Nº 1 2012 > Maritime
The maritime mobile service and safety systems for ships and ports
Frequency and Spectrum Management, Technical Manager, Directorate of Airspace Policy
The maritime industry is a global transporter of the goods of modern globalized economies. It has to take account of the interests of all who use the sea — for commercial, leisure or government purposes — in a manner that ensures the safety of all. The industry is regulated by the International Maritime Organization, which is the United Nations specialized agency responsible for the safety, security and efficiency of shipping and the prevention of maritime pollution.
According to a 2008 estimate, commercial shipping transported about 80 per cent of all international trade, carrying more than 7.7 billion tonnes of goods. And it contributed USD 380 billion to the global economy — equivalent to about 5 per cent of total world trade.
Mobile communications are key to the success of the maritime industry because they provide the medium by which maritime safety information, ship position reporting and weather forecasts, as well as other information, can be passed to ships at sea. For a vessel in trouble, the accuracy and update rate of the reporting of the ship’s position aids rescue, potentially avoiding the loss of the ship, saving the lives of the crew or preventing an environmental disaster.
Agenda items 1.9 and 1.10 are crucial for the maritime industry, including leisure craft, in enhancing the current maritime communication capabilities in a manner that enhances safety and security as well as increasing efficiency. Without a successful conclusion to these agenda items, the continuing efforts of the maritime industry to update its systems and react to new requirements, such as the need to enhance ship and port security, will be hampered.
Allowing new technologies for safety communications
Agenda item 1.9 addresses the use of the HF bands, which ships have traditionally employed extensively for long-distance safety and general communications, using Morse telegraphy, radio telex and radio telephony. The introduction of the Global Maritime Distress and Safety System (GMDSS) removed the dependence on Morse telegraphy by introducing a standard radio telex system known as narrow-band direct-printing.
The spectrum needs of the maritime mobile service in the HF bands are based on the introduction of new data exchange technologies as an alternative standard for radio telex, which is in rapid decline.
The International Maritime Organization has noted that narrow-band direct-printing is now used for the broadcasting of maritime safety information, ship reporting, weather forecasts and for business communications, for example by fishing fleets. Narrow-band direct-printing remains part of the International Convention for the Safety of Life at Sea (SOLAS) requirements for GMDSS for vessels sailing in sea areas that are beyond the range of MF and VHF coastal stations.
From a technical standpoint, all these functions could be provided by alternative data communication technologies. But some administrations continue to use narrow-band direct-printing, not only for maritime safety information operations but also for public services. Also, narrow-band direct-printing is the only GMDSS-recognized system for providing maritime safety information to ships that are out of sight of coastal stations.
Within the maritime mobile service, agenda item 1.9 provides an opportunity to improve the utility of the allocated spectrum by allowing new more efficient digital technologies to use certain parts of the spectrum addressed by Appendix 17 of the Radio Regulations.
As stated above, narrow-band direct-printing remains a SOLAS carriage requirement, together with the possibility of using Inmarsat satellite systems. It remains an option for distress communications, in particular in the polar regions where there is no coverage from geostationary satellites. This functionality could be preserved using the HF distress and safety frequencies listed in Appendix 15 of the Radio Regulations.
Radio telex is an old and limited system, and is now rarely supported by coast stations around the world. At WRC‑03, changes were made to the Radio Regulations that enabled the initial testing and possible future introduction of new digital technologies in the maritime mobile service covered by Appendix 17. These new digital technologies are becoming widely used.
How can the maritime industry implement new digital technologies, while protecting existing applications? Taking the following steps would allow the maritime industry to enter a new era of communications:
- reducing the current frequencies identified for narrow-band direct-printing use to core bands, which will include the GMDSS distress and safety requirement plus some other channels, in order to support current usage and to preclude the use of other technologies in these core bands;
- releasing, after a transition period, the narrow-band direct-printing frequencies not included in the core bands for use by new exchange technologies, while allowing administrations that choose to use these bands for narrow-band direct-printing to continue to do so without claiming protection or causing interference;
- releasing the frequency bands designated for facsimile, wideband telegraphy and Morse telegraphy so that these bands can be used for digitally modulated emissions, while allowing administrations that choose to use the bands for facsimile, wideband telegraphy and Morse telegraphy to continue to do so without claiming protection or causing interference;
- keeping the frequency bands designated for duplex radiotelephony (under Appendix 25 of the Radio Regulations), and allowing stations to use digitally modulated data emissions in the radiotelephony bands, in accordance with the Appendix 25 allotment Plan;
- avoiding interference between digital and analogue technologies, to ensure the smooth introduction of digital data technologies through various regulatory measures.
Harmonizing the spectrum for safety communications
Agenda item 1.10 addresses the maritime communication requirements to support safety systems for ships and port operations in the global context of trying to ensure the safe and efficient operation of global shipping. In addressing agenda item 1.10, work has focused on the harmonization of maritime spectrum in the following four primary areas:
- protection in the Radio Regulations for the spectrum used by the automatic information system, because two of these frequencies are used to ensure navigational safety, vessel traffic management in congested ports, and vessel tracking;
- use of two additional automatic information system frequencies for improved satellite detection and tracking of vessels, to enhance maritime safety and security;
- harmonization of the maritime mobile service in the frequency band 415 kHz to 526.5 kHz for enhanced data rate transmissions for maritime safety information, future eNav applications, and security broadcasts;
- harmonization under Appendix 18 of the Radio Regulations (156 MHz to 162 MHz) of a band for VHF digital services, using advanced data transmission techniques for enhanced port operations, and additional simplex channels from existing duplex channel pairs.
The International Maritime Organization requires that implementing an automatic information system improves the safety of navigation by assisting in the efficient navigation of ships, protection of the environment, and operation of vessel traffic services. This is to be achieved by satisfying the following functional requirements: a ship-to-ship mode for collision avoidance; a means for littoral States to obtain information about a ship and its cargo; and a vessel traffic services tool for ship-to-shore traffic management.
Although these functional requirements clearly specify safety and surveillance functions, the Radio Regulations only recognize the automatic identification system-search and rescue transponder operation as having a safety function. Modifying the Radio Regulations to reflect the true use of automatic information system frequencies is critical to search and rescue, safety of navigation, and the safe movement and tracking of vessels, which are all vital to the future of maritime safety.
Studies within ITU in response to WRC‑12 agenda item 1.10 have identified a number of VHF channels in Appendix 18 which can be used for improved satellite detection of automatic information systems. Additionally, as a result of these studies changes have been made to Recommendation ITU–R M.1371 in order to introduce a new message 27 dedicated to the satellite detection of automatic information system messages. Modifying the Radio Regulations to reflect the satellite monitoring of vessels equipped with automatic information systems is critical to search and rescue, safety of navigation, and the safe movement and tracking of vessels. Specifically, 156.775 MHz (Appendix 18 Channel 75) and 156.875 MHz (Appendix 18 Channel 76) for improved satellite detection of automatic information systems using message 27 are proposed for WRC‑12 adoption.
Article 33 of the Radio Regulations describes the operational procedures for maritime emergency and safety communications, including the transmission of maritime safety information. It is vital for the maritime community to have a globally harmonized primary allocation to the maritime mobile service in 415—526.5 kHz for maritime safety information, security related broadcasts, eNav applications, and data communication systems.
Recommendation ITU–R M.1842‑1 provides examples of potential VHF data exchange systems and recommends the use of Appendix 18 channels to support future digital technologies in the maritime mobile service. Expansion of optional simplex use of duplex channels in Appendix 18 will provide further benefits to maritime radiocommunications by relieving current congestion in the VHF maritime mobile bands, in accordance with Recommendation ITU–R M.1084‑4. Report ITU–R M.2010‑1, a study on efficiency in the VHF maritime mobile band, concluded that this spectrum efficiency option expands the number of usable communication channels with the minimum of compatibility problems. The analogue VHF radio on board vessels that travel internationally would have access to both the original two-frequency channels and their single-frequency derivatives, thus allowing port operations on two or single frequency channels.