Patent ID: 7353027

Claim:
A method of seamlessly handing off a mobile node from an old sub-network router to a new sub-network router in an Internet Protocol based wireless access network comprising: obtaining a handoff starting time from a lower layer complying with Open Systems Interconnections (OSI) model; using information from the lower layer of the OSI model to notify the mobile node that a connection with the old sub-network router will be discarded within a predetermined amount of time; obtaining a new care-of address for the mobile node from the new sub-network router; sending a request message from the mobile node to a base node via the new sub-network router requesting a new binding; creating a new care-of address binding in the base node; issuing two registration reply messages, one from the base node to the mobile node wherein a registration reply message is sent to the new care-of address via the new sub-network router indicating that the new care-of address binding has been created and a deregistration reply message (DRR) is sent from the base node to the old care-of address via the old sub-network router notifying the mobile node that binding with the old care-of address has been removed; and utilizing the deregistration reply message (DRR) to synchronize a transfer of old care-of address data packets stored on the old sub-network router to the mobile node, the home agent sending the two registration reply messages including the DRR after receiving the registration request message and using the DRR as a synchronization point.