eated accordingly in the network element. While the specific slice traffic treatment is left to operators, the selection and identification functionalities are specified by 3GPP. A VUE, wishing to attach to a slice, has to provide the network with the Network Slice Selection Assistance Information (NSSAI) parameters, identifying a slice, to enable the selec- tion of a slice instance for it (3GPP TS 23.501, 2019). The Network Slice Selection Function (NSSF), specifically added in the 5G system architecture (see Figure 13.2), is then respon- sible for slice selection. In particular, NSSAI includes Slice Service Type (SST) and, possibly, Slice Differentia- tor (SD). The SST refers to an expected network behavior. 3GPP proposes to define a specific standardized SST for V2X services (3GPP TR 23.786, 2019). A customized SST value facilitates the deployment of dedicated network slices for use of, for example, automotive industry. A standardized value could facilitate roaming support. Indeed, it can be expected that vehicles move fast and often cross over different countries/MNOs while being connected to the network. The standardized SST values (3GPP TR 23.501, 2019) are (i) 1 for the eMBB slice, (ii) 2 for the URLLC slice, (iii) 3 for the mIoT slice, and (iv) 4 for the V2X slice. 13 5G Network Slicing for V2X Communications: Technologies and Enablers The SD is an optional information that complements the SST and can help select among several network slice instances of the same type, e.g. to isolate the traffic related to different services provided over different slice instances. An SD could identify the Tenant ID, e.g. the car manufacturer, the road authority. 13.6.2 Literature Overview On a parallel and also faster lane than 3GPP efforts, literature works have been published on network slicing for V2X. Although the entire end-to-end chain of 5G radio, networks, applications, and services should be tailored to meet V2X requirements through network slicing, existing literature works target specific domains and network s