In telecommunication, a band - sometimes called a frequency band - is a specific range of frequencies in the radio frequency (RF) spectrum, which is divided among ranges from very low frequencies (vlf) toextremely high frequencies (ehf). Each band has a defined upper and lower frequency limit. Because two radio transmitters sharing the same frequency band cause mutual interference, band usage is regulated. International use of the radio spectrum is regulated by the International Telecommunication Union (ITU). Domestic use of the radio spectrum is regulated by national agencies such as the Federal Communications Commission (FCC) in the U.S. Regulatory organizations assign each transmission source a band of operation, a transmitter radiation pattern, and a maximum transmitter power. Bands, Frequency Ranges, and Allocations: (1) Very low frequencies (vlf) range from 3 to 30 kilohertz (kHz). Time signals and standard frequencies are among the users of this band. (2) Low frequencies (lf) range from 30 to 300 kHz. Fixed, maritime mobile and navigational systems and radio broadcasting are among the users of this band. (3) Medium frequencies (mf) range from 300 to 3000 kHz. Land, maritime mobile and radio broadcasting are among the users of this band. (4) High frequencies (hf) - also called shortwaves - range from 3 to 30 megahertz (MHz). Fixed, mobile, aeronautical and marine mobile, amateur radio, and radio broadcasting are among the users of this band. (5) Very high frequencies (vhf) range from 30 to 300 MHz. Fixed, mobile, aeronautical and marine mobile, amateur radio, television and radio broadcasting, and radio navigation are among the users of this band. (6) Ultra high frequencies (uhf) range from 300 to 3000 MHz. Fixed, mobile, aeronautical and marine mobile, amateur radio, television, radio navigation and location, meteorological, and space communication are among the users of this band. (7) Super high frequencies (shf) range from 3 to 30 gigahertz (GHz). Fixed, mobile, radio navigation and location, and space and satellite communication are among the users of this band. (8) Extremely high frequencies (ehf) range from 30 to 300 GHz. Amateur radio, satellite, and earth and space exploration are among the users of this band