CN101193449A

CN101193449A - System, method and device for realizing continuous multimedia session

Info

Publication number: CN101193449A
Application number: CNA2007101937789A
Authority: CN
Inventors: 朱东铭
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2006-11-27
Filing date: 2007-11-27
Publication date: 2008-06-04
Anticipated expiration: 2027-11-27
Also published as: CN101193449B

Abstract

The invention discloses a system, a method and an equipment for realizing multimedia conversation continuity, which aims to solve the problem of not supporting switch of different interconnection modes of multimedia conversation on a multi-mode terminal of the prior art. The system comprises a remote UE and an MCC UE is used for promoting a switch request between an association load and a multimedia load for multimedia conversation. The switch request is provided with switch context information. An MCC is used for promoting multimedia switch indication by the context switch information and sending to a DTF so as to map the switch process of multimedia conversation among the MCC, the UE and the DTF in the association load and the multimedia load to the switch process of multimedia conversation in different interconnection modes. The DTF is used for media negotiate with the remote UE by the multimedia switch indication so as to achieve the switch of multimedia conversation in different interconnection modes.

Description

Realize system, method and the device of multimedia conversation continuity

Technical field

The present invention relates to the mobile communication technology field, particularly relate to system, method and the device of realizing multimedia conversation continuity.

Background technology

In the past, the mobile communication operators person in a state or an area only disposes a kind of access network of standard.Under this network condition, the user uses the terminal of single mode to enjoy service.And in the world, exist the network coexisted situation of different systems.But along with the selection of network operator when the on-premise network, and the purchase of the merging between the network operator, a network operator may run the network of multiple standard simultaneously.On the other hand, the user has promoted the develop rapidly of access technology greatly to the growth of mobile application demand, and many new access technologies continue to bring out, as WiFi, WiMAX (Worldwide Interoperability for MicrowaveAccess, micro-wave access global inter communication) etc.Therefore under the access technology of isomery, guarantee professional continuity, become the active demand that the network operator satisfies customer requirements, promotes self competitiveness for the user provides seamless business to switch.Proposed at present to use same set of core net to support different access technologies and support the terminal (be multimode terminal, CSI terminal and VCC terminal all belong to the application of multimode terminal) of different access modules to satisfy this demand simultaneously.

CS (Circuit Switched, circuit switching) and IMS (IP Multimedia System, IP Multimedia System) in conjunction with professional CSI (Combining CS Bearers with IMS, comprehensive CS carrying and IMS) proposing, the Access Network side that is used to support packet domain (PS) can not be carried under the situation of real-time media, by strengthening terminal capability circuit domain (CS) and IMS territory advantage are combined, and cooperate access network and IMS network entity CSI-AS (Application Server, application server) to provide multimedia business experience for the user.Promptly for the real-time media composition, as: audio frequency, video etc., adopt the call bearer at the CS network; For non real-time medium composition, as: the sessions carry on packet network such as text; Under the endurable situation of user, also video can be carried in packet domain.Simultaneously, in order to guarantee business experience, CSI requires CS and IMS session must terminate to the same terminal of end subscriber, CS is called out and the session association (combination) of IMS gets up to offer the terminal use by user's terminal.The business of an association (combinational) can be to add CS voice, multimedia call in the IMS session; Or add some IMS sessions to existing CS voice, multimedia call and generate.

Among the above-mentioned CSI, the function of described CSI-AS comprises:

1, according to the session of setting up on network strategy selection merging or nonjoinder CSI Client-initiated (during caller) different access networks.

2, splitting the Multimedia session receive continues to the different access networks of CSI endpoint registration; When called ().

3, generate the relevant charge information of CSI.

4, the supplementary service that CSI is relevant is handled.

Among the above-mentioned CSI, from the Access Network ability, in order to use the different access technologies correlating sessions simultaneously, CSI requires GERAN network support double-transmission mode (DTM) technology, perhaps UTRAN (UMTSTerrestrial Radio Access Network, UMTS Terrestrial radio access network) many radio bearers of network support multi RAB (Radio Access Bearer, RAB) technology.Further, if be not limited to that the CS real-time media is called out and IMS non-real time media session related, terminal also can offer the user with the IMS session association on the different access technologies network, and such terminal can be thought the category that also belongs to Generalized C SI terminal.Offer the user as IMS text session association with IMS audio call in the WLAN carrying and PS carrying.

Splitting multimedia IMS session with CSI-AS is example, referring to shown in Figure 1, after CSI-AS receives multimedia IMS session, this IMS session is split as CS calls out and the IMS calling, promptly for the real-time media composition, as audio frequency, video etc. in the CS network carrying; For non real-time medium composition, as text etc. in carrying (under the endurable situation of user, also video can be carried in packet domain) on the packet network.Simultaneously, in order to guarantee business experience, the session after CSI requires to split must terminate to the same terminal of end subscriber.

Audio call (VCC) continuously is the application that provides at the IMS of user attaching network, and the ability of the audio call two-way switching between CS territory and IMS network that makes the user is provided.The IMS framework that merges makes has WLAN (Wireless Local Area Network, WLAN (wireless local area network)) provide popular GSM (Global System for Mobile Communications, global system for mobile communications) audio call to become possibility under the condition of Fu Gaiing.If be connected the seamless voice call service of realization between access network IP-CAN with IP in the CS territory, not only can alleviate the load of GSM/UMTS Radio Resource, also can increase the income of operator.In addition, provide wired operator of VoIP (Voice over IP, Voice over IP) service also can provide fused business to be benefited by 3GPP IMS framework.

Referring to shown in Figure 2, for 3GPP VCC implements framework, at the newly-increased one group of functional entity in IMS territory and CS territory, they are:

1, routing redirection entity ((Customized Applications forMobile network Enhanced Logic of the CAMEL among Fig. 2, mobile network strengthens logic and formulates application) app), be responsible for grappling control is called out in CS territory call re-direction to IMS territory.Can close and establish with the gsmSCF (Service Control Function, service control function) among Fig. 2 generally speaking, in the CS territory, be presented as a SCP (Service Control Point, service control point).

2, an adaptive entity in CS territory (CSAF among Fig. 2), responsible reception are rerouted to the CS territory calling in IMS territory and are converted into the IMS territory according to preservation information (may be mutual with CAMELApp) and call out.

3, controlled entity (DSF among Fig. 2) is selected in territory, is responsible in the IMS territory that various strategies such as login state, call state according to the user are made a strategic decision and controlling call is routed to the selected territory of continuing.

4, a territory switching controls entity (DTF among Fig. 2) is responsible for calling out in the grappling of IMS territory, carries out switching controls when switching generation.

Above-mentioned 4 functional entitys are collectively referred to as VCC (Voice Call Continuity, continuous voice call) operation controlling entity.

Based on above-mentioned VCC operation controlling entity, when the VCC terminal is carried out the voice conversation of an activity, just can initiate the territory and switch.Switch in order to carry out the territory, calling that the VCC terminal is initiated or that accept all will anchor to the DTF in the IMS network of this VCC terminal attaching.Described DTF is the application server with 3PCC function (third party call control).In VCC, the session control leg between DTF and the VCC terminal is called access leg, and that section session control leg between DTF and remote subscriber is called remote leg.Switch and just be to use new access leg to replace old access leg.The VCC terminal is than the more accurate power of each access network wireless signal of perception of core network generally speaking, so all be to be initiated by the direction of terminal to network for the higher territory handoff procedure of delay requirement.When user's VCC terminal detects factors such as wireless signal, judgement need be when source network switches to the purpose network, at special number of purpose calling network.Can be triggered to DTF by the call request to this number handles.Because former calling is finished grappling at DTF, DTF is according to related these new and old two callings of user ID.The medium in calling out according to new foundation and the remote subscriber terminal room of former calling are consulted medium again, have finished simultaneously to be switched in the media re-negotiation process and have called out corresponding Media Stream and be rerouted to from the port of multimode terminal the handover source network and switching purpose network corresponding port.New calling is also just set up successfully after finishing media negotiation, and this moment is by the calling in DTF or the VCC subscriber equipment release handover source network.User's voice is called out and has just been switched to the purpose network like this.User's voice is called out and can be kept not interrupting in switching, thereby has improved user's business experience.

Referring to shown in Figure 3, for calling out the flow process that switches to the IMS territory from the CS territory among the VCC.

1, VCC UE (User Equipment, subscriber equipment) judges that according to wireless environment calling out needs switches to the IMS territory, calls out special number VDI (VCC Domain Transfer URI, URI is switched in a VCC territory) territory in the IMS territory and switches; Call request is handled by the S-CSCF that P-CSCF is forwarded to VCC user attaching IMS network.

2, S-CSCF is triggered to the DTF processing according to caller iFC with calling.

3, DTF is according to inviting the VDI among the INVITE to determine that this is called out is the territory handoff request.And, find the session of grappling according to caller information.

4-8, DTF proxy user and remote subscriber use the media information in the handoff request heavily to consult SDP.

9, after the session foundation of purpose network was finished, DTF discharged the access part call resources of VCC user in the CS territory.

The inventor finds that in the invention process what existing VCC technology solved is the switching of voice conversation in the carrying of different access modules, and then can only realize the continuity of voice conversation.And do not support other media sessions (as: video, text etc.) that are associated with voice conversation to switch in the lump, promptly prior art can not solve the problem that Multimedia session on the multimode terminal (comprising some media sessions that are mutually related) switches in the carrying of different access modules.

In realizing embodiment of the invention process, the inventor finds that there are the following problems at least in the prior art:

Summary of the invention

The embodiment of the invention provides system, method and the device of realizing multimedia conversation continuity, does not support the problem that Multimedia session switches on the multimode terminal in order to solve prior art in the carrying of different access modules.

The system of the embodiment of the invention, comprise: remote user equipment UE, the signaling anchor point territory handoff functionality DTF that connects between first access leg and remote leg also is provided, wherein first access leg is that DTF sets up by related carrying with multimode terminal MCC UE, remote leg is to set up between DTF and remote user equipment, and MCCUE intercoms via this DTF mutually with far-end UE, during the switching of generation afterwards, MCC UE is used for initiating to carry switch contexts information second access leg and sets up request; DTF is used for reception and carries switch contexts information second access leg foundation request, and second access leg between foundation and MCC UE; And, carry out media negotiation with far-end UE according to described switch contexts information, and remote leg is rerouted to second access leg links to each other, MCC UE continues to communicate by letter with far-end UE.

The multimode terminal of the embodiment of the invention comprises: initiate the unit, be used to initiate the handoff request of Multimedia session between association carrying and multimedia carrying; The information adding device, the handoff request that is used for initiating in described initiation unit is added switch contexts information; Releasing unit is used for after the media negotiation success, discharges media negotiation to be switched Multimedia session before.

The medium switching entity of the embodiment of the invention comprises: acquiring unit is used for obtaining switch contexts information from the Multimedia session handoff request that MCC UE sends; Switch indicating member, be used for the described switch contexts information obtained according to acquiring unit, corresponding generation multimedia is switched indication, and send to DTF, so that the Multimedia session between MCC UE and the MCC is set up process at the Multimedia session that the process of setting up of related carrying is mapped on multimedia is carried between MCC and the DTF; Releasing unit is used for after the media negotiation success, discharges media negotiation to be switched Multimedia session before.

The territory handover (mih) functions of the embodiment of the invention comprises: the Multimedia session negotiation element, and be used for reception and carry switch contexts information second access leg foundation request, and second access leg between foundation and MCC UE; And, carry out media negotiation with far-end UE according to described switch contexts information, and remote leg is rerouted to second access leg links to each other, MCC UE continues to communicate by letter with far-end UE; Releasing unit is used for after the media negotiation success, discharges media negotiation to be switched Multimedia session before.The Multimedia session negotiation element, the multimedia that is used for sending according to front end is switched indication and is carried out media negotiation with far-end UE; Releasing unit is used for after the media negotiation success, discharges media negotiation to be switched Multimedia session before.

The method of the embodiment of the invention: the signaling anchor point territory handoff functionality DTF that connects between first access leg and remote leg is provided, wherein first access leg is that DTF sets up by related carrying with multimode terminal MCC UE, remote leg is to set up between DTF and remote user equipment, MCC UE intercoms via this DTF mutually with far-end UE, and the handoff procedure of Fa Shenging comprises the following steps: that DTF receives that MCC UE initiates to carry switch contexts information second access leg and sets up request afterwards; Second access leg between foundation and MCC UE; DTF carries out media negotiation according to described switch contexts information with far-end UE, remote leg is rerouted to second access leg link to each other, and MCC UE continues to communicate by letter with far-end UE.

Another system of the embodiment of the invention, comprise remote user equipment UE, also comprise the signaling anchor point territory handoff functionality DTF that connects between first access leg and remote leg is provided, wherein first access leg is that DTF and multimode terminal MCC UE set up by the multimedia carrying, remote leg is to set up between DTF and remote user equipment, and MCC UE intercoms via this DTF mutually with far-end UE, during the switching of generation afterwards, MCC UE is used for initiating to carry switch contexts information second access leg and sets up request; DTF is used for reception and carries switch contexts information second access leg foundation request, and second access leg between foundation and MCC UE; And, carry out media negotiation with far-end UE according to described switch contexts information, and remote leg is rerouted to second access leg links to each other, MCC UE continues to communicate by letter with far-end UE.

The other method of the embodiment of the invention, the signaling anchor point territory handoff functionality DTF that connects between first access leg and remote leg is provided, wherein first access leg is that DTF and multimode terminal MCC UE set up by the multimedia carrying, remote leg is to set up between DTF and remote user equipment, MCC UE intercoms via this DTF mutually with far-end UE, and the handoff procedure of Fa Shenging comprises the following steps: that DTF receives that MCC UE initiates to carry switch contexts information second access leg and sets up request afterwards; Second access leg between foundation and MCC UE; DTF carries out media negotiation according to described switch contexts information with far-end UE, remote leg is rerouted to second access leg link to each other, and MCC UE continues to communicate by letter with far-end UE.

The technical scheme of the embodiment of the invention has the following advantages:

The embodiment of the invention is by newly-increased MCC UE, and it can initiate the handoff request of Multimedia session between association carrying and multimedia carrying, and carries switch contexts information in this handoff request; By increasing the function of MCC, make it can be according to described switch contexts information, corresponding generation multimedia is switched indication, and send to DTF, MCC UE and the handoff procedure of Multimedia session between related carrying and multimedia carrying between the MCC are mapped to the handoff procedure of Multimedia session between different access modules between MCC and the DTF; By increasing the function of DTF, multimedia that its handover information that sends according to described MCC UE or MCC are sent is switched indication, carries out media negotiation with far-end UE, to finish the switching of Multimedia session between different access modules between MCC and this DTF.

So under the situation that does not influence the VCC existing procedure, solved the two-way problem of time switching of not limitting in the carrying of different access modules of Multimedia session on the multimode terminal, thereby provide call continuity for the Multimedia session of multimode terminal.Strengthen the ability of call continuity, the scope that provides of network operator's call continuity has been provided, thereby increased the scale of professional profit potentially.

Description of drawings

Fig. 1 is that CSI-AS splits multimedia IMS session diagram in the prior art;

Fig. 2 is that prior art 3GPP VCC implements configuration diagram;

Fig. 3 is for calling out the flow chart that switches to the IMS territory from the CS territory among the prior art VCC;

Fig. 4 is a system configuration schematic diagram in the embodiment of the invention;

Fig. 5 is system embodiment one schematic diagram of the present invention;

Fig. 6 is system embodiment two schematic diagrames of the present invention;

Fig. 7 is system embodiment three schematic diagrames of the present invention;

Fig. 8 is system embodiment four schematic diagrames of the present invention;

Fig. 9 is system embodiment five schematic diagrames of the present invention;

Figure 10 is a multimode terminal MCC UE structural representation in the embodiment of the invention;

Figure 11 is a medium switching entity MCC structural representation in the embodiment of the invention;

Figure 12 is a territory handover (mih) functions DTF structural representation in the embodiment of the invention;

Figure 13 is a method step flow chart in the embodiment of the invention;

Figure 14 carries the direct situation schematic diagram of initiating at the handoff request of each correlating sessions of residing access network for MCC UE in the embodiment of the invention in multimedia;

Figure 15 initiates described handoff request, the situation schematic diagram of initiation mode one wherein for MCC UE in the embodiment of the invention carries residing access network in association;

Figure 16 initiates described handoff request, the situation schematic diagram of initiation mode two wherein for MCC UE in the embodiment of the invention carries residing access network in association;

Figure 17 initiates described handoff request, the situation schematic diagram of initiation mode three wherein for MCC UE in the embodiment of the invention carries residing access network in association;

Figure 18 is the inventive method embodiment one signaling process figure;

Figure 19 is the inventive method embodiment two signaling process figure;

Figure 20 is the inventive method embodiment three signaling process figure;

Figure 21 is the inventive method embodiment four signaling process figure;

Figure 22 is the inventive method embodiment five signaling process figure;

Figure 23 is the inventive method embodiment six signaling process figure;

Figure 24 is the inventive method embodiment seven signaling process figure;

Figure 25 is the inventive method embodiment eight signaling process figure;

Figure 26 is the inventive method embodiment nine signaling process figure;

Figure 27 is the inventive method embodiment ten signaling process figure;

Figure 28 is the inventive method embodiment 11 signaling process figure.

Embodiment

Below in conjunction with drawings and Examples, the specific embodiment of the present invention is described in further detail:

For the Multimedia session on the multimode terminal can be switched in the carrying of different access modules.

The embodiment of the invention provides a kind of system that realizes multimedia conversation continuity, referring to shown in Figure 4, it comprises multimode terminal MCC UE (Multimedia Call Continuitycapable UE), medium switching entity MCC (Multimedia Call Continuity), the territory handover (mih) functions DTF that links to each other according to logical relation, and far-end UE; Further, between MCC UE and MCC, also can comprise the network interworking entity.

Described MCC UE supports three kinds of access modules at least, and (Multimedia session just shows as the combination of carrying each session thereon respectively when offering the user in the association carrying to be used to initiate Multimedia session; In essence and what end subscriber was carried out is a Multimedia session, only on carrying, association provides in the multimode terminal user side back of breaking because of the Access Network ability.) handoff request between the carrying of association carrying and multimedia, and in this handoff request, carry switch contexts information.

Further, described MCC UE can initiate the two-way switching of Multimedia session between association carrying and multimedia carrying; Described association is carried as the combination of at least two Access Network bearing modes, the session of associating bearing multimedia; Described multimedia is carried as the Access Network bearing mode of bearing multimedia session separately.

Explanation based on above-mentioned related carrying and multimedia carrying, when described handoff request direction is that multimedia carrying is when switching to related carrying, might related carrying can't carry switching Multimedia session before fully, the switching that need degrade (the expression multimedia that degrades composition loses some medium composition according to strategy after switching).So MCC UE judged whether earlier to need to reduce the Multimedia session quality before initiating handoff request, MCC UE carries the switchable media session relevant information and the indication that degrades according to judged result in switch contexts information.It is one of following that the strategy that judges whether need to reduce the Multimedia session quality comprises: judge whether the ability of switching destination supports current Multimedia session attribute, if do not support, then in switch contexts information, carry the common factor part of switching destination ability and current Multimedia session attribute; Strategy according to the default reduction Multimedia session quality of MCC UE; Indication according to the user.

Further, as a kind of optimization process, described MCC UE when called, in setting up the process of calling out, MCC notify its with MCC UE between related carrying on a session Multimedia session between corresponding MCC and far-end UE whether; And when the initiation of MCC UE desire switched to the Multimedia session handoff request of multimedia carrying with the association carrying, if Multimedia session between corresponding MCC and far-end UE, then this MCC UE initiated a handoff request; Otherwise, can initiate handoff request (being not limited to two handoff request) respectively at the session in the association carrying.

The different access modules of MCC UE support that respectively CS domain signaling or SIP (Session InitiationProtocol, Session initiation Protocol) signaling and MCC are mutual.When if MCC UE uses CS domain signaling and MCC mutual, arrive MCC after then finishing the conversion of CS domain signaling SIP signaling in the IMS network by the network interworking entity.

Described MCC, it increases some functions on the basis of CSI AS, place the session path between MCC UE and the territory handover (mih) functions DTF, be used for according to described switch contexts information, corresponding generation multimedia is switched indication, and send to DTF, so that MCC UE is mapped to the process of setting up that the Multimedia session between MCC and the DTF carries in multimedia with Multimedia session (being the access control leg) between the MCC in the process of setting up of related carrying.

Further, the operation that degrades of corresponding MCC, MCC receive handoff request and identify wherein carrying degrade the indication after, need not wait for the handoff request of other session associated again, directly according to the switchable media session relevant information of carrying in the switch contexts information in the handoff request of receiving, corresponding generation multimedia is switched indication, and sends to DTF.

Further, corresponding MCC initiates the optimization process of handoff request quantity, in setting up the process of calling out, MCC with its with MCC UE between in the related carrying session whether the information (being correlating sessions information) of a Multimedia session between corresponding MCC and far-end UE inform this MCC UE so that MCC UE judges the quantity of initiating handoff request in view of the above.

Described DTF, the session path that it places between MCC and the far-end UE is used for switching indication according to described multimedia, carries out media negotiation with far-end UE, to finish the switching of Multimedia session between different access modules between MCC and this DTF.

Described network interworking entity, if when MCC UE uses CS domain signaling and MCC mutual, then the network interworking entity is used for finishing the conversion between CS domain signaling and the IMS territory SIP signaling.

According to the direction of initiating handoff request and the difference of media negotiation mode, above-mentioned MCC UE, MCC and DTF might initiate to discharge media negotiation to be switched Multimedia session before after the media negotiation success.

In specific implementation, there is multiple deployment way in described MCC.Described MCC can be application server AS (comprise closing as AS or with other network element separately and establish as AS), by initial filter criteria iFC trigger mechanism, guarantees that this MCC is by network call; Perhaps described MCC guarantees that as the transfer entity of mutual signaling between MCC UE and the network this MCC is by network call.Below specifically describe the system of the embodiment of the invention by 4 system embodiments.

System embodiment one, MCC are as independent AS, referring to shown in Figure 5.

Among the native system embodiment, MCC adopts Sh interface and the HSS in the network (Home Subscriber Server, the home signature user server) communication that defines in the IMS network; MCC by the ISC interface in the IMS network directly or communicate by letter (comprise indirectly and communicating by letter with DTF) Session Initiation Protocol of this interface employing indirectly with other entity in the IMS network; Adopt internal interface mutual between gsmSCF and the CAMEL Service; Adopt internal interface mutual between CAMEL service and the CSAF; Wherein the MGCF entity belongs to CS and SIP signalling interworking functional entity.

When implementing with native system embodiment, MCC by the iFC trigger mechanism when call out arriving by network call, and guarantee MCC more close user side in calling by the iFC processed, promptly at described MCCUE during as caller, by the iFC trigger mechanism make MCC before DTF by network call; And at described MCC UE when called, by the iFC trigger mechanism make MCC after DTF by network call.

System embodiment two, MCC and territory selection functional entity DSF close and establish as AS, referring to shown in Figure 6.

Among the native system embodiment, the existing interface that MCC utilizes DSF directly or indirectly and the entity in the IMS network (comprise indirect with DTF) communicate by letter, these interfaces are respectively ISC and Sh; Adopt internal interface mutual between gsmSCF and the CAMEL Service; Adopt internal interface mutual between CAMEL service and the CSAF; Wherein the MGCF entity belongs to CS and SIP signalling interworking functional entity.

When implementing with native system embodiment, MCC closes when establishing AS by network call call out arriving by the iFC trigger mechanism, and the processed of passing through iFC guarantees MCC more close user side in calling, be described MCC UE during as caller, by the iFC trigger mechanism make described close establish AS before DTF by network call; And at described MCC UE when called, by the iFC trigger mechanism make close establish AS after DTF by network call.

System embodiment three, MCC are as independent AS, and MCC UE supports by call establishment and professional control in the SIP signaling control CS carrying of PS access bearer, referring to shown in Figure 7.

Among the native system embodiment, MCC is as ISC interface and serving CSCF (S-CSCF) (the Call Session Control Function by the IMS normalized definition of AS independently, call session control function module) communicates by letter, and transmit required switching, session control information by itself and DTF; Optionally, MCC supports the Ma interface can pass through the addressing of PSI mode; Optionally, the Sh interface between MCC support and HSS.

CSC cooperates foundation and the professional control of controlling session in this UECS carrying by the SIP signaling on the MCC UE PS access bearer with MCC UE.Optionally, the Sh interface between support and HSS.In order to control call establishment in the CS carrying, CSC is than the more close subscriber equipment of MCC.

When implementing with native system embodiment, by the iFC trigger mechanism, guarantee that MCC always is being called in the position of more close subscriber equipment than DTF, promptly at described MCCUE during as caller, by the iFC trigger mechanism make MCC before the handover (mih) functions DTF of territory by network call; And at described MCC UE when called, by the iFC trigger mechanism make MCC after DTF by network call.In like manner, guarantee the call by location of CSC than the more close subscriber equipment of MCC.

On concrete enforcement, also there is following possible compound mode:

1, CSC and MCC merge into an AS; Or

2, CSC and DSF, MCC merge into an AS; Or

3, MCC and CSC, DSF, DTF merge into an AS; Or

4, native system embodiment also can combine with system embodiment 1, and CSC and MCC merge into an AS; Or

5, native system embodiment also can combine with system embodiment 1, and CSC and MCC, DSF merge into an AS; Or

6, native system embodiment also can combine with system embodiment 1, and CSC and MCC, DSF, DTF merge into an AS.

System embodiment four, MCC and territory handover (mih) functions DTF close and establish as AS, referring to shown in Figure 8.

Among the native system embodiment, adopt internal interface between DTF and the DSF.MCC utilizes the existing interface of DTF to communicate by letter with the entity in the IMS network, and these interfaces are respectively ISC and Sh, Ma; Adopt internal interface mutual between gsmSCF and the CAMEL Service; Adopt internal interface mutual between CAMEL service and the CSAF; Wherein the MGCF entity belongs to CS and SIP signalling interworking functional entity.

When implementing with native system embodiment, MCC by the iFC trigger mechanism when call out arriving by network call, and communicate by letter with DTF by internal interface, and guarantee that by internal logic the MCC logic calls near user side, be that described MCC UE is during as caller, by described close the internal logic of establishing AS make MCC before DTF by network call, at described MCC UE when called, by described close the internal logic of establishing AS make MCC after DTF by network call.

System embodiment five, MCC are as the transfer entity of mutual signaling between MCC UE and the network, referring to shown in Figure 9.

Among the native system embodiment, MCC inserts proxy CSCF (P-CSCF) (Call Session Control Function by special register flow path, call session control function module) and between the signalling route of serving CSCF (S-CSCF), nature can insert that the MCC UE beginning exhales and any call path of terminating in; AGF (IAD function) is responsible for the call signaling of circuit domain and the conversion of SIP signaling.

Described special register flow path is for example: by at the S-CSCF configuration data.After S-CSCF receives registration request from user and finishes authentication, carry of the registration of the address of MCC UE to MCC.The address of the address of MCC being used as S-CSCF after registration is finished returns to MCC UE, user's log-on message before S-CSCF removes.MCC proxy user again is initiated to the registration of S-CSCF, and S-CSCF is used as the address of MCC the address of MCC UE.MCC just has been between MCC UE and the S-CSCF like this.

When implementing, when calling out this MCC of arrival, by network call with native system embodiment.

Corresponding said system, the embodiment of the invention also provides a kind of multimode terminal MCC UE, and referring to shown in Figure 10, it comprises interconnective initiation unit and information adding device, also comprises releasing unit; Further, also comprise the switching that links to each other with the information adding device judging unit that degrades, and interconnective far-end session information preserves unit and quantity indicating member, described quantity indicating member also with initiate the unit and link to each other.

Described initiation unit is used to initiate the handoff request of Multimedia session between association carrying and multimedia carrying.

Described information adding device, the handoff request that is used for initiating in described initiation unit is added switch contexts information.

The described switching judging unit that degrades, be used for before initiating unit initiation handoff request, judging whether earlier needs to reduce the Multimedia session quality, and carries switchable media session relevant information according to the corresponding information adding device of informing of judged result in switch contexts information.

Described far-end session information is preserved the unit, be used at this MCC UE when called, be kept at and set up in the calling procedure, whether the session between the notice MCC of network side transmitted and this MCC UE on the different bearer information of the same Multimedia session between corresponding MCC and far-end UE, MCC UE information in view of the above judges session correlating sessions each other on the different bearer, the related each other carrying of corresponding carrying.

Described quantity indicating member is used for preserving the information that the unit is preserved according to the far-end session information when the desire initiation switches to the handoff request of multimedia carrying with the association carrying, and the quantity of handoff request is initiated in corresponding indication initiation unit.

Described releasing unit is used for after the media negotiation success, discharges media negotiation to be switched Multimedia session before.

Corresponding said system, the embodiment of the invention also provides a kind of medium switching entity MCC, and referring to shown in Figure 11, it comprises interconnective acquiring unit and switches indicating member, also comprises releasing unit; Further, also can comprise far-end session information notification unit.

Described acquiring unit is used for obtaining switch contexts information from the Multimedia session handoff request that MCC UE sends.

Described switching indicating member, be used for the described switch contexts information obtained according to acquiring unit, corresponding generation multimedia is switched indication, and send to DTF, so that MCC UE is mapped to the process of setting up that the Multimedia session between MCC and the DTF carries in multimedia with Multimedia session between the MCC in the process of setting up of related carrying.

Described far-end session information notification unit, be used at MCC UE when called, in setting up calling procedure, with this MCC UE of information notification of the same Multimedia session between whether corresponding this MCC of the session on the different bearer between this MCC and MCC UE and far-end UE (be MCC UE information judge session correlating sessions each other on the different bearer, the related each other carrying of corresponding carrying) in view of the above.

Corresponding said system, the embodiment of the invention also provides a kind of territory handover (mih) functions DTF, and referring to shown in Figure 12, it comprises interconnective Multimedia session negotiation element and releasing unit.

Described Multimedia session negotiation element, the multimedia that is used for sending according to front end is switched indication and is carried out media negotiation with far-end UE.

The embodiment of the invention also provides a kind of method that realizes multimedia conversation continuity, referring to shown in Figure 13, comprises following key step:

S1, MCC UE initiate the handoff request of Multimedia session between association carrying and multimedia carrying, carry switch contexts information in this handoff request and (comprise the indication that expression is switched, include but not limited to use special called number of calling to represent; MCC UE that in setting up the bearer network of new access leg, support with media information to be switched medium correspondence, SDP information in being mapped to the IMS network or the bearer capability information among the CS; The identification information of to be switched medium, be used to orient the former session execution switching to be switched medium place, can use port information or its place session identification among the to be switched medium SDP to add that the identifier combination of medium forms in the session, also can be by the method for expressing of other form; And optionally also have the correlating sessions indication message, be used to indicate whether to have other correlating sessions to switch simultaneously).

Described Multimedia session comprises at the switching direction that switches between association carrying and multimedia carrying: the two-way switching between related carrying and the multimedia carrying; Described association is carried as the combination of at least two Access Network bearing modes, the session of associating bearing multimedia; But described multimedia is carried as the Access Network bearing mode of independent bearing Multimedia session.

When MCC UE (when the direction switched of described request switches to the multimedia carrying for related carrying) when multimedia is carried residing access network and initiated described handoff request, can be before initiating handoff request by MCC UE, judge current each session correlating sessions whether each other that is distributed in the different access networks, if correlating sessions is then initiated a handoff request at described correlating sessions each other; Perhaps MCC UE directly initiates the handoff request at correlating sessions, carries out relevance by MCC and judges.

S2, MCC are according to described switch contexts information, and corresponding generation multimedia is switched indication, and send to DTF.

Described MCC is according to described switch contexts information, corresponding generation multimedia is switched the process of indication, is about to MCC UE and is mapped to the process of setting up that the Multimedia session between MCC and the DTF carries in multimedia with Multimedia session between the MCC in the process of setting up of related carrying.

When DTF can discern the session of being asked, this step also can be omitted, i.e. the handoff request of MCC UE initiation is directly handled by DTF.In the system corresponding with this situation, MCC UE is used for initiating Multimedia session from the multimedia carrying and is carried to the handoff request that multimedia is carried from association, carries switch contexts information in this handoff request; DTF is used to receive described handoff request, and carries out media negotiation according to switch contexts information and far-end UE wherein, to finish described Multimedia session is carried to the multimedia carrying from association switching.MCC, the session path that it places between MCC UE and the DTF is used for discharging the session in the related carrying after the release indication of receiving DTF.

S3, DTF switch indication according to described multimedia, carry out media negotiation with far-end UE.

DTF sends the difference that multimedia is switched indication according to MCC or MCC UE, and the mode of carrying out media negotiation with far-end UE comprises: parallel media negotiation and serial media are consulted.

S4, after media negotiation success, discharge to be switched Multimedia session before the media negotiation.

Below specifically describe at different switching directions and media negotiation mode.

If among the step S1, MCC UE carries residing access network in multimedia initiates described handoff request (being that the direction that described request is switched switches to multimedia carrying (as the WLAN carrying) for related carrying).

Situation one, referring to shown in Figure 14, wherein: square expression non-real time media; Circular expression real-time media; Circular cover square expression multimedia; Two ellipse representations are two sessions at DTF.MCCUE directly initiates the handoff request at the session of CS bearing association, and at the handoff request of correlating sessions in the PS carrying, carries out relevance by MCC and judge, and finish the merging of above-mentioned two handoff request, switches to multimedia carrying (WLAN carrying).Only be carried on respectively among CS, the PS with real-time and non-real time media is example herein, is not limited thereto but use.According to following different situation, the MCC entity also can be in the signaling paths of the handoff request that MCC UE initiates by the multimedia carrying.

Carry switch contexts information in the described handoff request, wherein comprise at least: the indication that session is switched (uses special called number to represent or other sip message name, parameter, header field are represented), MCC UE are the multimedia composition information (comprising association attributeses such as media formats, port) of multimedia bearer network support, the sign of to be switched medium (can be the particular port information that the sign of medium place session adds medium property or independent media), and the indication that whether has other medium composition to switch.

Among the step S2, after MCC receives one of handoff request in the related carrying,, judge whether to receive all relevant handoff request according to the described indication that whether has other medium composition needs to switch; When judging whether to point to the Multimedia session that same far-end UE sets up according to each handoff request when all receiving, each other whether the media session of judging described each handoff request correspondence correlating sessions; If correlating sessions each other, then MCC merges the switch contexts information in each handoff request, corresponding generation multimedia is switched indication (multimedia switch the medium composition of supporting that indication comprises that MCC UE provides and the sign of the to be switched session between MCC and DTF) in switching the purpose network, and sends to DTF.

DTF switches indication according to described multimedia among the step S3, carries out media negotiation with far-end UE, and after the media negotiation success,

Discharge to be switched Multimedia session before the media negotiation described in the step S4, comprise one of following manner:, after then MCC receives the release message that DTF sends, discharge described correlating sessions respectively if DTF initiates to discharge; If MCC UE initiates to discharge, then MCC discharges the session between MCC and the DTF again after discharging described correlating sessions.

Whether each other situation two, MCC UE judged the current session correlating sessions that is distributed in the different access networks before initiating handoff request, as if correlating sessions each other, then initiate a handoff request at described each correlating sessions.

MCC UE judges the mode of correlating sessions, comprises one of following: as MCC UE during, can know whether the session that is distributed in the different access networks that local terminal is initiated points to same purpose user as caller, thus correlating sessions each other; When MCC UE when called, in setting up conversation procedure, notify MCC UE correlating sessions information by MCC, whether each other the correlating sessions information that MCC UE informs with MCC judge the current session correlating sessions that is distributed in the different access networks; MCC UE is according to predetermined strategy, always thinks the current session correlating sessions each other that is distributed in the different access networks.

Carry switch contexts information in the described handoff request, wherein comprise at least: session switch indication, MCC UE the multimedia bearer network that support with medium property information to be switched medium composition correspondence, and the identification information of to be switched medium (use the port information of medium or medium place session identification to add that media identification represents, can be used to locate the sign of correlating sessions or the Multimedia session sign of correlating sessions correspondence).

This situation specifically comprises the following steps:

A, MCC UE detect in the time of need switching to the multimedia carrying, and the territory Handover Number/sign in the call IMS network is carried switch contexts information.

According to the difference of the information of carrying, can walk B1 and B2 branch respectively:

B1, this calling is triggered to MCC receive after, MCC identifies the correlating sessions handoff request.Navigate to and the MCC of these two session associations and the Multimedia session between DTF generate multimedia switch indication (multimedia switch the medium composition of supporting that indication comprises that MCC UE provides and the sign of the to be switched session between MCC and DTF) in switching the purpose network according to this information, MCC carries the conversation request that this generation information is initiated to DTF, arrives DTF by the IMS forwarded.

B2, the sign of carrying the corresponding Multimedia session of correlating sessions in the described handoff request, DTF can discern, and handles so this request can directly be triggered to DTF.

After C, DTF receive that carrying multimedia switches the conversation request of indication, find session with remote subscriber, carry out medium according to the medium change flow of SIP and upgrade according to wherein former session identification.

After D ,-medium upgrade and finish, discharge the session/call in old (to be switched before the media negotiation) carrying.To be switched Multimedia session before the described release media negotiation comprises one of following manner: if DTF initiates to discharge, after then MCC receives the release message that DTF sends, discharge described correlating sessions respectively; If MCC UE initiates to discharge, then MCC discharges the session between MCC and the DTF again after discharging described correlating sessions.

If among the step S1, MCC UE carries residing access network in association initiates described handoff request (being that the direction that described request is switched is that the multimedia carrying switches to related carrying), and

After MCC receives each correlating sessions handoff request, carry out media negotiation with parallel pattern indication DTF and the remote subscriber of consulting medium.Only be carried on respectively among CS, the PS with real-time and non-real time media is example herein, is not limited thereto but use.According to following different situation, the MCC entity also can be in the session signaling path that MCC UE is undertaken by the multimedia carrying.

Initiate the handoff request mode one of Multimedia session, referring to shown in Figure 15, wherein, square expression non-real time media; Circular expression real-time media; Circular cover square expression multimedia; Two ellipse representations are two sessions at DTF.MCC UE initiates the handoff request of real-time media session and non-real time media session simultaneously at the destination network.

Carry switch contexts information in the handoff request, wherein comprise at least: indication, the MCCUE multimedia composition information in the destination network support is switched in session.The sign of to be switched medium place session (also can be other to be switched medium be associated information) is used at the to be switched session of the related access leg (between MCC and MCC UE) of MCC, i.e. that section session identification of square pecked line among Figure 15.To be switched session identification can be the CALL-ID header field among the SIP, also can be the sign of distributing voluntarily and transmitting between MCC and MCC UE, and MCC UE and MCC safeguard the corresponding relation of this sign and real session separately.(UE can receive a plurality of IMS sessions simultaneously in the IMS network) is special, when a handover source network has only one road Multimedia session, does not just need this information.And the indication that whether has other medium composition to switch.

Initiate the handoff request of Multimedia session in mode one, comprise the following steps:

A, MCC UE in real time and non-real time media switch the Handover Number/sign of calling out the network that is used to represent the session switching on the purpose network simultaneously, carry required switch contexts information respectively.

B, MCC receives that any request back is according to whether having the indication of other medium composition needs switching to wait for the another one handoff request, after collecting real-time and two handoff request of non-real time media, judge these two requests whether related (perhaps MCC calculates the result that the information of being associated of carrying in each handoff request obtains according to default rule and is particular value, and the media session of then judging each handoff request correspondence is correlating sessions each other) according to its to be switched session label information of carrying.Inspection navigates to according to this information by the back and the MCC of these two session associations and the Multimedia session between DTF generate multimedia switch indication (multimedia switch the medium composition of supporting that indication comprises that MCC UE provides and the sign of the to be switched session between MCC and DTF) in switching the purpose network.MCC carries the conversation request that this generation information is initiated to DTF, handles to DTF by the IMS forwarded.

After C, DTF received that carrying multimedia switches the handoff request of indication, the former session label information of carrying in based on context found the session with remote subscriber, carries out medium according to the medium change flow of SIP and upgrades.

After upgrading and finish, D, medium discharge the session/call in the old carrying.To be switched Multimedia session before the described release media negotiation comprises one of following manner: if DTF initiates to discharge, after then MCC receives the release message that DTF sends, discharge to be switched Multimedia session before the media negotiation; If MCCUE initiate to discharge, after then MCC receives the release message that MCC UE sends, discharge the Multimedia session between MCC and the DTF.

Initiate the handoff request mode two of Multimedia session, referring to shown in Figure 16, wherein: square expression non-real time media; Circular expression real-time media; Circular cover square expression multimedia; Two ellipse representations are two sessions at DTF.MCC UE initiates one tunnel handoff request earlier, initiates another road handoff request by MCC according to judgement of the information in this request and indication MCC UE.Only be carried on respectively among CS, the PS with real-time and non-real time media is example herein, is not limited thereto but use.According to following different situation, the MCC entity also can be in the session signaling path that MCC UE is undertaken by the multimedia carrying.

Carry switch contexts information in the handoff request, wherein comprise at least: indication, MCCUE multimedia composition information, the to be switched medium correlated identities information (including but not limited to the sign of to be switched medium place session) in the destination network support is switched in session, and the indication that whether has other medium composition to switch.

Initiate the handoff request of Multimedia session in mode two, comprise the following steps:

A, MCC UE switches Handover Number/identification number of calling out the network that is used to represent that session is switched on the purpose network at real-time or non real-time medium, carries required switch contexts information.

B, after MCC received request, when the indication according to switch contexts information had other medium to be switched, MCC determined the Handover Number that to be switched medium use.And in this request responding message, return to MCC UE.

C after MCC UE receives Handover Number, promptly is engraved in this Handover Number of switching purpose calling network of the to be switched medium in the indication of switch contexts information.

After D, MCC receive second medium handoff request, judge it is the Handover Number that oneself distributes according to its called number, just can in real time related and two sessions of non real-time.MCC is according to the former Multimedia session between the former session identification of deriving in the switch contexts information of receiving (can be derived by the identification information of to be switched medium) MCC that navigate to and this session association and DTF, and the SIP SDP information in two requests of receiving generates multimedia switching indication.MCC carries the conversation request that this generation information is initiated to DTF, handles to DTF by the IMS forwarded.

After E, DTF received the Multimedia session handoff request, the multimedia of carrying according to MCC was switched former session identification in the indication and is found session with remote subscriber, carries out medium according to the medium change flow of SIP and upgrades.

F, medium discharge the session/call in the old carrying after upgrading and finishing.To be switched Multimedia session before the described release media negotiation comprises one of following manner: if DTF initiates to discharge, after then MCC receives the release message that DTF sends, discharge to be switched Multimedia session before the media negotiation; If MCC UE initiate to discharge, after then MCC receives the release message that MCC UE sends, discharge the Multimedia session between MCC and the DTF.

Initiate the handoff request mode three of Multimedia session, referring to shown in Figure 17, wherein: square expression non-real time media; Circular expression real-time media; Circular cover square expression multimedia; Two ellipse representations are two sessions at DTF.MCC UE initiates one tunnel handoff request earlier, initiates another road handoff request according to the indication in this request to this MCC UE by MCC.Only be carried on respectively among CS, the PS with real-time and non-real time media is example herein, is not limited thereto but use.According to following different situation, the MCC entity also can be in the session signaling path that MCC UE is undertaken by the multimedia carrying.

Carry switch contexts information in the handoff request, wherein comprise at least: indication is switched in session,, MCCUE is in the sign (also can be other to be switched medium correlated identities information) of the multimedia composition information of destination network support, the place session of to be switched medium, and the indication that whether has other medium composition to switch; If also have other medium composition to need to switch, then also comprise the switching purpose network information of this medium composition.

Initiate the handoff request of Multimedia session in mode three, comprise the following steps:

A, MCC UE calling party on real-time or non real-time medium switching purpose network represents the Handover Number/identification number of the network that session is switched, and carries switch contexts information.

B, after MCC receives the request of carrying switch contexts information, when its indication has other medium to be switched, MCC is this user of switching purpose calling network of indication, and the switching (can be that MCC judges or parameter, field, the message body of other demonstration are indicated MCC UE by allowing MCC UE discern calling number) of to be switched medium is carried out in indication.MCC naturally can in real time related and non real-time two parts session like this.

After C, MCC UE receive the calling that MCC initiates, identify the switching that network is initiated to be switched medium according to wherein indication.Promptly in response message, return terminal and in this access network, support the SDP information of to be switched medium.

D, after MCC receives SDP in the second tunnel session, according to the former Multimedia session between the former session identification of deriving in the switch contexts information of receiving MCC that navigate to and this session association and DTF, and the SIP SDP information in two requests of receiving generates multimedia switching indication.MCC carries the conversation request that this generation information is initiated to DTF, handles to DTF by the IMS forwarded.

Three kinds of modes of initiating the handoff request of Multimedia session in the above-mentioned parallel media negotiation are consulted in the medium suitable equally in serial.After MCC received one of real-time and non real-time two-way handoff request, pattern indication DTF and the remote subscriber of consulting medium with serial carried out media negotiation, to switch this road media session; Treat that MCC receives that another road handoff request and DTF finish last one tunnel media negotiation that switches, MCC initiates media re-negotiation to DTF, with the media session of one tunnel switching back foundation in the related media information updating of carrying in another road handoff request.

Serial is consulted in the medium, and described release media negotiation is to be switched Multimedia session before, comprises one of following manner: if MCC initiates to discharge, then MCC discharges media negotiation to be switched Multimedia session before; If MCC UE initiate to discharge, after then MCC receives the release message that MCC UE sends.

In order to reach better effect, if being the multimedia carrying, the direction that described request is switched switches to related carrying, then MCC UE initiates before the Multimedia session switching, also can judge whether earlier needs to reduce the Multimedia session quality, and carries the switchable media session relevant information and the indication that degrades according to judged result in switch contexts information; MCC is according to described switchable media session relevant information, and corresponding generation multimedia is switched indication, and sends to DTF; Simultaneously MCC discharge its with MCC UE between the Multimedia session quality reduce media resource partly.

For example: when MCCUE switches to the related carrying of CS and PS combination with Multimedia session WLAN carrying, when not supporting DTM or multi RAB as access network for some reason, can only guarantee that a kind of medium are switched processing.

A, MCC UE is used to represent the Handover Number/sign of the network that session is switched at the purpose calling network of expectation switching media, and carries switch contexts information.Wherein indicate whether to have the identification information of to be switched session on the information, handover source network of other to be switched medium at least, this switches the indication that whether degrades and MCC UE at the medium composition information that switches the purpose network support.

B, MCC receive when having the switch contexts information of switching the indication that degrades, can use between SDP information in this session of receiving and corresponding MCC and DTF former Multimedia session sign to organize multimedia to switch indication (need not wait for other session associated).And after replacing switch contexts information handoff request is arrived DTF by the IMS forwarded.

C, the former session identification during the multimedia switching that DTF carries according to MCC is indicated finds the session with remote subscriber, and consults medium with far-end again according to SIP medium change flow.

D, after media re-negotiation was finished, DTF or MCC UE discharged former session (reducing the media resource of part comprising Multimedia session quality between MCC and the MCC UE).

In specific implementation, above-mentioned switch contexts information and multimedia are switched indication and are carried by following manner.

When be divided into three kinds of modes at CS:

1) MCC UE above-mentioned information is carried at the territory handoff request the user in user data cell, visit ground mobile switching centre (VMCS) receives that this request back is triggered to user's CAMEL application entity (CAMELService) preservation to user data cell by the user in the CAMEL Initial DP message.When the territory in CS territory handoff request is routed to the IMS network, obtain alternately after this information by CSAF and CAMELService and to be carried in this message when the assembling SIP conversation request message, it is identical in the transmission of IMS territory to carry mode and this information.This information is triggered to MCC in the SIP conversation request message and finishes the transmission of MCCUE to MCC afterwards.

2) MCC UE is carried at the user of territory handoff request in user data cell with above-mentioned information, visit ground mobile switching centre (VMCS) receives that this request back is by this cells of transmission such as interoffice signaling such as ISUP, BICC, be converted into any form or the combination of parameter, header field or message body in the SIP signaling again by IMS network interworking entity MGCF, be delivered to MCC by the SIP signaling more at last.

3) MCC UE is carried at the user of territory handoff request in user data cell with above-mentioned information, AGF receives that this request back by being converted into any form or the combination of parameter, header field or message body in the SIP signaling, is delivered to MCC by the SIP signaling at last again.

When in the IMS network, transmitting, transmit above-mentioned information by header field, field or the message body of expansion SIP signaling.

So far the method for embodiment of the invention general introduction finishes, above-mentioned MCC UE initiates to insert the content that relevant parallel media negotiation and serial media are consulted in the handoff request part of related carrying switching the purpose network, and it is suitable equally in partly to switch handoff request that the purpose network initiates to insert the multimedia carrying at MCC UE.

Below specifically describe the method for the embodiment of the invention by 9 method embodiment.

Method embodiment one, mode real-time and that non real-time initiates to switch simultaneously (are annotated: 1, this sentences CS carrying real-time media PS carrying non-real time media is example, using this method also can make Multimedia session switch to CS carrying and IP-CAN carrying combination in any, and the medium in each related carrying can realize that Multimedia session switches to the purpose of related bearer network according to the combination in any of the attribute that carries; 2, DTF uses the REINVITE mode to initiate media re-negotiation with the far-end session in the present embodiment, also can use medium change procedure among other SIP such as UPDATE etc.; Annotate 3, present embodiment can be applicable to system embodiment one, two, four, five, and MCC and DTF close when establishing in being applied to deployment way, and the mutual use internal interface between MCC and DTF carries out; 4, present embodiment has only shown crucial processing entities, is not to comprise the all-network entity; 5 and the far-end process of setting up of carrying out new session in media negotiation and the purpose network other order can be arranged, present embodiment only provides preferable implementation).Referring to shown in Figure 180, precondition: MCC UE carries out the conversation of IMS multimedia with remote user equipment under the IP2 access way, and MCC entity, DTF entity have been anchored on institute and have set up in the calling signaling path.Comprise the following steps:

A1-a3, MCC UE initiates the handoff request of real-time media in the CS territory, and carry switch contexts information, wherein comprise indication that non-real time media need switch and identification information that can the Central Plains session of locator field handover source network, the IMS network entity at first is forwarded to MCC with session and handles according to the iFC trigger mechanism.

1, if MCC receives the real-time media handoff request earlier, then judge and wait for the non real-time handoff request according to this switch contexts.

B1-b2, MCC UE initiates earlier the handoff request of non-real time media at IP-CAN1, and carries switch contexts information and comprise indication that real-time media in addition need switch and identification information that can the Central Plains session of locator field handover source network.The IMS network entity at first is forwarded to MCC with session and handles according to the iFC trigger mechanism, can not initiate heavily to consult after MCC receives earlier at once.

To be switched session identification between 2-3, that MCC navigates to according to the former session identification of deriving in media information in two handoff request and the switch contexts information and DTF generates multimedia and switches indication, is initiated to the conversation request of DTF and carries this information.This conversation request is forwarded to DTF through the IMS network processes.(MCC carries new SDP information in the SDP of session information, header field (as replace), field or the message body of expansion or the existing SIP signaling of use are represented to be switched session identification)

4, after DTF receives the conversation request of carrying the multimedia indication message, on the remote leg that navigates to according to this contextual information, initiate and the media re-negotiation of remote subscriber according to the SDP that newly provides.

5, DTF discharges the specified session in the handover source network after new bearer foundation is finished.(also can be that MCC UE initiates to discharge)

The pattern that information in method embodiment two, network based first via territory handoff request indication MCC UE initiates to switch on another road (annotate: 1, this sentences non-real time media and switches earlier and switch to example after the real-time media but be not limited thereto order; 2, present embodiment can be applicable to system embodiment one, two, four, five, and MCC and DTF close when establishing in being applied to deployment way, and the mutual use internal interface between MCC and DTF carries out; 3, this sentences CS carrying real-time media is example, uses this method and also can use other IP-CAN carrying real-time media, can realize that Multimedia session switches to the purpose of CSI combination bearer network; 4, DTF uses the REINVITE mode to initiate media re-negotiation with the far-end session in the present embodiment, also can use medium change procedure among other SIP such as UPDATE etc.; 5, present embodiment has only shown crucial processing entities, is not to comprise the all-network entity; 6 and the far-end process of setting up of carrying out new session in media negotiation and the purpose network other order can be arranged, present embodiment only provides preferable implementation).Referring to shown in Figure 19, precondition: MCC UE carries out the conversation of IMS multimedia with remote user equipment under the IP2 access way, and MCC entity, DTF entity have been anchored on institute and have set up in the calling signaling path.Comprise the following steps:

B1-b2, MCC UE initiates the handoff request of non-real time media earlier in the purpose territory, but and carry the switch contexts information representation and also have the indication that real-time media need switch and the identification information of locator field handover source network Central Plains session, the IMS network entity at first is forwarded to MCC with session and handles according to the iFC trigger mechanism.

1, MCC judges according to this switch contexts still has the real-time media needs to switch, and definite real-time media is the Handover Number that uses, and returns to MCC UE in Temporary Response.

A1-a3, MCC UE receive the territory switching flow of initiating real-time media behind this number as called number in the CS territory.

To be switched session identification between 2-3, that MCC navigates to according to the former session label information that derives in media information in two handoff request and the switch contexts information and DTF generates multimedia and switches indication, is initiated to the conversation request of DTF and carries this information.This conversation request is forwarded to DTF through the IMS network processes.(MCC carries new SDP information in the SDP of session information, header field (as replace), field or the message body of expansion or the existing SIP signaling of use are represented to be switched session identification)

Method embodiment three, MCC UE initiate earlier one tunnel handoff request, and the pattern of initiating to switch on another road by the indication in the network based request (annotate: 1, this sentences real-time media and switches earlier and switch to example behind the non-real time media but be not limited thereto order; 2, this sentences CS carrying real-time media is example, uses this method and also can use other IP-CAN carrying real-time media, can realize that Multimedia session switches to the purpose of related carrying; 3, DTF uses the REINVITE mode to initiate media re-negotiation with the far-end session in the present embodiment, also can use medium change procedure among other SIP such as UPDATE etc.; 4, present embodiment can be applicable to system embodiment one, two, four, five, and MCC and DTF close when establishing in being applied to deployment way, and the friendship between MCC and DTF uses internal interface to carry out; 5, present embodiment has only shown crucial processing entities, is not to comprise the all-network entity; 6 and the far-end process of setting up of carrying out new session in media negotiation and the purpose network other order can be arranged, present embodiment only provides preferable implementation).Referring to shown in Figure 20, precondition: MCC UE carries out the conversation of IMS multimedia with remote user equipment under the IP2 access way, and MCC entity, DTF entity have been anchored on institute and have set up in the calling signaling path.Comprise the following steps:

A1-a3, MCC UE initiates the handoff request of real-time media earlier in the purpose territory, but and carry the switch contexts information representation and also have non-real time media to switch and the relevant information of derived field handover source network Central Plains session identification, the IMS network entity at first is forwarded to MCC with session and handles according to the iFC trigger mechanism.

1, MCC judges still have non-real time media to be switched according to switch contexts, calls out MCC UE indication non-real time media and switch on IP-CAN1.

B1-b2, MCC UE receive that this calling back is a MCC PSI number according to calling number, and the offer of non-real time media promptly is provided in Temporary Response.

Method embodiment four, MCC UE by PS make a call the request carry switch to associating loaded information (notes: 1, present embodiment has only shown crucial processing entities, is not to comprise the all-network entity; 2, this sentences CS carrying real-time media is example but is not limited thereto; 3, DTF uses the REINVITE mode to initiate media re-negotiation with the far-end session in the present embodiment, also can use medium change procedure among other SIP such as UPDATE etc.; 4, present embodiment can be applicable to system embodiment three, and MCC and DTF close when establishing in being applied to deployment way, and the friendship between MCC and DTF uses internal interface to carry out; 5 and the far-end process of setting up of carrying out new session in media negotiation and the purpose network other order can be arranged, present embodiment only provides preferable implementation; 6, present embodiment closes with MCC and CSC and is made as example, but is not limited thereto application; 7, the related most preferred embodiment that only provides of CS and PS session, not getting rid of has alternate manner, as by calling number and switch related two sessions of indication, and mode such as related again after cooperating the recovery numbers of calling and called parties by CSAF and CAMEL service when ISUP is unavailable under striding situation such as international office).Referring to shown in Figure 21, precondition: MCC UE carries out the conversation of IMS multimedia with remote user equipment under the IP2 access way, and MCC entity, DTF entity have been anchored on institute and have set up in the calling signaling path; MCC UE supports the foundation by session in the PS control CS carrying.Comprise the following steps:

1-2, MCC UE is initiated to the call request of the non-real time media of special called number (as VDI) earlier on purpose IP1, but and carry the switch contexts information representation and also have real-time media need switch and the identification information of locator field handover source network Central Plains session, the IMS network entity at first is forwarded to MCC/CSC with session and handles according to the iFC trigger mechanism.

3, MCC/CSC judges still have real-time media to be switched according to switch contexts, waits for that the session in the CS carrying is set up request so that related these two conversation request.Alternatively, MCC/CSC carries PS session association information on CS session and the IP1 by set up the back of request in the IP1 session in response as 183, as to distribute a dynamic Handover Number VDN, this number can be the PSI number that points to MCC/CSC place AS at the IMS network.

4-6, after MCC UE receives response, according to the Handover Number that distributes as called number.Because called number is the PSI number of MCC/CSC, can call request be forwarded to MCC/CSC place AS according to the routing mode of PSI number and handles.(when using calling number, two sessions of switching indication association, described Handover Number can be realized being configured among the MCC UE, and needn't wait for the network dynamic assignment; The 4th step of this moment can postpone with the foundation that reduces hand off signaling with concurrent carrying out of the 1st step)

7, MCC/CSC is related two sessions of Handover Number that distribute in IP1 calls out according to called number.And navigate to according to the former session identification in the switch contexts information of in the IP1 session, carrying and DTF between to be switched session, generate multimedia according to the media information in switch contexts information and the conversation request and switch indication, and handover information is assembled into the SIP session sets up request message (MCC carries new SDP information in the SDP of session information, expansion or use header field (as replace), field or the message body of existing SIP signaling to represent to be switched session identification; Also can represent the Access Network information that this composite session is relevant, as comprise the Access Network information on CS and the IP1, use) for DTF or other professional AS header field, field or the message body of SIP signaling

8, MCC/CSC transmits conversation request to the IMS network.This conversation request of triggering by iFC is forwarded to the DTF processing.After DTF receives the conversation request of carrying the multimedia indication message, on the remote leg that navigates to according to this contextual information, initiate and the media re-negotiation of remote subscriber according to the SDP that newly provides.

9, DTF discharges the specified session in the handover source network after new bearer foundation is finished.(also can be that MCC UE initiates to discharge)

Method embodiment five, Multimedia session switch to the Access Network of not supporting DTM from IP-CAN2, guarantee that real-time media is accomplished to the switching on the CS, non-real time media is released because of degrading (to be annotated: 1, in real time example degrades that to report access network DTM ability with MCC UE be example in indication for this, but practical application is not limited thereto, and any terminal represents that to network information that this switching need degrade all meets the essence of the embodiment of the invention; 2, DTF uses the REINVITE mode to initiate media re-negotiation with the far-end session in the present embodiment, also can use medium change procedure among other SIP such as UPDATE etc.; 3, present embodiment can be applicable to system embodiment one to five, and MCC and DTF close when establishing in being applied to deployment way, and the friendship between MCC and DTF uses internal interface to carry out; 4, present embodiment has only shown crucial processing entities, is not to comprise the all-network entity; 5 and the far-end process of setting up of carrying out new session in media negotiation and the purpose network other order can be arranged, present embodiment only provides preferable implementation; 6, described step a3 also can directly be triggered to DTF and handle).Referring to shown in Figure 22, comprise the following steps:

A1-a3, MCC UE initiates the handoff request of real-time media earlier in the purpose territory, and carry switch contexts information and comprise indication that degrades (degrade in this example former because Access Network do not support DTM) and handover source network Central Plains, territory session identification, the IMS network entity at first is forwarded to MCC with session and handles according to the iFC trigger mechanism.

1-2, MCC determines to switch current media according to the indication that degrades, to be switched session identification between that then navigate to based on the former session identification of deriving in media information in the handoff request and the switch contexts information and DTF generates multimedia and switches indication, is initiated to the conversation request of DTF and carries this information.This conversation request is forwarded to DTF through the IMS network processes.(MCC carries new SDP information in the SDP of session information, header field (as replace), field or the message body of expansion or the existing SIP signaling of use are represented to be switched session identification)

3, after DTF receives the conversation request of carrying the multimedia indication message, on the remote leg that navigates to according to this contextual information, initiate and the media re-negotiation of remote subscriber according to the SDP that newly provides.

4, DTF discharges the specified session in the handover source network after the CS of real-time media carrying is set up successfully.(also can be that MCC UE initiates to discharge)

Method embodiment six, switch contexts information when CS inserts, be delivered to MCC mode one (annotate: 1, the method for present embodiment can be applicable to system embodiment one, two, four, five; 2, present embodiment has only shown crucial processing entities, is not to comprise the all-network entity).Referring to shown in Figure 23, comprise the following steps:

1, MCC UE carries correlating sessions territory switch contexts and be delivered to the VMCS of end office (EO) processing on User Network Interface in the User2User cell.

2, VMCS is signatory according to the user, and the information that will receive from user to the user cell is delivered to user attaching IMS network SCP application by CAMELInitialDP message, and (here SCP App represents the integral body of gsmSCP and CAMEL Service entity; This CAMEL message should be triggered to gsmSCP earlier, and then is delivered to CAMEL Service by internal interface) on; SCP App oneself or and CSAF distribute the routing number (IMRN) of IMS network alternately, and in the IDP response message, return to VMSC.

3, VMCS routes the call to the gateway MGCF processing of IMS network according to the number of changed course; MGCF adopts the Ma interface forward call to the CSAF entity.

4, CSAF when receiving the calling that the circuit domain route is come and SCP use the circuit domain information of obtaining storage alternately; And when assembling the SIP conversation request in view of the above, above-mentioned information sets is installed to suitable SIP information field.

5, CSAF handles forward call to S-CSCF.

6, S-CSCF handles the AS that calling is triggered to the MCC place according to iFC.

Method embodiment seven, switch contexts information when CS inserts, be delivered to MCC mode two (annotate: 1, the method for present embodiment can be applicable to system embodiment one, two, four, five; 2, present embodiment has only shown crucial processing entities, is not to comprise the all-network entity).Referring to shown in Figure 24, comprise the following steps:

1, MCC UE carries switch contexts information and be delivered to the VMCS of end office (EO) processing on User Network Interface in the User2User cell.

2, VMCS arrives the user profile unit with the user who receives to the user that user cell is assembled in the interoffice signaling (ISUP or BICC); And handle according to CAMEL changed course and calling to be redirected to MGCF to handle.

3, MGCF is assembled into the user in the sip message after the user profile cell translation becomes the parameter of SIP conversation request or header field or message body.

4,5, behind this SIP conversation request route IMS network, the conversation control entity of IMS network such as S-CSCF handle the AS that this request is forwarded to the MCC place according to the iFC trigger mechanism of caller.

Method embodiment eight, switch contexts information when CS inserts, be delivered to MCC mode three (annotate: 1, the method for present embodiment can be applicable to system embodiment five; 2, present embodiment has only shown crucial processing entities, is not to comprise the all-network entity).Referring to shown in Figure 25, comprise the following steps:

1, MCC UE carries switch contexts information and be delivered to access gateway AG F processing on User Network Interface in the User2User cell.

2, AGF is assembled into the user that receives in the sip message after user cell converts the parameter of SIP conversation request or header field or message body to.

3, AGF according to when registration information this SIP conversation request is forwarded to the IMS network of user attaching, the related entities of IMS network such as S-CSCF are triggered to MCC according to caller iFC with calling and handle.

The pattern that medium are consulted in method embodiment nine, mode serial real-time and that non real-time initiates to switch simultaneously (is annotated: 1, this sentences CS carrying real-time media is example, use this method and also can use other IP-CAN carrying real-time media, can realize that Multimedia session switches to the purpose of CSI combination bearer network; 2, DTF uses the REINVITE mode to initiate media re-negotiation with the far-end session in the present embodiment, also can use medium change procedure among other SIP such as UPDATE etc.; 3, present embodiment can be applicable to system embodiment one, two, four, five, and MCC and DTF close when establishing in being applied to deployment way, and the friendship between MCC and DTF uses internal interface to carry out; 4, present embodiment has only shown crucial processing entities, is not to comprise the all-network entity; 5 and the far-end process of setting up of carrying out new session in media negotiation and the purpose network other order can be arranged, present embodiment only provides preferable implementation).Referring to shown in Figure 26, comprise the following steps:

A1-a3, MCC UE initiates the handoff request of real-time media earlier in the CS territory, and carry the switch contexts information representation and also have non-real time media to switch and handover source network Central Plains, territory session identification, the IMS network entity at first is forwarded to MCC with session and handles according to the iFC trigger mechanism.

1, MCC receives the conversation request of carrying switch contexts information earlier, then judge have non real-time to be switched according to this switch contexts, and navigate to former Multimedia session between MCC and DTF with serial mode, use new real-time media to replace corresponding real-time media and former Multimedia session sign and generate multimedia and switch indication.

2, MCC carries multimedia and switches the conversation request that indication is initiated to DTF, handles to DTF by the IMS forwarded.

3, DTF information in view of the above navigates to the session of remote subscriber and uses the SDP that newly provides to carry out media re-negotiation in the session that navigates to.

4, DTF discharges the specified session in the handover source network after new bearer foundation is finished; MCC receives that discharging the continuation of request back waits for the non-real time media handoff request.

B1-b3, MCC UE initiates the handoff request of non-real time media earlier at IP-CAN1, and carries indication and the former session identification that switch contexts information comprises does not have other medium to switch.

5, after MCC receives this request earlier, navigate to respective session between MCC and DTF according to the to be switched session identification in this contextual information.In this session, initiate media re-negotiation, so that the non-real time media information of receiving is replaced between MCC and DTF the appropriate section in the multimedia composition in the respective session.

6, MCC discharges the specified session in the handover source network after media re-negotiation is finished.(also can be that MCC UE initiates to discharge)

Method embodiment ten, session from the association carrying switch to the multimedia carrying (annotate: 1, DTF uses the REINVITE mode to initiate media re-negotiation with the far-end session in the present embodiment, also can use medium change procedure among other SIP such as UPDATE etc.; 2, present embodiment can be applicable to system embodiment one to five, and MCC and DTF close when establishing in being applied to deployment way, and the mutual use internal interface between MCC and DTF carries out; 4, present embodiment has only shown crucial processing entities, is not to comprise the all-network entity; 5 and the far-end process of setting up of carrying out new session in media negotiation and the purpose network other order can be arranged, present embodiment only provides preferable implementation; 6, described step b2 and follow-up step also can directly be triggered to DTF without MCC and handle, and then MCC will discharge two sessions in the related carrying after the release indication of receiving DTF).Referring to shown in Figure 27, comprise the following steps:

B1-b2, MCC UE initiates the Multimedia session request on multimedia carrying IP-CAN1, and carrying switching of switch contexts information representation multimedia and handover source network Central Plains session identification, the IMS network entity at first is forwarded to MCC with session and handles according to the iFC trigger mechanism.

1, MCC receives the conversation request of carrying switch contexts information earlier, then navigates to former Multimedia session between MCC and DTF according to the former session identification of this switch contexts, uses new multimedia composition and former Multimedia session sign to generate multimedia and switches indication.

5, after MCC receives this request earlier, discharge the specified session in the handover source network.Wherein 5a is for discharging the flow process of non-real time media session; 5b is for discharging the flow process of real-time media session.(also can be that MCCUE discharges this two sessions respectively)

Method embodiment 11, MCC UE do when called and the network information mutual (annotate: 1, present embodiment can be applicable to system embodiment one to five, MCC and DTF close when establishing in being applied to deployment way, the mutual use internal interface between MCC and DTF carries out; 2, present embodiment has only shown crucial processing entities, is not to comprise the all-network entity; 3).Referring to shown in Figure 28, comprise the following steps:

1-2, the multimedia call of remote user equipment (with the #1 sign) arrives the home network of MCC UE and is triggered to the DTF grappling.

3-5, when DTF and MCC set up separately, (this sign can be the dialogue identifier of SIP session to the sign of a session of DTF distribution, or other sign that generates, can determine a session in that DTF is unique in a word) and this multimedia call (using the #2 sign after the grappling) is forwarded to MCC by the IMS network handles.MCC according to decision partition such as the Access Network characteristic of purpose MCC UE registration and network strategy this to media session.

6-7, MCC splits a part of session in the PS carrying, sets up in the request in session and carries session identification, association identification, and this information sets up request by the SIP session or other call request message sends to MCCUE.Session identification in view of the above, MCC UE can ask DTF to switch indicated session.Association identification in view of the above, MCC UE can judge that whether the session on this access bearer go up session correlating sessions each other on other access bearer with this UE.(also can realize the purpose of these two signs by a parameter, all receive same session identification, then can judge correlating sessions each other as the session on the different access bearers; This session identification and association identification can be carried with its various parameters, header field, field, message body in the SIP session).

8-8a when this session information, related information insert when transmitting at the CS of MCC UE, can be delivered to MCC UE the user that interconnection entity such as MGCF transfer the information in the SIP session among the CS behind the user profile unit;

8b when MCC UE support is communicated by letter with the CSC function, can transmit described information by USSD passage therebetween.

Preserve after MCC UE receives and mate and judge, discharge these signs when discharging simultaneously calling out.

In sum, the embodiment of the invention is by newly-increased MCC UE, and it can initiate the handoff request of Multimedia session between association carrying and multimedia carrying, and carries switch contexts information in this handoff request; By increasing the function of MCC, make it can be according to described switch contexts information, corresponding generation multimedia is switched indication, and send to DTF, MCC UE and the handoff procedure of Multimedia session between related carrying and multimedia carrying between the MCC are mapped to the handoff procedure of Multimedia session between different access modules between MCC and the DTF; By increasing the function of DTF, make it switch indication according to described multimedia, carry out media negotiation with far-end UE, to finish the switching of Multimedia session between different access modules between MCC and this DTF.

So under the situation that does not influence the VCC existing procedure, solved the problem that Multimedia session switches on the multimode terminal in the carrying of different access modules, thereby provide call continuity for the Multimedia session of multimode terminal.Strengthen the ability of call continuity, the scope that provides of network operator's call continuity has been provided, thereby increased the scale of professional profit potentially.

The above only is a preferred implementation of the present invention; should be pointed out that for those skilled in the art, under the prerequisite that does not break away from the principle of the invention; can also make some improvements and modifications, these improvements and modifications also should be considered as protection scope of the present invention.

Claims

1. system that realizes multimedia conversation continuity, comprise: remote user equipment UE, it is characterized in that, the signaling anchor point territory handoff functionality DTF that connects between first access leg and remote leg is provided, wherein first access leg is that DTF sets up by related carrying with multimode terminal MCC UE, and remote leg is to set up between DTF and remote user equipment, and MCC UE intercoms via this DTF mutually with far-end UE, during the switching of generation afterwards

MCC UE is used for initiating to carry switch contexts information second access leg and sets up request;

DTF is used for reception and carries switch contexts information second access leg foundation request, and second access leg between foundation and MCC UE; And, carry out media negotiation with far-end UE according to described switch contexts information, and remote leg is rerouted to second access leg links to each other, MCC UE continues to communicate by letter with far-end UE.

2. the system as claimed in claim 1 is characterized in that, also comprises:

Medium switching entity MCC, it is arranged in described first access leg, be used for carrying residing access network in multimedia and initiate described second access leg that carries switch contexts information when setting up request, be mapped to first access leg that the multimedia between this MCC and the DTF carries and set up process setting up process at first access leg in the related carrying between MCC UE and this MCC at MCC UE.

3. the system as claimed in claim 1 is characterized in that, described MCC UE can initiate the two-way switching of Multimedia session between association carrying and multimedia carrying;

Described association is carried as the combination of at least two Access Network bearing modes, the session of associating bearing multimedia;

Described multimedia is carried as the Access Network bearing mode of bearing multimedia session separately.

4. system as claimed in claim 2, it is characterized in that described MCC UE is when called, in the process of setting up first access leg, whether MCC notifies a whether Multimedia session between corresponding MCC and far-end UE of each session of being set up between itself and MCC UE, be correlating sessions promptly; And when the initiation of MCCUE desire switched to the handoff request of multimedia carrying with the association carrying, if Multimedia session between corresponding MCC and far-end UE, then this MCC UE initiated a handoff request.

5. system as claimed in claim 2 is characterized in that, if when MCC UE uses CS domain signaling and MCC mutual, also comprise between then described MCC UE and the MCC: the network interworking entity is used for

Finish the conversion between the SIP signaling in CS domain signaling and the IMS territory.

6. as each described system of claim 2 to 5, it is characterized in that described MCC is an application server AS, network calls described MCC by initial filter criteria iFC trigger mechanism.

7. system as claimed in claim 6 is characterized in that, described MCC is a stand-alone network elements, then at described MCC UE during as caller, by the iFC trigger mechanism make MCC before DTF by network call; And at described MCC UE when called, by the iFC trigger mechanism make MCC after DTF by network call.

8. system as claimed in claim 6 is characterized in that, also comprises territory selection functional entity DSF in the described system, and MCC and DSF close and establish, and then described MCC UE is during as caller, by the iFC trigger mechanism make described close establish AS before DTF by network call; And at described MCC UE when called, by the iFC trigger mechanism make close establish AS after DTF by network call.

9. system as claimed in claim 6 is characterized in that described MCC and DTF close and establish, and then call out to arrive described closing when establishing AS by the iFC trigger mechanism, and this MCC is by network call; And described MCC UE is during as caller, by described close the internal logic of establishing AS make MCC before DTF by network call; By network call.

10. as each described system of claim 2 to 5, it is characterized in that described MCC is the transfer entity of mutual signaling between MCC UE and the network, then MCC is inserted in the signaling paths between MCC UE and the network by special register flow path, and when calling out this MCC of arrival, by network call.

11. a multimode terminal is characterized in that, comprising:

Initiate the unit, be used to initiate the handoff request of Multimedia session between association carrying and multimedia carrying;

The information adding device, the handoff request that is used for initiating in described initiation unit is added switch contexts information;

Releasing unit is used for after the media negotiation success, discharges media negotiation to be switched Multimedia session before.

12. multimode terminal as claimed in claim 11 is characterized in that, also comprises:

Switch the judging unit that degrades, be used for before initiating unit initiation handoff request, judging whether earlier needs to reduce the Multimedia session quality, and carries switchable media session relevant information according to the corresponding information adding device of informing of judged result in switch contexts information.

13. multimode terminal as claimed in claim 11 is characterized in that, also comprises:

The far-end session information is preserved the unit, is used at this MCC UE being kept at and setting up in the calling procedure when called, and whether the each several part correlating sessions between the notice MCC of network side transmitted and this MCC UE the information of a Multimedia session between corresponding MCC and far-end UE;

The quantity indicating member is used for preserving the information that the unit is preserved according to the far-end session information when the desire initiation switches to the handoff request of multimedia carrying with the association carrying, and the quantity of handoff request is initiated in corresponding indication initiation unit.

14. a medium switching entity is characterized in that, comprising:

Acquiring unit is used for obtaining switch contexts information from the Multimedia session handoff request that MCC UE sends;

Switch indicating member, be used for the described switch contexts information obtained according to acquiring unit, corresponding generation multimedia is switched indication, and send to DTF, MCC UE and the handoff procedure of Multimedia session between related carrying and multimedia carrying between the MCC are mapped to the handoff procedure of Multimedia session between different access modules between MCC and the DTF;

15. medium switching entity as claimed in claim 14 is characterized in that, also comprises:

Far-end session information notification unit is used at MCC UE when called, in setting up calling procedure, with this MCC UE of information notification of a Multimedia session between corresponding this MCC and far-end UE whether of the each several part correlating sessions between this MCC and MCC UE.

16. a territory handover (mih) functions is characterized in that, comprising:

The Multimedia session negotiation element is used for reception and carries switch contexts information second access leg foundation request, and second access leg between foundation and MCC UE; And, carry out media negotiation with far-end UE according to described switch contexts information, and remote leg is rerouted to second access leg links to each other, MCC UE continues to communicate by letter with far-end UE;

17. method that realizes multimedia conversation continuity, it is characterized in that, the signaling anchor point territory handoff functionality DTF that connects between first access leg and remote leg is provided, wherein first access leg is that DTF sets up by related carrying with multimode terminal MCC UE, remote leg is to set up between DTF and remote user equipment, MCC UE intercoms via this DTF mutually with far-end UE, and the handoff procedure of Fa Shenging comprises the following steps: afterwards

DTF receives that MCC UE initiates to carry switch contexts information second access leg and sets up request;

Second access leg between foundation and MCC UE;

DTF carries out media negotiation according to described switch contexts information with far-end UE, remote leg is rerouted to second access leg link to each other, and MCC UE continues to communicate by letter with far-end UE.

18. method as claimed in claim 17 is characterized in that, MCC UE carries residing access network in multimedia initiates described second access leg foundation request of carrying switch contexts information, and comprises medium switching entity MCC in described first access leg; MCC sets up process with setting up first access leg that process is mapped in the multimedia carrying between MCC and the DTF at first access leg in the related carrying between MCC UE and the MCC;

Described association is carried as the combination of at least two Access Network bearing modes, the session of associating bearing multimedia; Part Multimedia session in described each related carrying is correlating sessions each other, and each correlating sessions is combined as a Multimedia session;

Described multimedia carrying is each Access Network bearing mode of bearing multimedia session separately.

19. method as claimed in claim 18 is characterized in that, described MCC sets up process with setting up first access leg that process is mapped in the multimedia carrying between MCC and the DTF at first access leg in the related carrying between MCC UE and the MCC, comprising:

MCC sets up relevant request or response message with first access leg in the association carrying and merges into call request or response message in the multimedia carrying;

MCC discharges relevant request or response message with first access leg in the association carrying and merges into call request or response message in the multimedia carrying;

First access leg that returns in the multimedia carrying is set up relevant response to MCC or request message splits response or the request message that each association is carried;

First access leg that returns in the multimedia carrying is discharged relevant response to MCC or request message splits response or the request message that each association is carried.

20. method as claimed in claim 18, it is characterized in that whether each other MCC UE judged the current session correlating sessions that is distributed in the different access networks before initiating handoff request, if correlating sessions is then initiated a handoff request at described all correlating sessions each other.

21. method as claimed in claim 20 is characterized in that, MCC UE judges the mode of correlating sessions, comprises one of following:

As MCC UE during as caller, whether each other what can know that local terminal initiates is distributed in each session correlating sessions in the different access networks;

When MCC UE when called, in setting up conversation procedure, notify MCC UE correlating sessions information by MCC, whether each other the correlating sessions information that MCC UE informs with MCC judge current each session correlating sessions that is distributed in the different access networks;

MCC UE is according to predetermined strategy, always thinks current each session correlating sessions each other that is distributed in the different access networks.

22. method as claimed in claim 21, it is characterized in that, carry switch contexts information in the described handoff request, wherein comprise at least: the indication that the expression Multimedia session switches, MCC UE the multimedia bearer network that support with media information to be switched medium composition correspondence, and sign of to be switched medium is gone up in each related carrying.

23., it is characterized in that as each described method of claim 17 to 22, after media negotiation success, also comprise the step that discharges Multimedia session to be switched before the media negotiation, it is one of following that delivery mode comprises:

If DTF initiate to discharge, after then MCC receives the release message that DTF sends, discharge described correlating sessions respectively;

If MCC UE initiates to discharge, then MCC discharges the session between MCC and the DTF again after discharging described correlating sessions.

24. method that realizes multimedia conversation continuity, it is characterized in that, the signaling anchor point territory handoff functionality DTF that connects between first access leg and remote leg is provided, wherein first access leg is that DTF and multimode terminal MCC UE set up by the multimedia carrying, remote leg is to set up between DTF and remote user equipment, MCC UE intercoms via this DTF mutually with far-end UE, and the handoff procedure of Fa Shenging comprises the following steps: that DTF receives that MCC UE initiates to carry switch contexts information second access leg and sets up request afterwards;

Second access leg between foundation and MCC UE;

25. method as claimed in claim 24 is characterized in that, MCC UE carries described second access leg that carries switch contexts information of residing access network initiation in association and sets up request by a medium switching entity MCC;

MCC is according to described switch contexts information, corresponding generation multimedia is switched indication, and send to DTF, to set up process with setting up second access leg that process is mapped in the multimedia carrying between MCC and the DTF at second access leg in the related carrying between MCC UE and the MCC;

Described multimedia carrying bearing multimedia session separately;

Described association is carried as the combination of at least two Access Network bearing modes, the session of associating bearing multimedia; Part Multimedia session in described each related carrying is correlating sessions each other, and each correlating sessions can be combined to a Multimedia session.

26. method as claimed in claim 25 is characterized in that, initiates described handoff request and comprises one of following manner:

Mode one, MCC UE initiate the handoff request that each association is carried simultaneously at the destination network;

Mode two, MCC UE elder generation initiate handoff request in one tunnel association carrying, initiate the handoff request that other association is carried by MCC according to judgement of the information in this request and indication MCC UE;

Mode three, MCC UE initiate handoff request earlier in one road related carrying, set up request to obtain handoff request required media information according to the indication in this request to the session that this MCC UE initiates in other related carrying by MCC;

When MCC receives handover information in each related carrying by one of above-mentioned three kinds of modes after, carry out media negotiation with parallel pattern indication DTF and the remote subscriber of consulting medium.

27. method as claimed in claim 26, it is characterized in that, in described mode one and the mode two, carry switch contexts information in the handoff request, wherein comprise at least: the indication that session is switched, MCC UE support at each related bearer network of destination with the media information of to be switched medium composition correspondence, the sign of to be switched medium, and the indication that whether has other medium composition to switch.

28. method as claimed in claim 27 is characterized in that, initiates the handoff request of Multimedia session in mode one, comprises the following steps:

After MCC receives one of handoff request in the related carrying,, judge whether to receive all relevant handoff request according to the described indication that whether has other medium composition needs to switch; When judging when all receiving, whether identical according to the former session identification in the to be switched media identification of carrying in each handoff request, each other whether the media session of judging described each handoff request correspondence correlating sessions; If exhale to be correlating sessions, then MCC merges each handoff request, and corresponding generation multimedia is switched indication, and sends to DTF.

29. method as claimed in claim 27 is characterized in that, initiates the handoff request of Multimedia session in mode two, comprises the following steps:

MCC UE initiates the handoff request in the one road related carrying earlier;

MCC judges whether to receive all relevant handoff request according to the described indication that whether has other medium composition needs to switch, if all relevant handoff request are not received in judgement, then MCC distributes Handover Number, and this Handover Number is returned to MCC UE;

MCC UE initiates handoff request in other related carrying in the mode of calling out this Handover Number, and the media session that MCC judges each handoff request correspondence according to this Handover Number is correlating sessions each other;

Afterwards, MCC merges each handoff request, and corresponding generation multimedia is switched indication, and sends to DTF.

30. method as claimed in claim 26, it is characterized in that, in the described mode three, carry switch contexts information in the handoff request, wherein comprise at least: Multimedia session switch that indication, MCC UE support at each related bearer network of destination with the media information of to be switched medium composition correspondence, the sign of to be switched medium, and the indication that whether has other medium composition to switch; If also have other medium composition to need to switch, then also comprise the switching purpose network information of this medium composition.

31. method as claimed in claim 30 is characterized in that, initiates the handoff request of Multimedia session in mode three, comprises the following steps:

MCC UE initiates the handoff request in the one road related carrying earlier;

MCC is according to the described indication that whether has other medium composition needs to switch, judge whether to receive all relevant handoff request, do not receive all relevant handoff request if judge, then MCC initiates the call request that other association is carried by the switching purpose network of the medium composition of unreceived handoff request correspondence to this MCC UE;

Carry media information in the response message of the call request of MCC UE in other related carrying;

Afterwards, the corresponding generation multimedia of MCC is switched indication, and sends to DTF.

32., it is characterized in that as each described method of claim 24 to 31, after media negotiation success, also comprise the step that discharges Multimedia session to be switched before the media negotiation, it is one of following that delivery mode comprises:

If DTF initiate to discharge, after then MCC receives the release message that DTF sends, discharge to be switched Multimedia session before the media negotiation;

If MCC UE initiate to discharge, after then MCC receives the release message that MCC UE sends, discharge the Multimedia session between MCC and the DTF.

33. method as claimed in claim 25 is characterized in that, initiates described handoff request and comprises one of following manner:

Handoff request in mode two, MCC UE initiation earlier one tunnel association carrying is initiated the handoff request that other association is carried by MCC according to judgement of the information in this request and indication MCC UE;

Mode three, MCC UE initiate one tunnel handoff request earlier, initiate call request that other association carry according to the indication in this request to this MCC UE by MCC;

When MCC by one of above-mentioned three kinds of modes, receive one of handoff request in each related carrying after, pattern indication DTF and the remote subscriber of consulting medium with serial carry out media negotiation, to switch this road media session; Treat that MCC receives that another road handoff request and DTF finish last one tunnel media negotiation that switches, MCC initiates media re-negotiation to DTF, with the media session of one tunnel switching back foundation in the related media information updating of carrying in another road handoff request.

34. method as claimed in claim 33 is characterized in that, to be switched Multimedia session before the described release media negotiation comprises one of following manner:

If MCC initiates to discharge, then MCC discharges media negotiation to be switched Multimedia session before;

If MCC UE initiate to discharge, after then MCC receives the release message that MCC UE sends.

35. method as claimed in claim 25, it is characterized in that, MCC UE initiates before the Multimedia session switching, and judging whether earlier needs to reduce the Multimedia session quality, and carries the switchable media session relevant information and the indication that degrades according to judged result in switch contexts information;

After MCC identified the indication that degrades, directly according to described switchable media session relevant information, corresponding generation multimedia was switched indication, and sends to DTF; And

After the media negotiation success, discharge the media resource of Multimedia session quality reduction part between MCC and the MCC UE in the lump at related network elements.

36. method as claimed in claim 24 is characterized in that, in the IMS territory, carries switch contexts information by header field, parameter or message body in the expansion SIP conversation request.

37. method as claimed in claim 36 is characterized in that, if MCC UE is in the IMS territory and initiates described handoff request, then when assembling SIP conversation request, described switch contexts information is carried in this request.

38. method as claimed in claim 36 is characterized in that, if MCC UE is in the CS territory and initiates described handoff request, then MCC UE passes to MCC with described switch contexts information, comprises the following steps:

The user that MCC UE is carried on handoff request with switch contexts information and should ask to send to network side in user data cell;

After the visit ground VMCS of mobile switching centre received this request, the CAMEL application entity CAMELService that the described switch contexts information of wherein carrying is triggered to the user preserved;

When the handoff request in the CS territory is routed to the IMS territory, mutual by adaptive entity CSAF in CS territory and CAMELService, obtaining described switch contexts information, and when assembling SIP conversation request, described switch contexts information is carried in this request;

CSAF arrives MCC with described SIP conversation request by the IMS forwarded.

39. method as claimed in claim 36 is characterized in that, if MCC UE is in the CS territory and initiates described handoff request, then MCC UE passes to MCC with described switch contexts information, comprises the following steps:

After VMCS receives this request, this request is forwarded to interworking function entity MGCF by interoffice signaling;

MGCF is converted to the SIP conversation request with described request;

MGCF arrives MCC with this SIP conversation request by the IMS forwarded.

40. method as claimed in claim 36 is characterized in that, if MCC UE is in the CS territory and initiates described handoff request, then MCC UE passes to MCC with described switch contexts information, comprises the following steps:

After IAD functional entity AGF receives this request, this request is converted to the SIP conversation request;

AGF sends to MCC with this SIP conversation request by the IMS network.

41. system that realizes multimedia conversation continuity, comprise: remote user equipment UE, it is characterized in that, the signaling anchor point territory handoff functionality DTF that connects between first access leg and remote leg is provided, wherein first access leg is that DTF and multimode terminal MCC UE set up by the multimedia carrying, and remote leg is to set up between DTF and remote user equipment, and MCC UE intercoms via this DTF mutually with far-end UE, during the switching of generation afterwards

42. system as claimed in claim 41 is characterized in that, also comprises:

Medium switching entity MCC, be used to receive MCC UE and carry described second access leg foundation request of carrying switch contexts information that residing access network is initiated in association, and according to described switch contexts information, corresponding generation multimedia is switched indication, send to DTF, to set up process with setting up second access leg that process is mapped in the multimedia carrying between MCC and the DTF at second access leg in the related carrying between MCC UE and the MCC, be about to second access leg in the related carrying and set up and discharge relevant request or response message and merge into call request or response message in the multimedia carrying, second access leg that returns in the multimedia carrying is set up and discharged relevant response or request message and split response or request message in each related carrying.

43. system as claimed in claim 41, it is characterized in that, described MCC UE judged whether earlier to need to reduce the Multimedia session quality before initiating handoff request, and MCC UE carries the switchable media session relevant information and the indication that degrades according to judged result in switch contexts information;

After MCC identified the indication that degrades, directly according to described switchable media session relevant information, corresponding generation multimedia was switched indication, and sends to DTF.

44. system as claimed in claim 43 is characterized in that, it is one of following that the described strategy that judges whether need to reduce the Multimedia session quality comprises:

Judge whether the ability of switching destination supports current Multimedia session attribute,, then in switch contexts information, carry the common factor part of switching destination ability and current Multimedia session attribute if do not support;

Strategy according to the default reduction Multimedia session quality of MCC UE;

Indication according to the user.