Energy-Efficient and Reliable Relay Path Determination in Wireless Sensor Networks with Mobile Sink

We present a relay path determination scheme that maximizes the network lifetime and guarantees the end-to-end reliability in the wireless sensor networks with mobile sink. The simple flooding algorithm may render an easy means for the determination but the resulting frequent collisions and profuse relay hops disable determining energy-efficient and reliable paths. To resolve this problem, we present a transmission backoff (TB)-based broadcasting algorithm that uses a transmission deferring approach to reduce the number of collisions and the number of the relay hops, while guaranteeing the end-to-end reliability. It is a distributed and stateless approach in which the relay path is determined by each node without any global and/or local exchange of network information. Each node decides whether or not to rebroadcast based on its own transmission backoff time, which is calculated using its residual battery energy and the target end-to-end reliability. Simulation results reveal that the proposed algorithm can achieve a longer network lifetime and a higher end-to-end reliability performance than other existing schemes.