Summary

Widely-used civilian unmanned aerial vehicles (UAVs) generate increasing requirements for communication and network capabilities, including seamless coverage, low latency, Gbps-level rate and high-accuracy positioning. Existing commercial products of civilian UAVs utilize a direct radio link, which is limited by service distance and quality. Therefore IMT-2020 can be employed for UAV communication. UAVs require simultaneous services with different characters, for which a brand new type of user terminal to IMT-2020 is required. Likewise, IMT-2020 is a novel communication network for UAVs since it was originally designed for ground coverage. With the purpose of implementing the support of civilian UAV operations in IMT-2020 networks and improving the quality of UAV application services, a set of functionalities is needed to bridge the gap for interoperation between unmanned aerial system (UAS) and IMT-2020 networks. Recommendation ITU-T Y.4421 provides a functional architecture for UAVs and UAV controllers using IMT-2020 networks and functionalities defined in the application layer, service and application support layer, and security capabilities. The motivation of this Recommendation is to solve the issues of civilian UAVs accessing and communicating in IMT-2020 networks using its transmission capabilities.