Performance analysis of IEEE 802.11e EDCA by a unified model

Performance evaluation of the upcoming 802.11e QoS-aware enhanced distributed channel access (EDCA) in WLANs has drawn extensive attention. The foundations for most of the studies are three major performance models in legacy distributed coordination function (DCF) analysis. In this paper, we first expose the common guiding principle behind these three seemingly different models. Subsequently, we propose a new unified performance model and analysis method to study the saturation throughput and delay performance of EDCA, under the assumption of a finite number of users and ideal channel conditions in a single-hop WLAN. This unified model is easy to understand and apply and helps increase the understanding of the existing performance analysis. In addition to its appealing simplicity, our unified model and analysis are validated well by simulation results. And ultimately, by means of the proposed model, we are able to evaluate the differentiation effects of EDCA parameters on WLAN performance in very broad settings, a feature which is essential for network design.