WO2008116373A1

WO2008116373A1 - A method for processing emergency service

Info

Publication number: WO2008116373A1
Application number: PCT/CN2008/000246
Authority: WO
Inventors: Zhendong Li
Original assignee: Zte Corporation
Priority date: 2007-03-26
Filing date: 2008-01-31
Publication date: 2008-10-02
Also published as: CN101277518A; CN101277518B

Abstract

A method for processing emergency service is disclosed in the present invention, it can process an emergency service initiated by a user while the user is in a visited network and a P-CSCF is in a home network. The method includes: initiating a service request by a user equipment UE when roaming, and informing the UE that the network the UE belonging to being different from the network the P-CSCF belonging to by the home network P-CSCF or home network Serving Call Session Control Function S-CSCF or home network Emergency Call Session Control Function E-CSCF when the Proxy Call Session Control Function P-CSCF serving the UE being in the home network, and triggering the UE re-find the visited network P-CSCF or switching to the circuit switch CS domain, reinitiating the emergency service.

Description

Emergency service processing method

Technical field

The present invention relates to the field of mobile communication technologies, and in particular, to a method for processing user emergency services in an IP Multimedia Subsystem (IMS).

Background technique

Emergency services are required in the IP Multimedia Subsystem (IMS). Standard designation in this area is currently underway in both 3GPP (3rd Generation Partnership Project) and 3GPP2 (3rd Generation Partnership Project 1). Figure 1 shows the architecture of the emergency call in 3GPP2. The network elements that have little to do with the content of the present invention have been omitted.

The premise of the present invention is that the user equipment (UE, User Equipment) uses a single IP (Simple IP).

Since services such as emergency call and location are closely related, and these services must be provided by the local network (ie, the network accessed by the user), and the P-CSCF (Proxy Call Session Control Function) is in the emergency service, it will find and The P-CSCF provides services in the E-CSCF (Emergency Call Session Control Function) of the same network. Therefore, in the figure, there is a basic premise for the system, that is, when the user is roaming, the P-CSCF must visit the network, so that the P-CSCF can find the E-CSCF of the visited network to provide emergency session service, otherwise it will not be able to Provide emergency business support.

However, in the existing IMS network, such a scenario is supported. As shown in FIG. 2, when the user roams, an IP address is assigned to the user, and a gateway PDSN (Packet Data Service Node) or GGSN (Gateway) that establishes the bearer channel is established. The GPRS support node) is on the visited network, but the P-CSCF is on the home network. In this scenario, the P-CSCF that is not visiting the network will not be able to find the E-CSCF of the visited network, which undermines the basic conditions of the emergency service. At this point, the user will not be able to use emergency services. Summary of the invention

The problem to be solved by the present invention is to provide a method for processing an emergency service, which is capable of handling an emergency service initiated by a P-CSCF on a home network while a user is visiting a network. In order to solve the above problem, the present invention provides a method for processing an emergency service, including: initiating an emergency service request when the user equipment UE roams, and when the proxy call session control function P-CSCF serving the UE is in the home network, The home network P-CSCF or the home network service call session control function S-CSCF or the home network emergency call session control function E-CSCF notifies the UE that it is not on the same network as the P-CSCF, triggering the UE to re-find the visited network P -CSCF or switch to the circuit switched CS domain to re-initiate emergency services.

Further, the method further includes the following steps:

(a) a user terminal in the visited network UE initiates an emergency service request to the proxy call session control function P-CSCF serving the UE in the home network;

(b) the UE receives a notification message from the P-CSCF, where the notification message carries information that the P-CSCF serving the UE is not in the visited network where the UE is located;

(c) The UE re-finds a P-CSCF on the visited network, or the UE switches to the circuit switched CS domain to initiate an emergency service.

Further, the emergency service request is an emergency registration.

Further, after receiving the emergency service request sent by the UE, the P-CSCF in the step (a) finds that it is not in the visited network where the UE is located, and sends a notification message to the UE, where the notification message carries the P-CSCF not in the UE. The information in the visited network.

Further, the P-CSCF determines whether the UE is in the same network as itself by using the access network information or the IP address of the UE.

Further, after receiving the emergency service request sent by the UE, the P-CSCF in the step (a) forwards the emergency service request to the serving call session control function S-CSCF of the UE home network, and the S-CSCF receives the After the emergency service request, it is found that the P-CSCF is not in the visited network where the UE is located, and the S-CSCF sends a notification message to the P-CSCF, where the notification message carries information that the P-CSCF is not in the visited network where the UE is located. The P-CSCF forwards the notification message to the UE.

Further, the S-CSCF determines whether the UE is related to the P- by using the access network information of the UE and the network information of the P-CSCF, or by using an IP address of the UE and an address of the P-CSCF. The CSCF is on the same network.

Further, after receiving the emergency service request sent by the UE, the P-CSCF in the step (a) The emergency service request is forwarded to the emergency call session control function E-CSCF of the UE home network, and after receiving the emergency service request, the E-CSCF finds that the P-CSCF is not in the visited network where the UE is located, E-CSCF Sending a notification message to the P-CSCF, where the notification message carries information that the P-CSCF is not in the visited network where the UE is located, and the P-CSCF forwards the notification message to the UE.

Further, the E-CSCF determines whether the UE is related to the P- by using the access network information of the UE and the network information of the P-CSCF, or by using an IP address of the UE and an address of the P-CSCF. The CSCF is on the same network.

Further, the notification message in step (b) is an emergency service request response.

Further, in the step (c), after the visited network re-discovers the P-CSCF, the UE initiates an emergency service request or an IP multimedia subsystem IMS registration request to the P-CSCF.

The present invention proposes a method for processing an emergency service. When a user roams to a visited network, and the P-CSCF is in the home network, the UE is informed by the P-CSCF, the S-CSCF or the E-CSCF, and the requested P-CSCF. The user is not in the same network, and the user UE re-searches the P-CSCF of the visited network or switches to the CS domain to re-initiate the emergency service, thereby solving the problem in the prior art that the UE and the P-CSCF are not in the same network. Business problem. The advantage of the present invention is that the decision point is in the network, the judgment is very simple, and the changes to the system are very small. BRIEF abstract

Figure 1 is a 3GPP2 emergency call architecture diagram;

2 is an example of a P-CSCF and a PDSN/GGSN of a 3GPP2 IMS network belonging to different networks; FIG. 3 is a first embodiment of the present invention, where the P-CSCF discovers that the UE is not in the same network, prompting the user to re-initiate the P-CSCF lookup. ;

4 is a second embodiment of the present invention, the S-CSCF (Serving Call Session Control Function) finds that the UE and the P-CSCF are not in the same network, and prompts the user to re-initiate the P-CSCF search;

FIG. 5 is a third embodiment of the present invention. The E-CSCF finds that the UE and the P-CSCF are not in the same network, and prompts the user to re-initiate the P-CSCF lookup. Preferred embodiment of the invention

The present invention is further described in detail with reference to the accompanying drawings and specific embodiments.

In the following implementation example, the UE (user terminal) is in the visited network, and the P-CSCF of the serving user UE is in the home network, which are two different networks.

First embodiment

3 is an example of a signaling flow of the present invention. When the P-CSCF of the home network receives an emergency service request, it is found that the P-CSCF and the UE are not in the same network. The message processing steps are as follows: Step 110: Initiating an emergency service request by the UE visiting the network, the request may be an emergency registration, or an emergency session establishment;

Step 120: The P-CSCF of the home network receives the emergency service request, and determines that it is not in the visited network where the UE is located, and can be determined by the IP address of the user UE, but is not limited to the IP address of the user UE, for example, Access network information that can pass through the UE;

Step 130: The P-CSCF of the home network sends an emergency service request response to the user UE, where the response message carries information that the P-CSCF is not in the network where the UE is located;

Step 140: After receiving the emergency service request response, the user UE determines that the user and the P-CSCF are not in the same network, and needs to re-discover a new P-CSCF in the visited network.

Step 150: The user UE initiates a new P-CSCF search process on the visited network.

Step 160: The user UE initiates an emergency service request or an IMS registration request to the P-CSCF found in the visited network, and the subsequent steps are consistent with the existing protocol process.

In another embodiment of the present invention, in step 140, after receiving the emergency service request response, the user UE determines that the user and the P-CSCF are not in the same network, and the UE can switch to the circuit switch (CS) domain. The emergency service using the CS domain ends.

The second embodiment usually does not receive an emergency service request from the S-CSCF of the home network, but in some cases In this case, the S-CSCF may also receive. In order to enhance the robustness of the network, this embodiment provides a processing flow when the S-CSCF receives an emergency service request. FIG. 4 shows an example of a signaling procedure of the present invention. When the S-CSCF of the home network receives an emergency service request, it is found that the P-CSCF and the UE are not in the same network. The message processing steps are as follows:

Step 210: Initiating an emergency service request by the UE that visits the network, where the request may be an emergency registration or an emergency session establishment;

Step 220: The P-CSCF of the home network forwards the request to the S-CSCF of the user UE home network;

Step 230: The S-CSCF of the home network receives the emergency service request, and determines that the P-CSCF is not in the visited network where the UE is located, which may be determined by the access network information of the UE and the network information of the P-CSCF. It can also be determined by the IP address of the user UE and the P-CSCF address, but is not limited thereto;

Step 240: The S-CSCF of the home network sends an emergency service request response to the P-CSCF of the home network, where the response carries information that the P-CSCF is not in the visited network where the UE is located;

Step 250: The P-CSCF of the home network forwards the emergency service request response to the user UE. Step 260: After receiving the emergency service request response, the user UE determines that the user and the P-CSCF are not in the same network, and needs to revisit the call. A new P-CSCF is found in the network;

Step 270: The user UE initiates a new P-CSCF search process on the visited network.

Step 280: The user UE initiates an emergency service request or an IMS registration request to the P-CSCF found in the visited network, and the subsequent steps are consistent with the existing protocol process.

In another embodiment of the present invention, in step 260, after receiving the emergency service request response, the user UE determines that the user and the P-CSCF are not in the same network, and the UE can switch to the circuit switch (CS) domain. The emergency service using the CS domain ends.

Third embodiment

Generally, when the home network P-CSCF receives the emergency service request, it finds that it is not in the same network as the requesting UE. The processing flow is as described in the first embodiment, but the P-CSCF cannot be excluded. Therefore, when the P-CSCF fails to make a correct judgment or There is a normal process to send the emergency service request to the E-CSCF. This embodiment provides a processing flow when the E-CSCF receives an emergency service request. FIG. 5 shows an example of a signaling procedure of the present invention. When the E-CSCF of the home network receives an emergency service request, it is found that the P-CSCF and the UE are not in the same network. The message processing steps are as follows:

Step 310: Initiating an emergency service request by the UE that visits the network, where the request may be an emergency registration or an emergency session establishment;

Step 320: The P-CSCF of the home network forwards the request to the E-CSCF of the home network of the user UE;

Step 330: The E-CSCF of the home network receives the emergency service request, and determines that the P-CSCF is not in the visited network where the UE is located, which may be determined by the access network information of the UE and the network information of the P-CSCF. It can be determined by the IP address of the user UE and the P-CSCF address, and is not limited thereto;

Step 340: The E-CSCF of the home network sends an emergency service request response to the P-CSCF, where the answer carries information that the P-CSCF is not in the visited network where the UE is located;

Step 350: The P-CSCF of the home network forwards the emergency service request response to the user UE. Step 360: After receiving the emergency service request response, the user UE determines that the user and the P-CSCF are not in the same network, and needs to re-visit A new P-CSCF is found in the network;

Step 370: The user UE initiates a new P-CSCF search process on the visited network.

Step 380: The user UE initiates an emergency service request or an IMS registration request to the P-CSCF found in the visited network, and the subsequent steps are consistent with the existing protocol process.

In another embodiment of the present invention, in step 360, after receiving the emergency service request response, the user UE determines that the user and the P-CSCF are not in the same network, and the UE can switch to the circuit switch (CS) domain. The emergency service using the CS domain ends.

In all the foregoing embodiments, the P-CSCF or the S-CSCF or the E-CSCF is not limited to using the emergency service request response message to carry information that the P-CSCF is not in the network where the UE is located, or may create a new notification message for notification. The information that the UE does not have the P-CSCF in the network where the UE is located. Of course, the present invention may be embodied in various other various modifications and changes without departing from the spirit and scope of the invention. And modifications are intended to fall within the scope of the appended claims.

Industrial applicability

With the method of the present invention, when the user UE roams to the visited network, and the P-CSCF is in the home network, the UE is notified by the P-CSCF, the S-CSCF or the E-CSCF that it is not on the same network as the requested P-CSCF. The UE is re-searched for the P-CSCF of the visited network or switched to the CS domain, and the emergency service is re-initiated, thereby solving the problem that the UE and the P-CSCF are not in the same network and cannot perform emergency services in the prior art. The invention realizes the single order, and the modification to the system is very small.

Claims

Claim

1. A method for processing an emergency service, characterized in that

When the user equipment UE roams, an emergency service request is initiated, and when the proxy call session control function P-CSCF serving the UE is in the home network, the home network P-CSCF or the home network service call session control function S-CSCF or The home network emergency call session control function E-CSCF notifies the UE that it is not in the same network as the P-CSCF, triggers the UE to re-search the visited network P-CSCF or switches to the circuit-switched CS domain, and re-initiates the emergency service.

2. The method according to claim 1, wherein the method further comprises: (a) the user terminal UE in the visited network initiates an emergency to the proxy call session control function P-CSCF of the home network serving the UE. Business request

(b) the UE receives a notification message from the P-CSCF, where the notification message carries information that the P-CSCF of the UE is not in the visited network where the UE is located;

3. The method of claim 2, wherein the emergency service request is an emergency registration.

The method according to claim 3, wherein, in the step (a), after receiving the emergency service request sent by the UE, the P-CSCF finds that it is not in the visited network where the UE is located, and sends a notification message to The UE, the notification message carries information that the P-CSCF is not in the visited network where the UE is located.

The method according to claim 4, wherein the P-CSCF determines whether the UE is in the same network as itself by using access network information or an IP address of the UE.

The method according to claim 3, wherein, in the step (a), after receiving the emergency service request sent by the UE, the P-CSCF forwards the emergency service request to the serving call session control of the UE home network. Function S-CSCF, after receiving the emergency service request, the S-CSCF sends The P-CSCF is not in the visited network where the UE is located, and the S-CSCF sends a notification message to the P-CSCF, where the notification message carries information that the P-CSCF is not in the visited network where the UE is located, and the P-CSCF will The notification message is forwarded to the UE.

The method according to claim 6, wherein the S-CSCF passes the access network information of the UE and the network information of the P-CSCF, or the IP address of the UE and the

The address of the P-CSCF determines whether the UE is in the same network as the P-CSCF.

The method according to claim 3, wherein in the step (a), after receiving the emergency service request sent by the UE, the P-CSCF forwards the emergency service request to the emergency call session control of the UE home network. The function E-CSCF, after receiving the emergency service request, the E-CSCF finds that the P-CSCF is not in the visited network where the UE is located, and the E-CSCF sends a notification message to the P-CSCF, where the notification message carries the P - The CSCF is not in the visited network where the UE is located, and the P-CSCF forwards the notification message to the UE.

The method according to claim 8, wherein the E-CSCF passes the access network information of the UE and the network information of the P-CSCF, or the IP address of the UE and the P-CSCF. An address, determining whether the UE is in the same network as the P-CSCF.

The method according to any one of claims 2 to 9, wherein the notification message in step (b) is an emergency service request response.

The method according to any one of claims 2 to 9, wherein in the step (c), after the visited network re-discovers the P-CSCF, the UE initiates an emergency to the P-CSCF. Service Request or IP Multimedia Subsystem IMS Registration Request.