DSL technologies | |
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Standard | |
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.992.4 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 |
Very-high-speed digital subscriber line 2 (VDSL2) is an access technology that exploits the existing infrastructure of copper wires that were originally deployed for traditional telephone service. It can be deployed from central offices, from fiber-optic connected cabinets located near the customer premises, or within buildings. It was defined in standard ITU-T G.993.2 finalized in 2005.[1]
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VDSL2 was the newest and most advanced standard of digital subscriber line (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 was intended to enable operators and carriers to gradually, flexibly, and cost-efficiently upgrade existing xDSL infrastructure.
The protocol was standardized in the International Telecommunication Union telecommunications sector (ITU-T) as Recommendation G.993.2. It was announced as finalized on 27 May 2005,[1] and first published on 17 February 2006. Several corrections and amendments were published in 2007 through 2011.[2]
VDSL2 is an enhancement to very-high-bitrate digital subscriber line (VDSL), Recommendation G.993.1. It permits the transmission of asymmetric and symmetric aggregate data rates up to 200 Mbit/s downstream and upstream 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 (1,600 ft) and 50 Mbit/s at 1 km (3,300 ft), but degrades at a much slower rate from there, and still outperforms VDSL. Starting from 1.6 km (1 mi) 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 4–5 km (2.5–3 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.
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. downstream throughput (Mbit/s) |
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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 | 200 |
Austria |
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Belgium |
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Czech Republic |
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Cyprus | |
Denmark |
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Estonia |
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Finland |
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France | Erenis was deploying VDSL1 and VDSL2 (as Fiber to the premises) until Neuf Cegetel, later absorbed by SFR, bought the company in April 2007.[14] There was no further VDSL deployment in France because the standard has never been approved by the sole owner of the historical copper local loop (France Telecom). VDSL2 use cases are currently evaluated by the DSL tech. introduction workgroup.[15] |
Germany |
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Greece |
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Hungary | T-Home is planning to provide VDSL2 from October 8, 2008. |
Iceland |
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Isle of Man |
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Italy |
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Ireland | eircom, in late 2006, announced a plan to start providing VDSL2 from 2007 in large cities. However Eircom has announced phase one of a fibre roll-out which they will deploy fibre cabinets along with vdsl2 and triple services. |
Netherlands |
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Norway |
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Poland |
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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. |
Romania | Romtelecom are now offering VDSL2 at 20 Mbit/s and 30 Mbit/s. They were planning to provide VDSL2 in the beginning of 2011 with 50 Mbit/s and 100 Mbit/s speed in 50 cities; in Romtelecom to reach new deals to offer 50 Mbit/s and 100 Mbit/s; |
Slovenia |
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Spain |
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Sweden |
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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 |
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United Kingdom | BT Group trialed VDSL2 in the Muswell Hill, London and Whitchurch, Cardiff Exchanges starting in July 2009. On 23 March 2009, they announced plans to deploy the service to 29 exchanges throughout England, Wales, Scotland and Northern Ireland.[30] On 9 July 2009, they announced plans to deploy the service to a further 69 exchanges throughout the UK by the summer of 2010.[31]
May 2010 BT announce £2.5billion plans to roll-out a mixture of VDSL2 FTTC (75%) & GPON FTTP (25%) to 66% of the UK by 2015 with VDSL2 speeds starting at 40Mbit/s down 10Mbit/s up potentially rising to 60Mbit/s down 15Mbit/s up [32]. In October 2011 BT announced that this roll-out was being accelerated such that it will be completed by 2014 (one year earlier than originally planned).[33] May 2011 BT announce plans to double download speeds to 80Mbit/s down and 20Mbit/s up on its VDSL2 network by 2012. This will be achieved by increasing ANFP spectrum usage to 17 MHz. 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, 5 km away.[34] The trial eventually resulted in Vtesse networks running the final service without Virgin Media's involvement under their own brand on 1 October 2010. Ripwire recently announced the availability of up to 40 Mbit/s VDSL2 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 which are collectively known as Digital Region Ltd an EU government backed project. The network will offer 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) and sub loop unbundling to provide the last mile connection to the consumer via existing copper. On 14 April 2010, Rutland Telecom announced that it is to deliver broadband speeds up to 40Mbit/s using a Fibre to the Cabinet solution in the Welsh notspot village of Erbistock. The initiative, backed by private investment, will be the first time that VDSL2 technology has been used in a Welsh rural village.[35] |
Bahrain | Lightspeed Communication announced that they will begin deploying VDSL2 technology for residential and business customers in 2012. downstream speed will be up to 80 Mbit/s.[36] |
Hong Kong | PCCW Limited (Netvigator) and Hutchison Global Communications (HGC) have deployed VDSL2 technology to serve residential and business customers since 2008. Netvigator provides up to 100 Mbit/s downstream and 30 Mbit/s upstream broadband service in VDSL2,[37] while HGC asserts that to provide up to 100 Mbit/s downstream and 100 Mbit/s upstream service.[38] However, due to equipment technical difficulties, HGC connection is pretty unstable. HGC is able to provide both 50 Mbit/s downstream and upstream in most districts of the coverage. |
India | MTNL has deployed VDSL technology in Mumbai and offers up to 20 Mbit/s downstream.[39]
Airtel has announced 50 Mbit/s Plans using VDSL2.[40] |
Israel | Bezeq has deployed FTTx with VDSL2 with brand name NGN in September 2009 offering speeds of 20 and 30 Mbit/s downstream and 1 Mbit/s upstream.[41] In October 2010 Bezeq has deployed 50 and 60 Mbit/s downstream speeds and limited upstream speeds of up to 1 Mbit/s. In the beginning of 2011 Bezeq will deploy 200 Mbit/s downstream speed using two copper pairs bonding. |
Macau | CTM start to test VDSL2 at the 3rd season of 2007. First will be tested in two main buildings in Macau. |
Malaysia | Telekom Malaysia deployed FTTx and VDSL2 with brand name UniFi in March 2010 offering symmetrical speeds of 5, 10 and 20 Mbit/s. |
Pakistan | PTCL is the first service provider worldwide to deploy a commercial VDSL2 Bonding solution and offers speed up to 50 Mbit/s - The highest speed offered by any Internet Service Provider in the country. |
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. |
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. |
Thailand |
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Canada |
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USA |
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Dominican Republic | Claro offers speeds ranging from 1Mbit/s down and 256kbit/s up to 50Mbit/s down and 2Mbit/s up. The upgrade to VDSL2 was required to provide enough bandwidth for the company's IPTV, data, and voice services all running on their POTS network. |
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 using Zhone Technologies, Inc. Equipment to provide VDSL2 service to Belo Horizonte, Salvador, Brasília, Curitiba, Goiânia, Porto Alegre, Campina Grande, Recife, Fortaleza, and other medium and small cities.[43]
Sercomtel has deployed a new VDSL2+ network on Londrina city. Reaches speed up to 70Mbit/s[44] on downstream, and 15Mbit/s upstream. |
Chile | Movistar is beginning to deploy Huawei VDSL2 equipment to some sectors in the city of Santiago. |
Australia |
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New Zealand |
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