VDSL

VDSL
Very high speed digital subscriber line transceivers
StatusIn force
Year started2001
Latest version(11/15)
November 2015
OrganizationITU-T
CommitteeITU-T Study Group 15
Related standardsG.993.1, G.993.2
Domaintelecommunications
LicenseFreely available
Websitewww.itu.int/rec/T-REC-G.993.2

Very high-speed digital subscriber line (VDSL)[1] and very high-speed digital subscriber line 2 (VDSL2)[2] are digital subscriber line (DSL) technologies providing data transmission faster than the earlier standards of asymmetric digital subscriber line (ADSL) G.992.1, G.992.3 (ADSL2) and G.992.5 (ADSL2+).

VDSL offers speeds of up to 52 Mbit/s downstream and 16 Mbit/s upstream,[3] over a single twisted pair of copper wires using the frequency band from 25 kHz to 12 MHz.[4] These rates mean that VDSL is capable of supporting applications such as high-definition television, as well as telephone services (voice over IP) and general Internet access, over a single connection. VDSL is deployed over existing wiring used for analog telephone service and lower-speed DSL connections. This standard was approved by the International Telecommunication Union (ITU) in November 2001.

Second-generation systems (VDSL2; ITU-T G.993.2 approved in February 2006)[5] use frequencies of up to 30 MHz to provide data rates exceeding 100 Mbit/s simultaneously in both the upstream and downstream directions. The maximum available bit rate is achieved at a range of about 300 metres (980 ft); performance degrades as the local loop attenuation increases.

  1. ^ "ITU-T Recommendation G.993.1: Very high speed digital subscriber line transceivers (VDSL)". Retrieved 24 July 2016.
  2. ^ "ITU-T Recommendation G.993.2: Very high speed digital subscriber line transceivers 2 (VDSL2)". Retrieved 24 July 2016.
  3. ^ "VDSL Speed". HowStuffWorks. 21 May 2001.
  4. ^ "G.993.1 (06/04)". ITU.
  5. ^ "New ITU Standard Delivers 10x ADSL Speeds: Vendors applaud landmark agreement on VDSL2". News release. International Telecommunication Union. 27 May 2005. Retrieved 22 September 2011.

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