Emergency signalling in an IP multimedia subsystem network

Patent metadata

Field	Value
Publication number	US-9560509-B2
Application number	US-201514674685-A
Country	US
Kind code	B2
Filing date	Mar 31, 2015
Priority date	Nov 2, 2009
Publication date	Jan 31, 2017
Grant date	Jan 31, 2017

Abstract

A method and apparatus for handling emergency signalling in an IP Multimedia Subsystem network. A Proxy-Call Session Control Function receives a message requesting set up of a session. The message is associated with an IP Multimedia Private Identity. The P-CSCF determines that the message relates to an emergency call. If an emergency override tag associated with the IMPI is provisioned or set at the P-CSCF, then the message is forwarding the SIP message to a Serving-Call Session Control Function (S-CSCF) for further handling. However, if an emergency override tag associated with the IMPI is not provisioned or set at the P-CSCF, the message is forwarded to an Emergency-Call Session Control Function (E-CSCF). The invention allows the P-CSCF to exercise control over the handling of emergency signalling.

First claim

The invention claimed is:

1. A method of handling emergency signaling in an Internet Protocol (IP) Multimedia Subsystem (IMS) network, the method comprising:
at a Proxy-Call Session Control Function (P-CSCF), receiving a message associated with an IP Multimedia Private Identity, the message requesting a setup of a session;
at the P-CSCF, determining that the message relates to an emergency call;
in an event that an emergency override tag associated with the IP Multimedia Private Identity is provisioned at the P-CSCF, forwarding the message to a Serving-Call Session Control Function (S-CSCF), wherein the S-CSCF handles the message and the emergency call; and
in an event that an emergency override tag associated with the IP Multimedia Private Identity is not provisioned at the P-CSCF, forwarding the message to an Emergency-Call Session Control Function (E-CSCF), wherein the E-CSCF handles the message and the emergency call.

2. The method according to claim 1 , wherein the emergency override tag is provisioned in an event that the IP Multimedia Private Identity is associated with one of a predetermined access network, a predetermined access network type, a predetermined authentication method, and a User Equipment that is not located in a visited network.

3. The method according to claim 1 , further comprising:
prior to receiving the message requesting setup of a session, receiving an emergency override tag for the IP Multimedia Private Identity registered from the S-CSCF in one of a SIP 200 OK message and a SIP NOTIFY message.

4. A Proxy-Call Session Control Function (P-CSCF) node for use in an Internet Protocol (IP) Multimedia Subsystem (IMS) network, the P-CSCF node comprising:
a receiver configured for receiving a message associated with an IP Multimedia Private Identity, the message requesting setup of a session;
at least one microprocessor;
a non-transitory computer-readable storage medium, coupled to the at least one microprocessor, comprising computer-readable instructions, when executed by the at least one microprocessor, are configured for:
determining that the message relates to an emergency call, and
determining if an emergency override tag associated with the IP Multimedia Private Identity is provisioned at the P-CSCF node; and

a transmitter configured for, in an event that an emergency override tag associated with the IP Multimedia Private Identity is provisioned at the P-CSCF, forwarding the message to a Serving-Call Session Control Function (S-CSCF), wherein the S-CSCF handles the message and the emergency call, and in an event that an emergency override tag associated with the IP Multimedia Private Identity is not provisioned at the P-CSCF, forwarding the message to an Emergency-Call Session Control Function (E-CSCF), wherein the E-CSCF handles the message and the emergency call.

5. The P-CSCF node according to claim 4 , wherein the receiver is configured for receiving an emergency override tag for the IP Multimedia Private Identity registered from a S-CSCF in one of a SIP 200 OK message and a SIP NOTIFY message.

Assignees

• Ericsson Telefon Ab L M
• ERICSSON TELEFON AB L M (publ)

Inventors

• Lindholm Fredrik
• Öberg Per

Classifications

• H04L65/1016

  IP multimedia subsystem [IMS] · CPC title

• H04W4/90

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

• H04W76/50

  for emergency connections · CPC title

• H04L65/1073

  Registration or de-registration · CPC title

• H04L65/1069 Primary

  Session establishment or de-establishment · CPC title