nd evolved LTE. The CN consists of various NFs, with a clear sep- aration of CP and UP functions (UPFs), as shown in Figure 13.2: (i) the AMF provides UE-based authentication, authorization, mobility management, etc.; (ii) the Authentica- tion Server Function (AUSF) stores data for authentication of UEs; (iii) the Unified Data Management (UDM) stores UEs' subscription data; (iv) the Session Management Function (SMF) is responsible for session management and also selects and controls the UPF for data transfer; (v) the Network Repository Function (NRF) is in charge of maintaining and providing information on the NF instances when deploying/updating/removing them; it also supports the service discovery function; (vi) the Network Exposure Function (NEF) is responsible for providing means to collect, store, and securely expose the services and Nnssf Nausf (R)AN Figure 13.2 5G system architecture (3GPP TS 23.501, 2019). 2 For those non-3GPP RATs, access to the 5G CN is provided by the Non-3GPP Inter Working Function (N3WIF) (3GPP TS 24.502, 2019). 13.4 Cloudification in V2X Environments capabilities provided by 3GPPI NFs (e.g. to third parties or among NFs themselves); (vii) the Application Function (AF) represents any additional CP functions that might be required, e.g. to implement network slicing. Some alternatives are under evaluation (3GPP TR 23.786, 2019) to deploy V2X function- alities within the 5G CN, e.g. to reuse the 5G Policy Control Function (PCF), or to reuse the EPS-based V2X architecture, or to deploy the V2X Control Function as a new CP entity in the 5G CN. 13.4 Cloudification in V2X Environments The 5GAA³ considers the automotive sector, among the vertical segments in the 5G ecosys- tem, as a key driver toward the adoption of (edge) cloudification solutions. Indeed, V2X requires a very low-latency environment for a significant part of the related use cases (about 10 ms). Autonomous driving is the most relevant and critical example in this respect. Such a capability is only offered by an edge computing