5.5. Communications

A remote tower facility used for the provision of aerodrome ATS, like a conventional tower facility, is required to enable ATCOs and AFISOs to perform voice/data link communication, as detailed below:

— Aeronautical mobile service (air-ground communications) in the area of responsibility, in accordance with relevant provisions of Regulation (EU) 2017/373 [4], Annex IV, Section 4.

— Aeronautical fixed service (ground-ground communications) in the area of responsibility, in accordance with relevant provisions of Regulation (EU) 2017/373 [4], Annex IV, Section 4.

In addition to the communication with the units and entities prescribed by Regulation (EU) 2017/373 [4] Annex IV Section 4 (as listed above), the remote tower infrastructure should also enable the ATCOs and the AFISOs to establish voice/data link communication with aerodrome personnel and/or any other entities as need be for the coordination and communication between the remote ATS unit and the aerodrome (and as documented in local agreements, see Section 5.1 and Chapter 7).

— Surface movement service (communications for the control of vehicles on manoeuvring areas at controlled^[27] aerodromes or for the management of vehicles and persons on the manoeuvring area at AFIS aerodromes) in the area of responsibility, in accordance with Regulation (EU) 2017/373 [4], ATS.OR.445.

‘Aeronautical mobile service’ and ‘surface movement service’ are typically established through the local radio equipment at the aerodrome. For remote aerodrome ATS, the RTC/RTM might need a dedicated connection (e.g. through WAN) to the local radio equipment at the aerodrome. This remote command of the aerodrome radio equipment might be subject to delays due to communication link latency. The maximum allowable delay should be determined by the local safety assessment, taking into account applicable standards and recommended practises (ICAO/EUROCAE^[28]) as well as the operational context, in order to ensure a timely communication between the ATCO/AFISO and aircraft and vehicles.

Also, for backup or emergency radio systems (refer to GM1 ATS.OR.400(a) to Regulation (EU) 2017/373 [4], a dedicated and independent backup connection between the aerodrome and the remote facility should be required. Standard fall-back solutions, such as handheld radios used in a conventional tower, may not be applicable in the remote tower scenario due to coverage limitations. Backup/emergency radios should also be installed in a different location than main radios.