How to Measure Trigger Based Frame WiFi

Updated Oct 28, 2020



  • PXIe-5840
  • PXIe-5841


  • WLAN Test Toolkit



In 802.11ax communications, the trigger frame is used for multiple purposes. One of them is to allocate ressources for a specific multi-user OFDMA transmission. NI WLAN Toolkit could support trigger frame generation and analysis ,but no detail description about how to measure trigger frame in help documents. So i post the measurement steps here for your reference.

Open WLAN Generation to generate one trigger frame for WIFI 802.11ax
1. Setting  the Standard, BW  and other parameters

2. Setting the PPDU type and Multi-user Configuration.

3. Setting other basic parameters, then click the "Generate" button to trigger the signal.

1. Open WLAN Analysis and click "Start" button to auto-measure the signal

2. Check the Frame Parameters in Analysis side as below, the frame parameters were wrong

3. Open the IQ Advanced Setting panel, set the OFDM Demod and OFDM Packet info as below.

4. Click  "auto range" button to measure the correct waveform length.

5. Because the frame was trigger based type, you should set the Max Symbol Used as "-1".