Model of Cumulation of Man-Made Radio Noise, Applied to Sources of Emissions Limited by EMC Standards, and Compared With Noise Measurements

In this article, a theoretical model on the cumulation of noise, generated by large numbers of man-made noise (MMN) sources in several types of residential environments, has been developed. The model is based on extensive propagation measurements and verified by earlier field strength measurements. From applying the model it appears that MMN sources, emitting powers that equals mains port conductive disturbance limits in the electromagnetic compatibility standards, do not explain the measured noise field strength values. In contrary, the model indicates that the average source power is significant higher than can be derived from the limit in the standards. That could mean that the average power at the mains port is substantial higher than what generally is assumed. But alternately, the power, delivered by other ports like the ports for dc power, for telecom and for other wiring, is much higher than thought and could indicate a disregarded aspect in the electromagnetic compatibility (EMC) standards.