A Handshake-Based Protocol Exploiting the Near-Far Effect in Underwater Acoustic Networks

We propose a scheme that opportunistically exploits received power diversity across different packets to both favor spatial reuse in underwater acoustic networks and limit the exposed terminal problem. Since the power attenuation in the underwater acoustic channel is large, such power differences are common. This situation, also referred to as the near-far effect and often considered a problem, is converted into a resource by means of multipacket reception (MPR). Yet, even without MPR capability our scheme offers performance benefits. Our scheme is simple, lightweight and distributed, and can be easily implemented over any protocol based on carrier-sense multiple access with collision avoidance. Our results show that higher throughput and lower transmission delay are achieved compared to a benchmark channel access protocol. Our results are validated and demonstrated in a lake experiment. To allow reproducibility, the implementation of our scheme is publicly available.