VDSL2 is really really fast. How fast? According to Ikanos estimates, it takes an “ADSL network more than 45 minutes to transmit up to 50 high-resolution photos at 3 Mb per photo. Sending the same number of photos can take less than a minute over VDSL/VDSL2 networks.”
VDSL, though once thought of as a good solution for bringing more bandwidth to the home has lagged because of its lack of reach. It has become popular in the overseas markets because densely populated countries like China and Korea have central offices that are much closer to consumer premises. VDSL2 standard, which uses about 30 MHz of spectrum (versus 12 MHz in VDSL) allows more data to be sent at higher speeds and over longer distances. BellSouth and SBC have plans to use super-fast DSL to connect their fiber nodes to consumer homes. Qwest for instance has about 40,000 customers who are using VDSL technologies. But eventually if they want to offer true triple play with high-definition streams, they will eventually have to migrate to VDSL2 technology which can handle three HDTV streams with relative ease. (Three HD streams at the very least because at present average American home has 3.1 televisions.) Of course there is that whole issue of US homes being too far from the Central office. The good news is that VDSL2 is going to be backward compatible with ADSL, ADSL2 and VDSL.
Here is a little comparison of more recent flavors of DSL
- ADSL has speeds up to 8 Mbps downstream and 1 Mbps upstream. Can be deployed from Central office and has a range of 15,000 feet and longer.
- ADSL2+ has a maximum speed of 25 Mbps downstream and 1 Mbps upstream. Can be deployed from Central office and has a range of 15,000 feet and longer
- VDSL , some chipsets that use the optional spectrum of 30 MHz can do 100 Mbps downstream and 50 Mbps upstream. Current carriers include NTT, KDDI, Korea Telecom, and Softbank BB of Japan. Has a range of about 5,000 feet
- VDSL2 has speeds of 100 Mbps downstream and 100 Mbps upstream. Has a range of about 12000
- DSL (ADSL) is limited to about 8 Mbps downstream and 1 Mbps upstream.
- ADSL2 is limited to about 25 Mbps downstream and 1 Mbps upstream.
- VDSL (Very High Bit Rate DSL) is limited to about 100 Mbps downstream and 50 Mbps upstream.
- VDSL2 is limited to about 100 Mbps downstream and 100 Mbps upstream.