CN1327680C - Method of establishing circuit exchange network to IMS network calling route - Google Patents

Abstract

The present invention discloses an establishing method for a calling route from a circuit switched network to an IMS network. The corresponding relation of tel-URI composed of E. 164 numbers of UE with the SIP-URI of the UE is established in an HSS of an IMS network. The method also comprises the following steps: A, after MGCF in an IMS network receives a calling of an E. 164 number carrying called UE, an SIP message of tel-URI composed of the E. 164 number carrying the called UE is structured and is transmitted to I-CSCF, wherein the calling is initiated by calling UE in a circuit switched network; B, the I-CSCF queries the corresponding relation established by the HSS to obtain the SIP-URI corresponding to the tel-URI composed of the E. 164 number carrying the called UE of the SIP message, and the SIP message is transmitted to the called UE according to the SIP-URI; the called UE and calling UE have SIP conversation negotiation, and the calling is completed. The method provided by the present invention realizes the establishment from a circuit switched network to an IMS network.

Description

A method for establishing call routing from a circuit switching network to an IMS network

technical field

The invention relates to the technology of establishing call routing in Internet Protocol Multimedia Subsystem (IMS) network, in particular to a method for establishing call routing from circuit switching network to IMS network.

Background technique

With the development of broadband networks, mobile communication is not limited to traditional voice communication, but can also combine multiple media services such as audio, video, pictures and text. A variety of media services can meet various needs of user equipment (UE) by combining with data services such as presence, short message, web page (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 UE 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 control function (CSCF), media gateway control function (MGCF), media resource function (MRF) and home subscribers. Server (HSS) and other functional entities. Among them, the CSCF can be further divided into three logical entities: the Serving CSCF (S-CSCF), the Proxy CSCF (P-CSCF) and the Inquiring CSCF (I-CSCF). S-CSCF is the service switching center of IMS, performs session control, maintains session state, is responsible for managing UE information, generates billing information, etc.; P-CSCF is the access point for UE to access IMS, completes UE registration, and is responsible for service quality ( QoS) control and security management, etc.; I-CSCF is responsible for the 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 the UE.

In the IMS, the Session Initiation Protocol (SIP) 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.

The IMS is applied in a packet network, a wireless local area (WLAN) network or a next generation (NGN) network defined in 3GPP2.

When the UE wants to access the IMS, it must use the public user identity to register with the IMS network side. The public user identity is used to identify the UE in the IMS network. The public user identity can use the Uniform Resource Identifier (SIP- URI, Session Initiation Protocol UniformResource Indentifier). A UE may have one or more public user identities.

Figure 1 is a flow chart of call setup signaling from the circuit switching network to the IMS network specified in the IMS network specification. Assuming that the circuit switching network is a public switched telephone network (PSTN), the specific steps are:

In step 100, the PSTN sends an initial address message (IAM) message to the MGCF, and the message carries a relay identifier and destination information that can call the called UE.

Step 101: After receiving the message, the MGCF establishes a connection from the PSTN to the packet switching network via the MGW through the H.248 command on the bearer plane.

Step 102, MGCF constructs a session initiation protocol access (SIP INVITE) request, which includes media description information, and subsequently enters the routing process from S-CSCF to S-CSCF (S-S routing process).

Step 103, the MGCF receives the response (Offer Response) message carrying the media flow capability of the called UE through the S-S routing process, that is, obtains the media flow capability of the called UE on the signaling plane.

In step 104, the MGCF modifies the connection parameters through the H.248 command and instructs the MGW to reserve resources required for the session.

In step 105, the MGCF determines the required media resources for the session, confirms the Offer Response message in step 103, and returns a local reservation status message (Response Conf), that is, a confirmation message of the Offer Response response to the peer.

Step 106. The peer returns a response message (Conf Ack), which is the confirmation message of the Response Conf message.

Step 107, the media gateway (MGW) in the circuit switching network reserves resources.

Step 108: After the resource reservation is completed, the MGCF returns a message (Reservation Conf) of successfully reserving resources to the peer end.

Step 109, the opposite end returns a response message (Reservation Conf) to the MGCF.

Step 110, performing a ringing (Ringing) process on the peer end.

Step 111, the MGCF forwards the Address Complete Message (ACM, AddressComplete Message) to the PSTN network.

Step 112, after the opposite end responds, the MGCF will receive the SIP 200 OK message sent by the called UE as the final response.

In step 113, the MGCF forwards the answer message (ANM, Answer Message) to the PSTN.

Step 114, the MGCF notifies the MGW through the H.248 command that the transmission of the media stream can be started.

Step 115, MGCF returns the confirmation message SIP ACK to SIP 200 OK.

The S-S routing process mentioned here refers to the process of how the S-CSCF routes the SIP message to the called UE in the IMS network, as shown in Figure 2, which is a signaling diagram of the S-S routing process when the call is terminated in the PSTN. Among them, the breakout gateway control function (BGCF, Breakout Gateway Control Function) is the interface between the S-CSCF and the circuit switching network, and the detailed description process can refer to TS 23.228 chapter 5.5.3. Each step in Figure 2 can be connected with the steps described in Figure 1. According to the current IMS specification, the MGCF is regarded as an S-SCSF in the IMS network. Therefore, if the calling UE that initiates the session is For the UE located in the PSTN network, the S-CSCF located in the home IMS network where the called UE is located in Figure 2 is considered to be the MGCF that receives the call from the PSTN network.

In the existing IMS specifications, MGCF is regarded as an MGCF with the same status as S-CSCF in many descriptions and process descriptions. Conversion between commands. However, according to the status and functions of MGCF, MGCF should be more like a P-CSCF rather than an S-CSCF, because there are many functions of the S-CSCF that the MGCF cannot implement, for example, the S-CSCF needs to save the IMS The subscription information of the user is not saved on the MGCF; the routing information addressed to the called UE is saved by the S-CSCF, but not saved on the MGCF. Therefore, from the point of view of signaling routing, the positions of MGCF and S-CSCF are different.

Since the MGCF does not store the subscription information and routing information of the IMS user like the S-CSCF, it cannot directly route from the PSTN to the BGCF or P-CSCF in the IMS network according to the relay identifier and destination information carried in the IAM message shown in Figure 1. Thereby, it is further routed to the called UE, and the call is established.

In order to establish a call, the MGCF must first route to the I-CSCF, and the I-CSCF queries the HSS that has pre-stored the subscription information of the IMS network user, thereby obtaining the routing information of the called UE with the relay identifier and destination information, and then routing to the called UE, but because the MGCF cannot trigger service control and cannot be routed to the I-CSCF, this method cannot be used.

Furthermore, due to the call signaling sent from the circuit switched network, for example, the IAM carried can only be the E.164 number identified in the circuit switched network to indicate the trunk identity and destination information, instead of the E.164 number that can be used in the IMS network. Therefore, even if the MGCF can route to the I-CSCF, it cannot query the routing information of the called UE according to the E.164 number, so that the connection from the circuit switching network to the IMS network The call setup process failed.

From the above analysis, it can be seen that there are misunderstandings in locating MGCF at present. When routing calls from the circuit-switched network in the IMS network, there are the following problems. As a result, the current routing process cannot be realized, and the follow-up Business processing also has an impact.

1. Since the MGCF does not store the subscription information of the IMS network user, it cannot decide to route the call from the circuit switching network to the BGCF or the P-CSCF like the S-CSCF, and further route to the called UE.

2. Since the MGCF cannot route to the I-CSCF to query the subscription information of the called UE, it is further impossible to query the routing information of the called UE based on the E.164 number used to indicate the relay identifier and destination information, so it is impossible to know Which S-CSCF is currently serving the called UE, so the S-CSCF serving the called UE cannot be directly addressed, so that the S-CSCF cannot perform subsequent procedures.

3. It is assumed that the MGCF can route the call from the circuit-switched network to the BGCF or P-CSCF for processing, thereby further routing to the called UE, but this will omit the service control process of the S-CSCF that provides services for the called UE , and the S-CSCF, as a service node in the IMS network, cannot be omitted, otherwise it will cause problems in billing and security.

To sum up, it is currently impossible to establish call routing from the circuit switching network to the IMS network.

Contents of the invention

In view of this, the main purpose of the present invention is to provide a method for establishing a call route from a circuit switching network to an IMS network, which can realize the establishment of a call route from a circuit switching network to an IMS network.

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

A method for establishing call routing from a circuit switching network to an Internet Protocol Multimedia Subsystem (IMS) network, in which a telephone uniform resource identifier tel-URI composed of an E.164 number of a user equipment UE and the telephone uniform resource identifier tel-URI and the The corresponding relationship of the uniform resource identifier SIP-URI used for the session initiation protocol of the UE, the method also includes:

A. After the media gateway control function MGCF in the IMS network receives a call from the calling UE in the circuit switching network carrying the E.164 number of the called UE, it constructs a tel- The Session Initiation Protocol SIP message of the URI is sent to the Inquiring Call Control Function I-CSCF;

B. The I-CSCF queries the corresponding relationship set by the HSS, obtains the SIP-URI corresponding to the tel-URI formed by the E.164 number of the called UE carried in the SIP message, obtains the routing information of the called UE according to the SIP-URI, and transfers the SIP The message is forwarded to the called UE, and the called UE and the calling UE perform a SIP session negotiation process to complete the call.

The process of setting the corresponding relationship is as follows: both the tel-URI and the SIP-URI formed by the E.164 number are saved as different public user identities of the same UE in the IMS network.

The tel-URI formed by the E.164 number is stored in the format of "tel:URI", wherein the URI part is the E.164 number.

The process of constructing the SIP message carrying the tel-URI formed by the E.164 number of the called UE described in step A is as follows: fill in the E.164 number of the called UE in the format of "tel:URI" in the constructed SIP message Request-URI field.

In step B, the I-CSCF inquires about the corresponding relationship set by the HSS through the Cx interface message carrying the tel-URI composed of the called UE's E.164 number.

The method of carrying the E.164 number of the called UE in the Cx interface message is as follows: the E.164 number of the called UE is filled in the public user identification field in the Cx interface message in the format of "tel:URI".

When there is more than one HSS in the IMS network, the corresponding relationship between the tel-URI formed by the E.164 number of the same UE and the HSS is set in the subscription location server SLF governing the HSS. Before step B, the method further includes:

The I-CSCF judges whether the tel-URI composed of the E.164 number of the called UE carried in the SIP message has a corresponding HSS, if yes, obtains the HSS of the stored called UE subscription information, and performs the subsequent process of step B; otherwise, The MGCF constructs an error response message for this call and sends it to the calling UE in the circuit switching network.

The process of sending the SIP message constructed according to the step B to the called UE is:

The I-CSCF queries the routing information of the UE stored in the HSS according to the SIP-URI, obtains the routing information of the called UE with the SIP-URI, determines the S-CSCF that provides services for the called UE, and learns the information of the S-CSCF Routing, sending the constructed SIP message to the S-CSCF;

The S-CSCF sends the SIP message to the called UE according to the routing information corresponding to the called UE.

The process of sending the SIP message to the I-CSCF described in step A is:

Set the I-CSCF address in the MGCF in advance, and the MGCF sends the SIP message to the I-CSCF corresponding to the address according to the set I-CSCF address;

Alternatively, an I-CSCF list is set in the MGCF in advance, and the MGCF selects an I-CSCF from the I-CSCF list according to the set rule, and sends the SIP message to the selected I-CSCF.

The correspondence is the correspondence between the tel-URI formed by the UE's E.164 number and multiple SIP-URIs of the UE.

It can be seen from the above solution that the present invention adds the corresponding relationship between the telephone uniform resource identifier (tel-URI) and the SIP-URI formed by the E.164 number of the same called UE in the HSS of the IMS network. Since the subscription information of the called UE with the SIP-URI has been stored in the HSS in the prior art, the subscription information includes: information about routing to the S-CSCF that provides services for the called UE and information about further routing to the called UE , processing process information and authentication information, etc., so when the MGCF of the IMS network receives the call carrying the E.164 number, it constructs a SIP message carrying the tel-URI composed of the E.164 number and sends it to the I-CSCF; the I-CSCF Obtain the SIP-URI corresponding to the tel-URI composed of the E.164 number carried in the SIP message according to the correspondence stored in advance by the HSS, so as to obtain the S-CSCF serving the called UE and the route to the S-CSCF, and send the SIP The message is sent to the S-CSCF, and the S-CSCF sends the SIP message to the called UE to complete the routing of the local call. Therefore, the method realizes the establishment of call routing from the circuit switching network to the IMS network.

Description of drawings

Figure 1 is a flow chart of call setup signaling from a circuit switched network to an IMS network specified in the IMS network specification;

Fig. 2 is the signaling flowchart of the S-CSCF in the IMS network routing the SIP message to the home IMS network where the called UE is located;

Fig. 3 is the signaling flowchart of the present invention establishing the call routing from the circuit switching network to the IMS network through the I-CSCF;

Fig. 4 is a flow chart of the method for establishing call routing from the circuit switching network to the IMS network according to the present invention.

Detailed ways

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

In order to realize the present invention, firstly, the MGCF must be able to route the call from the circuit-switched network to the I-CSCF, so that the I-CSCF can query the HSS to obtain the subscription information and routing information of the called UE, and the I-CSCF will route the call from the circuit-switched network according to the routing information. The call is routed to the S-CSCF that provides services for the called party, and further routed to the called UE. For the call routing process from the S-CSCF serving the called UE to the network where the called UE is located, refer to the process described in Figure 2. For the call routing process from the network where the called UE is located to the called UE, please refer to TS 23.228 Description of the corresponding chapter.

The present invention can pre-set the address of the I-CSCF in the MGCF, and first route to the I-CSCF with the pre-set I-CSCF address after a call from the circuit switching network comes. In the present invention, an I-CSCF address may not be pre-set in the MGCF, but an I-CSCF list is set, and the MGCF waits until there is a call from the circuit switching network, and selects an I-CSCF address from the I-CSCF list according to the set rules. The I-CSCF sends the SIP message converted by the call to the selected I-CSCF.

Fig. 3 is the signaling flowchart that the present invention establishes the call routing from the circuit switching network to the IMS network through the I-CSCF, and its specific process is:

Step 300: The calling UE in the circuit switching network initiates a call, and the PSTN sends an IAM message to the MGCF in the IMS network.

In step 301, the MGCF establishes a connection with the PSTN on the bearer plane through an H.248 command.

In step 302, the MGCF constructs a SIP INVITE message, and sends the constructed message to the I-CSCF.

The I-CSCF may be an I-CSCF with an I-CSCF address preset by the MGCF, or may be an I-CSCF arbitrarily selected by the MGCF.

Step 303, the I-CSCF sends a location query request (Location Query) to the HSS storing the subscription information of the called UE to obtain the routing information of the called UE.

Step 304, the HSS returns the routing information of the called UE to the I-CSCF.

Step 305, the I-CSCF determines the S-CSCF serving the called UE according to the routing information of the called UE, further determines the route to the called UE, and sends a SIP INVITE message to the S-CSCF serving the called UE.

In steps 306 to 307, the S-CSCF serving the called UE performs service control on the called UE and forwards the SIP INVITE message to the called UE through the next-hop functional entity according to the route to the called UE.

According to the prior art, the functional entity of the next hop of the S-CSCF is related to the terminating network of the current call. When the current call is terminated in the IMS network, the functional entity is the P-CSCF; when the current call is terminated in the PSTN network , the functional entity is BGCF.

Steps 308-310, the called UE sends an Offer Response message to the S-CSCF, and the S-CSCF forwards the Offer Response message to the MGCF through the I-CSCF, and the message indicates the media stream capability of the called UE.

In step 311, the MGCF modifies the connection parameters through the H.248 command and instructs the MGW to reserve resources required for the session.

Steps 312-314, MGCF decides the required media resources for the session, and MGCF sends the S-CSCF to the called UE through the I-CSCF and the S-CSCF serving the called UE according to the determined route to the S-CSCF and further to the called UE. The Response Conf is forwarded to the called UE through the next hop functional entity.

In steps 315-317, the called UE returns a Conf Ack to the MGCF via the S-CSCF and I-CSCF that provide services for the called UE.

Step 318, the MGW reserves resources.

Steps 319-321: After the resource reservation is completed, the MGCF forwards the Reservation Conf to the called UE through the next hop functional entity via the I-CSCF and the S-CSCF serving the called UE.

Steps 322-324, the called UE returns a response message (Reservation Conf) to the MGCF via the S-CSCF and I-CSCF providing services for the called UE.

In steps 325-327, the called UE performs a Ringing process via the S-CSCF and I-CSCF that provide services for the called UE.

Step 328, the MGCF forwards the ACM message to the PSTN network.

Steps 329-331: After the called UE responds, send a SIP 200 OK message to the MGCF via the S-CSCF and I-CSCF that provide services for the called UE.

Step 332, MGCF sends ANM message to PSTN.

In step 333, the MGCF notifies the MGW through the H.248 command that the transmission of the media stream can be started.

In steps 334-336, the MGCF returns an acknowledgment message SIP ACK to the SIP 200 OK via the I-CSCF and the S-CSCF serving the called UE.

In the prior art, the call from the circuit switching network carries the E.164 number used to identify the called UE information and the relay identity. Since the IMS network does not support the E.164 number, the E.164 number must be converted Only the SIP-URI supported by the IMS network can finally query the routing information of the called UE with the SIP-URI in the HSS. Therefore, for the present invention, how to route to the I-CSCF to query the routing information of the called UE and how to convert the E.164 number carried by the call from the circuit switching network to the SIP-URI supported by the IMS network are indispensable. The process of how to convert the E.164 number carried by the call from the circuit switching network into the SIP-URI supported by the IMS network will be described in detail below.

The present invention solves the call from the calling UE in the circuit switching network to the called IMS network by adding the corresponding relationship between the SIP-URI of the same UE in the IMS network and the tel-URI formed by the E.164 number on the HSS in the IMS network. When calling the UE, the SIP message cannot be routed in the IMS network, so that it cannot be routed to the S-CSCF serving the called UE and further routed to the called UE.

In an IMS network, each IMS network-subscribed UE has one or more public user identities, and the one or more public user identities may adopt a SIP-URI or "tel:URI" format. For each IMS network subscribed UE, the HSS saves all subscription information related to the UE, which is used for authentication and service processing. For a UE in an IMS network, it may not only need to communicate with a UE in another IMS network, but may also communicate with a UE in a circuit-switched network. Since the calling UE in the circuit-switching network can only use the E.164 number supported by the circuit-switching network when initiating a call, the UE on the IMS network also needs an E.164 number to communicate with the UE on the circuit-switching network. .164 numbers. The E.164 number may be newly allocated by the IMS network, or may inherit the E.164 number previously used by the UE in the circuit switching network. This E.164 number is written in the form of "tel:URI", such as: tel:+86-10-82882838, and is stored in the HSS as a public user identifier of the UE. At the same time, what is stored in the HSS is also the SIP-URI used by the UE for routing in the IMS network, and the tel-URI formed by the E.164 number of a UE is associated with the SIP-URI.

Fig. 4 is the flow chart of the method for setting up the call routing from the circuit switching network to the IMS network for the present invention, and its specific steps are:

Step 400, the calling UE in the circuit switching network initiates a call carrying an E.164 number, the call is used to call the called UE in the IMS network, and the E.164 number carried in the call is a number indicating the called UE.

Step 401, the call initiated by the calling UE is sent to the MGCF in the IMS network to which the called UE belongs through the circuit switched network, and the MGCF is an interworking gateway between the circuit switched network and the IMS network to which the called UE belongs.

Step 402: After receiving the call, the MGCF in the IMS network to which the called UE belongs constructs a SIP INVITE message according to the prior art, and the message carries a tel-URI composed of an E.164 number indicating the called UE.

The method for constructing the SIP INVITE message is: fill in the Request-URI field of the SIP INVITE message with the E.164 number indicating the called UE according to the "tel:URI" format, and then construct other fields of the SIP INVITE message. The construction methods of these fields are clearly defined in the existing IMS specification TS 23.228, including: setting the header of the Supported field to "100rel", inserting a P-Asserted-Identity header, and generating a unique IMS network The charging identifier is filled in the header of the P-Charging-Vector field, and the parameters identifying the IMS network where the MGCF is located are filled in the header of the P-Charging-Vector header field.

Step 403, the MGCF in the IMS network to which the called UE belongs sends the constructed SIP INVITE message to the I-CSCF in the IMS network to which the called UE belongs.

Step 404: After receiving the SIP INVITE message, the I-CSCF constructs a Cx interface message.

The public user identification field in the constructed Cx interface message is "tel:URI" in the Request-URI field in the SIP INVITE message from the MGCF.

Step 405, the I-CSCF sends a Cx interface message to the HSS to query the S-CSCF currently serving the called UE.

Step 406: After receiving the message, the HSS obtains the SIP-URI corresponding to the tel-URI composed of the E.164 number according to the set correspondence, and obtains the pre-stored subscription information of the called UE with the SIP-URI through query , obtain the S-CSCF that provides services for the called UE with the SIP-URI, and determine the route information to the obtained S-CSCF that provides services for the called UE.

Step 407, the HSS sends the obtained SIP-URI, the S-CSCF serving the called UE with the SIP-URI, the routing information to the called UE, and the subscription information of the called UE to the I-CSCF.

Step 408, the I-CSCF sends the SIP INVITE message to the obtained S-CSCF providing service for the called UE through the obtained routing information.

Step 409, the S-CSCF providing service for the called UE receives the SIP INVITE message, determines the route to the called UE, and sends the message to the called UE.

The processing procedure after the S-CSCF receives the SIP INVITE message is the same as that of the prior art.

Step 410, the calling UE and the called UE perform a SIP session negotiation process to complete the call.

The SIP INVITE provided by the present invention is only an example, and for other SIP messages, the present invention also handles like this.

In the present invention, if the HSS cannot obtain the corresponding SIP-URI according to the tel-URI formed by the E.164 number carried in the Cx interface message sent by the I-CSCF, then the call from the circuit-switched network can be forwarded according to the preset settings of the IMS network. According to the error handling, a call error message is returned to the calling UE in the circuit switching network.

When there are multiple HSSs in the IMS network, the I-CSCF needs to query the Subscription Locator Function (SLF, Subscription Locator Function) in the IMS network first. Correspondingly, the E.164 number of the same called UE is pre-stored in the SLF The corresponding relationship between tel-URI and HSS is completed by constructing the Dx interface message according to the tel-URI composed of the E.164 number, and the result obtained by querying the SLF is the one corresponding to the tel-URI composed of the UE’s E.164 number. The HSS of the called UE-related information, and then the I-CSCF sends a Cx message to the HSS to query the S-CSCF currently serving the UE corresponding to the SIP-URI.

In the present invention, if the SLF cannot obtain the corresponding HSS according to the tel-URI composed of the E.164 number carried in the Dx interface message sent by the I-CSCF, then the call from the circuit switching network can be sent according to the error code according to the preset settings of the IMS network. Processing, returning a call error message to the calling UE in the circuit switching network.

The circuit switching network described in the present invention may be PSTN.

The corresponding relationship in the present invention may be the corresponding relationship between the telephone uniform resource identifier tel-URI formed by the UE's E.164 number and multiple SIP-URIs of the UE.

The method provided by the present invention solves the shortcomings of the prior art: the present invention makes the call from the circuit-switched network routed to the I-CSCF to query the routing information of the called UE and the E The .164 number is converted to the SIP-URI supported by the IMS network, so the call from the circuit switching network can be routed to the S-CSCF that provides services for the called UE, and further routed to the called UE, so that the called UE can be called The S-CSCF that provides the service controls the service of the called UE, and completes the charging and security management of the called UE.

The method provided by the present invention can solve the problem that the calling UE in the existing circuit switching network and the called UE in the IMS network cannot be routed to the called UE in the IMS network when establishing a SIP session, and improves the IMS network The implementation and application of the IMS network make the IMS network more mature, more able to adapt to various network conditions in the actual implementation, and improve the user satisfaction of using the UE. Another advantage of the present invention is that there is little change to the existing IMS network, no need to add any physical equipment in the IMS network, only need to allocate E.164 numbers according to the needs of the UE, and at the same time add the same The corresponding relationship between the E.164 number of the UE and the SIP-URI can solve the technical problem proposed by the present invention, so it is very easy to realize for the operator of the IMS network.

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 (10)

1, a kind of circuit-switched network is to the method for building up of internet protocol multimedia subsystem IMS calling network route, it is characterized in that, E.164 the corresponding relation of the unified resource identifier SIP-URI that is used for Session initiation Protocol of phone unified resource identifier tel-URI that the number of user equipment (UE) constitutes and this UE is set in the home signature user server HSS of IMS network, and this method also comprises:

After MGCF MGCF in A, the IMS network received the calling of the E.164 number that carries called UE of initiating from calling UE in the circuit-switched network, the Session initiation Protocol sip message of constructing the tel-URI of the E.164 number formation of carrying called UE sent to query call controlled function I-CSCF;

The corresponding relation that B, I-CSCF inquiry HSS is provided with, obtain the SIP-URI of the tel-URI correspondence that the E.164 number of the entrained called UE of sip message constitutes, obtain the routing iinformation of called UE according to SIP-URI, sip message is transmitted to called UE, called UE and calling UE are carried out SIP session negotiation process, finish this calling.

2, the method for claim 1 is characterized in that, the process that corresponding relation is set is: E.164 the tel-URI of number formation preserves as the different public user identity of same UE in the IMS network with SIP-URI.

3, method as claimed in claim 2 is characterized in that, the tel-URI that described E.164 number constitutes adopts the form of " tel:URI " to preserve, and wherein URI partly is described E.164 number.

4, the method for claim 1, it is characterized in that the sip message process that the described structure of steps A carries the tel-URI that the E.164 number of called UE constitutes is: the E.164 number of called UE is filled into the Request-URI field in the sip message of being constructed with " tel:URI " form.

5, the method for claim 1 is characterized in that, the corresponding relation that the described I-CSCF of step B inquiry HSS is provided with is the Cx interface information query of the tel-URI that constitutes by the E.164 number that carries called UE.

6, method as claimed in claim 5 is characterized in that, the mode that described Cx interface message is carried the E.164 number of called UE is: the E.164 number of called UE is filled into public user identity field in the Cx interface message with " tel:URI " form.

7, the method for claim 1, it is characterized in that, when there is more than one HSS in the IMS network, tel-URI that the E.164 number of same UE constitutes and the corresponding relation of HSS are set in the signatory location-server SLF of administration HSS, before step B, this method further comprises:

I-CSCF judges whether the tel-URI that the E.164 number of the entrained called UE of sip message constitutes has corresponding HSS, if, the HSS of the called UE CAMEL-Subscription-Information that obtains storing, the subsequent process of execution in step B; Otherwise, construct response message that this calling makes mistakes by MGCF and send to calling UE in the circuit-switched network.

8, the method for claim 1 is characterized in that, the described process that sends to called UE according to sip message that will structure of step B is:

I-CSCF is according to the routing iinformation of the SIP-URI inquiry UE that HSS stored, acquisition has the routing iinformation of the called UE of this SIP-URI, being defined as called UE provides the S-CSCF of service, learns the route of this S-CSCF, and the sip message of being constructed is sent to this S-CSCF;

This S-CSCF sends to called UE according to the routing iinformation of called UE correspondence with sip message.

9, the method for claim 1 is characterized in that, the process that the described sip message of steps A sends to I-CSCF is:

At MGCF the I-CSCF address is set in advance, MGCF sends to sip message to I-CSCF that should the address according to the I-CSCF address that is provided with;

Perhaps at MGCF an I-CSCF tabulation is set in advance, MGCF selects an I-CSCF according to set rule from the I-CSCF tabulation, sip message is sent to selected I-CSCF.

10, the method for claim 1 is characterized in that, described corresponding relation is the corresponding relation of a plurality of SIP-URI of the phone unified resource identifier tel-URI that constitutes of the E.164 number of UE and this UE.

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