Impact of new 5G network components on out-of-band emissions at 23.8 GHz

The impact of 5G networks transmitting between 24.25- 27.5 GHz on Earth Exploration Satellite Services (EESS) microwave sounders used to measure atmospheric water vapor and temperature was widely discussed and modeled in preparation for setting emission recommendations by International Telecommunications Union (ITU) at the 2019 World Radio Congress (WRC-19). Since then, two new classes of network devices - 5G repeaters and high transmission power User Equipment (UE) for fixed wireless services - have been introduced and deployed in 28 GHz networks with expectations that they will also be deployed at 24 GHz. This paper discusses the (potentially significant) increase in interference from these new components along with open questions related to their regulatory status. While this paper discusses increases in interference to 23.8 GHz EESS measurements from 5G transmissions in the "24 GHz" band, it is important to recognize that repeaters and high power UEs need to be considered when modeling interference from 5G/6G networks in all bands. This paper also touches on whether the current ITU process and methodology to regulate interference with passive sensors (vendor applied hardware-based filtering based on long-term network forecasts and worst-case Monte Carlo modeling) can keep up with rapidly changing wireless technology and the increased competition for spectrum.