Patent ID: 7697940

Claim:
A network apparatus for a stable handoff in an IP-based mobile ad hoc network system, comprising: a movement-determining unit for determining movement depending on a signal strength upon reception of a packet from at least one of other network apparatuses operating on a communication mobile ad hoc network, and deciding a handoff to a new access router; a router-configuring unit for configuring information as pre-configured information on the new access router for the handoff by performing beforehand the handoff to the new access router according to results of determining movement in the movement-determining unit; and a handoff-processing unit for performing the handoff to the new access router by using the pre-configured information according to the results of determining movement in the movement-determining unit, wherein the movement-determining unit compares the signal strength with predetermined threshold values, broadcasts a neighbor information request (NI Req) message for requesting other network apparatuses in a range of 1 hop to transmit neighbor information, and determines a direction in which the network apparatus moves through reply messages transmitted in response to the NI Req message, wherein the movement-determining unit creates a neighbor information reply (NI Rep) message using a router address of a current access router if the broadcasted NI Req message is received, checks the reply messages that are transmitted from the other network apparatuses to the network apparatus that has requested neighbor information, transmits the NI Rep message if there is no NI Rep message having the same router address as the router address of the current access router, and does not transmits the NI Rep message if there is NI Rep message having the same router address as the router address of the current access router.