Digital Switchover
At the moment terrestrial digital and analogue transmissions are broadcast simultaneously. But while the analogue signal is maintained, the digital signal cannot be broadcast in full and at full power across the UK.
Digital Switchover is, as the name implies, the switching between analogue transmissions and digital transmissions. It involves the switch-off of the analogue terrestrial transmissions network and replacing it with an all digital terrestrial network. Once the analogue transmissions cease, the power can be increased dramatically on the digital signals.
To receive TV services after the switchover, all televisions will need to be able to receive digital transmissions, either by the purchase of a set-top box, or by the purchase of an Intigrated Digital Television (IDTV) or by satellite or cable. Video recorders will lose some of their functionality, for example they will no longer be able to record a different channel than is being viewed (unless they have an additional or dedicated digital tuner).
The whole digital switchover process will take about 5 years and each area will be given around 2 years notice about when the process is due to start in their region.
Households who cant presently receive digital terrestrial, and wont be able to until switchover will get prompts nearer the time, giving them the chance to connect and test equipment before analogue is completely switched off.
Messages appear on screen saying that from next month one analogue service (for example BBC2) will no longer be available
On the named date, the analogue service stops and the digital multiplex carrying BBC2 will move to the frequency channel vacated by that analogue BBC2.
Shortly afterwards, messages appear on screen saying that some or all of the remaining analogue services are about to stop
On the named day, or days, the remaining analogue transmissions will cease and the multiplexes carrying these services will move onto the frequencies vacated by the analogue channels.
Each of these changes is likely to happen over night. Each set top box or IDTV for terrestrial services will need to be re-scanned so the viewer can watch the terrestrial digital service at their new settings.