Propagation Channel Characteristics of Industrial Wireless Sensor Networks [Wireless Corner]

The wireless channel in an industrial environment behaves much differently when compared with wave propagation in home and office environments. This is due to the presence of significant noise and interference caused by large machinery and heavy multipath propagation effects induced by highly reflective structures. In this article, a comprehensive review of radio wave propagation in an industrial environment is presented. The reported channel models and measurement results, at different frequencies and link configurations, of path loss, noise, interference, multipath propagation, and time-varying channel conditions are discussed, and the factors that influence them are highlighted. In addition, open research issues on the propagation of radio waves in an industrial environment are identified.

Introduction

The productivity and efficiency of current industrial facilities can be greatly improved by using wireless sensor network (WSN) technology for remote control and automation as well as for efficient data collection [1], [2]. Traditionally, wire-based communication solutions are used for industrial automation purposes. But these systems are not widely deployed because they require expensive cables to be installed and maintained regularly. Generally, wired systems are considered to be more expensive than wireless solutions because they need shields to prevent severe exterior interferences, which are usually present in harsh industrial environments (e.g., high humidity, high temperature, and strong vibration) [3]. Unlike wire-based systems, WSNs can be installed in, e.g., the bearings of motors, engines, or other difficult (inaccessible or hazardous) environments [4]. However, wireless systems are subject to different propagation impairments, which may significantly degrade the system performance.