A Highly Reliable Ultralow-Latency Wireless Solution for Industrial Control Loops: Design and Evaluation

Abstract

We present the results of implementing and testing a wireless solution intended for direct one-to-one replacement of communication cables in fast industrial control loops. With an ultralow cycle time of 8000 packets/s on each unidirectional link, we measured packet error rates in the range of 1 error per 1 billion packets in the presence of industrial production-hall channel conditions, achieving an unprecedented combination of high reliability and low latency in fading channels. The transceivers were built using only easily accessible and affordable components. Frequency diversity and spatial diversity are exploited through coded orthogonal frequency-division multiplexing (OFDM) modulation and 2x2 multiple-input-multiple-output (MIMO) transmission. The replacement of cables by the devised wireless solution opens up possibilities from simplified reconfigurability and reduced maintenance cost to the introduction of entirely new production processes that are currently not possible.