N2 切换流程

sequenceDiagram participant UE participant S_gNB as 源gNB participant AMF participant T_gNB as 目标gNB participant SMF participant UPF S_gNB->>AMF: ① NGAP: Handover Required AMF->>T_gNB: ② NGAP: Handover Request T_gNB-->>AMF: ③ Handover Request Ack AMF-->>S_gNB: ④ Handover Command S_gNB->>UE: ⑤ RRC Reconfiguration UE->>T_gNB: ⑥ Handover Confirm T_gNB->>AMF: ⑦ Handover Notify AMF->>SMF: ⑧ UpdateSMContext(路径切换) SMF->>UPF: ⑨ N4 Modification AMF->>S_gNB: ⑩ UE Context Release Command