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

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-ofmagnitude 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 reservation mechanism that exploits space-time uncertainty and high latency to detect collisions and count contenders, achieving good throughput across all offered loads. It employs our low-power wake-up receiver to significantly reduce energy consumption. Finally, we evaluate design choices and protocol performance through extensive simulatio...

• Type: Conference
• Year: 2008
• Where: INFOCOM
• Authors: Affan A. Syed, Wei Ye, John S. Heidemann
• Keywords: Communications, Energy-efficient Media-access Protocols, INFOCOM 2008, Space-time Uncertainty, Underwater Acoustic Sensor