• Digital broadcasting technologies are data compression techniques. They are aimed at delivering “more for less”.

The development of MPEG and other digital video standards has allowed for greater volumes of video and audio data to be transmitted at higher speeds. Multichannelling is now commonplace in digital satellite and cable broadcasting. Terrestrial broadcasters can also benefit by broadcasting 3-5 programs in the same space as one analog channel.

Digital video can be transmitted at high speeds between broadcasters and other transmissions stations. Broadcasters have used digital formats to transmit program material at high speeds over computer and microwave networks.

• DVB-t television delivers better reception quality

Digital television in DVB-t format is free of ghosting and of many types of interference. There is no known solution for these reception problems in analog. Digital signals, which are broken into 'packets', disregard information received in between packets by means of a 'guard interval.' Coupled with several error correction routines, the guard interval effectively cleans digital signals so that received signal is nearly identical to transmitted signal.

DVB-t is suitable for high speed mobile television which had not been achievable with analog TV. Using the guard interval and error together pure signal, even when the antenna is moving through a noisy “signalscape”.

DVB-t is suitable for wide area “Single Frequency Networks”. Analog signals do not work at all when the same signal is broadcast into a single area as very significant ghosting occurs. Rebroadcasting of weak signals only occurs in analog by changing the frequency of the rebroadcast signal to avoid conficts. Digital signals, using guard intervals and error correction techniques, allow for the rebroadcast of same-frequency signals into adjoining areas. Single frequency networks are currently being used on the NSW central coast and south-east Queensland.

Digital video technologies has allowed broadcasters to store material on smaller magnetic hard-drives than in vast magnetic tape libraries. Broadcasters have been able to rationalise their physical tape libraries by storing programs on hard drives in-house and off-site.

• DVB-t television delivers widescreen pictures

Most digital TV programming is now being produced for the “Widescreen” (16:9) format, providing 33% more screen area than an ordinary 4:3 television display. Sports and movies benefit greatly by being shown in 16:9 format, but the format is also commonly used in dramas, variety and news programs.

DVB-t television delivers superior audio

Dolby Digital (where available) and other “surround sound” encoding systems allow viewers to experience “cinema” quality sound at home. Home theatre systems with 5.1 and 7.1 speaker configurations give viewers the full cinema experience, being enveloped by a studio-produced soundscape. Standard and high-definition digital programs are capable of carrying surround sound as an audio option.

• DVB-t television delivers more programming in the same channel allocations

Multi-channel

ABC and SBS are broadcasting multiple channels 24 hours per day. Commercial channels have so far been denied the oportunity to broadcast more than one channel, but this situation should change in the near future.

Multi-view

Broadcasters have so far only experimented with their “multiview” capabilities. Multiview especially enhances the viewers experience of sporting programs by showing alternative camera angles and/or scoreboards.

EPGs

Many channels now broadcast dedicated Electronic Program Guides (EPG) on their digital platform. These dedicated EPGs feature information about the day's programming in addition to showing a redued size screen image of their main channel.

Datacasting

Current broadcasters have been protected by law from new competition during the digital rollout. However, this protection may soon end. Some media players have been interested in digital TV for its ability to run multiple datacasting services. Currently under trial in Sydney is a traffic incident channel with views of major Sydney arterial roads.

• DVB-t set top boxes integrate easily with home entertainment and home cinema equipment

High quality analog and digital video interfaces to cutting edge display devices as well as older televisions and monitors. Set top box devices are built to provide older equipment the ability to show digital TV. Most also come equipped with outputs suitable for modern displays like projectors and flat panel screens.

Connects with digital surround sound processors and hifi audio equipment Many set top boxes have digital audio interfaces for connection to home theatre audio systems.

• DVB-t set top boxes will become “home convergence” receiver hubs

Interactive services are in very early development. Future set top boxes are likely to connect to telephone or home computer networks to provide full interactive services, such as home shopping, etc.