n the core side. The AMF receives the Non-Access Stratum (NAS) signaling from the UE via the access network and is also connected to the gNB for control plane signaling between the access network and the core network. The key functionalities are as follows: Terminates (Radio) Access Network Control Plane signaling (N2). Terminates NAS Signaling (N1). Provides Access Authentication and Access Authorization. Provides NAS ciphering and integrity protection. Enables registration management, connection management, reachability manage- ment, and mobility management. Provides transport and proxying for session management (SM) messages between the UE and the Session Management Function (SMF). Transports SMS messages between the UE and the Short Message Service Function (SMSF). Supports location services (e.g. routes messages between the UE and the Location Management Function (LMF) as well as between the RAN and the LMF). 5.3 5G Core Network Architecture 5.3.2 Session Management Function The SMF takes care of the session management, such as session establishment, modifica- tion, and release, including maintenance of the tunnel between the User Plane Function (UPF) and the access network node, for example, the gNB. Further functionality includes the following: Provides UE IP address allocation and management Selects and controls of the UPF Interfaces with policy functions Controls and co-ordinates charging data collection at the UPF Determines the Session and Service Continuity (SSC) mode of a protocol data unit (PDU) session 5.3.3 User Plane Function The user plane processing is covered by the UPF. There can be more than one UPF in the network, for example, one UPF handling the local traffic with the other UPF handling all other traffic. Services with very low latency requirements (such as those related to URLLC, etc.) are well suited for local UPF handling as additional latency due to the long transmission distance can be avoided. The key functionalities of the UPF are the following: Perform all UPFs on the packets: for