Testing Roadm Networks - Viavi 8100 V2 Series User Manual

Chapter 9 OSCA-710 Optical Spectrum Measurement

Testing ROADM networks

2 Press the
3 Press
Displaying relative results
By default, the table gives the results in absolute values. To obtain these results in rela-
tive values with respect to a reference channel:
1 Press the
2 Move the cursor on to the channel that is to serve as the reference.
3 Press the
The results are recalculated with respect to this channel of reference.
Testing ROADM networks
In ROADM networks, each channel may traverse different routes, optical amplifiers, and
add-drop filters, resulting in different OSNR for each channel. Conventional OSA
measurements are unreliable, as they indicate OSNR values that are too high: up to
10dB above the true OSNR. Using the POL-MUX OSNR method of OSCA-710 will
provide the true OSNR value in ROADM based networks.
Figure 166 ROADM network test
With OSCA-710, it is possible to measure the "true" in-band OSNR using the Stokes
analysis on the received polarized signals.
326
Channel key
and to move the cursor to the following or preceding channel:
Table Contents key, then
Set Ref. Channel
User Manual
Relative>/<Absolute
key.
78000010220 Rev. 024
to select Relative.