How Do I Make a PRACH Transmit On/Off Power Measurement?

How Do I Make a PRACH Transmit On/Off Power Measurement?

Last updated: January 15, 2009

Before performing any of these procedures, ensure that you have specified the proper Amplitude Offset for your test setup, and that the test set has been properly calibrated (see Calibrating the Test Set ).

Measuring 3GPP TS 34.121 5.4.1 Open Loop Power Control in the Uplink

  1. Set the downlink and uplink channels, and downlink channel levels:
    • Set Operating Mode ( F1 ) to Cell Off .
    • Set DL Channel ( F10 ) and Uplink Channel ( F11 ) to the appropriate "low range" frequencies for your UE's operating band, as specified by 3GPP TS 34.108 5.1.1 (for example, for operating band I, DL Channel = 10563 and Uplink Channel = 9613 ).
    • Ensure that the Downlink Channel Levels are set to their default values, as required by 3GPP TS 34.121 Table E.2.2 (select Generator Info , F3 on Call Control 2 of 5 ).
    • Set Operating Mode to Active Cell .
  2. Set uplink parameters:
    • Select Uplink Parameters ( F4 from the Call Control 2 of 5 menu).
    • Set PRACH Preambles to 4 .
    • Set PRACH Ramping Cycles (MMAX) to 1 (see Recommended PRACH Preambles and PRACH Ramping Cycles (MMAX) settings ).
    • Set Available Subchannels (Bit Mask) to only allow one available subchannel (for example, the default value of 000000000001).

    • Set Maximum Uplink Transmit Power Level to the specified maximum output power of your UE (for example, 21 dBm for power class 4).

      Note: Qqualmin and Qrxlevmin are fixed to -24 dB and -115 dBm in the test set, as required by 3GPP TS 34.121 Table 5.4.1.1a.

    • Select Close Menu ( F6 ).
  3. Set cell parameters:
    • Test Application: Press Cell Parameters ( F2 ).
      Lab Application: Press Cell Info ( F2 ), then Cell Parameters ( F2 ).
      ( from the Call Control 2 of 5 menu)
    • Ensure that Primary CPICH TX Power is set to its default value of 19 dBm .
    • Set Uplink Interference to -75 dBm .
    • Ensure that Constant Val ue is set to its default value of -10 dB .
    • Select Close Menu ( F6 ).
  4. Connect the UE to the test set, power it on and wait for it to camp to the test set's signal, but do not originate a call between the test set and UE (see How Do I Set Up a Call and Make a Connection? ).
  5. Set Cell Power ( F7 on Call Parms 1 of 3 ) to -25 dBm .
  6. Ensure that Call Limit State ( F10 on Call Parms 2 of 3 ) is set to its default value of Off (see Importance of Setting Call Limit State to Off before Initiating a PRACH Measurement ).
  7. Press the Measurement selection key.
  8. Select PRACH Transmit On/Off Power .
  9. Select PRACH TX On/Off Pwr Setup ( F1 ).
    • Ensure that Open Loop Power Error Upper Limit is set to its default value of 9 dB .
    • Ensure that Open Loop Power Error Lower Limit is set to its default value of -9 dB .
    • Select Close Menu ( F6 ).
  10. Press the START SINGLE key to begin the measurement.
  11. Verify that the Open Loop Power Error test result is Pass .
  12. To test "RX-middle" or "RX-Sensitivity level" cases:
    • Set cell parameters:
      • Press the CALL SETUP key.
      • Test Application: Press Cell Parameters ( F2 ).
        Lab Application: Press Cell Info ( F2 ), then Cell Parameters ( F2 ).
        ( from the Call Control 2 of 5 menu)
      • Set BCCH Update Page to Auto so the test set will notify the UE when you change the next two cell parameters.
      • Set Primary CPICH TX Power to 28 dBm or 19 dBm .
      • Set Uplink Interference to -101 dBm or -110 dBm .
      • Ensure that Constant Value is still set to -10 dB .
      • Select Close Menu ( F6 ).
    • Set Cell Power ( F7 ) to -65.7 dBm or -106.7 dBm .
    • Press the MEASUREMENT key to move to the Measurement/Instrument screen.
    • Ensure that the test set is in Idle state (see Test set may lock up if operations are attempted before the UE completes its PRACH sequence ), then press the START SINGLE key to begin the measurement.
    • Verify that the Open Loop Power Error test result is Pass .
  13. Repeat the test for "mid range" and "high range" frequencies. Note, if your UE does not camp to the test set at the new frequency, you may need to cycle the UE's power.

Measuring 3GPP TS 34.121 5.5.1 Transmit OFF Power

See Measuring 3GPP TS 34.121 5.5.2 Transmit ON/OFF Time Mask .

Measuring 3GPP TS 34.121 5.5.2 Transmit ON/OFF Time Mask

  1. Set the downlink and uplink channels, and downlink channel levels:
    • Set Operating Mode ( F1 ) to Cell Off .
    • Set DL Channel ( F10 ) and Uplink Channel ( F11 ) to the appropriate "low range" frequencies for your UE's operating band, as specified by 3GPP TS 34.108 5.1.1 (for example, for operating band I, DL Channel = 10563 and Uplink Channel = 9613 ).
    • Ensure that the Downlink Channel Levels are set to their default values as required by 3GPP TS 34.121 Table E.2.2. (select Generator Info , F3 on Call Control 2 of 5 ).
    • Set Operating Mode to Active Cell .
  2. Set uplink parameters:
    • Select Uplink Parameters ( F4 from the Call Control 2 of 5 menu).
    • Set PRACH Preambles to 4 .
    • Set PRACH Ramping Cycles (MMAX) to 1 (see Recommended PRACH Preambles and PRACH Ramping Cycles (MMAX) settings ).
    • Set Available Subchannels (Bit Mask) to only allow one available subchannel (for example, the default value of 000000000001).

    • Set Maximum Uplink Transmit Power Level to the specified maximum output power of your UE (for example, 21 dBm for power class 4).

      Note: Qqualmin and Qrxlevmin are fixed to -24 dB and -115 dBm in the test set, as required by 3GPP TS 34.121 Table 5.4.1.1a.

    • Select Close Menu ( F6 ).
  3. Set cell parameters:
    • Test Application: Press Cell Parameters ( F2 ).
      Lab Application: Press Cell Info ( F2 ), then Cell Parameters ( F2 ).
      ( from the Call Control 2 of 5 menu)
    • Ensure that Primary CPICH TX Power is set to its default value of 19 dBm .
    • Set Uplink Interference to the proper value for your UE's power class as required by 3GPP TS 34.121 Table 5.5.2.3 (for example, -98 dBm for power class 4).
    • Ensure that Constant Val ue is set to its default value of -10 dB .
    • Select Close Menu ( F6 ).
  4. Connect the UE to the test set, power it on and wait for it to camp to the test set's signal, but do not originate a call between the test set and UE (see How Do I Set Up a Call and Make a Connection? ).
  5. Set Cell Power ( F7 ) to -106.7 dBm .
  6. Ensure that Call Limit State ( F10 on Call Parms 2 of 3 ) is set to its default value of Off (see Importance of Setting Call Limit State to Off before Initiating a PRACH Measurement ).
  7. Press the Measurement selection key.
  8. Select PRACH Transmit On/Off Power .
  9. Select PRACH TX On/Off Pwr Setup ( F1 ).
    • Ensure that Off Power Limit is set to its default value of -55 dBm .
    • Set Open Loop Power Error Upper Limit to 1.7 or 2.7 dB , depending upon your UE's power class, as required by 3GPP TS 34.121 Table 5.2.2.
    • Ensure that Open Loop Power Error Lower Limit is set to its default value of -9 dB .
    • Select Close Menu ( F6 ).
  10. Press the START SINGLE key to begin the measurement.
  11. Verify that the Pre Burst Off Power , Open Loop Power Error and Post Burst Off Power test results are Pass .
  12. Repeat the test for "mid range" and "high range" frequencies. Note, if your UE does not camp to the test set at the new frequency, you may need to cycle the UE's power.

Related Topics

PRACH Transmit On/Off Power Measurement Description

PRACH Transmit On/Off Power Troubleshooting

Programming a PRACH Transmit On/Off Power Measurement