Digital TV is a recently introduced way of transmitting to the home the pictures and sound which make up a TV programme, together with other services like text and interactivity. It gives many advantages over the 'analogue' television transmission system that we have been using for nearly seventy years. Because the information needed to make up the TV programme is 'coded' into a digital stream of ones and noughts - like the way a computer works - the technical quality can be much better and more consistent. The digital stream takes up much less capacity in the airwaves, so that the space need in the past for just one analogue channel can now carry five, six or seven different programmes. This means a much greater choice of services to watch if you are a digital viewer. And that's not all. Digital TV can be widescreen. Many of your favourite programmes are in true widescreen on the digital channels - something analogue TV cannot do properly. And there is a whole new experience of interactivity on digital TV. By using your remote control, you can access all kinds of information: the new digital text is much clearer than the old teletext system, and 'enhanced TV' gives you the added enjoyment of related information running alongside the programme you are watching. Some digital systems allow you to choose your camera view of big events, or to increase your choice of information, whether it is news or sport or other content. Some digital services also provide access to internet pages through your TV set. One day we will all watch digital TV. The Government has said that it wants to start to switch off the analogue services sometime between 2006 and 2010 by when, it hopes, we will all have digital TVs or digital set-top boxes. But it has also said that this switch-off will only happen if most people have chosen for themselves to 'go digital' before those dates.
How to Receive Digital Television
Whether you receive your existing TV services by satellite, cable or terrestrial (with an aerial), the chances are you can change to digital whenever you want to.
Digital TV through an aerial (digital terrestrial television - DTT)
Digital TV can be received using a normal rooftop TV aerial. You will need a set-top box to go with your existing TV set, or you can buy a new digital TV set which is designed to pick up the new digital signals. About three-quarters of homes in the UK with a rooftop aerial should be able to receive digital TV, although in a sizeable minority of cases a new aerial will be required. This will be either because the digital channels are outside the band of channels the aerial was designed for, or because the aerial and the downlead are in poor condition. Very often in these cases an aerial which has seen long service can pick up a reasonably acceptable analogue signal but will not work with digital.
Digital TV using a dish (digital satellite)
To receive digital satellite in the UK you will need a set-top box to use with your existing TV set or a new digital TV set designed to receive the digital satellite signals. You will also need a new Sky 'minidish' on the outside of your house. Digital satellite signals reach to the vast majority of UK homes, but in a few cases reception may not be possible. This will be because the satellite is hidden from your home by trees, high hills or tall buildings, or because planning laws do not permit you to put up a dish (for example, if your house is a listed building).
Digital TV delivered by cable
To receive digital TV via a cable connection you will need to subscribe to one of the cable TV providers who will then provide you with a set-top box to go with your existing TV set. Many districts are now served by digital cable services, usually in towns and cities. The service provider will install a buried cable connection between the main cable in the street and your house.
