Radio ports (RPs) in an unlicensed personal communications system adaptively, autonomously set their interference threshold and/or transmission power levels. This may be done by the RP measuring the signal level on each of the available channels and then setting the interference threshold and/or power level according to these measurements. In a preferred method, the interference threshold is determined by measuring the signal level on each channel, ranking the channels in order of measured signal level, and using these rankings to determine the threshold. The transmission power level may be set with reference to the adaptive interference threshold level. This level is determined by using the system and FCC power limitations and current conditions to provide a satisfactory transmission level.