Chapter 3 Services
ADSL Service
Overview
technology is an important member of the x
family. It
allows more downstream bandwidth from the central office to the
subscriber side than upstream. The upstream uses the frequency
band from 30 KHz to 138 KHz. The downstream uses the fre-
quency band from 138 KHz to 1.104 MHz.
Asymmetry, combined with always-on access (eliminating the call
setup), makes ADSL ideal for Internet/Intranet surfing, VoD, and
remote
access.
Features
ADSL has the following features:
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ADSL complies with
T1.413 issue 2,
G.992.1, ITU-T
G.992.2, ITU-T G.996.1, ITU-T G.992.3, and ITU-T G.992.5
standards.
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It supports the
modulation mode.
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It supports the
mode.
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It uses the asymmetric transmission mode. The upstream rate
can reach up to 1 Mbps and downstream rate can reach up to
8 Mbps.
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It automatically adapts the rate (with the granularity of 32
Kbps) based on line conditions.
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ADSL
query
and
configuration
parameters
include
up-
stream/downstream rate, noise tolerance, output power and
line attenuation.
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It obtains bits quantity at each sub-carrier side.
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It provides the online loading function for programmable ap-
paratus and card software.
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It supports remote maintenance and remote software upgrade
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It supports line alarm maintenance and message report func-
tion
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Each ADSL interface supports eight
connections.
ADSL2/2+ Service
Overview
2/2+ is a new generation of ADSL broadband service access
technology. ADSL2/2+ is compatible with ADSL. In addition, it
supports higher rate and longer transmission distance.
Features
ADSL2/2+ has the following features:
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More operation modes
ADSL2/2+ technology supports three operation modes:
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annex A
This mode uses ADSL over
, with POTS service on the
same pair of lines.
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annex B
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