Dynamic Real-time Traffic Management in WLANs

We present in this paper a mechanism to provide intelligent QoS to IEEE 802.11e compliant devices. Our mechanism combines two schemes previously proposed in the literature, while at the same time offers considerable improvements on traffic management for the enhanced distributed channel access (EDCA) mode for IEEE 802.11e. We evaluate our mechanism, called ACI-EDCA, by simulations with the NS-2 simulator. We test the performance of our proposal with four classes of traffic: Voice over IP (VoIP), Video on Demand (VoD), best-effort, and background traffic. This work extends previous findings mainly focused on the analysis of throughput and medium access collisions. Since the IEEE 802.11e is considered of critical importance for delay sensitive applications, we compare the performance of the end-to-end delay and traffic variance over the fluctuation on the transmission time as key indicators of the QoS that the network may provide. Through extensive simulations with the NS-2 simulator, we show how our ACI-EDCA algorithm outperforms the other two mechanisms we consider.