The radio spectrum consists of a finite number of frequencies, typically with only one signal being able to be transmitted on a given frequency (if two users attempt to transmit on the same frequency in close proximity to each other, interference may occur). Therefore, to accommodate a large number of persons using the radio spectrum with minimum interference, the spectrum must be regulated and managed.
There are varying rules and regulations concerning the management of the spectrum in different parts of the world, however, one of the general practices is to divide the radio frequency spectrum into a number of frequency bands and designate the general purposes /services for which each band may be utilized. This process is referred to as the allocation of frequency bands to radiocommunication services.
The allocation of services to frequency bands helps the regulator to, among other things,
(1) assign frequencies to users based on the service required and
(2) narrow down potential causes of interference.