ZyXEL Communications IES-1248-51, Руководство пользователя

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IES-1248-51 User’s Guide
330 Chapter 49 ADSL Commands
The following table lists the line diagnostics test parameters that display, see the ITU-T’s
G.992.3 for more information.
49.2.10 SELT Diagnostic Set Command
Syntax:
ras> adsl linediag setselt <port number>
Table 79 Line Diagnostics Get 992.3 Command
LABEL DESCRIPTION
number_of_
subcarries
Discrete Multi-Tone (DMT) modulation divides up a line’s bandwidth into sub-
carriers (sub-channels) of 4.3125 KHz each.
The first number is the total number of DMT sub-carriers the ADSL connection is
using. The second number indicates how many upstream DMT sub-carriers the
ADSL connection is using.
hlinScale:
The channel characteristics function is represented in linear format by a scale
factor and a complex number. These are the maximum upstream and
downstream scale factors used in producing the channel characteristics
function.
latn:
This is the upstream and downstream Line Attenuation (in dB).
satn:
This is the upstream and downstream Signal Attenuation (in dB).
snrm:
This is the upstream and downstream Signal-to-Noise Ratio Margin (in dB). A
DMT sub-carrier’s SNR is the ratio between the received signal power and the
received noise power. The signal-to-noise ratio margin is the maximum that the
received noise power could increase with the IES-1248-51 still being able to
meet its transmission targets.
attndr:
This is the upstream and downstream Attainable Net Data Rate (in bit/s).
farEndActatp:
This is the upstream and downstream Far End Actual Aggregate Transmit
Power (in dBm)
i
This is the index number of the DMT sub-carrier.
li.rl
The channel characteristics function is represented in linear format by a scale
factor and a complex number. This is the real part of the complex number used
in producing the channel characteristics function for this sub-carrier.
li.im
The channel characteristics function is represented in linear format by a scale
factor and a complex number. This is the imaginary part of the complex number
used in producing the channel characteristics function for this sub-carrier
log
This is a format for providing channel characteristics. It provides magnitude
values in a logarithmic scale. It is measured in dB. This can be used in analyzing
the physical condition of the ADSL line.
QLN
The Quiet Line Noise for a DMT sub-carrier is the rms (root mean square) level
of the noise present on the line, when no ADSL signals are present. It is
measured in dBm. The QLN can be used in analyzing crosstalk.
SNR
This is the upstream and downstream Signal-to-Noise Ratio (in dB). A DMT sub-
carrier’s SNR is the ratio between the received signal power and the received
noise power. The SNR can be used in analyzing time dependent changes in
crosstalk levels and line attenuation (such as those caused by temperature
variations and moisture).