HSDPA Block Error Ratio Troubleshooting

Possible Setup Issues

• The HSDPA block error ratio (BLER) measurement can only be performed on a Radio Bearer Test Mode connection with a Channel Type of 12.2k RMC + HSDPA or 12.2k RMC + HSPA.
• See FDD Test Mode Considerations .
• If you experience unexpectedly high HSDPA BLER results, ensure that FRC Type is set to a configuration supported by your UE.
• If you set Measurement Timeout to On , ensure that the Measurement Timeout value is greater than the time the measurement needs to measure the desired Number of blocks to test .
• During front panel operation of this measurement, if Trigger Arm is set to Single , you must press the START SINGLE key to initiate the measurement.
• During remote operation of the HSDPA BLER measurement, you should configure the Trigger Arm to Single .
• Ensure that you have met the HSDPA Block Error Ratio Measurement Input Signal Requirements .
• Measurement results are influenced by any amplitude offsets that are entered, since the level into the UE is altered.
• In FDD Test operating mode, the test set does not signal the CQI Feedback Cycle (k) or CQI Repetition Factor to the UE, you must set the values manually in the UE. To ensure a valid Median CQI result, you must ensure that CQI Feedback Cycle (k) is greater than or equal to CQI Repetition Factor * 2ms (so that there are no collisions between new and repeated CQI information). See CQI Transmission Settings for more information about this requirement.

Troubleshooting Techniques

Check to see if an integrity indicator other than 0 (normal) was returned with the measurement result (see Integrity Indicator ).

• If Questionable MS-to-Cell Data (28) is returned, the setting you've chosen for Ack-Nack Repetition Factor is causing collisions between data being sent to the UE by the test set, and the repeated ACKs/NACKs being sent by the UE. You must ensure that the minimum inter-TTI of the active HSDPA channel is greater than or equal to Ack-Nack Repetition Factor * 2 ms (so that there are sufficient unused subframes on the uplink for the ACK/NACK repeats to be transmitted without colliding with new ACK/NACK information). Otherwise, the repeated ACK/NACK information will be sent by the UE when the test set expects ACK/NACK information for the block it just transmitted to the UE (a block that the UE ignored because it was sending an ACK or NACK repeat for a prior block). The test set would then treat the ACK/NACK repeat like ACK/NACK information for the current block, resulting in incorrect HSDPA BLER results.
• If Measurement Timeout (2) is returned, the value you entered for the measurement may be too small for the Number of blocks to test . In this case, either reduce the number of blocks to test or increase the timeout value.
• If Unsupported Configuration (22) is returned, you must set Channel Type to 12.2k RMC + HSDPA .

Related Topics

• HSDPA Block Error Ratio Measurement Description
• Integrity Indicator