THE forthcoming digital service is already being celebrated as 'the biggest development in broadcasting for a generation' and means more viewers will be able to get more channels, with clearer pictures and better sound.

Just as the digital quality of CDs changed the way we listened to music in the 1980s, so digitisation will transform the clarity and ease of watching TV in the future.

Yet many viewers are already happy with the old system and do not want to go through the inconvenience of changing their TV when the old service goes out of date in 2009.

So why has the Government gone to so much trouble to start up a new scheme and silence the old one, which seemed to be working?

Digital UK, the non-profit company formed by the Government last September to monitor the switch-over, says the digital system is being introduced so it will be fairer to everyone.

Not all British residents can receive digital channels under the current system, even if they have bought the right equipment, because the signalling output is not yet strong enough.

About one in five households are also unable to get good enough reception to pick up Channel Five on the old analogue system.

The 'spectrum' for TV channels is so narrow that at the moment digital services are competing with the old ones and only by stopping all broadcasts under the old system can networks boost the digital signals.

Using digital technology means all broadcasts will be of the same high standard and will not fluctuate in different areas depending on the strength of the signal.

By switching to digital, the TV companies will also free up a whole range of transmitter waves for other technology, such as high-definition TV or mobile phone networks.

Additionally, more viewers will have access to the extra channels run by TV networks - such as BBC Four, ITV2 and E4 - as well as special services for people with sight or hearing problems.

Ford Ennals, chief executive of Digital UK, said: 'The range of questions is extremely wide.

'What's clear is that even those who already have digital TV are looking for authoritative advice about switchover.

'Many people are so used to the choice and extra services that they just think of it as normal TV.

'We will be working with broadcasters, retailers and manufacturers to make sure everyone understands switchover and what it means for them, including those who already have digital TV on their main set but will need to convert second sets.'