Patent ID: 7924842
Filing Date: 2011-04-12
Classification: H04W

Abstract:
1. A packet transfer method in a communication network system comprising: a plurality of access routers which form predetermined communication areas thereunder, respectively; a mobile terminal which is connected to at least one of the plurality of access routers to perform packet communication with an arbitrary communication device via the connected access router; and a communication partner device which is the arbitrary communication device and which performs the packet communication with the mobile terminal, the method comprising: a connection candidate information setting step in which a communication device to perform processing concerned with an original packet adds, to the original packet, one of identification information of the plurality of access routers potentially connected to the mobile terminal and identification information of the mobile terminal for use when connected to the plurality of access routers potentially connected to the mobile terminal, respectively, as mobile terminal connection candidate information, before the original packet to be transmitted from the communication partner device to the mobile terminal reaches one of the plurality of access routers potentially connected to the mobile terminal; a connection confirming step in which one of the plurality of access routers potentially connected to the mobile terminal confirms whether or not the access router is currently connected to the mobile terminal thereunder, in a case where a packet constituted by adding the mobile terminal connection candidate information to the original packet is received; a packet transmission step in which the access router transmits, to the mobile terminal, the packet or the original packet constituted by removing the mobile terminal connection candidate information from the packet, in a case where it is confirmed in the connection confirming step that the mobile terminal is currently connected; and a packet transfer step in which the access router transfers the packet by unicast to another access router described in the mobile terminal connection candidate information, in a case where it is not confirmed in the connection confirming step that the mobile terminal is currently connected.