A Study Of Rate-Controlled Transport Protocol For Wireless Sensor Network

Almost all applications of Wireless Sensor Networks(WSN) require the flow of sensed data from multiple sources to a particular sink node, while traditional transport protocols in neither wired network nor Ad-Hoc network can apply directly. How to control the transport rate of each node effectively to mitigate congestion and how to deal with the fairness between data flows of different types have become the research focuses of transport protocols in WSN.In this article we studied many transport protocols for Wireless Sensor Networks, and present DRC, a dynamic rate control transport protocol suitable for constrained sensor nodes. We first describe the unique characteristics of WSN and the significance of researching on transport protocol for WSN. And then provide a summary of existing transport protocols for WSN and point out the fundamental causes of congestion and find out the solutions. After these analyses, we then discuss the DRC protocol in details. DRC is a protocol that reliably transport sensor data from many source to one sink with out incurring congestion collapse. By allocating sending rate for all nodes in the net, DRC helps them maximize throughput according to environment conditions, such as hops from sink, interference and so on. Based on priority system we defined, DRC keeps all data flows transport fairly by both rate control and queue management mechanisms. Flows with equal priority can get equal throughput, with out regarding their distance from sink. Finally, we evaluate DRC extensively on our wireless sensor network testbed and show that DRC achieves our design goal.