What is Digital TV?

Digital TV is replacing the existing analogue TV signal which transmits the terrestrial channels BBC One, BBC Two, ITV1, Channel 4 and - where available - Five to UK homes. Digital TV has a number of benefits over the old analogue system including improved reception sound and picture quality, a greater number of channels and the ability to watch programmes in glorious high definition (HD). HD TV boasts a sound and picture quality that would not be possible on normal terrestrial TV.

All this is possible due to the digital transmission signal being much more space efficient than the old signal. Programme information is converted and compressed into a digital format, using much less space on the airwaves than an analogue transmission. The signal is reduced to a binary code (e.g. 01100100 01101001 01100111 01101001 01110100 01100001 01101100 00100000 01010100 01010110) therefore the quality and consistency of the signal can be improved over the analogue equivalent.

Broadcasting programmes in this way enables multiple television channels to be carried in the space used currently by a single analogue channel, making more channels and features available to viewers. Digital TV platforms also allow you to record programmes as they are being broadcast for later viewing, and set timers to record - no more need for blank tapes or rewritable DVDs. Some Digital TV services also allow you to set timers remotely, from either your mobile phone or from your computer desktop.

Digital TV can be received by standard TV aerials, as well as via satellite or fibre-optic cable. All signals sent to a household are decoded by either a separate receiver, or a receiver that is built into a television set. The separate receivers are commonly known as set-top boxes, and sit outside your current television set. A TV set that has its own digital receiver is called an integrated digital TV set, mostly referred to as an IDTV set.

The process of replacing the old analogue signal with the new digital signal is referred to as the Digital Switchover. This involves the permanent shutdown of analogue transmissions which is happening now, on a region-by-region basis. For a timetable of shutdown dates and information on when the Digital Switchover is due to occur in your area, head over to our Digital Switchover page.