It is recognised that the current environment for maritime navigation is complicated and not well integrated. Navigation and communication systems are not generally designed to integrate with each other, making the mariner’s job more difficult. The International Maritime Organization (IMO) is seeking to harmonise maritime communications and navigation with the introduction of e-Navigation.
e-Navigation is expected to bring about the integration of existing systems and thereby facilitate more efficient voyages. It is foreseen that e-Navigation will provide new capabilities for both to ship operations and to shore operations. For ship operations e-Navigation will develop on-board navigation systems that benefit from the integration of the ship’s own sensors, supporting information, a standard user interface, and a comprehensive system for managing guard zones and alerts. Core technologies of such a system will include high integrity electronic positioning (e.g. multi-constellation GNSS with e-Loran), Electronic Navigation Charts (ENC) and an analysis capability to support decision making and reduce human error, actively engaging the mariner in the process of navigation while preventing distraction and overburdening.
On the shore side the management of vessel traffic and related services will be enhanced through better provision, co-ordination, and exchange of comprehensive data in formats that will be more easily understood and utilised by shore-based operators in support of vessel safety and efficiency. This is perceived as a major commercial benefit by port operators.
To facilitate the data transfer demanded of the e-Navigation applications, robust communication systems are required. It is therefore imperative that the requirements are derived and consolidated to ensure that the e-Navigation concept has the capability to deliver
what has been planned.
This article is based on a study of key, high level requirements for the communication systems that will be necessary to support e-Navigation applications and includes an initial assessment of candidate technologies against these requirements. The scope of the study, carried out by Helios, was the maritime network within the UK and the implementation and use of the e-Navigation communication infrastructure in the 2020 to 2030 timeframe. The applications assessed were those that best reflected the current and likely future status of e-Navigation within the defined timeframe, considering the IMO Strategy Implementation Plan (SIP).
The study considered both e-Navigation communications systems that were already under consideration by the General Lighthouse Authorities as well as other communication systems that could be available and deployed in the 2020-2030 timeframe.The candidate communication systems were assessed against their ability to support the user and performance requirements of each e-Navigation application in defined future usage scenarios. The high level requirements that were used to assess the communication systems included: capacity; coverage; availability, and confidentiality.
Future traffic scenarios for the Dover Strait and the North of Scotland were developed
to assess the number of vessels using each application, and hence the data demand on the communication systems. As might be expected, it was found that the Dover Strait would result in the greatest application data loads and therefore would be the main driver for developing the communication system requirements.
Key indicators used to assess each communication system were: the ratio of the average data load for an application against the maximum theoretical capacity of the system; and the time taken (or delay) for each system to serve peak application data loads.
It was found that the most data intense applications were the No Go Area and Telemedicine; requiring large amounts of bathymetric data to be sent and two-way video calls respectively. The least data intense applications were the Route Exchange and Vessel Operational Coordination Tool, where only position coordinates were required to be transferred.
Analysis found that when the VHF Data Exchange System (VDES) communication system reaches maturity it should provide significant advantages for a number of the applications, including the possibility of merging channels to cope with data rates required by the most demanding applications and providing coverage to regions otherwise unreachable by other technologies. It was also found that future developments in mobile telecommunications will provide faster data rates, capable of supporting greater data demand from vessel crews and passengers. However, the ground infra- structure for these technologies will be the limiting factor in providing coverage away from shore.
Based on the analysis, communication system(s) were selected that were considered to be the most suitable for supporting each e-Navigation application. The results can be seen in
the table (below).
Taking the results from this study, a number of conclusions were drawn relating to the communication systems available to e-Navigation. These were that: NAVDAT potentially provides a much better service than NAVTEX, but it does not provide the throughput that the more data intense applications could demand. VDES promises to be a good system for the more data intense applications, in particular if the satellite component of the system is fully realised.
The WiMax service has not taken off in spite of significant initial investment.The major provider within the UK plans to decommission its towers by the end of 2015. Therefore the LTE-Advanced option is now the main technology supporting 4G mobile data standards.
The latest developments in 4G/5G have helped with realising the full extent of personal communications and web access on board vessels.
Further developments in this field should focus on extended coverage, rather than capacity, to ensure the full benefits can be realised out to the current coverage of the 4G networks and beyond.
Digital VHF and HF, and the Inmarsat-C service, are designed for low data packages and rates. Therefore these systems are not suitable for e-Navigation applications requiring large amounts of data.