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A Guide to digital radio (Digital Audio Broadcasting)

What is DAB Digital Radio/Digital Audio Broadcasting?

Digital Audio Broadcasting, or DAB, is the technology behind digital radio. It brings a larger selection of different stations that broadcast in low, medium and high quality or in mono or stereo. Since there is limited space on DAB at the moment, some stations must broadcast in mono or at a lower quality "bitrate" in order that there is space for other stations.
Stations that broadcast mainly speech or talk are usually heard in mono on DAB
Stations that play music can usually be heard in stereo on DAB digital radio, though there are exceptions. Our multiplex listings show which ones broadcast in mono (m)


DAB digital radio logo                         

With DAB digital radio there's no hiss or crackle

There's no hiss or crackle to spoil the sound you're listening to, though there may be the presence of digital "artifacts" in the sound you hear, depending on the broadcast quality of the station on DAB digital radio.

You don't have to remember frequencies

There's no need to remember frequencies, either. You just look for the name of the station you want on the display of a DAB digital tuner and select it.

Remember when record shops started selling CDs? Listeners who were used to hearing their music on vinyl or cassette were suddenly given a third option. In the early days of CDs, the player itself was the expensive part of the deal, at least to start off with. The same is true of DAB digital radio. The DAB digital tuners that are available at the moment will leave quite a dent in your wallet. Prices are coming down, though. Once you've bought a tuner, listening to the radio is free.

DAB digital radio has other features that often aren't available with ordinary FM radios.

You can often find out what's playing next

You can display the name of the artist and track currently playing, or the current programme (if the station is set up to broadcast these things - most are now) and you can see what show or song is coming up next.

You don't have to re-tune to stay with national stations

National radio stations broadcast on the same frequency up and down the country, so unlike FM there's no need to keep re-tuning as a DAB digital radio in your car will automatically select the nearest transmitter for uninterrupted listening. If there's no DAB transmitter nearby, a DAB radio in your car may be able to tune back to FM.

However, you will need to retune your DAB digital radio if you're moving around the country listening to local DAB digital radio stations. If you enter an adjoining area whose local multiplex carries the same station, you can keep on listening to that station by re-tuning.

Having a digital display doesn't mean you have DAB digital radio

Many people think that if they have an ordinary FM radio labelled 'digital tuning' they can also receive DAB digital radio. The bad news is, they can't. Some people think that if they have a digital display on their FM radio they can also pick up DAB digital radio broadcasts as well. Unfortunately, this is not possible either.

Sometimes you'll read that DAB digital radio gives 'CD-quality sound'. DAB can sound very good, and in a few cases better than FM as there's no discernable hiss, but it's not as high-quality as CD. Some stations broadcast in mono, just like their AM equivalents, though DAB sounds much better than AM. Only a handful of stations broadcast at something approaching good FM quality - stations such as Virgin Radio and Classic FM use a high "bitrate" to sound good on DAB digital radio. Other stations use lower bitrates, so their sound may suffer from artifacting and a noticeable "wobble" in the stereo sound. This has been likened to the sound of "chattering monkeys" in the sound. The lack of hiss on DAB is a point worth mentioning.

It has a lot to do with where you live, but one of the best things about DAB digital radio is a wider choice of stations, and a wider selection of music types. There's also an increased selection of talk-based stations in some parts of the country.

DAB Digital radio is different to FM radio

DAB digital radio is different because, instead of being made up of analogue waves, the radio signal is transmitted digitally, as a series of 'zeros and ones'. You don't need a satellite dish to receive digital radio, just an aerial positioned in the correct place. However, you might have to install an external aerial in your loft, for example, if you live in a poor signal area; sometimes the wire that comes with a DAB digital radio isn't enough to allow good reception. You can find out more about DAB aerial installation from the Confederation of Aerial Industries (CAI) Limited on 0208 902 8998.

Traditional FM analogue radio waves are sensitive to noise or distortion from electrical equipment or the atmosphere. The waves can bounce off tall buildings and hills and become interrupted or distorted.

As DAB digital radio uses digital signals, with plenty of extra information transmitted to allow the tuner to fill in any missing bits, the DAB signal does not suffer from the same problems as the FM signal. If you live in a weak signal area, you'll find that, even with all that extra information, the sound sometimes breaks up. If you live in a strong signal area, you'll find you have uninterrupted listening without 'drop-outs'.

DAB digital radio uses a Single Frequency Network

On the FM waveband, many stations use several frequencies to allow the station to be heard over a large area. The radio spectrum isn't used very efficiently, and often you must re-tune to a different frequency to follow the same station. The radio signals in Digital Audio Broadcasting are transmitted using a single frequency network (SFN), where all transmitters use the same frequency for a particular station. So, it is possible to listen to Classic FM or BBC Radio 3 without interruption across a percentage area of the UK.

Each service feed comprises

  • the coded audio component
  • programme-associated data (PAD)
  • service information (SI)

The operator of the group of services or stations will bring all these individual feeds together to form an ensemble. The ensemble is carried to all of the appropriate transmitter sites where the services can be transmitted.

Up to ten digital programmes or services can be transmitted in one block known as a multiplex. This allows several programmes or services to be transmitted on a single frequency. This means that more services can be broadcast at the same time. The multiplex can carry a mixture of stereo and mono broadcasts, and data services. Data services might comprise of weather or travel information, which can be displayed on-screen in a web browser, for instance.

Coverage

Presently, BBC national digital radio covers only about 60 per cent of the population. Over the next couple of years more transmitters are to be added. National commercial digital radio fares much better at around 85 per cent. You can check for coverage in your area by checking the maps and coverage areas through our station listings. Transmitters for local and regional DAB digital radio are also being added before the multiplexes launch.

You can check coverage of national DAB digital radio using the links to maps on our national stations page (in the left-hand column), or for local stations choose your local area and look in the left-hand columns within our listings for a link to a coverage map, where available.

You can get a taster of what's available via the internet or digital television

You can also listen over the internet to many DAB digital radio stations, to get a taste of what's available. To do this, you'll need to download and install the latest versions of RealPlayer and Windows Media Player, as these convert the data coming into your computer into audio that you can hear through your speakers.

Of course, the quality won't be the same as true DAB digital radio, but at least you'll be able to hear the new stations available, which may help you to decide whether to buy a DAB digital radio tuner.

It's worth pointing out that station availability varies greatly across the country - different local and regional stations are available in different areas. You should check out our national and local station listings to find out what you can hear in your area, then look out for the live links to start listening. Many local and regional DAB stations broadcast over the internet.

The other way to receive a form of digital radio is via Sky digital satellite or Telewest digital cable television, however, the number of stations you can receive is limited and may not reflect what you would be able to hear on DAB digital radio in your area of the UK. Our listings giving channel numbers (or, more accurately, 'block numbers') for DAB digital radio (e.g. 11C, 12A, etc.) are not related to the Sky multiplex channel numbering system.

A number of DAB digital radio stations have signed deals with Sky so that their station can also be heard via satellite television. These stations include national talk radio station talkSPORT, plays and books station Oneword, music station Core and the BBC's 6 Music. It is unlikely local radio services will be carried on Sky, though there are networked services which are available on several local DAB digital radio multiplexes. Check our Sky satellite listings page or with your local dealer for details of services available.

Why do I need to buy a new radio?

Digital radio uses a completely different technology to normal FM/AM radio. For starters, the radio signal is transmitted digitally to the digital radio, which then decodes the information, turning it into sound that you can hear. DAB digital radio uses mp2 digital compression. The radio signal cannot be decoded by a normal analogue (AM/FM) radio.

Additionally, digital radio uses different frequencies than normal FM/AM radio (actually, those that were once used to broadcast black-and-white television!). Hence you need a digital radio to receive digital broadcasts.

Does it cost anything to listen, after buying a new radio?

No, not to radio stations. However, there may be a charge levied for downloading other music, games or software in the future. DAB Digital Radio technology allows listeners to receive any kind of data - even programs that you can run on your PC. These additional data services may cost money in the future for you to use them.

How many stations should I be able to receive?

DAB digital radio stations are transmitted in "multiplexes" - basically a large number of stations grouped together. It depends on where you live as to whether you can receive digital radio, and how many multiplexes you can pick up. If you can pick up a particular multiplex, you will be able to hear all of those stations that broadcast on the multiplex. You can check our pages to see whether you can receive the two national multiplexes by doing a postcode search or viewing a map, to give you a fair idea.

You may also be able to receive up to 3 local or regional digital multiplexes. Again, it depends on where you live as to how many local multiplexes you could pick up. For example, in Bristol there are two other multiplexes in addition to the two national multiplexes. The first is a regional multiplex that covers Bristol and the second is Bristol's very own local DAB digital radio multiplex. Check our local station listings for local and regional DAB digital radio multiplexes that you might be able to receive where you are.

Will the launch of a new multiplex mean that I won't be able to listen to stations on another multiplex any more?

When a new multiplex launches, it very rarely affects the services you can receive on other existing multiplexes. It is launched alongside any multiplex already broadcasting, using a different frequency. A new multiplex will give you a number of additional stations - broadening your choice. Occasionally, a station will transfer from one multiplex to another.

What is a multiplex?

A multiplex or ensemble can be thought of as simply a number of stations that are grouped together, to make it efficient for them to be transmitted digitally. However, there is a practical limit to the size of this group - and this is important as it means one DAB digital radio multiplex cannot carry more than about ten radio stations in total (although there is capacity for data services and such like, which take up much less room on a multiplex).

There are other local digital multiplexes (stations that are grouped together) that serve a particular area, for example: a multiplex that serves Tyne and Wear, one that serves South Yorkshire, and so on. These multiplexes contain different local radio stations depending on the area they serve. For example, Metro Radio is one station that is part of the local digital multiplex for Tyne and Wear, as it is a local radio station serving Newcastle. However Metro Radio is not available on the multiplex that serves South Yorkshire, for the simple reason that the station is local and relevant to Newcastle, not Sheffield.

There are two national DAB digital radio multiplexes

There are two national digital multiplexes - one that carries all of the BBC national radio stations, such as BBC Radio 1, 2, 3, 4 and Five Live, and a second that carries national commercial stations such as Classic FM, Virgin Radio and talkSPORT (except in Northern Ireland, which has different services). There are, however, stations such as Xfm, Capital Gold and Classic Gold that can be heard in several different parts of the country on local DAB digital radio. These stations have signed up with local operators to ensure they are heard on many local digital multiplexes. The reason for this may be that their parent companies operate the multiplex.

To summarise, it really depends on where you live as to which stations you can hear, and that is why our listings are divided up on both local, regional and national levels. DAB digital radio isn't too different to normal analogue radio in this respect; the number of services is still finite.

Where can I view coverage maps for multiplexes in my area?

Our national, regional and local station DAB digital radio listings contain links to coverage maps in the left-hand column, under the service listings, where available. Please note that not all operators currently provide coverage maps for you to view.

How much of the UK is covered by DAB digital radio?

All of the above stations are up and running, but a lot depends on where you live. Digital radio will eventually cover most of the United Kingdom, but at the moment there are many areas of the UK where you will not be able to receive digital radio. Presently, BBC national DAB digital radio covers about 80 per cent of the population, rising to 85 per cent by the end of 2004. During 2004 and beyond more transmitters are being added. National commercial digital radio fares at greater than 85 per cent of the population.

Even in areas where digital radio transmitters have been installed, the signal is often not strong enough to allow you to tune in to a multiplex. You may find that you need to install an external aerial, even if you've been able to pick up ordinary FM broadcasts perfectly well. This is because the transmitter sites are often situated further away than FM transmitters. You may find it is not possible to pick up BBC national digital radio very well, due to the lack of transmitters.

Transmitters are being built all over the country, but it will take some time before most of the population will be able to tune in. The local digital radio services are gradually being introduced, and new transmitters will have been built by the time the local multiplex launches in your area.

Which other stations can I listen to?

As well as the large national digital stations, you can also tune in to your existing BBC local radio station on digital radio. You might also find your local independent station as well. However, not all existing local radio stations have secured a place on digital radio, so it might be worth checking our listings to find out if your favourite station currently languishing on medium wave has made it onto digital radio!

We're listing local stations that have made it onto digital radio as soon as the licences for regional and local areas have been awarded, but you might like to see which services are in the pipeline at the official site for digital radio. There's also a timetable (and a revised timetable) on our news pages. Digital local radio is already available in many local areas, with most of the country receiving local digital radio by the end of 2004.

Can I listen to UK DAB digital radio stations if I live in Spain, Germany, etc.?

No, the DAB signals do not travel that far. You would not be able to pick up any UK services using a DAB digital tuner abroad. To see which country-specific services may be up and running in other countries, please see the World DAB site.

Can I listen to Capital FM on digital radio if I live in Scotland?

No, as Capital FM is a local radio station for London and the surrounding area. Just as it is not possible to hear Capital FM once you are out of the station's transmission area on a standard FM radio, it is equally not possible to hear Capital FM on a digital radio outside of its London transmission area. This is true of all other local and regional digital radio stations; they still all have a limited service area. The only way to hear Capital FM in, for example, Scotland is through your computer via their internet audio stream.

Why can't I hear every UK station on digital radio, no matter where I might be in the country?

For the simple reason there isn't enough room or capacity on DAB digital radio to carry every radio station. The way that digital radio signals are transmitted (as a multiplex group, or ensemble, made up of different stations) makes much more efficient use of the broadcast spectrum, but is is still not physically possible for every national, regional and local radio station to be heard everywhere in the UK.

Ready to buy?

Some more frequently asked questions about DAB digital radio, for example - how to tune in, which tuner to buy and how much they cost - are answered on our digital radio FAQs page.

DAB digital radios can be difficult to find on the high street, as they tend to get quickly snapped up, but you can buy a digital radio online, via this site.

Further information

We've more of your questions on our digital radio FAQs page, where you can find out how to tune in and listen to DAB digital radio, read information about tuners and radios available - and more! If you're ready to buy, you can check out our guide to the latest products and read reviews and feedback before you buy.

You can also find out more about Digital Audio Broadcasting from the BBC website or from Digital One's website. There is also an information provided by the Digital Radio Development Bureau. The telephone number for this is 08707 74 74 74.

You can email us or fill in a form with any comments or corrections regarding this article via our feedback page.

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