Xn Handover — full call flow

Direct gNB-to-gNB Handover

Xn handover is the most common and fastest handover type in 5G, used when source and target gNBs have a direct Xn interface and are served by the same AMF. The procedure has three phases: preparation where the source gNB sends UE context and PDU session information to the target, execution where the UE performs random access to the target cell, and completion where the target gNB requests a path switch through the AMF to redirect the user-plane tunnel from the old gNB to itself.