METHOD AND SYSTEM FOR ESTABLISHING EMERGENCY CALL

• US 20110310774A1
• Filed: 08/29/2011
• Published: 12/22/2011
• Est. Priority Date: 07/21/2006
• Status: Active Grant

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Inventors: Yang, Yanfei
• Granted Patent: US 9,001,835 B2
• Time in Patent Office: Days
• US Class Current: 370/259
• CPC Class Codes: H04L 65/40 Support for services or applications

Abstract

A method for establishing an emergency call includes: if an emergency call request message sent by a User Equipment (UE) contains an Internet Protocol Multimedia Subsystem Public User Identity (IMPU) in a TEL URI format, a Proxy-Call Session Control Function entity (P-CSCF) generates an IMPU in a Session Initiation Protocol (SIP) URI format according to the IMPU in the TEL URI format, sends both IMPUs to a Public Safety Answering Point (PSAP), and receives an emergency callback initiated by the PSAP. The PSAP initiates the emergency callback according to one of the two IMPUs. A system for establishing an emergency call includes a UE, a P-CSCF and a PSAP. The PSAP can always acquire the IMPU in the TEL URI format and the IMPU in the SIP URI format of the UE, and initiate an emergency callback to the UE according to the IMPU in the SIP URI format.

Claims

1. A method for establishing an emergency call, comprising:

receiving, by a Proxy-Call Session Control Function entity (P-CSCF) an emergency call request message;

if the emergency call request message contains an Internet Protocol Multimedia Subsystem Public User Identity (IMPU) in a Telephone Uniform Resource Identifier, (TEL URI), format, generating, by the P-CSCF, an IMPU in a Session Initiation Protocol (SIP) URI format according to the IMPU in the TEL URI format; and

sending, by the P-CSCF, the IMPU in the TEL URI format and the IMPU in the SIP URI format to a Public Safety Answering Point, PSAP.

2. The method of claim 1, wherein the sending, by the P-CSCF, the IMPU in the TEL URI format and the IMPU in the SIP URI format to the PSAP comprises:

sending, by the P-CSCF, the IMPU in the TEL URI format and the IMPU in the SIP URI format to the PSAP through containing the IMPU in the TEL URI format and the IMPU in the SIP URI format in a P-Asserted-Identity header.

3. The method of claim 1, wherein an associated relation between the IMPU in the TEL URI format and the IMPU in the SIP URI format is saved by the P-CSCF during a registration procedure.

4. The method of claim 3, wherein the generating, by the P-CSCF, the IMPU in the SIP URI format according to the IMPU in the TEL URI format, comprises:

searching, by the P-CSCF, in the associated relation saved in the P-CSCF, for the IMPU in the SIP URI format associated with the IMPU in the TEL URI format.

5. The method of claim 1, wherein the P-CSCF saves the SIP URI of an S-CSCF during a registration procedure.

6. The method of claim 5, wherein the generating, by the P-CSCF, the IMPU in the SIP URI format according to the IMPU in the TEL URI format, comprises:

obtaining, by the P-CSCF, the IMPU in the SIP URI format of the UE according to the SIP URI of the S-CSCF and the IMPU in the TEL URI format of the UE.

7. The method of claim 6, wherein the obtaining, by the P-CSCF, the IMPU in the SIP URI format of the UE according to the SIP URI of the S-CSCF and the IMPU in the TEL URI format of the UE, comprises:

obtaining, by the P-CSCF, an E.164 number of the UE according to the IMPU in the TEL URI format of the UE,

obtaining, by the P-CSCF, a home domain name of the UE by parsing the SIP URI of the S-CSCF, and

combining, by the P-CSCF, the E.164 number of the UE with the home domain name of the UE.

8. The method of claim 1, comprising:

receiving, by the P-CSCF, an emergency callback from the PSAP according to the IMPU in the TEL URI format or the IMPU in the SIP URI format.

9. The method of claim 8, wherein the emergency callback initiated by the PSAP, comprises:

if the PSAP is located in a Circuit-Switched, CS, domain, the emergency callback is initiated by the PSAP according to the IMPU in the TEL URI format saved in the PSAP; and

if the PSAP is located in a Packet-Switched, PS, domain, the emergency callback is initiated by the PSAP according to the IMPU in the SIP URI format saved in the PSAP.

10. A system for establishing an emergency call, comprising:

a Proxy-Call Session Control Function, P-CSCF, configured to receive an emergency call request message sent by a User Equipment (UE), the emergency call request message containing an Internet Protocol Multimedia Subsystem Public User Identity, IMPU, of the UE, generate an IMPU in a Session Initiation Protocol (SIP) Uniform Resource Identifier (URI) format, if the IMPU of the UE is in a Telephone Uniform Resource Identifier (TEL URI) format, and send the IMPU in the SIP URI format and the IMPU in the TEL URI format to a Public Safety Answering Point (PSAP); and

the PSAP, configured to initiate an emergency callback to the UE according to one of the IMPU in the SIP URI format and the IMPU in the TEL URI format received from the P-CSCF.

11. The system of claim 10, wherein the P-CSCF is configured to send the IMPU in the SIP URI format and the IMPU in the TEL URI format to the PSAP through containing the IMPU in the TEL URI format and the IMPU in the SIP URI format in a P-Asserted-Identity header.

12. A Proxy-Call Session Control Function (P-CSCF), comprising:

an Internet Protocol Multimedia Subsystem Public User Identity (IMPU) reception and detection module, and an IMPU format conversion module, wherein,

the IMPU reception and detection module is configured to receive an IMPU sent by a User Equipment (UE) and send the IMPU to the IMPU format conversion module if the IMPU is in a Telephone Uniform Resource Identifier (TEL URI) format; and

the IMPU format conversion module is configured to generate an IMPU in a Session Initiation Protocol (SIP) URI format according to the IMPU in the TEL URI format.

13. The P-CSCF of claim 12, wherein the P-CSCF is configured to send the IMPU in the SIP URI format and the IMPU in the TEL URI format to a Public Safety Answering Point (PSAP).

14. The P-CSCF of claim 13, wherein the P-CSCF is configured to send the IMPU in the SIP URI format and the IMPU in the TEL URI format to the PSAP through containing the IMPU in the TEL URI format and the IMPU in the SIP URI format in a P-Asserted-Identity header.