nokia gsm optimization

Nokia Radio Network Planning, Southern Region

AgendaIntroduction of NETWORK PERFORMANCE tools (AIS

Access Database for Optimization) Brief on main KPI formulasDrop call analysisSDCCH and TCH counters and meaningExplanation of RNO process

BTC Power control and related parameters recommendation.


Main Objective

Tools for daily Network Performance monitoring Iterative process to maintain and improve

network performanceDiscuss and understand the important BSC statistics in

GSM network.Identify the reason of the problem cells and rectify the

faults.


Optimization Activities Daily performance data monitoring and problems troubleshooting Weekly/Monthly quality report Neighbouring relationship and parameter setting review Coverage optimisation Frequency replan Feature setting design Drive test


Network Performance Measurement toolsNetwork Performance Measurement tools

A tailor made access database tools

- 519, 153 and 232 reports generate by NMS A tool that has been customized to few important levels

- PLMN level

- BSC Level

- Cluster Level

- Cell Level

- Top 20 worse performance cells

- Adjacencies handover statistics

- Timing advance statistics Macro to generate daily worse performance cells


Drop call analysis and its related Key Performance Indicators

TCH Drop Call Rate (DCR_4f)

TCH and SDCCH Availability ( 100%)

BCCH Missing Alarms ( should be 0, 1-3 is the acceptable value)

UL and DL quality (0 - 4)or 196 report, should be above 95%

Calls (To monitor daily call trends)

CSSR ( >95%)

UL interference band distribution (99.9% for Band 1) or 196 report

Handover Failure rate (< 5%) or 153 and 062 report

Average of call Distance (Base on Timing advance measurement) or 232 report

SDCCH/TCH Access and SDCCH/TCH success


Drop Call Analysis


Drop call analysis and its related counters

TCH/SDCCH Radio Fail

TCH/SDCCH_RF_Old_HO

TCH/SDCCH Abis_Fail_Call

TCH/SDCCH Abis_Fail_Old

TCH/SDCCH_A_IF_Fail_Call

TCH/SDCCH_A_IF_Fail_Old

TCH_TR_Fail (only for TCH channel)

TCH_TR_Fail_Old (only for TCH channel)

TCH_Act_Fail_Call(only for TCH channel)

TCH/SDCCH_LAPD_Fail

TCH/SDCCH_BTS_Fail

TCH/SDCCH_User_Act

TCH/SDCCH_Net_Act

TCH/SDCCH_BCSU_Reset


SDCCH useful counters

SDCCH REQUESTS/c1000sdcch_seiz_att

ASSIGNMENTS FOR CALLS,LU,SS

sdcch_assign

BLOCKED

sdcch_busy_att

RACH on CCCH/c3004

ch_req_msg_recREJECTED DUE TO ILLEGAL EST.CAUSE

ghost_ccch_res

AND OTHER FAILURES BEFORE ESTABL. INDICATION(incl.IMSI detach)

MOC (incl.SMS)

succ_seiz_orig

MTC (incl.SMS)

succ_seiz_term

CALL RE-EST.

sdcch_call_re_est

LOCATION UPDATEsdcch_loc_upd

EMERGENCY CALL

sdcch_emerg_call

SDCCH ACCESSES REJECTED IN BSC

TRUE SDCCH SEIZURES

SEIZURES FOR HO

sdcch_ho_seiz

SDCCH FAILURES

sdcch_abis_fail_call (corruptedmsgs, failed chan.act.)

TRUE SDCCH SEIZURES FOR CALL,SMS,SS

TRUE SDCCH SEIZURES FOR CALL & SS- succ_sdcch_sms_est- unsucc _sdcch_sms_est

other than sdcch_abis_* failures

small part of failures

Normal LU

Periodic LU

IMSI attach

MS accessing,

TCH

SDCCH-SDCCH HO

SDCCH Requests


SDCCH REQUESTS

sdcch_seiz_att

SEIZURES FOR CALLS AND LU

sdcch_assign

MOC (incl.SMS)

succ_seiz_orig

MTC (incl.SMS)

succ_seiz_term

EMERGENCY CALL

sdcch_emerg_call

Cell A

one of SDCCH fail counters is triggered

SDCCH_RADIO_FAILSDCCH_USER_ACSDCCH_BCSU_RESETSDCCH_NETW_ACTSDCCH_BTS_FAILSDCCH_LAPD_FAILSDCCH_A_IF_FAIL_CALL

One of these triggered

SDCCH Call drops

SDCCH Drop calls


TCH REQUESTS

tch_request

TCH REQUESTSFOR NEW CALL

tch_call_req

TCH SEIZURES FORNEW CALL

tch_norm_seiz

TCH SEIZURES FORHO tch_ho_seiz

DR OUT SUCC

msc_o_sdcch_tch+bsc_o_sdcch_tch

BLOCKED CALLS

tch_call_req-tch_norm_seiz -msc_o_sdcch_tch-bsc_o_sdcch_tch

TCH REQUESTSFOR HO

tch_request-tch_call_req-tch_fast_req

BLOCKED HO’S

tch_request -tch_call_req-tch_fast_req -tch_ho_seiz

TCHREQUESTSFORFCS

tch_fast_req

TCH FCS SEIZURE ATTEMPTS

tch_seiz_att_due_sdcch_conTCH FCS SEIZURES

tch_seiz_due_sdcch_con

BLOCKEDTCH FCS SEIZUREStch_seiz_att_due_sdcch_con-tch_seiz_due_sdcch_con

MS BSC/BTSTCH Requests


SDCCH REQUESTS

sdcch_seiz_att

SEIZURES FOR CALLS AND LU

sdcch_assign

MOC (incl.SMS)

succ_seiz_orig

MTC (incl.SMS)

succ_seiz_term

EMERGENCY CALL

sdcch_emerg_call

Cell A One of these triggered

TCH REQUESTS

tch_request

TCH REQUESTSFOR NEW CALL

tch_call_req

TCH SEIZURES FORNEW CALL

tch_norm_seiz

Call drops

TCH Drop Calls

TCH DROPS

TCH_RADIO_FAILTCH_RF_OLD_HOTCH_ABIS_FAIL_CALLTCH_ABIS_FAIL_OLDTCH_A_IF_FAIL_CALLTCH_A_IF_FAIL_OLDTCH_TR_FAILTCH_TR_FAIL_OLDTCH_LAPD_FAILTCH_BTS_FAILTCH_USER_ACTTCH_BCSU_RESETTCH_NETW_ACTTCH_ACT_FAIL_CALL


Drop call analysis, useful KPIs(counters) and formulas

BSCTCBTS

tch_radio_fail_oldtch_radio_fail

tch_abis_fail_calltch_abis_fail_old

tch_a_if_fail_old

tch_a_if_fail_call

tch_tr_fail_old tch_tr_failtch_bcsu_resettch_user_acttch_netw_acttch_act_fail_call


Drop call analysis, useful KPIs(counters) and formulasTCH/SDCCH Drop Call Rate (DCR_4f)

Drop Call (DCR_4f): 100*Sum([TCH_RADIO_FAIL]+[TCH_RF_OLD_HO]+[TCH_ABIS_FAIL_CALL]+

[TCH_ABIS_FAIL_OLD]+[TCH_A_IF_FAIL_CALL]+[TCH_A_IF_FAIL_OLD]+[TCH_TR_FAIL]+[TCH_TR_FAIL_OLD]+

[TCH_LAPD_FAIL]+[TCH_BTS_FAIL]+[TCH_USER_ACT]+[TCH_BCSU_RESET]+[TCH_NETW_ACT]+

[TCH_ACT_FAIL_CALL]) / Sum([TCH_NORM_SEIZ]+[TCH_SEIZ_DUE_SDCCH_CON]+[MSC_I_SDCCH_TCH]+

[BSC_I_SDCCH_TCH]+[CELL_SDCCH_TCH]+[MSC_I_TCH_TCH]+[BSC_I_TCH_TCH] - [MSC_O_TCH_TCH]-

[BSC_O_TCH_TCH])


Drop call analysis, useful KPIs(counters) and formulasUL and DL Quality distributions

UL Qual 0-4: 100*Sum(FREQ_UL_QUAL0]+[FREQ_UL_QUAL1]+[FREQ_UL_QUAL2]+

[FREQ_UL_QUAL3]+[FREQ_UL_QUAL4])/Sum([FREQ_UL_QUAL0]+[FREQ_UL_QUAL1]+

[FREQ_UL_QUAL2]+[FREQ_UL_QUAL3]+[FREQ_UL_QUAL4]+[FREQ_UL_QUAL5]+

[FREQ_UL_QUAL6]+[FREQ_UL_QUAL7])

DL Qual 0-4: 100*Sum(FREQ__DL_QUAL0]+[FREQ_DL_QUAL1]+[FREQ_DL_QUAL2]+

[FREQ_DL_QUAL3]+[FREQ_DL_QUAL4])/Sum([FREQ_DL_QUAL0]+[FREQ_DL_QUAL1]+

[FREQ_DL_QUAL2]+[FREQ_DL_QUAL3]+[FREQ_DL_QUAL4]+[FREQ_DL_QUAL5]+

[FREQ_DL_QUAL6]+[FREQ_DL_QUAL7])

or

Run 196 report to check UL and DL per TRX distribution


Drop call analysis, common problems

Hardware and transmission fault -> check TCH drop reason, TCH availability

and transmission.

Interference -> Check possible interference by using Mapinfo, Check UL and

DL quality, site too high? (check TA-232 distribution report)

Coverage problem/Island site

Handover problem -> To check if any potential neighbours is not defined or

missing of neighbour relation

Wrong feeder connection

Neighbour site down


Daily Top 10 or 20 Worse TCH/SDCCH DCR performance cells

Hardware fault RF problems

Check BTS alarm Check BCCH missing

Report to OMC

YesNo

Check frequency plan, neighbor site status (site down?), site to site distance (232 report), antenna height and antenna tilting - Mapinfo or Prediction tools

No

Refer KPIs trends like Calls, TCH drop rate and reason of drop, UL and DLquality, UL interference band, Handover performance, call distance, CSSR….

Majority drop due to TR_Fail, A_IF_Fail_Call, BTSYes

Suggestion for improvement

Conduct drive test

Yes

No

Optimization process, Worse TCH Drop Rate

Discuss with AIS’s Optimizationteam and Planning team. Issue work order for any suggestions.


Optimization process, Worse HO performance Daily Top 10 or 20 Worse handover performance cells

Hardware fault RF problems


Report to OMC

YesNo

Possible reasons: Target cell has co-channel/Adj channel interference, coverage gaps, hardware failure, neighbor BCCH/BSICfrequency not updated, wrong CGI format in MSC, wrong HO number in MSC, Non-symmetric HO relations, synchronization problem, excessive UL interference, site too high, Direct Retry traffic cause high HO Failures(KTU13).

Refer to handover reason, UL and DL quality, UL interference band

Check 153 HO report to find out majority failurestowards which cells?

Suggestion for improvement

Conduct drive test

Yes

No

Discuss with AIS’s Optimizationteam and Planning team. Issue work order for any suggestions.


Optimization process, lowest TCH Availabilty

Daily Top 10 or 20 lowest TCH Availability

Hardware fault


Report to OMC

>= 2 days

Yes

No

Accidentally blocked by user?


519/153 report from NMS

Weekly or Daily ActivitiesImport into

AIS database

Issue work order and monitor performance

Daily trends PLMN, BSC, Worse Cells monitoringby individual BSC responsible engineers

Detail analysis and suggestions for improvements

Discussion with AIS’s engineers for any suggestions


Iterative process to improve network quality

Frequency Retune

- 1/1, 2/2 or 3/3 reused…Depends on traffic loading and number of frequenies in the MA list.

Use of frequency hopping…consider to use/trial TRP = 2 (TCH/Hopping preferred)

- Improve DCR

- Degrade UL/DL quality( 0- 4)…acceptable!!!

Optimise Parameter setting

- BTS Power control…to perform trial!

- TRP setting….per area basics

- Quality margin handover (QMRG)….different setting in rural, suburban and urban area

- QDR/QUR setting for hopping cells

- Power budget handover (PBGT) …different setting in rural, suburban and urban area.

nokia gsm optimization

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