| DAB - Digital Audio Broadcasting |
The UK currently has the world's biggest digital radio network, with 103 transmitters, with two national DAB ensembles and forty eight local and regional DAB ensembles broadcasting over 250 commercial and 34 BBC radio stations across the UK.
In the capital of London there are already more than 51 different digital stations available. In addition to DAB, radio stations are also broadcast on digital television platforms, Digital Radio Mondiale on mediumwave and shortwave frequencies as well as internet radio in the UK.
Digital radio ensemble operators and stations need a broadcasting licence from the UK's media regulator Ofcom to broadcast. |
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| Digital radio in the United Kingdom is being promoted by radio stations and the broadcasting industry on the premise that it provides a wider choice of radio stations, is easier to use, and is resistant to the interference which other broadcast media are susceptible to. However, the price paid for the extra number of stations is that the audio quality on DAB is lower than on FM. Also some areas of the country are not presently covered by DAB; the BBC says that it may not provide coverage to the final 10% of the population, and may use DRM instead. |
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| Criticisms of DAB in the UK |
DAB provides low audio quality in the UK due to 98% of stereo stations using a bit rate level of 128 kbit/s with the MP2 audio codec, which provides much poorer sound quality than FM-quality.
Also, a large and growing number of music stations are transmitting in mono. Indeed, the bit rates used by the radio stations on other digital platforms, such as cable, terrestrial and satellite are usually higher than on DAB, so the audio quality is also higher.
For example, all of the BBC stations use higher bit rates on Freeview and satellite than on DAB, apart from the BBC World Service on Freeview.
In addition, Ofcom has said that even after extra spectrum has been allocated to DAB, it estimates that around 90 local radio stations will either be unable to transmit on DAB because there is no space for them on a local DAB multiplex or because they cannot afford the high transmission costs of DAB that the multiplex operators are charging.
However, Ofcom announced in 2005 that it regarded Digital Radio Mondiale (DRM) as being an option for the local stations unable to secure carriage or unable to pay the high transmission costs of DAB. |
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| DAB+ |
DAB+, a new digital radio standard using the HE-AAC encoding standard and announced by the WorldDAB organisation in 2006, is being considered for digital radio broadcasting in the UK.
HE-AAC encoding is more efficient than the MPEG-2 Layer II encoding standard currently used for DAB in the UK. DAB+ will either allow stations to broadcast at higher sound quality than currently possible with DAB, or allow more stations at the same quality currently broadcast on an ensemble.
The Digital Radio Development Bureau released a press statement in January 2007 in which they admitted that DAB+ will be used in the UK in future. Ofcom have said that the UK will switch to DAB+, but not until the vast majority of radio sets can work with DAB+.
If broadcasters and regulators dropped DAB in favour of DAB+ it is unlikely that current digital radio owners would be able to upgrade their model to receive the DAB+ signal.
Any change to DAB+ would have to be gradual, allowing those with non upgradable receivers to obtain new equipment. |
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| DAB frequency plan |
DAB radio stations in the United Kingdom are broadcast on a number of frequency blocks on VHF Band III.
The original plan devised in Wiesbaden for the framework of DAB in Europe was to allocate frequency blocks 11B to 12D for UK DAB broadcasting.
However, as part of its Review of Radio, Ofcom has expanded the frequency allocations for DAB and has advertised local and a national ensemble licence on blocks outside the original Wiesbaden plan on 10A to 10D and 11A.
Under a Maastricht plan in 2002, the UK also has L band allocations for local terrestrial DAB, though there are no plans to broadcast any digital radio stations on L band.
Ofcom auctioned spectrum in L band in 2008 for a number of uses, including terrestrial digital radio. On May 16, 2008, Ofcom declared that Qualcomm UK Spectrum Ltd had won the auction of L band frequencies in the UK.
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Block |
Frequency |
England and Wales |
Scotland |
N.Ireland |
10A |
209.936 MHz |
None |
None |
None |
10B |
211.648 MHz |
Local ensembles |
None |
None |
10C |
213.360 MHz |
Local ensembles |
None |
None |
10D |
215.072 MHz |
Local ensembles |
None |
None |
11A |
216.928 MHz |
Digital Two |
Digital Two |
Digital Two |
11B |
218.640 MHz |
Local ensembles |
Local ensembles |
None |
11C |
220.352 MHz |
Local ensembles |
Local ensembles |
None |
11D |
222.064 MHz |
Digital One ensemble |
Local and regional |
None |
12A |
223.936 MHz |
Local and regional (except West Wales) |
Digital One ensemble |
None |
12B |
225.648 MHz |
BBC national DAB ensemble |
BBC national DAB |
BBC national DAB |
12C |
227.360 MHz |
Local and regional (except the south coast) |
Local and regional |
None |
12D |
229.072 MHz |
Local ensembles (except the south coast) |
Local ensembles |
Local ensembles |
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| BBC DAB National |
| BBC National DAB is a Digital audio broadcasting multiplex owned and operated by the BBC and is transmitted from a number of transmitter sites across the country; it only carries BBC radio stations. |
Station |
Bitrate |
Audio |
Description |
| BBC Radio 1 |
128kbit/s |
Joint Stereo |
Youth orientated Popular music and speech. |
| BBC Radio 2 |
128kbit/s |
Joint Stereo |
Adult-oriented Pop Music |
| BBC Radio 3 |
192kbit/s |
Joint Stereo |
Classic Music |
| BBC Radio 4 (FM) |
128kbit/s |
Joint Stereo |
News & Speech |
| BBC Radio 5 Live |
80kbit/s |
Mono |
Live news and sport |
| BBC 6 Music |
128kbit/s |
Joint Stereo |
Classic rock Alternative rock Funk Indie Jazz Hip Hop |
| BBC Radio 7 |
80kbit/s |
Mono |
Comedy, Drama, and Children's programming |
| BBC 1Xtra |
128kbit/s |
Joint Stereo |
New Black / urban music |
| BBC Asian Network |
64kbit/s |
Mono |
South Asian orientated |
| BBC World Service |
64kbit/s |
Mono |
English language version of the BBC World Service |
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| Part Time Services |
| The BBC National DAB multiplex makes extensive use of dynamic ensemble reconfiguration to allow a number of part time services to broadcast. While these additional services are on air the bit rates of (one or more of) BBC Radio 3, BBC Radio 4, BBC Radio 5, and data services are reduced. |
| BBC Data Services |
Digital radio text is the scrolling information that is broadcast along with the audio content on DAB.
This can be dynamic programme information, an email address or phone number for a particular show, news headlines and sports results - and on some music networks 'now playing' track information.
Some of the latest DAB products can pick up a broadcast EPG (Electronic Programme Guide) which provides free, useful information programme information for up to 7 days in advance prior to broadcast, allowing users to record a particular show automatically - or even an entire series of programmes. |
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| Digital One |
| Digital One is a national commercial digital radio multiplex, jointly owned by GCap Media and Arqiva. The multiplex covers approximately 87% of the UK population from a total of 103 transmitters. It has no coverage, however, in Northern Ireland, where there is a shortage of frequencies due to nearby VHF analogue TV services in the Republic of Ireland. |
Station |
Bitrate |
Audio |
Description |
| Classic FM |
160kbit/s |
Joint Stereo |
National commercial classical music station. |
| Planet Rock |
128kbit/s |
Joint Stereo |
Semi-automated rock music station. |
| talkSPORT |
64kbit/s |
Mono |
National sports and talk station. |
| Absolute Radio |
160kbit/s |
Joint Stereo |
National rock music station. |
| Birdsong |
160kbit/s |
joint Stereo |
Originally used as a test transmission for Classic FM. |
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| Birdsong |
The Birdsong was originally used as a test transmission for Classic FM. It was recorded in 1992, in the back garden of Quentin Howard, CEO of the Digital One multiplex.
When financial news station Bloomberg, and rolling news station ITN News Radio ceased to broadcast within several months of one another in 2003, replacement audio services were never found due to a commitment in Digital One's broadcasting licence to provide a news station.
This resulted in a station playing a 36-minute, 56-second loop of birdsong and ambient sounds, entitled D1 Temp which broadcast for almost two years.
In June 2005, the capacity formerly used by the speech services, and later by the birdsong, was given over to a test transmission of video to mobile phones.
When the service Oneword ceased in 2008 the birdsong audio once again returned to the multiplex on the Oneword channel.
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| DAB Links |
| BBC Digital Radio BBC Digital Radio Information. |
| DAB Ensambles in the UK National & regional ensambles in the UK. |
| Digital One Website of the national commercial digital radio operator, full of useful information about national DAB stations. |
| Digital Radio Now A one-stop guide to DAB in the U.K., coverage, stations equipment and information on in car DAB. |
| Digital Radio Development Bureau The Digital Radio Development Bureau (DRDB) is a trade body funded and supported by the BBC and commercial radio multiplex operators. |
| uk-dab.info Website for DAB digital radio enthusiasts. |
| UTV DAB UTV DAB is responsible for operating a number of DAB Digital Radio Multiplexes across the country on behalf of the following joint venture companies: Switchdigital - (transmitting to Greater London, Central Scotland and Aberdeenshire) and UTV-BAUER - (covering Bradford & Huddersfield, Stoke-on-Trent and Swansea). |
| Wasted DAB Multiplex Capacity The DAB broadcasters often claim that they have to use low bit rates for their stereo stations in order to provide a wide range of stations, but in reality, this claim doesn't stand up to scrutiny. |
| World DAB Source of information on DAB around the world. |
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