Admission control based on rate-variance envelop for VBR traffic over IEEE 802.11e HCCA WLANs

With the increasing popularity of using wireless local area networks (WLANs) for Internet access, the controlled channel access mechanism in IEEE 802.11e WLANs, i.e., HCF controlled channel access (HCCA), has received much more attention since its inherent centralized mechanism is more efficient in handling time-bounded multimedia traffic. So far, only a few research studies address the admission control problem of variable bit rate (VBR) traffic over HCCA. These existing studies consider each traffic flow individually and, thus, cannot exploit the statistical multiplexing gain among multiple VBR traffic flows. In this paper, we apply the existing statistical multiplexing framework to the studied admission control problem, with all the features of IEEE 802.11e HCCA being taken into consideration. Experimental results show that our proposed admission control scheme achieves significant improvement in network utilization while still satisfying all the quality-of-service (QoS) requirements.