Nokia GSM optimization

1. Nokia Radio Network Planning, Southern Region
Agenda
 Introduction of NETWORK PERFORMANCE tools (AIS
Access Database for Optimization)
 Brief on main KPI formulas
 Drop call analysis
 SDCCH and TCH counters and meaning
 Explanation of RNO process
 BTC Power control and related parameters
recommendation.

2. Nokia Radio Network Planning, Southern Region
Main Objective
 Tools for daily Network Performance monitoring
 Iterative process to maintain and improve
network performance
 Discuss and understand the important BSC statistics in
GSM network.
 Identify the reason of the problem cells and rectify the
faults.

3. Nokia Radio Network Planning, Southern Region
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

4. Nokia Radio Network Planning, Southern Region
Network 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

5. Nokia Radio Network Planning, Southern Region
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

6. Nokia Radio Network Planning, Southern Region
Drop Call Analysis

7. Nokia Radio Network Planning, Southern Region
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

8. Nokia Radio Network Planning, Southern Region
SDCCH useful counters
SDCCH
REQUESTS
/c1000
sdcch_seiz_att
ASSIGNMENTS
FOR CALLS,LU,SS
sdcch_assign
BLOCKED
sdcch_busy_att
RACH on CCCH
/c3004
ch_req_msg_rec
REJECTED 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 UPDATE
sdcch_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
(corrupted
msgs, 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

9. Nokia Radio Network Planning, Southern Region
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_FAIL
SDCCH_USER_AC
SDCCH_BCSU_RESET
SDCCH_NETW_ACT
SDCCH_BTS_FAIL
SDCCH_LAPD_FAIL
SDCCH_A_IF_FAIL_CALL
One of these triggered
SDCCH Call drops
SDCCH Drop calls

10. Nokia Radio Network Planning, Southern Region
TCH REQUESTS
tch_request
TCH
REQUESTS
FOR NEW
CALL
tch_call_req
TCH SEIZURES
FOR
NEW CALL
tch_norm_seiz
TCH SEIZURES FOR
HO
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
REQUESTS
FOR HO
tch_request
-tch_call_req
-tch_fast_req
BLOCKED HO’S
tch_request -tch_call_req
-tch_fast_req -tch_ho_seiz
TCH
REQUESTS
FOR
FCS
tch_fast_req
TCH FCS SEIZURE
ATTEMPTS
tch_seiz_att_due_sdcch_con
TCH FCS SEIZURES
tch_seiz_due_sdcch_con
BLOCKED
TCH FCS SEIZURES
tch_seiz_att_due_sdcch_con
-tch_seiz_due_sdcch_con
MS BSC/BTS
TCH Requests

11. Nokia Radio Network Planning, Southern Region
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
REQUESTS
FOR NEW
CALL
tch_call_req
TCH SEIZURES FOR
NEW CALL
tch_norm_seiz
Call drops
TCH Drop Calls
TCH DROPS
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

12. Nokia Radio Network Planning, Southern Region
Drop call analysis, useful KPIs(counters) and formulas
BSC
TC
BTS
tch_radio_fail_old
tch_radio_fail
tch_abis_fail_call
tch_abis_fail_old
tch_a_if_fail_old
tch_a_if_fail_call
tch_tr_fail_old tch_tr_fail
tch_bcsu_reset
tch_user_act
tch_netw_act
tch_act_fail_call

13. Nokia Radio Network Planning, Southern Region
Drop call analysis, useful KPIs(counters) and formulas
 TCH/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_FAI
L_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_SDC
CH_TCH]+[MSC_I_TCH_TCH]+[BSC_I_TCH_TCH] - [MSC_O_TCH_TCH]-[BSC_O_TCH_TCH])

14. Nokia Radio Network Planning, Southern Region
Drop call analysis, useful KPIs(counters) and formulas
 UL 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_QUAL
3]+[FREQ_DL_QUAL4]+[FREQ_DL_QUAL5]+[FREQ_DL_QUAL6]+[FREQ_DL_QUAL7])
or
Run 196 report to check UL and DL per TRX distribution

15. Nokia Radio Network Planning, Southern Region
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

16. Nokia Radio Network Planning, Southern Region
Daily Top 10 or 20 Worse TCH/SDCCH DCR performance cells
Hardware fault RF problems
Check BTS alarm Check BCCH missing
Report to OMC
Yes
No
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, BTS
Yes
Suggestion for improvement
Conduct drive test
Yes
No
Optimization process, Worse TCH Drop Rate
Discuss with AIS’s
Optimization
team and Planning team. Issue
work
order for any suggestions.

17. Nokia Radio Network Planning, Southern Region
Optimization process, Worse HO performance
Daily Top 10 or 20 Worse handover performance cells
Hardware fault RF problems
Check BTS alarm Check BCCH missing
Report to OMC
Yes
No
Possible reasons: Target cell has co-channel/Adj channel interference, coverage gaps, hardware failure, neighbor BCCH/BSIC
frequency 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 failures
towards which cells?
Suggestion for improvement
Conduct drive test
Yes
No
Discuss with AIS’s
Optimization
team and Planning team. Issue
work
order for any suggestions.

18. Nokia Radio Network Planning, Southern Region
Optimization process, lowest TCH Availabilty
Daily Top 10 or 20 lowest TCH Availability
Hardware fault
Check BTS alarm Check BCCH missing
Report to OMC
>= 2 days
Yes
No
Accidentally
blocked by
user?

19. Nokia Radio Network Planning, Southern Region
519/153
report from
NMS
Weekly or Daily Activities
Import into
AIS database
Issue work order
and monitor
performance
Daily trends PLMN, BSC, Worse Cells monitoring
by individual BSC responsible engineers
Detail analysis and
suggestions for
improvements
Discussion with
AIS’s engineers for
any suggestions

20. Nokia Radio Network Planning, Southern Region
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.