Extended EDCA for Providing Bounded Delay Services in 802.11e WLANs

IEEE 802.11e Working Group has recently proposed an Enhanced Distributed Coordination Access (EDCA) scheme to improve the standard 802.11 Distributed Coordination Function (DCF) in order to provide service differentiation capabilities to WLANs. However, it has been widely demonstrated that EDCA does not provide an effective usage of the channel capacity, especially at high network loads.This paper proposes the Extended EDCA scheme as a distributed dynamic bandwidth allocation algorithm, providing delay guarantees to real-time media flows. Using the ns-2 simulator, we have shown that the proposed algorithm is able to provide a bounded delay service to multimedia flows in a wide range of network loads and frame loss ratios.