###### Abstract  
For a long time, the development of maritime communication has been restricted by the low data rate, high-latency and high cost of the current communication systems. The upgrade of new generation mobile communication technologies is attracting more and more attention to conduct a shore-based broadband mobile communication network with high-latency and high reliability to serve the maritime industries. This paper presents a solution by means of building a ship-to-infrastructure (S2I) and a ship-to-ship (S2S) wireless communication networks for an offshore region. We characterize the S2I and S2S channels at 5.9 GHz band based on the channel measurements in realistic environments. The channel characteristics, including power delay profile, delay spread, propagation path loss, are extracted and analyzed. In view of the difference between marine and terrestrial communications, we analyze the influencing factors of the offshore water, including effective reflection, divergence and shadowing from the water surface, and diffraction loss caused by the earth curvature. We also predict the power coverage range and the channel capacity for S2I and S2S wireless communications. Finally, the communication performance is evaluated according to the channel measurement and characterization analysis. The research results can be a reference for the construction of maritime communication networks. shore-based maritime communications; channel measurement; maritime safety; performance evaluation +
Footnote †: journal: Marine Science and Engineering  
0000-0001-998-2271-0000/0003  
0000-0002-16-0000/0000-00001-998-2271-0000/0  
dustry and smart ocean, and the ever-growing maritime economy, a more reliable wireless communication system with a higher data rate and a low cost is required urgently for the frequent maritime activities. Conventional communication systems used in offshore waters mainly include maritime radio communication, maritime satellite communication, and shore-based mobile communication based on terrestrial cellular networks. The maritime radio communication systems are customarily operated in MF/HF/VHF bands with a short coverage and a low data rate [6; 7; 8]. The satellite communication system can provide wide data coverage for the global areas, while the large propagation delay and high implementation cost limit the usage in maritime communications [9; 10]. Compared to the above two communication systems, the development of the shore-based mobile communication system for offshore waters is lagging behind. However, the current maritime wireless communication systems are difficult to meet the demand for smart ocean construction. It is thus attracting more and more interest to build a network on the basis of terrestrial communications for the offshore waters, such as 4G-LTE and 5G [11; 12] communication technologies. In addition, the guarantee of maritime safety also depends on fluent wireless communication technology to some extent. In coastal areas, most ships transmit and receive data via wireless communications networks based on radio frequency (RF), long-term evolution (LTE). Based on the ship-to-ship and ship-to-shore communication technologies, ships can be monitored and controlled remotely and the vessel status information to prevent ship-related accidents can be shared with each other [13]. With the development of wireless communication technology, millimeter wave (mm-Wave) is used to construct the collision prevention system as well, which is expected to replace the automatic identification system with a low data transmission [14]. Furthermore, the construction of smart ocean, including Internet of Ships (IoS), maritime data management and analysis, safety and security considerations, smart ships, smart transportation, smart ports, all depend on a fast and reliable wireless communication network [15].