RADAR

DFS with ath5k

• With a view to Dynamic Frequency Selection powered by RADAR PHY errors reported to the driver.

Visualisation of RADAR activity

Visualisation app

1. Patched ath5k driver reports PHY error details to userspace via debugfs.
2. Python daemon on Linux collects details, sweeps frequency ranges on-demand, and reports details to any connected client over the network.
3. .NET GUI visualises legitimate WiFi packets and RADAR errors over frequency/time, plots histograms of pulse width, RSSI distribution, time between pulses, and draws time-series graphic to help uncover repetition rate within a sample of pulses.

Spectrum Sweep

20MHz channel width

• Notice how RADAR errors are reported either side of a legitimate WiFi channel:

Counts vs. Frequency

RSSI vs. Frequency

10MHz channel width

• No WiFi operating at this channel width:

Counts vs. Time

RSSI vs. Frequency

5MHz channel width

• Some WiFi operating at this narrow channel width:

Counts vs. Frequency

RSSI vs. Frequency

Kurnell Weather RADAR

• 5500/5600MHz

Counts vs. Time

RSSI vs. Time

Pulse width vs. Time

Time between pulses vs. Time

• 1kHz PRF:

Time-series plot of pulses

• 5kHz PRF:

Time-series plot of pulses

Histogram of time between pulses

5800MHz

• DECT nearby?

RSSI vs. Frequency

Time-series plot of pulses

5140MHz

Counts vs. Time

RSSI vs. Time

Pulse width vs. Time