If the access probe power measurement is on and waiting to measure a probe, all other measurements (except digital average power) will not be able to execute. It is therefore recommended that you turn off the access probe power measurement before attempting any other measurements. To optimize access probe power measurement speed, it is also recommended that you turn off all other measurements when performing an access probe power measurement.
Possible Setup Issues
-
If
Trigger Arm
is set to
Single
during manual operation, you must press the
START SINGLE
key to arm the measurement before it can measure the power of an access probe.
-
During remote operation of this measurement, you should configure the Trigger Arm to Single. See
SETup:CAPPower:CONTinuous
or
SETup[:ALL]:CONTinuous:OFF|:ON
.
-
It is recommended that you always turn
Call Limit Mode
on when measuring access probe power. The easiest way to induce access probes from the access terminal is to page the access terminal. If you do not have call limit mode set to on, the connection will complete, which clears the access probe power result from the measurement screen. Set call limit mode back to off when you have finished measuring access probe power.
-
There are several parameters that affect the access probe measurement results, such as Call Limit Mode, Probe Initial Adjust, and Probe Power Step. See
Considerations when Making Access Probe Power Measurements
for details.
-
Access probe power measurements are triggered by a rise in RF power that must cross at least -45 dBm/1.23 MHz. See
How is an Access Probe Power Measurement Made?
for details.
Troubleshooting Techniques
-
Turn off the access probe power measurement. Turn on the channel power measurement and page the access terminal. Check to see if any access probes are detected by the channel power measurement. You can also use the spectrum monitor or an external spectrum analyzer to try to detect the access probes.
-
Turn call limit mode off and try to open a connection with the current setup.
-
Check to see if an integrity indicator other than 0 (normal) was returned with a measurement result (see Channel Power
Troubleshooting Techniques
).
Other Considerations
-
To help avoid over range or under range integrity indicators, correct for system path loss (see
Amplitude Offset
).
-
If you are manually controlling the test set's receiver, be certain that you have entered the correct frequency and power values for your test setup (see
Receiver Control
).
-
Under range occurs when testing access terminals with the Qualcomm DMSS 5500.
Access terminals with the Qualcomm DMSS 5500 transmit access probes that are several dB lower than expected. When testing these access terminals, you must manually range the receiver power to ensure that the input signal is within the required measurement range (see
Manual receiver power
and
Input Signal Requirements
).
When testing these access terminals at high cell power, you may find that the access probe power level is too close to the noise level to allow the measurement to trigger. In this case you may need to lower the cell power level until the access probe power becomes high enough to measure. Specifically, this problem may occur when performing the
3.1.2.3.1 Range of Open Loop Output Power
Test 1 (cell power of -25 dBm).
-
Ensure that the measurement is properly calibrated. See
Calibrating the Access Probe Power Measurement
.