5.10 Technical architecture, interdependencies and redundancy aspects

Service continuity requirements as well as interdependency aspects should be considered when designing the overall technical architecture of the complete system, i.e. all the facilities, installations and equipment enabling and supporting the remote aerodrome ATS, including the identification of redundancy needs. This would include the data transmission links between the aerodrome and the remote tower/facility, the number of cameras at the aerodrome (considering both the camera(s) used to provide the visual presentation image as well as the camera(s) used to provide the binocular functionality), the number of screens for the visual presentation, power supply needs, etc. Particularly the data transmission links would constitute a critical enabler as the visual surveillance system, aeronautical mobile service and surface movement control service voice communication, as well as monitoring and manoeuvring of systems/equipment on the aerodrome (e.g. camera management, aerodrome lights and navigation/landing systems) would rely on this communication link. Based on current best practices, it is recommended that the connection between the aerodrome and the remote facility is doubled and physically separated and that a third independent connection is used for backup/emergency radio purposes (unless the remote tower is situated close enough to the aerodrome so that this could be solved via standard fall-back solutions such as handheld radios with the sufficient radio coverage). When the ATS provider relies on third-party providers (e.g. network or telecom service providers), the requirements in Regulation (EU) 2017/373 [4] apply. As regards power supply needs, in case the remote tower facility is located away from the aerodrome (not located at an aerodrome), the power supply measures listed in Section 7.2.5.1 should be applied in an analogous manner. When ATS is provided to several aerodromes from one RTC/facility, the system architecture should be so designed to avoid interdependencies between the aerodromes/ATS units as far as practically possible. (Refer also to Sections 6.1.1 and 6.5.2, and Chapters 8 and 9.) As operations from an RTC brings interdependencies between the ATS provision to several aerodromes, Member States and competent authorities are advised to assess the acceptability of the level of interdependencies generated and take measures as deemed suitable. Those measures may include, but are not limited to: a requirement to have an aerodrome with independent ATS provision within a certain distance, an action on requirements for hours of service.