Digital television, also known as DVB-T, is a method of broadcasting that uses discrete (on-off) digital signals rather than the continuous signal of analog television. It will progressively replace analog TV broadcasts, beginning next year. Digital TV is already being broadcast in Australia and offers better image quality than traditional analog television.
Why is digital better than analog television?
Because digital signals take up less space on the transmission spectrum, digital television has a two-fold advantage over analog television. It means there’s more room for additional stations, and more room for additional data such as electronic program guide information and high-definition television signals to be broadcast. Digital television also has the advantage of being less susceptible to signal interference. It is free of the ghosting and signal noise that plague analog television.
The greatest advantage that digital television in Australia offers is an improvement in image quality. TV shows broadcast in both standard- and high-definition digital signals have clearer pictures and have more detail. The image quality of most high-definition broadcasts is better than DVDs.
Digital television has the added functionality of an electronic program guide. This guide, which is transmitted over the air along with the television signal, carries information about the shows that are currently being broadcast as well as future programs. While a few broadcasters only transmit information three days in advance, most digital television receivers have the ability to display upcoming shows up to seven days in advance.
When you're watching a high-definition digital channel, the digital television broadcast also includes a 5.1 surround-sound audio track. Many movies and other specialised broadcasts include the surround-sound audio, providing cinematic effects that you can enjoy on your home theatre system.
What do I need to watch digital television?
Both standard- and high-definition content is broadcast digitally. If you have an analog TV, you can buy a set-top box that will let you view digital TV stations. A set-top box that supports high-definition digital television will let you receive all available digital channels.
Set-top boxes usually connect to your television using a Composite audio/video connector — most televisions manufactured after 1990 have this connection. To check if your television has a Composite connector, look for three sockets on the rear of your television coloured yellow, white and red. Most of these set-top boxes have the ability to interpret the additional data of digital broadcasts, so they will allow you to view an electronic program guide.
If you have a flat-screen LCD or plasma television, it is likely to have an integrated digital television tuner and you will not need a additional set-top box, though some older televisions only have standard-definition tuners. The newest flat-screen televisions include high-definition digital tuners, which you will need to receive all digital channels.
When will analog television be switched off?
It has been announced that the analog television service will be switched off in regional areas of Victoria by the end of June 2010, with additional regional areas of Australia being switched off over a further one and a half years. Metropolitan areas will maintain their analog services the longest, but the current deadline for all of Australia to have analog television switched off is 31 December 2013. Visit http://www.dbcde.gov.au/media_broadcasting/television/digital_televison_switchover for more information.
What is Freeview?
Freeview is the latest digital television platform in Australia. It includes all the traditional television channels, and broadcasts using the same technology as standard digital television — think of it as an upgrade to the existing digital television network. It does not have any subscription fees, so all you have to do is purchase a set-top box or a television with an integrated digital tuner.
There is some confusion over Freeview branding and supported products. All current digital television tuners currently available will support the Freeview programming being broadcast. However, all Freeview-branded products must support an additional form of digital television decoding intended for future-proofing, but there are currently no plans to use this.
The Freeview platform boasts the ability to broadcast ‘up to 15’ channels. This gives each of the major broadcasters — ABC, SBS, Channel Seven, Channel Nine and Channel Ten — three separate digital channels. Channel Ten, for example, is using two of its channels to broadcast sports programming under the name “ONE” while the third channel maintains its original news and show programming. Additional new channels from other broadcasters will become available progressively from April this year.