FINAL REPORT - Stakeholders - Ofcom

educed frequency allocation would therefore result in a response within that allocation.
However, if non UK licensed vessels were to interrogate the device on a frequency
outside any reduced allocation, it would have to respond on the interrogating frequency,
otherwise its function would be impaired and it would not show up on the radar. If the
device (in particular an RTE) were mounted on a vessel out at sea, this is unlikely to be a
problem to any other users of the spectrum as the range of such devices is limited. For a
RACON mounted on a coastal feature, the main direction of the responding beam would
be out to sea, and hence the amount of interference caused inland would be minimal.
From a technical and social perspective, it therefore seems highly possible to reduce the
amount of spectrum available to maritime radars with minimal impact. Such a reduction
could not be achieved using many of the current systems employed which are, due to the
low cost nature of their construction, struggling even to fit with the existing ITU mask.
However, the use of more modern techniques would allow better frequency control and
thus a reduction in the required bandwidth.
From an economic standpoint, radars are typically replaced every 8 to 10 years, meaning
that it can take up to 25 years overall before old technologies are fully phased out.
However a reduction in spectrum does not require new technologies to be installed
(though operators may take the opportunity to do so if other changes take place). Instead,
some radars would require re-tuning away from the frequencies which were being
reassigned for other uses. The proportion of radars so affected would depend on how
much of the frequency were re-allocated. The financial impact would also be less than a
complete change-out of technology. A new maritime (ship-borne) radar typically costs
between £1000 and £10000 depending on the level of sophistication (the lower range of
prices applies only to small radars intended for small ships and pleasure craft). Thus, it is
reasonable to assume that re-tuning a radar would not cost, on average, more than
£2500, and even this amount would seem relatively large.
The 3 GHz band (2900 – 3100 MHz) is currently 200 MHz wide. The typical 3dB emitted
bandwidth of maritime radar is up to 50 MHz. Assuming this as a worst case, reducing the
amount of spectrum by 50 MHz (25%) would appear reasonable. The number of ships
registered (and hence licensed) in the UK (including the Isle of Man which is also covered
by UK maritime licensing) is estimated to be 11,000 19 . Thus a reasonable estimate of the
cost of retrieval of 50 MHz of spectrum, assuming that some modifications were required
to all vessels operating in the 3 GHz band is £23 million. The actual figure for the 3 GHz
band is likely to be lower than this as it is less common in use than the 9 GHz band (for
which more than one radar may be fitted to any given vessel).
A similar proportion of the 9 GHz band (being wider at 300 MHz wide) would return 75
MHz for similar costs. The cost at 9 GHz is likely to be higher as it is a more popular
frequency range, however as the centre frequency most commonly employed is 9410
MHz, which is towards the top of the 300 MHz wide allocation, it may well be relatively
straightforward to recover spectrum at the lower end of the band, where fewer radars are
operating.
However, maritime radars are not the only users of the bands allocated to maritime radar.
All are shared with military users (and in the case of the 3 GHz band, with aeronautical
radars). Whilst it may be possible for maritime users to change their use of spectrum, the
19 The Isle of Man has 9,000 registered vessels. Data for the UK, not being in the top 20
countries for which data is published, is unknown but must be less than 8,000 (the
number registered to the country in 20 th place). Being a relatively major maritime nation
we have therefore assumed that the UK has 2,000 registered vessels making a total of
11,000.
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