NR Sidelink Design Overview for Advanced V2X Service

3GPP standardization is currently studying the support of advanced vehicle-to-everything (V2X) services in Release 16. The NR sidelink (SL) being designed in 3GPP Release 16 to support advanced V2X services directly between vehicles and other road users is expected to finish early in 2020. Advanced V2X services primarily focus on platooning, cooperative driving, extended sensor, and remote driving use cases. A new QoS parameter of minimum communication range (MCR) introduced for 5G V2X means fulfillment of ultra-low latency and very high reliability requirements within a given MCR. Design for ultra-low latency and very high reliability enhancement is required to meet an end-to-end latency of 3 ms and high reliability up-to 99.999 percent. NR SL design studies V2X message delivery for periodic/aperiodic traffic type and different cast types such as unicast, groupcast, and broadcast traffic requiring substantial changes in network architecture, physical, and protocol layers. This article provides insights on the current 3GPP Release 16 NR SL design for NR V2X, the network architecture, security, and protocol enhancement. The PC5-QoS model for NR SL includes the newly introduced range parameter and connection establishment for both groupcast and unicast V2X communication using NR-PC5 RRC. In addition, the design of the NR SL physical layer addresses the necessary improvements needed in the SL physical layer structures, and procedures for reliable packet transmissions considering minimum communication range.