Docsis 3.1 Signal Testing And Troubleshooting - Viavi OneExpert ONX CATV 620 Quick Start Manual

DOCSIS 3.1 Signal Testing and Troubleshooting

Spectrum and noise identify portions of
a carrier where degradation may occur
and require possible profile adjustment.
Measuring MER across entire subcarrier list enables identifying
potential impairments with impact on higher level profiles
Unstable MER with drops below
30dB means only profiles running
256 QAM or lower will work.
Level variation within
the OFDM channel band
provides insight into
frequency-response
related issues.
Stable
QAM 2048 and 4096 will work.
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MER better than 40 dB means
In-Channel
Response identifies
roll-off and excessive
ripple
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