
Dynamic rate-adaptive noise margin
Configuring an ADSL Annex A LIM
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Dynamic rate-adaptive noise margin
Limitation
This capability is only available when the line is trained to ADSL2 or ADSL2+.
Behavior
When dynamic rate adaptation is in use, the downstream line adjusts its bit rate
dynamically (it
upshifts
to increase its bit rate or
downshifts
to reduce it) on the basis of
specified noise margins and intervals for which a noise level is maintained, provided that
the maximum or minimum bit rate has not been reached.
Figure 3-1, “Noise margins and
dynamic rate adaptation relationship” (p. 3-13)
illustrates the relationship between
margins and dynamic rate adaptation.
Important!
When
dynamic
rate adaptation is selected, the upstream data rate is set in
the same manner described for the
automatic-at-startup
setting.
Figure 3-1 Noise margins and dynamic rate adaptation relationship
Increase output power
Steady-state operations
Target noise margin
0dB margin
Upshift noise margin
Downshift noise margin
Steady-state operations
Increase bit rate (upshift)
Reduce bit rate (downshift)
Summary of Contents for STGRCR-ELIM-AP-48
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