A Multi-hop ARQ Protocol for an Underwater Acoustic Channel

— Underwater acoustic networks are envisaged to be the enabling technology for oceanographic data collection, pollution monitoring, offshore exploration and tactical surveillance applications. Unique characteristics of underwater acoustic channels such as large propagation delays and high bit error rates pose a challenge to designing reliable and ef cient communication protocols. In this paper, we propose an opportunistic acknowledgement scheme suited for Stop and Wait ARQ protocols and demonstrate using simulations that it achieves better latency and energy ef ciency than traditional non-opportunistic schemes for both one and two-dimensional multi-hop acoustic channels.