Priority based congestion control for heterogeneous traffic in multipath wireless sensor networks

Congestion occurs when too many sources are sending too much of data for network to handle. Congestion in a wireless sensor network can cause missing packets, low energy efficiency and long delay. A sensor node may have multiple sensors like light, temperature etc., with different transmission characteristics. Each application has different characteristics and requirements in terms of transmission rate, bandwidth, delay, and packet loss. Different types of data generated in heterogeneous wireless sensor networks have different priorities. In multi path wireless sensor networks, the data flow is forwarded in multiple paths to the sink node. It is very important to achieve weighted fairness for many WSN applications. In this paper we propose a priority based congestion control for heterogeneous traffic in multi path wireless sensor network. The proposed protocol allocates bandwidth proportional to the priority of many applications simultaneously running in the sensor nodes. Each sensor node route is own data as well as the data generated from other senor nodes. The parent node of each sensor node allocates the bandwidth based on the source traffic priority and transit traffic priority of the data from heterogeneous applications in the child nodes. Congestion is detected based on the packet service ratio and congestion notification is implicit. The normalized throughput comparison for simple fairness and weighted fairness is shown in the results.