How do I make a GSM Bad Frame Indication (BFI) Measurement?

How do I make a GSM Bad Frame Indication (BFI) Measurement?

Last updated: December 2, 2008

This section is only applicable to the lab applications and to GSM.

This procedure assumes that the BCH parameter for Cell Band is set up correctly for your mobile station and that the appropriate RF IN/OUT Amplitude Offsets have been set to offset loss between the mobile station and the test set.

Measuring 3GPP TS 51.010 Section 14.1.1 BFI

  1. Press the CALL SETUP key.
  2. Press BCH Parameters ( F7 ).
  3. Press Cell Power ( F7 ) and set cell power to a value 20 dB above the reference sensitivity level for the band in which you are testing. Reference sensitivity levels can be found in 3GPP TS 05.05 section 6.2.
  4. Press Return ( F12 ).
  5. Press TCH Parameters ( F8 ).
  6. Press Downlink Traffic Power ( F7 ) and select Power Reduction Level One (PRL One) . Enter 9 dB . (Set the power reduction level to 9 dB when performing 3GPP TS 51.010 test 14.1.1, 14.1.2, 14.1.5 or 14.1.6. The power used for downlink traffic channels will then be 11 dB above the reference sensitivity level if the cell power is set 20 dB above this level.)
  7. Verify that the Power Reduction Level Used Burst is set to PRL One .
  8. Press Traffic Channel ( F9 ) and enter a value in the middle of the ARFCN range for the band in which you are testing.
  9. Press MS TX Level ( F10 ) and enter the value for maximum power for the band in which you are testing.
  10. Press Channel Mode Setup ( F11 ).
  11. Press Channel Mode Config ( F7 ) and select the correct Logical Speech Channel .
  12. Connect the mobile station to the test set and turn in on. Allow it to camp to the test set's signal.
  13. Establish a GSM phone call.

       
    NOTE
    You MUST establish the GSM phone call before the following configuration steps. The measurement does not work correctly if you configure speech type and the mobile loopback before a call is established.
       

  14. Press the More softkey on the right side of the front panel display to access the TCH Parms ( 2 of 2 ) menu.
  15. Press Speech ( F10 ) and select SID.

       
    NOTE
    Step 15 is omitted and SIDs are not sent if the Logical Speech Channel is set to AFS (Adaptive Full) or AHS (Adaptive Half). This means that more frames are available for the measurement on AFS and AHS speech channel and there is no count of incorrectly marked SIDs.
       

  16. Press Mobile Loopback ( F9 ) and select Type A.
  17. Press the Measurement Selection key.
  18. Select GSM Bad Frame Indication . The measurement will start.
  19. Press Bad Frame Ind Setup ( F1 ).

       
    NOTE
    Notice that the default Samples to Test value is 492000 . This is the number specified in 3GPP TS 51.010 test 14.1.1, 14.1.2, 14.1.5 and 14.1.6 for this test. This measurement can take over 45 minutes to complete this number of samples.
       

  20. Select Speech Frame Delay and enter the appropriate value for your mobile station. You may not get expected results if this is not configured correctly. See Speech Frame Delay for more details about this parameter.
  21. Verify the measurement results meet the conformance requirements defined in 3GPP TS 51.010 section 14.1.1, 14.1.2, 14.1.5 or 14.1.6. Acceptable performance for the BFI test limit error rate is less than or equal to 0.041%.

Related Topics

GSM Bad Frame Indication (BFI) Measurement Description