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CPG07(2006)23 Annex 3
Draft CEPT Brief on agenda item 1.6
Agenda item 1.6:to consider additional allocations for the aeronautical mobile (R) service in parts of the bands between 108MHz and 6GHz, in accordance with Resolution414(WRC03) and, to study current satellite frequency allocations, that will support the modernization of civil aviation telecommunication systems, taking into account Resolution415 (WRC03)
Issue
This agenda item covers the following issues:
1to investigate, as a first step, the bands currently available for use by aeronautical systems in the frequency range between 108MHz and 6GHz in order to determine whether additional allocations to the aeronautical mobile (R) service are required and can be accommodated in these bands without placing undue constraints to services to which the frequency bands are currently allocated;
2to further investigate, in case the first step above would not lead to satisfactory results, also the frequency bands currently not available for use by aeronautical systems, subject to not constraining the existing and planned use of such bands, taking account of existing use and future requirements in these bands;
3to investigate how to accommodate the requirements for aeronautical systems in the bands 112-117.975 MHz, 960-1164 MHz and 5030-5 150 MHz.5091-5150MHz.
4to examine the possibility of broadening the services and applications of the use of current satellite frequency allocations in order to allow the expansion of ICAO CNS/ATM systems that can also support other nonaeronautical telecommunication services;
5to take appropriate actions, based on the results of the examination specified under 4.
Preliminary CEPT position
Resolution 414 (WRC-2003)
To support aeronautical mobile (R) service primary allocations in the bands [1126-117.975 MHz], 960-[1164] MHz and [5030[10][5091] - 5150 MHz conditional on satisfactory compatibility verification with [non ICAO-standard deployed systems in service. ICAO will perform sharing studies with ICAO systems and will design the future AM(R)S system in order to be compatible with those ICAO systems. Studies have established the possibility to design new AM(R)S systems to achieve compatibility with existing ICAO systems using the above bands. Furthermore in order to avoid any new AM(R)S system non conforming to ICAO standard which may raise compatibility issue with ARNS it is proposed to limit the new allocation to ICAO systems only.Such use shall be limited to systems that operate in accordance with international aeronautical standards]
[Security has been considered as a non-safety service and a Aeronautical Mobile Service (AMS) allocation for aeronautical security transmissions is supported under this resolution.]
The bands[1126-117.975 MHz] and 960-[1164] MHz should be preferably used for long range applications and the band [5030[10][5091]-5150 MHzfor short range applicationsaround airport.
Sharing studies of current aeronautical bands [with non ICAO systems][have to be presented are on-going ] in order to determine their suitability for an AM(R)S and/or AMS allocations. Those studies shall take into account that:
[-the band 960 -977 MHz is allocated to the aeronautical radionavigation service and is required for navigational purposes;
- not all system operated in this band under the radionavigation service are subject to standard and recommended practices published in Annex10 to the convention on international civil aviation]
[-the band 5010-5030 MHz is allocated to RNSS and new AM(R)S and/or AMS shall not impose constrains on operations or deployment of the RNSS;
-the requirements of the MLS shall take precedence over other uses of the band 5 030-5 150 MHz.
- the band 5030-5091 MHz is required to satisfy the aeronautical radionavigation service (MLS).]
Resolution 415 (WRC-2003)
With respect to issues identified in Resolution 415 CEPT will, if required, support the development of an appropriate ITU-R Recommendation that would detail the necessary technical and operating parameters that should be observed when implementing satellite systems that carry aeronautical communication traffic, noting that non-aeronautical traffic may also be carried over the same system with a view of seeking early implementation benefits.
CEPT is not in a position under this agenda item to support proposals for new allocations to AMSS and CEPT considers that no change is necessary to the current provisions relating to aeronautical safety services applicable in L-band MSS spectrum. However CEPT supports, according to Resolution 415, studies on the possibility to broaden the services and applications which may use the current satellite frequency allocations in other bands.
Background
General
During the preparations for the WRC-2003, CPG/PT1 developed a proposal for a future agenda item concerning the additional allocations for Aeronautical Mobile(R) service [and associated security requirements] between 108MHz and 6 GHz. CPG brought this proposal to the WRC-2003, and as an outcome of the Conference Resolution 414 (WRC-2003) was adopted and the item was placed on the provisional agenda for the WRC-2007 under agenda item 1.6.
Under this same agenda item WRC-2007 has to study current satellite frequency allocations, that will support the modernization of civil aviation telecommunication systems, taking into account Resolution415 (WRC03).
Reason for the European proposal at WRC-2003 was (and still is) that a new system in the Aeronautical Mobile (R) Service (AM(R)S) and additional spectrum resource are required to be in place by 2010 in order to overcome expected shortage in spectrum for line-of-sight air-ground communications. This would require a decision by 2007 on the necessary allocations. ICAO is also considering frequency bands, already allocated to aeronautical services, for the introduction of new technologies to support air navigation, including airborne and ground surveillance applications.
Resolution414 (WRC03)
Resolution 414 (WRC-2003) concerns the ‘consideration of the frequency range between 108 MHz and 6 GHz for new aeronautical applications’. The resolution was drafted during WRC-2003 to combine the European (and CITEL) proposal concerning the additional allocation for AM(R)S and the US proposal to review spectrum requirements for new civil aviation systems related to the provision of ground-based navigation and safety communications in and around airports for aircraft on the ground, and consider allocations or regulatory provisions to accommodate such systems, particularly in the band 50915150MHz.
[Requirements for Unmanned Aerial Vehicles (UAV’s)
The use of UAV’s must be considered when designing the functionality of a future AM(R)S system.
The requirement in controlled civilian airspaces could be significant due to the fact that the aircraft are unmanned. This places additional and more strenuous constraints on the radio communication bearer(s) and systems used.
Following an analysis of the possible expected links the chart below was generated to show, for the controlled civilian airspaces, all the likely links.
]
Developments in other regions
A proposal from the US / CITEL is expected for a suitable radio regulatory provision in order to permit the operation of the Universal Access Transceiver (UAT) systems on the frequency 978 MHz.
The possible use of (aeronautical) fixed links on airports in the band 5091-5150 MHz, as suggested by the US, is not supported by Europe, because the general idea is that fixed links are already allowed to operate in other frequency bands and that this is sufficient.
Developments in Europe
In line with ICAO, in Europe the bands 112-117.975 MHz, 960–1164 MHz and 50915030–5150 MHz will be[were][are being]studied. Other bands that also will be studied are the VOR band (112-117.975 MHz) and portions of the band 5010–5030 MHz and the band 5030–5091 MHz (the core band for the Microwave Landing System (MLS)).
Time gap between 2008 and the implementation date of a new system
The current VHF radiotelephony system operating in the band 117.975-137 MHz is facing increasing difficulties in finding assignable frequencies particularly over central Europe. More and more the outcome of the annual EUROCONTROL / ICAO frequency Block Planning exercises is that, [inde spite of the ongoing] [despite of the ongoing due to the slow] implementation of the VHF 8.33 KHz spacing scheme, it fails to identify any available frequency for an ATC sector which urgently needs the assignment of a new frequency.
CEPT recognises the difficulties that aviation is facing by the transfer from a 25 kHz channel spacing to 8.33 kHz spacing. Nevertheless European radio administrations urge their national Civil Aviation Authorities to support a rapid implementation of 8.33 kHz to optimise the use of this frequency band. [The European Commission had issued Eurocontrol with a mandate to develop a draft implementing rule on reduced air-ground voice channel spacing.]
Some administrations are of the opinion that a decision for the complete implementation of 8.33 kHz in all classes of airspace in 2009 will likely postpone the point of saturation to 2015. In their view this should be sufficient. Some administrations are of the view that this will happen before 2015.
Furthermore, considering the typical timeframe it takes to develop a new aeronautical system (decision on technology, initiation of standards, validation of standards and adoption of standards),it can be expected that the initial implementation for such a system will not to take place before 2016 and a full implementation between 2020 and 2025. This implies that a solution supporting voice requirements for the time gap between 2008 and the implementation date for a significant deployment (at least 50 %) of the new system should be found and that such a gap solution mightalso need a new frequency allocation at WRC 2007.
The way to solve the imminent congestion problem in the VHF band in the transition period between now and when the new AM(R)S system becomes available in circa 2016 is under study in Europe. A number of programmes are underway that will provide temporary alleviation to the VHF communications band for the next decade. Initiatives include:
1) frequency optimisation of the legacy VHF band (from 25 kHz towards a 8.33 kHz channel
separation); and
2) improving Air Traffic Service exchange through Data Links.
The band 112-117.975 MHz (the VOR band)
The study conducted indicates that it could be feasible on a pure spectrum management point of view to release to stop using a part of the current ARNS band between 108 - 117.975 MHz for navigation purposes to provide extra spectrum for the VHF AM(R)S. The proposed shifting of system shall not place additional constrains to the broadcasting service in the band below 108 MHz.
[Taking into account operational and technical issues, it might be possible to move some existing VHF communications services into a part of the VHF navigation band (108 – 117.975 MHz) thus providing some relief for VHF communications congestion. For example, data link systems could be concentrated in the navigation band using the new allocation.]
In any case the existing and future frequency requirements for navigation (VOR and GBAS) systems and possible surveillance applications (VDL Mode 4) should be guaranteed.
In order to prevent additional constrains to the broadcasting service any new allocation in this Band shall be subject to Resolution 413.
Currently there is no non ICAO systems operating in the band.
The band 960-[1164] MHz (part of the DME band)
Editorial note: There where two proposals presented to the Toulouse meeting and a decision which proposal has to be accepted or worked on, has to be made at the next meeting of PT3.
[Proposal 1:
Due to current experience it seems that, systems using pulse signal are compatible with DME equipment and that studies on a potential AM(R)S system within the DME band 960-1164 MHz need to be conducted.
It has to be noted:
- that any additional allocation in the band 960-1215 MHz shall be carefully studied in order to protect, to the maximum extent possible, the spectrum for the use of the JTIDS-MIDS system,
[- that compatibility studies have also to be performed with one military tactical telecommunication system, standardised by NATO, and operating within part of the DME band under national frequency clearance agreement between military and civil aviation authorities,
- that the continuation of the operation of JTIDS/MIDS in Europe, as mentioned in the European Common Allocation Table, should be guaranteed,]
- that any additional allocation in the band 960-1215 MHz shall be carefully studied in order to protect to the maximum extent possible the spectrum for the use of the JTIDS/MIDS system, in order to allow continuation of its operation in Europe, as mentioned in the European Common Allocation Table.
Reasons:
To align the CEPT background with the military preliminary position for agenda item 1.6 expressed during the last FMSC PWG meeting (March 2006).
- that not all system operated in this band under the radionavigation service are subject to standard and recommended practices published in Annex10 to the convention on international civil aviation.
- that other systems, such as Universal Access Transceiver (UAT) are planned in this band
- the fact that the lower DME band (960-977 MHz) is not extensively used.]
[Proposal 2:
- Compatibility studies with ARNS (DME/TACAN)
Due to cCurrent experience it seemshows that, systems using pulse signals are compatible with DME/TACAN equipment and that studies on a potential AM(R)S system within the DME band 960-1164 MHz need to be conducted.On the strength of this experience, studies show that it is possible to design new AM(R)S system that will be compatible with current ARNS systems (DME/TACAN). Accordingly ICAO will be in a position to standardize a new AM(R)S system compatible with these systems. Furthermore in order to avoid any new AM(R)S system non conforming to ICAO standard which may raise compatibility issue with ARNS it is proposed to limit the new allocation to ICAO systems only.
- Compatibility with JTIDS/MIDS
No studies have been performed, and cannot be discussed in ITU-R. However, administrations having interest in this matter, have national frequency clearance agreement in place to ensure that any evolution of the use of the DME band will take into account the protection of the JTIDS/MIDS system.
It has to be noted:
[- that compatibility studies have also to be performed outside the ITU-R process with one military tactical telecommunication system, standardised by NATO, and operating within part of the DME band under national frequency clearance agreement between military and civil aviation authorities,
- that the continuation of the operation of JTIDS/MIDS in Europe, as mentioned in the European Common Allocation Table, should be guaranteed,]
- Compatibility with RNSS above 1164 MHz
The PDNR ITU-R M [] recommends a maximum tolerable aggregate interference level compatible with RNSS systems receivers protection. Accordingly, a hard limit of XXX is proposed to be implemented in the Radio Regulation for RNSS receiver protection.
- Compatibility with mobile service below 960 MHz
Studies have been performed to establish compatibility with mobile service systems operating below 960 MHz and lead to the conclusion that there is a need for regulatory provisions in order to ensure the required MS systems operating in the mobile service a protection such as AM(R)S EIRP mask, frequency guard band … This is the object of ongoing studies.
It has to be noted:
- that other systems, such as Universal Access Transceiver (UAT) are planned in this band
- the fact that the lower DME band (960-977 MHz) is not extensively used.]
[The band 5000-5010 MHz
To provide the necessary protection to the Radio Astronomy Service operating in the band 4990-5000 MHz the band 5000-5010 MHz will not be considered.
The band 5010-5030 MHz
The band 5010-5030 MHz is allocated on a primary basis to the Aeronautical Radionavigation Service (ARNS) and to the aeronautical mobile satellite (route) service (AMS(R)S), under 5.367, making AMS(R)S subject to RR 9.21.
The band 5010–5030 MHz is also allocated to the radionavigation-satellite service (space-to-Earth) (space-to- space) on a primary basis, with restrictions given in footnote 5.443B.]
Editorial note: there is a need for inclusion of text explaining the NOC for both bands
The band 5030-5091 MHz (the core band for MLS)
- Compatibility with ARNS (MLS)
The channelling requirement for MLS of 200 channels based on capacity studies made by ICAO are in ICAO Annex 10, Volume I, Chapter 3, 3.11.4.1.1. The channelling plan for 200 channels, spaced 300 kHz apart between 5030 and 5090.7 MHz, including the pairing with DME, is at Table A in Annex10, Volume I, Chapter 3.
As indicated in the following figure, each airport could be fitted with MLS which necessitates up to 2 MLS channels per runway. When there are for example 2 runways in a particular airport, we could meet up to 4 different MLS channels of 300 KHz. Considering that for the protection of the MLS, the spacing between 2 adjacent channels must be at least 600 KHz (2 channels), each active channel needs 1.5 MHz protection bandwidth. Therefore, in this example a maximum of 4x5=20 MLS channels is occupied by MLS for its protection. As a consequence, in the area of this airport, a spectrum of 54 MHz of the MLS core band (60-4x1.5MHz) could theoretically be used for ground AM(R)S applications.
- Compatibility with AMS(R)S
There is currently no AMS(R)S system operating in this band therefore no characteristics available to perform compatibility studies.
The band 5091-5150 MHz (the extension band for MLS)
- Compatibility with ARNS (MLS)
It may be possible to use the band 5091-5150 MHz for other services than ARNS, preferably aeronautical, provided that aircraft to be fitted with MLS are equipped with anFlight Management System (FMS) capable of soft-pairing and selecting all the Nav Aids frequencies used for that MLS approach and landing. As 5091-5150 MHz band could be also a candidate band for agenda item 1.5, a link between studies for Agenda 1.5 and those for Agenda 1.6 is therefore needed.
- Compatibility with AMS(R)S
There is currently no AMS(R)S system operating in this band therefore no characteristics available to perform compatibility studies.