GADSS (including GFT)
The safety of air transport is a continuing concern of the aeronautical community and spectrum management is a key component. For decades, thanks to radio frequencies, aircraft have kept track of their flight paths with or without visibility, avoided collisions, communicated with air traffic control and achieved three-dimensional aircraft location.
The needs of the airline industry are still considerable and after the disappearance of the Malaysia Airlines flight MH370, WRC-15 decided to assign a frequency band as a matter of urgency to satellite reception of broadcasts (ADS-B) from commercial aircraft so as to ensure around the clock global aircraft tracking. The Iridium Next satellites, programmed to launch between July 2016 and 2019, will carry dedicated receivers with this assigned frequency. The system will be able to locate a disabled aircraft anywhere in the world and will furthermore have the capacity to process aircraft location data to facilitate air traffic control.
This decision is part of a much more exhaustive project aiming to improve inflight aircraft tracking and safety. The International Civil Aviation Organization (ICAO) is currently working on the definition of a Global Aeronautical Distress and Safety System (GADSS). The objective is to secure precise and updated location of an aircraft as soon as possible once abnormal aircraft behaviour is detected. According to ICAO, GADSS will consist of a set of systems for locating and alerting before the accident happens. Various technologies are under scrutiny, each of which responds in part to requirements.
With this in view, Airbus is working on the concept of black boxes for ejection before the crash while Boeing is in favour of using existing non-specific commercial satellite links for real-time data flows. COSPAS SARSAT, the CNES-supported global alert system for the detection and location of emergency radio beacons, could also contribute to GADSS when an aircraft sends out a distress call.
On another point, all-weather landing facilities are still central to ensuring flight regularity and safety. Existing systems require costly ground infrastructure only available in major airports, but in future onboard systems (Enhanced Flight Vision System/EFVS) could be of assistance for landing on smaller airfields. One solution under consideration would involve assigning millimetre wave radars in the 32 GHz band to the aeronautical radionavigation service.
Bearing in mind aircraft ranges, global spectrum harmonisation is essential to satisfy this kind of requirement.
Proposal 1
ANFR will keep abreast of ICAO deliberations on GADSS operational concepts and will work in consultation with the French Directorate General for Civil Aviation (DGAC) to determine which of the various applications on offer could meet GADSS requirements. If necessary, the Agency will arrange to make new spectrum resources available.
Proposal 2
After having recommended EFVS recognition to ITU, the Agency will contribute to research on compatibility with 5G in the 32 GHz band to ensure the possibility of global EFVS implementation.
High altitude platform stations (HAPS) are a recent development in digital connectivity. These objects, which may be balloons or self-piloted drones, will be flying at altitudes between 20 and 50 km, which is twice the cruising altitude of commercial flights and situated above meteorological disturbances such as storms. With their payload of telecommunications equipment, HAPS could in the near future provide Internet access in areas with no terrestrial service, either because of their remoteness or in the aftermath of a natural disaster. Their advantage over a satellite constellation is that they are less expensive and yet provide good coverage and acceptable bandwidth.
The most newsworthy of the HAPS-based projects for connecting populations with poor Internet access is probably the Google initiative. This is Project Loon, for which Google has entered into a partnership with CNES. It will be a network of helium-filled stratospheric balloons, the first of which were launched in June 2013 in New Zealand.
France is also contributing to research on these platforms through a French government investment plan, (Programme d’investissement d’avenir (PIA)/Investing in the Future) developed by the Commissariat général à l’investissement. €17 million have been earmarked for the Thales Alenia Space Stratobus project.
The HAPS concept is not new, but the progress made on drones now makes the project feasible at a reasonable cost. Following these recent developments, the international community of spectrum management agencies must review their respective positions within ITU on the spectrum required to implement these new services.
Proposal 1
Concerning the HAPS concept itself, ANFR will consult French stakeholders developing such projects on whether the current international legal definition ("a station on an object at an altitude of 20 to 50 km and at a specified, nominal, fixed point relative to the Earth") still matches the technological and operational developments envisaged for these systems.
Proposal 2
ANFR will consult French stakeholders regarding spectrum required for payloads onboard HAPS so as to determine whether the frequency bands that have already been identified — as well as the related technical and regulatory conditions — will be sufficient and adequate. If not, the Agency will consider the possibility of identifying the 38-39.5 GHz band for use by HAPS.
Proposal 3
Regarding the frequencies needed for HAPS control and their movements in the airspace, ANFR will consider, in cooperation with the French General Directorate for Civil Aviation (DGAC), whether conclusions arrived at for drones are also applicable or if there is a need to draft specific measures for HAPS.
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