Digital TV:
Digital TV was designed to replace the existing free-to-air analogue TV service. Digital TV is far superior to analogue TV in nearly every respect in that it provides a crystal-clear picture, and much higher quality digital sound. It also brings with it a large range of new features that are designed to enhance the viewing experience. Eventually the Australian Digital TV standard (known as DVB) will replace the existing analogue PAL format. 
Digital broadcasting began in major Australian cities on the 1^st January 2001, and is slowly expanding across regional Australia, to the point where it will be available from anywhere in Australia by the year 2004. The main benefits that Digital TV brings are:

• Widescreen (16:9) picture
• Near perfect digital reception, free of “ghosting and “snow”
• Standard Definition (SD) or High Definition (HD) pictures
• High quality Dolby Digital audio
• Multi-channel programming
• Closed Captioning for the hearing impaired
• Electronic Program Guides (EPG)
• Multi-camera views
• Program Enhancements
• Data-casting (information services)
• 'Program Overlap' features
• Interactive services such as home shopping & games
• Internet functions (limited to specific content)

A question I am asked regularly is: “Should I buy a new TV now or wait for Digital TV?” The answer to this depends entirely upon how much you are willing to spend, and whether high definition TV is of importance to you. Many people naturally assume that Digital TV is a specific type of TV, and that all Digital TV is in glorious high definition, but this is actually not the case. In Australia the government decided that Digital TV would be comprised of 2 separate standards, both of which will be broadcast simultaneously. The first of these is “Standard Definition”, commonly abbreviated to SD. The second is “High Definition” or HD. I’ll explain these in detail below.

Standard Definition (SD):
Standard definition broadcasts are made up of roughly the same amount of horizontal lines of resolution as existing analogue broadcasts or DVDs. This is usually in the vicinity of 576 lines in Australia (equal to the current PAL standard) and 480 lines in USA (equal to their NTSC format). Standard definition is also an interlaced format, which means that any existing TV on the market has the capability to display SDTV.  However most SD material is in the widescreen (16x9) format, so to view SD broadcasts the way they were intended you need a widescreen TV. When SD is viewed on a 4x3 TV, black bars will appear at the top and bottom of the screen to preserve the widescreen aspect ratio. This works in exactly the same way as DVDs.
To receive standard definition TV all you need is a set-top box, which are becoming readily available from most electrical stores in Australia. A set-top box will allow you to receive a digital broadcast and decode it into the analogue format for your TV to display. Set-top boxes also bring with them a host of other benefits, which I will explain in more detail below. 
To cut a long story short a so called “Digital TV” is simply any widescreen TV with either a digital set-top box, or the equivalent of a digital set top box built into the television itself. Standard definition will however look much better than the analogue TV you are used to, as you will get near perfect, ghost free reception with superior sharpness, and more vivid life-like colours. If you want to future proof yourself for SD Digital TV, your best bet is to buy a high quality widescreen TV now, then add a set top box later down the track. If you are interested in High Definition however, it’s a different story altogether.

High Definition (HD):
With the introduction of Digital TV broadcasts earlier this year, high definition TV is finally starting to make an entrance onto the market. Although TV channels are broadcasting very little high definition material at this stage, this will of course change in the future, to the point where every show broadcast will be available in standard definition, high definition and analogue.
High definition can actually be defined as any picture that is above the standard definition format of 576 lines interlaced. The HD formats, which will be used in Australia, are 576p (p = progressive), 720p  and 1080i. As to which of these formats provides the superior picture is a matter of opinion, as they all have their various merits. i.e. 1080i has more lines of resolution, while 720p has a more stable image with less jagged lines. There are currently very few displays available that can display 720p. Some support it, but most will convert 720p to either 576p or 1080i.  
At this stage there are only a couple of high definition direct view sets on the market in Australia. Unfortunately neither of these will actually display 720p or 1080i at full resolution, as they simply don’t have enough pixels to obtain the full 1920x1080 resolution required. They will however look far better than any TV that is only capable of displaying 576 lines of resolution. You are of course not just limited to a direct view set to view high definition. Other display options to view HDTV are a high resolution plasma screen or a projector capable of at least 1024x768.
Be warned that high definition displays are very expensive. The cheapest you will find one for is $5000, and you really need to spend at least $7,000 to get something of decent quality. 
No displays (including direct view sets) currently come with an HDTV receiver built in, so you still need to purchase a high definition set-top box to receive broadcasts. And of course high definition broadcasts are not just limited to a superior picture, they are also able to transmit up to 5.1 channels of Dolby Digital sound. This means you’ll get the same awesome digital sound quality from TV shows that you can enjoy from DVDs. Cool eh! :)
If you are just after a direct view or RPTV to watch DVDs and TV, my advice is to buy yourself a good quality standard definition widescreen TV now, and wait a few years for higher quality (and cheaper) high definition TVs to be released. However if you are looking at buying an expensive projector or plasma screen, then it might pay to spend the extra money to get something that can handle high resolutions.
There’s no doubt that high definition is the future, but it’s in its infancy at the moment, which means HD sets are a long way from reaching their full potential. Also worthy of note is that there are only a few hours of high definition broadcasts each week from the major channels, which means you really wont be getting the most out of a HDTV at this stage anyway. In a few years time you can expect nearly everything to be broadcast in the HD format.

Other benefits of Digital TV:
Aside from the enhancements to picture and sound quality, Digital TV also brings with it a number of user-friendly features. The most common of these are as follows:

Multi-view:
Multi-view is one of the most exciting features of Digital TV, in that it gives you direct control over what you are watching. While watching a program you are able to switch between multiple camera angles. These channels can be displayed simultaneously on screen, or you can switch between them in the full screen format. As you can imagine this technology will be particularly useful for sport broadcasts such as cricket or motor sport. This technology is very similar to the multi-angle feature found on some DVDs.

Multi-channelling:
Because a digital transmission can carry a lot more information than an analogue transmission, multiple TV channels can be broadcast at the same time. This is known as multi-channelling. Unfortunately only ABC and SBS are allowed to multi-channel as the government ruled against commercial stations having this power. In the future ABC & SBS will be broadcasting material such as educational programs, regional news, science and arts, children's programs, subtitled foreign programs, and foreign language news. 

Program enhancements:
Another similarity to DVD is the ability for TV stations to provide additional program enhancements to the show you are watching. Examples of this are multiple audio tracks (i.e. you could choose between multiple languages), action replays, actor or player profiles, or other related information. You will also be able to bring up additional information when watching special interest shows like cooking programs, where for example you might choose to view the recipe of the dish being cooked.

Data casting:
Because of the extra bandwidth available with digital broadcasting, the major TV channels (and eventually other licensed broadcasters) will have the option of providing additional information & services to viewers. Examples of these services are banking, bill paying, interactive shopping, educational programs, games, selected internet services and email. With the introduction of Digital TV it was expected that data casting would be a widespread service and not limited to the major TV broadcasters. Unfortunately the government ruled against this (at least for the time being) so for the immediate future only the major free-to-air providers will be able to offer data casting services. Data casting is expected to begin early 2002.

Closed Captioning (CC):
Closed captioning is a real-time sub-title service designed for the deaf or hearing impaired. All set top boxes and integrated digital TVs will have the option of turning on sub-titles when required. This works in exactly the same way as traditional closed-caption services (currently available via teletext) but is expected to be much more common with Digital TV. This feature can also be used to display sub-titles in multiple languages for foreign viewers who wish to watch TV sub-titled in their own language.

Electronic Program Guide (EPG):
An Electronic Program Guide is simply an electronic version of a typical TV program guide. The advantage of an electronic guide is the ability to see “what’s on now" and “what’s on next” as well as search for specific programs by category or theme (i.e you could perform a search for all upcoming movies over the next week). Additional information such as basic storyline, actors and running time can also be obtained via an EPG. Of course the other big advantage of an electronic program guide is that it will always be up-to-date. (no more annoying cancellation of shows without viewers knowing about it).

Interactive TV (iTV)
As the name suggests, Interactive TV is a feature that allows viewers to directly interact with a TV show or service from the comfort of their own home. This will allow features such as real-time voting in polls, booking of tickets while watching travel shows, purchasing goods via shopping shows etc. You can also expect so called “reality” shows to be taken to a new level with viewers being able to vote people off in real-time while the show is being broadcast. I have to admit this is one of the many Digital TV features I am very excited about.

 

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