CN102131232A

CN102131232A - Method and system for realizing service GPRS (General Packet Radio Service) supporting node and single-mode business continuity

Info

Publication number: CN102131232A
Application number: CN2010100006809A
Authority: CN
Inventors: 谢振华; 陶全军
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2010-01-15
Filing date: 2010-01-15
Publication date: 2011-07-20
Anticipated expiration: 2030-01-15
Also published as: CN102131232B

Abstract

The invention discloses a method and system for realizing a service GPRS (General Packet Radio Service) supporting node and single-mode business continuity. The method comprises the following steps of: when a handover request sent by an access network is received, initiating a first switching process to an SGSN (Service GPRS Supporting Node) by a control network element as a speech load, and obtaining first media information by the first switching process; initiating a second switching process to an MSC (Mobile Switching Centre) by the control network element; sending a transferred number to the MSC by the second switching process and obtaining second media information; initiating an IMS (Information Management System) conversation transferring process by the MSC by taking the transferred number as a target, and performing a CS (Circuit Switch) switching process; sending the second media information to the SGCN via the first switching process by the control network element; sending the first media information to the MSC through the second switching process; obtaining conversion media connection information by the SGSN; and setting the connection information of the media data according to the conversion media connection information, wherein the media data is packaged in the load built by the first switching process.

Description

The implementation method of Serving GPRS Support Node, single radio voice call continuity and system

Technical field

The present invention relates to the communications field, in particular to the implementation method and the system of a kind of Serving GPRS Support Node, single radio voice call continuity.

Background technology

IP Multimedia System (IP Multimedia Core Network Subsystem, abbreviate IMS as) be by third generation partner program (3rd Generation PartnershipProject, abbreviate 3GPP as) a kind of IP-based network framework of proposing, made up one opening and service environment flexibly, support multimedia application, can provide abundant multimedia service for the user.

In the IMS business system, key-course separates with operation layer, and key-course does not provide concrete business, and functions such as necessary triggering, route, charging only are provided to operation layer.Professional triggering and controlled function are by CSCF (Call Session ControlFunction in the key-course, be called for short CSCF, be divided into agency (Proxy), inquiry (Interrogating) and service (Serving) three types, that wherein take the main responsibility is Serving, and the Interrogating type is optional) finish; Operation layer is made up of a series of application servers (ApplicationServer abbreviates AS as), and concrete business service can be provided, and AS can be an independent entity, also can be arranged in S-CSCF.Key-course (S-CSCF) calls the business on the AS according to user's professional triggering of CAMEL-Subscription-Information control, realizes business function.Subscriber equipment (User Equipment, abbreviate UE as) be responsible for mutual with the user, some UE has the mode of multiple access network, comprise: by packet data domain (the Packet Switch of 3GPP, abbreviate PS as) (LTE or HSPA) access network, by circuit commutative field (Circuit Switch abbreviates CS as) access network etc.If CS network configuration enhanced mobile switching center (Mobile Switch Center, abbreviate MSC as), the interface and the IMS network interaction of Session Initiation Protocol are provided by the MSC that strengthens, then the Signalling exchange of IMS network and CS network can be realized by the MSC that strengthens, the media gateway (Media Gateway abbreviates MGW as) that medium can be controlled by the MSC that strengthens alternately realizes.

For the UE with plurality of access modes, if UE can only adopt a kind of access way access network sometime, then this UE is called single mode UE.If it is carrying out talk business under PS access way (LTE network or HSPA network), other are local and need change into when using the CS access way when UE moves to, the talk business that UE and network can provide certain mode that UE is being carried out is not interrupted, and this ability is called single radio voice call continuity.

Fig. 1 is existing single radio voice call continuity schematic diagram, the signaling paths and the media path of session between UE and far-end UE have been described, and behind the generation single radio voice call continuity, the signaling paths and the media path of session between UE and far-end UE, be simplicity of illustration and description, CSCF and business continuance AS (SCC AS) are made an entity, use the Session Initiation Protocol communication of standard between the two.

Wherein, 101 is that UE and PS Access Network (are enhancing Node B (the ehanced Node B of LTE network, abbreviate eNB as), or the radio network controller of HSPA network (Radio Network Controller, abbreviate RNC as)) between signaling paths, the space interface signaling agreement by LTE network or HSPA network communicates with one another; 102 is that the PS Access Network (is Mobility Management Entity (the Mobile ManagementEntity of LTE network with the control network element, abbreviate MME as), or the Serving GPRS Support Node of HSPA network (ServingGPRS Support Node abbreviates SGSN as)) signaling paths between; 103 is that PS network control network element and PS grouping of network data gateway (are gateway (the Serving Gateway of LTE network, abbreviate SGW as) and packet data network gateway (Packet DataNetwork Gateway, abbreviate PGW as), or the overall GPRS Support Node of HSPA network (Global GPRS Support Node abbreviates GGSN as)) signaling paths between; 104 is hand off signaling interface between PS network control network element and MSC, and by this interface, it is that UE prepares CS Internet resources and PS bearing resource that the PS network can be notified MSC; 105 is UE and CS Access Network, or, the signaling paths between UE and CS Access Network and the core net, the space interface signaling agreement by the CS network communicates with one another; 106 is the signaling paths between CS Access Network or CS core net and enhanced MSC; 107 is the part of the IMS signaling paths between UE and CSCF, and this part signaling paths is by the PS network delivery; 108 is the part of the IMS signaling paths between MSC and CSCF, and the end points of this part signaling paths is a PS grouping of network data gateway, and MSC and UE make the IMS network need not change the near-end access path by sharing this section signaling paths; 109 is another part of the IMS signaling paths between UE or MSC and CSCF, this part signaling paths is by the IP network transmission, the signaling data that sends on this signaling paths is forwarded to SCC AS by CSCF, to realize the session signaling of SCC AS control UE and far-end UE, for SCC AS, 109 are near-end visit (Access leg) path; 110 is the signaling paths between SCC AS/CSCF and the far-end UE, and the Session Initiation Protocol by IMS communicates with one another, and for SCC AS, 110 is far-end (Remote leg) path.

Before switching generation, UE sets up carrying by PS network and far-end UE, and wherein a part is the carrying in the PS network, and another part is the connection in the IP network; After the switching, UE is connected by three parts with medium between far-end UE and forms, and a part is that the CS medium connect, and a part is the carrying between MSC and PS grouping of network data gateway, and continuous with the connection in the IP network that former medium are connected.Medium before and after switching connect by sharing the identical connection of this section, make in the handoff procedure that need not carry out medium to far-end UE connects and upgrade operation.

Below the MGW of MSC and its control is described to simplify as an entity, adopt the interface of standard and flow process mutual therebetween.

Fig. 2 is existing single radio voice call continuity realization flow figure, described between UE and far-end UE and set up the IMS voice call, medium connect by UE be connected with PS between the PS Access Network, the PS Access Network connects and composes with the IP that PS between PS grouping of network data gateway is connected, reaches between PS grouping of network data gateway and far-end UE, UE switches and network is realized the process of single radio voice call continuity, and it is described below:

Step 201, UE send measurement report to the PS Access Network, for example, send Measurement report message, comprising the signal strength information of objective network;

Step 202, PS Access Network are according to signal strength signal intensity, and decision switches to the conversation of UE in the objective network, and the control network element transmission handoff request to the PS network for example, sends Handover Required message;

Step 203, control network element judge that UE has set up the carrying of voice call, decision switches to voice call and corresponding IMS signaling in the CS territory of objective network, send handoff request to MSC, for example, send PS to CS Handover Request message, carry the IMS protocol status information of UE and the IMS conversation media resource information of UE;

If step 204 UE also has other non-voice conversational class business, the control network element will simultaneously send handoff request to the PS territory of objective network, and these business are switched to the PS territory of target network, for example, send Forward Relocation Request message.

Step 205, MSC send handoff request to the CS territory of target network, if Target cell is controlled by MSC, then send Handover Request message, otherwise send MAP_Prepare_Handover Request message to the MSC of controlled target sub-district;

The CS territory of step 206, target network sends handoff response, for example, sends HandoverResponse message, carries ready CS media resource information, or sends MAP_Prepare_Handover Response message, carries Handover Number;

If step 207 Target cell be can't help MSC control, then MSC initiates the link setup request according to the Handover Number in the step 205, for example, sends IAM (initial address message) or INVITE (invitation) message, and the target of message is a Handover Number;

The MSC of step 208, controlled target sub-district receives the link setup request of step 207, and is according to Handover Number that this link setup request is related with handoff request, and sends the link setup response, such as sending ACM (message is finished in the address) or 183 Session Progress message;

Step 209, with step 204～207 time, MSC also is ready to bearing resource;

Step 210, MSC send handoff response to the control network element of PS network, and such as sending PS to CS Handover Response message, message is carried the bearing resource information of MSC;

If step 211 control network element has also sent handoff request to the PS territory of objective network, then the PS territory of objective network can send handoff response, such as sending Forward RelocationResponse message, the bearing resource information of carrying objective network;

Step 212, control network element associate step 210 and step 211, send switching command to the PS Access Network, such as sending Handover Command message, carry the bearing resource information of acquisition;

Step 213, PS Access Network send switching command to UE, if the PS network is the LTE network, then send Handover from LTE message, if the PS network is the HSPA network, then send Handover from UTRAN message;

Step 214, UE are modulated to objective network, and objective network can obtain notice;

If step 215 Target cell be can't help MSC control, then the MSC of controlled target sub-district sends the link setup response message to MSC, such as sending ANM (response message) or 200OK message;

Step 216, MSC receive that UE is modulated to the link setup response message that the MSC of the notice of objective network or controlled target sub-district sends, and send handoff completion message to the control network element of PS network, such as sending PS to CS Handover Complete message;

If step 217 control network element has sent handoff request to the PS territory of objective network, then the PS territory of objective network also can send handoff completion message to the control network element, such as sending Forward Relocation Complete message;

Step 218, control network element are sent completely acknowledge message to MSC immediately, such as sending PS to CS Handover Complete ACK message;

If step 219 control network element is received the message of step 217, be sent completely acknowledge message to the PS territory of objective network immediately, such as sending Forward RelocationComplete ACK message;

Step 220, MSC send updating message to PS grouping of network data gateway, such as sending Modify Bearer Request message, to upgrade the PS beared information, comprise the link information of chain of command and user's face;

If having sent to the PS territory of objective network, step 221 control network element finishes acknowledge message, the PS territory of objective network sends updating message to PS grouping of network data gateway, such as sending Modify Bearer Request message, to upgrade the PS beared information, comprise the link information of chain of command and user's face.Since then, switching is finished.

As mentioned above, in existing single radio voice call continuity implementation method, MSC requires to set up PS and connects, and at present MSC can only control MGW and sets up IP and connect, this just requires the equipment MSC in CS territory that the function in PS territory also must be provided, but the implementation of PS territory equipment and CS territory equipment there are differences, thereby will increase the complexity that realizes.

Summary of the invention

Main purpose of the present invention is to provide the implementation method and the system of a kind of SGSN, control network element, single radio voice call continuity, to address the above problem at least.

According to an aspect of the present invention, a kind of implementation method of single radio voice call continuity is provided, comprise: after the handoff request that receives the access network transmission, the control network element is that voice bearer is initiated first handoff procedure to SGSN, and obtains first media information by first handoff procedure; The control network element is initiated second handoff procedure to MSC, by second handoff procedure forwarding number is sent to MSC, and obtains second media information; MSC is that target is initiated IMS session transfer process with the forwarding number, and carries out the CS handoff procedure; The control network element sends second media information by first handoff procedure to SGSN, sends first media information by second handoff procedure to MSC; SGSN obtains the conversation media link information, and according to the conversation media link information link information of media data is set, and wherein, media data is encapsulated in the carrying of setting up by first handoff procedure.

According to a further aspect in the invention, provide a kind of realization system of single radio voice call continuity, having comprised: control network element, SGSN and MSC.Wherein, the control network element, be used for after the handoff request that receives the access network transmission, initiate first handoff procedure for voice bearer to SGSN, obtain first media information, and initiate second handoff procedure to MSC by first handoff procedure, by second handoff procedure forwarding number is sent to MSC, and obtain second media information, and send second media information by first handoff procedure to SGSN, send first media information by second handoff procedure to MSC; SGSN, be used at first handoff procedure, consult media information, and the link information of media data is set according to the conversation media link information of obtaining by first handoff procedure by first handoff procedure, wherein, this media data is encapsulated in the carrying of first handoff procedure foundation; MSC is used at second handoff procedure, is that target is initiated IMS session transfer process with the forwarding number, carries out the CS handoff procedure, and consults media information by second handoff procedure.

According to a further aspect of the invention, proposed a kind of SGSN, having comprised: hand-off process module, connection mapping block and packing data module.The hand-off process module, being used for by the control network element is that first handoff procedure that voice bearer is initiated is set up the carrying between SGSN and data gateway, consult media information and obtain the conversation media link information by first handoff procedure, and to connecting information and the conversation media link information that loaded information that the mapping block transmission sets up, medium that media information is represented connect; Connect mapping block, the information that is used for loaded information is connected with medium is carried out association store, and store session medium link information; The packing data module, be used for the media data that receiving media connects, according to the loaded information related that connects the mapping block storage media data is encapsulated in the carrying, and is encapsulated in the link information of the media data in the carrying according to the conversation media link information setting that connects the mapping block storage with the medium connection.

According to a further aspect of the invention, provide a kind of control network element, having comprised: receiver module, the first hand-off process module and the second hand-off process module.Wherein, receiver module is used to receive the handoff request that access network sends, and triggers the first hand-off process module and the second hand-off process module when receiving handoff request; The first hand-off process module is used to voice bearer to initiate first handoff procedure to SGSN, obtains first media information by first handoff procedure, and sends second media information to SGSN; The second hand-off process module is used for initiating second handoff procedure to MSC, by second handoff procedure forwarding number and above-mentioned first media information is sent to MSC, and obtains above-mentioned second media information.

By the present invention, the IP media data that the MGW that MSC is controlled by SGSN transmits is encapsulated into the carrying between that SGSN sets up and PS grouping of network data gateway, realized single radio voice call continuity, CS domain-functionalities and the PS domain-functionalities of having cut apart MSC, avoid switching the problem of IMS signaling bear, solved the chain of command replacement problem of PS grouping of network data gateway.

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 existing single radio voice call continuity schematic diagram;

Fig. 2 is existing single radio voice call continuity realization flow figure;

Fig. 3 A is the structural representation according to the realization system of the single radio voice call continuity of the embodiment of the invention;

Fig. 3 B is the single radio voice call continuity Organization Chart of the embodiment of the invention;

Fig. 4 A is the single radio voice call continuity schematic diagram of the embodiment of the invention;

Fig. 4 B is the SGSN functional schematic of the embodiment of the invention;

Fig. 5 is the flow chart according to the implementation method of the single radio voice call continuity of the embodiment of the invention;

Fig. 6 is the flow chart of the embodiment of the invention one;

Fig. 7 is the flow chart of the embodiment of the invention two;

Fig. 8 is the flow chart of the embodiment of the invention three;

Fig. 9 is the flow chart of the embodiment of the invention four;

Figure 10 is the flow chart of the embodiment of the invention five;

Figure 11 is the flow chart of the embodiment of the invention six;

Figure 12 is the flow chart of the embodiment of the invention seven;

Figure 13 is the structural representation according to the SGSN of the embodiment of the invention;

Figure 14 is the structural representation according to the first hand-off process module of the SGSN of the embodiment of the invention;

Figure 15 is the structural representation according to the control network element of the embodiment of the invention.

Embodiment

Hereinafter will describe the present invention with reference to the accompanying drawings and in conjunction with the embodiments in detail.Need to prove that under the situation of not conflicting, embodiment and the feature among the embodiment among the application can make up mutually.

At first the realization system according to the single radio voice call continuity of the embodiment of the invention is described below.

Fig. 3 A is the structural representation according to the realization system of the single radio voice call continuity of the embodiment of the invention, and as shown in Figure 3A, this realization system comprises: control network element 2, SGSN4 and MSC6.Further above-mentioned each network element is described below.

Control network element 2, be used for after the handoff request that receives the access network transmission, for the voice bearer of UE is initiated first handoff procedure to SGSN4, and initiate second handoff procedure to MSC6, obtain first media information by first handoff procedure, and send second media information to SGSN4, by second handoff procedure forwarding number and above-mentioned first media information are sent to MSC6, and obtain above-mentioned second media information by second handoff procedure; By first handoff procedure, can set up the carrying between SGSN4 and the data gateway, in concrete the application, first handoff procedure can be called handoff procedure between the wireless access technology net.

In concrete the application, above-mentioned first media information can comprise: the medium link information of SGSN4, and second media information can comprise: the medium link information of the media gateway (MGW) of MSC6 control.

SGSN4, be used for consulting media information at above-mentioned first handoff procedure, and the link information of media data is set according to the conversation media link information of obtaining by first handoff procedure, wherein, this media data is encapsulated in the carrying that described first handoff procedure sets up; By first handoff procedure and second handoff procedure, the medium that MSC6 can set up between the MGW of SGSN4 and MSC6 control are connected.

In concrete the application, SGSN4 and MSC6 carry out in the negotiations process of media information, and the media information that SGSN4 sends to MSC6 (sending by control network element 2) comprising: the medium link information of SGSN4; The media information that MSC6 sends to SGSN4 (sending by control network element 2) comprising: the medium link information of the media gateway (MGW) of MSC6 control.Particularly, SGSN4 sends the media information (being above-mentioned first media information) of SGSN4 to control network element 2 in above-mentioned first handoff procedure, MSC6 sends the media information (being above-mentioned second media information) of the MGW of MSC6 control to control network element 2 in above-mentioned second handoff procedure, and control network element 2 is after receiving above-mentioned first media information, by second handoff procedure this first media information is sent to MSC6, second media information is sent to SGSN4 by above-mentioned first handoff procedure.

MSC6 is used at above-mentioned second handoff procedure, is that target is initiated IMS session transfer process with the forwarding number, carries out the CS handoff procedure, and consults media information by described second handoff procedure.In concrete the application, second handoff procedure also can be called the single mode handoff procedure.

Further, also having a non-voice carrying if above-mentioned UE is current, then control network element 2 and also be used for when initiating above-mentioned first handoff procedure, is that the 3rd handoff procedure is initiated in the non-voice carrying.

In embodiments of the present invention, control network element 2 includes but not limited to following process to first handoff procedure that SGSN4 initiates: control network element 2 sends handoff request message (for the ease of difference to SGSN4, be called the first handoff request message in embodiments of the present invention, can carry above-mentioned second media information in this handoff request message); After SGSN4 receives the first handoff request message, return switching response message (can carry above-mentioned first media information in this switching response message) to control network element 2; After UE is modulated to objective network, SGSN4 sends handoff completion message (for ease of difference to control network element 2, in embodiments of the present invention this handoff completion message is referred to as first handoff completion message), control network element 2 is after receiving this handoff completion message, return switching to SGSN4 and finish acknowledge message (for the ease of difference, be called first switching in embodiments of the present invention and finish acknowledge message, can carry above-mentioned second media information in this message).

And control network element 2 includes but not limited to following process to second handoff procedure that MSC6 initiates: control network element 2 sends handoff request message (being called the second handoff request message in embodiments of the present invention) to MSC6; After MSC6 receives this handoff request, return switching response message (can carry above-mentioned second media information in this switching response message) to control network element 2; After UE is modulated to objective network, MSC6 sends handoff completion message (for ease of difference to control network element 2, in embodiments of the present invention this handoff completion message is referred to as second handoff completion message), control network element 2 is after receiving this handoff completion message, return switching to MSC6 and finish acknowledge message (be referred to as second switching in embodiments of the present invention and finish acknowledge message, can carry above-mentioned first media information in this message).

The 3rd handoff procedure is to the similar substantially difference of first handoff procedure and second handoff procedure, and the 3rd handoff procedure is that the control network element is initiated to target P S territory, and detailed process repeats no more.

Further, in first handoff procedure, receive the message of first handoff completion message that SGSN4 the sends handoff completion message of first handoff procedure (promptly at) and release voice bearer at control network element 2 after, control network element 2 also is used for sending first switching to SGSN4 and finishes acknowledge message, and, if control network element 2 has been initiated above-mentioned the 3rd handoff procedure, then control network element 2 and also be used to above-mentioned non-voice carrying transmission the 3rd switching to finish acknowledge message (promptly finishing acknowledge message) at the switching of the 3rd handoff procedure; And SGSN4 receive above-mentioned first switch finish acknowledge message after, releasing bearing resource.In concrete the application, SGSN4 can to switch after finishing acknowledge message be releasing bearing resource receiving first, also can be after receiving for first scheduled time of switching after finishing acknowledge message releasing bearing resource, perhaps releasing bearing resource when receiving releasing bearing message, perhaps, SGSN4 also can receive first switch finish acknowledge message after, send the bearer update request to data gateway, after the scheduled time after this bearer update request of transmission, releasing bearing resource.

In concrete the application, be based on according to the realization system of the above-mentioned single radio voice call continuity of the embodiment of the invention that the network architecture shown in Fig. 3 B finishes, because CS territory handover operation has been the process of standard, describe for simplifying, repeat no more the handoff procedure in CS territory, therefore, the access network entity of the target network of drawing also useless in the accompanying drawing below.

Below each section connection among Fig. 3 B is described.

301, UE and PS Access Network (are enhancing Node B (the ehanced NodeB of LTE network, abbreviate eNB as), or the radio network controller of HSPA network (Radio NetworkController, abbreviate RNC as)) between signaling interface, the space interface signaling agreement by LTE network or HSPA network communicates with one another;

302, UE and objective network Access Network (are the radio network controller (RNC) of 2G or 3G network, or base station sub-system (Base Station Subsystem abbreviates BSS as)) signaling interface between, the space interface signaling agreement by 2G or 3G network communicates with one another;

303, the signaling interface between PS Access Network and control network element (be the MME of LTE network, or the SGSN of HSPA network) is realized the mobile management function;

304, the signaling interface between PS network control network element and PS grouping of network data gateway (be the SGW and the PGW of LTE network, or the GGSN of HSPA network) is realized the bearer management function;

305, the signaling interface between PS network control network element and SGSN is realized the carrying handoff functionality;

306, signaling interface between control network element and MSC realizes that PS is to the CS handoff functionality;

307, the interface between objective network Access Network and MSC;

308, the internetwork signaling paths of MSC and IMS can be the IMS signaling interface, also can insert the IMS network by the IAD of IMS;

309, the interface of PS grouping of network data gateway and IMS network provides IP to connect.

Below signaling paths and the media path of realizing single radio voice call continuity in the embodiment of the invention is described, among the figure below, in order to simplify description, the MGW of MSC and control thereof is described as an entity, adopt the interface and the flow process of standard mutual between MSC and the MGW.

Fig. 4 A is the schematic diagram of the single radio voice call continuity of embodiment of the invention realization, the signaling paths and the media path of session between UE and far-end UE have been described, after switching, the media path of session between UE and far-end UE, and MSC has carried out signaling paths and media path after the IMS transfer operation, wherein the IMS transfer operation is consuming time long, and the media path after the switching is the migration path before the IMS transfer operation is finished just.

The former IMS session signaling of UE provides access service to be connected on the IP network by the PS network, and is connected to the IMS network by IP network, and former IMS voice call media path provides access service to be connected on the IP network by the PS network; After switching generation, the voice call medium of UE provide CS to insert by objective network, conversation control signaling is also realized by the CS signaling protocol, the MGW that the CS medium connect by MSC control is converted to the connection of IP medium, and be connected on the SGSN by IP network, the media data that SGSN connects the IP medium is encapsulated in the carrying to be realized and PS grouping of network data gateway switched-media data, after the switching, medium connect the IP medium coupling part shared PS network packet data gateway, and the IP medium after the switching connect and are carried as the transition medium and are connected; In the time of handover operation, MSC also carries out the transfer operation of IMS, and after transfer operation was finished, new medium connected and replaced the connection of transition medium, finish single radio voice call continuity.

Fig. 4 B is the SGSN4 functional schematic of the embodiment of the invention, described switch after, the MGW of MSC control is connected the carrying encapsulation of setting up by SGSN with the IP medium of SGSN after, realization and far-end UE communication, and for far-end UE, the medium link address is constant:

The MGW of MSC control sets up the IP medium with SGSN and is connected, thereby can transmit the IP media data, in the carrying between that SGSN encapsulates into its foundation with the IP media data and PS grouping of network data gateway, and the former link address of revising the connection of IP medium is UE's, the target link address is far-end UE's, thereby the reusable former IP medium of PS grouping of network data gateway connect, and can carry out media data between the MGW that realizes MSC control and far-end UE and exchange and need not to upgrade far-end.

MSC and SGSN consult media information by the handoff procedure on 305 and 306 interfaces among Fig. 3 B, connect to set up the IP medium; SGSN sets up carrying between SGSN and data gateway by the handoff procedure on 305 interfaces among Fig. 3 B, and obtains the conversation media link information by the handoff procedure on 305 interfaces among Fig. 3 B, thereby obtains the link address of UE and the link address of far-end UE.

Below the implementation method according to the single radio voice call continuity of the embodiment of the invention is described, this method can realize by the realization system of above-mentioned single radio voice call continuity.

Fig. 5 is the flow chart according to the implementation method of the single radio voice call continuity of the embodiment of the invention, and as shown in Figure 5, this method mainly may further comprise the steps (step S502-step S510):

Step S502, after the handoff request that receives the access network transmission, the control network element is that voice bearer is initiated first handoff procedure to SGSN, and obtains first media information by first handoff procedure;

In specific implementation process, if the current non-voice carrying (promptly this UE is current is also carrying out non-voice service) that also has UE is then controlled network element and also will be initiated the 3rd handoff procedure for the non-voice carrying.

In concrete the application, above-mentioned first handoff procedure that the control network element is initiated can be called handoff procedure between the wireless access technology net, does not specifically limit in embodiments of the present invention.

Step S504, the control network element is initiated second handoff procedure to MSC, by second handoff procedure forwarding number is sent to MSC, and obtains second media information;

In concrete the application, above-mentioned second handoff procedure that the control network element is initiated can be called the single mode handoff procedure, does not specifically limit in embodiments of the present invention.

Step S506, MSC are that target is initiated IMS session transfer process with the forwarding number, and carry out the CS handoff procedure;

CS medium after can setting up single radio voice call continuity and finish by IMS session transfer process and CS handoff procedure and the signaling paths between signaling paths, MSC and far-end UE, and the media path between MGW and far-end UE.

Step S508, the control network element sends second media information by first handoff procedure to SGSN, sends first media information by second handoff procedure to MSC;

In specific implementation process, SGSN comprises to first media information that MSC sends: the medium link information of SGSN;

MSC comprises to second media information that SGSN sends: the medium link information of the MGW of MSC control.

By above-mentioned first media information and second media information, the medium that can set up between the MGW of SGSN and MSC control are connected.

Step S510, SGSN obtains the conversation media link information by first handoff procedure, and according to the conversation media link information link information of media data is set, and wherein, this media data is encapsulated in the carrying of setting up by first handoff procedure.

In concrete application process, in above-mentioned first handoff procedure, after discharging former session or deleting voice in the former session, the control network element will receive the message of release (or deletion) voice bearer, thereby will feed back to switch and finish acknowledge message, in embodiments of the present invention, the processing that acknowledge message is finished in switching includes but not limited to following six kinds of methods:

Method one in the method, is switched to finish and is later than the IMS session and shifts and finish.Particularly, this method can realize by following steps:

Step 1, controlling network element in first handoff procedure that SGSN initiates, after the control network element receives the message of first handoff completion message that SGSN sends and release (or deletion) voice bearer, send first switching to SGSN and finish acknowledge message, if being the non-voice carrying, the control network element initiated above-mentioned the 3rd handoff procedure, after then receiving the message of deleting voice bearer, the control network element is also finished acknowledge message (promptly send the 3rd switching to target P S territory and finish acknowledge message) for the non-voice carrying sends the 3rd switching;

Step 2, SGSN receive above-mentioned first switch finish acknowledge message after, releasing bearing resource.

Method two, in the method, switching sends after finishing and being identified in the scheduled time.Particularly, this method can realize by following steps:

Step 1 is being controlled network element in first handoff procedure that SGSN initiates, and the control network element sends first switching to SGSN and finishes acknowledge message after receiving first handoff completion message of SGSN transmission and waiting for the scheduled time;

Method three, in the method, SGSN finishes acknowledge message in the switching that receives the transmission of control network element, discharges resource after the wait scheduled time.Particularly, this method can realize by following steps:

Step 1 is being controlled network element in first handoff procedure that SGSN initiates, and after the control network element receives first handoff completion message of SGSN transmission, sends first switching to SGSN immediately by standard procedure and finishes acknowledge message;

Step 2, SGSN receive above-mentioned first switch finish acknowledge message and wait for the scheduled time after, releasing bearing resource.

Method four, in the method, voice switch the back chain of command and are updated to SGSN, and the back discharges resource at the fixed time.Particularly, this method can realize by following steps:

Step 1, controlling network element in first handoff procedure that SGSN initiates, initiated above-mentioned the 3rd handoff procedure if the control network element is non-voice carrying, then send to SGSN first switch finish acknowledge message and wait for special time after, switch and finish acknowledge message for the non-voice carrying sends the 3rd;

Step 2, SGSN receives and picks up counting after acknowledge message is finished in switching, when Preset Time arrives or when receiving releasing bearing message, the SGSN releasing bearing resource.

Method five, in the method, voice switch the back chain of command and are updated to the control network element, and particularly, this method can realize by following steps:

Step 1, controlling network element in first handoff procedure that SGSN initiates, initiated above-mentioned the 3rd handoff procedure if control network element, then after finishing acknowledge message and wait for special time to SGSN transmission first switching, acknowledge message is finished in the 3rd switching that sends the non-voice carrying;

Step 2, SGSN receive first switch finish acknowledge message after, send the bearer update request and pick up counting to data gateway, wherein, carry the chain of command link information of control network element in this bearer update request;

Step 3, when Preset Time arrives, the SGSN releasing bearing resource.

Method six, in the method, voice switching back is with good conditionsi carries out timing to discharge resource.Particularly, this method can realize by following steps:

Step 1, controlling network element in first handoff procedure that SGSN initiates, if the control network element has been initiated above-mentioned the 3rd handoff procedure, then after finishing acknowledge message and wait for special time to SGSN transmission first switching, acknowledge message is finished in the 3rd switching that sends the non-voice carrying, wherein, first switching is finished and is carried indication information in the acknowledge message;

Step 2, SGSN receive first switch finish acknowledge message after owing to carry indication information in this message, therefore, pick up counting, and releasing bearing resource when arriving Preset Time or after receiving releasing bearing message.

In the method, do not carry above-mentioned indication information in the acknowledge message if first switching is finished, then do not carry out timing, SGSN is releasing bearing resource after receiving releasing bearing message.

In embodiments of the present invention, media path can be updated to and detour from the PS Access Network, particularly, can realize in the following manner: controlling network element in first handoff procedure that SGSN initiates, after the control network element receives handoff completion message, send the request that discharges voice bearer to the PS Access Network, and send the request of bearer update to data gateway.Thereby discharge the carrying that PS inserts the network segment.

In concrete the application, SGSN can obtain above-mentioned conversation media link information from the control network element, and particularly, the method that SGSN obtains above-mentioned conversation media link information includes but not limited to following three kinds:

Method 1, in above-mentioned first handoff procedure, the control network element carries the conversation media link information in the handoff request message (i.e. the first handoff request message) that sends to SGSN, and SGSN can obtain the conversation media link information by this handoff request message;

Method 2, control network element are carried at first with session medium link information and switch to finish and send to SGSN in the acknowledge message in above-mentioned first handoff procedure, and SGSN finishes acknowledge message by this switching can obtain the conversation media link information;

Method 3, in above-mentioned IMS session transfer process, MSC is a target with above-mentioned forwarding number, sends transfer request, and receives the Temporary Response message of this transfer request, wherein, carries the conversation media link information in this Temporary Response message; Then, above-mentioned second handoff procedure that MSC initiates at the control network element carries this conversation media link information in second handoff response that sends to the control network element or second handoff completion message handoff completion message of second handoff procedure (promptly at); Then, the control network element is in first handoff procedure of initiating to SGSN, switch to finish in the first handoff request message that sends to SGSN or first and carry this conversation media link information in the acknowledge message, switch and finish the conversation media link information of carrying in the acknowledge message thereby make SGSN can obtain first handoff request or second.

In concrete the application, the realization of said method 1 and method 2 has individual prerequisite: the control network element obtains the conversation media link information, and in concrete the application, the control network element can obtain the conversation media link information by UE.Particularly, the control network element is after the handoff request that receives the access network transmission, can obtain the media resource information of session to UE, perhaps, UE sends to the control network element with the media resource information of session when setting up session, wherein, the media resource information of this session comprises: the conversation media link information, or conversation media link information and codec information, like this, the control network element also can obtain the conversation media link information.Perhaps, in some cases, this conversation media link information is preserved in control network element this locality, then controls the conversation media link information that network element can directly obtain preservation, and need not to obtain from UE.

In specific implementation process, after above-mentioned IMS session transfer process was finished, MSC also needed to be released in the media resource that distributes in second handoff procedure.

Below by specific embodiment the technical scheme that the embodiment of the invention provides is described.

Embodiment one

In the present embodiment, described between UE and far-end UE and set up the IMS voice call, medium connect by UE is connected with PS between the PS Access Network, the PS Access Network connects and composes with the IP that PS between PS grouping of network data gateway is connected, reaches between PS grouping of network data gateway and far-end UE, UE switches and the process of network realization single radio voice call continuity.Fig. 6 is the flow chart of present embodiment, as shown in Figure 6, mainly may further comprise the steps:

Step 601, UE send measurement report to the PS Access Network, such as, send Measurement report message, comprising the signal strength information of objective network;

Step 602, PS Access Network are according to signal strength signal intensity, and decision switches to the conversation of UE in the objective network, to the control network element transmission handoff request of PS network, such as, send Handover Required message;

Step 603, the control network element judges that UE has set up the carrying of voice call, decision switches to voice call in the CS territory of objective network, obtain the media resource information of session from UE, such as, send ESM Information Request message to UE, UE sends ESMInformation Response message, carry the codec information of session, perhaps UE carries the codec information of session by Service Request message in the process that initiation session is set up, go back the medium link information of portability session in the message that UE sends, comprise that the medium of UE and far-end UE connect IP and port information;

If step 604 UE also has other non-voice conversational class business, the control network element sends handoff request to the PS territory of objective network, these business are switched to the PS territory of target network, such as, send Forward Relocation Request message to the PS territory of target network, carry other loaded information.

Step 605, control network element are initiated handoff procedure to MSC simultaneously, at first send handoff request, such as, send PS to CS Handover Request message, carry conversation media codec information, forwarding number.

Step 606, MSC carry out the CS handoff procedure, for UE prepares the CS media resource;

After step 607, MSC execute set-up procedure in the CS handoff procedure, initiate IMS session transfer process, at first initiate the INVITE of CS signaling Session Initiation Protocol or the INVITE of IMS signaling, target is a forwarding number, carry the media resource information of the MGW of MSC control, this request can be routed to the SCC AS in the IMS network;

Step 608, with step 607 simultaneously, MSC sends handoff response to SGSN, such as sending PS to CS Handover Response message, carries the media information (being the second above-mentioned media information) of the MGW of MSC control, comprises the medium link information of MGW;

Step 609, control network element are that voice bearer is initiated handoff procedure to SGSN, at first send handoff request, such as, send Forward Relocation Request message, carry the media information that obtains in information, conversation media resource information and the step 608 of voice bearer, if the conversation media link information UE in the conversation media resource information does not issue the control network element, then control network element and use voice bearer to set up the conversation media link information (being included in the TFT information) of the voice bearer that obtains in the process;

So far, SGSN can be in the carrying of be about to setting up the IP medium link address of configuration packages, be about to local link address that the IP medium of encapsulation connect and be configured to UE, the far-end link address is configured to far-end UE's.

Step 610, SGSN send handoff response to the control network element of PS network, and such as sending Forward Relocation Response message, message is carried the bearing resource information of SGSN and the media information of SGSN, comprises the medium link information of SGSN;

If step 611 control network element has also sent handoff request to the PS territory of objective network, then the PS territory of objective network can send handoff response, such as sending Forward RelocationResponse message, carries the bearing resource information in objective network PS territory;

Step 612, control network element associate step 610 and step 611, send switching command to the PS Access Network, such as sending Handover Command message, carry the bearing resource information of acquisition;

Step 613, PS Access Network send switching command to UE, if the PS network is the LTE network, then send Handover from LTE message, if the PS network is the HSPA network, then send Handover from UTRAN message;

Step 614, UE are modulated to objective network, and objective network can obtain notice;

Step 615, MSC receive UE and are modulated to the link setup response message that the MSC of the notice of objective network or controlled target sub-district sends, and send handoff completion message to the control network element, such as sending PS to CS Handover Complete message;

Step 616, control network element are sent completely acknowledge message to MSC immediately, such as sending PS to CS Handover Complete ACK message, carry the media information (i.e. first media information) that obtains in the step 610, so far, MSC can connect with the SGSN swap data by the IP medium;

After MSC receives the message of step 616, just can set up the IP medium between the MGW of MSC control and SGSN and be connected.

Step 617, with step 616 simultaneously, SGSN sends handoff completion message to the control network element of PS network, such as sending Forward Relocation Complete message;

If step 618 does not wish that media data detours from the PS Access Network, then control network element and send the releasing bearing request, to discharge the voice bearer resource in the PS Access Network to the PS Access Network;

After step 619, the step 618, the control network element sends the bearer update request to data gateway, to upgrade the carrying on the data gateway, data gateway is directly linked to each other with SGSN;

If step 620 control network element has sent handoff request to the PS territory of objective network, then the PS territory of objective network also can send handoff completion message to the control network element, such as, send Forward Relocation Complete message;

So far, the connection of CS medium is connected with the transition medium to be set up, wherein the transition medium connect and comprise that the upstream data medium connect and the downlink data media links, and wherein up media data is connected to: MGW-＞SGSN, the SGSN-＞data gateway of MSC control, and data gateway-＞far-end UE; Descending media data is connected to: far-end UE-＞data gateway, data gateway-＞the PS Access Network, the PS Access Network-＞data gateway (, then do not have aforementioned two sections between data gateway and the PS Access Network and be connected) if carried out step 618～519, data gateway-＞SGSN, SGSN-＞MGW.

After step 621, SCC AS receive the transfer request of step 608, according to the related former session of the number of UE, and to the far-end UE of former session transmission updating message, such as the reINVITE that sends the IMS signaling (heavily inviting) message or UPDATE (renewal) message, carry the media resource information that from step 608, obtains;

Step 622, far-end UE reply updating message, such as sending 200OK message, the new media resource information of carrying far-end UE;

Step 623, SCC AS receive the renewal response message, send transfer acknowledge message to MSC, such as, send 200OK message, the media resource information of carrying far-end UE;

Step 624, SCC AS discharges the near-end access path of former session, such as the BYE message that sends IMS, if perhaps UE also has the PS territory after switching to objective network, the voice medium that UE deletes former session connects, such as, send the reINVITE message of IMS, carry the media resource information of UE session this time, wherein the voice medium resource information be designated invalid, such as, port numbers is set to 0, and these operations all are standard procedures, its result can cause that PS grouping of network data gateway sends the operation of deletion voice bearer, if the HSPA network then is that GGSN initiates, if the LTE network, then be that PGW mails to SGW, initiate by SGW again;

Step 625, PS grouping of network data gateway (GGSN or SGW) send the operation that discharges voice bearer to the control network element of PS network, such as, send Delete BearerRequest, carry voice bearer information;

Step 626, control network element are sent completely acknowledge message to SGSN, such as sending Forward Relocation Complete ACK message;

Step 627, SGSN discharge the bearing resource on it;

If step 628 control network element has also sent handoff request to the PS territory of objective network, then also be sent completely acknowledge message to the PS territory of objective network, such as, send ForwardRelocation Complete ACK message;

The PS territory of step 629, objective network sends to PS grouping of network data gateway (SGW) upgrades bearer messages, such as, send Modify Bearer Request, to upgrade the PS beared information, comprise the link information of chain of command and user's face.

Since then, transfer operation and single radio voice call continuity operation are finished, final media path is that UE connects to the IP medium between far-end UE to the MGW that the CS medium connect and MSC controls between the MGW of MSC control, and the near-end access path of IMS signaling paths is revised as with MSC and links to each other.

Embodiment two

In the present embodiment, described between UE and far-end UE and set up the IMS voice call, medium connect by UE is connected with PS between the PS Access Network, the PS Access Network connects and composes with the IP that PS between PS grouping of network data gateway is connected, reaches between PS grouping of network data gateway and far-end UE, UE switches and the process of network realization single radio voice call continuity.Fig. 7 is the flow chart of present embodiment, as shown in Figure 7, mainly may further comprise the steps:

Step 701～702, identical with step 601～602 among Fig. 6;

Step 703～706, identical with step 604～607 among Fig. 6;

Step 707, SCC AS receive the transfer request of step 707, send Temporary Response message immediately, such as, send the 183 Session Progress message of IMS, carry the media resource information of former session, the media codec information and the conversation media link information that comprise former session, conversation media link information comprise the medium link address information of UE and far-end UE;

Step 708, MSC send handoff response to the control network element, such as, send PS to CSHandover Response message, carry the media information of the MGW of MSC control, the medium link information that comprises MGW is also carried the conversation media link information that obtains in the step 707;

Step 709, control network element are that voice bearer is initiated handoff procedure to SGSN, at first send handoff request, such as, send Forward Relocation Request message, carry the media information and the conversation media link information that obtain in the information of voice bearer and the step 708;

Step 710～722, identical with step 610～622 among Fig. 6;

Step 723, SCC AS receive the renewal of far-end UE and reply, to the updating message of MSC transmission IMS, such as sending UPDATE (renewal) message, the media resource information of carrying the far-end UE of acquisition;

Step 724, MSC send and upgrade response message, such as, send the 200OK message of CS signaling Session Initiation Protocol or the 200OK message of IMS signaling, carry the media resource information of the MGW of MSC control;

Step 725～731, identical with step 623～629 among Fig. 6.

Embodiment three

In the present embodiment, single radio voice call continuity has only voice to switch, in the present embodiment, described between UE and far-end UE and set up the IMS voice call, and not setting up non-voice connects, medium connect by UE be connected with PS between the PS Access Network, the PS Access Network connects and composes with the IP that PS between PS grouping of network data gateway is connected, reaches between PS grouping of network data gateway and far-end UE, UE switches and network is realized the process of single radio voice call continuity, Fig. 8 is realization flow figure of the present invention, mainly may further comprise the steps:

Step 801, identical with step 601～603 among Fig. 6, or identical with step 701～702 among Fig. 7;

Step 802, control network element are that voice bearer is initiated handoff procedure to SGSN, at first send handoff request, such as, send Forward Relocation Request message, carry information, the conversation media resource information of voice bearer, in concrete the application,, then control network element and use voice bearer to set up the conversation media link information (being included in the TFT information) of the voice bearer that obtains in the process if the conversation media link information UE in the conversation media resource information does not issue the control network element;

Step 803, with step 802 simultaneously, the control network element is initiated handoff procedure to MSC, at first sends handoff request, such as, send PS to CS Handover Request message, carry conversation media codec information, forwarding number.

If step 804 801 is used the step of Fig. 6,606～608 identical with Fig. 6 then, otherwise 705～708 identical with Fig. 7;

Step 807, in response to step 802, SGSN sends handoff response to the control network element of PS network, such as sending Forward Relocation Response message, message is carried the bearing resource information of SGSN and the media information of SGSN (i.e. first media information), comprises the medium link information of SGSN;

If step 808 801 is used the step of Fig. 6,612～619 identical with Fig. 6 then, otherwise 712～719 identical with Fig. 7;

Step 810, control network element are sent completely acknowledge message to SGSN, such as sending Forward Relocation Complete ACK message, carry the media information (i.e. second media information) that obtains in conversation media resource information and the step 804;

So far consulted the medium link information between SGSN and MSC.

If step 811 has non-voice carrying carrying out handover operation, then target P S territory also can send the bearer update request to data gateway, therefore SGSN and do not know whether the bearer update that step 804 is carried out can successfully upgrade chain of command, because of user's face that SGSN upgrades is affirmed different with user's face of target P S area update, upgrade successfully so user's face is sure, so after SGSN receives and finishes acknowledge message, start timer;

Step 812, with step 811 simultaneously, SGSN sends the bearer update request by standard procedure to data gateway, such as sending Modify Bearer Request message;

So far, the connection of CS medium is connected with the transition medium to be set up, wherein the transition medium connect and comprise that the upstream data medium connect and the downlink data media links, and wherein up media data is connected to: MGW-＞SGSN, SGSN-＞data gateway, and data gateway-＞far-end UE; Descending media data is connected to: far-end UE-＞data gateway, and data gateway-＞SGSN, SGSN-＞MGW.

Owing to carried out the step 618 among Fig. 6～519 (or the step 718 among Fig. 7～719) in the present embodiment, therefore, do not have in the present embodiment data gateway-＞PS Access Network and PS Access Network-＞these two sections connections of data gateway.

If step 813 step 801 is used the step of Fig. 6, and is then identical with step 621～624 of Fig. 6, otherwise identical with step 721～726 of Fig. 7;

Step 814, switch because of having only voice bearer, therefore the chain of command of data gateway has been upgraded in the renewal of step 812 operation, PS grouping of network data gateway (GGSN or SGW) such as sending Delete Bearer Request, carries voice bearer information to the operation that SGSN sends releasing bearing;

Step 815, SGSN receive the operation of releasing bearing, or the timer expiry of step 811, the SGSN releasing bearing resource.

Embodiment four

In the present embodiment, single radio voice call continuity promptly has voice that the realization flow figure of the switching of non-voice is also arranged, present embodiment has been described between UE and far-end UE and has been set up the IMS voice call, and set up the non-voice connection, medium connect by UE is connected with PS between the PS Access Network, the PS Access Network connects and composes with the IP that PS between PS grouping of network data gateway is connected, reaches between PS grouping of network data gateway and far-end UE, UE switches and the process of network realization single radio voice call continuity.Fig. 9 is the flow chart of present embodiment, as shown in Figure 9, mainly may further comprise the steps:

Step 901, identical with step 601～604 among Fig. 6 has wherein been carried out step 604, or identical with step 701～703 among Fig. 7, has wherein carried out step 703;

Step 902, with Fig. 8 in 802～807 identical;

If step 903 901 is used the step of Fig. 6, then 611～616 identical with Fig. 6 wherein carried out step 611, otherwise 711～716 identical with Fig. 7 wherein carried out step 711;

Step 904, SGSN send handoff completion message to the control network element of PS network, such as sending Forward Relocation Complete message;

If step 905 does not wish that media data detours from the PS Access Network, then control network element and send the releasing bearing request, to discharge the voice bearer resource in the PS Access Network to the PS Access Network;

After step 906, the step 905, the control network element sends the bearer update request to data gateway, to upgrade the carrying on the data gateway, data gateway is directly linked to each other with SGSN;

Step 907, owing to carried out the handover operation of non-voice carrying, target P S territory also sends handoff completion message to the control network element of PS network, such as, send ForwardRelocation Complete message;

Step 908, receive the message of step 907 after, the control network element starts timer;

Step 909, with step 908 simultaneously, the control network element sends to switch to SGSN finishes acknowledge message, such as, send Forward Relocation Complete Ack message, carry the media information that obtains in conversation media resource information and the step 902;

So far consulted the medium link information between SGSN and MSC.

If step 910 has non-voice carrying carrying out handover operation, then target P S territory also can send the bearer update request to data gateway, therefore, SGSN does not also know whether the bearer update that step 911 is carried out can successfully upgrade chain of command, because of user's face that SGSN upgrades is affirmed different with user's face of target P S area update, upgrade successfully so user's face is sure, then SGSN receive finish acknowledge message after, start timer;

Step 911, with step 910 simultaneously, SGSN sends the bearer update request by standard procedure to data gateway, such as sending Modify Bearer Request message, or to the request of data gateway transmission bearer update, carry the chain of command information of control network element, cause controlling network element to avoid the gap generation non-voice carrying releasing operation between step 911 and 914 and can not control this process;

Timer expiry in step 912, the step 908;

Step 913, control network element send to switch to target P S territory finishes acknowledge message, such as sending Forward Relocation Complete Ack message;

Step 914, target P S territory send the bearer update request by standard procedure to data gateway, such as sending Modify Bearer Request message;

Timer in the step 908 will guarantee that the message that the message in the step 914 is later than in the step 911 arrives data gateway.

So far, the connection of CS medium is connected with the transition medium to be set up, wherein the transition medium connect and comprise that the upstream data medium connect and the downlink data media links, and wherein up media data is connected to: MGW-＞SGSN, SGSN-＞data gateway, and data gateway-＞far-end UE; Descending media data is connected to: far-end UE-＞data gateway, data gateway-＞the PS Access Network, the PS Access Network-＞data gateway (, then do not have aforementioned two sections between data gateway and the PS Access Network and be connected) if carried out step 905～906, data gateway-＞SGSN, SGSN-＞MGW.

If step 915 901 is used the step of Fig. 6,621～624 identical with Fig. 6 then, otherwise 721～726 identical with Fig. 7;

The renewal operation of step 916, step 914 makes the chain of command of data gateway link to each other with target P S territory, and voice bearer is not controlled in target P S territory, therefore data gateway can not transmitted the message that voice bearer discharges and give SGSN, behind the timer expiry in the step 910, and the SGSN releasing bearing resource.

Embodiment five

In the present embodiment, described between UE and far-end UE and set up the IMS voice call, medium connect by UE is connected with PS between the PS Access Network, the PS Access Network connects and composes with the IP that PS between PS grouping of network data gateway is connected, reaches between PS grouping of network data gateway and far-end UE, UE switches and the process of network realization single radio voice call continuity.Figure 10 is the flow chart of present embodiment, as shown in figure 10, mainly may further comprise the steps:

Step 1001, identical with step 601～604 among Fig. 6, or identical with step 701～703 among Fig. 7;

Step 1001a, with Fig. 8 in 802～807 identical;

If step 1001b 901 uses the step of Fig. 6,611～616 identical with Fig. 6 then, otherwise 711～716 identical with Fig. 7;

Step 1002, SGSN send handoff completion message to the control network element of PS network, such as sending Forward Relocation Complete message;

If step 1003 does not wish that media data detours from the PS Access Network, then control network element and send the releasing bearing request, to discharge the voice bearer resource in the PS Access Network to the PS Access Network;

After step 1004, the step 1003, the control network element sends the bearer update request to data gateway, to upgrade the carrying on the data gateway, data gateway is directly linked to each other with SGSN;

Step 1005, owing to may carry out the handover operation of non-voice carrying, target P S territory also may send handoff completion message to the control network element of PS network, such as sending Forward Relocation Complete message;

Step 1006, receive the message of step 1002 after, if carried out the handover operation of non-voice carrying, then control network element and start timer;

Step 1007, control network element send to switch to SGSN finishes acknowledge message, such as sending Forward Relocation Complete Ack message, carries the media information that obtains among conversation media resource information and the step 1001a;

So far consulted the medium link information between SGSN and MSC.

Step 1008, SGSN receive to switch and finish acknowledge message, if this message is carried indication information, then start timer, otherwise do not start timer;

If the message in step 1009 step 1007 is not carried indication information, SGSN sends the bearer update request by standard procedure to data gateway, such as sending Modify BearerRequest message, otherwise SGSN sends the bearer update request by standard procedure to data gateway, or to the request of data gateway transmission bearer update, carry the chain of command information of control network element, cause controlling network element to avoid gap between step 1009 and possible step 1012 that non-voice carrying releasing operation takes place and to control this process;

If step 1010 has been carried out step 1006, the timer expiry in the step 1006;

If step 1011 has been carried out the handover operation of non-voice carrying, the control network element sends to switch to target P S territory finishes acknowledge message, such as sending Forward RelocationComplete Ack message;

Step 1012, target P S territory send the bearer update request by standard procedure to data gateway, such as sending Modify Bearer Request message;

Timer in the step 1006 will guarantee that the message that the message in the step 1012 is later than in the step 1009 arrives data gateway.

So far, the connection of CS medium is connected with the transition medium to be set up, wherein the transition medium connect and comprise that the upstream data medium connect and the downlink data media links, and wherein up media data is connected to: MGW-＞SGSN, SGSN-＞data gateway, and data gateway-＞far-end UE; Descending media data is connected to: far-end UE-＞data gateway, data gateway-＞the PS Access Network, the PS Access Network-＞data gateway (, then do not have aforementioned two sections between data gateway and the PS Access Network and be connected) if carried out step 1003～1004, data gateway-＞SGSN, SGSN-＞MGW.

If step 1,013 1001 is used the step of Fig. 6, and is then identical with step 621～624 of Fig. 6, otherwise identical with step 721～726 of Fig. 7;

If step 1014 is not carried out the handover operation of non-voice carrying, and step 1009 carries out by standard procedure, and then data gateway can discharge request with voice bearer and issue SGSN;

Step 1015, SGSN receive the operation of releasing bearing, or the timer expiry of step 1008, the SGSN releasing bearing resource.

Embodiment six

In the present embodiment, described between UE and far-end UE and set up the IMS voice call, medium connect by UE is connected with PS between the PS Access Network, the PS Access Network connects and composes with the IP that PS between PS grouping of network data gateway is connected, reaches between PS grouping of network data gateway and far-end UE, UE switches and the process of network realization single radio voice call continuity.Figure 11 is the flow chart of present embodiment, as shown in figure 11, mainly may further comprise the steps:

Step 1101, identical with step 601～617 among Fig. 6, or identical with step 701～717 among Fig. 7;

After step 1104, control network element are received the handoff completion message of SGSN transmission, start timer;

If step 1105 does not wish that media data detours from the PS Access Network, then control network element and send the releasing bearing request, to discharge the voice bearer resource in the PS Access Network to the PS Access Network;

After step 1106, the step 1105, the control network element sends the bearer update request to data gateway, to upgrade the carrying on the data gateway, data gateway is directly linked to each other with SGSN;

If step 1107 control network element has sent handoff request to the PS territory of objective network, then the PS territory of objective network also can send handoff completion message to the control network element, such as sending Forward Relocation Complete message;

Step 1108, control network element are received the handoff completion message that the PS territory of objective network sends, and are sent completely acknowledge message to the PS territory of objective network, such as sending ForwardRelocation Complete ACK message;

The PS territory of step 1109, objective network sends to PS grouping of network data gateway (SGW) upgrades bearer messages, such as sending Modify Bearer Request, to upgrade the PS beared information, comprises the link information of chain of command and user's face.

Step 1110, identical with step 621～624 among Fig. 6, or identical with step 721～726 among Fig. 7;

Timer expiry in step 1111, the step 1104;

Step 1112, control network element send to switch to SGSN finishes acknowledge message, such as sending Forward Relocation Complete Ack message;

Step 1113, SGSN discharge the bearing resource on it.

Embodiment seven

In the present embodiment, described between UE and far-end UE and set up the IMS voice call, medium connect by UE is connected with PS between the PS Access Network, the PS Access Network connects and composes with the IP that PS between PS grouping of network data gateway is connected, reaches between PS grouping of network data gateway and far-end UE, UE switches and the process of network realization single radio voice call continuity.Figure 12 is the flow chart of present embodiment, as shown in figure 12, mainly may further comprise the steps:

Step 1201, identical with step 601～604 among Fig. 6, or identical with step 701～703 among Fig. 7;

Step 1201a, with Fig. 8 in 802～807 identical;

If step 1201b 1201 uses the step of Fig. 6,611～616 identical with Fig. 6 then, otherwise 711～716 identical with Fig. 7;

Step 1202, SGSN send handoff completion message to the control network element of PS network, such as sending Forward Relocation Complete message;

If step 1203 does not wish that media data detours from the PS Access Network, then control network element and send the releasing bearing request, to discharge the voice bearer resource in the PS Access Network to the PS Access Network;

After step 1204, the step 1203, the control network element sends the bearer update request to data gateway, to upgrade the carrying on the data gateway, data gateway is directly linked to each other with SGSN;

Step 1205, owing to may carry out the handover operation of non-voice carrying, target P S territory also may send handoff completion message to the control network element of PS network, such as sending Forward Relocation Complete message;

Step 1206, control network element send to switch to SGSN finishes acknowledge message, such as sending Forward Relocation Complete Ack message, carries the media information that obtains among conversation media resource information and the step 1201a;

So far consulted the medium link information between SGSN and MSC.

Step 1207, SGSN receive to switch and finish acknowledge message, start timer;

If step 1208 has been carried out the handover operation of non-voice carrying, the control network element sends to switch to target P S territory finishes acknowledge message, such as sending Forward RelocationComplete Ack message;

Step 1209, target P S territory send the bearer update request by standard procedure to data gateway, such as sending Modify Bearer Request message;

So far, the connection of CS medium is connected with the transition medium to be set up, wherein the transition medium connect and comprise that the upstream data medium connect and the downlink data media links, and wherein up media data is connected to: MGW-＞SGSN, SGSN-＞data gateway, and data gateway-＞far-end UE; Descending media data is connected to: far-end UE-＞data gateway, data gateway-＞the PS Access Network, the PS Access Network-＞data gateway (, then do not have aforementioned two sections between data gateway and the PS Access Network and be connected) if carried out step 1203～1204, data gateway-＞SGSN, SGSN-＞MGW.

If step 1,210 1201 is used the step of Fig. 6, and is then identical with step 619～624 of Fig. 6, otherwise identical with step 719～726 of Fig. 7;

The timer expiry of step 1211, step 1207, the SGSN releasing bearing resource.

The SGSN that the embodiment of the invention is provided is described below.

Figure 13 is the structural representation according to the SGSN of the embodiment of the invention, as shown in figure 13, this SGSN mainly comprises: hand-off process module 10, being used for by the control network element is that first handoff procedure that the voice bearer of UE is initiated is set up the carrying between described SGSN and data gateway, consult media information and obtain the conversation media link information by described first handoff procedure, and transmit information and the described conversation media link information that the described loaded information set up, medium that described media information is represented connect to connecting mapping block 30; Connect mapping block 30, the information that is used for loaded information is connected with medium is carried out association store, and store session medium link information; Packing data module 50, be used for the media data that receiving media connects, according to the loaded information related that connects mapping block 30 storages media data is encapsulated in the above-mentioned carrying, and is encapsulated in the link information of the media data in the above-mentioned carrying according to the conversation media link information setting that connects mapping block 30 storages with the medium connection.

Further, as shown in figure 13, SGSN also comprises: data parse module 70 is used to receive the media data in the above-mentioned carrying, and according to the information that is connected with the medium of this bearing association that connects mapping block 30 storages media data is unpacked in the above-mentioned medium connection.

Preferably, as shown in figure 14, hand-off process module 10 comprises: receiving element 100 is used for receiving the control network element and finishes acknowledge message in the switching that first handoff procedure sends; Resource releasing unit 102, be used for receiving element 100 receive switch finish acknowledge message after, discharge the bearing resource of voice bearer.

Further, as shown in figure 14, hand-off process module 10 can also comprise: timer 104, be used for timing, and when arriving the scheduled time, trigger resource releasing unit 102.

Further, hand-off process module 10 can also comprise: transmitting element 106, be used for sending the bearer update request to data gateway, and wherein, the chain of command link information of control network element is carried in this bearer update request; Then timer 104 can start when transmitting element 100 sends the bearer update request, also can receive at receiving element 106 to start when acknowledge message is finished in switching.

Figure 15 is the structural representation according to the control network element of the embodiment of the invention, and as shown in figure 15, this control network element mainly comprises: receiver module 20, the first hand-off process module 40 and the second hand-off process module 60.Wherein, receiver module 20 is used to receive the handoff request that access network sends, and triggers the first hand-off process module 40 and the second hand-off process module 60 when receiving handoff request; The first hand-off process module 40 is used to voice bearer to initiate first handoff procedure to SGSN, obtains first media information by first handoff procedure, and sends second media information to SGSN; The second hand-off process module 60 is used for initiating second handoff procedure to MSC, by second handoff procedure forwarding number and first media information is sent to MSC, and obtains above-mentioned second media information.

Wherein, above-mentioned first media information comprises: the medium link information of SGSN; Second media information comprises: the medium link information of the MGW of MSC control.

From above description, as can be seen, the IP media data that the MGW that MSC is controlled by SGSN transmits is encapsulated into the carrying between that SGSN sets up and PS grouping of network data gateway, realized single radio voice call continuity, CS domain-functionalities and the PS domain-functionalities of having cut apart MSC, avoid switching the problem of IMS signaling bear, solved the chain of command replacement problem of PS grouping of network data gateway.

Obviously, those skilled in the art should be understood that, above-mentioned each module of the present invention or each step can realize with the general calculation device, they can concentrate on the single calculation element, perhaps be distributed on the network that a plurality of calculation element forms, alternatively, they can be realized with the executable program code of calculation element, thereby, they can be stored in the storage device and carry out by calculation element, and in some cases, can carry out step shown or that describe with the order that is different from herein, perhaps they are made into each integrated circuit modules respectively, perhaps a plurality of modules in them or step are made into the single integrated circuit module and realize.Like this, the present invention is not restricted to any specific hardware and software combination.

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

1. the implementation method of a single radio voice call continuity is characterized in that, comprising:

After the handoff request that receives the access network transmission, the control network element is that voice bearer is initiated first handoff procedure to Serving GPRS Support Node SGSN, and obtains first media information by first handoff procedure;

Described control network element is initiated second handoff procedure to moving exchanging center MSC, by described second handoff procedure forwarding number is sent to described MSC, and obtains second media information;

Described MSC is that target is initiated IMS session transfer process with described forwarding number, and carries out the CS handoff procedure;

Described control network element sends described second media information by described first handoff procedure to described SGSN, sends described first media information by described second handoff procedure to described MSC;

Described SGSN obtains the conversation media link information, and according to described conversation media link information the link information of media data is set, and wherein, described media data is encapsulated in the carrying of setting up by described first handoff procedure.

2. method according to claim 1 is characterized in that,

Described first media information comprises: the medium link information of described SGSN;

Described second media information comprises: the medium link information of the media gateway MGW of described MSC control.

3. method according to claim 1 is characterized in that, in described first handoff procedure that is described voice bearer initiation, described method also comprises:

After described control network element receives first handoff completion message that the message that discharges voice bearer and described SGSN send, send first switching to described SGSN and finish acknowledge message, the 3rd handoff procedure has been initiated in carrying if described control network element is non-voice, then finishes acknowledge message for described non-voice carrying sends the 3rd switching simultaneously;

Described SGSN receive described first switch finish acknowledge message after, releasing bearing resource.

4. method according to claim 1 is characterized in that, in described first handoff procedure that is described voice bearer initiation, described method also comprises:

Described control network element sends first switching to described SGSN and finishes acknowledge message after receiving first handoff completion message of described SGSN transmission and waiting for the scheduled time;

5. method according to claim 1 is characterized in that, in described first handoff procedure that is described voice bearer initiation, described method also comprises:

Described SGSN receive that described control network element sends first switch finish acknowledge message and wait for the scheduled time after, releasing bearing resource.

6. method according to claim 1 is characterized in that, if described control network element has been initiated the 3rd handoff procedure for the non-voice carrying, then described method also comprises:

Described control network element is finished acknowledge message for the non-voice carrying sends the 3rd switching after finishing acknowledge message and wait for the scheduled time to described SGSN transmission first switching;

Described SGSN receives described first switching and finishes acknowledge message, releasing bearing resource after waiting for the scheduled time or after receiving releasing bearing message.

7. method according to claim 1 is characterized in that, if described control network element has been initiated the 3rd handoff procedure for the non-voice carrying, then described method also comprises:

Described SGSN receive described first switch finish acknowledge message after, send the bearer update request to data gateway, wherein, the chain of command link information of described control network element is carried in described bearer update request;

Described SGSN is releasing bearing resource after waiting for the scheduled time.

8. method according to claim 1 is characterized in that, if described control network element has been initiated the 3rd handoff procedure for the non-voice carrying, then described method also comprises:

Described control network element is finished acknowledge message for described non-voice carrying sends the 3rd switching after described SGSN transmission first switching is finished acknowledge message and waited for the scheduled time, wherein, the described first described switching is finished and carried indication information in the acknowledge message;

Described SGSN receives described first switching and finishes acknowledge message, releasing bearing resource after waiting for special time or after receiving releasing bearing message.

9. method according to claim 1 is characterized in that, in described first handoff procedure, after described control network element received first handoff completion message, described method also comprised:

Described control network element sends the request that discharges voice bearer to the PS Access Network, and sends the request of bearer update to data gateway.

10. method according to claim 1 is characterized in that, described SGSN obtains described conversation media link information and comprises:

In described first handoff procedure, described control network element is in the first handoff request message that sends to described SGSN or first switch to finish and carry described conversation media link information in the acknowledge message;

Described SGSN obtains in the described first handoff request message or the described conversation media link information of carrying in the acknowledge message is finished in first switching.

11. method according to claim 10 is characterized in that,

Before described SGSN sent the described first handoff request message, described method also comprised at described control network element: described control network element obtains the media resource information of session to UE after the described handoff request that receives from access network; Perhaps,

Before acknowledge message was finished in described first switching, described method also comprises: described UE sent to described control network element with the media resource information of session when setting up session at described control network element;

Wherein, the media resource information of described session comprises: described conversation media link information, perhaps, described conversation media link information and codec information.

12. method according to claim 1 is characterized in that, described SGSN obtains the conversation media link information and comprises:

In described IMS session transfer process, described MSC sends transfer request, and receives the Temporary Response message of described transfer request, wherein, carries described conversation media link information in the described Temporary Response message;

In described second handoff procedure, described MSC carries described conversation media link information sending to described control network element in second handoff response or second handoff completion message;

Described control network element switches to finish and carries described conversation media link information in the acknowledge message sending first handoff request or first to described SGSN;

Described SGSN obtains described first handoff request or the described conversation media link information of carrying in the acknowledge message is finished in first switching.

13. method according to claim 1 is characterized in that, after described IMS session transfer process was finished, described method also comprised:

Described MSC is released in the media resource that distributes in described second handoff procedure.

14. the realization system of a single radio voice call continuity is characterized in that, comprising:

The control network element, be used for after the handoff request that receives the access network transmission, for voice bearer is initiated first handoff procedure to SGSN, initiate second handoff procedure to MSC, in described first handoff procedure, obtain first media information, and send second media information to described SGSN, in described second handoff procedure, forwarding number and described first media information are sent to described MSC, and obtain described second media information;

Described SGSN, be used for obtaining described second media information by described first handoff procedure, send described first media information, and the link information of media data is set according to the conversation media link information of obtaining by described first handoff procedure, wherein, described media data is encapsulated in the carrying of described first handoff procedure foundation;

Described MSC is used at described second handoff procedure, is that target is initiated IMS session transfer process with described forwarding number, carries out the CS handoff procedure, and obtains described first media information by described second handoff procedure, sends described second media information.

15. system according to claim 14 is characterized in that, described first media information comprises: the medium link information of described SGSN; Described second media information comprises: the medium link information of the media gateway MGW of described MSC control.

16. system according to claim 14 is characterized in that,

Described control network element also is used at described first handoff procedure, behind first handoff completion message of message that receives the release voice bearer and described SGSN transmission, send first switching to described SGSN and finish acknowledge message, if described control network element has been initiated the 3rd handoff procedure for the non-voice carrying, then for sending the 3rd switching, described non-voice carrying finishes acknowledge message simultaneously;

Described SGSN also be used for receive described first switch finish acknowledge message after, releasing bearing resource.

17. system according to claim 14 is characterized in that,

Described control network element also is used at described first handoff procedure, at first handoff completion message that receives described SGSN transmission and after waiting for the scheduled time, sends first switching to described SGSN and finishes acknowledge message;

Described SGSN also is used at described first handoff procedure, receive first switch finish acknowledge message after, releasing bearing resource.

18. a SGSN is characterized in that, comprising:

The hand-off process module, being used for by the control network element is that first handoff procedure that voice bearer is initiated is set up the carrying between described SGSN and data gateway, consult media information and obtain the conversation media link information by described first handoff procedure, and to connecting information and the described conversation media link information that described loaded information that the mapping block transmission sets up, medium that described media information is represented connect;

Described connection mapping block is used for the information that described loaded information is connected with described medium is carried out association store, and store session medium link information;

Described packing data module, be used to receive the media data that described medium connect, the loaded information related with described medium connection according to described connection mapping block storage is encapsulated into described media data in the described carrying, and is encapsulated in the link information of the described media data in the described carrying according to the described conversation media link information setting of described connection mapping block storage.

19. SGSN according to claim 18 is characterized in that, described SGSN also comprises:

The data parse module is used to receive the media data in the described carrying, and according to the information that is connected with the medium of described bearing association of described connection mapping block storage described media data is unpacked in the described medium connection.

20. SGSN according to claim 18 is characterized in that, the described first hand-off process module comprises:

Receiving element is used for receiving described control network element and finishes acknowledge message in the switching that described first handoff procedure sends;

The resource releasing unit is used for receiving after described switching finishes acknowledge message at described receiving element, discharges the bearing resource of described voice bearer.

21. SGSN according to claim 20 is characterized in that, the described first hand-off process module also comprises:

Timer is used for timing, triggers described resource releasing unit when arriving the scheduled time;

Transmitting element is used for sending the bearer update request to data gateway, and wherein, the chain of command link information of described control network element is carried in described bearer update request;

Described timer starts when described transmitting element sends described bearer update request or receives at described receiving element and starts when acknowledge message is finished in described switching.

22. a control network element is characterized in that, comprising:

Receiver module is used to receive the handoff request that access network sends, and triggers the first hand-off process module and the second hand-off process module when receiving described handoff request;

The described first hand-off process module is used to voice bearer to initiate first handoff procedure to SGSN, obtains first media information by first handoff procedure, and sends second media information to described SGSN;

The described second hand-off process module is used for initiating second handoff procedure to MSC, by second handoff procedure forwarding number and described first media information is sent to described MSC, and obtains described second media information.

23. control network element according to claim 22 is characterized in that,