Underwater optical wireless communications, networking, and localization: A survey

Abstract

Underwater wireless communications can be carried out through acoustic, radio frequency (RF), and optical waves. Compared to its bandwidth limited acoustic and RF counterparts, underwater optical wireless communications (UOWCs) can support higher data rates at low latency levels. However, severe aquatic channel conditions (e.g., absorption, scattering, turbulence, etc.) pose great challenges for UOWCs and significantly reduce the attainable communication ranges, which necessitates efficient networking and localization solutions. Therefore, we provide a comprehensive survey on the challenges, advances, and prospects of underwater optical wireless networks (UOWNs) from a layer by layer perspective which includes: 1) Potential network architectures; 2) Physical layer issues including propagation characteristics, channel modeling, and modulation techniques 3) Data link layer problems covering link configurations, link budgets, performance metrics, and multiple access schemes; 4) Network layer topics containing relaying techniques and potential routing algorithms; 5) Transport layer subjects such as connectivity, reliability, flow and congestion control; 6) Application layer goals and state-of-the-art UOWN applications, and 7) Localization and its impacts on UOWN layers. Finally, we outline the open research challenges and point out the future directions for underwater optical wireless communications, networking, and localization research.

A Software-Defined Opto-Acoustic Network Architecture for Internet of Underwater Things

“…To see the impacts of beamwidth and multifaceted IoUT nodes as a potential solution, let us consider an ad-hoc UON consisting of 50 nodes which are randomly distributed over a water volume of 500 m 3 . Following the Beer-Lambert channel model [2], Fig. 3a depicts the average E2E-Rate from IoUT nodes to a surface station located at the origin.…”

“…Unfortunately, the global positioning system (GPS) signals cannot propagate through the water due to the unique underwater channel characteristics. Noting that UAN localization literature is very well established, whereas recent UON localization schemes are designed based on either received signal strength (RSS) or time of arrival (ToA) based ranging techniques [2].…”

“…Nevertheless, 95% of the oceans are still unexplored because of the peculiarities of underwater communications, networking, and localization [2]. In this respect, IoUT significantly differs from its terrestrial counterpart (i.e., IoT) in almost every aspect of the network architecture design.…”

End-to-End Performance Analysis of Underwater Optical Wireless Relaying and Routing Techniques Under Location Uncertainty

“…Therefore, acoustic systems have received considerable attention in the past decades. As a result of the surface-induced pulse spread and frequency-dependent attenuation, acoustic communication data rates are restrained to around tens of kbps for ranges of a kilometer, and less than kbps for longer ranges [2]. Moreover, the low propagation speed of acoustic waves (1500 m/s) induces a high latency Authors are with Computer, Electrical, and Mathematical Sciences and Engineering Division at King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, KSA.…”

An Improved Accurate Solver for the Time-Dependent RTE in Underwater Optical Wireless Communications

“…With this permanent emphasis on researches in the marine medium, underwater wireless sensors network concept came on for enabling the concretization of several critical commercial and military applications and services [12]. In particular, wireless communication nodes such as wireless sensors, floating buoys, and submarines, require reliable links with higher data rates in order to fulfill communication requirements and exchange a relatively huge amount of data [13].…”