  A simple 'RF-flashlight' (or ground to satellite) interference testbed is
proposed to experimentally verify real-time geofencing (RTG) for protecting
passive Earth Exploration Satellite Services (EESS) radiometer measurements
from 5G or 6G mm-wave transmissions, and ground to satellite propagation models
used in the interference modeling of this spectrum coexistence scenario. RTG is
a stronger EESS protection mechanism than the current methodology recommended
by the ITU based on a worst-case interference threshold while simultaneously
enabling dynamic spectrum sharing and coexistence with 5G or 6G wireless
networks. Similarly, verifying more sophisticated RF propagation models that
include ground topology, buildings, and non-line-of-sight paths will provide
better estimates of interference than the current ITU line-of-sight model and,
thus, a more reliable basis for establishing a consensus among the spectrum
stakeholders.
