2G KPIs

1. 2G KPIs

2. TCH Drop <2%
(BBH)
{[Call Drops on TCH in Stable State (Traffic Channel)]+[Call
Drops in TCH Handovers (Traffic Channel)]}/{[Successful TCH
Seizures (Traffic Channel)]+[Successful TCH Seizures in TCH
Handovers (Traffic Channel)]}
CM33:Call Drops on Traffic Channel
CM33C:Call Drops on Radio Interface (Traffic
Channel)
CM330:Call Drops on Radio Interface in Stable State
(Traffic Channel)
CM331:Call Drops on Radio Interface in Handover
State (Traffic Channel)
CM332:Call Drops due to No MRs from MS for a Long
Time (Traffic Channel)
CM333:Call Drops due to Abis Terrestrial Link Failure
(Traffic Channel)
CM334:Call Drops due to Equipment Failure (Traffic
Channel)
CM335:Call Drops due to Forced Handover (Traffic
Channel)
Call Drop(RF Cause)
M3030A:Call Drops on TCH(TA) 0.00%
M3030B:Call Drops on TCH(Uplink Received Level) 81.82%
M3030C:Call Drops on TCH(Downlink Received Level) 0.00%
M3030D:Call Drops on TCH(Uplink and Downlink Received Level) 0.00%
M3030G:Call Drops on TCH(Uplink and Downlink FER) 0.00%
M3030H:Call Drops on TCH(Uplink Quality) 0.00%
M3030I:Call Drops on TCH(Downlink Quality) 9.09%
M3030J:Call Drops on TCH(Uplink and Downlink Quality) 0.00%
M3030K:Call Drops on TCH(Other) 9.09%
SDCCH DROP
<=2% (BBH)
(Call Drops on SDCCH)/(Successful SDCCH Seizures)
TCH Blocking
[Failed TCH Seizures due to Busy TCH (Traffic Channel)]/[TCH
Seizure Requests (Traffic Channel)]
SDCCH
BLOCKING
(Failed SDCCH Seizures due to Busy SDCCH)/(SDCCH Seizure
Requests)
CSSR
(%)
(100-SDCCH Congestion Rate(%))*(100-SDCCH Drop
Call Rate(%))*TCH Assignment Rate/10000
TCH Assignment Rate
K3013A:Successful TCH Seizures (Traffic
Channel)/K3010A:TCH Seizure Requests (Traffic
Channel)*100
K3010A:TCH Seizure
Requests (Traffic
Channel) (none)
K3013A:Successful TCH
Seizures (Traffic
Channel) (none)
K3010B:TCH
Seizure
Requests in
TCH
Handovers
(Traffic
Channel)
(none)
K3013B:Successful
TCH Seizures in TCH
handovers (Traffic
Channel) (none)
Formula Downlink TBF Congestion Rate
={[Number of Failed Downlink GPRS TBF Establishments due to No Channel]
+[Number of Failed Downlink EGPRS TBF Establishments due to No Channel]} x {100%}/
{[Number of Downlink GPRS TBF Establishment Attempts]
+[Number of Downlink EGPRS TBF Establishment Attempts]}
(A9103 + A9303) x 100%/(A9101 + A9301)
Formula Downlink TBF Establishment Success Rate
={[Number of Successful Downlink GPRS TBF Establishments]
+[Number of Successful Downlink EGPRS TBF Establishments]} x {100%}/
{[Number of Downlink GPRS TBF Establishment Attempts]
+[Number of Downlink EGPRS TBF Establishment Attempts]}
(A9102 + A9302) x 100%/(A9101 + A9301)
Calculate call drop counter
Connection failure
Error indication
Clear request
MS BTS BSC MSC
2G main KPIs as follows.
•TCH drop rate.
•SD drop rate.
•TCH congestion.
•SD congestion.
•TCH blocking.
•SD blocking.
•CSSR.
•TCH Assignment Success rate.
•HOSR.
•TCH utilization rate.
TCH Drop Rate:-
•A call drops when it is terminated abnormally. For example, a call is terminated because the BSC or the MS releases the TCH due to an exception.
•Call drop measurement: When receiving a Connection Failure or an Error Indication message from the BTS, the BSC sends the Clear Request message to the MSC an
•In normal cases, most call drops are caused by Um interface problems, and therefore you need to focus on these call drops. Call drops caused by Um interface pro
RACH Min.Access Level(dBm) is set to a too small value.
T200 SDCCH(5ms) and N200 of SDCCH are set to too small values.
MAIO is set improperly.
Handover parameters:
SDCCH HO Allowed is set to Yes.
T3103A(ms) and T3103C(ms) are set to too small values.
T3109(ms) is set to a too small value.
T3111(ms) is set to a too small value.
The length of timer T305/T308 is set to an invalid or too great value.
Disconnect Handover Protect Timer is set to a too small value.
The network planning is improper after the Um interface is synchronized.
Software Parameter 13 and MAX TA are set to too small values.
•TCH congestion/blocking
Reasons:-
•Alarms.
•HW Fault.
•Improper Parameter Setting.
•Faulty TRX.
•Transmission Issues.
•Increase in Customer base or Over utilized cell (less dedicated TCH channels defined)
Improvement:-
•Resolve the alarms & HW fault
•Replace the faulty TRX
•Add TRX or Timeslot based on the blocking
what is TCH Blocking and Drop?
TCH call Blocking , it present how many subscriber asks for TCH channel andnetwork reply with no available resource.
so it present how many subscriber request TCH channel to reject this request
•SD congestion/blocking
.
Add SD resources
Factors of SDCCH Congestion Rate in GSM
•Congestion Caused by Faults on Equipment or Transmission
•Congestion Caused by Insufficient Signalling Resources
The heavy traffic and burst traffic cause the SDCCH congestion
•Congestion Caused by Improper Data Configuration
The SDCCH congestion relates to the relevant parameters of the BSC such as SDCCH Availability, LAC and T3101 (the timer used in the immediate assignme
•Congestion Caused by Interference