Digital radio, known as DAB (Digital Audio Broadcasting), began in the autumn of last year, and digital television went on air a few weeks ago. The radio services are being transmitted throughout London and the South-east of England, while the television services are available in London and the Newcastle-upon-Tyne area.

Yet no receivers are currently available on the commercial market. Why is the BBC wasting money on transmitting new services when nobody can receive them or indeed will do in the foreseeable future? And what does this mean for education broadcasting?

Digital technology allows television and radio signals to be squeezed or compressed so that they occupy a much smaller part of the radio spectrum and need a lot less transmitter power. Since the system is entirely different technically, brand new television and radio receivers will be required.

In radio terms, where before there was spectrum space for just a few stations, there will now be room for dozens, although the exact number will still depend on the location and its proximity to centres of population (a greater number of stations will be possible in rural areas). Much the same goes for terrestrial television, with the potential of 10 to 20 channels.

When it comes to satellite broadcasting, where the technology already allows for many more channels, the sky is almost the limit. BSkyB is talking of a 200-channel digital package to be available in the near future. Cable systems already have optical fibres capable of carrying hundreds of channels and will soon have the potential to carry almost every programme currently transmitted anywhere in the world.

Thus broadcasting begins to spread its wings into the 21st century in the same way that the printed word has done over the course of the 20th. Whether any of this is desirable or feasible from an economic point of view is, of course, quite another matter. The BBC’s experiments are currently being carried out with the intention of establishing techniques and trying out various ideas before mass audiences use the system.

They are also intended as an incentive to encourage manufacturers to start churning out digital sets. The Government wants to switch off existing analogue television transmitters five years after digital television is formally launched. For that to happen the BBC, ITV and other broadcasters will need to master a particularly rapid learning curve.

On the educational front, there will no longer be a technical impediment to allowing schools broadcasts a channel, or perhaps several channels, of their own. This is ironic at a time when BBC Radio has abandoned schools broadcasting in favour of tape distribution. But we may yet see schools radio again, since among the BBC’s current DAB experiments are streamed channels devoted to sport, news and music.

The BBC also plans to transmit the “regional” programmes of BBC Scotland, BBC Northern Ireland and BBC Wales as part of the digital satellite services, with the result that viewers throughout Europe will be able to see Reporting Scotland or Dotaman. Whether they will have to pay is open to debate.

As with any new technology, the future is far from certain. BSkyB is almost certain to launch digital services well in advance of terrestrial stations, with the result that commercial deals between BSkyB and manufacturers may kill the market for terrestrial digital stone dead before it is launched.

Satellite can launch its 200 channel service across the whole of Europe on the same day whereas digital terrestrial will have to rely on the construction of a new transmitter network. And if the consumer can have immediate access to 200 or more channels, why wait for more technology to deliver another half-dozen?

But while the whole question of digital broadcasting is in a state of flux, perhaps now is the time for the educational lobby to make its views known to the BBC, the Independent Television Commission and the Government. The rewards could be reaped in a few years’ time.