Underwater Acoustic wireless sensor Networks: A Review of UWAWSN Architecture, Applications, Design Challenges, MAC Protocols

It is expected that Underwater Wireless Sensor Networks (UWSNs) will support a range of civil and military applications. Due to its potentially large impact on overall network performance, Medium Access Control (MAC) protocol has attracted considerable attention in UWSNs. Unlike terrestrial networks, which rely primarily on radio waves for communication, UWSNs use acoustic waves which present a new research challenge in MAC protocol design. This paper surveys existing state-of-the-art MAC protocols for UWSNs in order to address the development of MAC protocols in UWSNs. The efficiency of the UWSNs in terms of delay and throughput was the major concern of the MAC layer protocol design in the early development. Subsequently, the design of energy-efficient MAC protocols becomes a new focus of research because sensor nodes are generally powered by batteries that are less likely to recharge. Within this paper we first describe the acoustic environment underwater and the challenges to the design of MAC protocols within UWSNs. We then include a comparative analysis of different types of MAC protocols based on current diverse implementations. That survey will hopefully inspire more active research in this area.