Auxiliary Overhead Channel

From Wikipedia, the free encyclopedia

Please help improve this article or section by expanding it.
Further information might be found on the talk page or at requests for expansion. (November 2007)

This article may not meet the general notability guideline or one of the following specific guidelines for inclusion on Wikipedia: Biographies, Books, Companies, Fiction, Music, Neologisms, Numbers, Web content, or several proposals for new guidelines. If you are familiar with the subject matter, please expand or rewrite the article to establish its notability. The best way to address this concern is to reference published, third-party sources about the subject. If notability cannot be established, the article is more likely to be considered for redirection, merge or ultimately deletion, per Wikipedia:Guide to deletion.
This article has been tagged since November 2007.

This article does not cite any references or sources. (November 2007)
Please help improve this article by adding citations to reliable sources. Unverifiable material may be challenged and removed.

The Auxiliary Overhead Channel (AOC) is a control sub-channel used when transmitting digital sound, to transmit control information which is then interpreted by the receiver.

The ADSL bit swap process also makes use of an overhead control channel or so called AOC channel (Auxiliary Overhead Channel) to convey the bit swap request and bit swap acknowledge messages between the multi-carrier transceivers whose bit and power allocations will be updated as a result of the changing noise or line conditions.

The AOC bytes are carried as overhead bytes in the ADSL frame structure. As such, they are also modulated on the carriers and therefore also vulnerable to changing noise and/or line conditions. If the noise is severe on the carriers that convey the AOC bytes, the bitswap commands themselves may be impaired. In that case, the multi-carrier transceiver will be unable to successfully complete online reconfiguration.