A data channel is a means of broadcasting information over a UHF television-style channel which is of a similar format to HDTV combined with Teletext.
History[]
The initial bandwidth of teletext was up to 150 kilobaud, allowing the transmission of approximately 27,000 of texts per second. This doubled in 1982 with the introduction of HDTV. Several years later, the Open Broadcasting Association started a second channel which was entirely oriented toward broadcasting data, with a bandwidth of around 12 megabytes of data per second. This is available to a number of public services and can be bought into for a small fee. It contains text and a special vector graphics language, and is used by domestic computers and the Guide. However, it is not used for electronic newspapers because it is a condition that all information broadcast on it must be free at the point of use and it was considered a state monopoly on information.
Domestic computers and guides now all have facilities for receiving UHF frequency data for the purpose of using this channel and others.