LAUSR

The characteristics of the underwater acoustic communication such as large propagation delay, high bit error rate and half-duplex, bring challenges to traditional automatic repeat request (ARQ) schemes. In this paper, we propose cooperative ARQ protocols based on relay selection in wireless sensor networks. These protocols use cooperative relays that provide an alternative path along a specific source-to-destination route. This alternative path has higher channel quality than that of the direct source–destination path. The main advantage of our methods is that we do not need to be aware of the relays locations. In fact, the relays will be organized by creating a time table at the destination. Furthermore, we evaluate the proposed schemes by comparing them with conventional stop and wait (S&W) ARQ and some other works in terms of throughput efficiency. Analytical and computer simulation results show that the proposed cooperative retransmission protocols can significantly improve the throughput even in a network with a few cooperative relay nodes.