CN106685890B - An optimization method, device and system for calling VoLTE users - Google Patents

Abstract

The embodiment of the present invention discloses an optimization method for calling a VoLTE user, including: during the process that the called service of the VoLTE user is connected to the IP Multimedia Subsystem (IMS) domain through anchoring, in the service-call session control function entity ( When the S-CSCF) receives the signaling sent by the query-call session control function entity (I-CSCF), the S-CSCF records the incoming media gateway control function entity (MGCF) carried in the signaling sent by the I-CSCF When the S-CSCF obtains the routing number (CSRN) of the CS domain of the called user, the S-CSCF selects the incoming MGCF as the outgoing MGCF based on the recorded identification information of the incoming MGCF. The embodiment of the invention also discloses an optimization device and system for calling VoLTE users.

Description

An optimization method, device and system for calling VoLTE users

technical field

The present invention relates to VoLTE (Voice over LTE) technology of Long Term Evolution (LTE, Long Term Evolution), in particular to an optimization method, device and system for calling VoLTE users.

Background technique

The LTE voice solution is mainly based on VoLTE. When VoLTE users are covered by Time Division Long-Term Evolution (TD-LTE, TimeDivision-LTE) network wireless coverage, they can access IP A multimedia subsystem (IP Multimedia Subsystem, IMS) core network and an IMS service platform; at this time, the IMS core network completes VoLTE routing and call control, and the IMS service platform implements VoLTE service processing. When VoLTE users are not covered by TD-LTE network and not covered by 2G/Time Division-Synchronous Code Division Multiple Access (TD-SCDMA, Time Division-Synchronous Code Division Multiple Access) network, they can access via 2G or TD-SCDMA wireless network Core network circuit switched (Circuit Switched, CS) domain, the core network CS domain provides voice services for users.

At present, in order to ensure the voice communication between VoLTE users and 2G/3G users on the live network, technical implementation methods such as domain selection and anchoring can be used.

The domain selection and anchoring are described in detail below:

1) Domain selection

Since a terminal supporting VoLTE can have multiple modes, the terminal can be attached to different networks under different signal strength coverage, for example, sometimes attached to a 2G/3G network, and sometimes attached to an LTE network. Therefore, a terminal supporting VoLTE needs to choose to connect to one of the networks for voice calls when making a call. The process of choosing to connect to the network at this time is called domain selection. Specifically, when the user is the calling party, the terminal completes the domain selection according to the stored registration network information; when the user is the called party, the service centralization and continuity application server (Service Centralization and Continuity Application Server, SCC-AS) on the network side queries the converged attribution The location register (Home Location Register, HLR)/Home Subscriber Server (Home Subscriber Server, HSS) obtains the registration network information to complete the domain selection; here, the three-in-one HSS can also be used to replace the HLR/HSS to realize the corresponding functions. The integrated HSS includes IMS-HSS, System Architecture Evolution-Home Subscriber Server (System Architecture Evolution-HSS, SAE-HSS) and 2G/3G HLR. Here, when the user is called, the SCC-AS performs Terminating Access Domain Selection (T-ADS). At this time, it can query the three-in-one HSS for T-ADS information.

Figure 1 is a flow chart of VoLTE domain selection in the prior art, as shown in Figure 1, the process includes:

Step 11: The call session control function entity (Call Session Control Function, CSCF) receives the incoming invite message carrying the mobile subscriber number (Mobile Subscriber International ISDN/PSTNnumber, MSISDN) of the called user; here, the CSCF includes service-call session control Function entity (Serving-Call Session Control Function, S-CSCF) and query-call session control function entity (Interrogating-Call Session Control Function, I-CSCF).

Step 12: The CSCF sends the incoming invite message to the SCC-AS according to the iFC template data signed by the user, and triggers the SCC-AS.

Step 13: When the SCC-AS needs to query the T-ADS information of the called user from the integrated HLR/HSS, the SCC-AS sends a UDR/ATI message to the integrated HLR/HSS, which is used to request the called user T-ADS information. Here, the purpose of the SCC-AS querying the converged HLR/HSS is to determine which network the called user domain is selected for. If it can determine which network the called user domain is selected for before querying the converged HLR/HSS, there is no need to initiate a query.

Step 14: merge HLR/HSS after receiving UDR/ATI message, send IDR message to mobile management node (MobilityManagement Entity, MME), send IDR/PSI message to serving GPRS support node (Serving GPRS SupportNode, SGSN); Like this, The registration time stamp of the called user on the LTE network and GPRS/WCDMA/TD-SCDMA network can be queried; here, the MME returns the registration time stamp of the called user on the LTE network to the integrated HLR/HSS through the IDR message, and the SGSN will be Call the user's registration time stamp on the GPRS/WCDMA/TD-SCDMA network to return to the integrated HLR/HSS through the IDR/PSI message.

Step 15: The merged HLR/HSS sends the T-ADS information of the called user to the SCC-AS through the UDA/ATI_ACK message by comparing the time stamps; the SCC-AS determines that the called user is located in In CS domain, skip to step 16.

Step 16: The SCC-AS sends a UDR message to the fusion HLR/HSS, which is used to request the fusion HLR/HSS to query the routing number (CS domain routing number, CSRN) of the CS domain of the called user; the fusion HLR/HSS sends a message to the mobile interaction center server (Mobile Switch Center Server, MSCS) sends a PRN message, and after receiving the PRN message, the MSCS returns the called user's roaming number (Mobile Station Roaming Number, MSRN) to the integrated HLR/HSS; the integrated HLR/HSS is based on the called user's The MSRN of the MSRN obtains the CSRN of the called user, and sends the CSRN of the called user to the SCC-AS through a UDA message.

Step 17: The SCC-AS sends the CSRN of the called user to the CSCF through an invite message.

Step 18: The CSCF connects the call to the called user on a specific network according to the called user's CSRN; in the process of connecting the call to the called user by the CSRN, the CSCF needs to send the called user's CSRN to the media gateway through an invite message The control function entity (Media Gateway Control Function, MGCF)/media gateway (MediaGateway, MGW), the MGCF/MGW needs to send the MSISDN of the called user to the MSCS through an IAM message.

2) Anchoring

Anchoring refers to the process of routing calls from the CS domain to the IMS domain for service processing; the single anchoring solution is: first connect all called services of VoLTE users to the IMS domain, and trigger the called services in the IMS domain.

In the following two scenarios, a single anchor solution can be used to route call requests related to LTE users to the IMS domain:

Scenario 1: The calling user is a VoLTE user accessing from the CS domain. When calling a VoLTE user, the call is routed to the IMS domain to trigger the called service through the intelligent number change of the anchor (Anchor AS).

Scenario 2: The calling user is a CS domain network user. When calling a VoLTE user, the call is routed to the IMS domain to trigger the called service through the intelligent number change of the anchor (AnchorAS).

Figure 2 is a flow chart of the anchoring scheme in the prior art, as shown in Figure 2, the process includes:

Step 21: The calling end office (Visted Mobile Switching Centre, VMSC) initiates a query request to the three-in-one HSS at the called home location, and queries the terminating CAMELSubscription Information (T-CSI) of the called user. The three-in-one HSS returns the T-CSI of the called user to the calling VMSC.

Step 22: Based on the obtained T-CSI, the calling end office triggers the service control point (Service ControlPoint, SCP)/VoLTE application server (VoLTE AS), and sends the called number to the SCP/VoLTE AS, and the SCP/VoLTEAS Insert the routing code before the calling number to form an anchor code, and return the anchor code to the calling VMSC.

Step 23: Perform CS domain data configuration on the calling VMSC, and route the call to the called home location by sending signaling to the called gateway mobile switching center (Gateway Mobile Switching Center, GMSC) according to the anchor code GMSC, the called home GMSC directly routes the call to the incoming MGCF.

Usually, there are n MGCFs in the called home, where n is a natural number greater than 1. In this step, the incoming MGCF is any MGCF in the called home.

In this step, the path of the media stream is: calling VMSC—called home GMSC—incoming MGCF, and the path of signaling flow is: calling VMSC—first call coordination node (Call Mediation Node, CMN)—called Home GMSC—incoming MGCF.

Here, when the media stream passes through the incoming MGCF, if there are multiple IMS-MGWs connected to the incoming MGCF, the MGCF needs to control the use of one of the IMS-MGWs, and the IMS-MGW used in this step is recorded as IMS-MGW1.

Step 24: The incoming MGCF sends the message to the I-CSCF of the called user according to the default route, and the I-CSCF obtains the S-CSCF of the called user by querying the three-in-one HSS at the called home.

In this step, the path of the signaling flow is: the incoming MGCF—the I-CSCF of the called user—the three-in-one HSS at the called home.

Step 25: The I-CSCF of the called user routes the call to the S-CSCF of the called user by sending signaling; after that, the S-CSCF of the called user triggers the SCP/VoLTE AS, and the SCP/VoLTE AS includes the SCC-AS ; When the SCP/VoLTE AS is triggered, obtain the T-ADS information of the called user from the three-in-one HSS at the called home location.

Here, the signaling sent by the I-CSCF of the called user to the S-CSCF is presented as an invite message. In addition, in this step, the process of obtaining the T-ADS information of the called user has been explained in steps 13 to 14. I won't go into details here.

In this step, the path of the signaling flow is: I-CSCF of the called user—S-CSCF of the called user—SCP/VoLTE AS.

Step 26: When the SCP/VoLTE AS determines that the called user is located in the CS domain based on the T-ADS information of the called user, obtain the CSRN of the called user.

Here, the process of obtaining the CSRN of the called user has been described in steps 15 to 16, and will not be repeated here.

In this step, the path of the signaling flow is: SCP/VoLTE AS—three-in-one HSS at the called home—SCP/VoLTE AS.

Step 27: The SCP/VoLTE AS sends the CSRN of the called user to the S-CSCF of the called user, and the S-CSCF of the called user selects an outgoing MGCF among n MGCFs in the called home location; The CSRN of the called user routes the call to the called VMSC through the outgoing MGCF, and at this time the call is routed to the CS domain.

In this step, the path of the media flow is: the incoming MGCF of the called home - the outgoing MGCF - the called VMSC, and the path of the signaling flow is: the outgoing MGCF - the second call coordinating node - the called VMSC.

Here, the media stream needs to be realized by using an IMS-MGW when passing through the outbound MGCF, and the IMS-MGW in this step is denoted as IMS-MGW2.

Obviously, in the anchoring process shown in Figure 2, when the S-CSCF of the called user selects the outgoing MGCF, the probability of (n-1)/n that the outgoing MGCF is selected is different from the incoming MGCF, when n When the value is larger, the probability that the outgoing MGCF is different from the incoming MGCF will also become larger.

It can be seen that in the anchoring process shown in Figure 2, when the outgoing MGCF is different from the incoming MGCF, the signaling flow needs to cross two MGCFs in the entire anchoring process, thus causing a detour in the signaling flow , which increases the end-to-end call delay and reduces the efficiency of complaint handling and fault location.

Contents of the invention

In order to solve the above technical problems, the embodiments of the present invention expect to provide an optimization method, device and system for calling VoLTE users, which can reduce the detour of signaling flow and media flow, and improve the efficiency of complaint handling and fault location.

Technical scheme of the present invention is realized like this:

An embodiment of the present invention provides an optimization method for calling a VoLTE user, including:

When the called service of the VoLTE user is connected to the IP Multimedia Subsystem IMS domain through anchoring, when the serving-call session control function entity S-CSCF receives the signaling sent by the inquiry-call session control function entity I-CSCF , the S-CSCF records the identification information of the incoming media gateway control function entity MGCF carried in the signaling sent by the I-CSCF;

When the S-CSCF acquires the CS domain routing number CSRN of the called user, the S-CSCF selects the incoming MGCF as the outgoing MGCF based on the recorded identification information of the incoming MGCF.

In the above solution, before the S-CSCF receives the signaling sent by the I-CSCF, the method further includes: the gateway mobile switching center GMSC at the called home location selects the incoming MGCF, and routes the call to the incoming MGCF; the incoming MGCF Use an IMS-media gateway MGW to process the media flow for the first time, and record the identification information of the IMS-MGW used for the first time;

After the S-CSCF selects the incoming MGCF as the outgoing MGCF, the method further includes: the outgoing MGCF controls the initial use of the incoming MGCF based on the identification information of the IMS-MGW first used by the incoming MGCF. Use the IMS-MGW to handle media streams.

In the above solution, the S-CSCF selects the incoming MGCF as the outgoing MGCF based on the recorded identification information of the incoming MGCF, including: the S-CSCF acquires the list of MGCFs to which the CSRN belongs, and based on the recorded incoming MGCF When the identification information of the MGCF determines that the incoming MGCF belongs to the list of MGCFs to which the CSRN belongs, the incoming MGCF is selected as the outgoing MGCF.

In the above solution, before the S-CSCF receives the signaling sent by the I-CSCF, the method further includes: the incoming MGCF sends a signaling carrying the identification information of the incoming MGCF to the I-CSCF.

In the above solution, the signaling sent by the I-CSCF received by the S-CSCF is realized through an invite message.

The embodiment of the present invention also provides an optimization device for calling a VoLTE user, the device is set in the service-call session control function entity S-CSCF, and includes a recording module and a selection module; wherein,

The recording module is used to record the I-CSCF when the called service of the VoLTE user is connected to the IP Multimedia Subsystem IMS domain through anchoring and receiving the signaling sent by the query-call session control function entity I-CSCF. - the identification information of the incoming media gateway control function entity MGCF carried in the signaling sent by the CSCF;

The selection module is configured to select the incoming MGCF as the outgoing MGCF based on the recorded identification information of the incoming MGCF when the routing number CSRN of the CS domain of the called user is acquired.

In the above solution, the selection module is specifically used to obtain the MGCF list to which the CSRN belongs, and select the incoming MGCF as the outgoing MGCF when determining that the incoming MGCF belongs to the MGCF list to which the CSRN belongs based on the recorded identification information of the incoming MGCF .

In the above solution, the signaling sent by the I-CSCF received by the S-CSCF is implemented through an invite message.

An embodiment of the present invention also provides an optimization system for calling VoLTE users, including a call session control function entity S-CSCF and an incoming media gateway control function entity MGCF; wherein,

The S-CSCF is configured to record said The identification information of the incoming MGCF carried in the signaling sent by the I-CSCF; when the routing number CSRN of the CS domain of the called user is obtained, based on the recorded identification information of the incoming MGCF, the incoming MGCF is selected as the outgoing call MGCF;

The incoming MGCF is used to record the IMS-media gateway MGW used for the first time when the called service of the VoLTE user is connected to the IP Multimedia Subsystem IMS domain through anchoring to process the media stream for the first time. The identification information of the MGW; when routing the call to the called end office VMSC, based on the identification information of the IMS-MGW used for the first time by itself, it is controlled to use the IMS-MGW used for the first time by itself to process the media stream.

In the above solution, the incoming MGCF is further configured to send signaling carrying the identification information of the incoming MGCF to the I-CSCF.

An optimization method, device, and system for calling a VoLTE user provided by an embodiment of the present invention. When the S-CSCF receives the signaling sent by the I-CSCF, the S-CSCF records the information carried in the signaling sent by the I-CSCF. The identification information of the incoming MGCF; when the S-CSCF obtains the CSRN of the called user, the S-CSCF selects the incoming MGCF as the outgoing MGCF based on the recorded identification information of the incoming MGCF. In this way, the incoming MGCF and the outgoing MGCF are the same MGCF, thereby reducing detours in signaling flows and improving the efficiency of complaint handling and fault location.

Description of drawings

Fig. 1 is the domain selection flowchart of VoLTE in the prior art;

Fig. 2 is the flowchart of the anchoring scheme in the prior art;

Fig. 3 is the flow chart of the embodiment of the optimization method of calling VoLTE user of the present invention;

FIG. 4 is a schematic diagram of paths of signaling streams and media streams existing in the anchoring process shown in FIG. 2;

FIG. 5 is a schematic diagram of the paths of signaling streams and media streams present in an embodiment of an optimization method for calling a VoLTE user in the present invention;

FIG. 6 is a schematic structural diagram of an optimization device for calling a VoLTE user according to an embodiment of the present invention;

FIG. 7 is a schematic structural diagram of an optimization system for calling a VoLTE user according to an embodiment of the present invention.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention.

first embodiment

The embodiment of the present invention discloses an optimization method for calling a VoLTE user, and the method is suitable for optimizing an anchoring process when calling a VoLTE user located in a CS domain.

Fig. 3 is the flow chart of the embodiment of the optimization method of calling VoLTE user of the present invention, as shown in Fig. 3, this process includes:

Step 300: When the called home GMSC routes the call to the incoming MGCF, the called home GMSC selects the incoming MGCF, and the incoming MGCF sends its own identification information to the I-CSCF.

This step specifically includes: the called home GMSC selects one MGCF as an incoming MGCF among n MGCFs in the called home;

When the incoming MGCF sends the message to the I-CSCF in the IMS domain according to the default route, the incoming MGCF sends its own identification information to the I-CSCF; Feature information of other MGCFs among the n MGCFs in the home location.

In this step, the incoming MGCF can send its own identification information to the I-CSCF through the invite message. Specifically, the incoming MGCF identification information can be carried in the Via header field of the invite message. The following is carried in the Via header field An example of incoming MGCF identification information:

Via: SIP/2.0/TCP GZ.MGCF07.GD.CHINAMOBILE.COM:5060

In the Via header field, "MGCF07.GD.CHINAMOBILE.COM:5060" indicates the identification information of the incoming MGCF.

Further, this step also includes: in the process of routing the call to the incoming MGCF by the called home GMSC, the incoming MGCF needs to control the use of an IMS-MGW to process the media stream in each IMS-MGW connected to itself; The incoming MGCF records the identification information of the IMS-MGW used for the first time, and the identification information of the IMS-MGW includes characteristic information different from other IMS-MGWs connected to the incoming MGCF.

Here, the incoming MGCF may record the identification information of the first-used IMS-MGW through a Session Description Protocol (Session Description Protocol, SDP) message of the invite message.

Step 301: After the I-CSCF sends signaling to the S-CSCF, the S-CSCF records the identification information of the incoming MGCF carried in the signaling sent by the I-CSCF.

Here, the signaling sent by the I-CSCF to the S-CSCF can be implemented by using an invite message.

Step 302: Step 303 is executed when the S-CSCF receives the CSRN of the called user.

Here, the source of the called user's CSRN is the SCC-AS, and there are many existing implementation methods for the S-CSCF to obtain the called user's CSRN, which will not be repeated here.

In this step, if the S-CSCF can receive the CSRN of the called user, it means that the called user is located in the CS domain.

In addition, if the S-CSCF does not receive the CSRN of the called user when the called service of the VoLTE user is anchored to the IMS domain, it means that the called user is not located in the CS domain. Some anchoring schemes perform subsequent processes, which will not be repeated here.

Step 303: The S-CSCF judges whether the incoming MGCF belongs to the MGCF list to which the CSRN of the called user belongs; if not, skip to step 304; if yes, skip to step 305.

In this step, the S-CSCF judges whether the incoming MGCF belongs to the MGCF list to which the CSRN of the called user belongs, including: the S-CSCF acquires the locally configured MGCF list to which the CSRN of the called user belongs, and based on the recorded incoming MGCF The identification information of the MGCF is used to determine whether the incoming MGCF belongs to the MGCF list to which the CSRN of the called user belongs.

Step 304: The S-CSCF randomly selects an MGCF from the list of MGCFs to which the CSRN belongs as the outbound MGCF, and then ends the procedure.

After this step, the outgoing MGCF routes the call to the called VMSC according to the existing anchoring scheme.

Step 305: The S-CSCF selects the incoming MGCF as the outgoing MGCF based on the recorded identification information of the incoming MGCF.

In the existing anchoring technical solution, the incoming MGCF and the outgoing MGCF are two different MGCFs. Since there is signaling interaction between the two different MGCFs, it will increase the communication between the two different MGCFs. IP bearer network link load; relatively, in the first embodiment of the present invention, the incoming MGCF and the outgoing MGCF are the same MGCF, so that the IP bearer network link load between two different MGCFs can be avoided; At the same time, the detour of signaling flow can be reduced, and the efficiency of complaint handling and fault location can be improved.

Further, after the incoming MGCF is selected as the outgoing MGCF, this step further includes: the outgoing MGCF adopts the IMS-MGW identification information first used by the incoming MGCF based on the identification information of the incoming MGCF. The IMS-MGW handles media streams.

That is to say, in the first embodiment of the present invention, for the incoming MGCF, it is necessary to use an IMS-MGW to process the media stream for the first time when the called home GMSC routes the call to the incoming MGCF; After the outgoing MGCF is selected, the same IMS-MGW is used again to process the media stream.

Figure 4 is a schematic diagram of the path of signaling flow and media flow in the anchor process shown in Figure 2. As shown in Figure 4, CS represents the CS domain, invite represents the invite message, MGCF1 represents the incoming MGCF, and MGCF2 represents the outgoing MGCF, IMS-MGW1 represents the IMS-MGW used by the incoming MGCF, and IMS-MGW2 represents the IMS-MGW used by the outgoing MGCF. In Figure 4, the media flow is represented by a horizontal dotted line, and the signaling flow is represented by a horizontal solid line. It can be seen that in the anchoring process shown in Figure 2, when the outbound MGCF is different from the incoming MGCF, the signaling flow needs to cross 2 MGCFs in the entire anchoring process, and the corresponding media stream needs to cross 2 IMSs. -MGW, in this way, not only causes the detour of signaling flow and media flow, but also increases the end-to-end call delay, and reduces the efficiency of complaint handling and fault location.

In contrast, FIG. 5 is a schematic diagram of signaling flows and media flows in an embodiment of the optimization method for calling VoLTE users in the present invention. As shown in FIG. 5, CS represents the CS domain, and invite represents the invite message; incoming MGCF and The outgoing MGCF is the same MGCF, denoted as MGCF3; the IMS-MGW used twice by the incoming MGCF is denoted as IMS-MGW3; in Figure 5, the media flow is represented by a horizontal dotted line, and the signaling flow is represented by a horizontal solid line. By comparing Fig. 5 and Fig. 4, it can be seen that through the embodiment of the optimization method for calling VoLTE users in the present invention, the detour of signaling flow and media flow can be reduced, and the efficiency of complaint handling and fault location can be improved.

second embodiment

Based on the optimization method for calling a VoLTE user in the embodiment of the present invention, the embodiment of the present invention also provides an optimization device for calling a VoLTE user.

Figure 6 is a schematic diagram of the composition and structure of an optimization device for calling a VoLTE user according to an embodiment of the present invention. As shown in Figure 6, the device is set in the S-CSCF and includes a recording module 600 and a selection module 601; wherein,

The recording module 600 is configured to record the called service of the VoLTE user when receiving the signaling sent by the query-call session control function entity I-CSCF during the process of connecting the called service of the VoLTE user to the IP Multimedia Subsystem IMS domain through the anchor. The identification information of the incoming media gateway control function entity MGCF is carried in the signaling sent by the I-CSCF; here, the signaling sent by the I-CSCF received by the S-CSCF is realized through an invite message.

The selection module 601 is configured to select the incoming MGCF as the outgoing MGCF based on the recorded identification information of the incoming MGCF when the CS domain routing number CSRN of the called user is obtained.

Specifically, the selection module 601 is configured to obtain a list of MGCFs to which the CSRN belongs, and select the incoming MGCF as the outgoing MGCF when determining that the incoming MGCF belongs to the list of MGCFs to which the CSRN belongs based on the recorded identification information of the incoming MGCF.

In practical applications, both the recording module 600 and the selection module 601 can be composed of a central processing unit (Central Processing Unit, CPU), a microprocessor (Micro Processor Unit, MPU), a digital signal processor (Digital Signal Processor, DSP), or Field Programmable Gate Array (Field Programmable Gate Array, FPGA) and other implementations.

third embodiment

Based on the optimization method for calling a VoLTE user in the embodiment of the present invention, the embodiment of the present invention also provides an optimization system for calling a VoLTE user.

Fig. 7 is a schematic diagram of the composition and structure of an optimization system for calling a VoLTE user according to an embodiment of the present invention. As shown in Fig. 7, the system includes an S-CSCF 701 and an incoming MGCF 702; wherein,

The S-CSCF 701 is configured to record the called service of the VoLTE user when receiving the signaling sent by the query-call session control function entity I-CSCF during the process of connecting the called service of the VoLTE user to the IP Multimedia Subsystem IMS domain through the anchor. The identification information of the incoming MGCF carried in the signaling sent by the I-CSCF; when the routing number CSRN of the CS domain of the called user is obtained, based on the recorded identification information of the incoming MGCF, the incoming MGCF is selected as MGCF out.

The incoming MGCF 702 is used to record the IMS used for the first time when the called service of the VoLTE user is connected to the IP Multimedia Subsystem IMS domain through anchoring, when using an IMS-media gateway MGW to process the media stream for the first time - the identification information of the MGW; when routing the call to the called end office VMSC, based on the identification information of the IMS-MGW used for the first time by itself, control to use the IMS-MGW used for the first time by itself to process the media stream.

Further, the incoming MGCF 702 is also configured to send signaling carrying the identification information of the incoming MGCF to the I-CSCF.

Those skilled in the art should understand that the embodiments of the present invention may be provided as methods, systems, or computer program products. Accordingly, the present invention can take the form of a hardware embodiment, a software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) having computer-usable program code embodied therein.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It should be understood that each procedure and/or block in the flowchart and/or block diagram, and a combination of procedures and/or blocks in the flowchart and/or block diagram can be realized by computer program instructions. These computer program instructions may be provided to a general purpose computer, special purpose computer, embedded processor, or processor of other programmable data processing equipment to produce a machine such that the instructions executed by the processor of the computer or other programmable data processing equipment produce a An apparatus for realizing the functions specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing apparatus to operate in a specific manner, such that the instructions stored in the computer-readable memory produce an article of manufacture comprising instruction means, the instructions The device realizes the function specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions can also be loaded onto a computer or other programmable data processing device, causing a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process, thereby The instructions provide steps for implementing the functions specified in the flow chart or blocks of the flowchart and/or the block or blocks of the block diagrams.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention.

Claims (9)

1. An optimization method for calling a VoLTE user, characterized in that the method comprises: When the called service of the VoLTE user is connected to the IP Multimedia Subsystem IMS domain through anchoring, when the serving-call session control function entity S-CSCF receives the signaling sent by the inquiry-call session control function entity I-CSCF , the S-CSCF records the identification information of the incoming media gateway control function entity MGCF carried in the signaling sent by the I-CSCF; When the S-CSCF obtains the routing number CSRN of the CS domain of the called user, the S-CSCF selects the incoming MGCF as the outgoing MGCF based on the recorded identification information of the incoming MGCF; Wherein, the incoming MGCF uses an IMS-MGW for the first time to process the media stream, and records the identification information of the IMS-MGW used for the first time by itself; after the S-CSCF selects the incoming MGCF as the outgoing MGCF, the outgoing MGCF Based on the identification information of the IMS-MGW first used by the incoming MGCF, control the use of the IMS-MGW first used by the incoming MGCF to process the media stream. 2. The method according to claim 1, characterized in that, before the S-CSCF receives the signaling sent by the I-CSCF, the method further comprises: the gateway mobile switching center GMSC at the called home location selects an incoming MGCF, Route the call to the incoming MGCF. 3. The method according to claim 1, wherein the S-CSCF selects the incoming MGCF as the outgoing MGCF based on the recorded identification information of the incoming MGCF, comprising: the S-CSCF obtains the CSRN The home MGCF list, when it is determined based on the recorded identification information of the incoming MGCF that the incoming MGCF belongs to the CSRN's home MGCF list, select the incoming MGCF as the outgoing MGCF. 4. The method according to any one of claims 1 to 3, characterized in that, before the S-CSCF receives the signaling sent by the I-CSCF, the method further comprises: the incoming MGCF sends the signaling to the I-CSCF Signaling carrying the identification information of the incoming MGCF. 5. The method according to any one of claims 1 to 3, wherein the signaling sent by the I-CSCF received by the S-CSCF is implemented through an invite message. 6. An optimization device for calling VoLTE users, characterized in that the device is set in the service-call session control function entity S-CSCF, including a recording module and a selection module; wherein, The recording module is used to record the I-CSCF when the called service of the VoLTE user is connected to the IP Multimedia Subsystem IMS domain through anchoring and receiving the signaling sent by the query-call session control function entity I-CSCF. - the identification information of the incoming media gateway control functional entity MGCF carried in the signaling sent by the CSCF; A selection module, configured to select the incoming MGCF as the outgoing MGCF based on the recorded identification information of the incoming MGCF when the routing number CSRN of the CS domain of the called user is acquired; Wherein, the selection module is specifically configured to obtain a list of MGCFs to which the CSRN belongs, and select the incoming MGCF as the outgoing MGCF when determining that the incoming MGCF belongs to the list of MGCFs to which the CSRN belongs based on the recorded identification information of the incoming MGCF. 7. The device according to claim 6, wherein the signaling sent by the I-CSCF received by the S-CSCF is implemented through an invite message. 8. An optimization system for calling VoLTE users, characterized in that the system includes a call session control function entity S-CSCF and an incoming media gateway control function entity MGCF; wherein, The S-CSCF is configured to record the called service of the VoLTE user when receiving the signaling sent by the query-call session control function entity I-CSCF during the process of connecting the called service of the VoLTE user to the IP Multimedia Subsystem IMS domain through anchoring. The identification information of the incoming MGCF carried in the signaling sent by the I-CSCF; when the routing number CSRN of the CS domain of the called user is obtained, based on the recorded identification information of the incoming MGCF, the incoming MGCF is selected as the outgoing call MGCF; The incoming MGCF is used to record the IMS-media gateway MGW used for the first time when the called service of the VoLTE user is connected to the IP Multimedia Subsystem IMS domain through anchoring to process the media stream for the first time. The identification information of the MGW; when routing the call to the called end office VMSC, based on the identification information of the IMS-MGW used for the first time by itself, it is controlled to use the IMS-MGW used for the first time by itself to process the media stream. 9. The system according to claim 8, wherein the incoming MGCF is further configured to send signaling carrying the identification information of the incoming MGCF to the I-CSCF.