Analysis of GSM/GPRS cell with multiple data service classes

This paper is concerned with the performance modelling and evaluation of a General Packet Radio Service (GPRS) for a wireless Global System for Mobile telecommunication (GSM) cell involving both voice and multiple class data services under a complete partitioning scheme (CPS). The GPRS is modelled as a system of access and transfer queues in tandem having an external multiple class compound Poisson bursty traffic with geometrically distributed batches under first-come-first-served (FCFS) and generalised processor-sharing (PS) scheduling disciplines, respectively. The proposed queueing model is valid for both uplink and downlink connections and provides multiple class data services with different arrival rates, interarrival-time squared coefficients of variation (SCVs), file (burst) sizes and different PS discrimination service levels. Based on the principle of maximum entropy (ME), a product form approximation is characterised for the two queues in tandem, subject to queueing theoretic mean value constraints. The ME solution implies a decomposition of the system into individual single server building block queues, each of which can be analysed in isolation. Consequently, ME closed form expressions and simulation results for the aggregate state probability together with the marginal mean queue length and blocking probability are divised to assess the credibility of the ME solution and also to study the effect of external GPRS bursty traffic upon the performance of the wireless cell.