Editing Data link (section)

==Aviation==
In civil [[aviation]], a data-link system (known as [[Controller Pilot Data Link Communications]]) is used to send information between aircraft and [[air traffic control]]lers for example when an aircraft is too far from the ATC to make voice radio communication and [[radar]] observations possible. Such systems are used for aircraft crossing the [[Atlantic]], [[Pacific]] and [[Indian Ocean|Indian]] oceans. One such system, used by [[Nav Canada]] and [[NATS Holdings|NATS]] over the North Atlantic, uses a five-digit data link sequence number confirmed between air traffic control and the pilots of the aircraft before the aircraft proceeds to cross the ocean. This system uses the aircraft's [[flight management computer]] to send location, speed and altitude information about the aircraft to the ATC. ATC can then send messages to the aircraft regarding any necessary change of course. 

In [[unmanned aircraft]], land vehicles, boats, and spacecraft, a two-way ([[full-duplex]] or [[half-duplex]]) data-link is used to send [[control system|control signals]], and to receive [[telemetry]].