statistics data analysis and optimization v 4.0

Statistics Data Analysis

and Optimization V4.0

for HUAWEI GSM/GPRS/EDGE System

Compiled by Jin/JiangxinE-mail: [email protected]

2008/5/8

Chapter 1 GSM system1. Work items in an optimization project

2. Review of the GSM system

3. Based technology in GSM system

4. Drive test and analysis

5. Parameters in common use

6. OMCR statistics data and the formula in common use

7. Main methods in the performance analysis procedure

8. Selection and reselection

9. SDCCH congestion

10. TCH congestion and drops

11. Call progress introduction in common use

12. Power control algorithm

13. Handover algorithm

14. Cases according to statistics data

course contents









9. SDCCH congestion






Work items in optimization

Find the problems Statistics data DT and CQT Alarm check Custom complain

Analysis the problems Statistics analysis DT and analysis Alarm analysis Call process analysis Frequency plan and reuse

Solve the problems Trouble shooting Improve coverage Adjust TRX configuration Adjust antenna system Edit freq.plan table Neighbor relations Parameters

Checking and compare results Before and after modify Different BSC/Cells Different network

Problems in network Hardware trouble problem Freq. interfering problem Coverage problem HO relations problem “busy or idle” problem Traffic balance Underlay and overlay problem KPI Wireless parameter problem Especial problems (access,roaming,crossed talk,A-interface ….)

Steps for problem Find the problems Analysis the problems Resolve the problems Checking and compare results are throughout the optimization process.

Emphasis of the optimization

System performanceAccess

Channel success

Congestion

Drop

Handover

Traffic

Quality

Coverage

Frequency

1. Immediate assignment rate

2. CSSR

3. Wireless access rate

4. Sdcch success rate

5. Sdcch congestion rate

6. Sdcch drop call rate

7. Tch success rate

8. Tch congest rate

9. Tch drop call rate(including HO)

10. Tch drop call rate(excluding HO)

11. Ho success rate(from attempt)

12. Ho success rate(from command)

13. SD/TCH traffic

14. TCHF and TCHH traffic balance

15. Overlay and underlay traffic balance

16. Coverage rate (DT)

17. BER/MOS

Optimization flowing(1)

Collect system data

Analysis data and make optimization plan

Performance data of past week

Engineer parameter table

Freq. plan table

Neighbor list relation (internal and external)

Antenna information

System topology

Customer complain

Make optimization plan, hardware problem list,

DT plan, check cell health, consistency, frequency, LAC data, neighbor

Start optimization

Hardware solved and system test

Hardware solved and system test

Start optimization meeting

Output coverage chat,congestion rate,drop calls,interfering area according to the DT data.

And optimize frequency, adjust channels in the congestion cells and concentric lay, adj. parameters

Check and optimize the neighbor relation, correct neighbor data (internal and external neighbors)

Optimize parameters( general)

Put in suggestions and good plan

Optimization summarize and technology communion

Optimization flowing(2)

Coverage, frequency, channels, configuration, parameter

Neighbor relations optimization

Optimize parameters

compare the performance and put in suggestions

Optimization summarize









9. SDCCH congestion






PSTN Network

Billing Center

GBTS

TE

MT

MS

GBSC

Internet

A

Pb

Um

Gi

GSM network review

HLR/Auc/EIR

SMS-GMSC/IWMSC

MSC/VLR

SS7 Network

GSM Core Network

GGSN

CG

SGSN

DNS

GPRS Backbone

GbGb

Gs

Abis

Um

GPRS Core Network

EDGE PCU

OMC

FAN BOX

SWITCH BOX

FAN BOX

AIR BOX

AIR BOX

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TDU

Common equipment

TRXCDU

air/fan

Review of BTS312

CDU: Combiner & Divider Unit

TRX: Transceiver Module

PMU: Power Monitoring Unit

TMU: Timing/Transmission & Management

PSU: Power Supply Unit

TES: Transmission Extension power Supply

TEU: Transmission Extension Unit

TDU: Time Distribution Unit

Function: Core of siteTimingTransmissionManagement

BSC

External synchronous clock

MMI man-machine interface

ExternalAlarmingcontrol

BIU

OMU

EAC MCK

Standby MCK

Extended BIU

DBUS Internal data bus

CBUS Internal control bus

TDU Internal clock bus

TMU

Combiner

Distributor

Distributor

CouplerTX1TX2

TX-COMBTX-DUP

RX1RX2RX3RX4

HL-out

RX2RX3RX4

RX1

HL-inRXD

TX/RX-ANT

RXD-out

CDU

In common use way: 2TRX+1CDU: TX-COMB and TX-DUP ,HL_in and RXD-out connected2TRX+2CDU: TX-COMB and TX-DUP connected or not connected( less loss)4TRX+2CDU: TX-COMB and TX-DUP connected6TRX+1SCU+1/2CDU: TX-COMB and TX-DUP ,HL_in and HL_out connected8TRX+2SCU+1/2CDU: TX-COMB and TX-DUP ,HL_in and HL_out connected

Especially the TX_out can be connected with TX_DUP and it can decrease 3db of

combination loss.

Distributor

CouplerTX1

RX1RX2

TX/RX-ANT1

Distributor

CouplerTX1

RX3RX4

TX/RX-ANT2

EDU and SCU

Tx_Comb

TX4

TX3

TX2

TX1

3dBBridge

3dBBridge

3dBBridge

SCU: no coupler Four carriers are combined output through 2steps of 3dB bridges plug loss is 6.8dB.

EDU: No combined loss

Review of BTS3012

DPU: Digital Power Unit

TRU: Transceiver Unit

PMU: Power Monitoring Unit

TMU: Timing/Transmission & Management

Principle for RF send and receive mode:Send: combining when TRU combined actually no combining when TRU not combined actuallyReceive: dividing receiver when TRU combined indepandent receiver when TRU no combined

Access link check Dual polarizationantenna

TTAoption

Lightning arrester

BTS rack

Jumper connector(DIN)

DIN connector Lightning arrester/feederconnector(DIN)

Jumper/TTA Connector (DIN)jumper

Jumper/TTA connector(DIN)

Antenna Connector(DIN)

FAN BOX

SWITCH BOX

FAN BOX

AIR BOX

AIR BOX

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Inside jumper

TRX jumperTX and RDX cables









9. SDCCH congestion






Um layer

Communicate MNG(CM)

Radio resource (RR)

Mobility MNG(MM)

CPU

RACH BCCH AGCH/PCH SDCCH SACCH TCH FACCH

TCH0 TCH1 TCH2 ..SACCH ..TCH24 IDL

Multi-frame

Phy. link layer(L1)

Data link layer(L2)

Application layer(L3)

CM

MM

RR

LAPDm

SigL1

L3

L2

L1

MS

RR BTSM

LAPDm

SigL1

LAPD

SigL1

LAPD

SigL1

BTSM

RR

SCCP

MTP

BSSMAP

CM

MM

BSSMAP

SCCP

MTP

MSCBSCBTS

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GSM protocol stake

Speech/channel coding

Speech A/D 8KHz, 260bit Speech codeSection

20ms13kbit/s Channel code

Interleaving Burst pulseCipher

22.8kbit/s,456 bits,20ms

Modulate 33.8kbit/s

transmission

Speech coding : Coding type: RPE-LTP sampling 8Khz,and 20ms/frame, in each frame there are 4 sub-frame then get a rate of 13kbit/s. 260bits/20ms=13kbit/sChannel coding: 456bit/20ms=22.8kbit/s

From 260 bits to 456 bits in a speech frame

Parity check 3bitsConvolution

Coder

50bit *2

132bit

78bit

456bitTail 4bits

Interleave

1 2 3 4 5 6 7 8 ... ...452 453 454 455 456

Block

8

16

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456

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10

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450

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14

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454

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452

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455

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451

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453

.... ....

B0 B1 B2 B3 B4 B5 B6 B7

{A4,B0} {A5,B1} {A6,B2} {A7,B3} {B4,C0} {B5,C1} {B6,C2} {B7,C3}

Rectangular interleave

Diagonal interleave

456bit/8=57bit/frame

Two type of interleave: rectangular type and diagonal type

Frame structure and burst frame

0 1 2 3 2044 2045 2046 2047

0 1 2 3 48 49 5047

0 1 24 25

0 1 24 25 1 49 500

0 1 4 5 762 3

TB3

TB3

GP8.25 TB: Tail bit

TB3

TB3

GP8.25

GP: Guard period

TB3

TB3

GP8.25

TB3

TB3 GP 68.25

58 information bits 26 TSC 58 info bits

Constant bit 142

Info bit 39 Extended TS 64 Info. bit 39

sequence 41 Info bit 36

Normal burst (NB for traffic)

Freq correct burst(FB for for freq synchronization)

Sync burst (SB for time sync)

Access burst (AB for access)

1 hyper frame(for hopping FN)=2048 super-frames=2715648TDMA frames (3 hours, 28 minutes, 53 seconds and 760 milliseconds)

1 super-frame=1326TDMA frames (6.12 seconds)

1SACCH multiframe=26TDMA frames (120ms) 1 multiframe=51TDMA frames (235.4ms)

1TDMA frame=8 timeslots (120/26=4.615ms)

1 timeslot=156.25 bit duration (4.615/8=0.577ms)(1 bit duration: 0.577/156.25=3.69us)

BCCHCCCHSDCCH

TCHSACCH/TFACCH

1SACCH super-frame=104TDMA frames (480ms)

TS: training sequence

26-frame multi-frame24TCH/F+FACCH/F+1SACCH/TF+1idle (full-rate TCH)

1SACCH super-frame=4SACCH multi-frame=4*26=104frames(480ms) Full (Rxlevel/Rxqual)=(26-1idle) *4=100frame measure average Sub (Rxlevel/Rxqual)= 12 frame measure average( under DTX allowed) (52-59 frame and 4 SACCH frame)

TCH/H+FACCH/H+SACCH/TH (half-rate TCH)51-frames multi-frameMain BCCH: 5FCCH+5SCH+20BCCH+20CCCH+1idle=51frame Combined BCCH: (5FCCH+5SCH+4BCCH+12CCCH+16SDCCH/4+8SACCH/C4 )*2=102frameMain SDCCH : (32SDCCH/8+16SACCH/C8 +3idle)*2=102 frame

Combinations of frame and TA

TB

3

Information

571

Training sequence

261

TB

3

Information

57

147+8.25=156.25bit(0.577ms)

GB

3

1Bit period=0.577ms/156.25=3.68usTA=63bit/max*3.69us/bit=233us for normal cellRadius/max twice(ms to BTS to ms): 233us*300000km/s=70kmMax cell radius is 70km/2 35km1TA=1bit=554mTA=219bit/max in 2 timeslot extended cell,radius/max=120km

Channels

Broadcast control channel (BCCH)

Control channelCommon control channel (CCCH)

Voice channel(TCH)

FCH SCH BCCH(system information)

TCH/FAGCH RACH SDCCH FACCH

SACCH

TCH/H

TCH/9.6FTCH/ 4.8F, HTCH/ 2.4F, H

PCH

Common channel (CCH)

Dedicated channel (DCH)

Logical channel

FCCHSCHBCCHPCHAGCH

BCCH

CCCH

Common Channel

SDCCHSACCHFACCHTCH/FTCH/H

DCCH

TCH

Dedicated Channel

PCH AGCH

Downlink CCCH

RACH CCCHCommon Channel

SDCCHSACCHFACCHTCH/FTCH/H

DCCH

TCH

Dedicated ChannelRACH

Uplink CCCH

Downlink and uplink channels

CCCH configuration

Ccch_conf: ccch blocks in a 51 CCCH-multi-framesWhen one no-combined case:

bs_ag_blks_res: AGCH reserve blocks : 2bs_pa_mfrms: paging blocks : 2Paging sub-frame: (9-2)*(bs_pa_mfrms)=14

Ccch config Ccch blocks

one combined 3

one no-combined 9

two no-combined 18

three no-combined

27

four no-combined 36Pch blocks=Ccch blocks-(bs_ag_blks_res), if ccch_config=1 non_combined, bs_ag_blks_res=2, then PCH=9-2=7. each CCCH 51-multi-frames will be lasted 235.4msPch blocks/sec= Pch blocks/0.2354ms=29.7 blocks/sec 2 times in each Pch blocks for IMSI paging type 4 times in each Pch blocks for TMSI paging typeSo total paging times/max=Pch blocks/sec*(times in each Pch blocks)

Search for frequency correction burst

Search for synchronization sequence

Read system information

Listen paging message

Send access burst

Wait for signaling channel allocation

Call setup

Assign traffic channel

Conversation

Call release

FCCH

SCH

BCCH

PCH

RACH

AGCH

SDCCH

SDCCH

TCH

FACCH

idle mode

“off” state

dedicated mode

idle mode

Functions of Channels

Rxlevel calculation and transmit model

RxLev=EIRP-Path Loss

2, PATH LOSS (predigest formula, need to corrected in project)Okumura/Hata transmission model for 900M macro network.

Lp=69.55+26.16lg (f) -13.82lg (hb) +(44.9-6.55hb)lg (d) -A (hm) Lp: path loss (db) f : frequency (Mhz) hb : BTS antenna height (m) hm : MS antenna height (m) d: distance between MS with BTS

Cost-231/Hata transmission model for 1800 macro network

Lp=69.55+26.16lg(f) -13.82lg(hb) +(44.9-6.55hb)lg(d) -A(hm)-KCost-231/Walfish ikegami model for 900/1800 micro networkKeenan-motley model for 900/1800 indoor distribution system.Planning software for 900/1800 macro system

Path Loss(dB)=k1+k2log(d)+k3Hms+k4log(Hms)+k5log(Heff)+k6log(Heff)log(d) +k7(Diffraction Loss)+Clutter Loss

1, EIRP: efficient power of BTS.EIRP=10log[P_Forward(mW)-P_Reflected(mW)]+Tx_Antenna_Gain+Rx_Antenna_Gain-Rx_Feeder_Loss

P_Forward: power of forward direction(mW) P_Reflected: power of reflected direction(mW) Tx_Antenna_Gain: TX antenna gain of BTS (dbi) Rx_Antenna_Gain: RX antenna gain dbi) Rx_Feeder_Loss: loss of feeder cable

Path Loss(dB)=k1+k2log(d)+k3Hms+k4log(Hms)+k5log(Heff)+k6log(Heff)log(d) +k7(Diffraction Loss)+Clutter Loss

Note: the values are only reference to, and need to corrected in planning project.K1: loss constant for freq.

Density urban: K1=69.55+26.16lg(F)Urban : K1=69.55+26.16lg(F)-2[lg(F/28)]2-5.4)Country : K1=69.55+26.16lg(F)-4.78[lg(F)]2+18.33lg(F)-40.94)

K2: loss constant for distance: K3,K4: corrected coefficient for mobile antenna height K5,K6: corrected coefficient for BTS antenna heightK7: corrected constant for diffractionKclutter: corrected coefficient for clutter.

D: distance between mobile and (km)Hms: height of mobile antenna (m)Heff: efficient height of BTS antenna (m)

The case parameters in urban and country cities.

Planning software transmission model

Down-tilt, height and coverage

tg(B-A/2)=H/RB: down-tiltA: vertical beam widthH: antenna heightR1,2,3: coverage range

Frequency band and channels

890 915 935 960

Dulplex distance band : 45 MHz

GSM 900:

GSM 1800:

uplink downlink

1710 1785 1805 1880

Dulplex distance band : 95 MHz

uplink downlink

Uplink: F1=890.2+(n-1)*0.2 (MHz) ARFCN: 0-124Downlink: F2=uplink+45=f1+45 (MHz)

Uplink: F1=1710+(n-512)*0.2 (MHz) ARFCN: 512-884Downlink: F2=uplink+95=f1+95 (MHz)

Layers and priorities in dual band network

Background: Traffic increase rapidly Limited channels in 900 band Frequency re-use more difficult Quality decrease More free channels in 1800 band Offer loose frequency re-use in 1800

band

Parameters set: 900 cells offer coverage service (Layer 3) 1800 cells offer traffic service (Layer 2) MS stay in Layer 2 more (high cell priority) Set much CRO in 1800 cells Set easy access parameters in 1800 cells Set easy handover to 1800 cells Set 1800 TRU as overlay in concentric HO Set 900 TRU as underlay in concentric HO

RLT (DL) and SACCH multi-frame (UL)

Radio_link_timeout (DL,S(T100) )S+2 when MS decode a SACCH multi-frame correctly, S<= RLT/max. S -1 when MS can’t decode a SACCH multi-frame correctly.S=0,MS gives up the radio resource connection, a drop call occurs.

SACCH-multi-frames(UL)Value +2 when BTS decode a SACCH multi-frame,<= SACCH-multi-frames/max.Value –1 When BTS can’t decode a SACCH multi-frame,Value=0.BTS stop transmitting downlink SACCH. and start T3109.When T100 timeout in handset ,a drop call occurs.When T3109 timeout in BTS,BTS release channel, BSC sends “Clear request” to MSC.

Reasons of RF lossInterfering Bad rx_lev Incorrect PWR control parameter.Hardware problem.TRX Pwr class difference in the same cell.HO drops.Neighbor cell relations problem.Incorrect HO algorithm and parameters RLT,SACCH-multi-frame not correct.

Measure reports (MR) and SACCH frameMS measure the uplink and downlink during the dedication mode.MS/BTS measures and report the uplink/downlink information. The results are prepare for HO, pwr control

A SACCH super-frames is made of 4 SACCH multi-frames.Total 26 frames in one SACCH multi-frame.The MS deals with a full MR in a SACCH super-frames, the period is 480ms(4*120ms), MS retains the previous MR result of 480ms when it is in the next 480msMS decode the neighbor cells’s BSIC in idle frameMS retain MR result for 10s if MS find that a BCCH go out from “best 6 neighbor cells” to prevent stopping the MR when “HO request” is sent to this cell.

Contents in MRActual TA of MSActual tx-pwr of MSThe BA changes indicator DTX used indicatorThe rx_lev and rx_qual in uplink and downlinkThe rxlev,freq, BSIC of the 6 best neighbors

Frequency reuse and hopping

Common Reuse 4*3 pattern : 4 sites and 3 sector in one frequency groupLack of channel mode: BCCH 4*3, TCH 1*3 or 1*1 hoppingMRP:(multi-reuse pattern) freq. number of Bcch1≥ Tch2≥Tch3 ≥Tch4 ≥...... ≥ TchnIUO: intelligence underlay and overlayHopping: 4*3, 1*3, 1*1(1*3: MA >=2*TRX, ,1*1: MA >=2*TRX(total))

C/I=(useful signal)/(useless signal) =carrier/interference

Standard: C/I=9db project: C/I=12dbStandard: C/A=-9db, project: C/A=-6db

C/I must be comply for the formula as below: D=Distance of frequency re-useR=Radius of cellN=No. of frequency re-use (E.g. 4*3=12,1*3=3)

Hopping

Frequency

F0

Frame

F1

F2

F3

F4

Time

Hopping algorithm(HSN=0)MAI=(FN+MAIO)mod N, RFCHN=MA(MAI)

FH mode: base-band and RF hoppingMA: hopping frequency, 1*3,1*1 need MA>=2TRXsMAIO: No.of TRX-1HSN: 0-63TSC: BCCFN: 2048*51*26 used in hopping algorithmN: total of MA in one cell

BCCH channel no hopping (benefit to decode BCCH)SDCCH and TCH channel can hoppingBand hopping and RF hopping

Band hoppingUsing fixed frequency in each TRXUsing different TRX in different timeTCHs in BCCH TRX are hopping (option)MA=TRXsTRX problems Will effect performance

RF hoppingUsing vary frequency in each TRXUsing different TRX in different timeTCHs in BCCH TRX are no hoppingTRX problems will not effect performanceMore common than Band hopping

Frequency hopping (4*3, 1*3, 1*1)

4*3 hoppingSame frequency as 4*3(MA)

1*3 hoppingEach cell have a MA in same siteSame MA and MAIO in same direct cells in different sitesBe sure no neighbor-MAIO in same cell or in the same direct cells.Will get more interfering if the azimuth of sites is not regular

1*1 hoppingEach cell have the same MA in all cellsDifferent MAIO in each cell in one siteSame MAIO in same direct cells in different sites

No co-channel frequency carriers in one BTS. The frequency separation between BCCH and TCH in the same cell should be not less

than 400K. When frequency hopping is not used, the separation of TCH in the same cell should be

not less than 400K. In non-1*3 reuse mode, co-channel should be avoided between the immediately neighbor

BTS. Neighbor BTS should not have co-channels facing each other directly. Normally, with 1*3 reuse, the number of the hopping frequencies should be not less than

twice of the number of frequency hopping TRX in the same cell. Pay more attention to co-channel reuse, avoiding the situation that the same BCCH and

BSIC in adjacent area.

Frequency planning principles

Principle of AMR AMR (Adaptive Multi Rate) is the set of different speech code rate. BTS and MS select and adjust

the appropriate rate according to RQI, so that to improve the MOS quality of network. system select and adjust to low AMR when RQI is bad (or interfering is high); System select and adjust to high AMR when RQI is good (or interfering is low) AMR-FR set (8):12.2k(GSM EFR)/10.2k/7.95k/7.40k(IS-641)/6.70k/5.90k/5.15k/4.75k AMR-HR set (5):7.40k(IS-641)/6.70k/5.90k/5.15k/4.75k ；

Benefits to network: Offer better speech quality: the speech quality is

better than EFR/HR when system use AMR-FR and AMR-HR whether the interfering is high or low.

Improvement the re-use rate of frequency: the performance is better when system use the No. of frequency re-use=9(3*3) and 12(4*3) than N=12(4*3) and 18(6*3), It means that the system can offer higher No. of frequency re-use mode in the condition of the same speech quality.

Improvement the edge coverage. For C/I, AMR-FR 4.75k need 3dB while EFR 8dB to keep the FER<1%. It means that the performance is improved from 3dB to 8 dB in the coder-encoder between AMR-FR and EFR. So the MOS is improved at the edge of coverage.

Channel assignment of AMR

Channel assignment principle of AMR adjust AMR supports according to the busyness type, speech version, circuit pool when BSC receive

the assignment command message which sent from MSCBSC. Prefer to assign AMR channel if system support AMR. Prefer to assign common channel if system not support AMR

Parameters for AMR: A interface tag: Phase II+ (BSC32)CIC pool:27 Support FR speech version 1~3 Support HR speech version 1~3 (BSC32)Query TC: support FR/HR speech version 3 Support AMR:AMR switch support 。 active ACS(FR/HR):4 selected rate for AMR-FR, 3 selected rate for AMR-HR AMR start mode: the original AMR rate AMR UL/DL coding rate adj.th1: adjust threshold between 0-1, stet: 0.5db AMR UL/DL coding rate adj.th2: adjust threshold between 1-2, stet: 0.5db AMR UL/DL coding rate adj.th3: adjust threshold between 2-3, stet: 0.5db AMR UL/DL coding rate adj.hyst1: adjust hysist between 0-1, stet: 0.5db AMR UL/DL coding rate adj. hyst2: adjust t hysist between 1-2, stet: 0.5db AMR UL/DL coding rate adj. hyst3: adjust hysist between 2-3, stet: 0.5db

The parameters need to comply for these items:0 < th[i] < th[i+1] < 63; i = 1, 2 ；0 < th[i] + hyst[i] < th[i+1] + hyst[i+1] < 63; i = 1, 2 ；









9. SDCCH congestion






DT analysis and bad coverage/qualityDT analysis items

Coverage analysis (over CV, less CV, CV confusion, reflection, antenna connection wrong)BER analysis and suggestionFreq.interfering and C/I,C/A analysis HO analysis frequency HO, HO failure, HO drop)Call setup fail analysisHandover analysisDrop call analysis and suggestionLeak of micro cell and suggestionTA analysisPWR control analysisCQT

DT KPI’sRxlev(Full&Sub)Coverage rateRxqual(Full&Sub)Call setup success rateDrop call rate Handover Success rateTAPower control level

Reasons of bad coverageVSWR alarm and loss much in downlinkDown-tilt or azimuth is not in reasonStatic power class is too lowBar of the building and the surroundingHardware problem or jump cable problemFar distance between sitesWrong neighbor cell relationOver shootingCoverage confusionWrong Antenna connectionsAlone island effectIncorrect parameters

Reasons of bad qualityC/I,C/A interfering (freq.planning)Bad rx_level coverageVSWR and reflective freq.interfering (overlap)Hardware problemParameters of HOTMU and reference clockRF drop call processMiddle frequency interfering

Crossed cables and Yuanyang Crossed cables

Wrong crossed cablesPlanning azimuth 0/160/260DT azimuth 160/0/260Crossed cables between Cell 16101/16102

Yuanyang crossed cablessame Rxlevel in anywhere along azimuth directionsRxlevel in one direction are better than the other2 TX/RX are connect to Cell 1091(good signal)2 RDX are connect to Cell 1093(bad signal)

Wrong azimuth or Confused coverage

Wrong azimuthPlanning azimuth 85/170/240DT azimuth 330/220/60Neighbor relationship and frequency

Confused coverageNeed to check azimuth in cell 3201/3203Need to confirm in every cablesPending? Reflection?Neighbor relationship?

Wrong location and interfering

Wrong Long/LatiPlanning coverageNeighbor relationshipsFrequency interfering

Channel interferingPlanning coverage and azimuthBad Frequency planWrong coverage against planning

Overshooting and low coverage

Overshooting and interfering12km overshootingAdjacent frequency interferingNeighbor relationshipsDrop call

Low coverageDown-tilt, antenna heightPWR, VSWR, OOS,Surrounding

Spliter and Combiner problems

Spliter problemThere is a Spliter in cell id =GSP3671Azimuth=40/160no signal of GSP-1 in direction of 40 degreeNo installed Spliter yet

Combiner problemCrossed cables between 3011 and 3012Almost no signal in 3011Rxlevel loss have 30db via the combiner between GSM and CDMA

Jump cables or TRX problem in cabinet

Jump cables problem in cabinetTCH allocation always failure in some TRXVery less times in TCH seizure successful timesIncoming handover failure

One TRX OOS in cabinetOne of TRX in a cell have low signal suddenlyThe other TRXs have no problemVSWR alarm or OOS

OOS and no main service cell

Out of service (OOS)VSWR-2 alarm?LapD or transmission broken?No power supply?Locked?

No main service cellSimulate rxlevelNo cell can offer main serviceoffer a main service cellInstall a new main service cell or site

Wrong CGI in MSC

Wrong CGI in MSCMS can’t make any callsAll calls are blockedTCH seizure times for call are 0 timesSupport incoming and outgoing handover

Drop call analysis

Process of RF drop callsRLT+2 and until to the max_RLT if MS decode SACCH frame correctly ,RLT-1,if MS can’t decode SACCH frame , RLT is decreased to 0 when MS continue un-decoded SACCH frame, RF drop call occurs.uplink is as the same as downlink,the counter “SACCH multi-frame”.

Main reason of drop callsinterfering Bad rx_lev hardware problem.RLT, Sacch-multi-frame not correct.TRX Pwr class difference in the same cell.HO drops.Nei cell relations problem.Incorrect HO algorithm and parameters Handover drop callIncorrect PWR control parameter.









9. SDCCH congestion






BSC level taskBSC measurement performance

Cell level taskImmediate assignment SDCCHTCHCongestionDropHandoverConcentricChannel capacity and availability

TRX level taskPath balancedReceived LevelReceived QualityChannel allocationInterfering on idleTiming AdvancedRQI

Other taskA-interface performanceMTP statisticsGPRS/EGPRS resourceFrequency scanGSM cell to cell outgoing/incoming handover Especial abnormal cell tasks (according users’ need)

Traffic statistics task introduction

Channels CA300J:Channel Requests (Circuit Service)CA303J:Call Setup Indications (Circuit Service)CA304:Call Setup Indications Timed OutRA303G:Success Rate of Call Setup (Immediate Assignment)K3006:Configured SDCCHK3004:Traffic Volume on SDCCHK3000:SDCCH Seizure RequestsK3003:Successful SDCCH SeizuresCM30:Call Drops on SDCCHK3001:Failed SDCCH Seizures due to Busy SDCCHK3015:Available TCHsK3016:Configured TCHsCR3027:Mean Number of Available Channels (TCHF)CR3028:Mean Number of Available Channels (TCHH)K3014:Traffic Volume on TCH (Traffic Channel)K3024:Traffic Volume on TCH (Signaling Channel)Traffic Volume on TCHHK3010A:TCH Seizure Requests (Traffic Channel)K3013A:Successful TCH Seizures (Traffic Channel)K3011A:Failed TCH Seizures due to Busy TCH (Traffic ChannelTotal TCH Call DropsK3022:Call Drops on TCH (Signaling Channel)K3012A:Call Drops on TCH in Stable State (Traffic Channel)K3012B:Call Drops in TCH Handovers (Traffic Channel)CM330:Call Drops on Radio Interface in Stable State (Traffic Channel)CM3300:Call Drops on TCH in Stable State (Error Indication)CM3301:Call Drops on TCH in Stable State (Connection Failure)CM3302:Call Drops on TCH in Stable State (Release Indication)CM331:Call Drops on Radio Interface in Handover State (Traffic Channel)

Cell level statistics items introduction(1)HandoversCH310:Outgoing Internal Inter-Cell Handover RequestsCH311:Outgoing Internal Inter-Cell Handover CommandsCH313:Successful Outgoing Internal Inter-Cell HandoverH312A:Failed Outgoing Internal Inter-Cell Handovers (No Channel Available)CH312C:Failed Outgoing Internal Inter-Cell Handovers (Timer Expired)CH330:Outgoing External Inter-Cell Handover RequestsCH331:Outgoing External Inter-Cell Handover CommandsCH333:Successful Outgoing External Inter-Cell HandoversH332Kc:Failed Outgoing External Inter-Cell Handovers (Handover Request Rejected) (No Radio Resource Available)H332Kf:Failed Outgoing External Inter-Cell Handovers (Handover Request Rejected) (Invalid Cell)CH332C:Failed Outgoing External Inter-Cell Handovers (T8 Expired)CH342C:Failed Incoming External Inter-Cell Handovers (Timer Expired)CH300:Internal Intra-Cell Handover RequestsCH301:Internal Intra-Cell Handover CommandsCH303:Successful Internal Intra-Cell HandoversCH302A:Failed Internal Intra-Cell Handovers (No Channel Available)CH302C:Failed Internal Intra-Cell Handovers (Timer Expiry)CH320:Incoming Internal Inter-Cell Handover RequestsCH321:Incoming Internal Inter-Cell Handover ResponsesCH323:Successful Incoming Internal Inter-Cell HandoversH3229A:Failed Incoming Internal Inter-Cell Handovers (No Channel Available) (TCH)H322D:Failed Incoming Internal Inter-Cell Handovers (Reconnection to Old Channels)CH340:Incoming External Inter-Cell Handover RequestsCH341:Incoming External Inter-Cell Handover ResponsesCH343:Successful Incoming External Inter-Cell HandoversH3429A:Failed Incoming External Inter-Cell Handovers (No Channel Available) (TCH)H3429Ca:Failed Incoming External Inter-Cell Handovers (Timer Expired) (TCH) (Traffic Channel)

Cell level statistics items introduction(2)

ConcentricH3001:Internal Intra-Cell Handover Requests (Overlay to Underlay)CH3031:Successful Internal Intra-Cell Handovers (Overlay to Underlay)R3225K:Failed Handovers from Overlaid Subcell to Underlaid Subcell due to Busy Channels in Underlaid SubcellH3002:Internal Intra-Cell Handover Requests (Underlay to Overlay)CH3032:Successful Internal Intra-Cell Handovers (Underlay to Overlay)R3224K:Failed Handovers from Underlaid Subcell to Overlaid Subcell due to Busy Channels in Overlaid SubcellR3200:Channel Assignment Requests (Underlaid Subcell Only)R3202:Channel Assignment Requests (Underlaid Subcell Preferred)R3202B:TCH Assignment Requests (Underlaid Subcell Preferred)R3201:Channel Assignment Requests (Overlaid Subcell Only)R3203:Channel Assignment Requests (Overlaid Subcell Preferred)R3203B:TCH Assignment Requests (Overlaid Subcell Preferred)CR3557:Traffic Volume of TCHs (Underlaid Subcell)CR3558:Traffic Volume of TCHs (Overlaid Subcell)

Statistics in Trx levelIn common useMean Number of SDCCHs in Interference Band 1-5Mean Number of TCHFs in Interference Band 1-5Mean Number of TCHHs in Interference Band 1-5Uplink/Downlink Interference Indication Messages (SDCCH)Uplink/Downlink Interference Indication Messages (TCH) Number of MRs (Uplink-and-Downlink Balance Level = 1-11)Number of MRs (TA = 0-63)CR440A:Attempted Immediate AssignmentsCR440B:Successful Immediate AssignmentsR4419A:Attempted Assignments (TCH)R4419B:Completed Assignments (TCH)CR443A:Attempted HandoversCR443B:Completed HandoversS4350D:Radio Link Failures (SDCCH)S4357D:Radio Link Failures (TCHF)S4358D:Radio Link Failures (TCHH)

Received qualityquality 0=bit error rate 0.00-0.20% (average 0.14%)quality 1=bit error rate 0.20-0.40% (average 0.28%)quality 2=bit error rate 0.40-0.80% (average 0.57%)quality 3=bit error rate 0.80-1.60% (average 1.13%)quality 4=bit error rate 1.60-3.20% (average 2.26%)quality 5=bit error rate 3.20-6.40% (average 4.53%)quality 6=bit error rate 6.40-12.80% (average 9.05%)quality 7=bit error rate >12.80% (average 18.10%)

Received rxlevelNumber of MRs on uplink/downlink TCHF (receive level Rank 0-7 receive quality rank 0-7Number of MRs on uplink/downlink TCHH (receive level Rank 0-7 receive quality rank 0-7

Formulas in common use-1

TCH drop call rate (excluding HO) (%)=

K3022:Call Drops on TCH (Signaling Channel)+K3012A:Call Drops on TCH in Stable State (Traffic Channel)+K3012B:Call Drops in TCH Handovers (Traffic Channel)K3013A:Successful TCH Seizures (Traffic Channel)

TCH congestion rate (include ho)(%)=

K3011A:Failed TCH Seizures due to Busy TCH (Traffic Channel)+CH302A:Failed Internal Intra-Cell Handovers (No Channel Available)+H3229A:Failed Incoming Internal Inter-Cell Handovers (No Channel Available) (TCH)+H3429A:Failed Incoming External Inter-Cell Handovers (No Channel Available) (TCH)K3010A:TCH Seizure Requests (Traffic Channel)+CH300:Internal Intra-Cell Handover Requests+CH320:Incoming Internal Inter-Cell Handover Requests+CH340:Incoming External Inter-Cell Handover Requests

CA303J:Call Setup Indications (Circuit Service)CA300J:Channel Requests (Circuit Service)Imm-assignment success rate(%)=

K3022:Call Drops on TCH (Signaling Channel)+K3012A:Call Drops on TCH in Stable State (Traffic Channel)+K3012B:Call Drops in TCH Handovers (Traffic Channel)K3023:Successful TCH Seizures (Signaling Channel) K3013A:Successful TCH Seizures (Traffic Channel) K3013B:Successful TCH Seizures in TCH Handovers (Traffic Channel)

TCH drop call rate (all)(%)=

SDCCH congestion rate (%)= K3001:Failed SDCCH Seizures due to Busy SDCCHK3000:SDCCH Seizure Requests

SDCCH drop rate (%)= CM30:Call Drops on SDCCHK3003:Successful SDCCH Seizures

TCH success rate(%)=K3013A:Successful TCH Seizures (Traffic Channel)K3010A:TCH Seizure Requests (Traffic Channel)

Wireless Access success rate(%)= (100%-TCH congesting Rate)X(100%-SDCCH congesting Rate)

Handover outgoing success rate(%)=

CH313:Successful Outgoing Internal Inter-Cell Handover+CH333:Successful Outgoing External Inter-Cell Handovers+CH303:Successful Internal Intra-Cell HandoversCH310:Outgoing Internal Inter-Cell Handover Requests+CH330:Outgoing External Inter-Cell Handover Requests+CH300:Internal Intra-Cell Handover Requests

Radio outgoing HO success rate(%)=

CH313:Successful Outgoing Internal Inter-Cell Handover+CH333:Successful Outgoing External Inter-Cell Handovers+CH303:Successful Internal Intra-Cell HandoversCH311:Outgoing Internal Inter-Cell Handover Commands+CH331:Outgoing External Inter-Cell Handover Commands+CH300:Internal Intra-Cell Handover Requests

CSSR(%)=

RA303G:Success Rate of Call Setup (Immediate Assignment) *(100%-CM30:Call Drops on SDCCH/K3003:Successful SDCCH Seizures)*(K3013A:Successful TCH Seizures (Traffic Channel)K3010A:TCH Seizure Requests (Traffic Channel)

Formulas in common use-2









9. SDCCH congestion






Top 20 worst cells from statistics dataCompositor according to the cell level KPI’sSelect the top bad 20(or 10)cells in the main items according to times or rateAnalysis the relative bad KPI itemsSolved the bad cells that affect the BSS level performance result Worst cells

TOP 20 worst cells and DT method

●BSC level●Cell level●TRX level

We can resolve the problems from easy to difficult step by step.

DT methodAnalysis the coverage rationality Bad coverage area and bettermentAnalysis the abnormal layer 3 messageInterfering analysisCall setup failure analysisHO parametersPWR control parameters

Signal analysis method: Signaling analysis method requires engineer master every step and statistic counter.Trace the calls and analysis the signaling informationAnalysis problems in the call-process stepCompare the counters in the call process step and find out the max lost count point.Analysis the every detail call-process stepFind out the problem result

Signalling analysis and compare method

Parameter compare method: Compare the same parameters in different BSCCompare the different results in different parameter value Get the best parameter results









9. SDCCH congestion






Boundary model of cells and BA table

HO outgoing boundary,HO_out

Select boundary,Reselect

HO Incoming boundary,HO_in

BCCH neighbor listTransmit in”system information message type 2” in BCCH In use of select and reselect cells64 cells max

SACCH neighbor listTransmit in”system information message type 5” in SACCHIn use of handover32 cells max

The two tables can be different,but they are almost the same in common use.

Process of mobile turn on (selection)

MS have not save the present BCCH info. (initial turn on)Scan all the channel and assess the rx_lev in each ARFCNMS tune to the max rx-lev ， and judge if it is the BCCHIf it is the BCCH ,then MS try to decode the BCCH info.MS select the cell as flowing

Decode info.correctly,and the cell is among the PLMNThe cell is not BARED;C1>0

MS saved the present BCCH info. (When turn off)MS scan the saved BCCH when turn on the next timeMS select the cell as flowing

The cell is not bared ；C1>0

Else MS check if there is correct cells in the neighbor list.If there is one,then select the cell as service cellIf there are more,then select the C1/max cellIf there is no,then scan as the case of no BCCH info.

Cell reselection(C1&C2)

C1= (A - Max. (B, 0)) predigest=(Rxlev Average-rxlev_access_min ) thereinto:

A=Rxlev Average - rxlev_access_minB= ms_txpwr_max_cch - ms Max allowed power

ms Max allowed power(ms pwr class) ms_txpwr_max_cch(ms pwr class when access)

Reselect principle: (1)C1>0;(2)select C1/max cell

Ms occurs reselect cell in case of any one as below: Downlink failure (DSC=90/bs_pa_mfrms timeout)The cell is bared in BCCHThe C1 of the service cell is < 0 last 5sMs hasn’t reselect the cells in the past 15s:

To the same LAC, C1 of nei’s >present cell’s 5sTo the different LAC,C1 of nei’s >present cell’s value (C1+cell_reselect_hysteresis)Ms not reselection if has reselected in 15s

PT-T<0, H(pt-t)=0PT-T>=0, H(pt-t)=1T: time from set 6 best candidate cell to out of 6 cells

C2=C1+CRO-TO*H(pt-t)+CRH (for PT< 31)C2=C1-CRO+CRH (for PT= 31)

MS assess C2 of nei cell and service cell at least 5sIf C2of best nei cell>C2of service cell for 5s,then Ms select cellIf nei cell and service cell are in different LAC,should add CRH

Other parameters about reselect(1)CBA: No: normal, Yes: barredPI: No: C2 not used Yes: C2 used ，

PHASE2 MS reselection according to C2PHASE1 MS reselection according to C1

CBQ: No: normal ； Yes: low

CRO: =2*n dBTO: =10*n dBPT: =20*(n+1)sCRH=2*n dB

Cases: PI=0,C2 has no affect (suppose to the same layer)

micro A: C1=35, macro B: C1=45, so micro A: C1<macro B: C1, thus MS prefer to reselect B

PI=1,C2 have some affect (suppose to the same layer) micro CRO=20 ， macro CRO=0 so micro A: C2=55,> macro B: C2=45, thus MS prefer to reselect A









9. SDCCH congestion






SDCCH and Location updateMs will occur location update as follows:

Choose a new LAC cell as the serviceT3212 timeout ATT(IMSI attach and detach)Roaming location update (inter mobile operators)

Choose reasonable parameter with SD congestion cell

Partition LAC in reasonChoose correct parameter about T3212Add SDCCH channelsActive SDCCH dynamic configurationChoose correct C1,CRO,CRHSDCCH process died (reset BCCH TRX)

MS BTS BSC MSC

Channel_req Channel_Required(2)

Channel_Active(3)

Channel_Active_Ack(4)

IMMEDIATE ASSIGN COMMAND (5)

Establish_IND(Location Updating Req) (6)

CR(Complete_L3)

Location Updating Accepted (10)

TMSI Reallocation Complete (11)

CC

(NOTE 3) Clear_CMD

Clear_CMP

First SABM

SDCCH traffic includes: Call setup (MOC,MTC)Location updateSMSATTCDB (cell database broadcast)

SDCCH dynamic configuration parametersSDCCH dynamic allocation allowed

switch-yes/noIdle SD thrth.

TCH change to SD(for TCH>4 or TRXs)Cell SD maximum

=SD configured +8Tch minimum recovery times

minimum time from TCH to SDCCH and back to TCHIdle TCH thrth N1

When TCH change to SD,it is set a count as ResTIME.And during the period of SD return to TCH,

if idle SD>N1+8, then count-3->0,SD return to TCHIf idle SD<N1+8,then count+12<=restimeIf idle SD=N1+8,the not adjust.









9. SDCCH congestion






Reasons of congestion

Reasons of TCH congestionTraffic not balanced between service and neighborsTraffic not balanced between underlay and overlay in concentricHardware problem and some TRX OOS.Traffic is more than the capacity.Incorrect coverage areaIncorrect C1,C2 parametersIncorrect HO parametersTransmission problemSDCCH congestion but TCH traffic low

Ways to resolve TCH congestionResolve the hardware and transmission problemTraffic balanced to neighbors or lay with low traffic usageAdjust azimuth and downtilt so that adjust the coverage and trafficAdjust handover hysteresis,C1,C2,control the traffic directionAdjust “min DL level on candidate cell” in busy cellActive Half-Rate functionLower “TCH traffic busy threshold%”Active direct retryLayer and priority-PBGT handoverAllow load handover functionAdd more TCH channels or more TRXBalance the traffic between underlay and overlay

Normal Cell boundary model

HOoutgoing boundary,HO_out

Select boundary,Reselect

HOIncoming boundary,HO_in

Control traffic by cell boundaryrxlev_access_min↘C1/C2↗cell radius↗SD/TCH traffic↗rxlev_access_min ↗SD/TCH traffic↘congestion↘Min_DL_level_on candidate cell↗difficult to incoming HOtraffic↘congestion↘Adjust HO_hysteresisadjust handover boundaryadjust traffic between service cells and neighborsAdjust PGBT HO thrsh. as –HO parameter relief congestionAdjust PI, CRO ,PT, TO, CRH,TX_powerAdjust TRXs/channels/cells/sitesActive Half-rate functionOtoU(UtoO) HO Received Level Threshold↘MS stay more time in overlay traffic in underlay ↘congestion in underlay↘

Abnormal boundary (-PBGT and pingpong HO)

2-HO to nei cells1-setup

Rselect

HO_out.

Reselect>RHO_out reselect

C1= (A - Max. (B, 0))predigest=(Rxlev Average-rxlev_access_min ) Thereinto :

A=Rxlev Average - rxlev_access_minB= ms_txpwr_max_cch - ms Max allowed power(ms pwr class)

1, C1(cell A)-C1(cell B)=ΔRXLEV_BCCH-ΔRXLEV_ACCESS_MIN>02, PBGT(N)=-ΔRXLEV_BCCH >HO_MARGIN , so C1(cell B)-C1(cell A) ＝ HO_MARGIN+ΔRXLEV_ACCESS_MIN <0MS will setup calls in the cell A,and handover to cell B immediately.Note: Need to select “inter-cell ho thrsh.” =0 and “PBGT ho thrsh”<64. Inter-cell HO thrsh. In cell B to cell A Need more than the value from cell A to cell BOr this parameter will lead to pingpong HO when using –PBGP HO process.

HO to B

RHO_in>RHO_out lead to pingpong HO

RHO_OUT

HO to A RselectHO_out

HO_in

Eg.1: reselect>HO_outHO_MARGIN A→B= -5, RXLEV_ACCESS_MIN=5(-105dbm)HO_MARGIN B→A=8, RXLEV_ACCESS_MIN=5(-105dbm)To cell A: ΔRXLEV_ACCESS_MIN+HO_MARGIN ＝ (5-5)-5 ＝ -5<0The ms setup calls in cell A ,and immediately handover to cell B

Eg.2: reselect<HO_outHO_MARGIN A→B=-5, RXLEV_ACCESS_MIN=15(-95dbm)HO_MARGIN B→A=8, RXLEV_ACCESS_MIN=5(-105dbm)To cell A: ΔRXLEV_ACCESS_MIN+HO_MARGIN ＝ (15-5)-5 ＝ 5>0The ms setup calls in cell A ,but not HO to cell B immediately

Direct retry and load HO

Cell B

Cell ADR to the nei cells

RHO_out

Rselect

Sharing the traffic by DR(suggest not allowed)

MS2

MS1

RHO_out

MS1 ho to B

RHO_out

load ho thrsh

Load HO

MS1

MS1Load ho band

Load HO parameters: Load ho allowed (original cell and direct cell)System flux thrsh. For load hoLoad ho thrsh.Load req. on candidate cellLoad ho bandwidthLoad ho step periodLoad ho step level

Conditions of Direct Retry functionMS setup in cell A, No more free TCH channels in cell AActive DR in cell A and BThere is free TCH channels in cell B

TCH dropsReasons of drop callsInterfering Bad rx_lev Bad rx_qualCoverage confusedHardware problem and VSWRHO dropsNeighbor cell relations and data problem.Antenna physical parameter wrongCrossed feeder cablesWrong jump connect cables wrong in cabinetRLT, Sacch-multi-frame not correct.Incorrect HO algorithm and parametersTRX PWR class difference in the same cell.Incorrect PWR control parameter.Wrong configuration dataTransmission not in stableTMU version process problemRadio link not balanced

Drop statistics items for BSC32 (9 items)Unsuccessful TCH seizure (connection failure)Unsuccessful TCH seizure (error indicator)Unsuccessful TCH seizure (internal clear)Unsuccessful TCH seizure (release indicator)Unsuccessful TCH seizure (EMLPP)Unsuccessful cell internal handover with unsuccessful reversionUnsuccessful BSC internal handover with unsuccessful reversionUnsuccessful outgoing BSC handover with unsuccessful reversionUnsuccessful incoming BSC handover (timeout)

Drop items for BSC6000 (3 summary items)K3022: Call Drops on TCH (Signaling Channel)K3012A: Call Drops on TCH in Stable State (Traffic Channel)K3012B: Call Drops in TCH Handovers (Traffic Channel)

K3022: Call Drops on TCH (Signaling Channel)=[Call Drops on Radio Interface in Stable State (Signaling Channel)] +[Call Drops on Radio Interface in Handover State (Signaling Channel)] +[Call Drops due to No MRs from MS for a Long Time (Signaling Channel)] +[Call Drops due to Abis Terrestrial Link Failure (Signaling Channel)] +[Call Drops due to Equipment Failure (Signaling Channel)] +[Call Drops due to Forced Handover (Signaling Channel)]K3012A: Call Drops on TCH in Stable State (Traffic Channel)=[Call Drops on Radio Interface in Stable State (TCH)] +[Call Drops due to No MRs from MS for a Long Time (TCH)] +[Call Drops due to Abis Terrestrial Link Failure (TCH)] +[Call Drops due to Equipment Failure (TCH)] +[Call Drops due to Forced Handover (TCH)]K3012B: Call Drops in TCH Handovers (Traffic Channel)=[Failed Internal Intra-Cell Handovers (Timer Expired) (TCHF) (Traffic Channel)] +[Failed Internal Intra-Cell Handovers (Timer Expired) (TCHH) (Traffic Channel)] +[Failed Outgoing Internal Inter-Cell Handovers (Timer Expired) (TCHF) (Traffic Channel)] +[Failed Outgoing Internal Inter-Cell Handovers (Timer Expired) (TCHH) (Traffic Channel)] +[Failed Outgoing External Inter-Cell Handovers (T8 Expired) (TCHF) (Traffic Channel)] +[Failed Outgoing External Inter-Cell Handovers (T8 Expired) (TCHH) (Traffic Channel)] +[Failed Incoming External Inter-Cell Handovers (Timer Expired) (TCH) (Traffic Channel)]









9. SDCCH congestion






Call process of MOCMSC BSC BTS MS

Channel Request(RACH)1Channel Required2

Channel Activation3

Channel Activation Ack4

Immediate Assigment Command5 Immediate Assigment (AGCH)6

CM Service Request(SDCCH)7CM Service Request8CM Service Request9

UA(SDCCH)10Authentication Request11 Authentication Request(SDCCH)12

Authentication Reponse(SDCCH)13Authentication Reponse14

Ciphering Mode Command15Ciphering Mode Command16 Ciphering Mode Command(SDCCH)17

Ciphering Mode Complete(SDCCH)18Ciphering Mode Complete19

TMSI Reallocation Command20 TMSI Reallocation Command(SDCCH)21

TMSI Reallocation Complete(SDCCH)22TMSI Reallocation Complete23

Setup(SDCCH)24Setup25

Call Proceeding26Call Proceeding(SDCCH)27

Assignment Request28Channel Activation29


Assignment Command(SDCCH)31

SABM(FACCH)32Establish Indication33

UA(FACCH)34

Assignment Complete(FACCH)35Assignment Complete36

Channel Release37

RF Channel Release Ack41

Alerting42Alerting(FACCH)43

Connect(FACCH)45

Connect Ack(FACCH)46Connect Ack47

Measurement Report(SACCH)48Prep_Measurement Result49

Disconnect(FACCH)50Disconnect51

Connect44

Release52Release(FACCH)53

Release Complete(FACCH)54Release Complete55

Clear Command56Channel Release(FACCH)57

Deactivate SACCH58DISC(FACCH)59

UA(SACCH)60Release Indication61

RF Channel Release62

RF Channel Release Ack63Clear Complete64

SCCP Release65

SCCP Release Ack66

Estableish Indication

Deactive SACCH38

Release Indication39


Call process of MTCMSC BSC BTS MS

Channel Request(RACH)4Channel Required5

Channel Activation6


Immediate Assigment Command8 Immediate Assigment (AGCH)9

SABM Paging Response(SDCCH)10Paging Response(SDCCH)11Paging Response12

UA(SDCCH)13Authentication Request14 Authentication Request(SDCCH)15

Authentication Reponse(SDCCH)16Authentication Reponse17

Ciphering Mode Command18Ciphering Mode Command19 Ciphering Mode Command(SDCCH)20

Ciphering Mode Complete(SDCCH)21Ciphering Mode Complete22

TMSI Reallocation Command23 TMSI Reallocation Command(SDCCH)24

TMSI Reallocation Complete(SDCCH)25TMSI Reallocation Complete26

Setup(SDCCH)28Setup27

Call Comfirm30 Call Comfirm(SDCCH)29

Assignment Request31Channel Activation32


Assignment Command(SDCCH)34

SABM(FACCH)35Establish Indication36

UA(FACCH)37

Assignment Complete(FACCH)38Assignment Complete39

Channel Release40

Alerting46 Alerting(FACCH)45

Connect(FACCH)47

Connect Ack(FACCH)50Connect Ack49

Measurement Report(SACCH)51Prep-Measurement Result52

Disconnect(FACCH)53Disconnect54

Connect48

Release55Release(FACCH)56

Release Complete(FACCH)57Release Complete58

Clear Command59Channel Release(FACCH)60

Deactivate SACCH61DISC(FACCH)62

UA(SACCH)63Release Indication64


RF Channel Release Ack66Clear Complete67

SCCP Release68

SCCP Release Ack69

Paging1Paging Command2

Paging Request3

Establish Indication

Deactive SACCH41

Release Indication42


44 RF Channel Release Ack

Circuit paging call flowingA1: received circuit paging messages from MSC A2: received circuit paging messages from MSC via G-s interface B1: circuit paging command to BTS

Circuit Paging (BSC level)

CCCH overload call flowingA1: circuit paging PCH overloads of Abis interface B1: circuit paging CCCH overloads of Abis interface

Assignment (BSC level)

Assignment call processA1: assignment requestsC1-C2: unsuccessful assignments(requested terrestrial resource unavailableE1: unsuccessful assignments(invalid message content) G1-G6: unsuccessful assignments(no radio resource available) B2-B6: unsuccessful assignments(equipment failure) D1: unsuccessful assignments(terrestrial circuit already allocationF1-F3: unsuccessful assignments(radio interface fail,reversion to the previous channel)H2-H4: unsuccessful assignments(other causes)

MS BSC2BSC1 MSC/VLR

HANDOVER REQUIRED

HANDOVER REQUEST

HANDOVER REQ ACK

HANDOVER COMMAND

HANDOVER COMMAND

MS

HANDOVER ACCESSHANDOVER DETECT

HANDOVER COMPLETEHANDOVER COMPLETE

CLEAR COMMAND

CLEAR COMPLETE

A1 B1 C1

D1 , E1, F1

Outgoing BSC handover (BSC level)

Attempt outgoing BSC handoversA1: attempt outgoing BSC handovers B1: attempt outgoing BSC handovers (from 900) C1: attempt outgoing BSC handovers (from 1800)D1: outgoing BSC handovers E1: outgoing BSC handovers (900->1800) F1: outgoing BSC handovers (1800->900)

Successful outgoing BSC handoversA1: successful outgoing BSC handovers B1: successful outgoing BSC handovers (from 900 to 900) C1: successful outgoing BSC handovers (from 1800 to 1800) D1: successful outgoing BSC handovers (900->1800) E1: successful outgoing BSC handovers (1800->900)

Unsuccessful outgoing BSC handoversA1: unsuccessful outgoing BSC handovers with successful reversion B1-B3: unsuccessful outgoing BSC handovers with unsuccessful reversion

Incoming BSC HO (BSC level)

Unsuccessful incoming BSC handoversA1-A5 : unsuccessful incoming BSC handovers B1-B2: unsuccessful incoming BSC handovers(equipment failure) C1-C3: unsuccessful incoming BSC handovers (other causes) D1 : unsuccessful channel activation in incoming BSC handovers(NACK)

Successful Incoming BSC handoversA1: successful incoming BSC handovers B1: successful incoming BSC handovers(900->1800) C1: successful incoming BSC handovers(1800-900) D1: successful incoming BSC handovers(900 to 900) E1: successful incoming BSC handovers 1800to 1800) F1: attempt incoming BSC handovers

Immediate assignment processSD-ATT-C1: attempted SDCCH seizures(all)TCH -ATT-C1: attempted TCH seizures(all)TCH -ATT-C6: attempted TCH seizures for very early assignmentTCH -ATT-C7: attempted TCH seizures for SDCCH overflowSD-SUCC-C1: successful SDCCH seizures(all)SD-SUCC-C4: successful SDCCH seizures for immediate assignmentTCH -SUCC-C6: successful TCH seizures for very early assignmentTCH -SUCC-C1: successful TCH seizures(all)TCH -SUCC-C61: successful TCH allocation for very early assignmentTCH -SUCC-C62: successful TCH allocation for SDCCH overflow

Immediate assignment (cell level)

MS BTS BSC

.ASSIGN CMMAND

MSC

ASSIGNMENT REQUEST

SABM

UAESTABLISH INDICATION

ASSIGNMENT COMPLETE

(directly retry)HANDOVER REQIRED

(directly retry)HANDOVER REQUEST ACK

CHANNEL ACTIVATION

CHANNEL ACTIVATION ACK

TCH-ATT-C 2TCH-ATT-C 8TCH-ATT-C 9TCH-ATT-C 10TCH-ATT-C 5

TCH-ATT-C13

TCH-ATT-C14QUEUEING INDICATION

TCH-ATT-C16

TCH-ATT-BSC 2

TCH-SUCC-C23

TCH-SUCC-C21,22

TCH-SUCC-C51,54,55,56

TCH-SUCC-C52,53,54,55,56TCH-SUCC-C82,83

TCH-SUCC-C81TCH-SUCC-C91TCH-SUCC-C101

TCH-SUCC-C92,93TCH-SUCC-C102,103

TCH-SUCC-C13

TCH -ATT-C2: attempted TCH seizures(all) TCH -ATT-C5: attempted TCH seizures for call TCH -ATT-C8: attempted TCH seizures for MOC TCH -ATT-C9: attempted TCH seizures for MTC TCH -ATT-C10: attempted TCH seizures for call-reestablish TCH -ATT-C13: attempted TCH seizures for directed retry TCH -ATT-C14: TCH queue requests TCH -ATT-C16: TCH preemption

TCH -SUCC-C21--23: successful TCH seizures(all) TCH -SUCC-C51--53: successful TCH seizures for callTCH -SUCC-C81--83: successful TCH seizures for MOCTCH -SUCC-C91--93: successful TCH seizures for MTC TCH -SUCC-C101--103: successful TCH seizures for call-reestablishTCH -SUCC-C13: successful TCH for directed retryTCH -SUCC-C54: successful assignments of speech v1 TCH TCH -SUCC-C55: successful assignments of speech v2 TCH TCH -SUCC-C56: successful assignments of speech v3 TCH

Assignment (cell level)

TCH call drop (cell level)

Call drop processA1: TCH call drop (error indication)A2: TCH call drop (connection failure)

MS BTS' BSC Ori-Cell

HANDOVER ACCESS

UA

Intercell Handover Request

TCH-ATT-C11

BSC Des-Cell BTS''

MR Handover algorithm

HANDOVER COMMAND

Intercell Handover Response

HANDOVER DETECT

CH ACTCH ACT ACK

HANDOVER COMPLETE

Inter Clear Request(Handover Success)

TCH-ATT-BSC3SD-ATT-BSC2TCH-ATT-C17TCH-ATT-C3

TCH-SUCC-C17TCH-SUCC-C3

SD-SUCC-C2

SD-ATT-C2

SABM TCH-SUCC-C11

Internal inter cell HO

Internal inter cell handoversSD-ATT-C2: attempted SDCCH seizures(all) TCH -ATT-C3: attempted TCH seizures(all) TCH -ATT-C11: attempted TCH seizures for intraBSC incoming cell handover TCH -ATT-C17: attempted TCH seizures for intracell handover TCH -SUCC-C17 : successful TCH seizures for intracell handover TCH -SUCC-C3: successful TCH seizures(all) TCH -SUCC-C11: successful TCH seizures for intraBSC incoming cell handover SD-SUCC-C2: successful SDCCH seizures for handover, successful SDCCH seizures(all)

MS BTS BSC MSC/VLR

HANDOVER COMPLETE

HANDOVER COMMAND

A1, B1, C1, D1, E1

ASSIGNMENT REQUEST

ASSIGNMENT COMPLETE

MS BTS BSC MSC/VLR

HANDOVER COMPLETE

.HANDOVER COMMAND

HANDOVER PERFORMED

A1, B1 , C1, D1, E1, F1

Non_DR incoming inter cell HO in BSC(simulate with SDCCH handover)A1: successful intracell handoversB1: successful incoming internal intercell handovers C1: successful incoming internal intercell handovers (from900) D1: successful incoming internal intercell handovers (from1800)E1: successful dual-band intercell handovers F1: successful incoming internal intercell handovers successful incoming interBSC intercell handovers

DR incoming inter cell HO in BSC(simulate with SDCCH handover)A1: successful TCH seizures for intraBSC incoming cell handover B1: successful incoming internal intercell handovers (from900) C1: successful incoming internal intercell handovers (from1800) D1: successful dual-band intercell handovers E1: successful incoming internal intercell handovers

incoming internal inter cell HO failureA1-A7: unsuccessful incoming internal inter cell handoversB1-B6: unsuccessful incoming internal inter cell handovers(other causes)

Internal inter cell HO failure

Outgoing internal inter cell HO failureA1-A7: unsuccessful outgoing internal intercell handovers B1: unsuccessful outgoing internal intercell handovers (channel mode unacceptable)C1: unsuccessful outgoing internal intercell handovers (TA out of rage)D1: unsuccessful outgoing internal intercell handovers (freq. not implemented)E1: unsuccessful outgoing internal intercell handovers (timer expired)F1-F7: unsuccessful outgoing internal intercell handovers (other causes)G1: unsuccessful internal intercell handovers with successful reversion H1-H2: unsuccessful internal intercell handovers with unsuccessful reversion I1: unsuccessful outging cell handovers with successful reversion J1-J2: unsuccessful outging cell handovers with unsuccessful reversion

Outgoing interBSC inter cell HO

outgoing Inter bss inter cell HO attemptedA1: attempt outgoing interBSC intercell handovers B1: inter BSC outgoing cell handovers C1: outgoing interBSC inter cell handovers(to900cell) D1: outgoing interBSC inter cell handovers(to900cell) E1: successful dual-band intercell handovers F1: attempted outgoing intercell handovers(12 causes)

outgoing Inter bss inter cell HO successfulA1: successful outgoing interBSC intercell handovers B1: successful outgoing interBSC inter cell handovers(to900cell) C1: successful outgoing interBSC inter cell handovers(to900cell) D1: successful dual-band intercell handovers E1: successful outgoing intercell handovers(12 causes)

BTS BSC1 MSC/VLR

HANDOVER REQUIRED

HANDOVER COMMAND

CLEAR COMMANDCLEAR COMPLETE

A1, C1 HANDOVER FAILURE

HANDOVER FAILURE

CLEAR COMMAND

CONN FAIL IND

ERROR INDICATION

HANDOVER COMMAND

B1 , D1

B2 , D2

B3 , D3

inter bss outgling handover failureA1: unsuccessful outgoing BSC handovers with successful reversion B1-B3: unsuccessful outgoing BSC handovers with successful reversion C1: unsuccessful outgoing cell handovers with successful reversionD1-D3: unsuccessful outgoing cell handovers with unsuccessful reversion

MS Other BSC

HANDOVER ACCESS

UA

HANDOVER REQUIRED

TCH-ATT-C12

HUAWEI BSC HUAWEI BTS

HANDOVER COMMANDHANDOVER REQUEST ACK

HANDOVER DETECT

CH ACTCH ACT ACK

HANDOVER COMPLETE

TCH-ATT-BSC4SD-ATT-BSC3

MSC

TCH-ATT-C15 QUEUEING INDICATIONTCH-ATT-C4

TCH-SUCC-C4TCH-SUCC-C12

SD-SUCC-C3

SD-ATT-C3

SABM

HANDOVER REQUEST

Incoming interbsc inter cell HOSD-ATT-C3: attempted SDCCH seizures(all)TCH -ATT-C4: attempted TCH seizures(all) TCH -ATT-C12: attempted TCH seizures for inter bsc incoming handovers TCH -SUCC-C4: successful TCH seizures(all) TCH -SUCC-C12: successful TCH seizures for inter bsc incoming handoverSD -SUCC-C3: successful SDCCH seizures for handover

successful SDCCH seizures for(all)

Incoming interBSS inter cell HO

incoming inter bss HO Success A1: successful incoming inter bsc inter cell handover B1: successful dual-band intercell handovers C1: successful incoming intercell handovers

inter bss incoming handover failureA1-A5 : inter bsc incoming cell handovers

Intracell ho successA1: successful intracell handovers

Intracell ho failureA1-A7: unsuccessful intracell handovers

Intracell HO









9. SDCCH congestion






MR pre-processing Each MR has a serial number. the network will fill up MR according to interpolation algorithm. When

the serial numbers are discontinuous (some MRs missing). The simple interpolation algorithm is linearity interpolation according the previous and the later MRs

when missing MRs occur. Calculate average results of several consecutive MRs to obtain current information, reduce the

influence of some abnormal MR for judgment of PWC or HO. The relation parameters: allowed MR numbers lost, filter length

MR pre-processing and voting

MR MR MR MR MR MR

Consecutive MR flow

Filter length

MR MR MR MR

N

Consecutive MR flow

Interpolation m missing MRN+1 N+m+1 N+m+2

MR

MR voting (N/P) for GSM0508 protocolN(N1-N8): MR numbers used to voting process in PC and HO P(P1-P8): MR numbers exceeded voting threshold in PC and HO, The process will be performed when the numbers of P over the threshold in N. Parameters relation to PWR control: P1-4/N1-4 Parameters relation to HO: P5-8/N5-8 P/N5-8 >P/N1-4 When the rxqual or rxlev is not good ,the system try to adjust PWC before HO

• Process of power control commands– It takes 3 measurement report periods(3*480ms) from command

sending to execution.

SA0 SA1SA0 SA0SA1SA1 SA2SA2SA2 SA3SA3SA3

BTS sends the command for power control and TA in SACCH header.

MS obtains SACCH block

MS begins to send the measurement report of the last multi-frame.

In the 26 multi-frames, frame 12 sends SACCH.

BTS receives the measurement report

SACCCH report period: 26X4=104 frames (480ms)

MS adopts the new power level and TA

MS begins to set up a new SACCH header to report the new TA and power control message.

Power Control Overview

• Huawei PC algorithm: HW I and HW II power control

Measurement report pre-processing

Power control algorithm

selection

Yes

HW I power control

algorithm

HW II power control

algorithm

GSM0508 power control

Algorithm (ordinary)

PWC algorithm overview

Parameters of ordinary PWR control windowMS: uplink

UL PC allowedRx-lev thrsh.for UL increase=20(-90)N1/P1Rx_lev thrsh.for UL decrease=40(-70)N2/P2Rx_qual thrsh.for UL increase=5 N3/P3Rx_qual thrsh.for UL decrease=1N4/P4

BTS: downlinkDL PC allowedRx-lev thrsh.for DL increase=20(-90)Rx_lev thrsh.for DL decrease=40(-70)Rx_qual thrsh.for DL increase=5Rx_qual thrsh.for DL decrease=1PC period

MS(uplink) are independence correspondingly and the PWC is rapidGoal: adjust MS tx pwr to let BTS receive stable signal, reduce the uplink interference, reduce power of MS.

BTS(downlink) is relations all the MS in this cell and the PWC is slow. Goal: adjust BTS tx pwr to let MS receive stable signal, reduce the downlink interference, reduce power of BTS

So it mainly means UL PWC in the Power Control process on this hand.

-110 -110

MS(UL): Rx_lev thrsh.for UL decrease=40(-70)

Rx-lev thrsh.for UL increase=20(-90)

BTS(DL): Rx_lev thrsh.for DL decrease=40(-70)

Rx_lev thrsh.for DL increase=20(-80)

-80

-100

-70

-90

-80

-100

-70

-90

Rx_qual thrsh.for UL decrease=1Rx_qual thrsh.for DL decrease=1

Rx_qual thrsh.for UL increase=5Rx_qual thrsh.for DL increase=5

0 BER

2

4

6

7

0.14%(0-0.2%)

0.57%(0.4-0.8%)

2.26%(1.6-3.2%)

9.05%(6.4-12.8%)

18.10%(>12.8%)

grade

1 0.28%(0.2-0.4%)

3 1.13%(0.8-1.6%)

5 4.53%(3.2-6.4%)

Ordinary PWC window

The adjust value=(DL/ul rx_lev expected – current dl/ul rx_lev) * DL /ul rx_lev compensation

+[current dl/ul rx_qual – DL/ul rx_qual expected]*10* DL/ul rx_qual compensation

The adjust value <MAX PWC step Stable level = current level + the adjustment value

Huawei I PWC algorithm (average PWC)

MS: uplinkInitial RX_LEV ExpectedStable RX_LEV Expected>UL edge hoUL RX_LEV CompensationUL Qual. ExpectedUL Qual. CompensationMAX PWC Step

PWC IntervalMS PWC PeriodFilter Length for Initial RX_LEVFilter Length for Stable RX_LEVFilter Length for Qual.Power Increment after HO Fail.

BTS: downlinkDL RX_LEV ExpectedDL RX_LEV CompensationDL Qual. ExpectedDL Qual. CompensationMAX PWC Step

BTS PWC PeriodFilter Length for DL RX_LEVFilter Length for DL Qual.

Huawei II PWC algorithm (self-adapt PWC)

Lack of huawei I PWC algorithm: Average PWC algorithm has a delay when system analysis the MRs ,so system can’t adjust rapidly.System only analysis the past MR results and can’t expected the PC direct well.Exit the oscillate cases when the PWC process is near to the expected value.

Huawei II PWC algorithm: Adjust the LEV PWC direct in vary LEV value by comparing expected and current value.Adjust the QUAL PWC direct in fixed QUAL value by comparing expected and current valueAssess the final PWC direct and PWC value by calculating LEV PWC and QUAL PWC synthetically.When the PWC direction is the same ,the PWC value take the more value When the PWC direction is opposition , the PWC is preferred to the value of “PWC by LEV”.

PC by lev PC by qual PC by lev and qual

↓ AdjStep_Lev ↓ AdjStep_Qul ↓ max(AdjStep_Lev,AdjStep_Qul)

↓ AdjStep_Lev ↑ AdjStep_Qul No action

↓ AdjStep_Lev No action ↓ AdjStep_Lev

↑AdjStep_Lev ↓ AdjStep_Qul ↑AdjStep_Lev

↑AdjStep_Lev ↑ AdjStep_Qul ↑ max(AdjStep_Lev,AdjStep_Qul)

↑AdjStep_Lev No action ↑AdjStep_Lev No action ↓ AdjStep_Qul ↓ AdjStep_Qul No action ↑ AdjStep_Qul ↑ AdjStep_Qul No action No action No action

Huawei II PWC algorithm (PWC direct and value)

Adj. step_lev in UL: UL rx_lev<UL rx_lev lower thrsh. ,MS increase pwr adj. step_lev=(UL rx_lev lower thrsh. +UL rx_lev upper thrsh.)/2-ul rx_lev UL rx_lev >UL rx_lev upper thrsh., MS decrease pwr. adj. step_lev=ul rx_lev - (UL rx_lev lower thrsh. +UL rx_lev upper thrsh.)/2 UL rx_lev lower thrsh < UL rx_lev <UL rx_lev upper thrsh, no adjust pwr.

The adj. step_lev in DL ,adj.step_qual in UL/DL are the same as the adj. step_lev in UL.

PC by lev PC by qual PC by lev and qual

↓ AdjStep_Lev ↓ AdjStep_Qul ↓ max(AdjStep_Lev,AdjStep_Qul)

↓ AdjStep_Lev ↑ AdjStep_Qul No action

↓ AdjStep_Lev No action ↓ AdjStep_Lev

↑ AdjStep_Lev ↓ AdjStep_Qul ↑ AdjStep_Lev

↑ AdjStep_Lev ↑ AdjStep_Qul ↑ max(AdjStep_Lev,AdjStep_Qul)

↑ AdjStep_Lev No action ↑ AdjStep_Lev No action ↓ AdjStep_Qul ↓ AdjStep_Qul No action ↑ AdjStep_Qul ↑ AdjStep_Qul No action No action No action









9. SDCCH congestion






Summary and classification of HOSummary of HOHO can decrease drop calls and relief congestion when MS is movingMs report “best 6 neighbor cells” in MR and BSS votes whether HO occurs and direct nei cellSystem sends “handover command” message ,and start HO process. inside shows AFRCN,TS,BCCH,BSIC,PC level,TSC,HO cause, sync/Async about the direct cell.MS send “handover complete” in the direct cell if MS handovers to direct cell successfully.When MS HO to direct cell unsuccessfully, if ms reverse to the source cell successfully,ms sent HO failure message to system else if reverse unsuccessfully when the timer is timeout, HO call drop occurs in this case.The message “assignment command/complete” is used in intra-cell HOs.

Classification of HO Emergency HO

Timing Advance (TA) Emergency HO Bad quality (BQ) Emergency HO Rx_Level_Drop Emergency HO Interference Emergency HO

Load HO Normal HO

Edge HO Layer HO Power Budget (PBGT) HO

Speed-sensitive HO (Fast moving MS HO) Concentric Cell HO

Priority level of HO

M.R.preprocessing

Penalty processing

Basic ranking

Secondary ranking

HO voting

emergency HOTA

bad quality(BQ)rapid lev decrease

interfering

Load Sharing HO

normal HOEdgelayer

PBGT

Processing program

OMC forced HO

Directed retry

Overlaid/underlaid HO

Fast moving MS HO

HO penalty process (second step of HO algorithm process ) Penalty on the target cell when a HO fails. avoid to the ms select this cell again in the next HO voting process. Penalty on the original serving cell when an emergency HO ( base on BQ and TA ) is performed. avoid MS to be handed back to the BQ&TA cell again within penalty time. Penalty on other high priority layer cells after a fast moving HO is performed. avoid MS to be handed back to the high priority layer again within certain time(layer priority grade is 4). A new HO attempt is prohibited within the penalty time after an overlaid/underlaid HO fails.

HO penalty and ranking rules

Ranking rulesM rule for ranking neighbor cells

it can be put into the candidate cell list only if the cells comply for following conditions .To service cell: Rx_lev(s) –rxlev access min(s)-MAX(0,Pa(s)) > 0 Pa(0) =ms_txpwr_max_ccch(s) – ms_max_allowed_pwr(s)To nei cell: Rx_lev(n) –rxlev access min(n)-max(0,Pa(n)) –min_access_level_offset(n)>0

K rule for ranking neighbor cellsSort the result cells in descending order by rxlev according to M rule cells.

16bits rule for ranking cells: Both the serving cell and the neighbor cells have their own 16bits value. The smaller the value is, the higher the priority and position the cell is in the cell list.

Basic/Secondary Ranking(16 bit rule)

12345678910111213141516

The 6 strongest cell and service cell rx_lev bit000-110 and the strongest cell value is 000

The 6 strongest cell and service cell rx_lev bit000-110 and the strongest cell value is 000

Intercell ho hysteresis bitService cell=0Rx_lev(n)>rx_lev(s)+ho hys. Set 0else Set 1Compare intercell_ho_hysteresis and PBGT thrsh. The higher value is effective in the HO type

Intercell ho hysteresis bitService cell=0Rx_lev(n)>rx_lev(s)+ho hys. Set 0else Set 1Compare intercell_ho_hysteresis and PBGT thrsh. The higher value is effective in the HO type

Layer and cell priority bit4 layers and 16 cell priority/layer=64Pico is highest and umbrella is lowest.If rx_lev(s/n) is lower than inter_layer_ho_thrsh. and inter_layer_ho_hysteresis the bits are set 0

Layer and cell priority bit4 layers and 16 cell priority/layer=64Pico is highest and umbrella is lowest.If rx_lev(s/n) is lower than inter_layer_ho_thrsh. and inter_layer_ho_hysteresis the bits are set 0

Load sharing bitLoad(s)>load ho thrsh. Is set 1 else 0Means if it is load busy ,it is put a low part in the nei list

Load sharing bitLoad(s)>load ho thrsh. Is set 1 else 0Means if it is load busy ,it is put a low part in the nei list

Co_BSC/MSC bitService cell =0If nei cells and S_cell are in co_BSC/MSC,value is set 0 else 1If rx_lev(s/n) is lower than inter_layer_ho_thrsh. and inter_layer_ho_hysteresis the bits are set 0If co_BSC/MSC is not allowed the value is set 0.

Co_BSC/MSC bitService cell =0If nei cells and S_cell are in co_BSC/MSC,value is set 0 else 1If rx_lev(s/n) is lower than inter_layer_ho_thrsh. and inter_layer_ho_hysteresis the bits are set 0If co_BSC/MSC is not allowed the value is set 0.

Cell type bitInternal =0external-=1

Cell type bitInternal =0external-=1

Inter layer ho thrsh. BitRx_lev(s)>=inter layer ho thrsh.-inter layer ho hysteresis is set o, and 13,12,10-5 are set 0 ,Else set 1 Rx_lev(n)>= inter layer ho thrsh.+inter layer ho hysteresis is set o, and 13,12,10-5 are set 0 ,Else set 1

Inter layer ho thrsh. BitRx_lev(s)>=inter layer ho thrsh.-inter layer ho hysteresis is set o, and 13,12,10-5 are set 0 ,Else set 1 Rx_lev(n)>= inter layer ho thrsh.+inter layer ho hysteresis is set o, and 13,12,10-5 are set 0 ,Else set 1

Reserve bitReserve bit

Emergency HO and load HO voting

Emergency HO voting TA HO criterion :

TA of the serving cell > TA Thrsh. BQ HO criterion :

Uplink quality > UL Qual. ThrshDownlink quality > DL Qual. Thrsh.

Rx_Level_Drop HO: C1(nt)=A1×C(nt) ＋ A2×C(nt-t) ＋…＋ A8×C(nt-7t)C (nt) is the uplink RX_Level of the serving cell in the MR received at the time of "nt".Filter A1 ～ A8=value-10(A1+…+A8=80)，Filter B=compare valueIf C1(nt) ＜ B and C(nt)is below edge ho edge_rx_lev thrsh, it is considered as RLD.

Interference HO (DL&UL) : rx_lev>rxlev thrsh.for interf. HO rx_qual ＜ rxqual thrsh for interf. HO.

Load HO votingCell Load HO Criterions :

System load of BSC < system flux thrsh. for load HO load > load HO thrsh. Load of target cell < load HO threshold

Normal HO, fast moving HO and concentric HO votingNormal HO voting

Edge HO Criterion: Rx_lev <edge HO rx_lev thrsh. In N/P

Inter layer HO criterions: Rx_lev(n) > inter layer ho thrsh. + inter layer ho hysteresis. And target cell priority should be higher than the serving cell’s. PBGT HO Criterions :

PBGT(n)>PBGT ho thrsh. In N/PPBGT(n)=Scell[Min(ms txpwr max ccch,ms max allowed pwr)–rxlev dl-PWR_C_D]

Ncell[Min(ms txpwr max ccch,ms max allowed pwr)–rxlev dl(n)]

Fast moving HO votingWhen the serving cell is micro cell : MS moves the ms fast-moving valid cells (Q) in ms fast-moving watch cells (P>=Q) within MS Fast_Moving Time Thrsh. MS moving time=2Radius/Velocity <MS Fast_Moving Time Thrsh.

Concentric HO voting Criterion from overlaid(small) to underlaid(large):

TA value >=TA threshold + TA hysteresis Or Rx_lev <= Rx_lev threshold -Rx_lev hysteresis

Criterion from underlaid to overlaid: TA value <= TA threshold - TA hysteresis And Rx_lev <= Rx_lev threshold + Rx_lev hysteresis









9. SDCCH congestion






Congestion, interfering and TRXProblems: Interfering in PTCSCU-2(interfering level:-60~-80dBm), can not absorb any traffic PTCIJA-1-2-3 are decrease from 2/2/2 to 1/1/1 because of limit of transmission, and blocked some timeslot PTCSCR-1-2-3 are congestion

Resolve ways: Replace cell from 900 cell to 1800 cell in PTCSCU-2 to avoid interfering, and absorb some traffic. Add more transmission timeslot and recovery to 2/2/2 in PTCIJA-1-2-3 Make traffic balanced between PTCSCR-1/PTCIJA-3/PTCSCU-2 Adjust azimuth from 240 to 270 in PTCIJA-3 Adjust E-tilt from 2 to 7 in PTCSCR-1 Adjust azimuth from 120 to 150 in PTCSCU-2 Add a TRX in PTCSCR-1/2/3

Hardware problemcrossed feeder cablesProblems: There are more drop calls and handover failures times in each cell A little interfering in each cells in uplink(interfering band) and downlink(bad quality) MR are more in band 0~2 in path balance statistics result It showed crossed cables in this site: plan azimuth: 160/240/330, DT test 240/330/160.

Resolve ways: Have wrong frequency plan Get some frequency interfering Have wrong neighbor relationship Get some drop calls in each cells All statistics and DT test result are normal after adjust crossed cables

Hardware problem-TRX problemProblems: TRX configuration:2/2/2 in URJDG-1-2-3 TRX8(2nd in URJDG-3, 1 cabinet) can not seizure any TCH in several days Have “radio link alarm” in this TRX Can’t resolve the problems after swapping configuration data/slot in cabinet Result: TRX hardware problem Statistics results in cell and TRX level are normal after replaced TRX

Hardware problem-connecting cable wrong-312Problems: TRX configuration:3/5/3 in NSRDG-1-2-3 TRX12(5th TRX in NSRDG-2, two cabinet) can not seizure any TCH in some days Have “radio link alarm” in this TRX SCU+2CDU mode in this cell, 4 TRX connect to TX-DUP port in one CDU via 1st CDU. So that can decrease 1 bridge of combiner( save 3 dB of combiner loss) The other TRX connect to TX port in 2nd CDU. Result:wrong jump cables connecting. There is no jump cables between TX-COM and TX-DUP in 2nd CDU. Statistics results are normal after a jumped cable between TX-COM and TX-DUP.

Hardware problem-connecting cable wrong-3012Problems: In TRX 5, TRX configuration is 3/3/2 the path balance is main in RANK11, it

means that uplink is bad. Check on site, the RDX cables are

connecting wrong, it means there is no RDX receiver in TRX5

After adjust the connecting cable, the path balance in TRX5 is normal.

Configuration wrong-HO between systems-1Analysis-1 Low handover success rate(about 25%) and effect to the KPI of BSC level. Low handover performance of “outgong inter BSC intercell handover success The target cell of other BSC is belong to different system. Handover performance are normal from other BSC to present BSC in boundary. The loss times are local from “handover required” to “handover command” There is no “handover ACK” from MSC after “handover required” from BSC.

Analysis-2 BSC receive “handover reject” from A interface after “handover required” by Trace function. It show “ invalid information content” when decoded the “handover reject” information. There are 3 type of information are not defined by GSM0508 protocol, they only defined by different supplier.-- “Response Request ， Current Channel ， Speech Version” in BSSMAP. ECSC information between different band are be included in these 3 type information. One system defined 2 type of information but the other system defined 3 types. The result are normal after adjust the content of handover in MSC and activate ECSC in BSC.

The external handover between QRBSCH(T4503XA,XB,T4504XA,XB) and KRBSCN3 (T3013XB), from external BSC handover performance, handover normal from T3013XB to T4503XA,XB,T4504XA,XB), but all handovers failures from 4503XA,XB,T4504XA,XB(Huawei) to T3013XB(Nokia) with the reason of “invalid cell”.

We checked the Configure external LAC data in MSC,BSC and The external information from Irancell. the external cell information is the same.

Make a trace in A interface.In the interBSS incoming handover requirement message, it is showing that the external cell LAC=37F9(14329), but the LAC data which Irancell offered is 14327. this is the problem why all outgoing interBSS handovers are failure from T4503XAXB,T4504XA,T4504XB (Huawei) to T3103XB(Nokia).

The results after modify the external LAC number in MSC and BSC

Configuration wrong-HO between systems-2

Configuration problem-frequency and hopping

No hopping zone

hopping zone

hopping zone

Handover success rate is low in T4524XA, The target cell is T4106XA.

Check the frequency between T4524XA and T4106XA, and found TCH channel are the same in TCH=23 (not active hopping)

Check the data near these two site, only the sites in this zone are not active hopping function.

Active Hopping function in this zone, the handover success rate is normal in T4524XA.

Configuration wrong-TRX receiver mode in 3012Problems: TRX configuration is 2/2/2, in TRX 10,11, handover

success times is low after expansion. Check the data, the received mode is wrong. After adjust, the KPI is normal

Configuration wrong- MSC information wrongProblems: T4055,T4106 TCH seizure success times is 0. TCH traffic is low from incoming handover. Modified LAC number on 29th-Mar Wrong plan data (TABSCH6) and wrong BSC data in MSC(TABSCH2). TCH seizure normal after adjust the BSC information in MSC.

Configuration wrong-NCC permittedProblems: Difficult handover from T4110XA, XB to the other cells. Handover normal from TT4110XC to the other cells. Compare the parameters between T4110XA,XB,XC NCC permitted is only selected “0 allowed” The handover recovery to normal in T4110 after adjust NCC permitted.

Configuration wrong-BA table losedProblems: Drop call rate increased from 0.29% to 0.41% after some sites was cut over. RF drop call times are more than cut over. There almost no neighbor cells’ information in dedicate mode. But there are neighbor cells’ information in idle mode. BA1(BCCH) are not blank BA2(SACCH) are blank. Switch of “user input” are activate in these cells.

Result: Somebody activate the switch of “user input” wrongly when he made the autoconfig file. System only updated BA1 table, and BA2 need to added manually when “user input” are

activation.

Transmission-crossed connectingProblems: SRBSC has high congestion about 14%. Select the most congestion site T4781, arranged a DT team to test the site, found that there is only

T4795’ CGI and frequency near the T4781. But the two sites’ distance is 87KM, the only possible reason is that some wrong data has been configured or wrong connection between the two sites.

Checked the handover of T4795, found that the cell can only handover to the other two cells in same site. Added the T4795’s neighbor cell as the T4781 location. Later, the T4795’s handover and congestion performance is improved. But we do the same to the T4781. this site no any changed, the KPI of this site was also bad.

Checked other site with the same problem in T4784, high congestion and low HOSR. so it is possible that the three site has swap relation among T4781, T4795 and T4784. the KPI are rapidly enhanced in these three sites and SRBSC after we changed the neighborhood T4781 as T4784, T4795 as T4781, T4784 as T4795. It is proved situation what I suspected after we arranged a DT test.

BSS engineer feed back that they found the optic port of transmit had been swapped among these three site and recovery on 13th-Apr. And we change back to the neighborhood data in these cells. the below is the compare of the before and after adjust, total in T4781,T4784,T4795.

Transmission-problem in connectorProblems: Immediate assignment fail times in BSC fail is 34672, this site is 17912(51.66%), immediate

assignment success rate is about 20%, it lead to immediate assignment success rate in BSC level is 97.4%. it has affected the network for more than 2 months.

The problem is the transmission connector in DDF, the core (for signaling) and shielding (for ground protect) cable are connected together, The signaling is connecting to the ground.. It will lead to the transmission can’t bear any traffic and business, and TMU with alarms in all time. it is the reason of why there are so many immediate assignment fail times.

The KPI recovery to normal after re-do the connector

Version abnormal-TMU-1 the TRX was out of service in turns in T4090. it means that sometime OOS in some TRX, and the other time, the other TRX will OOS in burst. The traffic in these TRX will all be drop calls. When we check the result, the problem occurs suddenly, and found that the TRX with phase-loop

alarm. The KPI is normal after we reset the site in level 4.

Version abnormal-TMU-2 CSSR is low after cutover 18 sites from TABSCH6 to TABSCH5. Found there are 4939 times for TCH seizure failure times in T4084XC. TCH availability is 40%, TCH congestion rate is 1.1% Some channels in available TRX is red (can’t seizure any users) The KPI is normal after reset the site in level 4 on 3th-May.

Interfering-channel interfering In T4313XB have interference on TRX5, and HOSR is low, The most idle channels are in band4. Modify TCH frequency channel from 27 to 28. After modified frequency T4313B HOSR recover normal.

Chapter 2 GPRS/EDGE system

1. Review of the GPRS/EDGE system2. Based technology

3. Data rate and coding algorithm


5. Statistics task and formula in common use

6. Call flowing in GPRS/EDGE

Course contents

PSTN Network

Billing Center

GBTS

TE

MT

MS

GBSC

Internet

A

Pb

Um

Gi

HLR/Auc/EIR

SMS-GMSC/IWMSC

MSC/VLR

SS7 Network

GSM Core Network

GGSN

CG

SGSN

DNS

GPRS Backbone

GbGb

Gs

Abis

Um

GPRS Core Network

EDGE PCU

OMC

Review of GPRS/EDGE system

Review of GPRS/EDGE system

POMU: packet operation maintenance unit HSC: hot swap controller RPPU: radio packet process unit

13-15 for Gb interface Others for Pb interface 2 boards of L2PU in each RPPU Each RPPU support 100 EDGE channels/max or 120 GPRS channels/max Suggest 50%fixed/50%dynamic PDCH channels

Course contents


1. Review of the GPRS/EDGE system

2. Based technology





Total 52 frame =12blocks*4+4idle

Based technology

TBF: Temporary Block Flow: physical connection in packet network. simulated with RR connection in GSM.TFI: Temporary Flow Identity: flag of TBF. 5bit(value0-31) and the TFI belongs to especial TBF. it can use the same or different TFI in one TBF FBI: final block identity. 1 bit to indicator if it is the LAST RLC blockUSF: uplink state flag: 3bit(0-7): control MSs to using channels with UFI in “dynamic type” RRBP: Relative Reserved Block Period,3 bit(0-7) , defines the location when ms send to network with “packet control ACK”or packet DL ACK”MAC mode: Three type of MAC mode: fixed allocation, dynamic allocation, extend dynamic allocation

Fixed type: BSS allocation data block for MS with fixed type. BSS will re-allocation data block when the first data block finished transmission but still have data block. Dynamic type: BSS allocation data block for ms with temporary type. BSS assign the USF in different PDCH channels,the packet data will transmission if the USF are the same between MS decoded and BSS allocated.Extend dynamic type: simulate with “dynamic” but the timeslots can more than the timeslot capacity of MS. RLC mode: confirm mode: each packet block need to confirm in each TBF with MS and network during transmission. Or the packed block will resent until be confirmed by each other. And TBF will release after be confirmed “finish” with each other.Non-confirm mode: need not to confirm in each TBF. TBF will release after finish transmitting the packet blocks.

Classes of MSClass A: can use circuit and packet business in the same timeClass B: MS can attach on GSM and GPRS/EDGE network in the same time, but only can use one of circuit or packet business in the same time. MS select GSM or GPRS/EDGE network automatically.Class C: MS can not attach on GSM and GPRS/EDGE network in the same time. MS select GSM or GPRS/EDGE network manually.

.Network operate mode: NO1: the core network send paging message in Gs(SGSN to MSC) interface. MS only need to detect paging in one type of channel(PCH or PPCH).-with Gs interface NO2: paging message only be sent in PCH for CS and PS paging. Because the PPCH is not configuration –with neither Gs nor PPCH. NO3: paging message is sent in PCH (for CS) and PPCH (for PS), MS need to detect PCH and PPCH message in the same time. –with no Gs but PPCH

Multi-timeslots capacity(1-29)it shows the capacity of MS in uplink and downlink for packet service. 1+4 or 2+3 timeslots in common by now.

Multi-TBF in PDCH channel: it shows the capacity for TBF connection in each PDCH channel.default value: 4 uplink+4 downlink TBF in each PDCH channels in the same time.7 uplink TBF or 8 downlink TBF/max in each PDCH channels

Based technology

LQC(link quality control mode)LA: link adaptation: using different MCS scheme in same Family to retransmit and can re-divided 2 RLC blocks to re-transmit.(bad BEP in low MCS, good BEP in high MCS)IR: Incremental redundancy: different MCS scheme in same Family to retransmit

LLC PDU divide to RLC PDU

Data packetRLC/MAC header

LLCheader

SNDCPheader

LLC FCS Dummy bits

LLC PDU

RLC/MAC BLKS

SNDCP PDU

BSN=0 BSN=1 BSN=2 BSN=3 BSN=127 BSN=0 BSN=1

Data packetRLC/MACheader

LLCheader

SNDCPheader

LLC FCS Dummy bit

LLC PDU

RLC/MAC blks

BSN=0 BSN=1 BSN=2BSN=N

1560bit/max

LLC PDU delivery turns in confirm mode

LLC PDU delivery turns in non-confirm mode

RLC PDU recombine to LLC PDU

PDU transmission

PDP context

READY timer expiry or Force to TANDBY

PDP deactive

PDP context

PDU reception

PDP deactive or Cancel Location

MM State Model of MS MM State Model of SGSN

IDLE

READY

STANDBY

IDLE

READY

STANDBY

READY timer expiry or Force to STANDBY or Abnormal RLC condition

Implicit Detach or

t imer exprity

Implicit Detach or

Cancel Location

Three state of MM: Idle: without available RA informationStandby: can implement RA update, selection, reselection, paging function, finished attached to GPRS network Can active PDP context, but no TBF,no transmission with data blockReady: can send and receive UDP, selection, reselection, no paging, cell information sometime with data block transmission in uplink/downlink on TBF

Conversion among different states in MM

Course contents



2. Based technology





Modulating bitsD3i, d3i+1, d3i+2

Symbol parameter l

(1,1,1) 0

(0,1,1) 1

(0,1,0) 2

(0,0,0) 3

(0,0,1) 4

(1,0,1) 5

(1,0,0) 6

(1,1,0) 7

Coding scheme and rate


MCS-3

Family A

Family B

Family C

Family A padding

37 octets 37 octets 37 octets37 octets

MCS-6 MCS-9


MCS-2

MCS-5 MCS-7

22 octets22 octets

MCS-1

MCS-4

34 +3 octets34 +3 octets

MCS-3

MCS-6

MCS-8


Modem type Coding scheme

Bytes in RLC/MAC

Rate (kbps

)

PDCH/

16kbps

Binding idle ts(16kbps)/

max

Family

CS-(1-4)/GMSK

CS-1 23 9.05 1 / /

CS-2 33 13.4 1 / /

CS-3 39 15.6 2 6 /

CS-4 53 21.4 2 6 /

MCS-(1-4)GMSK

MCS-1 22 8.8 1 3 C

MSC-2 28 11.2 1 3 B

MSC-3 37 14.8 2 6 A

MCS-4 44 17.6 2 6 C

MCS-(5-9)8PSK

MCS-5 56 22.4 2 6 B

MCS-6 74 29.6 2 6 A

MCS-7 2*56 44.8 3 9 B

MCS-8 2*68 54.4 4 12 A

MCS-9 2*74 59.2 4 12 A


8PSK modeGMSK mode

9.112.2

14.4

20.2

8.811.2

14.817.6

22.4

29.6

44.8

54.4

59.2

0.0

10.0

20.0

30.0

40.0

50.0

60.0

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

kbps

GPRSEGPRS


Course contents



2. Based technology





Uplink Number of successful uplink TBF establishment Number of uplink TBF establishment attempts (UL) TBF successful assignment rate (user defined) Number of uplink TBF abnormal release due to no channel Number of uplink TBF establishment failures due to no channel (UL) TBF congestion rate (user defined) Number of uplink TBF abnormal release due to N3101 overflow (MS no response) Number of uplink TBF abnormal release due to N3103 overflow (MS no response) (UL) TBF drop rate (user defined) Number of successful uplink assignments Number of uplink assignments (UL) successful packet assignment rate (user defined)

TBF and packet performance

Downlink Number of successful downlink TBF establishment Number of downlink TBF establishment attempts (DL) TBF successful assignment rate (user defined) Number of downlink TBF abnormal release due to no channel Number of downlink TBF establishment failures due to no channel (DL) TBF congestion rate (user defined) Number of downlink TBF abnormal release due to N3105 overflow (DL) TBF Drop rate (user defined) Number of successful downlink assignments Number of downlink assignments (DL) successful packet assignment rate (user defined)

PDCH occupy Mean number of occupied PDCHs Mean number of available PDCHs Number of PDCHs occupied by downlink TBF Number of PDCHs occupied by uplink TBF Total number of PDCHs occupied by TBF PDCHs occupied rate Number of attempts at converting TCH to PDTCH Number of successful conversions from TCH to PDTCH Number of dynamic PDCHs reclaimed by BSC

PDCH resource, access and retain

Accessibility and retainability Packet Accessibility Packet Retainability

Formulas in common use

Packet Retainability(%)=100%--

Number of uplink TBF abnormal release due to N3101 overflow (MS no response) Number of uplink TBF abnormal release due to N3103 overflow (MS no response)Number of downlink TBF abnormal release due to N3105 overflow)Number of successful uplink TBF establishment Number of successful downlink TBF establishment

Number of Successful Uplink TBF Establishment

Number of Uplink TBF Establishment AttemptsPacket Accessibility(%)=

TBF uplink congestion rate(%)=

Number of uplink TBF establishment failures due to no channel Number of uplink TBF abnormal release due to no channelNumber of uplink TBF establishment attempts

TBF downlink congestion rate(%)=

Number of downlink TBF establishment failures due to no channel Number of downlink TBF abnormal release due to no channelNumber of downlink TBF establishment attempts

Number of Successful Uplink TBF Establishment

Number of Uplink TBF Establishment AttemptsTBF uplink assignment success rate(%)=

Number of Successful downlink TBF Establishment

Number of downlink TBF Establishment Attempts

TBF downlink assignment success rate(%)=

Uplink TBF call-drop rate(%)=

Number of uplink EGPRS TBF abnormal release due to N3101 overflowNumber of uplink EGPRS TBF abnormal release due to N3103 overflowNumber of successful uplink TBF establishment

Downlink TBF call-drop rate(%)=Number of downlink TBF abnormal release due to N3105 overflowNumber of successful downlink TBF establishment

packet uplink assignment success rate(%)=

Number of successful uplink assignmentsNumber of uplink assignments

packet downlink assignment success rate(%)=Number of successful downlinkNumber of downlink assignments

EDGE RLC/MAC DL performance Mean rate of downlink EGPRS RLC( kbits/s ) Mean throughput of downlink single EGPRS TBF( kbits ) Number of downlink EGPRS RLC control blocks(NUMBER) Number of downlink EGPRS RLC data blocks using MCS1~9 Number of downlink EGPRS RLC dummy blocks(NUMBER) Number of MCS demotions on downlink EGPRS TBF Number of MCS upgrades on downlink EGPRS TBF Retransmission rate of downlink EGPRS RLC data block using MCS1~9(%) Total number of downlink EGPRS RLC data blocks

EDGE RLC/MAC UL performance Mean rate of uplink EGPRS RLC( kbits/s ) Mean throughput of uplink single EGPRS TBF( kbits ) Number of uplink EGPRS RLC control blocks(NUMBER) Number of uplink EGPRS RLC data blocks using MCS1~9 Number of uplink EGPRS RLC dummy blocks(NUMBER) Number of MCS demotions on uplink EGPRS TBF Number of MCS upgrades on uplink EGPRS TBF Retransmission rate of uplink EGPRS RLC data block using MCS1~9(%) Total number of downlink EGPRS RLC data blocks

EDGE RLC/MAC performance

GPRS RLC/MAC DL performance Mean rate of downlink GPRS RLC( kbits/s ) Mean throughput of downlink single EGPRS TBF( kbits ) Number of downlink GPRS RLC control blocks(NUMBER) Number of downlink GPRS RLC data blocks using MCS1~4 Number of downlink GPRS RLC dummy blocks(NUMBER) Number of MCS demotions on downlink EGPRS TBF Number of MCS upgrades on downlink EGPRS TBF Retransmission rate of downlink EGPRS RLC data block using MCS1~4(%)

GPRS RLC/MAC UL performance Mean rate of uplink GPRS RLC( kbits/s ) Mean throughput of uplink single GPRS TBF( kbits ) Number of uplink GPRS RLC control blocks(NUMBER) Number of uplink GPRS RLC data blocks using MCS1~4 Number of uplink GPRS RLC dummy blocks(NUMBER) Number of MCS demotions on uplink GPRS TBF Number of MCS upgrades on uplink GPRS TBF Retransmission rate of uplink GPRS RLC data block using MCS1~4(%) Total number of downlink GPRS RLC data blocks

GPRS RLC/MAC performance

LLC DL performance Downlink throughput(kbits/s) mean length of downlink LLC_PDUs mean LLC_PDU bytes per downlink TBF number of downlink LLC_PDUs discarded due to FLUSH_LL received number of downlink LLC_PDUs discarded due to timeout total bytes of downlink LLC_PDUs received total bytes of downlink LLC_PDUs sent total number of downlink LLC_PDUs received total number of downlink TBFs total number of LLC_PDUs sent

LLC RLC/MAC UL performance mean length of uplink LLC_PDUs mean LLC_PDUs bytes per uplink TBF total bytes of uplink LLC_PDUs sent total numbers of uplink LLC_PDUs sent total number of uplink TBFs uplink throughput(kbits/s)

BEP performance Times of 8PSK_MEAN_BEP=1~32(times) Times of GMSK_MEAN_BEP=1~32(times)

LLC and BEP performance

Course contents



2. Based technology





Attach call flowing

Note: step2: option, occurs when MS move to new SGSNStep3: option,occurs when step 2 fail.Step4: option,occurs if there is no PDP context activeStep5: optionStep6: option, occurs when MS move to new SGSN or attach to network for the first time.Step7: relation with step1. Occurs when IMSI attach and Gs interface is configured

Detach ,packet paging, RA update(internal SGSN)

Detach: MS request Detach in most time . Also can SGSN.Packet paging: shows in Network Operator II (PCH configured only)RA updating : shows in internal SGSN.

PDP context active and deactivate in request by MS and network

Conversion between PS and CS

Conversion between PS and CSReason: relation with Class B of MS.Initial state: PS mode (in attach or standby or ready mode).Convert state: CS active (location update, cell reselection, incoming calls….)Suspend: plug up from PS.When finished CS ,MS will resume to PS mode (back to attach mode)

+T3190

-T3190

+T3141+T3164

-T3164+T3168

-T3141Reset N3101-T3168

For EDGE: EDGE packet channel request (11bit or 8bit) and indicate phase 1,phase 2, short access inside.For PS block: require to phase 1 and try to phase 2 access in non-confirm mode require and try to phase 2 access in confirm mode.For PS signalling (MM): require to phase 1 access.There is TFI and defined TBF in “immediate assignment”

Broken lines shows the phase 2 access polling information (TLLI)

Establish TBF in PS idle modeEstablish UL TBF in CCCH

phase 1 accessphase 2 access

Establish DL TBF in CCCH

Establish TBF in PS transmission modeEstablish UL TBF in DL transmissionEstablish DL TBF in UL transmission

Establish TBF (1)

Establish TBF in PS idle modeEstablish UL TBF in CCCH

phase 1 access phase 2 access

Establish DL TBF in CCCH

Establish TBF in PS transmission modeEstablish UL TBF in DL transmissionEstablish DL TBF in UL transmission

Establish TBF (2)

S/P: supplyment /polling: to indicator if RRBP is efficiencyS/P=0: no efficiencyS/P=1: efficiency

UL transmission in confirm and NON-confirm mode

Ws: windows size64~1024, need (Vs-Va)mod(SNS) Ws relation with multi-timeslot capacity Vs: 0~SNS-1 variable for sending state, Vs’=Vs+1 when finish sending blocks of BSN=VsVa: 0-SNS-1 variable for ACK state,update from ACK/NACK message

If T3182 timeout ,then N3102-pan_dec, until n3102=0 TBF releaseIf ms receive packet uplink ACK for (vs<va+ws),then N3102+pan-inc,

Timeslots 1 2 3 4 5 6 7 8

Window size 64~192 64~256 64~384 64~512 64~640 64~768 64~896 64~1024

In ONE TBF, WS only increase in RLC layerWS : 64~1024 Relation with PDCH ts.

MS BSS

RLC data block(TFI)

RLC data block(TFI,S/P=1(ES/P=01/10/11))

RLC data block(TFI)

Packet Downlink Ack/Nack

RLC data block(TFI)

RCL data block(FBI=1, S/P=1(ES/P=01/10/11))

Packet Downlink Ack/Nack(ÇëÇóÖØ «)

.

.

..

.

..

.

..ÖØÆôT3190

Packet Downlink Ack/Nack(FAI=1)

Æô¶¯T3191

Í £Ö¹ T3191

.

..RLC data block(TFI£¬ÖØ «Ö Ê¾)

RCL data block(FBI=1, S/P=1(ES/P=01/10/11))Æô¶¯T3191

Í £Ö¹ T3191 Æô¶¯T3193

PACKET DL ASSIGNMENT/PACKET TIMESLOT RECONFIGURE

(Control Ack=1)

ÖØÆôT3190

ÖØÆôT3190

ÖØÆôT3190

ÖØÆôT3190

ÖØÆôT3190

ÖØÆôT3190

Í £Ö¹ T3190 Æô¶¯T3192

Í £Ö¹ T3190

.

..RCL data block(FBI=1, S/P=1(ES/P=01/10/11))

Packet Downlink Ack/Nack(FAI=1)

Æô¶¯T3191

Í £Ö¹ T3191 Æô¶¯T3193Í £Ö¹ T3190 Æô¶¯T3192

ÖØÆôT3190

MS BSS

RLC data block(TFI)

RLC data block(TFI)

RCL data block(FBI=1, S/P=1(ES/P=01/10/11))

Packet Control Acknowledgement

.

.

..

.

..

.

..ÖØÆôT3190

Æô¶¯T3191

Í £Ö¹ T3191

.

..

PACKET DL ASSIGNMENT/PACKET TIMESLOT RECONFIGURE

(Control Ack=1)

ÖØÆôT3190

ÖØÆôT3190

ÖØÆôT3190

Í £Ö¹ T3190 Æô¶¯T3192

RCL data block(FBI=1, S/P=1(ES/P=01/10/11))Æô¶¯T3191

Í £Ö¹ T3191 Æô¶¯T3193Í £Ö¹ T3190 Æô¶¯T3192

Æô¶¯T3193

Í £Ö¹ T3192

Packet Control Acknowledgement

DL transmission in confirm and NON-confirm mode

network MS

PACKET TBF RELEASE(release UL TBF ， RRBP)

PACKET CONTROL ACKNOWLEDGMENT

RLC DATA BLOCK

(CV)

RLC DATA BLOCK

(CV=0)Release UL TBF

network MS

PACKET TBF RELEASE

(release DL TBF ， RRBP)

PACKET CONTROL ACKNOWLEDGMENT

To idle mode if there is no UL TBF

Stop detech DLPDCH

Release TBF in UL/DL

statistics data analysis and optimization v 4.0

Documents

system data analysis

u u tt t t t

optimization plan

analysis parameters

dt data

problems analysis

optimization hardware

analysis alarm analysis