Seamless Congestion Control over Wired and Wireless IEEE 802.11 Networks

We present a new approach for seamless congestion control over heterogeneous networks containing wired and wireless IEEE 802.11 links. The approach uses ECN (Explicit Congestion Notification) as a common signalling mechanism for conveying congestion information from both wired and wireless links. Two additional novel aspects of the approach are that ECN marking for a wireless link, due to the way resources are shared, is performed for both the uplink and the downlink based on measurements of the aggregate traffic in both directions, and the marking mechanism dynamically adapts to different traffic and load conditions. Simulation results demonstrate that our approach achieves higher fairness compared to drop-tail queueing, while achieving the same utilization, and can effectively control the average packet delay over the wireless link.