Emergency calls for internet protocol multimedia subsystem (IMS) over packet switched code division multiple access (CDMA) networks

• US 8,315,589 B2
• Filed: 09/30/2009
• Issued: 11/20/2012
• Est. Priority Date: 09/30/2009
• Status: Active Grant

• Current Assignee: Verizon Patent and Licensing Incorporated (Verizon Communications Inc.)
• Original Assignee: Verizon Patent and Licensing Incorporated (Verizon Communications Inc.)
• Inventors: Li, Mingxing S, Ritter, Phillip A
• Primary Examiner(s): Bost, Dwayne
• Assistant Examiner(s): STERNBANE, LAURENCE J
• Application Number:
  US12/571,063
• Publication Number:
  US 20110076982A1
• Time in Patent Office: 1,147 Days
• Field of Search: 455/404.1, 455/552.1, 455/412.2, 455/445
• US Class Current: 455/404.1
• CPC Class Codes: H04L 65/1016 IP multimedia subsystem [IMS]
• CPC Class Codes: H04M 2242/04 for emergency applications
• CPC Class Codes: H04W 36/0022 for transferring data sessions between adjacent core network technologies
• CPC Class Codes: H04W 36/00226 wherein the core network technologies comprise IP multimedia system [IMS], e.g. single radio voice call continuity [SRVCC]
• CPC Class Codes: H04W 4/90 Services for handling of emergency or hazardous situations, e.g. earthquake and tsunami warning systems [ETWS]
• CPC Class Codes: H04W 48/18 Selecting a network or a communication service
• CPC Class Codes: H04W 76/50 for emergency connections

Abstract

A mobile communication device receives initiation of an emergency call by a user of the mobile communication device, and determines whether a single-carrier radio transmission technology (1xRTT) network is available for the emergency call. The mobile communication device also routes the emergency call over the 1xRTT network when the 1xRTT network is available for the emergency call, and routes the emergency call over an enhanced high rate packet data (eHRPD) network when the 1xRTT network is unavailable for the emergency call.

Claims

1. A method comprising:

receiving, by a mobile communication device, initiation of an emergency call by a user of the mobile communication device;

determining, by the mobile communication device, whether a first type of network is available for the emergency call;

routing, by the mobile communication device, the emergency call over the first type of network when the first type of network is available for the emergency call;

determining, by the mobile communication device, whether the emergency call is connected over the first type of network when the first type of network is available for the emergency call;

connecting, by the mobile communication device, the emergency call to a particular point, via the first type of network, when the emergency call is connected over the first type of network;

providing, by the mobile communication device and when the emergency call is connected over the first type of network, a domain notification short message service (SMS) message, to a particular server of an Internet protocol multimedia subsystem (IMS) network and over the first type of network, indicating that the mobile communication device is connected over the first type of network; and

routing, by the mobile communication device, the emergency call over a second type of network when the first type of network is unavailable for the emergency call.

2. The method of claim 1, where the mobile communication device is dual registered in the first type of network and the second type of network.

3. The method of claim 1, where routing the emergency call over the second type of network comprises:

routing the emergency call over the second type of network and the IMS network.

4. The method of claim 1, further comprising:

determining whether the mobile communication device is registered in the second type of network;

determining whether the mobile communication device is registered in the IMS network; and

using a legacy emergency call routing method to route the emergency call when the mobile communication device is not registered in the second type of network and the IMS network.

5. The method of claim 1, where, when the emergency call is connected over the first type of network, the method further comprises:

ending the emergency call over the first type of network;

starting an emergency callback mode timer after the emergency call ends; and

remaining in an emergency callback mode for a time period, defined by the emergency callback mode timer, after an end of the emergency call over the first type of network.

6. The method of claim 5, further comprising:

returning to a non-emergency operating mode when the emergency callback mode timer expires or when the user initiates an exit from the emergency callback mode; and

connecting with the second type of network and performing a registration with the IMS network based on returning to the non-emergency operating mode.

7. The method of claim 1, where, when the first type of network is unavailable for the emergency call, the method further comprises:

connecting the emergency call to the particular point via the second type of network and the IMS network.

8. The method of claim 7, further comprising:

ending the emergency call over the second type of network;

starting an emergency callback mode timer after the emergency call ends; and

remaining in an emergency callback mode for a time period, defined by the emergency callback mode timer, after the ending of the emergency call over the second type of network.

9. The method of claim 8, further comprising:

returning to a non-emergency operating mode when the emergency callback mode timer expires or when the user initiates an exit from the emergency callback mode; and

searching for the first type of network based on returning to the non-emergency operating mode.

10. The method of claim 1, where the mobile communication device comprises one or more of:

a radiotelephone,

a personal communications system (PCS) terminal,

a wireless telephone,

a cellular telephone,

a smart phone,

a personal digital assistant (PDA), or

a laptop computer.

11. The method of claim 1, where the first type of network is a single-carrier radio transmission technology (1xRTT) network.

12. The method of claim 11, where the second type of network is an evolved high rate packet data (eHRPD) network.

13. The method of claim 1, where the particular point is a public safety answering point (PSAP).

14. A mobile communication device, comprising:

a memory; and

one or more processors to;

receive initiation of an emergency call by a user of the mobile communication device,

the mobile communication device being dual registered in a first type of network and a second type of network,

determine whether the first type of network is available for the emergency call,

route the emergency call over the first type of network when the first type of network is available for the emergency call,

determine whether the emergency call is connected over the first type of network when the first type of network is available for the emergency call,

connect the emergency call to a particular point, via the first type of network, when the emergency call is connected over the first type of network, and

provide, when the emergency call is connected over the first type of network, a domain notification short message service (SMS) message, to a call delivery application server of an Internet protocol multimedia subsystem (IMS) network and over the first type of network, indicating that the mobile communication device is connected to the first type of network.

15. The mobile communication device of claim 14, where, when the first type of network is unavailable for the emergency call, the one or more processors are further to:

route the emergency call over the second type of network and the IMS network.

16. The mobile communication device of claim 14, where the one or more processors are further to:

complete the emergency call over the first type of network,

start an emergency callback mode timer after completion of the emergency call, and

remain in an emergency callback mode for a time period, defined by the emergency callback mode timer, after an end of the emergency call over the first type of network.

17. The mobile communication device of claim 16, where the one or more processors are further to:

return to a non-emergency operating mode when the emergency callback mode timer expires or when the user initiates an exit from the emergency callback mode.

18. The mobile communication device of claim 14, where, when the first type of network is unavailable for the emergency call, the one or more processors are further to:

connect the emergency call to the particular point via the second type of network and the IMS network.

19. The mobile communication device of claim 18, where the one or more processors are further to:

complete the emergency call over the second type of network,

start an emergency callback mode timer after completion of the emergency call, and

remain in an emergency callback mode for a time period, defined by the emergency callback mode timer, after completion of the emergency call over the second type of network.

20. The mobile communication device of claim 19, where the one or more processors are further to:

return to a non-emergency operating mode when the emergency callback mode timer expires or when the user initiates an exit from the emergency callback mode.

21. The mobile communication device of claim 14, where the first type of network includes one or more of:

a base station,

a radio network controller,

a mobile switching center (MSC),

a home location register (HLR), and

a positioning determination entity (PDE).

22. The mobile communication device of claim 14, where the second type of network includes one or more of:

a base station,

a high rate packet data serving gateway (HSGW),

a packet data network gateway (PDN-GW),

a policy and charging rule function (PCRF), and

a home subscriber server front end (HSS-FE).

24. The mobile communication device of claim 14,

where the first type of network is a circuit switched code division multiple access (CDMA) network, and

where the second type of network is a packet switched CDMA network.

23. A non-transitory computer-readable storage medium containing instructions, the instructions comprising:

one or more instructions, executable by at least one processor of a mobile communication device, to receive initiation of an emergency call by a user of the mobile communication device,

the mobile communication device being dual registered in a first type of network and a second type of network;

one or more instructions, executable by the at least one processor, to determine that the first type of network is available for the emergency call;

one or more instructions, executable by the at least one processor, to route the emergency call over the first type of network after determining that the first type of network is available for the emergency call;

one or more instructions, executable by the at least one processor, to determine that the emergency call is connected over the first type of network;

one or more instructions, executable by the at least one processor, to connect the emergency call to a particular point, via the first type of network, after determining that the emergency call is connected over the first type of network; and

one or more instructions, executable by the at least one processor, to provide a domain notification short message service (SMS) message, to a particular server of an Internet protocol multimedia subsystem (IMS) network and over the first type of network, indicating that the mobile communication device is connected over the first type of network.

25. The non-transitory computer-readable storage medium of claim 23,

where the first type of network is a single-carrier radio transmission technology (1xRTT) network, and

where the second type of network is an evolved high rate packet data (eHRPD) network.