Throughput Analysis Model for IEEE 802.11e EDCA with Multiple Access Categories

IEEE 802.11e standard has been specified to support differentiated quality of service (QoS), one of the critical issues on the conventional IEEE 802.11 wireless local area networks (WLANs). Enhanced Distributed Channel Access (EDCA) is the fundamental and mandatory contention-based channel access method of IEEE 802.11e, and delivers traffic based on differentiated Access Categories (ACs). A general three dimensional Markov chain model of IEEE 802.11e EDCA for performance analysis is proposed in this paper. The analytical model considers multiple stations with an arbitrary number of different ACs. It also differentiates the contention window (CW) sizes and the arbitration interframe spaces (AIFSs), and considers virtual collision mechanism. Based on the model, the saturation throughput of EDCA is derived, and the accuracy of the proposed model is validated via simulations.