Abstract
This paper proposes a grid-based geographic routing protocol for underwater wireless sensor networks that uses cell disjoint paths to route data packets from source nodes to sink nodes. The proposed algorithm assumes that the monitored region is divided into logical 3D grids. It also assumes that the sensor nodes are mobile, have identical capabilities and equipped with localization services. The algorithm consists of four main components: gateway election algorithm, updating neighboring gateways' information, packet forwarding mechanism, and dealing with holes. Routing is performed in a grid-by-grid manner through gateways that uses disjoint paths to relay data packets to the destination. The disjoint paths and gateway election algorithm adopted in our protocol help balancing energy while achieving good delivery ratio and end-to-end delay. The proposed algorithm has been analytically evaluated by deriving approximations for the packet delivery ratio.