Experimental Assessment of Wi-Fi Signal Levels in Indoor Environments

Due to quasi stochastic signal emission and multi parametric dependence, the accurate assessment of electric field exposure levels in WLAN networks is proven to be a challenging task. In this paper we investigate the variations of Wi-Fi signal levels in indoor environments depending on different factors, including: transmission speed, traffic type and direction, positions of the receiver (line of sight and non-line of sight locations), distance between Wi-Fi devices in the network, and also the number of devices connected to the network. To obtain interdependencies between factors that influence electric field exposure levels we conducted in situ measurements in experimental Wi-Fi network, in different distances from both: access point and workstations. The measurements are carried out with a spectrum analyzer, in different scenarios, including good, medium and poor radio frequency signal propagation conditions. The results show that in complex operating scenarios of WLAN networks, as the number of stations increases, the exposure levels starts to slightly increase. The higher values of exposure levels are obtained for poor propagation conditions of Wi-Fi signals.