or an ng-eNB, that is, a Rel-15/16 LTE base station, terminating LTE user-plane and control-plane proto- cols to/from the UE. The gNBs and ng-eNBs are interconnected through Xn interface. The gNBs and ng-eNBs are also connected via NG interfaces to the 5GC. More specifically, NG-C interfaces NG-RAN nodes to the AMF and NG-U interfaces the NG-RAN nodes to the UPF [16]. In 5G network architecture, the gNB entity is responsible for performing functions corre- sponding to RRM including radio bearer control, radio admission control, connection mobil- ity control, dynamic allocation of resources to UEs in both uplink and downlink (scheduling). The gNB further performs IP header compression and encryption and integrity protection of data as well as selection of an AMF upon UE attachment when no routing to an AMF can be determined from the information provided by the UE. It also provides rout- ing of user-plane data toward UPF(s) along with routing of control-plane information toward AMF; the connection setup and release; scheduling and transmission of paging mes- sages originated from the AMF; scheduling and transmission of system information origi- nated from the AMF or network operation and management; measurement and reporting configuration for mobility and scheduling; session management; support of network slicing; QoS flow management and mapping to data radio bearers (DRBs); support of UEs in RRC_INACTIVE state; as well as RAN sharing and DC [16]. In NG-RAN architecture, the role of AMF is similar to that of MME in the EPC which hosts core network control-plane functions such as terminating NAS signaling and security; AS security control; internetwork signaling for mobility between 3GPP access networks; UE IP address allocation NAS security Inter cell RRM PDU session control RB control Idle state mobility handling AMF/UPF/SMF AMF/UPF/SMF Connection mobility control Radio admission control Measurement configuration Mobility anchoring and provision Dynamic resource PDU handling Internet allocation (scheduler) ((H)) (