Measuring Packet Error Rate (PER)

Measuring Packet Error Rate (PER)

Last updated: January 16, 2009

General Procedure

  1. Connect the access terminal to the test set's front panel RF IN/OUT connector and power it on.
  2. Wait for the access terminal to open a session and then open an FTAP (for subtype 0 physical layer) or FETAP (for subtype 2 physical layer) or FMCTAP (for subtype 3 physical layer) test data connection for AT's receiver test. See How Do I Open a Session and Test Data Connection? for detailed procedure.

       
    NOTE
    When more than one test set is configured to perform a multiple carrier measurement (see Multi-carrier Multi-unit (MCMU) ), not all parameters can be set on each test set because of the interaction between the test sets. For example, some parameters can not be set or changed on the auxiliary unit because it is controlled by the main unit, and some of the parameters of the auxiliary unit can be set as associated parameters on the main unit. For which parameters can or can not be set on a single test set, see Multicarrier Parameters and Multi-carrier Multi-unit Setting Interactions .

       

  3. Set the FTAP Rate ( F11 ) on the Call Parms 1 of 3 menu as needed if during an FTAP connection, or set the F-Traffic Format ( F12 ) on the Call Parms 1 of 3 menu as needed if during an FETAP or an FMCTAP connection.
  4. Initialize the PER measurement:
    • Press the Measurement selection key.
    • Turn the knob to highlight the Packet Error Rate measurement and press the knob.
  5. Select Packet Error Rate Setup ( F1 ) to access the Packet Error Rate Setup menu. From this menu you can configure measurement parameters such as Confidence Level , PER Requirement , as well as some general parameters that are required for some C.S0033 tests. For example, you can set AT Directed Packets , which helps you optimize PER test throughput.

       
    NOTE
    If Limited TAP is on while Test Application Protocol is set to FTAP, AT Directed Packets must not be greater than 50%.

       

  6. Select Close Menu ( F6 ) to close the Packet Error Rate Setup window.
  7. From the Call Parms menu, configure Cell Power ( F7 ) and FTAP Rate ( F11 ), as needed. See How Do I Change Call Parameters? for detailed procedure.

       
    NOTE
    If Limited TAP is on while Test Application Protocol is set to FTAP, RTAP Rate must be set to 9.6 kbps.

       

  8. From the Call Control menu, configure AWGN Power ( F3 ), as needed. (If you set AWGN Power too high relative to Cell Power, you may drop the connection). See How Do I Change Generator Information? for detailed procedure.
  9. Measure PER:
    • If the Trigger Arm field is set to Single , press the START SINGLE key to trigger each measurement.
    • If the Trigger Arm field is set to Continuous the measurement began executing as soon as you initialized it in step 3.

A typical display is shown below:

   
NOTE
The PER is measured on a per carrier basis for AT that supports Subtype 3 Physical Layer.

   

Testing 3.2.1 Demodulation of Forward Traffic Channel in AWGN

For details on performing the steps below, see the General Procedure above.

  1. 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 .
  2. Set the Control Channel Data Rate to 38.4 kbps (see How Do I Change Cell Parameters? ).
  3. C.S0033 specifies to set Pilot Drop to -14 dB. Set Pilot Drop to 28 (see How Do I Change Cell Parameters? ). Note that changing the Pilot Drop results in a session re-negotiation.
  4. Set up a Test Application session and open an FTAP or FETAP or FMCTAP connection. See How Do I Open a Session and Test Data Connection? for detailed procedure.
  5. Initialize the PER measurement.
  6. Set AT Directed Packets under the Application Config ( F10 on Call Parms 1 of 3 ) menu as needed (In an FTAP connection, if Limited TAP is on, AT Directed Packets must not be greater than 50%, and RTAP Rate must be set to 9.6 kbps).
  7. Set the ACK Channel Bit Fixed Mode Attribute (Fwd TAP) to Off under the Application Config ( F10 on Call Parms 1 of 3 ) menu. (Otherwise, you may drop the data connection when AWGN is applied. This recommendation is based on many of experiments.)
  8. Set Î or ( Cell Power ) to -55 dBm/1.23 MHz .
  9. Set I oc ( AWGN Power ) and Data Rate/Slots per Physical Layer Packet ( FTAP Rate ) or F-Traffic Format for tests 1-18 as specified by C.S0033.
    For example, set FTAP Rate to 2457.6 (1 Slot) for test 2 or 1843.2 (1 Slot) for test 3 if in an FTAP connection, or set F-Traffic Format to C (4096, 1, 64) for test 2 or B (3072, 1, 64) for test 3 if in an FETAP connection. For details on the data rate please refer to FTAP Rate and F-Traffic Format .
  10. Set Confidence Level to 95% and PER Requirement as specified by C.S0033.
  11. Set Maximum Packet Count as desired.
  12. Measure PER. For AT that supports Subtype 3 Physical Layer, the PER is measured on a per carrier basis.
  13. If your AT supports Subtype 2 Physical Layer, continue to measure PER for tests 19-28 and 30 with the following setups.
    • Set Pilot Drop to 32 (corresponding to -16 dB). Note: This results in a session re-negotiation. See How Do I Change Cell Parameters? .
    • Set up a Test Application session and open an FETAP connection. See How Do I Open a Session and Test Data Connection? for detailed procedure.
    • Set Î or ( Cell Power ), I oc ( AWGN Power ) and forward packet format (packet size, slots, preamble length, data rate) per Physical Layer Packet for tests 19-30 as specified by C.S0033.
      For example, for test 25, set the Cell Power to -55 dBm/1.23 MHz , the AWGN Power to -47.07 dBm/1.23 MHz . Set the F-Traffic Format to 1 (512, 16, 1024) (See F-Traffic Format for details) and the Max Forward Packet Duration to 4 slots which results in the nominal data rate of 19.2 kbps and the effective data rate of 76.8 kbps. (The Max Forward Packet Duration is set from the Termination Parameters menu, see How Do I Change Generator Information? for detailed procedure).
    • Repeat steps 10 -12 for tests 19-30.
  14. f your AT supports Subtype 3 Physical Layer and multi-carrier, continue to measure PER for tests 34-35 with the following setups.
    • Set up a Test Application session and open an FMCTAP connection. See How Do I Open a Session and Test Data Connection? for detailed procedure.
    • Set Î or ( Cell Power ), I oc ( AWGN Power ) and forward packet format (packet size, slots, preamble length, data rate) per Physical Layer Packet for tests 34-35 as specified by C.S0033 on each test set.
      For example, for test 35, set the Cell Power to -55 dBm/1.23 MHz , the AWGN Power to -77.1 dBm/1.23 MHz .
    • Repeat steps 10 -12 for tests 34-35.

Testing 3.2.2 Demodulation of Forward Traffic Channel in Multipath Fading Channel (Lab Application Only)

This test requires a faded signal with AWGN. When the test set is configured to generate faded forward channel signals with AWGN enabled, it requires a rear panel digital bus connection to an external PC running Baseband Studio software (see Digital Bus Information ).

The Baseband Studio software is capable of generating fading patterns and AWGN on the forward channel. RF power levels, including AWGN, are controlled by this software. (Note that when the test set is configured to generate a faded signal, the test set's internal AWGN generator is automatically turned off to allow the AWGN to be added by the external fading software. The resulting RF signal from the test set will have fading applied to the forward channel only, with no fading applied to AWGN.)

For detailed setup and operating instructions pertaining to the faded signal generation, refer to the:

E5515C Fading Solution Application Guide

(It can be downloaded at http://cp.literature.keysight.com/litweb/pdf/1000-1894.pdf ).

  1. 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 .
  2. Set the Control Channel Data Rate to 38.4 kbps (see How Do I Change Cell Parameters? ).
  3. C.S0033 specifies to set Pilot Drop to -14 dB. Set Pilot Drop to 28 (see How Do I Change Cell Parameters? ).
  4. Set up a Test Application session and open an FTAP or FETAP connection for tests 1-24. See How Do I Open a Session and Test Data Connection? for detailed procedure.
  5. Initialize the PER measurement. (See step 3 of General Procedure .)
  6. Set up the following key parameters from the Baseband Studio software. For example, for test 1:
    • Set the Cell Band to a value supported by your AT (for example, US PCS ).
    • Set the Channel to a value supported by your AT (for example, 425 ).
    • Set Î or ( Cell Power ) to -55 dBm/1.23 MHz .
    • Set I oc ( AWGN Power ) to -49 dBm/1.23 MHz (for Band 0: US Cellular) or -47.6 dBm/1.23 MHz (for Band 1: US PCS).
    • Select the 1xEV-DO Mobile Station fading configuration Case 1 from the standard Path Config menu.
  7. Set up the following key parameters from the Packet Error Rate Setup menu on the test set. For example, in test 1 as specified by C.S0033:
    • Set FTAP Rate to 38.4 (1 Slot) for test 3 or 76.8 (1 Slot) for test 4 if in an FTAP connection, or set F-Traffic Format to 1 (1024, 16, 1024) for test 3 or 2 (1024, 8, 512) for test 4 if in an FETAP connection. For details on the data rate please refer to FTAP Rate and F-Traffic Format .
    • Set Confidence Level to 95% and PER Requirement to 3.00% .
    • Set Maximum Packet Count as desired.
    • Set Minimum Packet Count to 375 for test 1. (C.S0033 specifies the minimum test duration required for channel simulator configuration 1 is 6000 slots. The test 1 specifies at data rate of 38.4 kbps (16 slots per packet). So the minimum packet count should be 6000/16=375 packets.)
    • Set AT Directed Packets as needed (if Limited TAP is on, AT Directed Packets must not be greater than 50%, and RTAP Rate must be set to 9.6 kbps).
  8. Measure PER. Repeat the steps 5-7 and change the parameters as required for each of the tests.
  9. If your AT supports Subtype 2 Physical Layer, continue to measure PER for tests 25-28 with the following setups.
    • Set up a Test Application session and open an FETAP connection. See How Do I Open a Session and Test Data Connection? for detailed procedure.
    • Follow the above steps 6-7, set Î or ( Cell Power ), I oc ( AWGN Power ) and transmission format (packet size, slots, preamble length, data rate) per Physical Layer Packet for tests 25-28 as specified by C.S0033.
      For example, for test 25, set the Cell Power to -55 dBm/1.23 MHz , the AWGN Power to -67.5 dBm/1.23 MHz (for Band 0: US Cellular) or -62.5 dBm/1.23 MHz (for Band 1: US PCS). Set the F-Traffic Format to 1 (512, 16, 1024) (See F-Traffic Format for details) and the Max Forward Packet Duration to 4 slots which results in the nominal data rate of 19.2 kbps and the effective data rate of 76.8 kbps. (The Max Forward Packet Duration is set from the Termination Parameters menu, see How Do I Change Generator Information? for detailed procedure).
  10. If your AT supports Subtype 3 Physical Layer, continue to measure PER for tests 29 with the following setups.
    • Set Pilot Drop to 32 (corresponding to -16 dB). Note: This results in a session re-negotiation. See How Do I Change Cell Parameters? .
    • Set up a Test Application session and open an FMCTAP connection. See How Do I Open a Session and Test Data Connection? for detailed procedure.
    • Follow the above steps 6-7, set Î or ( Cell Power ), I oc ( AWGN Power ) and transmission format (packet size, slots, preamble length, data rate) per Physical Layer Packet for test 29 as specified by C.S0033.
      For example, set the Cell Power to -55 dBm/1.23 MHz , the AWGN Power to -67.5 dBm/1.23 MHz (for Band 0: US Cellular). Set the F-Traffic Format to 1 (512, 16, 1024) (See F-Traffic Format for details) and the Max Forward Packet Duration to 4 slots which results in the nominal data rate of 19.2 kbps and the effective data rate of 76.8 kbps. (The Max Forward Packet Duration is set from the Termination Parameters menu, see How Do I Change Generator Information? for detailed procedure).
    • For AT that supports Subtype 3 Physical Layer, the PER is measured on a per carrier basis.

Testing 3.3.1 Receiver Sensitivity and Dynamic Range

For details on performing the steps below, see the General Procedure above.

  1. Set up a Test Application session and open an FTAP or FETAP or FMCTAP connection. See How Do I Open a Session and Test Data Connection? for detailed procedure.
  2. Initialize the PER measurement.
  3. Set AT Directed Packets as needed (if in a FTAP connection, Limited TAP is on, AT Directed Packets must not be greater than 50%, and RTAP Rate must be set to 9.6 kbps).
  4. Receiver Sensitivity
    • For AT that supports Subtype 0 or Subtype 2 Physical Layer (Test 1), Set Î or ( Cell Power ) to -105.5 dBm/1.23 MHz. Set FTAP Rate to 307.2 (2 Slot) if in an FTAP connection or set F-Traffic Format to 4 (1024, 2, 128) (corresponding to 307.2 kbps) if in an FETAP connection.
    • For AT that supports Subtype 3 Physical Layer (Test 4), Two Forward Traffic channels are required and with maximum allowable frequency separation (Max Forward Link Band with No Jammer reported by AT), Set Î or ( Cell Power ) to -105.5 dBm/1.23 MHz and F-Traffic Format to 4 (1024, 2, 128) (corresponding to 307.2 kbps) on both test sets.
  5. Dynamic Range
    • For AT that supports Subtype 0 or Subtype 2 Physical Layer (Test 1), Set Î or ( Cell Power ) to -25 dBm/1.23 MHz. Set FTAP Rate to 307.2 (2 Slot) for test 2 or 2457.6 (1 Slot) for test 3 if in an FTAP connection, or set F-Traffic Format to 4 (1024, 2, 128) for test 2 or C (4096, 1, 64) for test 3 if in an FETAP connection.
    • For AT that supports Subtype 3 Physical Layer (Test 5), Maximum number of Forward Traffic channels that can be demodulated by the AT (Max Number of Forward Link Supported reported by AT) are required. Set Î or ( Cell Power ) to -25 dBm/1.23 MHz and F-Traffic Format to 4 (1024, 2, 128) (corresponding to 307.2 kbps) on each test set.
  6. Set Confidence Level to 95% and PER Requirement to 0.50%.
  7. Set Maximum Packet Count as desired.
  8. Measure PER for each test. For AT that supports Subtype 3 Physical Layer, the PER is measured on a per carrier basis.

Testing 5.2 Data Rate Control Performance

This test requires a faded signal with AWGN. When the test set is configured to generate faded forward channel signals with AWGN enabled, it requires a rear panel digital bus connection to an external PC running Baseband Studio software (see Digital Bus Information ).

The Baseband Studio software is capable of generating fading patterns and AWGN on the forward channel. RF power levels, including AWGN, are controlled by this software. (Note that when the test set is configured to generate a faded signal, the test set's internal AWGN generator is automatically turned off to allow the AWGN to be added by the external fading software. The resulting RF signal from the test set will have fading applied to the forward channel only, with no fading applied to AWGN.)

For detailed setup and operating instructions pertaining to the faded signal generation, refer to the:

E5515C Fading Solution Application Guide

(It can be downloaded at http://cp.literature.keysight.com/litweb/pdf/1000-1894.pdf ).

  1. Set the DRC Value Fixed Mode Attribute to Off on the Application Config ( F10 on Call Parms 1 of 3 ) menu. See DRC Value Fixed Mode Attribute
  2. Set the Forward Early Termination State to On. To perform this, first select Call Control 2 of 3, select Generator Info(F3), then select Channel Data Info(F5), then Termination Parameters(F5), set the Forward Early Termination State to On.See Forward Early Termination State .

    Set the DRC Length to 2 slots. To perform this, first select Call Control 2 of 3, select Access Network Info(F2), then select Channel Gain/Traffic Info(F3), then Enhanced Traffic Parameters(F2), set the DRC Length to 2 slots. See DRC Length .

  3. 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
  4. Set the Control Channel Date Rate to 38.4 kbps and the AT Directed Packet to 100% on the Packet Error Rate Setup(F1). See Control Channel Data Rate
  5. Set Î or (Cell Power) to -55 dBm/1.23 MHz.
  6. For test 1, set I oc (AWGN Power) as specified by C.S0033. For test 2-5 which requires a faded signal, set I oc (AWGN Power) and Channel Simulator Configuration as specified by C.S0033.
  7. Set up a Test Application session and open an FTAP or FETAP or FMCTAP connection. See How Do I Open a Session and Test Data Connection? for detailed procedure.
  8. Set Confidence Level to 95% and PER Requirement to 2.00% as specified by C.S0033.
  9. Set Maximum Packet Count as desired (>=10000).
  10. Initialize the PER measurement.
  11. Measure FTC Throughput and PER for each test.

Related Topics


Standard Abstract:

Packet Error Rate (PER) Measurement Description

Programming a Packet Error Rate (PER) Measurement

Packet Error Rate Measurement Troubleshooting