SW: FAJ12157 - GSM - UMTS Cell Reselection and Handover


GSM RAN SW: FAJ12157 - GSM - UMTS Cell Reselection and Handover

WCDMA RAN: FAJ121154 - GSM Handover and Cell Re-selection

4.48.2 Summary

For voice calls that are established in WCDMA and terminates in GSM, this feature reduces the time that the subscribers are unreachable for incoming and outgoing calls after the calls are released.

This is made possible by supplying information about the WCDMA network to the MS at call release in GSM. The MS can then connect directly to the WCDMA network without performing LA/RA updates in GSM.


Title

4.48.3 Benefits

Fast Return to WCDMA after Call Release provides the following benefits:

Reduced time that a WCDMA user is unreachable after a call has been terminated in GSM

Reduced signaling load in the network due to fewer Location Area updates



The network capacity needed for signaling is reduced since there are fewer Location Area updates from users that establish their calls in WCDMA and end them in GSM.

Increased Revenue

The feature increases talk time since users can be reached by incoming calls or place calls, sooner after a call has ended.

4.48.4 Description

Fast Return to WCDMA after Call Release significantly reduces the time until a multi mode terminal is reachable in WCDMA after call release in GSM.

In areas with both GSM and WCDMA coverage, networks are typically configured to have multi-RAT terminals camping on WCDMA. For operators that want to push voice calls to GSM in these places, for example to save WCDMA capacity for mobile broadband connections, this feature is very beneficial.

When Fast Return to WCDMA after Call Release is active, the GSM network sends a list of WCDMA cells or FDD ARFCN's to the MS at call release in GSM. Using this list the MS selects a WCDMA cell that it connects directly to after the call is released. The LA and RA update procedures in GSM are thereby avoided. The list is included in the Information Element "Cell selection indicator after release of all TCH and SDCCH", which has been added to the 3GPP standards for this purpose.

If the feature is not used, an LA update takes place in GSM after the call release. The MS then starts the cell reselection procedure, selects a WCDMA cell and then performs one more LA update in WCDMA. During the two location update and the cell reselection procedures, the MS cannot respond to or initiate calls and packet transfers might be interrupted.


Title

A terminal that supports the new information element, benefits from the new functionality. A terminal that doesn't support receiving the "Cell selection indicator" information element simply ignores it.


Title

4.49 Find Faulty Antenna Data



Technology: GSM

4.49.1 Attention


Not applicable

Dependencies


GSM RAN SW: FAJ12150 - Real Time Event Data

Hardware impacts and dependencies The feature works for sTRUs, dTRUs and all future TRU types.

Internal product impacts and dependencies FAJ 121 50 Real Time Event Data is required.

Other node impacts and dependencies The presentation, ordering of measurements and analysis of data is made in OSS-RC (FAJ 121 1020 Find Faulty Antenna Expert).FAJ 121 46 GSM Real Time Performance Monitoring is a prerequisite in OSS-RC.



Title

4.49.2 Summary

With this feature, it is possible to gather data on the performance of the antenna system at every cell/sector. The data is collected from the antenna receive branches and structured for further processing in OSS-RC, thereby enabling the system to identify poor performing antenna installations as well as provide an indication of the type of fault.

4.49.3 Benefits

The feature will indicate malfunction caused by a number of common faults known from commercial networks, including broken feeders/connectors, corrosion over time, swapped feeder cables, misaligned receive antennas (including electrical tilt)

Categorization fault type is possible, supporting corrective measures by the operator

Data is collected with an absolute minimum of effort as well as very quickly for an entire network.



The value of the feature is that an easy detection of poor performing antenna installations is possible, which enables the operator to take corrective action and improve coverage and revenues in the existing network and with the existing customer base.

Many of these faulty antenna systems today go unnoticed for long periods of time, causing lower traffic and revenues for the operator.

The feature enables an entire network to be measured in less than an hour, which would be virtually impossible to do with manual measurements or site visits even with months at the operator’s disposal.

The impact of an improvement in the receive diversity, which is what the corrective actions described above enables, is well-known. Significant traffic will be recovered, both in coverage-limited and interference-limited cells.

For affected cells it also means that the end-user will experience an improved service level in general, which will have a positive impact on the overall impression of the network and very likely also the churn levels of the operator.


Title

A simplified operator business case based on increase in traffic revenues:

Assuming that 10% of cells in a network have some kind of fault in their antenna installations. (Field indications/ measurements/trials set the range between 5 and 30% of sectors/cells being faulty.)

A standard value of the negative impact of the fault is around 3 dB (half the receive power is lost).

By detecting the situation (and correcting the faults), the service areas are extended and the traffic increases, resulting in around 1% additional revenues (using Okumura-Hata propagation models for typical rural situations in conjunction with well-established Ericsson propagation models for urban indoor coverage from outside cells).

The costs associated with correcting antennas are much lower (<10%) than the accumulated revenue increase during first year. It should also be noted that these costs only appear when there is a known increase in revenues for a specific cell.

The first year business case, with assumptions above, is therefore indicated to be a 1% increase in revenues and just below 1% in added profit for the operator.

4.49.4 Description

The overall purpose of the feature is to identify degraded or faulty antenna installations.

The method used is by detecting a significant difference in the received signal strength on different RX paths belonging to the same TRX. The received signal strengths from both receive branches of the cell/sector are logged per measurement report to evaluate the antenna system.

The result information is communicated from BTS to BSC in the MEASUREMENT RESULT message, using real-time data collection (based on FAJ 121 50 Real Time Event Data in BSS and FAJ 121 46 GSM Real Time Performance Monitoring in OSS-RC).

Based upon this information an event-based application in OSS-RC is able to process and present necessary information. The fault indication is based upon the input data on standard deviation and average RXLEV difference values.

This evaluation is able to pinpoint the following faults:

1. Swapped feeders

2. Losses in RF path (of various kinds)


Title

3. Antenna diagram mismatch (of various kinds)

The maximum fault resolution is the TRX level, which has the benefit that faults that affect the entire cell while originating from a single TRX can be pinpointed.

4.49.4.1.1 Network Impact

4.49.4.1.1.1 BSC HW Impact

None

4.49.4.1.1.2 BTS HW Impact

The feature works for S-TRUs, D-TRUs and all future TRU types.

4.49.4.1.1.3 Dependencies to other BSS features

FAJ 121 50 Real Time Event Data is a prerequisite in BSS.

4.49.4.1.1.4 Dependencies to other network elements

The presentation, ordering of measurements and analysis of data is made in OSS-RC 4 (FAJ 121 1020 Find Faulty Antenna Expert).

FAJ 121 46 GSM Real Time Performance Monitoring is a prerequisite in OSS-RC.

4.49.4.1.1.5 Terminals

None


Title

4.50 Find Faulty Transmit Antenna Data



Technology: GSM

4.50.1 Attention


Not applicable

Dependencies


GSM RAN SW: FAJ12150 - Real Time Event Data

Hardware impacts and dependencies The FFTAD feature is supported for the PPC platform thereby supporting dTRU, DRU and RRU BTSs, as well as all later RBS 2000 TRU types.

Combiners involved when FFTAD is used must support synthesizer frequency hopping.

The feature is currently not supported on RBS 6000 (R)RUS.

Internal product impacts and dependencies The feature FAJ 121 50 Real Time Event Data is required.

NWI-E (previously referred to as the LAN switch) is required due to the dependency to the feature FAJ 12150 Real Time Event Data.

This feature Find Faulty Antenna Transmit Data handles measurements on the downlink and therefore complements the feature FAJ 122 617 Find Faulty Antenna Data (FFAD), which measures the performance of the uplink and also supports sTRUs.


Title

Other node impacts and dependencies The features requires the OSS-RC features FAJ 121 46 GSM R-PMO and FAJ 121 1288 Find Faulty Antenna Expert - Both Links Recording to be practically useful. It is only possible to start the data collection from R-PMO in OSS-RC, which means that the OSS-RC feature FAJ 121 46 GSM Real time Performance Monitoring (R-PMO) is required.


4.50.2 Summary

Find Faulty Transmit Antenna Data (FFTAD) enables measurement and data collections from all transmit paths on a BTS site.

The data collected during a recording period will facilitate the detection of poorly performing antennas, feeders, TRUs, as well as other performance degrading situations in the entire transmit (TX) paths of the BTS (including obstacles in the path between the antenna and the terminal.)

The operator will get a much improved ability to resolve any issues related to the TX paths in the BTS, leading to improvements in general performance, coverage and network characteristics.

4.50.3 Benefits

Network performance degrading errors and faults related to the transmit path of the BTSs can be detected and rectified.

Network coverage and vital Key Performance Indicators can be improved


4.50.3.1.1.1 Revenues

A degradation in the transmit performance can directly be shown to reduce the ability to carry traffic and will therefore lead to loss of revenues. The FFTAD feature will enable an efficient way to rectify these problems.


Title


Detecting transmit path (downlink) performance degradation has up to now required a tremendous effort in terms of skills and equipment. With the feature, the detection of poor performing BTSs as well as indication of the location of the fault within the BTS is made very simple. It is possible to direct repair and optimization teams to exactly the right BTSs as well as pinpointing the location of the problem within these BTSs. This will enable the operator save money by being more cost efficient.

4.50.3.1.1.3 CAPEX

By detecting and correcting transmit path related coverage problems (e.g. a coverage hole due to a misaligned TX antenna), unnecessary site additions can be avoided.

4.50.4 Description

The feature enables a recording to be done in the BTS where each TX path is measured and data is collected.

The feature will try all possible transmit paths in the BTS, using the actual ongoing calls. The feature will switch between TX paths in a transceiver hopping manner, tunable on a timeslot basis. This allows the BTS to control the content of the downlink measurement reports from the terminal on the uplink. The feature is continuously comparing the measurement results from a terminal on different paths that are immediately following each other with a very short time difference. By analyzing the reports it is possible to detect whether there are any significant inconsistencies between different transmit paths, including the detection of poorly performing TRXs.

During the recording period, features like Antenna Hopping and BTS Power Savings, if in use at the time of measurement, are temporarily disabled in order not to disturb and distort the data.


Title

4.51 Flexible Abis



Technology: GSM

4.51.1 Attention


Not applicable

Dependencies





4.51.2 Summary

The feature makes the roll out of EGPRS more cost effective as it reduces the extra transmission and PCU resources required. The savings are achieved by pooling Abis resources per RBS site, and by identifying GPRS and EGPRS capable mobiles and allocating the most suitable resources for those. This makes network wide roll out of EGPRS support economically more attractive.

4.51.3 Benefits

For operators introducing EGPRS, the feature will give:

A transmission saving on the links between the BSC and RBSs supporting EGPRS.

A more efficient PCU resource usage.


Title

A more cost efficient roll out of EGPRS support.

4.51.4 Description

4.51.4.1.1.1 General

Flexible Abis provides dynamic dimensioning of Packet Data Channels (PDCHs) based on traffic requirement and available resources. Abis paths will not be configured to be permanently connected to a TCH, but will be pooled resources. These pooled resources will be used when creating on-demand and semi-dedicated PDCHs. Dedicated PDCHs will still have dedicated Abis paths and PCU resources.

Without Flexible Abis, traffic channels (TCHs) configured to support EGPRS will have dedicated 64 kbps paths configured on Abis. These paths are used also when the TCH is used for voice traffic or GPRS CS 1-2. Furthermore, PCU resources to be able to handle EGPRS are allocated from the PCU pool, even when only GPRS MSs are active on that TCH.

With Flexible Abis, mobiles supporting GPRS and EGPRS are identified so that as little resources as possible are used from the Abis pools and the PCU pool when PDCHs are created.

4.51.4.1.1.2 Creation of a Packet Data Channel

To set up a packet flow one or more PDCHs are used. Three resources are used to create a PDCH; a TCH, an Abis path and PCU resources (GSL devices).

Time slots on the air interface (on the TRXs) are configured as TCHs supporting either GPRS CS 1-2 (B-TCH), GPRS CS 1-4 (G-TCH), or GPRS CS 1-4 and EGPRS (E-TCH).

On the Abis interface, an EGPRS capable PDCH (E-PDCH) or a GPRS CS 1-4 capable PDCH (G-PDCH) require a 64 kbps path, whereas other channel types require 16 kbps paths. In the same manner, an E-PDCH and a G-PDCH require 4 GSL sub-devices, whereas only one sub-device is required for a GPRS CS1-2 PDCH (B-PDCH).

For example, to be able to create a PDCH for EGPRS, an EGPRS capable traffic channel (E-TCH), a 64 kbps Abis path and 4 GSL sub-devices must be available.


Title

Figure 1. Minimum resources used to create Packet Data Channels

4.51.4.1.1.3 Pooling principles

With Flexible Abis, the Abis paths are allocated at PDCH allocation/ activation rather than at configuration. The paths are organized in a pool, with 16 kbps paths and 64 kbps paths, and a path is picked based on what type of PDCH is created.

When a traffic channel is to be used it is decided what type of PDCH is preferred. If EGPRS is requested (the channel is requested for an EGPRS capable MS), an E-PDCH is preferred. If on the other hand a channel is required for an MS supporting only GPRS, a B-PDCH should be created, regardless of if an E-TCH is used. For voice calls 16 kbps paths are preferred.

If the best suited resources are not available, the connection is set up with the resources available. A voice call or a GPRS MS for instance, will therefore use a 64 kbps Abis path if that is the only Abis path available.

Flexible Abis can be configured to support EGPRS and GPRS CS1-2, or EGPRS and GPRS CS1-4. When the system is configured to support GPRS CS1-2, but not CS3-4, E-PDCHs are the preferred choice only for EGPRS capable MSs. If the system is configured to support GPRS CS1-4, E-PDCHs are preferred for all GPRS and EGPRS traffic. The savings both on Abis and in the PCU pool will be less in the latter case.


Title

4.51.4.1.1.4 Improved resource utilization

Transmission savings are achieved by having fewer 64 kbps Abis paths allocated to the Transceiver Group (TG) than it has E-TCHs configured. Thereby time slots configured as E-TCH will not have 64 kbps paths allocated all the time, and can not all be used for E-PDCHs at the same time. The pooling of Abis resources per TG means that for a three sector site three cells use the same Abis pool. The total number of Abis paths, dedicated and in the pool, should be equal to the number of traffic channels in the TG.

The separation of GPRS and EGPRS capable MSs, and the preferred usage of B-PDCHs for GPRS, gives a more efficient PCU usage. As long as there are resources available to create B-PDCHs those will be used for GPRS traffic. Even if an E-TCH is used, a B-PDCH is created and only one GSL sub-device has to be used.

The gain with the feature depends completely on the channel allocation strategy for EGPRS followed by the operator. On-demand or semi-dedicated PDCHs must be used to get savings.

4.51.4.1.1.5 Upgrading and Downgrading

Up-grading and down-grading between B-PDCH and E-PDCH is introduced in order to make the pool more dynamic. When the TCH used for an E-PDCH becomes idle, or no EGPRS packet flows are active on the channel any longer, the 64 kbps Abis path can be returned to the pool. In case there are active GPRS flows on the channel when the EGPRS flow stops, these flows are halted and the E-PDCH is re-configured to a B-PDCH before the flows are started again. The 64 kbps Abis path and 3 GSL sub-devices are thus returned to the pool and made available to be used for other channels. The interruptions in the packet flow will not be noticeable to an end-user.

In a similar manner the active GPRS flows on a B-PDCH can be halted, and a re-configuration from a B-PDCH to an E-PDCH made. In this way an EGPRS MS with an ongoing EGPRS packet flow can get more E-PDCHs (timeslots) when Abis paths become available.

It is recommended that one dedicated E-PDCH is configured per cell. That will make it possible to start an EGPRS packet flow on at least one TCH, and upgrade to the number of slots the MS is capable of when Abis resources become available.

Example :


Title

A network shall support 4-slot EGPRS MSs. The penetration of EGPRS MSs is low. A three sector site has to have 4 TSs in each cell configured to support EGPRS (E-TCHs). Because of the low EGPRS MS penetration EGPRS is rarely requested from two of the cells within the site at the same time. One dedicated E-PDCH is configured per cell to avoid the risk that an EGPRS MS only gets GPRS. Flexible Abis is configured to support EGPRS and GPRS CS1-2.

Without Flexible Abis each E-TCH will have a 64 kbps Abis path configured, for dedicated and on-demand channels, giving a total of twelve 64 kbps paths. 4 GSL sub-devices are allocated to each dedicated E-PDCH and 4 GSL sub-devices is allocated on demand when an E-TCH is used for an on-demand PDCH.

With Flexible Abis a 64 kbps path has to be configured for each dedicated E-PDCH, one per cell. In addition to that, 3 on-demand E-PDCHs must be possible to set up in each cell in order to support 4-slot MSs, but these Abis paths can be shared within the TG. Thus the pool is configured with three 64 kbps paths. The pool is configured with six 16 kbps paths, so that the total number of Abis paths is 12 (equal to the number of E-TCHs configured in the TG).

The required transmission for these 12 E-TCHs has decreased from 12 times 64 kbps to 7.5 times 64 kbps. The limitation introduced in the network is that only 6 E-PDCHs can be used at any given time in these three cells together.

Abis transmission required without Flexible Abis: 12*64 kbps.

Abis transmission required with Flexible Abis: 6*64 + 6*16 kbps = 7.5*64 kbps.

The decrease in number of GSL devices used depends on the amount of GPRS traffic and the total traffic load in the cells. The 3 dedicated E-PDCHs will have dedicated 4 GSL sub-devices each. The six 16 kbps paths are preferred when creating on-demand PDCHs for GPRS MSs. Up to 6 times 3 GSL sub-devices can be saved for this TG.

4.51.5 Enhancement

4.51.5.1.1 Enhancement BSS R12

A number of enhancements are introduced in order to improve the performance of Flexible Abis. For example, the dynamic behavior is enhanced by improved downgrading and pre-emption, the resource utilization is improved by packing of paths on the link and on GSL devices and throughput is improved by using TBF mode change and allowing CS-3 and CS-4 on not dedicated channels when GPRS on 16 kbps Abis is configured.


Title

Some of the included enhancements are:

Packing of 16 kbps Abis paths

Improved allocation of GSL devices

Support of CS-3 and CS-4 when FLEX64KGPRS set to 16 kbps

Improved downgrading of Abis paths

PDCH pre-emption at Abis congestion

Consider upgrade from B- to E-PDCH in TBF-upgrade/re-reservation

Allocation of 16 kbps Abis paths will create some fragmentation limiting the number of available 64 kbps Abis paths. To counteract this, a packing mechanism is introduced. Packing of a 16 kbps Abis path used for circuit switched traffic is performed with intra-cell handover, i.e. another TCH in the cell is connected to the new Abis path and the mobile is directed to that TCH by an assignment message. Packing is started when the number of idle, non-split 64 kbps Abis paths in the pool goes below a threshold (set per TG). Packing shall be stopped when the number of idle 64 kbps Abis path exceeds the threshold.

The GSL devices of each RPP in the PCU are of two types, 16 kbps or 64 kbps. A 16k device is created as one fourth of a 64k device. If a 64k device is partly used as a 16k device the remaining part of that 64k device is unavailable for 64k traffic. This means that the number of available 64k devices can become zero, even without any traffic using 64k devices, by the fragmentation of the 64k devices. To make more 64k devices available the busy 16k devices should be packed into as few 64 k devices as possible. The packing shall be started when the number of available 64k devices falls below a predefined threshold (set per BSC). Packing shall be stopped when the number of idle 64 kbps GSL devices exceeds the threshold.

By introducing downgrading from CS1-4 TBFs to CS1-2 TBFs, CS3-4 is supported also on-demand and semidedicated E-PDCHs even if the system is configured to support GPRS on B-PDCHs (with 16 kbps Abis paths).

Improved downgrading of Abis paths from E-PDCH to B-PDCH allows the E-PDCH to be released before the resource for the B-PDCH is allocated. This allows for downgrading also when there are no idle resources when downgrade is to be performed.

PDCH pre-emption is used when there are TCHs available in the cell but no 16 kbps Abis paths in the pool to set up a circuit switched call. The pre-emption in BSS R11 is limited to the cell where the 16 kbps Abis path is needed. The pre-emption is extended to all cells supported by the same Abis pool, i.e. by the same TG.


Title

In order to take advantage of the possibility to change TBF mode (FAJ 121828, BSS R12 GPRS/EGPRS Improvements) an upgrade of a B-PDCH to an E-PDCH is considered as a trigger for the TBF reservation evaluation. The evaluation includes a possible change of TBF mode for any TBF.


Title

4.52 Flexible MAIO Management



Technology: GSM

4.52.1 Attention


Not applicable

Dependencies


Not Applicable


Not Applicable


Not Applicable


Not Applicable


Title

4.52.2 Summary

Mobile Allocation Index Offset (MAIO) Management enables usage of Fractional Load Planning (FLP) 1/1. The FLP 1/1 means that all cells in the radio network hop over all available TCH frequencies except for the ones reserved for the BCCH's or other purposes, e.g. indoor cells. Interference between the different traffic channels (TCH) will only occur randomly when two TCH's hops at the same frequency at the same time. The highest interference level normally occur when the same frequency is used simultaneously in cells belonging to the same site or when two adjacent channels are used at the same time in the same cell. Flexible MAIO Management prevents this with the result that the overall interference level in the network is minimized.

4.52.3 Benefits

Flexible MAIO Management enables a highly effective spectrum usage with the FLP reuse pattern 1/1, especially for narrow spectrum allocations. The FLP 1/3 will get a more effective implementation with Flexible MAIO Management. FLP requires a minimum of frequency planning with the result that the costs for cell planning and frequency optimization are decreased.

4.52.4 Description

Flexible MAIO Management gives the operator the opportunity to use the 1/1 reuse pattern. 1/1 is one of the patterns used in Fractional Load Planning, 1/3 is an example of other FLP reuse pattern. 1/1 is when all cells are using the same frequencies and 1/3 is when the frequencies are divided in 3 groups. Each group is reused in every third cell, if the sites have three sectors (cells) this means that all three groups are reused in every site. Common for the two methods are that the frequencies that are used in the FLP are using synthesized frequency hopping. The frequencies that are to be used for the BCCH's needs to be separated from the hopping frequencies and have to be planned according to traditional methods, as an example 4/12 reuse. The BCCH frequencies can not use frequency hopping when using 1/1 and 1/3, unless BCCH zerofilling is used...

Flexible MAIO Management gives the operator a tool to prevent Co-channel interference between cells in the same site at 1/1 reuse. The operator can also prevent adjacent channel interference within the same cell for 1/1 and 1/3 reuse.


Title

The operator can set MAIO values manually between 0 and the number of frequencies to hop over minus 1. The MAIO can be set individually for each TRX within a site. The operator can also choose an improved automatic strategy, which is the default option. This strategy should be used if no adjacent channels are allocated in co-sited cells, e.g. in a blocked 1/3 plan. The automatic strategy uses "even then odd MAIO strategy". This means that first all allowed even MAIO values in increasing order are used and then the odd allowed values in increasing order (e.g. if 5 TRX's were used in a cell with 7 frequencies, the order of MAIO allocation would be 0,2,4,6,1). This yields that the adjacent channel interference is minimized within the cell.


Title

4.53 Flexible Positioning Support



Technology: GSM

4.53.1 Attention


Not applicable

Dependencies


4.53.2 Summary

The Flexible Positioning Support feature gives the BSS support for introduction of mobile positioning services in the GSM Network.

Two different positioning methods are supported:

Cell Global Identity + Timing Advance (CGI+TA) positioning, with a typical accuracy of approximate 550 meters

Assisted Global Positioning System (AGPS) positioning, with a accuracy typical better than 10 meters

Three procedures to initiate positioning are supported:

Mobile Originated Location Request

Mobile Terminated Location Request

Network Induced Location Request


Title

4.53.3 Benefits

The Flexible Positioning Support feature will make it possible for the operator to increase revenue by introducing new location based services. Operators will also be able to fulfill the regulators requirement to locate subscribers that are making emergency calls.

4.53.4 Description

The Flexible Positioning Support supports two different methods to position circuit switched mobile terminals. Packet Switched terminals is also supported, but not while in Temporary Block Flow (TBF).

Cell Global Identity + Timing Advanced (CGI+TA) positioning, where the BSC provide the positioning information from serving cell. CGI+TA information is always sent to the MSC after page responses, at emergency calls, and when the MS requests to be positioned. The typical accuracy for CGI+TA is approximately 550 meters.

Assisted GPS (AGPS) positioning, where a Global Positioning System (GPS) receiver in the user equipment is used to position the MS. Assistance data is provided to the MS by the SMPC according to standards. The assistance data is used by the MS to improve the GPS receiver performance, in terms of latency and sensitivity. The typical accuracy is 10 meters.

The Serving Mobile Positioning Centre (SMPC) determines which positioning method to be used based on the accuracy requested and the methods supported by the MS and the system, and initiates the positioning procedure. It also makes the final positioning calculations when the method CGI+TA is used.

Mobile Originated Location Request (MO-LR) is initiated by the MS. MO-LR can either be used by the MS to send a positioning request or to require assistance data from the network. The location estimate is either returned to the MS or if the user so requires the location estimate will be sent to a LCS Client.

Mobile Terminated Location Request (MT-LR) is initiated by a LCS Client. The location estimate is returned to the LCS Client.

Network Induced Location Request (NI-LR) is initiated by the network. If the network detects that the MS establishes an emergency call, it initiates a positioning of the MS. The location estimate is made available to the emergency center by the network. Note: NI-LR is only applicable for the North American Market (positioning information is provided to the ESME and the ESNE). The procedure is identical to the MT-LR procedure from a BSS point of view.


Title

The BSC has an interface (Lb) to the SMPC. It supports procedures for communication between SMPC and MS, and between SMPC and MSC. One SMPC may be connected to up to 100 BSCs. The interface is standard.

The SMPC can also (instead of Lb) use Ericsson proprietary interface to MSC. This applies to networks where Lb is not available and the BSS vendor has yet to implement it. AGPS is not supported in that case.

Figure: System Overview

4.53.5 Enhancement

4.53.5.1.1.1 Enhancement BSS R11

Global Title Translation is introduced on the Lb Interface. This enables both geographical as well as N+1 redundancy for the SMPC. Global Title Translation support is also required in the SMPC.


Title

4.54 Flexible Priority Handling of Packet Data Channels



Technology: GSM

4.54.1 Attention


Not applicable

Dependencies




4.54.2 Summary

This feature allows a more flexible handling of on-demand packet data channels (PDCHs). PDCHs can be prioritized for packet data by restricting the pre-emption possibilities for speech. This would improve the end-user performance for packet data users allocated on on-demand channels.

4.54.3 Benefits

Possibility to improve the end-user performance for GPRS/EGPRS users allocated on on-demand channels

Less effort in planning the amount of dedicated PDCHs since on-demand PDCHs can be used instead

Efficient usage of radio resources between speech and packet data


Title

4.54.4 Description

The feature "Flexible priority handling of packet data channels" allows a flexible handling of on-demand PDCHs by restricting the pre-emption possibilities for speech.

Three different levels of pre-emption rules have been introduced:

CS traffic is allowed to pre-empt PDCHs if no idle timeslots are available for speech.

CS traffic is allowed to pre-empt non-essential PDCHs. These are PDCHs that do not carry the necessary signaling (e.g. Timing Advance). Only one PDCH in every packet data connection (multislot or not) carries the signaling. In case of a four slot MS this would mean that up to 3 PDCHs can be pre-empted by speech leaving one PDCH left for packet data transfer.

CS traffic allowed to pre-empt idle PDCHs only, which are PDCH currently not carrying packet data traffic.

4.54.5 Enhancement


A new function to limit the total number of on-demand PDCH in a channel group is introduced. This avoids the risk that GPRS/EGPRS traffic would consume all available resources in a channel group leaving nothing left for voice when a restrictive pre-emption strategy is deployed (CS not allowed to preempt PS). This may otherwise happen if many GPRS/EGPRS users would appear within a short time frame and the system is configured to try to open up new PDCHs for each new user. Services like push-to-talk could be seen to have this behavior.

The benefit is a more reliable voice service and better control over potentially very fast shifts in GPRS/EGPRS traffic load.

The function to keep track of the number of on-demand PDCHs that are pre-emptable in different cells is improved by moving the main controlling parameter to cell level. This change creates a more exact control for the operator of pre-emption in different cells with different pre-emption strategies in relation to CS functions.

The benefit is a better channel utilization due to an enhanced interaction per cell between PDCH pre-emption and the following functions:

Dynamic HR allocation and TCH packing functions (i.e. HR packing and DYMA)


Title

Cell Load Sharing

Subcell Load Distribution

GSM - UMTS Cell Reselection and Handover


Title

4.55 Frequency Allocation Support



Technology: GSM

4.55.1 Attention


Dependencies



Other node impacts and dependencies The OSS-RC features FAJ 122 474 Frequency Allocation Support and FAJ 122 629 Frequency Optimisation eXpert (FOX) increases value for the operator.


4.55.2 Summary

This feature facilitates the frequency planning for the operator by measuring uplink interference levels for frequencies in cells specified by the operator. The uplink interference measurements for a cell are saved on a file for further evaluation in OSS.

4.55.3 Benefits

Increased revenue and decreased operation cost for frequency planning by providing information on the best frequencies to use when adding new sites or TRX's, thus also increasing quality in the network.


Title

This feature provides measurements showing the best frequencies to be used in the cell when optimizing the frequency plan which will increase the capacity of the network and decrease/delay the need of new sites.

Decreased operation cost by reducing the amount of globally frequency plans needed.

Decreased operation cost in evaluating system performance when new frequency plans are implemented.

Provides possibilities to monitor how different radio network features implemented impacts on the interference level in the network which can be used to improve the quality in the network.

4.55.4 Description

Frequency Allocation Support, FAS, is a recording tool that measures the uplink signal strength for all cells and frequencies specified by the operator in the recording. The operator can order a FAS recording with up to 150 frequencies for one, several or all cells in the BSC. Maximum 10 FAS recordings can be initiated per BSC and a cell can only belong to one recording at a time.

The operator starts with defining the recording. The recording definition contains a list of cells and a list of frequencies. If a frequency specified cannot be measured by the TRX's in the cell that frequency will be discarded and no measurements done on that frequency.

The operator continues with initiating configuration of the TRX's according to the settings in the FAS recording. The BSC configures on which frequencies the TRX's shall measure on in the cells specified in the recording order. In order to configure a TRX the TRX must be in operation. Also the subordinate RX and at least two TS's must have been defined and are in operation.

At FAS recording initiation the recording time that is maximum 273 hours is specified by the operator. It is possible to stop and resume a FAS recording in order to record on a specific time each day.

The TRX's will measure the uplink interference on the frequencies ordered by the BSC. A sample is taken on each frequency and the measurement values stored in histograms per frequency with the same resolution as for RXLEV measurements. The histograms are saved in the TRX's in the RBS in order to reduce the number of data sent over the Abis interface.

When the recording time has elapsed the BSC stops the recording by ordering the TRX's to stop measuring on frequencies.


Title

The operator can now order the fetching of the interference measurements from all cells. The BSC assembles the measurements' values from all TRX's into one report covering all cells. The report contains the median, percentile value defined by the operator and number of samples for each frequency in each cell. A new report can be made with different percentile value specified by the operator.

The report can be fetched by OSS for further evaluation and graphical presentations.

4.55.5 Enhancement

FAS has been adapted to work together with the feature FAJ 121 085 Multi Band Cell. This is achieved by allowing measurements in all cells supporting a frequency band, regardless of the configured BCCH frequency band.


Title

4.56 Frequency Hopping



Technology: GSM

4.56.1 Attention


Not applicable

Dependencies


4.56.2 Summary

This feature allows configuration of GSM frequency hopping for connections on Traffic Channels (TCH) and on Signalling Channels (SDCCH). Baseband and synthesizer hopping are supported.

The principle of frequency hopping is that the mobile station transmits on one frequency during one time slot and then switches to a different frequency to transmit during the next time slot, etc. A predefined set of frequencies is used in each cell.

The main purpose of frequency hopping is to improve transmission quality on the air interface. The effects of fading due to multipath reflections can be reduced since the fading pattern is frequency dependent. In addition, the resistance against co-channel interference increases.

4.56.3 Benefits

With frequency hopping the speech quality perceived by the end user will be significantly better and the number of dropped calls will decrease.

The system planning margin can be reduced. This contributes to a network with higher capacity and/or higher speech quality.


Title

Frequency hopping enables the operator to give the subscribers a generally uniform speech quality. Slowly moving MS's in an urban environment have normally the lowest performance without frequency hopping. If frequency hopping is used, the performance will be roughly the same for MSs at all speeds.

This feature is extra valuable where interference (C/I) and multipath reflections are the dimensioning problems for radio network planners. It allows increased capacity if the frequency re-use distance is reduced.

4.56.4 Description

The connection quality and retention of calls can be increased mainly during disturbance conditions of two types:

Rayleigh fading, multipath reflections. If transmitted signals reach the receiver via multiple paths, destructive interference can be obtained, i.e. fading. This becomes a problem when a mobile is moving slowly. Frequency hopping will permit normal quality connections also for such mobiles. For every frequency hop, the fading pattern at the mobile station position will change.

Co-channel interference.

Frequency hopping spreads the interference more evenly among all active connections in the network.

It is possible to choose between cyclic or random frequency hopping, which gives different benefits depending on the application. For reducing the effect of Rayleigh fading cyclic frequency hopping is slightly better. For reducing co-channel interference, random hopping is superior.

Up to 16 hopping frequencies can be chosen, which takes care of all practical needs. The performance of the frequency hopping channel will be higher for a higher number of hopping frequencies. The relative gain per additional frequency will decrease.

At cell configuration, the frequencies in a cell are assigned to one or many channel groups. Within each channel group the channels will hop over the frequencies defined for that particular group. The configuration is done automatically, so that the actual available physical resources in a cell are matched against the configuration commands. The system returns the actual achieved configured resources, showing the result.


Title

If there are device faults, reconfiguration is automatically effected. The system attempts to re-establish the physical resources to as near to the original configuration as possible, according to priority rules. Physical channels are configured in descending priority order. For example, the Broadcast Control Channel (BCCH) has the highest priority.

Two types of frequency hopping are supported:

- Baseband hopping.

Each Transmitter (TX) will always transmit on the same frequency. The physical channel data will be sent from different TXs with every burst.

- Synthesizer hopping.

All bursts of a call are sent by the same TX, except for bursts that are transmitted on the BCCH frequency. These are transmitted on a separate TX, on a fixed frequency.

The amount of reduction of the system margin will depend on the actual radio network and traffic environment. To give an idea of the possible gains, a simulated example where random frequency hopping was used in conjunction with DTX uplink and DTX downlink showed that a reduction of the C/I system margin of 2 dB was possible. This figure would only be used within a cell planning methodology context, meaning that the dimensioning rule for cell planning could be changed.

The system margin can be further reduced if frequency hopping is used in conjunction with features that reduce the total amount of interference emitted in the system, for example MS Power Control and BTS Power Control.

The gain cannot be simply added to dB gains of other diversity mechanisms. However, the rule is that it is always profitable to add another diversity mechanism to the existing ones. The total gain will always grow, as seen in a statistical sense over all the different radio propagation environments encountered within a system.


Title

4.57 Frequency re-configuration with minimum disturbance



Technology: GSM

4.57.1 Attention


Not applicable

Dependencies


4.57.2 Summary

This feature gives the operator the possibility to change frequencies, including the BCCH and to remove or add transceivers in a frequency hopping cell without releasing any ongoing calls in the cell. The cell will be able to offer service to new traffic except when the BCCH is reconfiguration.

4.57.3 Benefits

Reduces the cell down time when changes in the frequency plan are implemented.

Increased availability of the BSS network during maintenance work and installation work of new TRXs by offering service to new traffic.

Decreased maintenance cost since frequency changes can be done during day time instead of night time. (Busy hour is not recommended).

Reduces the amount of site visits due to faulty installed equipment. Configuration of equipment can be done during day time when operation persons are on site.

Reduces disturbance at TRX recovery


Title

4.57.4 Description

4.57.4.1.1.1 Function

In a frequency hopping system an established connection will utilize several frequencies and a number of transmitters for the duration of the connection. With this feature it will be possible to reconfigure a frequency hopping system without halting any cells. A cell will instead be gradually, time slot by time slot, changed from the old to the new frequency hopping scheme, where ongoing calls are moved to transmitters not affected by the planned action. The channels that are on a specific time slot, in a cell that is to be updated, must first be freed from traffic. This is done by blocking all idle channels on that time slot, that is, making them unavailable for new connections and thereafter moving the traffic on the busy channels to another time slot through intra-cell handovers. If there still are busy channels after these actions the corresponding connections will be subject to forced release.

Once all channels on a time slot are freed from traffic the removal or addition of a transceiver/frequency will be performed. After updating the channels on that specific time slot with new configuration data, the channels will be deblocked and available for traffic usage.

This procedure continues until all time slots are updated with new configuration data. A capacity decrease will occur temporarily during the change period. In synthesized frequency hopping mode one time slot at a time will be blocked for traffic and the removal or addition of a frequency takes approximately 10 seconds. In baseband frequency hopping mode the removal or addition of a transceiver/frequency takes approximately 30 seconds. The relevant parameters in the System Information messages will also be updated during the reconfiguration.

As the BCCH channel is always non-hopping, reconfiguration of the BCCH frequency will not be necessary when a transceiver/frequency is added or removed. This ensures that the reconfiguration will not affect the behavior of Mobile Stations in idle mode.

4.57.4.1.1.2 Usage

This feature is used when a TRX is going to be changed out during operation of the cell or when a TRX is recovering from an outage.


Title

4.58 Full Rate AMR on 8 kbps Abis



Technology: GSM

4.58.1 Attention


Not applicable

Dependencies


GSM RAN SW: FAJ121055 - Adaptive Multi Rate (AMR)

GSM RAN SW: FAJ121358 - AMR Half Rate


Not Applicable


FAJ 121 055 Adaptive Multi Rate (AMR) and FAJ 121 358 AMR Half Rate are required.

FAJ 123 174 Packet Abis over TDM or FAJ 123 175 Packet Abis over IP is required in order to utilize the freed transmission bandwidth for data traffic.

FAJ 122 450 Flexible Abis is also supported but not recommended since it is not as efficient as Packet Abis over TDM/IP.


Not Applicable



Title

Terminals with support for AMR is required.

4.58.2 Summary

This feature saves Abis transmission resources at the same time as voice quality is maintained in best possible way. This is achieved by using a reduced AMR voice codec rate set for full rate AMR at traffic peaks. Less bandwidth is required on Abis, and the good characteristics of full rate traffic channels can still be used when planning the radio network.

4.58.3 Benefits

OPEX and CAPEX savings as the usage of Abis resources are optimized

CAPEX savings as a robust radio link is maintained with AMR full rate

Increased speech quality at low signal strength levels compared to AMR HR (maintained coverage)

Increased speech quality at high interference levels compared to AMR HR (maintained capacity)

4.58.4 Description

For optimization of the radio network, AMR FR is a strong tool to achieve coverage and frequency re-use, giving good voice quality also in less good radio environments. Abis transmission resources is saved by limiting the codec set and using 8 kbps paths on Abis at traffic peaks, without impacting the radio network planning.

For FAJ 122 450 Flexible Abis, Full Rate AMR on 8 kbps Abis allows for usage of 8 kbps Abis paths for AMR FR channels, instead of the 16 kbps paths usually required. This is achieved by allocating AMR FR calls with codecs restricted to maximum 7.4 kbps and using 8 kbps TRAU frames (as for HR). The reduced codec set is used when the number of Abis paths in the Abis pool has fallen below a threshold configured per TG. The codec set to be used will be the codec set chosen by the operator for AMR FR truncated to codec rates of 7.4 kbps and below.

For FAJ 121 997 Abis Optimization and FAJ 121 998 Abis over IP, the smaller TRAU frames will require less bandwidth on the shared transmission resource.


Title

4.59 Gb over IP



Technology: GSM

4.59.1 Attention


Not applicable

Dependencies

Hardware impacts and dependenciesThe BSC must be equipped with either the BSC LAN Switch or NWI-E to enable IP communication.


Other node impacts and dependencies FAJ 121 498 Gb over IP is required by an Ericsson SGSN


4.59.2 Summary

The introduction of Gb over IP will enable operators to build an IP network instead of Frame Relay (FR) between SGSN and BSC nodes. By this operators can utilize the advantages of an IP network carrying different types of traffic and the cost advantages an IP network will provide.

4.59.3 Benefits

CAPEX savings in transmission network and PCU.

OPEX reductions due to lower transmission cost and lower operational cost.


Title

Capacity on the Gb interface is not a limiting factor.

Enabler for SGSN in Pool.

4.59.4 Description

Gb over IP introduces the possibility to use IP transport for the Gb interface between the BSC and SGSN. The Gb over IP traffic is connected to a Gigabit Ethernet interface in the BSC. This means that BSCs and SGSNs located at the same site can be interconnected via a site Local Area Network (LAN). If the BSCs and SGSNs are located at different sites they can be interconnected via Site routers over a Wide Area Network (WAN).

The Gb over IP interface is fully redundant using Virtual Router Redundancy Protocol (VRRP) in the BSC IP network interface.

The Gb over IP feature is fully compliant with the 3GPP standard.

CAPEX will be lower due to:

IP infrastructure for the transmission network generally has a lower cost compared to Frame Relay infrastructure.

Using Gb over IP will require less RPP boards since there is no need to use GPH devices (interface to the Group Switch) on the RPP boards for the Gb interface. This means that each 64 kbps Time Slot that would have been used for Gb over FR instead can be used for Abis traffic, for example 1 EGPRS Time Slot.

OPEX will be reduced due to:

With Gb over IP the planning of transmission capacity for the Gb interface is substantially simplified compared to Gb over Frame Relay (FR).

The standardized Auto configuration procedure is used for setting up the link between BSC and SGSN. This means that only one IP-address for the SGSN needs to be defined in the BSC. The rest of the configuration is done automatically.

IP backbone networks combining different types of traffic can be used.

IP transmission capacity is cheaper than FR transmission capacity on many markets.

The transmission capacity for Gb over IP is not a limiting factor, that is one Gb over IP link can support all Gb over IP traffic between the BSC and the SGSN.


Title

4.60 GPRS



Technology: GSM

4.60.1 Attention


Not applicable

Dependencies

4.60.2 Summary

The General Packet Radio System (GPRS) feature enables packet switched data technology in GSM networks. Packet switched services allow end users to be always connected. These 2nd generation wireless datacom networks provide the foundation on which 3rd generation networks will be built. With the GPRS packet switched feature, data rates exceeding circuit switched features can be achieved.

4.60.3 Benefits

The feature has following benefits:

Usage of channels in a more efficient way since several users will be able to share the same channel.

GPRS will evolve the existing GSM infrastructure by allowing the introduction of wireless data and paving the way towards 3G networks.

GPRS has no impact on the Cell Planning by automatically adjusting the GPRS cell plan on the existing circuit switched cell plan.


Title

Flexible handling of PDCH's in terms of on-demand and dedicated channels allows operators to use the existing channels in the most efficient way for speech and data users.

The GPRS subscriber will have a fast set-up/access time to data services

4.60.4 Description

The GPRS feature enables packet switched data over existing GSM networks. This wireless data technology allows for example users to be always connected with the Internet. The GPRS feature in the BSS can be divided into different areas. Radio network impacts, specific Ericsson implementations of GPRS to give an even larger benefit and hardware impacts.

4.60.4.1.1.1 Radio Network

GPRS uses the same physical channels as circuit switched GSM but in a more efficient way since several GPRS users can share the same physical channel. To be able to transmit packet switched information over the radio at any given radio environment, GPRS uses different coding schemes aiming with their different amounts of error protection at different radio environments. To minimize the impact on the existing radio network, two GPRS coding schemes are available to be used over the radio.

4.60.4.1.1.2 GPRS coding schemes

The most robust coding scheme CS1 is always used for signaling while CS2 as well as CS1 can be used for data transfer. CS2 itself is more robust than speech protection, allowing a data-link between the mobile and the network also at radio-link conditions that would induce unacceptable speech quality in GSM. Consequently, in the implementation of GPRS, the existing GSM cell plan can be used to give at least the same coverage for GPRS CS2 as for GSM.


Title

4.60.4.1.1.3 Specific implementation of GPRS

To minimize the impact of the GPRS feature and in order to simplify the introduction of wireless data, the GPRS specific radio network parameters are automatically mapped onto the existing circuit switched parameters. This allows a fast rollout of a GPRS network equal to the existing circuit switched cell plan. Automatically mapped are even the parameters for GPRS MS power control, which is supported by the BSS.

A flexible handling of GPRS resources allows a prioritization of speech or data usage within a cell. The on-demand allocation of PDCHs (Packet Data Channels) uses the gaps between circuit switched sessions for packet switched users. These channels can be pre-empted by speech users if required. On-demand allocations of PDCHs are hence viewed as idle by circuit switched mobiles, and will not affect the (speech) blocking probability in the cell.

The dedicated allocation reserves a PDCH for packet data only. GPRS MSs always get access to a cell and neither can be pre-empted from a circuit switched user. Up to eight of these dedicated PDCHs can be allocated per cell.

One dedicated PDCH per cell can be configured as a PBCCH (Packet BCCH) allowing a more advanced GPRS paging and cell re-selection functionality by broadcasting GPRS specific cell parameters and control parameters (e.g. MS Power Control settings).

If none of the dedicated channels is configured as a PBCCH, all signaling as e.g. paging is than being handle by the BCCH for circuit as well as packet switched users. For GPRS three mobile classes have been standardized (class A, B and C) which all will be supported.

4.60.4.1.1.4 BSS Hardware

Within the BSS the GPRS feature is mainly software. The only new hardware introduced is the Packet Control Unit (PCU) allocated in the BSC. This new unit controls the packet handling from and to the Mobile Station.

4.60.5 Enhancement

The number of timeslots possible to reserve per user has been increased from four timeslots to eight timeslots allowing a more flexible and efficient channel allocation, leading to a significant increase in the GPRS end user throughput.

Improved allocation of dedicated PDCH, including higher priority to dedicated PDCH at channel allocation, leading to fast and reliable access to the GPRS services offered.


Title

Increased number of re-transmissions, making the GPRS connection more robust and error tolerant.

Allowing external cells in the GPRS BA list, decreasing the GPRS outage times.

Improved allocation of PDCH based on BTS capabilities for (EGPRS, CS 1-4 and CS 1-2) and GPRS Quality of Service, improving the GPRS End User Throughput.

Improved polling mechanisms, improving the GPRS end user throughput with up to 10 %.

New GPRS STS Counters, enabling efficient network performance monitoring & optimisation.


Title

4.61 GPRS coding scheme 3 and 4



Technology: GSM

4.61.1 Attention


Not applicable

Dependencies


4.61.2 Summary

The addition of coding scheme 3 and 4 (CS3/CS4) to the General Packet Radio System (GPRS) functionality is capitalizing on already existing terminal capabilities and is offering increased data throughput to all GPRS users. The feature supports coding scheme 3 and 4 as well as the link adaptation functionality. This makes it possible to utilize the less error-protected coding schemes adaptively in areas with high signal quality.

4.61.3 Benefits

The feature has the following benefits:

Coding scheme 3 and 4 (CS3/CS4) offers increased data throughput enabling better end-user perception of GPRS applications

CS3/CS4 capitalizes on existing terminal capabilities and enhances capacity as more users can be supported with maintained data throughput performance


Title

Better spectrum efficiency is achieved as GPRS link adaptation adaptively uses the most appropriate coding scheme (CS1, CS2, CS3 or CS4) at all times

CS3/CS4 gives an opportunity for operators to position themselves as offering higher data speed to the whole GPRS market place without need for new terminals

4.61.4 Description

The feature is an add-on to the GPRS feature and introduces the ability to utilize the coding schemes 3 and 4 (CS3/CS4) as standardized within the GPRS specifications. CS3/CS4 is supported only in the downlink and enables higher data speeds over the air interface as more data can be transmitted. All GPRS terminals will support CS3/CS4 in addition to the lower coding schemes CS1 and CS2 already supported in the GPRS feature. This means that there is no requirement for new terminals in order to capitalize on the benefit provided by this feature.

The feature will also increase the GPRS capacity by allowing more users to share the GPRS resources over time with maintained quality. The reason is that the total available bandwidth in the cell is increased when support for CS3/CS4 is introduced.

All GPRS coding schemes as defined in the GPRS standard:

The feature also includes GPRS link adaptation. The purpose of link adaptation is to choose the most appropriate coding scheme of all the four standardized coding schemes (CS1, CS2, CS3 and CS4) at all times in order to optimize throughput.


Title

There are a few limitations in the GPRS standard which may give unwanted behaviors when the radio environment is rapidly changing. For instance, blocks already sent with higher coding schemes must be re-transmitted using the same coding scheme when block errors occur. This and other effects are taken into account by the Ericsson link adaptation algorithm as it has been designed with robustness in mind to provide as high data throughput as possible over time.

It is possible to activate support for CS3/CS4 and link adaptation on a per cell level.

CS3/CS4 is supported on all EDGE capable HW platforms including the EDGE sTRU and the EDGE dTRU. In addition the non-EDGE dTRU is also supporting CS3/CS4.


Title

4.62 GPRS/EGPRS Load Optimization



Technology: GSM

4.62.1 Attention


Not applicable

Dependencies


4.62.2 Summary

GPRS/EGPRS Load optimization feature introduces a new and innovative way of improving overall user satisfaction and operator revenue. The feature intelligently divides the available radio resources between users sharing the same channels to reduce the amount of data retransmission. This is possible by scheduling users with better radio link more often to improve overall system and user throughput during periods of high load.

4.62.3 Benefits

System throughput may increase with up to 60% in high load situations and up to almost 100% for individual users.

The amount of satisfied users is increased significantly at high load situations.

A larger amount of satisfied users leads to more usage of data services, which increases operators' revenue.

EDGE users on EGPRS capable timeslots can be prioritized over GPRS to maximize EDGE user throughput.


Title

4.62.4 Description

The feature GPRS/EGPRS Load Optimization focuses the radio resources on MSs with high probability of correctly decoding the sent radio blocks to increase the effective throughput in the system. This leads to a significant improvement in user satisfaction in instances where high traffic load otherwise would degrade the service for all users. Simulations have shown that the amount of satisfied users in a system is increased significantly in high load situations.

Figure 1 shows how two users in a cell with different radio quality are sharing the same radio resources (left figure). By putting user #1 into low scheduling mode (right figure), user #2 experiences a 100% increase in throughput. In this particular case the effective total throughput for this cell is increased from 25 kbps up to 40 kbps (a 60% increase). Once user #2 has finished with the packet transfer the user #1 will be scheduled as normal again. Checks are also done continuously to see whether the quality of user #1 has improved. In such case the two users are scheduled normally again.

Figure 1. Two users sharing PDCHs where one is in a bad radio condition and thus put into low scheduling mode

A mobile is put into low scheduling mode when the radio link bitrate falls below a threshold that is configured by the operator per BSC. The radio link bitrate is calculated over a number of radio blocks to make sure that no temporary dips causes a user to be put into low scheduling mode. System information messages (e.g. for NACC) are always scheduled in normal scheduling mode.


Title

If the feature FAJ 121 32 Quality of Service (QoS) and Scheduling is activated, GPRS/EGPRS Load Optimization only affects Interactive and Background users. An Interactive user in low scheduling mode still has absolute priority over a Background user in normal scheduling mode.

Since the thresholds for bad radio environment are configured separately for GPRS and EGPRS, this feature can also be used to prioritize between GPRS and EGPRS. For instance, by setting the thresholds so that GPRS users are always put into low scheduling mode EGPRS users on EGPRS capable PDCHs are prioritized.


Title

4.63 GSM - UMTS Cell Reselection and Handover



Technology: GSM

4.63.1 Attention


Not applicable

Dependencies


4.63.2 Summary

This feature allows end-users with multi-RAT (Radio Access Technology) GSM/WCDMA Mobile Stations to roam between UTRAN (UMTS Terrestrial Radio Access Network) and GSM radio access network without loss of service (provided the service is supported in both networks). It gives support for mobility in idle mode, for handover of circuit switched connections (GSM to UTRAN, and vice versa), and for cell reselection/update for packed based service.

4.63.3 Benefits

The operator of both a GSM and a UTRAN system in an area can use these networks to complement each other.

The already built out coverage of GSM can be used, so that end-users with dual-RAT MSs will experience good coverage also in areas where there is no UTRAN coverage. This generates revenues short term and increases the quality perceived by end-users.

The new spectrum for UMTS can be used, so that the total capacity of the cellular network is enhanced. The traffic load can be shared between the systems, by directing MSs away from heavily loaded cells to the other system.


Title

By setting of parameters, the GSM network may also direct MSs to UTRAN whenever available.

4.63.4 Description

In packet modes and circuit switched idle mode, the MS procedures for cell reselection is controlled via standardized parameters sent over the air interface. UTRAN neighbors can be pointed at. Parameters are broadcast by the BSS to inform MSs when to start measure on UTRAN neighbors. MS measurements may start either when the MS is getting far from the RBS (signal strength in the present cell is becoming low), or when it is getting close to the RBS (signal strength in the present cell is becoming high).

Both GSM and UTRAN cells can be considered by the MS in the cell reselection procedure. An offset can be set by the network to make the MS prioritize GSM or UTRAN cells.

The BSS is able to recognize UTRAN cell identities, and accept handover from UTRAN to GSM.

In circuit switched active mode, information is sent to the MS to control the measurement on the UTRAN cells, in order to support handover from GSM to UTRAN. Reported MS measurements, extended to include both GSM and UTRAN cells, are evaluated in search of candidate cells for handover.

The decision to request a handover is based on signal strength and the load situation in the present system. A UTRAN cell will be considered as a candidate cell for handover if the load in the present cell is above a configured threshold, and the signal strength in the target cell is high enough.

Only handover and reselection between WCDMA FDD mode and GSM is supported.

4.63.5 Enhancement


By introducing urgency handover to WCDMA less dropped calls is achieved. In case of urgency (quality- or Timing advance problems) in the serving GSM cell, a handover to a WCDMA cell can be triggered without considering the load in the GSM cell. The radio criteria for the WCDMA cell must still be fulfilled before an inter-system handover can be triggered and the priority order between GSM and WCDMA cells is maintained.


Title

Real-Time Monitors for GSM -UMTS handovers has been improved with monitors for e.g. Number of Inter-System Handover Attempts, "Success" - rate, "Failure but not lost" - rate, "Failure and lost" - rate and Average UMTS cell quality.


Title

4.64 GSM-WCDMA Active BA List Recording



Technology: GSM

4.64.1 Attention


Not applicable

Dependencies


4.64.2 Summary

This feature supports seamless operation of GSM and WCDMA networks in the important area of neighbor cell relations between the two networks. The operator is supported in finding the most appropriate set of WCDMA neighbor cell relations for each cell in the GSM network.

4.64.3 Benefits

Increases radio network quality and decreases dropped call rate due to improved handover performance.

Increasing radio network quality by providing support for removal of neighboring cell relations seldom or never used.

Decreases the operation and maintenance cost by facilitating optimization of the neighboring cell relations for a combined GSM/WCDMA access network.


Title

4.64.4 Description

Handovers between GSM and WCDMA relies on having good neighbor relations. The feature GSM-WCDMA Active BA List Recording initiates measurements in the GSM network of the UMFIs (UTRAN Measurement Frequency Information) that are relevant. An UMFI in WCDMA is equivalent to a BCCH carrier in GSM, containing information on frequency, scrambling code and diversity.

When running FAJ 122 396 Active BA List Recording with FAJ 121 815 GSM-WCDMA Active BA List Recording activated, the measurement data for GSM/WCDMA is included in the recordings.

The output data can be evaluated and graphically presented using FAJ 121 886 Neighbouring Cell Support GSM-WCDMA.

With the information, the operator is able to optimize the WCDMA neighbors for all GSM cells in the recording. This is achieved by either adding neighbors that are necessary for handovers between GSM and WCDMA or by removing unnecessary neighbor cells that only make the MS measurements unreliable and therefore degrade handover performance. Continuous GSM-WCDMA optimization leads to better handover performance, better quality and less dropped calls experienced by the end-users.

The feature also has a positive impact on the potentially cumbersome optimization of GSM-WCDMA neighbor cell relations. The results can be produced with less time and effort, reducing or eradicating the need for time-consuming drive tests and error-prone neighbor cell estimations based on propagation models and maps.

The feature can be used for defining suitable WCDMA neighbors when a new GSM cell is added. It can also be used whenever a new WCDMA cell is added, the feature enables the operator to quickly define in which GSM cells the new WCDMA cell shall be defined as a neighbor. The feature also supports every-day optimization of the GSM/WCDMA neighbor cell relations regardless of whether new cells have been added or not.


Title

4.65 Half Rate Channels



Technology: GSM

4.65.1 Attention


Not applicable

Dependencies


Not Applicable


Not Applicable


Not Applicable


Not Applicable

4.65.2 Summary

Use of Half Rate Channels allows two subscribers to share one timeslot. This enables a much more efficient utilization of the radio spectrum, since the double amount of traffic channels are available on the air interface. The half rate speech codec that is included was defined within ETSI/GSM with enhanced spectrum efficiency as the main objective.

Half rate capable (dual rate) mobile stations are required.


Title

4.65.3 Benefits

Half Rate Channels have the following main benefits:

Potentially more than double traffic handling capacity, since two users can share a timeslot.

Fast deployment of extra radio network capacity since it is a software feature, which requires no extensive roll-out of new hardware.

4.65.4 Description

When Half Rate Channels is used two subscribers are interleaved on the same timeslot on the air interface. This means that twice as many traffic channels will be available in the same radio spectrum compared to using only full rate channels. This implies that there is a potential to more than double the traffic handling capacity of GSM network by introducing Half Rate Channels. The actual capacity gain is dependent not only on introducing the Half Rate Channels feature but also on the penetration of half rate capable terminals.

It is easy for an operator to enhance network capacity with half rate channels since introducing it has no significant impact on the radio network. An operator only has to introduce the relevant hardware and software into the network and ensure a fast growing penetration of half rate mobile stations. In comparison, enhancing capacity by adding more radio base stations requires, for example, radio network tuning and frequency re-planning.

The channel allocation scheme within the BSC will work so that physical channel fragmentation is avoided. Channels which are partly allocated for a half rate call will be selected for the next half rate call before a new idle full rate channel is taken. A re-packaging mechanism for ongoing half rate calls also has the purpose of avoiding channel fragmentation.

On the A-bis interface two users will also share a 16 kbit/s channel, hence no changes are required on the A-bis interface. In the BSC, the transcoder pool architecture is mandatory for the introduction of half rate channels. TRA R4 or later is required for support of Half Rate Channels.

All RBS 2000 are hardware prepared for support of Half Rate Channels. For the RBS 200, Half Rate Channels are only supported on the SPU++ (SPU+/SPE) platform.


Title

4.66 Handover on SDCCH



Technology: GSM

4.66.1 Attention


Not applicable

Dependencies


Not Applicable


Not Applicable


Not Applicable


Not Applicable

4.66.2 Summary

Handover is the procedure which takes place when a connection is moved to another channel. This feature provides an extension of the handover feature (NF 209.1) in order to also cover the case of handover between signaling channels (SDCCH).


Title

4.66.3 Benefits

Handover on SDCCH can limit the interference in the network (C/I ratio) and decrease the number of dropped calls.

This feature increases the security of

SMS delivery, since the average connection quality on the SDCCH is improved. When the use of SMS increases, so does the need for handover on SDCCH.

Call set-up can also benefit from this feature, due to better quality on the signaling channels.

4.66.4 Description

A signaling channel Stand alone Dedicated Control Channel (SDCCH) is a channel that can be used for signaling only, that is for example call set-up, location updating, or Short Message Service (SMS).

The regular handover (NF 209.1) takes place between traffic channels. This feature makes it possible to perform a handover between SDCCHs. The parameters that control the regular handover also control the handover on SDCCH.

If a call is initiated when the MS is close to the cell border and moving towards it or if the MS has not chosen the best cell, a handover on SDCCH might be necessary.

When the cellular systems mature, the SMS point-to-point traffic will grow. SMS uses the SDCCH longer than the few seconds needed for call set-up and location updating. It will become increasingly important to use handover not only for traffic channels, but also for the signaling channels.

Handover (including locating) is one of the available ways to control interference.

The feature is implemented in software in the MSC, BSC, and BTS.


Title

4.67 Handover Power Boost



Technology: GSM

4.67.1 Attention


Not applicable

Dependencies


Not Applicable


Not Applicable


Not Applicable


Not Applicable

4.67.2 Summary

This feature provides the possibility for all cells to ensure that Handover Command is always sent with maximum power allowed in the cell. This is especially useful when power control is active and the interference situation is severe.


Title

4.67.3 Benefits

The number of dropped calls in the networks will decrease thus increasing subscriber perceived quality and revenue for the operator. This is especially important in micro cells where the power regulations (BTS and MS) have lowered the power used in the BTS and mobile.

4.67.4 Description

Sharp signal strength decrease for mobiles may occur when the mobile user goes around a corner or enters a building. This feature tries to save connections suffering from fast signal strength decrease and is operator defined on a per cell basis.

In order for this feature to function the message between the BSC and the BTS containing the handover command is enhanced to include additional information about uplink and downlink power in the serving cell.

The uplink power level is used to order the mobile to increase the power used in the serving cell when the handover command is segmented on layer 2.

The downlink power is equal to the nominal power, that is, the maximum power the BTS is allowed to use in the cell, whereas the uplink power is equal to the maximum power the mobile is capable of or permitted to use.

When this feature is active the BSC will order the BTS, by adding the additional information in the message between the BSC and the BTS, to transmit handover command using nominal power. The handover message will be transmitted to the mobile using the new power level and the mobile will reply using the new power level in the serving cell.

During a handover, when this feature is active, the normal power regulation is inhibited.

The BTS ignores all BTS or mobile power command messages sent by the BSC on the serving cell until the MS has acknowledged the handover command.


Title

4.68 Handover with Usage of Service Indicator



Technology: GSM

4.68.1 Attention


Not applicable

Dependencies


4.68.2 Summary

Handover with Usage of Service Indicator gives support for service based handovers, which means the MSC can affect which radio access network is used for a connection, GSM or WCDMA. The service indicator is used by the BSC when deciding on CS handover from GSM to WCDMA.

4.68.3 Benefits

Improved mobility control

Improved service perception by DTM users

Reduced system load from inter-RAT handovers


Title

4.68.4 Description

Handover with Usage of Service Indicator is used together with core network features for intersystem handover and roaming restrictions to direct MSs to preferred radio access network, GSM or WCDMA. A consistent network behavior will be achieved for MSs in different modes. For instance, roaming restrictions can be used to prevent MSs to re-select to a part of the combined GSM/WCDMA radio network. By using the service indicator, handover can also be prevented to that part of the network, giving similar behavior for network controlled and MS controlled cell changes.

Handover with Usage of Service Indicator increases service availability for users with DTM capable mobiles, and subscription restrictions for access to WCDMA service, by preventing handover to WCDMA. Packet services would be unavailable for as long as the call is ongoing via the WCDMA network.

By preventing CS connections to be handed over to WCDMA for users with subscription restrictions for access to WCDMA service, also the load on the WCDMA network and the overall load from handovers are decreased.

The MSC may set the service indicator for a connection. The MSC includes the service indicator at an assignment or handover into BSS. The service indicator values "should", "should not" and "shall not" are used (if set) to indicate how potential handovers of a connection to WCDMA shall be evaluated.

"Should" means that a handover to WCDMA should be initiated as soon as possible

"Should not" means that a connection is kept in GSM as long as possible

"Shall not" means that a handover to WCDMA is never initiated for that connection.

A "should" makes the BSC take only the measurements on the target cell into account when deciding to require a handover to WCDMA. The cell load threshold is omitted and handover to WCDMA is done a soon as measurements on a WCDMA cell indicate a quality above the threshold.

On a received "should not" the BSC does not initiate handover to WCDMA unless there is an urgency situation, even if the load threshold for inter-RAT handover is passed. These connections can not be used by the BSC to unload the GSM cell.

A "shall not" result in that WCDMA neighbors are removed from the cell candidate list. The connection is not handed over to WCDMA for any reason, but kept in GSM until terminated (or dropped).


Title

For connections without a service indicator sent by the MSC the evaluation for handover is done according to the normal criteria for GSM - UMTS Cell Reselection and Handover.


Title

4.69 High Speed Circuit Switched Data



Technology: GSM

4.69.1 Attention


Not applicable

Dependencies

MSC-S: FAJ122954 - High-Speed Datacom Service

4.69.2 Summary

This feature provides to the operator the possibility to offer data services up to 38.4 kbit/s, 4 time slots, in BSS. Dynamic allocation of time slots during the connection is also supported and information of time slots used during the connection continuously reported to the MSC for charging purposes.

4.69.3 Benefits

Increased revenue by the possibility of offering higher data rates to existing subscribers.

Increased revenue by the possibility of offering new competitive data applications attracting new end-users.

Improved image by positioning the operator as a high quality provider of data applications.


Title

4.69.4 Description

The feature High Speed Circuit Switched Data (HSCSD) provides higher data rates. The higher user data rates are achieved by assigning several full rate channels to one data call. The maximum air interface user rate is 38.4 kbit/s, corresponding to 4 time slots carrying 9.6 kbit/s user data each.

This feature can be activated on a per cell basis (one, several or all cells) in the BSC.

All channels in a HSCSD configuration must be of the same type, either TCH/F9.6, or TCH/F4.8 thus offering the following data rates:

Transparent data with data rate 4.8 Kbit/s. Time slot End-user data rate (Kbit/s)

4.8

9.6

14.4

19.2

Transparent data with data rate 9.6 Kbit/s. Time slot End-user data rate (Kbit/s)

9.6

19.2

28.8

38.4

Non-transparent data with Radio interface data rate 12 Kbit/s. Time slot Radio interface data rate (Kbit/s)

12

24

36

48

A HSCSD configuration consists of one main channel and up to three secondary channels. The main channel is the only one carrying an FACCH.


Title

When a HSCSD connection is set up the subscriber states his wanted Air Interface User Rate (AIUR), which the network then tries to set up. When setting up the call, the network tries to maximize the downlink data rate first and then the total data rate given in the request from the subscriber.

For a transparent data connection the given AIUR must equal the demanded for the connection to be set up. In a transparent HSCSD connection, no reduction of used time slots will take place at congestion for incoming calls.

A non-transparent data connection may be set up although the demanded AIUR is not met initially. The network will then continuously during the connection try to increase the number of used time slots in order to fulfill the user requested AIUR.

A user can change his demanded AIUR during a non-transparent call. If the new requested number of time slots is less than the number of time slots being used, the excess of time slots will be removed and free capacity in the cell. If the demanded number of time slots is higher, the network will continuously try to upgrade the HSCSD connection to meet the new demand.

If the HSCSD connection is transparent the AIUR cannot be changed during the call unless a new Assignment Request message with a new AIUR is received from the MSC.

Extended range cells will not support HSCSD connections using more than one time slot. If the data call is in cells supporting HSCSD and passing through to an extended range cell, the HSCSD connection will temporarily be converted to an ordinary data call using only one time slot for a non-transparent data connection. For transparent data connections, handover for the connections will not be done to an extended range cell.

4.69.5 Enhancement

HSCSD downgrading at congestion will allow the operator to use the existing spare capacity for HSCSD users thus reducing the need for additional new TRX's for provision of capacity and increasing the air time.

If a cell is congested at a new call attempt the BSC will look for ongoing non-transparent HSCSD connections using more than one time slot. The non-transparent HSCSD connection with the most number of used time slots allocated will be reduced with one. The time slot will be allocated to the new call attempt thus reducing the cell congestion and relief network planning.

HSCSD downgrading of a non-transparent call at congestion is controlled with a BSC exchange property.


Title

4.70 Idle Channel Measurement



Technology: GSM

4.70.1 Attention


Not applicable

Dependencies


4.70.2 Summary

The feature Idle Channel Measurement is continuously measuring the interference level on unused idle channels, and uses this information at allocation to set up new calls on the best available channels.

This feature also provides statistics that can be used to monitor the interference level in a cell. This information can be used to improve the radio network, thus providing a higher speech quality to the subscribers.

4.70.3 Benefits

Increased performance and quality

Increased network control

Enhanced diagnostics of interference in the network.


Title

4.70.4 Description

The BTS measures signal levels on unused channels in the same way as uplink measurements are made for an active call as defined in GSM TS 05.08. An averaging parameter can de defined for a number of SACCH multiframe periods (of about 0.5 seconds each). The resulting averaged value per channel is compared to five interference classes into one of which the averaged value fits. The interference classes can be defined by the operator.

At channel allocation in a cell, an idle channel from the lowest interference band will be used for a connection if this feature is activated.

Idle Channel Measurement handles the following logical channel types:

TCH/F, Full rate traffic channel

SDCCH/8, Subchannels of Stand alone dedicated control channel

SDCCH/4, Subchannels of Stand alone dedicated control channel.

If the Frequency Hopping feature is not active for a channel, the interference class information will correspond to a fixed frequency and time slot number.

If the Frequency Hopping feature is active for a channel, the interference class information will correspond to a time slot number, hopping over the frequencies defined by the hopping sequence.

The statistics that can be provided are the number of idle TCH channels within each interference band and subcell type (overlaid, underlaid/normal).

The feature Idle Channel Measurement can be activated/deactivated per cell or only used for statistical purposes.


Title

4.71 Increased SDCCH Capacity



Technology: GSM

4.71.1 Attention


Not applicable

Dependencies


Not Applicable


Not Applicable


Not Applicable


Not Applicable

4.71.2 Summary

The feature Increased SDCCH Capacity doubles the number of SDCCH/8 that it is possible to define in a cell. This is especially needed to handle the increased SMS traffic in GSM networks.


Title

4.71.3 Benefits

Enough SDCCH signaling capacity to cope with the increasing SMS traffic in GSM networks.

4.71.4 Description

With Increased SDCCH Capacity the number of SDCCH that it is possible to allocate in a cell is doubled. This means that the maximum number of SDCCH/8 timeslots that can be configured in a cell is increased from one to two times the number of transceivers in a cell. There is also an upper limit for the total number of SDCCH/8 timeslots in a cell, which is increased from 16 to 32 SDCCH/8 timeslots. This limit is regardless of the number of transceivers in a cell, so even if there are 17 transceivers in a cell the maximum number of SDCCH/8 timeslots is still 32.

When combined BCCH is used it is also counted as one SDCCH/8 timeslot, and the maximum number of SDCCH/8 is therefore reduced by one.

With the feature Increased SDCCH Capacity there should be enough SDCCH capacity to handle any increase in SMS and other services using SDCCH.


Title

4.72 Increased Throughput in Extended Range Cells



Technology: GSM

4.72.1 Attention


Not applicable

Dependencies


GSM RAN SW: FAJ12152 - Extended Range Cell 121 km


Not Applicable


FAJ 121 152 Extended Range Cell 121 km is required.

FAJ 121 606, Extended Dynamic Allocation is required to enable more than 2 timeslots in the uplink.


Not Applicable


Not Applicable


Title

4.72.2 Summary

This feature enables GPRS/EGPRS multislot support in Extended Range cells. It also makes it possible to have standard multislot allocation in an overlaid subcells connected to an underlaid subcell running in Extended Range mode. The result is a significant increase in throughput in rural areas where extended range cells are deployed.

4.72.3 Benefits

The feature provides the following benefits:

Throughput is doubled in the downlink for cells and subcells in extended range mode (0-121km)

Throughput is 4 times higher in overlaid subcells (both downlink and uplink) attached to an underlaid subcell in extended range mode (0-35km)

Operator Value

The operator value of this feature comes mostly from two areas:

Increased possibility to use data services in extended range cells with good performance

Better data image as even rural areas can be marketed as having good data throughput


Title

The value of better data throughput in rural areas is very dependent on the data usage in such areas. However, it is very likely that for remote areas the only data connection to rely on is "over the air". One typical example is ferries between islands. Being able to use multislot EDGE in such areas would significantly increase the satisfaction and make it feasible to even work remotely using e.g. a laptop.

This may lead to quite a lot of data traffic in some of these cells which otherwise would not be possible to attract with the risk of churn as a result

4.72.4 Description

When FAJ 121 152, Extended Range feature is activated it is possible to extend the cell radius from 35 km up to 121 km. This is accomplished by using only every second timeslot in order to cater for the long propagation delays.

Most GPRS/EGPRS terminals support 4 timeslots downlink and 2 timeslots uplink. As only every other timeslot is usable in an Extended Range cell this corresponds to 2 timeslots downlink and 1 timeslot uplink. The Increased Throughput in Extended Range Cells feature supports multislot operation even in these types of cells.

Furthermore the feature enables support of multislot users in the overlaid subcell when the underlaid subcell is in extended range mode. To support standard multislot allocation for an overlaid subcell in this case requires knowledge of the users location, as the coverage area of the overlaid subcell is smaller.

The terminals TA value (timing advance) is therefore considered at TBF (radio link session) setup. This allows the system to decide, based on the TA, whether the channels should be set up on the overlaid subcell (with normal multislot allocation) or in the underlaid (with extended range mode allocation). The overlaid subcell can be set as preferred so that the terminal always uses this subcell when being close enough to the base station.

When the user moves toward the subcell border the network monitors the TA value to be able to move the data connection to the underlaid (extended range) subcell when the user reaches the subcell border. When the user moves back closer to the base station the data connection is moved back into the overlaid (normal) subcell in a similar manner.

To be able to use 4 timeslots uplink the feature FAJ 121 606, Extended Dynamic Allocation also needs to be activated.


Title

4.73 Interference Rejection Combining (IRC)



Technology: GSM

4.73.1 Attention


Not applicable

Dependencies



IRC requires receive antenna diversity which means that it is not supported on for example RBS 2409.


Not Applicable


Not Applicable


Not Applicable

4.73.2 Summary

Interference Rejection Combining (IRC) is an interference suppression algorithm which significantly improves the uplink radio quality. This can increase radio network capacity and improve both speech quality and data throughput.


Title

4.73.3 Benefits

Increased radio network capacity due to significantly improved uplink performance.

Improved speech quality since interference is reduced.

Increased data throughput due to fewer retransmissions and the possibility to use higher coding schemes.

Solves uplink interference problems.

4.73.4 Description

Interference Rejection Combining is a new receiver algorithm for the transceiver which drastically improves interference robustness. Simulations show that IRC can provide a C/I gain of up to 11 dB, with a value in typical urban environments of around 5-6 dB, compared to the currently used receive algorithm.

A prerequisite for IRC is that two receive antennas (receive antenna diversity) are used. This means that in the transceiver there are two versions of the signal available that are slightly different due to the antenna diversity. IRC also uses the training sequence (as defined by the Training Sequence Code, TSC), which is a known bit pattern in the middle of each burst. By comparing the received signal with the training sequence it is possible to estimate the characteristics of the interfering signal. The IRC algorithm can utilize this information to efficiently remove interference from the wanted signal.

IRC performs best when the desired signal and the interfering signal are synchronized in time, since then the interfering signal is the same during the whole burst and the interference characteristics estimated during the training sequence are more likely to be valid for the whole burst.

In order to have synchronized interference between cells on the same site, the features FAJ 122 854 RBS 2000 Synchronization or FAJ 122 855 RBS 200 and 2000 in the same Cell might be needed depending on the site configuration and the RBS type. To also have synchronized interference between cells located on different sites, the feature FAJ 122 081 Synchronized Radio Networks is needed.

The gain that IRC provides solves interference problems that are encountered on the uplink, this also means that radio network capacity can increase in places where the uplink is the limiting link. In all networks IRC improves speech quality and data throughput in the uplink, thereby increasing subscriber satisfaction.

In radio environments not limited by interference, IRC performs as well as the currently available receiver diversity algorithm.


Title

IRC is available for all dTRU, sTRU and other BTSs based on the same HW platform like for example RBS 2308/2309. Older transceivers, i.e. classic TRU, RBS 2301/2302/2401 and RBS 200, cannot be supported due to the increased processing capacity required by the IRC algorithm.

4.73.5 Enhancement

The performance of the Interference Rejection Combining (IRC) algorithm is improved for the case where the wanted signal and the interfering signal are synchronized. This means that the enhancement is especially useful in networks using the feature FAJ 122 081 Synchronized Radio Networks where all interference is synchronized. Simulations show that interference suppression is further enhanced by up to 2 dB for GMSK modulated signals in this situation.

The benefits are even better speech quality and data throughput in the uplink and increased radio network capacity.


Title

4.74 Intra-Cell Handover



Technology: GSM

4.74.1 Attention


Not applicable

Dependencies


Not Applicable


Not Applicable


Not Applicable


Not Applicable

4.74.2 Summary

Intra-cell handover is the procedure which takes place when an MS connection is moved to another channel within the same sub-cell (or under certain conditions, to another sub-cell). This is done when the quality of the connection, at a certain signal strength, is considered too low.


Title

4.74.3 Benefits

The main benefit of this feature is that it maintains good speech quality for the end user.

The loss of revenue for the operator associated with the number of dropped calls is reduced. Without this feature calls might be dropped if the speech quality on the current channel is adversely affected by temporary interference. For example, from base stations in the downlink or from mobiles in the uplink causing co- or adjacent channel interference. With this feature, disturbances will have less impact on the network.

The fast switching ensures smooth handover. This means that speech quality will be maintained even during handover so that the user does not perceive an interruption during the call.

The enhancement makes Intra-cell handover even more efficient than before in order to maximize speech quality.

4.74.4 Description

Decreased connection quality may occur as a result of temporary interference. In this situation, conditions are likely to improve by trying another channel within the same cell. Intra-cell handover is done when the current channel is disturbed, although the signal strength measurements show satisfactory values.

The maximum number of consecutive intra-cell handovers and the minimum time between each intra cell handover can be configured.

4.74.5 Enhancement


New quality thresholds in Intra-Cell Handover are added for terminals using the AMR full rate speech codec. This makes it possible to set separate thresholds for intra-cell handover, in order to allow higher RxQual values before an intra-cell handover is performed for these terminals. The need for this is due to the high robustness of the AMR full rate speech codec, which allows it to function even in severely interfered conditions. The separate thresholds make it possible to avoid unnecessary intra-cell handovers for terminals using the AMR full rate speech codec.


Title

4.75 LAPD Concentration



Technology: GSM

4.75.1 Attention


Not applicable

Dependencies


4.75.2 Summary

The LAPD concentration feature is introduced into the RBS 200/RBS 2000 to improve the transmission network utilization between the BSC and the RBS nodes. This feature will allow many TRX's to share the same 64 kbit/s physical connection for LAPD signaling links instead of using one 64 kbit/s connection per TRX. The result is improved transmission efficiency between the BSC and the radio base stations.

This feature cannot be used together with LAPD multiplexing.

4.75.3 Benefits

LAPD concentration offers operators more efficient signaling transmission provisioning between a BSC and BTS. It allows a number of TRX's to share the same physical connection. Transmission costs for the signaling links towards the BTS will be reduced when a number of links are concentrated upon one 64 kbit/s Abis PCM time slot. A maximum of four TRX's can be concentrated on the same link.

If concentrating signaling links from 4 TRX's on the same link, the required transmission capacity is approximately 25% less than in non-concentrated signaling transmission.


Title

4.75.4 Description

Each time slot on a PCM link has a bandwidth of 64 kbit/s. Each PCM link has either 32 time slots for E1(2 Mbit/s) links, or 24 time slots for T1(1.5 Mbit/s) links. A concentrated link is one of the number of logical links which share this 64k path. The links have no particular fixed bandwidth, being implemented as separately addressed messages sent over the common path. A concentration group is a set of LAPD signaling links concentrated on one such path. The concentration factor is the number of concentrated links within a concentration group.

LAPD concentration uses the concentrator within the RBS 200/RBS 2000 to concentrate OML and RSL signaling from a number of TRX's onto one physical path, thus reducing the number of 64 kbit/s transmission links needed to provide signaling connections between the BSC and BTS.

At the BSC site the concentrated links are terminated within the Transceiver Handler (TRH).

At the RBS 200 site, the board EMRP-S handles the LAPD concentration. This concentrator board which is located in the Transmission Remote Interface (TRI) is needed to be able to use this feature. The EMRP-S occupies one of the 10 device slots in the TRI.

RBS 2000 supports embedded concentrator functionality as part of DXU, but this is modeled as a separate Managed Object (MO) within BSC. The concentrator is also used (transparently) to separate CF signaling from TRX signaling.

The LAPD concentration can be activated per transceiver group. When the function is activated a specific TRX can be excluded from the activated group. The concentration factor can be set per BSC, but can also be modified per transceiver group.

The actual concentration factor shall depend on:

The expected traffic load per transceiver

The maximum number of TRX's per TRH.

LAPD concentration for RBS 200/RBS 2000 is most efficient for saving transmission resources at RBS sites with 3 TRX's or more.


Title

4.76 LAPD Multiplexing, RBS 2000



Technology: GSM

4.76.1 Attention


Not applicable

Dependencies


4.76.2 Summary

The LAPD multiplexing feature means that the Abis LAPD signaling links and traffic links are multiplexed on the same 64 kbit/s link. This feature saves Abis transmission resources and is especially useful for sites with a small number of TRX's, typically 2 or less. Subrate switching in the BSC node is required for this feature.

4.76.3 Benefits

LAPD multiplexing saves Abis transmission resources and is especially useful for cells with capacity corresponding to up to two TRX's.

LAPD multiplexing also makes it possible to have very small sites where a cell is supported by only one 64 kbit/s transmission link from BSC to RBS 2000. In such a cell it will be possible to have three full rate channels.

Only 2 PCM time slots per TRX are needed in a cell with up to 2 TRX's. This means that the transmission capacity improvement for each TRX is approximately 33%.


Title

4.76.4 Description

In order to avoid the need for separate 64 kbit/s links for signaling, 16 or 32 kbit/s subrate links not used for traffic channels will be used for transmission of LAPD signaling links from transceivers in BTS; that is, RBS 2000, to Transceiver Handlers (TRH's) in BSC.

The links not used for traffic channels are the time slots in a transceiver configured as control channels (BCCH, CCCH, and SDCCH). No transmission resources on the Abis interface are thus needed for these channels.

The transmission rate has to be reduced to16 or 32 kbit/s in order to multiplex the LAPD channels.

This feature requires subrate switching at the BSC site. Handling of sub-rate channels is supported by RBS 2000.


Title

4.77 Mobile Crosstalk Control (MCC)



Technology: GSM

4.77.1 Attention


Not applicable

Dependencies


4.77.2 Summary

This feature reduces the acoustic echo generated from mobile phones. A specially designed algorithm implemented in the transcoder is used.

4.77.3 Benefits

The end users will perceive an enhanced speech quality, since MCC reduces the amount of acoustic echoes, created in the MS.

As the MCC algorithm is implemented in the transcoder, it will also work for intra-PLMN, MS-MS calls.

4.77.4 Description

Mobile Crosstalk Control reduces the amount of acoustic echoes created in the MS. This feature is implemented in the transcoder SW.


Title

4.77.5 Enhancement

The improved MCC algorithm has faster convergence time, that is, it adapts faster when the conditions for the acoustic echo change. Moreover, higher echo levels, which can occur in car hands-free kits, are also cancelled.


Title

4.78 MSC in Pool support in BSC



Technology: GSM

4.78.1 Attention


Not applicable

Dependencies



Other node impacts and dependencies FAJ 121 297, MSC in Pool is required for Ericsson MSC.


4.78.2 Summary

MSC in Pool means that up to 32 MSCs can be connected to a number of BSC/TRCs to form a pool of MSCs. MSC in pool will reduce the operators CAPEX and OPEX by e.g. load sharing and reduced signaling load in the Core Network.

The BSC support for MSC in Pool means that the BSCs control the traffic distribution and load balancing between MSCs. Furthermore, the BSCs can move traffic between MSCs and completely remove traffic from MSCs that needs to be taken out of service for maintenance reasons.


Title

4.78.3 Benefits

Load sharing between MSCs (capacity and node efficiency increase).

Fewer inter MSC handovers and reduced inter MSC signaling at Location Update.

Possible to add new MSCs with less traffic disturbance.

Redundancy on core network level.

Improved service availability at planned maintenance where an MSC needs to be taken out of service.

Enables the use of larger BSCs connected to existing MSCs.

4.78.4 Description

An MSC Pool is defined as a pool of up to 32 MSC/VLR nodes linked to a number of BSC/TRC nodes. Each BSC/TRC in the MSC Pool Area is connected via the A interface to each MSC/VLR node of the pool.

When a subscriber roams into a MSC Pool Area, the involved BSC/TRC selects one of the MSC/VLR nodes in the pool, according to a traffic distribution algorithm. The subscriber registers in the selected MSC/VLR and remains registered in the same MSC/VLR until he or she moves out of the MSC Pool Area.


Title

Figure 1: MSC Pool Area consisting of five Location Areas

The Load sharing mechanism implies that the total MSC capacity in the pool can be dimensioned for the maximum traffic of the MSC Pool Area, meaning that the total required MSC capacity can be reduced compared to a non pooled network. This is especially beneficial if different types of areas are covered by one Pool Area, e.g. a residential area with traffic peaks after working hours and an industrial area with traffic peaks during working hours.

Since the MS stays in the same MSC/VLR as long as it is in the same MSC Pool Area, the number of inter MSC handovers and Inter MSC Location Updates per MSC will be reduced. This means that the load and signaling related to these activities in the CN will be reduced compared with a non pooled network.

With MSC in Pool MSC splits can be avoided when more capacity is needed and the existing MSC can not be expanded further. This means that the service availability of the network will be improved compared to a non pooled network since the new node can be connected and configured with less traffic disturbance.

Sometimes it is necessary to take an MSC out of service, or remove it from the pool. In addition to the 3GPP standards, Ericsson has implemented a function to redirect the traffic from one MSC to the other MSCs in the pool. This is called MSC reselection. With this function it is possible to move a certain part of the subscribers to another MSC at the next registration activity or to move all subscribers at the next access to the network.

If one MSC would be temporarily (and unintentionally) out of service, the function Alternative Routing can redirect the traffic to the other MSCs. After a failure the MSs will be redirected at the next network access. This is also a function in addition to the functionality standardized by 3GPP.

4.78.5 Enhancement

Not applicable


Title

4.79 Multi Band BSC



Technology: GSM

4.79.1 Attention


Not applicable

Dependencies


Not Applicable


Not Applicable


Not Applicable


Not Applicable

4.79.2 Summary

This feature lets operators having access to more than one frequency band use the same BSC to support BTS equipment of GSM 800, 900 and 1800 or 1900 bands simultaneously in the same BSC.


Title

4.79.3 Benefits

Operators will get the following benefits when using Multi Band BSC:

Cost savings as one BSC will be able to support more than one frequency band, thus no additional BSC's are initially required.

Faster roll-out of a network in a new GSM frequency band, since GSM infrastructure for an already existing frequency band can be used.

4.79.4 Description

The operator will be able to define a mixed BSC that is capable of handling BTS equipment from more than one frequency band. At definition of cells in such a BSC, the operator will define the cells in the ordinary way, including the frequency band, which handles GSM 800, 900, 1800, or 1900.

Note that due to standards changes that were done to enable handover to/from the GSM 1900 band and other GSM frequency bands, it is not possible to connect GSM 1800 and GSM 1900 BTS equipment to the same BSC.


Title

4.80 Multi Band Cell



Technology: GSM

4.80.1 Attention


Not applicable

Dependencies


GSM RAN SW: FAJ1210894 - Radio Network Efficiency


Not Applicable


The functionality Dynamic Overlaid/Underlaid Subcells, Multi Band BSC and Multi Band Services which are part of the feature FAJ 121 0894 Radio Network Efficiency are required.


Not Applicable


Not Applicable


Title

4.80.2 Summary

Multi Band Cell makes it possible to mix transceivers from different frequency bands in one cell, with a BCCH in only one of the frequency bands. For the radio network this enables both increased capacity and savings in operation and maintenance cost.

4.80.3 Benefits

Increased radio network capacity, since frequencies for BCCH only have to be reserved in one of the frequency bands.

Reduced cost for radio network handling, as there are significantly fewer cells.

Improved radio network quality, because fewer neighbor cells means that MSs finds the best handover candidate more often.

Enhanced radio network performance in dual band GSM/WCDMA networks, as fewer GSM neighbor cells enables reporting of more WCDMA neighbor cells.

4.80.4 Description

The Multi Band Cell feature allows transceivers from different frequency bands to be used in the same cell. This is achieved by allocating frequencies and transceivers from different frequency bands to different subcells. In each subcell there can only be equipment belonging to one frequency band. The use of subcell means that the feature Dynamic Overlaid/Underlaid Subcells is a prerequisite in order to use Multi Band Cell. Multi Band Cell can handle any combination of three frequency bands from the GSM 800/900/1800/1900 bands except the 1800/1900 combination. This is due to limitations in the 3GPP GSM standards. Note that E-GSM is treated as part of the GSM 900 band, which implies that E-GSM frequencies can only be used in subcells where GSM 900 is also used.

To compensate for the different propagation properties of the different frequency bands, an offset is used between the lower GSM 800/900 and the higher GSM 1800/1900 bands.

The traffic distribution functionality and coverage criteria that Dynamic Overlaid/Underlaid Subcells provides, further enhances the performance of a Multi Band Cell network.


Title

Since there is no need to have separate cells for each frequency band, the number of cells are noticeably reduced. This simplifies operation and maintenance of the radio network, as there are fewer neighbor cell relations to configure. For the same reason, network quality also improves, fewer neighbor cells makes it much easier for the terminal to find the best handover candidate, which leads to higher handover success rate. This effect is also very advantageous in combined dual band GSM and WCDMA networks. Less GSM neighbor cells means that more WCDMA neighbor cells can be handled, hence GSM/WCDMA handover performance is increased.

When Multi Band Cell is used, a BCCH is only needed in one of the frequency bands. This means that those frequencies that would have been used for the no longer needed BCCH now can be planned as TCH frequencies. If frequency hopping is used a much tighter frequency reuse is possible compared to the frequency reuse of a BCCH carrier. In networks with narrow frequency bands the tighter frequency reuse results in a substantial capacity gain.

The features Multi Band BSC, which makes it possible to connect transceivers belonging to different frequency bands to the same BSC, and Multi Band Services, which enables handover between different frequency bands are required in order to use Multi Band Cell.

Transceivers that are connected to the same cell must be synchronized, this means that they must either be connected to the same DXU, or in case they are connected to different DXUs, those DXUs must be synchronized. Synchronization of DXUs are realized with the features FAJ 122 854 RBS 2000 Synchronization or FAJ 122 855 RBS 200 and 2000 in the same Cell depending on the site configuration and RBS type.

4.80.5 Enhancement


The enhancement improves the handover performance in multiband cells. As an alternative to compensating propagation differences by using a static offset, the measured signal strength on the BCCH of the serving cell is included in the locating decision. This increases the locating accuracy for connections using the non-BCCH frequency band and simplifies the tuning of multiband cells. The coverage border between the frequency bands can be set with better precision, since the cell border is the same for both frequency bands.

By improving the handover performance in the manner described, the enhancement not only removes unwanted ping-pong and merry-go-round effects, it also reduces the number of dropped calls and improves speech quality.


Title

Some new PM objects are added in order to improve the operability of multi band cells, for example GPRS MSs frequency band capabilities monitors that assist the operator's decision of where allocation of GPRS/EGPRS channels shall be allowed.


Title

4.81 Multi Band Services



Technology: GSM

4.81.1 Attention


Not applicable

Dependencies


Not Applicable


Not Applicable


Not Applicable


Not Applicable

4.81.2 Summary

This feature enables operators using more than one frequency band to support handover between different bands. This will lead to lower cost for additional capacity and coverage.


Title

4.81.3 Benefits

Capacity increase of an already existing GSM network by adding frequencies from another band in hot-spot areas.

Increased coverage of an already existing GSM 1800 or 1900 network by adding GSM 800 or 900 frequencies.

4.81.4 Description

The BSC supports handover between the GSM 800, 900 and 1800 or 1900 frequency bands. Handover between the GSM 1800 and 1900 frequency bands is not supported, which is according to the GSM standards.

In a network that have cells from multiple frequency bands, the operator will be able to define cells belonging to different frequency bands as neighbors. Mobile stations that support multiple frequency bands will then be able to inform the network with measurement reports on all available frequency bands. For these mobile stations the network can then initiate handovers between the used frequency bands.

By allowing cells that belongs to different frequency bands to cooperate, the advantages of each frequency band can be fully exploited in order to minimize the cost for additional capacity and/or coverage.


Title

4.82 Multi Layered HCS



Technology: GSM

4.82.1 Attention


Not applicable

Dependencies


Not Applicable


Not Applicable


Not Applicable


Not Applicable

4.82.2 Summary

Multi layered HCS is an efficient traffic handling mechanism that increases the utilization of the capacity available in each cell, thereby increasing actual network capacity beyond what is otherwise possible.


Title

Multi Layered HCS facilitates the implementation of a layered cell structure in several frequency bands. Cells of different types, i.e. normal (macro) cells, micro cells, and an indoor (pico) cells, will be configured in different layers for easy handling.

The main objective is to direct the traffic towards the band and the cell layer preferred by the operator, for instance indoor cells or GSM 1800 cells, where capacity is available. Differentiation between cells is accomplished by assigning cells to different layers.

4.82.3 Benefits

Increased network capacity, network accessibility, and service quality due to better utilization of available cell capacity.

Easier parameter setting: no need to set parameters for priorities between every cell. The cell will instead be mapped in to the layer with the suitable priorities.

Implementation of an effective multi-band network is simplified by ensuring that the preferred frequency band is fully utilized.

The extended number of layers makes it easier to use micro and macro cell configurations in more than one frequency band at the same time.

The better definition of the band and layer will improve performance in GSM indoor solutions.

4.82.4 Description

Multi layered HCS is an efficient traffic handling mechanism that allows cells to cooperate with each other. The utilization rate of the capacity available in each cell is increased, and network capacity is enhanced beyond what is otherwise possible.

Multi layered HCS enables operators to create different, layered, structures consisting of normal (macro) cells, micro cells and indoor (pico) cells, belonging to the different frequency bands, all within the same network. Multi Layered HCS provides excellent flexibility in cell planning, allowing the use of up to 8 layers in up to 8 bands of contiguous or singular cells. The layers can be freely distributed between the bands to accommodate many different requirements.

Multi layered HCS does not put any limitations on possible frequency bands. Cells from any frequency band defined in a BSC can be handled.


Title

The selection of band has higher priority than selection of layer, i.e. a cell in the band designated HCS Band 1 will be preferred before any cell in any layer of HCS Band 2 and HCS Band 3. The layers within each band are also prioritized. Layers with a lower number within the selected band have priority before layers with higher numbers.

The following is an example of an HCS Band and Layer combination where all together 6 layers are used in 3 bands:

HCS Band 1:

Layer 1: GSM 1800 Business indoor cells

Layer 2: GSM 900 indoor cells

HCS Band 2:

Layer 3: GSM 1800 micro cells

Layer 4: GSM 1800 macro cells

HCS Band 3:

Layer 5: GSM 900 micro cells

Layer 6: GSM 900 macro cells

In the example Multi Layered HCS will make calls in HCS Band 3 try to handover to the micro cell layer which is the layer with the lower number, since it is more beneficial for the radio network capacity. The same behavior is true for HCS Bands 1 and 2 as well. Likewise Multi Layered HCS will try to move any call in HCS Bands 2 or 3 to a cell in a lower band if a cell with acceptable signal strength is found. As a result mobile terminals will not always be served by the "best cell" from a power budget point of view, but by a cell that is good enough, in the lowest possible band and layer in order to increase the capacity in the radio network.

Multi Layered HCS also takes into consideration the speed of mobiles. Slow or not moving mobiles will be treated according to the description above, while fast-moving mobiles will stay in the layer where they access the network. The reason for this is to keep the number of handovers down and thereby decrease the risk for dropped calls.


Title

4.82.5 Enhancement

Traffic distribution based on cell traffic load is introduced for the feature Multi Layered HCS. This leads to a more efficient utilization of the radio network where load imbalances between the different layers and bands can be evened out, which increases quality and capacity. The enhancement also makes configuration and optimization of a network with HCS easier, which lowers operation and maintenance costs and improves radio network quality.

The traffic load criterion works as a complement to the existing signal strength based criterion. Hence HCS takes both signal strength and traffic load into consideration when deciding to move a call to another cell.

HCS only moves calls to another cell if the traffic level in the originating cell is above a certain threshold. This ensures that the available capacity in lower prioritized cells is utilized as well.

In a similar fashion, a cell is only eligible to receive HCS initiated handovers if the traffic level in the cell is below another threshold. The reason for this threshold is to avoid that high priority cells become congested. For example in high priority micro cells this can be used to give room for on demand GPRS channels or to take advantage of the additional coverage commonly provided by such cells. When the traffic load is above the threshold it is still possible to do normal and quality based handovers.


Title

4.83 Multiple Core Network Support



Technology: GSM

4.83.1 Attention


Not applicable

Dependencies


GSM RAN SW: FAJ121516 - Multiple PLMN Support

GSM RAN SW: FAJ121786 - Gb over IP


The BSC IP network interface is required (for Gb over IP).


FAJ 121 786 Gb over IP is required. FAJ 121 516 Multiple PLMN Support is required if more than one PLMN code is used in different cells belonging to the shared BSC.


FAJ 121 1267 Multiple Core Network Support Management, MCNSM in OSS-RC is required.

Only one SMPC (Serving Mobile Positioning Centre) node can be connected to the BSC.


Not Applicable


Title

4.83.2 Summary

The feature enables operators to share the Radio Access Network while keeping individual Core Networks. The GSM RAN infrastructure (BSC, RBS, antennas etc) are shared.

4.83.3 Benefits

The Multiple CN Support feature benefits are:

Provides CAPEX & OPEX savings to operators

Ensures control of end user service and brand

Supports sharing of RAN without losing control of core network

Simplifies agreement between operators


Shared Networks increases the coverage and addressable market of an operator, and with a more attractive service the operator will have the opportunity to benefit from new revenues from roaming subscribers, new subscribers, increased revenue from his present subscribers as well as lower churn and costs connected to this.

The main value for the co-operating operators is that the cooperation between the operators can be as simple as possible. Their individual core networks are not affected, and business sensitive information kept within the operators' own core networks.

4.83.4 Description

The feature Multiple Core Network Support, together with the already available feature Multiple PLMN Support, makes it possible for operators to share GSM RAN while still using their separate core networks. Multiple core networks are supported for both PS and CS domains.

The Multiple CN Support feature supports network configurations where up to eight operators share the same Radio Access Network, with direct connections between the shared BSC and the individual Core Network nodes (MSCs and SGSNs).


Title

The usage of separate core networks builds on that separate PLMNs are used. The Multiple PLMN Support feature must therefore be used for operators to keep their own radio networks (own PLMN identity and cells). Routing of connections to the correct core network is based on the identity of the cell (CGI) that is used for the connection.

One OSS is supporting the shared RAN, and the configuration of all PLMNs supported by that RAN. OSS provides the possibility to export/import cell data based on PLMN-id. Both cell statistics and cell configuration data is provided.

The interfaces to the core network are not affected and follow standards. MSC in Pool and SGSN in Pool are supported for one or more of the co-operating operators.


Title

4.84 Multiple PLMN Support



Technology: GSM

4.84.1 Attention


Not applicable

Dependencies


Not Applicable


Not Applicable


Depending on the network configuration the feature FAJ 121 515 Support of Multiple PLMNs in the MSC might be required.


Not Applicable

4.84.2 Summary

The feature is introduced in order to support sharing of the BSS infrastructure between operators with their own PLMNs.


Title

4.84.3 Benefits

This feature allows operators to share the BSS (e.g. BSC, RBSs, transmission), while still having their own, separate transceivers, cells and frequencies. This will make it possible to reduce infrastructure costs, especially in rural areas where the cells have few TRXs.

4.84.4 Description

The feature allows configuration of cells with different MCCs and MNCs in the same BSC and RBS. For example, an RBS can have three cells with an MCC/MNC belonging to one operator and three cells with another MCC/MNC belonging to another operator.

The same antennas can be used for cells belonging to the different PLMNs. In the example above the same antennas are used for cells belonging to the different PLMNs and covering the same area (two cells per sector).

The cells belonging to the different PLMNs will constitute separate radio networks, without handover or cell reselection between them. Furthermore, these radio networks will have separate TRXs.

The feature does only effect the configuration of the BSC and RBS, not characteristics as for instance the maximum number of cells supported or the maximum number of TRXs. The configuration rules of the RBSs are unchanged, e.g. regarding number of sectors (antennas) supported and frequencies supported.


Title

The interfaces towards the core network nodes (A and Gb) are not affected. One OSS and one SMPC are associated with a BSS. Support in the core network nodes is required to separate the traffic in the radio networks (PLMNs) supported by the BSS.


Title

4.85 Network Analyzer Interface



Technology: GSM

4.85.1 Attention


Not applicable

Dependencies


4.85.2 Summary

The feature reduces the cost for operators that want to use a protocol analyzer or similar for trouble shooting in BSS, since one protocol analyzer can listen to any link connected through a BSC. This is accomplished by copying the information from the desired link to the port where the protocol analyzer is connected.

4.85.3 Benefits

The benefits of Network Analyzer Interface are:

Reduced cost for monitoring and trouble shooting since, ideally only one protocol analyzer is needed per BSC.

Shorter time to start trouble shooting since connection between the protocol analyzer and the desired link is made with commands in the BSC.


Title



Reduced cost for O&M. Monitoring A and Abis interfaces is made less complex. Significantly fewer protocol analyzers are needed.

4.85.4 Description

The Network Analyzer Interface makes it possible to connect a protocol analyzer to any link in a BSC. The connection is made by configuring the BSC to copy the information from the desired link going through the BSC to the test position port where the protocol analyzer is connected.

For operators that want to use protocol analyzers to monitor and trouble shoot in the BSC, the feature can significantly reduce the required number of protocol analyzers. This can be accomplished since instead of connecting every Abis and A-interface link directly to a protocol analyzer, ideally only one protocol analyzers connected to test positions in the BSC is needed.

The feature can for example be used to listen to signaling, speech or data sent on an Abis link.

4.85.5 Enhancement

The capability to monitor on the A interface is provided. For example this makes it possible to use the Network Analyzer Interface to trouble shoot speech quality problems in the TRA.

The configuration and handling of monitoring HR calls is improved.


Title

4.86 Operation and Maintenance Terminal



Technology: GSM

4.86.1 Attention


Not applicable

Dependencies





4.86.2 Summary

The Operation and Maintenance Terminal (OMT) is an element manager for RBS 2000 and RBS 6000 base stations. The most important functionality in the OMT is configuration and fault localization. The OMT is needed for RBS 2000 and RBS 6000 (GSM part) configuration and greatly simplifies the work at fault localization.

4.86.3 Benefits

The OMT contributes with:

The time for configuration and installation of an RBS is minimized.

The time for fault localization is minimized.


Title

Minimizing faults on site during site configuration.

4.86.4 Description

The OMT is an element manager for RBS 2000 and RBS 6000 base stations and should be a part of each field technician's tool-box.

The OMT is mainly used for:

Configuration:

The OMT user describes the RBS HW and sends this description to the RBS for storage. The RBS SW uses this description to be able to work properly.

Fault localization:

When performing fault localization for RUs, without a corresponding fault indicator on the RBS HW, the OMT greatly simplifies the work.

The OMT SW is installed on a PC, which is connected to the OMT port on an RBS for communication with the RBS. An OMT cable is used for this connection.

Requirements on the PC:

A PC with a processor that fulfils the operating system requirements. Windows 2000, Windows XP or Windows Vista

At least 50 Megabytes available hard disk space.

At least 512 MB of RAM.

1 serial port and serial cable (To be able to connect an OMT PC with USB port to an RBS an USB-serial port adapter is needed).

4.86.5 Enhancement

Support for new RBS 6000 configurations: New RBS 6000 HW configurations are supported.


Title

4.87 Optimized Throughput at GSM to WCDMA Cell Change



Technology: GSM

4.87.1 Attention


Not applicable

Dependencies


4.87.2 Summary

Optimized Throughput at GSM to WCDMA Cell Change avoids long interruptions for packet data services when users are moving from GPRS/EDGE to WCDMA. This is possible by only allowing the terminal to reselect to a WCDMA cell when the user is not transferring data.

4.87.3 Benefits

The end-user perceived outage time when performing a cell reselection from a GSM cell to a WCDMA cell is around 10-20 seconds. By avoiding this long interruption altogether, the feature improves the end-user performance significantly. For EDGE more than 350 kb of data can be downloaded during the same time by staying in GSM than moving to WCDMA.


In areas where WCDMA coverage is poor, end users are able to experience good data services without constant interruptions due to inter-system cell reselections.


Title

Also, if load sharing is deployed in the WCDMA network, users may be moved to GPRS/EDGE. Then this feature avoids instant reselections of users back to WCDMA.

In areas where WCDMA coverage is poor, end users are able to experience good data services without constant interruptions due to inter-system cell reselections.

Also, if load sharing is deployed in the WCDMA network, users may be moved to GPRS/EDGE. Then this feature avoids instant reselections of users back to WCDMA.

4.87.4 Description

There are several occasions when a user is camping on WCDMA but still uses GSM for packet data. Either the WCDMA system actively moves certain users for one reason or another to the GSM system or the user simply falls out of WCDMA coverage and is redirected to GSM. In both cases it is desirable to keep the user in GSM. Otherwise the user reverts back to WCDMA as soon as WCDMA coverage is improved and this leads to long interruption in the packet transfer. When performing a cell reselection from a GSM cell to a WCDMA cell the end-user perceived outage time is around 10-20 seconds.

Optimized Throughput at GSM to WCDMA Cell Change is based on the standardized function Network Control Mode 2 (NC2). NC2 makes it possible to control the cell reselection decision for GPRS/EGPRS mobile stations in packet transfer mode and is part of the BSS 06A SW upgrade.

The feature is activated only for dual mode (GSM/WCDMA) capable terminals in cells that have at least one neighboring WCDMA cell. This ensures that only the terminals that benefit from the feature are affected. When the terminal is ordered to NC2, the terminal is told how often it shall send measurement reports to the system.

Optimized Throughput at GSM to WCDMA Cell Change keeps the user on GPRS or EGPRS as long as the user is actively transferring data, thus avoiding long interruptions. Once the terminal has finished the packet transfer it is released from NC2 mode. It then automatically moves to WCDMA if the terminals cell reselection algorithm still prefers WCDMA.


Title

4.88 PSU Power Savings



Technology: GSM

4.88.1 Attention


Not applicable

Dependencies

Hardware impacts and dependencies The feature is supported only by the RBS 2x06 series and the RBS 2x16 Version 2.




4.88.2 Summary

PSU Power Savings enables power savings, and thereby a reduction of operational spending, by more efficient use of the Power Supply Units in the RBSs in the network.

With this SW feature activated, the RBS power consumption is reduced during normal operation of the RBS. This is accomplished by putting a PSU that is NOT needed into power saving mode, in which it consumes less power. In situations where the PSU is again required, for instance at charging of batteries or an increase in traffic, the feature will immediately put them back into service.


Title

The feature is implemented in and valid for the RBS 2x06 series and the RBS 2x16 Version 2, which means that a significant part of the installed base is addressed.

4.88.3 Benefits

The OPEX (in terms of electricity bills) is reduced by less power consumption of the BTS



For many GSM operators, the power consumption cost represents a large share of the OPEX. A reduction of the consumed power will directly affect the operator's OPEX.

A simplified operator business case can be based on the number of installed BTSs:

The power savings per BTS is up to 25W, depending on the PSU type in the BTS.

The savings are affected by the traffic levels and how often batteries are charged, but as a general case it is assumed that the savings is relevant for 100% of the daily cycle, resulting in a yearly saving per BTS of up to 225 kWh/BTS.

For a reasonably sized network of 10,000 BTS the saving amounts to 2 200 MWh, corresponding to annual savings of around 330 k€ for the operator (at an electricity price of 0.15 €/kWh).

Note that different PSUs delivered with RBS 2x06 have different power savings characteristics, above figures are average cases.

The feature can also avoid the cost of operator staff actually going to RBS sites to manually turn off PSUs.

4.88.3.1.1.2 Other - Operator branding and perception

Another significant value for an operator is the fact that the feature will enable the operator to enhance its environmental profile.


Title

4.88.4 Description

The feature reduces the BTS site power consumption without affecting traffic and network quality.

The feature is activated (and de-activated) in the BSC per Transceiver Group. The actual functionality resides in the BTS and the BTS itself will determine whether it is capable of running the feature or not.

The feature constantly monitors the power situation at the BTS. During normal operation - in reality meaning that a number of criteria related to alarms, voltage levels, power requirements etc must be fulfilled - the BTS will put a PSU into power saving mode and thereby reduce the overall power consumption.

Whenever the need for power increases to levels requiring more power than the current PSU configuration will be able to deliver (or failure in meeting a number of other criteria), the BTS will automatically and very quickly (a matter of seconds) put the PSU into service again.

A number of statistical counters are associated with the feature, making it possible to evaluate the impact of the feature.

The feature is supported only by the RBS 2x06 series and the RBS 2x16 Version 2.


Title

4.89 Quality of Service (QoS) and Scheduling



Technology: GSM

4.89.1 Attention


Not applicable

Dependencies




4.89.2 Summary

QoS has been harmonized and standardized for both GSM and UMTS. QoS and Scheduling introduces the QoS classes Interactive and Background that enable operators to differentiate between users on a per subscriber basis.

4.89.3 Benefits

GPRS/EGPRS users will perceive a higher quality of the radio bearer service when QoS is introduced.

QoS allows the operator to differentiate between users by giving them different profiles in terms of throughput and priority.

QoS gives an increased flexibility as tariffs can be set depending on QoS profiles, leading to increased revenue gains.


Title

QoS functionality gives the operator the ability to control an end to end quality of service.

4.89.4 Description

This feature introduces QoS as standardized in release '99 as well as release '97. Release '97 allows a MS to have several parallel Packet Data Protocols (PDP) context activated. Each PDP context specifies the requirements for a particular service. This means that the requirements on applications e.g. email, within a PDP context, are the same. Each PDP context requires its own (MS) IP address. Normally only one IP address is supported by the MS which results in that all applications using the PDP address will experience the same QoS independent of the applications. In release '99 it will be possible to support user applications with different QoS profiles for one user with one common MS IP address. The complete QoS profile is sent to the BSS. The BSS will check the attributes in the QoS information towards the current radio resource situation. If necessary, the BSS will modify the attributes.

In release '99 four QoS classes have been standardized in harmonization with UMTS.

These classes are:

Conversational class including the highest requirements on application throughput and delay (e.g. real time services such as voice over packet radio)

Streaming class also with requirements on application throughput and delay (e.g. video streaming)

Interactive class including three priorities to differentiate between users (e.g. www browsing)

Background class with best effort (e.g. email)

The QoS classes Interactive and Background will be supported by this feature for terminals of release '99 onwards. Users in the Interactive class will experience a higher throughput depending on the subscribed priority while users in the Background class will be scheduled on radio resources not used by the Interactive class. This allows the operator to differentiate between e.g. business users and low end users. With a new packet handling procedure and the complete QoS profile stored in the BSS, the scheduling and radio resource allocation is being made in the BSS in an more efficient way. MS's with different QoS can be differentiated. The radio resources are distributed between the MS's according to the QoS profile.


Title

4.89.5 Enhancement

The QoS classes Interactive and Background will be supported by this feature also for terminals of release '98 or older. In this case the QoS profile as specified in the release '97 3GPP TS will be used for differentiation. The Precedence class and the Peak Throughput class are mapped onto the Interactive/Background classes and the Maximum Bitrate respectively.

The benefit of this is significant as the usability of the feature is extended also to the case when terminals and SGSNs only are compliant to release '98 or older. All the listed benefits can thus be achieved regardless of the amount of release '99 compliant terminals on the market.


Title

4.90 Queuing of WCDMA Calls in BSS



Technology: GSM

4.90.1 Attention


Not applicable

Dependencies


GSM RAN SW: FAJ121362 - Call Queuing




Not Applicable


FAJ 121 362 Call Queuing is required.


In WCDMA RAN, support to do directed retry to GSM at congestion is required.

In the MSC, FAJ 122 619 Enhanced Multi-Level Precedence and Pre-emption is required. In the HLR, FAJ 122 637 Enhanced Multi-level Precedence and Pre emption Service in HLR is required.



Title

Not Applicable

4.90.2 Summary

The feature Queuing of WCDMA Calls in BSS allows the operator to provide enhanced network accessibility in GSM to prioritized WCDMA subscribers during network congestion.

4.90.3 Benefits

Queuing of WCDMA Calls in BSS provides the following benefits:

Provides enhanced network accessibility for prioritized subscribers



Reduced infrastructure cost, since less radio network capacity is required to provide higher network accessibility to prioritized subscribers in a combined WCDMA/GSM network. By using queuing with priority, over-dimensioning of the channel capacity is not needed.


Operators can offer high network accessibility subscriptions at premium rates.

4.90.4 Description

The feature Queuing of WCDMA Calls in BSS makes it possible to provide enhanced network accessibility in GSM to prioritized subscribers coming from the WCDMA network via the directed retry procedure.

Directed retry is used during call set up in WCMDA to send the call to GSM during congestion in the WCDMA network. Priority and queuing information is sent from the core network to BSS as part of the directed retry procedure. The high priority subscriber is then queued in BSS together with other high priority subscribers according to his priority and time of arrival in BSS.


Title

The feature FAJ 121 362 Call Queuing provides the functions for queuing according to priority and is used for subscribers calling in GSM. Queuing of WCDMA Calls in BSS adds the functionality to include prioritized WCDMA subscribers coming to BSS through directed retry from WCDMA in the queue.


Title

4.91 Random Fill Bits



Technology: GSM

4.91.1 Attention


Not applicable

Dependencies


The feature is supported for all RBS 6000 and RBS 2000 using sTRU/dTRU/DRU or cTRU combined with DXU-21 and equivalent platforms.


Not Applicable


Not Applicable


Random Fill Bits on the uplink requires support in terminals and is mandatory for terminals supporting 3GPP Rel-6.

4.91.2 Summary

Random Fill Bits reduces the amount of known information sent on the air interface to improve security of the A5 encryption algorithms in GSM. The risk for eavesdropping and fraud is therefore reduced.


Title

4.91.3 Benefits

Improved security for the A5 encryption algorithms, especially A5/1

Reduced risk for eavesdropping and fraud

By providing the safest possible network, subscribers do not move to other networks, hence churn is reduced.

Compensation costs for subscribers subjected to fraud are avoided.

The feature bridges the gap until A5/3 is available in infrastructure and terminals.

4.91.4 Description

Fill bits are added to messages when they are sent over the air, if they are smaller than the fixed message size used on the air interface. The feature Random Fill Bits reduces the amount of known information sent over the air interface on the downlink. Instead of using the fixed value (00101011) previously mandated in 3GPP a random value is used.

Random Fill Bits makes it harder to crack the A5 encryption algorithms used in GSM to protect voice calls and signaling connections like SMS on the air interface. The risk for eavesdropping and fraud is reduced.

The feature is especially useful for the A5/1 algorithm, which is close to being cracked. Random Fill Bits delays the time until the A5/1 algorithm is actually cracked. For both terminals and transceivers that lack A5/3 capability, Random Fill Bits is an important measure to increase subscriber security.

The usage of random fill bits on the uplink and downlink is independent of each other. BSS controls the usage on the downlink and the MS on the uplink.


Title

4.92 RBS 200 and 2000 in the same Cell



Technology: GSM

4.92.1 Attention


Not applicable

Dependencies


4.92.2 Summary

The feature enables that RBS 200 and 2000 can be combined in the same cell.

4.92.3 Benefits

RBS 200 and 2000 in the same cell secures the operators investments done in RBS 200 infrastructure for the future:

No expensive replacements of RBS 200 to RBS 2000 is needed since new functionality released for RBS 2000, not supported by RBS 200, will anyhow be available in the cell.

Expansions of capacity in RBS 200 sites can easily be done with RBS 2000 cabinets.

Reduced costs by using the same antenna system for RBS 200 and 2000.

4.92.4 Description

Description, function:


Title

The function synchronizes the TG's in the RBS 200 and 2000. This enables usage of the two different HW in the same cell. The different TG's within the TG cluster works together according to the master and slave logic. One of the TG's is selected as master and the other TG's in the TG cluster are configured as slaves.

The master TG synchronizes towards the PCM-reference or the optional reference. The slave TG's synchronizes towards the master TG. The RBS 200 can only be defined as a master.

Description, use:

The possibility to have different hardware enables easy extension of cells, today served by existing RBS 200 equipment, with RBS 2000 hardware.


Title

4.93 RBS 2000 Synchronisation



Technology: GSM

4.93.1 Attention


Not applicable

Dependencies


Not Applicable


Not Applicable


Not Applicable


Not Applicable

4.93.2 Summary

RBS 2000 synchronisation allows TRX's belonging to different BTS's to be used within the same cell. This enables the build of very high capacity cells and usage of more than one frequency band in the same cell.


Title

4.93.3 Benefits

The synchronization of TRX's belonging to different BTS parts or cabinets allows the building of cells with an unrestricted number of TRX's, from a synchronization point of view.

RBS 2000 may be extended beyond 12 TRU's at least up to 128 TRU's in a cell

An extension cabinet can be placed up to a distance of 100 m from the master cabinet.

4.93.4 Description

Description, function: The task of the RBS 2000 synchronisation function is to keep Transceiver Groups (TG's) within a TG cluster synchronized. This is done via an external synchronization bus. The different TG's within the TG cluster works together according to the master and slave logic. One of the TG's is selected as master and the other TG's in the TG cluster are configured as slaves.

The master TG synchronizes towards the PCM-reference or the optional reference. The slave TG's synchronizes towards the master TG. It is possible to connect up to 32 TRX's in maximum 16 TG's in one TG-cluster. The maximum length on the external timing bus between the first and the last TG in the cluster is 100 meters. Synchronization is also possible in the air with the limitation that the antennas for the different TG's in the TG cluster must be located on the same mast.

Description, use: RBS 2000 synchronisation can be used by the operator to allow building cells with very high capacity, by connecting a large number of TRX's to the same cell. The hardware can reside in any number of RBS 2000:s but still be used in a common cell.

Parts of a cell belonging to different cabinets can easily be connected together.

4.93.5 Enhancement

All manual work in order to implement TG synch is now automatic and will reduce the OPEX when using TG synch. This includes automatic calculation of the timing function compensation values for all RBS 2000 macro BTS's using DXU-11 or DXU-21, and master reselection. This will reduce the risks of errors that can have negative consequences on the radio network quality and dropped calls.


Title

When a master TG goes down or is unable to provide timing information to the slaves, one of the slave TG's in the cluster is automatically selected as a new master. This increases the stability and performance of the RBS and reduces the number of dropped calls. Prior to this the operator had to manually reconfigure the slave TG within 2 minutes if intracell TG synch is used in order not to drop any calls.

When a master TG comes back into service it is automatically configured as a slave TG and the timing function compensation values are recalculated automatically. This will reduce the operating cost for the operator, as site visits and expensive re-configuration of the RBS is avoided.


Title

4.94 Real Time Event Data



Technology: GSM

4.94.1 Attention


Not applicable

Dependencies


In the BSC a board in the PCU is used for event handling. The the event data is transferred to OSS-RC and/or ENIQ over IP.


Not Applicable


In OSS-RC the event data from the BSC can be post processed using the features FAJ 121 46 GSM Real time Performance Monitoring (R-PMO) and FAJ 121 602 GSM Real time Performance Monitoring Database Export Interface.

In ENIQ Statistics the event data from the BSC can be post processed using the feature FAJ 121 1274 Ericsson GSM BSS EBS Tech Pack.

Event data logs generated with R-PMO in OSS-RC can be post processed using Ericsson RAN Analyzer.


Not Applicable


Title

4.94.2 Summary

The Real Time Event Data (RTED) feature provides access to radio network events on a real time basis. Together with the OSS feature Real time Performance Monitoring (R-PMO) it provides an effective and user friendly way to monitor network performance both in real time and with post processing from the OMC site. The feature complements the already existing possibilities of performance measurements and recordings in BSC and OSS.

4.94.3 Benefits

Very quick and accurate feedback of the radio network performance, for example after parameter changes.

Time stamped events allows for traceability between parameter tuning and radio network performance.

High degree of flexibility with user configured monitors.

Statistics with high granularity complementing the traditional BSC counters.

Detailed network performance analysis down to a call by call level by post processing the event data in TEMS Visualization.

The need for drive tests is decreased.



The task of monitoring network performance is simplified and made faster. Instant feedback to parameter changes is now possible. There is also reduced need for drive testing since all terminals in the network can be used for monitoring purposes.


Utilizing RTED/R-PMO to help improve for example drop call rate and similar important network performance KPI's can reduce churn and increase talk time.


Title

4.94.4 Description

The feature introduces a reporting mechanism in the BSC that provides information about events in the radio network, i.e. event data, on a real time basis. The event data is time stamped, which for example makes it possible to monitor speech quality immediately before and after a parameter change has been introduced. The feature complements the existing performance measurement and recording functions in BSC and OSS, by providing faster access to requested event data.

Using the feature GSM Real-time Performance Monitoring (R-PMO) in OSS-RC there is a number of ways to handle the event data. It can be viewed in graphs and tables in real time. It can be stored as statistics and used as a complement to the BSC counters. The event data can also be stored as it is using the REDE (Raw Event Data Export) interface for post processing in TEMS Visualization, to for example provide a call by call performance analysis.

Since event data from all terminals in the chosen cells are collected the need for drive testing is significantly reduced. By using the feature, feedback from radio network design and optimization activities is available instantly.

Network performance areas that can be monitored by using Real Time Event Data and the R-PMO feature together are for instance:

Traffic load in Erlang

Speech Quality

Call performance

Handover performance

GPRS/EGPRS performance

The information can be used to for example monitor speech quality before and after a Handover, or to monitor traffic load in a recently activated cell and its neighbors.

Using event data to calculate monitors, allows a high degree of flexibility enabling the operator to configure monitors according to their own requirements. Many monitors provide filters that make it possible to monitor performance on a level not possible with traditional BSC counters, for example down to channel group, TRX id, speech codec or MS capability.

An RPP board in the PCU is used for event handling in the BSC and for transferring collected events to OSS on a TCP/IP format. To avoid impacting the traffic execution performance in the BSC, the event mechanism is subject to load control.


Title

4.94.5 Enhancement

4.94.5.1.1 Enhancements in BSS 07B

The reporting of UTRAN cells is enhanced to show the real names of UTRAN cells instead of cell pointers. The cells names are visible in the output from the REDE interface available in R-PMO. Post processing and interpretation of the data is simplified. No conversion tables between pointers and real names are required any longer.


Title

4.95 Real Time Trace



Technology: GSM

4.95.1 Attention


Not applicable

Dependencies


MSC-S: FAJ1212405 - IMSI Visibility

OSS-RC: FAJ1211133 - Real Time Trace Manager (RTTM)


The BSC IP network interface is required.


Not Applicable


FAJ 121 1133 Real Time Trace Manager (RTTM) is required in OSS-RC.

FAJ 121 2405 IMSI Visibility is required in the MSC-S.


Not Applicable


Title

4.95.2 Summary

The feature makes it possible to trace individual subscribers or mobile stations. Information generated for the traced connections can be viewed in real time. For example, when and why they drop calls can be seen. This allows operators to provide better services to important subscribers and to make more efficient drive tests.

4.95.3 Benefits

Real Time Trace gives the following benefits:

Trace selected subscribers, for example VIPs and complaining subscribers in order to provide an increased service level.

Help the police by tracing suspected criminals or stolen MSs.

More efficient drive testing due to better visibility and instant feedback.



O&M cost is reduced since it is easier to discover and solve network inconsistencies when drive testing is made more efficient.

Reduce churn by tracing selected subscribers like VIPs or subscribers complaining of poor service. Providing an increased service level makes it easier to retain these subscribers.

4.95.4 Description

Real Time Trace enables tracing of individual subscribers and mobile stations. Traces can be initiated using either IMSI or IMEI. Up to 1000 active traces can be handled simultaneously by BSS. Out of these traces, depending on the traffic load in the BSC, between 30 and up to a maximum of 100 traces can simultaneously collect and send connection data to OSS-RC. Real Time Trace handles both circuit switched and packet switched communications. During a trace it is also possible to see when an individual subscriber or mobile station is moving to or coming from WCDMA radio networks.


Title

The information generated during a trace can be viewed in real time in OSS-RC. For example when a voice call is made it is possible to see when it is set up and network details such as serving cell, allocated radio channel and frequencies. During the call, measurement report data for the radio link can be viewed in both text and graphic form. When the call ends, it is possible to see how it was terminated and the reason why.

Administration and configuration of all traces and display of trace results are performed using the Real Time Trace Manager feature in OSS-RC. Trace data is always stored in OSS-RC for later reviewing and investigation.

4.95.5 Enhancement


The number of active traces handled by Real Time Trace in a BSC is increased from 100 to 1000. The increased tracing capacity makes it easier to use the feature for many different tasks at the same time.

The process to download trace configuration data from OSS-RC to the BSC is improved to minimize start up time. This is especially useful after a BSC restart when configuration data for all traces have to be sent from OSS-RC to the restarted BSC.

The load regulation of traces in the BSC is enhanced to minimize the impact to traces already collecting data. When the BSC is overloaded new traces are not allowed to start sending data to OSS until the load has decreased. If a trace is inhibited to send data, the Real Time Trace Manager application in OSS-RC is informed so that a notification can be displayed in the trace log.


Title

4.96 Remote OMT over IP



Technology: GSM

4.96.1 Attention


Not applicable

Dependencies





4.96.2 Summary

The Remote OMT over IP makes it possible to perform OMT functionality on a remote RBS 2000 or RBS 6000 (GSM part) via a remotely located BSC without allocating a whole timeslot between BSC and RBS. Remote OMT over IP and BSC communicates over TCP/IP. The OMT signaling is embedded in the LAPD signaling between the BSC and the RBS.

The Remote OMT over IP is used as a complement to the OMT to reduce the number of site visits. Remote OMT over IP will also make it possible for experts to remotely guide service personnel at site and it will also make it easier to prepare for a site visit.


Title

4.96.3 Benefits

Retrieves detailed information about an RBS remotely from a TCP/IP network connected BSCs.

Performs fault localization of an RBS remotely from a TCP/IP network connected BSCs. This means that it will be easier to prepare for a site visit and it will be possible for experts to remotely guide service personnel at site.

Performs "hardware reset" of an RBS remotely from a TCP/IP network connected BSCs.

Benefits with Remote OMT over IP compared to Remote OMT:

A whole time slot does not have to be allocated for OMT signaling. The signaling is embedded in the LAPD signaling.

It is much easier to establish a connection for the OMT signaling as it is not needed to set up a path in the transmission network. Access to an IP network is the only thing that is needed.

OMT functionality can be performed from many remote sites (from anywhere with a TCP/IP connection).

4.96.4 Description

The Remote OMT over IP is used to remotely perform OMT functionality from a TCP/IP network connecting BSCs.

The Remote OMT over IP is mainly used for:

Getting detailed information about an RBS. The information can be used to remotely verify that an RBS is correctly configured and to perform preventive maintenance.

Fault localization of an RBS. Experts can use the Remote OMT over IP to perform fault localization and to guide service personnel at site.

Restart of a whole RBS or a part of an RBS. The same type of restart that is achieved by pushing a reset button in an RBS can be performed with the Remote OMT over IP. This may be useful in situations with abnormal RBS behavior.

The Remote OMT over IP is installed on a PC. Remote OMT over IP and BSC communicates over TCP/IP. The signaling between the BSC and the RBS is embedded in the LAPD signaling.


Title

Four OMT users can be connected to one BSC at the same time. Each OMT user can be connected to one RBS. Several users can not be connected to the same RBS.

From the BSC it will be possible to enable/disable Remote OMT over IP communication with BSC/BTS.

There exist two access possibilities, via APG 40/43 or via STOC (Signaling Terminal for Open Communication). STOC is a Regional Processor based hardware with a specific SW that allows the BSC to be linked to a TCP/IP channel. Encryption (SSH2) and Ethernet redundancy is supported when accessing via APG.


A PC with a processor that fulfils the operating system requirements

Windows 2000, Windows XP or Windows Vista

At least 50 Megabytes available hard disk space

At least 512 MB of RAM

Remote OMT over IP needs a network adapter to access to the TCP/IP network connected to the BSC

4.96.5 Enhancement



Title

4.97 Remote Operation and Maintenance Terminal



Technology: GSM

4.97.1 Attention


Not applicable

Dependencies





4.97.2 Summary

The Remote Operation and Maintenance Terminal (Remote OMT) makes it possible to perform OMT functionality, for RBS 2000 and RBS 6000 (GSM part) base stations, from a BSC site. The Remote OMT is used as a complement to the OMT to reduce the number of site visits and to be able to send people, without expert knowledge, to site for fault handling.

4.97.3 Benefits

The Remote OMT makes it possible to:

Retrieve detailed information about an RBS remotely from a BSC site.


Title

Perform fault localization of an RBS remotely from a BSC site. This means that personnel without expert knowledge about the RBS can be sent to a site for replacement of a faulty unit.

Perform "hardware reset" of an RBS remotely from a BSC site.

4.97.4 Description

To be able to perform OMT functionality from a central site the Remote OMT can be used. The Remote OMT is used as a complement to the OMT.

The Remote OMT is mainly used for:

Fault localization of an RBS - Personnel, with good knowledge about RBS can use the Remote OMT to perform fault localization and describe for a person with less RBS knowledge what has to be done on site. The person, with less RBS knowledge, is sent to the site to handle the fault.

Getting detailed information about an RBS -The information can be used to remotely verify that an RBS is correctly configured and to perform preventive maintenance.

Restart of a whole RBS or a part of an RBS - The same type of restart that is achieved by pushing a reset button in an RBS can be performed with the Remote OMT. This may be useful in situations with abnormal RBS behavior.

The Remote OMT is installed on a PC, which is connected to an E1 or T1 interface on a BSC for communication with an RBS.

To establish a connection between Remote OMT and an RBS, a path in the transmission network is set up. The Remote OMT uses one PCM timeslot for the communication with an RBS. The user can select any PCM timeslot that is free to use for this communication.


A PC with a processor that fulfils the operating system requirements

Windows 2000, Windows XP or Windows Vista

At least 50 Megabytes available hard disk space

At least 512 MB of RAM

Remote OMT needs PCM card and cable to connect to the BSC

Remote OMT uses one PCM timeslot for communication with an RBS.


Title

4.97.5 Enhancement



Title

4.98 Self Configuring Transcoder Pools



Technology: GSM

4.98.1 Attention


Not applicable

Dependencies


4.98.2 Summary

Self Configuring Transcoder Pools offers automatic reconfiguration of transcoder HW and transcoder pools based on transcoder pool usage statistics. This implies more efficient usage of transcoder resources, especially when used together with Dynamic Half Rate Allocation. Operation and maintenance cost is reduced, due to that monitoring of the transcoder pool usage and reconfiguration of transcoder HW will not be needed.

4.98.3 Benefits

The benefits of the feature are:

Cost savings due to simplified Operation & Maintenance

More efficient usage of transcoder resources

4.98.4 Description

The feature offers automatic reconfiguration of transcoder HW and transcoder pools based on transcoder pool usage statistics.


Title

The BSC identifies which HW and which pools that shall be reconfigured. An OSS application is then triggered that performs the reconfiguration of the HW and the transcoder pools. A minimum of 24 channels and a maximum of 96 channels are reconfigured each time.

The feature supports both immediate reconfiguration and delayed (during night time) reconfiguration.

Evaluation of idle transcoder resources in each pool is performed every 10th second. When immediate reconfiguration is selected, the mean average usage over the last two minutes is calculated and used as decision criteria. Delayed reconfiguration means that a reconfiguration is performed every 1 to 7 days. The mean average usage during the last hour is calculated and highest average during the period of 1 to 7 days is used as decision criteria.

Immediate reconfiguration is recommended for maximum HW utilization when used together with Dynamic Half Rate Allocation.

Due to the new allocation mechanism, where free device groups are kept free as long as possible, idle channels for reconfiguration will always be available. No blocking of resources or intra-cell handovers to release transcoder channels will be needed.

The operator is able to specify if the reconfiguration shall be performed immediately or at a specific time. The time for delayed reconfiguration can be set as well as the thresholds for when transcoder resources are allowed to be added or removed from each pool.


Title

4.99 Semi-Dedicated PDCH



Technology: GSM

4.99.1 Attention


Not applicable

Dependencies

4.99.2 Summary

The Semi-Dedicated PDCH feature improves the utilization of PCU resources while maintaining the high accessibility for GPRS and EGPRS services that a dedicated timeslot provides. This makes it possible to aggressively allocate resources for GPRS/EGPRS at reduced cost.

4.99.3 Benefits

More channels can be reserved for packet data services as the cost of reserving timeslots for GPRS/EGPRS is reduced significantly.

The operator can aggressively improve accessibility and throughput for GPRS/EGPRS without risking poor hardware utilization of PCU resources.

The operator can dimension the RPP boards in the PCU according to the expected GPRS/EGPRS traffic load while still reserving channels for packet data in each cell.

Up to sixteen channels can be reserved in a cell for GPRS/EGPRS ensuring high quality data services almost regardless of the packet data load in each cell.


Title

4.99.4 Description

GPRS/EGPRS accessibility is dependent on free capacity in the radio network. By reserving at least one timeslot for GPRS/EGPRS users per cell, the end users will always have access to packet data services. In case of further need for GPRS capacity, when traffic is growing, reserving even more timeslots is recommended.

This feature introduces a new operator configured PDCH type, called semi-dedicated PDCH, that allows an operator to reserve timeslots for packet data users at a significantly reduced cost. The reason is that with semi-dedicated PDCH timeslots are reserved over the air for GPRS/EGPRS but the PCU resources are only used when data traffic is generated.

The following definition applies for the different PDCH types:

A dedicated PDCH is a PDCH permanently allocated in a cell with associated hardware in the PCU. This PDCH type is also referred to as a fixed PDCH.

A semi-dedicated PDCH is a PDCH that is permanently allocated in a cell but not always activated, i.e. hardware in the PCU is not tied to the channel until the packet switched traffic requires it. A semi-dedicated PDCH can not be pre-empted by circuit switched (CS) calls.

An on-demand PDCH is a PDCH that is only activated and used when needed under the condition that there is idle timeslots in the cell.

For a semi-dedicated PDCH, PCU resources (GSL devices) are assigned and released in a similar way as for an on-demand PDCHs. This means that there is a time-out handling (using the same timer as for the on-demand PDCHs) before it is de-activated and the GSL device is released. If the value of the timer is higher than 30 seconds the PDCH is de-activated and the GSL device released after 30 seconds. This maximum time of 30 seconds is to ensure that GSL devices are not kept too long which prevents other cells from using them. For on demand PDCHs longer times of the timer can be valuable to protect the channels from being used by CS, but for semi-dedicated PDCHs this is not needed as they can never be used by CS.

With the introduction of Semi-Dedicated PDCH it is also possible to reserve up to 16 timeslots in a cell for packet data users as either semi-dedicated or dedicated PDCHs. The total number of dedicated and semi-dedicated PDCHs in the cell can however not exceed 16, or 8 if extended range is used in the cell.

A semi-dedicated PDCH can not be used as a Master PDCH.


Title

4.100 SGSN in Pool support in BSC



Technology: GSM

4.100.1 Attention


Not applicable

Dependencies

Hardware impacts and dependenciesNot Applicable

Internal product impacts and dependenciesFAJ 121 786 - Gb over IP is required.

Other node impacts and dependenciesFAJ 121 788 - SGSN Pool for GSM is required for Ericsson SGSN.

Terminal impacts and dependenciesNot Applicable

4.100.2 Summary

SGSN Pool makes it possible to connect a BSC to several SGSN nodes. This introduces a more flexible and efficient architecture with built-in network redundancy, which replaces the traditional hierarchical network structure. Now improved, one BSC can be connected to 32 SGSNs.

4.100.3 Benefits

Improved service availability due to redundancy of SGSN nodes.

Capacity and node efficiency in the Core Network due to load sharing between SGSNs.


Title

Fewer interruptions and reduced inter SGSN signaling due to fewer Routing Area Updates.

Enables less traffic disturbance and improved operational efficiency when adding new SGSNs.

4.100.4 Description

An SGSN in Pool consists of a number of SGSN and BSC nodes. One BSC can be connected to up to 32 SGSN nodes. The SGSN in Pool-area comprises all areas (cells) of one or more BSCs that are served by a certain group of SGSNs in parallel. One or more of the SGSNs in this group may in addition serve areas served by BSCs outside the Pool-area or may also serve other Pool-areas.


Title

When an MS enters a new BSC the Network Resource Identifier (NRI) is retrieved from the MS. NRI is a specific parameter used to identify the SGSN assigned to serve a mobile station. The NRI is part of the Temporary Mobile Subscriber Identity (TMSI) and P-TMSI, which is assigned by the SGSN. The BSC will route the PS traffic from the MS to the SGSN indicated by the NRI and vice versa. If the NRI isn't recognized by the BSC the BSC will select an SGSN randomly. Capacity can be more efficiently used by exploiting non-coincident busy hours. Consider for example two service areas with peak loads at 10 am and 10 pm respectively. By creating a common Pool-area will the combined peak load of the SGSNs be less than the sum of the peak load of the individual SGSNs. SGSN in Pool leads to fewer inter-SGSN Routing Area Updates. This will reduce the signaling load of the CN and provide better GPRS/EGPRS performance due to reduced interruptions. The introduction of new SGSNs in the network is simplified since it is not necessary to move BSCs from one SGSN to a new one when more capacity is needed. The configuration of the new SGSN can be identical with the already existing SGSN in the pool. There is no need to change the configuration and service areas just because a new SGSN is added to the network. The addition of new SGSNs can be done without any service disruption. SGSN in Pool will increase the service availability. GPRS/EGPRS based services will still be available in the whole Pool-area even if an SGSN node becomes unavailable. If a SGSN which is part of a Pool-area fails, the ongoing GPRS/EGPRS sessions via this SGSN will be interrupted. With the redundancy provided by SGSN in Pool the MSs can immediately make a new attach and continue with a new GPRS session, if the capacities in the remaining SGSNs of the Pool-area are sufficient. With SGSN in Pool it is possible to connect more than one SGSN nodes to one BSC. This means that the maximum size of the BSCs PCU is not limited by the capacity of a single

4.100.4.1.1.1 SGSN node

The SGSN in Pool support in BSC is implemented according to the 3GPP specification TS 23.236 v5.2.0.

4.100.5 Enhancement

Enhancements in BSS 08B:

Number of SGSN in pool increased from 16 to 32

Aligned solution across Ericsson nodes, 32 SGSN can be connected to one BSC when using SGSN in pool

Enhancements in BSS G11B:

An enhancement to the feature in BSS 08B


Title

CAP parameter introduced in SGSN in pool feature

SGSN for new session is selected based on SGSN capacity - controlled by CAP parameter

Aligned solution across Ericsson nodes


Title

4.101 SIGTRAN Support in BSC



Technology: GSM

4.101.1 Attention


Not applicable

Dependencies

Hardware impacts and dependenciesFor all BSC nodes, with the exception of EvoC 8200/BSC, SLI boards are required.


Other node impacts and dependencies In MSS, SIGTRAN is supported from Ericsson MSC R11 / MGw R3.1 and MSC R12 / MSS R4 (MSC-S R12 & MGw R4).Ericsson Mobile Positioning System has support for SIGTRAN from MPS 8.0.


4.101.2 Summary

This feature makes it possible to transport Signaling System No.7 (SS7) signaling traffic over IP, on the following BSC interfaces:

interface to MSC or MSC-S/MGw

Ater-interface to BSC/TRC

Lb interface to SMPC node in positioning system


Title

Introduction of SIGTRAN follows earlier introductions of Gb over IP and Abis over IP. Now all site-external interfaces can be run over IP in a modern layered architecture implementation where the MGw is normally co-located with the BSC.

4.101.3 Benefits

General consolidation of competence towards IP, simplifications of configuration and possibilities for capacity savings in the core network are the primary drivers:

SIGTRAN in BSC is a step towards all IP, followingGb over IP and Abis over IP. With SIGTRAN, the BSC follows same principles as core network for all SS7 over IP signaling.

Further, for Mobile Soft Switch (Layered Architecture) there is no need to do BSSAP/BSMAP SS7 configuration in the MGw which saves effort for the operator. Moreover, there are operator saving in the MGw (ATM card saving).

Also SGw capacity is saved in the combined MGw/SGw when BSSAP signaling is bypassing the MGw in the IP network. Thanks to that, more SGw capacity becomes available for IP to TDM translation (M3UA to MTP3 translation). Or, for larger MGw's more MGw processors can be dedicated for call handling instead of signaling which means higher MGw capacity.



Signalling Transport over IP (SIGTRAN) provides the operator with a possibility to build and IP-based SS7 signaling transport network. This is especially attractive for operators that use an IP based transport backbone also for other services. IP multi-service use cases allow the operator to optimize the overall transmission related costs.

The IP-based SS7 signaling transport network can transport all of the operators signaling traffic. Once it has been introduced, scalability of the signaling network capacity is not anymore a problem. Enlarging the IP infrastructure with more router capacity will increase the signaling capacity without any need to re-engineer the complete signaling network.

The site simplifications in configuration and the use of IP routers save administration costs for the operator.

By consolidation of all signaling to IP, the operator can concentrate competence build up to IP area, which saves cost. IP competence is generally more widely available than SS7 competence.


Title

Further, there are direct hardware savings in the core network, both SGw capacity in combined MGw/SGw, and in MGw when SIGTRAN is used instead of HSL.

If positioning system is used, there are direct hardware savings in the SMPC node by saving the SS7 signaling HW.

Overall, the main values are operator-internal "soft values" and SIGTRAN needs to be part of a strategy of consolidating towards IP. The feature will also bring valuable IP transport experience and allow the operator to make a strategic move towards 'All IP' solutions.

4.101.4 Description

All SS7 configurations are supported, i.e. ANSI, ETSI and MPT/TTC.

SS7/C7 and SIGTRAN can be run at the same time on the same BSC, where an application could be e.g. running SIGTRAN on Lb interface and SS7 on the A interface.

The throughput of SIGTRAN is significantly higher compared to NB signaling and HSL links and will fulfill the BSC needs. Calculations based on typical traffic model shows that even a large BSC with a capacity of 12000 Erlang can be handled by a single SLI board (1+1 for redundancy).

SCTP (Stream Control Transfer Protocol) together with the adaptation layer M3UA form the binding layer between the application protocols (e.g. MAP) and the IP network in order to provide a reliable transport mechanism.

The signaling transport technology can be defined per route set. A route set consists of all routes towards a certain Destination Point Code (DPC). Hence, this feature makes it possible to transport the signaling traffic towards selected destinations over an IP bearer, whereas the rest of the signaling traffic can still be transported over other types of bearers.


Title

4.102 Smooth GSM to WCDMA Unloading



Technology: GSM

4.102.1 Attention


Not applicable

Dependencies


4.102.2 Summary

The feature helps assuring resource availability in GSM cells and limits handover load at high load situations. Handover cause codes are used between the GSM BSC and the UTRAN RNC to improve the load based inter-RAT handover.

4.102.3 Benefits

Less risk for dropped calls associated with intersystem handover as number of load triggered handovers is reduced

Less risk for congestion in GSM cell because the cause for handovers are known

Better network dimensioning because of improved network monitoring capabilities

4.102.4 Description

Smooth GSM to WCDMA Unloading helps avoiding congestion in GSM cells by looking at the reason for incoming handovers from WCDMA. It also helps WCDMA avoid overload situations by providing the reason for a required handover from GSM to WCDMA. Logging of handover results for handovers of the different reasons are done.


Title

In addition the rate with which unloading of a GSM cell is done is reduced in order to even out system load, and not perform more handovers than required to keep the load in the GSM cell below the load threshold. The number of load triggered handovers allowed per second is configurable per cell.

If a handover request message with cause value "Directed Retry" or "Reduce Load in serving cell" is received from the WCDMA RNC (via the MSC) and the load in the target GSM cell is above the configured load threshold for GSM to WCDMA handover, the incoming handover is rejected. The cause value "No radio resources available" is used to indicate the reason to the requesting RNC. If a handover request is received with other cause values the handover is not subject to load sharing, and is not rejected due to high load.

The BSC indicates the reason for the handover to the WCDMA RNC. If load in GSM is the reason for a handover required (the load threshold passed) that is indicated by sending the cause value "Reduce load in serving cell". This makes it possible for the WCDMA RNC to distinguish between load sharing and handovers due to other reasons, which should not be subject to load sharing, and to treat them differently.

In case the handover is rejected by the WCDMA RNC due to load in the target WCDMA cell, the UTRAN RNC may indicate the reason by sending the cause value "no resources available" (which should be mapped by the MSC to "No radio Resource Available"). The cause value will be used to trigger the sending of R-PMO events.


Title

4.103 SMS Cell Broadcast



Technology: GSM

4.103.1 Attention


Not applicable

Dependencies


Not Applicable


Not Applicable


Not Applicable


Not Applicable

4.103.2 Summary

SMS Cell Broadcast (SMS-CB) is a teleservice which enables an information provider to send short messages to all MSs in an area. The area may be as small as a single cell or as large as the whole PLMN. The service is similar to teletext, offered on television.


Title

A MS may receive a number of messages which can be selected by the subscriber. The subscriber may search through the different messages to find information that is interesting. SMS-CB messages are not acknowledged by the MS.

4.103.3 Benefits

An operator can increase revenue using SMS-CB by selling air time to advertisers. The resulting advertisements will most probably stimulate subscribers to place calls in the network thereby creating additional revenue.

An operator can enhance his image as a provider of advanced services thereby gaining a competitive edge on new competing operators. Providing innovative services will also allow him to differentiate his services from those of his competitors.

Examples of services which can be provided to end users are: traffic information, weather forecasts, or short news flashes. Since different SMS-CB messages can be defined in different cells, the information can be specific for a certain geographical location. For example, it may show the telephone numbers for the hotels, tourist information offices, police stations or health care offices which are close to the position of the subscriber.

Providing end users with "new" services, free of charge, will help to attract new subscribers to the operator's network.

Operators can enhance their image as a reliable service provider by providing information about the network, free of charge, on new teleservices or on planned outages due to maintenance activities.

For end users, SMS-CB allows many new services which could help them save both time and money. For example, if a subscriber is informed that he is in the home location, he would know that calls could now be made at the lower cost rate. This could result in longer calls or even more calls being made!

4.103.4 Description

A short message is stored in the BSC by operator command. The message is broadcast in one or numerous cells. All MSs which are camped on, that is, listening in on the cell(s) may decode the message. The implementation of the MS defines how the user accesses the message. The transmission of each message may be scheduled: the start and end time as well as the period between transmissions of each message can be specified.


Title

Transmission of the messages takes place on the Cell Broadcast Channel (CBCH). Therefore, SMS-CB has only marginal influence on cell channel dimensioning and no impact on traffic dimensioning. One message contains up to 93 7-bit characters, 82 8-bit characters or 40 UCS2 16-bits characters. Up to 96 message pages in total can be broadcasted in one cell at the same time.

The Cell Broadcast Channel (CBCH) is supported by using one Stand Alone Dedicated Control Channel (SDCCH/8) or by using one of the combined BCCH/SDCCH channels (SDCCH/4).

This feature provides support for GSM Phase 2+. Message Identifier, Message Code, Update Number and Serial Number are included.

The geographical scope is a parameter which can be set. It makes it possible for an operator to define the area for which a message code is unique (cell wide, Location Area wide or PLMN wide), and whether an immediate display or a display under user interaction should be made of the message.

Languages supported: German, English, Italian, French, Spanish, Dutch, Swedish, Danish, Portuguese, Finnish, Norwegian, Greek, Turkish, Arabian, Bengali, Chinese, Gujarati, Hebrew, Japanese, Kannada, Korean, Malayalam, Oriya, Tamil, Telugu, Thai and Tibetan.

In addition to the 7 bit encoding and the 8 bit encoding (added in R7), 16-bit encoding scheme (UCS2) is supported. This enables all mobiles to encode the SMS-CB.

4.103.5 Enhancement


SMS Cell Broadcast can now be used when Master PDCH is activated. This is achieved through support for broadcasting of the PSI8 message on the PBCCH.


Title

4.104 Software Power Boost



Technology: GSM

4.104.1 Attention


Not applicable

Dependencies


Supported on RBS 6000 with RUG and all RBS 2000. For RBS 2101/2102/2202 CDU-A is required and for RBS 2106/2206 CDU-G in uncombined mode is required.


Software Power Boost can not be combined with FAJ 122 078 Transmitter Coherent Combining (TCC).

It is not recommended to use Software Power Boost together with LMU based positioning methods, for example U-TDOA, since positioning accuracy is affected.


Not Applicable


Not Applicable


Title

4.104.2 Summary

Software Power Boost enhances the coverage area of base stations, making it possible to achieve larger coverage compared to normal base stations. This is valuable for new operators who strive for fast and easily built coverage. An increased coverage area can also be useful in regions where the capacity load is limited for the foreseeable future.

4.104.3 Benefits

The main benefit with Software Power Boost is increased coverage on RBS sites where it is deployed.

Increased coverage has a number of advantageous effects:

Cost savings as fewer RBS sites are needed to cover a certain areas.

Shorter time to launch a network because fewer sites are needed.

Better indoor coverage.

Improved network quality since coverage gaps can be handled from existing sites.

The feature also allows easy reconfiguration between the coverage enhancing software power boost mode and normal operation, which enables quick adaptation to changing coverage/capacity requirements in a network.

4.104.4 Description

With Software Power Boost (or Tx Delay Diversity as it is also known) the transceivers are used in "pairs", that is two normal transceivers transmit the same data on the same frequency. A small time delay is inserted between the transceivers, which causes a diversity effect in the terminal, since it receives two independently faded radio signals thus improving the received signal quality. This is possible since the equalizer in the handset receiver is specified to handle a wide time delay spread.

The feature gives a downlink diversity gain of around 3 dB depending upon the surrounding environment. In a flat environment this can correspond to a 20-30 % decrease in number of sites required to achieve ubiquitous coverage. This is directly translated into reduced cost since a large part of the radio network cost is tied to the number of sites. Increased coverage of RBS sites is also beneficial when rolling out a new network or covering new areas since services can be launched with fewer sites, leading to earlier network launch.


Title

Software Power Boost is also of interest for live networks. For example, coverage gaps can be bridged using only existing sites. Thus a cause for high drop-call rates and/or poor indoor coverage can be avoided without additional sites.

By combining Software Power Boost with FAJ 122 430 Dynamic Overlaid/Underlaid Subcells it is possible to increase capacity without sacrificing the coverage enhancements provided by Software Power Boost. This is possible since with Dynamic OL/UL Subcells the cell is split into two subcells, where the underlaid subcell operates in Software Power Boost mode while the overlaid subcell uses normal mode. Extra capacity is thereby efficiently added by transceivers allocated to the overlaid subcell.

In normal operation two transceivers corresponds to two carriers but in Software Power Boost mode capacity is reduced to one carrier. Reconfiguration of the RBS 2000 mode of operation between normal operation and Software Power Boost mode can be done from the BSC and does not require additional site visits. It is therefore possible to quickly adapt the radio network to changing coverage and capacity requirements.

Software Power Boost is supported on all RBS 2000. For RBS 2102/2202 and RBS 2101 CDU-A is required, and for RBS 2106/2206 CDU-G in uncombined mode is required.

Software Power Boost can not be used together with the feature FAJ 122 078 Transmitter Coherent Combining (TCC) simultaneously in the same cell/sector or subcell.

It is not recommended to use Software Power Boost together with LMU based positioning methods, for example E-OTD. When Software Power Boost is used, the same signal is sent twice with a slight delay and the LMU will not know which signal is the correct one, which leads to decreased positioning accuracy.


Title

4.105 Spatial Triggers Performance



Technology: GSM

4.105.1 Attention


Not applicable

Dependencies


HLR: FAJ122471 - Spatial Triggers Support in HLR

MSC-S: FAJ121608 - Spatial Triggers


Not Applicable


Not Applicable


The featues FAJ 121 608 Spatial Triggers in the MSC-S and FAJ 122 471 Spatial Triggers Support in HLR in the HLR are required. Support is also required in the GMPC.


Not Applicable


Title

4.105.2 Summary

The feature Spatial Triggers Performance enhances the accuracy of Spatial Triggers. The feature provides CGI/TA accuracy instead of CGI accuracy. Although depending on network density, this typically means 50% higher accuracy.

4.105.3 Benefits

Improved accuracy for Spatial Triggers by about 50%.

Applications that utilize Spatial Triggers and require higher accuracy than what is possible with CGI can be enabled.

4.105.4 Description

Spatial Triggers is an alert functionality, where a user/object "A" is notified when a spatial criterion is met by another user/object "B", i.e. when the user/object "B" leaves or enters a geographic area that has been defined by the user/object "A".

Examples of applications where Spatial Triggers are very useful include FriendFinder/Dating, Security, Fleet Management and Push Advertisements.

The feature Spatial Triggers Performance provides the Core Network and Gateway Mobile Positioning Centre (GMPC) with CGI and TA information. Having CGI and TA compared to only CGI improves the accuracy of Spatial Triggers by about 50%, as information about distance from the site is added (by TA). The improvement in relative and absolute terms is dependent on network site density, but 50% is typically the case for Suburban and Rural environments.

Based upon Ericsson traffic model assumptions the whereabouts of a subscribing user is updated with CGI and TA every 23 minutes, with this feature - compared to once every 5 hours without it.

The Core Network and Gateway Mobile Positioning Centre (GMPC) are provided with CGI and TA information for the following events:

Mobile Originated Traffic

Mobile Terminated Traffic

Periodic Location Update

Location Area Update

Mobile Originating SMS


Title

Mobile Termination SMS

Supplementary Services Activation

Supplementary Services Deactivation

CGI and TA is also sent in MS page response and at emergency call with the feature FAJ 121 51 Flexible Positioning Support.

In addition, the GMPC can at anytime get a fresh CGI /TA update by e.g. sending an SMS type 0 ('dummy SMS'). Without this feature only fresh CGIs are available.


Title

4.106 Speech Quality Priority



Technology: GSM

4.106.1 Attention


Not applicable

Dependencies





Not Applicable


One or more of the features FAJ 122 582 Dynamic Half Rate Allocation, FAJ 121 361 Dynamic FR/HR Adaptation and FAJ 121 846 Abis Triggered HR Allocation are required.



It is recommended to use parameter profiles in OSS-RC to simplify administration of parameter settings for the different subscriber priority levels.



Title

Not Applicable

4.106.2 Summary

Speech Quality Priority makes it possible to manage the allocation of HR based on subscriber priority. This enables a reduction of CAPEX/OPEX since fewer transceivers are needed. Low priority subscribers can have a high HR utilization without impacting on the service quality of high priority subscribers.

4.106.3 Benefits

The Speech Quality Priority feature provides the following benefits:

Increased half rate utilization during traffic peaks

Ensure that high priority users enjoy the best possible speech quality

Ensure adequate speech quality for low priority subscribers without preventing high utilization of half rate during traffic peaks



Fewer transceivers are needed since it is possible to dimension for a higher utilization of half rate among low priority users without impacting on the service quality of high priority subscribers. This is especially useful for handling traffic peaks.

Save transmission cost by letting low priority subscribers use HR on the Abis interface.


It is possible to have a premium subscription with higher service quality for high priority subscribers.

4.106.4 Description

The Speech Quality Priority feature introduces subscriber priority as a criterion when determining if a subscriber shall be allocated a full rate or a half rate traffic channel.


Title

Speech Quality Priority impacts all features that govern the allocation of full rate and half rate channels. Dynamic Half Rate Allocation, Dynamic FR/HR Allocation, Abis Triggered HR Allocation and Full Rate AMR on 8kbps Abis all benefits from the subscriber priority handling enabled by Speech Quality Priority.

At call setup and handover, separate thresholds for each priority level are provided for cell traffic load, Abis interface load and signal strength. Low priority subscribers are transferred to half rate channels first, when the cell traffic load or Abis load thresholds used for ongoing calls are triggered by increasing traffic load. When the traffic load decreases high priority subscribers are transferred back to full rate channels first. The radio link quality thresholds used when transferring a call from a full rate to half rate channel and vice versa are configured separately for each subscriber priority level.

Altogether this ensures that the best possible speech quality can be provided to high priority subscribers at all times. Simultaneously adequate quality can be provided to subscribers with lower priority without impacting the congestion control available through the use of half rate channels.


Title

4.107 Speech Quality Supervision



Technology: GSM

4.107.1 Attention


Not applicable

Dependencies


Not Applicable


SQI downlink, FER distribution and FER drop statistics, requires that Enhanced Measurement Reporting is active.


Not Applicable


Not Applicable

4.107.2 Summary

Speech Quality Supervision (SQS) allow operators to get information about the subjective speech quality in the network (as perceived by the end users).

The enhanced performance indications that SQS provides shortens the time needed for network quality improvements.


Title

4.107.3 Benefits

Improved connection quality, since better monitoring capability makes it easier to improve network quality.

Longer call times, fewer calls being disconnected due to poor speech quality

Reduced O & M cost, SQS gives the operator an opportunity to deploy speech quality measurements throughout the entire network rapidly and cost-effectively.

4.107.4 Description

Speech Quality Supervision (SQS) is a function that enables monitoring of the subjective speech quality on the uplink and downlink throughout the whole network. A Speech Quality Index (SQI) value is calculated in the BTS using Bit Error Rate (BER) and Frame Erasure Rate (FER) data collected in the BTS and in the MS, for each ongoing speech call in each cell or subcell. The data is sent to the BSC, where the SQI values are sorted into three categories representing Good, Acceptable and Unsatisfactory speech quality. SQS makes it possible to quickly assess the speech quality in a network as it is perceived by all subscribers.

The SQI algorithm is based on the correlation between the RXQUAL, BER and FER measurement values and the subjective speech quality (as experienced by the end user). Extensive testing performed to validate the used algorithms shows a correlation of more than 93% in all measured cases.

The speech quality for individual calls can also be traced with SQS using the feature FAJ 122 299 Mobile Traffic Recording (MTR).

The combined use of SQS and the feature FAJ 122 522 Measurement Result Recording (MRR) enables operators to quickly solve quality problems in a network. By using SQS it is possible to rapidly pinpoint problem cells without having to analyze numerous different counters. Once a problem cell has been identified MRR is used to investigate the problem in more detail. This also makes cell planning easier as cell plans can easily be tested and optimized.

SQS decreases the need for drive tests as the speech quality for every call within a BSC can be monitored, from network level down to subcell level.

SQS support calls using the full rate (FR), enhanced full rate (EFR), half rate (HR) and adaptive multi rate (AMR) speech codecs.


Title

4.107.5 Enhancement


The enhancements of the SQS feature are made possible by the feature FAJ 121 821 Enhanced Measurement Reporting.

The feature enables full visibility of the speech quality status in a network, thereby allowing better optimization of the radio network. This is achieved by providing SQI for the downlink for terminals capable of Enhanced Measurement Reporting (EMR). The corresponding counters (STS), monitors (R-PMO) and MTR data that are currently available for the uplink are added for the downlink. The ability to monitor both links of a call is important since the speech quality can be different in the two links.

New FER distribution statistics are introduced in both STS and R-PMO based on data in the enhanced measurement reports. Since FER is unique for each codec it is possible to see the FER distribution separately for each speech codec. The new FER statistics are available for both the up- and downlink, however downlink statistics can only be provided for terminals supporting EMR. FER distribution data is also added in MRR.

Dropped call counter due to high FER are added as a complement to the existing call drop counters based on RXQUAL and RXLEV. Using FER a much better indication regarding the speech quality at call drops is received.


Title

4.108 Statistics based on Measurement Results



Technology: GSM

4.108.1 Attention


Not applicable

Dependencies


4.108.2 Summary

This feature extracts the information from the measurement reports sent from the mobiles and BTS's and creates histogram reports of signal strength, quality, timing advance, etc. on a subcell level.

4.108.3 Benefits

Provides means to observe and monitor the radio link performance for each cell in the network

Increased radio network quality by providing enhanced possibilities to tune the radio network for the operator. As an example this feature supports the operator in understanding if poor quality in a cell is related to interference (improve frequency plan) or coverage (new cell or antennas needed).

Decreased cost of operation because measurements are provided by the system thus decreasing the number of radio network measurement investigations needed by the operator in evaluating the radio network.

Improves radio network feature quality verification as the impacts on activating a new feature can be measured by the BSS system in a faster and more accurate way.


Title

4.108.4 Description

During a call the mobile continuously sends measurement reports to the BTS. This information, together with the BTS measurements on the uplink, is sent to BSC.

This feature records the measurement reports and provides the information to the operator. The feature can be started for a cell(s) or for all cells in the BSC. The recording duration time can be from 15 minutes to 168 hours (one week).

When the feature is activated by operator commands the BSC starts the recording. The measurement reports are collected in histograms per subcell.

The following information is provided in the histogram:

Uplink and downlink signal strength

Uplink and downlink signal quality

Uplink and downlink path loss

Power level used by the MS and the Base Station

Timing advance value

It is also possible to start a recording on different criteria. For a triggering criterion it is possible to specify bigger or equal to a value, equal to a value or lesser or equal to a value.

The different triggering criteria of when measurement reports shall be recorded are one of the following:

Uplink signal strength

Downlink signal strength

Uplink signal quality

Downlink signal quality

Timing advance value

At the end of every recording, the collected statistics are saved on a file in the BSC. This file can be fetched by OSS for further evaluation.


Title

4.108.5 Enhancement


Measurement results are now available on a per channel group basis. The resolution has earlier been limited to the sub-cell level. As a result problems with a specific transceiver will be easier to identify when a specific channel group can be studied in detail. This also enables optimization for different quality needs in different channel groups.

Monitoring of the Path loss difference (Path loss Downlink - Path loss Uplink) has been introduced. Assuming an equal path loss in up- and downlink of the air interface, it will now be possible to find differences in the gain and loss balance between the transceiver input/output and the antenna. This will result in direct control over faulty antenna and feeder connections and to identify faulty feeder installations where the uplink and downlink are measured from different cell sectors (swapped feeders).

A new filtering option is AMR full rate. A recording can consist of only connections using AMR full rate, no connections using AMR full rate or connections using any speech codec. This enables targeted optimization activities when AMR mobile stations are introduced in the network. For example the performance of the feature AMR Power Control can be optimized.

The total number of collected measurement reports in the cell will be presented, which is a way to validate collected statistics in recordings when filtering has been used.


Title

4.109 Support for 1024 cells in BSC



Technology: GSM

4.109.1 Attention


Not applicable

Dependencies


4.109.2 Summary

The system limits for the maximum number of internal cells, External cells and neighboring cell relations are increased. This is useful to support large BSCs and BSCs in complex radio network environments with high numbers of neighboring cell relations.

4.109.3 Benefits


CAPEX savings for areas where BSCs with more than 512 cells are needed, for example in rural areas.

Increased flexibility in handling of neighboring cells in multi band networks due to increased neighboring cell relations.

OPEX savings due to reduced number of BSCs needed.

Improved GPRS/EGPRS performance due to fewer inter-BSC cell reselections.


Title

4.109.4 Description

This feature increases the BSC/TRC system limit for maximum number of Internal Cells from 512 to 1024. To align with the increase in maximum number of Internal Cells, the following system limits are also increased:

External Cells from 512 to 2048

Neighboring cell relations from 8192 to 32768

In multi band networks there is a need for more neighboring cell relations since there are more cell neighbors. The relation between the maximum number of cells and maximum number of neighboring cell relations is doubled to improve the flexibility when planning multi band networks.

Fewer BSCs leads to improved GPRS/EGPRS performance since the service interruption time is longer at inter BSC cell reselections compared to intra BSC cell reselections. With this feature it is possible to build larger BSCs which leads to fewer inter BSC cell reselections.

This feature handles GSM cells and cell relations. WCDMA Cells are handled by FAJ 121 617, 2048 WCDMA Neighbor Cells.


Title

4.110 Support for 4000 TRXs per BSC



Technology: GSM

4.110.1 Attention


Not applicable

Dependencies

Hardware impacts and dependencies Increasing the number of TRXes of a BSC might require memory expansion on APZ 212 30/3x.




4.110.2 Summary

This feature increases the maximum number of supported TRXs to 4095 in a BSC and BSC/TRC. The feature will reduce the operators CAPEX and OPEX by e.g. fewer sites and simplified network growth.

4.110.3 Benefits

The main benefit with 'Support for 4000 TRXs per BSC' is the possibility to have fewer BSCs in high traffic capacity areas. Fewer BSCs and BSC splits gives the following benefits:

CAPEX savings due to reduced number of BSCs needed.

More cost effective upgrade of BSCs in operation.


Title

Operation and maintenance savings due to fewer nodes.

Reduced signaling and load.

Improved GPRS/EGPRS performance due to fewer inter-BSC cell reselections.



By reducing the number of sites the overall cost will be reduced for the operator for power, maintenance and operation

CAPEX

By reducing the number of nodes the investment in HW is reduced for the operator

Fewer nodes have a positive impact on transport network costs.

4.110.4 Description

The Support for 4000 TRXs per BSC feature increases the maximum number of supported TRXs from 2048 to 4095.

The possibility to build larger BSCs and BSC/TRCs means that savings can be done due to that fewer nodes can be used. Network roll-out will be easier and existing growing networks can be expanded with fewer BSC splits.

SW upgrades will be more cost effective since fewer nodes needs to be updated. Operation and maintenance costs will also be reduced due to fewer nodes to manage and visit for maintenance reasons.

The reduced number of nodes will also lead to reduced signaling and load on the BSCs due to reduced number of Inter-BSC handovers and cell reselections.

New product packages are defined for new nodes.

New nodes can be ordered in a number of capacity steps up to the maximum configuration that supports up to 4095 TRXs.

High Speed Signaling Link is required to support the increased signaling, unless the


Title

BSC/TRC is connected to a Pool of MSCs. If MSC in Pool is used the signaling load will be divided on several A-interfaces.

4.110.5 Enhancement

Enhancement in BSS 09A

In addition to APZ 212 55, BSCs based on APZ 212 30/33/33C may be expanded up to 4095 TRXs.


Title

4.111 Support of Remote BSCs



Technology: GSM

4.111.1 Attention


Not applicable

Dependencies


4.111.2 Summary

This feature provides the possibility to support remote BSC's by physically separating the transcoder units from the BSC and placing the transcoders in the TRC. The interface between the TRC and the BSC is called Ater.

BSC (without transcoders) and the TRC are introduced as two new types of (physical) network elements. Together with the existing combined BSC/TRC, the BSC and the TRC provides the operator with a flexible way of implementing different BSS topologies.

Up to 16 BSC's can be connected to one TRC and up to 15 BSC's can be connected to a BSC/TRC. The trucking achieved in the TRC or BSC/TRC reduces the number of transcoders needed.

4.111.3 Benefits

Flexibility to mix any type of network topologies. Operators get the possibility to build networks with smaller low capacity BSC's (without transcoder resources) in rural areas placed remotely in the network or high capacity BSC/TRC's in urban areas placed close to the MSC.


Title

Decreased transmission cost when building for coverage in rural areas. Reusing the existing BSC/TRC and replacing transmission hubs with BSC's decreases the transmission cost and increases the capacity in the existing BSC/TRC and in the network in total.

The Ater interface between the TRC or BSC/TRC and the BSC carries 4 speech calls (Full rate or Enhanced Full rate) or 8 speech calls (Half rate) per PCM timeslot thus uses the PCM timeslots efficiently.

Possibility to lower infrastructure cost when sharing transcoder resources for up to sixteen BSC's. The TRC or BSC/TRC node makes it possible to configure a network with several smaller BSC's sharing pooled transcoder resources in a common TRC or BSC/TRC. This reduces the total number of required transcoder resources in a network with up to 20%. Especially in case several types of transcoder units are required to provide different services, such as different speech codecs, etc.

Reduced infrastructure cost because of possibility to switch both on Ater- and A-interface in the TRC or BSC/TRC. The switching possibilities makes the TRC or BSC/TRC future proof since new services requiring new complex transcoders can be added in a cost efficient way, thus reducing infrastructure cost.

New supervision functionality in order to detect faults and incorrect configurations. This will lower the cost of operation and make it possible to increase revenue.

Remotely placed BSC's can be fully controlled from OSS. All necessary maintenance, except for hardware changes, can be made from OSS.

4.111.4 Description

To allow a more flexible system structure three types of (physical) network elements are included in BSS:

BSC (without transcoders)

TRC

The existing combined BSC/TRC.

The TRC node has the ability to support up to sixteen BSC's over the Ater interface. The transcoders in the various TRA pools in a TRC can be shared between all BSC's associated with the TRC. One of the connected BSC's may be residing on the same physical platform as the TRC, that is, in a combined BSC/TRC network element.


Title

One TRC or BSC/TRC can be connected to up to four MSC's. This makes it possible to build rather large Trace's or BSC/TRC's supporting several MSC's. One BSC is still controlled by one specific MSC.

The TRC or BSC/TRC can contain several transcoder resource pools, one pool per type of transcoder resource (for example, Full Rate, Enhanced Full Rate and Half Rate).

The A-interface signaling remains unchanged in the new system structure. For communication between the TRC or BSC/TRC and a remote BSC a Signaling System number 7 based Ericsson proprietary communication protocol is used. In the case of a combined BSC/TRC internal signaling between the TRC and BSC part is used.

The TRC or BSC/TRC node handles the Ater transmission interface resources. The operation and maintenance signaling and handling of the Ater interface (that is, Block/Ack, Unblock/Ack, Reset Circuit/Ack and Unequipped Circuit) is similar to the current implementation on the A interface.

At call set up, and after signaling connection set up, an assignment request is sent via the MSC to the BSC. The request is sent directly to the BSC and can pass transparently through the TRC or BSC/TRC. The BSC received the assignment request and requests a transcoder device from the TRC or BSC/TRC also indicating the A-interface CIC to be used for this specific call. The TRC or BSC/TRC allocates a transcoder device and the time slot on the Ater interface, which is connected to the A-interface CIC specified by the MSC. The TRC or BSC/TRC replies to the BSC, which establishes the connection to the mobile.

New administration functions for handling of BSC and TRC are introduced. Some of them are:

TRC Destination Point Codes

Ater Signaling Type

Ater Transmission Type

A and Ater interface connections (CICs)

BSC and TRC Ater Digital Paths

BSC and TRC Ater Line Terminal Devices

BSC and TRC Call Path Tracing


Title

Various Ater interface resource statistics information (such as amount of Allocation Attempts, Congestion, Available Seized and Blocked Ater resources).

Seizure Supervision and Blocking Supervision of the Ater Line Terminal Devices in the TRC are also available.


Title

4.112 Synchronized Radio Networks



Technology: GSM

4.112.1 Attention


Not applicable

Dependencies


Supported on RBS 6000 and RBS 2000 equipped with DXU-21 or similar platform such as RBS 2308.

The feature requires that a GPS receiver supporting the Ericsson GPS synchronization interface is connected to the RBS.


Not Applicable


Not Applicable


Not Applicable


Title

4.112.2 Summary

The feature makes it possible to run synchronized radio networks by connecting GPS receivers to the radio base stations. It is also an enabler for multi standard mixed mode since it allows connection of synchronization from a DUL or DUW.

Network wide synchronization enables increased spectrum efficiency and network performance.

4.112.3 Benefits

Increased radio network capacity with up to 30%, with maintained network quality.

Up to double efficiency of interference suppression features.

Enables multi standard mixed mode

4.112.4 Description

Synchronized Radio Networks enables an entire GSM network to be synchronized by connecting GPS receivers on each BTS site. In such a network, the base stations are frame synchronized so that bursts are aligned and transmitted at the same time in different cells. The base station are aligned to each other using the time synchronization reference provided by the GPS receiver. The alignment of the BTSs introduces the possibility to tighten the frequency reuse.

Synchronized Radio Networks offers the possibility to frame synchronize cells located on different sites with each other. This gives opportunities to enhance performance even more for FLP networks, since interfering cells can be handled no matter on which site they are located. In a synchronized radio network interference is not only managed by planning of MAIO but also appropriate handling of HSN and FN Offset are needed. As a basis for the planning it is necessary to identify which cells are interfering each other, this is described in the ICDM (Inter-Cell Dependency Matrix). For efficient operations and best performance of synchronized FLP networks it is strongly recommended to use the feature FAJ 123 162 Automatic FLP.

Networks synchronization also improves the efficiency of the interference suppression feature FAJ 122 083 Interference Rejection Combining (IRC). IRC performs best when the interference is the same during the whole burst, which due to the alignment of bursts between all cells is the case in a synchronized radio network. To ensure the best possible interference suppresion performance it is recommended to either FAJ 123 162 Automatic FLP or FAJ 123 163 Automatic IRC Tuning.


Title

Synchronized Radio Networks is fault tolerant and has built-in recovery mechanisms. A frame synchronized base station is able to uphold synchronization to the nominal position even though the synchronization information needed for the calculation of the nominal position is temporary unavailable, e.g. due to temporary GPS satellite shadow. If the base station is unable to uphold synchronization to the nominal position, e.g. due to deactivation of GPS, permanent GPS satellite shadow or equipment failure, then the base station is still able to provide service by automatically selecting a backup synchronization source. The synchronization to the nominal position is automatically recovered when enough number of GPS satellites are available or when the equipment failure is recovered.

An alternative solution to build a synchronized radio network is to use the feature FAJ 121 3204 BTS Soft Synchronization. Both soft synchronized and GPS synchronized BTSs can coexist in a synchronized radio network.


Title

4.113 Tandem Free Operation



Technology: GSM

4.113.1 Attention


Not applicable

Dependencies


For BSCs with transcoders, TRA R6 or later is required.

Supported on RBS 6000 and all RBS 2000 except RBS 2301 prior to R6A.


One or more of the features FAJ 121 329, Enhanced Full Rate (EFR), FAJ 121 055, Adaptive Multi Rate (AMR) and FAJ 121 358, AMR Half Rate are required.


To enable transmission savings in the core network, the features FAJ 121 866 TFO/TrFO Interworking in the MSC-S and FAJ 121 939 Tandem Free Operation (TFO) in the M-MGw are required.


Not Applicable


Title

4.113.2 Summary

Tandem Free Operation (TFO) enables transmission of GSM encoded speech end to end through the network. This both improves voice quality and substantially reduces the transmission bandwidth requirements in the core network.

4.113.3 Benefits

Tandem Free Operation gives the following benefits:

A four to eight times reduction of the transmission bandwidth needed in the core network for a call.

Improved voice quality for MS to MS calls.



The cost for backbone transmission can be significantly reduced since the bandwidth needed for voice calls can be significantly reduced.


Improved voice quality can reduce churn and increase talk time. The image of being a high quality operator can also help attract new subscribers.

4.113.4 Description

When Tandem Free Operation (TFO) is used the speech is not decoded or encoded in the BSS transcoder, instead it is sent encoded through the system from one MS to the other, or from the MS to the transcoder at the edge of the core network. This means that a call only uses 16 kbps of a 64 kbps timeslot on the A interface. However multiplexing of calls is not standardized for BSS, so each 64 kbps timeslot is still only capable of carrying one call.

In a core network using layered architecture with TFO-TrFO (Transcoder Free Operation) interworking deployed in the MSC Server and MGw (Media Gateway) a further reduction can be made, for example for AMR only 4.75 to 12.2 kbps needs to be transmitted through the backbone network. Considering that about 40% of the time during a call there is silence and DTX applies, the average bit rate is even lower.


Title

The reduction in bandwidth required for a call enables substantial transmission savings in the core network, especially when packet based transmission is used. For example, a normal 64 kbps PCM encoded call requires a bandwidth of 147 kbps, when transmitted over an IPv4 network. In contrast to this a call in TrFO mode only requires 20 kbps with DTX active on IPv4 and only about 10 kbps on ATM.

In a monolithic core network using traditional MSCs, transmission savings are also possible with TFO. In this case multiplexers supporting TFO are needed between the MSCs to multiplex four calls into each 64 kbps timeslot on the E interface.

Since all speech decoding/encoding stages in the network are bypassed when TFO is used, TFO enhances speech quality for MS to MS calls. The improvement is larger for speech codec modes with low bit rate, such as the lower AMR modes.

TFO between GSM and WCDMA, and between Full Rate AMR and Half Rate AMR is supported. TFO in BSS is supported for the EFR, Full Rate AMR and Half Rate AMR speech codecs.

4.113.5 Enhancement

The operation and maintenance of TFO is improved. The activation procedure is simplified by minimizing the number of MML commands needed. It is also easier to see if TFO is active for a certain call and to evaluate how much TFO is used.


Title

4.114 Tight BCCH Frequency Reuse



Technology: GSM

4.114.1 Attention


Not applicable

Dependencies


Not Applicable


Not Applicable


Not Applicable


Not Applicable

4.114.2 Summary

This feature enables the operator to apply significantly tighter frequency reuse of BCCH frequencies and thereby increasing traffic capacity in the network.

The feature is designed for frequency planning strategies where the BCCH is non-hopping, as for instance in the case of Fractional Load Planning (FLP).


Title

4.114.3 Benefits

Introducing Tight BCCH Frequency Reuse in a network where the BCCH carrier is not frequency hopping gives the following benefits:

Better spectrum efficiency by enabling a substantial tightening of the frequency reuse for the non-hopping BCCH carriers.

Reduced need for investment in new sites/cells, due to increased capacity in existing cells.

Better end user speech quality since non-hopping traffic channels (on the BCCH carrier), less robust to interference, will only be used in the inner parts of a cell.

Easier initial EGPRS deployment.

Improved accessibility due to decreased number of random access failures.

4.114.4 Description

The feature ensures that the traffic channels on the BCCH carrier are used by MSs that are close to the BTS where interference is less severe than on the outskirts of the cell. The feature works by applying separate path loss and DTCB (Distance-To-Cell-Border) thresholds on channel group 0, where the BCCH resides.

This means that a substantial tightening of the frequency reuse on BCCH is possible, freeing up frequencies - no longer needed for BCCH - to be used for increasing macro-cell capacity, implementing micro-cell layers or for special/temporary use when solving capacity or quality issues.

The feature is applicable in networks where the BCCH carrier is non-hopping, which is common when using FLP (Fractional Load Planning). By implementing Tight BCCH frequency Reuse in these networks it is possible to significantly tighten the frequency reuse of the BCCH carriers. To guarantee acceptable speech quality on non-hopping traffic channels a frequency reuse of ~18 and more is common. When Tight BCCH Frequency Reuse is used the reuse can be tightened to ~12 with maintained good speech quality. This means that a non frequency hopping BCCH carrier can have similar frequency reuse as a frequency hopping BCCH carrier with equal speech quality.


Title

The initial deployment of EGPRS in a baseband-hopping network is made easier with the feature. This is achieved by installing one new EGPRS-capable TRU in each cell where EGPRS is required. The BCCH is then assigned to the new TRU and set to non-hopping, while the other TRUs continue base-band hopping. Tight BCCH Frequency Reuse is necessary for maintaining good speech quality on the traffic channels of the non-hopping, but EGPRS capable, BCCH carrier. Without the feature it would be necessary to either allocate more spectrum to the non-hopping BCCH carriers, which wastes valuable spectrum and may lower the overall network capacity, or to replace all TRUs in the cell with EGPRS capable ones in order to support EGPRS, which increases initial investment.

Provided that FAJ 122 260 Dynamic MS Power Control is applied to the uplink, the added benefit of traffic on the BCCH being close to the BTS, is that uplink interference levels on BCCH frequencies generally decrease. This results in an improved accessibility and fewer random access failures.

The thresholds in Tight BCCH Frequency Reuse only affects traffic channels and not control channels, therefore the BCCH and any SDCCH channels will function over the entire cell. Due to the more robust coding of the signaling channels the increased interference caused by the tighter frequency reuse will not impact signaling performance.

The feature does not require subcells to be implemented. If subcells are used, the BCCH (in channel group 0) can be placed in either of the two subcells. This provides additional flexibility and more options especially in multiband networks, where it is beneficial to put the BCCH in the low-frequency spectrum in order to provide best possible idle mode coverage.

Due to the new feature, a new set of CHAP (Channel Allocation Profile) values is supported to enable Immediate Assignment on TCH in situations where the BCCH is in the overlaid subcell.


Title

4.115 Traffic Level Measurement Data



Technology: GSM

4.115.1 Attention


Not applicable

Dependencies


The BSC IP network interface is required.


Not Applicable


In MPS (Mobile Positioning System) the feature INF 901 2472 Anonymous Bulk Location Data Support is required.

To enable correlation of data from connections made at different occasions by same user FAJ 121 2405 IMSI Visibility is required in the MSC-S.


Not Applicable


Title

4.115.2 Summary

The feature collects and exports subscriber information that for example can be used to produce real time road traffic information. This information can for example help road users avoid traffic jams or be used by road authorities when planning the road system.

4.115.3 Benefits

Cost efficient service provisioning

Increased revenue by providing new services

Improved subscriber satisfaction

4.115.4 Description

The feature Traffic Level Measurement Data sends simplified measurement report data containing cell id and TA (Timing Advance) in real time for all active connections in a BSC to MPS. This data can for example be used to generate anonymous locating information for all subscribers, which then is used to calculate real time road traffic information. This information can be provided to road users to help them plan their journeys both before and after departure. The information can also be used by road authorities when planning new roads etc.

Applications providing road traffic information are already available on certain markets today. With this feature there is no longer a need to use Abis analyzers or probes to generate the network data needed as input. This both simplifies and reduces the cost for setting up and maintaining this kind of service.

Many subscribers are using roads to travel to and from places and most want to make their trip as quick as possible, and for example not get caught up in traffic jams. Providing traffic information can therefore be a very popular service that can both increase operators revenue and improve subscriber satisfaction.

Road traffic statistics are also valuable for road authorities that use it to plan upgrades, extensions etc. of the road system. Today they have to resort to use many different means like, CCTV, magnetic coils, GPS equipped test cars etc., to try to obtain this information. These methods are often expensive to deploy and maintain and/or provide limited information. By using data already available in the mobile networks, road traffic statistics that are much more complete from both a coverage and quantity point of view, can be provided by operators in a cost efficient way.


Title

4.116 Transmission Performance Supervision of T1 Trunks



Technology: GSM

4.116.1 Attention


Not applicable

Dependencies


4.116.2 Summary

This feature reports and supervises the transmission quality on 1.544 Mbit/s trunks, at the BSC end. These trunks can be towards RBS's or MSC. Supervision is done through interworking with other Statistics and Traffic Measurements (STS) and OSS features.

If the BSC and the RBS or MSC are connected by an external transmission network such as a leased line network, then this feature only supervises the transmission path from the BSC to the external transmission equipment. If a 'transparent' external network such as a radio link is used, then this feature provides end-to-end supervision.

This feature requires ETC24/96, which supports extended superframe, performance report message according to ANSI T1.403, and DS1 metallic interface.

4.116.3 Benefits

This feature enables the operator to maintain high transmission quality on the digital transmission path. At the BSC, transmission performance and quality is monitored for both incoming and outgoing traffic on the T1 trunk.


Title

Transmission costs are a significant concern when operating a network. For network operators who must lease transmission links from a leased line operator, it is vital that full utilization of expensive transmission links is maintained. Transmission alarms from the hardware are continuously supervised so that possible faults are quickly discovered and maintenance staff alerted. Loop tests can also be initiated by the operator at the BSC. This allows the operator to check newly installed links.

Historical performance information is stored in STS (IOG 11) and can be retrieved via OSS. This information on transmission performance over time can be a valuable input to optimizing transmission efficiency.

4.116.4 Description

Transmission performance quality is supervised by a number of parameters. Counters will be provided in STS for local presentation or distribution to network management nodes. These counters will be used to monitor the performance of the digital transmission path in both directions.

Both the ITU-T and Bellcore/ANSI standards in relation to transmission performance supervision are adhered to.

The transmission performance quality is based on:



Slip Frequency (SF)

Eroded Seconds (ES)

Severely Eroded Second (SES)

Unavailable Seconds (UAS).

Performance Report Messages (PRM) are sent using the LAP-D/G.921 protocol. Without PRM, only the performance/quality of incoming traffic on the T1 trunk from the local side could be monitored.

The digital path is continuously supervised in order to detect fault and fault indications, for example, loss of incoming signal. If a fault is detected an alarm is issued (after the alarm fault filtering time).


Title

The operator has the possibility to initiate payload and line loopback tests. These can be used as a maintenance tool to investigate and aid solving possible problems on T1 trunks. If the trunk from the BSC is connected to 'non-transparent' transmission equipment such as a Digital Cross Connect, then only the link from the BSC to the DXC will be tested.


Title

4.117 Transmitter Coherent Combining (TCC)



Technology: GSM

4.117.1 Attention


Not applicable

Dependencies


Supported on RBS 6000 with RUG and RBS 2000 with either DRU or dTRU and CDU-G. Note that early versions of dTRU might not support TCC.


TCC can not be combined with the feature FAJ 121 489 Software Power Boost.


Not Applicable


Not Applicable


Title

4.117.2 Summary

Transmitter Coherent Combing (TCC) increases the maximum output power with 2.5 dB by using both transmitters of a dTRU to implement one carrier. This is achieved by sending identical bursts at the same time on both transmitters. TCC can be used to increase coverage, which is very valuable for operators with an existing 800 or 900 MHz network expanding into a higher frequency band (1800 or 1900) since it enables reuse of existing sites. It is also valuable for new GSM 1800 and GSM 1900 operators, who strive for fast and easily built coverage.

4.117.3 Benefits

2.5 dB higher output power, which enables a 20 to 30% decrease in required sites to achieve ubiquitous coverage.

A high degree of flexibility, since no extra hardware or site visits are needed to change between coverage or capacity mode.

Easy expansion without need to add antennas as well as a possibility to mix transmitters working in different modes in the same cell since only one TX antenna is needed per TCC carrier.

4.117.4 Description

Transmitter Coherent Combing (TCC) increases the maximum output power of a RBS 2106/2206 with an additional 2.5 dB. This is achieved by loss-less combining and using the two transmitters of a dTRU to implement one carrier by sending identical bursts coherently on the same frequency with equal amplitude and phase. The increased power can, for instance, be used to increase the cell range of rural sites and the loss-less combining means that only one transmit antenna is needed per TCC carrier.

Activation and deactivation of TCC is easily performed by configuration commands and requires no site visits since no special hardware or additional Abis transmission timeslots are needed.

It is possible to mix transceivers working in normal and TCC mode within the same cell. This together with the feature Dynamic Overlaid/Underlaid Subcells gives the ability to optimize traffic distribution within a cell, which gives a solution that offers both coverage and capacity at the same time.


Title

Further benefits of TCC can be exemplified by the case of bridging coverage gaps in a live network. Assume that a coverage gap exists between two cells. This could be noticed as high drop call rate or poor indoor coverage. Using TCC in the existing sites is the most economical way of bridging the coverage gap. Later when the capacity demand increases and new sites are deployed the extra coverage is no longer needed. It is now that the flexibility of TCC reveals its full value as the capacity can be increased from one TCC carrier to two normal carriers without site visit.


Title

5 New Features in GSM RAN G10A - OPTIONAL FEATURES


Title

5.1 Dynamic Half Rate for AMR-WB



Technology: GSM

5.1.1 Attention


Not applicable

Dependencies



GSM RAN SW: FAJ123137 - AMR Wide Band


Not Applicable


FAJ 123 137 AMR Wide band and FAJ 122 315 Half rate Channels are required.

FAJ 121 358 AMR Half Rate is strongly recommended.


Not Applicable


Not Applicable


Title

5.1.2 Summary

Dynamic Half Rate for AMR-WB makes it possible to allocate standard Half Rate or HR-AMR to AMR-WB users at very high traffic loads. This allows the operator to avoid congestion at traffic peaks, while minimizing the speech quality impact for AMR-WB users.

5.1.3 Benefits

Minimizes speech quality reduction for AMR-WB users



Dynamic Half Rate for AMR-WB minimizes speech quality reduction for AMR-WB users, which helps keeping the end-user churn at a low rate.

5.1.4 Description

Dynamic Half Rate for AMR-WB provides separate cell traffic load and Abis transmission load thresholds for control of half rate channel allocation at call set up and handover. This makes it possible for the operator to allocate half rate channels to non AMR-WB terminals first and only allocate half rate channels for AMR-WB capable MS if cell traffic load or Abis transmission load is very high.

The half rate speech codecs used together with this feature are the standard Half Rate codec and the Half Rate AMR codec.

The speech quality difference is very large between the half rate codecs and the AMR-WB codec. It is therefore important to allocate AMR-WB to subscribers with AMR-WB capable terminals as much as possible in order to avoid disappointed subscribers.


Title

5.2 EDGE Evolution – Dual Carrier



Technology: GSM

5.2.1 Attention


Not applicable

Dependencies

Hardware impacts and dependencies The feature is supported on all EDGE capable hardware. All EDGE capable RBS models from RBS 2x02 and onwards support Dual Carrier

Internal product impacts and dependencies Depending on operator's initial EDGE configuration, the amount of EDGE timeslots may have to be increased, which may put additional requirements on Abis, PCU and Gb dimensioning. To minimize cost of transmission, FAJ 123 174, Packet Abis over TDM or FAJ 123 175, Packet Abis over IP is recommended


Terminal impacts and dependencies 3GPP Rel-7 terminals supporting Dual Carrier Downlink (DCDL) are required

GSM RAN SW: FAJ12131 - EGPRS

5.2.2 Summary

Being part of EDGE Evolution, Dual Carrier enables demanding mobile broadband and other high bit rate services in the GSM/EDGE network. The downlink bit rate to the end-users is doubled compared to a single carrier allocation.


Title

5.2.3 Benefits

Double downlink bitrates, up to 592 kbps in downlink (using 8-PSK and 2x5 timeslots)

Fast and cost efficient roll out of mobile broadband services, software upgrade only

Better experience for users who fall out of WCDMA or LTE coverage to GSM



With the increased EDGE bitrates it is possible to maintain a mobile broadband service in the GSM network. Therefore investments in WCDMA or LTE can be focused on sites with higher capacity demands, which optimize the total business case for Mobile Broadband.


With twice as high bit rate delivered to the end-users it is possible to address new services and revenues within the GSM/EDGE network, for example mobile broadband. In addition, high-end data users benefits from improved performance, for example web surfing on a Smartphone.

5.2.4 Description

By allowing transmission on two downlink GSM carriers simultaneously to the same user, it is possible to allocate more EDGE timeslots to this user. With Dual Carrier, up to 10 timeslots can be allocated to a single user, thus improving bitrates significantly compared to terminals with 4-5 timeslots. For example, using 8-PSK, the peak rate to a single user is 592 Kbit/s when 10 timeslots are allocated.

The two carriers allocated to the dual carrier user can be any two carriers within the same frequency band. This mean that there is no impact on existing frequency planning or frequency hopping when enabling dual carrier in a cell. In addition, the timeslot sharing mechanisms remain the same meaning that the timeslots allocated to a dual carrier user can be shared with other dual carrier or single carrier GPRS/EDGE users.


Title

With Dual Carrier, the mechanisms for on-demand and dedicated PDCH still apply. Therefore it is possible to configure only one or a few dedicated timeslots in the cell to guarantee PS availability during the busy hour, but outside the busy hour let on-demand PDCHs be allocated so that Dual Carrier can be used. Therefore deployment of dual carrier can be done with no reduction in voice capacity.

All bitrates mentioned are the maximum RLC bit rate in good radio conditions.

Dual Carrier is only applicable in the downlink direction and only for EDGE connections.


Title

5.3 GSM-LTE Cell Reselection



Technology: GSM

5.3.1 Attention


Not applicable

Dependencies


5.3.2 Summary

With this feature a GSM/LTE capable terminal in GSM is able perform cell reselection to LTE in both idle and packet transfer mode. Support for defining LTE neighbors is added to the BSS in order for the terminal to measure and select neighboring LTE cells.

5.3.3 Benefits

Enabling basic mobility and interworking from GSM to LTE

Users with GSM/LTE capability currently in GSM can move to LTE as soon as coverage from LTE is available.

Priority between GSM, WCDMA and LTE is configurable per cell which enables different IRAT strategies per area.


Title



The combined coverage of GSM, WCDMA and LTE can be utilized to optimize roll out of new systems which reduces CAPEX.


For operators deploying LTE it is possible for dual-mode capable users to move from GSM to LTE, thus making full use of the LTE system wherever there is coverage.

5.3.4 Description

GSM-LTE Cell Reselection covers cell reselection in idle and packet transfer modes without the network taking part in the decisions of which cells to select. The GSM network broadcasts system information and defines neighbor lists needed for cell reselection. The feature enables LTE capable terminals to detect LTE access and perform a cell reselection to LTE.

With this feature it is possible to set priority between GSM, WCDMA and LTE cells. The operator can configure which system terminals shall prefer in different areas.

The estimated application level outage during the GSM to LTE cell reselection is approximately six seconds including effects from TCP slow start and radio bearer establishment.

Note that users engaged in a CS call do not move to LTE since it is BSS that is then in control and the normal CS mobility is applied.


Title

5.4 Multiple CCCH



Technology: GSM

5.4.1 Attention


Not applicable

Dependencies




Not Applicable


Not Applicable


Terminal support is required.

5.4.2 Summary

Multiple CCCH makes it possible to configure up to 3 additional Common Control Channels (CCCH) per cell. This provides increased CCCH capacity in cells where this is required.


Title

5.4.3 Benefits

Handle more connection set ups, such as speech calls, SMS and PS transfers in a cell



Reduces the need for alternative solutions like for example location area split and cell split, which are both costly and time consuming.


Increased traffic since lost calls and degradation of other services due to control channel congestion is minimized.

This is important in cells with many transceivers, especially when they are located on a location area border, and in cells with heavy GPRS/EDGE traffic which depending on the content can require many paging messages during a transfer.

5.4.4 Description

Multiple CCCH makes it possible to configure up to three additional CCCH per cell. These additional CCCHs are also referred to as channel combination VI in the 3GPP standard. This significantly increases the capacity for paging and access in cells.

All CCCH configured in a cell are allocated on the BCCH carrier. The timeslots used for the additional CCCH are number two, four and six.

When Multiple CCCH is used together with GPRS/EDGE extra considerations might be needed since it becomes harder to achieve efficient multislot allocations on the BCCH carrier if many additional CCCH are used.

An MS that is allocated to one of the extra CCCHs reads system information transmitted on that timeslot.


Title

5.5 Time Slot Power Savings



Technology: GSM

5.5.1 Attention


Not applicable

Dependencies

Hardware impacts and dependencies The feature requires TRX types RUG (all models), DRU (R4 and higher) or dTRU (R6A and higher).

Internal product impacts and dependencies Note that the feature is fully compatible with FAJ 122 931 BTS Power Savings, the two features can co-exist on the same RBS.



5.5.2 Summary

The power amplifier is de-activated when there is no traffic on a timeslot. This results in the RBS consuming less power and thereby reducing the power consumption of the entire site.

5.5.3 Benefits

The OPEX (in terms of electricity bills or in some cases fuel costs) is reduced by less power consumption of the BTS, as well as less energy losses due to power conversion and active cooling


Title

The deactivation of timeslots is transparent to all other functionality, with for instance no impact on channel allocation and frequency hopping in the base band hopping case



The energy consumption of the radio network is reduced and OPEX is lowered.

The savings by the feature can be estimated by calculating the difference between the number of channels in a cell and the average traffic (Erlangs) carried (both CS and PS).

A simplified method, when the data traffic is relatively low, would be to use Erlang-B traffic formula. In situations where DTX is used, the activity factor (the amount of time the DTX function results in no transmission due to the end-user being silent) need to be applied to the voice traffic.

The saved energy is estimated by multiplying the number of deactivated channels with the total power savings per timeslot when deactivated (an approximate value is 2-3 W/time slot depending on the type of RBS and site). The figures are then easily extended to savings for the entire network by summing up the savings for all cells.


Title

5.5.3.1.1.2 Corporate Responsibility

Reducing wasteful energy usage and supporting an environmentally friendly image of the operator/company.

5.5.4 Description

When time slots in GSM are not needed for carrying traffic, the power amplifier bias is adjusted for the duration of the time slot (and consecutive time slots when applicable) resulting in a much lower power consumption. The feature reacts instantaneously to the traffic on the time slot, including when DTX is active during a voice call and also for packet data when the PDCH has nothing to transmit.

The feature requires no reconfiguration of TRX or channels when active and is completely transparent for all other features.

There are STS counters for observability of the number of time slots being deactivated during a given period.


Title

6 New Features in GSM RAN G10B - OPTIONAL FEATURES


Title

6.1 A-interface over IP



Technology: GSM

6.1.1 Attention


Not applicable

Dependencies


M-MGw: FAJ1210720 - A-interface over IP

MSC-S: FAJ1210726 - A-interface over IP


AXE 810 based BSC or later is required, that is High Capacity BSC, High Density BSC and Evo Controller nodes.

One or more AGW Boards (AGWB) is required in the BSC.

TRA boards are required in the BSC to support CSD and FAX in GSM RAN G10B. From G11B TRA boards are not required anymore since CSD and FAX are handled by the AGW.


FAJ 122 626 SIGTRAN Support in BSC is recommended

Discontinuous Transmission (DTX) Uplink, which is part of the feature FAJ 121 0894 Radio Network Efficiency is strongly recommended in order to ensure maximum reduction of required transmission bandwidth on the A-interface

FAJ 122 438 High Speed Circuit Switched Data (HSCSD) is not supported with A-interface over IP


Title


Support for A-interface over IP in the MSC and MGW is required.

When IP is used on the A-interface it is no longer possible to synchronize the BSC via the transmission interface from the MGW. A separate connection to a synchronization source is needed, for example a central building clock.

Mixing IP and TDM transmission on the A-interface in the same BSC requires support in the MGW and MSC.


Not Applicable

6.1.2 Summary

The feature A-interface over IP introduces the possibility to use IP transmission for the connection between the BSC and the MGW. This brings about a number of benefits, for example reduced bandwidth on the A-interface and TRA HW savings in the BSC.

6.1.3 Benefits

A-interface over IP provides the following benefits:

Enhanced transcoder (TRA) utilization, since transcoding can be done in the MGW.

Fewer TRA’s is needed since Transcoder Free Operation (TrFO) can be used for MS to MS calls.

Speech quality is improved when TrFO is used.

Reduced transmission cost for the A interface since less bandwidth is needed due to the use of compressed speech, RTP multiplexing and header compression.

Easier and cheaper to implement and maintain “MGW in Pool” and MSC in Pool functionality in the network.

TRA pooling with WCDMA in the MGW when common network architecture for GSM and WCDMA is used.


Title



With A-interface over IP there is no longer a need to have TRA HW in the BSC for speech services. Depending on the number of TrFO calls the amount of HW used for transcoding in the MGW may also be reduced. When transcoding is performed in the MGW these resources can also be shared with WCDMA.

E1/T1 transmission equipment in the BSC for the A-interface is no longer needed.

The required bandwidth on the A-interface is reduced by ~60% when sending compressed speech over IP compared to PCM over TDM transmission. If RTP multiplexing and header compression is also enabled then savings of up to 85% is possible.

The feature A-interface over IP makes it both easier and cheaper to connect the BSC to multiple MSC’s (MSC in Pool) and MGW’s, thereby enabling redundancy and load sharing for these nodes.

Another step to full IP in BSS which reduces operation and maintenance cost when only one type of transmission technology has to be supported.

6.1.4 Description

The feature A-interface over IP, which is standardized in 3GPP Rel-8, introduces two major changes to the interworking between BSS and MSS. The first is the usage of IP based transmission for the connection between the BSC and the MGW, the second change is the placement of the TRA function in the MGW.

When IP is used for the A-interface, the payload is sent using the standard RTP/UDP/IP protocol between the BSC and the MGW. In case TRA in the BSC is used the 64 kbps PCM data is packaged and sent over the IP protocol. If TRA in MGW is used the compressed speech frames are formatted and sent over the IP protocol. During the set up of each call the BSC and the MSC-Server negotiates which type of transmission to use on the A-interface and if TRA in BSC or MGW should be used.


Title

The TRA function can be placed in either or both the BSC and MGW. However it is recommended to use TRA in the MGW together with IP transport on the A-interface. This is because sending 64 kbps speech or data over IP increases the bandwidth needed by ~20%. On the other hand sending compressed speech over IP reduces the bandwidth needed by ~60%. Placing the TRA in the MGW also makes TrFO (Transcoder Free Operation) possible, which means that no TRA at all is required for MS to MS calls using the same speech codec in both MS's. TrFO gives the same speech quality increase as the feature FAJ 121 25 Tandem Free Operation.

RTP multiplexing and header compression is supported for the A-interface. The functionality is automatically activated when it is supported by the MGW. Together with compressed speech it enables bandwidth savings on the A-interface with up to 85% compared to using PCM over TDM transmission.

Using IP on the A-interface makes it cheaper and much easier to connect a BSC to multiple MSC-Servers and MGW's compared to traditional TDM based transmission link. For example TDM requires predefined connections in each BSC/MGW, which is not needed when A-interface over IP is used.

The A-interface over IP feature simplifies the transmission network configuration in the BSC and MGW since point to point address definition is not required.

The feature is implemented in the A-interface Gateway (AGW) which consists of a number of AGW Boards (AGWB). N+X redundancy is supported in the AGW.

CSD (Circuit Switched Data) and Facsimile (FAX) are supported for A-interface over IP using TRA in the BSC.


Title

6.2 Antenna Control – Standard TMA



Technology: GSM

6.2.1 Attention


Not applicable

Dependencies

Hardware impacts and dependencies The feature requires a radio unit from the RBS 6000 family.Requires a TMA complying with voltage and current specifications stated by Ericsson.




6.2.2 Summary

The feature enables - through the RBS - supervision and power feed for standard Tower Mounted Amplifiers (TMA), thereby eliminating the need for external and dedicated HW. It is applicable to the RBS 6000 family.

6.2.3 Benefits

Less HW needed at RBS sites

No need for costly installation

Efficient O&M of standard TMAs


Title



No need for installation of extra HW for supervision and power feed for TMAs.

Efficient O&M (alarms and configuration) since it is an integrated part of the BSS system.

Operator Business Case example:

The market price for the alternative solution of having external HW is estimated to approximately 1000 € per 3-sector site. Costs for the installation itself and regular maintenance (market dependent) need to be added in order to get the full impact on operator cost.

6.2.4 Description

6.2.4.1.1 Technical Description

The radio units in the RBS will provide the power and also supervise standard TMAs by monitoring the current consumed by the TMA. A standard TMA is any TMA complying with Ericsson’s normal voltage and current specifications and supporting very rudimentary supervision, but not any advanced and standardized interface (like AISG, Antenna Interface Standards Group), where more advanced supervision options are possible.

Alarms are raised by the RBS when the TMA does not function properly, either degraded or completely down. This is done for the TMAs in both receive branches (when applicable).

6.2.4.1.2 Network Impact

6.2.4.1.2.1 BSC HW Impact

None

6.2.4.1.2.2 BTS HW Impact

The feature requires a radio unit from the RBS 6000 family.


Title

6.2.4.1.2.3 Dependencies to other BSS features

None

6.2.4.1.2.4 Dependencies to other network elements

Requires a TMA complying with voltage and current specifications stated by Ericsson.

6.2.4.1.2.5 Terminals

None


Title

6.3 Automatic FLP



Technology: GSM

6.3.1 Attention


Not applicable

Dependencies


BTS with filter combiners are not supported when FLP is used.

From G14B the following is valid for the BSC:

HC BSC, HD BSC and Evo 8100: Depending on if redundancy is required one or two GSH boards are needed for the Automatic FLP application. In the two board solution 1+1 redundancy is supported. If NTP and BTS Soft Synchronization is used the same boards can support Automatic FLP.

Evo Controller 8200/BSC: One or two (for redundancy) processing cores on EPB1 to house the Automatic FLP application. If BTS Soft Synchronization is used the same processing cores can support Automatic FLP.


Automatic FLP as such does not require that any other feature is used. However, since the purpose of Automatic FLP is to run high capacity FLP networks it is recommended that all radio network features related to running such networks are used, for example DTX, Dynamic Power Control, AMR, IRC, VAMOS etc.

To maximize perfomance of Automatic FLP it is recommended to synchronize the radio network by using the feature FAJ 121 3204, BTS Soft Synchronization. Radio network synchronization is also possible by connecting GPS to the BTS's with the feature FAJ 122 081, Synchronized Radio Networks.


Title

The feature FAJ 123 163, Automatic IRC Tuning is not needed when Automatic FLP is used since the functionality of that feature is included in Automatic FLP.


Not Applicable


Not Applicable

6.3.2 Summary

Automatic FLP allows operators to increase traffic capacity and spectrum efficiency with minimum effort. It ensures that the GSM radio network always has the optimum cell configuration to achieve maximum performance from the FLP (Frequency Load Planning) method.

6.3.3 Benefits

Increased traffic capacity and spectrum efficiency since operators can easily run FLP radio networks with very high frequency load, including fully synchronized networks.

Significantly reduced O&M effort for running all types of FLP networks by automatically ensuring that the optimum cell configuration is always used

Maximizes performance in all types of FLP networks.



Increased spectrum efficiency enables more traffic to be handled by the existing sites, thereby reducing the need for additional sites.

Automatic FLP significantly reduces the effort and knowledge it takes to run a GSM network that has both very high traffic capacity and high spectrum efficiency with good quality.

Apart from some simple initial configuration the feature is designed to be totally autonomous and handle the FLP radio network configuration on its own without manual supervision.


Title

6.3.4 Description

The Automatic FLP feature enables self optimizing FLP (Frequency Load Planning) networks. It automates the FLP related cell data configuration and re-configuration work in a network using the FLP method.

6.3.4.1.1.1 Synchronization monitoring

The cell to cell synchronization status for all cells in a BSC is continuously monitored. Based on this information cells are divided into synchronization clusters. Cells configured to the same cluster must be frame synchronized to each other and belong to the same BSC.

The BTS’s belonging to a BSC running Automatic FLP can be synchronized through different methods, for example PCM or GPS. The feature automatically recognizes which cells are synchronized to each other and handles them accordingly.

6.3.4.1.1.2 Interference matrix

A cell to cell relation interference matrix is maintained in the BSC, by compiling data from daily interference recordings during busy hour. These recordings are handled automatically by the feature and do not impact other recordings in the BSC.

6.3.4.1.1.3 Cell configuration

Configuration of cell data related to the FLP method (for example MAIO, HSN and FNOFFSET) is performed automatically. Input data to the configuration are:

Synchronization status

Interference matrix

HW configuration

When any of the input data changes the feature automatically re-configures the required cell data to ensure optimum performance. For example, re-configuration is initiated if two cells lose synchronization to each other due to GPS problems on a site, or a TRX is added in a cell during capacity extensions.

To avoid unnecessary interference between cells belonging to different BSC’s, inter BSC coordination of certain configuration data is done.


Title

Allocation of the hopping frequencies used in the Automatic FLP cells is done by the operator. This is an easy task in a FLP network.

The performance of Automatic FLP is monitored using the normal radio network performance statistics in the BSC and OSS.

Planning of the BCCH frequencies is not done by Automatic FLP. Instead OSS tools like for example Ericsson Frequency Optimizer can be used.

6.3.4.2 Standards

Based on Ericsson development and not 3GPP.


Title

6.4 Automatic IRC Tuning



Technology: GSM

6.4.1 Attention


Not applicable

Dependencies


From G14B the following is valid for the BSC:

HC BSC, HD BSC and Evo 8100: Depending on if redundancy is required one or two GSH boards are needed for the Automatic IRC Tuning application. In the two board solution 1+1 redundancy is supported. If NTP and BTS Soft Synchronization is used the same boards can support Automatic IRC Tuning.

Evo Controller 8200/BSC: One or two (for redundancy) processing cores on EPB1 to house the Automatic IRC Tuning application. If BTS Soft Synchronization is used the same processing cores can support Automatic IRC Tuning.


Automatic IRC Tuning as such does not require that any other feature is used. However, since the purpose of Automatic FLP is to optimize the performance of interference suppressing features it is recommended to use it together with FAJ 122 083, Interference Rejection Combining (IRC) and FAJ 121 0815, VAMOS.

To maximize perfomance of Automatic IRC Tuning it is recommended to synchronize the radio network by using the feature FAJ 121 3204, BTS Soft Synchronization. Radio network synchronization is also possible by connecting GPS to the BTS's with the feature FAJ 122 081, Synchronized Radio Networks.

Automatic IRC Tuning is not needed if FAJ 123 162, Automatic FLP is used.


Title


Not Applicable


Not Applicable

6.4.2 Summary

Automatic IRC Tuning ensures maximum performance gain from the Interference Rejection Combining (IRC) feature. This is achieved by automatically optimizing cell configuration data related to IRC.

6.4.3 Benefits

Improved network quality and capacity due to better IRC performance for both voice and data

Reduced O&M cost for optimizing IRC performance



Increased network quality reduces churn.

Lower O&M cost since the feature removes the need for manual configuration of cell data related to IRC.

6.4.4 Description

Automatic IRC Tuning provides automatic configuration and re-configuration of cell data (TSC and FSOFFSET) related to the feature FAJ 122 083, Interference Rejection Combining (IRC).

The feature works between neighbor cells that have at least one common frequency and are synchronized to each other.

The feature automatically monitors if cells are synchronized and the cell to cell interference situation. Based on this, the cell configuration is optimized to ensure the best possible IRC performance.


Title

6.4.4.1 Standards

Based on Ericsson development and not 3GPP.


Title

6.5 GSM MCPA Intelligent Power Management



Technology: GSM

6.5.1 Attention


Not applicable

Dependencies


GSM RAN SW: FAJ122287 - Discontinuous Transmission (DTX) Downlink

GSM RAN SW: FAJ122910 - Dynamic BTS Power Control

Hardware impacts and dependencies The feature is supported on all Radio Units supported by RBS 6000 with DUG-20.


BTS G11B SW is minimum required BTS SW level to activate the feature.

FAJ 122 287 Discontinuous Transmission (DTX) Downlink and FAJ 122 910 Dynamic BTS Power Control are required. FAJ 121 1871 GPRS/EGPRS Downlink Power Control and FAJ 123 164 Reduced Power Level After Handover are highly recommended.




Title

6.5.2 Summary

In an MCPA (Multi Carrier Power Amplifier) based RBS several carriers are connected to the same power amplifier and then to the same antenna. The available MCPA output power can be seen as a common resource shared between the RF carriers.

One of the main advantages with MCPA based RBSs is the opportunity to save power and provide high capacity configurations with a minimum amount of hardware.

By maximizing the use of HW capabilities, the feature GSM MCPA Intelligent Power Management ensures high capacity MCPA configurations with minimum impact on important Key Performance Indicators, such as speech quality and packet data throughput.

6.5.3 Benefits

Maximized usage of available MCPA output power, leading to increased capacity and/or coverage per MCPA, as well as energy savings

Efficient handling of the power resource in MCPA secures radio network characteristics, such as EDGE throughput and voice quality

6.5.3.1.1.1 Operator Value

Cost of Ownership

For operators with a need for high capacity GSM sites (>2 carriers per sector), MCPA configurations together with GSM MCPA Intelligent Power Management and other BSS features require less radio hardware than traditional SCPA (Single Carrier Power Amplifier) technology.

In Radio Units supporting 4 GSM TRXes up to 80 W (4 * 20 W) may be configured. In Radio Units supporting 8 GSM TRXes up to 160 W (8 *20 W) may be configured. Without the feature additional Radio Unit HW would have to be deployed.

6.5.4 Description

The MCPA provides a pool of output power that is shared between the RF carriers. With MCPA there is an opportunity to "over-allocate" power in the MCPA, by taking advantage of the statistical gain, i.e. using the fact that not all connections need full output power at the same time.


Title

Dynamic BTS Power Control, Discontinuous Transmission (DTX) Downlink, Reduced Power Level After Handover are general BSS features that make it possible to take advantage of the variations in output power need. These features actively reduce the required output power, resulting in statistical gain and an opportunity to configure more output power than the MCPA rated output power.

Even with above features active, there may still be short periods where the available MCPA output power is not enough, depending on traffic and cell characteristics. This is because the MCPA HW has certain capabilities that cannot violated. The feature GSM MPCA Intelligent Power Management secures minimal performance impact during those periods.

The feature includes a power back-off priority list, which is used to decide how to reduce output power. EDGE 8PSK and other higher order modulation schemes are backed off first. If not enough, then the output power for packet data channels with GMSK and then Voice Channels is reduced. BCCH and other signaling channels have the highest priority to protect.

The result of the feature is that 8 TRX * 20 W can be configured in a 80 or 100 W MCPA with minimum impact on KPIs, such as EDGE throughput and voice quality. It shall also be noted that there is no static average power decrease for higher order modulation schemes, such as 8PSK, as it is in SCPA.

The picture below illustrates that the MCPA for shorter periods of time allows for power levels that are above the required long term average power. The requirement on long term average is defined by the HW capabilities. The feature GSM MCPA Intelligent Power Management ensures that the HW capabilities are used to its full extent, without impacting long term performance of the HW.


Title


Title

6.6 IMSI Handover GSM to GSM



Technology: GSM

6.6.1 Attention


Not applicable

Dependencies


MSC-S: FAJ1212405 - IMSI Visibility


Not Applicable


Not Applicable


FAJ 121 2405 IMSI Visibility is required in the MSC-S.


Not Applicable

6.6.2 Summary

This functionality allows selective Inter PLMN GSM to GSM handover based on the IMSI number. It is very useful in a shared BSS network, where there is a need for the operator to keep its own subscribers in the home PLMN or in a PLMN with roaming agreements.


Title

6.6.3 Benefits

Very useful in a shared BSS network where terminals are moving between shared network and own network and IMSI is the only way to handover to the preferred PLMN when leaving the shared area.



Operators can control the handover to preferred PLMN based on the IMSI, leading to minimizing the costs associated with interconnection fees.

Increased Revenues

Terminals in active mode connected to the preferred PLMN are able to use all the services contracted.

6.6.4 Description

IMSI Handover GSM to GSM makes it possible to control better the handover mainly in border cells or in BSS Shared Networks.

When leaving the border area or the shared BSS area, the active (CS mode) terminals are directed to their own PLMN area or to an area belonging to their national roaming partner. This can not be done without knowledge of their home PLMN (IMSI number). MSC sends the IMSI number to the BSC for all MS calls.

In the example below based on a shared network PLMN C (BSS and MSC in common for both operators A and B), the PLMN A's subscribers use IMSI number range (xxxa) and PLMN B´s subscribers use IMSI number range (xxxb). Depending on the IMSI number, the active terminals belonging to PLMN A will measure on different neighboring cells compared to the ones belonging to PLMN B. The same neighboring cell list is sent to all active terminals in the cell, but terminals can only measure on the frequencies permitted included in NCC-Permitted (allowed NCCs on the BCCH carriers to be reported in the measurement report). Different NCC-Permitted sets are configured and sent to the terminals according to their specific IMSI.

Example how to use IMSI Handover GSM to GSM in a shared network.


Title


Title

6.7 Packet Data Efficiency



Technology: GSM, Wireless Broadband

6.7.1 Attention


Not applicable

Dependencies




Terminal impacts and dependencies EDGE or GPRS capable terminals are required

6.7.2 Summary

This feature enables the operator to increase the efficiency of Packet Data Channels (PDCHs), enabling increased data volumes using fewer radio resources, while maintaining voice KPIs.

PS data traffic in GSM is increasing exponentially in many networks due to growth of both Smartphone and M2M devices. Without the feature, this growth would require larger number of timeslots to be configured for PS, thus competing with voice capacity requirements.

This is beneficial in enabling growth in PS data traffic due to Smartphones and M2M devices


Title

6.7.3 Benefits

Increase data traffic capacity by up to 100%

Increase number of Smartphone/M2M devices that can be serviced and supported in the network

Improved efficiency of energy saving features like BTS Power Savings, PS Downlink Power Control, etc.

Decreased PCU load

Improved speech quality; less PS resources implies fewer HR calls

Operator Value

Total Cost of Ownership

More efficient utilization of installed TRX capacity can be attained. With PS traffic growth, need for TRX and PCU expansions is reduced.

Improved end-user experience; happier users leads to reduced churn

Increased Revenues

Increased carried data traffic by up to 100%, and thus revenue, is achieved by the improved efficiency of On-Demand Packet Data Channels

6.7.4 Description

This feature introduces new algorithms that control the allocation, and de-allocation, of On-Demand Packet Data Channels (ODPDCHs).

Traditionally, additional OD-PDCHs are allocated based on the average number of Temporary Block Flows (TBFs) stacked on each PDCH (Multiplexing). With this new feature, OD-PDCHs are instead allocated based on the average user traffic carried by the existing PDCHs.

This not only allows more efficient use of timeslot resources, where more data traffic can be carried using fewer PDCHs, but also is better suited to serve data users in a voice non-busy hour scenario.

Allocation of additional PDCHs will no longer blindly consider a terminal's multislot class if carried traffic on the existing PDCHs is below the utilization threshold.


Title

For Smartphone applications that are bursty in nature, such as Chat/IM, Push Messages, etc, only single PDCHs are now allocated when data in the buffer is below a configurable threshold. Without this functionality, PDCHs allocations for such traffic cases would be higher and inefficient.

When de-allocation or pre-emption of a PDCH is triggered, the PDCH is selected such that fragmentation or splitting of the PSET is avoided. The aim is to keep the PDCHs grouped together to increase TBF efficiency.

A round robin method for allocation of signaling TBFs across all PDCHs is introduced. This protects traffic flows and provides signaling robustness compared to the legacy allocation on a single PDCH.


Title

6.8 Reduced Power Level After Handover



Technology: GSM

6.8.1 Attention


Not applicable

Dependencies


GSM RAN SW: FAJ1210894 - Radio Network Efficiency


Not Applicable


One or both of the MS and BTS Dynamic Power Control functions have to be used, which means that the feature FAJ 121 0894 Radio Nework Efficiency is required.


Not Applicable


Not Applicable

6.8.2 Summary

The feature reduces transmitted output power after handover. This increases spectrum efficiency, MCPA utilization and reduces RBS energy consumption.


Title

6.8.3 Benefits

Up to 20% total output power reduction in a network, with increased spectrum efficiency and capacity as a result

Better utilization of output power in MCPA based RBS

Reduced energy consumption in the RBS

Prolonged battery standby and talk times in the MS



Reducing output power by 20% allows the network to carry that that much additional traffic without adding new RBS sites. The number of sites required in a network to carry a certain amount of traffic can therefore be reduced by ~20%.

Lower output power lowers energy consumption of the RBS.

6.8.4 Description

With the feature, the power control algorithm does not revert to maximum power level on the new channel after a channel change. Instead signal strength for serving channel, target cell, frequency band of existing and target channel and handover type is taken into consideration to determine a more appropriate lower power level. Reduced power level is used at inter cell handover, intra cell handover, SDCCH handover and at SDCCH to TCH allocation.


Title

The picture shows an example of how the power control algorithm works during a call. It is not the actual algorithm but shows the principle of the feature. One can see that the power level after each handover is at lower than maximum level.

In order to ensure that handover performance is not impacted the reduced lower power level is used for speech while signaling messages are still sent without reduction of the power level.

Reduced Power Level After Handover is independent of MS and RBS model and works in both up and downlink, provided that the respective Dynamic Power Control feature is used.


all features in gsm ran sw g10b

Documents