tutorial umts

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Software solutions in radiocommunications

TutorialNovember 2008

UMTS 3G network design

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TABLE OF CONTENTS

1 DEFINITION OF THE SERVICE AREA ____________________________________ 4

2 GENERATION OF MOBILE 3G (SUBSCRIBERS) ___________________________ 62.1 Introduction ______________________________________________________________________ 62.2 Selection of the service area _________________________________________________________ 82.3 Creation of the subscriber database ___________________________________________________ 82.3.1 Definition of the locations of the subscriber: __________________________________________ 112.3.2 Definition of the parameters of the subscribers ________________________________________ 112.3.4 Definition of the number of subscribers to generate_____________________________________ 142.4 Generation of subscribers ________________________________________________________ 152.4.1 Generation of subscriber for Voice service (12.2 kbps) __________________________________ 162.4.2 Generation of subscriber for CS (128kbps) service: ____________________________________ 182.4.3 Generation of subscriber for PS (384kbps) service:_____________________________________ 202.5 Display the subscribers on the map___________________________________________________ 22

3 DEFINITION OF SIMULATION PARAMETERS ___________________________ 263.1 Definition of the propagation model __________________________________________________ 263.2 Definition of the clutter parameters___________________________________________________ 273.3 Definition of the limit distance ______________________________________________________ 293.4 Definition of other simulation parameters______________________________________________ 303.5 Saving the simulation parameters ____________________________________________________ 32

4 UMTS PRE DESIGN ____________________________________________________ 334.1 Cell range and cell coverage estimation _______________________________________________ 334.2 Traffic calculation ________________________________________________________________ 354.3 Conclusion______________________________________________________________________ 38

5 MANAGEMENT AND SELECTION OF EXISTING GSM SITES ______________ 395.1 Import of existing 2G sites__________________________________________________________ 405.2 Setting of the existing UMTS parameters ______________________________________________ 445.3 Selection of the best existing sites ____________________________________________________ 58

6 IMPROVEMENT OF THE CURRENT UMTS NETWORK ___________________ 686.1 Additional site searching with the function “Prospective planning” _________________________ 686.2 Final result _____________________________________________________________________ 74

7 UMTS COVERAGE CALCULATION AND ANALYSIS ______________________ 757.1 Pilot coverage calculation__________________________________________________________ 757.2 Ec/I0 forward calculation __________________________________________________________ 777.3 Ec/I0 forward pilot pollution________________________________________________________ 787.4 Eb/N0 forward calculation _________________________________________________________ 79

8 W-CDMA TRAFFIC ANALYSIS__________________________________________ 808.1 Station traffic calculation __________________________________________________________ 808.2 The Monte Carlo method___________________________________________________________ 82

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The target of the initial planning phase for a UMTS network is to estimate the required site density and site configurations for the area of interest. Initial planning activities include radio link budget and coverage analysis, capacity evaluation and lastly estimation of the amount of BS hardware and sites, the service distribution, traffic density, traffic growth estimates and QoS requirements are already essential elements in the initial planning phase.The purpose of this tutorial is to describe an UMTS FDD (Frequency Division Duplex) system and how the various features are modelled in ICS telecom. This tutorial illustrates, step by step, the different functions and options available in ICS telecom in order to deploy a mobile UMTS network according to the Global System for Mobile communication (GSM) or eventually other technologies.

This tutorial has been divided in 8 sections:

PART I: CREATION OF THE SERVICE AREA

PART II: GENERATION OF 3G MOBILES

PART III: SIMULATION PARAMETERS

PART IV: UMTS PRE DESIGN

PART V: SELECTION OF THE BEST 3G CANDIDATES.

PART VI: IMPROVEMENT OF THE 3G NETWORK

PART VII: UMTS COVERAGE CALCULATION.

PART VIII: W- CDMA TRAFFIC CALCULATION

The technical parameters used in this tutorial are given as example and cannot be considered as reference parameters.

Before starting this tutorial we advice you to create an empty directory to save all the files that will be mentioned during this tutorial.

If you want to follow this tutorial you must load the project named UMTS Tutorial.PRO located in the subdirectory Tutorial UMTS\High Resolution Cartographic Data.

This tutorial has been created with the version 9.0.6 of ICS telecom.

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1 DEFINITION OF THE SERVICE AREA

At first, coverage should be planned according to the set targets. These may be different for different services and area types. The definition of a service area allows to create an area of interest in which all the future calculations will be carried out and to define some objectives of deployment that will validate the different future results. This part explains how to create a service area with ICS telecom.

Step 1: Select the Polygon Draw option on the left tool bar and click on draw mask.

Step 2: Left click on the map to draw your service area (polygon) and right click to close it.

Left click Right click

Step 3: Select save mask, to save your service area as a raster polygon. Name it and save it.

Step 4: Select continue, then add polygon to vector file…

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Step 5: Choose the parameters of display (pattern, colour…) of the vector polygon according to your tastes and click on OK.

Remark: if the polygon is not displayed, go to menu Map/Vector layer/Display and activate all.

Step 6: Go to menu File/Save/Save vector file (.VEC) to save you service area as a vector polygon. Name it and save it.

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2 GENERATION OF MOBILE 3G (SUBSCRIBERS)

2.1 IntroductionCapacity evaluation and lastly estimation of the amount of UE, the service distribution, traffic density, and traffic requirements are already essential elements in the initial planning phase. For the UMTS technology each UE type is defined according to specific technical parameters such as transmission power range (for uplink power control), noise figure and reception capabilities (especially the Ec/I0 and Eb/N0 levels)…ICS telecom allows to deal with all the traffic requirement for a UMTS network. All the parameters are fully supported and modelled by the tool via a subscriber data base.

This part of the tutorial is to describe how to set the subscribers parameters and to generate a population of terminals according to different type of services.

A typical case will be done and the following classes of subscribers will be randomly generated inside the service area and used in this tutorial.

Bellow, some technical parameters for UMTS mobiles (pedestrian - 3km/h):

Class of service

Numberof subs

DL activity factor (%)

UL activity factor (%)

DL demand (Kbit/s)UL demand

(Kbit/s)Eb/N0

(DL)Eb/N0

(UL)Ec/I0

Voice 500 7 7 12.2 12.2 6 dB 6dB >= -13dB

CS 300 6 6 128 128 5 dB 5 dB >= -13dB

PS 100 5 5 384 384 3 dB 5 dB >= -13dB

Fig1: Distribution of UMTS subscribers in ICS telecom(The subscribers are pointed toward their serving base station)

The UMTS access is divided into two methods:

PS mode: Packet switching is a communications method in which packets (discrete blocks of data) are routed between nodes over data links shared with other traffic. In each network node, packets are queued or buffered, resulting in variable delay. This contrasts with the other principal paradigm, circuit switching, which sets up a limited number of constant bit rate and constant delay connections between nodes for their exclusive use for the duration of the communication.

http://en.wikipedia.org/wiki/Routing

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CS mode: In contrast with Packet Switched data networks, circuit switched systems maintain a dedicated circuit for the duration of a call or session, much like a telephone line that remains for the duration of a voice call - even if neither party is speaking and no information is being sent. While packet switched networks can offer greater efficiencies in traffic routing and use of network resources where there are long periods of inactivity, circuit switching remains an attractive option for lengthy, uninterrupted sessions such as large file transfers, voice calls or videoconferencing.

Note: We assume that the study is based on an UMTS system used Frequency Division Duplex (FDD) mode and without synchronization between sectors. The UL and DL transmissions are allocated separate frequency bands as shown in the following table:

Operating Band Frequency band UL Frequencies UE transmit

(MHz)

DL Frequencies UE receive

(MHz)

Channel Number

(UARFCN) UL

Channel Number

(UARFCN) DLI 2100 1920-1980 2110-2170 9612-9888 10562 - 10838

________________________________________SHORTCUT________________________________________

If you want to skip this part of the tutorial, load the subscriber database located in the subdirectory Tutorial UMTS\Subscribers\Subscriber database.

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__________________________________________________________________________________________

2.2 Selection of the service area

Step 1: Select the Polygon Draw option on the left tool bar, click on load mask and select the file you saved previously (or the file named Service area.PLG and located in the subdirectory Tutorial UMTS\Service area)

Step 2: Then click on continue and select generate subscribers…

2.3 Creation of the subscriber database

Step 1: In the following window click on DB sub…

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Step 2: Click on New link… (*)

Step 2.1: Create a new folder and name the database. Then click on Open

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Step 2.2: Double click on the database link to select it.

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2.3.1 Definition of the locations of the subscriber:

Step 1: Select clutter code 0 (rural) and unselect the other clutter codes.

Step 2: Select Generate subscribers inside selection to generate subscribers inside the service area.

Remark: By selecting these two options the subscribers will be generated only on open areas of the service area.

2.3.2 Definition of the parameters of the subscribers

Each subscriber can have different service usage characteristics, which are used as inputs to the simulations. The terminal parameters can be manually defined as shown bellow:

Step 1: Click on Parameters…

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The WCDMA parameters defined in the subscriber’s parameters windows are:

Subscribers’ parameters windows

Step 2: Set the basic technical parameters of the receivers: The nominal power: “Nominal power (W)” The range of power control in dB: “Dynamic (dB)” The antenna gain of the transmitter: “Tx ant gain (dBi)” The cable losses: “Losses (dB)” The antenna height: “Antenna height (m)” The bandwidth of the carrier (UL and DL) : “ TX bandwidth” and “Rx bandwidth”

The sensitivity of the mobile: “Threshold (dBuV/m” The frequency transmitted by the mobile: “Frequency (MHz)”

Step 3: Define the horizontal and vertical antenna patterns. Set to Omni.

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Remark: We are considering that mobile receivers have omnidirectionnal antennas.

Step 10d: Define the traffic parameters:

Total traffic required by the mobile (kbps): “kbit/s :dl” Total traffic transmitted by the mobile in DL (kbps): “kbit/s: ul”. The activity factor in UL and DL (*): “activity : ul” and “ “activity: dl” The spreading rate applied on the traffic channel: Mchips/s

Set also the connection criteria to consider:

Ec/I0 required (dB) for the forward pilot channel. Eb/N0 required (dB) for the forward traffic channel. Eb/N0 required (dB) for the uplink traffic channel.

Notes:

1. Regarding to the activity factor, the activity factor of each subscriber will be taken into account in the following way in the calculation of the bit rate demand: Effective bit rate demand = Bit rate demand * activity factor.

2. The requirement on forward and reverse traffic channels can be different (asymmetric traffic).

Step 4: Define the administrative information: type of subscriber, colour of the subscriber, other information…

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Step 5g: Save the parameters by clicking on Save. Name the parameter file. And click on Close.

2.3.4 Definition of the number of subscribers to generate

In our case, we will assume that the number of subscribers with voice service is five hundred. This number is defined on the box “maximum subscribers”:

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2.4 Generation of subscribers

Click on the box “Parameters” in order to define the technical parameters of the 3G mobiles:

The subscribers’ parameters window is displayed…

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2.4.1 Generation of subscriber for Voice service (12.2 kbps)

Step 1: Click on Load and select the parameter file named “UMTS Subscriber_Voice service.TRX “located in the subdirectory Tutorial UMTS\Subscribers.

Step 2: Define the administrative information: type of subscriber, colour of the subscriber, other information.

The final subscriber parameter box for this type of service should looks like:

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Step 3: Define the number of subscriber and click on Start.

Result: In the end of generation, 500 mobiles (with voice service) will be created and saved on the DB subscriber.database.SUR

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2.4.2 Generation of subscriber for CS (128kbps) service:

Step 1: Click on Load and select the parameter file named: “UMTS subscriber_CS128kbps.TRX “located in the subdirectory Tutorial UMTS\Subscribers.



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Step 3: define the number of subscriber to generate and click on Start.

Result: In the end of generation of subscribers, 300 mobiles (with CS service 128Kbps) will be created and saved on the DB subscriber.database.SUR

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2.4.3 Generation of subscriber for PS (384kbps) service: Step 1: Click on Load and select the parameter file named: “UMTS_Subscriber_PS384kbps .TRX”

located in the subdirectory Tutorial UMTS\Subscribers.



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Step 3: Define the number of subscriber to generate and click on Start.

Result: In the end of generation of subscribers, 100 mobiles (with CS service 128Kbps) will be created and saved on the DB subscriber.database.SUR

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2.5 Display the subscribers on the map

Nine hundred subscribers have been created and generated on a subscriber data base. This subscriber’sdatabase included three types of services:

Voice service (500 UE). PS 128kbps (300 UE). CS 384kbps (100 UE).

Now if you want to display this population of subscribers, follows the steps described bellow:

Step1: Go to Base/DB subscriber… on the left tool bar.

Step 2: Double click on the database name to edit it.

Step 3: Click on Select all. Check that the 900 subscribers are well selected.

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Step 4: Then click on Change tech; set 1 in the field declare orphan = 1 (0=noc) and click on OK.

Remark: orphan subscribers are subscribers not yet parented to any base station.

Step 5: Close the database. The subscribers should appear on the map.

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Fig2: Distribution of the 3G terminals inside the service area(Blue colour: Voice service; red colour: 128kbps; yellow colour: 384kbps)

Step 6: If the subscribers are not displayed on the map, click on F5 on your keyboard, check option Display subscriber and click on Close.

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3 DEFINITION OF SIMULATION PARAMETERS

This part deals with the different simulation parameters that can influence the results of our future calculations.

The main simulation parameters needed are the following ones:

Propagation model Clutter attenuations Distance of calculation Other parameters (unit, default Rx antenna height…) Downlink and uplink threshold

________________________________________SHORTCUT________________________________________

If you want to skip this part of the tutorial, load the parameter file named “Simulation parameters.PRM “, located in the subdirectory Tutorial UMTS\Project\Simulation parameters.

__________________________________________________________________________________________

3.1 Definition of the propagation model

Step 1: Go to menu Tools/Propagation model… and then click on Model to open the propagation model window.

Step 2: Set the different components of the propagation model: ITU-R 525 / Deygout 94method / Standard; and click on Close.

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Remark: for more details about the propagation models, please refer to chapter 2.

3.2 Definition of the clutter parameters

Step 1: Go to menu Tools/Clutter options… to open the clutter parameters window

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Step 2: Check the option dB/km and define some linear (first column) and flat (second column) attenuations for the clutter codes 5 (vegetation) and 9 (building).Then uncheck the option default and define a clutter height for clutter code 5 (vegetation).

And on the lower right corner of this window check the following two options: T/R over ground spot and T/R over clutter.

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Remark 1: In the dB/km mode the attenuations are taken into account only if the receiver is located inside a clutter class.

Remark 3: The "(R)" section refers to objects “Subscribers. "Over ground spot" : When a receiving antenna is inside a given clutter or building, the first pixels around the receiver are considered as an obstacle.

Remark 4: The "(T)" section defines antenna height reference for objects "Stations".

Remark 5: The flat and linear attenuations will be taken into account only during the coverage calculation. It will allow us in the future to improve the network for indoor receptions, without recalculating the coverages.

Step 3: Click on OK.

3.3 Definition of the limit distance

Step 1: On the left tool bar select the option Distance Limit and click on Global distance:…

Step 2: Set the maximum calculation distance limit in km and click on OK.

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3.4 Definition of other simulation parameters

Step 1: Go to menu Files/Preferences…

Step 2: Select the following options: Orient sub antenna – parenting; Circular calculation limit; Unit: dBm; Subscriber/station call-sign checking and default Rx antenna height (m).

Then click on Close.

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3.5 Definition of the threshold

Step 1: On the left tool bar select the option Threshold.

Step 2: Set the threshold value and click on Close.

Remark: the option “converter” allows to convert the unit of threshold value (from dBu to dbm or from dBm to dBu.

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3.5 Saving the simulation parameters

Step 1: Go to menu File/Save/Save parameter file (.PRM). Name it and save it.

Step 2: In the following confirmation window click on YES to update your project.

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4 UMTS PRE DESIGN

This paragraph is dedicated to the calculation of the pre design for a 3G network. During the first step of the 3G network design, the operator must be able to calculate the average number of site required according tothe following constraints:

The cell range in DL and UL for a given service area. The capacity required for a given population of 3G mobile and for each kind of service (Voice, PS,

and CS).ICS telecom can be used by the RF engineer in order to estimate the average number of 3G site (for a given area) and to have a first view of his future network. Those functions are presented in this paragraph and an example of a dimensioning case will be seen in this section.

4.1 Cell range and cell coverage estimation Description of the function: This function is used to calculate the max cell range (km) for a given node Baccording to the Input data used in the link budget. This function can be used to estimate:

The cell range in free space (in DL or UL). The threshold required for a given service (voice, data, HSDPA, HSUPA…) and according to the

constraints of the transmitter.As explained in the introduction of this paragraph, this function can be useful during the first steps of the UMTS design, especially for the calculation of the average number of node B required.

For the calculation, go in "W-UMTS/Network analysis...”

The following window is displayed :

The input data of the link budget (frequency, EIRP of the transmitter, KTBF…) must be set and then the cell range (km) and the threshold required are automatically calculated. Note that:

1. This function can be used for the downlink and uplink budget calculation. 2. This function can be used for any kind of mobile network (GSM, CDMA, W-CDMA…).

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Let’s calculate the average number of the 3G site required for our service area.

Fig1: UMTS service area in red colour (41.26km²)

We can assume that the most important coverage constraint for a mobile system is the uplink budget (signal transmitted by the mobile to the base station).

INPUT UPLINK BUDGET (IN URBAN ENVIRONMENT):

Tx Frequency (MHz) 1920EIRP Tx Power (dBm) 21KTBF (dBm) -104Mchips/s 3.84Cable and combiner losses (dB) 0Average Eb/N0 (dB) 6Rx antenna gain (dBi) 18Rx losses (dB) * 50Fade margin (dB) 7.3Soft handover gain (dB) 3

Rx losses (dB) *: Cable losses + Average building attenuation (maximum allowed propagation loss). : 2 + 48Note that the UL cell range can be also calculated in free space, in this case Rx losses: 2dB.

For those parameters, the calculated cell range via the function “Cell range calculator” is 2.17km (as shown bellow):

Now is easy to determinate the number of node B required for our service area:

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After the calculation of the maximum cell range the coverage area can be calculated: The surface of the service area is 41.26km² The surface covered by a tri sector node B is equal to π*2.17² that is 14.78km².

The minimal number of station to cover the service area is 41.26/14.78 that is about 3 stations.

4.2 Traffic calculation The WCDMA radio link budget is slightly more complex than the TDMA one (GSM network) because the number of simultaneous users have a direct impact on coverage. From the beginning of network evolution the operator should have knowledge and vision of subscriber distribution in order to estimate the correct configuration (number of sectors, number of carriers) in term of capacity requirement for the network.

ICS telecom allows via the function “Traffic calculator” to calculate the required number of sectors for a given population of subscribers.

Description of the function: This function is used to calculate the number of simultaneous subscriber’s connection for a given service type (Voice, PS, and CS) and according to the Input data’s (Rx threshold required, user bit rate, Eb/N0 required…).

For the calculation, go in "W-CDMA/Traffic calculator...”

The following window is automatically displayed :

Let’s calculate the number of sectors required in the present case:

Below the subscribers’ parameters:

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Class of service Number of subscribers UL activity factor (%) User bit rate (Kbit/s) Eb/N0 (UL) Power control Voice 500 7 12.2 6dB 0 dB

CS 300 6 128 5 dB 0 dB

PS 100 5 384 5 dB 0 dB

We assume the following additional parameters:

Minimum threshold required for the base station (node B): -100dBm.

Base station KTBF: -104dBm

1. CAPACITY REQUIERED FOR 500 SUBSCRIBERS USING VOICE SERVICE:

The first step is to calculate the maximum capacity of connection for one sector (we assume the service is only dedicated to the voice):

Go in "W-CDMA/Traffic calculator...” and set the parameters. The result is the following:

Result: If the traffic (%) of each subscriber is equal to 7, the number of simultaneous connection for a given sector is equal to 2820.

One sector is enough to take in charge the capacity of 500 subscribers for voice service.

Note that a traffic factor equal to 7% means that each subscriber is connected 7% of the time.

2. CAPACITY REQUIERED FOR 300 SUBSCRIBERS USING CS SERVICE:

The first step is to calculate the maximum capacity of connection for one sector (we assume the service is only dedicated to the CS):


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One sector is enough to take in charge the capacity of 300 subscribers for CS service.

Note that for a critical case, if the traffic factor (%) is equals to 70 the maximum capacity will be only 30 simultaneous subscribers. The number of sector required will be 300 divided by 30 that is 10 sectors.

3. CAPACITY REQUIERED FOR 100 SUBSCRIBERS USING PS SERVICE:

The first step is to calculate the maximum capacity of connection for one sector (we assume the service is only dedicated to the PS):


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One sector is enough to take in charge the capacity of 100 subscribers for PS service.

4.3 Conclusion

As shown before, the dimensioning of the network depends of two main constraints: maximum cell range (depending of the propagations aspects) and the traffic distribution of the population of subscribers.

The last calculations shown that (during the beginning of the UMTS design), the most important constraints are in term of cell range and not in term of traffic. The “average” number of node B expected for the 3G design dedicated to our service area is 3 (See section 4.1) that is 9 sectors.

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5 MANAGEMENT AND SELECTION OF EXISTING GSM SITES

The target of the initial planning phase is to estimate the required site density and site configurations for the area of interest. Initial planning activities include to take into account the existing network (GSM or eventually other technologies) for the selection of the UMTS base stations (node B). This part of the tutorial treats with the methods of import of an existing BTS data base and how do modify the current GSM parameters by UMTS parameters (frequency, antenna type, pilot power, KTBF…). The next chapters focus on the procedure to determinate the best sites and how to improve this initial planning by an automatic UMTS search site.

Swap of the Current cellular network with ICS telecom

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5.1 Import of existing 2G sites

This paragraph presents the methods of import of base station via an .EWF file format or an external data base (ASCII file).

________________________________________SHORTCUT________________________________________

If you want to skip this part of the tutorial load directly the GSM base stations via our .EWF file:

Load the parameter file named “Simulation parameters.PRM “, located in the subdirectory Tutorial UMTS\Project

And load the network file named “Existing GSM Base station.EWF “located in the subdirectory: “Tutorial UMTS\Project/Existing GSM network.EWF”.

The existing GSM network is displayed on the map:

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Fig3: Existing GSM base stations inside the service area

__________________________________________________________________________

Another method of import of BTS can be used if the format of the data base is an ASCII file. On this case, follows the different steps described bellow:

Step 1: Go to menu Files/Import/Generic ASCII/ file…

Step 2: In the lower right corner of the following window, click on the “browse” button and select the file named “Existing GSM sites .csv” located in the subdirectory Tutorial UMTSProject. Then, specify the type of separator (comma) and click on refresh.

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Step 3: Define the Default coordinate code (coordinate system + datum) associated to the coordinates of the existing sites: 4DMS in our case.

Then select the definition of each column:

Col 1: Callsign; Col 2: Address; Col 3: Info(1); Col 4: X or long; Col 5: Y or lat; Col 6: antenna (m); Col 7: Frequency (MHz); Col 8: Azimuths (°). Col 9: Network ID.

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Step 4: Click on Import on map. Click on OK and close the window.

The existing sites have been imported and are displayed on map.

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5.2 Setting of the existing UMTS parameters

The purpose of this paragraph is to update all the technical parameters of the base station. For that, please follows the different steps described bellow:

Step1: On the left tool bar, select List/Station list…

Step2: Select one station from the station list and then open the parameters of the base station (left click):

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The station parameters window is displayed…

Step3: Select the first GSM station from the station list and double click on it and choose parameters…

The base station parameter windows displayed…

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Step4: Select the icon located on the right top corner of the window and then select the option “Load TRX” in order to load all the missing GSM parameters of the BTS.

Step5: Then click on load, select the file named “GSM900_BTS.TRX” located in the subdirectory TUTORIAL UMTS\GSM base stations and click on OK.

All the Technical parameters of the GSM base station are updated (nominal power, frequency of the transmitter, antenna height, antenna type…):

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Step5: Repeat the same steps for the rest of the base stations or directly via the function “Object/Load TRX…”

The next paragraphs will consist to swap this whole of GSM base stations to UMTS base station with the appropriate technical parameters.

5.2 Migrating GSM network

This paragraph explains how to swap existing GSM base station to node B. This part describes the functions used to modify automatically all the GSM stations parameters by new UMTS parameters.

We can assume that for a typical node B the technical parameters as follows:

General parametersFrequency of the transmitter (MHz): 2110

Tx and Rx Bandwidth (KHz) 5000Cable losses (dB) 2

Nominal power of the cabinet (W) 10Antenna gain (dBi) 18

Traffic parametersPilot power (%) 10

Paging power (% pilot power) 20Synch power (% pilot) 20

Mchips/s 3.84Downlink bit rate (kbps) 5000

Uplink bit rate (kbps) 5000Other parameters

KTBF (dBm) -104Noise floor -104

Sensitivity (dBm) -99 (45 dBu)Coverage threshold (dBm) -99 (45dBu)

Step 1: On the left tool bar, select List/Station list…

Step 2: On the station list window, click on Changes (tec)…

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Then define the following technical parameters, and click on OK.

Step 3: On the station list window click on Changes (gen)…

Then define the following general parameters, and click on OK.

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Step 4: On the station list window click on Changes (ant)…

Then set the antenna gain as well as the antenna type (horizontal and vertical pattern) and click on update upd, to update the gain.

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Click on H-pattern. Then click on load, select the file named UMTS BS.SPH located in the subdirectory Tutorial UMTS\Node B and click on OK.

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Click on V-pattern. Then click on load, select the file named UMTS BS.SPV located in the subdirectory Tutorial UMTS\Base Stations and click on OK.

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Finally, click on OK to apply the antenna changes:

Step 5: The new parameters are the following:

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Step 6: Check that all the parameters have well applied. Select on of the station, double click on it and choose parameters…

In the General tab, you should have the following parameters:

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In the Patterns tab, you should have the following parameters:

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In the Channels tab, you should have the following parameters:

And finally, in the advanced tab, you should have the following parameters:

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Step 7: On the upper right corner of the Tx/Rx parameters window, click on the following button, select Save TRX… to save the node B parameters. Name and save the file.

Finally click on OK to close the Tx/Rx parameters window.

Step 8: Go to menu File/Save/Save network file (.EWF), name your network and save it.

Click on YES in the following confirmation window to update your project.

Result: The GSM network is now swapped to a UMTS network. The next step will consist to find the best stations in term of connection of 3G mobiles. This analysis will be done during the next paragraph.

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5.3 Selection of the best existing sites

The objective of this paragraph is to determinate the best stations according to two following constraints: The population of UMTS mobiles and the Ec/I0 criterion. In the end of this chapter the best sites will be those who will connect the more UMTS subscribers.

Step 1: Go to Base/DB subscriber… on the left tool bar.

Double click on the database name to edit it.

Click on Select all. Check that the 900 subscribers are well selected.

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Then click on Change tech; set 1 in the field declare orphan = 1 (0=noc) and click on OK.

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Close the database. You should have the following map.

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Step 2: Go to menu W_CDMA/Parenting…

The following window is displayed:

The “Subscriber CDMA parenting” function will be used to perform a parenting taking into account the Ec/I0 and the Eb/N0 reverse constraint.The function will be used to calculate the number of connected mobile by base station. With this method the user is able to find the best stations in term of connection.

Description of the function:

First option: “Connecting to best server – Ec/I0”: This option consists to check for each subscriber to have a pilot coverage in term of Ec/I0. Then each subscriber will be connected to that station giving the best Ec/I0 ratio, that is, the best server.

Remark: Power control gain sets the improvement in Ec/I0 owing to base station controlling their power thrown on the channel they share: Ec/I0 forward = Ec/[sum (I)-PCG]

Second option: “Connecting to best server – WCDMA”: This option consists to checks parenting on the basis of a complete analysis for connectivity, this Ec/N0 forward and Eb/N0 reverse.

Remark: Power control gain sets the improvement in Eb/N0 owing to base station controlling their power thrown on the channel they share: Eb/N0 forward = Eb/[sum(I)-PCG]

In the end of the calculation, two cases can be occurred: First case: The mobile is connected to a given station; the mobile is called “parented”.

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Second case: the mobile can’t be connected to a base station; the mobile is called “Orphan”.

Before to start the calculation; the user must select the list of the base station and the list of subscribers used during the analysis. Then, the maximum distance of calculation (that is the maximum distance between a subscriber and a nodeB).

The calculation of the interferences is done according the IRF mask defined on the option IRF (for more details Regarding to the IRF mask, please refer to the document “Frequency assignment and interference analysis”)

Step 3: Select the option “Connecting to best server – Ec/I0” and click to the option “IRF…“

The following window is displayed:

Then set zero as protection ratio for the co-channel and click close.

Step 4: Click “Start”

ICS telecom is calculating the number of connected mobile in term of Ec/I0…

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Step 4: At the end of the calculation a report is automatically generated. This report gives the repartition of connections on each station in term of Ec/I0.

The result shown that with the current 7 stations we can connect 63.89% of the 900 subscribers.The best candidates are the following sites:

Site 1 {BTS_1; BTS1_2; BTS1_3}

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Site 2 {BTS2_1; BTS2_1; BTS2_2} Site 3 { BTS3_1; BTS3_2; BTS3_3}

Bellow the result of the parenting: All the terminals connected are automatically displayed with an azimuth in direction of the best site. In blue colour are delimited the best candidates in term of connection:

Fig4: Distribution of the mobiles connected (parented) according to the potential node B.

The best candidates (BTS2; BTS3; BTS1) are shown above by a blue radius. In the end of the calculation the azimuth of the parented mobiles are automatically updated toward the best stations (even if the antenna type of the mobile is omnidirectional). The mobiles defined by a point (without azimuth) represents the no parented mobile that is the orphan mobiles. In the present case the orphan mobiles are not connected may be because the minimum threshold required is not reached or because the Ec/Io received by the mobile is too low.

Station Call-sign (UMTS

candidates)Connected UMTS

subscribersTotal UMTS subscribers Connected UMTS subscribers per site

1 BTS1_1 167 900 318

2 BTS1_2 63 900 318

3 BTS1_3 88 900 318

4 BTS2_1 63 900 169

5 BTS2_2 77 900 169

6 BTS2_3 29 900 169

7 BTS3_1 7 900 34

8 BTS3_2 9 900 34

9 BTS3_3 18 900 34

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10 BTS4_1 0 900 22

11 BTS4_2 17 900 22

12 BTS4_3 5 900 22

16 BTS5_1 2 900 9

17 BTS5_2 4 900 9

18 BTS5_3 3 900 9

13 BTS6_1 0 900 1

14 BTS6_2 0 900 1

15 BTS6_3 1 900 1

19 BTS7_1 2 900 22

20 BTS7_2 11 900 22

21 BTS7_3 9 900 22

Step 5: On the left tool bar, select List/Station list… Select the unwanted potential sites (sites 8, 9 and 10) and click on Deactivate. Then click on Close.

Step 6: On your keyboard select Ctrl+R and click on YES in the following window.

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You should have finally on your map, 3 activated sites

Step 7: Go to menu File/Save/Save network file (.EWF), name your network and save it.

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Note: This file has been saved and is available in the subdirectory Tutorial UMTS\node B/Best UMTS candidates .EWF

Click on YES in the confirmation window to update your project.

Result: In the end of this step only 3 existing sites have been selected over the 7 available for the design of the UMTS network. The next step of the study will consist to improve the UMTS network by adding of new sites in order to connect the rest of the population of subscribers that is 42% of the 900 subscribers.

Bellow the number of connected subscribers for the three best candidates:




BTS1 BTS1_1 167 900 318

BTS1 BTS1_2 63 900 318

BTS1 BTS1_3 88 900 318

BTS2 BTS2_1 63 900 169

BTS2 BTS2_2 77 900 169

BTS2 BTS2_3 29 900 169

BTS3 BTS3_1 7 900 34BTS3 BTS3_2 9 900 34BTS3 BTS3_3 18 900 34

Connection of the 3G mobile according to the best UMTS candidates

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6 IMPROVEMENT OF THE CURRENT UMTS NETWORK

This paragraph introduces the concept of auto planning for the improvement of the current network. If the goals of the network are known it can be planned automatically whilst maintaining coverage, traffic and interference accuracy. In developing the goals, parameters such as the number of sites to be deployed, the Quality of Service that users are to enjoy and the available spectrum need to be specified. Data on the equipment to be used and behavioral information on the calls users make must also be specified.

6.1 Additional site searching with the function “Prospective planning”The objective of this part is to find an additional site in order to improve the current network and to connect at least 80% of the total population of subscribers.

Step 1a: Go to menu WCDMA/Prospective planning

The following window is automatically displayed:

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Step 1b: In the following window, define on which type of clutter the additional site will be located: clutter 9 (Building) in our case (like the potential UMTS candidates).

Step 1c: Then define the site constraints:

We want to add three additional site:

It will be a tri-sectors site with an azimuth spacing of 120°:

The site will be created if it can connect at least 7 subscribers

We want to stop the search for new sites if 95% of the subscribers are connected:

Then click to the option in order to define the node B parameters which will add for the improvement of the network. Then define the site constraints: :

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Set the general parameters

Set the antennas parameters

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Set the advanced parameters

________________________________________SHORTCUT________________________________________

If you want to update automatically the correct parameters of the node B, load the node B parameters located in the subdirectory Tutorial UMTS\Subscribers\NodeB parameters.

________________________________________________________________________________

Step 1d: Then select the option and set the maximum distance of calculation

Step 1e: Set the power control (dB) used by the MS with the option

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________________________________________SHORTCUT________________________________________

If you want to update automatically all the constraints of the window “Prospective planning from subscriber Ec/I0 “, load the all the constraints define on the file “UMTS.PNG” located in the subdirectory Tutorial UMTS\Project

________________________________________________________________________________

Step 1f: Finally click on START to launch the function.

At the end of the calculation three new sites are created and a report is automatically generated. It gives the number of subscribers that will be connected to the new site.

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In our case 82.22% of the MS are connected and the additional site will be able to connect 218 subscribers.

Click on Quit to close the report and to see the location of the additional.

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Step 1g: Go to menu File/Save/Save network file (.EWF), name your network and save it.

Click on YES in the confirmation window to update your project.

Note that the time of calculation may be very long , if you want to load directly the additional sites, please load the file “Final UMTS network.EWF” available in the subdirectory Tutorial UMTS\node B.

6.2 Final result

With this additional site our network can connect now 82% of the 900 subscribers (that is 738 subscribers).We can assume that the objective of 80% of connections is achieved.This calculation has been done with taking into account not only the threshold level required but also the Ec/I0 criterion.

Fig1 : Final UMTS network design.

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7 UMTS COVERAGE CALCULATION AND ANALYSIS

When the target of connection has been reached, the user can calculate and display different maps of coverage:

1. Pilot coverage taking into account the part of the EIRP allocated to pilot channel.2. EC/I0 forward coverage.3. Ec/I0 forward pilot pollution4. Eb/N0 forward calculation

The different methods of calculation will be explained in this chapter.

7.1 Pilot coverage calculation

Description of the function: The coverage in terms of field strength received can be performed in ICS telecom. The transmitting power considered is the percentage of pilot power set in each station. For that, go in "W-CDMA/Network calculation/Pilot coverage...”.

Set the receiving antenna height and click on "START":

In the end of the calculation, the result of the coverage is as follows:

Fig1: Pilot coverage map in ICS telecom

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Then save again the .EWF file called “Final UMTS network” in order to save the calculated coverage.

________________________________________SHORTCUT________________________________________

As the time of calculation may be long, if you want to display the coverage result, you can import directly the file “Final UMTS network.EWF” located on the folder Tutorial UMTS/Project and then go to Coverage/Network analysis/Composite coverage display.

________________________________________________________________________________

The user can also filter the result of coverage only in the street (Go to the function “Map/Filter/General filter” and then selected the clutter “code 0” called ‘Rural” dedicated to the street environment).

Fig1: “Outdoor Pilot coverage for a node B”

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7.2 Ec/I0 forward calculation

Description of the function: The traffic can be analyzed directly on the map by creating an Ec/I0 forward map for a given traffic demand per point on the map.

Go in "W-CDMA/Network analysis...”

Select the option “Ec/I0 forward calculation” and define the power control gain simulated and then click Start…

Fig1: Map of Ec/I0 forward for the UMTS network

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7.3 Ec/I0 forward pilot pollution

Description of the function: This function is used to calculate a map showing on each point how many non-interfered pilot signals are received on each point can be displayed.


Set the relevant parameters in the following window and click on "Start":

Fig 1: Map of Ec/I0 forward pilot for the UMTS network.

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7.4 Eb/N0 forward calculation

Description of the function: The traffic can also be analyzed directly on the map by creating an Eb/N0 forward map for a given traffic demand per point on the map.


Set the relevant parameters in the following window and click on "Start":

Fig1: Map of Eb/N0 forward for the UMTS network

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8 W-CDMA TRAFFIC ANALYSIS

This chapter treats with methods of traffic calculation deals by ICS telecom for a UMTS network. Two methods can be used:

1. The traffic calculation according to the capacity of the node B and the request in traffic of the subscribers.

2. Traffic calculation according to the Monte-Carlo Method.

8.1 Station traffic calculationThe user is able to calculate the distribution of the traffic in DL according to the capacity of each node B (defined on the advanced parameters) and the traffic request of the subscribers.

Traffic parameters for the 3G mobiles

Note that the factor of activity used in the traffic parameters of the subscribers parameters means that the mobile is connected X% of the time. In the present case, if the factor of activity is equal to 5 it means that the mobile is only connected 5% of the time. In term of traffic calculation, the request in DL of the subscriber will be considered as is equal to 12.2kbps * 0.05.The result of the calculation is displayed in the end of the calculation of the parenting Ec/I0 (refer to the chapter 4.3). When the calculation is finished a window is automatically displayed, you need just to click “List” and read the excel report (as shown bellow).

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Station Call-signBit rate DL (Mbit/s)

Connected UMTS subscribers

Total UMTS subscribers

Connected UMTS subscribers per site

1 BTS1_1 0.4276 102 900 245

2 BTS1_2 0.2191 55 900 245

3 BTS1_3 0.4145 88 900 245

4 BTS2_1 0.1301 27 900 117

5 BTS2_2 0.2874 68 900 117

6 BTS2_3 0.0866 22 900 117

7 BTS3_1 0.0192 1 900 17

8 BTS3_2 0.0268 4 900 17

9 BTS3_3 0.0491 12 900 17

10 c314645 0.1707 23 900 219

11 c399609 0.5059 124 900 219

12 c983977 0.3081 72 900 219

13 c232337 0.0000 0 900 68

14 c520859 0.1277 23 900 68

15 c494949 0.2502 45 900 68

16 c893520 0.1435 32 900 74

17 c857203 0.0433 12 900 74

18 c903561 0.1262 30 900 74

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8.2 The Monte Carlo method

Description of the function: This function is based on the Monte-Carlo algorithm. The Monte-Carlo method is used to generate random traffic demand. The result of this calculation is a statistical report giving for each pass the status of each connection.The method of calculation is as follows:

First step: All the subscribers selected from the database are parented to the nodes B according to the best Ec/I0 >= Ec/I0 required by the subscriber (box “parameterssubscriber”). The result of this calculation is the number of subscribers which are able to be connected in term of Ec/I0: NB.

Second step: For each pass, ICS telecom calculates a random factor of activity (between Min activity and Max activity) and for a given value of activity factor the parented subscribers are activated. Then, the number of connection in term of Eb/N0 is calculated by the tool: NBC.

Third step: The result is displayed, that is the following distribution: The ratio between the number of connection in Eb/N0 and the number of subscribers able to be connected in term of Ec/I0: NB/NBC*100

Go in "W-CDMA/WUMTS activity...":

Then set the relevant parameters in the following window and click on "Start":

ICS telecom is calculating the number of connection according to the random factor of activity and the number of passes (as shown bellow):

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In the end of the calculation the distribution of the connections are displayed:

A report can be generated with the option “Report”:

PassTotal subscribers

(Ec/I0)Selected connected

(Ec/I0)Connected subscribers

(Eb/N0) Percentage (%) Activity factorMean Eb/N0 reverse (dB)

1 740 362 362 100.00 0.51 520.82

2 740 396 396 100.00 0.50 521.78

3 740 587 587 100.00 0.79 521.33

4 740 46 46 100.00 0.06 518.02

5 740 314 314 100.00 0.43 521.23

6 740 699 699 100.00 0.93 521.21

7 740 65 65 100.00 0.11 521.13

8 740 418 418 100.00 0.56 521.05

9 740 733 733 100.00 0.99 521.13

10 740 215 215 100.00 0.29 520.59

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To create the modified notification files, follow the process define in section 7.1.

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Software solutions in radiocommunications

tutorial umts

Documents

existing umts parameters

generation of subscribers

umts coverage calculation

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service area

clutter parameters

traffic calculation

pilot coverage calculation