olemus
tagasisidestatud veaparandus:
saate kordamise taotlus,
kui vastuvõtupoolel avastati viga

täpsemalt
https://www.youtube.com/watch?v=eviQzHhBm_I

http://etutorials.org/Networking/wimax+technology+broadband+wireless+access/Part+Three+WiMAX+Multiple+Access+MAC+Layer+and+Qos+Management/Chapter+8+MAC+Functions+and+MAC+Frames/8.7+Automatic+Repeat+Request+ARQ/

standardid
https://tools.ietf.org/html/rfc3366