VDSL Standards
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 quadrature amplitude modulation (QAM) and discrete multi-tone modulation (DMT). In 2006, ITU-T standardized VDSL in recommendation G.993.2 which specified only DMT modulation for VDSL2.
| Version | Standard name | Common name | Downstream rate | Upstream rate | Approved in |
|---|---|---|---|---|---|
| VDSL | ITU G.993.1 | VDSL | 55 Mbit/s | 3Mbit/s | 2004-06-13 |
| VDSL | ITU G.993.2 | VDSL2 | 100 Mbit/s | 100 Mbit/s | 2006-02-17 |
Read more about this topic: Very-high-bit-rate Digital Subscriber Line
Famous quotes containing the word standards:
“The things a man has to have are hope and confidence in himself against odds, and sometimes he needs somebody, his pal or his mother or his wife or God, to give him that confidence. He’s got to have some inner standards worth fighting for or there won’t be any way to bring him into conflict. And he must be ready to choose death before dishonor without making too much song and dance about it. That’s all there is to it.”
—Clark Gable (1901–1960)