Ultra-Reliable Low-Latency in 5G: A Close Reality or a Distant Goal?

Ultra-Reliable Low-Latency Communication (URLLC) was introduced in 5G to meet the demanding requirements of latencies as low as 0.5 ms and reliability of 99.999 % for specific applications. Despite over a decade of discussions on URLLC, achieving these standards in real-world implementations remains challenging. We argue that it is unclear if and how URLLC can be attained and a holistic system-level perspective that addresses all the system's inherent bottlenecks is needed. Inspired by a real-world 5G testbed, we present this comprehensive vision and show how to achieve latency requirements by outlining the necessary design choices across all system layers, including the processing and radio units.