The FCC has modified unwanted emissions limits for mobile operations for the 24.25-24.45 GHz and 24.75-25.25 GHz bands to prevent interference with passive systems in the 23.6-24.0 GHz band. The changes align with decisions made at the 2019 World Radiocommunication Conference (WRC-19).
In the Report and Order, the Commission says the 23.6-24.0 GHz band is critical for passive sensors that measure weak natural radio emissions vital for meteorology, climatology, and satellite radar operations. The limits apply to both current and future mobile devices, with stricter limits coming into effect after September 1, 2027.
The rules set two phases: Phase 1 limits (-33 dBW/200 MHz for base stations and -29 dBW/200 MHz for mobile stations) apply immediately. Phase 2 limits (-39 dBW/200 MHz for base stations and -35 dBW/200 MHz for mobile stations) apply to devices deployed after September 2027.
The FCC adopted the WRC-19 timetable for implementing these limits, balancing the need to protect scientific observations while enabling 5G deployment. The Commission rejected proposals to accelerate Phase 2 or allow older equipment to be used indefinitely under Phase 1 limits. Additionally, the agency agreed to require that equipment modified or replaced after 2027 must meet Phase 2 limits, with modifications only affecting emissions requiring compliance.
By Leslie Stimson, Inside Towers Washington Bureau Chief
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