Agilent Technologies 8960 Series Reference Manual page 453

Loopback Bit Error Ratio Troubleshooting
Possible Setup Issues
During remote operation of the loopback bit error ratio measurement, you should configure the trigger arm to
single. See "SETup:WBERror"
The mobile station (UE) must be configured in loopback mode 1, described in 3GPP TS 34.109. This requires
the mobile station to decode the dedicated traffic channel (DTCH) data from the downlink and resend it in the
uplink DTCH. When using FDD Test operating mode, this requires the operator to manually configure the
mobile station during testing; no overhead messaging or signaling is provided to set up the mobile station in
this operating mode.
This measurement always uses protocol triggering. A measurement cannot be made unless the mobile station
(UE) is synchronized to the test set's downlink signal and is transmitting a corresponding uplink signal.
Measurement results are affected by any amplitude offsets that are entered, since the level into the UE is
altered.
Interpreting Integrity Indicator Values
If Measurement Timeout (2) is returned, the test set initiated the measurement and attempted to post the
measurement results before the measurement had completed. This is typically occurs when either of the
following conditions exist:
• The measurement timeout value you entered for the measurement is too small for the number of bits being
used. In this case, either reduce the number of bits to test or increase the timeout value.
• The measurement did not start due because it could not align the received data with the transmitted data.
This happens if any of the following conditions occur:
— The test set is unable to synchronize to the uplink signal.
— The UE is not configured for the proper loopback mode.
— The UE is not configured for the proper uplink transport format.
If Synch Not Found (11) is returned, the test set lost synchronization with the uplink for some period of time
during the measurement.
If Over Range (5) is returned, the signal exceeds the maximum allowable level for the test set or is above the
level expected by the test set.
If Under Range (6) is returned, the signal is below the minimum allowable level for the test set or is below the
level expected by the test set.
Related Topics
"Integrity Indicator"
"Loopback Bit Error Ratio Measurement Description"
and "Triggering of Measurements" .
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Loopback Bit Error Ratio Troubleshooting
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