A Look Inside 5G Standards to Support Time Synchronization for Smart Manufacturing

Connectivity has a major role in the current transformation of smart manufacturing. 5G is foreseen as an integral part of an end-to-end networking infrastructure supporting smart manufacturing operation. The integration of 5G with time-sensitive networking (TSN)is seen as a holistic communication solution for smart factories. The next generation of industrialization consists of real-time processes, automation, fixed and cellular networks, and high diversity of devices. The integration of fixed and cellular devices in a single infrastructure to enable end-to-end deterministic communications requires high accuracy of time synchronization. The transport technologies in fixed networks have been evolving toward TSN and deterministic networking to fulfill the requirements for industrial communications. The latest cellular specifications for 5G are targeting ultra-reliable and low-latency communications that enable the Industrial Internet of Things. This article describes the state of the art for integrating TSN with 5G networks based on the support given in 3GPP TS 23.501 Release 16. The requirements for time synchronization in factory automation and integration with 5G networks are presented, together with the most recent advancements in the standardization process.