nd allowed/non-allowed area, etc.), when it allocates registration area to the UE, that is, the set of tracking areas in TAI list. In 5GS; however, NG-RAN also supports the loca- tion tracking for the UEs in RRC_INACTIVE state. In that state, the core network knows that the UE is somewhere within the NG-RAN, but the NG-RAN node needs a new location tracking functionality to determine the exact location of the UE because the connection between the UE and the NG-RAN node is not active. In EPS, when downlink traffic for a UE in the RRC_IDLE state arrives at the SGW, the MME performs a paging procedure based on the detected location of the UE. However, 5GS supports two types of paging, namely core-network-initiated paging and access- network-initiated paging. The UE in RRC_IDLE and RRC_INACTIVE states may use DRX in order to reduce power consumption. While in RRC_IDLE, the UE monitors 5GC- initiated paging, in RRC_INACTIVE, the UE is reachable via RAN-initiated paging and 5GC-initiated paging. The RAN and 5GC paging occasions overlap and the same paging mechanism is used. In core-network-initiated paging, the default paging procedure is requested by the core network when the UE is in the CM-IDLE state. The newly introduced RAN-initiated paging mode is used for the UEs in the RRC_INACTIVE state. Since a UE in the RRC_INACTIVE state is in the CM-CONNECTED state (see Fig. 1.81), the core net- work simply forwards the data or the signaling messages to the corresponding RAN when data or signaling messages arrive for the UE. Therefore, RAN itself generates the paging message and performs paging to find the updated location of the UE, and then sends the data or signaling messages to the UE. The 5GC can transmit additional assistance informa- tion for RAN paging [16]. Service area restriction also known as mobility-on-demand, which defines areas where the UE may or may not initiate communication with the network, is a concept to selectively support mobility of devices on a need basis. It includes supporting UE's mobility at 