Toward Automatic Subsea Operations Using Real-Time Underwater Optical Wireless Sensor Networks

Abstract

Automatic subsea operations using real-time underwater optical wireless sensor networks are mooted as a new paradigm of underwater Internet of Things in this paper. To this end, we develop an underwater optical wireless sensor network prototype called AquaE-net, which consists of an optical hub and two sensor nodes with temperature, salinity, conductivity, and pH sensing capabilities. Clock synchronization is realized in AquaEnet, which paves the way for future underwater positioning and navigation. Moreover, real-time and bi-directional network communication with 100% packet success rates has been realized by AquaE-net in free space and turbid water in the harbor of the Red Sea at King Abdullah University of Science and Technology. This is the first step toward future effective marine environmental monitoring and marine resources exploration.

Reinforcement Learning-Based Adaptive Switching Scheme for Hybrid Optical-Acoustic AUV Mobile Network

“…Obtain the channel estimation Xtjt using the relation in (24). 8: end if Feedback Stage 9: if τ = 1 then 10:…”

“…By networking a swarm of AUVs equipped with both optical and acoustic communication systems, such a hybrid network enables high-bandwidth and low-latency underwater video transmission and real-time underwater operation and control [9,22]. However, implementing such a network is not trivial as the associated challenges should be addressed carefully due to the limitations of the system, the hostile environments, as well as the mobility of AUVs [23,24]. Among them, one critical issue is to maximize the hybrid network throughput by exploiting the complementary communicating technologies in terms of both acoustic and optical, especially the optical waves, as UWOC suffers from limited communication range [23].…”

Current Trend in Optical Internet of Underwater Things

“…However, there are only a few theoretical and simulation studies on UWOC network implementation [120]- [122]. In [16], the first opticalbased UWSN prototype, named AquaE-net (as shown in Fig. 9(c)), was developed, which consists of an optical hub, two sensor nodes, and a real-time monitoring software platform for shore-based stations.…”

“…(b) A hybrid solar cell system to achieve optimal energy harvesting and signal detection [14]. (c) The first optical based underwater wireless sensor network prototype [16]. (d) Real-time digital video surveillance prototype [17].…”

“…In this case, solar cells with dual functions of signal acquisition and energy harvesting have been proposed as detectors in UWOC systems [11], [13]- [15]. To further promote the implementation of IoUT, underwater optical wireless sensor networks, and UWOC-based 2K real digital video surveillance have been studied experimentally [16], [17]. This review is structured as follows: Section 2 presents the comparison between underwater acoustic, RF, and optical communication technologies in IoUT and introduces the research progress of optical wireless communications and channel studies.…”