Performance ModeHing of a Wireless GSM/GPRS Cell under Partial Sharing Scheme* Demetres D. Kouvatsos, Yue Li, and Irfan Awan Department of Computing, School of lnformatics, University of Bradford BD7 lDP, Bradford, West Yorkshire, England, UK {D.D.Kouvatsos, Y.Li5, Abstract. Novel analytic and simulation methodologies are devised for the performance modeHing and evaluation of a wireless GSM/GPRS cell with bursty multiple dass flows of voice calls and data packets subject to a traffic handling partial sharing scheme (PSS). In this context, a delay network model is proposed consisting of two interacting multiple dass GE-type delay systerns, namely a GSM GE/GE/ c/ c loss system with c servers and a GPRS GE/GE/1/N/PS delay system with finite capacity N and discriminatory processor share (PS) transf er rule. The principle of maximum entropy (ME) is used to characterize analytic solutions, subject to appropriate GE-type delay theoretic mean value constraints and dosed form expressions for state and blocking probability distributions are obtained. FUrthermore, related simulation programs in Java are developed. Typical numerical examples are included to compare the ME solutions against simulation and to study the effect of bursty multiple dass traffies upon the performance of the cell. Keywords: Global System for Mobile Telecommunication (GSM), Gen- eral Packet Radio Service (GPRS), wireless GSM/ GPRS cell, partial sharing scheme (PSS), quality-of-service(QoS), maximum entropy (ME) principle, performance evaluation, generalized exponential (GE) distri- bution. 1 Introduction Cost-effective algorithms for queueing and delay network models under various traffi.c handling schemes are widely recognized as powerful and realistic tools for the performance evaluation and prediction of complex mobile networks with ever increasing volumes of multimedia traffic. Most ofthe published performance studies in the field are based on simulation modeHing and numerical solution of Markov models covering different traffi.c scenarios, mostly at voice calllevel, with single or multiple service classes(e.g.,[l- 3]). Notably, Foh et al [3] proposed a single server infinite capacity queue for modeHing GPRS data packet traffi.c in a Markovi an environment and applied * This work is supported by the EU IST project IASON under grant IST-2000-32392. N. Mitrauet al. (Eds.): NETWORKING 2004, LNCS 3042, pp. 1252-1 262, 2004. @ IFIP International Federation for Inf ormat ion Processing 2004