Improvement of Energy, Lifetime and Delays in Underwater Wireless Sensor Networks by Effective Deployment of Relay Nodes

According to the importance of underwater exploration, the attention of many researchers has been attracted to under-water sensor networks (UWSNs). Problems of UWSNs are large propagation delay, low bandwidth, and limited ener-gy. Because of these reasons, in this paper, we propose a new routing method in UWSNs that considers these factors and also achieves better load balancing in the network. In this method, relay nodes are used for routing. The relay nodes have a higher traffic load compared to the other nodes. They remove some burden from the overloaded nodes. The relay nodes shorten the transmission distance between source and destination. They have more energy compared to the other nodes. Our results show that the deployment of relay nodes in sensor networks helps to balance energy consumption and enhance the network lifetime. Nodes, after calculating the distance to the relay nodes and finding the nearest relay node, transmit packets to the nearest relay node for onetime immediately, so this method does not have holding time and it has less delay. The results are compared with DBR and CODBR. The results show that our method achieves more network lifetime, less delay and energy consumption compared to DBR and CODBR.