International Civil Aviation Organization
ACP WG-F/28 WP15
AERONAUTICAL COMMUNICATIONS PANEL (ACP)
28th MEETING OF WORKING GROUP F
Lima, Peru 12-22 March 2013
Agenda Item 6:
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.
1.
INTRODUCTION
1.1
One of the items considered at the ICAO ACP WG-F/26 meeting in March 2012 was use
of systems operating under fixed satellite service (FSS) allocations to support unmanned aircraft system
(UAS) control and non-payload communications (CNPC) links. The item caused considerable discussion
in conjunction with development of the ICAO position for agenda item 1.5 of WRC-15 including the
associated Resolution 153 (WRC-12).
1.2
The ITU-R has determined that 34 MHz and 56 MHz of spectrum would be required for
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the terrestrial 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.
1.3
WRC-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 in non-segregated
airspace. Such satellites could be used to address both near and far-term UAS requirements.
2.
DISCUSSION
2.1
The “resolves” of Resolution 153 associated with agenda item 1.5, WRC-15 states, “to
consider, based on the results of ITU-R studies referred to invites 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 considering e).”
2.2
Appendix D of the ACP WG-F/26 meeting report reflects the discussion. It includes the
statement of certain “conditions” which should be met in fulfilling the objectives of this agenda item.
These were developed during this last meeting of ACP WG-F.
2.3
Working 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. WP4A is providing support for this work. Studies and regulatory work have been initiated including
responses to the “ICAO Conditions”. The Annex 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 Kaband (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 indicate that commercial Ku/Ka band FSS satellites can support UAS
control links and meet the desired link availability.
3.
ACTION BY THE MEETING
3.1
It is proposed that the meeting support the development of the studies and regulations for
agenda item 1.5, WRC-15, 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, which will be addressing the issue at their meeting in
May 2013.
3.2
The meeting is asked to provide guidance on how the required material should be
reflected in: ICAO SARPS; ITU Radio Regulations/Recommendations/Resolutions; other documents.
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ANNEX
1
INTRODUCTION
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 Resolution 153 (WRC12). The resolves of this 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)
which set forth eight 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
operator/aviation authority contract specifications. Further information can be found in the associated
document,” Types of information to be Considered in Control and Non-payload Communications of UAS
to Ensure Safe Operation in the Non-Segmented Air Space” (ACP-WGF28 WP14)
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 a recently drafted ICAO position on agenda item 1.5, ICAO WG-F
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.
2.1
ICAO 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;
UAS CNPC links in specified frequency bands not establishing priority in the Radio Regulations
over any station operating in a primary service allocated to these bands, including stations
operating in the fixed-satellite service, nor establish priority in relation to other communication
links within the fixed-satellite service;
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
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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.
2.2
ICAO 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.
2.3
ICAO Condition: That the assignments and use of the relevant frequency bands have to be
consistent with 4.10 of the Radio Regulations.
No. 4.10 of the RR provides that “special consideration” must be given to frequencies being used for safe
operation. 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 operator based on guidance from
aviation authorities.
2.4
ICAO Condition: Knowledge that any assignment operating in those frequency bands has been
successfully coordinated under Article 9 of the Radio Regulations (e.g. any caveats placed on that
assignment have been addressed and resolved).
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 levels as
a consequence of coordination would not be suitable for UAS CNPC communications. 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. Provision
for such operation would be incorporated into agreed specifications between FSS and UAS operators with
guidance from aviation authorities.
2.5
ICAO Condition: That all assignments used by satellite systems for the provision of UAS
CNPC links are registered with favourable findings in the Master International Frequency
Register (MIFR).
This is a condition that typically FSS satellite operators seek to meet before offering any type of service.
This status is public knowledge through indication in the ITU Radiocommunication Bureau (BR) data
bases and can be easily verified, and/or specified/indicated in any arrangement to provide UAS CNPC
services. It is understood that ICAO in this condition was concerned about registrations of assignments
made under RR. No. 11.41. However, as long as the ICAO SARPs can be satisfied, such networks are
capable of providing safe operation. As example, Inmarsat provides existing AMS(R)S communications
under a registration filing made under No. 11.41. Any necessary considerations would be incorporated
into agreements/contracts between the FSS satellite and UAS operators based on guidance from aviation
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authorities.
2.6
ICAO 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. The
requirement for such reports could be incorporated into agreements/contracts between FSS satellite and
UAS operators based on guidance from aviation authorities.
2.7
ICAO Condition: That realistic worst case conditions with inclusion of a 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.
2.8
ICAO 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.
3.0
CONTROL OF UAS IN NON-SEGREGATED AIR SPACE
How would a satellite operator meeting the conditions above support UAS CNPC operation in nonsegregated 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 based on guidance from
aviation authorities. Such arrangements contain the details of the performance that must be provided in
order to avoid breach of contract. It is the details of these contracts which set forth the technical
conditions that ensure the safe operation of the UAS in the non-segregated air space. The details typically
included in contracts encompass availability requirements, redundancy, non-pre-emptive status, etc. They
can also include, for example, the type of special requirements indicated under # 2.3 above. As the UAS
CNPC capability is to be provided under contract/agreement between FSS and UAS operators with
guidance from aviation authorities, it is expected that the agreements/contracts will dictate the required
performance regime. If adequate performance is not available for such a service within an FSS network or
on specific FSS channels, it will not or 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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