Performance Evaluation of Wireless Absolute Time Synchronization for Mission-Critical Industry

There are several advantages to build a mission-critical industry wireless rather than wired. However, it was not able to provide strictly as low-latency, reliability, and absolute time synchronization (ATS) as wired. With the recent advance of mobile communication standards, especially 5G URLLC, the possibility of wireless realization to the industry that requires below-$1 \mu \mathrm{s}$ ATS timing accuracy has been opened. In this paper, we present first a physical-layer frame structure suitable for factory automation, a representative mission-driven industrial application. Under this structure, through computer evaluation, we provide and compare ATS performances based on both-link techniques related with synchronization in 4G and 5G standards.