FINAL REPORT - Stakeholders - Ofcom

interest to broadcasters and manufacturers alike but a UK and possibly Irish only solution
would probably not provide a sufficient market base to proceed with such a project.
There is also an argument for reducing MF and LF radiocommunications utilisation in the
near term in view of likely EMC problems with unintentional RF radiators, including wireline
electronic communications networks in the conurbations. Once optical fibre or fixed
wireless access to the home has become widely deployed such a policy, if adopted could
be reviewed.
Recommendation 6.2: Section 6.3 and sections 6.5, 6.6 and 6.7 below have
indicated a possibility for new technology or change of use within the foreseeable future.
However either option would benefit from a European market and harmonised frequency
bands to ease co-ordination difficulties and provide economies of scale for industry. It is
therefore recommended that the UK lobby for a CEPT DSI process for the band 30 kHz to
30 MHz within the CEPT ECC and the European Commission’s Radio Policy Committee,
as well as introducing relevant technical, operational, economic and regulatory issues
contained in this Report into the committee structure and decision making processes of
the relevant international bodies. The overall objective should be to continue to promote
innovation in the spectrum management process at the international level.
6.4 GMDSS in the United Kingdom
Before addressing maritime communications with respect to the services and
technologies found in specific bands, it is necessary to address the Global Maritime
Distress and Safety System (GMDSS) from a UK perspective. The GMDSS was first
introduced into the IMO’s SOLAS Convention in 1988; it is addressed in several places
throughout this Chapter because the regulatory and standardisation regime including
carriage requirements for SOLAS vessels is somewhat different to those which are
applicable to non SOLAS ships.
IMO’s recommended GMDSS configuration uses a combination of digital selective (DSC)
calling which uses telegraphy for automatic reception based on frequency shift keying. A
DSC transmission provides key details of the vessel in an emergency situation, its
geographical coordinates (entered manually or via a GPS interface) and the nature of the
difficulty. The system then switches to a voice channel for a further exchange of
information. Within the GMDSS, frequency pairs are used (see table 6-2 below), with one
frequency designated for DSC and the other for radiotelephony. MF and HF DSC use
radio Telex type signals (F1B) with a data rate of 100 Baud.
In the UK there are only VHF and MF DSC coast stations, for sea areas A1 and A2
respectively, the station locations and the range of coverage provided by these stations is
shown below. There are nine MF equipped coast stations, namely: Aberdeen, Clyde,
Falmouth, Holyhead, Humber, Milford Haven, Shetland, Stornoway and Tyne Tees. Sea
area A1 extends 30-50 nautical miles from the coast and sea area A2 extends to 150 -
250 nautical miles but excludes A1 designated areas. See table 6-1 and figure 6-3 below.
Area
Description
A1 - within range of
shore-based VHF
stations
A2 - within range of
shore-based MF
stations
A3 - within
Inmarsat satellite
range
Distance 40 - 90 km About 90 - 750 km 70º N to 70º S
latitude
Radio VHF MF
VHF
HF or Inmarsat
MF
VHF
A4 - other areas (i.e.
beyond Inmarsat
range)
North of 70º N or S of
70º S
HF
MF
VHF
Table 6-1 Description of Sea Areas and radio link characteristics
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