Performance modelling of IEEE 802.11 DCF using equilibrium point analysis

Abstract

Modelling and performance analysis of Medium Access Control (MAC) protocols in Wireless Local Area Networks (WLANs) has attracted lots of research efforts recently. Although many analytical models for IEEE 802.11 Distributed Coordination Function (DCF) have been reported, most existing studies have not considered traffic dynamics but concentrated on its throughput performance under the saturation condition, assuming that there are always packets available for transmission in each station and thus simplifying the analytical modelling and derivation. The comprehensive performance study under non-saturated traffic situations is still an open problem. In this paper, we propose an analytical performance model for IEEE 802.11 DCF protocol using multidimensional discrete-time Markov chain and Equilibrium Point Analysis (EPA), and present how to model the binary backoff scheme under more flexible traffic sources. We validate the accuracy of the model by comparing the analytical results with those obtained from simulation experiments. Finally, we use the proposed model to investigate the impact of different parameter settings on the performance of this protocol and present some valuable results.