Characterisation of highly absorbent and highly reflective radio wave propagation environments in industrial applications

Experience has shown that Bluetooth, Wireless LAN (WLAN), Digital Enhanced Cordless Telecommunications (DECT) and other Industrial, Scientific and Medical (ISM) frequency band wireless technologies developed for office use, have encountered problems when used in critical industrial applications. The development of more reliable wireless solutions requires extensive knowledge of industrial environments with regards to both electromagnetic interference and wave propagation. This study presents the results of the analysis of two important classes of industrial environments having opposite characteristics, one being highly absorbent and the other being highly reflective, with respect to radio wave propagation. The analysis comprises both multipath and path loss characterisation. The results show that wireless solutions with different fundamental properties must be chosen for each of these environments to ensure high reliability. The conclusions of this work can be used as an important reference for further research in this area, as well as the design of new standards and guidelines for selecting wireless solutions in similar industrial environment classes.