Radio channel characterization at 5.85 GHz for wireless M2M communication of industrial robots

The fourth industrial revolution, also referred to as Industrie 4.0, has triggered a number of research projects to improve communication systems for industrial environments. Wireless technologies for mission-critical machine-to-machine communication are expected to enable very efficient and highly flexible production processes. It is especially challenging for wireless interfaces to fulfill the required end-to-end latency and the reliability constraints of the automation industry. In order to design novel PHY and MAC schemes for ultra low delay, ultra reliable and deterministic transmission of data, e.g., through optimized pulse shaping, we study the indoor radio propagation in a representative factory automation cell where industrial robots are to be controlled. We performed channel measurements using a broadband channel sounder at 5.85 GHz carrier frequency. During the measurements, the robots were in motion and executed a typical pick-and-place process. From the recorded data we evaluate the channel characteristics and calculate relevant delay statistics. We distinguish two measurement series that differ in the scattering environment and present the derived parameters. Finally, we discuss the impact of our results on the design of new 5G waveforms for industrial radio systems.