Frequency allocation
Use of radio frequency bands of the electromagnetic spectrum is regulated by governments in most countries, in a Spectrum management
Spectrum management
Spectrum management is the process of regulating the use of radio frequencies to promote efficient use and gain a net social benefit.The term radio spectrum typically refers to the full frequency range from 3 kHz to 300 GHz that may be used for wireless communication...

 process known as frequency allocation or spectrum allocation. Radio propagation
Radio propagation
Radio propagation is the behavior of radio waves when they are transmitted, or propagated from one point on the Earth to another, or into various parts of the atmosphere...

 does not stop at national boundaries. Giving technical and economic reasons, governments have sought to harmonise the allocation of RF bands and their standardization.

A number of forums and standards bodies work on standards for frequency allocation, including:
  • International Telecommunication Union
    International Telecommunication Union
    The International Telecommunication Union is the specialized agency of the United Nations which is responsible for information and communication technologies...

  • European Conference of Postal and Telecommunications Administrations
    European Conference of Postal and Telecommunications Administrations
    The European Conference of Postal and Telecommunications Administrations was established on June 26, 1959, as a coordinating body for European state telecommunications and postal organizations...

  • European Telecommunications Standards Institute
    European Telecommunications Standards Institute
    The European Telecommunications Standards Institute is an independent, non-profit, standardization organization in the telecommunications industry in Europe, with worldwide projection...

  • International Special Committee on Radio Interference (Comité international spécial des perturbations radioélectriques - CISPR)

These standards bodies have assigned frequency bands in three types of allocation:
  • No one may transmit: frequencies reserved for radio astronomy to avoid interference at radio telescope
    Radio telescope
    A radio telescope is a form of directional radio antenna used in radio astronomy. The same types of antennas are also used in tracking and collecting data from satellites and space probes...

  • Anyone may transmit, as long as they respect certain transmission power and other limits: open spectrum
    Open spectrum
    Open spectrum is a movement to get the Federal Communications Commission to provide more unlicensed, radio frequency spectrum that is available for use by all...

     bands such as the unlicensed ISM band
    ISM band
    The industrial, scientific and medical radio bands are radio bands reserved internationally for the use of radio frequency energy for industrial, scientific and medical purposes other than communications....

    s and the unlicensed ultra-wideband
    Ultra-wideband is a radio technology that can be used at very low energy levels for short-range high-bandwidth communications by using a large portion of the radio spectrum. UWB has traditional applications in non-cooperative radar imaging...

     band, and the somewhat more regulated amateur radio frequency allocations. Often users use a "listen before talk" contention based protocol
    Contention based protocol
    A contention-based protocol is a communications protocol for operating wireless telecommunication equipment that allows many users to use the same radio channel without pre-coordination...

  • Only the licensed user of that band may transmit: the licensing body may give the same frequency to several users as a form of frequency reuse if they cannot interfere because their coverage map
    Coverage map
    Coverage maps are designed to indicate the service areas of radiocommunication transmitting stations. Typically these may be produced for radio or television stations, for mobile telephone networks and for satellite networks. Such maps are alternatively known as propagation maps...

     areas never overlap.

High-demand sections of the electromagnetic spectrum may sometimes be allocated through auction
Spectrum auction
A spectrum auction is a process whereby a government uses an auction system to sell the rights to transmit signals over specific bands of the electromagnetic spectrum and to assign scarce spectrum resources. Depending on the specific auction format used, a spectrum auction can last from a single...


Daily impact

Every day, users rely on allocation of frequencies for efficient use of such devices as:
  • cell phone
  • cordless phone
  • garage door opener
  • car key remote control
    Remote control
    A remote control is a component of an electronics device, most commonly a television set, used for operating the television device wirelessly from a short line-of-sight distance.The remote control is usually contracted to remote...

  • broadcast television and audio
    Broadcasting is the distribution of audio and video content to a dispersed audience via any audio visual medium. Receiving parties may include the general public or a relatively large subset of thereof...

  • Standard time broadcast
  • vehicle-speed radar
    Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...

    , air traffic radar, weather radar
  • mobile radio
  • Global Positioning System
    Global Positioning System
    The Global Positioning System is a space-based global navigation satellite system that provides location and time information in all weather, anywhere on or near the Earth, where there is an unobstructed line of sight to four or more GPS satellites...

     (GPS) navigation
  • satellite TV broadcast reception; also backend signal dissemination
  • Microwave oven
    Microwave oven
    A microwave oven is a kitchen appliance that heats food by dielectric heating, using microwave radiation to heat polarized molecules within the food...

  • Bluetooth
    Bluetooth is a proprietary open wireless technology standard for exchanging data over short distances from fixed and mobile devices, creating personal area networks with high levels of security...

  • Wifi
    WIFI is a radio station broadcasting a brokered format. Licensed to Florence, New Jersey, USA, the station is currently operated by Florence Broadcasting Partners, LLC.This station was previously owned by Real Life Broadcasting...

  • Zigbee
    ZigBee is a specification for a suite of high level communication protocols using small, low-power digital radios based on an IEEE 802 standard for personal area networks. Applications include wireless light switches, electrical meters with in-home-displays, and other consumer and industrial...

  • RFID devices such as active badges, passports, wireless gasoline token, no-contact credit-cards, and product tags
  • toll-road payment vehicle transponders
  • Citizen's band radio and Family Radio Service
    Family Radio Service
    The Family Radio Service is an improved walkie talkie radio system authorized in the United States since 1996. This personal radio service uses channelized frequencies in the ultra high frequency band. It does not suffer the interference effects found on citizens' band at 27 MHz, or the...

  • Radio control
    Radio control
    Radio control is the use of radio signals to remotely control a device. The term is used frequently to refer to the control of model vehicles from a hand-held radio transmitter...

    , including Radio-controlled model
    Radio-controlled model
    A radio-controlled model is a model that is steerable with the use of radio control. All types of vehicles imaginable have had RC systems installed in them, including cars, boats, planes, and even helicopters and scale railway locomotives....

     aircraft and vehicles
  • wireless microphones and musical instrument links

Power levels vary widely (from 1 milliwatt in a Bluetooth node to 1 kilowatt in a microwave oven). While the general RF band controls propagation characteristics, who uses what is arbitrary and historical. A particular frequency may require line of sight, or may be attenuated by rain, but whether it carries ambulance or pizza delivery traffic depends on where you live.

Earlier equipment could not process higher frequencies, nor was it compact enough to support certain uses. Over time the exploitable frequencies have increased and semiconductors have shrunk. A tube radio is neither mobile nor reasonably battery powered; GPS works at 1,500 MHz and fits in your pocket. You might use a Bluetooth headset to talk to your mobile phone which is trunked on a microwave link, and at the other end someone is on a cordless phone.

International conventions

The range of "radio frequencies" is a matter of international convention. The separation of countries into the three formal ITU RF allocation regions is one source of different RF allocation policies in different parts of the world. The definition of the ITU Regions is based largely on longitude. According to ITU Radio Regulations
Radio Regulations
The Radio Regulations is an intergovernmental treaty text of the International Telecommunication Union , the Geneva-based specialised agency of the United Nations which coordinates and standardises the operation of telecommunication networks and services and advances the development of...

 section 5.1: Member States assign licenses to stations; article 5 of the ITU regulations allocates frequencies to services (such as broadcasting and mobile). The ITU divides the world into five administrative regions:
A: the Americas,
B: Western Europe,
C: Eastern Europe and Northern Asia,
D: Africa, and
E: Asia and Australasia.

The ITU also categorises states into three Radio regulatory Regions:
Region 1: Europe, Middle East, Africa, the former Soviet Union, including Siberia; and Mongolia;
Region 2: North and South America and Pacific (East of the International Date Line);
Region 3: Asia, Australia and the Pacific Rim (West of the International Date Line).

Thus, the RF allocations fundamentally differ between continents. Longitude may traverse continents, for example, the 40°E meridian crosses Europe (Russia), Asia (Middle East) and Africa.

The division between Europe and the other regions is the root of the different RF allocations in the ITU Radio Regulations, and standards around the world. ITU-R Study group 1 details how and why there are three separate Regions.

See also

  • Amateur radio frequency allocations
    Amateur radio frequency allocations
    Amateur radio frequency allocation is done by national telecommunications authorities. Globally, the International Telecommunication Union oversees how much radio spectrum is set aside for amateur radio transmissions...

  • Bandplan
    A bandplan or band plan is a plan for using a particular band of radio frequencies, that are a portion of the electromagnetic spectrum . Each bandplan defines the frequency range to be included, how channels are to be defined, and what will be carried on those channels...

  • Broadcast license
    Broadcast license
    A broadcast license or broadcast license is a specific type of spectrum license that grants the licensee the privilege to use a portion of the radio frequency spectrum in a given geographical area for broadcasting purposes. The licenses are generally straddled with additional restrictions that...

  • Cellular frequencies
    Cellular frequencies
    All cellular phone networks worldwide use a portion of the radio frequency spectrum designated as ultra high frequency, or "UHF", for the transmission and reception of their signals. The ultra high frequency band is also shared with television, Wi-Fi and Bluetooth transmission...

  • Radio Resource Management
    Radio resource management
    Radio resource management is the system level control of co-channel interference and other radio transmission characteristics in wireless communication systems, for example cellular networks, wireless networks and broadcasting systems...

  • Spectrum management
    Spectrum management
    Spectrum management is the process of regulating the use of radio frequencies to promote efficient use and gain a net social benefit.The term radio spectrum typically refers to the full frequency range from 3 kHz to 300 GHz that may be used for wireless communication...

  • Ultra-wideband
    Ultra-wideband is a radio technology that can be used at very low energy levels for short-range high-bandwidth communications by using a large portion of the radio spectrum. UWB has traditional applications in non-cooperative radar imaging...

  • Frequency coordinator
    Frequency coordinator
    In 1982, the United States Congress provided the Federal Communications Commission the statutory authority to use frequency coordinators to assist in developing and managing the Private Land Mobile Radio spectrum...

  • Earth observation satellites transmission frequencies
    Earth observation satellites transmission frequencies
    The earth is constantly being monitored by a great number earth observation satellites. These artificial satellites have onboard sensors from which they gather data. The data is transmitted back to earth via radio frequency...

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.