Maritime Communications and Remote Voyage Monitoring

For ships at sea, communicating with other ships or even to land-based sites has always been a very difficult task. Around 1900, the installation of wireless communication equipment on ships began. This form of communication initially used radio waves in the MF (Medium Frequency) band. Ever since it has been undergoing various technological innovations. At present, in addition to typical terrestrial communication in the VHF band, satellite communication using microwaves is also possible. Further, these forms of data communication have replaced the telegraph and telephone. Even now, however, the speed and capacity of data communication are significantly less than that of the land-based data communication network. After reviewing the situation of maritime communication, this paper studies the data communication for autonomous navigation of ships that is currently in demand focusing on remote monitoring. It appears that few instances of obtaining verification through detailed on-board data related to real-time communication have previously been possible. That being the case, the authors posit that it is worthwhile to demonstrate the feasibility of obtaining relevant verification based on actual data via a university training vessel equipped with the latest data collection system - a system that is relatively unavailable even on new, large-scale merchant ships. Particularly for digital data, maritime communication remains mainly via relatively slow and expensive narrowband satellite transmission. Though speedier and more efficient data transfer is possible through the use of simple data compression, the costs for this mode are currently prohibitively high. It is posited that economical, speedy, and efficient data transfer via data compression will increasingly become economically available for more ships in the future.