ACP WGC6/WP26

AERONAUTICAL COMMUNICATIONS PANEL (ACP)

Working Group C – 6th meeting

Toulouse, France

20 – 24 October 2003

Agenda items 7: Assessment of spectrum requirements

Process for an AM(R)S allocation for new terrestrial system

Presented by EUROCONTROL

Prepared by Ch Pelmoine and Ph Renaud

SUMMARY

Aviation has been successful in requesting the ITU WRC 2003 to introduce an agenda item for additional radio band allocation at WRC 2007.

ANC 11 has identified the need to progress investigation of new communication systems operating outside VHF band.

Considering the limited timeframe in the ITU process, this paper is proposing a sharing of role and activities between WG C and WG F to achieve this objective in time for WRC 07.

1Capacity Shortcoming and ANC 11 Outcome

Despite the introduction of a new channelisation in Europe (8.33), the main mobile communication VHF- system currently used in Europe (i.e. VHF) is expected to reach again its capacity limits during the next decade due to the predicted traffic growth (please refer to the WGC WP “Evolution of the AM(R)S VHF capacity in the ECAC States”).

The need to investigate new communication systems operating outside the VHF band to provide extra capacity in some regions as well as capability to support new applications was recognised at the 11th ANC.

Recommendation 7/4 — Investigation of future technology alternatives for air-ground communications

That ICAO

a) investigate new terrestrial and satellite-based technologies, on the basis of their potential for ICAO standardization for aeronautical mobile communications use, taking into account the safety-critical standards of aviation and the associated cost issues;

b) [...] and

c) assess the needs for additional aeronautical spectrum to meet requirements for increased communications capacity and new applications, and assist States in securing appropriate additional allocations by the ITU.

ANC 11 recognised the need to progress investigation of terrestrial-based and of satellite-based systems.

For satellite systems an AMS(R)S allocation already exists in a band which is not extensively used for safety services and which has attractive merits (e.g. considerable past investments). It is proposed to concentrate current investigation on this allocation, and consider other allocations only in the case of extra capacity need or difficulty to operate in this band.

For terrestrial systems, the situation is different. There is no available AM(R)S extra capacity existing for hosting new technologies able to support traffic growth and efficiency improvement. Several organisations have undertaken action to assess systems operating in non current AM(R)S allocation.

2Opportunities behind the ITU WRC03 Decision

Anticipating the ANC11 recommendation, the aviation undertook a co-ordinated action at WRC 2003 to have the capabilities to develop new application and to cope with the present growing saturation of the AM(R)S VHF band at 118-137 MHz resulting in the request for additional spectrum.

As a result of this action WRC03 introduced in the agenda for WRC07 (see resolution [COM 7/6]) the following agenda item:

“consideration of the frequency range between 108 MHz and 6 GHz for new aeronautical applications”

Resolution [COM7/6] recommends to first investigate in the aviation bands; If not feasible, a second step would be to investigate the non aviation bands. Because of the pressure from the non-aviation users, it seems quite unlikely that aviation can rely to get an allocation outside its present “real estate”.

The process for ITU is a complex and short-term mechanism. The following table illustrates the timeframe for positively filling the WRC 07 agenda.

Anticipated task of ITU (SG8B, CPM) and regional groups (CEPT, …) / aviation input
Q1-Q2 2004 / Organising the work / Commitment on work programme
Q3-Q4 2004 / Allocation and compatibility discussion based on initial aviation spectrum requirement / Aviation short list of candidate bands, based on potential technologies and traffic scenarios
Q1-Q2 2005 / Analysis of potential allocation options with the aim of limiting their number / Aviation preferred options.
Initial compatibility studies
Q3-Q4 2005 / Focus studies on limited options. / Progress compatibility studies
Q1-Q2 2006 / Focus studies on limited options. (difficult compatibility issues are predicted) / Advanced compatibility studies
Q3-Q4 2006 / Selection of the (or very minimum number of) option(s) / The aviation preferred option
Greater chance of success if CPM can select the preferred aviation option
2007 / Decision to allocate or not at that conference an allocation. Possible further studies can be requested for the next cycle of 3 years / TOO LATE

As it can be seen, the process is very short. Non successful WRC07 would have the following impacts for aviation:

CONSEQUENCE OF A NEGATIVE DECISION BY WRC2007

The worst negative decision would be “no new AM(R)S allocation”. Such a decision would result in severe constraints, it would limit the aviation traffic development as well as the introduction of new services enabling ATM enhancement.

Another threat is to delay an AM(R)S new allocation to a further WRC (e.g. in 2010). Such a delay, although non-crucial at a first glance, would have also negative impact. Indeed, allocation of spectrum is not the end of a system development and implementation story. The hosting band (which has impact on airborne integration, coverage, propagation, compatibility, economy) has to be identified in the first step of the development. This means that an allocation postponed at WRC2010 would break down the dynamic movement which has been created and therefore delaying the complete process of more than 3 years.

The last but not least threat would be an allocation outside the aviation preferred-options, which could mean for example issue of cohabitation between existing services and the new one (e.g. refer to the decision to allocate RNNS in ARNS without completing the compatibility studies). This could result in reduction of the envisaged capacity (both for existing and new services), additional costs and more complex transition phases

In conclusion, it is important to not miss the WRC 07 and to provide the conference with the most appropriate convincing information. To achieve this goal, many technical, operational and economical studies have to be conducted in this very short timeframe.

Identification of the groups with the appropriate expertise to carry these studies is fundamental as well as a clear definition of their role and a good understanding of the objective and interdependencies of their tasks.

3Need for an Appropriate Aviation Organisation to comply with the ITU timeframe

The ICAO ACP is the essential leader of this process. Only the ICAO can avoid national or regional entities promoting different requirements and justifications for the new allocation.

It is essential also to integrate “spectrum” experts and “Communication System/Concept” experts and not just limit the actions in one of these groups of expertise.

ACP has these two magic groups. WG C in charge of the System and Concept for communication and WG F in charge of spectrum policy, strategy and spectrum requirement identification for aviation.

4Role of WG C and WG F in the new AM(R)S allocation process

This section is an attempt to describe the perception (by the authors) of the role of WG C and WG F in this business.

The expectation during the WG C 6 meeting is to:

  1. Refine the role of WG C and to propose a common work programme (with WG F), and also
  2. Provide a perception of the WG F role as well as the inter-relation between WG C – WG F tasks.

If accepted by the WG C, this refined document should be sent to WG F for a similar analysis and then be basis for a common work.

4.1Objective of this process

The objective of this common process is to provide the required justification at WRC 07 for a new AM(R)S spectrum allocation. It has to take into account the specific time frame of the ITU process which differs from the ICAO and industry standardisation timeframe which is expected to be longer.

It is therefore clear that an in-depth definition of applications and operational scenarios, investigation and selection of technologies, and standard development, although it would be ideal, is not realistic for WRC07 (and even in the time frame of WRC-10).

4.2Respective roles of ACP WG C and ACP WG F

ACP WG C

The ACP WGC must be the focal point for the establishment of the operational scenarios, the identification of the ATM services/applications and the resulting traffic of communication.

The WG C shall also identify a limited number of most appropriate technologies which are directly related to the band selection and are dimensioning for the quantity of spectrum to be required. Identification of the upper layer mechanisms is not relevant in this process. The signal form, including the modulation type is essential for spectrum capacity and radio compatibility.

Based on the proposals from ACP WG F, the WG C has to consider which spectrum allocation seems the most appropriate to comply with the identified scenario (considering issues such as coverage, propagation characteristics)

ACP WG F

The ACP WG F is the focal point for defining the spectrum requirement. It must identify all potential but feasible spectrum bands which could support AM(R)S allocation.

Based on evaluation of traffic and on the most appropriate technology(ies) as identified by ACP WG C, the WG F shall define a volume of spectrum in the band as reviewed by the WG C.

WG F shall then undertake all the appropriate actions to co-ordinate the aviation position for WRC07.

4.3Proposed Work programme for ACP WGC and WG F

There is also a need to define a common work programme to be progressed between ACP WG C and WG F.

A first example is provided in attachment 1and is proposed to be used as a basis of discussion during the ACP WG C 6 meeting.

5Recommendation

With the aim of maximising the chance for a new AM(R)S allocation at WRC07, WG C 6 is invited to:

  • Consider the proposal as described in this paper
  • and, if acceptable:
  • Review the WG C role,
  • Propose a common work programme,
  • Provide its perception of the WG F role and perceived work programme
  • Send these information to WG F for similar review

It is also recommended to create a common WG C / WG F drafting group to progress the work

Attachment 1

Basis of a Common work programme between WG C and WG F

# / Task / Date
1 / Scenarios
Identify the applications and traffic in typical geographical area – Note: to be consistent with the ANC11 7/4 recommendation, the future communication infrastructure is assumed to be composed of two main components (terrestrial and satellite-based). Therefore, although this analysis is considering AM(R)S, both technologies are considered supporting the ATM in a complementary / WG C / Mid 2004
2 / Transition, including timescales
The ITU will likely request a time-phased approach for allocating the spectrum capacity / End 2004
3 / Select a limited number (eg 3) of candidate bands
Among the band as proposed by WG F, select a limited number of options based on aspects such as coverage, propagation, radio compatibility, initial spectrum capacity computation) / WG C / WGF / Mid 2004
4 / Technology
Identification of a limited number of technology(ies) – the outcome will be limited to the major characteristics which have a significant impact on the spectrum to be required (e.g. CDMA Vs TDMA, typical bandwidth, typical modulation) / WG C / End 2004
5 / Communication Traffic
Evaluation of a typical traffic figures in the main areas / WG C / End 2004
6 / Final band identification
Consider the band(s) which are appropriate considering (e.g. compatibility with non aviation systems and other aviation systems, final spectrum capacity calculation) / WG C / WG F / Mid 2005
Endorsement of the preferred aviation band / ACP 1 / Mid 2005
7 / Bandwidth
Based on the previous outcome identify the spectrum bandwidth required to support the scenerio, traffic, and the limited number of identified technologies and a limited number of potential AM(R)S allocations / WG F / Mid 2005
8 / Promote position
Promote this position in the relevant spectrum groups / WG F

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