Enabling URLLC in 5G NR IIoT Networks: A Full-Stack End-to-End Analysis

This paper addresses the problem of enabling inter-machine ultra-reliable low-latency communication (URLLC) in 5th generation (5G) NR Industrial Internet of Things (IIoT) networks. In particular, we consider a common Standalone Non-Public Network (SNPN) architecture proposed by the 5G Alliance for Connected Industries and Automation (5G-ACIA), and formalize a full-stack end-to-end (E2E) latency analysis where semi-persistent uplink scheduling is considered in detail and compared with a baseline grant-based approach. Through simulations, we demonstrate that semi-persistent scheduling outperforms the baseline scheme and provides an E2E latency below 1 ms, thereby representing a desirable solution to allocate resources for URLLC. Notably, we provide numerical guidelines for dimensioning 3GPP-compliant IIoT networks for both periodic and aperiodic traffic applications, and as a function of the number of machines in the factory and of the offered traffic.