Book excerpt: NG-RAN and 5G-NR describes the deployment of 5G NSA (non standalone 5G) and 5G-SA (standalone 5G). 5G-NSA deals with radio access entities. For the 5G-NSA mode, dual MR DC connectivity is based on radio measurements, allowing the master 4G base station MeNB to add or remove a secondary 5G node SgNB. This book describes the architecture of the NG radio access network and the 5G-NR radio interface according to the 3GPP (3rd Generation Partnership Project) specifications. The overall architecture of the NG-RAN, including the NG, Xn and F1 interfaces and their interaction with the radio interface, are also described. The 5G-NR physical layer is mainly connected by implementing antennas, which improves transmission capacity. 5G-SA deals with the 5G Core network. In the 5G-SA model, the mobile is attached to the 5G Core network through NG-RAN. The book explains radio procedure, from switching on a device to establishing a data connection, and how this connection is maintained even if mobility is involved for both 5G-SA and 5G-NSA deployment. NG-RAN and 5G-NR is devoted to the radio access network, but mobile registration, establishment procedures and re-establishment procedures are also explained.