KR100744568B1 - Method for dynamic call forwarding between wibro network and other network which is different kind of the wibro network - Google Patents

Abstract

A dynamic call forwarding method between a WiBro(Wireless Broadband Internet) network and another network is provided to enable a multi-mode terminal to receive a call incoming through the WiBro network even though the terminal which receives a WiBro network service is out of a WiBro network service area, thereby improving a call success rate. A call generated by another terminal is incoming in a WiBro network(S501), and the incoming call passes through SIP(Session Initiation Protocol)-ISUP(ISDN User Part) signaling mapping and media conversion processes(S502), then the call is delivered to an S-CSCF(Serving-Call Session Control Function)(S503). The S-CSCF checks the current state of a DBDM(Dual Band Dual Mode) terminal(S504), and decides whether to conduct call forwarding or to deliver a release message(S505). The S-CSCF selects a CDMA(Code Division Multiple Access) network, and the call is incoming in the CDMA network through media conversion(S508). The incoming call passes through SIP-ISUP mapping and media conversion processes, and is connected to the DBDM terminal if state of the DBDM terminal is normal in the CDMA network(S509-S511).

Description

Method for dynamic call forwarding between wibro network and other network which is different kind of the wibro network}

1 illustrates a structure of a portable internet to which the present invention is applied.

2 illustrates the structure of an IMS of 3GPP to which the present invention is applied.

3 illustrates a structure of an IMS-based portable Internet, that is, a WiBro network to which the present invention is applied.

4 is a diagram for explaining dynamic call transfer between a WiBro network and a heterogeneous network according to an embodiment of the present invention.

5 is a flowchart illustrating a dynamic call transfer between a WiBro network and a heterogeneous network according to an embodiment of the present invention.

The present invention relates to a dynamic call switching method between a WiBro network and a heterogeneous network, and more particularly, even if a multi-mode terminal receiving WiBro network service leaves the WiBro network service area, a call received through the WiBro network is automatically transferred. The present invention relates to a dynamic call switching method between a WiBro network and a heterogeneous network, which can be received in a network.

Existing wireless Internet services such as wireless LAN and CDMA2000 1x EV-DO have various problems in service coverage, transmission speed, and charge, and these problems are obstacles in activating the wireless internet market in providing services.

Therefore, the mobile Internet using the 2.3GHz frequency has newly emerged as a next-generation wireless Internet service that has the features of wide coverage, fast transmission speed, and low usage fee by supplementing the problems of the existing wireless Internet service. The portable Internet using this 2.3 GHz band is usually called a WiBro network.

In terms of integrated wired and wireless services, 2.3GHz mobile Internet is emerging as a new growth engine for the IT industry, and is attracting much attention as a new revenue model for operators and manufacturers. The portable Internet can also provide packetization, personalization and mobility of data, trends in the telecommunications market. It is possible to build a mobile Internet based on IMS of 3GPP and create new service through interworking with existing network.

In the early days of WiBro commercialization, however, it was commercialized through pilot services in parts of Seoul. Therefore, due to such a limitation of service coverage, services can only be achieved within a limited range.

In addition, operators plan to build a WiBro network and expand the service market step by step, so there are only a limited number of serviceable areas in the early stage of WiBro commercialization. As a result, when the Portable Subscriber Station (PSS) is out of the mobile Internet service area, it is frequently placed in an inactive state (a service unavailable state). In other words, services are only available in certain regions. Such a situation may seriously impede the activation of the mobile Internet market.

Therefore, in order to overcome the limitations of the service area or service area that may appear early in the commercialization of WiBro, the dynamic call forwarding method, which is a static call forwarding method provided as an additional service type of communication service, is provided. It is necessary to improve.

The technical problem to be achieved by the present invention is that even if the multi-mode terminal receiving the WiBro network service is out of the WiBro network service area, it is possible to receive a call received through the WiBro network, thereby limiting the service area that may appear in the early WiBro commercialization. It is to provide a dynamic call switching method between WiBro and heterogeneous networks that can overcome the problem.

In order to achieve the above technical problem, a dynamic call switching method between a WiBro network and a heterogeneous network according to the present invention is a multimode terminal. The multimode terminal may receive a service from a WiBro network and at least one heterogeneous network different from the WiBro network. Yes—moving out of this WiBro service area and moving to the heterogeneous network service area; Registering the multi-mode terminal with the heterogeneous network as the mode of the multi-mode terminal is changed from the mode of the wibro network to the mode of the heterogeneous network; Transmitting, by the multi-mode terminal, a message indicating that a service can be provided in the heterogeneous network to a location server of the WiBro network; Storing, by the location server, the content of the message; If the Serving-Call Session Control Function (hereinafter referred to as S-CSCF) of the WiBro network detects that a call is received from the other terminal to the multi-mode terminal, the state of the multi-mode terminal is transmitted through the location server. Obtaining information about the; And if the S-CSCF determines that the multi-mode terminal can be serviced in the heterogeneous network based on the obtained information, forwarding the received call to the heterogeneous network.

Preferably, the heterogeneous network comprises a CDMA network.

Preferably, the transition of the mode causes the transition from the mode of the WiBro network to the mode of the heterogeneous network if the strength of the signal from the WiBro network is below a predetermined threshold.

Preferably, the step of registering in the heterogeneous network, the location information of the multi-mode terminal in the service area of the CDMA network is a visitor location register (VLR) / Mobile Switching Center (MCS) And registering with a home location register (hereinafter referred to as HLR) of the CDMA network.

Preferably, the step of transmitting the message includes automatically transmitting the message through a short message service (SMS).

Preferably, the obtaining of the information on the state of the multi-mode terminal, the S-CSCF querying the location server of the state of the multi-mode terminal; And obtaining, by the S-CSCF, information about the state from the location server.

Advantageously, the step of delivering to the heterogeneous network comprises: S-CSCF forwarding the incoming call to BGCF; Selecting, by the Breakout Gateway Control Function (BGCF), a Media Gateway Control Function (MGCF) interworking with the heterogeneous network; And the selected MGCF sends an initial message of a session initiation protocol (SIP) corresponding to the incoming call to an initial address message of an ISDN user part (ISP) protocol. Initial Address Message (hereinafter referred to as IAM), the method comprising the step of transmitting the incoming call to the heterogeneous network.

Preferably, the multi-mode terminal further comprises the step of receiving the incoming call from the heterogeneous network.

According to an aspect of the present invention, there is provided a dynamic call switching method between a WiBro network and a heterogeneous network, the method comprising: moving a multimode terminal out of a WiBro service area to the heterogeneous network service area; Registering the multi-mode terminal with the heterogeneous network as the mode of the multi-mode terminal is changed from the mode of the wibro network to the mode of the heterogeneous network; When the S-CSCF of the WiBro network detects that a call is received from another terminal to the multimode terminal, confirming whether the multi-mode terminal is active in the WiBro network; And if it is determined that it is active in the WiBro network, the S-CSCF forwarding the incoming call to the heterogeneous network.

Preferably, the heterogeneous network comprises a CDMA network.

Preferably, the transition of the mode causes the transition from the mode of the WiBro network to the mode of the heterogeneous network if the strength of the signal from the WiBro network is less than or equal to a predetermined threshold.

Preferably, the registering in the heterogeneous network includes registering location information of the multi-mode terminal in the service area of the CDMA network to the HLR of the CDMA network via the VLR / MCS.

Advantageously, the step of delivering to the heterogeneous network comprises: S-CSCF forwarding the incoming call to BGCF; Selecting, by the BGCF, an MGCF to interwork with the heterogeneous network; And transmitting, by the selected MGCF, the incoming call of the SIP corresponding to the incoming call to the IAM of the ISUP protocol, the incoming call to the heterogeneous network.

Preferably, the multi-mode terminal further comprises the step of receiving the incoming call from the heterogeneous network.

Hereinafter, a method and an apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

The present invention has been made in response to the above requirements, and is one of the core elements of the mobile Internet and the next generation mobile communication network, which has solved the disadvantages of the space limitation of the existing wired Internet service, the low transmission speed and the high usage fee of the mobile Internet service. WiBro is established through the combination of IMS (IP Multimedia Subsystem), which has the advantages of providing large data services and global roaming.

Currently, the WiBro service area has five locations including KT in Sinchon, Gangnam, Seocho, Songpa, and Bundang, and six locations in SKT, including Anam-dong, Haengdang-dong, and Sinchon. It is insufficient.

Accordingly, the present invention for overcoming the problems of service coverage that may appear in the early stages of WiBro commercialization is as follows. First, a WiBro terminal is produced as a multimode terminal, wherein the multimode terminal can receive services from the WiBro network and at least one heterogeneous network different from the WiBro network. Next, the present invention allows the call to the WiBro network to be received through the dynamic transfer even if the WiBro terminal leaves the WiBro service area. Here, an example of the heterogeneous network may include a CDMA network, but is not limited thereto. For example, the multi-mode terminal is a dual band dual mode (hereinafter, referred to as DBDM) terminal capable of receiving services of a CDMA network and a WiBro network. When the DBDM terminal leaves the WiBro network service area, when the CDMA mode is turned on, that is, active, the CDMA network detects this state and manages the location of the terminal of the mobile Internet. (Presence Server: hereinafter, PS) provides the information on the current state of the DBDM, and the WiBro network transmits the call to the DBDM terminal in CDMA mode dynamically using the location information of the PS to the WiBro network .

1 illustrates a structure of a portable internet to which the present invention is applied.

The mobile Internet basically provides MIP (Mobile Internet Protocol) to provide a seamless service to mobile terminals indoors and outdoors in a cellular network configuration using broadband wireless transmission technology in the 2.3 GHz frequency band. Therefore, the mobile terminal can receive services continuously even between the subnets (ER: edge routers). It also provides a simple IP service that cannot be moved between subnets.

Referring to FIG. 1, the PSS 101 is an end point of a wireless channel, and according to a radio access station (RAS) 102 and an orthogonal frequency division modulation access (OFDMA) scheme according to a radio access standard. Communicate

The RAS 102 is a device for connecting a wireless network and a wired network to control a radio channel according to the characteristics of each network, and is connected to the wired network to provide a wireless packet data service directly to the PSS. Examples of the main functions of the RAS 102 include a function for transmitting and receiving a radio signal, a modulation / modulation signal processing function for a packet traffic signal, a protocol processing, and a routing function.

An ACR 103 is connected to a plurality of RASs to manage the RASs, and performs a handover control function to ensure high-speed mobility. For this purpose, RAS and ACR are connected based on the IP protocol and are configured based on Gigabit Ethernet switch for high speed packet transmission.

The edge router 104 is a router that connects the operator IP network and the mobile Internet and is connected to a plurality of ACRs. In addition, the edge router 104 is a terminal of the operator IP network, and can provide the mobile Internet service to the PSS 101 by interworking with a high-speed Internet network or a 3GPP network.

AAA (Authentication, Authorization, Accounting) server 105 authenticates and authorizes a mobile Internet service subscriber. It is in charge of functions such as billing.

The home agent (HA) 106 performs a home agent function to provide a Mobile IP service to a PSS (terminal).

The operator IP network 107 is an independent network of communication providers, and may be independently configured to provide a portable Internet service or may be configured to accommodate the portable Internet as an existing network. High-speed Internet represents the network of operators currently in place.

The edge router 108 is a router for interworking between the operator IP network and the public IP network 109.

2 illustrates the structure of an IMS of 3GPP to which the present invention is applied.

The evolution of All IP networks and services is based on the packet access capability of existing 3G networks. The main goal of this evolution is to introduce new IP multimedia domains into the mobile telecommunications core network by constructing an IP-based open architecture and service platform that supports the rapid and rapid deployment of new multimedia-based services. This evolution of All IP networks and services is originally an upgrade of IP transport, but in that vision it is evolving as a concept with higher-level multimedia service applications, which in turn is the concept of an IMS domain.

Several years ago, 3GPP and 3GPP2, the international standardization organizations of mobile networks, agreed on a standard to single roaming for all IP networks to be international roaming, and the Harmonized IMS model agreed between 3GPP and 3GPP2. ).

Referring to FIG. 2, the terminal 201 serves as a terminal for receiving a wireless Internet service and performs internet access in a mobile communication network.

The access network 202 is an access network for providing a wireless Internet access to a terminal, and is composed of a Radio Network Control (RNC), a Serving GPRS Network (SGSN), and a Gateway GPRS Network (GGSN).

The IP network 203 is a network of other providers that are constructing IMS of 3GPP.

Public Switched Telephone Network (PSTN) / Public Land Mobile Network (PLMN) 204 represents a general landline telephone subscriber network or a wireless telephone subscriber network.

The remaining components are the core functions of the IMS (IP Multimedia Subsystem) 205, which will be briefly described as follows.

Proxy-call session control function (hereinafter referred to as P-CSCF), serving-call session control function (hereinafter referred to as S-CSCF) and relay-call session control function (Interogating) Call Session Control Function (hereinafter referred to as I-CSCF) belongs to a CSCF that performs a call control function based on a Session Initiation Protocol (SIP) for providing various multimedia services on a 3GPP network. Do this.

The Home Subscriber Server (HSS) performs the functions of the Home Location Register (HLR) and the Authentication Center (AUC) and manages subscriber information of all IP networks. . Here, examples of subscriber information management include subscriber mobility management, user authentication information generation, service profile management, and the like.

The Media Gateway Control Function (MGCF) controls various media gates using the Megaco / H.248 protocol. MGCF specifically provides interworking with PSTN or other mobile communication systems and performs Class 4 Switching and Class 5 Switching.

The media gateway (MGW) performs a gateway function to another network.

A media resource function controller (MRFC) controls a media stream resource in a multimedia resource function processor (MRFP).

MRFP is responsible for media management and multiplexing.

The Breakout Gateway Control Function (BGCF) controls calls routed to a Public Switched Telephone Network (PSTN) or CS (Circuit Switching) domain.

Policy Decision Function (PDF) controls GPRS bearer authorization, QoS charging related function, and gating function, which is a service-based policy. In addition, PDF controls Diffserv inter-working, acceptance and interworking for resource reservation protocol.

Open Service Access-Service Capability Server (OSA-SCS) provides an interface to facilitate new service windows using basic network functionality.

In addition, examples of other components included in the 3GPP IMS include Domain Name System (DNS) for resolving Name to address, Dynamic Host Configuration Protocol (DHCP) for obtaining dynamic IP addresses, and E. 164 DNS / ENUM, which maps between a number system and an IP number system. Here, ENUM (Telephone Numbering Mapping) accepts E.164 phone numbers used in daily life as Internet Information Name System (DNS) as information identifiers, telephones, emails, homepages, faxes, etc. It performs a function to make various communication connections with one ENUM number.

3 illustrates a structure of an IMS-based portable Internet, that is, a WiBro network, to which the present invention is applied.

The portable Internet network 301 is connected to the provider IP network 302 and represents a structure interworking with the 3GPP standardized IMS subsystem 303. In addition, the network management function (NMS: Network Management System) for managing the mobile Internet 301 and the IMS subsystem 303, the HSS system-the HSS system and the HLR and AuC functions to perform the existing mobile subscriber management and All IP network It is composed of a server 304 that performs the function of performing subscriber information management in < RTI ID = 0.0 > and < / RTI >

In addition, interworking with the public IP network (305) and PSTN / PLMN (306) can use the existing Internet network, and interwork with wired telephone subscribers and wireless telephone network.

4 is a diagram for explaining dynamic call transfer between a WiBro network and a heterogeneous network according to an embodiment of the present invention.

1) When the DBDM terminal UE2 capable of receiving the services of the WiBro network and the CDMA network moves from an area 410 to an area 414 as shown in FIG. 4, that is, roaming and serving a WiBro network service area. If it is out of the network, it detects that it is out of the WiBro service area and turns on the CDMA mode. At this time, the WiBro mode is OFF, and the DBDM terminal UE2 is de-registration from the WiBro network. On the other hand, as an example of a method for detecting that the WiBro network service area is out of the WiBro network, a method of determining whether the WiBro network service area is out of the WiBro network service area is less than a predetermined threshold, but is not necessarily limited thereto.

2) Location information of the DBDM terminal UE2 located in the area indicated by reference numeral 414 and belonging to the CDMA network service area is referred to as a visitor location register (VLR) / mobile switching center (MCS) (413). Is registered in the Home Location Register (HLR) 412 of the CDMA network.

3) Then, the DBDM terminal UE2 automatically transmits the message "Short Message Service (hereinafter referred to as SMS)" to the message "The DBDM terminal UE2 can be serviced in the CDMA network service area beyond the WiBro service area." WiBro transmits to a location server (hereinafter, referred to as PS) 408. This message is delivered from the DBDM terminal UE2 to the PS 408 via the VLR / MCS 413, the HLR 412, and the gateway 411. Meanwhile, according to another embodiment of the present invention, without transmitting the message to the PS 408, the WiBro network confirms only the state in which the DBDM terminal UE2 is unregistered from the WiBro network, and the CDMA network Forwards the call.

4) After the PS 408 receives the SMS, the WiBro subscriber corresponding to the DBDM terminal UE2 can service the CDMA area in the location information database managed by the PS 408. That is, the PS 408 is active in the CDMA network. Record the status.

5) At this time, when a call is received from the other terminal UE1, such as a CDMA terminal, to the DBDM terminal UE2, the S-CSCF 407 of the IMS-based WiBro calls the call corresponding to the incoming call by the CS network 401. Signaling Gateway (hereinafter referred to as SGW) 402, MGCF 403, I-CSCF 404, HSS 405 and SIP AS 406.

6) The S-CSCF 407 queries the PS 408 to confirm the current state of the DBDM terminal UE2. This query is made via the SIP AS 406, S-CSCF 407.

7) When the S-CSCF 407 receives information from the PS 408 that the DBDM terminal UE2 is inactive in the WiBro network area and is active in the CDMA network area, the S-CSCF 407 receives CDMA. In order to forward the call to the network, it forwards the call to BGCF 420.

8) The BGCF 420 selects an appropriate MGCF 421 to interwork with the CDMA network corresponding to the call.

9) The selected MGCF 421 converts an Invite message of the Session Initiation Protocol (SIP) corresponding to the call through message mapping to an ISDN User Part (ISSUP). A method of converting the protocol into an initial address message (IAM), which forwards the call to the CDMA network. Here, the message corresponding to the call is delivered to the DBDM terminal UE2 via the MGCF 421, the SGW 422, the HLR 412, and the VLR 413.

10) If such a procedure is normally performed, the DBDM terminal UE2 may receive a call corresponding to a call made to a WiBro subscriber.

5 is a flowchart illustrating a dynamic call transfer between a WiBro network and a heterogeneous network according to an embodiment of the present invention.

The procedure of this embodiment will be described with reference to FIG. 5 shows another terminal UE1 when a DBDM terminal UE2 capable of receiving WiBro and CDMA services is moved from an area 410 to an area 414 as shown in FIG. 4. It will be described on the assumption that a call is received from the DBDM terminal UE2 to the DBDM terminal UE2.

In this case, the state of the DBDM terminal UE2 is a state in which a service is available in the CDMA region, and the PS 408 is a state in which information about the state is recorded in a location information database managed by the DBDM terminal UE2.

A call generated by another terminal is introduced into a WiBro network from a CS network (PSTN, CS PLMN) (step S501). The incoming call is subjected to SIP-ISUP signaling mapping and media conversion (step S502). 407).

The S-CSCF 407 queries the PS 408 to obtain the presence information of the called terminal corresponding to the call, and checks the state of the DBDM terminal that is the called terminal (step S504).

The S-CSCF 407 determines whether to send a REL (release) message or perform a call transfer according to the confirmation result (step S505). The confirmation result indicates that the DBDM terminal UE2 provides a service in another network such as a CDMA network. If it is possible, the process proceeds to step S508, otherwise it sends a REL (Release Signal: SIP message) to the calling party and terminates the call (step S506).

S-CSCF 407 selects the CDMA network, and the call is CDMA through S-CSCF 407, BGCF 420, MGCF 421, SIP-ISUP mapping, and Media conversion via IM-MGW. It is introduced into the network (step S508).

The call introduced through the CDMA network through the SIP-ISUP mapping and the media conversion (step S509), if the state of the DBDM terminal UE2 is normal in the CDMA network (step S510), the DBDM in the CDMA mode The call is connected to the terminal UE2 (step S511). If such a procedure is normally performed, the DBDM terminal UE2 in the CDMA mode may receive a call made to a WiBro subscriber.

In addition, a case in which the DBDM terminal UE2 leaves the WiBro service area and then reenters the WiBro service area will be described. In this case, when the DBDM terminal UE2 detects that the signal strength received from the WiBro network is greater than or equal to a predetermined threshold, the DBDM UE UE2 determines that it belongs to the WiBro network service area, and the mode of the DBDM terminal UE2 is changed from the CDMA mode to the WiBro mode. As a result, the DBDM terminal (UE2) can receive a call to the WiBro subscriber in the WiBro network itself, in which case no call transfer procedure is required.

The invention can also be embodied as computer readable code on a computer readable recording medium. Computer-readable recording media include all kinds of recording devices that store data that can be read by a computer system. Examples of computer-readable recording media include ROM, RAM, CD-ROM, magnetic tape, floppy disks, optical data storage devices, and the like, which are also implemented in the form of carrier waves (for example, transmission over the Internet). Include. The computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion. In addition, functional programs, codes, and code segments for implementing the present invention can be easily inferred by programmers in the art to which the present invention belongs.

Such a method and apparatus of the present invention have been described with reference to the embodiments shown in the drawings for clarity, but these are merely exemplary, and various modifications and equivalent other embodiments are possible to those skilled in the art. Will understand. Therefore, the true technical protection scope of the present invention will be defined by the appended claims.

According to the present invention, by transferring a call to the mobile Internet to another network, the DBDM terminal outside the mobile Internet service area can receive the call. More specific effects will be described as follows.

The existing call transfer method is a static method, in which a subscriber directly applies to operators in the form of an additional service, and a subscriber inputs a call transfer destination number as needed, whereas the present invention provides a dynamic call transfer method. When the UE is out of the service coverage in the WiBro network, it detects this and automatically performs a call transfer to a heterogeneous network such as CDMA. Therefore, according to the present invention, first, the limitation of the service area that occurs in the initial stage of the market entry of the WiBro service can be overcome, and second, when the terminal is out of the WiBro network receiving area, it dynamically detects the heterogeneous network ( CS PLMN, PSTN) can be interworked, and thirdly, through this, it is possible to dynamically call forwarding (call forwarding) incoming calls to the WiBro network. Fourth, by overcoming WiBro service coverage, WiBro market entry can be activated. Fifth, the call success rate can be improved by enabling incoming calls to mobile networks (CS PLMN and PSTN).

Claims (15)

A multi-mode terminal, wherein the multi-mode terminal can receive services from a WiBro network and at least one heterogeneous network different from the WiBro network; moving from the WiBro service area to the heterogeneous network service area; Registering the multi-mode terminal with the heterogeneous network as the mode of the multi-mode terminal is changed from the mode of the wibro network to the mode of the heterogeneous network; Transmitting, by the multi-mode terminal, a message indicating that a service can be received in the heterogeneous network to a location server of the WiBro network; Storing, by the location server, the content of the message; If the Serving-Call Session Control Function (hereinafter referred to as S-CSCF) of the WiBro network detects that a call is received from the other terminal to the multi-mode terminal, the state of the multi-mode terminal is transmitted through the location server. Obtaining information about the; And And when the S-CSCF determines that the multi-mode terminal can be serviced in the heterogeneous network based on the obtained information, transmitting the received call to the heterogeneous network. Dynamic call transfer method for heterogeneous manganese. The method of claim 1, The heterogeneous network comprises a CDMA network, the dynamic call switching method between the WiBro network and heterogeneous network. The method of claim 1, wherein the transition of the mode is And when the signal strength from the WiBro network is less than or equal to a predetermined threshold, transitioning from the WiBro network to the mode of the heterogeneous network. The method of claim 2, wherein registering with the heterogeneous network comprises: In the service area of the CDMA network, the location information of the multi-mode terminal is transmitted to the home location register of the CDMA network via the Visitor Location Register (VLR) / Mobile Switching Center (MCS). Register: A method for dynamic call switching between a WiBro network and a heterogeneous network, which comprises registering the HLR. The method of claim 1, wherein transmitting the message comprises: And automatically transmitting the message through a short message service (SMS). The method of claim 1, wherein the obtaining of the information about the state of the multimode terminal comprises: The S-CSCF querying the location server for the status of the multimode terminal; And And obtaining, by the S-CSCF, information about the state from the location server. The method of claim 2, wherein the transferring to the heterogeneous network comprises: Transmitting, by the S-CSCF, the incoming call to a Breakout Gateway Control Function (BGCF); Selecting, by the BGCF, a Media Gateway Control Function (MGCF) interworking with the heterogeneous network; And The selected MGCF sends an initial message of a session initiation protocol (SIP) corresponding to the incoming call to an initial address message of an ISDN user part (ISP) protocol. Address Message: A method for converting to IAM), comprising: forwarding the incoming call to the heterogeneous network. The method of claim 1, And receiving, by the multi-mode terminal, the incoming call from the heterogeneous network. A multimode terminal, wherein the multimode terminal can receive services from a WiBro network and at least one heterogeneous network different from the WiBro network; moving from the WiBro service area to the heterogeneous network service area; Registering the multi-mode terminal with the heterogeneous network as the mode of the multi-mode terminal is changed from the mode of the wibro network to the mode of the heterogeneous network; When the S-CSCF of the WiBro network detects that a call is received from another terminal to the multimode terminal, confirming whether the multi-mode terminal is active in the WiBro network; And And determining that the S-CSCF forwards the incoming call to the heterogeneous network if it is determined that the WiBro network is in an active state. The method of claim 9, The heterogeneous network comprises a CDMA network, the dynamic call switching method between the WiBro network and heterogeneous network. 10. The method of claim 9, wherein the transition of modes is And when the signal strength from the WiBro network is less than or equal to a predetermined threshold, transitioning from the WiBro network to the mode of the heterogeneous network. The method of claim 10, wherein registering in the heterogeneous network comprises: And registering the location information of the multimode terminal in the service area of the CDMA network to the HLR of the CDMA network via the VLR / MCS. The method of claim 10, wherein the step of delivering to the heterogeneous network, S-CSCF forwarding the incoming call to the BGCF; Selecting, by the BGCF, an MGCF to interwork with the heterogeneous network; And The selected MGCF converts the initial message of the SIP corresponding to the incoming call into the IAM of the ISUP protocol, and forwards the incoming call to the heterogeneous network. Dynamic transfer method. The method of claim 9, And receiving, by the multi-mode terminal, the incoming call from the heterogeneous network. A computer-readable recording medium containing a program for performing the method according to any one of claims 1 to 14.

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