CN102158496B - Call processing aiming at IMS (Internet protocol Multimedia Subsystem) registration user - Google Patents

Abstract

The invention proposes a method for providing IMS (Internet protocol Multimedia Subsystem) services to users having circuit-switched controlled terminals. In particular, it is proposed, in order to allow IMS to take full call and service control, to combine circuit-switched and packet-based multimedia functionality in a new node type called Mobile Access Gateway Control Function (MAGCF). In particular, the invention provides a method for ensuring that the MAGCF node acts as a roaming anchor point in order to enforce the handling of originating and terminating calls in the IMS.

Description

Call treatment for the IMS registered user

The application divides an application, and its female case application number is 200580052193.4, and its female case applying date is on December 1st, 2005, and the international application no of its female case application is: PCT/EP2005/012788.

The invention technical field

The present invention relates to carry out call treatment for the equipment of (the circuit switched controlled) user with circuit switching control and by termination (port) to the user in IMS territory.

Background

The third generation (3G) network such as UMTS (universal telecommunication network) and CDMA 2000 provides the high-speed wireless the Internet access to the mobile subscriber on loose overlay area.For 3G network, for supporting telephone and multimedia service, defined the honeycomb access that IP Multimedia System IMS is provided to Internet service.IMS uses packet-switch technology, particularly IP network and other to be used for the IETF agreement that service provides.2nd generation network such as GSM provides the voice based on circuit-switched technology.The advantage of IMS provides enhancement service, for example in conjunction with the multimedia service of voice-and-data.In addition, use IP network to allow the service arrangement of Simple fast as independent potential standard.

Session initiation protocol (session initiation protocol) SIP has been selected as being used in IMS between user equipment (UE) and the IMS and the signaling between each assembly of IMS.IMS also finishes voice and multimedia call in the internet with SIP.In order to use the IMS service, the equipment of communication user must be supported IMS, this means to implement SIP at subscriber equipment.

The simplified network architecture of IMS is described below.The node that provides service related in the IMS architecture is provided especially.

The assembly of IMS system has CSCF (CSCF), media gateway (MGW)/MGCF (MGCF), home subscriber register (HSR), application server (AS).

CSCF takes on call server and processes call signaling, its support and control Multimedia session and executive address translation function.CSCF can be divided into S-CSCF, I-CSCF and P-CSCF by function.Proxy CSCF (P-CSCF) is that first make contact in the IMS network and its provide the mandate to bearing resource (bearer resource), and it further is forwarded to definite I-CSCF by the home domain name that provides such as the user is provided to the SIP registration request that receives from user equipment (UE).In the opposite direction, it is transmitted the SIP request or responds UE.In addition, CSCF is forwarded to sip server (S-CSCF) to the sip message that receives from UE, and the title of this sip server is to be received by P-CSCF as the result of registration process.

Inquiry-CSCF (I-CSCF) predetermined arrive the subscriber (subscriber) of (destined to) Virtual network operator or is currently located at contact point (contact point) in the carrier network of all connections of the roamer in the Virtual network operator coverage.In carrier network, may exist a plurality of I-CSCF.The major function that I-CSCF carries out is to the user assignment S-CSCF that carries out the SIP registration.

Service call conversation control function (S-CSCF) is the node of carrying out the session management of IMS network.In network, some S-CSCF can be arranged.The major function of S-CSCF comprises: accept registration request, carry out alternately with service platform in order to support service from UE.It further provides the information relevant with Service events position, the advice of charge of notice and the additional media resource of tone/declaration (announcement) (for example as) for end points (endpoint).

Home subscriber register HSR is centralized subscriber database.HSR and I-CSCF and S-CSCF provide about the information of subscriber position and subscriber's reservation (subscription) information fetching.HSR is responsible for processing following user related information: user ID, numbering and address information, the user security information that is used for discriminating (authentication) and authorizes.HSR supports user's registration, and stores inter-system location information.

IMS supports node some and legacy network interworking, for example MGCF (MGCF).

MGCF carries out the protocol conversion between cellular call control protocol and the IMS agreement.For example, MGCF receives sip message and is converted into suitable isup message from CSCF.Thereby the major function of MGCF is to be another kind of form with signaling message from a kind of format conversion upwards at up link and downlink side.In UMTS, this is mainly between the pulse code modulation in PSTN (PCM) and the IP-based form.

IMS access server host (host) also carries out the service that the user asks.

The UMTS system allows the mobile subscriber who operates under the group mode to set up audio call with SIP as signaling protocol as previously mentioned.Sip message is sent to communicate the request to the CSCF (CSCF) among the IMS.In this case, these data transmit in whole UMTS network as grouping.

Thereby, for 3G network IMS has been deployed as with packet-switch technology service is provided, wherein SIP is applied to signaling protocol.But current most of subscriber equipmenies are not supported to provide the IMS technology of voice service with SIP as signaling protocol, and this is because described subscriber equipment is applicable to the circuit switching control domain.Thereby, in order to access IMS, must carry out subscriber equipment adaptively, this causes changing the problem of terminating machine.

Other problems that can occur provide conversational services.Real-time carrying is provided in IMS, and it can not provide voice service efficiently.In order to provide voice service by GSM or WCDMA access efficiently, will use the circuit switching access.

Summary of the invention and description

Therefore, an object of the present invention is for the solution that the packet switching multimedia service is provided to the subscriber equipment that operates in the circuit switching control domain.

The present invention is open in independent claims.

Favourable embodiment is disclosed in the dependent claims, and this dependent claims is open in the appropriate section of specification.

The invention discloses and be applicable in packet-based multimedia system territory the access gateway node (MAGCF) called out for the user terminal processes of the circuit switching control that is positioned at the circuit switching control domain, wherein said access gateway node comprises (originating) circuit-switched logic that starts, and this circuit-switched logic that starts is applicable to circuit-switched call is routed to the routing number of access gateway node and receive or directly receive the circuit-switched call of starting from circuit switching control user terminal from the service walking circuit function of exchange that the walking circuit function of exchange is provided by being used to.In addition, this access gateway node comprises the packet-based multimedia logic that starts, and this multimedia logic is applicable to send the packet-based multimedia call that starts by the proxy-call session control function as an access network nodes part to packet-based multimedia domain, MMD.Comprise in addition termination (terminating) call function body (functionality), it comprises the packet-based multimedia logic of termination, this termination multimedia logic is applicable to receive addressed (address to) to the packet-based multimedia call of the termination of proxy-call session control function from packet-based multimedia domain, MMD, it also comprises the termination circuit exchange logic, and this termination circuit exchange logic is applicable to send the termination circuit switched call to the user terminal of circuit switching control.In addition, also have translation function, this translation function is applicable to the circuit-switched call of starting is converted to start packet-based multimedia call and will stop the group-based multimedia call be converted to the termination circuit switched call.

In addition, the invention discloses a kind of method for calling out for the circuit switching control user terminal processes that is positioned at the circuit switching control domain at packet-based multimedia domain, MMD.Said method comprising the steps of:

Carrying out the calling origination process comprises:

Circuit-switched call is routed to the routing number of access gateway node (MAGCF) and receives or directly receive the circuit-switched call of starting from the user terminal of circuit switching control from service walking circuit function of exchange by being used to, and

The circuit-switched call of will starting is converted to the packet-based multimedia call that starts, and

Send the packet-based multimedia call that starts by integrated (integrated) proxy-call session control function to packet-based multimedia domain, MMD, and

Carrying out the calling termination procedure comprises:

Receive the packet-based multimedia call of termination that is addressed to integrated proxy-call session control function from packet-based multimedia domain, MMD, and

To stop packet-based multimedia call and be converted to the termination circuit switched call, and

User terminal to circuit switching control sends the termination circuit switched call.

In addition, favourable embodiment is described in the dependent claims.

For so that those skilled in the art can understand the present invention fully, the below will describe the preferred embodiments of the present invention in detail, but these detailed embodiment and are not intended to restriction only as example of the present invention.Following description is with reference to accompanying drawing, wherein

Fig. 1 illustrates schematically showing according to the architecture of access gateway node of the present invention.

Fig. 2 illustrates the flow chart of the embodiment of the invention of the call originate method that will carry out at access gateway node.

Fig. 3 illustrates the flow chart of the embodiment of the invention of the calling terminating method that will carry out at access gateway node.

Fig. 4 illustrates the embodiments of the invention that MAGCF is comprised as roaming anchor point (anchor point).

Fig. 5 illustrates the another embodiment of the present invention that MAGCF is comprised as the roaming anchor point.

Fig. 6 is illustrated in the illustrative examples that calling is started in the home network.

Fig. 7 is illustrated in the embodiment that is used for calling out the signaling sequence that starts in the home network.

Fig. 8 is illustrated in the illustrative examples that calling is started in the accesses network.

Fig. 9 is illustrated in the embodiment that is used for calling out the signaling sequence that starts in the accesses network.

Figure 10 is illustrated in and calls out the illustrative examples that stops in the home network.

Figure 11 is illustrated in the embodiment that is used for calling out the signaling sequence that stops in the home network.

Figure 12 is illustrated in and calls out the exemplary schematic embodiment that stops in the accesses network.

It should be noted that term " entity ", " node ", " module ", " logic " in the context of the invention refer to the combination of any appropriate of the hardware and software that predetermined function is provided in communication network.In this manner, if when not providing clear and definite definition, then described term refers to mainly which is deployed into logic entity on some physical entities, but also can refer to be positioned at the physical entity of a physical location.

It should be noted that the term " user " in the context of the invention refers to the subscriber equipment of circuit switching control, wherein said subscriber equipment is the combination of hardware and software.If do not point out difference, then term " user " should be regarded as having identical implication with " user terminal " but in the following description.

Preferably, communication network is mobile communications network, for example, is the cordless communication network that operates according to GSM, GPRS (general packet exchange radio) or UMTS (universal mobile telephone system) or the 3G system such as EDGE, CDMA2000.And preferably, the packet switching multimedia domain, MMD is IP Multimedia System (IMS).

In order to allow IMS to carry out full call (full call) and Service controll, propose the logic function body of honeycomb switching center and the logic function body of IMS are incorporated in the access gateway node according to the present invention, it is called as MAGCF below.Especially, the present invention proposes this new MAGCF node and comprises Service Circuit function of exchange body, for example as MSC or as the MSC-S of roamer's service MSC or be used for being terminated to the roamer's of the network that does not have the MAGCF functive the GMSC-S of calling, and comprise that alternatively the gsmSCF and its further MAGCF of proposition that are used to roamer's originating call have packet switching multimedia function body, it is proxy-call session control function especially, for example as the P-CSCF that is used for sip message is forwarded to IMS and is forwarded to the user from IMS from the user.Usually, can say MAGCF in the packet switching multimedia domain, MMD, represent have circuit-switched terminals be used for process.In addition, the present invention proposes the protocol conversion between MGCF execution cellular call control protocol and the IMS agreement.Integrated user agent's task is that realization IMS function and representative of consumer are processed.

This basic conception is to guarantee that MAGCF processes all starting and end call, perhaps in other words, guarantees that MAGCF is the anchor point that honeycomb is linked into IMS.

The present invention concentrates on and sets up and the process user calling.But before setting up the packet switching Multimedia session, the user need to carry out registration process in order to allow circuit switching and IMS territory know described user's position.This registration is to carry out by Session Initiation Protocol with as the user agent that a MAGCF part and representative of consumer are carried out registration.

The below will describe wherein MAGCF as the registration of anchor point.For example, given embodiment has described and changed service MSC-S when roaming into access.In the time of in roaming into the accesses network of not supporting MAGCF, the last MAGCF that is responsible for is held as anchor point.

According to the present invention, described MAGCF node has the MSC functive, for example MSC-S and the IMS functive of user agent UA form and integrated P-CSCF.Therefore MAGCF has the ability of communicating by letter with IMS with HLR, and at least one MAGCF predicts for the user in the home network.A plurality of MSC are provided in network usually, and wherein MSC is responsible for being arranged in the user of the lane place that is assigned to MSC.The change of the responsible MSC that causes owing to moving of user means to be intended to by carry out associated being updated in registered user among the new MSC and nullifying the startup of the roam procedure that is used for from old MSC of being necessary at corresponding node.After entering new lane place, terminal sends position updating request to new MSC.When receiving this message, it is new in it is responsible for scope that MSC identifies this subscriber, thereby contact HLR upgrades positional information.When receiving location update message, HLR is just to old MSC notice: the subscriber has roamed into new MSC area.According to the present invention, the user serves the part that MSC can be MAGCF, and perhaps roaming in the situation of accesses network it the user also can be to be positioned at the MSC commonly used of described accesses network and partly to communicate by letter with the circuit switching of MAGCF.No longer send message from HLR under the both of these case of service subscriber at MSC.Be that new MAGCF is assigned to the user in this case in the situation of a part of MAGCF at MSC, this causes that the change of address of the service MAGCF among the S-CSCF and it have caused that also the address with S-CSCF is stored among the MAGCF.Be not in the situation of a part of MAGCF at service MSC, for example possible when the user roam in accesses network this thing happens, in this case, serves that MSC may change but MAGCF remains unchanged.For to the IMS system registry, when receiving the position and upgrade, HLR checks the whether part of MAGCF of MSC.HLR checks the subscriber of the request of sending in addition.For the IMS function is provided to the user, described user has to be ported to the IMS system.In other words, the user must announce to change to the IMS system on one's own initiative or system can determine to port cellular users to the IMS system.Relevant user's corresponding notice will be stated in HLR.The user not by the situation of termination under, propose for the behavior of phone user's application standard, as known.Be terminated to the user in the situation of IMS, propose HLR and send all parameters to MAGCF, described parameter is stored in the SIM card in the subscriber equipment usually.When receiving parameter, act on behalf of in order in the IMS system, register and subscribe the subscriber with regard to contact user.Preferably applied agreement for registration and reservation is Session Initiation Protocol, and the user agent also implements the SIP function in this case.In the IMS registration process, the user agent represents subscriber's action.Register and required carry out by the IMS entity that is integrated among the MAGCF in steps.For example these steps can comprise that the user to differentiating differentiates.But need to prove this discriminating and optional, this has been differentiated the fact of a part that accesses for circuit switching and can have been supposed further that MAGCF is connected to believable VPN because this solution may depend on the user.The result of registration is MAGCF storage S-CSCF address and follows for the IMS rule of registering, the MAGCF address that the subscriber that the S-CSCF storage is registered can arrive, and the P-CSCF address that preferably is integrated among the MAGCF is stored.

If the user roams in the accesses network that does not have the MAGCF functive and then roaming in the situation of MSC, then propose current MAGCF and keep the user is responsible for.In the situation of not distributing MAGCF to the user, then propose to adopt acquiescence MAGCF.Therefore as long as the user is in the accesses network, then position updating process just is restricted to the MSC that upgrades among the HLR but not responsible MAGCF.

After finishing registration, start the session establishment process that comprises the IMS call establishment.

Thereby after successfully registering, MAGCF knows that S-CSCF and S-CSCF have the MAGCF address, especially, knows P-CSCF, and the function of described P-CSCF is the part of the MAGCF that proposes.

The process of how to force (enforce) service MAGCF to carry out call treatment will be described according to the present invention below.This situation may occur in the time of for example in roaming into remote access network, wherein not have the MAGCF functive to use.In this case, propose to use last service MAGCF as the roaming anchor.

Described call handling process according to Fig. 1, the schematically illustrated conduct of Fig. 1 has the structure of the MAGCF of user's the circuit switching (CS) network of circuit switching control terminal MS and the anchor point between the packet switching multi-media network PS.Exist the circuit-switched logic that starts, Org CS is applicable to receive the circuit-switched call of starting.In the situation of a part of MAGCF at service MSC, described calling can be directly from the user terminal reception of circuit switching control.When home network and Limited service MSC are included in MAGCF this situation can appear when the user is arranged in.Replacedly, MAGCF can receive originating call from service walking circuit function of exchange, and for example it can be the MSC/VLR for the accesses network that the user is processed.The calling subscriber contacts MSC/VLR in known manner in this case, for example uses the B number, and MSC/VLR must route the call to the MAGCF that the user is responsible for according to the present invention.This is by distributing routing number to guarantee.In further describing, will provide two kinds of methods that are used for distributing routing number; A kind ofly be based on the roaming number of distributing to calling and the MAGCF that is about to be routed to unique mode call identifying.For assignment numbers, will adopt intelligent network IN function.In the second approach, utilize prefix to strengthen the B number, this prefix has defined how the B number is routed to MAGCF.But also will the routing number that distribute according to the indication about the access gateway node of service-user that receives from User Catalog (for example HLR) be described according to these two kinds of methods.

That CS call out to be directly to receive from user terminal no matter start or receive by MSC/VLR, the MAGCF CS Call Transfer of will starting in converting unit becomes to be transferred to the packet-based multimedia call of the packet-based multimedia logic Orig PS that starts in next step, and this Orig PS is applicable to send the packet-based multimedia call that starts to packet-based multimedia domain, MMD.According to the present invention, propose the part of proxy-call session control function P-CSCF as access gateway node.Proxy CSCF (P-CSCF) is the first make contact in the IMS network, and it will be forwarded to S-CSCF to the sip message that the user receives, and wherein the as a result P-CSCF as registration process has received S-CSCF name.In the opposite direction, it is forwarded to UE with SIP request or response.Described P-CSCF also is used to arrive the MAGCF that stops for calling out.Thereby propose to stop packet-based multimedia logic, and Term PS, it is applicable to receive the packet-based multimedia call of termination from packet-based multimedia domain, MMD.Described calling is routed to MAGCF by the address of proxy-call session control function P-CSCF.Described calling is converted into the termination circuit switched call in translation function Conv, and is sent to the user terminal of circuit switching control by termination circuit exchange logic Term CS.End call is the user terminal that is sent straight to circuit switching control in the situation of a part of circuit-switching function at the Service Circuit switching node, perhaps is routed to the Service Circuit switching node in the situation of the part that described Service Circuit switching node is not circuit-switching function.

Further propose MAGCF and have inhibition (suppression) function, the circuit-switched call of starting that this function is applicable to suppress to receive is processed in circuit commutative field.This guarantees that originating call is processed veritably in the IMS territory.For to the switched call of user's delivery circuit, will guarantee that the packet-based multimedia call of the termination that receives is terminated in MAGCF.

Below with reference to Fig. 2 and Fig. 3 a method according to the present present invention is described.Fig. 2 illustrates the situation about starting of calling out.MAGCF receives the circuit-switched call of starting in the first step 21.Described calling can be integrated in the situation among the MAGCF directly at service walking circuit function of exchange MSC, and the user terminal from circuit switching control receives.Under the user is the situation processed by independent service walking circuit function of exchange, route the call to service MAGCF by routing number.The distribution of routing number will be further described.In step 22, circuit-switched call is converted into starts packet-based multimedia call and be sent to packet-based multimedia domain, MMD, 24 in step 23.In the packet switching multimedia segment, proxy-call session control function P-CSCF relates to the forwarding of calling.

Fig. 3 illustrates and calls out the embodiment that stops.Stopping packet-based multimedia call in step 31 is received from packet-based multimedia domain, MMD.Carry out the route of calling out by proxy-call session control function P-CSCF.In step 32, call out and be converted into termination circuit switched call and aforesaid by directly or be sent to the user terminal of circuit switching control by service MSC/VLR.

The below will provide embodiments of the invention.

The below will describe embodiment, user shown in it in accesses network, roam and by in the situation of the MSC/VLR service of the part of non-service MAGCF to the distribution of route number.In order to be routed to from all originating calls of service MSC/VLR roaming anchor MAGCF, be used as example CAMEL mechanism.The CAMEL method is not restricted to this as example and the present invention.

The below will be described in some substantive characteristics of the CAMEL network that uses in the one embodiment of the invention.CAMEL is even allows outside mobile subscriber roams into home network the time Virtual network operator that the network characterization of operator's special services is provided to mobile subscriber.According to the CAMEL architecture, CAMEL Service controll functive (gsmSCF) is provided for subscriber's Home PLMN, and it has comprised implements the required CAMEL service logic of operator's special services.In addition, also exist CAMEL service function of exchange body (gsmSSF), it participates in transaction and carries out the instruction that is provided by gsmSCF.Be generally used for that the agreement between the node is CAMEL Application Part (CAP) agreement in the CAMEL architecture.In the CAMEL frame, so-called trigger detection point (TDP) is defined, and it has stipulated the time point in the transaction when gsmSCF should be touched.GsmSSF opens dialogue to gsmSCF when satisfying TDP.Wherein especially exist a plurality of functives that define for gsmSCF; Can provide to gsmSCF the information of relevant ongoing affairs, for example the duration of destination-address and affairs.

Turn back to embodiments of the invention, in order to ensure processing all callings by service MAGCF, below will provide two kinds of possible methods for this reason.Roaming number is used to dynamically distribute to the calling for be routed to service MAGCF from service MSC/VLR in the first solution, and the second solution has been revised the actual B number of dialing by adding prefix.

The first scheme is based on the concept of using interim roaming number.To this solution be described for Fig. 4.

Figure 4 illustrates MSC/VLR, described MSC/VLR service is arranged in the user of its coverage, and described coverage is the A accesses network.According to the present invention, MSC/VLR and the MAGCF that is positioned at home network (A ownership) communicate, and this home network comprises the gsmSCF functive.Thereby MAGCF provides and being connected of circuit commutative field.On the other hand, MAGCF provides with IMS and especially communicates by letter with the signaling of S-CSCF.S-CSCF is the user's service node in the IMS territory.It is taken on call server and processes call signaling.In addition, according to Fig. 4, also exist IMS AS, its host also carries out the service that the user asks.This AS for example is responsible for call-flow and mutual with subscriber's user interface.IMS AS is to the IMS delivery service, for example putting call through immediately after connection (push-to-talk), ring-back tone, prepayment call card, multimedia conferencing and Multimedia Message transmission (messaging) service logic.Exist in addition HLR, this HLR is the customer data base that is arranged in circuit-switched network.

According to a preferred embodiment of the invention, propose two independently layer carry out the transmission of user plane and subscriber signaling.In user plane, correspondingly need between network element to change IP-based media stream.Multimedia gateway (MGW) node is responsible for this function.Multimedia resource function processor (MRFP) (MRFP) provides attached (adjunct) media processing for application layer, and for example audio mix, content are recorded with playback, codec code conversion (codec transcoding), statistics and obtained (statistic obtaining) and be connected to MGW.MRFP is not exclusively used in independent application but the shared resource of media processing as a plurality of application is provided.Media resource function controller (MRFC) provides the agent functionality of the media resource between AS and the MRFP resource in IMS, and can be implemented as the part of application server or be embodied as independent network element.

According to Fig. 4, represent by a dotted line flowing of signaling information, and solid line represents flowing of user plane.

For Fig. 4, for call treatment is delivered to MAGCF and has proposed following steps.

When the user moved to accesses network, at first the executing location renewal process was so that notice HLR user's reposition.By the communication between MAP realization MSC/VLR and the HLR.Thereby HLR receives the MAP message of upgrading the position, and HLR determines whether sending node supports the MAGCF functive.This can be by comprising to come self-supporting MAGCF functive the indication of sending node realize.Replacedly, HLR can check the predefine tabulation of managing in HLR.Do not support the MAGCF functive if HLR determines to send the node that upgrades the position, then propose HLR and the CAMEL data are added to the data that send by MAP operation insertion subscriber data.These CAMEL data provide the CAMEL trigger detection point of " Collect_Info ", and its instruct MS C/VLR foundation is connected with gsmSCF's, and this gsmSCF is responsible for process user calling in home network.In the time will contacting the address of gsmSCF, HLR comprises the address of current service MAGCF in step 41.Do not have in HLR in the situation of known service MAGCF, HLR can use predefined acquiescence MAGCF.As the result of position fixing process, MSC/VLR has the contact address of MAGCF.MSC/VLR receives the setup requests that comprises the B number of calling out in step 42.One receives call request, just triggers immediately CAMEL trigger detection point " Collect_Info ", and its result is that the gsmSCF by the CAMEL subscription data institute addressing that receives from HLR is processed and contacted to MSC/VLR time-out call setup.CAP message Initial DP is sent to the gsmSCF that comprises the B number.Because HLR provide the service MAGCF the address as gsmSCF Address, so in step 43 in fact MAGCF contacted.In subsequent step 44, MAGCF distributes interim roaming number to be used for to this MAGCF routing call.The B number that the MAGCF storage receives is so that after this it can arrive correct B number with the roaming number call matches that enters.In step 45, MAGCF instruct MS C/VLR is routed to this roaming number with originating call.The connection of CAP message is sent to MSC/VLR from MAGCF.The roaming number that passes through to receive, in step 46 service MSC/VLR with the call routing that keeps to MAGCF.In step 47, MAGCF receives the calling with roaming number that enters.Then MAGCF checks the B number of initially dialing, and this B number is stored when distributing roaming number.B number as called destination is used to route the call to S-CSCF in step 48, this S-CSCF is responsible for serving the A subscriber to be used for carrying out the service of starting.

Thereby described method has guaranteed that the originating call of initiating is forwarded to MAGCF in order to process in the IMS territory in accesses network.This call treatment will be further described in the back.

The below will provide the second method, and described the second method is used for all originating calls are routed to as the MAGCF node of roaming anchor point.This solution is based on adding prefix to the concept of B number and will being described for Fig. 5.Fig. 5 has comprised disclosed all nodes for Fig. 4, and difference is that gsmSCF is described to independent node.But this should not be regarded as any restriction to protection range of the present invention.According to present embodiment, gsmSCF is used as database and adds particular prefix to the B number, wherein said prefix for selected MAGCF must be specific and preferably different prefix be used to different selected MAGCF nodes.Thereby because gsmSCF is the central point that adds prefix, it is illustrated as separate nodes, but gsmSCF can with any other node place (co-locate) that coexists.Return Fig. 5, to similar in the first method, HLR determines to send the node that upgrades the position and whether supports the MAGCF functive in step 51.Should determine and to be carried out by any preferred method, as disclosed in the first method.In step 51, if determine to send upgrading the node of position, HLR do not support the MAGCF function, then HLR sends and has current which MAGCF served and served the address of gsmSCF to the user the CAMEL trigger detection point of " Collect_Info " of indication.Replacedly send the address of service gsmSCF and in this case any gsmSCF in the home network can be contacted.As already mentioned, if there is not known service MAGCF in HLR, then HLR can use predefined acquiescence MAGCF.Receipt of call is set up request in carrying the service MSC/VLR of called B number in step 52.CAMEL trigger detection point " Collect_Info " is triggered immediately when receiving described request, this cause that MSC/VLR suspends that call setup is processed and contact by the gsmSCF of the CAMEL subscription data institute addressing that receives from HLR.In step 53, CAP message InitialDP is sent to the gsmSCF of the indication that comprises B number and service MAGCF.It is current just in service subscriber which MAGCF gsmSCF identifies according to the designator that receives.Then gsmSCF adds prefix to the B number, and it is specific for service MAGCF.Preferably, predefine prefix in gsmSCF.The B number that then gsmSCF will revise turns back to the call setup that this new digit is proceeded in MSC/VLR and request.The connection of CAP message is sent to MSC/VLR from gsmSCF in step 54 for this reason.In step 55, the B number of the prefixing of passing through to receive, service MSC/VLR routes the call to MAGCF.MAGCF receives the calling with prefix B number that enters and removes this prefix.Should be mentioned that preferably MSC/VLR also provides the A number, in order to allow the subscriber of the correct service of MAGCF identification.In step 56, this calling is routed to the S-CSCF for the A subscriber of the execution service of starting.Here the B number is used as called destination again.

Thereby second method guaranteed that also all originating calls all are provided for the MAGCF of service-user.

In these two kinds of methods, when roaming in the network of not supporting the MAGCF functive, the MAGCF of last service is used as roaming anchor.But because IMS AS is responsible for processing all services, the service execution in MSC/VLR must be suppressed.Preferably propose a kind of mechanism of filtering subscriber data and process any service to prevent MSC/VLR.HLR knows that the subscriber just roams in remote access network.Therefore when sending MAP operation insertion subscriber data, HLR filtered out all assistant services and subscribes before sending data to MSC/VLR.In addition, propose when roaming in home network, subscriber data is not filtered and MAGCF must suppress any service and enables (invocation).Another possibility is also to filter subscriber data when subscriber data is sent to MAGCF in home network.

The below will be illustrated in the basic architecture that is used for carrying out originating call in the home network for Fig. 6.Fig. 6 shows as the user A that calls out originating user.Described user is connected to MAGCF by radio access network (for example UTRAN or GERAN).Because the user carries out calling in home network, so it is directly connected to the MSC-S part of MAGCF node.The IMS part of MAGCF node is sent to S-CSCF by Session Initiation Protocol with connection.Integrated P-CSCF knows the address of S-CSCF especially.Also exist the IMS AS node of communicating by letter with S-CSCF.

Dotted lines flowing of signaling message.Also described MGW and MRFP node in Fig. 6, it relates to the transmission by the indicated user plane of solid line.

According to Fig. 6, when receiving call request from terminal in MAGCF, MAGCF never calls any service of starting and it does not check the B number that receives yet in step 61.MAGCF routes the call to serviced subscriber's IMS.In step 62, because the P-CSCF of MAGCF still knows the S-CSCF from the IMS registration, be routed directly to S-CSCF so call out.In step 63, S-CSCF comprises be used to calling the service of starting and to the IMS AS of the analysis of the B number dialed.The inspection of the service of starting for example can comprise the calls supplementary services of forbidding (bar) all outputs, it can for example forbid serving in order to forbid that he calls out when still allowing all end calls can reach described user when being used when the 3rd people makes a phone call, and then can activating.

In addition, MAGCF selects MGW to come the process user plane.IMS AS comprises the MRFP for the treatment of user plane.MGW and MRFP are preferably independently node.

The below will describe for Fig. 7 the message flow sequence of originating call in the home network.In Fig. 7, calling subscriber UE A initiates the calling to called subscriber B: IMS is described.Because the user comes to carry out calling in home network by the MSC-S function that contact is integrated in the MAGCF node, described so have the MAGCF node of MSC-S functive.In addition, exist A:S-CSCF, it is the service S-CSCF of originating user, and A:IMS AS is responsible for this user.The direction of the mobile and arrow Indication message exchange of the line Indication message of between two entities, drawing.

In the first step in calling subscriber's calling origination process, UE A sends the 24.0008:CS service request to MAGCF, arrives especially MSC-S.As known, described node is at first carried out calling subscriber's circuit switching is differentiated, and sends 24.008 user described in the follow-up step: set up message, this message is by 24.008: call proceeding message is confirmed.As previously mentioned, MAGCF know the S-CSCF that is responsible for the user the address and thereby described address be used to start the IMS call establishment.Especially, integrated P-CSCF knows the address of S-CSCF.SIP in first step: invite to be sent to the S-CSCF that serves calling subscriber A.Described message comprises the telephone number of parameter such as called subscriber B, the tel-URL of user A and session description protocol parameters SDP A.Exchange in the frame of the SDP negotiation process of SDP parameter between communication entity, described communication entity is for starting and stopping the user.In negotiations process, also the media characteristic such as the quantity of Media Stream or codec etc. is held consultation.

Return Fig. 7, in order to call the service of starting and to analyze the B number of dialing, A:S-CSCF sends ISC: invite (Tel-URL SDP A) to A:IMS AS.One receives from A:IMS AS and to reply, and A:S-CSCF just sends SIP: invite (SIP-URL, SDP A) message to stopping user, B:IMS.In subsequent step, start the SDP negotiation process by the SIP:183 session process (SDP B) that carries proposed SDP parameter from stopping user's transmission.In order to check whether proposed SDP parameter is supported and in order to keep the required resource of session parameter of consulting, described message is forwarded to MAGCF, the RAN (radio access network) that contact is responsible for after this MAGCF.This is by allocation request message and assigned message and carry out.In the step below, MAGCF sends SIP by A:S-CSCF: update message to B:IMS, described B:IMS agrees (agree on) new argument by sending SIP:200 OK (renewal) message.Under the called subscriber is idle and can the situation of receipt of call, corresponding indication, i.e. SIP:180 ring is sent to MAGCF, and it converts this indication to circuit switched protocol message, and namely 24.008: report to the police.Receive SIP:200 Ok (invitation) message from called subscriber B:IMS after, 24.008: connection message is sent to originating user UE A in order to finish the process of foundation.Be successfully completed the affirmation of call establishment by 24.008: connect Ack and SIP:Ack message and be sent to the termination user.After being successfully completed call establishment, can carry out audio call.

To provide below for the embodiment that carries out originating call at the remote access network of not supporting the MAGCF functive.In this case, for the user who roams in this network, last service MAGCF is used as roaming anchor point.As front embodiment was described, in order to force to carry out call treatment in anchor MAGCF, when subscriber data was inserted into MSC/VLR, HLR added the CAMEL data to subscriber data.Thereby when receiving call request, MSC/VLR notices the CAMEL data, and it is so that this calling is routed to roaming anchor MAGCF.After calling has arrived MAGCF, as in the home network, continuing call setup, namely call out and be forwarded to S-CSCF to be used for carrying out the service of starting.

Below with reference to Fig. 9 that message flow is shown the originating call process is shown in more detail.Fig. 9 is corresponding to Fig. 7, and its difference is that the MSC/VLR that is arranged in accesses network in Fig. 9 is plotted in addition.In addition, in Fig. 9, describe MAGCF and had the gsmSCF functive.But this can not be regarded as limitation of the present invention.Replacedly gsmSCF can be used as independent node provides.

In first step, 24.008: set up (B number) afterwards, user UE sends the 24.0008:CM service request information to MSC/VLR, and it is by message 24.008: call treatment is confirmed.The reception of this message means that for MSC/VLR the user wishes to set up and being connected of the user with B number.But in registration process, MSC/VLR has received CAMEL message from HLR, and as described in the embodiment in front, this message informing: the user will be processed by gsmSCF.According to this information, MSC/VLR routes the call to MAGCF by gsmSCF.Among the embodiment in front, discussed how to route the call to MAGCF.Show in this particular example by using roaming number to carry out route.According to the method, MSC/VLR has the address of gsmSCF, and it also is the address of MAGCF.Contact MAGCF by this address, CAP:InitialDP (B number).One receives this message, and MAGCF just carries out the process that is used for providing routing number, and it comprises and distributes roaming number and the routing number that distributes is relevant with the B number.In order to come this calling of route by roaming number ISUP:IAM (roaming number), described roaming number passes through CAP: connect (roaming number) message and be sent to MSC/VLR.Remaining process is identical with the step that causes as described in Figure 7 transmission calling origination process.

The below will be described in for Figure 10 the embodiment of the end call in the home network.The structural correspondence of Figure 10 is in the structure of Fig. 6.In step 101, S-CSCF receives the calling that will end at user B.In step 102 and 103, S-CSCF participates in into the executive termination service IMS AS.Here regard to mode identical in the situation of starting before and check the service that stops the subscriber.For example, when roaming into external (abroad), can activate all are entered forbidding of calling.In this example, IMS checks whether the user has subscribed this service, then roams in the external situation described user, and calling is prevented from.

The address that S-CSCF learns service MAGCF according to the IMS registration process is as top embodiment is described.The address of the known integrated P-CSCF of S-CSCF especially.Be forwarded to MAGCF by the Session Initiation Protocol calling, be forwarded to especially proxy gateway, be arranged in the P-CSCF of MAGCF 104.MAGCF is terminated to the calling of terminal, but never calls any service.Termination means that the IMS calling ends at MAGCF and is converted into the CS calling, and then this calling is forwarded to the party B-subscriber by for example 24.0008 agreements by access network, and this access network for example is UTRAN or GERAN, 105.Described calling is confined to the route of signaling information with stopping routing optimization.Proposition is routed directly to access network with payload information by MRFP and MGW, as describing by solid line among Fig. 6.

The below illustrates the message flow of calling out termination procedure for Figure 11.Figure 11 illustrates IMS user A:IMS and wishes to be connected to user B, UE B.In first step, contact I-CSCF, it is responsible for predetermined all connections that arrive the subscriber of this Virtual network operator or be currently located at the roamer in the Virtual network operator coverage in carrier network.Utilize SIP: invite (SIP URL, SDP A) to carry out this contact.In carrier network, can there be a plurality of available I-CSCF.The major function that I-CSCF carries out is to the user assignment S-CSCF that carries out the SIP registration.According to the present invention, S-CSCF knows the address of MAGCF and especially is integrated in the address of the P-CSCF among the MAGCF, thereby SIP: invitation can be forwarded to MAGCF.Before forwarding the message to MAGCF, for Figure 11, pass through ISC: invitation message contacts B:IMS AS in order to stop the IMS service.One receives SIP: invite (SIP-URL, SDP A), just in MAGCF, stop IMS calling and start-up circuit exchange processing, comprise and send 24.008: page message is to called subscriber UE B, executive circuit exchange discriminating, and by 24.008: call setup and 24.008: confirming call message is established to the calling of UE B.The remainder of this process and similar process as described in Figure 7.This means the IMS part that is positioned at MAGCF, namely P-CSCF sends SIP:183 session process (SDP B) message to the A:IMS user with proposed parameter.Pass through SIP according to Figure 11: upgrade and the renewal of SIP:2000K message two side execution parameter of communicating by letter.When parameter was assigned with, bell signal will occur, 24.008: report to the police, SIP:180 ring, and connection procedure, 24.008: connect, the SIP:2000K (invitations) with acknowledge message, SIP:ACK with are connected: connection ACK is performed.

The calling subscriber might occur certainly be positioned at the accessed accesses network B with MAGCF functive.The below will describe this situation for Figure 12, and wherein Figure 12 shows the end call for user B.In this case, the IMS of calling part is responsible user and take among the MAGCF that roams anchor and be terminated.Thereby end call is routed to S-CSCF, 121, and then it make IMS AS participate in into the executive termination service 122 and 123.As previously mentioned, S-CSCF learns the address of service MAGCF according to the IMS registration process.Thereby, call out and preferably be sent to MAGCF by Session Initiation Protocol, 124.Described MAGCF recognizes that it takes on the roaming anchor, thereby when receiving end call in MAGCF, MAGCF recognizes its directly end call, and MSC/VLR is participated in into.Therefore MAGCF takes on GMSC and inquires roaming information to HLR.HLR obtains roaming number from service the MSC/VLR, and 126, and it is returned to MAGCF, 125.Then be routed to MSC/VLR from MAGCF, 127 by using roaming number to call out.It should be noted that and in HLR, not carry out any service that this is because IMS AS is responsible for carrying out described service.Signaling sequence is identical with sequence described in Figure 11, and difference is corresponding signaling, and the signaling that is preferably based on MAP will exchange between MAGCF, HLR and MSC/VLR, and wherein said MSC/VLR is responsible for setting up and being connected of user B.

The above embodiments are based on and will be integrated into such as the subscriber equipment of the circuit switching that provides among GSM or GPRS control during the IMS of be combined with UMTS and developing serves.But the invention is not restricted to these networks.Other example can be the CDMA2000 that respective nodes is provided as the existing node among GPRS or the UMTS.

Claims (9)

1. access gateway node (MAGCF), the user terminal (MS) that is applicable to control for the circuit switching that is arranged in circuit switching control domain (CS) in packet-based multimedia system (IMS) territory is processed and is called out, and wherein said access gateway node (MAGCF) comprising:

-the circuit-switched logic that starts (Org CS) is applicable to receive the circuit-switched call of starting from the user terminal (MS) of circuit switching control,

-packet-based multimedia the logic that starts (Org PS), be applicable to send to packet-based multimedia domain, MMD (IMS) by the packet-based multimedia call that will start of the proxy-call session control function unit (P-CSCF) as the part of access gateway node (MAGCF), and

-termination packet-based multimedia logic (Term PS), be applicable to receive the packet-based multimedia call of termination from packet-based multimedia domain, MMD (IMS), described multimedia call is addressed to the proxy-call session control function unit (P-CSCF) as the part of access gateway node (MAGCF), and

-termination circuit exchange logic (Term CS) is applicable to send the termination circuit switched call to the user terminal of circuit switching control, and

-translation function unit (Conv) is applicable to be converted to the packet-based multimedia call and set up process and will stop packet-based multimedia call and be converted to the termination circuit switched call by initiating circuit-switched call of starting by starting the circuit-switched call of will starting of packet-based call establishment.

2. access gateway node as claimed in claim 1 (MAGCF), wherein to be applicable at the Service Circuit switching node be that the situation of the part of circuit-switching function unit issues the only circuit-switched call of making arrangements for his funeral to the user to the termination circuit exchange logic.

3. access gateway node as claimed in claim 1 (MAGCF), wherein said access gateway node comprises the registration logic, described registration logic is applicable to the registration process of the user of executive circuit exchange control in packet-based multimedia domain, MMD, wherein said registration process causes the address of stores service CSCF unit in access gateway node, and causes that the address with access gateway node offers the service call conversation control function unit.

4. access gateway node as claimed in claim 3 (MAGCF), wherein the address of proxy-call session control function unit can obtain from access gateway node.

5. access gateway node as claimed in claim 1 (MAGCF), wherein access gateway node comprises the inhibit feature unit, the circuit-switched call of starting that described inhibit feature unit is applicable to suppress to receive is processed in circuit commutative field.

6. access gateway node as claimed in claim 1 (MAGCF), wherein access gateway node comprises the expiry feature unit, described expiry feature unit is applicable to the packet-based multimedia call of termination that stops receiving.

7. be used to the user terminal (MS) of the circuit switching control that is arranged in circuit switching control domain (CS) to process the method for calling out, wherein said calling will be processed with the following step of carrying out in described access gateway node (MAGCF) in packet-based multimedia domain, MMD (IMS):

-carry out and call out origination process, comprising:

-receive the circuit-switched call of starting from the user terminal of circuit switching control, and

-be converted to the packet-based multimedia call (22) that starts by starting the circuit-switched call of will starting of packet-based call establishment, and

-send the packet-based multimedia call that starts to packet-based multimedia domain, MMD (23) by integrated proxy-call session control function unit, and

-carry out the calling termination procedure to comprise:

-receiving the packet-based multimedia call of termination from packet-based multimedia domain, MMD, described multimedia call is addressed to integrated proxy-call session control function unit (30,31), and

-set up process and will stop packet-based multimedia call and be converted to termination circuit switched call (32) by initiating circuit-switched call, and

-send the termination circuit switched call to the user terminal (33) of circuit switching control.

8. method as claimed in claim 7, the circuit-switched call of starting that wherein suppresses to receive in access gateway node is processed in circuit commutative field.

9. method as claimed in claim 7, the packet-based multimedia call of termination that wherein stops receiving stops in access gateway node.

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