A Novel Congestion Control Scheme in Wireless Sensor Networks

The event-driven nature of wireless sensor networks (WSNs) leads to unpredictable network load. As a result, congestion may occur at sensors that receive more data than they can forward, which causes energy waste, throughput reduction and packet loss. In this paper, we propose a rate-based fairness-aware congestion control protocol (FACC), which controls congestion and achieves approximately fair bandwidth allocation for different flows. In FACC, we categorize intermediate relaying sensor nodes into near-source nodes and near-sink nodes. Near-source nodes maintain per-flow state, and allocate an approximately fair rate to each passing flow. On the other hand, near-sink nodes do not need to maintain per-flow state and use a light-weight probabilistic dropping algorithm based on queue occupancy and hit frequency. Our simulation results and analysis show that FACC provides better performance than previous approaches in terms of throughput, packet loss, and fairness.