Underwater Internet of Things in Smart Ocean: System Architecture and Open Issues

The development of the smart ocean requires that various features of the ocean be explored and understood. The Underwater Internet of Things (UIoT), an extension of the Internet of Things (IoT) to the underwater environment, constitutes powerful technology for achieving the smart ocean. This article provides an overview of the UIoT with emphasis on current advances, future system architecture, applications, challenges, and open issues. The UIoT is enabled by the most recent developments in autonomous underwater vehicles, smart sensors, underwater communication technologies, and underwater routing protocols. In the coming years, the UIoT is expected to bridge diverse technologies for sensing the ocean, allowing it to become a smart network of interconnected underwater objects that has self-learning and intelligent computing capabilities. This article first provides a horizontal overview of the UIoT. Then, we present a five-layer system architecture for the future UIoT, which consists of a sensing, communication, networking, fusion, and application layer. Finally, we suggest the current challenges and the future UIoT research trends, in which cloud computing, fog computing, and artificial intelligence are combined.

I. Introduction

An increasing number of physical objects are rapidly being connected to the Internet, realizing the idea of the Internet of Things (IoT) [1], [2]. In recent years, the IoT has developed rapidly and enabled numerous applications with different characteristics in many fields, such as the smart home [3], [4], transportation [5], [6], healthcare [7], [8], industrial automation [9], [10], and emergency response [11], [12]. For human, the ocean not only has a large amount of oil, gas, and fish resources, but is also an important channel for the international trade and a potential energy resource, such as tidal energy and the kinetic energy of the ocean currents [13]–[15]. However, there remains a lack of intelligent and convenient applications for the ocean because of the complexity of the underwater environment and the expense of the underwater equipment. As an extension of the IoT in the underwater environment, the Underwater IoT is increasingly becoming a powerful technology for developing the smart ocean [16], [17]. Here, Underwater IoT is defined as UIoT that is a smart network with self-learning and intelligent computing capabilities. It can sense, monitor, and identify underwater objects by wired or wireless communication for building smart ocean.