Performance Analysis of Uplink GPRS Traffic after a BTS Failure

Abstract

The data traffic is burstier and has longer connection time as compared to voice traffic. Global System for Mobile (GSM) was developed to carry the voice traffic and it is not suitable for carrying data traffic. General packet radio service (GPRS) has been well integrated in the GSM networks to accomplish efficient spectrum utilization for data traffic. In uplink, users are required to reserve the slot for sending packets using slotted ALOHA protocol. Depending upon coding scheme, each packet has some forward error correction capability and retransmissions are also done if errors are more. If a base transreceiver station (BTS) stops functioning (i.e., fails) then the users of its area will not get any service. In this case, absolute radio frequency channel number (ARFCN)s, which were assigned to the failed cell, should be transmitted by neighbor BTS such that some service should be available to users of the failed cell. It will affect the blocking probability, the cochannel interference thus bit error rate (BER), throughput etc. GPRS users will be adversely affected but it is far better than the case of no service. In this paper, the overall impact of BTS failure on the performance of GPRS uplink traffic has been quantified. The role of various parameters is discussed such that end users as well as cellular operator will get maximum benefits.