N2 Handover (N2-based Handover)

N2 handover is the 5G handover procedure (3GPP TS 23.502) executed via the AMF over the N2 interface when the Xn interface is unavailable between source and target gNBs, or for inter-AMF mobility. The AMF orchestrates the target-side resource setup, path switch on the UPF, and NAS security context transfer. Slower than Xn but mandatory for AMF changes.

Categories: Radio Access NetworkCore NetworkSignaling

N2 Handover in context

The radio access network is the layer where mobile devices attach to the operator's infrastructure. Attacks in this layer include IMSI catching, rogue base stations, downgrade attacks and jamming, and defenses hinge on mutual authentication, integrity-protected signaling and Open RAN supply-chain hygiene.

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 N2 Handover in the wider telecom-security picture, review N3, AMF, SRVCC, S1AP, RANAP and IPsec.

Related terms

Related topic hubs

More from the TelcoSec Glossary

Browse the full TelcoSec Glossary, the Ultimate Guide to Mobile Network Security, or the P1 Arsenal of telecom-security tools.