ARQ

ARQ is an acronym for Automatic Repeat-reQuest. Error control for data transmission in which the receiver detects transmission errors in a message and automatically requests a retransmission from the transmitter.

Note: Usually, when the transmitter receives the ARQ, the transmitter retransmits the message until it is either correctly received or the error persists beyond a predetermined number of retransmissions. Synonyms error-detecting-and-feedback system, repeat-request system.

Source: from Federal Standard 1037C and from MIL-STD-188