Broadband
Broadband in telecommunications is a term that refers to a signaling method that includes or handles a relatively wide range of frequencies, which may be divided into channels or frequency bins. Broadband is always a relative term, understood according to its context. The wider the bandwidth, greater is 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 "normal" may be capable of receiving a certain range of channels; one described as "broadband" will receive more channels. In data communications a modem will transmit a bandwidth of 64 kilobits per seconds (kbit/s) over a telephone line; over the same telephone line a bandwidth of several megabits per second can be handled by ADSL, which is described as broadband (relative to a modem over a telephone line, although much less than can be achieved over a fibre optic circuit, for example).[citation needed]
Broadband in data communications may have the same meaning as above, so that data transmission over a fiber optic cable would be referred to as broadband as compared to a telephone modem operating at 600 bits per second.[citation needed]
However, broadband in data communications is frequently used in a more technical sense to refer to data transmission where multiple pieces of data are sent simultaneously to increase the effective rate of transmission, regardless of actual data rate. In network engineering this term is used for methods where two or more signals share a medium.[citation needed]
The various forms of Digital Subscriber Line (DSL) services are broadband in the sense that digital information is sent over a high-bandwidth channel above the baseband voice channel on a single pair of wires.[citation needed]
A 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 provisioned over cable modem is a common alternative to DSL.[citation needed]
Users who need more than DSL or cable modem speeds will often use metro ethernet, when available, rather than older and often more expensive (per megabit) than T-carrier, E-carrier in appropriate parts of the world, or Asynchronous Transfer Mode. Metro ethernet is usually implemented over a metropolitan all-optical network.[citation needed]
Retrieved from "http://en.wikipedia.org/wiki/Broadband"
Broadband in data communications may have the same meaning as above, so that data transmission over a fiber optic cable would be referred to as broadband as compared to a telephone modem operating at 600 bits per second.[citation needed]
However, broadband in data communications is frequently used in a more technical sense to refer to data transmission where multiple pieces of data are sent simultaneously to increase the effective rate of transmission, regardless of actual data rate. In network engineering this term is used for methods where two or more signals share a medium.[citation needed]
The various forms of Digital Subscriber Line (DSL) services are broadband in the sense that digital information is sent over a high-bandwidth channel above the baseband voice channel on a single pair of wires.[citation needed]
A 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 provisioned over cable modem is a common alternative to DSL.[citation needed]
Users who need more than DSL or cable modem speeds will often use metro ethernet, when available, rather than older and often more expensive (per megabit) than T-carrier, E-carrier in appropriate parts of the world, or Asynchronous Transfer Mode. Metro ethernet is usually implemented over a metropolitan all-optical network.[citation needed]
Retrieved from "http://en.wikipedia.org/wiki/Broadband"
Broadband Internet access, often shortened to just "broadband", is high speed Internet access—typically contrasted with dial-up access over modem.
Dial-up modems are generally only capable of a maximum bitrate of 56 kbit/s (kilobits per second) and require the full use of a telephone line—whereas broadband technologies supply at least double this speed and generally without disrupting telephone use.
Although various minimum speeds have been used in definitions of broadband, ranging up from 64 kbit/s up to 1.0 Mbit/s, the OECD Broadband Statistics report is typical in counting only download speeds equal to or faster than 256 kbit/s as broadband, and the US FCC use 200 kbit/s in their definition.
Speeds are defined in terms of maximum download because several common consumer broadband technologies such as ADSL are "asymmetric" - supporting much slower upload speeds than download.
"Broadband penetration" is now treated as a key economic indicator.
Dial-up modems are generally only capable of a maximum bitrate of 56 kbit/s (kilobits per second) and require the full use of a telephone line—whereas broadband technologies supply at least double this speed and generally without disrupting telephone use.
Although various minimum speeds have been used in definitions of broadband, ranging up from 64 kbit/s up to 1.0 Mbit/s, the OECD Broadband Statistics report is typical in counting only download speeds equal to or faster than 256 kbit/s as broadband, and the US FCC use 200 kbit/s in their definition.
Speeds are defined in terms of maximum download because several common consumer broadband technologies such as ADSL are "asymmetric" - supporting much slower upload speeds than download.
"Broadband penetration" is now treated as a key economic indicator.
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