Pipelined Transmission MAC for String Underwater Acoustic Networks

Despite effort spent over past years, an efficient MAC protocol design is still a challenging issue in underwater acoustic networks (UANs) mostly due to two factors: first, the long propagation delay of the acoustic signal in underwater environment; and second, the high variability of the environment. In this paper, we introduce a new MAC protocol for string UANs called Pipelined Transmission MAC (PTMAC). This protocol is essentially scheduling-based which pipelines data transmission to optimize network performance. The main contributions of the paper are: (1) design and implement a pilot version of PTMAC; (2) measure the performance of the protocol in the real open sea environment; and (3) propose a distributed method to improve the performance of the protocol through picking the appropriate maximum packet length. With this work, we introduce a working protocol for applications such as oil pipe monitoring, sea environment surveillance; as well as provide a baseline for performance comparison for future MAC protocols.