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 is where subscriber sessions, mobility and policy live. 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. Core exposure is the difference between a single-subscriber leak and a fleet-wide breach.
To place Registration Update (5G) in the wider telecom-security picture, review NSSF, CSCF, IMS, NSSAI, N8 and N2 Handover.
Related terms
Related topic hubs
- Tracking Area Update LTE TAU procedure and its signaling risks.
- Diameter Security 4G/LTE Diameter threats across IPX/roaming and DEA defenses.
- 5G Security 5G SBA, SEPP, SUCI, 5G-AKA, N32 and service-based interface security.
- LTE Security Training Training on 4G/LTE core, Diameter, NAS and RRC security.
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