Broadband
Encyclopedia
The term broadband refers to a telecommunications signal or device of greater bandwidth, in some sense, than another standard or usual signal or device (and the broader the band, the greater the capacity for traffic). Different criteria for "broad" have been applied in different contexts and at different times. Its origin is in physics, acoustics
and radio systems engineering, where it had been used with a meaning similar to wideband
.
However, the term became popularized through the 1990s as a vague marketing term for Internet access
.
.
Broadband is always a relative term
, understood according to its context. The wider (or broader) the bandwidth of a channel, the greater the information-carrying capacity, given the same channel quality. In radio
, for example, a very narrow-band signal will carry Morse code
; a broader band will carry speech; a still broader band is required to carry music
without losing the high audio frequencies
required for realistic sound reproduction.
This broad band is often divided into channels or frequency bins using passband
techniques to allow frequency-division multiplexing
, instead of sending one higher-quality signal.
A television
antenna described as "broadband" may be capable of receiving a wide range of channels; while a single-frequency or Lo-VHF antenna is "narrowband" since it receives only 1 to 5 channels.
The US federal standard FS-1037C defines "broadband" just as a synonym for wideband
.
In data communications a 56k modem
will transmit a data rate of 56 kilobits per second (kbit/s) over a 4 kilohertz wide telephone line
(narrowband or voiceband
).
The various forms of Digital Subscriber Line
(DSL) services are broadband in the sense that digital information is sent over a high-bandwidth channel. This channel is at higher frequency than the baseband
voice channel, so it can support plain old telephone service
on a single pair of wires at the same time.
However when that same line is converted to a non-loaded twisted-pair wire (no telephone filters), it becomes hundreds of kilohertz wide (broadband) and can carry several megabits per second using very-high-bitrate digital subscriber line (VDSL) techniques.
In the late 1980s, the Broadband Integrated Services Digital Network
(B-ISDN) used the term to refer to a broad range of bit rate
s, independent of physical modulation details.
s use a simple line code
to transmit one type of signal using a medium's full bandwidth using its baseband
(from zero through the highest frequency needed).
Most versions of the popular Ethernet
family are given names such as the original 1980s 10BASE5
to indicate this.
Networks that use cable modem
s on standard cable television
infrastructure are called broadband to indicate the wide range of frequencies that can include multiple data users as well as traditional television channels on the same cable.
Broadband systems usually use a different radio frequency
modulated by the data signal for each band.
The total bandwidth of the medium is larger than the bandwidth of any channel.
The 10BROAD36
broadband variant of Ethernet was standardized by 1985, but was not commercially successful.
The DOCSIS
standard became available to consumers in the late 1990s, to provide Internet access
to cable television residential customers. Matters were further confused by the fact that the 10PASS-TS
standard for Ethernet ratified in 2008 used DSL technology, and both cable and DSL modems often have Ethernet connectors on them.
Power lines
have also been used for various types of data communication. Although some systems for remote control are based on narrowband
signaling, modern high-speed systems use broadband signaling to achieve very high data rates. One example is the ITU-T
G.hn
standard, which provides a way to create a high-speed (up to 1 Gigabit/s) Local area network
using existing home wiring (including power lines, but also phone lines and coaxial cables
).
video
distribution is traditionally used to refer to systems such as cable television
, where the individual channels are modulated
on carriers at fixed frequencies. In this context, baseband
is the term's antonym
, referring to a single channel of analog video, typically in composite
form with separate baseband audio
. The act of demodulating converts broadband video to baseband video.
However, broadband video in the context of streaming
Internet
video has come to mean video files that have bitrates high enough to require broadband Internet access
for viewing.
Broadband video is also sometimes used to describe IPTV
Video on demand
.
defined "broadband service" in 1988 as requiring transmission channels capable of supporting bit rate
s greater than the primary rate
which ranged from about 1.5 to 2 Mbit/s.
The US National Information Infrastructure
project during the 1990s brought the term into public policy debates.
Broadband became a marketing buzzword
for telephone and cable companies to sell their more expensive higher data rate products, especially for Internet access
.
In the US National Broadband Plan
of 2009 it was defined as "Internet access that is always on and faster than the traditional dial-up access".
The same agency has defined it differently through the years.
Even though information signals generally travel nearly the speed of light
in the medium no matter what the bit rate, higher rate services are often marketed as "faster" or "higher speeds". (This use of the word "speed" may or may not be appropriate, depending on context. It would be accurate, for instance, to say that a file of a given size will typically take less time to finish transferring if it is being transmitted via broadband as opposed to dial-up.) Consumers are also targeted by advertisements for peak transmission rates, while actual end-to-end rates observed in practice can be lower due to other factors.
Acoustics
Acoustics is the interdisciplinary science that deals with the study of all mechanical waves in gases, liquids, and solids including vibration, sound, ultrasound and infrasound. A scientist who works in the field of acoustics is an acoustician while someone working in the field of acoustics...
and radio systems engineering, where it had been used with a meaning similar to wideband
Wideband
In communications, wideband is a relative term used to describe a wide range of frequencies in a spectrum. A system is typically described as wideband if the message bandwidth significantly exceeds the channel's coherence bandwidth....
.
However, the term became popularized through the 1990s as a vague marketing term for Internet access
Internet access
Many technologies and service plans for Internet access allow customers to connect to the Internet.Consumer use first became popular through dial-up connections in the 20th century....
.
In telecommunication
Broadband in telecommunications refers to a signaling method that includes or handles a relatively wide range (or band) of frequenciesFrequency
Frequency is the number of occurrences of a repeating event per unit time. It is also referred to as temporal frequency.The period is the duration of one cycle in a repeating event, so the period is the reciprocal of the frequency...
.
Broadband is always a relative term
Relative term
A relative term is a term that makes two or more distinct references to objects . A relative term is typically expressed in ordinary language by means of a phrase with explicit or implicit blanks...
, understood according to its context. The wider (or broader) the bandwidth of a channel, the greater the information-carrying capacity, given the same channel quality. In radio
Radio
Radio is the transmission of signals through free space by modulation of electromagnetic waves with frequencies below those of visible light. Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space...
, for example, a very narrow-band signal will carry Morse code
Morse code
Morse code is a method of transmitting textual information as a series of on-off tones, lights, or clicks that can be directly understood by a skilled listener or observer without special equipment...
; a broader band will carry speech; a still broader band is required to carry music
Music
Music is an art form whose medium is sound and silence. Its common elements are pitch , rhythm , dynamics, and the sonic qualities of timbre and texture...
without losing the high audio frequencies
Audio frequency
An audio frequency or audible frequency is characterized as a periodic vibration whose frequency is audible to the average human...
required for realistic sound reproduction.
This broad band is often divided into channels or frequency bins using passband
Passband
A passband is the range of frequencies or wavelengths that can pass through a filter without being attenuated.A bandpass filtered signal , is known as a bandpass signal, as opposed to a baseband signal....
techniques to allow frequency-division multiplexing
Frequency-division multiplexing
Frequency-division multiplexing is a form of signal multiplexing which involves assigning non-overlapping frequency ranges to different signals or to each "user" of a medium.- Telephone :...
, instead of sending one higher-quality signal.
A television
Television
Television is a telecommunication medium for transmitting and receiving moving images that can be monochrome or colored, with accompanying sound...
antenna described as "broadband" may be capable of receiving a wide range of channels; while a single-frequency or Lo-VHF antenna is "narrowband" since it receives only 1 to 5 channels.
The US federal standard FS-1037C defines "broadband" just as a synonym for wideband
Wideband
In communications, wideband is a relative term used to describe a wide range of frequencies in a spectrum. A system is typically described as wideband if the message bandwidth significantly exceeds the channel's coherence bandwidth....
.
In data communications a 56k modem
56K modem
56k modems are voiceband modems nominally capable of download speeds up to 56 kbit/s . In the late 1990s, they were the most popular access method for personal Internet usage, but their use had declined as broadband technologies such as DSL gained wider availability.-Speed:The 56 kbit/s...
will transmit a data rate of 56 kilobits per second (kbit/s) over a 4 kilohertz wide telephone line
Telephone line
A telephone line or telephone circuit is a single-user circuit on a telephone communication system...
(narrowband or voiceband
Voiceband
In electronics, voiceband means the typical human hearing frequency range that is from 20 Hz to 20 kHz. In telephony, it means the frequency range normally transmitted by a telephone line, generally about 200–3600 Hz. Frequency-division multiplexing in telephony normally uses...
).
The various forms of Digital Subscriber Line
Digital Subscriber Line
Digital subscriber line is a family of technologies that provides digital data transmission over the wires of a local telephone network. DSL originally stood for digital subscriber loop. In telecommunications marketing, the term DSL is widely understood to mean Asymmetric Digital Subscriber Line ,...
(DSL) services are broadband in the sense that digital information is sent over a high-bandwidth channel. This channel is at higher frequency than the baseband
Baseband
In telecommunications and signal processing, baseband is an adjective that describes signals and systems whose range of frequencies is measured from close to 0 hertz to a cut-off frequency, a maximum bandwidth or highest signal frequency; it is sometimes used as a noun for a band of frequencies...
voice channel, so it can support plain old telephone service
Plain old telephone service
Plain old telephone service is the voice-grade telephone service that remains the basic form of residential and small business service connection to the telephone network in many parts of the world....
on a single pair of wires at the same time.
However when that same line is converted to a non-loaded twisted-pair wire (no telephone filters), it becomes hundreds of kilohertz wide (broadband) and can carry several megabits per second using very-high-bitrate digital subscriber line (VDSL) techniques.
In the late 1980s, the Broadband Integrated Services Digital Network
Broadband Integrated Services Digital Network
In the 1980s the telecommunications industry expected that digital services would follow much the same pattern as voice services did on the public switched telephone network, and conceived a grandiose end-to-end circuit switched services, known as Broadband Integrated Services Digital Network...
(B-ISDN) used the term to refer to a broad range of bit rate
Bit rate
In telecommunications and computing, bit rate is the number of bits that are conveyed or processed per unit of time....
s, independent of physical modulation details.
In computer networks
Many computer networkComputer network
A computer network, often simply referred to as a network, is a collection of hardware components and computers interconnected by communication channels that allow sharing of resources and information....
s use a simple line code
Line code
In telecommunication, a line code is a code chosen for use within a communications system for baseband transmission purposes...
to transmit one type of signal using a medium's full bandwidth using its baseband
Baseband
In telecommunications and signal processing, baseband is an adjective that describes signals and systems whose range of frequencies is measured from close to 0 hertz to a cut-off frequency, a maximum bandwidth or highest signal frequency; it is sometimes used as a noun for a band of frequencies...
(from zero through the highest frequency needed).
Most versions of the popular Ethernet
Ethernet
Ethernet is a family of computer networking technologies for local area networks commercially introduced in 1980. Standardized in IEEE 802.3, Ethernet has largely replaced competing wired LAN technologies....
family are given names such as the original 1980s 10BASE5
10BASE5
10BASE5 was the original commercially available variant of Ethernet.For its physical layer it used cable similar to RG-8/U coaxial cable but with extra braided shielding. This is a stiff, diameter cable with an impedance of 50 ohms , a solid center conductor, a foam insulating filler, a shielding...
to indicate this.
Networks that use cable modem
Cable modem
A cable modem is a type of network bridge and modem that provides bi-directional data communication via radio frequency channels on a HFC and RFoG infrastructure. Cable modems are primarily used to deliver broadband Internet access in the form of cable Internet, taking advantage of the high...
s on standard cable television
Cable television
Cable television is a system of providing television programs to consumers via radio frequency signals transmitted to televisions through coaxial cables or digital light pulses through fixed optical fibers located on the subscriber's property, much like the over-the-air method used in traditional...
infrastructure are called broadband to indicate the wide range of frequencies that can include multiple data users as well as traditional television channels on the same cable.
Broadband systems usually use a different radio frequency
Radio frequency
Radio frequency is a rate of oscillation in the range of about 3 kHz to 300 GHz, which corresponds to the frequency of radio waves, and the alternating currents which carry radio signals...
modulated by the data signal for each band.
The total bandwidth of the medium is larger than the bandwidth of any channel.
The 10BROAD36
10BROAD36
10BROAD36 is an obsolete computer network standard in the Ethernet family. It was developed during the 1980s and specified in IEEE 802.3b-1985....
broadband variant of Ethernet was standardized by 1985, but was not commercially successful.
The DOCSIS
DOCSIS
Data Over Cable Service Interface Specification is an international telecommunications standard that permits the addition of high-speed data transfer to an existing cable TV system...
standard became available to consumers in the late 1990s, to provide Internet access
Internet access
Many technologies and service plans for Internet access allow customers to connect to the Internet.Consumer use first became popular through dial-up connections in the 20th century....
to cable television residential customers. Matters were further confused by the fact that the 10PASS-TS
10PASS-TS
10PASS-TS is an IEEE 802.3-2008 Physical Layer specification for a full-duplex short reach point-to-point Ethernet link over voice-grade copper wiring, used in Ethernet in the first mile applications....
standard for Ethernet ratified in 2008 used DSL technology, and both cable and DSL modems often have Ethernet connectors on them.
Power lines
Power line communication
Power line communication or power line carrier , also known as power line digital subscriber line , mains communication, power line telecom , power line networking , or broadband over power lines are systems for carrying data on a conductor also used for electric power transmission.A wide range...
have also been used for various types of data communication. Although some systems for remote control are based on narrowband
Narrowband
In radio, narrowband describes a channel in which the bandwidth of the message does not significantly exceed the channel's coherence bandwidth. It is a common misconception that narrowband refers to a channel which occupies only a "small" amount of space on the radio spectrum.The opposite of...
signaling, modern high-speed systems use broadband signaling to achieve very high data rates. One example is the ITU-T
ITU-T
The ITU Telecommunication Standardization Sector is one of the three sectors of the International Telecommunication Union ; it coordinates standards for telecommunications....
G.hn
G.hn
G.hn is the common name for a home network technology family of standards developed under the International Telecommunication Union's Standardization arm and promoted by the HomeGrid Forum...
standard, which provides a way to create a high-speed (up to 1 Gigabit/s) Local area network
Local area network
A local area network is a computer network that interconnects computers in a limited area such as a home, school, computer laboratory, or office building...
using existing home wiring (including power lines, but also phone lines and coaxial cables
Ethernet over coax
Ethernet over Coax is a family of technologies that supports the transmission of Ethernet frames over coaxial cable.- History :The first Ethernet standard, known as 10BASE5 in the family of IEEE 802.3, specified baseband operation over coaxial cable...
).
In video
Broadband in analogAnalog signal
An analog or analogue signal is any continuous signal for which the time varying feature of the signal is a representation of some other time varying quantity, i.e., analogous to another time varying signal. It differs from a digital signal in terms of small fluctuations in the signal which are...
video
Video
Video is the technology of electronically capturing, recording, processing, storing, transmitting, and reconstructing a sequence of still images representing scenes in motion.- History :...
distribution is traditionally used to refer to systems such as cable television
Cable television
Cable television is a system of providing television programs to consumers via radio frequency signals transmitted to televisions through coaxial cables or digital light pulses through fixed optical fibers located on the subscriber's property, much like the over-the-air method used in traditional...
, where the individual channels are modulated
Modulation
In electronics and telecommunications, modulation is the process of varying one or more properties of a high-frequency periodic waveform, called the carrier signal, with a modulating signal which typically contains information to be transmitted...
on carriers at fixed frequencies. In this context, baseband
Baseband
In telecommunications and signal processing, baseband is an adjective that describes signals and systems whose range of frequencies is measured from close to 0 hertz to a cut-off frequency, a maximum bandwidth or highest signal frequency; it is sometimes used as a noun for a band of frequencies...
is the term's antonym
Antonym
In lexical semantics, opposites are words that lie in an inherently incompatible binary relationship as in the opposite pairs male : female, long : short, up : down, and precede : follow. The notion of incompatibility here refers to the fact that one word in an opposite pair entails that it is not...
, referring to a single channel of analog video, typically in composite
Composite video
Composite video is the format of an analog television signal before it is combined with a sound signal and modulated onto an RF carrier. In contrast to component video it contains all required video information, including colors in a single line-level signal...
form with separate baseband audio
Sound recording and reproduction
Sound recording and reproduction is an electrical or mechanical inscription and re-creation of sound waves, such as spoken voice, singing, instrumental music, or sound effects. The two main classes of sound recording technology are analog recording and digital recording...
. The act of demodulating converts broadband video to baseband video.
However, broadband video in the context of streaming
Streaming media
Streaming media is multimedia that is constantly received by and presented to an end-user while being delivered by a streaming provider.The term "presented" is used in this article in a general sense that includes audio or video playback. The name refers to the delivery method of the medium rather...
Internet
Internet
The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide...
video has come to mean video files that have bitrates high enough to require broadband Internet access
Broadband Internet access
Broadband Internet access, often shortened to just "broadband", is a high data rate, low-latency connection to the Internet— typically contrasted with dial-up access using a 56 kbit/s modem or satellite Internet with inherently high latency....
for viewing.
Broadband video is also sometimes used to describe IPTV
IPTV
Internet Protocol television is a system through which television services are delivered using the Internet protocol suite over a packet-switched network such as the Internet, instead of being delivered through traditional terrestrial, satellite signal, and cable television formats.IPTV services...
Video on demand
Video on demand
Video on Demand or Audio and Video On Demand are systems which allow users to select and watch/listen to video or audio content on demand...
.
Internet access
The standards group CCITTITU-T
The ITU Telecommunication Standardization Sector is one of the three sectors of the International Telecommunication Union ; it coordinates standards for telecommunications....
defined "broadband service" in 1988 as requiring transmission channels capable of supporting bit rate
Bit rate
In telecommunications and computing, bit rate is the number of bits that are conveyed or processed per unit of time....
s greater than the primary rate
Primary rate interface
The Primary Rate Interface is a standardized telecommunications service level within the Integrated Services Digital Network specification for carrying multiple DS0 voice and data transmissions between a network and a user....
which ranged from about 1.5 to 2 Mbit/s.
The US National Information Infrastructure
National Information Infrastructure
The National Information Infrastructure was the product of the High Performance Computing and Communication Act of 1991. It was a telecommunications policy buzzword, which was popularized during the Clinton Administration under the leadership of Vice-President Al Gore...
project during the 1990s brought the term into public policy debates.
Broadband became a marketing buzzword
Buzzword
A buzzword is a term of art, salesmanship, politics, or technical jargon that is used in the media and wider society outside of its originally narrow technical context....
for telephone and cable companies to sell their more expensive higher data rate products, especially for Internet access
Internet access
Many technologies and service plans for Internet access allow customers to connect to the Internet.Consumer use first became popular through dial-up connections in the 20th century....
.
In the US National Broadband Plan
National Broadband Plan (United States)
Connecting America: The National Broadband Plan, unveiled March 16, 2010, is a FCC plan which deals with improving broadband Internet access throughout the United States. One goal was providing 100 million American households with access to 100 Mbit/s connections by 2020...
of 2009 it was defined as "Internet access that is always on and faster than the traditional dial-up access".
The same agency has defined it differently through the years.
Even though information signals generally travel nearly the speed of light
Speed of light
The speed of light in vacuum, usually denoted by c, is a physical constant important in many areas of physics. Its value is 299,792,458 metres per second, a figure that is exact since the length of the metre is defined from this constant and the international standard for time...
in the medium no matter what the bit rate, higher rate services are often marketed as "faster" or "higher speeds". (This use of the word "speed" may or may not be appropriate, depending on context. It would be accurate, for instance, to say that a file of a given size will typically take less time to finish transferring if it is being transmitted via broadband as opposed to dial-up.) Consumers are also targeted by advertisements for peak transmission rates, while actual end-to-end rates observed in practice can be lower due to other factors.
See also
- Broadband Integrated Services Digital NetworkBroadband Integrated Services Digital NetworkIn the 1980s the telecommunications industry expected that digital services would follow much the same pattern as voice services did on the public switched telephone network, and conceived a grandiose end-to-end circuit switched services, known as Broadband Integrated Services Digital Network...
- Broadband mapping in the United StatesBroadband mapping in the United StatesBroadband mapping in the United States are efforts to describe geographically how Internet access service from telephone and cable TV companies is available in terms of available speed and price. Mapping has been done on the national as well as the state level...
- National broadband plans from around the worldNational broadband plans from around the worldBroadband is a term normally considered to be synonymous with a high-speed connection to the internet. The term itself is technology neutral; broadband can be delived by a range of technologies including DSL, LTE or next generation access. This page presents an overview of official Government...
- Mobile broadbandMobile BroadbandMobile broadband is the marketing term for wireless Internet access through a portable modem, mobile phone or other mobile device.-Description:...
- Wireless broadband
- Ultra-widebandUltra-widebandUltra-wideband is a radio technology that can be used at very low energy levels for short-range high-bandwidth communications by using a large portion of the radio spectrum. UWB has traditional applications in non-cooperative radar imaging...
- WidebandWidebandIn communications, wideband is a relative term used to describe a wide range of frequencies in a spectrum. A system is typically described as wideband if the message bandwidth significantly exceeds the channel's coherence bandwidth....
- NarrowbandNarrowbandIn radio, narrowband describes a channel in which the bandwidth of the message does not significantly exceed the channel's coherence bandwidth. It is a common misconception that narrowband refers to a channel which occupies only a "small" amount of space on the radio spectrum.The opposite of...
- Broadband universal serviceBroadband universal serviceBroadband universal service, also known as "universal broadband service", refers to government efforts to ensure all citizens have access to Internet service...