VDSL or VHDSL (Very High Bitrate DSL)1 is a DSL technology providing faster data transmission over a single flat untwisted or twisted pair of copper wires. These fast speeds mean that VDSL is capable of supporting high bandwidth applications such as HDTV, as well as telephone services (Voice over IP) and general Internet access, over a single connection. VDSL is deployed over existing wiring used for POTS (Plain Old Telephone System) and lower-speed DSL connections.
Second-generation VDSL2 systems (ITU-T G.993.2) utilize bandwidth 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.
Currently, the standard 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 QAM (Quadrature amplitude modulation) and DMT (Discrete Multi-Tone modulation.) In 2006, ITU-T standardized VDSL in recommendation G.993.2 which specified only DMT modulation for VDSL2.
Supply
As of 2006, the market is still small, except in Japan and South Korea, where VDSL is predominant.
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- The sole VDSL supplier is TransACT, who use VDSL for Digital TV, Internet and WAN applications over their Fibre-To-The-Curb network in Canberra.
- 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.2
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- Belgacom is providing VDSL in parts of the country (about 6% coverage), but limited to 17 Mbit/s down and 640 kbit/s up, with a monthly download limit of 35 GB. VDSL2 coverage is at 50% in November 2007 (internal Belgacom nota)
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- Telefonica is providing VDSL in some areas of São Paulo with plans ranging from 8 Mbit/s to 30 Mbit/s down and 5 Mbit/s up. The access is provided under Speedy brand and has no apparent bandwidth cap or limitation. The plans are offered in duos (internet + telephony) and trios (internet + telephony + digital IP TV), also known as Triple play (telecommunications), and cost up to $ 300 USD /month.
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- 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 recently changed to September 2008. Cybercity has also announced plans to introduce VDSL.
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- Provided in Oulu by DNA, in Turku by Auria, in various cities by Nebula and in Helsinki by 24 Online. The services provided in Turku and Oulu are actually based on Cisco's LRE. A few universities also provide fiber-optic VDSLs to their students.
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- Erenis is offering both internet and telephone over VDSL in Paris. The broadband is 60 Mbit/s down and 6 Mbit/s up3
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- VDSL is currently available in 28 major cities with 25/5 Mbit downstream/upstream or 50/10 Mbit downstream/upstream. The infrastructure is mostly owned by T-Home, subsidiary of Deutsche Telekom who is planning to invest approximately € 3 billion to set up the requisite VDSL infrastructure in 50 cities until approximately 2007; despite a ruling by the European Commission in December 2004 that would force the company to make parts of this new infrastructure immediately available to competitors, deployment is ongoing. The extent and the terms of infrastructure access are still to be determined. The theoretical bandwidth right now is 100/100Mbit (synchronous line) downstream/upstream but is limited by T-Home to 50/10 Mbit downstream/upstream. Cost for the 25/5 Mbit VDSL service is set at €59,95 and for the 50/10 Mbit VDSL service €64.95, both prices are basic (70 TV channels including some HDTV channels) IPTV channel package, for the premium (100 TV channels including some HDTV channels) IPTV package T-Home is asking an additional €15 which also includes some Pay-TV perks like soccer and movie packages. There no additional charge for data throughput. VDSL from T-Home is bundled with a flat rate. Local providers like Netcologne offer up to 100/10 rates.
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- Starting in October of 2008 the largest Hungarian incumbent offers 25 Mbit/s subscriptions to approximately 100 000 households after upgrading part of their network to VDSL.4
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- VDSL is offered by HGC. A 10 Mbit/s up and down connection costs less than $11-20 USD/month with a 18-month contract (price is negotiable and each customer get different prices and plans), with unlimited traffic. However, the stability is very low. Disconnection is common.
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- VDSL is indirectly offered in many areas by NTT, Japan's largest telco, in conjunction with FTTH service. It is used as a mechanism to wire apartments and other existing construction as a lower cost alternative to pulling optical fiber to each unit.
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- Alcatel Lucent is also a provider of VDSL in Malaysia.
- Telekom Malaysia is planning to deploy combine technology with VDSL.
- VDSL Network S.B. is also a provider of VDSL technology more 3 years in Malaysia. [[[www.vdslnetwork.com]]]
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- 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.
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- 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.
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- VDSL will be released within a one kilometre range of the Auckland city exchange by Vodafone, who plans to extend coverage after this 'test'. Testing also occurring for friendly users in Glenfield and Ponsonby.
- VDSL2 announced by TelstraClear on 16 October 2008, will be released in seven main centres, including Wellington, Christchurch, Auckland, and Napier. With speeds of up to 30 Mbit symmetrical.
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- VDSL appeared on 8 February, 2005. It is provided by SCTS, offers Internet speeds ranging from 4 Mbit/s / 1.5 Mbit/s to 12 Mbit/s / 6 Mbit/s at Saratov city. Connection costs around €7-50 per month (including 125-1024 MB of external incoming traffic). Traffic costs around €0,03-0,05 per megabyte.
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- 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 to 60 Mbit/s / 25 Mbit/s at more than 120 locations across the country (75% coverage). A 10 Mbit/s / 10 Mbit/s connection costs €46 per month.
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- KT and other several providers offer VDSL in the place where FTTH is not available. The speed is varied from 4Mbit/s to 100Mbit/s by payment plans, about $25-$40 USD/month.
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- VDSL roll-out by Telefonica began in 2005 in selected places in Madrid. Commercial launch up is planned for 2008.
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- Used in the Bluewin TV television-over-IP service and in the DSL service with 15 Mbit/s downstream and 1 Mbit/s upstream, introduced in July 2007. The city of Zurich had a vote about putting VDSL infrastructure in place in 2007 which was approved by the voters. This "Fiber to the Home" network will be run by the cities power company and will offer maximum speeds of around 100Mbit bandwidth though it's not clear what the upload speeds or pricing will be. The Swiss telecom giant Swisscom offers VDSL in most of Switzerland.
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- VDSL is available in Taiwan in the Fiber To The Building (FTTB) service provided by Chunghwa Telecom, the largest telecommunication company in Taiwan. FTTB has a maximum connection speed of up to 100 Mbit/s downstream and 5 Mbit/s upstream.
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- Turk Telekom began offering VDSL2 services as of July 1, 2008 across 73 of Turkey's 81 provinces. VDSL2 will initially be offered with 30 megabit speed and will shortly climb to 70 megabits. Two packages in the form of 16Mbit download/1Mbit upload or 32Mbit download/1Mbit upload speeds are made available for the first four months. 16Mbit will sell for approximately $105, while 32Mbit will sell for $140.5
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- Qwest provides Internet access and television service over FTTN VDSL in Denver, Colorado and Phoenix, Arizona. Qwest's rate structure only extends to 20 Mbit/s down, for $100/month.
- AT&T provides Internet and television service over VDSL in 25 cities under the trade-name U-Verse. The AT&T service is based on FTTN, Fiber to the Node and FTTP is also used.
- Verizon offers its FiOS service in some metropolitan areas at speed of up to 50 Mbit/s. The Verizon service is based on FTTP, and normally CAT5e Ethernet (or MoCA over coax) 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.
See also
References
- ^ KPN - KPN starts VDSL trials
- ^ BroadbandNext Update - ASX announcement
- ^ http://www.erenis.fr/particulier_web.htm
- ^ Csomagban kínált szolgáltatások, VDSL-internet és új ADSL-csomagok a Magyar Telekom új márkájának égisze alatt
- ^ http://www.turktelekom.com.tr/tt/portal/Guncel/Detay/vdsl2
- ^ B. Lee, J. Cioffi, et al. (September 2007). "Gigabit DSL". IEEE Transactions on Communication. 55 (9): 1689–1692. doi:10.1109/TCOMM.2007.904374.
External links
