CN1770687A - Method for confirming service call control function selection starting time - Google Patents

Abstract

The invention discloses a method for determining when to initiate service call control function selection. When the HSS receives a request from I-CSCF to inquire about the registration status of a user with a public user ID, if it is judged that the current registration status of the user is not already Registered status and S-CSCF has been assigned, pre-set the selection S-CSCF conditions in the HSS, if the conditions are met, then send the user's S-CSCF capability information to the I-CSCF, otherwise, the user will be assigned S-CSCF sends to I-CSCF to provide S-CSCF service for the user. The method can prevent invalid S-CSCF selection from being initiated, reduce the load of the Cx interface, and reduce the requirement on the processing capability of the I-CSCF.

Description

A method of determining when to initiate a service call to control feature selection

technical field

The present invention relates to a technique for initiating Serving Call Control Function (S-CSCF) selection in Internet Protocol (IP) Multimedia Subsystem (IMS) domain, and in particular to a method for determining when to initiate S-CSCF selection.

Background technique

With the development of broadband network, mobile communication is not limited to traditional voice communication, and various media services such as audio, video, picture and text will be gradually developed. A variety of media services can meet various needs of users by combining with data services such as presence, short message, webpage (WEB) browsing, location information, push service (PUSH) and file sharing.

Driven by a variety of data service applications, standard organizations such as 3GPP and 3GPP2 have successively launched the IMS architecture, aiming to use a standardized open structure in the mobile network to realize a variety of multimedia service applications and provide users with more Choice and richer feelings.

In the 3GPP version 5 (R5, Release) stage, IMS was introduced. IMS is superimposed on the packet domain network, and consists of call state control function (CSCF), media gateway control function (MGCF), media resource function (MRF) and home subscription Subscriber Server (HSS) and other functional entities, among which CSCF can be divided into three logical entities: S-CSCF, Proxy CSCF (P-CSCF) and Inquiry CSCF (I-CSCF). S-CSCF is the service switching center of IMS, which performs session control, maintains session state, manages user information, generates billing information, etc.; P-CSCF is the access point for terminal users to access IMS, completes user registration, and is responsible for service quality (QoS) control and security management, etc., I-CSCF is responsible for intercommunication between IMS domains, manages the allocation and selection of S-CSCF, hides network topology and configuration from the outside, and generates charging data, etc. The MGCF controls the gateway to realize the intercommunication between the IMS and other networks. MRF provides media resources. The HSS stores subscription data and configuration information of IMS users.

In the IMS, the Session Initiation (SIP) protocol is used as the signaling control protocol of the IP multimedia session; the Diameter protocol is used on the Cx interface between the HSS and the I-CSCF and the HSS and the S-CSCF to exchange information.

IMS can also be applied in packet networks, wireless local area (WLAN) networks or next generation (NGN) networks defined in 3GPP2.

Currently, when a user wants to access the IMS, he must register with the IMS network side using a subscribed public user ID, which is used to identify the user in the IMS network. A user may have one or more subscribed public user identities.

The process when a user registers in the IMS is shown in Figure 1, and the specific steps are:

Step 100, the user initiates a REGISTER message carrying the public user identifier of the user to the I-CSCF.

Step 101. After receiving the message, the I-CSCF sends a query request carrying the public user ID of the user to the HSS to query the current registration status of the user.

Step 102, the HSS determines whether the current registration status of the user is registered, unregistered or deregistered according to the user's public user ID carried in the request.

There are three registration statuses of users: registered status, unregistered status and logout status. The registered state means that the user has actively registered and has been assigned an S-CSCF in the registered state; the unregistered state means that the user has not registered, but was assigned an S-CSCF when it was once the object of access.

Step 103. If the registration status of the user is already registered, the HSS directly returns to the I-CSCF the S-CSCF that provides services for the user.

Step 104: If the user's registration status is unregistered, the HSS returns the user's S-CSCF capability information and the assigned S-CSCF to the I-CSCF, and the I-CSCF decides whether to initiate the user's registration based on the above information. S-CSCF selection;

The user's S-CSCF capability information is obtained from the user's subscription data stored in the HSS.

Step 105, if the user's registration status is deregistered, the HSS returns the user's S-CSCF capability information to the I-CSCF, so that the I-CSCF initiates the user's S-CSCF selection according to the user's S-CSCF capability information .

When the user registers for the first time, since the user registration status stored in the HSS can only be an unregistered status or a logout status, it is sufficient to perform step 104 or step 105 accordingly.

Similarly, when a user is the object to be accessed, the I-CSCF obtains an access request carrying the public user ID of the user, and the I-CSCF sends a query request to the HSS, determines the user according to the public user ID carried in the request, and determines the User's registration status: if it is registered or unregistered, HSS will directly return the saved S-CSCF serving the user to the I-CSCF for use; if it is deregistered, HSS can use the obtained public user Identify, find the subscription data of the user, and return the S-CSCF capability information that meets the most stringent service subscription requirements of the user in the return query request message.

It can be seen from the above description that during the user registration process, if the user’s status saved in the HSS is not registered, the HSS will send the user’s S-CSCF capability information to the I-CSCF, and then make the I-CSCF It is very likely that the CSCF will initiate an invalid S-CSCF selection, which will increase the load on the Cx interface, and at the same time put forward high requirements on the processing capability of the I-CSCF. When the user is the object to be accessed, if the user's registration status saved by the HSS is a logout status, the HSS will directly send the user's S-CSCF capability information to the I-CSCF without performing other effective prevention options. - The measures of the CSCF may also cause the I-CSCF to initiate an invalid S-CSCF selection process, increasing the load of the Cx interface, and at the same time putting forward high requirements on the processing capability of the I-CSCF.

Contents of the invention

In view of this, the main purpose of the present invention is to provide a method for determining when to initiate S-CSCF selection, which can prevent the initiation of invalid S-CSCF selection, reduce the Cx interface load, and reduce the I-CSCF processing capacity. Require.

According to above-mentioned purpose, technical scheme of the present invention is achieved like this:

A method of determining when to initiate a service call control function selection, the method comprising:

A. Inquiry call control function I-CSCF sends an inquiry request carrying a public user identifier to the home subscriber server HSS;

B. The HSS determines the user according to the public user identification carried in the request, and judges whether the user's current registration status is registered according to the stored user configuration information, and if so, controls the stored service call for the user Function S-CSCF sends to I-CSCF; otherwise, execute step C;

C. The HSS judges whether the S-CSCF assigned to the user is stored, and if yes, execute step D; otherwise, the HSS obtains the S-CSCF capability information that meets the most stringent service subscription requirements of the user from the stored user subscription data Send to I-CSCF for S-CSCF selection.

D. The HSS judges whether the set S-CSCF selection condition is not met, and if so, sends the S-CSCF allocated to the user to the I-CSCF as the S-CSCF serving the user; otherwise, the HSS selects the S-CSCF from the stored The S-CSCF capability information that meets the most stringent service subscription requirements of the user is obtained from the user subscription data and the S-CSCF allocated for the user is sent to the I-CSCF to determine whether to select an S-CSCF. The S-CSCF selection condition set in step D is: the change of the user subscription data stored in the HSS leads to the change of the S-CSCF capability information, or the change of the S-CSCF configuration leads to the change of the S-CSCF capability information.

The HSS sets the selection flag bit for users who meet the conditions for selecting the S-CSCF;

The process of judging whether the set S-CSCF selection condition is not met as described in step D is: judging whether the user has a selection flag, and if so, it meets the S-CSCF selection condition; otherwise, it does not meet the S-CSCF selection condition;

In step D, after the HSS obtains the S-CSCF capability information meeting the subscription requirements of the user and sends it to the I-CSCF for S-CSCF selection, the method further includes: the HSS clears the flag bit set for the user.

If the HSS determines that the current registration status of the user is a logout status, before step C, the method further includes:

C1. Judging whether other public user identifications of the stored user except the public user identification carried by the query request have been registered, if so, sending the stored S-CSCF serving the user with this other public user identification to I - CSCF; otherwise, perform the subsequent process of step C.

The S-CSCF allocated to the user in step C is allocated and stored in the HSS when the user is the access object.

The query request in step A is a registration status query request (Cx-Query or Cx-Select-Pull), or a user location query request (Cx-Location-Query).

A method for determining when to initiate service call control function selection, directly saving the re-selected S-CSCF through HSS local operation and maintenance when the user S-CSCF selection condition is met; the method also includes:

A1. The I-CSCF sends to the HSS a query request carrying the public user identity and the desired S-CSCF identity;

B1. The HSS judges whether the request carries the S-CSCF identifier that is desired to be selected. If so, the HSS determines the user according to the public user identifier carried in the request, and obtains the S that meets the most stringent service subscription requirements of the user from the stored subscription data of the user. - Send the CSCF capability information and the allocated S-CSCF to the I-CSCF to decide whether to select an S-CSCF; otherwise, directly send the stored S-CSCF serving the user to the I-CSCF.

The set S-CSCF selection condition is: the change of the user subscription data stored in the HSS leads to the change of the S-CSCF capability information, or the change of the S-CSCF configuration leads to the change of the S-CSCF capability information.

The query request in step A is a registration status query request (Cx-Query or Cx-Select-Pull), or a user location query request (Cx-Location-Query).

It can be seen from the above solution that when the HSS receives a request from the I-CSCF to query the registration status of a user with a public user ID, if it determines that the current registration status of the user is not registered and the S-CSCF has been assigned, and Instead of directly sending the user's S-CSCF capability information to the I-CSCF as in the prior art, the HSS pre-sets the selection S-CSCF condition, and if the condition is met, then sends the user's S-CSCF to the I-CSCF. CSCF capability information, otherwise, send the S-CSCF allocated to the user to the I-CSCF to provide S-CSCF services for the user. Therefore, since the conditions for selecting the S-CSCF can be set as required, the method provided by the present invention can reduce the number of times to initiate S-CSCF selection, prevent invalid S-CSCF selection from being initiated, reduce the load of the Cx interface, and reduce the processing of the I-CSCF. capability requirements.

Description of drawings

Figure 1 is a flow chart of the process when a user registers in the IMS.

Fig. 2 is a flowchart of determining when to select an S-CSCF when a user registers for the first time in the present invention.

Fig. 3 is a flowchart of determining when to select an S-CSCF during the registration process of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention more clear, the present invention will be further described in detail by citing the following embodiments and referring to the accompanying drawings.

In the present invention, the selection of the S-CSCF occurs in the following situations: 1. When the user registers, if the previously allocated S-CSCF is currently unavailable, the HSS must send the user's S-CSCF capability information to the I-CSCF , for the I-CSCF to choose; 2. When the user registers for the first time, the HSS determines whether the S-CSCF has been allocated when the unregistered user is the access object. If it has been allocated, the HSS needs to determine whether to initiate For the selection of S-CSCF, if necessary, return the capability information required by the I-CSCF to select the S-CSCF and the allocated S-CSCF in the return message of the query request, and save the selected S-CSCF, otherwise , directly assigning the user as the access object to the S-CSCF and sending it to the I-CSCF.

Fig. 2 is the flowchart of determining when to select S-CSCF when the user registers for the first time in the present invention, and its specific steps are:

Step 200, the I-CSCF receives the first registration message carrying the user's public user ID sent by the user;

Step 201, the I-CSCF sends a query request carrying the user's public user ID to the HSS;

Step 202, the HSS determines the user according to the public user identifier of the user carried in the request, and judges whether the user has been allocated an S-CSCF, if yes, executes step 203; otherwise, executes step 204;

Step 203, the HSS judges whether the user meets the conditions for initiating S-CSCF selection, if yes, executes step 206; otherwise, executes step 205;

Step 204. According to the existing technology, the HSS queries the subscription data of the user according to the public user identifier of the user carried in the request, and returns the query request message to carry the S-CSCF capability information that meets the most stringent service subscription requirements of the user. It is used when I-CSCF selects S-CSCF, and saves the selected S-CSCF;

Step 205, the HSS sends the S-CSCF allocated by the user to the I-CSCF in the message returning the query request;

Step 206: According to the prior art, the HSS queries the user's subscription data according to the user's public user ID carried in the request, and returns the query request message to carry the S-CSCF capability information and For the S-CSCF that has been allocated, the I-CSCF decides whether to initiate S-CSCF selection for the user according to the above information.

When is the S-CSCF selection performed when the user is in the registration process except for the first registration, or when the user is accessed as an access object? As shown in Figure 3, Figure 3 is a flowchart of determining when to select an S-CSCF in the registration process of the present invention, and its specific steps are:

Step 300, the I-CSCF receives a registration message (REGESITE) initiated by the user or a message (INVITE) to visit the user, sends a query request carrying the public user ID of the user to the HSS, and queries the current registration status of the user;

Step 301, the HSS determines the user according to the public user identifier of the user carried in the request, and judges whether the current registration status of the user is registered, unregistered or deregistered;

Step 302, if the registration status of the user is registered, proceed according to the prior art, that is, the HSS directly returns to the I-CSCF the S-CSCF that provides services for the user;

Step 303, if the registration status of the user is unregistered status, then the HSS judges whether the condition for initiating S-CSCF selection is met, and if yes, executes step 304; otherwise, executes step 305;

Step 304, according to the existing technology, the HSS queries the subscription data of the user according to the public user identifier of the user carried in the query request, and returns the query request message carrying the S-CSCF capability set that meets the most stringent service subscription requirements of the user The information and the allocated S-CSCF are sent to the I-CSCF for use when the I-CSCF decides whether to select the S-CSCF;

Step 305, the HSS sends the S-CSCF allocated by the user to the I-CSCF in the message returning the query request;

Step 306, if the registration status of the user is a logout status, then the HSS judges the registration status corresponding to other public user IDs stored by the user, if it is an unregistered status, perform step 309; if it is a registered status, perform step 306 308; If it is in the logout state, execute step 307;

Step 307, the HSS queries the user's subscription data according to the user's public user ID carried in the query request, and returns the query request message to carry the S-CSCF capability information that meets the user's most stringent service subscription requirements for the I-CSCF Used when selecting S-CSCF, and save the selected S-CSCF;

Step 308, the HSS sends the S-CSCF assigned to other public user identities owned by the user to the I-CSCF in the message returning the query request;

Step 309 , the HSS judges whether the condition for initiating S-CSCF selection is met according to the other public user identifier, and if yes, executes step 304 ; otherwise, executes step 308 .

In Figure 2 and Figure 3, the selection condition of the initiating S-CSCF can be configured in the HSS by the operator during specific networking. The selection condition of the initiating S-CSCF can be: when the user subscription data stored in the HSS changes , resulting in the change of the S-CSCF capability information selected according to the user subscription data, then the HSS considers that the condition for initiating S-CSCF selection is met; when the configuration of the S-CSCF changes and the original S-CSCF support capability is not the updated S-CSCF A subset of supporting capabilities, then the HSS considers that the conditions for initiating S-CSCF selection are met. Similar conditions can also be added according to the operator's network configuration and operation conditions.

The HSS can set the corresponding flag bit when the condition selected by the S-CSCF is met, and when the user receiving the service of the S-CSCF initiates registration, re-registers, or is an unregistered accessed object next time, it will be determined according to the flag bit It is necessary to notify the I-CSCF to initiate the S-CSCF selection process. After the selected S-CSCF is saved in the HSS, clear this flag bit, so as to ensure that the S-CSCF currently serving the user must be able to satisfy all the subscription data of the user. S-CSCF required.

In addition to using the above method to determine when to perform the S-CSCF selection process, the present invention can also allow the operator to determine when to perform the S-CSCF selection process. This process is: when the settings in the HSS change, such as user subscription data updates, or S-CSCF configuration upgrades, etc., resulting in the need to re-select a service S-CSCF for the user, the HSS can directly Make changes in the local database. When the I-CSCF queries the HSS for the S-CSCF currently serving the user next time, the obtained S-CSCF can directly meet the contract service requirements, so no subsequent S-CSCF selection process is required.

When the operator decides when to select the S-CSCF, the HSS only selects the S-CSCF when the I-CSCF requests it, that is, the I-CSCF registers the status inquiry request (Cx-Query or Cx-Select- Pull), or the user location query request (Cx-Location-Query) carries the desired S-CSCF identifier, and the HSS returns the S-CSCF capability information and the allocated S-CSCF for the I-CSCF to decide whether to perform S-CSCF choose. Otherwise, after receiving the query request from the I-CSCF, the HSS judges whether the user has been allocated an S-CSCF. If not, the HSS returns the S-CSCF capability information that meets the most stringent subscription requirements of the user to the I-CSCF, otherwise , without judging whether the condition for initiating S-CSCF selection is met, and directly returns the saved S-CSCF in the registered state to the I-CSCF.

The present invention realizes that the HSS notifies the I-CSCF to initiate the S-CSCF selection only when the condition for initiating the S-CSCF selection set by the operator is met, by determining the real timing for initiating the S-CSCF selection, thereby avoiding the transmission of a large number of S-CSCFs on the Cx interface. Redundant information causes a burden on equipment and wastes processing power.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the scope of the present invention. within the scope of protection.

Claims (9)

1, a kind of determining when initiated the method that serving-call session control function is selected, and it is characterized in that this method comprises:

A, query call controlled function I-CSCF send the query requests of carrying public user identity to home signature user server HSS;

B, HSS determine the user according to the public user identity that this request is carried, judge according to this user configuration information of being stored whether the current login state of this user is registered state, if the serving-call session control function S-CSCF for this user's service that is stored is sent to I-CSCF; Otherwise, execution in step C;

C, HSS judge whether to have stored the S-CSCF that distributes for this user, if, execution in step D; Otherwise HSS obtains from this user contracting data of being stored and meets S-CSCF ability information that the strictest service contracting of this user requires and send to I-CSCF and carry out S-CSCF and select.

D, HSS judge whether not satisfy the S-CSCF alternative condition that is provided with, if then will send to I-CSCF as the S-CSCF that gives this user's service for the S-CSCF that this user distributes; Otherwise HSS obtains from this user contracting data of being stored and meets the S-CSCF ability information that the strictest service contracting of this user requires and send to I-CSCF the S-CSCF that distributes for this user, and whether decision carries out S-CSCF is selected.

2, the method for claim 1, it is characterized in that the S-CSCF alternative condition of the described setting of step D is: the user contracting data change that HSS stored causes the S-CSCF ability information to change or the S-CSCF configuration change causes the S-CSCF ability information to change.

3, the method for claim 1 is characterized in that, HSS gives to satisfy and selects the user of S-CSCF condition that the selection marker position is set;

Step D is described to judge whether that not satisfying the S-CSCF alternative condition process that is provided with is: judge whether this user has the selection marker position, if having, then meet the S-CSCF alternative condition; Otherwise, then do not meet the S-CSCF alternative condition;

The described HSS of step D obtains and meets the signatory S-CSCF ability information that requires of this user and send to I-CSCF and carry out after S-CSCF selects, and this method also comprises: HSS removes the flag bit that is provided with to this user.

4, the method for claim 1 is characterized in that, if HSS judges that when the current login state of this user was exit state, before step C, this method also comprised:

C1, judge whether other public user identity of this user's that stores the public user identity that carries except query requests has been registered, if the S-CSCF that this user for having these other public user identity who is stored is served sends to I-CSCF; Otherwise, the subsequent process of execution in step C.

5, the method for claim 1 is characterized in that, the described S-CSCF that distributes for this user of step C distributes during as access object and is stored among the HSS this user.

6, the method for claim 1 is characterized in that, the described query requests of steps A is login state query requests (Cx-Query or Cx-Select-Pull) or customer location query requests (Cx-Location-Query).

7, a kind of determining when initiated the method that serving-call session control function is selected, and it is characterized in that, the mode of directly safeguarding by the HSS local operation when satisfying this user S-CSCF alternative condition is preserved the S-CSCF that reselects; This method also comprises:

A1, I-CSCF send the query requests of carrying public user identity and wishing to select the S-CSCF sign to HSS;

B1, HSS judge whether this request is carried hope and selected the S-CSCF sign, if, HSS determines the user according to the public user identity that this request is carried, obtain from this user contracting data of being stored and meet the S-CSCF ability information that the strictest service contracting of this user requires and the S-CSCF that has distributed sends to I-CSCF, whether decision carries out S-CSCF is selected; Otherwise, directly the S-CSCF for this user's service that is stored is sent to I-CSCF.

8, method as claimed in claim 7 is characterized in that, the S-CSCF alternative condition of described setting is: the user contracting data change that HSS stored causes the S-CSCF ability information to change or the S-CSCF configuration change causes the S-CSCF ability information to change.

9, method as claimed in claim 7 is characterized in that, the described query requests of steps A is login state query requests (Cx-Query or Cx-Select-Pull) or customer location query requests (Cx-Location-Query).

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