WIA-NR: Ultra-Reliable Low-Latency Communication for Industrial Wireless Control Networks over Unlicensed Bands

With the deep integration of information, communication and operation technologies, industrial wireless control networks (IWCNs) are playing key roles to drive industrial revolution. This article proposes a 5G-based new radio (NR) for IWCNs to realize ultra-reliable low-latency communication over unlicensed bands, namely WIA-NR. We first define a hierarchical star network topology, which employs a hybrid centralized and distributed system management architecture. Then, a three-layer protocol stack is defined by integrating some fundamental functions of 5G and proposing new functions to enhance reliability and timeliness. The key technologies include dynamic multi-channel listen before talk, adaptive channel hopping, over-the-air time synchronization, industrial data priority scheduling, aggregation and disaggregation. Finally, system-level simulations are performed to evaluate the performance of WIA-NR. The results show that WIA-NR can achieve less than 1 ms latency under 99.999 percent reliability constraint, which can well satisfy critical industrial control. Meanwhile, WIA-NR can harmoniously coexist with WiFi over unlicensed bands.