Network coding to combat packet loss in underwater networks

Abstract

Channel variability and a high level of ambient noise lead to significant probability of packet loss in many underwater networks. Techniques based on acknowledgements and re-transmissions (such as ARQ) can be used to build robust networks over the unreliable links between underwater nodes. An alternative solution based on erasure codes can also be used to combat the packet loss. However, both solutions rely on a node re-transmitting information originating at that node. We propose an alternative solution based on network coding, where nodes transmit packets which are composed partially from information originating at that node, and partially from information received by that node from other nodes. The intuition behind this solution is to effectively route the information over good paths in the network rather than to simply rely on re-transmission of the information by the originating nodes. In this paper, we show that our proposed solution indeed performs better than the acknowledgment and erasure coding based solutions, and has the potential to effectively combat the high packet loss experienced by many underwater networks.