Emergency call handling within IP multimedia system (IMS) networks

Patent metadata

Field	Value
Publication number	US-10305657-B2
Application number	US-201715727405-A
Country	US
Kind code	B2
Filing date	Oct 6, 2017
Priority date	Jun 1, 2016
Publication date	May 28, 2019
Grant date	May 28, 2019

Abstract

Systems and methods are described herein for handling E911 communications within IMS networks, such as Voice over LTE (VoLTE) networks. In some embodiments, the systems and methods, via various communication nodes, handle or otherwise govern emergency calls within the VoLTE network, by sending an INVITE message from a sender node of the VoLTE network to a recipient node of the VoLTE network, and starting a retry timer at the sender node that is specific to handling E911 calls by the VoLTE network.

First claim

What is claimed is:

1. A computer-implementable method, comprising:
sending, in response to receiving a call provisioning request, an INVITE message to at least one recipient node in a telecommunications network;
establishing a standard call retry timer for a generic call placed to the telecommunications network,
wherein the standard call retry timer is associated with an receiving acknowledgement message from the recipient node of the sent INVITE when the sent INVITE message is based on a standard call placed to the telecommunications network; and

setting an E911 call retry timer associated with an E911 call placed to the telecommunications network,
wherein the E911 call retry timer is associated with receiving an acknowledgement message from the recipient node of the sent INVITE message when the sent INVITE message is based on an E911 call placed to the telecommunications network.

2. The computer-implementable method of claim 1 , further comprising sending additional INVITE messages to at least one alternative recipient node in response to determining that acknowledgement messages have not been received from the recipient node within time periods associated with the E911 call retry timer or the standard call retry timer.

3. The computer-implementable method of claim 1 , wherein the method is executed within a proxy call session control function (P-CSCF) node of the telecommunications network, and the recipient node is an emergency call session control function (E-CSCF) node of the telecommunications network, and the E911 call retry timer is specific to handling E911 calls by a P-CSCF/E-CSCF interface.

4. The computer-implementable method of claim 1 , wherein the method is executed within a proxy call session control function (P-CSCF) node of the telecommunications network.

5. The computer-implementable method of claim 1 , wherein the method is executed within an emergency call session control function (E-CSCF) node of the telecommunications network.

6. The computer-implementable method of claim 1 , wherein the method is executed within a media gateway control function (MGCF) node of the telecommunications network.

7. The computer-implementable method of claim 1 , wherein the duration of the 911 call retry timer is configured by an administrator of the telecommunications network.

8. At least one non-transitory, computer-readable medium carrying instructions, which when executed by at least one data processor, performs a method, the method comprising:
sending, in response to receiving a call provisioning request, an INVITE message to at least one recipient node in a telecommunications network;
establishing a standard call retry timer for a generic call placed to the telecommunications network,
wherein the standard call retry timer is associated with an receiving acknowledgement message from the recipient node of the sent INVITE when the sent INVITE message is based on a standard call placed to the telecommunications network; and

setting an E911 call retry timer associated with an E911 call placed to the telecommunications network,
wherein the E911 call retry timer is associated with receiving an acknowledgement message from the recipient node of the sent INVITE message when the sent INVITE message is based on an E911 call placed to the telecommunications network.

9. The non-transitory computer-readable medium of claim 8 , further comprising sending additional INVITE messages to at least one alternative recipient node in response to determining that acknowledgement messages have not been received from the recipient node within time periods associated with the E911 call retry timer or the standard call retry timer.

10. The non-transitory computer-readable medium of claim 8 , wherein the method is executed within a proxy call session control function (P-CSCF) node of the telecommunications network, and the recipient node is an emergency call session control function (E-CSCF) node of the telecommunications network, and the E911 call retry timer is specific to handling E911 calls by a P-CSCF/E-CSCF interface.

11. The non-transitory computer-readable medium of claim 8 , wherein the method is executed within a proxy call session control function (P-CSCF) node of the telecommunications network.

12. The non-transitory computer-readable medium of claim 8 , wherein the method is executed within an emergency call session control function (E-CSCF) node of the telecommunications network.

13. The non-transitory computer-readable medium of claim 8 , wherein the method is executed within a media gateway control function (MGCF) node of the telecommunications network.

14. The non-transitory computer-readable medium of claim 8 , wherein the duration of the 911 call retry timer is configured by an administrator of the telecommunications network.

Assignees

• T Mobile Usa Inc
• T Mobile Usa Inc

Inventors

• Kaul Mayank
• Mufti Shujaur Rehman

Classifications

• H04W76/50

  for emergency connections · CPC title

• H04L65/1069

  Session establishment or de-establishment · CPC title

• H04W76/18

  Management of setup rejection or failure · CPC title

• H04M3/5116

  for emergency applications · CPC title

• H04W4/90

  Services for handling of emergency or hazardous situations, e.g. earthquake and tsunami warning systems [ETWS] · CPC title