GSM OPTIMISATION

HANDBOOK

1. Introduction 32. Support Arrangement 43. Optimisation Team Structure 54. Bad Perfromance FisH Bone diagram 65. Information Preparation 76. General Optimisation Proceedure 87. Alarm Analysis 98. Statistics Investigation Procedure 109. Drive Test 12

9.1. Drive Test Reminder 129.2. Drive Test Log Investigation Consideration 12

10. Frequeny Planning 1310.1. BCCH and BSIC planning criteria 1310.2. Frequency Assignment Criteria 1310.3. Frequency Retune Procedure 14

11. Add Neighbor Criteria 1412. High Rise Building Coverage 1513. Maximum System Configuration 1514. HDPC Setting Template 17

14.1. TX Power and Power Control 1714.2. Handover 2014.3. Multiband 2214.4. Miscellaneous 22

15. Tools Available 2416. Problem Root Cause 25

16.1. High SDCCH Blocking 25

16.2. High TCH Blocking 2616.3. SDCCH Access Failure Rate 2716.4. Handover Failure & Loss 2816.5. MSC Connection Rate 2916.5. SDCCH and TCH RF Loss 3016.6. Power Control 3116.7. Handover Problem 3116.8. Others 32

1. IntroductionTeamwork, “listen to order”, cycle time reduction and follow procedure are critical toevery successful optimisation.

Below is the optimisation flow chart:

Data PreparationData Collection

Data Analysis

Satisfactory Result?No

Optimisation

Yes

Complete

2. Support ArrangementBest engineering arrangement arrives at local office

All engineers return to Beijing to derive plan

PEG arrives local office to discuss the optimisation plan with Account Team and Customer

Start optimisation

Engineers perform brief audit in Beijing to understand REAL situation

Contractor prepares optimisation information

in Beijing

OMC Engineer arrives local office to setup data collection platform

PEG derives optimisation plan

PEG audits network in Beijing

PEG prepares INFORMATION FOR OPTIMISTION

Account Team supplies required information

Optimisation FlowPEG Arrangement

PEG discuss with account teams to identify optimisation targets.

Monthly performance meeting to identify optimisation targets.

Start optimisation and skill transfer and acquisition

3. Optimisation Team StructureTeam Leader

BSS ControllerStatistics Monitoring

Alarm MonitoringD.B. & Feature Controller

Drive Test Log Investigator

MONITORINGACTION

Job FunctionBSS Controller- Understand fully on BTS maintenance, BSS configuration

Alarm Monitoring,- Monitor daily alarm

Statistics Monitoring- Investigate problem from statistics

D.B. & Feature Controller- Check database and monitor feature deployment process

Drive Test Log Investigator- Investigate problem from drive test log

4. Bad Perfromance FisH Bone diagramFrequency

Plan

Network Topology

Signaling

Mobile

Bad Performance

Database

Setting

Coverage

Software

Hardware

Capacity

External

Interference

Neighbor

Calculation

Statistics Pegging and Retrieval

Cable

Connection

Documentation

Example of each major problems:a. Database Setting – improper HOPC settingsb. Neighbor – wrong external neighbor’s BCCH or BSIC values, missing

neighborc. Coverage – weak, highly overlapped, improper antenna downtilt and

orientationd. External Interference – microwave, repeater, faulty alarme. Calculation – incorrect statistics equationsf. Cable Connection – no/cross connectiong. Statistics Pegging and Collection – SW problem on statistics pegging, or

retrievalh. Capacity – lack of TRCU, improper channel configuration, lack of RSL, MTL

linksi. Frequency Plan – co-channel, adj-channel, improper BSIC planningj. Software – bugk. Hardware – wrong cable connection, faulty combiner and filter, PCM link

downl. Network Topology – bad site location selection, redundant site deployed

m. Signaling – Improper cause value and message sequencen. Mobile – faulty mobile in term of signaling or frequency hopping capabilityo. Documentation – wrong feature/parameter usage description

5. Information PreparationInformation from Account Team Output Generated from Left Column DataBSS Scripts Cell, Site, BSC, RTF. Neighbor, External

Neighbor Check, TEMS Cell DefinitionsCurrent and planning site map with main road,site location, antenna height, orientation anddown tilt in NetPlan format

NetPlan ARFCN plots

Nighttime Full Power Drive Test TEMS log withLat., Lon., both directions need to be driven

NetPlan rxlevel, rxqualilty, overlapping routemaps

Latest 1 week Informix statistics NetPlan Erlang, Blocking %, Drop Call %, TotalLoss, Call Setup Failure % Plots

Antenna configuration informationBusy area, VIP spots and main route marked oncity mapProject in last 3 and coming 3 months

Site outage listTools and network features availabilityLast 3 month system performance historyLast 2 day event and alarm log

6. General Optimisation Proceedure1 day

Data Collection & Check Local Office NetPlan Information

2 daysData Preparation & NetPlan Information Correction

2 daysNetwork Audit from

1. Alarm

2. Statistics

3. Database

4. Check customer statistics equations

1. Hardware Fix (Sleeping Cell, OOS TCU, OOS TS

2. Path Balance Issue, Faulty TCU from TCH_RF_Loss Issue)

3. GCLK shift and frequent Phase Lock Loop failure from Alarm

Hardware2 days

2 daysDatabase, Interference & Capacity

1. Suggest Better Database Setting (Channel Reconfiguration, Standard HOPC, Blocking Timer , Congestion Relief)

2. Capture External Interference

3. Frequency Retune for high IOI, BER and TCH_RF_LOSS

4. Audit External Neighbor

5. Improper ARFCN:BSIC Planning

6. GPROC loading

7. RSL & MTL Usage

Solve Blocking by:

a. BCCH Optimisation

b. Neighor Optimisation

c. Add Radio

d. Site Reconfiguration

e. Add Site

f. Antenna Refinement

Network Topology Problem due to no available ARFCN is found by:

a. Site Replacement

b. Coverage Optimisation

c. Capacity Dimensioning

2 daysCapacityNetwork Topology

TEMS Log & FP. mainly on

a. Undecoded BCCH

b. Missing Neighbor

c. HO Failure

d. Incorrect External Neighbor

e. Weak Coverage

f. High Overlapping

g. use non-dominant server

by ARFCN retune, neighor change and coverage

Statistics & DB. mainly on

a. SDCCH Access Failure

b. CSFR

c. Drop Call

d. TCH_RF_Loss

e. HO_Loss

f. HO_Failure

by ARFCN retune, neighor change and coverage

12 daysFP, Neighobr and Coverage

7. Alarm Analysis

Below lists some important alarms that we focus,a. Critical and major alarmb. Alarms affect voice quality like MSI, KSW, RXCDR, DRIM, DRIc. GCLK affects HOd. Link alarms affect site availability and voice qualitye. XBL alarm affects acknowledgement of OOS CIC

8. Statistics Analysis Procedure

Statistics Tree Diagram

Firstly, we need to understand account teams and customer performance equation.

Problem Identification from Statistics1. per carrier on HW, external interference, channel interference, coveragea. PATH_BALANCE for faulty hardware (Every 3 days)b. IOI for external interference and bad channel assignment (Every Day)c. BER for external interference and bad channel assignment (Every Day)d. TCH_RF_LOSS for faulty hardware and bad channel assignment (Every Day)e. CHAN_REQ_FAIL_ROLL for faulty hardware and BCCH and SDCCH coverage footprint

difference (Every Day)2. per cell on usagea. AVAILABLE_TCH and AVAILABLE_SDCCH (Every Day)b. BUSY_SDCCH_MAX, SDCCH Blocking for faulty hardware (Every Day)c. SDCCH_CONGESTION and BUSY_SDCCH_MEAN for phantom RACH (Weekly)d. BUSY_TCH_MAX, TCH Blocking for faulty hardware (Every Day)e. OK_ACC_PROC_SUC_RACH for sleeping cell (Every Day)f. No TOTAL_CALL, OUT_INTRA_BSS_ATMPT, OUT_INTER_BSS_ATMPT (Every Day)g. CONN_REFUSED { - IMSI_DETACH} for CIC blocking (Weekly)h. cell without any statistics for OOS cell (Every Day)3. per cell on dual band mobile usagea. MA_ACCESS_BY_TYPE (Weekly)b. MS_TCH_USAGE_BY_TYPE (Weekly)4. per cell on Cipher Modea. CIPHER_MODE_FAIL (Weekly)5. per cell on loadinga. BSS GPROC loading mean 70% (Weekly)

b. MSC Processor Loading and Subscriber (Weekly)c. RSL TX, RX Utilisation mean 25% (Weekly)d. MTL TX, RX Utilisation mean 20% (Weekly)e. Pages per second (Weekly)f. ALLOC_SDCCH, ALLOC_SDCCH_FAIL ,OK_ACC_PROC relationship (Weekly)g. HO per call (Weekly)6. per cell on paginga. PCH_PAGE_Q_DISCARD (Weekly)7. per cell for BCCH and BSIC planninga. INV_EST_CAUSE_RACH and BAD_HO_REFNUM_MS (Weekly)8. per cell inter-BSS HO monitoringa. OUT_INTER_BSS_MS_FAIL + OUT_INTER_BSS_MS_LOST = HP_MSC_REQ_FAIL (not

include blocking) (Weekly)b. OUT_INTER_BSS_MS_ATMPT = HO_MSC_REQ_FAIL + HO_MSC_REQ_OK (Weekly)

Below all are daily task:9. evaluate targeta. calculate system total call, total loss, ho loss, rf loss, drop call%b. calculate how many total loss reduction is required to achieve the goalc. do (b) again for other statistics

10. select worst cells and BSCsd. pick worst 20 cells and worst 5 BSCs

11. per cell on TCH Assignmenta. CONN_REQ_TO_MSCb. MA_REQ_FROM_MSC, CONN_REFUSED { - IMSI_DETACH}, if CONN_REFUSED is high,

MSC procedure is required.c. MA_CMD_TO_MS_BLKD, MA_CMD_TO_MSd. MA_FAIL_FROM_MS, MA_COMPLETE_TO_MSC (same as TOTAL_CALL)

12. per cell on HO Causea. OUT_HO_CAUSE13. per cell on HO Failure

a. OUT_INTRA_BSS_HO_FAIL, OUT_INTER_BSS_HO_FAIL, IN_INTRA_BSS_HO_FAIL andIN_INTER_BSS_MS_NO_SEIZE for ho failues

14. per cell on TCH_RF_LOSS, SD_RF_LOSS, HO Lossa. TCH_RF_LOSS, OUT_INTRA_BSS_HO_REQ, OUT_INTRA_BSS_HO_ATMPT,

OUT_INTER_BSS_HO_REQ, OUT_INTER_BSS_HO_ATMPTb. SD_RF_LOSS and HO_LOSS relationship on cell coveragec. OUT_INTER_BSS_HO_LOSTMS, OUT_INTRA_BSS_HO_LOSTMS,

OUT_INTRA_CELL_HO_LOSTMS

For hardware fix, it usually takes 3 days to fix, hence we suggest to review those statistics every 3days. For system loading and usage, we will visit them once in a week.Weekly and every 3 days statistics should be reviewed when that corrective action is done.

Special Request

For growth planning per cell on blocked call setup, we can use ALLOC_TCH_FAIL –HO_FAIL_NO_RESUORCES_INTRA_BSS - HO_FAIL_NO_RESUORCES_INTER_BSS -HO_FAIL_NO_RESUORCES_INTRA_CELL to estimate expanded network total calls.

For coverage analysis and improve MSC connection rate, we can use per LACACCESS_PER_RACH – PAGING_RESPONSE. Difference tells us how many no page reponses.

9. Drive Test

1. Drive Test Reminder

i. prepare cell definition fileii. 2mins per call

iii. 10-15mins per log fileiv. force to appropriate band (GSM only, DCS only or Dual)v. mark benchmark route per log file in map

vi. mark on maps about (a) drop call (b) weak coverage (c) lot of rxquality (d)bad coverage

vii. fill in drive test problem sheet

2. Drive Test Log Investigation Consideration

General TEMS Log Investigation Concern1. check undecoded BCCH – this affects RF loss and creates log of ping pong

handover2. decoded neighbor but no handover is attempted – due to missing neighbor or

incorrect external neighbor path3. focus on drop call and rxqual greater than 4 for non-hopping, 5 for hopping

for at least 4 seconds4. look for handover failure – investigation target cell assigned ARFCN/MA from

ASSIGNMENT COMMAND and HANDOVER COMMAND5. mark down weak coverage area, no dominant server, say less than –85dBm6. mark down highly overlapped area

Besides, be careful that when you see a decoded cell, that cell is not definitely aneighbor of serving, it can be due to serving cell having a neighbor which has sameBCCH as decoded cell.

Note: (a) Focus on new site database(b) Due to CCB, no SFH can be deployed(c) Dedicated ARFCN/MA is different from BCCH

(d) After Assignment and Handover, the cell ID may not be updated yet due toserious rxquality at DL.

10. Frequeny Planning

1. BCCH and BSIC planning criteriaa. Cells have same BCCH and BSIC that increases TEMS log review

troublesome.b. Nearby cells have same BCCH:BSIC with ARFCN:BSIC.c. Nearby cells have adjacent BCCH with ARFCN and same BSIC.

2. Frequency Assignment Criteria

Non-hopping Case

can’t be co- or adj-cahannelserving cellco-channel

adjacent channel

Hopping Case for non-BCCH

co-channeladjacentchannel

serving cell

BCCH in hopping case is same as the non-hopping case.

3. Frequency Retune ProcedureFrequencies can be grouped into 5 types, they are:-

a. same site co- and adj-channel to BCCHb. adjacent site co- and adj-channel to BCCHc. adjacent site co-channel to ARFCNd. same site co-channel to ARFCNe. same site adj-channel to ARFCNf. adjacent site adj-channel to ARFCNg. others ARFCN

Priority of ARFCN retune is from g. to e. for fix and BBH, from g. to d. for SFH. If noavailable ARFCN can be found, site planning need to be reviewed.Besides, 400k separation is required for CCB.58, 70 shouldn’t be used for BCCH.MCell generates UL interference on channel 50 and 56.

11. Add Neighbor CriteriaIn general, LOS and 2nd Round Interferer will be added as neighbor; however, for 3rd

Round, this is very network dependant. field knowledge is required to make thedecision.

3rd Round Interferer2nd Round Interferer

LOS interfererserving cell

12. High Rise Building CoverageIntroduce high rise building coverage must make sure to have good street coverage.

盄盄Micro

Macro

High Rise Building

High Rise Building – provide high level (likely above 8th floor) high rise buildingcoverageMacro – provide low floors and street level coverageMicro – provide street level and indoor coverage

13. Maximum System ConfigurationIt is important to understand how system grows from phase to phase. It can bedescribed in 3 phases.

Phase 1: Only macro layer, antenna located at tower top with small downtilt. Antennauses large vertical beam-width.

Phase 2: Start to introduce micro layer, and increase macro cell downtilt and lowermacro cell height of macro antenna.

Phase 3: Introduce high rise building coverage to office building and hotel. Beforedeploying this kind of coverage, street level coverage MUST be strong enough (likelymore than –75dBm) to protect interference from high rise building coverage.

For a mature network which its system rxlevel has reach average –75dBm, it is timefor us to deploy SFH to expand system capacity.

14. HDPC Setting Template

1. TX Power and Power ControlTX Power

ParameterCurrent

Setting

Suggest

SettingReason

max_tx_ms

max_tx_bts

Downlink Power Control due to Level

ParameterCurrent

Setting

Suggest

SettingReason

decision_alg_num

bts_power_control_allowed

bts_p_con_ack (TIMER)

bts_p_con_interval

(TIMER)

pow_inc_step_size

pow_red_step_size

rxlev_dl_pc, hreqave

rxlev_dl_pc, hreqt

decision_1_dl_rxlev_av_p

l_rxlev_dl_p

u_rxlev_dl_p

decision_1_n1

decision_1_p1

decision_1_n2

decision_1_p2

Downlink Power Control due to Quality

ParameterCurrent

Setting

Suggest

SettingReason

decision_alg_num

bts_power_control_allowed

bts_p_con_ack (TIMER)

bts_p_con_interval

(TIMER)

pow_inc_step_size

pow_red_step_size

rxqual_dl_pc, hreqave

rxqual_dl_pc, hreqt

rxqual_dl_pc, qual_weight

decision_1_dl_rxqual_av_p

l_rxqual_dl_p

u_rxqual_dl_p

decision_1_n3

decision_1_p3

decision_1_n4

decision_1_p4

w_qual

Uplink Power Control due to Level

ParameterCurrent

Setting

Suggest

SettingReason

decision_alg_num

ms_power_control_allowed

ms_p_con_ack

ms_p_con_interval

pow_inc_step_size

pow_red_step_size

rxlev_ul_pc, hreqave

rxlev_ul_pc, hreqt

decision_1_ul_rxlev_av_p

l_rxlev_ul_p

u_rxlev_ul_p

decision_1_n1

decision_1_p1

decision_1_n2

decision_1_p2

Uplink Power Control due to Quality

ParameterCurrent

Setting

Suggest

SettingReason

decision_alg_num

ms_power_control_allowed

ms_p_con_ack

ms_p_con_interval

pow_inc_step_size

pow_red_step_size

rxqual_ul_pc, hreqave

rxqual_ul_pc, hreqt

rxqual_ul_pc, qual_weight

decision_1_ul_rxqual_av_p

l_rxqual_ul_p

u_rxqual_ul_p

decision_1_n3

decision_1_p3

decision_1_n4

decision_1_p4

w_qual

Data and Hopping Quality Power Control

ParameterCurrent

Setting

Suggest

SettingReason

data_qual_flag

l_rxqual_dl_p_data

l_rxqual_ul_p_data

hop_qual_enabled

l_rxqual_dl_p_hopping

l_rxqual_ul_p_hopping

Standard MS HO Power, MS Ho Power Level based on Path Loss Calculations (GSR3)

ParameterCurrent

Setting

Suggest

SettingReason

handover_power_level

use_derived_ho_power 0 1 Reduce MS UL power and interference

Optimised Power Control (GSR4)

ParameterCurrent

Setting

Suggest

SettingReason

dyn_step_adj

dyn_step_adj_fmpr

pow_inc_step_size_dl

pow_inc_step_size_ul

pow_red_step_size_dl

pow_red_step_size_ul

Oscillation Prevention for MS Power Control

ParameterCurrent

Setting

Suggest

SettingReason

mspwr_alg

Rapid MS Power Down

ParameterCurrent

Setting

Suggest

SettingReason

rpd_pwr_down

rpd_period (TIMER)

rpd_trigger

rpd_offset

2. HandoverInter-cell Handover

ParameterCurrent

Setting

Suggest

SettingReason

inter_cell_handover_allowed

Intra-cell Handover

ParameterCurrent

Setting

Suggest

SettingReason

intra_cell_handover_allowed

ho_ack (TIMER)

hop_count

hop_count_ timer

Uplink Quality

ParameterCurrent

Setting

Suggest

SettingReason

ul_rxqual_ho_allowed

rxqual_ul_ho, hreqave

rxqual_ul_ho, hreqt

rxqual_ul_ho, qual_weight

rxqual_ul_ho,

qual_pwr_flag

rxqual_ul_ho, qual_margin

rxqual_ul_ho,

adj_qual_margin

decision_1_ul_rxqual_av_h

l_rxqual_ul_h

u_rxqual_ul_h

decision_1_n6

decision_1_p6

w_qual

Uplink Interference

ParameterCurrent

Setting

Suggest

SettingReason

interfer_ho_allowed

rxlev_ul_ho, hreqave

rxlev_ul_ho, hreqt

rxlev_ul_ho, qual_margin

rxlev_ul_ho,

adj_qual_margin

decision_1_ul_rxlev_av_ih

u_rxlev_ul_ih

decision_1_n7

decision_1_p7

Downlink Quality

ParameterCurrent

Setting

Suggest

SettingReason

dl_rxqual_ho_allowed

rxqual_dl_ho, hreqave

rxqual_dl_ho, hreqt

rxqual_dl_ho, qual_weight

rxqual_dl_ho,

qual_pwr_flag

rxqual_dl_ho, qual_margin

rxqual_dl_ho,

adj_qual_margin

decision_1_dl_rxqual_av_h

l_rxqual_dl_h

u_rxqual_dl_h

decision_1_n6

decision_1_p6

w_qual

Downlink Interference

ParameterCurrent

Setting

Suggest

SettingReason

interfer_ho_allowed

rxlev_dl_ho, hreqave

rxlev_dl_ho, hreqt

rxlev_dl_ho, qual_margin

rxlev_dl_ho,

adj_qual_margin

decision_1_dl_rxlev_av_ih

u_rxlev_dl_ih

decision_1_n7

decision_1_p7

Uplink Level

ParameterCurrent

Setting

Suggest

SettingReason

ul_rxlev_ho_allowed

rxlev_ul_ho, hreqave

rxlev_ul_ho, hreqt

decision_1_ul_rxlev_av_h

l_rxlev_ul_h

u_rxlev_ul_h

deicion_1_n5

decision_1_p5

Downlink Level

ParameterCurrent

Setting

Suggest

SettingReason

dl_rxlev_ho_allowed

rxlev_dl_ho, hreqave

rxlev_dl_ho, hreqt

decision_1_dl_rxlev_av_h

l_rxlev_dl_h

u_rxlev_dl_h

decision_1_n5

decision_1_p5

Distance

ParameterCurrent

Setting

Suggest

SettingReason

ms_distance_allowed

rel_tim_adv, hreqave

rel_tim_adv, hreqt

decision_1_tim_adv_av_alg

ms_max_range

decision_1_n8

decision_1_p8

poor_initial_assignment

timing_advance_period

(TIMER)

Define the interval between timing advance changes

Power Budget

ParameterCurrent

Setting

Suggest

SettingReason

pwr_handover_allowed

rxlev_dl_ho, hreqave

rxlev_dl_ho, hreqt

surround_cell, hreqave

decision_1_pbgt_rxlev_av_h

decision_1_ncell_rxlev_av_h_calc

max_tx_ms (serving cell)

ms_tx_pwr_max_def (internal

neighbor default)

ms_tx_pwr_max_cell (external

neighbor)

use_neighbor_pbgt_hreqave 1

Data and Hopping Quality Handover Control

ParameterCurrent

Setting

Suggest

SettingReason

data_qual_flag

l_rxqual_dl_h_data

l_rxqual_ul_h_data

hop_qual_enabled

l_rxqual_dl_h_hopping

l_rxqual_ul_h_hopping

3. Multiband

Multiband Handover

ParameterCurrent

Setting

Suggest

SettingReason

mb_preference

phase2_classmark_ allowed

early_classmark_sending

early_classmark_delay

interband_ho_allowed

band_preference

band_preference_mode

multiband_reporting

4. MiscellaneousCriteria 1

ParameterCurrent

Setting

Suggest

SettingReason

rxlev_min_def 5 rxlev_min_def (internal neighbor default)

rxlev_min_cell 5 rxlev_min_cell (external neighbor)

Criteria 2

ParameterCurrent

Setting

Suggest

SettingReason

ho_margin_def 4,5

Neighboring Cell Processing

ParameterCurrent

Setting

Suggest

SettingReason

ncell_pro 0

disuse_cnt_hreqave 0

ho_only_max_pwr 1

neighbor_journal 0

worse_neighbor_ho 0

Alternative Processing of Rxqual Measurements

ParameterCurrent

SettingSuggest Setting Reason

alt_qual_proc 0 0 Quality Band Unit

Broadcast Control Channel Allocation (BA) Reinitialization

ParameterCurrent

SettingSuggest Setting Reason

ba_alloac_proc 1

Missing Report

ParameterCurrent

SettingSuggest Setting Reason

missing_rpt 0 0 Waiting for the actual data

Handover Timer

ParameterCurrent

SettingSuggest Setting Reason

handover_recongnized_period

bssmap_t7

Link Disconnection

ParameterCurrent

SettingSuggest Setting Reason

radio_link_timeout

rr_t3109

link_about_to_fail

link_fail

full_pwr_rfloss

15. Tools AvailableCOP – Event Counting Tool, Call Trace Product, Generic Look Up, Cell Analysis Tool 2TEMS and SafcoK1103Web StatisitcsNetPlanBSS DatabaseGEP

16. Problem Root Cause

1. High SDCCH BlockingHIGH SD BLOCKING

BUSY_SD_MAX

=MAX CONFIGUREDSD

Find faulty TS from BER stats or check alarm

SD_MEAN_HOCDING TIME CONVERGES to T3101

May due to Phantom RACH and HO access burst, check any same ARFCN and BSIC

Path Imbalance (SDCCH not on BCCH carrier)

1. Check Neighbor BCCH being Interfered

2. Missing Neighbor or incorrect neighbor DB Path, TOTAL_CALL/ALLOC_TCH may be used

3. Review OK_ACC_PROC like CM_SERVICE_REQ_CALL, PAGE_RESPONSE,LOCATION UPDATE

4. Neighbor Cell Outage or own cell carrier outage (l carrier can have max 2 SD)

5. Coverage Hole

Lot of location Update?

END

Is out_INTRA_BSS_HO_RETURN AND out_INTER_BSS_HO_RETURN A LOT?

END

Check neighbor in_intra_BSS_ho_return and in_inter_bss_ho_Seize, if high, Check neighbor´s fp

LAC BORDER REDESIGN， check t3121

7. No TCH BLOKING, ENABLE CHANNEL RE CONFIGUPATION

8. Neighbor´s tx power reduced

NN

NNYYYY

2. High TCH BlockingHIGH TCH BLOCKING

BUSY_TCH_MAX

=MAX_CONFIGURED_TCH

Find faulty TS From BER Stats or check alarm

1. Any neighbor´s BCCH interfered

2. Missing Neighbor or incorrect Neighbor BSIC

3. Its GCLK SHIFT causes neighbor´s bsic undecoded

4. Long timer setting

a. intra_BSS HO_rrt3103

b. channel release_rrt3109

5. check out_intra_bss_no_return and out_inter_bss_ho_return, it is high

END

6. Check any co-located or close

micro-cell,see whether traffic

offload is possible by optismisig

DB

7. If SD has no blocking. May reconfigure channels or enable channel reconfiguration feature

Find neighbors which has high

in_intra_bss_ho_return in_inter_bss_ho_seize then

check its fp

9. Coverage hole and improper DT & orientation

10. Add radio to cell without

adding new cabinet

8. check adjacent cell busy_tch_max, if the busy_tch_max-8>configured TCH

Site reconfiguration

Reduce ho margin and enable congestion relief

N

Y

Y

N

N

Y

11. Increase of single or dualband MSs.

12. Inappropriate congestion HO setting

3. SDCCH Access Failure RateNote: SDCCH blocking is excluded.

LOW SDCCH ACCESS SUCCESS RATE

1. Phantom RACH, check any same ARFCN and BSIC

2. Path Balance, BCCH is OK bat SD carrier not OK

3. Link balance, DB power setting

4. HW Problem, check per carrier chan_req_ms_fail stats. or check alarm

5. UL Interference

a. External check night line IOI

b. High cell site

c. High UL Path Loss

d. Co. or adj. – channel interference

6. Excessive TA

4. Handover Failure & LossHigh HO Loss / Failure

1. Poor serving cell HDPC setting

2. Short rr_t3103

4. Bad fp or external Interference -find % of UL/DL Quality by out_ho_cause

5. HO Failure

- Incorrect External Neighbor Database

7. HO failure

- Check target cell fp

3. MSC Problem

6. Handover_power_level is max?

8. HW (DRCU, Filter…) Fault

9. Radio Calibration

5. MSC Connection RateLow MSC Connection Rate

1. Paging Overflow Causing Discard

2. Coverage Hole

3. SD RF loss

4. TCH BLOCKING

5. Infrequent Location Update

6. Cipher Mode Fail8. MSC Connection Refused (MTL Congested)

7. Proper setting on ms_txpwr_max_cch and ms_txpwr_max_def

9. Call clearing timer (t3109<<radio_link_timeout) causing unclear call generating UL interference

SDCCH and TCH RF Loss

High SD & TCH RF LOSS

1. a. Neighbor´s BCCH Interfered

b. External Interference

c. Use guard band

d. Use AMPS frequency

2. Hardware

(a)Path balance

-idea is 108;³120 (serious UL Path Loss)

;£100 (serious DL Path Loss)

(b)Radio

-check per carrier RF loss stats

(c) Neighbor cell outage

(d) GCLK SHIFT

3. Neighbor Blocking

-check (OUT_INTRA_BSS_HO_REQ_OUT_INTRA_BSS_HO_ATTEMPT)

or (OUT_INTER_BSS_REQ_TO_MSC_OUT_TNETER_BSS_HO_ATTEMPT)

and check neighbor¢s ALLOC_TCH_FAIL

4. Missing Neighbor, usually by drive test or trace-call

5. Coverage hole, check UL Path Loss

7. SD RF LOSS

a. Inconsistent coverage

b. Not enough overlapping

c. No SDCCH HO

8. Poor HDPC setting

9. Is out_intra_bss_ho_return

and out_inter_bss_ho_return

a lot?

END

Check neighbor in_intra_bss_ho_return and in_inter_bss_ho_seize if high, check neighbor¢s fp

N

Y

6. Power ControlSudden Power Drop

1. Incorrect call clearing timer setting2. Faulty hardware

Slow Power Control1. ho_only_max_pwr is turned on2. Bad xx_p_con_ack and xx_p_con_interval

Power Control Window1. Any external interference2. Frequency planning technique3. Speed of power down and up4. Street or indoor coverage

7. Handover ProblemPing Pong Handover

1. Bad radio calibration2. Hardware fault3. Negative handover allowed

4. Quality handover without turning on qual_pwr flag5. Especially air combing, one of TX, RX antenna is blocked by building

Negative Handover1. Neighbor journal2. qual_margin_flag=03. Bad radio calibration between BCCH and non-BCCH4. Turn on ho_magrin_rxqual feature with default value

No and Delay Handover1. Inappriorate hreqave, hreqt and N & P voting2. Negative handover margin3. Improper setting on handover_recognised_period and bssmap_t74. Improper HO algorithm (Type 4, 6)5. Blocking

8. OthersLow Erlang Usage1. Inappropriate C1, C2 and handover criteria

High Rxqual1. Adjacent site interference2. Same site MAIO assignment problem3. High internal same site hit rate4. External interference like cordless phone, alarm, BTS hardware

Undecode BSIC1. GCLK shift2. BCCH interfered

Spurious Coverage1. Coverage optimization2. TA control

Killed Paging1. Too many access grant block reserved2. Location area too large

No Paging After Mobile is on certain time period1. MSC Location Update Timer < BSS Location Update Timer

No Call Setup1. LACI is different between BSS and MSC2. Cell BAR

Immediate Assignment Reject

1. NO SDCCH4/32