On Underwater Wireless Sensor Networks Routing Protocols: A Review

Underwater sensor networks (UWSNs) play a significant role in ocean exploration and monitoring by gathering information and routing it to the ground stations. Therefore, the design of efficient routing protocols is necessary as it guarantees robust and reliable data delivery from the source nodes to the destination nodes. However, the effects of underwater environment, dynamic nature of the channel for acoustic, radio and optical waves, and harsh underwater noise conditions, make the routing protocol design a challenging task. This article overviews various issues which are faced in designing the routing protocols and summarizes the popular routing protocols for UWSNs alongside their pros and cons. More specifically, the routing protocols are characterized into three main categories; localization-based, localization-free and cooperative schemes. The performance of these protocols are discussed with respect to various network parameters such as energy consumption, network lifetime, delay, reliability, and communication overheads. Towards the end, new directions for potential research in improving routing protocols performance in UWSNs are highlighted.