Digital switchover is a process in which the analog terrestrial transmissions network is switched off and is replaced with an all digital terrestrial network. It is also known as the analog swith-off.
Digital switchover in the UK will take place between the years 2008 and 2012. Digital television is a more efficient way of broadcasting than analog. Sound and pictures are converted into a digital format and compressed using as few bits as possible which means that more services can be delivered in less space.Digital TV gives • Improved quality pictures • More TV channels • Subscription channels with more features • Radio through TV • Interactive features • On screen programming guide(EPG),multicasting • Recordable subtitles and audio descriptions Digital TV also enables transmission of pictures in widescreen format which will adjust to fit both widescreen TVs and TVs with squarer displays which means they can adjust to both standard definition TVs(SDTV) and high definition TVs(HDTV).Digital TV frees up airwaves that could be used for innovations such as mobile TV or high definition TV.
Digital TV has better reception than analog. There are a number of ways to receive digital television. The oldest method is using a aerial in which viewing is limited to whatever the aerial picks up. Then there are digital satellites and digital cables. Digital cables deliver services through fiber optic cables.
A dish mounted outside the house receives the digital satellite signals.Nowadays a set top box is used which decodes the digital signals into signals that even an analog TV can understand. Digital transmissions can also be viewed directly using an integrated digital television set (IDTV). Digital transmissions can also have various levels of interactivity with the receiver.
Electronic programming guide (EPG) offered by digital television can give access to the receiver to the various television listings and their descriptions many days in advance.Digital transmission allows four to eight TV services inclusive of radio and text based services to be broadcast in a single frequency while an analog transmission allows only one single channel to be broadcast. For the same amount of bandwidth you can transmit more information with digital than with analog. A single frequency channel carrying multiple services is called a digital multiplex(MUX).
The UK currently uses six MUXs for broadcasting its digital terrestrial services(DTT). Digital signal is now broadcast at low power so as not to interfere with the analog transmission.If an analog transmission is subjected to interference pictures can still be received although they might be of low quality and not very clear because of weak signals but with digital transmissions there are only two possibilities either the picture can be seen or not seen, there can not be any low quality pictures because of weak signals. If the picture is seen it is seen with the best clarity.
If the switchover from analog to digital is complete broadcasters no longer have to transmit the same services in both analog and digital forms.With analog transmissions only four or five channels can be viewed but with digital up to thirty channels can be viewed. With features as subtitling, audio descriptions and sign language switchover is especially beneficial for people with sensory impairment. The UK is planning the digital switchover TV region by TV region. Change from analog to digital is a giant leap in the world of broadcasting. By planning the digital switchover the UK sure hopes that all households get to see television with better quality, better picture, better sound and last but not the least of all remain a world leader in taking up the latest technology.Referenceshttp://en.wikipedia.org/wiki/Digital_switchover
