Advances in Underwater Acoustic Networking

The field of underwater acoustic networking is growing rapidly thanks to the key role it plays in many military and commercial applications. Among these are disaster prevention, tactical surveillance, offshore exploration, pollution monitoring and oceanographic data collection. The underwater acoustic propagation channel presents formidable challenges, including slow propagation of acoustic waves, limited bandwidth, high and variable propagation delay. Furthermore, it is affected by fading, Doppler spread and multipath propagation. Therefore, efficient protocol design tailored for underwater acoustic sensor networks entails many challenges across different layers of the networking protocol stack. The objective of this chapter is to provide an overview of the recent advances in underwater acoustic communication and networking. We briefly describe the typical communication architecture of an underwater network followed by a discussion on the basics of underwater acoustic propagation and the state of the art in acoustic communication techniques at the physical layer. We then present an overview of the recent advances in protocol design at the medium access control and network layers as well as in cross-layer design. Finally, we provide a detailed discussion of the existing underwater acoustic platforms for experimental evaluation of underwater acoustic networks.