Section: 6 Security procedures between UE and 5G network functions 6.0 General
Content: When the UE is capable of connecting to 5GC and EPC and connected to an ng-eNB which is connected to both EPC and 5GC, the UE has the ability to select which core network to connect to as described in clause 4.8.4 in TS24.501[35]. If the UE selects the EPC, the UE shall use security procedure as in TS33.401[10]. Otherwise, if the UE selects 5GC, the UE shall use the security procedures as per this document. For an ng-eNB which can connect to EPC and 5GC, the ng-eNB shall choose the corresponding security procedures based on the UE selected type of core netowrk, i.e., when EPC is selected, the ng-eNB shall use security procedures as described in TS33.401[10]. On the other hand, when 5GC is selected, the ng-eNB shall use security procedures as described in this document.