A Multi-QoS Aggregation Mechanism for Improved Fairness in WLAN

The 802.11e and subsequently the 802.11n amendments brought Quality of Service (QoS) into the Wireless Local Area Network (WLAN) arena, in order to provide higher access priority to certain types of traffic such as video and voice. Unfortunately these improvements are not enough, since in very dense and highly loaded network conditions they can provide more harm than benefits, by making the lower priority traffic starve and increasing the average collision rate. This lack of performance in the Medium Access Control (MAC) layer is where we focused our work. We propose a solution that avoids the starvation of the lowest priority Access Categories (AC), taking into account the priority defined by the 802.11e amendment and at negligible or extremely low cost for the high priority ones. Simulation results presented in this paper prove the effectiveness of the method by showing delay improvements up to 92% in overcrowded and overloaded networks.