Narrowband signals are signals that occupy a narrow range of frequencies or that have a small
fractional bandwidth. In the
audio
Audio most commonly refers to sound, as it is transmitted in signal form. It may also refer to:
Sound
*Audio signal, an electrical representation of sound
*Audio frequency, a frequency in the audio spectrum
* Digital audio, representation of sou ...
spectrum, narrowband sounds are sounds that occupy a narrow range of
frequencies
Frequency is the number of occurrences of a repeating event per unit of time. It is also occasionally referred to as ''temporal frequency'' for clarity, and is distinct from ''angular frequency''. Frequency is measured in hertz (Hz) which is e ...
. In
telephony
Telephony ( ) is the field of technology involving the development, application, and deployment of telecommunication services for the purpose of electronic transmission of voice, fax, or data, between distant parties. The history of telephony is i ...
, narrowband is usually considered to cover frequencies 300–3400 Hz, i.e. the
voiceband
A voice frequency (VF) or voice band is the range of audio frequencies used for the transmission of speech.
Frequency band
In telephony, the usable voice frequency band ranges from approximately 300 to 3400 Hz. It is for this reason t ...
.
In
radio communications
Radio is the technology of signaling and communicating using radio waves. Radio waves are electromagnetic waves of frequency between 30 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmi ...
, a narrowband channel is a
channel in which the
bandwidth of the message does not significantly exceed the channel's
coherence bandwidth.
In the study of wired channels, ''narrowband'' implies that the channel under consideration is sufficiently narrow that its
frequency response can be considered flat. The message bandwidth will therefore be less than the
coherence bandwidth of the channel. That is, no channel has perfectly
flat fading, but the analysis of many aspects of wireless systems is greatly simplified if flat fading can be assumed.
Two-way radio narrowband
Two-Way Radio Narrowbanding refers to a U.S.
Federal Communications Commission
The Federal Communications Commission (FCC) is an independent agency of the United States federal government that regulates communications by radio, television, wire, satellite, and cable across the United States. The FCC maintains jurisdicti ...
(FCC) Order issued in December 2004 requiring all CFR 47 Part 90 VHF (150-174 MHz) and UHF (421-470 MHz) PLMR (Private Land Mobile Radio) licensees operating legacy wideband (25 kHz bandwidth) voice or data/
SCADA
Supervisory control and data acquisition (SCADA) is a control system architecture comprising computers, networked data communications and graphical user interfaces for high-level supervision of machines and processes. It also covers sensors and o ...
systems to migrate to narrowband (12.5 kHz bandwidth or equivalent) systems by January 1, 2013.
[{{Cite web , url=http://hraunfoss.fcc.gov/edocs_public/attachmatch/FCC-04-292A1.pdf , title=FCC Order issued in December of 2004 , access-date=2010-08-29 , archive-date=2013-07-24 , archive-url=https://web.archive.org/web/20130724045248/http://hraunfoss.fcc.gov/edocs_public/attachmatch/FCC-04-292A1.pdf , url-status=dead ]
See also
*
Broadband
In telecommunications, broadband is wide bandwidth data transmission which transports multiple signals at a wide range of frequencies and Internet traffic types, that enables messages to be sent simultaneously, used in fast internet connections. ...
*
Electromagnetic interference
Electromagnetic interference (EMI), also called radio-frequency interference (RFI) when in the radio frequency spectrum, is a disturbance generated by an external source that affects an electrical circuit by electromagnetic induction, electrost ...
*
Land mobile service
*
Rural internet
Rural Internet describes the characteristics of Internet service in rural areas (also referred to as "the country" or "countryside"), which are settled places outside towns and cities. Inhabitants live in villages, hamlets, on farms and in other ...
*
Ultra-wideband
*
Wideband
*
Narrowband IoT
References
External links
FCC websiteFCC Part 90 LMR VHF/UHF Narrowbanding Information and Licensee ResourcesNarrowbanding Resource Guide for 2013
Radio