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Managing the Radio Spectrum |
The radio spectrum is an important national resource which is in increasing demand by many kinds of users. It supports an enormous range of services and applications, and is increasingly important to business efficiency, international competitiveness and for services we all take for granted.
Radio plays an important part in our everyday life. Economic success is becoming increasingly dependent on good and efficient radio communications. As well as entertaining and informing us, and assisting safe travel, businesses using radio employ thousands of people. Many more thousands are employed in manufacturing, installing and maintaining radio in its many diverse forms. Radio is of vital importance in the success of businesses such as taxi firms and freight transport. Telephone traffic is often carried by radio over links between cities and on international links via satellites.
We also rely on radio to ensure a swift response from the safety and emergency services, police, fire and ambulance; for air traffic control and maritime communications to ensure safe passage of aircraft and shipping, and distress communications where safety of life is paramount. Safe passage of aircraft and shipping is also dependent on radar - another form of radio used for navigation and for accurate prediction of weather.
Most people enjoy the benefits of using radio whether it is to watch TV, listen to radio at home or in their car, listening to actors or singers using radio microphones, or making telephone calls.
The radio frequency spectrum (see Figure 1) is a small part of what is known as the electromagnetic spectrum which is made up of a range of physical phenomena including gamma rays, X-rays, ultra violet radiation, visible light, infrared radiation and radio waves. If equipment generating radio frequency energy (a transmitter) is connected to an antenna (or aerial) the energy is radiated in the form of radio waves. Some of the radiated energy can then be collected by another antenna which, when coupled to a radio receiver, enables a link to be made between the transmitter and receiver. Superimposing information on the radio carrier wave enables messages to be transmitted. This is known as radio communication.
The way in which radio waves propagate or travel through the atmosphere varies with the frequency 1 of transmission. In general, the lower the frequency the further the distance that radio waves will travel. As the frequency increases the waves may be obstructed or deflected by hills and buildings. At extremely high frequencies, rainfall and other weather conditions can significantly limit the effective operating range of radio communications. These propagation phenomena mean that different bands of frequencies are suited to particular types of radio use, e.g., for national and international broadcasting the long-wave (approximately 148-283 kHz) and medium-wave (approximately 526-1606 kHz) bands are used. At the higher frequencies such as VHF (Very High Frequency - 30 to 300 MHz) and UHF (Ultra High Frequency - 300 to 3000 MHz), where the effective transmission range is shorter, the bands are more suited to local broadcasting or local coverage for mobile radio systems. At higher frequencies it is possible to allocate wider channels (i.e., more bandwidth) and this allows more information to be transmitted per channel than at lower frequencies. For example, at VHF, because of the greater bandwidth available, high quality stereo music can be transmitted, but a typical channel in the long wave bands will support only a low quality music broadcast.
1. Frequency is the number of cycles per second. Frequency is measured in Hertz (Hz) and commonly used units are kiloHertz (kHz) or 1000s of Hertz, MegaHertz (MHz) or millions of Hertz and GigaHertz (GHz) or 1000 millions of Hertz.
Because of the demands for radiocommunication services it is often necessary for users to share the same frequencies. For example, frequencies used by local broadcast radio stations in the VHF band may be re-used up to about 10 times throughout the UK, whereas in the case of a frequency used for a high power national broadcasting service in the medium-wave band it may only be feasible to re-use it about 3 times throughout the whole of Europe. At very high microwave frequencies, used for instance by point to point links, frequency re-use of 100 times or more may be possible in the UK. With current technology the highest concentration of use tends to occur in the VHF and UHF bands particularly amongst mobile radio users. This concentration means that the spectrum must be used as efficiently as possible by re-using frequencies many times and by users sharing channels rather than having exclusive use of them.
Radio waves, used by millions of radio users worldwide, do not conveniently stop at political or administrative boundaries. Without adequate planning and management the radio signals from different users and services would interfere with each other and, above a certain level of interference, radio would become useless as a means of communication. It is the role of the Agency to manage the radio spectrum so as to ensure that it is used in the most efficient and effective way to the overall benefit of the UK.
The Agency plans and manages spectrum use to ensure that the right kind of spectrum is available for those who need it, that it is used efficiently and with as little interference as possible.
In reaching decisions on the allocation and assignment of
frequencies the Agency has to take into account the often competing
requirements of radio users. Government policies must also be considered within the
overall aim of achieving the optimum spectrum use for the benefit of all users.
The Agency does this by:
Because our use of radio in the UK can effect our continental neighbours and vice versa, careful planning and coordination with neighbouring countries is essential. This imposes some constraints on our use of the spectrum but it also provides opportunities for UK businesses and users. There is a growing trend within Europe and on a more global basis to harmonise the use of radio wherever possible. This means agreeing that frequencies are used for similar applications in neighbouring countries and that, where appropriate, European standards and specifications are set for the approval of radio equipment. Harmonisation, particularly within Europe, benefits the UK in that it eases and speeds coordination between radio administrations, creates a wider and more open market for our manufacturers and, through increased competition, provides the consumer with a wider choice of equipment and services. Therefore, management of the spectrum must be based on international agreements. Here the Agency plays a key role, participating in many international negotiations to protect and promote the best interests of the UK.
Regulation of the spectrum is essential to ensure that everyone obtains the service from its use which they require. This is done by controlling use through licensing, by developing technical specifications for the performance of equipment and by ensuring that those specifications are complied with.
The purpose of such regulation is to ensure that users of a particular service on a particular set of frequencies do not interfere with each other, or with other services. So, where radio equipment has the potential to cause interference to other users of the spectrum, users of such equipment must obtain a Wireless Telegraphy Act (WT-Act) licence. It is an offence to install and use radio transmission equipment without a licence unless it is exempt as described below.
Wherever possible the Agency aims to exempt the use of the radio spectrum from licensing so as to reduce the burden on users. Many low-power devices such as metal detectors, radio controls for model aircraft and some types of radio microphones, due to the low levels of their radio-frequency emissions, are unlikely to cause interference to other users. Therefore they are exempt from the requirement for a WT-Act licence. Full details of exempt devices can be obtained from the address below.
Occasionally interference may occur to reception of radio transmissions. Sources of interference can range from other legitimate radio transmitters which may be malfunctioning, incorrectly installed or improperly operated, to unauthorised broadcasters. The Agency takes great care in all aspects of planning and assigning frequencies to users, taking account not only of the type and location of the proposed use but, most importantly, of other existing or planned users of the spectrum.
Nevertheless, despite all the care taken in designing and installing radio equipment and planning the frequencies on which it can operate, unwanted interference may occur from other sources. The Agency has a network of Local Offices across the UK (details are on information sheet RA 206) through which the local staff offer customers advice about radio services and investigate complaints of interference. If necessary, the Agency's local staff use their legal powers to remove or reduce interference.
The Agency continually consults with manufacturers and users of radio to determine their views and requirements, to develop and explain policies to them and to agree standards for radio equipment. Consultation takes place both formally and informally. It is the aim of the Agency to be open with our customers in seeking their views and explaining the reasons for reaching decisions that affect their use of radio. To further this aim, in March 1995, the Radiocommunications Agency produces a Strategy for the use of the radio spectrum, detailing;
a) the Agency's view of trends in radiocommunications,
b) key policy objectives and how Agency aims to achieve them,
c) Strategies for specific services, focusing on broadcasting, fixed, fixed satellite, mobile comunications, space research and astronomy.
This document is revised annually and all users of the radio spectrum are invited to comment.
Formal consultation is done via committees with representatives from users and industry covering key areas such as broadcasting, fixed and mobile services. There are also several committees dealing with international technical and quality standards, and recommendations on the use of radio which provide feedback to industry and briefing for the UK representation on those international bodies.
A rolling programme of reviews of the radio spectrum has now been in progress for some years. Each review examines, and publishes a report on, a particular range of frequencies to determine how effectively it is being used, and makes recommendations on improving efficiency in its use. Public comment is invited during the review.
Informal consultations occur at ad-hoc meetings, at seminars, trade exhibitions and the annual Roadshow events. The Agency produces an Annual Report describing its work during the past year and highlighting issues that may arise in the year ahead.
The Agency has an ongoing programme of research and development in radio communication technologies and spectrum management techniques. The National Radio Propagation Committee advises the Agency on its radio propagation research programme and ensures that the results of the research are shared amongst the radio community.
The Agency is part of DTI and its staff are civil servants, but it is managed as far as possible on business lines. Planning and managing the spectrum requires specialist expertise and by far the largest group of staff (nearly half the total) are radio engineering and technical specialists. There is also a team of information technology specialists supporting the extensive use of computer systems in the Agency. The remainder of the staff fill administrative and managerial roles. Many of the staff are located in the Agency's headquarters, with others at the Radio Technology Laboratory which does research, development and testing of radio equipment, the Baldock Radio Monitoring Station which has fixed and mobile facilities for monitoring the radio spectrum, and the Agency's network of local offices.
Details of the Agency's expenditure and income are published in the Annual Report.
If you have a Wireless Telegraphy Act licence your licence fee helps to pay for all this activity.
As an Executive Agency of DTI, RA is required to recover its full costs. This is done by charging fees for Wireless Telegraphy Act licences and by recovering costs from other government departments and major users of the spectrum. The level of licence fees is set each year by an order of Parliament.
The Agency is committed to improving the quality of service which it provides to all of its customers. Our annual performance targets reflect the priorities of our customers. We aim to keep licence fees as low as possible, without sacrificing the quality of our spectrum management service, by constantly improving our efficiency. Since being established as a "Next Steps" executive agency in April 1990, average fee increases have been kept well below inflation, despite increasing demands on the spectrum and the extra work that entails.
RA publishes a range of information leaflets, guidance notes and technical specifications dealing with most aspects of radio use. If you require information on any topic please contact:
| The Library Radiocommunications Agency Wyndham House 189 Marsh Wall, London E14 9SX Telephone: 071 211 0502/0505 e-mail: library@ra.gsi.gov.uk or visit our website at: |
The Role of the Radiocommunications Agency
The role of the Radiocommunications Agency is to regulate the use of the civil radio spectrum in the national interest.
negotiating and planning the UK's use of the spectrum, with
the rest of the world where necessary
agreeing equipment standards with industry
licensing users so as to enable them to co-exist with each
other
investigating interference and enforcing the relevant
legislation
researching ways of increasing the usability of the
available spectrum
maximise the number of good quality channels available for
civil use
investigate and do our best to resolve causes of
interference to authorised radio services
consult widely with customers and be easily accessible for
enquiries and discussion
publish standards of service, to deliver these standards and
to review them over time
provide services efficiently and cost-effectively
| RA235 (Rev 3) JULY 1998 |  |
