When evaluating a site with multiple transmitters operating at the same time, the operators and licensees of which transmitters are responsible for mitigating over-exposure situations?
Why At multiple-transmitter sites the FCC apportions responsibility by contribution: any licensee whose station produces 5 percent or more of the applicable MPE limit in an area where the combined exposure from all sources exceeds the limit shares responsibility for fixing the problem. The threshold is expressed in fraction of the exposure limit (power density or SAR), not in watts, so a low-power station close to people can still be over the 5 percent line. Stations contributing less than 5 percent are considered insignificant contributors and are not held responsible.
Watch out The choice saying 20 percent sets the bar far too high, and the duty cycle answers confuse the separate issue of averaging transmit time when you compute your own exposure, which is not how responsibility is divided at a shared site.
Shared site, shared blame at 5 percent: contribute a twentieth of the MPE limit and you own part of the problem.