Guaranteeing per Station and Per Flow Fairness of Downstream and Upstream Flows over IEEE 802.11 WLAN

Distributed Coordination Function (DCF) in IEEE 802.11 WLANs cannot guarantee both per-station and per-flow fairness among wireless stations. Several solutions to this problem have been proposed. However, per-flow fairness causes per-station unfairness and vice versa due to the fact that each wireless station may transmit different number of flows. In this paper, a novel method has been proposed to allocate fair bandwidth among wireless users and also between flows within each of wireless stations while maintaining maximum available total throughput for different link and wireless delays. Under this method the bandwidth allocation between TCP upstream and downstream flows within each wireless station is equal while all stations enjoy from a higher throughput compare to the previous proposed methods and the total throughput is ensured. In addition, bandwidth is allocated almost fair among all stations providing partial per-station fairness as well.