The future air navigation system is an avionics system which provides direct data link communication between the pilot and the air traffic controller

The communication includes air traffic control clearances, pilot requests and position reporting.

FANS in the cockpit enable the flight crew to read and answer the controller pilot data link communication message received from the ground .

The traditional atc system uses analogue radio system for aircraft communications, navigation and surveillance

COMMUNICATION USING – ADS-B OUT  & ADS-B IN