Analytical performance evaluation of Internet access over GPRS and its comparison with simulation results

In this paper, we discuss the results of recently published analytical concepts for performance evaluation of packetswitched mobile radio networks. For comparison we regard the results of a simulation system (GPRSim), which emulates the GSM General Packet Radio Service (GPRS) in great detail. Our scope is to identify the possible reasons for deviations between analytical and simulation results in order to support the further development in this area. In the regarded analytical modelling framework, which is presented by U. Vornefeld [1, 2] source modelling is done by characterization of WWW traffic with means of marked Markovian arrival processes (MMAP), accordingly GPRS performance measures are derived by analysis of an MMAP/G/1 queue. By evaluation of WWW traffic generated during stochastic simulation we show that important characteristics of recent Internet traffic are depicted by Vornefeld’s analytical source model. We find that the regarded analytical approach is well suited for understanding the general impact of various system parameters. Nevertheless, although the analytical model uses a very detailed characterization of WWW traffic, for quantitative performance analysis simulation results are still required.