Internet of Maritime Things Platform for Remote Marine Water Quality Monitoring

In this article, we show the development and implementation of the Internet of Maritime Things (IoMT) platform that supports long-range and high-rate communication for remote and online marine water quality monitoring. We first develop the IoMT device and gateway that interwork with international standard Internet-of-Things (IoT) software platforms for universal utilization in the field of marine monitoring. The proposed IoMT device and gateway play a role similar to the IoT device and gateway on land, but it is optimized for marine use with consideration of the practical characteristics of using sensors in the ocean. Furthermore, to realize long-range and high-rate communication between marine sensors and a control center (CC) on land, an automatic beam adjustment system for directional antennas is developed. This enables the use of directional antennas, which can support long-range and high-rate communication by automatically adjusting the beam angle between the antennas while exchanging their control information, despite the antennas being shifted by undulation from the sea. Finally, we conduct real sea experiments to identify the performances of the proposed IoMT platform in various environments. The results show that the proposed IoMT platform can collect data from marine sensors as well as high definition camera video from distances of 25 and 40 km to the CC on land under one-hop and two-hop transmissions, respectively. These results indicate that the proposed IoMT platform provides at least twofold performance improvement in terms of communication coverage under a similar data rate condition, compared with existing commercial wireless networks (e.g., LTE in the ocean) not utilizing satellite communications.