KR101440687B1 - Communication system, control method, and recording medium for call processing - Google Patents

Abstract

The present invention relates to a communication system for call connection processing, a control method therefor, and a recording medium. A source IMS network call processing apparatus for processing a call connection request by a terminal connected to an IMS (IP Multimedia Subsystem) network according to the present invention; a subscriber IMS network processing apparatus connected to an IMS network and a legacy network, The control method of the communication system including the integrated management server includes the steps of the originating IMS network call processing device transmitting a location information request signal to the subscriber integrated management server according to a call connection request received from the originating terminal; The subscriber integrated management server extracts subscription network information corresponding to a calling party according to the location information request signal and transmits the extracted subscription network information to the calling IMS network call processing device in a location information response signal; The originating IMS network call processing device transmits a call connection request signal to either the called IMS network call processing device or the called party's legacy network call connection device according to the subscription network information included in the location information response signal .

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a communication system, a communication method,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication system for performing call connection processing, a control method therefor, and a recording medium, and more particularly to a communication system for efficiently performing call connection processing to an IMS network and a legacy network, .

With the development of mobile communication technology, terminals using various communication networks have been mixed, and each mobile communication company operates a system capable of providing communication services to all the various kinds of terminals.

The IMS (IP Multimedia Subsystem) network, which is one of the various communication networks, integrates services and networks classified according to the wired / wireless and wireless access networks into a single infrastructure to provide a multimedia service such as video, ) Based on open technology standard communication network.

This IMS network aims at implementing signalling and bearer for all services of existing mobile communication network in IP based network, and it is aimed to provide services for voice, video, messaging, data, and web based technology to wireless subscribers IMS network services are widely used in recent years.

For example, a voice call may be provided through an existing legacy network (for example, a Code Division Multiple Access (CDMA) network), while a video call service may be provided to customers through an IMS network.

However, since the types of terminals connected to the various communication networks are different, in order to connect a call to the counterpart terminal, the counterpart terminal must first determine whether it is a terminal connectable to the IMS network or a terminal connectable to the CMDA network.

In order to make such a determination, for example, when an LTE (Long Term Evolution) terminal connected to an IMS requests a call connection, a Call State Control Function (CSCF) in the IMS network is a type of a subscriber locator function Transmits the request signal (Enum Query) and uses the information received from the SLF to identify the network information of the called subscriber (that is, information indicating which communication network is connected).

That is, if the called subscriber is an IMS network subscriber, the SLF sends the domain of the called subscriber to the CSCF. If the called subscriber is a legacy network subscriber, the SLF transmits a response signal including no domain to the CSCF. It is possible to confirm the communication network to which the called subscriber has joined according to whether a domain is included in the received response signal.

1 and 2 show a conventional process in which a calling terminal connected to an IMS network is connected to a called terminal connected to an IMS network or a called terminal connected to a legacy network, respectively.

Briefly, in FIG. 1, the P / S-CSCF sends an ENUM Query to the SLF, receives the response, and determines whether there is domain information of the called subscriber. If there is domain information, And the I-CSCF obtains the location information of the called terminal from the HSS and transmits an Invite message to the called P / S-CSCF.

In FIG. 2, the P-CSCF and the S-CSCF / BGCF are distinguished from each other. When the P-CSCF transmits an Invite message to the S-CSCF / BGCF, the S-CSCF / BGCF transmits an ENUM Query to the SLF, If the domain information of the called subscriber is not included in the response signal, the Invite message is transmitted to the MGCF so that the call is connected to the called terminal through the legacy network.

As described above, conventionally, it is determined whether the Invite message is transmitted to the called CSCF or the called MGCF after the ENUM Query is always transmitted to the SLF and the response is received.

However, if a failure occurs in the SLF or the subscriber information is missing in the SLF, the CSCF can not receive the incoming domain information, and even if the called subscriber is an IMS network subscriber, the CSCF erroneously determines the subscriber information and causes the call processing to the legacy network . In addition, SLF, which is a separate server, must be used to identify the subscriber network of the called subscriber, which is an additional disadvantage in the construction and operation of the SLF.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems (and disadvantages) of the related art, and it is an object of the present invention to provide a method and apparatus for processing a call connection using conventional devices without operating a separate SLF A communication system, a control method thereof, and a recording medium.

In order to achieve the above object, there is provided an IMS network system comprising: a source IMS network call processing apparatus for processing a call connection request by a terminal connected to an IP Multimedia Subsystem (IMS) network according to the present invention; an IMS network processing apparatus connected to an IMS network and a legacy network A communication system including a subscriber integrated management server for performing subscriber mobility management is characterized in that the subscriber integrated management server extracts subscription network information corresponding to a calling party according to a location information request signal received from the IMS network call processing device, And transmits the information request signal to the source IMS network call processing device. The source IMS network call processing device transmits a location information request signal to the subscriber integrated management server according to a call connection request received from the source terminal Based on the subscription network information included in the location information response signal received from the subscriber integrated management server And transmits a call connection request signal to either the called party IMS network call processing device or the called party legacy network call connection device.

In order to achieve the above object, there is provided an IMS network call processing apparatus for processing a call connection request by a terminal connected to an IP Multimedia Subsystem (IMS) network according to the present invention, an IMS network, a legacy network, And a subscriber integrated management server for performing subscriber mobility management, wherein the source IMS network call processing device transmits location information to the subscriber integrated management server in response to a call connection request received from the source terminal, Transmitting a request signal; The subscriber integrated management server extracts subscription network information corresponding to a calling party according to the location information request signal and transmits the extracted subscription network information to the calling IMS network call processing device in a location information response signal; The originating IMS network call processing device transmits a call connection request signal to either the called IMS network call processing device or the called party's legacy network call connection device according to the subscription network information included in the location information response signal .

As described above, according to the present invention, there is no need for a separate server such as the SLF to determine a subscription network to which the called party subscribes, and in particular, a calling side IMS network call processing apparatus And the subscriber integrated management server, the overall call connection processing speed is increased.

1 is a control flowchart illustrating a process of establishing a call connection from a conventional IMS network to an IMS network,
2 is a control flowchart illustrating a process of establishing a call connection from a conventional IMS network to a legacy network,
3 is a schematic configuration diagram of an overall system including a communication system according to an embodiment of the present invention,
FIG. 4 is a flowchart illustrating a process of establishing a call connection from an IMS network to an IMS network according to an embodiment of the present invention.
5 is a control flowchart illustrating a process of establishing a call connection from an IMS network to a legacy network according to an embodiment of the present invention,
6 is a control flowchart of a P / S-CSCF according to an embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

The communication system according to an embodiment of the present invention includes an originating IMS network call processing apparatus 100 and a subscriber integrated management server 200 as shown in FIG. And a destination legacy network call connection device 400. [

Here, the destination IMS network call processing apparatus 300 is a device for establishing a call connection with a destination terminal connected to an IMS (IP Multimedia Subsystem) network (i.e., a terminal of a communication partner) (Call State Control Function). Here, the CSCF includes a Proxy Call State Control Function (P-CSCF), an Interrogating Call State Control Function (I-CSCF), and a Serving Call State Control Function (S-CSCF).

The destination legacy network call connection device 400 is a device for establishing a call connection with a destination terminal connected to a legacy network (for example, a CDMA (Code Division Multiple Access) network). For example, And may correspond to a destination MGCF (Media Gateway Control Function).

The subscriber integrated management server 200 is connected to the IMS network and the legacy network to perform subscriber mobility management, and also manages information on a communication network (i.e., access network) to which each subscriber subscribes. For example, the subscriber integrated management server 200 may correspond to a server since an HSS (Home Subscriber Server) and an HLR (Home Location Register) are integrally configured.

The subscriber integrated management server 200 extracts the subscription network information corresponding to the calling party (i.e., called party) according to the location information request signal received from the IMS network call processing device, And transmits it to the processing apparatus 100.

The originating IMS network call processing apparatus 100 processes a call connection request by the originating terminal connected to the IMS network, and in the same manner as the terminating IMS network call processing apparatus 300 described above, the CSCF (i.e., originating CSCF) .

The originating IMS network call processing apparatus 100 transmits a location information request signal to the subscriber integrated management server 200 according to a call connection request received from the originating terminal, And transmits a call connection request signal to one of the destination IMS network call processing device 300 and the destination legacy network call connection device 400 according to the subscription network information included in the information response signal.

For example, when the MGCF information is included in the specific server name field of the location information response signal received from the integrated subscriber management server 200, the calling IMS network call processing apparatus 100 determines whether the called terminal 520 is a legacy network And if the CSCF information is included in the specific server name field of the location information response signal received from the subscriber integrated management server 200, the calling side MGCF requests the call connection to the calling side MGCF, 100 determines that the terminating terminal 520 is in the IMS network and requests call connection to the called CSCF.

On the other hand, the calling side IMS network call processing apparatus 100 determines whether the customer is a customer based on the called party's telephone number received from the calling side terminal, and if the customer is a customer of the calling side, the subscriber integrated management server 200 A location information request signal can be transmitted.

To this end, the IMS network call processing apparatus must include information on the telephone number of the telephone number assigned to the subscriber customers, or include a function of real-time communication with a predetermined server having such information.

As a result of the determination, if it is not a customer, the calling IMS network call processing apparatus 100 may transmit a call connection request signal to the corresponding third party mobile communication system through the MGCF.

The originating IMS network call processing apparatus 100 determines whether there is an abnormality with respect to at least one destination legacy network call connection apparatus 400 at a predetermined time interval and transmits a location information response When the legacy network information is included in the signal, the legacy network connection apparatus 400 selects any one of the legacy network call connection apparatuses 400 previously determined as a normal operation and transmits a call connection request signal.

Of course, the calling side IMS network call processing apparatus 100 may determine whether or not each MGCF normally operates at the time of receiving the location information response signal. However, for quick processing, it is necessary to previously determine whether each MGCF is abnormal It is preferable to determine the time interval.

Hereinafter, signals and control flows of a communication system according to an embodiment of the present invention will be described in detail with reference to FIG. 4 to FIG. For the sake of comparison with FIGS. 1 and 2, the CSCF will be described separately as P / S-CSCF and I-CSCF.

First, referring to FIG. 4, a description will be made of a case where the called party joins the IMS network.

When the originating terminal 510 connected to the IMS network transmits a Invite message to the P / S-CSCF as a call connection request (step S1), the P / S-CSCF transmits the station number of the called party telephone number included in the Invite message It is determined whether the customer is a customer based on the basis (step S2). For example, the Invite message transmitted by the originating terminal 510 may include information such as "INVITE tel: +821080801111 SIP / 2.0 ", where '+821080801111' corresponds to the other party's telephone number.

As a result of the determination, if the customer is a customer, the P / S-CSCF changes the other party's telephone number to the telephone number to which the domain is combined, and sends the Invite message to the I-CSCF (step S3). For example, the P / S-CSCF may send an INVITE message containing information such as " INVITE sip: SIP / 2.0 "to the I-CSCF.

The I-CSCF sends a Location Information Request (LIR) as a location information request signal to the HSS / HLR (corresponding to the subscriber integrated management server 200 according to the present invention) to confirm the location of the terminating terminal 520 S5).

Then, the HSS determines whether the communication network to which the calling party (i.e., the called party) subscribes is an IMS network or a legacy network, as well as determines the location of the called party (step S6) (LIA), which is an information response signal, to the I-CSCF (step S7).

In FIG. 4, it is assumed that the receiving terminal 520 is subscribed to the IMS network. Therefore, the HSS may include information 'sip: scscf1.lte-lguplus.co.kr' in a specific field of the LIA, for example.

Upon receiving the LIA from the HSS, the I-CSCF confirms the information included in the specific field, i.e., 'sip: scscf1.lte-lguplus.co.kr', determines that the called subscriber is an IMS network subscriber, Can determine that a call connection is possible through a specific server including the name " SCSCF1 ".

Accordingly, the I-CSCF sends an Invite message to the called P / S-CSCF corresponding to the specific server address (step S9), and the called P / S-CSCF sends an Invite message to the called terminal 520 (Step S11).

Thereafter, the call connection process between the originating terminal 510 and the terminating terminal 520 and the call connection process between the terminating terminal 520 and the terminating terminal 520 is a known technology, and thus a detailed description thereof will be omitted .

Hereinafter, a process in the case where the called party joins the legacy network will be described with reference to FIG.

When the calling terminal 510 connected to the IMS network sends a call connection request to the P / S-CSCF as a call connection request (step S21), the P / S-CSCF sends the station number of the called party telephone number included in the Invite message It is determined whether the customer is a customer based on the basis (step S22). For example, the Invite message transmitted by the originating terminal 510 may include information such as "INVITE tel: +821080801111 SIP / 2.0 ", where '+821080801111' corresponds to the other party's telephone number as described above.

As a result of the judgment, if the customer is a customer, the P / S-CSCF changes the other party's telephone number to the telephone number to which the domain is combined, and sends the Invite message to the I-CSCF. For example, the P / S-CSCF may send an INVITE message containing information such as " INVITE sip: SIP / 2.0 "to the I-CSCF.

The I-CSCF transmits a location information request (LIR) as a location information request signal to the HSS / HLR to confirm the location of the terminating terminal 520 (step S25).

Then, the HSS determines whether the communication network to which the communication counterparty (i.e., the called party) subscribes is an IMS network or a legacy network (step S26). Then, the HSS transmits the location information response signal LIA (Step S27). In this embodiment, since the receiving terminal 520 is assumed to be subscribed to the legacy network, the HSS transmits 'sip: mgcf1.' To the I-CSCF in a specific field of the LIA. lguplus.co.kr '.

Upon receiving the LIA from the HSS, the I-CSCF confirms the information included in the specific field, i.e., 'sip: mgcf1.lguplus.co.kr', determines that the called subscriber is a legacy S network subscriber, It can be determined that a call connection is possible through a specific server including the name 'MGCF1'.

Thus, the I-CSCF may send an Invite message to the P / S-CSCF to forward the call connection to the destination legacy network call connection device 400, MGCF (step S29). At this time, the I-CSCF can include a signal in the corresponding Invite via the BGCF that performs the function of selecting an appropriate MGCF considering routing optimization.

Of course, the I-CSCF may also send an Invite message directly to the P / S-CSCF including the information 'sip: mgcf1.lguplus.co.kr'.

Accordingly, the P / S-CSCF transmits an Invite message to the MGCF (step S31), and a process of causing the MGCF to establish a call connection between the originating terminal 510 and the terminating terminal 520 via the IGS, same.

1 of the prior art FIG. 1 showing the call connection in the IMS network and FIG. 3 according to the present invention and comparing FIG. 2 of the prior art showing the call connection between the IMS network and the legacy network and FIG. 4 according to the present invention, Can be clearly seen.

Hereinafter, a control flow including a process of periodically checking the state of the MGCF by the P / S-CSCF will be described with reference to FIG.

That is, FIG. 6 shows a case where the calling P / S-CSCF judges whether the normal operation is to be performed for a plurality of MGCFs and stores them, and when an Invite message is received to connect a call from the I-CSCF to the legacy network, And transmits the call connection request signal, i.e., the Invite message, to the MGCF.

Specifically, the calling side P / S-CSCF periodically transmits a signal to a plurality of MGCFs (step S51), analyzes the response to the corresponding signal, and stores the status information of each MGCF, that is, (Step S53).

This is continued at a predetermined time interval while the request message to connect the call from the I-CSCF to the legacy network is not received (step S55) (step S57).

If a request message to connect a call from the I-CSCF to the legacy network is received (step S55), the P / S-CSCF extracts previously stored normal operation status information (step S59) and selects a normally operating MGCF Step S61), and transmits an Invite message to the selected MGCF (step S63).

By storing the normal operation state of each MGCF in advance as described above, the Invite message can be immediately transmitted to the MGCF that operates normally, so that the time delay due to the error processing at the time of transmitting the call connection signal can be prevented.

Needless to say, the process of performing each of the above-described embodiments can be performed by a program stored in a predetermined recording medium (for example, a computer readable medium).

The present invention is not limited to the above-described specific embodiments, and various modifications and changes may be made without departing from the gist of the present invention. It is to be understood that such variations and modifications are intended to be included in the scope of the appended claims.

100: calling side IMS network call processing device 200: subscriber integrated management server
300: Destination IMS network call processing device 400: Destination legacy network call connection device
510: originating terminal 520: incoming terminal

Claims (8)

An originating IMS network call processing device for processing a call connection request by a terminal connected to an IMS (IP Multimedia Subsystem) network; a subscriber integrated management server connected to an IMS network and a legacy network to perform subscriber mobility management; A method for controlling a communication system,
(a) the originating IMS network call processing device transmitting a location information request signal to the subscriber integrated management server according to a call connection request received from the originating terminal;
(b) the subscriber integrated management server extracts the subscription network information corresponding to the called party according to the location information request signal, and transmits the extracted location information to the calling IMS network call processing device in the location information response signal;
(c) the originating IMS network call processing device transmits a call connection request signal to either the called IMS network call processing device or the called party's legacy network call connection device according to the subscription network information included in the location information response signal The method comprising the steps of: The method according to claim 1,
The step (a)
(a1) the originating IMS network call processing device judging whether the customer is a customer based on the station number of the destination telephone number received from the originating terminal;
(a2) if it is determined by the step (a1) that the source IMS network call processing apparatus transmits a location information request signal to the called side to the subscriber integrated management server Method of controlling the system. The method according to claim 1,
Further comprising the step of determining whether the source IMS network call processing apparatus is abnormal with respect to at least one destination legacy network call connection apparatus at a predetermined time interval,
Wherein, in the step (c), a call connection request signal is transmitted by selecting any one of the legacy legacy network call connection devices judged as normal operation. A computer-readable recording medium storing a program for executing the method according to any one of claims 1 to 3. An originating IMS network call processing device for processing a call connection request by a terminal connected to an IMS (IP Multimedia Subsystem) network; a subscriber integrated management server connected to an IMS network and a legacy network to perform subscriber mobility management; A communication system comprising:
The subscriber integrated management server extracts the subscription network information corresponding to the calling party according to the location information request signal received from the IMS network call processing device, and transmits the extracted subscription network information to the calling IMS network call processing device ,
The originating IMS network call processing apparatus transmits a location information request signal to the subscriber integrated management server in response to a call connection request received from the originating terminal, And the call connection request signal is transmitted to one of the destination IMS network call processing device and the destination legacy network call connection device according to the network information. 6. The method of claim 5,
The calling IMS network call processing device is a CSCF (Call State Control Function)
And the subscriber integrated management server is an HSS / Home Location Register (HLR). The method according to claim 5 or 6,
The originating IMS network call processing device determines whether the customer is a customer based on the station number of the called party's telephone number received from the originating terminal, and if the customer is a customer, the location information request signal To the communication system. The method according to claim 5 or 6,
The originating IMS network call processing device determines whether there is an abnormality with respect to at least one called party's legacy network call connection device at a predetermined time interval and includes the legacy network information in the location information response signal received from the subscriber integrated management server The mobile terminal selects one of the called legacy network call connection devices determined to be a normal operation and transmits a call connection request signal.

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