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 soun ...
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 th ...
.
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 transmitt ...
, 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
In signal processing and electronics, the frequency response of a system is the quantitative measure of the magnitude and phase of the output as a function of input frequency. The frequency response is widely used in the design and analysis of s ...
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
In wireless communications, fading is variation of the attenuation of a signal with various variables. These variables include time, geographical position, and radio frequency. Fading is often modeled as a random process. A fading channel is ...
, 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 jurisd ...
(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 an ...
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
Land mobile service (short: LMS) is – in line to ITU Radio Regulations – a mobile service between base stations and land mobile stations, or between land mobile stations.
In accordance with ''ITU Radio Regulations'' (article 1) variations o ...
*
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
Ultra-wideband (UWB, ultra wideband, ultra-wide band and ultraband) is a radio technology that can use a very low energy level for short-range, high-bandwidth communications over a large portion of the radio spectrum. UWB has traditional applicati ...
*
Wideband
In communications, a system is wideband when the message bandwidth significantly exceeds the coherence bandwidth of the channel. Some communication links have such a high data rate that they are forced to use a wide bandwidth; other links may h ...
*
Narrowband IoT
Narrowband Internet of things (NB-IoT) is a low-power wide-area network (LPWAN) radio technology standard developed by 3GPP for cellular devices and services. The specification was frozen in 3GPP Release 13 ( LTE Advanced Pro), in June 2016. Ot ...
References
External links
FCC websiteFCC Part 90 LMR VHF/UHF Narrowbanding Information and Licensee ResourcesNarrowbanding Resource Guide for 2013
Radio