T-Lohi: A New Class of MAC Protocols for Underwater Acoustic Sensor Networks

Affan A. Syed, Wei Ye, and John Heidemann
USC/Information Sciences Institute

Abstract

This paper introduces T-Lohi, a new class of distributed and energy-efficient media-access protocols (MAC) for underwater acoustic sensor networks (UWSN). MAC design for UWSN faces significant challenges. For example, acoustic communication suffers from latencies five orders-of-magnitude larger than radio communication, so a naive CSMA MAC would require very long listen time resulting in low throughput and poor energy efficiency. In this paper, we first identify unique characteristics in underwater networking that may affect all MACs, such as space-time uncertainty and deafness conditions. We then develop T-Lohi employing a novel tone-based contention resolution mechanism that exploits space-time uncertainty and high latency to detect collisions and count contenders, achieving good throughput across all offered loads. Lohi uses our low-power wake-up receiver to significantly reduce energy consumption. Finally, we evaluate design choices and protocol performance through extensive simulation. The results show that the energy cost of packet transmission is within 3-9% of optimal, and that Lohi achieves good channel utilization, within 30% utilization of the theoretical maximum. We also show that Lohi is stable and fair under both low and very high offered loads.

Availability

This paper is available in several formats: abstract web page with pointers and cites, PDF, paper copies can be obtained by mail to the authors. Copyright terms for this paper appear below.

Reference

Syed08a
Affan A. Syed, Wei Ye, and John Heidemann. T-Lohi: A New Class of MAC Protocols for Underwater Acoustic Sensor Networks. In Proceedings of the IEEE Infocom, p. to appear. Phoenix, Arizona, USA, IEEE. April, 2008. <http://www.isi.edu/~johnh/PAPERS/Syed08a.html>.
@inproceedings{Syed08a,
	author = "Affan A. Syed and Wei Ye and John Heidemann",
	title = "{T-Lohi}: A New Class of {MAC} Protocols for
                         Underwater Acoustic Sensor Networks",
	booktitle = "Proceedings of the  {IEEE} Infocom",
	year = "2008",
	publisher = "{IEEE}",
	address = "Phoenix, Arizona, USA",
	month = "April",
	pages = "to appear",
	keywords = "Lohi, underwater MAC, acoustic networks",
	supporting = "The simulator used in this paper is available at
                         \url{http://www.isi.edu/ilense/software/}.",
	myorganization = "USC/Information Sciences Institute",
	copyrightholder = "{IEEE}",
	url = "http://www.isi.edu/~johnh/PAPERS/Syed08a.html",
	pdfurl = "http://www.isi.edu/~johnh/PAPERS/Syed08a.pdf",
}

Copyright

This paper is copyright © 2008 by IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.