Section: 5 General architecture 5.1 General
Content: The protocols over Uu and NG interfaces are divided into two structures: - User plane protocols These are the protocols implementing the actual PDU Session service, i.e. carrying user data through the access stratum. - Control plane protocols These are the protocols for controlling the PDU Sessions and the connection between the UE and the network from different aspects (including requesting the service, controlling different transmission resources, handover etc.). Also a mechanism for transparent transfer of NAS messages is included.