Tech-invite3GPPspecsGlossariesIETFRFCsGroupsSIPABNFsWorld Map


 
 
Here   Top   Up   Prev   Next
5GS – General Registration – 23 of 25
Signalling flow for TS 23.502 General Register - New AMF to UE: Registration Accept


Step 21, verbatim
New AMF to UE: Registration Accept (5G-GUTI, Registration Area, Mobility restrictions, PDU Session status, Allowed NSSAI, [Mapping Of Allowed NSSAI], [Configured NSSAI for the Serving PLMN], [Mapping Of Configured NSSAI], Periodic Registration Update timer, LADN Information and accepted MICO mode, IMS Voice over PS session supported Indication, Emergency Service Support indicator, Accepted DRX parameters, Network support of Interworking without N26), Network Slicing Subscription Change Indication. The Allowed NSSAI for the Access Type for the UE is included in the N2 message carrying the Registration Accept message.
The AMF sends a Registration Accept message to the UE indicating that the Registration Request has been accepted. 5G‑GUTI is included if the AMF allocates a new 5G‑GUTI. If the UE is already in RM-REGISTERED state via another access in the same or equivalent PLMN, the UE shall use the 5G‑GUTI received in the Registration Accept for both registrations. If no 5G‑GUTI is included in the Registration Accept, then the UE uses the 5G‑GUTI assigned for the existing registration also for the new registration. If the AMF allocates a new Registration area, it shall send the Registration area to the UE via Registration Accept message. If there is no Registration area included in the Registration Accept message, the UE shall consider the old Registration Area as valid. Mobility Restrictions is included in case mobility restrictions applies for the UE and Registration Type is not Emergency Registration. The AMF indicates the established PDU Sessions to the UE in the PDU Session status. The UE removes locally any internal resources related to PDU Sessions that are not marked as established in the received PDU Session status. If the AMF invokes the Nsmf_PDUSession_UpdateSMContext procedure for UP activation of PDU Session(s) in step 18 and receives rejection from the SMF, then the AMF indicates to the UE the PDU Session ID and the cause why the User Plane resources were not activated. When the UE is connected to the two AMFs belonging to different PLMN via 3GPP access and non-3GPP access then the UE removes locally any internal resources related to the PDU Session of the current PLMN that are not marked as established in received PDU Session status. If the PDU Session status information was in the Registration Request, the AMF shall indicate the PDU Session status to the UE. The Mapping Of Allowed NSSAI is the mapping of each S‑NSSAI of the Allowed NSSAI to the S‑NSSAIs of the Configured NSSAI for the HPLMN. The Mapping Of Configured NSSAI is the mapping of each S‑NSSAI of the Configured NSSAI for the Serving PLMN to the S‑NSSAIs of the Configured NSSAI for the HPLMN. The AMF shall include in the Registration Accept message the LADN Information for LADNs, defined in TS 23.501 [2] clause 5.6.5, that are available within the Registration area determined by the AMF for the UE. If the UE included MICO mode in the request, then AMF responds whether MICO mode should be used.
In the case of registration over 3GPP access, the AMF sets the IMS Voice over PS session supported Indication as described in clause 5.16.3.2 of TS 23.501 [2]. In order to set the IMS Voice over PS session supported Indication the AMF may need to perform the UE/RAN Radio information and Compatibility Request procedure in clause 4.2.8a to check the compatibility of the UE and NG-RAN radio capabilities related to IMS Voice over PS. If the AMF hasn't received Voice Support Match Indicator from the NG-RAN on time then, based on implementation, AMF may set IMS Voice over PS session supported Indication and update it at a later stage.
In the case of registration over non-3GPP access, the AMF sets the IMS Voice over PS session supported Indication as described in clause 5.16.3.2a of TS 23.501 [2].
The Emergency Service Support indicator informs the UE that emergency services are supported, i.e. the UE is allowed to request PDU Session for emergency services. If the AMF received "MPS priority" from the UDM as part of Access and Mobility Subscription data, based on operator policy, "MPS priority" is included in the Registration Accept message to the UE to inform the UE whether configuration of Access Identity 1 is valid within the selected PLMN, as specified in TS 24.501 [25]. The Accepted DRX parameters are defined in clause 5.4.5 of TS 23.501 [2]. The AMF sets the Interworking without N26 parameter as described in clause 5.17.2.3.1 of TS 23.501 [2].
RRC Inactive Assistance Information might be provided to NG-RAN (see TS 23.501 [2] clause 5.3.3.2.5) in this step.
If the UDM intends to indicate the UE that subscription has changed, the Network Slicing Subscription Change Indication is included. If the AMF includes Network Slicing Subscription Change Indication, then the UE shall locally erase all the network slicing configuration for all PLMNs and, if applicable, update the configuration for the current PLMN based on any received information.