Support for V2V and V2X services has been introduced in LTE during Releases 14 and 15, in order to expand the 3GPP platform to the automotive industry. These work items defined an LTE SL suitable for vehicular applications, and complementary enhancements to the cellular infrastructure.
Further to this work, SA WG1 have defined Stage 1 requirements for support of enhanced V2X use cases, which are broadly arranged into four use case groups:
Vehicles Platooning enables the vehicles to dynamically form a platoon travelling together. All the vehicles in the platoon obtain information from the leading vehicle to manage this platoon. These information allow the vehicles to drive closer than normal in a coordinated manner, going to the same direction and travelling together.
Extended Sensors enables the exchange of raw or processed data gathered through local sensors or live video images among vehicles, road site units, devices of pedestrian and V2X application servers. The vehicles can increase the perception of their environment beyond of what their own sensors can detect and have a more broad and holistic view of the local situation. High data rate is one of the key characteristics.
Advanced Driving enables semi-automated or full-automated driving. Each vehicle and/or RSU shares its own perception data obtained from its local sensors with vehicles in proximity and that allows vehicles to synchronize and coordinate their trajectories or manoeuvres. Each vehicle shares its driving intention with vehicles in proximity too.
Remote Driving enables a remote driver or a V2X application to operate a remote vehicle for those passengers who cannot drive by themselves or remote vehicles located in dangerous environments. For a case where variation is limited and routes are predictable, such as public transportation, driving based on cloud computing can be used. High reliability and low latency are the main requirements.
In TSG RAN, a set of corresponding 5G RAN requirements, channel models, etc. for NR have been defined in TR 38.913
and TR 37.885
This study investigates the RAN aspects of supporting these advanced use cases and requirements in NR, as phase 3 of V2X support in the 3GPP platform. This TR reports the study's findings on: NR SL design for V2X; Uu enhancements for advanced V2X use cases; Uu-based SL resource allocation/configuration by LTE and NR; RAT and interface selection; QoS management; and non-cochannel coexistence between NR and LTE SLs. The study addresses unlicensed ITS bands and licensed bands in frequency ranges below and above 6 GHz, i.e. FR1 and FR2, up to 52.6 GHz. As can be seen from these aspects, NR V2X will complement LTE V2X for advanced V2X services and support interworking with LTE V2X.
In the remainder of this document, the NR SL or the LTE SL may be referred to specifically. When no RAT is indicated, the NR SL is meant.