Mobile IP system and data routing method of the same

• US 20020059433A1
• Filed: 11/13/2001
• Published: 05/16/2002
• Est. Priority Date: 11/14/2000
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Oh, Suk Sang
• Granted Patent: US 7,475,144 B2
• Time in Patent Office: Days
• US Class Current: 709/227
• CPC Class Codes: H04W 36/0011 for data sessions of end-to-end connection
• CPC Class Codes: H04W 36/0019 adapted for mobile IP [MIP]
• CPC Class Codes: H04W 36/02 Buffering or recovering information during reselection ; Modification of the traffic flow during hand-off
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]

Abstract

A mobile Internet Protocol (IP) system and a data routing method of the mobile IP system are disclosed. According to the present invention, even if a mobile node moves from a first foreign agent to a second foreign agent while it receives data packets from the first foreign agent, the first foreign agent keeps storing the data packets it its buffer, and it sends the stored data to the second foreign agent indicated in a notification message received from the mobile node. Therefore, the host does not need to retransmit the data packets to the second foreign agent again. This will greatly increase reliability of the data transmission in the IP system and can reduce the overhead of the whole system.

Claims

1. A mobile Internet Protocol (IP) system, comprising:

a mobile node initially linked to a first foreign network;

a home agent receiving a set of data packets, which are supposed to be transmitted to said mobile node, said home agent being included in a home network of said mobile node; and

a first foreign agent initially receiving said packets from said home agent and storing them in a buffer and additionally sending said stored packets to a second foreign agent included in a second foreign network if said mobile node is moved to said second foreign network, said first foreign agent being included in said first foreign network.

2. The mobile IP system of claim 1, wherein said first foreign agent deletes said stored packets after sending said stored packets to said second foreign agent.

3. The mobile IP system of claim 1, wherein said first foreign agent additionally sends said stored packets to said mobile node if said mobile node continues to be linked to said first foreign network.

4. The mobile IP system of claim 3, wherein said first foreign agent deletes said stored packets after sending said stored packets to said mobile node.

5. The mobile IP system of claim 1, wherein said buffer is coupled to said first foreign agent.

6. The mobile IP system of claim 1, wherein said mobile node sends a notification message to said first foreign agent if said mobile node is moved to said second foreign network.

7. The mobile IP system of claim 6, wherein said first foreign agent determines whether said mobile node is moved to said second foreign network by checking whether said notification message is received from said mobile node.

8. A method of transmitting data in a mobile Internet Protocol (IP) network, the method comprising the steps of:

(a) transmitting a set of data packets to a home agent of a mobile node, said mobile node being currently linked to a first foreign network having a first foreign agent;

(b) sending said packets received by said home agent to said first foreign agent and storing them in a first buffer;

(c) sending a notification message to said first foreign agent if said mobile node moves to a second foreign network having a second foreign agent;

(d) sending said packets stored in said first buffer to said second foreign agent and storing them in a second buffer if said first foreign agent receives said notification message; and

(e) transmitting said packets stored in said second buffer to said mobile node.

9. The method of claim 8, wherein said first buffer is coupled to said first foreign agent.

10. The method of claim 8, wherein said second buffer is coupled to said second foreign agent.

11. The method of claim 8 further comprising a step of deleting said packets stored in said first buffer after sending said packets stored in said first buffer to said second foreign agent.

12. The method of claim 8 further comprising a step of transmitting said packets stored in said first buffer to said mobile node if said mobile node continues to be linked to said first foreign network.

13. The method of claim 12 further comprising a step of deleting said packets stored in said first buffer after transmitting said packets stored in said first buffer to said mobile node.

14. The method of claim 8, wherein said notification message is generated from said mobile node.

16. The method of claim 15 further comprising a step of deleting said packets stored in said buffer after transmitting said packets stored in said buffer to said second foreign agent.

17. The method of claim 15 further comprising a step of transmitting said packets stored in said buffer to said mobile node if said mobile node continues to be linked to said first foreign network.

18. The method of claim 17 further comprising a step of deleting said packets stored in said buffer after transmitting said packets stored in said buffer to said mobile node.

19. The method of claim 15, wherein said buffer is coupled to said first foreign agent.

20. The method of claim 15, wherein said mobile node sends a notification message to said first foreign agent if said mobile node is moved to said second foreign network.

21. The method of claim 20, wherein said determination step (c) is performed by checking whether said notification message is received from said mobile node.

22. The method of claim 20, wherein an IP address of said second foreign agent is indicated in said notification message.

15. A data routing method of a first foreign agent in a mobile Internet Protocol (IP) network, the method comprising the steps of:

(a) receiving a set of data packets and storing them in a buffer;

(b) determining a mobile node to which said packets are supposed to be transmitted;

(c) determining if said determined mobile node is moved to a second foreign network having a second foreign agent; and

(d) transmitting said packets stored in said buffer to said second foreign agent if said mobile node is moved to said second foreign network.