5ghz radar DFS attack. #1192
Description
A 5ghz DOS attack using simulated DFS Radar noise forcing the AP to cease transmission a per DFS requirements nd changing chanel, details below.
Dynamic Frequency Selection (DFS) and Radar Detection in 5 GHz CPE Systems
DFS Requirements for 5 GHz CPE Devices
Wireless Customer Premises Equipment (CPE) operating in the 5 GHz band must comply with Dynamic Frequency Selection (DFS) regulations to avoid interfering with radar systems. Regulatory bodies like the FCC (USA), ETSI (Europe), and Industry Canada mandate DFS for specific 5 GHz channels (e.g., 5250–5350 MHz and 5470–5725 MHz) to protect incumbent radar services such as weather, aeronautical, and military radars.
Radar Detection and Channel Monitoring
CPE devices must monitor DFS channels for radar signals before and during transmission. If radar is detected:
The device must stop transmitting within 260 ms.
It must vacate the channel and switch to an alternative DFS or non-DFS channel after a 60-second silent period to verify safety.
The device must broadcast a channel-switch announcement (CSA) to clients.
Key Regulatory and Technical References
ERC Report 15 (1992): Early study on radar-RLAN coexistence, establishing that no more than 6 radars should be within a 50 km radius of a RLAN to avoid harmful interference.
ETSI EN 301 893: Standard defining DFS requirements for RLANs in Europe, including detection sensitivity and channel selection procedures.
FCC and ETSI DFS Rules: Mandate detection of radar pulses as short as 0.5 μs and require devices to avoid channels with active radar signals.
EUMETNET Recommendations (2008): Highlight interference risks from 5 GHz RLANs to European C-band meteorological radars, with over 12 European countries reporting interference cases.
Conclusion
5 GHz CPE devices must implement robust DFS mechanisms to detect and respond to radar signals. Regulatory compliance is critical, especially in regions with high radar density. Testing with SDR tools and using advanced detection hardware can significantly improve reliability and reduce service disruptions.