Aggregate Interference Dynamics in 6 GHz High-Density Coexistence Scenarios under Automated Frequency Coordination

<title>Abstract</title> <p>The Automated Frequency Coordination (AFC) system is crucial for managing spectrum sharing in the 6 GHz band, ensuring that unlicensed (secondary) transmitters can coexist with protected (licensed, primary) incumbent systems. Specifically, this study focuses on the aggregate impact of densely deployed Standard Power (SP) Wi-Fi 6E devices operating under the stringent-6 dB interference-to-noise (I/N) protection criterion. This paper bridges the gap between regulatory compliance and scientific analysis by transforming technical AFC pipelines into a unified analytical framework. By integrating location-based queries, incumbent database lookups, and grid-based interference assessments, the framework utilizes established path loss models, including free-space path loss (FSPL), WINNER II, and the Irregular Terrain Model (ITM), alongside interference-to-noise ratio (INR) thresholds to iteratively optimize Equivalent Isotropically Radiated Power (EIRP) and channel bandwidth allocations. We present ”New AFC,” a high-fidelity Python-based simulator used to validate these processes against state-of-the-art studies. Through rigorous Monte Carlo simulations and sensitivity analysis, we identify critical ”edge cases” where standard regulatory models may underestimate interference risks. Specifically, we identify and formalize two distinct interference phenomena: the ”Clutter Cliff,” where minor environmental changes drastically shift interference outcomes, and the ”Lighthouse Effect” involving rare but catastrophic interference spikes caused by precise angular alignment with high-gain incumbent antennas. Furthermore, 1 we demonstrate the ”Undershoot Phenomenon,” revealing how elevation differences can create deceptive cones of silence that transition abruptly into high-risk danger zones. These findings provide a scientific foundation for optimizing spectrum use while maintaining robust protection for existing receivers in high-density coexistence scenarios.</p>