System and method for conditionally attempting an emergency call setup

• US 8,315,591 B2
• Filed: 07/01/2011
• Issued: 11/20/2012
• Est. Priority Date: 01/05/2007
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Blackberry Limited
• Inventors: Sokondar, Eniko
• Primary Examiner(s): Hu, Jinsong
• Assistant Examiner(s): Elhag, Magdi
• Application Number:
  US13/175,664
• Publication Number:
  US 20120003954A1
• Time in Patent Office: 508 Days
• Field of Search: 455/404.1, 455/412.2, 455/420
• US Class Current: 455/404.1
• CPC Class Codes: H04L 12/66 Arrangements for connecting between networks having differing types of switching systems, e.g. gateways

Abstract

A system and method are provided for a communications device to conditionally attempt an emergency call setup. The communications device maintains at least one condition for attempting emergency call setups. Upon receiving a message prompting an emergency call setup, the communications device attempts the emergency call setup only if any of the at least one conditions is satisfied. The at least one condition is defined such that the communications device does not erroneously attempt to establish an emergency call when there is no emergency. The at least one condition might for example include whether the message prompting the emergency call setup indicates a message source that is trusted by the user of the mobile device. A system and method are also provided for a communications network to block at least some of the messages from being delivered to their target communications device.

Claims

1. A method performed by a mobile communications device comprising:

maintaining an identification, which was received from a network element, of a trusted source;

receiving a message from a Proxy Call Session Control Function (P-CSCF) prompting an emergency call setup, the message being a response message received in response to a request message from the mobile communications device;

determining whether a message source indicated by the message is the same as the identification of the trusted source; and

attempting the emergency call setup only if the message source indicated by the message is determined to be the same as the identification of the trusted source, wherein the message source indicated by the message is the P-CSCF.

2. The method of claim 1 wherein the message prompting the emergency call setup:

is a 380 alternative service message.

3. The method of claim 1 wherein the request message is a Session Initiation Protocol (SIP) INVITE request.

4. A non-transitory computer readable medium having computer executable instructions stored thereon for execution on a processor so as to implement the method of claim 1.

5. A mobile communications device comprising:

a memory configured to maintain an identification, which was received from a network element, of a trusted source;

a communications subsystem configured to receive a message from a Proxy Call Session Control Function (P-CSCF) prompting an emergency call setup, the message being a response message received in response to a request message from the mobile communications device;

a processor configured to determine whether a message source indicated by the message is the same as the identification of the trusted source,

the processor being further configured to attempt the emergency call setup only if the message source indicated by the message is determined to be the same as the identification of the trusted source, wherein the message source indicated by the message is the P-CSCF.

6. The mobile communications device of claim 5 wherein the communications subsystem is a wireless access radio operable to communicate with a wireless network.

7. A communications network element comprising:

a processor configured to send an identity of a trusted source to a mobile communication device;

the processor being further configured to send, to the mobile communication device, a message from a Proxy Call Session Control Function (P-CSCF) that prompts an emergency call setup by said device, the message being a response message sent in response to a request message received from the mobile communications device,

wherein the message includes an indication of a message source, the indication being usable by the mobile communication device to determine whether the message source is the same as the trusted source, wherein the message source indicated by the message is the P-CSCF.

8. The communications network element of claim 7 wherein the message:

is a 380 alternative service message.

9. The communications network element of claim 8 wherein the processor is further configured to execute the Proxy Call Session Control Function (P-CSCF) for sending the 380 alternative service message.

10. A non-transitory computer readable medium storing instructions which cause execution of a method comprising:

sending an identity of a trusted source to a mobile communication device; and

sending, to the mobile communication device, a message from a Proxy Call Session Control Function (P-CSCF) prompting an emergency call setup by said device, the message being a response message sent in response to a request message received from the mobile communications device,

wherein the message includes an indication of a message source, the indication being usable by the mobile communication device to determine whether the message source is the same as the identity of the trusted source, wherein the identity of the message source indicated by the message is the P-CSCF.

11. The non-transitory computer readable medium of claim 10 wherein the message is a 380 alternative service message.