Asymmetric Digital Subscriber Line

digital telephone line for fast Internet connection through regular telephone cables (the line is asymmetrical because the connection is faster in one direction than the other), ADSL

Asymmetric Digital Subscriber Line (ADSL) is a form of DSL, a data communications technology that enables faster data transmission over copper telephone lines than a conventional voiceband modem can provide. It does this by utilizing frequencies that are not used by a voice telephone call. A splitter - or microfilter - allows a single telephone connection to be used for both ADSL service and voice calls at the same time. Because phone lines vary in quality and were not originally engineered with ADSL in mind, it can generally only be used over short distances, typically less than 3mi (5 km).
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<communications, protocol> (ADSL, or Asymmetric Digital Subscriber Loop) A form of Digital Subscriber Line in which the bandwidth available for downstream connection is significantly larger then for upstream. Although designed to minimise the effect of crosstalk between the upstream and downstream channels this setup is well suited for web browsing and client-server applications as well as for some emerging applications such as video on demand.
The data-rate of ADSL strongly depends on the length and quality of the line connecting the end-user to the telephone company. Typically the upstream data flow is between 16 and 640 kilobits per second while the downstream data flow is between 1.5 and 9 megabits per second. ADSL also provides a voice channel.
ADSL can carry digital data, analog voice, and broadcast MPEG2 video in a variety of implementations to meet customer needs.
["Data Cooks, But Will Vendors Get Burned?", "Supercomm Spotlight On ADSL" & "Lucent Sells Paradine", Wilson & Carol, Inter@ctive Week Vol. 3 #13, p1 & 6, June 24 1996].
See also Carrierless Amplitude/Phase Modulation, Discrete MultiTone.
ADSL Forum.
(1998-05-18)