radio frequency, range of electromagnetic waves with a frequency
or wavelength suitable for utilization in radio communication.
Some of these waves serve as carriers of the lower-frequency
audio waves; others are modulated by video or digital
information. Short waves have relatively high frequencies; long
waves have relatively low frequencies. Radio waves are
identified by their frequencies, expressed in kilohertz (kHz),
i.e., thousands of cycles per second, in megahertz (MHz), i.e.,
millions of cycles per second, or in gigahertz, i.e., billions
of cycles per seconds. Signals in the amplitude modulation (AM)
broadcast band have frequencies ranging from 540 to 1,800 kHz.
Frequency modulation (FM) broadcast frequencies range from 88
MHz to 108 MHz. A range, or band, of radio frequencies is
regularly assigned to a broadcasting station or service by the
nation in which it operates. In the United States, the Federal
Communications Commission is responsible for that task.
Countries cooperate on on a worldwide basis