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Very High Speed Digital Subscriber Line

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Very High Speed Digital Subscriber Line

DSL technologies
ADSL ANSI T1.413 Issue 2
ITU G.992.1 (G.DMT)
ITU G.992.2 (G.Lite)
ADSL2 ITU G.992.3
ITU G.992.3 Annex J
ITU G.992.3 Annex L
ITU G.992.4
ADSL2+ ITU G.992.5
ITU G.992.5 Annex M
HDSL ITU G.991.1
VDSL ITU G.993.1
VDSL2 ITU G.993.2

Very-high-bit-rate digital subscriber line (VDSL or VHDSL)[1] is a digital subscriber line (DSL) technology providing data transmission faster than ADSL over a single flat untwisted or twisted pair of copper wires (up to 52 Mbit/s downstream and 16 Mbit/s upstream),[2] and on coaxial cable (up to 85 Mbit/s down- and upstream)[3] 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 ITU in November 2001.

Second-generation systems (VDSL2; ITU-T G.993.2 approved in February 2006) 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 meters; performance degrades as the loop attenuation increases.


The concept of VDSL was first published in 1991 through a joint Bellcore-Stanford research study. The study searched for potential successors to the then-prevalent HDSL and relatively new ADSL, which were both 1.5 Mbit/s. Specifically, it explored the feasibility of symmetric and asymmetric data rates exceeding 10 Mbit/s on short phone lines.

VDSL standards

VDSL uses up to 7 different frequency bands, which enables customization of data rate between upstream and downstream depending on the service offering and spectrum regulations. First generation VDSL standard specified both quadrature amplitude modulation (QAM) and discrete multi-tone modulation (DMT). In 2006, ITU-T standardized VDSL in recommendation G.993.2 which specified only DMT modulation for VDSL2.

Version Standard name Common name Downstream rate Upstream rate Approved in
VDSL ITU G.993.1 VDSL 55 Mbit/s 3Mbit/s 2004-06-13
VDSL ITU G.993.2 VDSL2 100 Mbit/s 100 Mbit/s 2006-02-17



  • VDSL is being rolled out mostly in the Hotel Industry in Mauritius by a private Network Solution Integrator company, Enterprise Data Services Ltd (EDS LTD). EDS is not an ISP, but provide the VDSL in hotels as opposed to the expensive cost of fiber optic. The service enables the hotels to provide both wired and wireless Broadband Internet access, video on-demand and music on-demand as well as IP telephony to the residents. Since November 2004, till date, EDS has already completed such installation in 12 hotels.
  • In March 2012 Telkom officially announced that it has begun rolling out 3,700 multi-service access nodes (MSANs) that will replace 2,700 older generation cabinets and add another 1,000 to their number. MSANs that will be installed can be used to offer VDSL services. In January 2013 Telkom announced which 3 areas would receive the new 20 Mbit/s and 40 Mbit/s VDSL services by March 2013.[5]


Hong Kong
  • VDSL is offered by HGC[6] and PCCW. A 10 Mbit/s up and up to 30 Mbit/s down connection costs less than US$11–34 per month with a 18-month to 24-month contract (price is negotiable and each customer get different prices and plans), with unlimited traffic.
  • VDSL plan launched by MTNL[7] (ISP for Delhi NCR and Mumbai[8] for Mumbai city on 25 December 2009. The plan costs US$110 and has a limit of 20GB for data transfer amount and 20 Mbit/s for data transfer speed. After crossing the limit the user has to pay approximately $10 per GB downloaded.[9] Bharti Airtel has introduced a new VDSL plan on 28 March 2010 with speeds of 50 Mbit/s and 100GB of data transfer.The plan cost $300. While Bharat Sanchar Nigam Limited (BSNL) has also launched 2 VDSL plans 16 Mbit/s and 24 Mbit/s which costs approximately $100 and approximately $300, respectively.[10]
  • On August 28, 2009 Bezeq communication company started testing VDSL with 20, 25, 30 and 40 Mbit/s (asymmetric, up speed 1 Mbit/s) in certain areas in north Israel.
  • VDSL services are provided since late 2009 using the Next generation network (NGN) of Bezeq communication company. As of 26/02/2012 NGN is still not available in all areas of the country. The maximum download speed is up to 100 Mbit/s.[11]
  • VDSL is offered by SoftBank also offer competing VDSL services.
  • Japan's VDSL offerings use an FTTx access line network architecture.
  • Alcatel Lucent is also a provider of VDSL in Malaysia.
  • Telekom Malaysia is deploying VDSL with its UniFi service in high-rise and residential apartment buildings.
  • VDSL Network S.B.[12] has also been a provider of VDSL technology for more than 3 years in Malaysia.
  • VDSL2 is offered by PTCL to provide data rates of Up to 100 Mbit/s for 20,000 PKR (US$200) per month. PTCL also offers 100 Mbit/s data rates on the GPON service in selected areas of Pakistan. The 100 Mbit/s connection is based on a dual bonded VDSL link.
South Korea
  • KT and other several providers offer VDSL in the place where FTTH is not available. The speed is varied from 4 Mbit/s to 100 Mbit/s by payment plans, about US$25–40 per month.
  • The VDSL modem is, and never marketed as such, a final link between the telephone line and their building's fiber terminal. As of 2011, FTTB service bandwidth is 100 Mbit/s download and 10 Mbit/s upload, and is a major improvement over ADSL in terms of attaining maximum contract bandwidth.
  • True Corp announced on 30 June 2010 that it would offer "Ultra hi-speed Internet", a VDSL2 services, for high-end condominiums. It's said to be Thailand's first ISP to provide a VDSL2 services. True Corp will offers two packages a 50 Mbit/s downstream and 3 Mbit/s upstream or 30 Mbit/s downstream and 2 Mbit/s. There are no specific date about when it will be available, it said that soon, within 2010.


  • Telekom Austria started providing VDSL2 under the name Gigaspeed in rural areas in November 2009. As of November 2010 Telekom Austria started a widespread campaign to bring VDSL2 (GigaSpeed) to as many customers as possible in metropolitan areas.[13]
  • Belgacom was one of the early adopters of VDSL1, which has since been outphased for the more widely used VDSL2, supplying up to 50/6[14] Mbit/s (DS/US) of videograde quality to support its single-, dual- and mostly triple-play customers all over Belgium. The technology deployment accompanied a large-scale FTTC investment.
  • VDSL2 is offered since June 2013 only by a smaller telecom H1 Telekom in urban areas. Speeds go from 20/2 to 50/15 Mbit/s. It's also available in triple play packages that include TV and telephone. However, internet-only packages aren't available: customers have to get it with phone service. Prices go from 199 kn/month (about 25 euros) for 20/2 connection with 1000 free phone minutes to 299 kn (about 40 euros) for 50/15 Mbit/s connection with 1000 phone minutes included.
Czech Republic
  • VDSL2 is offered by Telefónica O2 in most areas. While the full speed offered is 40 Mbit/s, in some areas only slower speeds can be attained (as of January 2013). O2 do not provide the end user with the ability to customize the upload / download stream, however it can be arranged with its level 2 technical support assistance after clear expression of being aware of potential instability of the connection.
  • TDC is providing VDSL in two larger city areas in Copenhagen and Aarhus from February 2008, most urban parts (100 largest city areas) was announced for March 2008, but this was changed to September 2008. Fullrate and Telenor are providing VDSL the same places as TDC, as they have access to their nodes.
  • Provided in Oulu by DNA, in Turku by Sonera, in various cities by Nebula and in Helsinki and Tampere by Sonera. The services provided in Turku and Oulu are actually based on Cisco's LRE, although at least in Oulu the technology has since been changed to VDSL2. A few universities also provide fiber-optic VDSLs to their students.
  • Erenis (bought by Neuf-Cegetel, now part of SFR) was offering both internet and telephone over VDSL in Paris using FTTB. The broadband was 60 Mbit/s downstream and 6 Mbit/s upstream.[15] This offer has been discontinued in Q2-2007.
  • The French regulator, so called Arcep, have started the evaluation [16] of VDSL2 technology in FTTC mode since July 2011. It's still unclear if field trials or deployment will start in 2012.
  • VDSL2 is currently available in large parts of over 50 major cities through outdoor DSLAMs and in small parts of over 750 cities and towns through the existing indoor DSLAMs with 25:5 Mbit/s or 50:10 Mbit/s downstream/upstream. The infrastructure is mostly owned by Deutsche Telekom, and based on VDSL2 technology with FTTC. The theoretical bandwidth right now is 100:100 Mbit/s (synchronous line) downstream/upstream, but is limited by T-Home to 50:10 Mbit/s downstream/upstream. While VDSL2 was originally only available to customers who purchased the triple play package "Entertain" (starting at €54.95 per month for 25:5 Mbit/s or €59.95 for 50:10 Mbit/s), VDSL2 is now also available to double play customers (starting at €44.95 for 25:5 Mbit/s, with 50:10 Mbit/s available as an option for an additional €5 per month). Competing providers, such as 1&1 and Hansenet, provide double and triple play services on top of Deutsche Telekom's VDSL2, although operating telephony as an NGN service. Local providers, offer up to 120/5 rates. Deutsche Telekom started vectoring of VDSL2 in December 2012 (investing 6 billion Euros) for reaching 100 MBit/s download rate and a higher upload speed.
  • OTE has decided to invest in VDSL2 as a transitional technology until FTTH hits the market.[17]
  • Cyta Hellas as of December 12, 2011 is the first telecommunications company to offer VDSL2 in Greece at speeds of 50/10Mbit/s and 35/3Mbit/s.[18]
  • Starting in October 2008 the largest Hungarian incumbent offers 25 Mbit/s subscriptions to approximately 100,000 households after upgrading part of their network to VDSL.[19]
  • Provided in Akureyri/North East by Tengir.
  • The telecom company Síminn is now implementing VDSL to much of the capital of Reykjavík, starting in 2010. The service is known as Ljósnet[20] and most of the connections available with this service are VDSL2 but some users are apparently being offered GPONsame marketing name.
  • Vortex sells VDSL.
  • TSC has been running VDSL on TUT DSLAM since 2002 and is now running VDSL2 on SINO Telcom DSLAM.
  • TSC is believed to be the first company to run VDSL on public telephone lines.
  • eircom Wholesale launched its FTTC (fibre to the cabinet) VDSL2 network with initial speeds of 70 Mbit/s download and 20 Mbit/s upload on the 20th May 2013.[21] The network and all customer modems being supplied support vectoring technology which will allow higher speeds when it is enabled at some stage in the future. The eircom Wholesale FTTC network is available to all Irish telecommunications providers, including eircom's own retail division on a neutral basis. These companies can use the wholesale network to provide FTTC products to their customers under their own brands with their own billing systems and core national and international networks. The VDSL2 product is available either with or without a POTS dial tone from the local exchange. Where customers opt to retain a dial tone they can continue to use traditional telephone services from their preferred provider alongside their VDSL2 or, where they opt for only a VDSL2 connection, they can provide voice services using VoIP. Most providers supply an access gateway device that contains a VDSL2 modem, router, WiFi hub and two VoIP ports for telephone service (even if these are not enabled).
Isle of Man

Wi-Manx,*Sure:Cable and Wireless and Manx Telecom on the Isle of Man are now offering VDSL at max 40 Mb download and max 2 Mb upload speeds, up from the current 16 Mb/800 kb ADSL2 service. This is available to customers within 2 km of the exchange and will also be available to customers of the other Isle of Man based broadband suppliers.


In 2012, Telecom Italia launched FTTC (Fiber to the cabinet) in some Italian cities such Milan, Rome and Naples, with the offerts "Tuttofibra" at €59 per month and "Internetfibra" at €50 per month. These offerts have the VDSL speed of 30 Mbit/s download and 3 Mbit/s upload, but will be probably changed in 100/10 Mbit/s during next years.

  • VDSL rollout will soon start in Malta via GO ISP at speeds of up to 35  Mbit/s downstream.
  • VDSL only, at a 30 Mbit/s downstream / 2 Mbit/s upstream rate, is offered to residential clients of Monaco Telecom, the incumbent monopoly operator for fixed lines, television and internet provision. At February 2011, this internet service costs €35 per month, use of the provided Monaco Telecom "MT Box", a rebranded Thomson TG789vn modem, is obligatory.
  • VDSL roll-out is being tested by the company KPN. KPN hardly invested in ADSL2+ in 2006, despite the current coverage of only 57% (2007), because they see a better future in VDSL.
  • VDSL is rolled out by Tele2 in 25 different cities on September 1, 2009.
  • VDSL2 was first announced by NextGenTel at the start of 2009, and is now also offered by Tafjord Marked (Mimer) in Ålesund, PowerTech Information Systems in Tønsberg and Oslo and Drangedal Everk (DEAN) in Drangedal. Telenor started offering VDSL subscriptions on Feb 1 2011. Speeds are 25/5, 30/10 and 40/10. NextGenTel has different speeds (30/5 and 40/20) and Powertech has only one tier of 50/20.
  • VDSL2 is offered by Orange Polska in two download speed tiers of 40 Mbit/s and 80 Mbit/s. The highest tier cost is $31 or €24 per month with 2 year contract.
  • VDSL2 is offered in urban areas by Romtelecom at speeds of 30 Mbit/s up to 100 Mbit/s for €10.54 per month with unlimited traffic and includes phone line.
  • VDSL appeared on 8 February 2005. It is provided by megabyte.
  • VDSL appeared on 1 October 2005. It is provided by T-2, offering triple play services with Internet speeds ranging from 1 Mbit/s:256 kbit/s (€16) to 60:25 Mbit/s (€73) at more than 120 locations across the country (75% coverage). A 40:15 Mbit/s connection costs €63 per month.
  • VDSL roll-out by Telefonica began in 2005 in selected places in Madrid. Commercial launch up started on September 2009 (combined with free national telephone calls and TV-over-IP service)[22] and December 2009 (combined with free national calls).[23]
  • Used in the Swisscom TV (former: Bluewin TV)[24] television-over-IP service and in the DSL service with up to 50 Mbit/s downstream and 5 Mbit/s upstream, introduced with lower bitrates in November 2006. The city of Zurich had a vote about putting Fibre (and not VDSL) infrastructure in place in 2007 which was approved by the voters. This "Fiber to the Home" network will be run by the city's power company and will offer maximum speeds of around 100 Mbit bandwidth though it's not clear what the upload speeds or pricing will be. The Swiss telecom giant Swisscom offers VDSL2 in most of Switzerland and is currently migrating the ADSL-lines to VDSL2.
  • Turk Telekom offers VDSL2 services for resale by Turkish ISPs as of July 1, 2008 across 73 of Turkey's 81 provinces. Packages ranging from 20 Mbit/s download/1 Mbit/s upload to 100 Mbit/s download/1 Mbit/s upload speeds are available. 20 Mbit/s will sell for approximately $20, while 100 Mbit/s will sell for $66.[25] Turkish ISP's that will offer the service include TTNET,[26][27] Tellcom,[28] Biri,[29] and Smile.[30]
United Kingdom

British Telecom and resellers:

  • Openreach, the Access Network delivery arm of BT Group conducted successful trials of VDSL using FTTC technology in the Muswell Hill area of North London. Following this trial national rollout commenced under the banner of NGA (Next Generation Access) starting with selected exchange areas around the UK. The product initially offered downstream bit rates of up to 40 Mbit/s and upstream of up to 10 Mbit/s dependent on the distance between the new DSLAM street-cabinet and the end user's premises, and by late 2012, this had increased to downstream bit rates of up to nearly 80 Mbit/s and upstream of up to 20 Mbit/s.[31] Alongside this Openreach are conducting additional trials into the deployment of FTTP (Fibre to the Premises) which although more expensive & complex to implement can provide downstream rates of up to 110 Mbit/s and is thought to be more future proofed than FTTC. Original projections indicated that FTTC was significantly cheaper to implement than FTTP, however current thinking is that the cost difference between the two technologies may be smaller than at first envisaged.
  • As of 2011, the Openreach product is also resold by other ISPs.

Other providers:

  • A number of smaller regional ISPs also exist and sell VDSL based services.
  • For example, Rutland telecom currently offer VDSL technology in some parts of the UK, mainly focused around the county of Rutland. Rutland telecom was the first ISP to offer VDSL services in the UK.[32] Also ask4 Ltd, Ripwire & DRBSY LTD[33] announced the availability of up to 40 Mbit/s VDSL services for business users and consumers across South Yorkshire which utilises the infrastructure being rolled out by the four main councils in the area; Sheffield, Rotherham, Doncaster and Barnsley (collectively known as Digital Region Ltd),[34] an EU government backed project. The network offers up to 40 Mbit/s downstream and up to 10 Mbit/s upstream with an assured level of service. The infrastructure consists of FTTC (Fibre to the Cabinet) with sub loop unbundling to provide the last mile connection to the consumer via existing copper.

North America

United States
  • CenturyLink provides Internet access over FTTN VDSL in Denver, Colorado; Salt Lake City, Utah; Boise, Idaho; Phoenix, Arizona; Seattle, Washington; Omaha, Nebraska; Minneapolis; and the surrounding areas of these cities. In Seattle, Denver, and Minneapolis areas, CenturyLink's rate structure extends up to 40 Mbit/s downstream and 20 Mbit/s upstream, for around $80 per month (December 2011). In Boise, CenturyLink offers 40, 20, or 12 Mbit/s downstream and 5 Mbit/s upstream over VDSL. Other locations are known to support up to 20 Mbit/s downstream.
  • AT&T provides Internet access and television service over VDSL in several regions under the trade-name U-verse. The AT&T service is based on FTTN; FTTP is also used.
  • Verizon offers its FiOS service in some metropolitan areas at speed of up to 300 Mbit/s. The Verizon service is based on FTTP, and normally CAT5e Ethernet (or MoCA ) is used to deliver data service throughout the home. However, VDSL is used in MDUs when running CAT5e or coax to individual units is not practical.
  • LocalTel Communications of Wenatchee, WA offers a single VDSL line to an apartment complex next to their Network Operations Center. Offering 100 Mbit/s Down and 100 Mbit/s up.


  • The sole VDSL supplier in Canberra is TransACT, who use VDSL for Digital TV, Internet and WAN applications over their Fibre-To-The-Curb network.
  • EFTel has commenced a rollout of VDSL2 compatible MSAN (Multi-Service Access Node) technology to exchanges across Australia as part of their BroadbandNext network. As of September 2008, EFTel have successfully installed MSANs in 55 exchanges in readiness for the ratification of VDSL2 in Australia.[35]
  • iiNet began trialing VDSL in Perth in December 2008 offering 100 Mbit/50 Mbit speeds.[36]
  • TPG Telecom have announced that they will deploy VSDL with vectoring to achieve 100Mbit/s downstream speeds in multi dwelling residences in selected inner-city areas.[37]
New Zealand
  • VDSL2 is widely available in towns and cities throughout New Zealand that have been cabinetised as part of Chorus' NGN (Next Generation Network) rollout. Available profiles are 8B (50 Mbit/s) and 17A (100 Mbit/s); which profile is deployed is determined by Chorus at time of installation. All plans are upload speed limited to 10 Mbit/s.
  • VDSL2 is also available to some business customers of Vodafone New Zealand utilizing the network assets of TelstraClear (which Vodafone acquired in 2012).

South America

  • Since mid-2009, Iplan networks NSS started providing FTTH VDSL home connections in the city of Buenos Aires and main areas of La Plata, Quilmes, Lomas de Zamora, Córdoba, Rosario and Mar del Plata. The home service is available through their "Internet Optimo" plan which goes from 2 MB up to 10 MB (80 Mbit/s), providing the same download and upload speed (starting at ARS162 -US$40.50- for 2 Mbit/s).[38]
  • GVT is providing a VDSL network, that reaches speeds up to 50 Mbit/s and 5 Mbit/s upload in their service plans. The company uses equipment of Keymile corp. and Zhone Technologies, Inc.
  • TIM is providing a VDSL network, that reaches speeds up to 50 Mbit/s and 30 Mbit/s upload in their service plans.

See also


Aware, Inc., VDSL2 White Paper, Rev 2

External links

  • ITU-T Recommendation G.993.1: Very high speed digital subscriber line transceivers
  • UK Broadband Usergroup
  • ThinkBroadband
  • The UNH-IOL DSL Knowledgebase (advanced tutorials)
  • Motorola Broadband
  • EFTel VDSL
  • Vdsl Technology and company news
  • VDSL2 chip vendor Metanoia communications Inc. Taiwan
  • 'VDSL van KPN'
  • RiPWiRE
  • DRBSY Ltd
  • IPLAN Networks Argentina
  • VDSL2 by PTCL in Pakistan

ja:デジタル加入者線#VDSL sv:Digital Subscriber Line#VDSL

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