Patent ID: 7782819

Claim:
A mobile communication system comprising a plurality of radio base stations each of which has a function of sending received radio data to the IP network as IP packet data and sending IP packet data received from the IP network as radio data and a mobile node with a function of sending and receiving radio data to and from the radio base station for communicating with a correspondent node by connecting with the IP network via the radio base station, wherein the mobile node sends to a handover source radio base station address information of a link to which a handover destination radio base station is connected when the mobile node performs a handover, and each of the radio base stations has a measurement part measuring a data transfer time from the radio base station to the handover destination radio base station that is specified by the address information when it receives the address information from the mobile node, and each of the radio base stations transfers the IP packet data destined to the mobile node that is received from the IP network to the handover destination radio base station that is specified by the address information, while sending the data to the mobile node as radio data at a sending timing based on the data transfer time.