Band (radio)
A band is a small section of the spectrum of radio communication frequencies, in which channels are usually used or set aside for the same purpose. Examples include:
- aircraft band (108~136 MHz), for air traffic control
- FM broadcast band (88~108 MHz, except 76~90 in Japan)
- AM broadcast band (530~1610kHz, to 1700 in the Americas)
- upper VHF TV band (174~216 MHz in the Americas)
- L band (1452~1492 MHz) for digital radio (DAB) outside the US
- amateur radio bands among several different frequencies
- shortwave bands, including several amateur and broadcast sub-bands
- military bands
- radionavigation beacons, such as LORAN and GPS
- citizens' band
Each of these bands has a basic bandplan which dictates how it is to be used and shared, to avoid interference and to set protocol for the compatibility of transmitters and receivers.
Note that as a matter of physics, bands are divided at wavelengths of 10n metres, or frequencies of 3×10n hertz. For example, 30 MHz or 10 m divides shortwave (lower and longer) from VHF (shorter and higher). These are the parts of the radio spectrum, and not its frequency allocation.