August 2001
Digital radio

Digital development

More and better ??

As the launch of US satellite radio nears and receiver prices look as if they become low enough to spark more take-up of digital radio, we felt it was time to re-visit the general topic of digital.
The first truism about digital is that it can offer more and it can offer better.
The question is what the terms mean? More? Certainly in the sense that more channels can be put into the same amount of spectrum with the same theoretical technical quality because digital compression can eliminate the transmission of redundant information which an analogue signal cannot; at its simplest level a continuous musical note once defined only needs a start and end instruction to transmit in digital whereas it has to be transmitted continuously in analogue form.
Better? Certainly in the sense that the balance can then be struck to use enough bandwidth per channel to ensure CD quality if so desired!
More again? Certainly in the sense that the digital signal can also carry other information, be it basic text and displays or two-way information, which would permit e or m-commerce via the radio receiver.
Better? Well in an automobile anything that distracts is a potential hazard including tuning the current analogue receiver so maybe the downsides of the additional facilities should be seen in the same light as those of using a mobile phone whilst driving!

Striking the balance: Bandwidth.

The above thus leads inexorably to the usual practical conclusion. How much the development of digital radio ends up as a benefit to the listener depends upon the balance struck between conflicting demands.
Cram too many channels into the bandwidth and the technical quality benefits will suffer! On the other hand, there is little point in having so much bandwidth that the extra frequency sampling provides additional clarity only distinguishable to those with exceptional hearing who are listening in a specially designed acoustic environment.
At the creation stage, of music for example, the balance should be towards getting close to perfections since everything after the original can only be degraded. At the transmission stage, it's pretty clear from the success of MP3, that most people are quite happy with standards that are certainly sub hi-fi just as they are with digital cameras whose output quality is not that of a fairly cheap 35mm film camera, never mind a quality large format one. Better then at a certain stage to go for more channels.
For this we would suggest a benchmark that, when listening in a quiet room with reasonable acoustics, an 18-year-old with good hearing (not too much Walkman, pop concerts etc to have damaged the ears) can easily tell the difference between renditions of the same item of classical music with low and high volume segments on good quality speakers.
A subjective standard maybe but one that would ensure that pretty well everyone listening starts off with a signal as good as it need be. When they're in a motor vehicle or noisy environment there won't be any audible difference but listening with due attention in a quiet room will get the quality advantage. So far, in the UK at least, the bandwidth being allocated per channel is fine for this criterion. .

Striking the balance: Content.

An even more subjective area here and one where conclusions depend how far you actually believe the free market should dominate.
In the US the general tendency is to let it and allow changes of format to depend on market demand; In other areas of the world, including the UK and Canada, the regulator does have clout over format and with the limited number of analogue channels available this can be defended as producing a wider range of services than would be available otherwise
In the case of digital, the extra channels do somewhat weaken this argument. And in the case of satellite digital the area covered means that even a minority interest can attract a cumulatively large audience. Overall our feeling is that formats should be part of a licence but that, with the extra numbers of channels digital permits, changes should be generally allowed unless there is a strong public interest case against a change.
If there are 30 channels, we would have no problem with a dozen top 40 channels in the mix and would rather hope that adding a thirteenth would mean, as an example, that it would get a lower audience than a drama, comedy, talk, news, classical or jazz channel. If that were the case the market would deliver; the problem might arise if the costs of providing a good news channel, which we consider is in the public interest in a democracy, meant the accountants trimming the news budget too much.
To remedy that scenario, we would suggest a levy on all stations related to duties to provide services considered of public interest as part of the cost of using public spectrum (The alternative might be to kill radio and allow mobile communications operators to take the lot!)
If thought out thoroughly and linked to a credit and debit system, those who meet the requirements will spend the money in-house enhancing their service (as with training budgets in the German system), and those who are above par will be eligible for a transfer from those who choose not to got that route.
Again no problem here: If the dozen pop stations all choose to go for wall-to-wall pop we wouldn't stop them but would feel it fair, for example, that they all contributed to giving the news stations additional resources for boosting their reporting strengths.

Additional features.

And what of the additional possibilities?
Some are just a quantitative not a qualitative change in the sense that the multiplicity of more channels allows a niche-approach: Apparently the automakers think already that SUV drivers are different from Jaguar drivers who in turn differ from those in sports cars so we could easily have niche-channels targeting such perceived groups.
With some of the other possibilities, as with mobile phones, we do think it sensible to think before starting off whether they might cause distractions and risk lives when used by a driver. Again a question of balance, particularly where it's a matter of commerce: we would argue that allowing someone to buy on impulse a CD of a pop album they have just heard is not something we should risk lives for.
Thus complicated systems to do this should in our view be illegal and proper research done on simple and least distracting methods where any two-way communication is required. Voice-recognition systems are developing well and we would think voice commands much less distracting than having to push a button; maybe they can even be tied in to individual voice recognition, which only allows a "recognized" voice to issue the command?
And what about GPS (Global Positioning Satellite) systems, which would pinpoint a position? Could be invaluable in distress cases by allowing satellite-radio equipped automobiles to have the same kind of emergency systems as modern ships now do. After all, it only needs an emergency transmitter that can be set off by one button push to both raise an alarm and give a location.
Which raises another point, that of range with satellite services. Canadian regulation,for example, may mean that receivers for Sirius and XM cannot currently be sold legally since the services are not subject to Canadian regulation.
Unless, however, vehicles are to be taken apart when crossing borders, US citizens will have the service when travelling and Canadians may well wish to take them.
All the more reason, therefore, to think hard about technicalities and content now. The signals will automatically cross borders and we would prefer thought to be given about sensibilities of nationals and cultures before, not after, problems arise.
This would seem far more sensible for the listener than having incompatible technology (pace the movie industry system of regional DVDs) from country to country, for commercial, technological, or regulatory reasons.
At the moment the radio receiver bought on one continent will work on all continents; for a portable device that's a big plus and we would not like to see it lost in the move to digital.

Any views? Please comment on the above. For that matter, if you can put the time aside, we'd like your "Guest comment" pages this year to stimulate more feedback and dialogue.

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