ACP WG-F/19 WPxx

AERONAUTICAL COMMUNICATIONS PANEL (ACP)

NINETEENTH MEETING OF WORKING GROUP F

Bangkok, Thailand10 – 18December 2009

Agenda Item: 1.3 / The need for globally harmonized and protected frequency bands for UAS operation in non-segregated airspace

TITLE

(Presented by Eric Allaix)

SUMMARY
WRC-2011 has on its agenda the spectrum requirements for the safe and seamless integration of unmanned aircraft systems (UAS) in non segregated airspaces (Agenda Item 1.3 and WRC07 Resolution 421 refer).
ACTION
It is proposed :
- to take into consideration this proposal;
- that WGF approved this proposal in order to permit ICAO to contribute to the next ITU-R WP 5B meeting in May 2010 in the scope of WRC-12 preparation.

1Background

WRC-2011 has on its agenda the spectrum requirements for the safe and seamless integration of unmanned aircraft systems (UAS) in non segregated airspaces (Agenda Item 1.3 and WRC07 Resolution 421 refer). In order to make sure that UAS will meet the same safety and regularity of flight standards as that defined by ICAO for piloted aircraft this involves finding suitable spectrum for the following needed unmanned aircraft (UA) communications and functions:

  • command and control (C2) of the UA by its remote pilot ,
  • relay of ATC/ATS communications via the UA radio between the pilot and the ATC Officer
  • sense and avoid (S&A) neighbouring aircraft and terrain.

2Issue

To set the context for the WRC preparatory work on going within ITU this paper first reviews the current operating constraints under which a military or a State aircraft can be authorized to access non-segregated airspace . This authorization is only granted on an ad-hoc basis, subject to approval from that State’s civil aviation authorities, thereby limited to that country’s airspace. Such a scheme can hardly be generalised globally to permit UAS to fly internationally. This is the main reason why WRC07 adopted this Resolution 421 and endorsed the Agenda Item 1.3 of WRC-2011.

The draft ICAO Position to the WRC11 on this specific agenda item , currently under development and about to be released to ITU this year , states :Spectrum for UAS for safety and regularity of flight, and in particular when the UAS operates in civil airspace, needs to be accommodated under an allocation to the aeronautical mobile (R) service(AM(R)S), aeronautical mobile satellite (R) service(AMS(R)S), or the Aeronautical Radionavigation service(ARNS), in order to receive the sufficient status and protection from harmful interference

In accordance with ICAO standards and recommended practises (SARPS), the aircraft airworthiness and certification process regarding flight safety communications requires the use of protected frequency bands as recognized by ITU and also, of globally harmonized spectrum to ensure world wide inter-operability..

Among the UAS community some stake-holders advocate the alternative use of unprotected spectrum, arguing that interference mitigation measures such as radio equipment redundancy and interference protection hardening techniques, initially developed for military purposes, can be implemented in practice to ensure the high level of communication performance and integrity suitable to meet the safety objectives of WRC11 Agenda Item 1.3.

Besides being costly in terms spectrum resources, such an alternative requires an ad-hoc certification process by a State civil aviation authority with validity restricted to its national airspace. As a prerequisite that authority would need a thorough analysis of potential interference risks of both accidental and malicious nature associated with the use of non protected spectrum. And those risks would need to be assessed as to their critical impact on aeronautical safety and appropriate mitigation measures taken to meet the ICAO-defined target level of safety.

Furthermore by not adhering to the ICAO standards and regulatory framework - whose purpose is to allow ICAO contracting States to mutually recognize aircraft certification and operation approval granted nationally in each one of them - UAS access to non segregated airspace internationally could only be granted on an ad-hoc national basis. As such this access would then be limited to those countries’ airspace for which an UAS operator would have first obtained authorizations to fly through, following individual requests filed for each one of those. In the long run such an approach could be most detrimental to UAS industries and operators’ interests.

3Conclusion

Spectrum allocations for UAS, excluding payload, should be of the type AM(R)S and AMS(R)S.

4Action to be taken

WGF is invited to contribute to the next WP5B meeting (May 2010) on this subject in order to give more explanation on the necessary allocation to safety and regularity of flight allocations (AM(R)S and AMS(R)S allocations) to answer to WRC-12 A.I. 1.3 to support UAS operations, excluding payload.

______