Proposal for Chapter 12: Radio Spectrum Allocation

AMCP WGC4/ WP6

AERONAUTICAL MOBILE COMMUNICATIONS PANEL

Working Group C

Fourth Meeting

Montreal, CANADA

27-30 May 2002

Agenda Item 4. Report to AMCP/8

Proposal for chapter 12: Radio Spectrum Allocation

Presented by Kors van den Boogaard (IATA)

Prepared by Alessandro Capretti and Kors van den Boogaard

1.  Introduction

WG-C, in its assessment of the future utilisation of the VHF communication system, concluded that taking into account the traffic growth and the introduction of new application, the present VHF allocation would not suffice in the long term. Already in some parts of the world it is expected that the VHF band will be saturated around 2010. Therefore, the meet the future air-ground communication need, the VHF com. system needs to be complemented with a system operating in another frequency band.

2. WG-C Action taken

Noting the long process toward a new spectrum allocation for Aeronautical Mobile safety service (AM(R)S) , WG-C requested WG-F to provide an inventory of potential bands which could be earmarked for AMS(R).

The reply from WG-F is incorporated in the proposed material for chapter 12 of the rpeort to AMCP/8 in the Attachment..

3. Recommendation

WG-C is requested to comment on the attachment and to agree on its inclusion in the report to AMCP/8.

Attachement

Proposed chapter 12.3 for report to AMCP/8

12.3 Radio Spectrum Allocation

12.3.1  Introduction

12.3.1.1 There will be an increasing demand for aeronautical mobile communication resulting from the increase of traffic and the implementation of new concepts and new services for ATM, airline operations and passenger services.

12.3.1.2 Most of the current safety air-ground information exchanges is carried out in the COM VHF band which will be saturated at least in some part of North America and Europe around 2010.

12.3.1.3 The cater to the expected communication need, the possibility for a mobile communication system operating outside the crowded VHF band has to be explored. Within this exploration the early identification of candidate spectrum bands where such a system could operate is essential.

12.3.1.4 Based on a set of assumped conditions which mainly concern the International Telecommunication Union (ITU) environment, candidate bands have been assessed on its potential to relieve the congestion of the VHF com. band.

12.3.2  Assumed conditions

12.3.2.1 The assumed conditions are in relation to the spectrum allocation process. It has to be noted that fulfilment of these conditions are in general outside the direct influence sphere of the civil aviation administration and require commitment from the national authorities responsible for the radio spectrum policy.

12.3.2.2 The following conditions apply:

·  Any future aeronautical system need to be accommodated under appropriate aeronautical allocations.

·  In principle, civil aviation will continue to require exclusive, world-wide allocations for critical radio services; however, considering the depletion of the non allocated useable radio spectrum, it is highly unlikely that the ITU could allocate any additional radio spectrum for exclusive aeronautical use in the future.

·  Where sharing with non-aeronautical services becomes unavoidable, it shall be ensured that enforceable regulatory pro-active measures to protect aeronautical allocations are in place.

·  Commercial interests will continue to pressure the ITU to gain access to existing aeronautical allocations. International aviation will increasingly require co-ordinated strategies and efforts to justify those allocations and when needed to obtain additional spectrum for aviation use.

·  When the bands considered are presently not allocated to the AM(R)S (or AMS(R)S), it is required to make the necessary changes to the ITU Radio Regulations to introduce such an allocation.

12.3.3. Spectrum Requirements

12.3.3.1 New aeronautical requirements for additional spectrum may be developed due to:

a)  requirements for new aeronautical radio navigation systems;

b)  requirements for new radio location systems;

c)  requirements for new aeronautical air/ground communication systems.

12.3.3.2 New spectrum requirements for aeronautical radio navigation systems are considered unlikely. At this moment no such requirements have been identified, even on a long-term basis. However, the introduction of systems used for aeronautical navigation purposes, are in principle belonging to the AM(R)S from a radio regulatory point of view (such as GNSS augmentation systems) and may require that existing Aeronautical Radio Navigation Service (ARNS) allocations be modified accordingly.

12.3.3.3 The long-term requirement for radio location systems will diminish with the increasing introduction of airborne dependent surveillance. The transfer from a radio location service to a communication service can only be accommodated with a partially transfer from the spectrum allocated for radio location to an expansion of the AM(R) S allocation.

12.3.3.4 The introduction of new VHF air/ground communication systems can only emerge provided sufficient capacity for introducing these systems is found in the VHF band (e.g. due to frequency assignment planning constraints). For a possible introduction of a more frequency efficient systems in a congested VHF band, the access to a relatively small band (of the order of 10 MHz) might provide the necessary capacity.

12.3.3.5 The development of wide-band data transmissions will provide aviation with the opportunity to introduce new applications to improve security, safety and efficiency. In this case new frequency bands in the order of 30-50 MHz may be necessary.

12.4 Review of potential candidate aeronautical bands

·  74.8 - 75.2 MHz This band might become available for future systems in case marker beacons would be phased out. Due to limited bandwidth, this band is not considered useful for development of a global communications system.

·  108 – 118.000 MHz Not to be considered consideration, as aviation is already looking for an additional allocation to support GBAS and VDL Mode 4.

·  328.6 - 335.4 MHz Global use of Glidepath equipment is expected to continue for the foreseeable future, particularly for higher Category ILS (CAT III). The bandwidth is limited. When significant reduction in ILS requirements can be foreseen, e.g. due to increased use of MLS or GNSS for final approach and landing, this band could be a serious candidate for AM(R)S use. Particularly for air-ground data communications, to accommodate overflow requirements that cannot be met in the VHF band.

·  960 - 1215 MHz : Services currently supported in this band are expected to continue well beyond 2010. Many difficulties are already foreseen in accommodating the RNSS use introduced by WRC-2000, which makes this band an unlikely candidate despite favorable propagation characteristics. Nevertheless, the band could be considered to accommodate overflow requirements that cannot be met in the VHF band.

·  1 545 - 1 555 MHz, 1 646.5 - 1656.5 MHz : These bands, previously exclusively allocated to the AMS(R)S, have been reduced to generic MSS allocations by previous WRCs, with provisions for priority use by aviation. Current AMSS SARPs compliant systems operate in these bands. No AM(R)S allocation exists, however there are signs that due to the lower than expected market for MSS , communication providers are seeking a partly reallocation of the band to terrestrial services. There might be benefits to aviation to follow this trend.

·  1670-1675 MHz, 1800-1805 MHz: (Only for Europe?) These bands are presently allocated to a non safety terrestrial aeronautical service i.e. the terrestrial flight telephone system.(TFTS). Systems standards are in place and systems have been installed. The lack of a mature business case for this service caused the system operation to seize and the band is under consideration to be reallocated. In case this band has the potential to obtain a safety allocation it might be an appropriate candidate.

·  2 700 - 2 900 MHz Not to be considered viable due to the number of ground based radars operating worldwide.

·  4 200 - 4 400 MHz Not being considered consideration due to requirements for radio altimeters.

·  5 030 - 5 250 MHz This band appears to have the best potential for a future aeronautical communications service. However, due to relatively high propagation losses, this band is less suitable to conventional long-range services using nominal powers available on aircraft (alternative uses include terminal area applications or data-only communications). Furthermore, appropriate regulatory provisions would need to be introduced to enable safe use of this band for aeronautical communications.

Within this band, three sub bands can be identified:

-  The 5 030 - 5 091 MHz sub band is the current MLS band and needs to be reserved for MLS

-  The band 5 091 – 5 150 MHz (“MLS extension” band). Subject to the requirement to maintain its availability for extended MLS use (under review by WRC-2003), this band could be used for digital air/ground communication systems. Introduction of the AM(R)S would most likely need to ensure protection of the current use by the fixed-satellite service (feeder links for non-geostationary orbit systems).

-  The 5 150 – 5 250 MHz sub band is used by the fixed-satellite service and by the mobile service for a variety of licensed and non-licensed applications, so that there is very little scope for the originally intended ARNS use of the band. This band is also under review by WRC-2003, to introduce regulatory measures to protect the FSS from the MS. Only non-safety-related use of this band should be considered.

12.5 Review of potential non-aeronautical candidate bands.

12.5.1 Introduction of aeronautical systems in bands below 10 GHz that are not currently allocated to aeronautical services is unlikely, due to the heavy use of these bands by a variety of radio services.

12.5.2. The use of spectrum above 10 GHz needs to be considered in the light of the prevailing propagation conditions. In particular, bands above 30 GHz suffer from excessive attenuation. It is noted however that bands around 13, 15 and 30 GHz are used for aeronautical radionavigation (radar) and that the 14 GHz band is considered for (non-safety) aeronautical mobile satellite systems. An inventory of the uses of these bands, with a view to assessing availability under acceptable sharing conditions is required.

12.5.3. It should also be noted that various bands above 10 GHz are allocate to generic radionavigation or mobile services. These bands are therefore potentially available for use by aeronautical systems (terrestrial or satellite-based as applicable).

12.6 Conclusion

12.6.1 Concluding, it would seem that under present and expected future conditions, the 5 GHz band would be the most likely candidate to support a new aeronautical communication service. Furthermore, WGC should consider the technical feasibility of using bands above 10 GHz in light of the prevailing propagation conditions and of the associated system design constraints.

12.6.2  To relieve the anticipated congestion in the VHF band, a partly reallocation of the 1/5/1/6 GHz should be considered from the bands in which presently AMS(R)S and the TFTS operates. For the longer term, when aviation is fully relying on MLS and GNSS for its precision approach, the Glide Slope band might be a suitable candidate.

12.6.3  Although aviation should also look for additional spectrum outside the bands allocated to aviation, the basic aviation requirements for safety services and global allocation might be difficult to meet in bands allocated for non-safety services..

12.6.4  It should be noted that any proposal to change or obtain radio spectrum allocations will have a lead time of at least six years, hence aviation has to decide as soon as possible on the appropriate band.