Michael DeJadon

The FCC is moving to allow higher power mobile Wi Fi devices in the 6 GHz band using geofencing. On paper this looks exciting. It promises outdoor Wi Fi that works while moving. We can finally get out those AR and VR headsets the kids keep talking about. The challenge is execution. Today very low power 6 GHz devices operate around 14 dBm EIRP which is about 25 milliwatts. The new geofenced variable power class allows up to 24 dBm EIRP or 250 milliwatts. That is a 10 dB increase. In ideal free space that gives about three times the range. In real outdoor environments with clutter it is closer to two times. Still meaningful and enough to unlock new use cases. The interference risk is real. Large parts of the 6 GHz band are already used by fixed microwave links that carry carrier backhaul and public safety traffic. These receivers are extremely sensitive. Interference impact depends on geometry antenna patterns bandwidth and fade margin. But a simple sanity check shows the issue. A 250 milliwatt device at 6 GHz five kilometers away lands near minus 98 dBm into an isotropic receiver. If a high gain dish ever sees that energy near boresight it can degrade performance. That is why protection cannot be hand waved away. Geofencing is the proposed solution. The idea is simple. Keep devices out of exclusion zones around fixed microwave receivers. The zones themselves are mostly static. What must be dynamic is device positioning and integrity. If a headset loses reliable location it must shut down immediately. That fail safe behavior is critical. Let’s consider scale. Millions of mobile devices. Many moving. Even if each device respects exclusion zones perfectly the aggregate noise floor still rises in dense areas. Wi Fi adapts rates gracefully. Fixed microwave does not. So what will likely happen ? Urban areas with dense fiber and fewer microwave hops will see the best results. Suburban and rural regions where microwave remains common will be more fragile. If interference complaints rise the response will be predictable. Larger exclusion zones lower usable power and reduced benefit. This does not mean the idea is wrong. It means success depends on execution. Strong location assurance with automatic shutdown on uncertainty. Accurate and current registration of incumbent links with real enforcement. Conservative rollout followed by expansion based on measured data not optimism. The physics works. The risk is operational. If this is done right 6 GHz mobile Wi Fi becomes a quiet success. If done poorly we retreat back to lower power. Execution will decide the outcome. We all know how famously execution is successful in RF.

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