| DSL technologies | |
|---|---|
| Standard | |
| ADSL | ANSI T1.413 Issue 2 ITU G.992.1 (G.DMT) ITU G.992.2 (G.Lite) |
| ADSL2 | ITU G.992.3/4 ITU G.992.3 Annex J ITU G.992.3 Annex L |
| ADSL2+ | ITU G.992.5 ITU G.992.5 Annex M |
| HDSL | ITU G.991.1 |
| HDSL2 | |
| IDSL | |
| MSDSL | |
| PDSL | |
| RADSL | |
| SDSL | |
| SHDSL | ITU G.991.2 |
| UDSL | |
| VDSL | ITU G.993.1 |
| VDSL2 | ITU G.993.2 |
VDSL2 (Very High Speed Digital Subscriber Line 2) is an access technology that exploits the existing infrastructure of copper wires that were originally deployed for POTS. It can be deployed from central offices, from fibre-fed cabinets located near the customer premises, or within buildings.
VDSL2 is the newest and most advanced standard of DSL broadband wireline communications. Designed to support the wide deployment of Triple Play services such as voice, video, data, high definition television (HDTV) and interactive gaming. VDSL2 is purported to enable operators and carriers to gradually, flexibly, and cost efficiently upgrade existing xDSL-infrastructure.
It has been standardized as ITU G.993.2 in February, 2006.
ITU-T G.993.2 (VDSL2) is an enhancement to G.993.1 (VDSL) that permits the transmission of asymmetric and symmetric aggregate data rates up to 200 Mbit/s on twisted pairs using a bandwidth up to 30 MHz.
VDSL2 deteriorates quickly from a theoretical maximum of 250 Mbit/s at 'source' to 100 Mbit/s at 0.5 km (1640 ft) and 50 Mbit/s at 1 km (3280 ft), but degrades at a much slower rate from there, and still outperforms VDSL. Starting from 1.6 km (1 mile) its performance is equal to ADSL2+.
ADSL-like long reach performance is one of the key advantages of VDSL2. LR-VDSL2 enabled systems are capable of supporting speeds of around 1-4 Mbit/s (downstream) over distances of 4 to 5 km (2 ½ to 3 miles), gradually increasing the bit rate up to symmetric 100 Mbit/s as loop-length shortens. This means that VDSL2-based systems, unlike VDSL1 systems, are not limited to short local loops or MTU/MDUs only, but can also be used for medium range applications.
Contents |
Profiles
VDSL2 is quite a complex protocol. The standard defines a wide range of profiles that can be used in different VDSL deployment architectures; in the central office, in the cabinet or in the building for example.
| Profile | Bandwidth (MHz) | Number of carriers | Carrier bandwidth (kHz) | Power (dBm) | Max. Throughput (Mbit/s, downstream) |
|---|---|---|---|---|---|
| 8a | 8.832 | 2048 | 4.3125 | +17.5 | 50 |
| 8b | 8.832 | 2048 | 4.3125 | +20.5 | 50 |
| 8c | 8.5 | 1972 | 4.3125 | +11.5 | 50 |
| 8d | 8.832 | 2048 | 4.3125 | +14.5 | 50 |
| 12a | 12 | 2783 | 4.3125 | +14.5 | 68 |
| 12b | 12 | 2783 | 4.3125 | +14.5 | 68 |
| 17a | 17.664 | 4096 | 4.3125 | +14.5 | 100 |
| 30a | 30 | 3479 | 8.625 | +14.5 | 100 |
Deployment
Europe
| Belgium | Belgacom announced it will provide HDTV services (20 Mbit/s) using VDSL2 to 60% of the households by Spring 2008. Belgacom is rolling out Alcatel-Lucent VDSL2 equipment in over 16,000 street cabinets (Q1-2009). Belgacom also provides VDSL2 to smaller enterprises, download speeds are limited at 20 Mbit/s while upload speeds are capped at 1.4 Mbit/s or 1.8 Mbit/s, depending on what product.
Since the end of May 2009 Dommel offers VDSL2. Dommel has limited the speed at 18mbit. The first 2 km there is no decrease of speed. This is because Dommel sends the signal out at a much higher rate. When the signal reaches the consumer, the speed is limited to 18 MBit/s. |
| Denmark | |
| Finland |
|
| France | Erenis is deploying VDSL1 & VDSL2 at the basement: FTTB |
| Germany | T-Home, the landline division of Deutsche Telekom, offers VDSL2 services with download speeds up to 50 Mbit/s and upload speeds up to 10 Mbit/s based on FTTC. They started in late 2006 with offering VDSL2 in the 12 largest cities in Germany, in 2007 Residents in over 50 cities have access to VDSL2.[4] It is used to provide Triple play services. Further expansions are planned. |
| Hungary | T-Home is planning to provide VDSL2 from October 8, 2008. |
| Italy |
|
| Ireland | eircom announced their plan to start providing VDSL2 within the year 2007. However there is not yet any firm date for any deployment as of May 2009. |
| Norway |
|
| Netherlands | |
| Portugal | Clix (ISP) and Portugal Telecom are planning to provide VDSL2 + FTTH in the end of 2008, new technology of PTInovação (PT Labs) called mediaDSLAM can provide 100 Mbit/s in a long range, 4/5 km of main "source", against 0.5 km. |
| Spain | Jazztel and Telefónica are testing the deployment of VDSL2. They were planning to provide VDSL2 in 2007 or 2008 start, but it was never deployed for commercial use at the end, preferring the FTTH technology. |
| Slovenia |
|
| Sweden |
|
| Switzerland | Swisscom is deploying VDSL2 and it is now available to customers since July 1, 2007. Since December 2006 it is in use for IPTV. |
| Turkey |
|
| United Kingdom | BT Group is trialing VDSL2 in the Muswell Hill, London and Witchurch, South Glamorgan Exchanges starting in July 2009. On 23rd March 2009 they announced plans to deploy the service to 29 exchanges throughout England, Wales, Scotland and Northern Ireland. [11] On 9th July 2009 they announced plans to deploy the service to a further 69 exchanges throughout the UK by the summer of 2010 [12]
On 8 October 2009, it was revealed that Virgin Media will trial VDSL2. Residents of Higher Pill, in Saltash, and nearby Hatt will be offered free broadband via a VDSL2 line to a roadside cabinet. The cabinets will be linked to Virgin Media backhaul via new fibre laid by Vtesse Networks through BT's local exchange, 5km away. [13] |
Asia
| Hong Kong | PCCW Limited (Netvigator) and Hutchison Global Communications (HGC) have deployed VDSL2 technology to serve residential and business customers since 2008. Netvigator provides only up to 30Mbit/s downstream and 10Mbit/s upstream broadband service in VDSL2[14], while HGC asserts that to provide up to 100Mbit/s downstream and 100Mbit/s upstream service[15]. However, due to equipment technical difficulties, HGC is able to provide both 50Mbit/s downstream and upstream in most districts of the coverage. |
| Malaysia | TM is planning to deploy VDSL2 in end 2009. Customers will enjoy at least 1 Mbit/s speed. |
| Singapore | SingTel tied up with Ericsson to deploy a technical trial of VDSL2 starting June 2006. However, no service plans announced as of yet and SingTel is preferring FTTH over VDSL2. |
| Macau | CTM start to test VDSL2 at the 3rd season of 2007. First will be tested in two main buildings in Macau. |
| Taiwan | October 2007, Chunghwa Telecom (CHT) has awarded ZyXEL Communications to provide VDSL2 equipments (DSLAM and CPE) for its "Next Generation Access Network" project. The project involves 340-thousand lines and will provide high speed Triple play services to these subscribers. |
North America
| Canada | SaskTel, a crown corporation of the province of Saskatchewan, has officially announced the deployment of VDSL2. SaskTel is using VDSL2 to increase the amount of bandwidth to its customers, allowing more HDTV streams with its MAX Entertainment Service. |
| USA |
|
South America
| Argentina | IPLAN Telecomunicaciones is beginning to deploy Allied Telesis VDSL2 equipment to replace old LRE Cisco equipment among their 10K customers in Buenos Aires. |
| Brazil | GVT is beginning to deploy VDSL2 equipment in Salvador, Brasília, Curitiba, Goiânia, Porto Alegre and other medium and small cities[16]. |
Oceania
| Australia |
|
| New Zealand |
|
See also
- Very High Speed Digital Subscriber Line
- Broadband Internet access
- DOCSIS
- Fiber to the x
- Passive optical network (PON)
- List of device bandwidths
References
- ^ TDC indfører 50 Mbit/s bredbånd (Danish), TDC Press release.
- ^ 3. kvartal 2006: Øget indtjening og vækst (Danish), Cybercity Press release.
- ^ Turbo til dit bredbånd.
- ^ Heise Online: Network Expansion Plans August 2006 (ger.)
- ^ http://www.nextgentel.no/privat/bredband/vdsl2/
- ^ Snart klart för blixtbredband (Swedish), IDG.se.
- ^ Telenor Buys Nordic Internet Companies for $1.06 Bln (Update4), Bloomberg.
- ^ TeliaSonera storsatsar på snabbare bredband i Sverige (Swedish), TeliaSonera.
- ^ Bredbandsbolaget lanserar turbo-dsl (Swedish), Ny Teknik.
- ^ Price converted by XE.com on 2008-02-24
- ^ BT Openreach: GEA over FTTC roll - out announcement
- ^ BT Press Release: BT speeds up super-fast-fibre plans
- ^ Virgin Media to trial IPTV off-cable network.
- ^ http://promo.netvigator.com/eng/
- ^ http://www.hgcbroadband.com/superbroadband.html
- ^ List of cities with avaliability (Port.)
- ^ New-era broadband faster but no cheaper, NZHerald.co.nz article.
- ^ Computerworld > Vodafone to announce $50 million LLU investment
- ^ Telecom testing high-speed broadband, Stuff.co.nz article.
External links
ITU official documents
- ITU-T Recommendation G.993.2: Very high speed digital subscriber line transceivers 2 (VDSL2)
- ITU-T Recommendations: Series G
- ITU-T
- Press Release on ITU-T G.993.2
Other
- The Definitive Guide on Ethernet Extenders by the Ethernet Extender Experts
- Versa Technology - VDSL2 Solutions & Applications
- TraceSpan Communications - VDSL Xpert
- Centillium Communications
- Alcatel-Lucent
- Ikanos Communications
- Conexant
- Netopia
- Aktino
- The UNH-IOL DSL Knowledgebase (advanced tutorials)
- Migrating to VDSL2 ... includes graphs Download/Upload speeds vs. Distance for VDSL2/ADSL2(+)
- VDSL2 for Business Services: A New Frontier for DMT Technology
- Future Proof Telecommunications Networks With VDSL2
- The Standardization of VDSL2
- Deutsche Telekom opts for VDSL2
- Infineon's VDSL2 Solution
- Infineon VINAX solution used by Deutsche Telekom
- Overview and Deployment Issues
- Comtrend VDSL2
- Broadcom's VDSL2 CPE solution
- VDSL2 Knowledgebase - Turkish
- VDSL2 chip vendor Metanoia communications Inc. Taiwan
- Proscend VDSL2 LAN Extender
This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)




