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)(1) in Wireless Local Area Networks (WLAN) drew extensive attention in these two year. The foundations of most of the studies up-to-date 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, by abstracting, unifying and extending this common principle, we propose a new unified performance model and analysis method to study the saturation throughput and delay performance of EDCA, under the assumption of finite number of users and ideal channel conditions in a single-hop WLAN. Combining the strengths of all three models, this unified model is easy to understand and apply; on the other hand, it helps increase the understanding of the existing performance analysis. In addition to its appealing simplicity, our unified model and analysis are validated very 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.