METHOD AND APPARATUS FOR WIRELESS COMMUNICATION WITH LOW-OVERHEAD MOBILITY MANAGEMENT

• US 20090238145A1
• Filed: 03/30/2009
• Published: 09/24/2009
• Est. Priority Date: 02/21/2001
• Status: Active Grant

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Chitrapu, Prabhakar R., Shahrier, Sharif M.
• Granted Patent: US 8,213,385 B2
• Time in Patent Office: Days
• US Class Current: 370/331
• CPC Class Codes: C07C 43/313 containing halogen
• CPC Class Codes: C07C 69/63 of saturated acids
• CPC Class Codes: C07D 307/79 with only hydrogen atoms, hydrocarbon or substituted hydrocarbon radicals, directly attached to carbon atoms of the hetero ring
• CPC Class Codes: H04L 45/26 Route discovery packet
• CPC Class Codes: H04L 61/00 Network arrangements, protocols or services for addressing or naming
• CPC Class Codes: H04L 61/25 of the same type
• CPC Class Codes: H04L 61/2514 between local and global IP addresses
• CPC Class Codes: H04L 61/2535 Multiple local networks, e.g. resolving potential IP address conflicts
• CPC Class Codes: H04L 61/255 Maintenance or indexing of mapping tables
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: H04W 36/00835 Determination of neighbour cell lists
• CPC Class Codes: H04W 40/36 due to handover
• CPC Class Codes: H04W 8/04 Registration at HLR or HSS [Home Subscriber Server]
• CPC Class Codes: H04W 8/082 for traffic bypassing of mobility servers, e.g. location registers, home PLMNs or home agents
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]
• CPC Class Codes: H04W 84/105 PBS [Private Base Station] network H04W84/12 - H04W84/16 take precedence
• CPC Class Codes: H04W 88/005 Data network PoA devices

Abstract

A method and apparatus for supporting handover of mobile communications is provided. A router performs routing services in a service area. The router maintains a location table configured to store current router addresses of mobile nodes that have the router as a home router. The router receives data intended for mobile nodes that are listed in the location table and are in the routers service area. The router receives a user datagram protocol (UDP) message from a mobile node when it leaves the service area. The UDP message includes an IP address of a new router in the mobile node'"'"'s new service area. The router updates the location table with the new IP address and transmits data intended for the mobile node to the new router until the data is redirected at the source.

Claims

1. A wireless communication apparatus comprising:

a first router configured to facilitate a hand-off of a wireless communication conducted in a first area of service between a corresponding node (CN) and a mobile node (MN) that has the first router as a home router such that at completion of the hand-off, the wireless communication is conducted in a second area of service between the CN and the MN via a second router without sending data of the wireless communication to the first router;

the first router including a location table;

the location table configured to store current router addresses of MNs having the first router as a home router;

the first router configured to receive data of the wireless communication sent from the CN to the MN before the hand-off;

the first router configured to obtain an IP address of the second router for the hand-off in response to the MN moving to the second area of service by receiving a message sent from the MN that contains the IP address of the second router;

the first router configured to update the location table with the received IP address of the second router for the MN; and

the first router configured to forward data of the wireless communication received from the CN to the second router after the MN stops receiving data of the wireless communication from the first router and before completion of the hand-off.

2. The wireless communication apparatus of claim 1 wherein the first router is configured to receive user datagram protocol (UDP) messages and to send an acknowledgement message to the MN in response to receiving the message sent from the MN that contains the IP address of the second router.

3. The wireless communication apparatus of claim 1 wherein the location table is configured as a mobile-home database (MHD) and is configured to store a data record for each MN served by the first router that has an index field for an index value, a flag for indicating a home association with the first router, a local address field for a current local address of the respective MN, and a router address field for an address of a home router of where the respective MN is a visiting MN.

4. The wireless communication of claim 3 wherein the MHD is configured to be updated in response to MNs moving to or from the first area of service by updating the respective data records to reflect updated current locations of the MNs.

5. A method to facilitate hand-off of a wireless communication conducted in a first area of service between a corresponding node (CN) and a mobile node (MN) that has a first router as a home router such that at completion of the hand-off, the wireless communication is conducted in a second area of service between the CN and the MN via a second router without sending data of the wireless communication to the first router, the method comprising:

providing the first router with a location table configured to store current router addresses of MNs having the first router as a home router;

receiving data of the wireless communication by the first router sent from the CN to the MN before the hand-off;

obtaining an IP address of the second router for the hand-off in response to the MN moving to the second area of service by the first router receiving a message sent from the MN that contains the IP address of the second router;

updating the location table with the received IP address of the second router for the MN; and

forwarding data of the wireless communication received from the CN by the first router to the second router after the MN stops receiving data of the wireless communication from the first router and before completion of the hand-off.

6. The method of claim 5 wherein the first router receives user datagram protocol (UDP) messages and sends an acknowledgement message to the MN in response to receiving the message sent from the MN that contains the IP address of the second router.

7. The method of claim 5 wherein the first router is provided with a location table that is configured to store a data record for each MN served by the first router that has an index field for an index value, a flag for indicating a home association with the first router, a local address field for a current local address of the respective MN, and a router address field for an address of a home router of where the respective MN is a visiting MN.

8. The method of claim 7 wherein the location table is updated in response to MNs moving to or from the first area of service by updating the respective data records to reflect updated current locations of the MNs.

9. A method for a first router to facilitate a hand-off of a wireless communication comprising:

the first router;

maintaining a location table including a current router address of a mobile node (MN) conducting the wireless communication over a first wireless link to the first router;

receiving data of the wireless communication sent to the MN from a corresponding node (CN) prior to completion of the hand-off;

in response to the MN moving to a location in which the wireless communication will be conducted over a second wireless link to a second router after the hand-off without sending data to the first router, obtaining an IP address of the second router by receiving a message containing the IP address of the second router from the MN;

updating the location table; and

forwarding data of the wireless communication received from the CN to the second router that is not received by the MN over the first wireless link to complete the hand-off.

10. The method of claim 9 wherein the first router receives user datagram protocol (UDP) messages and sends an acknowledgement message to the MN in response to receiving the message sent from the MN that contains the IP address of the second router.

11. The method of claim 9 wherein the location table is configured as a mobile-home database (MHD) having data records for MNs that include:

an index field,

a flag indicating a type of association with the first router,

a current local address, and

an address of a home router where the data record is for a visiting node;

wherein the location table is maintained by updating the MHD data records.

12. The method of claim 11 wherein the MHD data records are updated when MNs move out of an area serviced by the first router such that the data records for MNs that are not visiting nodes are changed to reflect current locations and the data records for MN that are visiting nodes are deleted.

13. A wireless communication apparatus comprising:

a first router configured to facilitate a hand-off of a wireless communication conducted by a mobile node (MN) over a first wireless link to the first router in which the wireless communication is conducted over a second wireless link to a second router without sending data to the first router after completion of the hand-off;

the first router including a location table that stores current router addresses of MNs conducting wireless communications over wireless links to the first router;

the first router configured to receive data of the wireless communication sent to the MN from a corresponding node (CN) prior to completion of the hand-off;

the first router configured to obtain an IP address of the second router in response to the MN moving to a location for initiation of the hand-off by receiving a message containing the IP address of the second router from the MN;

the first router configured to update the location table after receiving the message; and

the first router configured to forward data of the wireless communication received from the CN to the second router that is not received by the MN over the first wireless link to complete the hand-off.

14. The wireless communication apparatus of claim 13 wherein the first router is configured to receive user datagram protocol (UDP) messages and to send an acknowledgement message to the MN in response to receiving the message sent from the MN that contains the IP address of the second router.

15. The wireless communication apparatus of claim 13 wherein the location table is configured as a mobile-home database (MHD) having data records for MNs that include:

an index field,

a flag indicating a type of association with the first router,

a current local address, and

an address of a home router where the data record is for a visiting node.

16. The wireless communication apparatus claim 15 wherein the MHD is configured to update the data records when MNs move out of an area serviced by the first router such that the data records for MNs that are not visiting nodes are changed to reflect current locations and the data records for MN that are visiting nodes are deleted.