The primary sources of electromagnetic interference at the site of geomagnetic detector usage include urban public wireless Wi-Fi signals, 2G, 3G, and 4G wireless communication networks, GPS, and IoT devices. To counter these interference sources, ClairGeo-M employs the following four technical measures to achieve an optimal anti-interference solution:

- Direct Sequence Spread Spectrum (DSSS) to suppress in-band interference

• Transmit signals in a broadcast format within the specific transmission frequency of the device.
• Before spatial transmission of user data, a "spreading code" is attached to achieve spread spectrum transmission.
• The receiver eliminates interference during the demodulation process. Noise signals are simultaneously removed during the extraction of the spreading code and extraction of the valid signal.

- Effective suppression of 100% of out-of-band interference

• Adding a shielding cover
• Increasing the rectangular coefficient of the filter
• Enhancing the frequency-selective capability of the antenna
• Improving the receiver's anti-blocking capability

- Dual-channel communication technology

• While individual channel may experience strong interference signals and losing vehicles for interference, system will shift to secondary channel for data transmission. 

- System networking technology

• Introducing the concept of time slots to reduce transmission time and mitigate the probability of interference
• Pre-coding intersection lock-in technology to ensure the accuracy of transmission
• Using directional antennas for transmission, constructing angles reasonably to reduce the strength of interference signals

For more information: https://www.trafficlair.com/ClairGeo/ClairGeo-M.html