Handling of user access-dependent information in a core network subsystem

1. A Proxy Call Session Control Function (P-CSCF), for use in a system having a core network subsystem accessed by an IP-connectivity access network, said P-CSCF comprising:

a first sub-entity configured to obtain user access-dependent information from said IP-connectivity access network from AAA signaling sent by an element of said IP-connectivity access network to a server, the AAA signaling being sent to the server in the context of an access network procedure relating to a user terminal, and the element of said IP-connectivity access network functioning as a gateway with the core network subsystem; wherein

the user access-dependent information includes at least one of (i) a current location of the user terminal within the system and (ii) a radio access technology currently being used by the user terminal to access the system.

2. The P-CSCF according to claim 1 , comprising:

a storage device for storing the user access-dependent information obtained from said AAA signaling.

3. The P-CSCF according to claim 1 , wherein the first sub-entity is further configured to signal to another entity, in the context of a core network subsystem procedure relating to the user terminal, user access-dependent information as obtained from said AAA signaling.

4. The P-CSCF according to claim 3 , comprising:

a second sub-entity configured to signal said user access-dependent information obtained from said AAA signaling in addition to user access-dependent information signaled by the user terminal.

5. The P-CSCF according to claim 3 , comprising:

a second sub-entity configured to signal user access-dependent information obtained from said AAA signaling in replacement of user access-dependent information signaled by the user terminal.

6. The P-CSCF according to claim 3 , comprising:

a second sub-entity configured to signal said user access-dependent information obtained from said AAA signaling in addition to node location-dependent information.

7. The P-CSCF according to claim 3 , comprising:

a second sub-entity configured to signal user access-dependent information obtained from said AAA signaling in replacement of node location-dependent information.

8. The P-CSCF according to claim 3 , wherein said signaling between the first sub-entity and the another entity corresponds to SIP (Session Initiation Protocol) signaling.

9. The P-CSCF according to claim 4 , wherein said user access-dependent information signaled by the user terminal corresponds to the content of a “P-Access-Network-Info” SIP header.

10. The P-CSCF according to claim 6 , wherein said node location-dependent information corresponds to the content of a “P-Visited-Network-Id” SIP header.

11. The P-CSCF according to claim 3 , comprising:

a second sub-entity configured for signing said signaled user access-dependent information, by using a signature mechanism indicating that said information has been validated by a trusted entity.

12. The P-CSCF according to claim 5 , wherein said user access-dependent information signaled by the user terminal corresponds to the content of a “P-Access-Network-Info” SIP header.

13. The P-CSCF according to claim 7 , wherein said node location-dependent information corresponds to the content of a “P-Visited-Network-Id” SIP header.

14. One of an Interrogating Call Session Control Function (I-CSCF) and a Serving Call Session Control Function (S-CSCF), for use in a system having a core network subsystem accessed by an IP-connectivity access network, comprising:

a first sub-entity configured to receive user access-dependent information as obtained from said IP-connectivity access network, said information being signaled to said one of I-CSCF and S-CSCF by a Proxy Call Session Control Function (P-CSCF) of said core network subsystem, in the context of a core network subsystem procedure relating to a user terminal, the user access-dependent information being obtained by the P-CSCF from AAA signaling sent from an element of said IP-connectivity access network to a server, the AAA signaling being sent to the server in the context of the access network procedure relating to the user terminal, and said element of said IP-connectivity access network functioning as a gateway with the core network subsystem; wherein

the user-access dependent information includes at least one of (i) a current location of the user terminal within the system and (ii) a radio access technology currently being used by the user terminal to access the system.

15. The one of I-CSCF and S-CSCF according to claim 14 , wherein the one of I-CSCF and S-CSCF is configured to use said received user access-dependent information, for control of service delivery to a user.

16. The one of I-CSCF and S-CSCF according to claim 15 , comprising:

a third sub-entity configured to use said received user access-dependent information, for checking roaming rights for a user.

17. The one of I-CSCF and S-CSCF according to claim 16 , comprising:

a fourth sub-entity configured to signal said received user access-dependent information to an authorization server.

18. The one of I-CSCF and S-CSCF according to claim 17 , comprising:

a fifth sub-entity configured to signal said user access-dependent information in addition to node location-dependent information signaled by said fourth sub-entity.

19. The one of I-CSCF and S-CSCF according to claim 17 , comprising:

a fifth sub-entity configured to signal said user access-dependent information in replacement of node location information signaled by said fourth sub-entity.

20. The one of I-CSCF and S-CSCF according to claim 15 , wherein said node location-dependent information signaled by said fourth sub-entity corresponds to the content of a “P-Visited-Network-Id” SIP header.

21. The one of I-CSCF and S-CSCF according to claim 14 , wherein the first sub-entity is further configured to provide an Application Server (AS) with said received user access-dependent information, in P-Access-Network-Info.