Registration Update (5G) (Mobility/Periodic Registration Update)

Registration Update is the 5G equivalent (TS 23.502) of LTE TAU: mobility-triggered when the UE enters a new Tracking Area outside its Registration Area, or periodic based on a timer. It refreshes the UE's registration with the AMF, may trigger AMF relocation, and includes NAS security-mode command when integrity/ciphering context changes.

Categories: Core Network

Registration Update (5G) in context

The mobile core carries subscriber sessions, mobility and policy. In 4G it is the EPC (MME, HSS, S/PGW); in 5G it is the Service-Based Architecture with AMF, SMF, UPF, AUSF, UDM and the NRF.

To place Registration Update (5G) in the wider telecom-security picture, review 5G, 5G SA, 5G NSA, 5G SBA, ACL and AES — each entry cross-references back to this page so you can walk the topic in either direction.

Related terms

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