LEER: Layer-Based and Energy-Efficient Routing Protocol for Underwater Sensor Networks

Radio signals attenuate largely when propagating in water, while optical signals have large scattering in water. Therefore, acoustic signals are used for communication in underwater sensor networks (UWSNs). Data transmission in underwater sensor networks is facing challenges due to the characteristics of underwater acoustic channels. In addition, high energy consumption and long latency bring about increased challenges for the design of routing protocols in UWSNs. In this paper, we propose a routing protocol called Layer-based and Energy-efficient Routing (LEER) Protocol to solve the void area routing problem as well as the long end-to-end delay and high energy consumption problems in UWSNs. In LEER, each node extracts the layer field information from Hello messages received and updates its own layer to avoid the void area problem, and all nodes forward packets to the sink node without the need for full-dimensional location information. Simulation results show that the LEER protocol outperforms the depth-based routing (DBR) protocol in terms of delivery rate and end-to-end delay.