Finding Disturbers - JDS Uniphase HST-3000 User Manual

Chapter 2 VDSL Testing
Testing in modem emulate mode
Finding
disturbers
20
2 Press the Display soft key to view different types of statis-
tics.
See "Modem emulate results" on page 60
on interpreting the results.
3 Press the Results soft key to clear the results or save
them to a text file.
For more information on saving results and managing the
files, see the HST-3000 Base Unit User's Guide.
4 Press the DSL Stop soft key to stop the modem.
All DSL results will remain in view until the modem is
started again or another test is selected.
Testing line quality is complete.
The graphical displays can be useful tools for finding
disturbers.
The graphs are pictorial representations of the bits per tone
(BPT) and signal to noise ratio (SNR). On Infineon SIMs,
H.log, PSD, and QLN graphs are also available. Using these
graphs to locate interference is not a precise method.
However, this process can help you isolate the frequency
where the interference occurs. You can then use that informa-
tion to identify possible sources of interference.
To find disturbers
1 After running the test, press the Display soft key and then
select Graphs.
2 Press the Graphs soft key.
NOTE:
The graphs only appear if you are connected to the line and
the modem has trained on the line.
3 Select View BPT graph.
HST-3000 VDSL Testing User's Guide
for information