A statistical hybrid traffic control for IEEE 802.11e WLANs

The IEEE 802.11e WLAN supports prioritized Quality of Services (QoSs), but it needs additional mechanisms to support also the strict QoS required by real-time services. It has been shown that best performance is achieved when the WLAN is unsaturated. Therefore, a call admission control scheme is required to maintain the WLAN working in the unsaturated case. In this paper, we propose an analytical model for the capacity assignment necessary to satisfy the delay requirements for a given number of real-time flows belonging to two different traffic classes. At the same time, our analysis includes a rate control algorithm, as proposed in literature, that allows the best-effort traffic to fully use the residual bandwidth left by the real-time traffic, thereby achieving high channel utilization.