KR101528675B1 - Call processing system of ims network and control method thereof, bgcf included in the system and control method thereof - Google Patents

Abstract

The present invention relates to a call processing system and control method for an IMS (IP Multimedia Subsystem) network, a Breakout Gateway Control Function (BGCF) included in the call processing system, and a control method thereof. (IMS), which includes an Home Subscriber Server (HSS), a Call Session Control Function (CSCF), a Breakout Gateway Control Function (BGCF), and a Media Gateway Control Function (MGCF) Subsystem) network, the HSS extracts the called party exchange information corresponding to the called party number according to the subscriber location information inquiry signal of the CSCF and transmits the extracted information to the CSCF in the subscriber location information response signal, Transmits the subscriber location information inquiry signal to the HSS in response to a call connection request of the originating terminal and delivers the called exchange information included in the subscriber location information response signal received from the HSS to the BGCF, And a database in which specific MGCF information is matched, wherein the MGCF corresponding to the destination exchange information received from the CSCF is stored in the sphere By using a database, it characterized in that it transmits the call connection request signal to select, the selected MGCF.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a call processing system and its control method for an IMS (IP Multimedia Subsystem) network, a breakout gateway control function (BGCF) included in the call processing system, THE SYSTEM AND CONTROL METHOD THEREOF}

The present invention relates to a call processing system and control method for an IMS (IP Multimedia Subsystem) network, a Breakout Gateway Control Function (BGCF) included in the call processing system, and a control method thereof.

The IP Multimedia Subsystem (IMS) is part of the standardization work for the 3G mobile phone system on the UMTS network in the 3GPP, and the structure is established for the first time when SIP based multimedia is added in Release 5 of 3GPP. Support is also provided for GPRS networks.

An example of the IMS network configuration is shown in FIG. 1, and the configuration itself of the IMS network is well known as being defined in the specification, and thus a detailed description thereof will be omitted.

Currently, the IMS network is configured to interwork with various networks. For example, terminals connected to a legacy network (for example, a CDMA network) as well as terminals connected to a Voice over Long Term Evolution (VoLTE) Can communicate with each other through the network.

However, a processing procedure in the IMS network when a VoLTE network subscriber calls a subscriber of a CDMA is as shown in FIG.

When the VoLTE terminal transmits a call connection request signal to the CSCF, the CSCF requests the HSS to authenticate the calling subscriber and then requests the location information of the called subscriber.

After processing the authentication of the calling subscriber, the HSS sends a response signal to the CSCF informing that the called subscriber is a CDMA network subscriber.

After confirming that the called subscriber is a CDMA network subscriber, the CSCF transmits a call connection request signal to the BGCF to the called subscriber, and the BGCF transmits a call connection request signal to an arbitrary MGCF of the plurality of MGCFs.

That is, there may be a plurality of MGCFs in each region, and the BGCF transmits a call connection request signal to any one of the MGCFs (i.e., refer to the standard of 3GPP TS 24.229).

The MGCF then sends the incoming call to the gateway exchange in its area and the gateway exchange checks the location of the destination exchange from the HLR. If the gateway exchange and the destination exchange in the area where the MGCF is located are not located in the same area , The gateway exchanger is a gateway exchanger in the area where the destination exchange is located, and transmits the incoming call using the circuit network.

The gateway exchanger in the area where the destination exchange is located then transfers the incoming call to the destination exchange and the destination exchange delivers the incoming call to the CDMA terminal.

However, when the area where the calling VoLTE terminal is located and the area where the receiving CDMA terminal is located are distant from each other, for example, when the VoLTE terminal in the Seoul area tries to make a call with the CDMA terminal in the Busan area, There is a problem that resources are additionally occupied and time is delayed.

In other words, when the MGCF and the CDMA exchanger are distributed locally, when MGCF of the MGCF managed by the BGCF selects the MGCF to transmit the incoming call, the MGCF in the Seoul area transmits an incoming call to the gateway exchanger in Seoul In this case, the gateway exchanges in the Seoul area receiving the incoming call will further occupy the line resources of the remote (ie, from Seoul to Busan) and connect to the gateway exchanger in the Busan area.

Thus, the additional occupancy of circuit resources from Seoul to Busan causes an additional extension of the remote line, thereby causing unnecessary costs and causing a problem of lowering the success rate of the call connection.

Patent No. 10-0744568

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and its object is to provide an IMS (IP) system for minimizing resources occupied for a call connection when a call is connected from a VoLTE terminal to a CDMA terminal, Multimedia Subsystem) network, a control method thereof, and a BGCF (Breakout Gateway Control Function) included in the call processing system and a control method thereof.

In order to achieve the above object, the mobile communication system according to the present invention includes an Home Subscriber Server (HSS), a Call Session Control Function (CSCF), a Breakout Gateway Control Function (BGCF), and a Media Gateway Control Function (MGCF) The HSS extracts the called party exchange information corresponding to the called party number according to the subscriber location information inquiry signal of the CSCF and includes it in the subscriber location information response signal The CSCF transmits a subscriber location information inquiry signal to the HSS according to the call connection request of the originating terminal and transmits the subscriber exchange information included in the subscriber location information response signal received from the HSS to the BGCF Wherein the BGCF comprises a database in which each exchange information and specific MGCF information are matched, and wherein the destination exchange Selects the MGCF corresponding to the base information using the provided database, and transmits a call connection request signal to the selected MGCF.

In order to achieve the above object, a BGCF (Breakout Gateway Control Function) included in a call processing system of an IP Multimedia Subsystem (IMS) network for transmitting an outgoing call to a legacy network according to the present invention includes an MGCF (Media Gateway Control Function) and a CSCF (Call Session Control Function) for processing a call session; A database unit in which each exchange information and specific MGCF information are matched; A selector for selecting an MGCF matching the destination exchange information by referring to data stored in the database unit when a call connection request signal including destination exchange information is received from the CSCF; And a transmission unit for transmitting a call connection request signal to the MGCF selected by the selection unit through the communication interface unit.

In order to achieve the above object, the mobile communication system according to the present invention includes a Home Subscriber Server (HSS), a Call Session Control Function (CSCF), a Breakout Gateway Control Function (BGCF), and a Media Gateway Control Function (MGCF) A control method performed by a call processing system of an IMS (IP Multimedia Subsystem) network for transmitting an originating call includes: transmitting a subscriber location information inquiry signal to the HSS according to a call connection request of an originating terminal; The HSS extracting the called party exchange information corresponding to the called party number according to the subscriber location information inquiry signal of the CSCF, and transmitting the extracted information to the CSCF in the subscriber location information response signal; Transmitting, by the CSCF, the called party exchange information included in the subscriber location information response signal received from the HSS to the BGCF; The BGCF having a database in which each exchange information and specific MGCF information are matched selects an MGCF corresponding to the destination exchange information received from the CSCF based on the database provided and then sends a call connection request signal to the selected MGCF And transmitting the data.

In order to achieve the above object, a control method of a BGCF (Breakout Gateway Control Function) included in a call processing system of an IP Multimedia Subsystem (IMS) network for transmitting an outgoing call to a legacy network according to the present invention includes: Establishing a database in which specific MGCF (Media Gateway Control Function) information is matched; Selecting an MGCF matching the destination exchange information by referring to data stored in the database unit when a call connection request signal including destination exchange information is received from a Call Session Control Function (CSCF); And transmitting a call connection request signal to the selected MGCF.

As described above, according to the present invention, when the calling terminal connected to the IMS network makes a call to the called terminal connected to the legacy network, occupancy of the circuit network resources can be minimized and the call connection success rate can be increased.

1 is a schematic configuration diagram of a conventional IMS network,
2 is a diagram showing the constituent elements of the conventional IMS network as compared with the present embodiment and the signal flow thereof,
FIG. 3 is a diagram illustrating a call processing system in an IMS network and a call processing process in conjunction with a legacy network according to an embodiment of the present invention,
4 is a functional block diagram of the BGCF of FIG. 3,
5 is a control flowchart of a call processing system in an IMS network according to an embodiment of the present invention.

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

An example of the overall configuration of a call processing system of an IMS (IP Multimedia Subsystem) network according to an embodiment of the present invention is shown in FIG.

However, in the present embodiment, characteristic components of the components of FIG. 1 will be described with reference to FIG.

The call processing system of the IMS network 100 includes a home subscriber server (HSS) 120, a call session control function (CSCF) 110, a breakout gateway control function (BGCF) 130, (Media Gateway Control Functions) 140_1 to 140_n.

Here, the HSS 120 is a kind of database server that stores all information necessary for session control and service control, and can operate in conjunction with an HLR storing physical location information (i.e., base station information) of the mobile communication terminal.

The information stored in the HSS 120 includes subscriber identification information (service subscription status, etc.), user authentication information, S-CSCF selection information, information for selecting individual applications (User Profile), IN (mobile intelligent network) CAMEL support information, and the like.

In the present invention, the HSS 120 matches the called party exchange information corresponding to the called party number, extracts the called party exchange information corresponding to the called party number according to the subscriber location information inquiry signal of the CSCF 110, And transmits the signal to the CSCF (110). For this, the HSS 120 needs to register in advance the destination exchange information of the area where the terminal corresponding to the called party number is located. For example, when the destination terminal 400 is interworked with the HLR (Home Location Register) The corresponding destination exchange information can be registered.

Here, the subscriber location information inquiry signal transmitted from the CSCF 110 to the HSS 120 may correspond to a Location-Info-Request (LIR) signal according to the IMS network 100 standard, and the HSS 120 may transmit the Location- ) May be a Location-Info-Answer (LIA) signal.

That is, the HSS 120 can additionally include the destination exchange information in the standard LIA signal and transmit it to the CSCF 110.

The CSCF 110 is a functional element responsible for call or session control functions for end-to-end multimedia communication in the IMS network 100. The CSCF 110 logically includes a Proxy CSCF, an S-CSCF, an I-CSCF Interrogating CSCF.

The P-CSCF performs authorization and QoS management of bearer resources using IPSec as the first point of access to the IMS delivery network by the subscriber terminal, and the S-CSCF performs subscriber authentication and session-based service control I-CSCF, S-CSCF, S-CSCF, and S-CSCF. The I-CSCF performs the function of transferring the SIP message received from the visited network to the home network S-CSCF. CSCF 110. Since general functions of the CSCFs are merely known technologies in the IMS network 100, a detailed description thereof will be omitted.

The CSCF 110 transmits a subscriber location information inquiry signal to the HSS 120 according to a call connection request of the originating terminal 300 and transmits the subscriber location information inquiry signal to the called party And transfers the exchange information to the BGCF (130).

For example, the CSCF 110 may include the destination exchange information in the call connection auction signal and forward it to the BGCF 130.

The BGCF 130 performs a function of selecting an MGCF 140_1 to 140_n to be transmitted when a session request message transmitted to the IMS is received on a circuit network.

In particular, in the present invention, the BGCF 130 includes a database in which each exchange information and specific MGCF information are matched. The BGCF 130 includes MGCFs 140_1 to 140 - n corresponding to the destination exchange information received from the CSCF 110, And transmits a call connection request signal to the selected MGCF 140_1 to 140_n.

The function block of the BGCF 130 is as shown in FIG.

The BGCF 130 may include a communication interface unit 131, a database unit 132, a selection unit 133, and a transmission unit 134 as shown in FIG.

Here, the communication interface unit 131 is connected to the MGCFs 140_1 to 140 - n for interworking with the legacy network 200 and the CSCF 110 for processing a call session, and performs an interface function for communication. Here, the legacy network 200 refers to a conventional network interworking with the IMS network 100, and may mean, for example, a Code Division Multiple Access (CDMA) network.

The database unit 132 stores and stores each exchange information and specific MGCF information. Here, the exchange unit 132 located in the same unit area and the CSCF 110 may be matched to each other.

For example, in the database unit 132, the exchange located in the Seoul area and the CSCF 110 located in the Seoul area are matched with each other, and the exchange located in the Busan area and the CSCF 110 located in the Busan area may be matched with each other will be.

When the call connection request signal including the destination exchange information is received from the CSCF 110, the selection unit 133 refers to the data stored in the database unit 132 and selects the MGCFs 140_1 to 140_n ).

For example, when the call connection request signal received from the CSCF 110 includes the destination exchange information located in Busan, the selector 133 selects the MGCF information located in Busan Can be selected.

The transmitting unit 134 transmits a call connection request signal to the MGCFs 140_1 to 140_n corresponding to the MGCF information selected by the selecting unit 133 through the communication interface unit 131. [

Hereinafter, a control flow between the components of the call processing system of the IMS network 100 according to an embodiment of the present invention will be described with reference to FIG.

First, when the CSCF 110 detects a call connection request signal (i.e., an INVITE signal) from a calling terminal (e.g., VoLTE terminal) (step S1), the CSCF 110 transmits a subscriber location information inquiry signal (LIR) to the HSS 120 (Step S3).

The HSS 120 extracts the destination exchange information corresponding to the telephone number of the destination MS 400 included in the LIR signal (step S5). For example, the HSS 120 can extract the information of the destination exchange where the destination terminal 400 is directly connected, that is, the destination exchange located closest to the destination terminal 400.

The HSS 120 then includes the destination exchange information in the LIA signal and transmits it to the CSCF 110 (step S7).

The CSCF 110 includes the destination exchange information received from the HSS 120 in the call connection request signal INVITE to the BGCF 130 (step S11).

Meanwhile, the BGCF 130 has a database in which the destination exchange and the MGCF 140_1 to 140_n are matched (step S9). When the call connection request signal INVITE is received from the CSCF 110, Extracts the destination exchange information from the call connection request signal, and extracts the MGCF information corresponding to the extracted destination exchange information from the prepared database (step S13).

Then, the BGCF 130 transmits a call connection request signal INVITE to the MGCFs 140_1 to 140_n corresponding to the extracted MGCF information (step S15).

That is, the process of the MGCF 140-1 to 140_n receiving the call connection request signal from the BGCF 130 transmits the call connection request signal to the destination exchange of the legacy network is the same as the conventional process.

3, the MGCF 140_1 to 140_n receiving the call connection request signal transmits a call connection request signal to the gateway exchange in the corresponding area, and the gateway exchange in the corresponding area transmits the call connection request signal to the destination terminal 400 And transmits a call connection request signal to the terminating terminal 400 via the destination exchange.

Comparing FIG. 2 and FIG. 3, the characteristics of the present invention can be clearly seen.

That is, when the VoLTE originating terminal 300 directly connected to the IMS network 100 makes a call to the CDMA call receiving terminal 400 connected to the legacy network 200, the BGCF 130 has conventionally been connected to the arbitrary MGCF 140_1 ' The gateway exchange associated with the corresponding MGCF 140_1 'has to be connected to the gateway exchange 220_n' of the other region by occupying the remote network 220_1 'by transmitting the call connection request signal, but the BGCF 130 selects the MGCF 140_n in the same area as the destination exchange and transmits a call connection request signal to the MGCF 140_n, the MGCF 140_n transmits the call connection request to the gateway exchanger 220_n The call connection request signal can be transmitted to the destination switching center 230_n, thereby avoiding occupation of network resources for connection to other areas.

In other words, IP-based communication does not consistently occupy a specific resource by performing packet communication, but in the case of a line-to-point communication, the line passing through the call connection process, that is, the resource is always occupied until the call is terminated It is inefficient compared to packet communication.

Therefore, the present invention minimizes the route of the circuit network communication using the packet communication period, thereby reducing the occupancy rate of the circuit network resources, thereby achieving the cost saving effect and the lowering of the call failure rate. In other words, when occupancy of the line between the remote locations is low, the failure rate of the incoming call due to the lack of the connection line may be lowered.

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: IMS network 200: legacy network
110: CSCF 120: HSS
130: BGCF 140_1 to 140_n: MGCF
300: originating terminal 400: incoming terminal
131: Communication interface unit 132: Database unit
133: selection unit 134:

Claims (9)

(IP Multimedia Subsystem) network including an HSS (Home Subscriber Server), a CSCF (Call Session Control Function), a Breakout Gateway Control Function (BGCF), and a Media Gateway Control Function (MGCF) In a call processing system,
The HSS stores destination exchange information of a legacy network corresponding to each destination number. The HSS extracts the destination exchange information of the legacy network corresponding to the destination number according to the subscriber location information inquiry signal of the CSCF, Signal and transmits it to the CSCF,
The CSCF transmits a subscriber location information inquiry signal to the HSS in response to a call connection request of the originating terminal and delivers the called party exchange information of the legacy network included in the subscriber location information response signal received from the HSS to the BGCF,
The BGCF includes a database in which each exchange information and specific MGCF information are matched. The BGCF selects an MGCF corresponding to destination exchange information of the legacy network received from the CSCF using the provided database, And transmits a connection request signal to the IMS network. The method according to claim 1,
Wherein the subscriber location information inquiry signal is a Location-Info-Request (LIR) signal and the subscriber location information response signal is a Location-Info-Answer (LIA) signal. The method according to claim 1,
Wherein the database provided in the BGCF includes an exchange located in the same unit area and a CSCF matched with each other. delete (IP Multimedia Subsystem) network including an HSS (Home Subscriber Server), a CSCF (Call Session Control Function), a Breakout Gateway Control Function (BGCF), and a Media Gateway Control Function (MGCF) A control method performed by a call processing system,
The CSCF transmitting a subscriber location information inquiry signal to the HSS according to a call connection request of an originating terminal;
Side switching center information of the legacy network corresponding to the called number according to the subscriber location information inquiry signal of the CSCF and stores the subscriber location information in the legacy network corresponding to the called number, Signal to the CSCF;
Transmitting, by the CSCF, the called party exchange information of the legacy network included in the subscriber location information response signal received from the HSS to the BGCF;
The BGCF having a database in which each exchange information and specific MGCF information are matched selects an MGCF corresponding to the called party exchange information of the legacy network received from the CSCF based on the database provided, And transmitting the request signal to the IMS network. 6. The method of claim 5,
Wherein the subscriber location information inquiry signal is a Location-Info-Request (LIR) signal and the subscriber location information response signal is a Location-Info-Answer (LIA) signal. 6. The method of claim 5,
Wherein the database provided in the BGCF includes an exchange located in the same unit area and a CSCF matched with each other. delete A computer-readable recording medium recording a program for executing the method according to any one of claims 5 to 7.

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