NTN: from 5G NR to 6G

5G New radio (NR) supports different vertical domain services (e.g., Vehicle to everything (V2X), Non-terrestrial networks (NTN), Virtual Reality (VR)), etc. In this paper, we provide an overview of 3rd generation partnership project (3GPP) NTN covering Release 17 and the current work items for Release 18. We also discuss the main research challenges to enhance NTN services. We then provide the innovations and challenges to be considered in 6G design.