In this latest demo, Karl shows how gr-802-11 — a GNU Radio based OFDM transceiver for IEEE 802.11a/g/p networks — can be used with the LimeSDR Mini to observe and record Wi-Fi signals. In the video, we can see the application configured for a 20 MHz channel in the 2.4 GHz band, with a QAM constellation being displayed as data is transferred between a smartphone and laptop.

The Wi-Fi signal is captured to a file which can then subsequently be read by the popular network protocol analyser, Wireshark. The benefits of using an SDR with Wireshark instead of 802.11 hardware include that you don’t need to worry about whether your WLAN adapter is filtering packets, and of course you’re free to modify the physical layer since it’s software.

Andrew and the LimeSDR Mini Team