Patent ID: 8504045

Claim:
A mobile communication method in which a mobile station performs a handover from a handover-source radio base station to a handover-target radio base station, the method comprising the steps of: (A) judging whether or not user plane data to be forwarded to the handover-target radio base station exists for each access bearer set up with an upper level node, when a handover for the mobile station is determined to be performed; (B) notifying, to the handover-target radio base station, a result of the judgment by using a handover request message for the mobile station; (C) setting up a data forwarding tunnel for forwarding user plane data from the handover-source radio base station to the handover-target radio base station only for an access bearer for which the user plane data to be forwarded exists, and notifying, to the handover-source radio base station, setup information on the data forwarding tunnel by using a handover request response message for the handover request message; and (D) forwarding the user plane data to the handover-target radio base station by the handover-source radio base station via the data forwarding tunnel on the basis of the setup information on the data forwarding tunnel, wherein the handover request message for the mobile station includes a list of the access bearers for which the user plane data to be forwarded to the handover-target radio base station exists.