सदस्य:MNCEBroadband
This page is about telecommunications signalling methods. For high-speed Internet access, see Broadband Internet access.
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The term broadband refers to a telecommunications signal of greater bandwidth, in some sense, than another standard or usual signal (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 radio systems engineering, but became popularized after MediaOne adopted it as part of a marketing campaign in 1996 to sell their high speed data access. The slogan was "This is Broadband. This is the Way". The term has never been formally defined, even though it is used widely and has been the subject of many policy debates, and the FCC "National Broadband Plan".
Contents [hide] 1 In telecommunication 2 In DSL 3 In Ethernet 4 In power-line communication 5 In video 6 See also 7 References 8 External links
[edit] In telecommunicationBroadband in telecommunications refers to a signaling method that includes or handles a relatively wide range (or band) of frequencies, which may be divided into channels or frequency bins. 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. 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. 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 only receives 1 to 5 channels. In data communications a digital modem will transmit a datarate of 56 kilobits per seconds (kbit/s) over a 4 kilohertz wide telephone line (narrowband or voiceband). However when that same line is converted to an non-loaded twisted-pair wire (no telephone filters), it becomes hundreds of kilohertz wide (broadband) and can carry several megabits per second (ADSL).
[edit] In DSLThe 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 located above (i.e., at higher frequency than) the baseband voice channel on a single pair of wires.[1]
[edit] In EthernetA baseband transmission sends one type of signal using a medium's full bandwidth, as in 100BASE-T Ethernet. Ethernet, however, is the common interface to broadband modems such as DSL data links, and has a high data rate itself, so is sometimes referred to as broadband. Ethernet provided over cable modem is a common alternative to DSL.
[edit] In power-line communicationPower 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).
Broadband Over Powerline (BPL) has been a subject of experimentation but not deployment.
[edit] In videoBroadband in analog video distribution is traditionally used to refer to systems such as cable television, where the individual channels are modulated on carriers at fixed frequencies.[2] 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 .[3] 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 in order to view them.
Broadband video is also sometimes used to describe IPTV Video on demand.[4]
[edit] See alsoBISDN Broadband Integrated Services Digital Network Broadband mapping in the United States Full service broadband Global broadband and innovations Mobile broadband Narrowband National broadband plans from around the world Ultra-wideband Wideband Wireless broadband [edit] References1.^ broadband - Definitions from Dictionary.com 2.^ Home Technology Integration and Cedia Installer I By Ron Gilster, Helen Heneveld 3.^ Cabling Installation & Maintenance 4.^ The Guardian: BT Vision boasts 150,000 customers [edit] External linksBroadband gap European broadband portal DSL / Broadband resourcesde:Breitbandkommunikation hi:विस्तृत पट्टी no:Bredbånd ru:Broadband fi:Laajakaista ta:அகன்றவரிசை ur:عریض الشریط zh-yue:寬頻 zh:寬頻