Using Poincare Plots for Feature Extraction of the Dynamics of Electromagnetic Field Exposures when Using Different Protocols of Wi-Fi Communications

Wi-Fi network devices emit electromagnetic radiation which is of interest for human exposure safety. Based on the quasi-stochastic time-variability of such signals emitted in two different protocols belonging to the 4th and the 5th generations, namely IEEE 802.11 - n and ac, we demonstrate here that specific temporal patterns can be extracted from the time series, if we use the representation of Poincare plots. Practically, the main parameters of the Poincare ellipses are different for the two communication protocols, directions of data transmission and bandwidths used. When energy density per transferred bit was computed, it was also revealed that there is a linear relationship between this one and the Poincare ellipse area. Based on the mean electric field strengths measured near a Wi-Fi device by directly collecting the amplitude probability density traces of the emitted powers, one can extract the features of short- and long-term exposure profile variations in different wireless data transmission configurations.