The Sound of Communication in Underwater Acoustic Sensor Networks

Abstract

Abstract. The interdisciplinary understanding required for the design and analysis of underwater acoustic sensor networks presents formidable constraints and challenges for computer scientists and engineers. However, underwater environments have never been much of a constraint to the rich animal life they support at all depths of our seas and oceans. Indeed, it is known that nature has taken advantage of this environment to develop a rich variety of efficient communication strategies throughout the long history of evolutionary change and adaptation. The wealth of knowledge to be discovered will continue to dazzle and fascinate the world. For the communications in underwater sensor networks, acoustic signaling is the preferred choice for designers because sound propagation is the most efficient when compared to other forms, like thermal, light, and electromagnetic. It is within this acoustic environment that researchers have to innovate and develop new ideas and methodologies so as to advance the state-of-the-art. In this position paper, several fundamental issues and connections are discussed that arise in the study of underwater wireless sensor networks. Throughout the nature of the underwater environment is emphasized how one can take advantage of it. A variety of ideas and solutions that could be of value for further research is proposed. Moreover, fundamental issues in topology control, directional underwater transducers, and monitoring and surveillance are discussed.

A Directional Selective Power Routing Protocol for the Internet of Underwater Things

“…e depth of water is another factor that impacts the sound speed where it increases by the increase in water pressure. erefore, in deep underwater communications where the acoustic waves are required to travel for distances up to a few kilometers, the slow speed of sound results in huge propagation delays [3,12]. Hence, for time sensitive IoUT applications, optimized delivery techniques in the presence of such long delays are required.…”

“…e acoustic waves suffer from absorption loss that is directly affected by the imperfections of the water medium, the frequency used by acoustic transceivers, and the distance traveled by the acoustics signal. e absorption loss of both radio and optical waves is much higher than that for acoustic waves [12]. Moreover, the multipath propagation can severely affect the acoustic based communication in under water medium.…”

Overview of Underwater Communication Technology

“…This technology contributes to the underwater navigation and to obtain information. It is a technique that uses underwater sound propagation to navigate, communicate with or detect objects (such as submarines and mines) on or under the surface of the water by projecting sound and detecting the echoes from the objects [3]. However, the physical characteristics of the underwater environment, such as temperature, pressure, salinity, and water density give huge impact to the propagation of sonar waves underwater as these physical characteristics change drastically over the air-water interface.…”

“…The sound propagates in water at a higher speed than air propagation (about 1500 m/s in water compared to about 340 m/s in air), which makes sea water a favourable medium for the transmission of sound [5]. The propagation of sound underwater is affected by temperature, salinity, hydrostatic pressure and other factors, its speed in the ocean varies from 1450 to 1540 m/s [3]. Sound speed as a function of these three parameters became available in the 1920s.…”

Future Vision for Autonomous Ocean Observations

“…Underwater life has evolved sophisticated acoustics-based communications suited to their environmental conditions. Animal communication systems are a source of inspiration for new technology, and also a consideration in developing methods that do not conflict with or disrupt natural communications (Li et al, 2017;Barbeau et al, 2018;Sherlock et al, 2018).…”