OMO124000 BSC6900 GPRS EDGE V9R11 Build-In PCU Radio Network Optimization Parameters ISSUE1.03

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Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved.

GPRS/EDGE Radio Network Optimization Parameters

Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page1

Foreword The PCU performance parameters are essential to the

GPRS/EDGE network. Proper setting of such parameters

can improve performance of the packet services.


Contents1. GPRS/EDGE Cell Parameters

2. GPRS/EDGE Power Control

3. GPRS/EDGE Cell Reselection

4. GPRS/EDGE Performance Parameters


GPRS/EDGE Cell Parameters

NOM

T3168

T3192

DRX_TIMER_MAX

BS_CV_MAX

PAN

N3101

N3103

N3105


Network Operation Mode (Paging Co-Ordination)

Network Mode

Configure

GsConfigure PCCH

CS paging Message

PS Paging Message

Idle ModePacket

Dedicated Mod

I Yes Yes

PPCH PPCHPCCCH

Or CCCHPACCHPCH PCH

PACCH -

II No No PCH PCH CCCH CCCH

III No YesPCH PPCH

CCCH CCCHPCH PCH

Paging co-ordination means that the network sends CS

paging messages on the PS channel, i.e., on the GPRS/EDGE

paging channel or on the GPRS/EDGE traffic channel, so the

MS needs only to monitor that channel.


See the notes!


NOM

BSC-level

Cell-level

Data Configuration of Paging Co-Ordination

Page6


T3168 T3168 is used to set the maximum duration for the

MS to wait for the packet uplink assignment

message PCU

Packet Channel Request

Immediate Assignment Command

Packet Resource Request

Condiction BLER T3168 recommendation（ms）

Very Good BLER<2% 500

Good 2%<BLER<5% 1000

Bad 5%<BLER<10% 2000

T3168 Packet Uplink Assignment


MS PCU

Packet Uplink Assignment

Uplink Data Block

Downlink Data Block

Packet Downlink Ack/NACK (channel request description)

③

①

②

④

⑤

⑥

Uplink Data Block

Uplink Data Block

UL TBF Establishment during DL Data Transmission

T3168

T3168


Data Configuration of T3168


T3192 The timer is for the MS to wait for TBF release after receiving

the last data block.

PCU

T3192

Packet Downlink Ack/Nack（FAI=1）

PACKET DOWNLINK ASSIGNMENTTFI

Final ACKIdentifier

Downlink Data Block (FBI＝1)

Downlink Data Block


Data Configuration of T3192

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DRX_TIMER_MAX The MS request keeps the maximum value of non-DRX

mode.

Packet transmission mode

Non_DRX DRX

Packet idle mode

Non_DRX

DRX_TIMER_MAX (s)

Value（Sencond） 0 1 2 4 8 16 32 64

Packet idle mode


See the notes!


Data Configuration of DRX_TIMER_MAX

Page14


Packet Signaling Processing

Packet Downlink Ack/Nack（FAI=1）

T3192=500ms

Non DRX mode= 4s

DRX mode

DRX mode

Ready Mode

Downlink Data Block

Downlink Data Block (FBI)


BS_CV_MAX The mobile station shall send the Countdown Value (CV)

in each uplink RLC data block to indicate the current

number of remaining RLC data blocks for the uplink TBF

The CV shall be calculated as follows:

.,15,__,

,then

.1integer Let

otherwiseMAXCVBSxifx

CV

KNTSNBSTBCroundx


Examples of CV Procedure(1)BSN’ CV

139 15

140 14

141 13

142 12

143 11

144 10

145 9

146 8

147 7

148 6

149 5

150 4

151 3

152 2

153 1

154 0

BSN’ CV

139 15

140 15

141 15

142 15

143 15

144 15

145 15

146 15

147 15

148 6

149 5

150 4

151 3

152 2

153 1

154 0

TBC= 155NTS=1BS_CV_MAX=15



Examples of CV Procedure(2)TS0 TS1 TS2

BSN’ CV BSN’ CV BSN’ CV

125 15 126 15 127 15

128 15 129 15 130 15

131 15 132 15 133 15

134 15 135 15 136 6

137 6 138 6 139 5

140 5 141 5 142 4

143 4 144 4 145 3

146 3 147 3 148 2

149 5 150 5 151 5

152 4 153 4 154 4

155 3 156 3 157 3

158 2 159 2 160 2

161 1 162 1 163 1

164 0


TBC= 155 ->165, because the channel coding scheme is changed


Data Configuration of BS_CV_MAX

Page19


PAN(Piggy-backed Ack/Nack ) PAN_DEC: Set the decrease step length of the N3102 counter of the MS

PAN_INC: Set the increase step length of the N3102 counter of the MS

PAN_MAX: Set the maximum value of the N3102 counter of the MS

Packet Uplink Ack/NackN3102

PAN_MAX

- PAN_DEC

+ PAN_INC

Abnormal Release

T3182

T3182

T3182 T3182

T3182

Perform Cell Re-selection


PAN(Piggy-backed Ack/Nack )

PCU

N3102+2

Timeout

Suppose PAN_INC=2

T3182

Suppose PAN_DEC=1

N3102- 1

Uplink Data Block

Packet Uplink Ack/Nack

Uplink Data Block

Packet Uplink Ack/Nack


Data Configuration of PAN

Page22


N3101

PCU

Downlink Data Block /

Packet Uplink Assignment (valid USF)

N3101+1Uplink Data Block

Packet Polling Request


N3103

PCU

Packet Uplink Ack/Nack (FAI=1)

Packet Control Ack(or Access Burst 8bit)N3103+1

Uplink Data Block (CV=0)

Packet Uplink Ack/Nack (FAI=1)


N3105

PCU

Packet Downlink Ack/NackN3105+1

Downlink Data Block (RRBP)

Downlink Data Block (RRBP)


Data Configuration of N3101/3/5

Page26


GPRS/EDGE Power Control Purpose of GPRS/EDGE power control

Save the power

Reduce the interference of the network

GPRS/EDGE power control is complex than GSM for

discontinuous transmission

Normally now just uplink power control is implemented


GPRS/EDGE Power Control According GPRS/EDGE principle, GPRS/EDGE MS output power as below：

Pch = Min (o - ch – *( C+48) , Pmax)

Pch: The PDCH output power in every independent uplink link, the unit is

dBm;

o: 39dBm for GSM 900, 36dBm for DCS1800

ch: Gamma, specified power control parameter for MS and the channel

: Alpha, set by the network side. For open-loop power control, it is 1.0

C: the receiving signal level of MS

Pmax: the maximum allowed transmit power for MS. If PBCCH exists, it is

GPRS/EDGE_MS_TXPWR_MAX_CCH; otherwise, it is

MS_TXPWR_MAX_CCH.


GPRS/EDGE Power Control


GPRS/EDGE Cell Reselection During ready and standby mode, MS will occur cell reselection

MS-controlled Cell reselection(also called autonomous cell reselection)

will be triggered upon the following 5 kinds of conditions

Current serving cell is prohibited

Down link fails(DSC)

C1servingcell <0 for 5s

MS starts a cell reselection if the access times exceed [MS MAX

Retrans]


GPRS/EDGE Cell Reselection If PBCCH no exists, the cell reselection is basically the same as GSM

cell reselection

When the two cells locates in the different routing areas or the

MS is in READY mode, the C2N must be greater than C2S+CRH

(>5s)

When the two cells locates in the same routing area and the MS is

in STANDBY mode, the C2N must be greater than C2S (>5s)


Cell Reselection in Standby Mode

RA 1 RA 2

Cell A

Cell B

Cell C

C2A>C2BC2C>C2B＋CRH


Cell Reselection in Ready Mode

C2B>C2A＋CRH

RA 1

Cell A Cell B


Cell Reselection Mode——Network Control Mode

NCM DefinitionWhether MS send the M.R

MS StatusCell Reselection

Mode

NC0Normal MS Control Mode

NoReady & Standby

Controlled by MS

NC1MS Control with M.R Mode

Yes Only Ready Controlled by MS

NC2Network Control Mode

Yes Only ReadyControlled by

network


Network Control Mode


In the NC2 mode and Ready state, the MS periodically sends packet

measurement reports to the BSC. The BSC determines whether to perform cell

reselection.

The NC2 feature supports

Intra-BSC cell reselection

Inter-BSC cell reselection

GERAN-to-UTRAN cell reselection

GERAN-to-EUTRAN cell reselection

Page38

Serving cell A

Neighbor cell B

Neighbor cell c

change to cell C

NC2 Feature


Trigger Condition to NC2 Procedure In NC2 mode, any of the following events triggers a network-

controlled cell reselection.

The MS signal strength keeps falling, and a neighboring cell with stronger signal

strength exists.

The MS signal quality keeps deteriorating, and a neighboring cell with better signal

quality exists.

The serving cell of the MS is overloaded, and a neighboring cell with lighter load

and stronger signal strength exists.

The SGSN indicates that the RAT(such as, GERAN, UTRAN, or EUTRAN) suitable for

the MS is different from the current RAT.

In Standby state, the MS initiates autonomous cell reselection regardless of

the NC mode.

Page39


Data Configuration of NC21. Run the BSC6900 MML command SET GCELLGPRS. In this step, set

the parameters as follows

Page40


Data Configuration of NC22. Run the BSC6900 MML command SET GCELLPSBASE.

Page41


In NC0/NC1 mode and packet transfer mode, the MS requests the

SItargetcell from the BSC when performing cell reselection.

NACC is classified into

Intra-BSC NACC

Inter-BSC NACC

UTRAN->GERAN NACC

EUTRAN->GERAN NACC

Page42

NACC(Network Assisted Cell Change)

Cell A Cell B

System information of cell B

Serving CellTarget Cell

Begin

Serving cell supports NACC?

Target cell supports NACC?

BSC delivers system information of target

cell

End

Yes

Yes

No

No


Trigger Condition to NACC Procedure The MS initiates the NACC procedure only when an autonomous cell

reselection is trigger

In NC0/NC1 mode and packet transfer mode, any of the following

events triggers an NACC procedure

C1target cell <0 for 5s

C2target cell >C2servingcell

Down link fails(DSC)

When in Standby status, MS performs the cell reselect by itself and

does not initiate the NACC procedure

Page43


Intra-BSC NACC Procedure

Page44

MS BSC

PACKET CELL CHANGE NOTIFICATION

PACKET NEIGHBOUR CELL DATA

PACKET CELL CHANGE CONTINUE

PACKET SI STATUS

PACKET SERVING CELL DATA

Obtain system messages of the target cell

It’s optical according the data configuration “PACKET SI”(in the next slide)


Inter-BSC NACC Procedure

Page45

MS Old BSC

PACKET CELL CHANGE NOTIFICATION

PACKET NEIGHBOUR CELL DATA

PACKET CELL CHANGE CONTINUE

PACKET SI STATUS

PACKET SERVING CELL DATA

Target BSC

RIM procedure

Obtain system messages of the target cell


Activate intra-BSC NACC

1. Run the BSC6900 MML command SET GCELLPSBASE

2. Run the BSC6900 MML command SET GCELLGPRS

Data Configuration of NACC in Intra-BSC

Page46

Set to “NC0(NC0)” or “ NC1(NC1)”


Activate inter-BSC NACC

1. Run the BSC6900 MML command SET GCELLGPRS

2. Run the BSC6900 MML command MOD NSE

3. Run the BSC6900 MML command RST SIGBVC to activate RIM

Data Configuration of NACC in Inter-BSC

Page47Page47


Dynamic PDCH Channel Conversion

When dynamic PDCH conversion will be triggered?

PDCH required failure (such as reach the max threshold)

No meet the multiple timeslot

The TBF numbers higher than ”Uplink (Downlink) Multiplex

Threshold of Dynamic Channel Conversion”



Which channel will be convert to dynamic PDCH

TCH/F channels can be converted to dynamic PDCH, the

maximum dynamic PDCH number will be restricted by

reasons listed below：

The max PDCH number restricted by License

Maximum Ratio Threshold of PDCHs in a Cell

Maximum PDCH numbers of carrier

Reservation Threshold of Dynamic Channel Conversion



When the dynamic PDCH channel will be converted to

TCH channel?

Timer of Releasing Idle dynamic Channel

CS services preemption

All dynamic channels can be preempted

Control channels cannot be preempted

Dynamic channels carrying services cannot be preempted


GPRS/EDGE Channel Priority Type



TRX2

EGPRS

Normal

EDGE MS GPRS/EDGE MS



TRX2

EGPRS

Priority

EDGE MS

×reject

EGPRSPriority

GPRS/EDGE MSGPRS/EDGE

MS


GPRS/EDGE&EDGE Coding Scheme

8PSKGMSK

9.0513.4

15.6

21.4

8.811.2

14.817.6

22.4

29.6

44.8

54.4

59.2

0.00

10.00

20.00

30.00

40.00

50.00

60.00

CS-1 CS-3 CS-4 MCS-1 MCS-2 MCS-3 MCS-4 MCS-5 MCS-6 MCS-7 MCS-8 MCS-9

Kbps

GPRS

EDGE

CS-2


Appendix

Codec

GPRS/EDGE

CS1 CS2 CS3 CS4

EDGE MCS1 MCS2 MCS3 MCS4 MCS5 MCS6 MCS7 MCS8 MCS9

Idle Timeslot

1+0 1+1 1+2 1+3


Appendix


Summary In this course, we have learned:

The function of GPRS/EDGE cell parameters

The function of GPRS/EDGE cell reselection parameters

The function of GPRS/EDGE performance parameters

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OMO124000 BSC6900 GPRS EDGE V9R11 Build-In PCU Radio Network Optimization Parameters ISSUE1.03

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