Mobile internet protocol system and route optimization method therefor

• US 7,116,654 B2
• Filed: 07/11/2002
• Issued: 10/03/2006
• Est. Priority Date: 08/16/2001
• Status: Expired due to Fees

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kim, Kil-Lyeon
• Primary Examiner(s): HO, DUC CHI
• Application Number:
  US10/192,613
• Publication Number:
  US 20030035387A1
• Time in Patent Office: 1,545 Days
• Field of Search: None
• US Class Current: 370/338
• CPC Class Codes: H04L 61/4511 using domain name system [DNS]
• 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 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]

Abstract

There is provided a route optimization method in a mobile Internet Protocol (IP) system using a mobile Internet Protocol. When a mobile host (MH) moves over the Internet and is assigned to a care-of-address (CoA) corresponding to a changed point of attachment to the Internet, it sends a registration request message containing the care-of address to a home agent (HA) via a foreign agent (FA). The home agent stores the care-of address in relation to a domain name of the mobile host in an internal domain name server database. Upon receipt of a query about the mobile host by domain name from a correspondent node (CN), the home agent sends the care-of address corresponding to the domain name of the mobile host together with caching prevention information to the correspondent node. The caching prevention information is set to prevent the correspondent node or another domain name server from caching the care-of address of the mobile host. The correspondent node communicates with the mobile host using the care-of address.

Claims

1. A route optimization method in a mobile Internet Protocol system using a mobile Internet Protocol, the method comprising:

sending a registration request message containing a care-of address to a home agent through a foreign agent when a mobile host is assigned to the care-of address corresponding to a changed point of access to the Internet, the home agent being a part of a home network for the mobile host to access the Internet, the foreign agent being a part of a foreign network for the mobile host to access the Internet, the home agent being distinguishable from the foreign agent;

storing the care-of address in an internal domain name server database by the home agent, the care-of address being stored to correspond to domain name of the mobile host;

when a query by domain name about the mobile host is received from a correspondent node, sending the care-of address corresponding to the domain name of the mobile host together with caching prevention information to the correspondent node from the home agent, the caching prevention information being set to prevent the correspondent node from caching the care-of address of the mobile host, the caching prevention information being set to prevent any domain name server from caching the care-of address of the mobile host; and

communicating with the mobile host by the correspondent node using the care-of address corresponding to the domain name of the mobile host.

2. The method of claim 1, the caching prevention information being time-to-live set to 0.

3. The method of claim 1, further comprising accessing the Internet through the home agent by the mobile host and then accessing the Internet through the foreign agent by the mobile host, before said sending of the registration request message.

4. The method of claim 3, further comprising connecting the foreign agent, the home agent, and the correspondent node together through the Internet.

5. The method of claim 4, the foreign agent, the home agent, the mobile host, and the correspondent node each being a respective computer.

6. The method of claim 4, the mobile host being one selected from among a personal digital assistant, a wearable computer, a notebook computer, and a telephone.

7. The method of claim 6, further comprising:

before said storing of the care-of address in the database, storing the domain name of the mobile host in the database to correspond with a first address associated with the mobile host accessing the Internet through the home agent;

the care-of address being an address associated with the mobile host accessing the Internet through the foreign agent, the care-of address being distinguishable from the first address.

8. A communication optimization method for communicating through the Internet, the method comprising:

providing a domain name to a mobile host;

storing in a database a care-of address to correspond to the domain name of the mobile host, said storing being performed by a home agent when the care-of address of the mobile host is received, the care-of address corresponding to a new point of attachment when the mobile host attaches to the Internet from the new point of attachment;

sending the care-of address corresponding to the domain name of the mobile host together with caching prevention information to a correspondent node by the home agent in response to a query about the mobile host by domain name from the correspondent node, the caching prevention information being set to prevent the correspondent node from caching the care-of address of the mobile host, the caching prevention information being set to prevent any domain name server from caching the care-of address of the mobile host; and

communicating with the mobile host by the correspondent node using the care-of address corresponding to the domain name of the mobile host.

9. The method of claim 8, further comprising connecting the foreign agent, the home agent, and the correspondent node together through the Internet.

10. The method of claim 8, the caching prevention information being time-to-live set to 0.

11. The method of claim 8, the mobile host being one selected from among a personal digital assistant, a wearable computer, a notebook computer, and a telephone.

12. A mobile Internet Protocol system, comprising:

an Internet;

a mobile host having a domain name and establishing a link with the Internet;

a home agent in a home network, said mobile host attaching to the Internet through said home agent when said mobile host is in the home network; and

a foreign agent in a foreign network, said mobile host attaching to the Internet through said foreign agent when said mobile host is moved from the home network to the foreign network;

said home agent storing in a domain name server database a care-of address of said mobile host to correspond to the domain name when said mobile host is attached to the Internet through said foreign agent, said home agent storing the care-of address in response to a registration request message sent to said home agent when said mobile host is moved to the foreign network, the registration request message containing the care-of address;

said home agent sending to a correspondent node the care-of address and caching prevention information in response to a query from the correspondent node about said mobile host, the query being by domain name, the caching prevention information being set to prevent the correspondent node from caching the care-of address of the mobile host, the caching prevention information being set to prevent any domain name server from caching the care-of address of said mobile host.

13. The system of claim 12, the link established by said mobile host with the Internet being a wireless link.

14. The system of claim 13, said mobile host being positioned in the home network and attaching to the Internet through said home agent and said home agent storing a first address to correspond to the domain name before the care-of address is stored to correspond to the domain name, said mobile host being positioned in the foreign network and attaching to the Internet through said foreign agent and said foreign agent sending the registration request message to said home agent after the first address is stored and before the care-of address is stored, the first address corresponding to an identifier of said mobile host when said mobile host is in the home network, the care-of address corresponding to an identifier of said mobile host when said mobile host is in the foreign network, the first address and the care-of address each being associated with the domain name.

15. The system of claim 14, the wireless link being one selected from among a light communication link and a radio communication link.

16. The system of claim 12, said mobile host being positioned in the home network and attaching to the Internet through said home agent and said home agent storing a first address to correspond to the domain name before the care-of address is stored to correspond to the domain name, said mobile host being positioned in the foreign network and attaching to the Internet through said foreign agent and said foreign agent sending the registration request message to said home agent after the first address is stored and before the care-of address is stored, the first address corresponding to an identifier of said mobile host when said mobile host is in the home network, the care-of address corresponding to an identifier of said mobile host when said mobile host is in the foreign network, the first address and the care-of address each being associated with the domain name.

17. The system of claim 16, said home agent and said foreign agent and the correspondent node each corresponding to a respective computer, said mobile host being one selected from among a personal digital assistant, a wearable computer, a notebook computer, and a telephone.

18. The system of claim 17, the caching prevention information being time-to-live set to 0.

19. The system of claim 18, the link established by said mobile host with the Internet being a wireless link.