CN101193034A - A system for selecting route in intercommunication between IMS network and CS network - Google Patents

Abstract

The invention provides a system for selecting a route when an IP subsystem network of multimedia is communicated with a circuit switching network. An entity for controlling calling status is used after receiving a calling request which is initiated by a calling subscriber in the IP subsystem network of multimedia to a called subscriber in the circuit switching network. According to an identification code of the called subscriber, the entity for controlling calling status initiates a query on the called location in an assignment client server where the called subscriber is, then receives a query response message of the query on the called location, and selects an export network gateway according to the query on the called location in the query response message to complete the communication with the circuit switching network; and the assignment client server is used for generating the query response message including the called location message when receiving the query on the called location, and sending the query response message to the entity for controlling calling status. By the technical proposal, the invention realizes signaling optimization and avoids speech path detour to a certain extent.

Description

Select the system of route when a kind of IMS network and CS network interworking

Technical field

The present invention relates to wireless communication field and routing optimality, select the system of route when particularly a kind of IMS network and CS network interworking.

Background technology

Development along with mobile communication technology, single speech communication mode can not satisfy user's needs, what the user needed is a kind of emerging multi-media communication mode, this communication modes can not only be handled basic voice and video communication, can also support functions such as instant message, collaborative work and Streaming Media.3GPP (3rd Generation Partnership Project, third generation partner program) has proposed IP Multimedia System (IMS, IP Multimedia Subsystem) on the basis of packet domain.

Topmost functional entity has call conversation control function entity (CSCF among the IMS, Call Session Control Function), home subscriber server (HSS, HomeSubscriber Server) and and CS (Circuit Switched, circuit switching)/PSTN (Public Switched Telephone Network, public switch telephone network) network element BGCF (the Breakout Gateway Control Function entity of intercommunication, Border Gateway ControlFunction), MGCF (MGCF entity, Media Gateway ControlFunction).CSCF has three kinds of logic entity P-CSCF (Proxy Call SessionControl Function, Proxy Call Session Control Function), I-CSCF (InterrogatingCall Session Control Function, the query call conversation control function) and S-CSCF (Serving Call Session Control Function, service call conversation control function).Wherein, P-CSCF is the access point that the user inserts the IMS network; I-CSCF can serve as all users' of network tie point when called (), also can be as the Service Access Point of roamer in the current network service area.S-CSCF finishes CCF, finishes professional the triggering and professional control.The Breakout Gateway Control Function entity is used for selecting the network that links to each other with the CS/PSTN point of interface.Main and the media gateway of MGCF entity is finished media control function together.

At present, whether when IMS and CS network carry out intercommunication, judging conversation request by calling party's S-CSCF is calling to the CS network; If conversation request is the calling to the CS network, calling party S-CSCF selects the BGCF an of this locality, sends conversation request to BGCF; BGCF receives conversation request, and according to called number information (as 1390516XXXX), whether decision selects the MGCF striking out still to be routed to the BGCF of other networks in this locality; If from the MGCF striking out of this locality, then BGCF selects suitable MGCF to carry out outbound call.The network that is routed to other if desired carries out striking out, and BGCF sends to the BGCF of other networks with the session request, selects suitable MGCF striking out by the BGCF of other networks.

Related application mainly contains in the existing patent documentation: application number is that the Chinese patent application of CN02146760 " realizes the method and apparatus of mobile route " in the IP network.

Chinese patent application CN02146760 discusses be how in IP network the called number according to the user select route, do not relate to the home subscriber server device and obtain the customer position information process; When IP network and CS network interworking, if the CS network user exists under the situation of roaming, IP network and CS network interworking exist signaling and alternative channel problem.

Optimize the solution of route when therefore needing a kind of IMS network and CS network interworking, avoid unnecessary alternative channel.

Summary of the invention

Select the system of route when main purpose of the present invention is a kind of IMS network and CS network interworking are provided, be used for realizing to a certain extent signaling optimization and avoid alternative channel.

To achieve these goals, select the system of route when the invention provides a kind of IP Multimedia System network and circuit-switched network intercommunication, it comprises: the call state controlled entity, be used for after the called subscriber's who arrives circuit-switched network that the calling subscriber who receives the IP Multimedia System network initiates call request, identification code according to the called subscriber, be initiated to the called position enquiring of called subscriber place home subscriber server, receive the query response message of called position enquiring then, and select to export gateway according to the called positional information in the query response message, to finish the intercommunication with circuit-switched network; And home subscriber server, be used for when receiving called position enquiring, generate the query response message that comprises called positional information, and query response message is sent to the call state controlled entity.

The call state controlled entity is used in and judges according to called positional information is under local out situation, selects the outlet gateway of circuit-switched network in same local domain with the called subscriber place.The call state controlled entity is used in to judge according to called positional information and is not under local out situation, send the conversation request of carrying called positional information to other call state controlled entities, select to export gateway by other call state controlled entities.

The call state controlled entity includes but not limited to: call conversation control function entity, Breakout Gateway Control Function entity, MGCF entity and application server.

The Breakout Gateway Control Function entity is used in to be received after the call request, identification code according to the called subscriber, send MAP operation A TI to home subscriber server, carry out called position enquiring, and after receiving the query response message that carries called MS C or VLR number, select to export gateway according to called positional information.

If it is from local out that the Breakout Gateway Control Function entity is judged according to called positional information, and there are one or more MGCF entities this locality, then therefrom select a MGCF entity, to finish the intercommunication with circuit-switched network; If judging according to called positional information, the Breakout Gateway Control Function entity is not from local out, then according to called positional information, selection and called MS C or VLR number are at the Breakout Gateway Control Function entity of same local network, transmission is carried the conversation request of called positional information to selected Breakout Gateway Control Function entity, after selected Breakout Gateway Control Function entity is received conversation request, under the situation that has one or more MGCF entities, select a MGCF entity, to finish the intercommunication with circuit-switched network.

Service call session control function entity is used in to be received after the call request, session is triggered to application server, application server is according to called subscriber's identification code, send MAP operation A TI to home subscriber server, carry out called position enquiring, application server is after receiving the query response message that carries called MS C or VLR number, send conversational response to service call session control function entity, service call session control function entity to the Breakout Gateway Control Function entity send carry called MS C or VLR number conversation request, the Breakout Gateway Control Function entity is selected the outlet gateway according to called positional information.

If it is from local out that service call session control function entity is judged according to called positional information, and there are one or more MGCF entities this locality, then therefrom select a MGCF entity, to finish the intercommunication with circuit-switched network; If judging according to called positional information, service call session control function entity is not from local out, then according to called positional information, selection and called MS C or VLR number are at the Breakout Gateway Control Function entity of same local network, transmission is carried the conversation request of called positional information to selected Breakout Gateway Control Function entity, after selected Breakout Gateway Control Function entity is received conversation request, under the situation that has one or more MGCF entities, select a MGCF entity, to finish the intercommunication with circuit-switched network.

By technique scheme, realize signaling optimization to a certain extent and avoided alternative channel.

Description of drawings

Accompanying drawing described herein is used to provide further understanding of the present invention, constitutes the application's a part, and illustrative examples of the present invention and explanation thereof are used to explain the present invention, do not constitute improper qualification of the present invention.In the accompanying drawings:

Fig. 1 is the flow chart according to the method for selection route of the present invention;

Fig. 2 is the block diagram according to the system of selection route of the present invention;

Fig. 3 is according to the IMS network of realizing based on the IMS Control Network of the embodiment of the invention and the block diagram of CS network interworking;

Fig. 4 is according to the IMS network of realizing based on the IMS business network of the embodiment of the invention and the block diagram of CS network interworking;

Fig. 5 be caller according to the embodiment of the invention in this locality, the called subscriber roams into the signaling and the speech channel of calling subscriber's network and optimizes schematic diagram; And

Fig. 6 is that the calling subscriber according to the embodiment of the invention roams into called subscriber's network, and the called subscriber roams into the signaling and the speech channel of calling subscriber's network and optimizes schematic diagram.

Embodiment

Describe the present invention below with reference to the accompanying drawings in detail.

Fig. 1 is the flow chart according to the method for optimization route of the present invention.

With reference to Fig. 1, select the method for route may further comprise the steps during according to IP Multimedia System network of the present invention and circuit-switched network intercommunication:

Step S102, the call state controlled entity of IP Multimedia System network receive the called subscriber's who arrives circuit-switched network that the calling subscriber initiates call request.

The call state controlled entity can include but not limited to: call conversation control function entity, Breakout Gateway Control Function entity, MGCF entity and application server.

Step S104, call state controlled entity are initiated to the called position enquiring of called subscriber place home subscriber server according to called subscriber's identification code.

Step S106, the call state controlled entity is received the query response message of called position enquiring.

Step S108, the call state controlled entity is selected the outlet gateway according to the called positional information in the query response message, to finish the intercommunication with circuit-switched network.

If judging according to called positional information is local out, then select the outlet gateway of circuit-switched network in same local domain with the called subscriber place.Not that local out, then the call state controlled entity sends the conversation request of carrying called positional information to other call state controlled entities, selects to export gateway by other call state controlled entities if judge according to called positional information.

Alternatively, in step S102, the Breakout Gateway Control Function entity is received call request; In step S104, the Breakout Gateway Control Function entity sends MAP operation A TI to home subscriber server according to called subscriber's identification code, carries out called position enquiring; In step S106, the Breakout Gateway Control Function entity is received the query response message that carries called MS C or VLR number; In step S108, the Breakout Gateway Control Function entity is selected the outlet gateway according to called positional information.

Further, be from local out if judge, and there are one or more MGCF entities this locality according to called positional information, then therefrom select a MGCF entity, to finish the intercommunication with circuit-switched network; Be not from local out if judge according to called positional information, then according to called positional information, selection and called MS C or VLR number are at the Breakout Gateway Control Function entity of same local network, transmission is carried the conversation request of called positional information to selected Breakout Gateway Control Function entity, after selected Breakout Gateway Control Function entity is received conversation request, under the situation that has one or more MGCF entities, select a MGCF entity, to finish the intercommunication with circuit-switched network.

Alternatively, in step S102, service call session control function entity is received call request, and service call session control function entity is triggered to application server with session; In step S104, application server sends MAP operation A TI to home subscriber server according to called subscriber's identification code, carries out called position enquiring; In step S106, after application server is received the query response message that carries called MS C or VLR number, send conversational response to service call session control function entity, service call session control function entity to the Breakout Gateway Control Function entity send carry called MS C or VLR number conversation request; In step S108, the Breakout Gateway Control Function entity is selected the outlet gateway according to called positional information.

Further, be from local out if judge, and there are one or more MGCF entities this locality according to called positional information, then therefrom select a MGCF entity, to finish the intercommunication with circuit-switched network; Be not from local out if judge according to called positional information, then according to called positional information, selection and called MS C or VLR number are at the Breakout Gateway Control Function entity of same local network, transmission is carried the conversation request of called positional information to selected Breakout Gateway Control Function entity, after selected Breakout Gateway Control Function entity is received conversation request, under the situation that has one or more MGCF entities, select a MGCF entity, to finish the intercommunication with circuit-switched network.

Fig. 2 is the diagrammatic sketch according to the system of optimization route of the present invention.

With reference to Fig. 2, select the system of route to comprise during according to IP Multimedia System network of the present invention and circuit-switched network intercommunication: call state controlledentity 201, be used for after the called subscriber's who arrives circuit-switched network that the calling subscriber who receives the IP Multimedia System network initiates call request, identification code according to the called subscriber, be initiated to the called position enquiring of called subscriber place home subscriber server, receive the query response message of called position enquiring then, and select to export gateway according to the called positional information in the query response message, to finish the intercommunication with circuit-switched network; And home subscriber server 202, be used for when receiving called position enquiring, generate the query response message that comprises called positional information, and query response message is sent to call state controlledentity 201.

Call state controlledentity 201 is used in and judges according to called positional information is under local out situation, selects the outlet gateway of circuit-switched network in same local domain with the called subscriber place.Call state controlledentity 201 is used in to judge according to called positional information and is not under local out situation, send the conversation request of carrying called positional information to other call state controlledentities 201, select to export gateway by other call state controlledentities 201.

Call state controlledentity 201 includes but not limited to: call conversation control function entity, Breakout Gateway Control Function entity, MGCF entity and application server.

The Breakout Gateway Control Function entity is used in to be received after the call request, identification code according to the called subscriber, send MAP operation A TI to home subscriber server 202, carry out called position enquiring, and after receiving the query response message that carries called MS C or VLR number, select to export gateway according to called positional information.

If it is from local out that the Breakout Gateway Control Function entity is judged according to called positional information, and there are one or more MGCF entities this locality, then therefrom select a MGCF entity, to finish the intercommunication with circuit-switched network; If judging according to called positional information, the Breakout Gateway Control Function entity is not from local out, then according to called positional information, selection and called MS C or VLR number are at the Breakout Gateway Control Function entity of same local network, transmission is carried the conversation request of called positional information to selected Breakout Gateway Control Function entity, after selected Breakout Gateway Control Function entity is received conversation request, under the situation that has one or more MGCF entities, select a MGCF entity, to finish the intercommunication with circuit-switched network.

Service call session control function entity is used in to be received after the call request, session is triggered to application server, application server is according to called subscriber's identification code, send MAP operation A TI to home subscriber server 202, carry out called position enquiring, application server is after receiving the query response message that carries called MS C or VLR number, send conversational response to service call session control function entity, service call session control function entity to the Breakout Gateway Control Function entity send carry called MS C or VLR number conversation request, the Breakout Gateway Control Function entity is selected the outlet gateway according to called positional information.

If it is from local out that service call session control function entity is judged according to called positional information, and there are one or more MGCF entities this locality, then therefrom select a MGCF entity, to finish the intercommunication with circuit-switched network; If judging according to called positional information, service call session control function entity is not from local out, then according to called positional information, selection and called MS C or VLR number are at the Breakout Gateway Control Function entity of same local network, transmission is carried the conversation request of called positional information to selected Breakout Gateway Control Function entity, after selected Breakout Gateway Control Function entity is received conversation request, under the situation that has one or more MGCF entities, select a MGCF entity, to finish the intercommunication with circuit-switched network.

The method and system of the routing optimality when the objective of the invention is to realize a kind of IMS network and CS network interworking solves a series of problems that exist in the prior art.

The present invention fully takes into account the CS network user and has ambulant characteristics, when IMS network and CS network interworking, IMS calling network State Control entity is by carrying out alternately with home subscriber server, obtain called positional information, select the outlet gateway according to called positional information then, blindness when having avoided the call state controlled entity to select the outlet gateway has realized the routing optimization of signaling, has avoided unnecessary alternative channel.

The present invention comprises following key step during the route optimizational function when finishing IMS and CS network interworking:

Step 1: the call state controlled entity of IMS network receives that the calling subscriber is initiated to the CS network user's audio call.

Step 2: the call state controlled entity is initiated to the called position enquiring of called subscriber place home subscriber server according to called number.

Step 3: the call state controlled entity is received the query response message of called position enquiring.

Step 4: the call state controlled entity judges whether local out according to called positional information, if, then select suitable outlet gateway (such as this gateway and called place CS network in same local domain), finish intercommunication with the CS network by the outlet gateway.If not, the call state controlled entity sends the call state controlled entity of conversation request to other suitable IP network, carry called positional information in the conversation request, select suitable outlet gateway, finish intercommunication with the CS network by the outlet gateway by this call state controlled entity.

Route optimization relates to IMS call state control network element (as P-CSCF, S-CSCF, BGCF, MGCF, HSS and AS etc. when IMS that the present invention describes and CS intercommunication.Wherein, P-CSCF finishes the user and inserts the IMS function.S-CSCF finishes custom calling service logic control function and the professional function that triggers.BGCF and MGCF finish the network interworking function with CS together.HSS finishes the user contracting data management function.AS finishes service logic control) and grouping domain network element GGSN (Gateway GPRS Support Node, Gateway GPRS Support Node) (GGSN provides the transmission and the user media routing function of IMS signaling).

Now propose the embodiment of two kinds of IMS network internal, a kind ofly realize, a kind ofly realize based on the IMS business network based on the IMS Control Network based on the present invention.But the invention is not restricted to these concrete schemes.

With reference to Fig. 3 embodiment 1 is described:

Step 1: BGCF receives that the IMS network user is initiated to the CS network user's conversation request.

Step 2: BGCF sends MAP (MAP:Mobile Application Part) operation A TI to HSS inquiry called subscriber position enquiring according to called number.

Step 3: BGCF receives the response of called subscriber's position enquiring message of HSS, wherein carries MSC number or VLR number.

Step 4: BGCF is according to called MSC number or VLR number, decision whether from local out (sign of judgement can be the MSC at called place or VLR whether with BGCF at same local network).If from local out, and this locality then selects suitable MGCF when a plurality of MGCF is arranged, and finishes intercommunication with the CS network by MGCF.If not from local out, then according to called positional information, selection and called MSC number or VLR number send message to this BGCF at the BGCF of a local network, wherein carry called positional information; After target BGCF received conversation request, if when having a plurality of MGCF, BGCF selected suitable MGCF striking out, finished intercommunication with the CS network by MGCF.

With reference to Fig. 4 embodiment 2 is described:

Step 1: S-CSCF receives that the IMS network user is initiated to the CS network user's conversation request.S-CSCF is triggered to the AS server with session.

Step 2: after AS finishes processing logic,, send MAP (MAP:Mobile Application Part) operation A TI to HSS inquiry called subscriber position enquiring according to called number.

Step 3: AS receives the response of called subscriber's position enquiring message of HSS, wherein carries MSC number or VLR number.AS sends conversational response to S-CSCF; Because calling is the calling to the CS network, S-CSCF sends request to BGCF, wherein carries called MSC number or VLR number that AS obtains from HSS.

Step 4: BGCF is according to called MSC number or VLR number, decision whether from local out (sign of judgement can be the MSC at called place or VLR whether with BGCF at same local network).If from local out, and this locality then selects suitable MGCF when a plurality of MGCF is arranged, and finishes intercommunication with the CS network by MGCF.If not from local out, then according to called positional information, selection and called MSC number or VLR number send message to this BGCF at the BGCF of a local network, wherein carry called positional information; After target BGCF received conversation request, if when having a plurality of MGCF, BGCF selected suitable MGCF striking out, finished intercommunication with the CS network by MGCF.

The INVITE request message that the S-CSCF that BGCF receives sends wherein carries called MS C/VLR number.

Describe caller in this locality below with reference to Fig. 5, the called subscriber roams into the signaling and the speech channel of calling subscriber's network and optimizes schematic diagram.

UE2 is the IMS user of local network 2 among the figure, and UE1 is the CS user of local network 1, and when UE1 roamed into local network 2, UE2 called out UE1.

The solid line representative is if call state controlled entity BGCF does not have called positional information among the figure, but carry out the out signalling route of selecting according to called number, what dotted line was represented is the call state controlled entity---borde gateway controlled function BGCF (Border GatewayControl Function) adopts scheme provided by the invention, after going earlier HSS to obtain called positional information, carry out the out signalling route of selecting according to called positional information.

As can be seen from the figure, the route before not having to optimize is passed through local network twice, and the signaling after optimizing is only at local network.Signalling route has obtained bigger improvement.In addition, speech channel is the same with signaling, the scheme before not having to optimize, and speech channel is passed through local network twice; Scheme after the optimization, speech channel are all at local network.

Describe the calling subscriber below with reference to Fig. 6 and roam into called subscriber's network, the called subscriber roams into the signaling and the speech channel of calling subscriber's network and optimizes schematic diagram.

UE1 is the CS user of local network 2, and UE2 is the IMS user of local network 1, and UE1 roams into local network 1, and UE2 roams into local network 2, and UE2 calls out UE1.

The solid line representative is speech channel before not optimizing among the figure; Dotted line is speech channel behind employing the present invention.As can be seen from the figure, the scheme speech channel before optimizing is passed through local network twice, and after the optimization, speech channel is all at local network.

The above is the preferred embodiments of the present invention only, is not limited to the present invention, and for a person skilled in the art, the present invention can have various changes and variation.Within the spirit and principles in the present invention all, any modification of being done, be equal to replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (8)

1. select the system of route when IP Multimedia System network and circuit-switched network intercommunication, it is characterized in that, comprising:

The call state controlled entity, be used for after the called subscriber's who arrives described circuit-switched network that the calling subscriber who receives described IP Multimedia System network initiates call request, identification code according to described called subscriber, be initiated to the called position enquiring of described called subscriber place home subscriber server, receive the query response message of described called position enquiring then, and select to export gateway according to the called positional information in the described query response message, to finish the intercommunication with described circuit-switched network; And

Described home subscriber server is used for generating the described query response message that comprises described called positional information, and described query response message being sent to described call state controlled entity when receiving described called position enquiring.

2. system according to claim 1, it is characterized in that, it is under local out situation that described call state controlled entity is used for judging according to described called positional information, selects the outlet gateway of described circuit-switched network in same local domain with described called subscriber place.

3. system according to claim 1, it is characterized in that, described call state controlled entity is used for not being under local out situation judging according to described called positional information, send the conversation request of carrying described called positional information to other call state controlled entities, select to export gateway by described other call state controlled entities.

4. according to each described system in the claim 1 to 3, it is characterized in that, described call state controlled entity comprise following one of at least: call conversation control function entity, Breakout Gateway Control Function entity, MGCF entity and application server.

5. system according to claim 4, it is characterized in that, described Breakout Gateway Control Function entity is used for after receiving described call request, identification code according to described called subscriber, send MAP operation A TI to described home subscriber server, carry out described called position enquiring, and after receiving the described query response message that carries called MS C or VLR number, select to export gateway according to described called positional information.

6. system according to claim 5, it is characterized in that, if it is from local out that described Breakout Gateway Control Function entity is judged according to described called positional information, and there are one or more described MGCF entities this locality, then therefrom select a described MGCF entity, to finish the intercommunication with described circuit-switched network; If judging according to described called positional information, described Breakout Gateway Control Function entity is not from local out, then according to described called positional information, selection and described called MS C or VLR number are at the described Breakout Gateway Control Function entity of same local network, transmission is carried the conversation request of described called positional information to selected Breakout Gateway Control Function entity, after selected Breakout Gateway Control Function entity is received conversation request, under the situation that has one or more described MGCF entities, select a described MGCF entity, to finish the intercommunication with described circuit-switched network.

7. system according to claim 4, it is characterized in that, service call session control function entity is used for after receiving described call request, session is triggered to application server, described application server is according to described called subscriber's identification code, send MAP operation A TI to described home subscriber server, carry out described called position enquiring, described application server is after receiving the described query response message that carries called MS C or VLR number, send conversational response to described service call session control function entity, described service call session control function entity to described Breakout Gateway Control Function entity send carry described called MS C or VLR number conversation request, described Breakout Gateway Control Function entity is selected the outlet gateway according to described called positional information.

8. system according to claim 7, it is characterized in that, if it is from local out that service call session control function entity is judged according to described called positional information, and there are one or more described MGCF entities this locality, then therefrom select a described MGCF entity, to finish the intercommunication with described circuit-switched network; If judging according to described called positional information, service call session control function entity is not from local out, then according to described called positional information, selection and described called MS C or VLR number are at the described Breakout Gateway Control Function entity of same local network, transmission is carried the conversation request of described called positional information to selected Breakout Gateway Control Function entity, after selected Breakout Gateway Control Function entity is received conversation request, under the situation that has one or more described MGCF entities, select a described MGCF entity, to finish the intercommunication with described circuit-switched network.

Images