Radio frequency spectrum
The radio spectrum is the part of the electromagnetic spectrum from 1 Hz to 3000 GHz (3 THz) allocated to some 40 Radiocommunication services in line to the Radio Regulations (RR) of the International Telecommunication Union (ITU)
Telecommunications media: The radio-frequency spectrum
Before 1930 the radio spectrum above 30 megahertz was virtually empty of man-made signals. Today, civilian radio signals populate the radio spectrum in eight frequency bands, ranging from very low frequency (VLF), starting at 3 kilohertz, and extending to extremely high frequency (EHF), ending at 300 gigahertz.
