Improving the Performance of IEEE 802.11e with an Advanced Scheduling Heuristic

The new standard IEEE 802.11e targets at enhancing the legacy 802.11 so that QoS management over WLAN standards becomes possible. This is done by the introduction of two new functions, the enhanced distributed channel access (EDCA) and the hybrid coordination function controlled channel access (HCCA) for offering diffserv and intserv functionalities. The efficient coordination of both functions plays a crucial role in terms of the performance of 802.11e. In this paper we propose a new method for the calculation of the service interval by using the send rates of different traffic streams and suggest an advanced way to determine which one of the functions for which kind of streams to deploy. We show that despite its simplicity the proposed methods decrease packet delay and loss rates significantly and increases the number of streams having acceptable QoS levels.