Analysis of Capacity Limitation in Nigerian GSM Networks and the Effects on Service Providers and Subscribers

摘要

The performance of GSM network is measured in terms of KPIs (Key PerformanceudIndicators) based on statistics generated from the network. The most important of theseudperformance indicators from the operators’ perspective are BER (bit error rate), the FERud(frame error rate) and the DCR (dropped call rate).udThe Dropped Call Rate (DCR) is a measure of the calls dropped in a network as it gives audquick overview of network quality and revenues lost. This makes it one of the mostudimportant parameters in network optimization. At the frame level in the NMS (NetworkudManagement System), the DCR is measured against the Slow Associated Control Channelud(SACCH) frame. If the SACCH frame is not received, then it is considered to be droppedudcalls.udFor this work data was acquired form the Network Management System of various GSMudoperators in Nigeria (e.g. MTN, Celtel, Globacom etc.). The acquired data was analyzedudto statistically illustrate the extent of revenue that is lost as a result of dropped calls andudthe consequent impact on the customers/subscribers.