Method and means for providing enhanced subscriber identity confidentiality during roming in a cellular radio communication system

• US 20040052224A1
• Filed: 10/02/2003
• Published: 03/18/2004
• Est. Priority Date: 10/24/2000
• Status: Abandoned Application

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Arvidsson, Ake, Willgert, Mikael, Niska, Hakan, Laiho, Keijo, Toivanen, Kyosti
• Application Number:
  US10/399,930
• Publication Number:
  US 20040052224A1
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04W 12/02 Protecting privacy or anonymity, e.g. protecting personally identifiable information [PII]
• CPC Class Codes: H04W 8/06 Registration at serving network Location Register, VLR or user mobility server
• CPC Class Codes: H04W 8/12 between location registers or mobility servers

Abstract

The present invention relates to a method and means for roaming in a cellular radio communication system with a pool of core network nodes, e.g. an MSC-pool (201). A Subscriber Identification Service Node (SISN) is used to handle roaming from a service area supported by a previous MSC/VLR (205) in the MSC-pool to a service area supported by a new MSC/VLR (303) arranged outside of the MSC-pool. The SISN (301) receives an identity request from the new MSC/VLR (303) and forwards it to the previous MSC/VLR (205). The SISN receives a response from the previous MSC/VLR and relays it to the new MSC/VLR. This means that the SISN helps the new MSC/VLR (303) to retrieve data from the right MSC/VLR within the MSC-pool (201).

Claims

1. A node in a radio communication system, where said system includes at least a first and a second core network node (203-205) that are arranged in a first pool of core network nodes (201), and where said first pool of core network nodes (201) is arranged to support mobile stations in a first service area (311),

characterised in that said node (301) includes means (501, 502) for acting as said first core network node towards a third core network node (303) arranged outside of said first pool of core network nodes (201) if a first mobile station (312), that is registered in said first core network node (203), roams from said first service area (311) into a second service area (302) supported by said third core network node (303).

2. The node as claimed in claim 1, wherein said node (301) includes means for identifying (501) and communicating (502) with said first core network node (203) and means for identifying (501) and communicating (502) with said third core network node (303).

3. The node as claimed in claim 2, wherein said means for communicating (502) includes means for identifying a core network node identifier in a message which is received from said third core network node (303).

4. The node as claimed in claim 3, wherein said means for identifying (501) includes means for identifying the core network node identifier in a TMSI which is received from said third core network node (303).

5. The node as claimed in claim 3 or 4, wherein said means for identifying (501) includes a CNNI-address table that enables said node to translate a core network node identifier to the correct network address of said first core network node (203).

6. The node as claimed in one of claims 1-5, wherein said node (301) includes means for moving at least parts of the subscriber registrations in a first VLR to a third VLR, where said first VLR is arranged in said first core network node (203) and said third VLR is arranged in said third core network node (303).

7. The node as claimed in one of claims 3-6, wherein said node includes means for supervising the response time of said message and means for triggering a response to said third core network node when said response time has elapsed.

8. The node as claimed in one of claims 1-7, wherein said node (301) includes means for administrating the operation and maintenance of core network node identifiers in said first pool of core network nodes (201).

9. The node as claimed in one of claims 1-8, wherein said node (301) includes means for moving at least parts of the subscriber registrations in a third VLR to a fourth VLR, where both said third VLR and said fourth VLR are arranged in said first pool of core network nodes (201).

10. The node as claimed in one of claims 1-9, wherein said node (301) is arranged in said first pool of core network nodes (201).

11. A core network node characterised in that said core network node includes at least one node (301) as claimed in one of claims 1 to 10 and at least one MSC/VLR or SGSN.

12. A radio communication system characterised in that said system includes at least one node (301) as claimed in one of claims 1 to 10.

13. A method of roaming in a radio communication system where said system includes at least a first and a second core network node (203-205) that are arranged in a first pool of core network nodes (201), wherein said first pool of core network nodes (201) is arranged to support mobile stations in a first service area (311), and where said system also includes a third core network node (303) that is arranged to support mobile stations in a second service area (302), and where a mobile station, that is moving from said first service area (311) into said second service area (302), has made contact (601) with said third core network node, characterised in the following steps:

transmitting (603), from said third core network node (303) to a pre-determined node (301), a request for specific information that are stored in said first core network node (203-205);

obtaining (604-606), in said pre-determined node (301), said specific information from said first core network node (203-205); and

forwarding (607) said specific information in said pre-determined node (301) to said third core network node (303).

14. The method as claimed in claim 13, wherein said step of obtaining (604-606) includes the steps of:

identifying (604) said first core network node,

forwarding (605) said request to said first core network node; and

receiving (606) a response from said first core network node with said specific information.

15. The method as claimed in claim 14, wherein said pre-determined node (301) identifies (604) said first core network node by a core network node identifier.

16. The method as claimed in claim 15, wherein said core network node identifier is included in a TMSI.

17. The method as claimed in claim 15, wherein said core network node identifier is included in a P-TMSI.

18. The method as claimed in one of claims 15-17, wherein said pre-determined node (301) finds the network address to said first core network node (203-205) in a table with the help of said core network node identifier.

19. The method as claimed in one of claims 13-18, wherein said specific information is the IMSI or authentication data.

20. The method as claimed in one of claims 13-19, wherein said third core network node (303) contacts (608) an HLR after said step of forwarding (607).

21. The method as claimed in one of claims 13-20, wherein at least parts of the subscriber information in said first core network node (203) is moved to said third core network node (303).