RCA for KPI in GSM Network

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KPI (Key Performance Indicator)

TCH Drop: disconnect a unwanted call is known as TCH drop   [TCH Drop = (TNDROP)/TCASSAL*100]
SDCCH Drop Rate = [(CNDROP-CNRELCONG)/ (CMSESTAB)]*100 %
SDCCH Blocking = (CCONGS)\(CCALLS)*100
TASR = (TCASSAL) / (TASSALL) *100
HOSR = (SUMOHSUCC+SUMEOHSUCC)/ (SUMOHOATT+SUMEOHATT)*100
Random Access Success Rate = (CNROCNT)/ (CNROCNT+RAACCFA) * 100

RAACCFA: Failed Random Access
CNROCNT: All accepted Random Access

TCH DROP
HO FAIL
DLQ
Low Signal strength DL & UL
Less,  Many or  Mismatch NBR
BCCH & TCH Frequency Interference
Bad Quality DL & UL
TCH Cong at target cell
Interference or error  on E1
High TA
Low SS or Bad Qual on cell border
Mismatch MAIO & HSN
Bad Parameter regulation
Mismatch HO algorithm
Hardware Issue, faulty or Alarm
High ICM, VSWR or path imbalance
Mismatch HO parameter setting
 Antenna Faulty/ feeder
E1 error & Transmission fault
Sector swap
Time-slot Issue
Bad Parameter setting
CO-BCCH / BSIC
Poor Coverage and Spill
Drop call due to Handover
HO Delay
High Utilization (>150%)
Less,  Many or  Mismatch NBR or HO Delay
uncorrected NBR planning
Ater Issue or Ater Circuit Faulty
Suddenly drop
Interference or error  on E1

wrong combing
Hardware fault ( Alarm & Swap)

Bad Antenna installation


Hardware fault ( Alarm & Swap)


Low SACCH multiframe value
TASR
SD & TCH Congetion
Low RLT value
Poor coverage, Weak UL
High utilization
Low ACCMIN Value
High utilization ( FR utilization)>150%
less Half rate
Low RACCH_access_min
Hardware alarm or Trx Faulty
HCS feature
length of timer T3103 is low
abis or A interface congestion or error

length of timer T3109 is low


length of timer T3111 is low


Length of timer T305/T308 is set to great value.


SD DROP
PSR
RACH
Low SS, Bad Qual, and High TA
Parameter of PSR is MFRMS and timer is T3113
Poor BSIC Plan
LAC Boundary
incorrect cell parameter
Poor BCCH Plan
SW congestion
excess paging discard
Poor Coverage and Spill
Due to TCH Congestion
incorrect MSC parameter
Phantom RACCH
Hardware or TS faulty
poor paging streagady
Faulty antenna and cable
Interference or error  on E1
SD congestion
Poor ACCMIN and CRO
drop call due to TCH congestion
combined BCCH
Mismatch MAXRET & TX

uncorrected LAC dimension


abis or A interface congestion or error


decreasing signaling load on CCCH



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