Problem Analysis Flow Charts for GSM KPIs:
Page1 : HIGH TCH DROP RATEPage2 : LOW TCH MHT Page3 : SDCCH CONGESTIONPage4 : INTER MSC HOPage5 : INTER MSC HOPage6 : FAILED HOPage7 : NO HO ATTEMPTPage8 : PING-PONG HANDOVERSPage9 : RACH FAILUREPage10 : HIGH SDCCH DROP RATEPage11 : TCH ACCESS FAILPage12 : SDCCH ACCESS FAILPage13 : CALL BLOCK RATEPage14 : TCH ASSIGNMENT FAILURE RATEPage15 : INTEGRITYPage16 : RETAINABILITY Page17 : INTERFERENCE ANALYSISPage18 : SS ANALYSISPage19 : HARDWARE ANALYSIS
LOW TCH MHT
LOW TCH MHT< 10 sec
(2)
DR/E > 1.2(2)
HIGH DROPCALL RATE ?
DROP ANALYSIS
CHECK LOCATION OF
CELL
MICRO?ENABLE
FASTMSREG
HO PERFORMANCE
(4)
MANY OUTGOING
HANDOVERS FROM CELL
CHECK LOCATING
PARAMETERS
END
YES
NO
YES
NO
YES
NO
HW ANALYSIS
HW PROBLEM
??REPAIR IT
YES
NO
B
B
BAD QUALITY
BAD QUALITY
HO??(5)
INTERFERENCE ANALYSIS
YES
NO
SDCCH CONGESTIONTIME %
> 0.5(1)
H/W AvailablilityCheck (1)
SDCCHAvailability %
< 99.5
INFROM BSS GROUP
Site Position
Check CRH & Location Area
Border
Cell at LA Border?
TCH Traffic
TCHCongestion
> 2 ?(2)
Add TCH or sites
Periodic Registration
Too many?(3)
Change Interval T3212
B
Comb. BCCH/SDCCH
?
Make it Non Combined
Mean holding Time
MHT1 & MHT2 > 5 sec
(1)
H/W Check
Dimensioning
SDCCH Under
Dimensioned? (1)
IncreaseSDCCH
Channel Configuration
YES
NO
YES
NO
YES
NO
YES
NO
YES
NO
YES
NO
YES
NO
B
SDCCH CONGESTION
END
NO
Immediate assignment on
TCH
Activated? Activate NO
HO FAIL % > 5(4)
WrongNeighbour Relation?
Correct definition
TARGET CELL’S
BSIC & BCCH SAME WITH A CLOSE
CELL ?
CHANGE BSIC OR BCCH
UNNECESSARY NEIGHBOURS
??
ERASE UNNECESSARY NEIGHBOURS
Faulty parameter setting?
B
NEIGHBOUR CELL DEFINITION
Locating Parameters
YES
NO
YES
NO
YES
YES
CORRECT ITYES
FAILED HO
NO
LOW SS AT BORDER?
BAD QUALITY
? (5)
INTERFERENCE ANALYSIS
YES
NO
NO
B
ACTIVE BA LIST
RECORDING
SS ANALYSIS
NO
NO
Missing Neighbours
???
DEFINE NEIGHBOURSHIP
NO
YES
NOBTS & MS
PWR CNT USED IN THE REGION PROPERLY??
ACTIVATE IT!
RN FEATURES
LAPD AND DIP(14 & 13)
TRANSMISSION QUALITY BAD?
INFORM RN-TR
ANTENNA
WRONG FEEDER?
SWAP
CROSSCONNECTION
?CORRECT IT
HIDDEN ANTENNA
CHANGE POSITION
TOO HIGH VSWR?RXMFP
CHECK THE INSTALLATION
YES
NO
YES
NO
YES
NO
YES
NO
NO
YES
END
INCORRECTDOWNTILT??
YESCORRECT IT
NOIRC, DTX,
HANDOVER POWER BOOST
USED ??
ACTIVATE IT!
YES
YES
PING-PONG HANDOVER % > 20
(5)
(BSPWRB-BSPWR) &(BSPWRT-
BSTXPWR)WRONG ??
CORRECT OUTPUT POWER
PARAMETERS
LOCATING PARAMETERS
YES
PING-PONG HANDOVER
CLS PARAMETERS
WRONG?? CORRECT ITYES
NO
HCS PARAMETERS
WRONG?? CORRECT ITYES
NO
BAD QUALITY
BAD QUALITY
HANDOVER??(5)
INTERFERENCEANALYSIS
YES
END
(LHYST, KHYST, LOFFSET, KOFFSET)
WRONG ??
CORRECT OUTPUT POWER
PARAMETERS
YES
NO
NO
RANDOM ACCESSFAIL % > 5
(6)
BSIC & FREQUENCY
ACCESS FROM
COCHANNEL?
CHECK SAE
S/W FILE CONGESTION?
AFTSP:TEST=110,LOG;
CELL PARAMETER
LOW MAXTA?
CHANGE BSIC OR FREQUENCY
INCREASE SAE
INCREASE MAXTA
YES
NO
YES
NO
B
B
HARDWARE ANALYSIS
H/W PROBLEM?
REPAIR OR REPLACE
YES
YES
NO
NO
TA ANALYSIS
RACH FAILURE
SITE POSITION
UMBRELLA?TILT OR LOWER
ANTENNA
NOISE LEVEL(9)
UNKNOWN ACCESS?
REDUCE INTERFERENCE
YES
NO
SOLVED? END
END
YES
NO
YES
ANY OTHER
CELL EXIST IN THE AREA
??
TILT & POWER TUNING OR
CONFIG CHANGE
NO
YES
NO
TA CAUSED
TCH & SDCCH DROPSEXIST??
(7&8)
YESEXTENDED
RANGE
NO
SDCCH DROP % > 2(1)
DROP REASONS(8)
TOO HIGH TA?
CHECK TALIM&MAXTA OR ACTIVATE
EXTENDED RANGE
YES
HIGH SDCCH DROP RATE
LOW SS?
BQ?
PERFORM SS ANALYSIS
PERFORM INTERFRENCE
ANALYSIS
SITE POSITION
UMBRELLA?CHANGE
FREQUENCY OR DOWN TILT
END
YES
YES
NO
YES
NO
HARDWARE ANALYSIS
HW FAULT? REPAIR IT!YES
NO
NO
NO
TCH ACCESS FAIL
TCH ACCESS FAIL % > 5
(2)
CHECK HANDOVERSTATISTICS
(4)
PROBLEM RELATED WITH ONE
NEIGHBOUR?
PERFORM FAILED
HANDOVER ANALYSIS
HARDWAREANALYSIS
HWPROBLEM
?
INFORM CN-BSS
COVERAGE
AS PREDICTED
?
CHECK ANTENNA
INSTALLATION
GOOD SERVER EXIST?
DOWN TILT,ADD NEW SITE
END
YES
NO
YES
NO
YES
NO
YES
NO
TRU CONFIGURATION &
OSS DEFINITION CHECK
CORRECT IT!
YES
YES
SDCCH ACCESS FAIL
SDCCH ACCESS FAIL % > 5
(1)
SAME BSIC-BCCH
SAME BSIC&BCCH
?
CHANGE BSIC&BCCH
INTERFERENCE
SAME BCCH
?CHANGE BCCH
H/W ANALYSIS
PROBLEM?INFORM CN-BSS
END
YES
NO
YES
NO
YES
NO
ANTENNA
WRONG FEEDER?
SWAP
CROSSCONNECTION
?CORRECT IT
HIDDEN ANTENNA
CHANGE POSITION
TOO HIGH VSWR?RXMFP
CHECK THE INSTALLATION
YES
NO
YES
NO
YES
NO
NO
YES
INCORRECTDOWNTILT??
YESCORRECT IT
B
B
TCH CONGTIME%
> 2(2)
CHECK TCHCAPACITY
YES
NO
NO
CALL BLOCK %
CHECK HARDWARE
NO
CALL BLOCK % > 1(10)
CHECK RN FEATURES
CLS ACTIVE ?
ACTIVATE IT ! NO
YES
HALF-RATE ACTIVE ? ACTIVATE IT !
NO
YES
ASSIG. TO OTHER CELL
??ACTIVATE IT !
NO
ADD CAPACITY
POSSIBLE TO ADD TRX??
ADD TRX
NO
YES
POSSIBLE TO ADD CABINET??
ADD CABINETYES
NO
END
TRA CONGESTION
?(17)
YES
NO
ADD TRA DEVICE
NO
TRA CONGESTION
RXMFP:MO=RXOTG-..,FAULTY,SUBORD;
INFORM CN-BSS
RXMOP:MO=RXORTX-..-..;
INFORM CN-BSS
RXELP:MO=RXOTG-..;
INFORM CN-BSS
RXAPP:MO=RXOTG-..;
YES
NO
YES
YES
NO
NO
RXMFP:MO=RXOTG-..,FAULTY,SUBORD;
INFORM CN-BSS
YES
END
TCH ASSIGNMENT FAIL % > 2(10)
LOW OUTPUT POWER
??
ADJUST POWER LEVEL
OUTPUT POWER
YES
NO
NO
TCH ASSIGNMENT FAILURE
CHECK HARDWARE
HW FAULT?
INFORM CN-BSS
YES
NO
CHECK COVERAGE
PERFORM DRIVE TEST
DOMINANT SERVER EXISTS?
ADD SITE & CELL
NO
CHECK INTERFERENCE WITH
MRR, FAS & ICM
DISTURBANCE ON SDCCH OR TARGET TCH
IMPROVE FREQUENCY
PLAN
NO
B
B
ROUTECONG ??
(16)INFORM CN-BSS
BSC ROUTECONGESTION
YES
NO
NO
END
YES
INTEGRITY % < 97(11)
LOW SS??
SS ANALYSIS
LOW SS(12)
YES
NO
INTEGRITY
HW ANALYSIS
PROBLEM ??INFORM CN-BSS
YES
NO
INTERFERENCEANALYSIS
END
RETAINABILITY % < 97(18)
DROP % > 1(2)
DROP ANALYSIS
DROP ANALYSIS
YES
NO
NO
RETAINABILITY
BAD QUALITY DISCONNECTION
BQ DISCON. % > 3
(19)
INTERFERENCEANALYSIS
YES
NO
NO
END
INTERFERENCE ANALYSIS
BAD QUALITY
SS LOW?(12)
NO
YES PERFORM SSANALYSIS
CO-CHANNEL OR
ADJ.CHANNEL INTERFERENCE
AVAILABLE FREQUENCY
?
YESCHANGE
FREQUENCY
NO
HCS
UPPER LAYER
INTERFERING THE LOWER
LAYER?
YESCHANGE THE
LAYERTHR
NO
OVERDIMENSIONED CELLS
CELL OVERDIMENSIONED
?(2)
YES TRX REMOVAL
B
B
OVERSHOOTING
DRIVE TEST& ICDM
ANALYSIS
CROSS CONNECTION
?
YES
INFORM O&M
IS ANY OTHER CELL
OVERSHOOTING ??
YES TILT & POWER DECREASE IN THE
CELL OVERSHOOTING
NO
IS THE SERVING CELL
OVERSHOOTING ??
YES TILT & POWER DECREASE IN THE
CELL OVERSHOOTING
NO
END
SS ANALYSIS
LOW SS
CTR & MRR
NO
LOW SS DOWNLINK?
(12)
LOW SS BOTHLINK?
(12)
YES YESOVERSHOOTING? RURAL?
NO ANTENNA CONFIGURATION
CHANGE
NO
HARDWARE & CONFIGURATION
CHECK
CONNECTOR,TRX,BTS
RECEIVER,ANTENNA POSITION
CHECK
YES
ADD NEW SITE
NO
TRX PROBLEM
HOPPING OFF,OBSERVE
FROM OSS
INFORM OMC
YESRECEIVER PROBLEM
RXMFP AND DRIVE TEST
LOW SS UPLINK?
(12)USE TMA
NODIVERSITY PROBLEM
??
TOO HIGH VSWR?
NO
CHECK OUTPUT POWER
LOW OUTPUT POWER
??
INCREASEOUTPUT POWER
1. GSM & GPRS Technology Package / Radio Network Technology Package / Cell Statistics / Cell SDCCH
2. GSM & GPRS Technology Package / Radio Network Technology Package / Cell Statistics / Cell TCH
3. GSM & GPRS Technology Package / Core Network Technology Package / Traffic / Location Update
4. GSM & GPRS Technology Package / Radio Network Technology Package / Handover / Handover Requests & Causes
5. GSM & GPRS Technology Package / Radio Network Technology Package / Handover / Handover Requests & Causes
6. GSM & GPRS Technology Package / Radio Network Technology Package / Cell Statistics / RACH
7. GSM & GPRS Technology Package / Radio Network Technology Package / Cell Statistics / TCH Drop Reasons
8. GSM & GPRS Technology Package / Radio Network Technology Package / Cell Statistics / SDCCH Drop Reasons
9. GSM & GPRS Technology Package / Radio Network Technology Package / RIR10. GSM & GPRS Technology Package / Radio Network Technology Package / Cell
Statistics / Cell Service Quality Reports / Cell Service Quality Detailed - CSSR11. GSM & GPRS Technology Package / Radio Network Technology Package / Cell
Statistics / Voice Quality - RxQual 12. GSM & GPRS Technology Package / Radio Network Technology Package / MRR /
Signal Strength 13. GSM & GPRS Technology Package / Radio Network Technology Package / TN
Reports / DIP 14. GSM & GPRS Technology Package / Radio Network Technology Package / TN
Reports / LAPD15. GSM & GPRS Technology Package / Radio Network Technology Package / Packet
Switching / Cell Based IP Delays / IP Discards16. GSM & GPRS Technology Package / Core Network Technology Package / Traffic /
Route / Route – BSC17. GSM & GPRS Technology Package / Core Network Technology Package / Traffic /
Transcoder18. GSM & GPRS Technology Package / Radio Network Technology Package / Cell
Statistics / Cell Service Quality Reports / Cell Service Quality Detailed 19. GSM & GPRS Technology Package / Radio Network Technology Package / Cell
Statistics / Disconnection
