Abstract: Disclosed is a system for providing handover of a mobile node in a wireless network supporting Mobile IP (Internet Protocol). The mobile node sends, when handover is needed, a request for neighbor access router information to a first access router currently communicating with the mobile node, and selects, if the neighbor access router information is received, a second access router serving as a target access router using the received neighbor access router information. The first access router exchanges access router information with a neighbor access router, provides neighbor access router information to the mobile node upon receiving the neighbor access router information request from the mobile node, and redirects data to be delivered to the mobile node to the second access router to which the mobile node will be handed over. The second access router forwards data to be delivered to the mobile node, received from the first access router, to the corresponding mobile node.

Abstract: In a network system including at least one mobility anchor point (MAP) for managing mobility of a mobile node (MN) and a plurality of routers connected to the at least one MAP in a hierarchical structure, the MAP sends a MAP option to at least one router located on a higher level than the MAP. When receiving the MAP option, the router located on the higher level sends an updated MAP option to neighboring routers, after incrementing a predetermined upward value comprised in the MAP option. MAPs distributed in the network system can deliver MAP options regardless of the hierarchical structure of routers, and hence the MN can maximize its location privacy. Because the MAP performs MAP domain announcement using a DOMAIN option, service use of routers outside the MAP domain can be limited, and the number of times that a MAP is changed can be reduced.

Abstract: Disclosed is a method for calculating a routing cost or a hop count of a mobile IP (Internet Protocol) in an IP network. The IP network can communicate with the MN having a mobile IP and includes a plurality of access routers. If the MN moves to a new access router, the MN generates a distance measurement request message and transmits the generated distance measurement request message to an access router serving as a regional anchor point (RAP) of the MN. Upon receiving the distance measurement request message, the access router serving as the RAP generates an acknowledgement message having an initial hop limit field value and a hop limit value, and transmits the acknowledgement message. The MN calculates a hop count using the initial hop limit field value and the hop limit value.

Abstract: A method for maintaining data transmission from a corresponding node when a mobile node moves from a first access router to a second access router in a network system, the method comprising: transmitting using the mobile node a home address of the mobile node and a one care-of address (CoA) assigned from the first access router to the corresponding node and a home agent, when the mobile node is located in the first access router; and transmitting using the mobile node the home address, the one CoA, and another CoA assigned from the second access router to the first access router so that data from the corresponding node is received via the first access router and the second access router, when the mobile node moves from the first access router to the second access router and the second access router is located within a predetermined distance from the first access router.