Features

Version 1.0

20th Oct 2005

List of Features

1. Dynamic Power Control

2. HCSDedicated

Idle

3. Multi Band UL/OL (Single BCCH)

4. Half Rate

5. TCC

IRC

1. BTS Dynamic Power Control

BTS Dynamic Power Control

Introduction:With the Dynamic BTS Power Control feature, the output power of a Base Transceiver Station (BTS) can be controlled to maintain a desired received signal strength and quality in the mobile station (MS) during a connection.

Thus reducing the over all interference level in the network.

General:Dynamic BTS Power Control is performed for Traffic Channels (TCH) as well as for Stand Alone Dedicated Control Channels (SDCCH).

Power control of the SDCCH is enabled with the switch SDCCHREG.

All time slots on the BCCH frequency are transmitted on full power.

Algorithm (I)

Consists of 4 stages

9702718

Preparation ofinput data

Filtering ofmeasure-ments

Calculation of power order

Send power order (REGINTDL)

Every SACCH period

Algorithm (II): Stage 1 – Preparation of input data

At SACCH period k, the output power used by the BTS (TRU) is given by the equation below:

BTS (TRU) output power (k) (dBm) = BSPWRT – 2 * PL used (1)Where PL used = 0-15

All signal strength and quality measurements are compensated before the filtering according to the equations below:

SS_COMP = SS TCH + 2 * PL used (2)

Q_COMP = RxQual (dB) + 2 * PL used (3)

Algorithm (III):Stage 2 – Filtering of measurements

The filtering for both signal strength and quality is done with exponential non-linear filters.

SS FILTERED (k) = b * SS_COMP(k) + a * SS FILTERED (k-1) (4)

If SS_COMP(k) < SS FILTERED (k-1)then L = SSLENDL

else L = SSLENDL * UPDWNRATIO / 100

Algorithm (IV):Stage 2 – Filtering of measurements (cont)

Quality filtering is performed in the same way as for signal strength.

Q FILTERED (k) = b * Q_COMP(k) + a * Q FILTERED (k-1) (5)

 If Q_COMP(k) < Q FILTERED (k-1)

then L = QLENDL

else L = QLENDL * UPDWNRATIO / 100

Algorithm (V): Stage 3 – Calculation of power order

The basic power orders for regulation (pu1 and pu2) are given by the following expression:

pui (dB) = ai * (SSDESDL – SS FILTERED ) + bi * (QDESDL_dB - Q FILTERED ) (6)

i = 1, 2Where the parameters ai and bi are defined as follows:

a1 = LCOMPDL / 100 (pathloss compensation)

b1 = QCOMPDL / 100 (quality compensation)

a2 = 0.3 (pathloss compensation, serve as a limitation for regulation close to noise floor)

b2 = 0.4 (quality compensation, serve as a limitation for regulation close to noise floor)

QDESDL [dtqu]

0 10 20 30 40 50 60 70

rxqual 0 1 2 3 4 5 6 7C/ I [dB] 23 19 17 15 13 11 8 4

QDESDL expressed in C/ I is called QDESDL_dB which is the value used in the calculations

Chart (I): Stage 3 – Calculation of power order

Base station output power and MS signal strength versus path loss. Quality is not taken into account.

20 dB regulation with LCOMPDL = 10

SSDESDL = -75

BTS output power versus RxQual. Signal strength is not taken into account.

QDESDL = 30

20 dB regulation with QCOMPDL = 60

20 dB regulation with QCOMPDL = 60

Chart (II): Stage 3 – Calculation of power order

Algorithm (VI): Stage 3 – Calculation of power order (cont)

The resulting power order is called the unconstrained power order, pu.

pu = max(pu1, pu2) (7)

Note:Dynamic power range limitation is applied if the unconstrained power order, pu is outside the dynamic range:The highest allowed power order is zero (0). This corresponds full power according to BSPWRT.The lowest allowed power order is given by maximum of

(a) –30, BSPWRT – (Minimum BTS output power (H/W limit))(b) BSTXPWR – BSPWRMIN.

The power order is then converted to power level PL used representation and transmitted to the BTS:

PL used = Int (-pu/2) [0-15] (8)

Algorithm (VIII):Stage 4 – Send power order

When a power order is sent it takes REGINTDL SACCH periods before the next power order can be sent.

If this power order differs from the previous one, it is sent.

If it does not differ from the previous one, a new order is calculated every SACCH period until a different power order is obtained. Then, that order is sent and REGINTDL SACCH periods must elapse before a new order can be sent again.

List of related Parameters

ParameterCurrent Value Range Unit Brief Discription

SSDESDL -90 -110 to -47 dBm Desired value for RxLev that the regulation will aim in the regulation processQDESDL 30 0 to 70 dtqu Desired value for RxQual that the regulation will aim in the regulation process

LCOMPDL 5 0 to 100 % Pathloss compensationQCOMPDL 55 1 to 100 % Quality compensationREGINTDL 1 1 to 10 SACCH Period Minimum Time Between power ordersSSLENDL 3 3 to 15 SACCH Period Signal strength filter length (averaging)QLENDL 3 1 to 20 SACCH Period Quality filter length (averaging)

SDCCHREG OFF ON, OFF Enables power control on the SDCCHBSPWRMIN -20 -20 to +50 dBm Minimum BTS output power. (ie. 47-20 = 27dBm)BSTXPWR 0 to 80 dBm BTS output power on the TCH frequencies

UPDWNRATIO 200 100 to 700 % Ratio between up and down regulation speedSTEPLIMDL OFF ON, OFF Down regulation can be limited to 2 dB per SACCH

Current/Default Settings

1

11

21

31

41

51

61

01

23

45

67

0

2

4

6

8

10

12

Regulation (dB)

RXLev

RXQual

10-12

8-10

6-8

4-6

2-4

0-2

SSDESDL

QDESDL

LCOMPDL

QCOMPDL

-90

30

5

55

Example of Settings (I)

1

11

21

31

41

51

61

01

23

45

67

0

5

10

15

20

Regulation (dB)

RXLev

RXQual

15-20

10-15

5-10

0-5

SSDESDL

QDESDL

LCOMPDL

QCOMPDL

-90

30

10

55

Example of Settings (II)

1

11

21

31

41

51

61

01

23

45

67

0

5

10

15

20

Regulation (dB)

RXLev

RXQual

15-20

10-15

5-10

0-5

SSDESDL

QDESDL

LCOMPDL

QCOMPDL

-90

30

5

60

Example of Settings (III)

1

11

21

31

41

51

61

01

23

45

67

0

5

10

15

20

25

Regulation (dB)

RXLev

RXQual

20-25

15-20

10-15

5-10

0-5

SSDESDL

QDESDL

LCOMPDL

QCOMPDL

-90

30

10

60

2. HCS - Hierarchical Cell Structure

HCS - Hierarchical Cell Structure Hierarchical Cell Structures (HCS) is a way of displacing the cell borders.

HCS cells can be given priority over stronger cellsHCS provides the required logical function to distribute the traffic between cells HCS Use Up to eight layers (in up to eight bands)

Layer 1 has higher priority than Layer 2, Layer 3, Layer 4, ...Layer 2 has higher priority than Layer 3, Layer 4, Layer 5, ...

The layers can be distributed over the HCS bands in a variety of combinations as long as their order is maintained

Result:Move the handover border from the signal strength border to a new handover border controlled by the band threshold ,i.e, larger service area

Benefits:Fully utilizing the radio capacity, by adjusting the effective cell coverageOffering sufficient quality, smaller cells might provide better quality even is not stronger

HCS - Layer and Band parametersMain Controlling Parameters:

HCSBANDTHR: decides if the cell should be prioritized over stronger cells from other HCS bandsLAYERTHR: decides if the cell should be prioritized over stronger cells in the same HCS band

For each cellLAYERTHR: Signal strength threshold LAYERHYST: Hysteresis

For each bandHCSBANDTHR: Signal strength thresholdHCSBANDHYST: Hysteresis

For serving cell, the band threshold isHCSBANDTHR-HCSBANDHYSTLAYERTHR-LAYERHYST

For neighboring cells, the band threshold is HCSBANDTHR+HCSBANDHYSTLAYERTHR+LAYERHYST

HCS - Algorithm

HCS band evaluation rearranges the candidate list in Locating according to the priority rules

In general, the cells that have met the sufficient signal strength level

(better than band or layer threshold) will be evaluated by HCS ranking

cells in HCS ranking (i.e. prioritized cells) will be placed on top of the list that does not meet HCS criteria (i.e. non-prioritized cells).

Ranking for prioritized cells: the lower the layer, the higher priority & the higher in the ranking

Ranking for non-prioritized cells: based on basic ranking

HCS - AlgorithmBasic ranking list are re-sorted by HCS algorithmMust fulfill the following to be qualified as candidate in HCS band evaluation:

Neighboring cells:SS > HCSBANDTHRn + HCSBANDHYSTn

Serving cell: SS > HCSBANDTHRs – HCSBANDHYSTs

Else => non-prioritized cells(sorted last in final list according to basic ranking)

If strongest within the own band => HCS ranking listCells not strongest in band => next criteria; must fulfill:

Neighboring cells:SS >= LAYERTHRn + LAYERHYSTn

Serving cell:SS >= LAYERTHRs – LAYERHYSTs

Else => non-prioritized cellsStrongest cells from each layer => HCS ranking list (The rest of cells are non-prioritized & sorted last in final list according to basic ranking)At most only one cell from each layer prioritized for HCS rankingPrioritized cells for HCS ranking are sorted in ascending layer numbering order

HCS - Example

HCS Band

HCS Layer

HCS Layer Discription

HCS BandThr

HCS BandHyst

Layer ThrLayer Hyst

Band 3 Layer2 Inbuilding sites -105 2 -85 2Band 3 Layer3 Micro hotspots -105 2 -70 2Band 3 Layer5 Micro coldspots -105 2 -90 2Band 3 Layer6 Macro cells -105 2 -105 2Band 3 Layer7 Umbrella (High Sites) -105 2 -105 2

-90dBm (serving cell)

-88dBm

Layer 7

Layer 3

Layer 2

Layer 5

-68dBm

-70dBm (serving cell)

-83dBm

-85dBm (serving cell)

-70dBm (serving cell)

-83dBm

-83dBm

-68dBm

Layer 6

-105dBm (serving cell)

-103dBmUmbrella Sites

Macro Cell

900 Micro Cold spot

900 Micro Hot Spot

1800 Micro Hot Spot

Inbuilding 900/1800

85dBm (serving

cell)

HCS - Fast Moving Mobiles

To prevent fast moving mobiles from doing HO to lower layer cells, a penalty is used

PSSTEMP - SS penalty valuePSSTEMP =0, (0 – 63 dB)

PTIMTEMP - SS penalty durationPTIMTEMP = 0, (0 – 600 sec)

FASTMSREG - activates the registration of fast moving MSsFASTMSREG = OFF

THO - time interval to measure the number of HOTHO = 30sec, (range 10 - 100 sec)

NHO - the number of inter-cell HOs ( during THO ) which labels an MS as fast.

NHO = 3, (range 2 -10 HOs)

9702900

HCS – Idle Mode

Normal Cell Selection: the MS will try to select the most suitable cell to camp on.

A cell is considered suitable if:it belongs to the selected PLMN,

it is not barred

it does not belong to a location area included in the list of "forbidden location areas for roaming",

another PLMN than the home PLMN.

the cell selection criterion is fulfilled.

Cell Selection Criterion: While in idle mode, the MS continuously calculates the cell selection quantity, C1.

The cell selection criterion is satisfied if C1 > 0 . C1 = (received signal level - ACCMIN ) - max(CCHPWR - P, 0)

HCS – Idle Mode

Cell Reselection: In order to control the traffic distribution between cells, to favor certain cells in idle mode similarly as in dedicated mode, by HCS.

For example, in a microcell environment there can be a need for controlling the cell reselection rate especially for fast moving mobiles.

For these purposes, additional cell reselection parameters, CRO, TO and PT, are broadcasted on the BCCH of each cell.

The cell reselection process employs a cell reselection quantity C2

HCS – Idle Mode Cell Reselection Algorithm and Parameters

C2 is calculated as follows: C2 = C1 + CRO – TO * H (PT – T) for: PT<>31

C2 = C1 – CRO for: PT=31

T is a timer and CRO, TO and PT are parameters.

CRO: Cell reselection offset. Defines an offset to encourage or discourage MSs to select the cell while it is camping on another cell (0 – 63, 2dB steps)

TO: Temporary offset during PT (0 – 7, 10dB steps)

PT: Defines penalty time (duration) for which TO is applied. (0 – 31, 10 or 20sec intervals, )

HCS parameters

Macro/Micro Settings, example

Parameter Default Recommended Value Unitvalue value range

LAYER 6/2 1 to 8

LAYERTHR 105/70 150 to 0 -dBm

HCSBAND 3 1 to 8

HBANDTHR 105 150 to 0 -dBm

LAYERHYST 2 2 0 to 63 dB

HCSBANDHYST 2 2 0 to 63 dB

PSSTEMP 0 0 0 to 63 dB

PTIMTEMP 0 0 0 to 600 s

FASTMSREG OFF ON, OFF

THO 30 10 to 100 s

NHO 3 2 to 10

HCS Flowchart

A, B, C, D, E, F, G

>Band threshold?

>Layer threshold?

Strongest in band?

Strongest in layer?

HCS Ranking (Layer Ranking)

A,B,C

Basic Ranking

D,E,F,G

Basic Ranking list

No (E)No (B,D,E,F)

No (D, F)

No (G)

Yes (B)

Yes (B, D, F)

Yes (A, C)

Yes (A, B, C, D, E, F)

HCS flowchart

Hierarchical Cell Structure Trial/Example

Investigate Cell Dragging Affects Under HCS Test the functionality of the feature

Slow HO out of Micro HCS Cells

Trial Settings: BTS Power Control Active:

Layerthr=70 (Layer 3 & 5), LayerHyst=2

BTS Power Control Inactive:Layerthr=70 (Layer 3 & 5), LayerHyst=2

BTS Power Control

- 72 dBm

BTS Pwr Ctrl ON: RxLev=-72 – PC Reg – AveDelay = -72 – 10 – 3 = -85 (dBm)BTS Pwr Ctrl OFF: RxLev=-72– AveDelay = -72– 3 = -75 (dBm)

MYA1 - BTS Pwr Ctrl Active

HO Out

HO Out

HO Out

HO Out

MYA1 - BTS Pwr Ctrl Inactive

HO Out

HO Out

HO Out

HO Out

MYA1 - BTS Pwr Ctrl Active (RxQual)

MYA1 - BTS Pwr Ctrl Active (RxQual/RxLev)

MYA1 - BTS Pwr Ctrl Inactive (RxQual)

MYA1 - BTS Pwr Ctrl Inactive (RxQual/RxLev)

3. Multi Band UL/OL (Single BCCH)

General Description

In a multi band cell it is possible to configure two (or three) different frequency bands in a cell with only one BCCH

The BCCH is configured to one of the frequency bands

While TCH resources could be in the other frequency band, provide more capacity to be used for traffic.

To correctly locate MSs, the network has to be aware of the differences in propagation between the bands

Differences in propagation

For the CS traffic, the BSC compensates for the difference, by applying a frequency band group offset, defined by a cell parameter FBOFFS

RxLev = RxLev + FBOFFS.FBOFFS = Propagation (Delta) + EiRPBCCH - EiRPnon-BCCH

Propagation Delta (free space) between GSM900 & 1800 is ~7dBDepending on the environment Propagation difference could be much larger ~10dB is a typical conservative value used

ParametersThe Main controlling parameters should be planned and optimized so they define as accurately as possible the coverage border of the OL

SCTYPE: Identifies the subcell type UL/OLLOL: Pathloss threshold.LOLHYST: Hysteresis for pathloss.TAOL: Timing advance threshold.TAOLHYST: Hysteresis for timing advance. FBOFFS: frequency band group offsetMBCRAC: Defines the way that GPRS/EGPRS MS frequency band capabilities are handled:

0 MS frequency capability is considered when allocating channels for TBF transfers. If not available, only the BCCH frequency band is available. 1 All GPRS/EGPRS MSs are assumed to be capable of both frequency bands.

Other ParametersBSPWR: The BTS output power at the reference point for the BCCH frequencyBSTXPWR: The BTS output power at the reference point for the Non-BCCH frequencies with in a cell. Set per Subcell

Algorithm

Subcell Changes:

UL to OLSS>BSPWR(UL)-LOL+LOLHYST

OL to ULSS_non-BCCH <BSTXPWR(OL) -LOL-LOLHYST-FBOFFS),

BSTXPWRBCCH 40 SS > BSTXPWRBCCH - LOL + LOLHYSTBSTXPWRNON-BCCH 40 SS > -74

LOL 117LOLHYST 3FBOFFS 9

BSTXPWRNON-BCCH - LOL - LOLHYSTSS < BSTXPWRNON-BCCH - LOL - LOLHYST - FBOFFS

SS < -89

Input Parameter Value UnderLay to Overlay (900 to 1800)

SS + FBOFFS <Overlay to UnderLay (1800 to 900)

4. Half Rate

Dynamic Half Rate

Dynamic Half Rate Allocation may allocate Dual Rate capable MS in high load situations.

It is important that the allocation of a channel is done efficiently for a new connection so that high utilization of channels is obtained while good speech quality is maintained for the existing connections

Dynamic Mode Adaptation increases the capacity by changing the mode for ongoing connections from Full Rate to Half Rate

Half Rate connections are packed and Full Rate Channels are therefore released.

If the speech quality for a Half Rate MS becomes unacceptably low the system may upgrade the MS to Full Rate if certain conditions are met

What is Half Rate

idle

idleFR FR FR FR HRHR

1 2 3 4 5 6 7 8

FR FR

idleFR

1 2 3 4 5 6 7 8

FR FR HRHR FR HR

HRidle

idleFR FR FR FR idleFR FR FR FR HRHRHRHR

1 2 3 4 5 6 7 8

FR FR

idleFR

1 2 3 4 5 6 7 8

FR FR HRHRHRHR FR HR

HRHRHR

FR Gross TCH rate = (2*57 Bits/1 Normal Burst) * (1 Normal Burst/ Traffic Frame) *(24 Traffic Frames/26 –Frame Multiframe)

/(120 mSec/26-frame MultiFrame) = 22.8 kbps

HR Gross TCH Rate = (2*(57/2)Bits/1 Normal Burst) * (1 Normal Burst/ Traffic Frame) * (24 Traffic Frames/26 –Frame Multiframe) /

(120 mSec/26-frame MultiFrame) = 11.4 kbps

Half Rate Main Controlling Parameters (I)DHA: is used to turn the feature Dynamic Half Rate Allocation ON or OFF. The parameter is set per cell.DTHNAMR: is the threshold parameter for non AMR HR but DR capable MS:s at channel allocation below which a DR capable MS will be allocated on a HR channel. The parameter expresses the ratio between idle and de-blocked TCH:s in percent and is set per cell.

DMQB is used to switch ON or OFF the quality based channel rate switching from HR to FR. The parameter is set per cell. DMQBNAMR: (45) is the threshold triggering a switch from a HR channel to a FR if the filtered value of either rxqual_dl or rxqual_ul expressed in dtqu units for a non AMR DR capable MS is exceeding this threshold. The higher value of the parameter the poorer radio quality is accepted before switching to FR. The parameter is set per cell and is given in dtqu.

DMQG: is used to switch the quality based channel rate switching from FR to HR channels ON or OFF. The parameter is set per cell.DMQGNAMR: (25-38) is the threshold triggering a switch from a FR channel to a HR if the filtered value of either rxqual_dl or rxqual_ul expressed in dtqu units for a non AMR DR capable MS is less than this threshold. The higher value of the parameter the poorer radio quality is accepted before switching to HR. The parameter is set per cell and is given in dtqu.Note: that to avoid a unstable situation this parameter should be strictly less than DMQBNAMR. Otherwise there is a potential risk of a "ping-pong" effect degrading the performance of the channel allocation algorithm.

DMSUPP: is the parameter controlling the activation of DYMA. It is set per cell. DMTHNAMR: (3-80) is the HR packing threshold parameter for non AMR but DR capable MS:s. Above this value FR channels will have precedence over HR channels in the allocation and below this value HR channels will have precedence over FR channels. The parameter expresses the ratio between idle and de-blocked TCH:s in percent and is set per cell.

Parameter for AMR HR capable MSsDTHAMRDMQBAMRDMQGAMR. DMTHAMR

Half Rate Main Controlling Parameters (II)

Parameter name Default value

Recommended value

Value range Unit

DHA OFF ON ON/OFF -

DMQB OFF ON ON/OFF -

DMQBAMR 50 50 0 to 100 dtqu

DMQBNAMR 45 45 0 to 100 dtqu

DMQG OFF ON ON/OFF -

DMQGAMR 35 35 0 to 100 dtqu

DMQGNAMR 30 30 0 to 100 dtqu

DMSUPP OFF ON ON/OFF -

DMTHAMR 20 20 0 to 100 %

DMTHNAMR 10 10 0 to 100 %

DTHAMR 30 30 0 to 100 %

DTHNAMR 15 15 0 to 100 %

Half Rate Parameters & Algorithm

Dynamic Half Rate Allocation main ParametersDHA

Dynamic Half Rate Allocation, = ON

DTHAMRDynamic HR Allocation threshold AMR capable mobiles [%]

DTHNAMRDynamic HR Allocation threshold for non-AMR-mobiles [%]

Half Rate Algorithm (I)

Must calculate DTHNAMR and DTHAMR based on the configuration of the cell ( 2TRX, 3 TRX, 4TRX, etc) Based on a “commercial” strategy as to when launch AMR HR and plain HR based on how many Timeslots are Idle before DHA actually “kicks-in”?? – How aggressive?DTHNAMR (Non-AMR Connections)= ( # Idle TS’s left in Cell when to Activate HR+1)/( Total # TS’s in the Cell)DTHAMR (ForAMR Connections)= ( # Idle TS’s left in Cell when to Activate HR+1+1)/( Total # TS’s in the Cell)Total TCH’s for Voice = (Total TS’s in Cell – ( BCCH TS - # SDCCH’s TS’s - # FPDCH’s(GPRS/EDGE)

# Idle TS’s for HR or for AMR HR depends on TCH CONG% stats cell by cell, the TCH Utilization % in the Cell, and the actual # TCH’s for Voice Traffic ( i.e. subtract the BCCH, the SDCCH/8’s and the dedicated FPDCH’s for GPRS/EDGE).In other Ericsson networks, this was based (conservatively) on a function (FUNCTION IDLE TS’s) which is a “look-up” table based on the # TCH’s for Voice Traffic and the TCH Utilization % for the cell at BH.

Half Rate Algorithm (II)Lets calculate now the parameters DTHNAMR and DTHAMR

DTHNAMR ( 1 TRX, 1 SDCCH/8 ) = 2/( 8 -1 -1 -1) = 2/5 = 0.4 = 40% , i.e. ( BCCH, 1 SDCCH/8, 1 FPDCH)DTHNAMR ( 2 TRX, 1 SDCCH/8 ) = 2/ ( 16 -1-1-1) = 2/13 = 0.1538 = 15.4%, i.e. ( BCCH, 1 SDCCH/8, 1 FPDCH)DTHNAMR ( 2 TRX, 2 SDCCH/8’s ) = 2/ ( 16 -1-2-1) = 2/12 = 0.1666 = 16.7%, i.e. ( BCCH, 2 SDCCH/8’s, 1 FPDCH)DTHNAMR ( 3 TRX, 2 SDCCH/8’s ) = 2/ ( 24 -1-2-1) = 2/20 = 0.10 = 10.0%, i.e. ( BCCH, 2 SDCCH/8’s, 1 FPDCH)DTHNAMR ( 4 TRX, 2 SDCCH/8’s ) = 2/ ( 32 -1-2-1) = 2/28 = 0.0714= 7.14%, i.e. ( BCCH, 2 SDCCH/8’s, 1 FPDCH)

Now what should be the strategy for AMR HR, should it have the same value as HR?, or if the % penetration of AMR HR MS’s in Maxis is high, should it be set at 1 TS higher than HR?Example:DTHNAMR ( 1 TRX, 1 SDCCH/8 ) = (2+1) /( 8 -1 -1 -1) = 3/5 = 0.6 = 60% , i.e. ( BCCH, 1 SDCCH/8, 1 FPDCH)So with this setting when there are 3 Idle TS’s in the 1 TRX cell, then AMR HR will be set first, although if you notice in the algorithm AMR HR takes priority over plain “HR” if the MS is AMR HR capable! – So AMR HR comes in the moment the # Idle TS’s is less < 60% compared to HR which will only be activated when the condition to be below the threshold of < 40% idle TS’s is met.

NOTE: These parameters ARE NOT STATIC, every week every cell must be checked with TCH UTILIZATION % or OCCUPANCY to see how many Idle TS’s should be considered based on Occupancy!.

Half Rate Algorithm –Function Idle Time Slots

Notice that for :For 1and 2 TRX ( # TCH’s) </= 16 . Idle TS’s = 2 regardless of Occupancy or TCH Utilization.For 3 TRX’s ( # TCH’s) </= 24. Idle TS’s =2 except when the cell has very high TCH Utilization , ie. OCCUPANCY >/= 90%.These settings are “conservative”. They can be changed for the needs of the Operator. Instead of “2” in the Look Up table, may want to try 3 or 4 which will activate DHA sooner.

Technical Description - Performance

Experiment 1b - Test Results

1.0

2.0

3.0

4.0

5.0

Conditions

MOS

Sel. Requir.

AMR-HR

EFR

FR

HR

No Errors

C/I=19 dB

C/I=16 dB

C/I=13 dB

C/I=10 dB

C/I= 7 dB

C/I= 4 dB

5. TCC

Transmitter Coherent Combining, TCC

Ericsson solution to improve Down Link

Enhance power output at ARP from 45.5 dBm to 48 dBm (63 W) from RBS 2206

Two combined transmitters working as one gives 6dB more output than two combined transmitters working as individuals

Antenna combining basic principle

Combine two TX signals onto one antenna (hybrid combining

Half of the power sum from TX1 and 2 will reach the antenna

The other half is dissipated as heath

PAA

PAB

C=0,5A+0,5B

D=0,5A+0,5B

Antenna combining special case

When the TX1 and TX2 signals are identical, then

This function is named TCC

PAA

PAA

C=A+A=2A

D=0

The power sum from TX1 and TX2 will reach the antenna

Nothing will be lost here.

TCC benefits

High output power with Maintained qualitycompensation for aging still remains

compensation for high temperature still remains

IM not applicable since same carrier used

noise is not correlated so no “TCC effect occurs” for noise

MTBF is unaffected (a booster adds problem to the system)

Flexibility since TCC is activated with SW commanddTRU can be reconfigured as normal combined or un-combined

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