D-MAC: Media access control architecture for underwater acoustic sensor networks

Physical properties of hydroacoustic communication channels differ significantly from those of conventional terrestrial radio channels, the former being characterized by long propagation delays, limited bandwidth, extremely complex and rapidly varying reverberation etc. As an important feature of underwater acoustic modems is the half-duplex nature of communication, development of underwater acoustic sensor networks demands a substantial redesign of algorithms and techniques that target underwater data transfers on both physical and data-link layers. In this paper we present a new media channel access protocol architecture that combines two media access algorithms for transferring different data types, namely the burst data and short instant messages. Such combination of communication algorithms opens a broad range of options for implementation at the network layer. A comparison efficiency analysis of the burst media access algorithm and the short-term media access algorithm is provided to answer the question of delimiting short and long messages.