Figure1: ADSL2+ compared to ADSL/ADSL2 in terms of bandwidth
ADSL2 Plus
ADSL2Plus (also known as
ADSL2+), has joined the ADSL2 family In January 2003 as standard
g992.5 after been approved by the ITU.
ADSL2+ doubles the
downstream frequency band from 1.1Mhz in basic ADSL2, up to 2.2Mhz in
ADSL2+, therefore increases the downstream data rate on shorter phone lines,
reaching 20Mbps on lines of max length
of 5000ft (~1.5km). ADSL2+ upstream remains 1Mbps, depending of course on loop
conditions.
Figure1: ADSL2+
compared to ADSL/ADSL2 in terms of bandwidth
ADSL2+ can also be used to reduce crosstalk. Thanks to his ability to use only tones between 1.1Mhz-2.2Mhz, it can mask all downstream frequencies below 1.1Mhz. This comes in handy when ADSL2+ services from a remote terminal co-exist with other ADSL services (from the CO) and are sharing the same binder. Crosstalk interferences from the remote terminal could be performance hazard for the ADSL services coming from the CO. The masking of frequencies below 1.1 from the remote terminal eliminates the crosstalk interferences almost completely.
Figure2: reducing
crosstalk with ADSL2+
