Hello uLVa
these formulas depends on vendor
TCH Call Blocked =
some vendor call this KPI TCH congestion rate (%) = TCH overflow*100/TCH attempts
2 TCH Assign Success Rate
= TCH assign request /tch attempts
3 Call Success Rate
100-TCH assign failure
0r TCH seizure succ attepts/TCH attempts
4 Drop Call Rate
Most of vendors have two call drop
SDCCH and TCH
TCH call drop rate (%)
TCH call drop /TCH sizure attemots
also for SDCCH
5 SDCCH Call Blocked
SDCCH congestion
6 SDCCH Assign Success Rate
$7 Handover Success Rate
handover request/handover attepts
depends on Handover type
8 Handover Failure Rate
by small search in google you will get alot paper about this topic
good luck