Digital television is a form of broadcasting that turns pictures and sound into computer .
It effectively converges your television into a form of computer so that it can.
connect to the Internet, receive interactive programmes and carry many more channels. .
There are three ways that digital transmissions can be received - through your TV aerial, via .
a satellite dish and via cable. You will need a set-top box to decode the digital signals and .
receive digital television. Before digital TV, there was analogue television. Analogue .
broadcasting began in the 1940's and 1950's. This converts sound and pictures into waves, .
which are transmitted through the air and received by your indoor aerial. Sky digital is the .
main digital broadcaster in Britain. .
In 1989 BSB ( British Satellite Broadcasting ) was due to go on air, but was eventually .
opened during the Spring of 1990. The delay gave Rupert Murdoch's analogue service Sky .
Television the opportunity to build up an audience ahead of BSB's opening and eventually in .
December 1990, the two services "merged" under the renamed British Sky Broadcasting. In .
1998 Sky digital launches, offering viewers a choice of over 140 channels. More than .
100,000 digital satellite decoders are sold in the first 30 days. According to Sky Digital's .
"In Britain and Ireland today more than 7.015 homes receive Sky Digital.".
The digital satellite platform now offers over 385 digital TV and audio channels. The .
analogue signal is delivered in a continuous wave, which can be easily interrupted, .
resulting in poor picture quality. The digital broadcasting signal is compressed and converted .
into the binary language of computers - ones and zeros - through the digital decoder. .
Analogue signals don't allow the viewer to send signals back to the broadcaster. With .
Digital TV, signals can be sent back to the broadcaster allowing the viewer to interact with .
the TV and channel. Sky calls this service Sky Active.