en the V2X application server and the V2X control function in the operator's network. The V2X application server may connect to V2X control functions belonging to multiple PLMNs. V3: This reference point is between the UE and the V2X control function in UE's home PLMN. It is based on the service authorization and provisioning part of the PC3 refer- ence point. It is applicable to both PC5 and LTE-Uu-based V2X communication and optionally eMBMS and LTE-Uu-based V2X communication. V4: This reference point is between the home subscriber server (HSS) and the V2X con- trol function in the operator's network. V5: This reference point is between the V2X applications in the UEs, and is not speci- fied in 3GPP specifications. V6: This reference point is between the V2X control function in the home PLMN and the V2X control function in the visited PLMN. PC5: This reference point is between the UEs for direct communication over user-plane for V2X service. S6a: In case of V2X service, S6a is used to download V2X service-related subscription information to mobility management entity (MME) during E-UTRAN attach procedure or to inform MME subscription information in the HSS has changed. S1-MME: In case of V2X service, it is used to convey the V2X service authorization from the MME to eNB. xMB: This reference point is between the V2X application server (e.g., content pro- vider) and the BM-SC. 806 Chapter 7 MB2: This reference point is between the V2X application server and the BM-SC. SGmb/SGi-mb/M1/M3: The SGmb/SGi-mb/M1/M3 reference points are internal to the eMBMS system. LTE-Uu: This reference point is between the UE and the E-UTRAN. The V2N and communication via the network represent suitable applications for the net- work slicing. For instance, autonomous driving or safety/emergency services would require URLLC network slice. Meanwhile, some infotainment services or personal mobility ser- vices would require either a best-effort slice or an eMBB. A vehicle can access different slices at the same time, with passengers watchi