Aeronautical Communications Officers (ACO) are responsible for the provision of aeronautical communication services Communication Centers at different locations. The aeronautical communication services include aeronautical fixed services and aeronautical broadcasting services.
Aeronautical fixed service
An aeronautical fixed service (AFS) is a service between specified fixed points provided primarily for the safety of air navigation and for the regular, efficient and economical operation of air services. ("Air service" means any scheduled air service performed by aircraft for the public transport of passengers, mail or cargo.) The AFS is provided by voice and data networks, including AFTN.
However, any aeronautical radiocommunication between specified fixed points is a fixed service
Aeronautical broadcasting service
An Aeronautical Broadcasting Service (ABS) is a broadcasting service intended for the transmission of information relating to air navigation.