Further Enhanced Urllc And Industrial IoT Support With Release-17 5g New Radio

Abstract

The 5G new radio (NR) standard has been designed since its initial release - 3GPP Release 15 - to support ultra-reliable low-latency communications (URLLC) requiring one-way down-link (DL) or uplink (UL) user-plane latencies of 1 ms with reliability of at least 99.999 percent. The following releases - Release 16 and 17- have further raised the bar, not only by offering further reduced latencies down to 0.5 ms and increased reliability up to 99.99999 percent, but also by supporting new industrial internet of things (IIoT) use cases demanding - among other things - time synchronization with 1 µs accuracy. This article provides an overview of the latest IIoT and URLLC-related enhancements adopted in the 5G NR standard, with focus on the recently standardized Release 17 features. This includes enhancements to the hybrid automatic repeat request (HARQ) and channel quality indicator (CQI) feed-back from the UE, propagation delay compensation for more accurate time synchronization, reliability and latency enhancements tailored to deployments on unlicensed bands, and scheduling optimizations taking into account different traffic priorities and higher-layer requirements of the industrial applications. Example performance results show how NR Release 17 offers improved performance over a wider range of deployment scenarios and frequency bands. Finally, an out-look toward expected URLLC and IIoT enhancements in future releases is provided.