Programming a GSM Bad Frame Indication (BFI) Measurement
Last updated: December 2, 2008
This section is only applicable to the lab applications.
General Programming Procedure
The following procedure assumes that the mobile station's antenna output is connected to the RF IN/OUT connector.
-
Set up the BFI measurement parameters using the SETup:BFI commands (see
SETup:<BFINdication|BFI>
). See
BFI Measurement Parameters
for information about the configurable parameters.
-
Set up the System Type if your mobile station does not support the default (see
CALL[:CELL]:BCHannel:SCELl
). To change the System Type:
-
Turn the cell off by changing the operating mode to OFF using the following command:
CALL:OPERating:MODE
.
-
Change the system type to GSM, GPRS or EGPRS as desired using the following command:
CALL[:CELL]:BCHannel:SCELl
.
-
Turn the cell back on using the CALL:OPER:MODE command.
-
Set up the Broadcast Channel.
-
Set the mobile station's transmit level using the following command:
CALL:MS:TXLevel[:SELected]
. (Set the mobile station's transmit level to maximum power when performing 3GPP TS 51.010 test 14.1.1.)
-
Set up the Downlink Traffic Power to be different from the cell power by defining a Power Reduction Level using the following command:
CALL:TCHannel:PREDuction:LEVel([1]|2)
(Set the power reduction level to 9 dB when performing 3GPP TS 51.010 test 14.1.1. 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.) Assign the Power Reduction Level you just defined to the GSM burst using the following command:
CALL:TCHannel:PREDuction:BURSt
.
-
Establish a GSM call. See
Step 4: Make a Connection
for more details.
-
Reconfigure the Traffic Channel.
-
Set the TCH to transmit in Discontinuous Transmission (DTX) mode by setting the downlink speech to "SID" using the following command:
CALL:TCHannel:DOWNlink:SPEech
.
-
Set the mobile station loopback to Type A using the following command:
CALL:TCHannel:LOOPback
. In a Type A loopback, the mobile station loops back every good speech frame and loops back bad speech frames as all zeros.
-
Initiate the BFI measurement using the following command:
INITiate:<measurement mnemonic>[:ON]
. The <measurement mnemonic> for the BFI measurement is either BFINdication or BFI.
-
Use
FETCh:<BFINdication|BFI>[:ALL]?
to obtain the measurement results.
Programming Example: 14.1.1.1 Bad Frame Indication - TCH/FS - Random RF input
10 OUTPUT 714;"*RST"
20 OUTPUT 714;"SET:BFI:SAMP 492000"
30 OUTPUT 714;"SET:BFI:SFD 4"
40 OUTPUT 714;"CALL:POW -82"
50 OUTPUT 714;"CALL:MS:TXL 30"
60 OUTPUT 714;"CALL:TCH:PRED:LEV2 9"
70 ! Turn on the mobile station and allow it to camp.
80 OUTPUT 714;"CALL:ORIG:SEQ"
90 OUTPUT 714;"CALL:ORIG:DONE?"
100 ENTER 714;Orig
110 IF NOT Orig THEN
120 PRINT "CALL FAILED"
130 STOP
140 END IF
150 OUTPUT 714;"CALL:TCH:DOWN:SPE SID"
160 OUTPUT 714;"CALL:TCH:LOOP A"
170 OUTPUT 714;"INIT:BFI"
180 OUTPUT 714;"FETC:BFI?"
190 ENTER 714;Integrity,Samples,Ubframes,Bsid,Sidsent
200 OUTPUT 714;"CALL:TCH:LOOP OFF"
210 OUTPUT 714;"CALL:TCH:DOWN:SPE ECHO"
220 END