Inter-frame space (IFS)-based distributed fair queuing in IEEE 802.11 WLANs

In this paper, we study fair queuing in the MAC layer of IEEE 802.11 with the distributed coordination function (DCF). In particular, we propose an IFS-based distributed fair queuing (IDFQ) mechanism to provide differentiated service in conformance with the 802.11 standard. IDFQ is designed to emulate self-clocked fair queuing (SCFQ) in a distributed manner. There is no backoff in IDFQ. Thus, it provides better stability and improved aggregate throughput, as compared to existing work. Simulation results show that IDFQ supports differentiated service for different flows in proportion to their weights. More importantly, it outperforms existing solutions in terms of fairness and stability, rendering IDFQ an excellent candidate to provide weighted fairness for IEEE 802.11 WLANs.