Network: Play it by the numbers

The digital TV revolution has begun. But what does it all mean?

IF THE advertising hoardings are to be believed, televisions around the country feel undervalued, bored and neglected. Over the next few weeks, the picture will literally change. Digital TV is here, and the humble box will take on a new lease of life.

Digital means better sound and pictures, interactivity and more channels. With digital, the television has the potential to take on some of the territory currently occupied by the personal computer. Interactive shopping, electronic banking and even e-mail will be features of the digital revolution.

So, unfortunately, is confusion. Rival broadcasters, equipment manufacturers and service providers will compete for our attention. Some digital television will be free. BBC1 and BBC2, for example, are already operating on the new system. Other channels will charge for their services. Sky will offer up to 200 digital channels through a satellite dish. But to muddle matters further, some of the most popular Sky channels, such as sport and movies, will be available from November to viewers without a satellite dish - through ON Digital, the start-up broadcaster.

Early next year, the cable operators will start their own version of digital services; again, the main Sky channels will be part of the package. And none of the new services will work with existing televisions, satellite or cable decoders.

Instead, viewers will have to buy a digital set-up box, even if they only want to watch free services from the BBC or ITV. The cheapest set- top boxes will cost around pounds 200. By the end of the year, sets with integrated digital decoders will also be on sale, at around the cost of a conventional, up-market television set. In a situation which recalls the early days of the home video recorder market, when VHS, Betamax and Philips Video2000 formats fought for space in our living-rooms, digital set-top boxes will be incompatible with rival services. So, to watch Sky digital via a satellite, viewers need a Sky set-top box. To watch ON Digital, viewers need its boxes. To watch cable next year, viewers will need a cable box, which is different again.

Digital TV is less a new form of television than a new way of transmitting programmes, suggests Andrew Marre, communications director for ON Digital. "People get hung up about digital, and we are in danger of frightening consumers," he says. "We are about delivering programmes, not technology. Digital is a means to an end: it allows us to take the capacity of one channel and lets you have four, five or six channels in the same space."

ON Digital has the simplest approach of all the digital networks: it uses a standard television aerial to send its signals. This means that any viewer can receive the service, as long as they have a digital set- top box and fall within the coverage area. When ON launches on 15 November, there will be some parts of the country where the service will not work. But for the most basic options, including the BBC's two new, digital- only channels, ITV's offering including ITV2, Channel 4 and Channel 5, there is no charge and no need to register with ON.

The company, though, hopes viewers will sign up for either its primary or its premium channels, too. Primary channels include Sky1, Eurosport, Granada Plus and Carlton Food Network; ON Digital is a joint venture between Granada and Carlton. There will be a monthly charge for the primary channels, and for the option to add premier channels, including movies and Sky Sports.

More TV alone, though, is unlikely to win over the public in droves: the take-up of satellite and cable TV already shows this. New programming ideas might. Interactive services will also play their part. As the different digital TV technologies support quite different levels of interactivity, it may well decide which service dominates the market.

"With broadcasting TV services, you will get the same thing whether it is cable or satellite or terrestrial," says Stephen Adshead, analyst at Datamonitor. "With interactive services, there is a big difference. With satellite and terrestrial you have one point for broadcast. Millions of different subscribers will pick up the same signal. You can have two-way communications through the cable network, and fast Internet access."

All digital television will offer some degree of interactive services. There will be much-improved, digital teletext, electronic shopping and electronic banking. All three systems will offer e-mail in the near future, and some set-top boxes come fitted with a modem to support this.

The real test will come when cable services come on stream. As well as digital TV channels, the cable operators will be able to offer full access to the Internet, at far greater speeds than ordinary modems. Already, cable operators are planning set-top boxes with computer interfaces on the back, which will let computer owners take advantage of the network's power when they go online.

Potentially, a digital TV with a cable connection can do much of what a PC can do now. Some things, such as home shopping, may well be more suited to digital TV.

Most homes have a TV, but only 5 per cent are connected to the Net. Anyone who can develop a livingroom-friendly way of going online has a golden opportunity.