What is digital television?
Free to view digital television is a replacement technology for existing free-to-air analog services. It provides better picture quality and enhanced sound, plus a variety of new features that enhance the viewing experience.
The digital television industry in Australia is using the DVB-T standard, first developed in Europe, rather than the American-developed ATSC standard. DVB-T is proving to be a very high quality system and is being used in many countries around the world. In Australia it will replace the analog PAL system.
When did digital television commence?
Digital television transmissions commenced on 1 January 2001 in Australia's five major capital cities - Sydney, Melbourne, Brisbane, Adelaide and Perth.
Outside of the major metropolitan areas, digital television transmissions have begun in many of the major regional centres and are continuing to be implemented at a rate of approximately two transmitters a week. For further details go to DBA's Reception Locator.
A timetable for the commencement of digital terrestrial television broadcasting in remote parts of Australia has not yet been established by government.
What benefits will digital television provide?
Free to view digital television is a far more efficient and flexible transmission system than the current analog system. It allows broadcasters to offer viewers a range of new and different services.
Australian digital television features include:
Ghost free reception
Widescreen 16:9 pictures
Standard Definition pictures (SD)
High Definition pictures (HD)
High quality audio and surround sound
Multi-channel programming on ABC and SBS
Closed Captioning of programs for the hearing impaired
Electronic Program Guides (EPGs) with now & next program information for some channels
In selected markets, on-screen program guide channel with today's program information for Nine Network, Seven Network, Network Ten & SBS In selected markets, HD demonstration channels
Multi-camera views and enhancements during selected programs
What happens to my existing analog TV set?
Free to view broadcasters will simulcast (broadcast both analogue and digital signals) for at least eight years in an area, so metropolitan viewers will continue to be able to use current analogue television sets to receive broadcasts without the need for a set top box until at least the end of 2008.
After the end of simulcasting in an area, the addition of a digital tv set top box will allow viewers to receive and display digital transmissions on their analogue TV sets.
Viewers using digital set top boxes will also be able to receive the other features of free to view digital television, such as better picture quality, clearer sound and extra channels. However, as most existing analog sets have a 4:3 screen aspect ratio (shape), using a digital set-top box with a 4:3 analog television set may affect the way widescreen (16:9) transmissions are displayed. Use of a widescreen display will enhance the digital experience. For more information click here.
To experience the full picture quality benefits of free to view digital television, including access to High Definition pictures, you will require an integrated digital television or display panel (known as an iDTV) with a High Definition tuner, or a television or display panel that is capable of displaying the High Definition television signal in combination with a set top box that incorporates a High Definition digital tuner.
Can my 4:3 analog TV set display Digital TV to its full effect?
No. You are able to view digital television on your 4:3 analog television with the addition of a digital tv set top box, but you will not be able to see widescreen pictures displayed to full effect. Some set top boxes will give you the option of viewing widescreen pictures in letterbox format (black bars top and bottom) or centre cut full screen format (with the 4:3 section cut out of the 16:9 picture).
Will my Video Cassette Recorder (VCR) still work?
Yes. During and after the simulcast period, you will be able to record the digital channel on view - provided that your set-top box or digital television has an analog output - and VCRs will also continue to play back pre-recorded tapes. Many will find the picture quality of recorded digital programs is better than that of analog programs.
During the simulcast period VCRs will be able to record any analog program while a different digital program is being viewed. However, unless your digital set top box has two tuners (www.dba.org.au/receivers), VCRs will not be able to record a separate digital broadcast from that which is currently being viewed on the screen.
Current VHS video recorders will still only record VHS-quality pictures.
In some areas of Australia, the channel used by the video output may be the same as that used by a new digital television channel. In this instance, the video output on your VCR may need retuning or require the use of the audio/video (A/V) connection if present.
Will digital televisions connect with VCRs, DVDs and sound systems etc?
Yes. Although connection options will vary from manufacturer to manufacturer, all digital televisions are likely to have audio/video (A/V) inputs that accept external devices such as VCRs, DVDs, sound systems and video cameras.
Will I need to upgrade my antenna?
If your antenna and antenna cabling is relatively new and in good condition, you should not need to replace your antenna. However as we find many digital reception problems are related to the antenna and or cabling, you should consider replace the antenna and cabling to receive uninterrupted digital television viewing.
Viewers in areas of poor analogue reception should seek specialist advice about antenna requirements for digital television reception in their area.
DBA recommends that all viewers use quad shielded
cable from the antenna to the television (including the fly-lead from the
wall plate to the set top box or television) to ensure electrical impulse
noise does not interfere with the digital reception.
For further information go to the Digital
Television installation tips for houses or Digital
Television installation tips for apartments.
Why are digital TV pictures sharper than analog TV pictures
Analog television can suffer from multipath interference, which results in a ghosted picture on your screen.
Free to view digital tv is not affected by multipath
interference and picture flutter. So the digital result is a sharper,
cleaner and clearer picture.
In areas of low signal strength, viewers of analogue television may experience
snowy pictures. Without adequate signal strength being delivered
to a digital set top box, digital television may not improve the viewing
experience compared to analogue.
The digital TV picture and sound may be further affected by poor quality cables and connectors. DBA recommends the use of quality F-type connectors and quad shielded coax cables to ensure optimum picture and sound performance.
Is audio better on digital television than on analog?
Yes. Australian television programming has traditionally been broadcast with FM stereo sound.
Digital television will be transmitted with MPEG digital stereo sound (the equivalent of CD quality) and/or Dolby Digital Sound (2, 4 or 5 channels) where available, thereby providing markedly superior audio services.
What multichannel services are the ABC and SBS offering?
There are two additional multi-channel services provided by the ABC and SBS:
ABC2
SBS World News
What radio services are the ABC and SBS offering?
SBS provides two multilingual radio services on all its digital television services
SBS Radio 1
SBS Radio 2
ABC broadcasts its two internet radio services
DiG
DiG Jazz
Is digital television likely to cause interference?
Typically no. Digital television is not inherently prone to causing interference and is markedly superior to analog television in that respect. But the planning of channel allocations for digital television has entailed the occupation by digital television broadcasts of some channels formerly used for other purposes, eg, as output channels for VCRs.
For further information on the alternative arrangements that can be made by those VCR users or if you believe you are experiencing an interference problem, please go to www.dba.org/interference.
Explanations of Digital Television Terms
What is widescreen?
Digital television is broadcast in a native widescreen mode. Widescreen television has a different aspect ratio (ratio of width to height) than traditional analogue television. The aspect ratio of a widescreen is 16:9, while Australian viewers have been accustomed to viewing a 4:3 aspect ratio since television began in this country.
Widescreen will, in many cases, literally mean you see more of the picture. Most movies are currently made in 16:9 and are converted to 4:3 to allow us to watch them on television or video, so there is a lot of information that you don't see on your television that you would see in the cinema version of the film. Live sporting events will benefit in particular from the extra detail and wider frame.
For some time now television production has been converting to widescreen, with the majority of local television programming now being made in widescreen while increasing amounts of overseas programming shown in Australia is also being made available in a widescreen format.
What is a digital television set top box?
A digital television set top box receives and decodes digital terrestrial television transmissions into a form suitable for display on analogue television sets, display panels or other screen display devices such as computer monitors or projectors.
Analogue television sets currently in use in Australia cannot display digital transmissions on their screens without being connected to such a digital television set top box receiver.
What does a set top box do?
The capability of a digital television set top box will depend upon its specifications.
A digital television set top box, when connected to a 4:3 analog television set, will usually give viewers an improved signal, better picture quality and multichannelling. Some set-top boxes may also provide viewers with datacasting services and video, audio and data enhancements.
What is an integrated digital television receiver?
This is a television set with in-built digital television tuner providing the capability to receive and display digital television transmissions.
Integrated digital televisions (iDTV) generally incorporate a high quality widescreen display and a high-level audio capability with appropriate audio/video connectors. An iDTV does not require a digital television set top box to receive digital television though an additional set top box could be connected to provide recording or other functionality.
What are Standard Definition (SD) pictures?
Standard Definition picture quality is superior to that obtained from analogue television broadcasts traditionally viewed on 4:3 television sets, and is ghost free and in widescreen format.
The Standard Definition picture resolution is 576 lines x 720 active pixels @ 50Hz interlaced (576i).
The Federal Government requires broadcasters to provide a digital Standard Definition signal at all times, even when High Definition programs are being broadcast. This is to ensure that viewers with Standard Definition receivers will always be able to receive a digital television service even when the higher quality High Definition television signal is being transmitted. For further information click here.
What are High Definition (HD) pictures?
High Definition television broadcast pictures have image resolution which is superior to Standard Definition pictures and to the existing analog television broadcast offering a quality improvement of up to three times the improvement in detail.
Australian broadcasters are using two different levels of high definition;
1440 active pixels x 1080 lines @ 50Hz interlaced
720 active pixels x 576 lines @ 50Hz progressive
The benefits of High Definition pictures at the highest resolution are particularly noticeable on larger screen sets and when using projection equipment.
High Definition pictures are also ghost free and in widescreen format. When viewed on an High Definition capable television screen the viewer can enjoy cinema-quality viewing with Dolby Digital sound (where available with some High Definition programming).
Commercial free to air broadcasters are required to transmit a minimum of 1040 hours of native High Definition programming (including advertisements) each year. In regional areas this requirement applies two years after the commencement of digital tv transmissions in an area. Programs transmitted in High Definition will also be simultaneously broadcast in Standard Definition (also known as the simulcast).
What is multi-view service?
A multi-view service as the potential to let you as a viewer, select from a variety of camera angles or may provide additional information that is related to an particular event. Multi-view services are particularly suited to sporting events like cricket, tennis and motor racing.
Multi-view services can be delivered via additional channels to the main program. The viewer can then select, via remote control, the additional channel which could provide a different full screen view of the event, alternative audio commentary or related information. For more information click here.
What is multichannelling?
Because a digital television broadcast signal can carry much
more data than an analog television broadcast signal, is it possible for
broadcasters to provide more than one channel of Standard Definition television
programming at the same time. This is known as multichannelling.
The Federal Government has decided that commercial broadcasters are not
allowed to multichannel, but that the ABC and SBS may do so.
The ABC and SBS are allowed to broadcast, in addition to their main services, a wide range of programs including educational programs, regional news and current affairs, science and arts programs, children's programs, subtitled foreign programs, foreign language news and occasional dramas.
The ABC and SBS are also able to transmit their radio services through their television channels, extending the reach of these services. The ABC also broadcasts its internet radio service - DiG - via digital television.
Broadcasters are also offering a number of program guide and information data channels and some are from time to time, providing High Definiton demonstration channels.
What are program enhancements?
Viewers of digital television will have a wide choice of enhancements to regular programming. Enhancements are separate channels of video, data or audio, which are related to the program on the primary channel.
Sports programs may offer the choice of a different camera angle, altenative audio commentary, action replays, player profiles or other information.
What is closed captioning?
Closed captioning provides deaf and hearing-impaired viewers with the text of what is being spoken on television. The text is usually shown in a black box at the bottom of the picture. Hearing-impaired viewers will be familiar with current analog captioning which can be received on analog receivers with teletext capability.
Captioning is normally closed to viewers but can be accessed by those who need it.
Closed captioning does not interfere with normal viewing.
The Australia digital terrestrial television (DTT) receiver standard that applies to both digital television set top boxes and integrated digital televisions, is not mandatory but currently states that all receivers should have closed captioning decoding capability, including the ability to:
(a) decode and display teletext page 801 closed captioning,
(b) decode and display DVB bitmapped Subtitles - (a system in use by other countries but not by Australian broadcasters), and
(c) pass teletext closed caption data out on the Standard Definition video output in the VBI (Vertical Blanking Interval) so that a standard analogue television (PAL) receiver fitted with teletext decoding can display it.
As captions are currently provided in the teletext style with all Australian broadcasters’ prime time programs, this is the more important digital set top box capability to those viewers who wish to see closed captions.
Many digital set top boxes have teletext closed captioning
display capabilities - with these set top boxes, a television connected
to them doesn't also need to be able to decode teletext closed captions,
as the feature is provided by the set top box.
There are some digital set top boxes that do not include closed captioning
decoding and display capability. However a few of these do pass the closed
caption data out on the video output (via the VBI - see (c) above), and
when these set top boxes are connected to a standard teletext-capable TV
set, access to the closed captions can be had by viewers.
Therefore, any consumer intending to purchase a digital
television set top box or an integrated digital television and use closed
captioning should, before purchase, check on the set top box or integrated
digital television's capabilities.
Closed captioning of programming is incorporated in all English language
news and current affairs programs as well as for all prime time programs
(6.00pm to 10.30pm).
Of course, when available, closed captions can continue to be viewed on a standard PAL teletext-capable TV set that is tuned to analog broadcasts. However, many more digital television programs incorporate closed captioning than do analogue television programs.
What is an Electronic Program Guide or EPG?
An EPG is the electronic version of a printed program guide. Using your remote control you will be able to see on-screen what's on now and what's on next for all free-to-air services. You may also be able to search for a particular program by theme or category, eg sporting programs, movies etc.
Extra text and picture information (eg story line, episode description etc) can be called up as well. The EPG is always up-to-date and available at the click of a remote control button.
Updated 29 June, 2006