OPTICOM OPERA Broadcast, User Manual

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C H A P T E R 6 : T E L E P H O N Y B A N D V O I C E Q U A L I T Y
T E S T I N G
150
Echo
Files
(always)
Sources:
Phone
Li
(if voiceboard
included)
OptiCall.exe
Offline
Audio Interface
Option
Figure 6.30:
Kinds of signal sources for the Echo measurement
6.7.4 Echo Algorithm Properties
Figure 6.31
shows the algorithm properties of the echo algorithm. There is
only one value, the maximum delay of the expected echo. This value may
range from 10ms up to 1000ms. Choosing a lower value will lead to a faster
calculation of the echo delay.
Figure 6.31:
Echo algorithm properties
6.7.5 Specific Settings for the Echo Measurement
When performing echo measurements,
the only settings available are "Invert
test signals" and "Remove DC from signal". It is recommended to switch off the
first and to switch on the second parameter, as shown in
Figure 6.32
All
other parameters are disabled for the Echo algorithm.
Note:
Not all signal preprocessing options are available for the Echo
algorithm. They must be set to fixed values in order to achieve
proper measurement results and are therefore disabled.