Communication network system comprising 5G core network nodes, CNN, such as Session Management Function, SMF, a Policy Control function, PCF, an Online Charging System OCS, and a Network Exposure Function, NEF, the system further comprising a radio access node, RAN, and a User Entity, UE, the system further comprising a user plane function, UPF, communicating with a data network, DN; and a control plane comprising an Access Mobility Function, AMF, the system being adapted for the AMF - retrieving (301, 4-2, 5-1) or determining a registration area, RA, for the UE, the CNN - retrieving (4-2, 4-3, 6-2, 6-3; 5-2, 7-2) a service area associated with a UPF, slice or Local Area Data Network, LADN, the service area being identified by Tracking Area Identifiers, TAIs, and - allocating a Presence Reporting Area, PRA, based on the service area and corresponding to a list of cells, gNBs and / or TAIs, - informing (4-4, 4-5, 6-4, 6-5, 302; 5-3, 7-3) the AMF of the PRA, the AMF - defining or retrieving a UE Reporting Area, URA, in dependence of the RA and the PRA, wherein, the URA is defined as the overlapping or joint area of PRA and RA, - transmitting (304, 4-11) the URA, to the UE, or - transmitting (305, 5-8) the URA to the RAN, the AMF moreover being adapted for - receiving an indication of direction of movement into or out of the URA of the UE, - transmitting (4-13, 4-14, 6-13, 6-14) an indication of direction of movement into or out of the URA of the UE to a SMF or a plurality of SMF's. the AMF - retrieving (301, 4-2, 5-1) or determining a registration area, RA, for the UE, - retrieving (301, 4-2, 5-1) or determining a registration area, RA, for the UE, the CNN - retrieving (4-2, 4-3, 6-2, 6-3; 5-2, 7-2) a service area associated with a UPF, slice or Local Area Data Network, LADN, the service area being identified by Tracking Area Identifiers, TAIs, and - allocating a Presence Reporting Area, PRA, based on the service area and corresponding to a list of cells, gNBs and / or TAIs, - informing (4-4, 4-5, 6-4, 6-5, 302; 5-3, 7-3) the AMF of the PRA, - retrieving (4-2, 4-3, 6-2, 6-3; 5-2, 7-2) a service area associated with a UPF, slice or Local Area Data Network, LADN, the service area being identified by Tracking Area Identifiers, TAIs, and - allocating a Presence Reporting Area, PRA, based on the service area and corresponding to a list of cells, gNBs and / or TAIs, - informing (4-4, 4-5, 6-4, 6-5, 302; 5-3, 7-3) the AMF of the PRA, the AMF - defining or retrieving a UE Reporting Area, URA, in dependence of the RA and the PRA, wherein, the URA is defined as the overlapping or joint area of PRA and RA, - transmitting (304, 4-11) the URA, to the UE, or - transmitting (305, 5-8) the URA to the RAN, - defining or retrieving a UE Reporting Area, URA, in dependence of the RA and the PRA, wherein, the URA is defined as the overlapping or joint area of PRA and RA, - transmitting (304, 4-11) the URA, to the UE, or - transmitting (305, 5-8) the URA to the RAN, the AMF moreover being adapted for - receiving an indication of direction of movement into or out of the URA of the UE, - transmitting (4-13, 4-14, 6-13, 6-14) an indication of direction of movement into or out of the URA of the UE to a SMF or a plurality of SMF's. - receiving an indication of direction of movement into or out of the URA of the UE, - transmitting (4-13, 4-14, 6-13, 6-14) an indication of direction of movement into or out of the URA of the UE to a SMF or a plurality of SMF's. <EOS>