Broadcasting technology in Great Britain is in the midst of the digital revolution. The switchover from analogue to digital television will be completed in 2012. And the plan is that from 2015, with near-universal DAB coverage, analogue radio will be reserved for small local stations. Everything else will use digital audio broadcasting.
With DAB radio, a digital signal is decoded by the receiver so as to give vastly clearer and more reliable reception than can be achieved with analogue radio. The great majority of listeners still use the old technology, but those who buy a digital radio are buying into the future.
Digital Radio Tuning and Digital Audio Broadcasting
Although commercial DAB receivers have been available for more than a decade, Radio Today reported that analogue still accounted for nearly eighty per cent of the market at the end of 2009. Many are still confused about digital audio broadcasting, and the most common misunderstanding is that digital radio tuning must pick up digital radio broadcasting. Not so.
Digital radio tuning can be used for both analogue radio and DAB radio. If a radio is advertised as having digital tuning, this always means that the signal received is analogue. To receive digital audio broadcasting, it is necessary to buy a digital radio: digital tuning and digital broadcasting are not the same thing.
Digital Audio Broadcasting v Analogue Radio
So how does digital audio broadcasting differ from analogue radio? Well, from the point of view of the listener, the difference is roughly that between CD and vinyl or tape: the sound is much clearer, and extraneous noise is eliminated.
As for the technology, analogue radio uses radio waves directly to carry the signal, whereas DAB encodes it digitally. The advantage of this is that all the problems with the analogue signal are filtered out – for example, the way that it can be blocked or deflected by buildings or hills.
Then there is the fact that DAB is much more economical with frequencies: multiplexing means that several audio channels can be broadcast simultaneously over the same frequency channel. A very wide choice is thus on offer, and tuning in requires no more than finding the name of the station on the digital display.
Still, there are those who dislike digital radio. The main complaint is that, however clear the reception, it gives poorer sound quality than FM. This perception is borne out by Professor Sverre Holm's "informal listening test", which identifies a "more smeared stereo image". For speech, this is unimportant, but the effect on music can be somewhat soulless: a little of the music is actually missing. However, digital technology is improving, and the new DAB+ offers superior sound quality.
DAB Coverage
By far the largest digital radio broadcaster in the UK is the BBC, which has recently announced its plans for digital radio. Its digital signals, which presently reach the homes of some eighty-five per cent of the population, will cover a further seven per cent over the next twelve months.
Equally important is in-car DAB coverage. As yet, very few cars have digital radios, but they will necessarily become standard in due course. Today, eighty-three per cent of the UK’s motorway network is covered by the BBC, and this will grow by ten per cent by the middle of 2011. A major advantage of in-car DAB is that national DAB radio stations are broadcast on exactly the same frequency nationwide, so the signal remains constant.
Buy a Digital Radio
Although most of the radios on the market are still analogue, this will not be the case for much longer: who wants to buy a radio which will be obsolete in a few years? DAB radios remain considerably more expensive than their analogue counterparts, but the cost is coming down: already it is possible to buy a digital radio for little over £30.
The 2015 target for the analogue switch-off may prove overambitious, but the switch-off will come sooner or later. Universal DAB coverage will be necessary, but affordability will be the key: cheap digital radios will ultimately seal the doom of analogue radio.
Iain Manson - A Life – of Sorts Born in 1950 of a Scottish father and a Welsh mother, Iain Manson was brought up in Scotland, and graduated ...
