Well as is now obvious the UK went the route of multiplexes of digital services highly compressed at 5 - 3mbits MPEG2, giving us 30 channels on Freeview. But we could have also had a good number of high quality widescreen high bit rate channels or possibly even a few HDTV ones.

But just what is HDTV, how does it work and why would we want it anyway, we'll try to answer all of these in HDTV explained.

What is HDTV

The Analogue PAL transmission standard has served us well since the early days of BBC colour transmissions but the current 625 line system is hardly high resolution we are all used to much greater levels of detail in screen images, its more than likely that you are reading this article on a screen set to 800 x 600 or 1024 x 768. HDTV brings enhanced resolutions to the domestic TV set in two standards a vertical resolution of 720p and 1080i the P and I represent the canning method used P is progressive scan which scans every line of the screen once, the I is for interlaced the same as the PAL system where alternate lines are scanned on each frame.

Of course the entire transmission chain needs to be upgraded to cope with HDTV and its this huge investment that is holding back growth, from the cameras to professional VTR's the additional bandwidth of the HDTV signal requires new equipment this has only really been taken up so far by the Japanese broadcasters NHK in particular.

The encoders used for HDTV are complex compared to the DTV standards in use on for example the Bskyb platform, here a single encoder creates an MPEG2 transport stream of anywhere between 2.5 and 6 mbits but HDTV is far more bandwidth intensive requiring at least 15mbits possibly much more depending on the nature of the material encoded. The HDTV encoder is also increased in complexity using overlapping encoding whereby a number of encoders work together to encode the image, each encoders area to scan is overlapped to minimise artefacts around the boundaries.

What is the benefit to me?

All this extra bandwidth and image resolution brings you one big benefit better pictures in fact much better, having seen HDTV images during a recent test I can only compare it to the first time I tried to compare VHS with a DVD. Plus HDTV is widescreen as standard giving you the full cinematic experience on all images

How do I watch it?

Currently there are only 2 services available in mainland Europe both via satellite, HDTV screens are more similar to PC TFT screens in resolution so its more than likely that decoders will be provided allowing you to use you PC screen, however the refresh rates of these screens can be poor so the US model of specialist HDTV screens hitting the market is starting to be repeated in Europe. It is widely expected that these new screens will have in built HDTV tuners rather than outboard boxes, although Roku and a few other manufacturers have made outboard decoders.  Of course Sony and other large electrical manufacturers have HDTV sets waiting in the wings for European consumers but it is predicted that Europe will be even slower than the sluggish USA to take up HDTV and without government incentives we could be waiting many years.

Broadcasters are starting to shoot material in HD, many films are now edited on HD as its cheaper than film in some instances, plus many live events are now being shot in HD and relayed to the USA and Japan for the HD enabled networks, so there is content available, perhaps not enough to make a good channel.

But with signals taking 4 times more bandwidth, equipment costing much more and very few European households able to watch HD signals its going to take a big push from someone with lots of cash to burn to bring HD into European homes anytime soon.