Performance modeling and QoS evaluation of MAC/RLC layer in GSM/GPRS networks

In this paper we present an analytical model to study the performance of channel sharing schemes to support both circuit switched voice and packet data services in a GSM/GPRS network. We study three channel sharing schemes: 1) fixed sharing in which cell channels are statically partitioned into two sets one for voice calls and the other for data traffic; 2) partial sharing in which n_data channels are reserved for data while the remaining N $n_data channels are shared by voice and data with preemptive priority for voice calls; and 3) complete sharing in which all the channels shared by voice and data with preemptive priority to voice calls. We investigate several key issues such as call blocking rate and mean packet delay for different cell loads with the data source modeled by Markov modulated Poisson process (MMPP). We validate the mathematical model through simulations and quantify the impact of the data source model and the call load on the mean packet delay for different channel sharing schemes.