Achieving Ultra-Reliable Low-Latency Communications: Challenges and Envisioned System Enhancements

Ultra-reliable low-latency communications (URLLC) have the potential to enable a new range of applications and services: from wireless control and automation in industrial environments, to self-driving vehicles. The fifth generation (5G) wireless systems are faced by different challenges for supporting URLLC. Some of the challenges, particularly in downlink direction, are related to the reliability requirements for both data and control channels, the need for accurate and flexible link adaptation, reducing the processing time of data retransmissions, and the multiplexing of URLLC with other services. This article considers these challenges and proposes state-of-the-art solutions covering different aspects of the radio interface. In addition, system-level simulation results are presented, showing how the proposed techniques can work in harmony in order to fulfill the ambitious latency and reliability requirements of upcoming URLLC applications.