WO2007036147A1

WO2007036147A1 - A method and system for establishing an initial call in the service of the voice service continuity

Info

Publication number: WO2007036147A1
Application number: PCT/CN2006/002530
Authority: WO
Inventors: Dongming Zhu; Xiaoqin Duan
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2005-09-30
Filing date: 2006-09-26
Publication date: 2007-04-05
Also published as: CN1802022A; CN1802022B

Abstract

A method and system for establishing an initial call in the service of the voice service continuity comprises: the user terminal notifies its register state in the CS domain to the application server, the application server determines the mode of the call originated by the user terminal according to the information of the route controlling mode supported by the CS domain network which is currently registered by the user terminal, and notifies it to the user terminal; thereafter, when the user terminal originates a call of the CS domain, it can originate a call according to the mode of the notified originated call. Therefore, the present invention can use maximumly the CAMEL of the calling side CS domain to have an establishment of the initial call and anchor the call to AS with the DTF function. It not only ensures the maturity that the calling side CS domain implements the static anchoring to the call based on the CAMEL scheme, but also uses the USSD/SIP Notify/Prefix scheme as the supplement of the CAMEL scheme, so as to avoid the failure of the calling static grappling resulting from the CAMEL ability lack of the calling side CS domain.

Description

TECHNICAL FIELD The present invention relates to the field of network communication technologies, and in particular, to a method and system for establishing an initial call in a voice service continuity service. Background technique

The UMTS (Universal Mobile Telecommunications System) core network is divided into CS (Circuit Switched), PS (Packet Switched), and IMS (IP Multimedia Subsystem) from the 3GPP R5 (3rd Generation Partnership Project) phase. ) Three subsystems.

The CS Domain (Circuit Switched Domain) is used to provide users with connections for circuit-type services. The CS domain mainly includes: MSC (MSC Server/CS-MGW, Mobile Switch Center Server/CS-Media Gateway, Mobile Switching Center Server/Circuit Domain-Media Gateway), GMSC (Gateway MSC, Gateway Mobile Switching Center) and IWF (lnterWorking) Function, interworking function). The MSC completes the switching and signaling control functions of the circuit-switched service; the GMSC is the MSC that completes the mobile subscriber routing function in a certain network, and can be set up or divided with the MSC; the IWF is closely related to the MSC, and the PLMN is completed. Land mobile network) and ISDN (Integrated Services Digital Network), PSTN (Public Telephone Switching Network), PDN (Packet Data Network), to achieve network interworking, IWF specific functions and services and networks The types are closely related.

PS Domain (Packet Switched Domain) is used to provide users with a connection for packet-type services. The PS domain mainly includes: GSN (GPRS Support Node), BG (Border Gateway), HLR/AuC (Location Home Register/Authentication Center) ), VLR (visit location register), EIR (device identification register), MSC, etc. The GSN includes an SGSN (GPRS Support Node) and a GGSN (Gateway GPRS Support Node), and is used to complete the transmission of the packet of the packet service user; the SGSN provides the connection between the core network and the wireless access system BSS, RNS, and completes Functions such as mobility management and session management of packet data services to manage MS mobile and communication services within the mobile network; GGSN is an interface between the mobile communication system and other public data networks, and the GGSN also has query location information. The function. In addition, both the SGSN and the GGSN provide charging information. BG is used to complete the interworking between two GPRS networks and ensure the security of network interworking. The HLR is used to complete the management of user subscription data and location information, user subscription data such as MSISDN, IMSI, PDP ADDRESS, contracted telecommunication service and supplementary service and its service scope, etc., location information such as MSRN, MSC/VLR number, SGSN Number, GMLC, etc. AUC is mainly used to store the user's authentication algorithm and key. The VLR is used to process various data information of visited users. EIR is used to store user equipment identity IMEI information.

IMS is a subsystem superimposed on the existing packet domain in the WCDMA network added in the 3GPP R5 phase. The packet domain is used as the bearer channel for the upper layer control signaling and media transmission, and the SIP protocol is introduced as the service control protocol. By using SIP's simple, easy-to-expand, and convenient media combination, it provides a rich multimedia service by separating service control from bearer control. The main functional entities in the IMS include a session control entity CSCF that controls functions such as user registration and session control, an application server AS that provides various service logic control functions, and a home subscriber server HSS that centrally manages user subscription data, and is used to implement circuit switching. MGCF I IM-MGW (Media Gateway Control Function) for network interworking. The user accesses the IMS through the current local proxy node P-CSCF. The session and service trigger control and the service control interaction with the AS are completed by the home domain service node S-CSCF where the user is registered.

The IMS architecture defined by the 3GPP standard comprehensively solves the key operational problems such as roaming charging, QoS (quality of service), and security assurance that need to be solved under the IP bearer to provide multimedia services. Moreover, 3GPP has also begun to implement WLAN (Wireless Local Area Network) access and UMTS interworking such as l-WLAN (Intellective of WLAN), fixed broadband access (IMSGnFBK Fixed Broadband access to IMS, fixed broadband access IMS) } and Research on topics such as all-IP network (All-IP Network) for multiple access technologies, so that users will be able to connect through different single-mode terminals or multiple types of different terminals according to their subscriptions. The access network of the technology accesses the IMS to obtain a unified multimedia service, such as a VoIP (Voice over IP, IP-based voice) service.

Currently, 3GPP proposes an IMS control static anchoring call control scheme to solve the problem of switching between two domains, such as CS domain and IMS domain. The core idea of the solution is to assign an AS (Application Servor) as a DTF (Domain Transfer Function) to the user in the IMS home domain, and to the user from the CS domain or the IMS domain. The relevant call/meeting tongue will be transmitted to the AS for anchoring control. In this way, the AS performs subsequent handover control processing on the anchored call/session regardless of the inter-domain handover from the CS domain to the IMS domain or the inter-domain handover from the IMS domain to the CS domain.

For the session control mode in IMS, it is convenient to insert an anchor point in the call path. The AS controls the session, that is, the iFC (initial filter Criteria) is used to trigger the session to the AS.

The call control mode for the CS domain itself is not easy to insert an anchor AS in the call path. Therefore, the 3GPP specification currently describes various implementation scenarios for the call initiated by the CS domain to the anchor AS.

For the initial call initiated when the calling side is the CS domain, that is, the call initiated by the calling station VMSC (Visited Mobile Switch Center) after receiving the call setup message of the UE, network side routing control may be adopted. Use CA MEL '(Mobile Network Enhanced Logic Customized Application) scheme} and terminal side routing control {ie use USSD (Unstructured Supplemental Service Data) and SIP Notify (Session Initiation Protocol Notif y) "Notification" operation) and Prefix (prefix) scheme} mode, routing the call to the anchor AS;

For the initial call initiated when the called side is the CS domain, the GMSC of the called home network can use the CAMEL scheme after receiving the call from the calling side, after the call is initiated according to the analysis of the called information by the GMSC. And the signaling interception scheme routes the call to the anchor point AS.

This function of routing the initial call to the anchor AS is called the DSF (Domain Selection Function) function. For the CS domain, the entity with DSF capability can be gsmSCF; for the IMS domain, the entity with DSF capability can be an AS. The routing decision entity gsmSCF in the CS domain may be in the same physical entity as the routing decision entity AS in the IMS domain.

The VCC (Voice Service Continuity) user cross-domain handover control procedure using the static anchor scheme will be described below. As shown in FIG. 1, when the call is initially established, for example, the UE (A) initiates a call for the UE (B). Then, the call inserts an anchor AS in the call path of the calling side UE (A) through the DSF-enabled gsmSCF or AS, and the AS enables the B2BUA (Back-to-Back User Agent) function to divide the call on the calling side into two. The AS termination segment and the AS initiation segment are two segments. The AS termination segment is a call segment between the UE (A) and the AS, and the AS initiation segment is a call segment between the AS and the UE (B).

In the subsequent call process, when the UE (Α') detects that the inter-domain handover condition is satisfied, it is desirable to forward the current call from the UE. (A) Switching to the UE (Α') for subsequent call control. At this time, the UE (Α') initiates a new call for the AS that is anchoring the current call, and the AS determines after receiving the call. When the inter-domain handover is required, the AS connects the newly initiated call of the UE (Α') with the AS-initiated segment, and then releases the call of the AS termination segment, so that under the control of the anchor AS, the UE (Α' And the call with the UE (B) is terminated, the call segment between the previous UE (A) and the AS is released, and the handover between the UE (A) and the UE (Α') is completed.

The above-mentioned function of anchoring the call and performing the handover process when the inter-domain handover occurs is called a DTF (Domain Transfer Function) function. Under the static anchor scheme, the entity having the DTF function is the IMS. An AS in the domain. The routing decision point gsmSCF or AS with DSF function can be in the same physical entity as the AS with DTF function.

Moreover, the UE (A) here may be a terminal of the CS domain, and the UE (Α') may be a terminal of the IMS domain, and the same call of the user is realized by the call handover of the UE (A) to the UE (Α') Call continuity from the CS domain to the IMS domain.

Similarly, when the call is initially established, an anchor AS can be inserted in the call path of the calling side UE (B) to implement call control of the inter-domain handover on the subsequent called side.

When the user of the CS domain initiates a call as the calling party, and uses the network side routing control mode, that is, the CAMEL mechanism is used in the CS domain to trigger the initiated call to the AS for anchoring, the corresponding processing flow is as shown in FIG. 2 Specifically, the following steps are included:

In step 2-1, the UE registered to the VMSC initiates a call setup Setup message.

Go to step 2-2. The VMSC triggers the call to the DSF-enabled gsmSCF through the Initial DP (Initial Detection Point) message according to the CAMEL subscription information on the calling side.

Go to step 2-3, the gsmSCF with the DSF function generates an IMRN (IMS Routing Number) that points to an AS in the IMS domain with the DTF function, so that the VMSC routes the call to the DTF according to the routing number;

The DSF-enabled gsmSCF can construct the IMRN by adding a call reference number after the DTF's identification information DTF PSI (DTF Public Service Identities), and then pass the CAMEL connect (CAMEL connect) by the DSF-enabled gsmSCF. The message is sent to the VMSC by the IMRN.

To step 2-4, the VMSC routes the call to the MGCF (Media Gateway Control Function) in the IMS network to which the calling party belongs according to the IMRN through the IAM (Initial Address Full Message) message.

Go to step 2-5, the MGCF determines that the called information in the IAM message is an IMRN that points to the DTF-enabled AS, and sends an INVITE message to the I-CSCF, where the called information Request-URI (requesting resource unified positioning) The identifier is the TEL URI (the URI of the phone number format) format of the IMRN. '

Go to step 2-6. The I-CSCF queries the HSS for the routing information according to the Request-URI, and obtains the AS address information associated with the IMRN, that is, the AS address information with the DTF function, and then the I-CSCF forwards the packet to the DTF-enabled AS. INVITE message. Here, in order to support the HSS to return the corresponding DTF-enabled AS information according to the IMRN including the DTF PSI information, the correspondence between the DTF PSI data and the AS address information having the DTF function needs to be configured in the HSS.

After step 2-7, after the session information received by the AS with the DTF function includes the IMRN session of the DTF PSI information, the session is anchored, that is, the B2BUA (Back-to-Back User Agent) function is triggered, and the AS receives the session. And then initiating a new session for the original called information, that is, the AS having the DTF function obtains the S-CSCF information of the calling user side through the Sh interface with the HSS. The session is then routed to the S-CSCF and the session is routed by the S-CSCF to the original called side.

Here, in the process of routing the call to the original called side by the S-CSCF, when the original called information is in the Tel-URI format, the S-CSCF performs ENUM DNS (E.164 Number Domain Name System E.164, domain name conversion) System) conversion function, if the original called number can be converted into a SIP URI (Primary Session Protocol URI) format, subsequent call routing is performed in the IMS domain, otherwise, the S-CSCF routes the call to the BGCF of the IMS domain (Breakout Gateway Control Function border gateway control function), the call is finally routed by the BGCF to the PSTN (Public Switched Telephone Network) or CS domain via the MGCF, and finally the call is connected to the called party by the PSTN or CS domain. When the DTF-enabled AS enables the B2BUA function, the DTF maintains the state for the session terminated in the DTF and the newly initiated session in the DTF to control the inter-domain handover that may be initiated by subsequent users.

Since the CS domain of the calling user's visited place does not necessarily support CAMEL, it is necessary to consider other alternative ways to route the call to the AS. Currently, the 3GPP specification provides USSD based and SIP Notify based on the terminal side routing control mode and based on the Prefix. Three mechanisms of (prefix).

The USSD mechanism is applied to the UE that is not registered to the IMS domain. The basic principle is that when the UE initiates a call to the VMSC, the called address information in the call signaling carries the DTF PSU that points to the DTF-enabled AS, and the VMSC passes the MGCF. Route the call to an AS with DTF capability in the IMS domain. The actual called information, such as the number information of the UE (B), is carried in the USSD signaling sent by the UE to the DSF-enabled gsmSCF, so that after the DSD-enabled gsmSCF receives the USSD signaling, The AS of the DTF function interacts to notify the DTF of the real called information of the currently received session, and the gpUSSD signaling carries the number information of the UE (B), so that the AS with the DTF function anchors the received call initiated by the UE. That is, the AS starts the B2BUA function, terminates the AS receiving the session, and then initiates a new session for the original called information, where the original called information is obtained from the USSD signaling received by the DSF-enabled gsmSCF. Subsequent processing, as described in steps 2-7 of Figure 2, routes the session to the called user according to the original called information in the new session initiated by the AS.

When a user in the CS domain initiates a call as a calling party, if the terminal-side routing control mode is used, that is, the USSD mechanism is used to trigger the initiated call to the AS for anchoring, the corresponding processing flow is as shown in FIG. 3, specifically including the following. Steps:

In step 3-1, the UE registered to the VMSC initiates a call setup Setup message, and the called information carried in the setup is a number including DTF PSI information, and the message further carries the UE-assigned identifier for uniquely identifying the UE and the DTF. The call reference number of the first call, the VMSC routes the UE-initiated call to the DTF-enabled AS via the MGCF/I-CSCF according to the called number including the DTF PSI information;

Here, the process of routing the UE-initiated call to the DTF-enabled AS is similar to the process described in steps 2-4 through 2-6.

After the UE receives the Call Protion message sent by the i"VMSC, the UE initiates the USSD signaling to the VMSC in the application mode, where the USSD signaling carries the actual called information of the current call, and in the step The call reference number assigned by the UE in 3-1.

Go to step 3 - 3, the VMSC forwards the USSD signaling to the HLR, and the HLR forwards the USSD signaling to the USSD signaling processing function entity having the DTF function, such as the gsmSCF, where the USSD signaling processing function entity and the step having the DTF function are performed. The AS with DTF function in 3-1 can be the same physical entity; AS and/or USSD signaling processing function with DTF function according to the actual called information and call reference number of the call carried in the received USSD signaling. The entity associates the session received in step 3-1 and steps 3-1 The received called information in the session is updated to be the actual called information carried by the USSCH command.

Go to Step 3-4. The DTF-enabled AS and the domain USSD signaling processing function entity perform the anchor control on the session after the step 3-1 receives the called information in the session.

Here, the DTF-enabled AS and the domain USSD signaling processing function entity perform the same process of anchoring the session.

2-7 is similar.

The SIP Notify mechanism is applied to the UE that has been registered to the IMS domain. The basic principle is the same as that of the USSD mechanism. When the SPUE initiates a call to the VMSC, the called address information in the call signaling carries the AS with the DTF function. The DTF PSI, whereby the VMSC routes the call to the AS with DTF capability in the IMS domain via the MGCF. The actual called information, such as the number information of the UE (B), is carried in the SIP Notify signaling sent by the UE currently registered to the IMS domain to the AS having the DSF function, so that the AS with the DSF function receives the After the SIP Notify signaling, it interacts with the AS with the DTF function, and notifies the DTF of the real called information of the currently received session, that is, the SIP Notify signaling carries the number information of the UE (B), thereby having the DTF function AS. The received call initiated by the UE is anchored, that is, the AS starts the B2BUA function, terminates the AS receiving the session, and then initiates a new session for the original called information, where the original called information is received from the AS having the DSF function. Obtained in the SIP Notify signaling. Subsequent processing, as described in steps 2-7 of Figure 2, routes the session to the called user according to the original called information in the new session initiated by the AS.

When the user of the CS domain initiates a call as the calling party, if the terminal side routing control mode is used, that is, the SIP Notify mechanism is used to trigger the initiated call to the AS for anchoring, the corresponding processing flow is as shown in FIG. 4, which specifically includes The following steps:

In step 4-1, the same processing as step 3-1 is used.

After the UE receives the Call Protion message sent by the VMSC, the UE sends the SIP Notify signaling to the AS with the DTF function, where the SIP Notify signaling carries the actual called information of the current call, and The call reference number assigned by the UE in step 4-1.

Go to step 4-3, according to the actual called information and the call reference number of the call carried in the received SIP Notify signaling, the AS with DTF function associates the session received in step 4-1, and step 4- 1 The received called information in the session is updated to the actual called information of the call carried by the SIP Notify signaling.

Step 4-4, the AS with the DTF function performs the anchor control on the session after updating the called information in the session received in step 4-1;

Here, the process of anchoring the session by the AS with DTF function is similar to that of steps 2-7.

In addition, the prefix-based mechanism can be applied to the UE not registered to the IMS domain, and the applicable domain UE has already registered to the IMS domain. The basic principle is that the UE will point to the DTF PSI of the DTF-enabled AS when initiating a call to the VMSC. As the real called information, a number prefix such as the number information of the UE (B) is carried in the called address information in the call signaling, so that the VMSC will call according to the prefix information before the domain called number, that is, the DTF PSI. Routed to the AS with the DTF function in the IMS domain via the MGCF, so that the AS with the DTF function anchors the received call initiated by the UE, that is, the AS initiates the B2BUA function, terminates the AS receiving the session, and then initiates a call for the original A new session called information. Here, the original called information is parsed from the called information in the call received by the DSF-enabled AS, that is, the AS having the DSF function strips the number prefix in the called information in the received call, and restores the true Called information. Subsequent processing is as described in steps 2-7 of Figure 2, according to the original called information in the new session initiated by the AS. The message is routed to the called user and then connected.

It can be seen that when a user in the CS domain initiates a call as a calling party, there are two modes of network side routing control and terminal side routing control. For the network-side routing control mode, the UE-initiated call is an ordinary call for the real called, and the CAMEL capability of the network redirects the call to a DTF-enabled AS for anchoring the call; for the terminal-side routing control mode The call logic of the terminal needs to be modified. The call initiated by the UE is a special call for the AS with DTF function, and the real called number is processed by the subsequent UE to the AS and/or USSD signaling with DTF function. The USSD/SIP Notify signaling carried by the entity is carried in the additional information after the prefix DTF PSI in the called information, and the AS and/or USSD signaling processing entity having the DTF function is based on the USSD/SIP Notify signaling or It is the true selling called information carried in the additional information after the prefix DTF PSI in the call signaling, and the called information of the call is updated, and then the call is anchored.

Thus, for a call, the UE can initiate a normal call or can initiate a special call. Therefore, the CAMEL-based network-side routing control scheme and the USSD/SIP Notify/Prefix-based terminal-side routing control scheme provided in the current 3GPP specifications are two competing schemes, that is, the UE uses the USSD/SIP Notify/Prefix-based The terminal-side routing control scheme initiates a call. Beiqing enables the calling side of the CAMEL capable to access the circuit domain network. At this time, the CAMEL-based network-side routing control scheme cannot be used.

In the network, the CAMEL-based network-side routing control scheme is limited by whether the calling party circuit domain network supports CAMEL capability, and the CAMEL scheme has been maturely applied; the terminal-side routing control scheme based on USSD/SIP Notify/Prefix is not subject to the calling party. Visiting the limitations of circuit domain network capabilities, but currently the solution has not been actually applied in the network.

Therefore, it is hoped that there will be a technical solution for the processing of the two schemes, but there is no corresponding technical solution to meet this demand. Summary of the invention

It is an object of the present invention to provide a method and system for establishing an initial call in a voice service continuity service such that a CAMEL-based network side routing control scheme is used in the case where the calling side circuit domain network supports CAMEL, and the calling The side circuit domain network does not support CAMEL and uses a terminal-side routing control scheme based on USSD/SIP Notify/Prefix.

The object of the invention is achieved by the following technical solutions:

The present invention also provides a method for establishing an initial call in a voice service continuity service, including:

The user terminal of the voice service continuity service notifies the application server of its registration status in the circuit domain;

After receiving the notification, the application server determines a manner in which the user terminal initiates a call according to the routing control mode information supported by the circuit domain network currently registered by the user terminal, and notifies the user terminal of the determined manner of initiating the call;

When the user terminal initiates a circuit domain call, the call is initiated according to the manner in which the application server notifies the originating call. The processing of notifying the application server of its registration status in the circuit domain includes:

After the user terminal completes the location update of the circuit domain, the manner of notifying the SIP Notify or the short message by using the unstructured supplementary data service USSD or the session initiation protocol will include the user terminal identifier, the location update completion notification indication information, and the current UE status. A message of the registered circuit domain network identification information is sent to the application server.

The application server includes: an application server including a call cross-domain handover control function DTF. In the present invention, before performing the processing of determining the manner in which the user terminal initiates the call, the method further includes: after receiving the location update completion notification message sent by the user terminal, the application server sends the subscription information to the home location register HLR of the user terminal. Query the ATSI message;

After receiving the ATSI message, the HLR returns, to the application server, user subscription information including a routing control mode supported by the circuit domain network currently registered by the user;

Alternatively, before performing the process of determining the manner in which the user terminal initiates the call, the method further includes:

The application server queries the data configuration information according to the received circuit domain network identification information that is currently registered by the UE, and obtains a routing control mode supported by the circuit domain network currently registered by the UE, where the data configuration information includes each of the possible roaming locations of the user terminal. Routing control mode information supported by the circuit domain network.

The processing for determining the manner in which the user terminal initiates the call includes:

The application server determines whether the circuit domain network currently registered by the user terminal supports the network side routing control mode, and if yes, notifies the user terminal to initiate a call in the normal call initiation mode corresponding to the network side routing control mode, otherwise, notifies the user terminal to The call origination mode corresponding to the terminal side routing control mode initiates a call.

In the present invention,

The network side routing control mode includes: a mobile network enhanced logic customized application CAMEL routing control mode; the terminal side routing control mode includes: an unstructured supplementary data service USSD routing control mechanism, a SIP Notify routing control mechanism, and a prefix Prefix routing control mechanism.

The process of determining whether the circuit domain network currently registered by the user terminal supports the network side routing control mode includes: when the application server determines that the circuit domain network currently registered by the user terminal supports the CAMEL phase 2 CAMEL phase 2 or above, It is then determined that the circuit domain network currently registered by the user supports the CAMEL route control mode.

The process of notifying the user terminal of the determined manner of initiating the call includes: the application server notifying the user terminal by using the USSD or SIP Notify or the short message to specify the manner in which the call is initiated. - The method further includes:

When the user terminal determines that the location update is not the location update inside the mobile switching center MSC/visiting location register VLR according to the location updated area location identifier, the application server notifies the application server that the location update is completed, and the application server receives the terminal location update. After the message, determining, according to the network where the terminal is currently located, the manner in which the terminal initiates the call and notifying the terminal of the determined call mode; or

After the application server receives the location update notification message sent by the user terminal, and determines, according to the saved location area identifier, that the location update of the user terminal is not the location update of the MSC/VLR, the terminal determines that the terminal initiates according to the network where the terminal is currently located. The way the call is made and the terminal is notified of the determined call mode.

The present invention provides a system for establishing an initial call in a voice service continuity service, including a user terminal and an application server, and further includes:

The notification module is disposed in the user terminal, and is configured to notify the application server of the registration status of the application server in the circuit domain; the call mode determining module is configured to be set in the application server, and is used for triggering the notification message sent by the notification module. Determining, according to a routing control mode supported by the circuit domain network currently registered by the user, a manner in which the user terminal initiates a call, and notifying the user terminal; The call initiation module is configured to be set in the user terminal, and configured to initiate a call according to the mode information of the originating call that is determined by the call mode determining module.

In the system of the present invention, when the notification module is a location update notification module for notifying a user terminal location update message, the system further includes:

The location update determination module is configured to: in the user terminal or the application server, determine whether the location update is a location update in the MSC/VLR according to the location update identifier after the location update, and if yes, the location update notification module or the call is not triggered. The mode determining module, otherwise, triggers the location update notification module or the call mode determining module.

The call mode determining module includes:

The subscription information obtaining module is configured to: obtain, by the ATSI message, the user subscription information including the routing control mode information supported by the circuit domain network currently registered by the user, or query the data configuration by using the circuit domain network identification information currently registered by the UE. The information acquires routing control mode information supported by the circuit domain network currently registered by the user;

a call mode determining module, configured to determine, according to the user subscription information, a routing control module supported by the user, and further determine a manner in which the user terminal initiates the call;

The call mode notification module: notifies the user terminal of the manner in which the determined user terminal initiates the call.

It can be seen from the technical solution provided by the present invention that in the static anchor scheme of the voice service continuity service, when the circuit domain user is used as the call originating call anchored in the DTF-enabled AS, the present invention provides An implementation scheme for the fusion processing of the terminal side routing control scheme based on USSD/SIP Notify/Prefix and the network side routing control scheme based on CAMEL is proposed, that is, the CAMEL is supported in the calling side circuit domain network. The CAMEL-based network-side routing control scheme uses a terminal-side routing control scheme based on USSD/SIP Notify/Prefix in the case where the calling-side circuit domain network does not support CAMEL.

Therefore, the implementation of the present invention enables the establishment of an initial call using the CAMEL of the calling side circuit domain in the network, and anchors the call on the gsmSCF having the DTF function, ensuring the calling side based on the CAMEL scheme. The maturity of the static anchoring of the call in the circuit domain, and the use of the USSD/SIP Notify/Prefix scheme as a supplement to the CAMEL scheme, avoids the failure of static anchoring of the call due to insufficient CAMEL capability of the calling side circuit domain. . DRAWINGS

1 is a schematic diagram of implementing VCC user cross-switching control by using a static anchor point in the prior art;

2 is a flow chart of a CAMEL-based network side routing control scheme in the prior art;

3 is a flowchart of a terminal-side routing control scheme based on USSD in the prior art;

4 is a flowchart of a terminal side routing control scheme based on SI P Notify in the prior art;

FIG. 5 is a schematic diagram of a specific implementation process of the method according to the present invention; FIG.

FIG. 6 is a schematic diagram of a specific implementation structure of the system according to the present invention. · detailed description The present invention is mainly applied to a static anchor scheme of a voice service continuity service. When a call initiated by a circuit domain user as a caller needs to be anchored in an AS with DTF function, it is possible to fuse different route control modes, The manner in which the user terminal initiates the call is controlled, so that the user terminal can determine the manner of initiating the call according to the routing control mode supported by the current network side (ie, the VLR), and initiate the establishment of the initial call, so as to flexibly support the corresponding routing control mode.

That is to say, the core of the present invention is to provide a scheme for combining the terminal side routing control scheme based on USSD/SIP Notify/Prefix and the network side routing control scheme based on CAMEL, that is, the calling side circuit The case where the domain network supports CAMEL uses a CAMEL-based network-side routing control scheme to use a terminal-side control scheme based on USSD/SIP Notify/Prefix only if the calling-side circuit domain network does not support CAMEL. Therefore, in the network, the CAMEL of the calling side circuit domain can be maximally utilized to establish the initial call, and the call is anchored on the DTF-enabled AS, and the calling side circuit domain pair call based on the CAM EL scheme is guaranteed. The maturity of static anchoring is performed; at the same time, the USSD/SI P Notify/Prefix scheme can be used as a supplement to the CAMEL scheme to avoid the failure of static anchoring of the call caused by insufficient CAMEL capability in the calling side circuit domain. The method of the present invention will be described below, and the present invention mainly includes the following processing:

(1) the UE located in the circuit domain and having contracted the VCC service completes its registration status in the circuit domain (such as the VLR), that is, after the location update, notifying the application server that the location update of the circuit domain has been completed, wherein the The application server can be an application server with DTF capability;

In the process, the UE may notify the application server having the DTF function to perform a location update operation by using a USSD or a SIP Notify or a short message, where the UE needs to carry the identifier of the UE in the notification message sent by the UE to the application server. The information, and the information indicating that the message is a location update completion notification, may further carry the circuit domain network identification information currently registered by the UE;

(2) After receiving the location update completion notification message of the VCC user, the application server queries to determine the routing control mode information supported by the circuit domain network currently registered by the user;

Specifically, after receiving the location update completion notification message, the application server sends an ATSI (Any Time Subscription Interrogation) message to the HLR to which the user belongs, and the HLR returns the current VCC after receiving the ATSI message. The subscription information of the user includes the CAMEL support capability of the VLR currently registered by the UE (Supported CAMEL phases in VLR, CMAEL version supported in the VLR).

In addition, the corresponding data configuration information may be configured in an application server having a DTF function, where the data configuration information includes CAMEL support capability information of all circuit domain networks that the user can roam, that is, routing control supported by each circuit domain network. Mode information; In this way, the DTF can query the routing control mode supported by the circuit domain network currently registered by the user, and the corresponding processing procedure is specifically as follows: The DTF queries the data configuration according to the received circuit domain network identification information currently registered by the UE. Information, obtain the CAMEL support capability corresponding to the circuit domain network currently registered by the UE.

(3) After the application server obtains the CAMEL support capability of the circuit domain network currently registered by the UE, if the circuit domain network currently registered by the UE can support the CAMEL, the application server notifies the UE to adopt the network routing control mode corresponding to the circuit domain call. The call initiation mode is initiated in a normal manner. Otherwise, if the circuit domain network currently registered by the UE cannot support the CAMEL capability, the application server notifies the UE that the terminal route control mode is initiated in a special manner when initiating the circuit domain call, for example, Pick Initiating a call by using a call origination mode corresponding to the USSD/SIP Notify/Prefix routing control mode;

In the process, the application server may also obtain the CAMEL support capability of the circuit domain network currently registered by the UE by determining the CAMEL support capability of the currently registered VLR of the UE, which may be: Supported CAMEL phases in the application server. When the VLR parameter indicates that the VLR can support CAMEL Phase 2 or above, it notifies the UE to initiate in a normal manner when initiating a circuit domain call. Otherwise, if the currently registered VLR of the UE cannot support CAMEL Phase 2, the application server notifies the UE. Initiating a circuit domain call, initiated in a special manner as shown in Figures 3 and/or 4;

In addition, in the process, the application server may notify the UE to initiate in a normal manner or a special manner when initiating a circuit domain call by means of USSD or SIP Notify or a short message. The notification message sent by the application server to the UE needs to carry indication information indicating that the UE initiates the call in a normal manner or in a special manner.

(4) When the UE initiates a call in the circuit domain, it is initiated according to the indication of the application server in a normal manner or in a special manner; the process is specifically: when the UE initiates a call in the circuit domain, if the indication information sent by the application server When the call is initiated in the normal manner, the UE initiates a call according to the manner shown in FIG. 2 in the prior art. If the indication information sent by the application server is to initiate a call according to a special manner, the UE according to FIG. 3 in the prior art. Or initiate a call in the manner shown in Figure 4.

It should be noted that the UE can not only perform location update between different MSCs/VLRs, but also perform location update under the same MSC/VLR, for example, location update and periodic location update within the MSC/VLR. Both are location updates under the same MSC/VLR. For such location update under the same MSC/VLR, since the MSC/VLR does not change, its CAMEL support capability does not change. In this case, if the location update is not distinguished, it is the location within the same MSCA/LR. The update is also a location update between different MSCA/LRs, but the location update notification message is sent to the application server once the location update occurs, causing the application server to redundantly access the HLR and increase the signaling load of the HLR.

Therefore, in order to prevent the remaining processing in the system from affecting the performance of the system, in the above case, the processing of the above processes (1) to (4) may not be performed. Specifically, the UE or the application server first identifies the location update under the same MSC/VLR during the process of performing the process (1) to the process (4), and stops the subsequent processing to avoid redundant processing on system performance. influences.

When the location of the location update is identified by the UE, the corresponding processing (1) is:

(1) After completing the location update of the circuit domain, the UE compares the obtained LAI (Location Area Identification) information after the location update with the LAI stored after the last location update, because one MSC/VLR The address information may have a certain correspondence with an LAI. Therefore, if the UE can derive the same MSC/VLR address information according to the two LAIs, it is determined that the location update is a location update in the MSC/VLR, and the application is not applied. The server sends the location update completion notification message to stop the subsequent processing; otherwise, if the UE cannot derive the same MSC/VLR address information, it determines that the location update is a location update between the MSC/VLR, and then sends the location to the application server. Update the completion notification information and continue with the subsequent processing. ,

When the location update situation is identified on the application server, the corresponding processes (1) and (2) are:

(1) After the UE of the user who has subscribed to the VCC service in the circuit domain completes the location update, the application server is notified that the user has completed the location update of the circuit domain, and the location update completion notification message needs to be carried in the location update request. Stored LAI information; (2) After receiving the location update completion notification information of the VCC user, the application server stores the LAI, and compares the LAI information with the last time the UE sends the LAI information in the location update completion notification message according to the UE. If the application server can derive the same MSC/VLR address information according to the two LAIs, and then determine that the location update is a location update in the MSC/VLR, the application server does not send an ATSI message to the HLR, and stops the subsequent processing; otherwise If the application server cannot derive the same MSC/VLR address information, it is determined that the location update is the location update between the MSC/VLR, and the application server sends an ATSI message to the HLR, and continues to perform the subsequent processing. For a better understanding of the present invention, the invention will be described in detail below with reference to the accompanying drawings. The specific implementation manner of the method for establishing an initial call in the voice service continuity service provided by the present invention is as shown in FIG. 5. The example only uses the location update situation identification on the UE and the ATTI operation interaction circuit obtained by using the DTF and the HLR. The method of CAMEL support capability of the domain network is described as an example, which specifically includes the following processing steps:

Step 5-1. The user who has signed the VCC service completes the location update process of the circuit domain;

Step 5-2. Compare the LAI after the location update with the LAI before the location update. If the UE can derive the same MSC/VLR address information according to the two LAIs, determine that the location update is the location within the MSC/VLR. Update, the location update completion notification information is not sent to the application server having the DTF function, the embodiment ends, otherwise, step 5-3 is performed;

In this step, the LAI information after the location update in the LOCATION UPDATING ACCE PT (Location Update Accept) message sent by the MSC received in the location update process is compared with the previously stored LAI information of the previous location update; Step 5-3: The UE sends a location update completion notification to the application server that has the DTF function.

艮卩, if the UE cannot derive the same MSC/VLR address information, it is determined that the current location update is a location update between the MSC/VLR, and the UE sends the DTF-enabled application in the manner of USSD or SIP Notify signaling. The server sends a location update completion notification message, where the message carries the identity information of the UE, such as an MSISDN (Mobile Station International ISDN Number), and also needs to carry corresponding information indicating that the message is a location update completion notification;

Step 5-4: After receiving the location update completion notification of the VCC user, the application server having the DTF function sends an ATSI message to the home HLR of the UE according to the identifier information of the UE.

Step 5-5: After receiving the ATSI message, the HLR returns an ATSI response message to the application server with the DTF function, where the message carries the subscription information of the current VCC user, where the subscription information includes the VLR currently supported by the UE. Routing control mode information, specifically whether to support information of the CAMEL route control mode;

Step 5-6: The application server with the DTF function determines the CAMEL support capability of the currently registered VLR of the UE according to the Supported CAMEL phases in VLR parameter in the subscription information of the current VCC user returned by the HLR, if the currently registered VLR of the UE can support For CAMEL Phase 2 or above, perform steps 5-7. Otherwise, perform steps 5-8.

Step 5-7: The application server with the DTF function sends the USSD signaling or the SIP Notify or the short message to the UE, and notifies the UE to initiate in a normal manner when the circuit domain call is initiated. When the subsequent UE initiates a call in the circuit domain, the call is initiated according to the manner shown in FIG. 2 of the prior art, and the processing in this embodiment ends.

Step 5-8: The application server with the DTF function sends USSD signaling or SIP Notify or short message to the UE, and notifies the UE to initiate in a special manner when initiating the circuit domain call. When the subsequent UE initiates a call in the circuit domain, it is as shown in FIG. 3 or FIG. 4 of the prior art. In the manner of initiating a call, the processing of this embodiment ends. The present invention also provides a system for establishing an initial call in the voice service continuity industry. The specific implementation structure of the system is as shown in FIG. 6, including a user terminal and an application server including a DTF function, and further includes:

The notification module is configured to be used in the user terminal to notify the application server of the registration status of the application server in the circuit domain; the module may be a location update notification module, specifically for when the user terminal performs the location update operation or after completion Notifying the application server;

The call mode determining module is configured to be configured in the application server that includes the DTF function, and configured to determine, according to a routing control mode supported by the circuit domain network currently registered by the user, the user terminal, triggered by the location update message sent by the location update notification module. The manner in which the call is initiated, for example, the normal call origination mode shown in FIG. 2, or the special call origination mode shown in FIG. 3 and FIG. 4, after which the determined call origination manner is notified to the user terminal;

The call initiation module is configured to be configured in the user terminal, and is configured to initiate a call according to the mode information of the originating call that is determined by the call mode determining module, that is, the module does not initiate the call in only one manner as described in the prior art. However, according to the actual network-supported routing control mode, the corresponding call initiation mode needs to be selected to initiate a call, thereby facilitating the integration processing of multiple routing control modes;

The call mode determining module specifically includes the following modules:

The subscription information obtaining module is configured to acquire the HLR of the user terminal by using the ATSI message, or obtain the routing control mode information supported by the circuit domain network currently registered by the user by using the circuit domain network identification information currently queried by the UE to query the data configuration information. Signing information;

The call mode notification module: notifies the user terminal of the determined manner in which the user terminal initiates the call.

In order to effectively avoid redundant processing affecting the efficiency of the system, the system of the present invention further includes: '

The location update determination module is configured to determine, in the user terminal or the application server, whether the location update is a location update within the MSC VLR according to the location update identifier, and if yes, the location update notification module or the call mode is not triggered. The module is determined, otherwise, the location update notification module or the call mode determination module is triggered.

The specific implementation of the processing functions of the various modules in the system of the present invention has been described in the prior methods of the present invention and will not be described in detail herein.

In the static anchor scheme of the voice service continuity service, the present invention provides a method for USSD/SIP Notify based on anchoring a call initiated by a circuit domain user as a caller in an AS with DTF function. /Prefix terminal-side routing control scheme and CAMEL-based network-side routing control scheme for the fusion processing scheme, that is, the CAMEL-based network-side routing control scheme is used in the case where the calling side circuit domain network supports CAMEL, only in A terminal-side routing control scheme based on USSD/SIP Notify/Prefix is used when the calling side circuit domain network does not support CAMEL. The CAMEL of the calling side circuit domain is maximized to establish the initial call and the call is anchored to the DTF-enabled gsmSCF, which ensures the static anchoring of the call by the calling side circuit domain based on the CAMEL scheme. Sex, while using the USSD/SIP Notify/Prefix side As a supplement to the CAMEL scheme, the case avoids the failure of static anchoring of calls caused by insufficient CAMEL capability in the calling side circuit domain.

The above is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of changes or within the technical scope disclosed by the present invention. Alternatives are intended to be covered by the scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

Rights request

A method for establishing an initial call in a voice service continuity service, comprising:

After receiving the notification, the application server determines, according to the routing control mode information supported by the circuit domain network currently registered by the user terminal, a manner in which the user terminal initiates a call, and notifies the user terminal of the determined manner of initiating the call;

When the user terminal initiates a circuit domain call, the call is initiated according to the manner in which the application server notifies the originating call.

2. The method for establishing an initial call in a voice service continuity service according to claim 1, wherein the processing of the registration application server in the registration state of the circuit domain includes:

After the user terminal completes the location update of the circuit domain, the manner of notifying the SI P Notify or the short message by using the unstructured supplementary data service USSD or the session initiation protocol includes the user terminal identifier, the location update completion notification indication information, and the UE. A message of the currently registered circuit domain network identification information is sent to the application server.

The method for establishing an initial call in a voice service continuity service according to claim 1, wherein the application server comprises: an application server including a call cross-domain handover control function DTF.

The method for establishing an initial call in a voice service continuity service according to claim 1, 2 or 3, wherein before the performing the process of determining the manner in which the user terminal initiates the call, the method further includes:

After receiving the location update completion notification message sent by the user terminal, the application server sends a subscription information query ATSI message to the home location register HLR of the user terminal;

The application server queries the data configuration information according to the received circuit domain network identification information that is currently registered by the UE, and obtains a routing control mode supported by the circuit domain network currently registered by the UE, where the data configuration information includes circuits that may be roaming as user terminals. Route control mode information supported by the domain network.

The method for establishing an initial call in a voice service continuity service according to claim 4, wherein the processing of determining a manner in which the user terminal initiates a call comprises: determining, by the application server, that the user terminal is currently registered Whether the circuit domain network supports the network side routing control mode. If yes, the user terminal is notified to initiate a call in the normal call initiation mode corresponding to the network side routing control mode. Otherwise, the user terminal is notified to use the call initiation mode corresponding to the terminal side routing control mode. Initiate a call.

The method for establishing an initial call in a voice service continuity service according to claim 5, wherein: the network side route control mode comprises: a mobile network enhanced logic customized application CAMEL route control mode; The terminal side routing control modes include: an unstructured supplementary data service USSD routing control mechanism, a SIP Notify routing control mechanism, and a prefix Prefix routing control mechanism.

The method for establishing an initial call in a voice service continuity service according to claim 5, wherein the processing of determining whether the circuit domain network currently registered by the user terminal supports the network side route control mode comprises: : '

When the application server determines that the circuit domain network currently registered by the user terminal supports the CAMEL phase 2 CAMEL phase 2 or In the previous version, it is determined that the circuit domain network currently registered by the user supports the CAMEL route control mode.

The method for establishing an initial call in a voice service continuity service according to claim 5, wherein the processing of notifying the user terminal of the determined manner of initiating the call comprises:

The application server notifies the user terminal by means of USSD or SIP Notify or a short message specifying the originating call.

The method for establishing an initial call in a voice service continuity service according to claim 4, wherein the method further comprises:

10. A system for establishing an initial call in a voice service continuity service, comprising a user terminal and an application server, and further comprising:

The notification module is disposed in the user terminal, and is configured to notify the application server of the registration status of the application server in the circuit domain; the call mode determining module is configured to be set in the application server, and is used for triggering the notification message sent by the notification module. And determining, according to the routing control mode supported by the circuit domain network currently registered by the user, a manner in which the user terminal initiates a call, and notifying the user terminal; the call initiation module is configured to be configured in the user terminal, and configured to determine, according to the call mode determining module, the concurrent initiation The call mode information initiates the call.

11. The system for establishing an initial call in a voice service continuity service according to claim 10, wherein when the notification module is a location update notification module for notifying a user terminal location update message, The system further includes: a location update determination module: configured to determine, in the user terminal or the application server, whether the location update is a location update within the MSC/VLR according to the location update identifier after the location update, and if yes, does not trigger The location update notification module or the call mode determination module, otherwise, the location update notification module or the call mode determination module is triggered.

The system for establishing an initial call in a voice service continuity service according to claim 10 or 11, wherein the call mode determining module comprises: