Table of Contents
Advertisement
Configuring the ADSL Line Interfaces
Configuring ATM ADSL-DMT interfaces
Setting the interleave bit-rate for optimum performance
For optimum performance when using the Stinger MRT, under most conditions
interleave bit rates can be configured as shown in the following example. The
example shows how the bit rates are set for the first interface of a Stinger MRT.
admin> read al-dmt {1 1 1}
AL-DMT/{ shelf-1 slot-1 1 } read
admin> set interleave-path-config max-bitrate-up = 1280
admin> set interleave-path-config max-bitrate-down = 12480
admin> set interleave-path-config min-bitrate-up = 32
admin> set interleave-path-config min-bitrate-down = 32
admin> write
Margin-Config subprofile
The bit error rate (BER) is the percentage of erroneous bits in the total number of
transmitted bits. The noise margins can be controlled to ensure that the line provides
a BER of 10
Noise margin parameters
The Margin-Config subprofile contains the parameters that configure noise margins.
Noise margins are defined in decibels (dB). A BER of 10
tolerates a certain level of random frequency voltage (noise) with respect to its
received signal. If the maximum noise level is exceeded, the ADSL transceiver unit
(ATU) attempts to reduce the far-end output power. If the noise drops below a
minimum margin, the ATU attempts to increase the far-end power output until the
noise level is at or above the configured minimum.
Although the noise-margin settings can be from 1dB to 31dB, the modem software
limits the maximum noise margin to 15dB. If you specify a setting greater than 15dB,
the modem software uses 15dB. Figure 7-1 illustrates the relationship of margin
parameters to power adjustments.
Figure 7-1. Relationship between noise margin parameters and power adjustments
Reduce output power
Steady-state operations
Increase output power
The target noise margin parameters are supported by the Stinger MRT. The minimum
noise margin and maximum additional noise margin parameters are not used and are not
detailed here. Consult the Stinger ADSL 48-port G.lite Line Interface Module (LIM) Guide, at
http://www.lucentdocs.com/ins or http://www.lucent.com/support,
for additional information about setting the noise margin parameters.
7-10
-7
or better, as required by DMT standards.
-7
represents 0dB. The line
Maximum additional
noise margin
Target noise margin
Minimum noise margin
0dB margin
Stinger® MRT Getting Started Guide
Advertisement
Table of Contents
