An Evidence Theory Based Opportunistic Routing Protocol for Underwater Acoustic Sensor Networks

Underwater acoustic sensor networks (UASNs) have attracted much attention due to their wide applications in various fields. However, as the sensor nodes are powered by batteries with limited energy and the batteries are difficult to be replaced, extending network lifetime should be taken as one of the primary objectives of network performance. In addition, due to the unreliable communication between nodes, the long propagation delay and high error rate, it is challenging to design a reliable routing protocol for UASNs. In this paper, we propose a Dempster-Shafer evidence theory-based opportunistic routing (EBOR) protocol to forward the packets to the surface sink. In EBOR, the source node considers both residual energy and packet delivery probability as evidence to determine an optimal next hop. With trust-based computation, the number of neighbors participating in forwarding is optimized to reduce energy consumption. Subsequently, the source node enables to schedule the packets transmission toward the surface sink efficiently based on the trust of nodes. Thus, the EBOR protocol can extend the network lifetime by uniformly distributing the residual energy and achieve a higher packet delivery ratio. The simulation results show that the EBOR protocol outperforms other protocols in terms of packet delivery ratio and energy efficiency.