A Simple Way to Reduce Congestion in Wireless Sensor Networks

Most wireless sensor networks performs a data collecting task, which means every node collects data of the environment such as temperature, humidity and shaking, then send them to the sink. In this case, all nodes would frequently send small packets to the sink, when the network is large, it will lead to heavy traffic load, especially in the area near the sink, nodes will suffer great congestion and packet loss, which makes them the bottleneck of the entire network. Here we propose a simple method to reduce congestion in wireless sensor networks, we call it packet combining protocol (PCP). When running PCP, a node doesn't forward the packets that were routed to it immediately, but extract the payloads as well as some source node information from the original packet, then the node put a certain number payloads into one new packet and route them toward the sink, PCP takes no extra calculations or transmissions at all. By running PCP, we not only reduced the total number of packets transmitted in the network, but also reduced the total data length transmitted to the sink. The result of the simulation shows that our method could reduce packet congestion by about 45%-85% and increase the successful packet delivery rate by about 5% to 25%.