Bandwidth is a measurement of how much information (voice, data etc.) can be sent via given frequencies in the electromagnetic spectrum.
Visible light is a familiar spectrum, ranging in frequencies from red to violet with each color being a unique frequency. Frequencies are measured in Hertz (Hz), although the older method of cycles per second is more intuitive.
Radio waves also have a spectrum of frequencies all of which are lower than light.
The spectrum of common radio frequencies range from the radio AM dial (Kilohertz/KHz) to broadcast television and FM radio (MegaHertz/MHz) and into things like WiFi at 2.4 GigaHertz (GHz). Kilo=Thousands. Mega=Millions Giga=Billions.
Within an assigned frequency band – such as the 2.4 GHz. WiFi band — there are smaller slices of frequencies called channels, each of which can provide bandwidth to carry information without interfering with other channels.
In the wireless world, if you add up all of the bands which are approved for use, this is known as the assigned wireless spectrum.
The bands, and the width of the channels needed to create bandwidth are measured in MegaHertz (MHz). This is often confusing to the initiated since MHz can refer to a specific frequency, to a band of frequencies and to the actual amount of spectrum being used.
Spectrum and Bandwidth – Deficit and Crunch
“Spectrum deficit” and “spectrum crunch” are used most commonly among those associated with providing and regulating wireless services.
However, a survey among executives, engineers, investors and financial analysts who are involved with other (non-carrier) technologies found that the phrase was not as instantly intuitive as bandwidth crunch which is the directly observable consequence of spectrum deficits, crunches, or shortages.