SYSTEM AND METHOD FOR ENABLING SESSION CONTEXT CONTINUITY OF LOCAL SERVICE AVAILABILITY IN LOCAL CELLULAR COVERAGE

• US 20110170517A1
• Filed: 01/11/2010
• Published: 07/14/2011
• Est. Priority Date: 01/11/2010
• Status: Active Grant

• Current Assignee: Blackberry Limited
• Original Assignee: Blackberry Limited
• Inventors: Choi, Noun, Bakker, Jan Hendrik Lucas
• Granted Patent: US 8,477,724 B2
• Time in Patent Office: Days
• US Class Current: 370/331
• CPC Class Codes: H04W 36/0027 for a plurality of data sessions of end-to-end connections, e.g. multi-call or multi-bearer end-to-end data connections
• CPC Class Codes: H04W 36/0033 with transfer of context information
• CPC Class Codes: H04W 36/12 Reselecting a serving backbone network switching or routing node
• CPC Class Codes: H04W 36/125 involving different types of service backbones
• CPC Class Codes: H04W 36/385 of the core network
• CPC Class Codes: H04W 48/08 Access restriction or access information delivery, e.g. discovery data delivery signalling during connection H04W76/00
• CPC Class Codes: H04W 76/22 Manipulation of transport tunnels
• CPC Class Codes: H04W 84/045 using private Base Stations, e.g. femto Base Stations, home Node B

Abstract

Local IP Access (LIPA) allows an IP-capable user equipment (UE) connected via a femto cell direct access to other IP-capable devices in the local IP network. Selected IP Traffic Offload (SIPTO) is used to offload selected types of IP traffic towards a defined IP network close to the UE'"'"'s point of attachment to the access network. LIPA PDN Connectivity indicates a PDP Context or a PDN Connection that gives access to services located in the local IP network of the femto cell subsystem. SIPTO PDN Connectivity indicates a PDP Context or PDN Connection that allows offload of selected types of IP traffic towards a defined IP network close to the UE'"'"'s point of attachment to the access network. Systems, devices and methods are described herein that enable the identification of the type of connectivity available to a UE and enable session continuity for local cellular coverage.

Claims

1. A method for use in a mobility management entity of a network in which simultaneous use of multiple serving gateways is supported, the method comprising:

receiving a request for a handover (HO);

sending a request to create a session context to a target serving gateway (S-GW);

receiving a response that includes information to enable creation of the session context;

sending a request to delete a session context of local connectivity with a local serving gateway (LS-GW);

receiving a response that indicates that the session context of local connectivity has been deleted;

sending a request to forward relocation of one or more PDP contexts or PDN connections to be handed over.

2. The method of claim 1 wherein sending a request to create a session context to a target S-GW comprises:

sending a CREATE SESSION REQUEST message.

3. The method of claim 1 wherein receiving a response that includes information to enable creation of the session context comprises:

receiving a CREATE SESSION RESPONSE message.

4. The method of claim 1 wherein sending a request to delete a session context of connectivity to a local packet gateway (LP-GW) comprises:

sending a Delete Session Request message.

7. The method of claim 1 wherein the LS GW is at least one of:

resides in a H(e)NB Subsystem;

has connectivity with at least one LS PW.

8. The method of claim 1 wherein receiving a response that indicates that the current session of local connectivity has been deleted comprises:

receiving a Delete Session Response messages.

20. A mobility management entity (MME) configured to perform the method of claim 1.

5. The method of claim 5 wherein sending a Delete Session Request message comprises:

a cause value and tunnel endpoint identifier (TEID).

6. The method of claim 5 wherein the cause value is set to indicate a session context is a reallocated session context.

9. A computer readable medium in a mobility management entity configured to store thereon a data structure, the data structure comprising one or more of the following entries:

an indication of the connectivity type;

address information for a local serving gateway;

tunnel endpoint identifiers for a local serving gateway;

an address of a local serving gateway for each packet data network (PDN) connection.

10. The computer readable medium of claim 9 wherein the indication of the connectivity type comprises at least one of Local access to IP resources (LIPA), Selected IP Traffic Offload (SIPTO), remote SIPTO (R-SIPTO), local SIPTO (L-SIPTO), H(e)NB SIPTO (H-SIPTO), Remote access to local IP resources, emergency, non-LIPA and non-SIPTO

11. The computer readable medium of claim 9 wherein the address information is one of:

internet protocol (IP) address information;

or

a fully qualified domain name (FQDN).

12. A method comprising:

a source MME providing a target MME context information of at least one user equipment (UE) which has at least one session served by a local serving gateways.

13. The method of claim 12 wherein the context information comprises at least one of:

an indication of the connectivity type;

address information for a local serving gateway;

tunnel endpoint identifiers for a local serving gateway;

an address of a local serving gateway for each packet data network (PDN) connection.

21. A mobility management entity (MME) configured to perform the method of claim 12.

14. A method for reallocation in a mobility management entity of a network in which simultaneous use of multiple serving gateways is supported, the method comprising:

receiving a request for a handover;

determining a connectivity type of a first session context;

responsive to said determination;

sending a request to create a second session context to a target serving gateway (S-GW) that includes the context information;

receiving a response that includes information to enable creation of the second session context;

sending a request to delete a first session context of local connectivity with a local serving gateway (LS-GW);

receiving a response that indicates that the first session context of local connectivity has been deleted.

15. The method of claim 14, wherein the first session context includes information of a session to a LP GW and the second session context includes information of the same session to the same LP GW.

16. The method of claim 14 wherein the target S-GW is already being used for at least one session and sending the request to create a session to the target CN S-GW comprises:

sending a request to create a second session context of a session served by a local serving gateway (LS GW) via the S-GW in addition to a first session context.

17. The method of claim 14, wherein if there is a current session with a current S-GW, which is different from the target S-GW, in addition to the current session with the LS-GW, the method further comprising:

sending a request to delete the current session with the current CN S-GW;

receiving a response that indicates that the current session with the current CN S-GW has been deleted.

22. A mobility management entity (MME) configured to perform the method of claim 14.

18. A method for reallocation in a mobility management entity of a network in which simultaneous use of multiple serving gateways is supported, the method comprising:

receiving a request for a handover;

determining a connectivity type of a third session context;

responsive to said determination;

sending a request to create a second session context to a target local serving gateway (LS-GW);

receiving a response that includes information to enable creation of the second session context;

sending a request to delete a third session context with a core network (CN) serving gateway (S-GW);

receiving a response that indicates that the third session context has been deleted;

the core network (CN) serving gateway maintaining a first session context.

19. The method of claim 18, wherein the third session context includes information of a session to a LP GW and the second session context includes information of the same session to the same LP GW.

23. A mobility management entity (MME) configured to perform the method of claim 18.