METHODS AND APPARATUS FOR CONTROLLING CIRCUIT SWITCHED FALL BACK OF A MOBILE STATION FROM E-UTRAN TO UTRAN/GERAN IN A FULL-MULTI-OPERATOR CORE NETWORK

• US 20130163560A1
• Filed: 12/12/2012
• Published: 06/27/2013
• Est. Priority Date: 12/21/2011
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Diachina, John Walter, Schliwa-Bertling, Paul, Molander, Anders
• Granted Patent: US 9,148,824 B2
• Time in Patent Office: Days
• US Class Current: 370/331
• CPC Class Codes: H04W 36/00224 between packet switched [PS] and circuit switched [CS] network technologies, e.g. circuit switched fallback [CSFB]

Abstract

Packet Switched (PS) handover based Circuit Switched Fall Back (CSFB) of a mobile station is controlled from an Evolved Universal Terrestrial Radio Access Network (E-UTRAN) cell to a target Universal Terrestrial Radio Access Network (UTRAN) cell or a target GSM EDGE Radio Access Network (GERAN) cell in a PS domain. A network node receives a handover request from a SGSN. A PLMN ID associated with the SGSN is identified. A set of PLMN IDs transmitted as system information by the target UTRAN cell or the target GERAN cell is identified. A PLMN ID index is generated to indicate an association between the PLMN ID associated with the SGSN and one of the PLMN IDs of the set. The PLMN ID index is communicated toward the mobile station for use during PS handover based CSFB. The mobile station embeds the PLMN ID index in a Location Area Update (LAU) message, and transmits the LAU message to a target BSS/RNS of the GERAN/UTRAN cell for use during the PS handover based CSFB.

Claims

1. A method in a radio telecommunications network for controlling Packet Switched (PS) handover based Circuit Switched Fall Back, CSFB, of a mobile station from an Evolved Universal Terrestrial Radio Access Network, E-UTRAN, serving cell to a target Universal Terrestrial Radio Access Network, UTRAN, cell or a target GSM EDGE Radio Access Network, GERAN, cell in a PS domain, the method comprising the steps of:

receiving a handover request from a Serving GPRS Support Node, SGSN;

identifying a Public Land Mobile Network, PLMN, ID associated with the SGSN responsive to the handover request;

identifying a set of a plurality of PLMN IDs transmitted as system information by the target UTRAN cell or the target GERAN cell;

generating a PLMN ID index that indicates an association between the PLMN ID associated with the SGSN and one of the PLMN IDs of the set; and

communicating the PLMN ID index in a handover command sent to the mobile station during the PS handover based CSFB.

2. The method of claim 1, further comprising the steps of:

receiving a Location Area. Update, LAU, message from the mobile station, the LAU message containing the PLMN ID index; and

selecting a MSC responsive to the PLMN ID index.

3. The method of claim 2, further comprising the step of:

identifying the PLMN ID index from a skip indicator information element of the LAU message.

4. The method of claim 2, wherein the step of selecting a MSC responsive to the PLMN ID index, comprises the step of:

selecting one of the PLMN IDs transmitted as system information by the target UTRAN cell or the target GERAN cell responsive to the PLMN ID index of the LAU message.

5. The method of claim 2, further comprising the step of:

forwarding the LAU message to a Mobile Switching Centre, MSC, that corresponds to the PLMN ID index of the LAU message.

6. The method of claim 1, wherein the handover request is a Packet Switched, PS, handover request.

7. The method of claim 1, wherein:

the set of the PLMN IDs comprises an ordered list of PLMN IDs; and

the step of generating a PLMN ID index that indicates an association between the PLMN ID associated with the SGSN and one of the PLMN IDs of the set, comprises the step of generating the PLMN ID index in response to the location of the PLMN ID associated with the SGSN in the ordered list of PLMN IDs.

8. The method of claim 1, wherein the set of the PLMN IDs comprises PLMN IDs of a plurality of different operators of a FULL-Multi-Operator Core Network, FULL-MOCN.

9. The method of claim 1, wherein the step of communicating the PLMN ID index toward the mobile station for use during the PS handover based CSFB comprises the steps of:

embedding the PLMN ID index as an information element in a handover command message; and

communicating the handover command message toward the mobile station.

10. The method of claim 9, wherein the step of embedding the PLMN ID index as an information element in a handover command message comprises the step of:

embedding the PLMN ID index in a Target BSS to Source BSS Transparent Container carried within the handover command message.

11. The method of claim 1, wherein the radio telecommunications network comprises a Base Station Subsystem, BSS, or a Radio Network Subsystem, RNS.

21. The network node of claim 1, wherein:

the set of the PLMN IDs comprises an ordered list of PLMN IDs; and

the operations further comprise generating the PLMN ID index in response to the location of the PLMN ID associated with the SGSN in the ordered list of PLMN IDs.

22. The network node of claim 1, wherein the operations further comprise:

embedding the PLMN ID index in a Target BSS to Source BSS Transparent Container carried within the handover command message; and

communicating the handover command message toward the mobile station.

23. The network node of claim 1, further comprising circuitry of a Base Station Subsystem, BSS, or a Radio Network Subsystem, RNS.

12. A method by a mobile station for controlling Packet Switched (PS) handover based Circuit Switched Fall Back, CSFB, of the mobile station from a Evolved Universal Terrestrial Radio Access Network, E-UTRAN, serving cell to a target Universal Terrestrial Radio Access Network, UTRAN, cell or a target GSM EDGE Radio Access Network, GERAN, cell in a PS domain, the method comprising the steps of:

transmitting an extended service request message to an eNodeB of the E-UTRAN serving cell;

receiving a handover command message from the eNodeB of the E-UTRAN serving cell responsive to the extended service request message, wherein the handover command contains a PLMN ID index;

embedding the PLMN ID index in a Location Area Update, LAU, message; and

transmitting the LAU message in one of the target UTRAN cell or the target GERAN cell to which the mobile station was directed by the handover command message.

13. The method of claim 12, wherein the PLMN ID index identifies a PLMN ID of one of a plurality of different operators of a FULL-Multi-Operator Core Network, FULL-MOCN.

14. The method of claim 12, wherein the step of receiving the handover command message from the E-UTRAN serving cell comprises the step of:

extracting the PLMN ID index from a Target BSS to Source BSS Transparent Container carried within the handover command message.

15. The method of claim 12, wherein the step of embedding the PLMN ID index in a Location Area Update, LAU, message comprises the step of:

embedding the PLMN ID index in a skip indicator information element of the LAU message.

16. A network node for controlling Packet Switched (PS) handover based Circuit Switched Fall Back, CSFB, of a mobile station from an Evolved Universal Terrestrial Radio Access Network, E-UTRAN, serving cell to a target Universal Terrestrial Radio Access Network, UTRAN, cell or a target GSM EDGE Radio Access Network, GERAN, cell in a PS domain, the network node comprising:

at least one processor; and

at least one memory coupled to the at least one processor and comprising computer readable program code that when executed by the at least one processor causes the at least one processor to perform operations comprising;

receiving a handover request from a Serving GPRS Support Node, SGSN;

identifying a Public Land Mobile Network, PLMN, ID associated with the SGSN responsive to the handover request;

identifying a set of a plurality of PLMN IDs transmitted as system information by the target UTRAN cell or the target GERAN cell;

generating a PLMN ID index that indicates an association between the PLMN ID associated with the SGSN and one of the PLMN IDs of the set; and

communicating the PLMN ID index toward the mobile station for use during the PS handover based CSFB.

17. The network node of claim 16, wherein the operations further comprise:

receiving a Location Area Update, LAU, message from the mobile station, the LAU message containing the PLMN ID index; and

selecting a MSC responsive to the PLMN ID index.

18. The network node of claim 17, wherein the operations further comprise:

identifying the PLMN ID index from a skip indicator information element of the LAU message.

19. The network node of claim 17, wherein the operations further comprise:

selecting one of the PLMN IDs transmitted as system information by the target UTRAN cell or the target GERAN cell responsive to the PLMN ID index of the LAU message.

20. The network node of claim 17, wherein the operations further comprise:

forwarding the LAU message to a Mobile Switching Centre, MSC, that is identified by the PLMN ID index of the LAU message.

24. A mobile station for controlling Packet Switched (PS) handover based Circuit Switched Fall Back, CSFB, of the mobile station from an Evolved Universal Terrestrial Radio Access Network, E-UTRAN, cell to a target Universal Terrestrial Radio Access Network, UTRAN, cell or a target GSM EDGE Radio Access Network, GERAN, cell in a PS domain, the mobile station comprising:

at least one processor; and

at least one memory coupled to the at least one processor and comprising computer readable program code that when executed by the at least one processor causes the at least one processor to perform operations comprising;

transmitting an extended service request message to an eNodeB of the E-UTRAN serving cell;

receiving a handover command message from the eNodeB of the E-UTRAN serving cell responsive to the extended service request message, wherein the handover command contains a PLMN ID index;

embedding the PLMN ID index in a Location Area Update, LAU, message; and

transmitting the LAU message in one of the UTRAN cell or the GERAN cell to which the mobile station was directed by the handover command message.

25. The mobile station of claim 24, wherein the operations further comprise:

extracting the PLMN ID index from a Target BSS to Source BSS Transparent Container carried within the handover command message; and

embedding the PLMN ID index in a skip indicator information element of the LAU message.