Editing Automatic repeat request (section)

==Examples==
The [[Transmission Control Protocol]] uses a variant of [[Go-Back-N ARQ]] to ensure reliable transmission of data over the [[Internet Protocol]], which does not provide guaranteed delivery of packets; with Selective Acknowledgement (SACK), it uses [[Selective Repeat ARQ]].

[[IEEE 802.11]] wireless networking uses ARQ retransmissions at the data-link layer.<ref>{{cite web |url=https://warpproject.org/trac/wiki/802.11/MAC/Lower/Retransmissions |title=802.11 Reference Design: Recovery Procedures and Retransmit Limits |access-date=2020-07-21}}</ref>

[[ITU-T G.hn]] uses [[Hybrid automatic repeat request|hybrid ARQ]], a mixture of high-rate [[forward error correction]] (FEC) and ARQ. It is a high-speed [[local area network]] standard that can operate at data rates up to 1&nbsp;Gbit/s over existing home wiring ([[Power line communication|power lines]], phone lines and [[Ethernet over coax|coaxial cables]]). G.hn uses [[CRC-32C]] for Error Detection, [[Low-density parity-check code|LDPC]] for FEC and selective repeat for ARQ.

ARQ systems are widely used on shortwave radio to ensure reliable delivery of data such as for telegrams.  These systems came in forms called [[ARQ-E]] and [[ARQ-M]], which also included the ability to multiplex two or four channels.

A number of patents exist for the use of ARQ in live video contribution environments. In these high throughput environments negative acknowledgements are used to drive down overheads.