公开(公告)号：US20230254738A1

公开(公告)日：2023-08-10

申请号：US18103800

申请日：2023-01-31

Applicant: MEDIATEK INC.

Inventor： CHIEN-CHUN HUANG-FU ,  Bo-Hun Chen ,  Shang-Wu Li ,  Yu-Kai Gao

IPC: H04W36/00

CPC classification number: H04W36/0022 ,  H04W36/0072

Abstract: A method of enhancing session continuity for system interworking is proposed. Upon a UE performs inter-system change from A/Gb mode or Iu mode to S1 mode, the UE identifies that some PDN connection(s) are not associated with a PDU session ID (PSI). In one novel aspect, the UE deactivates all EPS bearer contexts for such PDN connection(s) locally, includes the EPS bearer context status IE in a TRACKING AREA UPDATE REQUEST message of a tracking area updating (TAU) procedure upon inter-system change from A/Gb mode or Iu mode to S1 mode, and then initiates UE requested PDN connectivity procedure(s) for such PDN connection(s). Furthermore, if no EPS bearer exists after local deactivation and EMM-REGISTERED without PDN connection is not supported by the UE, then the UE initiates a re-attach procedure followed by the UE requested PDN connectivity procedure(s) for such PDN connection (s) .