Narrowband signals are signals that occupy a narrow range of frequencies or that have a small
fractional bandwidth. In the
audio spectrum, ''narrowband sounds'' are sounds that occupy a narrow range of
frequencies. In
telephony
Telephony ( ) is the field of technology involving the development, application, and deployment of telecommunications services for the purpose of electronic transmission of voice, fax, or data, between distant parties. The history of telephony is ...
, narrowband is usually considered to cover frequencies 300–3400 Hz, i.e. the
voiceband.
In
radio communications, a narrowband channel is a
channel in which the
bandwidth of the message does not significantly exceed the channel's
coherence bandwidth
Coherence bandwidth is a statistical measurement of the range of frequencies over which the channel can be considered "flat", or in other words the approximate maximum bandwidth or frequency interval over which two frequencies of a signal are like ...
.
In the study of wired channels, ''narrowband'' implies that the channel under consideration is sufficiently narrow that its
frequency response
In signal processing and electronics, the frequency response of a system is the quantitative measure of the magnitude and Phase (waves), phase of the output as a function of input frequency. The frequency response is widely used in the design and ...
can be considered flat. The message bandwidth will therefore be less than the
coherence bandwidth
Coherence bandwidth is a statistical measurement of the range of frequencies over which the channel can be considered "flat", or in other words the approximate maximum bandwidth or frequency interval over which two frequencies of a signal are like ...
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 government that regulates communications by radio, television, wire, internet, wi-fi, satellite, and cable across the United States. The FCC maintains j ...
(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 systems to migrate to narrowband (12.5 kHz bandwidth or equivalent) systems by 1 January 2013.
See also
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Broadband
In telecommunications, broadband or high speed is the wide-bandwidth (signal processing), bandwidth data transmission that exploits signals at a wide spread of frequencies or several different simultaneous frequencies, and is used in fast Inter ...
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Electromagnetic interference
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Land mobile service
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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, Hamlet (place), hamlets, on far ...
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Ultra-wideband
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Wideband
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Narrowband IoT
Call 911References
External links
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* {{cite web , title=Narrowbanding resource guide , year=2013 , url=http://www.narrowband.us/ , via=narrowband.us
Radio