Uplink State Flag (USF) BLER

Last updated: December 3, 2008

This measurement is not applicable to GSM.

The USF is only used by the mobile station when the test set's Medium Access Mode mode is set to Dynamic Allocation , Extended Dynamic Allocation , or Automatic Dynamic Allocation .

This section details the test set's operation for the following:

Assigned Uplink State Flag (USF) BLER

Unassigned USF Mode

Manual Unassigned USF

Operating Considerations

• Assigned Uplink State Flag (USF) BLER

  Assigned Uplink State Flag (USF) BLER is a measurement report. It is displayed in the Error Reports section of the Call Setup screen.

  The Assigned USF BLER report is an indication of the number of PDTCH blocks incorrectly decoded (USF bits only) by the mobile station. This report is calculated by counting the number of blocks that the mobile station fails to transmit as a consequence of incorrectly decoding the USF of the block preceding the expected transmission period. This serves as an indication of the mobile station's receiver performance.

  The GPIB command to change this parameter is CALL:(PDTCH|PDTChannel):MACCess[:DYNamic]:USFLag[:ASSigned] .

• Unassigned USF Mode

  Unassigned Uplink State Flag (USF) BLER is a measurement report. It is displayed in the Error Reports section of the Call Setup screen.

  The Unassigned USF BLER is the ratio of PDTCH blocks in which the USF bits were decoded incorrectly by the mobile station to the total number of PDTCH blocks transmitted from the test set. The Unassigned USF BLER measurement report allows you to verify if the mobile station is transmitting at inappropriate times as a result of the incorrectly decoded blocks.

  There are three modes available for the Unassigned USF to operate in:

  • Manual Unassigned USF

    See Manual Unassigned USF

  • Random Unassigned USF

    When the Random Unassigned USF mode is selected the test set pseudo-randomly assigns a value to the Unassigned USF. The test set never assigns the Unassigned USF the same value as the Assigned USF.

  • Random Burst

    When the Random Burst mode is selected the test set transmits a random GMSK modulated burst. This mode is only selectable when the connection type is ETSI Type A.

  The GPIB command to change this parameter is CALL:(PDTCH|PDTChannel):MACCess[:DYNamic]:USFLag:UNASsigned:MODE .

• Manual Unassigned USF

  When the Unassigned USF Mode is set to Manual USF, the test set uses the value set for the Manual Unassigned USF parameter as the value for the USF value.

  The values for the Assigned USF and the Unassigned USF cannot be the same. If the value of the Assigned USF is changed to a value that is the same as what the Unassigned USF is currently set to, the Unassigned USF will change to the default value of 7 as long as 7 is not the value the Assigned USF is being changed to. If the Assigned USF value is changed to 7 when the Unassigned USF value is 7, the Unassigned USF value is changed to 0.

  The GPIB command to change this parameter is CALL:(PDTCH|PDTChannel):MACCess[:DYNamic]:USFLag:UNASsigned[:MANual] .

• Operating Considerations

  The following table shows the valid connection types in which the Assigned and Unassigned USF BLER measurement can be performed.

  Connection Type	Manual/Random USF	Random Burst
  Auto	Not when on a voice or circuit switched data call.
  ETSI A	Yes	Yes
  ETSI B	Yes	No
  ETSI B	Yes	No
  BLER	No (uplink TBF is not present)	No (uplink TBF is not present)
  SRB Loopback	Yes	No