VeEX RXT-6000e, User Manual

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11.0 Jitter and Wander
Accessing Jitter and Wander
Go to
OTN/SDH/SONET Testing
from the
Test Mode Selection
, then select the following:
For SONET or SDH signals : Home (Main Menu) > SONET/SDH Tools > More > Jitter & Wander
Jitter & Wander displays the Jitter Measurements showing measurements and analysis of jitter in received signal.
Jitter and Wander are usually described as the phase noise in digital signals. This is a natural occurrence in
telecommunication networks.
Excessive jitter can lead to transmission errors and deterioration in network quality. ITU defines jitter as follows: "The
short-term variations of the significant instances of a digital signal from their ideal positions in time (where short-term
implies these variations are of frequency greater than or equal to 10 Hz)." The long-term variation (less than 10 Hz) of
a digital signal is called wander.
In simple terms, jitter is an unwanted phase modulation of the digital signal that may cause errors or bit slips in a
digital circuit and deteriorate the performance of a transmission network.
In lower-rate digital systems, systematic jitter is dominant. In higher-rate systems, random jitter may become more
important. Test environment parameters that affect jitter performance are test sequences, bit rate, pulse shape, cable
characteristics, temperature, cross-talk, and noise.
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11.1 Jitter Measurement & Generation (Jitter icon)
Tapping the Jitter icon brings up the Jitter Measurement and Generation screen.
Jitter Measurement and Generation Menu
The Jitter measurements menu allows the user to measure and analyze received signal jitter. The measurement
example is shown above (the vertical grid spacing is 2.0 UIpp). The red bar indicates Max. peak jitter during testing
and the yellow bar indicates the current peak jitter.
Setup
RXT-6200_RXT6000e_Module_Manual Page 176 of 387