VDSL

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It has been suggested that VDSL2 be merged into this article or section. (Discuss)

VDSL (very high bit-rate DSL) is an xDSL technology providing data transmission up to a theoretical limit of 52 Mbit/s downstream and 12 Mbit/s upstream over a single twisted pair of wires. Compare HDSL (High bit-rate Digital Subscriber Line).

Currently, the standard VDSL uses up to 4 different frequency bands, two for upstream (from the client to the telco) and two for downstream. The standard modulation technique is either QAM (Quadrature amplitude modulation) or DMT (Discrete multitone modulation) which are not compatible, but have similar performance. The current mostly used technology is DMT (the same technology used in cable modems).

The available bit rates ranges from about 26 Mbit/s symmetric for a loop of about 1500 m, up to 100 Mbit/s symmetric for a few hundred metres.

VDSL is capable of supporting high bandwidth applications such as HDTV. Qwest is currently prototyping the service and may offer a HDTV package as early as 1Q 05.

A new VDSL standard is now available, named VDSL2; no current rollouts are known.

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Supply

As of 2004, the market is still small, except in Japan and South Korea, where VDSL is predominant.

Australia
- The sole VDSL supplier is TransACT, who use VDSL for Digital TV, Internet and WAN applications over their Fibre-To-The-Curb network. (VDSL is not ratified for use on Telstra supplied copper lines in Australia yet, and Telstra has publicly voiced opposition to VDSL).

Belgium
- Belgacom is providing VDSL in parts of the country (about 6% coverage), but limited to 9 Mbit/s down, 400 kbit/s up and with a monthly download limit of 90 GiB.

Canada
- VDSL is offered in urban areas by SaskTel in Saskatchewan, MTS in Manitoba, and Bell ExpressVu in Ontario and Quebec.

Finland
- It's provided in Oulu by Finnet and in Turku by Auria.

France
- Erenis is offering both internet and telephone over VDSL in Paris. The broadband is 60Mbps down and 6Mbps up [1]

Hong Kong
- VDSL is offered by HGC.

Japan
- VDSL is offered in many areas by NTT, Japan's largest telco, in addition to other providers, in conjunction with FTTH service.

Netherlands
- VDSL Roll-out is tested by the company KPN and is expected in Q1 2006 to be used. ADSL2+ is allready being used but only on limited parts of the network.

Slovenia
- VDSL appeared on 1 October 2005. It is provided by T-2.net, offering triple play services with internet speeds ranging from 1Mbps/256kbps to 20Mbps/10Mbps at more than 120 locations across the country. A 10Mbps/10Mbps connection costs around US$50 per month. There is no fair-use policy (uncapped downloads).