Asymmetric Digital Subscriber Line


asymmetric digital subscriber line

[¦ā·sə′me·trik ¦dij·ə·dəl ‚səb′skrī·bər ‚līn] (communications) A broadband communication technology designed for use on conventional telephone lines, which reserves more bandwidth for receiving data (1-8 megabits per second) than for sending data (100-800 kilobits per second). Abbreviated ADSL.

Asymmetric Digital Subscriber Line

(communications, protocol)(ADSL, or Asymmetric DigitalSubscriber Loop) A form of Digital Subscriber Line in whichthe bandwidth available for downstream connection issignificantly larger then for upstream. Although designedto minimise the effect of crosstalk between the upstream anddownstream channels this setup is well suited for web browsing and client-server applications as well as forsome emerging applications such as video on demand.

The data-rate of ADSL strongly depends on the length andquality of the line connecting the end-user to the telephonecompany. Typically the upstream data flow is between 16 and640 kilobits per second while the downstream data flow isbetween 1.5 and 9 megabits per second. ADSL also provides avoice channel.

ADSL can carry digital data, analog voice, and broadcastMPEG2 video in a variety of implementations to meet customerneeds.

["Data Cooks, But Will Vendors Get Burned?", "SupercommSpotlight 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.