Congestion Control in Multihop Wireless Networks

Conventional congestion control protocols, such as the Transmission Control Protocol (TCP), suffer from performance degradation in multihop wireless networks, due to the unique characteristics of shared wireless media. On the other hand, lack of precise congestion indication and coordination among nodes that compete for the shared wireless channel makes TCP fail to allocate resource efficiently and fairly among flows. In this paper, we present a novel Explicit Wireless Congestion Control Protocol (EWCCP) for stationary multihop wireless networks. By exploiting explicit coordination and multibit explicit feedback from routers, EWCCP gains fine-grain control and is robust to the dynamics of the wireless channel. EWCCP stabilizes at a smaller but more optimal sending window size as compared to TCP and achieves low buffer occupation and low delay. With explicit coordination, EWCCP allocates resource fairly among flows that compete for the shared channel. Extensive analysis and simulations demonstrate that EWCCP achieves proportional fairness and is a viable congestion control scheme for multihop wireless networks