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DIGITAL RADIO Introduction Digital technology has made the multiplex concept possible; several different programme services may be 'multiplexed' together and transmitted simultaneously. The result is that many areas throughout the UK benefit from greater choice. For instance, listeners are currently able to listen to three national analogue commercial radio services (Classic FM, Virgin Radio and talkSPORT). Digital One, the national commercial digital radio operator, offers these three services in addition to a further seven new digital only services. All services can be heard in digital quality; excellent fidelity and the robust signal serves the mobile radio user well. Some data may also be carried, which can produce visual information on a small screen on the radio set. This can comprise information to support the radio programming or advertising, or can, to some extent, be unrelated data for private or public use. Listeners
will have to invest in new radios to hear the new stations. Several manufacturers
are now perfecting their designs which retailers are starting to make
available. As with all new technology, the early designs are rather more
expensive than traditional radio sets, although the price is expected
to fall. Several sorts of sets are available including portable radios,
hi-fi stacks and car radios. PC cards are also available which bring digital
radio to the desktop and associated data to the computer screen. All applications are considered on merit. This is not a highest cash-bid process. All applicants are required to pay an application fee. The Authority then considers each applicant’s proposals in full; their constitution; their plans for the new radio services; their financial arrangements and projections; and their technical plans. When
making the award, the Authority is required to consider the following
principal factors:
Local multiplex criteria:
What is happening now? The Authority is concentrating on advertising local multiplex licences in the main population centres within the UK, facilitating a local, then a regional multiplex in each of these main conurbations, apart from in Greater London where an additional multiplex is available. This pace of progress, together with the services on the national commercial radio multiplex could bring listeners in major areas up to 24 digital radio services (London 32), plus a further selection (6-8) on the BBC's own separate national multiplex. For an up-to-date timetable of planned new areas for advertisement of Digital Multiplex Service Licences click here. For
an up-to-date list of areas already awarded Digital Multiplex Service
Licences, Digital/Analogue Simulcasting Any analogue radio service that broadcasts on a digital multiplex has its analogue licence automatically extended for a further eight years. Further Technical Background Digital Radio is a major technical advance in audio transmission. A conventional (AM/FM) transmitter sends radio waves into the air modifying them in a way which directly mimics the original sounds sent by the radio studio. Radios understand what this modification (called "modulation") means, and can reproduce the original electronic mimicry of a microphone or other sound source, to drive a loudspeaker. This method of transmission is prone to signal distortion and interference; after all, AM radio systems were first developed around 100 years ago and FM followed some 50 years later. They were designed for a former era and expectations have increased greatly since then. The new digital transmission system has been specially designed to meet the needs of today's listeners. Digital Radio, like compact disc (CD), is fully digital. This means that instead of using electronic circuits to mimic sounds directly, they are instead translated into a fast sequence of numbers: ones and zeros, and just before the radio has to drive the loudspeaker, the digits are converted back to the electronic mimicry (analogue). The Eureka 147 Digital Radio system is the method used. This has been accepted as a world-wide standard by the International Telecommunications Union. It is being implemented, or is planned for implementation throughout Europe, and already in other places such as Canada, Mexico, Australia, Singapore, and China. Eureka 147 was designed by a European project team for use in all environments, particularly mobile. The capacity of a multiplex is divided to accommodate the different elements carried on it. Each of those elements uses a 'bit-rate'; the higher the figure, effectively the higher the quality of broadcast. The Authority has resolved to require that all programme services on a multiplex use at least a minimum bit-rate, dependent on whether each is at the time predominantly speech or music, mono or stereo, in order to support a robust technical quality; e.g. 128 kbit/s for stereo music. However, the Authority hopes that the flexibility to use higher bit rates for better audio quality will be used creatively to maximise digital radio's appeal to the public. In the case of the simulcasting of the existing national radio services, the Secretary of State will reserve a specific amount. Spectrum Allocation The UK government has, to date, allocated seven 'frequency blocks', using 12.5 MHz of radio spectrum in VHF Band III, from 217.5 to 230 MHz. For national Digital Radio, a single frequency can be used to cover the entire country with a common multiplex service, thus eliminating the need for retuning. For local and regional services, a honeycomb of lower power networks will be used to provide precise local area coverage on a single frequency. Of the seven frequency blocks, two are already allotted by European agreement: one is to be used for an Independent National Radio network, and one for a BBC national network. The other five are being introduced under the terms of a European framework agreement, although there are some geographical restrictions to the availability of some of these frequency blocks, particularly along the coastal strips of South and South East England, and in Northern Ireland. At present, more spectrum (in the 'L-Band' range - 1452-1467.5 MHz) is planned for Digital Radio in the UK in 2007, although some initiatives in Europe also look to further VHF Band III frequencies being released for Digital Radio. Information Note The
Radio Authority is responsible for licensing and regulating Independent
Radio in accordance with the statutory requirements of the Broadcasting
Acts 1990 and 1996. It plans frequencies; appoints licensees with a view
to broadening listener choice; enforces the ownership rules; and regulates
programming and advertising. It is funded solely by the licence fees paid
to it by each of its licensees and by application fees. |
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