Measuring Graphical Access Probe Power

Measuring Graphical Access Probe Power

Last updated: June 20, 2006

This section is only applicable to the lab application.

   
NOTE
Channel power calibration should be performed if the test set is being used for the first time or the operating environment has changed significantly since the last calibration was performed. The channel power calibration also calibrates the graphical access probe power measurement. See Calibrating the Test Set for details.
   

General Procedure

  1. Connect the access terminal to the test set's front panel RF IN/OUT connector and power it on. If the access terminal does not automatically open a session, perform whatever actions are necessary to open a session. See How Do I Open a Session and Test Data Connection? for more details.
  2. Initialize the graphical access probe power measurement:
    • Press the Measurement selection key.
    • Turn the knob to highlight the Graphical Access Probe Power measurement and press the knob.
  3. Select Graphical Access Probe Pwr Setup ( F1 ) to access the Graphical Access Probe Power Setup menu. Turn the knob to select the parameters and set the value as required for your test situation. For example,
    • set Probe Power Step to 2.0 dB .
    • set Probe Num Step to 6 .
    • set Probe Sequence Max to 4 .
    • set Preamble Length (Frames) to 7 .

       
    NOTE
    The Probe Sequence Max is a "Configurable Attribute" that is configured during the Session Negotiate State . Its value can not be changed when a session is open and Call Limit Mode is on.
       

  4. Select Close Menu ( F6 ) to close the Graphical Access Probe Power Setup menu.
  5. Set the access network to ignore all access attempts by setting Call Limit Mode to On ( F10 on the Call Parms 2 of 3 menu). See How Do I Change Call Parameters? for more details.
       
    NOTE

    It is recommended that you always turn Call Limit Mode on when measuring graphical 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, when you page the access terminal, 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.

       

  6. Press the START SINGLE key to arm the measurement. The measurement result will not be returned until you complete step 7.
       
    IMPORTANT

    The measurement will not operate until you arm it by pressing the Start Single key.

       

  7. In order to perform the graphical access probe power measurement, the access terminal must send access probes. The easiest way to induce this is to page the AT (open a connection) by selecting Start Data Connection ( F3 on the Call Control 2 of 2 menu).
  8. When the AT sends access probes as specified in step 3, their power levels will be measured and displayed. As shown below, the measurement results are displayed in both a tabular and a bar graph formats (see Graphical Access Probe Power Measurement Results for more description).
  9. (Optional) To adjust the display view, see Set Up the Graphical View .
  10. After finishing the measurements:
    • End the connection attempt by selecting End Data Connection ( F3 on the Control 2 of 2 menu).
    • Turn the Call Limit Mode back to Off .
    • Turn the graphical access probe power measurement off by pressing the Measurement selection key, selecting Graphical Access Probe Power , then Close Measurement ( F4 ).

   
IMPORTANT
If the access probe power measurement is on and waiting to measure a probe, all other measurements will not be able to execute. It is therefore recommended that you turn off the graphical access probe power measurement before attempting any other measurements.
   

Set Up the Graphical View

  1. Press the More key on the left side of the display until 1 of 2 is displayed.
  2. Press the Graph Control ( F2 ) key.
  3. Select the Start ( F3 ) and Span ( F4 ) to adjust the span of the graph display. The graph window can be adjusted to include the entire 120 second range or only a portion of the 120 second time period of particular interests. The graph can display up to 60 access probes, labeled 0 through 59.
  4. The Marker Mode ( F1 ) sets the mode of the active marker.
    • When Position is selected, use the Marker Position ( F2 ) to position the marker at any bar across the current span of the graph. Measurement results that correspond with the bar at the position marker (in this example, the power levels for the 7th access probe and the time offset relative to the 1st access probe) are displayed above the graph and become highlighted in the table below the graph.
    • When Delta is selected, it first freezes the current position marker and uses it as a reference marker. A second marker is created at the position specified by the Delta Position ( F2 ) offset from that of the position marker. Any change in power between the second marker and the position marker is calculated as delta values. Measurement results that correspond with the position marker and the delta marker (in this example, the two values to the right of the "Mkr" indicates the power levels for the 7th access probe and the time offset relative to the 1st access probe, and the two values to the right of the delta symbol indicates the delta power and time between the 9th access probe and the 7th access probe) are displayed above the graph and become highlighted in the table below the graph.
  5. (Optional) Press the MEASUREMENT RESET key to clear the display.

Testing 4.3.1 Range of Open Loop Output Power

For details on performing the steps below, see the General Procedure above. The 4.3.1 test can also be performed with Access Probe Power measurement, see Measuring Access Probe Power .

  1. This test specifies using Default Access Channel MAC Protocol and Access Parameter message. See To Configure the Test Set to Default Access Channel MAC Subtype for detailed procedure.
  2. Set the Cell Band and Channel as needed and wait for access terminal automatically opening a session.
  3. Initialize the graphical access probe measurement.
  4. Set Probe Power Step to 0 dB . This ensures that all access probes in the probe sequence will transmit at the same power level, rather than incrementing in power.
  5. Set Probe Sequence Max to 1 .
  6. Set Preamble Length to 7 .
  7. Set Open Loop Adjust to 78 dB or 81 dB , depending upon band class (for example, use 78 for US Cellular band, or use 81 for US PCS band).
  8. C.S0033 specifies to set the AN forward packet activity to 100%. Forward packet activity is fixed in the test set, always set to 100%. See Fixed Settings .
  9. Set the access network to ignore all access attempts by setting Call Limit Mode to On .
  10. Set Î or ( Cell Power ) to -25 , -65 or approximately -95 dBm/1.23 MHz (value depends on band class and access terminal class) for tests 1-3 as specified by C.S0033.
  11. Press the Start Single key to arm the measurement.

       
    IMPORTANT
    The measurement will not operate until you arm it by pressing the Start Single key.
       

  12. Send a page to the access terminal by selecting Start Data Connection .
  13. Measure access probe power.
  14. Stop the page to the access terminal by selecting Stop Data Connection .
  15. Perform steps 10-14 for tests 1-3.