| 释义 |
ADSL2+ (Asymmetric Digital Subscriber Line version 2 plus) Specified by the ITU-T in Rec- ommendation G.992.5 and G.992.4 (January 2003), ADSL2+ doubles the downstream data rate, in comparison to ADSL2, to as much as 24.5 Mbps over local loops up to approximately 5,000 feet (1,500 meters) in length.The upstream rate remains at a maximum of 1 Mbps. In order to achieve this enhanced data rate, ADSL2+ increases the downstream frequency range to 2.2 MHz and increases the number of subcarriers to 512.The analog POTS channel remains at 4 kHz and the upstream data channel remains capped at 140 kHz. See also ADSL, ADSL2, analog, downstream, frequency, local loop, POTS, subcarrier, and upstream. |