Simplex communication

Simplex communication refers to communication that occurs in one direction only. Two definitions have arisen over time: a common definition, which is used an ANSI standard and elsewhere, and an ITU-T definition.


 * ANSI definition: A "simplex circuit" is one where all signals can flow in only one direction. These systems are often employed in broadcast networks, where the receivers do not need to send any data back to the transmitter/broadcaster.


 * ITU-T definition: A "simplex circuit" is one where signals can flow in only one direction at a time. At other times signals can flow in the reverse direction. A more common term for this application is half-duplex.