What are the benefits of digital radio over traditional analogue broadcasts

Asks Margaret

A. There are many benefits to digital radio which include improved sound quality, no interference, no frequencies, no retuning while you're in the car and a larger selection of radio channels to choose from. In addition, most digital broadcasters will have space to broadcast text and data services, which are still in their pilot stages - but each digital broadcaster has reserved 20% of its capacity for data when it is introduced.

The Digital Radio Development Bureau(DRDB) will also provide each digital broadcaster with TPEG - real time traffic information. And if you’re looking for something a bit cooler from digital radio than was available on analogue take note that you’ll soon be able to programme your radio to save, replay and download any radio programme.

Q. So if there are no frequencies how will you be able to tune your radio in

A. Instead of separate frequencies for each radio station or channel, digital radio operates within a single block of frequencies called a multiplex - one multiplex can contain many stereo and mono radio channels within it. Digital radio uses the spectrum more efficiently than AM/FM because each transmitter broadcasts multiple stations within one multiplex, as opposed to one station per frequency with existing services.

The governing body for all radio in the UK - the Radio Authority - has allocated seven multiplexes to the UK within the 217.5-230.0MHz spectrum.

In reality frequencies will still exist (for example Digital One operates in frequency 222.064 in England & Wales and frequency 223.936 in Scotland) but you won’t have to know what they are because when you tune into a station its name and not its frequency will appear on the LED screen and national digital stations will be broadcast on the same frequency throughout the whole country (known as single frequency networks or SFN’s) - so you will not have to retune while you’re on the move in your car. In addition, local stations will broadcast on the same frequency within their transmission area.

Added to this is the benefit of interference free listening, once you have tuned into a channel you will have found it - its signal will not fade or waver and its sound quality will be clear.

Q. How many digital radio channels are there at the moment

A. There are six from the BBC and ten commercial channels nationally - plus lots of local digital channels. It is estimated that any digital radio listener will be able to listen to 24 digital channels at the present time. It is believed that there will be 300+ digital radio channels throughout the UK by the end of 2002.

Q. Is the coverage for digital radio 100% already

A. Digital coverage of the UK will not reach 100% for some time - however, most of the UK is covered at the moment (approximately 48 million people can pick up digital radio if they want to) Digital One, the commercial national network already covers 80% of the UK at present and this will be increased to 85% by the end of 2003. Currently, the BBC covers 65% of the UK with its digital channels and this will increase, as more transmitters go live, to 80% by the end of 2003 and to 85% in 2004.

Q. Will digital radio provide lots of new radio channels, or will it just offer the same as analogue but in a digital format

A. It will offer a mixture of both old and new. For example the BBC offers its main radio stations - Radio 1, Radio 2, Radio 3, Radio 4, Radio 5 Live and BBC World Service in both analogue and digital formats and it launched its first digital only channel - 6 Music - on 11 March (2002).

In addition to this new station the BBC is due to launch another digital only station, currently known as Network X, for its young black listeners in the spring of 2002 and Network Z will launch in the summer of 2002 and will concentrate on drama, comedy and children's programmes. Its Asian Network (currently broadcast on AM only) will also be added to its digital package this year.

The same mixture of old and new is a familiar thread with the commercial network, Digital One. It offers analogue favourites Classic FM, Virgin Radio, Talk Sport in a digital format plus new digital offerings like Core (popular music hits), ITN (news and comment), Planet Rock (rock music), Bloomberg Radio (24 hour news and financial information), Life Digital Radio (music channel), Oneword (the world's first digital channel exclusively dedicated to the spoken word in all its forms), Prime Time Radio (easy listening and melodic music), and the Digizone (the world's first national multimedia radio service packed with games, pictures etc that can be accessed via a Wavefinder or Psion's digital radio receiver - and offers full interactive action).

Q. How can I listen to digital radio - will I have to buy a new radio or an aerial

A. It is more than likely that your current receiving equipment cannot pick up digital signals - which means that you will have to invest in new equipment to receive it (just as you do for digital TV).

You will have to have a digital receiver to pick up digital signals (and most digital receivers will have an aerial attached) but once you've shelled out for this all your channels are free - you do not have to pay a connection or subscription fee as with digital TV. All digital receivers (or radios) should be DAB compliant.

Q. Will I be able to listen to local stations outside of my local area e.g. a local Liverpool station in Birmingham

A. Unfortunately digital radio will not provide this service because local stations are only licensed to broadcast within their local area - to broadcast outside of this i.e. nationally they need a national licence.

Q. Is there an international standard for digital radio

A. There is a European standard known as Eureka 147 that defines digital radio and besides Europe the standard has also been adopted in Australia, Canada, South Africa and South Korea - the US uses its own, alternative, standard - if you require more information on this it is available online at www.worlddab.org.

Q. Will analogue radio be switched off at some point and if so when

A. There will be a switch off date in the future but the government has yet to announce when this will be, some industry insiders believe this will be in 2020.

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By Karen Anderson