Key Performance Indicators (KPI) For

GSM

KPI Overview

KPIs are defined through the definition and measurement of key parameters of input and output of internal network system and/or maintenance & operation progress of enterprise

KPIs are primary metrics to evaluate process performance as indicators of quantitative management, and to measure progress towards the enterprise's goals.

KPI

1 CSSR

2 SDCCH KPIs

1 SDCCH Blocking

2 SDCCH Drop Rate

3 TCH KPIs

1 TCH Blocking

2 TCH Assignment Failure

3 TCH Drop Rate

4 TCH Traffic

KPI

4 GPRS KPI

1 Packet Downlink Assignment Success Rate

2 Packet Uplink Assignment Success Rate

3 Abnormal Uplink TBF Release

4 Abnormal Downlink TBF Release

5 Downlink Data .

6 Uplink Data

7 Downlink Data

8 Downlink LLC Discards

9 Uplink LLC Discards

5 Handover KPI

Handover Success Rate

Incoming Handover Success Rate

Outgoing Handover Success Rate

CSSR

CSSR ( Call Setup Success Ratio)

The CSSR indicates the probability of successful calls initiated by the MS. The CSSR is an important KPI for evaluating the network performance.

Formula

CSSR = (1-SDCCH Drop Rate)*(1- SD Blocking Rate)*(1-TCH Blocking)*(1-TCH Assignment failure)

Typical Values for CSSR

100% - 95%

SDCCH KPI

SDCCH Blocking

Use

This KPI indicates if there is blocking on signaling resources on in a cell. SDCCH blocking will result in blocked calls, blocked SMSs and failed location updates.

Formula

100*(AttSDCCHSeizuresMeetingSDCCHBlockedState/(AttImmediateAssingProcs+AttSDCCHSeizuresMeetingSDCCHBlockedState))

SDCCH Drop Rate

Use

This KPI counts the ratio of all SDCCH failures to successful SDCCH seizures.

Typical values are 1 - 3% in remote sites

Formula

100*(NbrOfLostRadioLinksSDCCH/succImmediateAssingProcs)

TCH KPI

TCH Traffic (Erlang)Use

Provides the amount of traffic in Erlang calculated in a cell

Formula

Erlang Load

Note:

For 2 Trx Erlang can reach up to 17 Erlang

TCH Drop RateUse

This KPI counts the ratio of all TCH failures to TCH seizures. This formula counts TCH failures due to radio and the TCHs dropped due to failed handovers.

Formula

100*([NbrNbrOfLostRadioLinksTCH] + [unsuccessfullinternalHandoversWithLossConnection])/([succTCHSeizures] + [SuccHandoverTCHSeizures])

TCH KPI

TCH Blocking

Use

This KPI counts the ratio of all TCH blocks due to no TCH resources available. This KPI indicates if there is blocking on TCH in a cell. TCH blocking will result in blocked calls.

Typical values are 2-5% for remote cells

Formula

100*(AttTCHSeizuresMeetingTCHBlockedState/attTCHSeizures)

TCH Assignment Failure

Use

This KPI counts the ratio of attempted TCH allocations to successful TCH allocations. This KPIdoes not include TCH Blocking.

Formula

100-(100*(succTCHSeizures)/ (attTCHSeizures-AttTCHSeizuresMeetingTCHBlockedState))

Handover KPI

Handover Success RateUse

This KPI measures the overall Handover success rate in a cell. This KPI includes both incoming and outgoing handover.

Formula

100*SuccessfulInternalHandover/ (UnsuccessfulInternalHandovers+SuccessfulInternalHandover)

Incoming/Outgoing Handover Success Rate

Usego

This KPI measures the incoming / outgoing Handover success rate in a cell.

Formula (1) incoming

100* succIncomingInternalInterCellHDOs/attIncomingInternalInterCellHDOs

Formula (2) outgoing

100*succOutgoingInternalInterCellHDOs/attOutgoingInternalInterCellHDOs

GPRS KPI

Packet Downlink Assignment Success Rate

Use

This KPI measures the Packet Downlink Assignment Success Rate

Formula

100*Successful Packet Downlink Assignments on CCCH/Packet Downlink Assignments onCCCH/

Packet Uplink Assignment Success Rate

Use

This KPI measures the Packet Uplink Assignment Success Rate

Formula

100*Successful Packet Uplink Assignments on CCCH/Packet Uplink Assignments on CCCH/

GPRS KPI

Abnormal Uplink TBF ReleaseUse

This KPI measures the Abnormal Uplink TBF Release Rate

Formula

100*(Established Uplink TBFs-Successful Uplink TBFs)/Established Uplink TBFs

TBF Uplink Establishment Success RateUse

This KPI measures the TBF Uplink Establishment Success Rate

Formula

100*Established Uplink TBFs/Attempted Uplink TBFs

GPRS KPI

1 Uplink DataUse

This KPI measures the amount of uplink data in octets.

Formula

Uplink Data =Uplink LLC Octets

2 Downlink LLC Discards

Use

This KPI measures the amount of LLC PDUs in the downlink discarded due to all causes.

Formula

Downlink LLC PDU Discards

3 Downlink DataUse

This KPI measures the amount of downlink data in octets.

Formula

Downlink Data =Downlink LLC Octets

4 Uplink LLC Discards

Use

This KPI measures the amount of LLC PDUs in the uplink discarded due to all causes.

2.4.13.2 Formula

Uplink LLC PDU Discards