Intra-flow network coding based multipath routing protocol for event-driven wireless sensor networks

Concerning event-driven wireless sensor network scenario where the traffic has burst-bulk characteristic, an intra-flow network coding based opportunistic multipath routing protocol called CodePaths was proposed. A routing metric taking delay and congestion factors into account has been defined and implemented, which is used to establish gradient field from nodes to sink. When an event occurs in the network area, nodes employ random linear network coding to mix packets and assign "forwarding opportunities" to downstream nodes based on routing gradients and link qualities. Consequently, an interleaving-paths mesh is constructed between the source and sink. Encoded packets are routed through the mesh and finally decoded by the sink node. Extensive simulation results indicate that CodePaths adapts to the randomness of events. It achieves high throughput and low latency and the packet delivery rate keeps upon 95%. Moreover, it minimizes the data transmission and energy consumption while guaranteeing reasonable reliability.