KR20080018749A - A method and apparatus for reducing impacts on the csi network originating csi interworking applied - Google Patents

Abstract

A method and an apparatus for processing messages supporting voice and multimedia services in a communication network are provided to enable a CSI AS to offer operation for discriminating a call control flow in consideration of the performance of a called or calling terminal, thereby omitting unnecessary call processing processes between networks. A method for processing messages supporting voice and multimedia services in a communication network comprises the following steps of: allowing a receiving AS(Application Server) supporting a CSI(Combination of CS and IMS Services) through a CS(Circuit Switched) call and an IMS(Internet Protocol Multimedia Sub system) session to receive a request message(700); checking whether a terminal transmitting the request message is a terminal supporting the CSI(708); checking whether a terminal to receive the request message is a terminal supporting the CSI(702); and bypass transmitting the request message to the same domain as a source domain when it is checked that the calling terminal and the called terminal supports the CSI(710).

Description

A method and apparatus for reducing impacts on the CSI network originating CSI interworking applied}

1 is a diagram schematically illustrating a structure of a mobile communication network supporting a CSI service to which the present invention is applied;

2 is a diagram illustrating a control signal connection structure between a CSI terminal and an IMS terminal according to the prior art;

3 is a diagram illustrating a control signal connection structure between a CSI terminal and an IMS terminal when performing CSI interworking in a receiving side network;

4 is a diagram illustrating a control signal connection structure between a CSI terminal and an IMS terminal when performing CSI interworking in an originating network;

5 is a diagram illustrating a control signal connection structure between CSI terminals in a receiving side communication network to which the present invention is applied;

6 is a diagram illustrating a control signal connection structure between CSI terminals of an originating communication network to which the present invention is applied;

7 is a flowchart illustrating an operation of a CSI AS when performing CSI interworking in a receiving side network according to an embodiment of the present invention.

8 is a flowchart illustrating an operation of a CSI AS when performing CSI interworking in an originating network according to an embodiment of the present invention.

9 is a flowchart illustrating an operation of a CSI AS when a CSI AS receives a reception notification signal from an MSC when interworking between a CSI terminal and an IMS terminal in an originating network according to an embodiment of the present invention.

The present invention relates to a communication network, and more particularly, to a method and apparatus for processing a message in a communication network supporting voice and multimedia services.

Circuit Switched (hereinafter referred to as CS) scheme is for typical voice services, and means a scheme in which a CS based fixed call route is formed between one user and the other user. .

The Internet Protocol Multimedia Subsystem (hereinafter referred to as 'IMS') is an unfixed, packet-based switch based on the Internet Protocol (hereinafter referred to as IP). Using call paths, data services, messaging services, and file transfer services are supported by increasing the efficiency of transmission and ensuring reliability. These IMS can support not only simple one-to-one calls but also connections involving multiple users. In CS method, message is transmitted through CS call. In IMS, message is transmitted through IMS session.

1 is a diagram illustrating a structure of a mobile communication network supporting voice call and packet data to which the present invention is applied. In particular, it is a diagram briefly showing the structure of a mobile communication network supporting a CSI service to which the present invention is applied.

FIG. 1 illustrates, for example, based on a Universal Mobile Telecommunication Service (UMTS) mobile communication network based on Global System for Mobile Communications (GSM) and General Packet Radio Services (GPRS).

Referring to FIG. 1, a mobile communication network supporting a CSI service includes a radio access network (hereinafter referred to as "RAN") 104 and a core network (hereinafter referred to as "CN") 106. Consists of The RAN 104 enables a user terminal (hereinafter referred to as UE) 102 to be connected to the CN 106. Since the structure of the RAN 104 is already known according to the radio access technology and the like used, a detailed description thereof will be omitted.

CN 106 is composed of CS domain 114, PS domain 108, and IMS domain 122. The CS domain 114 is composed of entities that support CS calls. Representatively, the CS domain 114 includes a Mobile Switching Center (MSC) 120 and a Media Gateway (hereinafter referred to as "MSC"). MGW ') 116, 118. The MSC 120 is in charge of a central control function that processes signals from and to the mobile telephone base station and adjusts the mobile telephone base station to operate efficiently. MGWs 116 and 118 are responsible for supporting radio bearer traffic and control traffic.

The PS domain 108 supports packet-based services, and a serving GPRS support node (hereinafter referred to as 'SGSN') 110 and a gateway GPRS support node (hereinafter referred to as 'GGSN'). 112). The SGSN 110 manages information on the location of each terminal, and performs security related functions and access control. GGSN 112 is SGSN 110 and a Public Switched Telephone Network (hereinafter referred to as PSTN) / Integrated Services Digital Network (hereinafter referred to as "ISDN") / Packet Data Network ( An entity of a GPRS network serving as a wireless gateway between external networks 130, such as Packet Data Network (hereinafter, referred to as 'PDN'). The terminal 102 may access the external network 130 using the GGSN 112.

IMS domain 122 is comprised of entities that support IMS sessions. In particular, a serving-call session control function server (hereinafter referred to as 'S-CSCF') 124, an application server (hereinafter referred to as 'AS') 126, media gateway control A function server / media gateway (hereinafter referred to as MGCF / MGW) 128 is shown.

The S-CSCF 124 establishes an IMS session and is responsible for receiving and processing a Session Initiation Protocol (SIP) message transmitted from the UE 102. The S-CSCF 124 forwards the SIP message to the entities in the IMS domain 122 to provide the service as requested by the terminal 102, so that the session is completed. AS 126 is an entity for providing an application to a user, such as Push To Talk over Cellular (PoC) for providing Push-To-Talk (PTT) service via email or cellular, and MGCF / MGW 128 is an IMS user. An entity that allows CS users to communicate. The MGCF / MGW performs a protocol conversion and a media packet conversion on the voice signal generated from the CS domain to perform digital packet conversion on the analog voice signal. Here, the MGCF / MGW 128 is an entity including a breakout gateway control function (hereinafter, referred to as 'BGCF'). BGCF is a network entity that selects MGCF, which is a point of contact with the CS network.

In addition to the above-mentioned entities, there may be several other entities in each domain, and other entities in each domain may be involved for the CSI service.

2 is a diagram illustrating a communication control flow between a CSI terminal and an IMS terminal. Here, 210 denotes a CSI terminal, 230 denotes an IMS terminal, a thin dotted line indicates a signal flow of a CS call, and a thick dotted line indicates a signal flow of an IMS call.

Referring to FIG. 2, the voice call request signal 220 generated by the CSI terminal 210 passes through the CS domain 1 214 and the CS domain 2 234, and the IMS domain 236 and the PS domain of the receiving side network. It is delivered to the IMS terminal 230 via (232). This is because the IMS terminal 230 is a terminal accessible through the IMS domain 236 and the PS domain 232.

On the other hand, the IMS session request signal 222 generated by the CSI terminal 210 is transmitted to the IMS terminal 230 through the IMS domain 1 216 and the IMS domain 2 236 according to the non-real time service connection.

However, the IMS terminal 230 has a problem that the two sessions requested by the CSI terminal 210 (voice call request signals according to real time services and data request signals corresponding to non real time services) can be treated as independent sessions. Have

In other words, when the receiving IMS terminal 230 cannot handle the multi-session, one of the two sessions requested by the CSI terminal 210 may be rejected by the IMS terminal 230.

Therefore, from the standpoint of the IMS terminal 230, the call request according to the real-time service 220 and the non-real-time service 222 is treated as an independent session with each other, any later call request is generated to the call request that occurred first This causes a problem that the call request is rejected because it is handled by the call.

In addition, although not shown in FIG. 2, the call requested from the IMS terminal 230 is divided into a call for processing data in the network 1 and a call according to voice, that is, the IMS domain 1 214 according to data processing. The call goes through the PS domain 1 212 and the CS domain 1 214 according to the voice call.

Recently, the wireless internet service market is developing technology to support mobile internet service, not just fixed internet.

Therefore, in order to support a stable service at a higher speed, a specific call processing procedure for supporting a CS call and an IMS service is required in a wireless communication network. In particular, call processing for a call requested from a terminal supporting the CS call and the IMS service should be proposed not to include an unnecessary call path.

Accordingly, the present invention devised to solve the problems of the prior art operating as described above is to provide a method and apparatus for processing a message of a communication network supporting voice and multimedia services in a communication network system.

An embodiment of the present invention, which was created to achieve the above object, is a circuit switched (CS) call and an Internet protocol multimedia subsystem (IMS) in a message processing method for supporting voice and multimedia services in a communication network. Receiving a request message by a receiving application server (AS) supporting an integrated multimedia service (CSI) through a session; checking whether the terminal sending the request message is a terminal supporting CSI; And confirming whether the terminal to receive the terminal supports the CSI and transmitting the request message to the same domain as the originating domain when the calling terminal and the receiving terminal confirm that the terminal supports the CSI. It is characterized by.

An embodiment of the present invention, which is invented to achieve the above object, in a communication network, a method for processing a message supporting voice and multimedia services, comprising a circuit switched (CS) call and an Internet protocol multimedia subsystem (IMS). Receiving the request message by the originating application server (AS) supporting the integrated multimedia service (CSI) through the session; confirming whether the terminal sending the request message is the terminal supporting the CSI; If the terminal is not the CSI terminal, characterized in that it comprises the step of bypass transmission to the IMS domain.

Hereinafter, with reference to the accompanying drawings will be described in detail the operating principle of the preferred embodiment of the present invention. In the following description of the present invention, detailed descriptions of well-known functions or configurations will be omitted if it is determined that the detailed description of the present invention may unnecessarily obscure the subject matter of the present invention. Terms to be described later are terms defined in consideration of functions in the present invention, and may be changed according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout the specification.

The present invention described below is a combined CS call and IMS session (hereinafter referred to as 'CSS') and an Internet Multimedia Multimedia Subsystem (IMS) session. CSI '), in particular, a terminal supporting the CSI service (hereinafter referred to as a' CSI terminal ') and a terminal using an IMS session for real time voice or video call (hereinafter' IMS terminal 'or' VoIP (Voice) over Internet Protocol), and a method and apparatus for communication between terminals.

In addition, when the CSI terminal is used in a network providing an interworking service (hereinafter referred to as 'originating CSI interworking') for a call requested by a CSI terminal, the present invention prevents inefficient generation of a call path and also supports a network that supports originating CSI interworking. And providing a method and apparatus for processing a control signal to cause a call path to be generated as in a network that is not.

In addition, in the following, the originating party is defined as 'origination' and the called party is defined as 'terminations' in relation to the occurrence of the call.

Here, the CSI service uses a CS call for voice transmission, that is, a voice call, and an IMS session for improved packet switched (PS) service, for example, message transmission or file transmission. Accordingly, the CSI terminal uses a CS call for a real time voice call and an IMS session for the non-real time PS service. In the CSI service, a voice call is considered as a service using a CS call. However, when the CS network supports a video call, the CS call may be used for not only the voice call but also the video call.

Hereinafter, in the embodiment of the present specification, a voice call service is a representative example of a service using a CS call in a CSI service, and a message session relay protocol (MSRP) as a representative PS service using IMS. A messaging service using the same method will be described as an example. This example is for convenience of description and various services may be applied in practice.

Hereinafter, in describing the present invention in detail, messages according to specific network components and specific protocols will be used. However, the wireless Internet service method, which is a basic object of the present invention, is applicable to other communication systems having a similar technical background and channel form with a slight modification without departing from the scope of the present invention. In the judgment of those skilled in the art will be possible.

3 and 4 illustrate a method of extending the interworking process for a call request message requested by a CSI terminal in a network supporting a CSI service.

3 illustrates a control signal connection structure between a CSI terminal and an IMS terminal when originating CSI interworking with respect to a call request signal generated from a CSI terminal in a receiving side network.

Referring to FIG. 3, the voice call request message 322 generated by the CSI terminal 302 is delivered to the CSI AS 336 in the form of an INVITE message through the IMS domain 2 334 of the receiving side network. CSI AS 336 sends a direct response to CS Domain 1 314 for the INVITE message.

Similarly, the session request message 320 generated by the CSI terminal 302 is also transmitted to the CSI AS 336 via the IMS domain 2 334, and the CSI AS 336 receives the received session request message 320. Rather than forwarding directly to IMS terminal 304, a response message is sent directly to the calling CSI terminal 302.

Thereafter, the CSI AS 336 combines the received voice call request message 322 and the session request message 320 into a single multimedia session request message 324 to form a new INVITE message, and then to the IMS terminal 304. To pass. This process is called '3rd Party Call Control' (hereinafter referred to as '3PCC').

In other words, when the CSI terminal 302 sends a multimedia session request consisting of the voice call request 322 and the IMS session request 320 to the IMS terminal 304, the voice call request generated by the CSI terminal 302 ( 322 and the IMS session request 320 are converted into a single multimedia session request signal 324 including voice call and IMS session by the CSI application server (hereinafter referred to as CSI AS) 336 and the IMS terminal 304 Is delivered.

Upon receiving the multimedia session request message generated through this method, the IMS terminal 304 converts the two call request messages 320 and 322 generated by the CSI terminal 302 into one call request message 324. Will receive.

Thus, as shown in FIG. 2, the call processing requested by the CSI terminal 302 fails.

4 illustrates a control signal connection structure between the CSI terminal and the IMS terminal when interworking between the CSI terminal and the IMS terminal in the calling network.

Referring to FIG. 4, when the CSI terminal 402 sends a multimedia session request including a voice call request 422 and an IMS session request 420 to the IMS terminal 404, the CSI terminal generates the voice call request generated by the CSI terminal. The IMS session request is converted by the CSI AS 418 into a single multimedia session request signal including a voice call and an IMS session and forwarded to the IMS terminal 404.

When the voice call request message 422 generated by the CSI terminal 402 is delivered to the CS domain 1 414, the CSI AS (Customized Applications for Mobile networks Enhanced Logic (CAMEL) or Mobile Application Part (MAP) protocol) is used. Inform 418 that the call request message has arrived, and the CSI AS 418 determines whether to process the call request message through the IMS domain 1 416.

When the CSI AS 418 receives the call request message in the form of an INVITE message through the MGCF of the IMS domain 1 416, the CSI AS 418 sends a response directly to the CS domain 1 414 in response to the INVITE message. . Similarly, if the session request message 420 generated by the CSI terminal 402 is also transmitted to the CSI AS 418 via the IMS domain 1 416 through the PS domain 1 412, the CSI AS 418 receives the received message. The response message is sent directly to the CSI terminal 402 without transferring the session request message to the IMS domain 2 434.

Accordingly, the CSI AS 418 merges the voice call request message and the session request message received at the CS domain 1 314 and the IMS domain 1 416 into a single multimedia session request message 424 to the IMS domain 2 434. To pass.

Upon receiving the multimedia session request message generated through this method, the IMS terminal 404 receives the two call request messages 420 and 422 generated by the CSI terminal 402 as one call request message 424. As a result, the call processing requested by the CSI terminal 402 does not occur.

FIG. 5 illustrates a communication network according to the present invention. In particular, when CSI originating CSI interworking is performed in a receiving network, a control signal connection structure between CSI terminals is illustrated.

Referring to FIG. 5, the voice call request message 522 sent from the CSI terminal 1 502 to the CSI terminal 2 504 is directly transmitted from the CS domain 1 514 via the CS domain 2 534 to the CSI terminal 2 504. Is delivered.

However, the IMS session request message 520 sent by the CSI terminal 1 502 is transmitted from the receiving IMS domain 2 536 to the CSI AS 538. Upon receiving the request message 520, the CSI AS 538 confirms that the request message is sent by the terminal supporting the CSI service, and performs a 3PCC operation to perform originating CSI interworking. That is, the CSI AS 538 responds directly to the request message and sends a new call request message 524 to the CSI terminal 2 (504).

However, in this case, the voice call request message sent to CS domain 2 534 is not forwarded to IMS domain 2 536, so the 3PCC procedure that CSI AS 538 performs on the IMS session request message is unnecessary.

Accordingly, the present invention requires a method of determining whether to perform an originating CSI interworking procedure when the CSI AS 538 receives a session request message from a terminal supporting a CSI service. This will be described in more detail with reference to FIG. 7.

6 is a diagram illustrating a control signal connection structure between CSI terminals when performing originating CSI interworking in a communication network to which the present invention is applied, particularly in an originating network.

Referring to FIG. 6, if the voice call request message 622 sent from the CSI terminal 1 602 to the CSI terminal 2 604 is received in the CS domain 1 614, the IMS domain 1 616 in the form of an INVITE message is received. And received by the CSI AS 1 618. CSI AS 1 618 sends a response message to CS domain 1 614 to perform originating CSI interworking on the INVITE message, and starts 3PCC operation.

In addition, the IMS session request message 620 sent by the CSI UE 1 602 to the CSI terminal 2 604 is received by the CSI AS 1 618 via the IMS domain 616. If the request message 620 confirms that the message is sent by the terminal supporting the CSI service, CSI AS 1 (618) is the voice call request message 622 and the IMS session request message 620 according to the originating CSI interworking procedure Combined into a single multimedia request message 624 and delivered to IMS Domain 2 636 of the receiving side network.

Receiving a multimedia session request 624 including a voice call, IMS domain 2 636 forwards the multimedia session request message to CSI AS 2 638. When the CSI AS 2 638 confirms that the request message 624 is a message directed to the CSI terminal 2 604, the voice call is delivered to the CS domain, and the non-voice call is performed to the IMS domain. A new voice call request message 626 and a new IMS session request message 628 are generated and delivered to the CSI terminal 2 604 through the CS domain 2 634 and the IMS domain 2 632, respectively.

However, when a call is generated between CSI terminals, the voice call request message 622 is preferably delivered directly to the CSI terminal 2 604 through the CS domain 1 614 and the CS domain 2 634 (640). The IMS session request message 620 does not go through the 3PCC procedure of the CSI AS 1 618 and the CSI AS 2 638, but directly through the IMS domain 1 616 and the IMS domain 2 636. Is preferably delivered.

That is, it is preferable that the call request message sent by the CSI terminal 1 602 be delivered in the same path as the 640 message, and the IMS session request message is delivered in the same path as the 642 message. Therefore, when the CSI AS 1 618 receives the session request message from the terminal supporting the CSI service, it is necessary to determine whether to perform the originating CSI interworking procedure. This will be described in more detail with reference to FIG. 8 below.

7 is a flowchart illustrating an operation of a CSI AS performing originating CSI interworking in a receiving side network according to an embodiment of the present invention. That is, this is a signal flow diagram illustrating a process of processing an INVITE message by a CSI AS side of CSI termination in the communication network illustrated in FIG. 5.

Referring to FIG. 7, in step 700, the CSI AS receives an INVITE message from the S-CSCF of the IMS domain. In step 702, the CSI AS checks whether the receiver of the INVITE message is a CSI terminal and is connected to a CS domain.

In this case, if the receiving terminal is a terminal supporting the CSI service and the terminal is connected to the CS domain (702Y), the process proceeds to step 704 to check whether the calling terminal supports the CSI service. If the calling terminal supports the CSI service in step 704, since the INVITE message is a request between the terminals supporting the CSI service, the CSI AS proceeds to step 710 and passes the INVITE message as it is without a separate processing procedure. Let's do it. It also does not participate in subsequent call processing message processes.

That is, the CSI AS confirming that both the originating terminal and the receiving terminal support the CSI service performs a 3PCC procedure of separately performing an IMS session request message by controlling to transmit a voice call request message through the CS domain 1 and the CS domain 2. Do not perform.

Here, when the CSI AS does not know whether the receiving terminal accesses the CS domain, it is assumed that the CSI AS is connected to the CS domain. And, whether or not the receiver is a CSI terminal can be known by checking capability information of the registered terminal through a '3rd party registration process' with the CSI AS. That is, when the CSI terminal registers in the IMS domain, it can be known through terminal information registration.

In addition, whether the calling terminal supports the CSI service includes the + g.3gpp.cs-voice, + g.3gpp.cs-video message, or MGCF included in the INVITE message in the ISUP IAM (Initial Address Message) message. User-User (hereinafter referred to as UUS) -1 converted together with the service information can be confirmed. The MGCF is a method for converting an ISDN (ISDN User Part) signal to a SIP protocol, and may use SIP-T (SIP for Telephony) or NSS (Narrowband Signaling Syntax), and the USS information may include an INVITE message along with the converted ISUP information. Included in

If the originating terminal does not support the CSI service in step 704, the CSI AS performs a termination logic procedure to deliver the voice call component of the INVITE message to the CS domain and the remaining call component to the IMS domain. Perform.

On the other hand, when the receiving terminal is the IMS terminal or the CS network is not provided in the network in which the receiving terminal is located in step 702, the CSI AS checks whether the calling terminal supports the CSI service in step 708. If the CSI AS confirms that the calling terminal supports the CSI service (708Y), in step 712, the CSI AS processes the INVITE message according to the originating CSI interworking procedure.

That is, according to the originating CSI interworking procedure, the CSI AS performs a 3PCC procedure to hold the voice call until the calling terminal transmits an IMS session request, and constitutes a single multimedia session request signal including the voice call and the IMS session. In this case, a new session request signal including the same call information as the voice call is generated and delivered to the receiving terminal. If the voice call is not held, when the CSI AS receives the IMS session request sent by the calling terminal later, the CSI AS configures a single multimedia session request signal including the voice call and the IMS session and transmits the same to the receiving terminal.

However, if it is determined in step 708 that the calling terminal does not provide the CSI service (708N), since the voice call request message through the CS domain will not be received from the same calling terminal, the process proceeds to step 710 where the CSI AS receives the INVITE message. Pass through without processing, and do not participate in subsequent call processing.

As described above, when the CSI AS checks whether the calling terminal and the receiving terminal support the CSI service, and confirms that the CSI terminal is a CSI terminal, the request message is sent directly to the domain according to the call specification without a separate 3PCC procedure for the requested INVITE message. To pass.

As described, according to the embodiment of the present invention, the CSI AS confirms that the calling terminal and the receiving terminal support the CSI service, and performs an unnecessary 3PCC operation on the IMS session request message transmitted by the calling CSI terminal. Instead, it passes directly to the IMS domain. That is, the CSI AS does not perform unnecessary message transmission between communication networks because it does not perform the 3PCC operation by performing originating CSI interworking with respect to terminals supporting the CSI service as conventionally, and loads the load of the CSI AS. Has the advantage of reducing.

In other words, when the CSI AS exists in the called network, the CSI AS determines whether the called terminal is a CSI terminal and bypasses the 3PCC operation to simplify the inter-network call processing.

8 is a flowchart illustrating the operation of a CSI AS originating CSI interworking in an originating network according to a preferred embodiment of the present invention. That is, this is a signal flow diagram illustrating a process of processing an INVITE message by a CSI AS on the CSI origination side in the communication network illustrated in FIG. 6.

Referring to FIG. 8, in step 800, the CSI AS receives an INVITE message. In step 802, the CSI AS checks whether the sender of the INVITE message is a CSI terminal. If the calling terminal is not the CSI terminal (802N), the process proceeds to step 818 without passing the INVITE message as it is, and does not participate in subsequent call processing.

On the other hand, if the sender of the INVITE message is a CSI terminal (802Y), the flow proceeds to step 804 to check whether the INVITE message is a message received from the CS domain.

If the requested INVITE message is a message received from the CS domain (804Y), flow proceeds to step 816. In step 816, the CSI AS performs an originating CSI interworking procedure on the INVITE message delivered from the CS domain to the CSI AS. Here, the INVITE message transmitted from the CS domain to the CSI AS is a signal obtained by converting a voice signal transmitted through the CS domain by the MGCF / MGW of the IMS domain into an IMS INVITE message.

If the INVITE message is not a message received from the CS domain in step 806, the INVITE message may be regarded as a message transmitted by the CSI terminal through the IMS domain. In step 806, the CSI AS checks whether there is a session connected to the calling terminal and the receiving terminal, each of which is identical to the calling address and the receiving address included in the INVITE message, during the session to which the CSI interworking procedure is applied. If there is such a session, the process proceeds to step 816 and the INVITE message is regarded as a request message associated with the session, and performs the originating CSI interworking procedure.

In other words, in step 816, the CSI AS confirms that a voice call request message is transmitted through the calling CS domain and later requests an IMS session through the IMS domain. The control process is performed. That is, after processing the previously transmitted CS call message according to the 3PCC procedure and transmitting the response message to the CS domain, if it detects that the IMS session request message is transmitted, a multimedia request message is configured and delivered to the receiving side network. Thereafter, the receiving network separates one multimedia request message, delivers a CS call message to the CS domain, and delivers an IMS session message to the IMS domain to perform CSI interworking.

On the other hand, if there is no such session in step 806, it is checked in step 808 whether the receiving terminal belongs to the same network as the calling terminal. If the receiving terminal belongs to the same network as the calling terminal, in step 810, the CSI AS checks whether the receiving terminal is a terminal capable of a CS call. However, if the receiving terminal does not belong to the same network as the calling terminal, in step 812, the receiving terminal checks whether the receiving terminal is a terminal capable of a CS call.

In step 814, the CSI AS knows whether the receiving terminal is capable of CS, or performs a capability exchange procedure with the receiving terminal by sending an OPTIONS request to the receiving terminal, or subscribes to the CSI AS belonging to the receiving network. (SUBSCRIBE) message, a method of sending a MESSAGE message to find out the state of the receiving terminal, and the like.

If the receiving terminal is capable of a CS call in step 814, since the INVITE message is a message for call generation between CSI terminals, in step 818, the CSI AS passes the INVITE message as it is without a separate processing procedure. Is not involved in the call processing process. On the other hand, if the receiving terminal is not possible to call the CS in step 814, the CSI AS performs the originating CSI interworking for the INVITE message in step 816.

As described above, when the CSI AS exists in the calling network, the CSI AS of the calling network receives the information of the called terminal from the CSI AS of the called network and determines whether the called terminal is a CSI terminal to participate in the 3PCC. Bypass the request message.

9 is a diagram illustrating a message processing process when an originating CSI AS receives a voice call request arrival signal from an MSC of an originating CS domain when performing originating CSI interworking in an originating network according to an embodiment of the present invention. It is a flow chart.

Referring to FIG. 9, in step 900, the CSI AS receives a signal indicating that a voice call request signal has been received in the CS domain from the MSC. For example, the CSI AS receives an IAM message from an MSC of the CS domain through a CAMEL protocol.

In step 901, the CSI AS checks whether the calling terminal is a terminal supporting the CSI service. In this case, if the originating terminal does not support the CSI service, the flow proceeds to step 914 notifying the MSC not to transmit the voice call request signal to the IMS domain. That is, no anchoring operation is performed.

On the other hand, if it is determined in step 901 that the calling terminal is a terminal supporting the CSI service, in step 902, the CSI AS is identical to the call request message from the same calling terminal as the call request message received during the session to which the CSI interworking procedure is being applied. Check if there is a session connected to the receiving terminal.

If there is such a session, the flow proceeds to step 912 where it is assumed that the voice call request is associated with an existing session being processed in the CSI AS and the voice call message received in the CS domain since it must be delivered through the existing session in the CSI AS. Inform the MSC to receive the CSI AS through the IMS domain (hereinafter referred to as the 'anchoring procedure').

If there is no session associated with the voice call request signal in step 902, in step 904, it is determined whether the receiving terminal of the voice call request signal is a user of the same network. Checks the information of the receiving terminal to determine whether the receiving terminal supports the CS call.

On the other hand, if the receiving terminal is not a user of the same network in step 904, the process proceeds to step 908, the CSI AS checks whether the receiving terminal supports the CS call. In step 908, the CSI AS knows whether the receiving terminal is capable of CS, by performing an OPTIONS request to the receiving terminal, performing a capability exchange procedure with the receiving terminal, or subscribing to a CSI AS belonging to the receiving network. (SUBSCRIBE) includes a method for determining the status of the receiving terminal by sending a message or MESSAGE message.

If the receiving side is the CSI terminal in step 910, since the corresponding voice call is a voice call between the CSI terminals, the process proceeds to step 914 and the CSI AS notifies the MSC not to anchor the voice call request message. On the other hand, if the receiving side does not support the CS call, in step 912, the CSI AS informs the MSC to anchor the voice call for the originating CSI interworking procedure.

In the present invention operating as described in detail above, the effects obtained by the representative ones of the disclosed inventions will be briefly described as follows.

The present invention has the advantage of eliminating unnecessary call processing between networks by providing an operation of distinguishing a call control flow in consideration of the performance of an incoming and outgoing terminal.

In other words, in a network in which an interworking procedure for a call request message sent from a CSI terminal to an IMS terminal is applied, the CSI AS selectively applies interworking for a call request message to each interworking procedure, thereby making a call connection process between CSI terminals. Unnecessary waste of network resources can be prevented.

Claims (7)

In a communication network, a method for processing a message supporting voice and multimedia services, Receiving a request message by a receiving application server (AS) supporting integrated multimedia services (CSI) through a circuit switched (CS) call and an Internet Protocol Multimedia Subsystem (IMS) session; Checking whether the terminal that has sent the request message is a terminal that supports CSI; Checking whether the terminal to receive the request message is a terminal supporting CSI; And confirming that the originating terminal and the receiving terminal are terminals supporting CSI, transmitting the request message to the same domain as the originating domain. The method of claim 1, And when the calling terminal is a terminal supporting IMS and the receiving terminal is an IMS terminal, transmitting the request message to the IMS domain. The method of claim 1, And when the calling terminal is a terminal supporting CSI and the receiving terminal is an IMS terminal, transmitting the request message to the IMS domain. In a communication network, a method for processing a message supporting voice and multimedia services, Receiving a request message by an originating application server (AS) supporting integrated multimedia services (CSI) over a circuit switched (CS) call and an Internet Protocol Multimedia Subsystem (IMS) session; Checking whether the terminal that has sent the request message is a terminal that supports CSI; Receiving information about whether a called terminal is a terminal supporting CSI from a called application server; And confirming that the originating terminal and the receiving terminal are terminals supporting CSI, transmitting the request message to the same domain as the originating domain. The method of claim 4, wherein Checking whether the request message is a message transmitted from a CS domain, And constructing the request message and the IMS session message into one multimedia request message and transmitting the same to the IMS domain. The method of claim 4, wherein Confirm that the request message is a message transmitted from an IMS domain, If the receiving terminal is a CSI terminal, the message processing method comprising the step of bypass transmission to the same IMS domain. In a communication network, a method for processing a message supporting voice and multimedia services, Receiving a request message from a CS domain by an originating application server (AS) supporting integrated multimedia services (CSI) over a circuit switched (CS) call and an Internet Protocol Multimedia Subsystem (IMS) session; Checking whether the terminal that has sent the request message is a terminal that supports CSI; If the originating terminal is not the CSI terminal, the message processing method comprising the step of bypass transmission to the CS domain.

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