Efficient routing protocols for data packet delivery are crucial to underwater
sensor networks (UWSNs). However, communication in UWSNs is a challenging task
because of the characteristics of the acoustic channel. Network coding is a promising
technique for efficient data packet delivery thanks to the broadcast nature of acoustic
channels and the relatively high computation capabilities of the sensor nodes. In this work,
we present GPNC, a novel geographic routing protocol for UWSNs that incorporates
partial network coding to encode data packets and uses sensor nodes’ location information
to greedily forward data packets to sink nodes. GPNC can effectively reduce network
delays and retransmissions of redundant packets causing additional network energy
consumption. Simulation results show that GPNC can significantly improve network
throughput and packet delivery ratio, while reducing energy consumption and network
latency when compared with other routing protocols.