On energy efficiency in underwater wireless sensor networks with cooperative routing

In this paper, we exploit cooperative communication for designing an energy-efficient routing algorithm in underwater wireless sensor networks (UWSNs). Each network node is equipped with a single omnidirectional antenna and multiple node coordinates while taking advantage of spatial diversity. This research work is limited in scope to amplify-and-forward (AF) scheme at the relay node and fixed ratio combining (FRC) strategy at the receiver node. Cooperative diversity at the physical layer and multi-hop routing at the network layer enable us to formulate minimum energy routing as a joint optimization of the transmission power at physical layer and link selection at the network layer. Simulations results show that our proposed cooperative energy-efficient routing for UWSN (Co-EEUWSN) performs better than the selected non-cooperative routing protocols (depth-based routing (DBR) and energy-efficient DBR (EEDBR)) and cooperative DBR (Co-DBR) in terms of packet delivery ratio, end-to-end delay, and energy efficiency.