Admission Control in the IEEE 802.11e WLANs Based on Analytical Modelling and Game Theory

Admission control is an important mechanism for the provisioning of the user-perceived Quality-of-Service (QoS) in the IEEE 802.11e Wireless Local Area Networks (WLANs). In this paper, we present an efficient admission control scheme based on analytical modelling and non-cooperative game theory where the Access Point (AP) and new users are the players. The decision of admission control is made by virtue of the strategies to maximize the utilities of the players, which are determined by the QoS performance metrics in terms of the end-to-end delay and frame loss probability. To obtain these required performance metrics, we develop a new analytical model incorporating the Contention Window (CW) and Transmission Opportunity (TXOP) differentiation schemes in the IEEE 802.11e protocol under unsaturated working conditions. The efficiency of the proposed admission control scheme is validated via NS-2 simulation experiments. The numerical results demonstrate that the proposed admission control scheme can maintain the system operation at an optimal point where the utility of the AP is maximized subject to the QoS constraints of both the real-time and non-real-time users.