FINAL REPORT - Stakeholders - Ofcom

potential band sharing services. Improved spectrum utilisation characteristics should be a
standardisation objective. Standardisation could be carried out by industry bodies such as
EUROCAE for technical standards or by EUROCONTROL for operational standards.
Global aspects would require the involvement of ICAO. It is considered that increased
standardisation would achieve operational benefits as well as spectrum utilisation benefits.
8.1.2 Secondary radar
The two frequencies 1030 MHz and 1090 MHz are key to any consideration of secondary
radar. The principal developments which will influence the use of these frequencies include
the transfer to Mode S from current SSR and the implementation of ADS-B services using
1090 MHz with a resulting possibility that congestion may occur. It is therefore necessary
to ensure that the tailoring of SSR Pulse Repetition Frequencies conforms to ICAO
recommendations. The implementation of Mode S SSR in the UK should be encouraged
(allowing selective addressing and potentially fewer replies) coupled with the
implementation of measures to encourage hardware roll out and the implementation of
controller tools which use the resulting data.
With respect to Mode S Extended Squitter implementation it has been proposed that
Ofcom should work with the CAA in ensuring that data downlinked from the aircraft is not
superfluous to requirements. In particular this would mean reviewing the need for regular
broadcast of DAPs.
The 1090MHz channel will be severely constrained in the medium term. A review of the
future use of this band should be carried out. The review should ensure that any new
applications meet clearly defined operational requirements; if not, studies should be
performed to assess the potential benefit against the cost to an already saturated channel.
The studies should also assess the timescales over which the applications will remain
effective given that increase in traffic will further saturate the channel. Crucially, it should
be ensured that introduction of new applications do not impact on existing safety of life
applications such as SSR and ACAS. Other technologies for ADS-B should also be
evaluated to ensure that spectrum efficient solutions are developed and implemented. In
addition the possibility of further utilising 1030MHz (for example, for TIS-B) should be
encouraged and studied.
8.1.3 Aeronautical Radio-Navigation Services
The timely decommissioning of aged radio navigation aids which become surplus to
requirements has been identified as an issue, in particular, NDBs and VORs. However the
operational requirements of the affected players and the capability of envisaged
replacement systems must be assessed particularly from a safety and security viewpoint.
Furthermore, in the interests of spectrum efficiency it may be opportune to conduct a study
concerning the rationalisation of DME spectrum, in particular addressing the long-term
spectrum requirements for DME. This would include an investigation into the feasibility and
practical implications of de-pairing VOR, DME and ILS frequencies and de-tripling
ILS/MLS/DME assignments. The possible effects of UAT (ADS-B datalink) on DME
frequencies should also be studied.
8.2 Maritime Radiodetermination
A notable outcome of this study is the reaffirmation that the 5 GHz band is little used by
(commercial) maritime radar in and around the UK. It is already shared with PMSE
applications and HiperLAN. Further sharing of this spectrum with other suitably compatible
services may be feasible and could be investigated. On the basis that some of the
technological advances developed for aeronautical radar may find their way to the maritime
sector a reduction in the allocations to maritime radar at 3, 5 and 9 GHz might be
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