An Energy-Efficient MAC Protocol for Underwater Wireless Acoustic Networks

Abstract

We propose a distributed, scalable, energy-efficient MAC protocol that works despite long, unknown propagation delays of the underwater acoustic medium. This protocol can be used for delay-tolerant applications such as underwater ecological sensor networks between energy-limited nodes. Our protocol differs significantly from ALOHA, MACA, and MACAW protocols in that energy is the main performance metric in our case rather than bandwidth utilization. It is shown that under a realistic underwater sensor network scenario, our proposed MAC protocol wastes only 3 percent of the transmit energy due to collisions, when an average number of 1-hop neighbors is 5, and the duty cycle is 0.004. This distributed, scalable MAC protocol has the potential to serve as a primer for the development of energy-efficient MAC protocols for future underwater sensor networks.

Analyzing the Performance of Multi-hop Underwater Acoustic Sensor Networks

“…MAC Design efforts for UANs cover the spectrum of techniques employed by wireless networks, to include channel allocation [1,8], carrier-sense techniques using duty cycles [11], adaptive reservation-based protocols [12], and topologyaware protocols [13]. Each of these designs seems to offer certain advantages for specific UAN issues.…”

R-MAC: An Energy-Efficient MAC Protocol for Underwater Sensor Networks

“…A random access based MAC protocol for underwater sensor networks is proposed in [12]. Due to the fundamental limitation of random access, this protocol only works well for the networks with very low and evenly distributed traffic.…”

“…Contention-based protocols includes random access methods [1,11,12] and collision avoidance methods [7,3,5]. In a random access protocol, the sender sends packets without coordination.…”

A comparative performance evaluation of MAC protocols for underwater sensor networks

“…A different approach to channel access was proposed in [5]. This solution is strictly tied to a sleeping schedule, which is optimized for minimal energy consumption and does not consider bandwidth utilization or access delay as objectives.…”