Underwater hybrid routing protocol for UWSNs

In Underwater Wireless Sensor Networks (UWSNs), many flooding-based routing protocols have been proposed because of their low routing overhead. However, they rely on the location information and current underwater localization techniques cannot provide the exact location information to all sensor node. Therefore, we need a new routing protocol which considers the characteristics of underwater localization in order to support packet transmissions from both localized nodes and unlocalized nodes to the sink. In this paper, we therefore propose an Underwater Hybrid Routing Protocol (UHRP) which has the hybrid features of flooding-based routing protocols and reactive ad-hoc routing protocols, based on our new routing metric. In addition, the expanded ring search technique is revised to be applied to reduce routing overhead in underwater environment.