Patent ID: 7529214

Claim:
A communication system including a plurality of transfer devices for transferring packets to a current location of a mobile terminal, a plurality of access router devices arranged in a network to be able to connect to the mobile terminal, a plurality of routers connecting the plurality of access router devices and each of the plurality of transfer devices, and the mobile terminal connected to a first of the plurality of access router devices to receive the packets from one of the plurality of a transfer devices through the first access router device, the system comprising: a first transmitter provided at the mobile terminal configured to transmit instruction information, which instructs one of the plurality of transfer devices to transfer the packets to the mobile terminal, to an anycast address assigned in common with the plurality of transfer devices; a second transmitter provided at the first access router device configured to receive the instruction information and to relay the instruction information to a router included in the plurality of routers and connected to the first access router device; a third transmitter provided at the plurality of routers or the first access router device configured to transmit the instruction information to a nearest transfer device which has a shortest distance from the first access router device on the network among the plurality of transfer devices to which the anycast address is assigned; and a fourth transmitter provided at the nearest transfer device configured to receive the instruction information and to transmit specification information, which specifies the nearest transfer device, to the mobile terminal, wherein when the mobile terminal executes a handoff from the first access router to a second access router, and an on-link care of address used by the mobile terminal is changed from a first on-link care of address to a second on-link care of address based on the handoff, the mobile terminal performs unicast transmission to transmit instruction information that includes the second on-link care of address to be used by the mobile terminal after the handoff to the nearest transfer device having a shortest distance from the first access router to which the mobile terminal was connected prior to the handoff.