An efficient depth-based forwarding protocol for underwater wireless sensor networks

The communication in the underwater wireless sensor networks (UWSN) faces many challenges and it consumes much more energy while the packet delivery ratio is low. In this paper, an efficient depth based forwarding (EDBF) protocol for the UWSN is proposed. The protocol uses the weight to select the next hop for data forwarding, which takes full account of the depth factor, the energy ratio and the next hop forwarding quality. First, the depth factor calculated by the relative depth is used for determining the forwarding direction. Second, the energy ratio helps to ensure the load balance. Finally, the next hop forwarding quality is mainly calculated based on implicit acknowledgement (ACK) mechanism to avoid the worse links and the void areas. Besides, the EDBF protocol greatly reduces the use of control packets. Therefore, the EDBF protocol can timely update the routing table, which is well adapted to the dynamic underwater environment. A large number of simulations have been repeatedly executed to verify the effectiveness and the feasibility of the EDBF protocol.