Alcatel Call Drop Analysis

Alcatel Call Drop AnalysisAlcatel Call Drop ReasonsIn Robi Network, Call Preemption Option is not present. 2Call Drop Due to Radio ProblemsThis kind of call drop happens mainly of TCH drops in TCH established phase due to radio link failure per TRX.This counter takes TCH in traffic or in signaling mode into account. Typically this fault occurs with:A 48.058 CONNECTION FAILURE INDICATION message with a cause value of "radio link failure" is received on Abis interface for a TCH channel (after successful seizure). 2) A 48.058 ERROR INDICATION message is received on Abis interface and leads to a loss of call. Call drop due to radio problems can be classified into:

1) Call_drop_DL_Interference 6) Call_drop_Short_Distance 2) Call_drop_DL_Level 7) Call_drop_UL_Interference 3) Call_drop_DL_Quality 8) Call_drop_UL_Level 4) Call_drop_Long_Distance 9) Call_drop_UL_Quality 5) Call_drop_Other_Causes

Call Drop Due to DL InterferenceAmount of drops due to DL Interference is generally low in Network ( 2G): whenever the timer supervising the handover procedure on the serving cell (T8) expires, except if a 48.008 CLEAR COMMAND with "normal event/call control" cause was received from the MSC, leading to a normal call release. In such a case, the handover is considered as successful. 3) Intra-cell TCH handover: whenever the timer supervising the handover procedure expires. 4) 2G -> 3G HO: whenever the timer supervising the 2G-3G handover procedure on the serving cell expires, except if a 48.008 CLEAR COMMAND with "normal event/call control" cause was received from the MSC, leading to a normal call release. In such a case, the 2G->3G handover is considered as successful.Reports required for TCH Drop RCACall drop measurements per cellTCH call fail per cell Uplink-and-Downlink Balance Measurement per TRXRadio Link Failure measurement per TRXReceive Quality measurement per TRXTCHF receive level measurement per TRXTCHH receive level measurement per TRXGSM Cell to Cell Incoming HO measurementGSM cell to cell Outgoing HO measurementMR measurement upon HO per cellChannel seizure measurement per TRX (Most important)Number of MR based on TA per TRX

Identifying Bad cellsKPIThreshold Load on PCH> 40%RACH Success rate30%SMS>5%Load on AGCH>40%SDCCH seizure for Location Update >35%MHT of SDCCH>10%SDCCH Congestion>0.5%CSSR1%Incoming HO to Assignments>50%Outgoing HO to Assignments>50%HOSR4%DL Strength HO ratio>5%