ABSTRACT
Controller-Pilot Data Link Communication (CPDLC) is recognised as one of the enabling technologies of the future, improved CNS/ATMI environment. Anyone who has used High Frequency (HFq) radio communication in aviation or for any other purpose will recognise the shortcomings of the system. Its performance varies with the time of day, there is considerable background noise and reception fades and swells. In addition, in areas like the North Atlantic, where traffic is heavy, radio frequency congestion significantly hinders the transmission of operational data and adds to the other difficulties. Yet HF q is still the primary medium for Air Traffic Control communications in areas more than approximately 200 miles from the nearest Very High Frequency (VHFq) ground station. CPDLC, a communications method similar in principle to e-mail, represents a considerable improvement in quality of information transfer with enhanced message clarity and timeliness, and reductions in potential for errors.
