Several studies have characterized industrial environments as being highly reflective. In this paper, we provide the data obtained from electromagnetic field measurements performed at the warehouse of a paper mill. The data is also compared to simulated data. This data proves the existence of non-reflective and very high absorption industrial environments where wireless communication is impossible at certain frequencies. Furthermore, in such environment, radio performance cannot be improved by multiple antenna solutions such as MIMO (Multiple Input Multiple Output) since multiple reflections are effectively absorbed.

Electrical and mechanical machinery, highly reflective industrial facilities and co-existing communication systems are the major sources of disturbances in wireless industrial applications. Characterization of industrial environments is important for the development of standards, to assess current and future deployment of wireless technologies, and to provide systems integrators and end user with guidelines. In this paper some deductions from measurements carried out at three industrial environments using traditional electric field strength, amplitude probability distribution (APD) and multipath time dispersion measurements are presented. These measurements have given surprising and interesting results.

It is well known that industrial and factory environments present considerable challenges for wireless communications. Because every industrial environment is different, and may offer a unique set of obstacles to effective wireless communication, a site characterization is needed at first step in determining improvements of existent wireless technologies to increase the reliability. In this work electric field strength and APD measurements have been performed to characterize electromagnetic interference in an industrial paper plant. Common characteristics of the industrial environments affecting wireless communication were identified. Additionally, results show high interference levels at the frequencies for the DECT band 1880-1890 MHz. The interference level is correlated to the working mode of the electrical engines used in the process.

Wireless communications in industrial environments are maintained under persistent adverse conditions, such as noise, fading and many electromagnetic interference sources. These electromagnetic interferences exhibit usually impulsive characteristics and it can seriously degrade the performance of the current wireless systems. Over the last few years, the amplitude probability distribution (APD) had been formally written into CISPR16 as a measure of the emitted electromagnetic energy from electrical equipment. In this approach we present two APD measurement methods. The first method based on 12-bit A/D converter and the second one based on in-phase and quadrature components of the impulsive noise at frequencies between 20 and 3000 MHz. Electromagnetic interference measurements in three different industrial environments were performed using the developed methods with promising results.