FINAL REPORT - Stakeholders - Ofcom

The demand for the L-Band GNSS frequencies will become increasingly widespread
throughout Europe as the reliance on GNSS for airborne navigation increases. Issues
surrounding the possible interference from ARNS (DMEs) in the 1164-1215MHz band
must be resolved in the near future. This is due to problems at high altitudes (when
several DME stations are visible to the antenna, the in-band signals increase), and this in
spite of directional antenna. Although the ITU has addressed the issue, there is an ongoing
discussion on the extent of the problem (the conclusion of which will be important,
as the introduction of the L5 band at 1176.45 MHz +/-12 MHz for GPS and the E5 band at
1188-1208MHz for Galileo will have an impact). WRC-03 established Resolutions 609 &
610 (WRC-03) and Recommendation 608 (WRC-03). Further solutions may include the
reallocation of the DMEs, or by the further limiting of the power flux density of either
system.
• From the perspective of the 1215-1300 MHz band, the situation is complicated.
The rights of existing ARNS (in the form of primary radars) are defended by
several parties. Whether this is valid, and if so how to protect ARNS, has
remained a matter for debate for 3-4 years.
Although limits have been successfully imposed in the lower L-band to protect DME, the
technology issues are different here – the military currently uses the GPS allocation inband
(GPS L2) for precise positioning services and it strongly defends the right to
maximum signal strength. As Galileo is introduced, a new band (E6) will be used; this falls
in the middle of the UK’s primary radar frequency pattern. Evidently, if E6 becomes a
prime civil signal carrier frequency, the effects on ARNS will become more prevalent than
is currently the case. The UK, through CAA, MoD and Ofcom, is currently looking at this
issue. ICAO is also preparing studies to resolve the debate. WRC-03 modified Radio
Regulation footnotes 5.329, 5.331 and established Resolutions 608 and 610 (WRC-03) in
relation to the use of the band 1215 – 1300 MHz.
The 1559-1626.5MHz allocations are strongly defended by the relevant aviation bodies
(e.g. ICAO); although 72 countries (Europe/Middle East) have established fixed services
allocated to this band (Footnotes 5.362B and 5.362C), the ITU agreed at WRC2000 that
the usability of GNSS was constrained by these fixed services, and as such, the
allocation should be ceased as soon as practicable. As a result, in many countries these
fixed services remain a primary allocation until 2005, and then become a secondary (noninterfering)
service until 2015, when they shall cease. Note that the UK is not included in
this footnote (i.e. no fixed services in this band) but neighbouring countries (i.e. France)
are.
From the Earth-space perspective, the allocation of 1300-1350 MHz to Galileo ground
stations is subject to studies in geographical separation criteria between the ground
stations and radio-navigation aids (primary radars) (WRC2000 – Resolution 607).
From the socio-economic point of view, there have been major investments in Galileo
(and EGNOS) by European organisations, agencies and companies – in order to justify
this, they will want to see solid returns. Political pressure is likely to be brought to ensure
that GNSS sees increasing demand.
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