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ACP-WGF29WP 07
/
International Civil Aviation Organization /
ACP WG-F/29 WP07

Nairobi, Kenya September 2013

Agenda Item 7: / Development of material for ITU-R meetings

Operation of Unmanned Aircraft Systems Under a Fixed Satellite Service Allocation

(Presented by John Nelsen)

SUMMARY
This paper addresses the ICAO “conditions” contained in their position on WRC-15 agenda item 1.5.
ACTION
It is proposed that ICAO support WRC-15 agenda item 1.5 and the benefits offered from allowing UAS (non-payload) control links to operate using a fixed satellite service allocation if the necessary technical and regulatory provisions required for such operation are developed consistent with the ICAO conditions. This paper addresses each of those conditions and provides potential resolutions. The meeting is requested to consider each of those potential resolutions and concur or provide updates as appropriate.

1.INTRODUCTION

1.1One of the items under considerationby ICAO ACP WG-F has been use of systems operating under fixed satellite service (FSS) allocations to support unmanned aircraft system (UAS) control and non-payload communications (CNPC) links. At ICAO ACP WG-F/28 in March 2013, a draft ICAO position for agenda item 1.5 of WRC-15 including the associated Resolution 153 (WRC-12) was developed. This draft position was approved by the ICAO Council at its 27 May 2013 meeting.

1.2 The ITU-R has determined that 34 MHz and 56 MHz of spectrum would be required for theterrestrial and satellite components of the UAS CNPC, respectively. WRC-12 considered that UAS operating beyond line-of-sight (BLOS) could utilize the existing 5030-5091 MHz AMS(R)S allocation, however it must be recognized that no current or near-future satellite systems use that band or are planned to use that band. As a result, that band could not be used to support near-term UAS CNPC BLOS operations.

1.3WRC-15 agenda item 1.5 provides the basis for developing radio regulations for satellites in the fixed satellite service to be used to provide for the BLOS operation of UAS CNPC in non-segregated airspace. Such satellites could be used to address both near and far-term UAS CNPC requirements.

2.discussion

2.1The “resolves” of Resolution 153 associated with WRC-15 Agenda Item 1.5 states, “to consider, based on the results of ITU-R studies referred to ininvites ITU-R below, the possible regulatory actions to support the use of FSS frequency bands for the UAS CNPC links, as mentioned in the above considerings, ensuring the safe operation of UAS CNPC links, consistent with recognizing e).”

2.2The ACP WG-F/27 & 28 meeting reports reflect the meeting discussion on that topic. The result was the statement of certain “conditions” which should be met in fulfilling the objectives of this agenda item.

2.3Working Party 5B is the lead ITU-R group for developing the related Conference Preparatory(CPM) text based on the indicated studies and development of the necessary regulations. WP-4A is providing support for this work. Studies and regulatory work have been initiated including responses to the “ICAO Conditions”. The Annex to this paper describes how ITU-R Working Parties are responding to these conditions.

2.4 Existing commercial FSS systems at Ku and Ka-band offer immediate access to spectrum to support UAS. Specifically, various segments of the FSS Ku-band (10.95 – 14.5 GHz) and FSS Ka-band (17.30 – 31.0 GHz) are suitable for UAS CNPC links. Furthermore, initial technical studies by the ITU-R in WP-5B and WP-4A indicatethat commercial Ku/Ka band FSS satellites can support UAS control links and meet the desired link availability.

3.ACTion by the meeting

3.1It is proposed that the meeting support the development of the studies and regulations for WRC-15 Agenda Item 1.5 and in particular review the proposed responses contained in the Annex addressing each of the ICAO conditions and determine if additional material is required. This material could then be input to ITU-R Working Party 4A and Working Party 5B, as appropriate, which will be addressing the issue at their meetings in September and November 2013, respectively.

3.2The meeting is asked to provide guidance on how the required material should be reflected in: ICAO SARPS; ITU Radio Regulations/Recommendations/Resolutions; other documents.

ANNEX

1.INTRODUCTION

WRC-15 Agenda Item 1.5 is to consider the use of frequency bands allocated to the fixed satellite service (FSS) not subject to Appendices 30, 30A and 30B for control and non-payload communications (CNPC) of unmanned aircraft systems (UAS) in non-segregated airspace in accordance with Resolution153 (WRC-12). The resolves of that Resolution call for studies regarding the regulatory actions to support such an application. This annex initiates consideration of the necessary regulatory requirements. It benefits from the recent meeting of ICAO Aeronautical Communications Panel (ACP) Working Group-F (WG-F)/28, March 2013, which set forth conditions which would need to be met for FSS CNPC of UAS in non-segregated airspace. This annex proposes how these conditions can be satisfied, including where appropriate through aviation authority certification of the UAS CNPC service as satisfying ICAO Standards and Recommended Practices (SARPS).

2.Civil Aviation Conditions

The ICAO ACP WG-F is the body within that organization which develops draft ICAO positions on WRC agenda items. As part of the most recently drafted ICAO position on agenda item 1.5, ICAO WG-F/28 included a set of conditions which would need to be met by any satellite system supporting UAS CNPC. Demonstration of how those conditions could be met by FSS providers would support a positive outcome for agenda item 1.5. A description of those conditions is provided in the sections below along with a description as to how they would be met by the FSS.

2.1ICAO Condition: The technical and regulatory actions should be limited to the case of UAS using satellites, as studied, and not set a precedent that puts other aeronautical safety services at risk.

Several unique radio regulatory provisions are expected to be developed for the FSS bands where UAS CNPC application would be provided. These would include a footnote allowing use of FSS by UAS aircraft earth stations, describing the characteristics of service necessary to ensure safe operation, and pointing to a Resolution which provides additional requirements. The Resolution would include resolves covering for example the following:

  • Identification of frequency bands in Nos. 5.DN and 5.UP that may be used by GSO FSS networks for CNPC, provided that they meet the technical requirements contained in an Annex to the Resolution ;
  • Frequency bands to be used by UA and UACS stations limited to UAS CNPC links;
  • Transmissions in the UAS CNPC link as comprising UAS telecommand and telemetry data, sense and avoid data from the UA to the associated UACS, and relay of voice communication between the air traffic control (ATC) and the UACS.

These provisions would be limited to UAS CNPC and would only become applicable when such an application was provided.

2.2ICAO Condition: All frequency bands which carry aeronautical safety communications need to be clearly identified in the Radio Regulations.

Footnotes and associated regulatory provisions will be indicated in the allocations only for specific frequency bands to enable their use to support UAS CNPC applications. It is understood that such use must be certified in accordance with ICAO procedures as meeting ICAO SARPS.

2.3ICAO Condition: That the assignments and use of the relevant frequency bands have to be consistent with 4.10 of the Radio Regulations which recognizes that safety services require special measures to ensure their freedom from harmful interference .

No. 4.10 of the RR provides that special consideration must be given to frequencies being used for safety services. It is expected that appropriate special considerations from an operational stand point will be specified by ICAO (see # 2.8 below), and that these would be reflected in their standards and recommended practices (SARPs). These SARPs, as well as additional considerations as necessary would be incorporated into agreed specifications between the satellite and UAS operators. If the required performance criteria cannot be met, the system will not be certified by the requisite aviation authorities for use.

2.4ICAO Condition: Knowledge that any assignment operating in those frequency bands:

- is in conformity with the technical criteria of the Radio Regulations.

- Has been successfully co-ordinated including cases where co-ordination was not completed but the ITU examination of probability of harmful interference resulted in a favourable finding or any caveats placed on that assignment have been addressed and resolved such that the assignment is able to satisfy the requirements to provide BLOS communications for UAS;

- and has been recorded in the International Master Frequency Register.

In practice the coordination agreements between satellite operators would spell out any specifics as regards the use of frequencies on a particular satellite network, and would impact any satellite/UAS operator agreement. FSS networks or channels which could not meet the necessary performance levelsas a consequence of coordination would not be suitable for UAS CNPC communications and would not be certified by requisite aviation authorities for such use. The ITU is conservative in determining coordination requirements under Article 9. In practice, satellites that have not completed coordination may nonetheless be fully capable of providing safe services which are fully compliant with ICAO SARPs applicable in conjunction with providing UAS CNPC services. (As example, Inmarsat provides existing AMS(R)S communications under a registration filing made under No. 11.41.) Provisions for operation would be incorporated into agreed specifications between FSS and UAS operators and subject to certification for UAS CNPC use by requisite aviation authorities.

2.5ICAO Condition: That interference to systems is reported in a transparent manner and addressed in the appropriate time-scale.

Rapid interference resolution is in the general interest of each satellite operator. Unless interference is of the nature to be reported under Article 15 of the RR there is no day to day reporting mechanism for interference. WP 4A indicates there have been very few reports of harmful interference. However, a regular update on the state of interference could be included in reports to aviation authorities. ICAO SARPS could impose reporting requirements beyond those in the RR. Such ICAO requirements could be incorporated into agreements/contracts between FSS satellite and UAS operators and be a condition of certification for UAS CNPC use by requisite aviation authorities.

2.6ICAO Condition: That realistic worst case conditions, including an appropriate safety margin, can be applied during compatibility studies.

It is understood that studies being conducted already take this condition into account. In particular, sharing studies for FSS CNPC are being performed exactly as they are currently done for AMS(R)S as described in WP-18 to the 27th meeting of WG-F. Such conditions could also be taken into account for future studies of other uses of bands identified for UAS CNPC.

2.7ICAO Condition: That any operational considerations for UAS will be handled in ICAO and not in the ITU.

It is expected that ITU and ICAO will carry out their mutual responsibilities in a cooperative manner, just as they have in areas involving the provision of AMS(R)S. It is important that the respective roles of ICAO and the ITU be fully understood to ensure appropriate separation of regulatory needs to be addressed in the RR and operational issues to be addressed by ICAO processes.

3.0Control of UAS in Non-Segregated Air Space

How would a satellite operator meeting the conditions above support UAS CNPC operation in non-segregated air space? The specific nature of the service being provided to a user is dependent on the contractual arrangement between the satellite network operator and the UAS user, and the terms of that contract would need to be certified for UAS CNPC use by requisite aviation authorities. The performance specifications encompass availability requirements, redundancy, non-pre-emptive status, etc., and these contracts set forth the technical conditions that ensure the safe operation of the UAS in the non-segregated air space If adequate performance is not available for such a service within an FSS network or on specific FSS channels to be certified by the requisite aviation authority,it cannot be provided on those networks/channels.

4.0 SUMMARY

The sections above describe how the ICAO ACP WG-F conditions could be met by the FSS to support UAS CNPC applications. With proper codification of the actions indicated it is expected that the FSS can support the safe operation of such applications.

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