Patent ID: 11943830
Assignee: HUAWEI TECHNOLOGIES CO., LTD.
Field: Digital communication (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A communication system comprising:
a control plane (CP) functional entity, a target radio access node (RAN), and a source RAN, wherein
the target RAN is configured to receive a re-establishment request message from user equipment (UE), and send a first message to the CP functional entity based on the re-establishment request message,
wherein the re-establishment request message comprises a second message authentication code (MAC) generation parameter and a MAC of the UE, and
wherein the first message comprises the second MAC generation parameter and the MAC;
the CP functional entity is configured to receive the first message from the target RAN, verify the MAC based on the second MAC generation parameter comprised in the first message, and in response to successful verification of the MAC, send a second message to the source RAN,
wherein the second message is used to request the source RAN to send undelivered non-access stratum (NAS) packet data unit (PDU) of the UE to the CP functional entity; and
the source RAN is configured to send the undelivered NAS PDU of the UE stored on the source RAN to the CP functional entity.