Patent ID: 7912008

Claim:
A mobile communication method comprising: transmitting, by a mobile router, a binding update message in which the mobile router, managing a mobile local network moving between networks as one unit, notifies a home agent of a care-of-address of the mobile router which was acquired at a network to which the mobile local network has gone; determining, by the mobile router based on information received from the home agent in an acknowledgment message, whether the home agent, at a time the home agent receives the binding update message, has without delay sent route information concerning a route to the mobile local network which the mobile router manages to a gateway of a home network; responsive to the home agent having sent the route information to the gateway of the home network, effecting route control depending upon the route information; and responsive to the mobile router determining that the home agent has not sent the route information to the gateway of the home network, sending, by the mobile router to the home agent, a further message using a routing protocol to indicate the route information to the home agent, and notifying the route information to the home network, wherein: the determining of whether the home agent has without delay sent the route information to the gateway of the home network includes determining whether the received acknowledgement message includes an acknowledgment flag that indicates the home agent has notified the gateway concerning the routing information, and responsive to the received acknowledgement flag indicating that the home agent has not notified the gateway concerning the routing information, transmitting, by the mobile router to the home agent, the routing information, as the further message, via a tunnel to the mobile local network.