Mobile Management for Mobile Hosts

• US 20030228868A1
• Filed: 04/01/2003
• Published: 12/11/2003
• Est. Priority Date: 10/09/2000
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Turanyi, Zoltan, Valko, Andras
• Granted Patent: US 6,990,339 B2
• Time in Patent Office: Days
• US Class Current: 455/432.1
• CPC Class Codes: H04L 61/00 Network arrangements, protocols or services for addressing or naming
• CPC Class Codes: H04L 61/50 Address allocation
• CPC Class Codes: H04W 36/0019 adapted for mobile IP [MIP]
• 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]

Abstract

The present invention relates to a system having a mobile host (1) which can attach to different access networks (3A, 3B) for carrying on an active communications session with a correspondent host (2). The mobile host (1) has an identifier (NAI) which is independent of the access network (3A, 3B) to which the mobile host (1) is attached, but is assigned a communications address(IP Address) for carrying on an active communications session with a correspondent host (2), which address changes for example depending on the access network (3A, 3B) to which the mobile host (1) is attached. The system has a database (UNS User Name Service) which registers the association of the mobile host identifier (NAI) and the current communications address (IP address) of the mobile host (1). The correspondent host (2) is informed of the identifier (NAI) of the mobile host (1) when an active communications session is first established between the mobile host (1) and the correspondent host (2), and the correspondent host (2) accesses the database (UNS) to determine the current communications address of the mobile host (1). In accordance with the present invention, the mobile host (1) is engaged in an active communications session: detects when the communications address (IP address) of the mobile host (1) changes, for example as a result of attachment of the mobile host (1) to a different access network (3A, 3B): and upon detection of such a change of the communications address (IP address), sends a message (HANDOVER MESSAGE) to the recorded correspondent host (2), the message containing the mobile host'"'"'s (1) identifier (NAI). The correspondent host (2) then uses the identifier (NAI) to access the database (UNS) to obtain the changed communications address (IP address) of the mobile host (1). The invention also provides related met hods and mobile hosts.

Claims

1. A system comprising a mobile host (1) which can attach to different access networks (3A, 3B) of the system for carrying on an active communications session with a correspondent host (2) of the system,

the mobile host (1) having an identifier (NAI) which is independent of the access network (3A, 3B) to which the mobile host (1) is attached, and

the mobile host (1) being assigned a communications address (IP Address) for carrying on an active communications session with a correspondent host (2), which communications address (IP address) changes, for example depending on the access network (3A. 3B) to which the mobile host (1) is currently attached, a database (UNS—

User Name Service) of the system registering the association of the mobile host identifier (NAI) and the current communications address (IP address) of the mobile host (1),

the correspondent host (2) being informed of the identifier (NAI) of the mobile host (1) when an active communications session is first established between the mobile host (1) and the correspondent host (2),

the correspondent host (2) accessing the database (UNS) to determine the current communications address of the mobile host (1), for use in communicating with the mobile host (1),

wherein

the mobile host (1) comprises a control unit (1A) which

maintains a record of the correspondent host (2) with which the mobile host (1) is engaged in an active communications session,

detects when the communications address (IP address) of the mobile host (1) changes, for example as a result of attachment of the mobile host (1) to a different access network (3A, 3B), and

upon detection of such a change of the communications address (IP address), sends a message (HANDOVER MESSAGE) to the recorded correspondent host (2), the message containing the mobile host'"'"'s (1) identifier (NAI);

the correspondent host, (2) then using the identifier (NAI) to access the database (UNS) to obtain the changed communications address (IP address) of the mobile host (1), for use in further communicating with the mobile host (1).

2. A system as in claim 1, wherein said message (HANDOVER MESSAGE) also contains the mobile host'"'"'s (1) changed communications address (IP address).

3. A system as claimed in claim 1 or 2, wherein the access networks are wireless access networks, and communications between the mobile host (1) and the correspondent host (2) are carried out via the Internet.

4. A method of maintaining an active communications session of a mobile host (1) with a correspondent host (2), which mobile host can attach to different access networks (3A, 3B) for carrying on a communications session with the correspondent host (2), during migration of the mobile host (1) from one access network to another, the method comprising:

assigning an identifier (NAI) to the mobile host (1), which identifier is independent of the access network (3A, 3B) to which the mobile host (1) is attached, and

assigning a communications address (IP Address) to the mobile host (1), for carrying on an active communications session with the correspondent host (2), which communications address (IP address) changes, for example depending on the access network (3A. 3B) to which the mobile host (1) is currently attached,

registering in a database (UNS—

User Name Service) the association of the mobile host identifier (NAI) and the current communications address (IP address) of the mobile host (1),

informing the correspondent host (2) of the identifier (NAI) of the mobile host (1) when an active communications session is first established between the mobile host (1) and the correspondent host (2), the correspondent host (2) accessing the database (UNS) to determine the current communications address of the mobile host (1), for use in communicating with the mobile host (1),

and the method further comprising

maintaining, in a control unit (1A) of the mobile host (1), a record of the correspondent host (2) with which the mobile host (1) is engaged in an active communications session,

detecting when the communications address (IP address) of the mobile host (1) changes, for example as a result of attachment of the mobile host (1) to a different access network (3A, 3B), and

upon detection of such a change of the communications address (IP address), sending a message (HANDOVER MESSAGE) to the recorded correspondent host (2), the message containing the mobile host'"'"'s (1) identifier (NAI);

the correspondent host (2) then using the identifier (NAI) to access the database (UNS) to obtain the changed communications address (IP address) of the mobile host (1), for use in further communicating with the mobile host (1).

5. A method as in claim 4, comprising sending also the mobile host'"'"'s (1) changed communications address (IP address) in said message (HANDOVER MESSAGE).

6. A method as claimed in claim 4 or 5, wherein wireless access networks are employed as the access networks, and communications between the mobile host (1) and the correspondent host (2) are carried out via the Internet.

7. A mobile host which can attach to different access networks (3A, 3B) for carrying on a communications session with a correspondent host,

the mobile host (1) having an assigned identifier (NAI), which identifier is independent of the access network (3A, 3B) to which the mobile host (1) is attached,

the mobile host (1) having an assigned a communications address (IP Address), for use in carrying on an active communications session with the correspondent host (2), which communications address (IP address) changes, for example depending on the access network (3A. 3B) to which the mobile host (1) is currently attached, and

the mobile host (1) being operable to inform the correspondent host (2) of the identifier (NAI) of the mobile host (1) when an active communications session is first established between the mobile host (1) and the correspondent host (2),

and the mobile host (1) further comprising:

a control unit (1A) operable to store a record of the correspondent host (2) with which the mobile host (1) is engaged in an active communications session,

a detector which is operable to detect when the communications address (IP address) of the mobile host (1) changes, for example as a result of migration of the mobile host (1) from one access network (3A, 3B) to another, and

a sender which is operable, upon detection of such a change of the communications address (IP address), to send a message (HANDOVER MESSAGE) to the correspondent host (2), the message containing the mobile host'"'"'s (1) identifier (NAI).

8. A mobile host as claimed in claim 7, wherein said sender operable to send said message (HANDOVER MESSAGE) is operable to send also the mobile host'"'"'s (1) changed communications address (IP address) in said message.

9. A mobile host as claimed in claim 7 or 8, wherein the mobile host (1) can attach to wireless access networks, as the access networks, and is operable to communicate with the correspondent host (2) via a wireless access network and the Internet.

10. (New) A method for maintaining an active communications session between a mobile host and a correspondent host, said mobile host served by a particular one of a plurality of access networks and capable of moving into a geographical area being served by a different access network and being served by said different access network, said method comprising the steps of:

assigning an identifier to said mobile host wherein said identifier is independent of said access network currently serving said mobile host;

assigning a network address to said mobile host for establishing a communication session with said correspondent host wherein said network address is dependent on said access network currently serving said mobile host and changeable when said mobile host is later served by a different access network;

registering data with a network database wherein said data correlates said assigned identifier with said assigned network address for said mobile host; and

informing said correspondent host of said identifier when an active communication session is first established between said mobile host and said correspondent host;

wherein said network address assigned to said mobile host is accessible by said correspondent host when said identifier is provided by said correspondent host to said network database.

11. (New) The method of claim 10 further comprising the steps of:

storing a second network address identifying said correspondent host within said mobile host, said correspondent host currently maintaining a communication session with said mobile host;

detecting said network address assigned to the mobile host being changed in response to said mobile host being served by a different access network; and

sending a message to said correspondent host indicating the change of said network address wherein said message is identified with said identifier.

12. (New) The method of claim 11 further comprising the step of said mobile host updating said network database with said changed network address.

13. (New) The method of claim 12 further comprising the step of said correspondent host communicating with said network database to obtain the changed network address in response to receiving said message.

14. (New) The method of claim 11 wherein said message further includes the changed network address.

15. (New) The method of claim 11 wherein said correspondent host uses said changed network address to further maintain said communication session with said mobile host in response to receiving said message.

16. (New) A mobile host for maintaining an active communications session with a correspondent host over an packet based telecommunications network wherein said packet based telecommunications network includes a network database, and said mobile host is served by a particular one of a plurality of access networks and capable of moving into a geographical area being served by a different access network and being served by said different access network, said mobile host comprising:

an identifier associated with said mobile host wherein said identifier is independent of said access network currently serving said mobile host;

a network address associated with said mobile host for establishing a communication session with said correspondent host wherein said network address is dependent on said access network currently serving said mobile host and changeable when said mobile host is later served by a different access network;

wherein said mobile host registers data with said network database wherein said data correlates said assigned identifier with said assigned network address for said mobile host; and

means for informing said correspondent host of said identifier when an active communication session is first established between said mobile host and said correspondent host;

wherein said network address assigned to said mobile host is accessible by said correspondent host when said identifier is provided by said correspondent host to said network database.

17. (New) The mobile host of claim 16 further comprising a control unit for storing a second network address identifying said correspondent host, said correspondent host currently maintaining a communication session with said mobile host wherein said control unit detecting said network address assigned to the mobile host being changed in response to said mobile host being served by a different access network and sending a message to said correspondent host indicating the change of said network address wherein said message is identified with said identifier.

18. (New) The mobile host of claim 17 further updating said network database with said changed network address.

19. (New) The mobile host of claim 16 wherein said message further includes the changed network address.

20. (New) A packet based telecommunication network for establishing a communication session between a mobile host capable of being served by a plurality of access networks and a correspondent host, comprising the steps of:

assigning a first identifier to said mobile host wherein said first identifier is independent of said access networks;

assigning a second identifier to said mobile host when said mobile host is being served by a particular one of said access networks wherein said second identifier is dependent on said access network currently serving said mobile host;

storing a record correlating said first identifier with said second identifier within a network database associated with said packet based telecommunication network wherein said network database provides said second identifier in response to a request being received with said first identifier;

communicating a message transmitted by said mobile host informing said correspondent host of said first identifier when an active communication session is first established between said mobile host and said correspondent host; and

informing said correspondent host of said second identifier by said network database in response to said network database receiving a request from said correspondent host wherein said request includes said first identifier.

21. (New) The mobile host of claim 20 further comprising a control unit for storing a network address associated with said correspondent host, said correspondent host currently maintaining a communication session with said mobile host and said control unit further detecting said second identifier being changed to a changed identifier in response to said mobile host being served by a different access network and sending a message to said correspondent host indicating the change of said second identifier wherein said message includes said first identifier.

22. (New) The mobile host of claim 21 further updating the network database with a changed identifier and correlating said changed identifier with the first identifier.

23. (New) The packet based telecommunication network of claim 21 further communicating the changed identifier to said correspondent host in response to receiving a second request from said correspondent host.

24. (New) The mobile host of claim 21 wherein said message further includes said changed identifier.

25. (New) The packet based telecommunication network of claim 21 wherein said correspondent host uses said changed identifier to further maintain said communication session with said mobile host in response to receiving said message.