An Enhanced Service Differentiation Mechanism for QoS Provisioning in IEEE 802.11e Wireless Networks

There are a number of works trying to adjust the contention window (CW) in order to provide differentiated service in IEEE 802.11-based wireless networks. However, these protocols cannot deliver firm service guarantees while maintaining high network utilization, particularly under congested network conditions. In this paper, we propose an adaptive enhanced service differentiation mechanism for QoS provisioning in IEEE 802.11e wireless networks. The mechanism includes traffic conditioning and adaptive MID CW updating rule with service differentiation based on per queue. Relative priorities are provisioned by adjusting the size of the CW of each traffic class taking into account both applications requirements and network conditions. Simulation results show that the proposed mechanism outperforms the basic EDCA scheme of 802.11e and another proposed scheme AEDCF in terms of network utilization, goodput and delay.