Improving congestion control performance and fairness in multihop ad hoc network

Abstract

This is a preliminary step towards a systematic approach to jointly design TCP congestion control algorithms and MAC algorithms, TCP tends to overshoot the network capacity and its granularity of sending rate adjustment is too coarse because the minimum increase in window size is the size of one packet upon each TCP acknowledgment or during each round trip time. A new wireless congestion control protocol is defined based on the channel busyness ratio. In this protocol, each forwarding node determines the inter-node and intra-node fair channel resource allocation and allocates the resource to the passing flows by monitoring and possibly overwriting the feedback field of the data packets according to its measured channel busyness ratio. Clearly, the sending rate of each flow is determined by the channel utilisation status at the bottleneck node. Through NS2 simulations, we conclude that channel utilisation, delay and fairness are better for WCCP than the traditional TCP.