Few topics are as basic to RF and Wireless communications as the RF spectrum. On this
page, we provide some introductory material and interesting resources on the nature of the RF
spectrum and spectrum allocations.
The term Radio Frequency (RF or rf) refers to the electromagnetic field that is generated
when an alternating current is input to an antenna. This field, also
called an RF field or radio wave, can be used for wireless broadcasting and communications over a
significant portion of the electromagnetic radiation spectrum -- from about 9 kilohertz (kHz) to
thousands of gigahertz (GHz). This portion is referred to as the RF Spectrum. As the frequency
is increased beyond the RF spectrum, electromagnetic energy takes the form of infrared (IR),
visible light, ultraviolet (UV), X rays, and gamma rays.
Many types of wireless devices make use of RF fields -- radio, television, cordless and cellular
telephones, satellite communication systems, and many measuring and instrumentation systems used
in manufacturing. Some wireless devices, such as remote control boxes and cordless mice,
operate at IR or visible light frequencies. The RF spectrum is divided into several ranges, or bands.
Each of these bands, other than the lowest frequency segment, represents an increase of frequency
corresponding to an order of magnitude (power of ten). The chart at the top of the page depcits the
eight bands in the RF spectrum, showing frequency and bandwidth ranges.
Internationally, the RF spectrum is allocated by the International Telecommunication Union (ITU)
to various classes of service according to different regions of the world. Within the United States
and its possessions, the RF spectrum is further allocated to non-Government and Government users.
The Federal Communications Commission (FCC), acting under the authority of Congress, is
responsible for the allocation and assignment of frequencies to non-Government users. The
National Telecommunications and Information Administration (NTIA) is responsible for the
allocation and assignment of frequencies to departments and agencies of the U.S. Government.
NTIA performs its functions through the assistance of the Interdepartment Radio Advisory
Committee (IRAC). The IRAC is also responsible for maintaining the National Table of
Frequency Allocations. Coordination between non-Government and Government users of
the RF spectrum is accomplished by joint meetings of the FCC and the NTIA. The NTIA
is also responsible for maintaining the National Table of Frequency Allocations.
Coordination between non-Government and Government users of the RF spectrum is
accomplished by joint meetings of the FCC and the NTIA.
The NTIA Manual of Regulations & Procedures for Federal Radio Frequency Management is
the guidebook for frequency authorization in the United States and Possessions.
Within the manual the required information is defined and the standards and guidelines
are provided. The process for filing with the NTIA is provided in detail in Chapter 9
of the NTIA manual.
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