Paging for circuit switched fallback (CSFB) in long term evolution (LTE) connected mode

• US 9,578,571 B2
• Filed: 08/31/2015
• Issued: 02/21/2017
• Est. Priority Date: 06/09/2012
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Kodali, Sree Ram
• Primary Examiner(s): TRAN, MONG-THUY THI
• Application Number:
  US14/841,639
• Publication Number:
  US 20160100344A1
• Time in Patent Office: 540 Days
• Field of Search: 455/437, 455/435.2, 455/439, 455/444, 455/448, 370/328, 370/331
• US Class Current: 1/1
• CPC Class Codes: H04W 36/0022 for transferring data sessions between adjacent core network technologies
• CPC Class Codes: H04W 36/14 Reselecting a network or an air interface
• CPC Class Codes: H04W 68/02 Arrangements for increasing efficiency of notification or paging channel
• CPC Class Codes: H04W 68/12 Inter-network notification
• CPC Class Codes: H04W 76/27 Transitions between radio resource control [RRC] states
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Abstract

Methods, apparatuses and computer readable media are described that analyze and communicate signaling messages between a mobile wireless device and a wireless access network to realize a circuit switched fallback (CSFB) procedure when the mobile wireless device is initially in a radio resource control connected mode with the wireless network. A set of information elements of a paging message is analyzed, and based on contents of the set of information elements and an internal state of the mobile wireless device, connections between the mobile wireless device and first and second wireless access networks are changed to realize the CSFB procedure.

Claims

1. A method to respond to paging messages by an apparatus of a mobile wireless device, the method comprising:

by the apparatus of the mobile wireless device;

receiving, from a first wireless network while in a radio resource control (RRC) connected state, a paging message that uniquely identifies the mobile wireless device, originates from a second wireless network, and is not a public warning system message; and

in response to receipt of the paging message while in the RRC connected state;

disconnecting the mobile wireless device from the first wireless network by releasing a first RRC connection to the first wireless network locally in the mobile wireless device by at least changing an internal state of the mobile wireless device from the RRC connected state to an RRC idle state,

establishing a second RRC connection to the first wireless network,

responding to the paging message via the second RRC connection,

and

subsequently establishing a connection of the mobile wireless device to the second wireless network.

2. The method recited in claim 1, wherein responding to the paging message comprises sending an extended service request to the first wireless network indicating a positive circuit-switched fall back (CSFB) response;

and the method further comprises;

receiving, via the second RRC connection, a signaling message from the first wireless network indicating redirection to the second wireless network.

3. The method recited in claim 1, wherein receipt of the paging message while in the RRC connected state indicates a connection state for the mobile wireless device maintained by the first wireless network is an RRC idle state.

4. The method recited in claim 1, wherein the paging message comprises a core network (CN) domain information element (IE) set to a circuit-switched (CS) domain.

5. The method recited in claim 1, wherein the paging message is not a circuit-switched (CS) service notification message for initiating a CS fallback (CSFB) procedure when the mobile wireless device is in the RRC connected state.

6. The method recited in claim 1, wherein the public warning system message comprises a commercial mobile alert service (CMAS) message or an earthquake and tsunami warning system (ETWS) message.

7. The method recited in claim 1, wherein the paging message includes a user equipment (UE) information element (IE) that indicates the paging message is intended for the mobile wireless device.

8. The method recited in claim 1, wherein the first wireless network operates according to a long term evolution (LTE) wireless communication protocol, and the second wireless network operates according to a non-LTE wireless communication protocol.

9. The method recited in claim 1, wherein the paging message includes an indication of an incoming mobile terminated voice call for the mobile wireless device to be completed over the second wireless network.

10. An apparatus comprising:

processing circuitry configurable to control establishing and releasing connections with a first wireless network and a second wireless network;

wireless circuitry configurable to communicate with the first wireless network according to a first wireless communication protocol and the second wireless network according to a second wireless communication protocol;

wherein execution of instructions by the processing circuitry causes the apparatus to;

receive, from the first wireless network, while in a radio resource control (RRC) connected state, a paging message that uniquely identifies a mobile wireless device, originates from the second wireless network, and is not a public warning system message; and

in response to receipt of the paging message while in the RRC connected state;

disconnect from the first wireless network by releasing a first RRC connection to the first wireless network locally in the mobile wireless device by at least changing an internal state of the mobile wireless device from the RRC connected state to an RRC idle state,

establish a second RRC connection to the first wireless network,

respond to the paging message via the second RRC connection,

and

subsequently establish a connection to the second wireless network.

11. The apparatus recited in claim 10, wherein execution of the instructions by the processing circuitry further causes the apparatus to:

respond to the paging message by at least sending an extended service request to the first wireless network indicating a positive circuit-switched fall back (CSFB) response; and

receive a signaling message from the first wireless network indicating redirection to the second wireless network.

12. The apparatus recited in claim 10, wherein receipt of the paging message while in the RRC connected state indicates a connection state for the mobile wireless device maintained by the first wireless network is an RRC idle state.

13. The apparatus recited in claim 10, wherein the paging message comprises a core network (CN) domain information element (IE) set to a circuit-switched (CS) domain.

14. The apparatus recited in claim 10, wherein the paging message is not a circuit-switched (CS) service notification message for initiating a CS fallback (CSFB) procedure when the mobile wireless device is in the RRC connected state.

15. A non-transitory storage device storing computer-executable instructions that, when executed, cause an apparatus to:

receive, from a first wireless network, while in a radio resource control (RRC) connected state, a paging message that uniquely identifies a mobile wireless device, originates from a second wireless network, and is not a public warning system message; and

in response to receipt of the paging message while in the RRC connected state;

disconnect from the first wireless network by releasing a first RRC connection to the first wireless network locally in the mobile wireless device by at least changing an internal state of the mobile wireless device from the RRC connected state to an RRC idle state,

establish a second RRC connection to the first wireless network,

respond to the paging message via the second RRC connection, and

subsequently establish a connection to the second wireless network.

16. The non-transitory storage device recited in claim 15, wherein execution of the computer-executable instructions further causes the apparatus to:

respond to the paging message by at least sending an extended service request to the first wireless network indicating a positive circuit-switched fall back (CSFB) response; and

receive a signaling message from the first wireless network indicating redirection to the second wireless network.

17. The non-transitory storage device recited in claim 15, wherein receipt of the paging message while in the RRC connected state indicates a connection state for the mobile wireless device maintained by the first wireless network is an RRC idle state.

18. The non-transitory storage device recited in claim 15, wherein:

the paging message comprises a core network (CN) domain information element (IE) set to a circuit-switched (CS) domain, and

the paging message is not a circuit-switched (CS) service notification message for initiating a CS fallback (CSFB) procedure when the mobile wireless device is in the RRC connected state.

19. The non-transitory storage device recited in claim 15, wherein the paging message includes a user equipment (UE) information element (IE) that indicates the paging message is intended for the mobile wireless device.

20. The non-transitory storage device recited in claim 15, wherein the paging message includes an indication of an incoming mobile terminated voice call for the mobile wireless device to be completed over the second wireless network.