Energy-Efficient Collision Avoidance MAC Protocols for Underwater Sensor Networks: Survey and Challenges

Abstract

The Medium Access Control (MAC) layer protocol is the most important part of any network, and is considered to be a fundamental protocol that aids in enhancing the performance of networks and communications. However, the MAC protocol’s design for underwater sensor networks (UWSNs) has introduced various challenges. This is due to long underwater acoustic propagation delay, high mobility, low available bandwidth, and high error probability. These unique acoustic channel characteristics make contention-based MAC protocols significantly more expensive than other protocol contentions. Therefore, re-transmission and collisions should effectively be managed at the MAC layer to decrease the energy cost and to enhance the network’s throughput. Consequently, handshake-based and random access-based MAC protocols do not perform as efficiently as their achieved performance in terrestrial networks. To tackle this complicated problem, this paper surveys the current collision-free MAC protocols proposed in the literature for UWSNs. We first review the unique characteristic of underwater sensor networks and its negative impact on the MAC layer. It is then followed by a discussion about the problem definition, challenges, and features associated with the design of MAC protocols in UWANs. Afterwards, currently available collision-free MAC design strategies in UWSNs are classified and investigated. The advantages and disadvantages of each design strategy along with the recent advances are then presented. Finally, we present a qualitative comparison of these strategies and also discuss some possible future directions.

A Study of Standardizing Frequencies Using Channel Raster for Underwater Wireless Acoustic Sensor Networks

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An Efficient Void Aware Framework for Enabling Internet of Underwater Things

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Performance Prediction of Underwater Acoustic Communications Based on Channel Impulse Responses

“…For the general communication system, it is often desirable to establish a relationship between channel characteristics and the receiver decoding performance; however, the complex UWA environment often makes this a challenging task. Reliable prediction of the UWA communication performance is an enabling technology for many useful methods and systems, including adaptive networking and adaptive modulation strategies [1,2], for both point-to-point communications and underwater sensor networks; please refer to [3,4] for corresponding system characteristics and challenges.…”