International Journal of Computer Theory and Engineering

Abstract

In wireless sensor networks, contention causes message collisions, which are very likely to occur when traffic is frequent and correlated, and hence decreases the lifetime of the network. Also congestion happens due to contention which is caused by concurrent transmissions. In this paper, we propose to develop a Hop-by-hop congestion control protocol for wireless sensor networks to mitigate traffic contention. In our proposed protocol, each node calculates its node rank based on the parameters buffer Size, hop count, channel busy ratio and MAC overhead. When the node rank crosses a threshold value T, the sensor node will set a congestion bit in every packet it forwards. If the congestion bit is set, the downstream node calculates the Rate Adjustment Feedback based on the rank and propagates this value upstream towards the source nodes. The source nodes will adjust their transmission rates dynamically based on this feedback. By simulation results, we show that our proposed protocol attains better throughput and packet delivery ratio with reduced energy consumption.