Efficient Provisioning of Real-Time QoS Guarantees in IEEE 802.11e WLANs

In this paper we propose the Real-Time HCCA (RTH) scheduler, to support Quality of Service (QoS) in an IEEE 802.11e network using the Hybrid Coordinator Function (HCF) Controlled Channel Access (HCCA) function. RTH provides each admitted flow with real-time QoS guarantees. In addition, we evaluate the performance of RTH, with and without the QAck 802.11e option, in terms of the admission control limit and the amount of channel capacity that is left for contention-based access. In doing so, we also compare RTH with the sample scheduler that was proposed in IEEE 802.11e. Our analysis shows that RTH can admit a higher number of flows than the sample scheduler, when the flows have different QoS requirements. RTH also helps to increase the amount of bandwidth which is left for contention-based access.