Statistical validation of WLAN range calculated with propagation models for industrial environments by chipset-level received signal strength measurements

The wireless range of an IEEE 802.11b/g system as predicted by an empirical model for path loss and temporal fading is validated statistically by measurements of the received signal strength or RSS reported by WLAN monitoring software. This validation is made for indoor industrial environments. In this work, a comparison between a link budget based on industrial propagation models and site surveys executed with WLAN monitoring software is made for two types of industrial environments, namely production centres and warehouses, and for three practically important 802.11b/g data rates of 2, 11 and 18 Mbps. In general, wireless ranges calculated with the link budget and extracted from the site survey measurements are in good agreement. An important finding is that in production centres, the site survey measurements show severe attenuation of the 802.11b/g signal in the presence of large obstacles with approximately the same height as the access point. This phenomenon can cause a noticeable overestimation of the real wireless range by the link budget. Furthermore, it is shown that changing the receiving antenna s height between 0.5, 1.5 and 2 m has only very limited effect on the wireless range.