Topic summary
Error-correction
Extracted from the Wikipedia article Error detection and correction.
Principles
If the channel characteristics cannot be determined or are highly variable, an error-detection scheme may be combined with a system for retransmission of erroneous data. This is known as automatic repeat request (ARQ), and is most notably used on the Internet. An alternate approach for error control is hybrid automatic repeat request (HARQ), which is a combination of ARQ and error-correction coding.