Efficient admission control for IEEE 802.11e wireless LANs to support real-time traffic

Without good admission control scheme, quality of service (QoS) requirement cannot be guaranteed, especially for real-time transmission such as voice and video in IEEE 802.11e wireless local area networks (WLANs). In this paper, an efficient admission control scheme that performs at medium access control (MAC) layer is proposed in IEEE 802.11e enhanced distributed channel access (EDCA) WLAN. The admission control strategy was implemented in access point (AP), which employed collision probability and access delay measures from active flows to estimate the throughput and packet delay of each traffic class by an unsaturation analytical model. The proposed scheme guarantees a uniform QoS level in terms of maximum tolerable packet delay and required bandwidth for all real-time traffic. For best effort traffic, the proposed scheme guarantees QoS in terms of maximum tolerable packet delay to avoid starvation and guarantee fairness. Simulation results prove that the proposed admission control scheme is effective to make right admission control to protect existed real-time traffic, which improves the performance of real-time traffic in terms of delay and throughput.