PAGING FOR CSFB IN LTE CONNECTED MODE

• US 20130331054A1
• Filed: 05/23/2013
• Published: 12/12/2013
• Est. Priority Date: 06/09/2012
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Kodali, Sree Ram
• Granted Patent: US 9,125,122 B2
• Time in Patent Office: Days
• US Class Current: 455/404.1
• 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 a mobile wireless device, the method comprising:

by the mobile wireless device;

receiving a paging message from a first wireless network;

determining that the paging message includes a first information element uniquely identifying the mobile wireless device;

determining that the paging message includes a second information element indicating that the paging message originates from a second wireless network;

determining that the paging message does not include a third information element indicating the paging message is a public warning system message; and

when an internal state of the mobile wireless device indicates the mobile wireless device is connected to the first wireless network, after receiving the paging message and after determining the paging message includes the first and second information elements and does not include the third information element, disconnecting the mobile wireless device from the first wireless network and establishing a connection of the mobile wireless device to the second wireless network.

2. The method recited in claim 1, wherein the second information element indicates the second wireless network is a circuit switched (CS) network, and the first wireless network is a packet switched (PS) network.

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

4. The method recited in claim 1, wherein the first information element includes a mobile subscriber identity that uniquely identifies the mobile wireless device.

5. 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.

6. 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.

7. The method recited in claim 1, wherein disconnecting the mobile wireless device from the first wireless network comprises releasing a first radio resource control (RRC) connection to the first wireless network locally in the mobile wireless device.

8. The method recited in claim 7, wherein disconnecting the mobile wireless device from the first wireless network further comprises:

establishing a second RRC connection between the mobile wireless device and the first wireless network;

sending an extended service request message to the first wireless network, the extended service request message indicating a positive circuit switched fallback (CSFB) response to the paging message; and

receiving a signaling message from the first wireless network, the signaling message indicating release of the second RRC connection and redirection of the mobile wireless device to the second wireless network.

9. The method recited in claim 1, wherein establishing the connection of the mobile wireless device to the second wireless network comprises:

sending a paging response message to the second wireless network; and

establishing a circuit switched voice connection over the second wireless network.

10. The method recited in claim 1, wherein disconnecting the mobile wireless device from the first wireless network comprises:

sending a first extended service request message to the first wireless network, the first extended service request message indicating a first positive circuit switched fallback (CSFB) response to the paging message;

when receiving a first signaling message from the first wireless network in response to the first extended service request message, the first signaling message redirecting the mobile wireless device to the second wireless network, releasing a first radio resource control (RRC) connection of the mobile wireless device to the first wireless network; and

when not receiving the first signaling message from the first wireless network in response to the first extended service request message,

releasing the first RRC connection of the mobile wireless device to the first wireless network,

establishing a second RRC connection to the first wireless network,

sending a second extended service request message to the first wireless network indicating a second positive CSFB response to the paging message,

receiving a second signaling message from the first wireless network in response to the second extended service request message redirecting the mobile wireless device to the second wireless network, and

in response to receiving the second signaling message, releasing the second RRC connection of the mobile wireless device to the first wireless network.

11. A mobile wireless device comprising:

one or more processors configured to control establishing and releasing connections between the mobile wireless device and a first wireless network and a second wireless network;

one or more transmitters configured to transmit signals to the first wireless network according to a first wireless communication protocol and to the second wireless network according to a second wireless communication protocol; and

one or more receivers configured to receive signals from the first and second wireless networks;

wherein the one or more processors are further configured to;

obtain a paging message received by the one or more receivers from the first wireless network;

determine that the paging message includes a first information element uniquely identifying the mobile wireless device;

determine that the paging message includes a second information element indicating the paging message originates from the second wireless network;

determine that the paging message does not include a third information element indicating that the paging message is a public warning system message; and

disconnect the mobile wireless device from the first wireless network and establish a connection of the mobile wireless device to the second wireless network when (1) an internal state of the mobile wireless device indicates that the mobile wireless device is connected to the first wireless network upon receipt of the paging message and (2) the paging message includes the first and second information elements and does not include the third information element.

12. The mobile wireless device recited in claim 11, wherein the second information element indicates the second wireless network is a circuit switched (CS) network, and the first wireless network is a packet switched (PS) network.

13. The mobile wireless device recited in claim 11, wherein the public warning system message is a commercial mobile alert service (CMAS) message or an earthquake and tsunami warning system (ETWS) message.

14. The mobile wireless device recited in claim 11, wherein the first information element includes a mobile subscriber identity that uniquely identifies the mobile wireless device.

15. The mobile wireless device recited in claim 11, wherein the first wireless communication protocol is a long term evolution (LTE) wireless communication protocol, and the second wireless communication protocol is a non-LTE wireless communication protocol.

16. The mobile wireless device recited in claim 11, 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.

17. The mobile wireless device recited in claim 11, wherein disconnect the mobile wireless device from the first wireless network comprises release a first radio resource (RRC) connection to the first wireless network locally in the mobile wireless device.

18. The mobile wireless device recited in claim 17, wherein the one or more processors are further configured to:

establish a second RRC connection between the mobile wireless device and the first wireless network;

provide to the one or more transmitters an extended service request message to send to the first wireless network, the extended service request message indicating a positive circuit switched fallback (CSFB) response to the paging message; and

obtain a signaling message received by the one or more receivers from the first wireless network, the signaling message indicating release of the second RRC connection and redirection of the mobile wireless device to the second wireless network.

19. The mobile wireless device recited in claim 11, wherein establish the connection of the mobile wireless device to the second wireless network comprises:

provide a paging response message to the one or more transmitters to send to the second wireless network; and

establish a circuit switched voice connection over the second wireless network.

20. The mobile wireless device recited in claim 11, wherein disconnect the mobile wireless device from the first wireless network comprises:

provide a first extended service request message to the one or more transmitters to send to the first wireless network, the first extended service request message indicating a first positive circuit switched fallback (CSFB) response to the paging message;

when a first signaling message is received by the one or more receivers from the first wireless network in response to the first extended service request message, the first signaling message redirecting the mobile wireless device to the second wireless network, release a first radio resource control (RRC) connection of the mobile wireless device to the first wireless network; and

when the one or more receivers do not receive the first signaling message from the first wireless network in response to the first extended service request message,

release the first RRC connection of the mobile wireless device to the first wireless network,

establish a second RRC connection to the first wireless network,

provide to the one or more transmitters a second extended service request message to transmit to the first wireless network, the second extended service request message indicating a second positive CSFB response to the paging message,

obtain from the one or more receivers a second signaling message received from the first wireless network in response to the second extended service request message, the second signaling message redirecting the mobile wireless device to the second wireless network, and

in response to receipt of the second signaling message, releasing the second RRC connection of the mobile wireless device to the first wireless network.

21. A computer program product encoded as computer program code in a non-transitory computer readable medium for responding to paging messages by a mobile wireless device, the computer program product comprising:

computer program code for receiving a paging message from a first wireless network;

computer program code for determining that the paging message includes a first information element uniquely identifying the mobile wireless device;

computer program code for determining that the paging message includes a second information element indicating that the paging message originates from a second wireless network;

computer program code for determining that the paging message does not include a third information element indicating that the paging message is a public warning system message; and

computer program code for, when an internal state of the mobile wireless device indicates that the mobile wireless device is connected to the first wireless network upon receiving the paging message and after executing the computer program code for determining that the paging message includes the first and second information elements and does not include the third information element, disconnecting the mobile wireless device from the first wireless network and establishing a connection of the mobile wireless device to the second wireless network.