Forward Power Control Information

Last updated: November 28, 2010

This section is only applicable to the lab application.

When the F2 (Forward Power Control ) on Call Control 4 of 4 menu is pressed, the Forward Power Control Information screen (see Forward Power Control Information ) is displayed to provide some useful results associated with forward power control (FPC) operation:

Forward Power Control Information

Inner/Outer Loop Power Control Information

Current F-FCH/Traffic Level

Indicates the average level of F-FCH (Ec/Ior) currently generated by the test set. When a call is connected with FPC mode set to 000-Primary 800,
- it is updated at every 25 frames (each 20 ms) interval.
- if this value is greater than the Current Maximum F-FCH Level , the Current F-FCH/Traffic Level will be clipped to the Current Maximum F-FCH Level, and no error is posted.
- if this value is less than - 30 dB, the Current F-FCH/Traffic Level will be clipped to -30 dB, and no error is posted.
GPIB Command: CALL:STATus:FCHannel[:CELL[1]][:LEVel][:SELected]?
MS Reported F-FCH Current Setpoint

Indicates the outer loop Eb/Nt setpoint of the F-FCH last requested from the MS (see To Request an Outer Loop Report from the MS ) when a call is connected in FPC Mode set to 000-Primary 800 . The MS will send an Outer Loop Report Message in the FPC_FCH_CURR_SETPT field (in units of 0.125 dB) in response to the request. (MS Reported F-FCH Current Setpoint (dB) = FPC_FCH_CURR_SETPT * 0.125 dB).

GPIB Command: CALL[:CELL]:FPControl:OLReport:FCHannel:SETPoint:CURRent?

To Request an Outer Loop Report from the MS

When a call is connected with FPC Mode set to 000-Primary 800 , the current outer loop Eb/Nt setpoint of the F-FCH can be requested from the MS by pressing the F4 (Request Outer Loop Report ) or sending the CALL[:CELL]:FPControl:OLReport:REQuest command. The MS reported information is then displayed on the MS Reported F-FCH Current Setpoint field.

This request actually performs two actions, clearing the last retrieved results and then updating those results according to the MS's response. Note that if the test set does not receive an Outer Loop Report Message from the MS after a request, the MS Reported F-FCH Current Setpoint will be cleared and an error will be generated to indicate the error condition.

To Clear the Outer Loop Report Result

Whenever you press the F2 (Clear Outer Loop Report ) on FPC Info 2 of 2 or send the CALL[:CELL]:FPControl:OLReport:CLEar command, the MS Reported F-FCH Current Setpoint result will be cleared.

MS Reported Frame Error Rate Information

To support the forward power control on the F-FCH in FPC mode 000-Primary 800 (see FPC Mode ), the MS reports frame error rate statistics to the test set via the Power Measurement Report Message (PMRM) when any of the following conditions exists:

the Threshold Report Enable is set to On and the number of bad frames detected on the F-FCH (which is recorded in the BAD_FRAMES counter in the MS, see Background Information ) reaches the specified Bad Frame Threshold (Frames) , or
the Periodic Report Enable is set to On and the total number of frames received on the F-FCH (which is recorded in the TOT_FRAMES counter in the MS, see Background Information ) reaches the specified Frame Interval of Report (Frames) .

When the test set receives a PMRM from the MS, the following results will be updated on the MS Reported Frame Error Rate Information window (see Forward Power Control Information ).

MS Reported FER

Indicates the frame error rate, in percentage. It is calculated as: Bad Frames/Total Frames *100.

GPIB Command: CALL:MS:FERate:REPort:RATio?
Bad Frames/Total Frames

Bad Frames indicate the number of bad frames detected on the F-FCH by the MS and Total Frames indicate the total number of frames received on the F-FCH by the MS. They are corresponding to the ERRORS_DETECTED and PWR_MEAS_FRAMES fields in the PMRM reported from the MS.

The maximum value of the ERRORS_DETECTED is 31. When the number of the detected bad frames exceeds 31, the ERRORS_DETECTED will remain at 31 or roll back to zero depending upon the mobile station's design.

GPIB Commands: CALL:MS:FERate:REPort:BAD? and CALL:MS:FERate:REPort:TOTal?

To Clear the MS Reported Frame Error Rate Information

To clear the information on the MS Reported Frame Error Rate Information screen, press the F3 (Clear MS Reported FER ) on FPC Info 2 of 2 menu or send CALL:MS:FERate:REPort:CLEar command.

MS Reported Erasure Indicator Bit (EIB) Information

When a call is connected with FPC Mode set to 011-EIB , the test set maintains a set of EIB counters. These EIB counters will keep track of how many good/bad frames that were sent from the test set as specified (see F-FCH Frame Pattern Setup ) are matched with the EIBs reported from the MS when the EIB counters are started (see To Start/Stop EIB Counters ). All these EIB counters can be queried with one command (see CALL[:CELL]:FPControl:EIBCount[:ALL]? ).

For details on how the MS reports EIBs in response to the received frame, see FPC Mode '011' .

NOTE

The actual good frames sent from the test set may be greater than the specified good frames. See Signaling Frame Quality for details.

Good Frames Matched: indicates how many good frames sent from the test set are reported as good frames by the MS. This counter is increased by one for each sent good frame when the corresponding EIB is reported as 0 (indicating good frame) by the MS.
Good Frames Not Matched: indicates how many good frames sent from the test set are reported as bad frames by the MS. This counter is increased by one for each sent good frames when the corresponding EIB is reported as 1 (indicating bad frame) by the MS.
Good Frames Not Received: indicates how many good frames sent from the test set are not received by the MS. This counter is increased by one for each sent good frame when the corresponding EIBs are not received from the MS.

NOTE
The standard specifies that the MS will turn off its transmitter when it receives 12 continuous bad frames and will turn on the transmitter again when it receives two good frames. When the MS's transmitter is turned off, the test set will not receive EIBs on the reverse power control sub-channel.
Bad Frames Matched: indicates how many bad frames sent from the test set are reported as bad frames by the MS. This counter is increased by one for each sent bad frame when the corresponding EIB is reported as 1 (indicating bad frame) by the MS.
Bad Frames Not Matched: indicates how many bad frames sent from the test set are reported as good frames by the MS. This counter is increased by one for each sent bad frames when the corresponding EIB is reported as 0 (indicating good frame) by the MS.
Bad Frames Not Received: indicates how many bad frames sent from the test set are not received by the MS. This counter is increased by one for each sent bad frame when the corresponding EIBs are not received from the MS.

NOTE
The standard specifies that the MS will turn off its transmitter when it receives 12 continuous bad frames and will turn on the transmitter when it receives two good frames. When the MS's transmitter is turned off, the test set will not receive EIBs on the reverse pilot channel.
F-FCH/Traffic Frame Pattern State:

Indicates the corresponding state that you set from the F-FCH/Traffic Frame Pattern Setup menu. See F-FCH/Traffic Frame Pattern State .
Good/Bad Frames and Bad Frame Ratio:

Indicates the good/bad frame pattern that you set from the F-FCH/Traffic Frame Pattern Setup menu. It corresponds to the settings of the F-FCH/Traffic Frame Pattern Good Frames and F-FCH/Traffic Frame Pattern Bad Frames .

Bad Frame Ratio indicates the percentage of the bad frames in the specified frame pattern. It is equal to F-FCH/Traffic Frame Pattern Bad Frames / ( F-FCH/Traffic Frame Pattern Good Frames + F-FCH/Traffic Frame Pattern Good Frames ) * 100
Signaling Frame Quality:

Indicates the corresponding state that you set from the F-FCH/Traffic Frame Pattern Setup menu. See Signaling Frame Quality .

To Start/Stop EIB Counters

To start the EIB counters, the FPC Mode must be set to 011- EIB .

When a call is connected and the F5 (Start EIB Counters ) is pressed or the CALL[:CELL]:FPControl:EIBCount:STARt command is sent, all of the EIB counters are cleared to zeroes and then start to increment according to the received EIBs from the MS. The running count of these EIB counters can be monitored from the MS Reported Erasure Indicator Bit (EIB) Information window.

All of EIB counters will stop incrementing when the F5 (Stop EIB Counters ) is pressed or the CALL[:CELL]:FPControl:EIBCount:STARt command is sent.

When the FPC Mode is changed from '011 - EIB' to any other FPC mode, or the call status is changed from Connected to Idle, the test set will suspend all of EIB counters and remain at the last values.

To Clear the MS Reported Erasure Indicator Bit (EIB) Information

To clear the results on the MS Reported Erasure Indicator Bit (EIB) Information window, press the F4 (Clear EIB Counters ) on FPC Info 2 of 2 or send CALL[:CELL]:FPControl:EIBCount:CLEar command.

Forward Power Control Parameters

The Forward Power Control Parameters window (see Forward Power Control Information ) displays the parameter values that you set from the FPC Parameters menu (see FPC Parameters ) except that:

Current Maximum F-FCH Level

Indicates the actual upper limit of F-FCH level (Ec/Ior) that the test set is allowed to be adjusted to in FPC mode 000-Primary 800 according to the forward power control from the MS. It may be different from what you set (see Maximum F-FCH Level ) due to an invalid set caused by the code level summation check (see Considerations When Setting Code Channel States and levels ). The Current FPC Maximum F-FCH Level is not available if the test set is not in FPC mode 000-Primary 800.

GPIB Command: CALL:STATus:FPControl:FCHannel:LEVel:MAXimum?
External AWGN Power

An external AWGN value is displayed when the test set is configured to generate faded forward channel signals with AWGN. This setup requires a rear panel digital bus connection to an external PC running Baseband Studio software. See Digital Bus Information for details.

Forward Power Control Information