In telecommunication a data link is the means of connecting one location to another for the purpose of transmitting and receiving information. It can also refer to a set of electronics assemblies, consisting of a transmitter and a receiver (two pieces of data terminal equipment) and the interconnecting data telecommunication circuit. These are governed by a link protocol enabling digital data to be transferred from a data source to a data sink.
There are at least three types of basic data-link configurations that can be conceived of and used:
- Simplex communications, most commonly meaning all communications in one direction only.
- Half-duplex communications, meaning communications in both directions, but not both ways simultaneously.
- Duplex communications, communications in both directions simultaneously.
In civil aviation, a data-link system (known as Controller Pilot Data Link Communications) is used to send information between aircraft and air traffic controllers 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 and Pacific oceans. One such system, used by NavCanada and 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 military aviation, a data-link may also carry weapons targeting information or information to help warplanes land on aircraft carriers.
... A Tactical Data Link (TDL) uses a data link standard in order to provide communication via radio waves or cable used by the U.S ... TDL to transmit, relay and receive tactical data ...
... several sets of communication protocols emerged to fill the gaps between the data-link layer and the application layer of the OSI reference model ... It is at the data-link layer, though, that most modern LANs diverge from the Internet ... Asynchronous Transfer Mode (ATM) or Multiprotocol Label Switching (MPLS) are typical data-link protocols for larger networks such as WANs Ethernet and Token Ring are typical data-li ...
... JREAP BACN Multifunction Advanced Data Link Tactical Common Data Link Inter/Intra Flight Data Link (IFDL) ISMART MANDRIL SIMPLE ...
... Controller–pilot data link communication (CPDLC) is a means of communication between controller and pilot, using data link for ATC communication ... An auxiliary capability is provided to allow a ground system to use data link to forward a CPDLC message to another ground system ... Closure of the dialogue does not necessarily terminate the link, since there can be several dialogues between controller and pilot while an aircraft transits the ATSU airspace ...
Famous quotes containing the words link and/or data:
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—Paula C. Lowe (20th century)
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—Susan Sontag (b. 1933)