KR101574317B1 - Method for providing efficient incoming call and system therefor - Google Patents

Abstract

A method of receiving an outgoing call originated from a circuit-switched network according to an aspect of the present invention to a called terminal registered in an IMS (IP Multimedia Subsystem) network, comprising the steps of: Receiving the S-CSCF (Serving-Call Session Control Function) information registered in the location and storing the S-CSCF in the subscriber profile of the called terminal; The home location register of the circuit-switched network receiving a routing information request for an incoming call of the outgoing call from an exchange of the circuit-switched network; And a home location register of the circuit-switched network sending the stored S-CSCF information to an exchange of the circuit-switched network in response to the routing information request.

Description

[0001] METHOD FOR PROVIDING EFFICIENT INCOMING CALL AND SYSTEM THEREFOR [0002]

The present invention relates to a separate routing process for efficiently providing an incoming call, and more particularly, to a method for performing separate routing process for each S-CSCF (Location-Controlled Call Control Function) .

In response to the rapid development of mobile communication and Internet technologies and the various demands of subscribers, recent mobile communication services include a high-speed packet data service capable of transmitting large-capacity digital data as well as e-mail and still images to mobile terminals, , And thus the mobile communication system is evolving from a voice-based Circuit Switched (CS) domain to a packet-based PS (Packet Switched) domain.

The core network of the mobile communication system has changed from a circuit-switched (CS) network, which is an existing circuit-based network, to a packet-switched network, which is a packet-based network, and further evolved into a core network based on an IP . A system for providing an IP multimedia service to a subscriber through the IP-based core network is called an IMS (IP Multimedia Subsystem) network.

In such a mobile communication system, a voice call is provided through the CS network or by using the IMS network, or by interworking between the CS network and the IMS network. A typical example of the interworking between the CS network and the IMS network is a case where a call is originated from a terminal connected to the CS network and a call is received to a called terminal connected to the IMS network.

There are the following problems in providing a voice call service through interworking between the CS network and the IMS network. That is, when an incoming call is transferred from the CS network to the IMS network, the MGCF (Media Gateway Control Function) connecting the CS network and the IMS network can not directly know the S-CSCF, CSCF forwards the address allocation request message of the S-CSCF to the HSS (Home Subscriber Server) in the IMS network, and the I-CSCF forwards the call to the S-CSCF corresponding to the received address Incoming call connection is made through routing process.

As described above, when routing an incoming call from the CS network to the IMS network, the prior art can not have the address information of the S-CSCF registered by the called terminal in the CS network, and it is impossible to know the S-CSCF directly in the MGCF, There is not a separate routing function by itself. Accordingly, a problem occurs in that a network load occurs due to an excessive node, and an incoming call is not connected when an HSS failure occurs in the IMS network.

Korean Patent No. 10-0943586 (issued Feb. 23, 2010)

SUMMARY OF THE INVENTION The present invention has been proposed in order to solve the above-mentioned problems, and it is an object of the present invention to provide a home location register of the CS network for efficiently processing incoming calls from the CS network to the IMS network, And to provide a system and a method for performing separate routing processing by transmitting and storing S-CSCF information.

Other objects and advantages of the present invention will become apparent from the following description, and it will be understood by those skilled in the art that the present invention is not limited thereto. It will also be readily apparent that the objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.

According to an aspect of the present invention, there is provided a method of receiving an outgoing call originated from a circuit-switched network to a called terminal registered in an IP Multimedia Subsystem (IMS) network, Receiving an S-CSCF (Serving-Call Session Control Function) information registered by the destination terminal from the IMS network, allocating an Internet Protocol Multimedia Routing Number (IMRN) for each S-CSCF and storing the IMRN in a subscriber profile of the called terminal ; The home location register of the circuit-switched network receiving a routing information request for an incoming call of the outgoing call from an exchange of the circuit-switched network; And a home location register of the circuit-switched network sending the stored S-CSCF information to an exchange of the circuit-switched network in response to the routing information request.

A method for receiving an outgoing call originated from the circuit-switched network to a destination terminal registered in an IP Multimedia Subsystem (IMS) network, the method comprising: receiving a call connection request including the S-CSCF information from the circuit- To a Media Gateway Control Function (MGCF) for interworking between the IMS networks; And transmitting, by the MGCF, a signaling message for call connection directly to the S-CSCF based on the S-CSCF information without passing through an interrogating-call session control function (I-CSCF).

In the storing in the subscriber profile, the home location register may receive the S-CSCF information registered by the called terminal from the S-CSCF or TAS of the IMS network.

According to another aspect of the present invention, there is provided a system for processing an outgoing call originated from a circuit switching network to an IMS (IP Multimedia Subsystem) network, the system comprising: Transmission means for transmitting information of the S-CSCF in which the terminal is registered to the home location register of the circuit-switched network; And storing information of the S-CSCF transmitted from the transmission means in a subscriber profile of the called terminal, and upon receipt of a routing information request for an incoming call of the outgoing call from the exchange of the circuit-switched network, And a home location register of the circuit-switched network.

Wherein the system further comprises a Media Gateway Control Subsystem (MGCF) for interworking between the circuit-switched network and the IMS network, wherein the MGCF comprises: Upon receiving a call connection request including the S-CSCF information from the exchange of the circuit-switching network, a signaling message for call connection can be directly transmitted to the S-CSCF based on the S-CSCF information without passing through the I-CSCF.

The home location register may receive the S-CSCF information registered by the called terminal from the S-CSCF or TAS of the IMS network.

According to an aspect of the present invention, a home location register receives an address of an S-CSCF in which a called terminal registers a location, sets and stores an IMRN of a call differently, and accesses the S-CSCF directly through an MGCF Therefore, it is possible to prevent unnecessary traffic from occurring in the IMS network.

In addition, it is possible to process the incoming call even when the home subscriber server in the IMS network fails, and it is possible to minimize the time required to connect the incoming call by minimizing the passage of unnecessary nodes.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate presently preferred embodiments of the invention and, together with the specific details for carrying out the invention, And shall not be construed as limited to the matters described.
FIG. 1 illustrates a separate routing processing system for providing an efficient incoming call according to an embodiment of the present invention; FIG.
2 is a diagram illustrating a location registration procedure of a terminal to an IMS network according to an embodiment of the present invention;
3 is a diagram illustrating an inbound call processing procedure according to a separate routing processing method for providing an inbound call efficiently according to an embodiment of the present invention;
4 is a table showing an address and an IMRN of an S-CSCF where a terminal stored in a home location register according to an embodiment of the present invention is registered.

The foregoing and other objects, features and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings, in which: There will be. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Throughout the specification, when an element is referred to as "comprising ", it means that it can include other elements as well, without excluding other elements unless specifically stated otherwise. Also, the term "part" or the like, as described in the specification, means a unit for processing at least one function or operation, and may be implemented by hardware, software, or a combination of hardware and software.

FIG. 1 illustrates a separate routing processing system for providing an efficient incoming call according to an embodiment of the present invention. Referring to FIG.

Referring to FIG. 1, a separate routing processing system for providing an efficient incoming call according to the present invention includes UEs (User Equipment) 110, 210, a mobile switching center (MSC) 120, an HLR (Home Location Register) 130, a Media Gateway Control Function (MGCF) 140, an LTE access network, a Call Session Control Function (CSCF) 220, a Home Subscriber Server ) 230, and a TAS (Telephony Application Server) 240.

The terminal 110 (210) may be a mobile communication terminal capable of processing SIP signaling, and may be any communication device capable of performing IP-based communication such as a mobile phone as well as a personal portable terminal. Lt; / RTI > For example, the terminal may be a cellular phone, a personal communication service (PCS) phone, a PDA phone, a GSM phone, a WCDMA phone, a CDMA-2000 phone, a DMB phone, or an LTE phone.

The MSC 120 performs a central control function for processing a signal transmitted / received from a base station (not shown) and adjusting the base station to operate efficiently. The MSC 120 manages the location of the terminal 110 and inquires the location registration information of the user to the HLR 130. When a response to the inquiry is received, Transmits the request message, and performs an incoming call connection to the terminal 210 at the corresponding location.

The home location register (HLR) 130 manages service subscriber information in a Circuit Switched (CS) domain domain. According to the present invention, the home location register (HLR) 130 receives the address of the S-CSCF 225 where the called terminal 210 is registered from the S-CSCF 225 or the TAS 240 of the IMS network And stores the received call address in the subscriber profile of the called terminal, and sets the Internet Protocol Multimedia Routing Number (IMRN) for each S-CSCF according to the stored address, thereby separating the incoming call.

The information of the S-CSCF stored in the home location register (HLR) 130 is transmitted from the S-CSCF 225 or the TAS 240 of the IMS network to the called terminal 210 The address information of the registered S-CSCF and the routing number, i.e., IMRN information, which are differently allocated according to the call of the S-CSCF.

In this case, the plurality of S-CSCFs 225 in the IMS network have predetermined identification numbers for identifying the S-CSCF 225 in order to perform efficient routing, Routing is possible.

The MGCF 140 performs a function of forwarding a converted request message to the S-CSCF 225 and converting the signaling for a call coming from the public switched telephone network (PSTN) to an IMS (IP Multimedia Subsystem) . In this embodiment, the MGCF 140 receives the IMNN and the telephone number of the called terminal 210 related to the call connection from the exchange (MSC) 120 and directly connects to the S-CSCF 225 matching the IMRN Message. ≪ / RTI >

The LTE (Long Term Evolution) access network is a wireless Internet network, which is considered as a next generation mobile communication technology. The LTE (Long Term Evolution) access network is an eNodeB 251 that plays a role of connecting to a terminal wirelessly. An MME (Mobile Mobility Entity) 253 acting as a role for security mobility management, and a P-GW (PDN-GateWay) 255 serving as a gateway for sending and receiving packets to / from an external communication network in the mobile communication network. When the message for call connection is routed to the S-CSCF 225, the LTE access network can make a call by connecting a call to a terminal corresponding to the telephone number included in the routed message.

The CSCF 220 is used for Session Initiation Protocol (SIP) -based multimedia session control such as subscriber registration, authentication, service triggering, routing, various call control, and address handling Basic functions can be performed. In addition, the subscribed terminal can be registered in the home subscriber server (HSS) 230 to provide SIP signaling and state management functions.

The CSCF 220 may include a Proxy-CSCF 221, an Interrogating-CSCF 223, and an S-CSCF 225.

The P-CSCF 221 serves as a first point for the terminal 210 to access the IMS. The P-CSCF 221 plays the same role as the SIP proxy server. The P-CSCF 221 performs compression / release of SIP messages, authentication of bearer resources, And a function of delivering a SIP registration request from the terminal to the I-CSCF 223.

When the registration request message is transmitted from the terminal 210, the P-CSCF 221 can forward the registration request message to the I-CSCF 223. The P-CSCF 221 stores the address of the S-CSCF allocated in the registration request message process, and upon receiving a session start request message from the terminal, forwards the P-CSCF 221 to the S-CSCF 225 via the I-CSCF 223 .

The I-CSCF 223 is responsible for receiving SIP requests from other networks and routing them to the S-CSCF 225.

The I-CSCF 223 obtains the address list of the available S-CSCF from the home subscriber server in the process of registering the user of the terminal, that is, the subscriber, and determines the S-CSCF (225) .

When the registration request message is received from the I-CSCF 223, the S-CSCF 225 registers the subscriber in the home subscriber server (HSS) 230 and obtains the subscriber profile from the home subscriber server (HSS) . The S-CSCF 225 performs the control service while managing the session state of the actually registered user. In addition, the S-CSCF 225 provides information related to the service resources to the user.

The CSCF 220 according to the present invention can simultaneously perform the functions of the P-CSCF 221, the I-CSCF 223, and the S-CSCF 225.

The S-CSCF 225 according to the present invention can receive a call connection message from the MGCF 140 and send the message to the called terminal 210 to establish an incoming call connection. That is, when the called terminal performs location registration with the specific S-CSCF 225 through the IMS network, the S-CSCF 225 transmits the address information to the HLR 130 of the CS network. At this time, the TAS 240 receives the address information from the S-CSCF 225 where the UE 210 is registered, and transmits the address information of the S-CSCF to the HLR 130 of the CS network . The home location register (HLR) 130 allocates a routing number, i.e., an IMRN, according to a call of the address of the received S-CSCF, and stores the routing number in the subscriber profile. Upon receiving a call connection request from the originating terminal, the home location register receives a routing information request message from the exchange and searches for the S-CSCF based on the registered location information of the terminating terminal 210 in response thereto. Accordingly, the MSC 120 transfers information of the S-CSCF where the called terminal 210 is registered to the MGCF 140, and the MGCF 140 directly connects to the S-CSCF 225 This is possible. At this time, the information of the S-CSCF may include a telephone number of the called terminal and a routing number of the S-CSCF to which the called terminal is registered.

The home subscriber server (HSS) 230 is a centralized database for managing subscriber information developed in the home location register of mobile communication. It is a centralized database for managing subscriber information such as user registration / change management, authentication, authorization, location, session routing, Can be performed.

The home subscriber server (HSS) 230 performs the location registration of the terminal according to the location registration procedure when the terminal attempts to register the location in the IMS network to receive the VoLTE voice service.

The location registration procedure of the terminal will be described later in detail with reference to FIG.

The TAS 240 is a system for providing a multimedia supplementary service between users in an IMS network. The TAS 240 provides services such as a caller display service, a call / termination prohibition, a call forwarding, a lettering, and a coloring, .

The TAS 240 may receive the address of the specific registered S-CSCF from the S-CSCF and forward it to the HLR 130.

When the TAS 240 receives a call connection from the MGCF 140 to the S-CSCF 225, the TAS 240 receives a service request message from the S-CSCF 225 and transmits information related to the called service to the S- To the terminal 225 to process the incoming call to the terminal.

As described above, in the separate routing processing system according to the present invention, when the UE completes the location registration with the S-CSCF 225 of the IMS network in order to receive the VoLTE service, the HLR 130 transmits the S -The address of the CSCF is received and the IMRN is stored differently. Accordingly, it is possible to provide an efficient connection by performing separate routing processing using the IMRN mapped to the address of the stored S-CSCF when processing the incoming call.

2 is a diagram illustrating a location registration procedure of a terminal to an IMS network according to an embodiment of the present invention.

As shown in FIG. 2, the terminal 210 sends a registration request message to the P-CSCF 221 to perform location registration (S201). The P-CSCF 221, which has received the registration request message, transmits the registration request message to the I-CSCF 223. The I-CSCF 223 transmits the registration request message to the home subscriber server (HSS) 230 in the IMS network Requesting the allocation of the S-CSCF 225 for location registration of the terminal 210 and receiving a response thereto (S203) (S205) (S207).

The I-CSCF 223 assigned the S-CSCF 225 to perform the location registration of the UE 210 transmits the registration message to the S-CSCF 225 allocated thereto, and the S- The home subscriber server (HSS) 230 requests authentication information of the terminal to register the location (S209) (S211). The home subscriber server (HSS) 230 delivers the requested authentication information to the S-CSCF 225, and the S-CSCF 225 transmits a response to the I-CSCF indicating that the authentication for the terminal is insufficient yet The I-CSCF transfers the response to the P-CSCF in turn, and the P-CSCF requests the terminal to request the registration request message again (S213) (S215) (S217) (S219).

The terminal 210 generates authentication data and transmits the authentication data to the P-CSCF 221. The P-CSCF 221 transmits the authentication data to the I-CSCF 223 (S221) (S223). The I-CSCF 223 forwards the authentication data of the terminal to the home subscriber server (HSS) 230, the S-CSCF 225 for location registration is allocated, and the corresponding S-CSCF 255 (S225) (S227) (S229). The S-CSCF 225 requests the subscriber information of the terminal to be registered in the home subscriber server (HSS) 230, downloads the subscriber information, and completes the location registration (S2231) (S233). Then, the S-CSCF 225 informs the location registration completion message by sequentially transmitting the location registration completion message of the terminal through the I-CSCF 223 and the P-CSCF 221 to the terminal (S235) (S237) ) (S239).

The S-CSCF 225 which has completed the location registration of the UE 210 transmits the address information to the HLR 130. The HLR 130 transmits the address information to the S- Can be stored in the form of a table. At this time, the home location register (HLR) 130 may allocate and store the IMRN of the call differently according to the address of the S-CSCF.

Although the location of the registered S-CSCF is directly transferred from the S-CSCF 225 to the home location register (HLR) 130 in the present embodiment, the address of the S- And the TAS 240 may forward the address of the S-CSCF to the HLR 130. [

FIG. 3 is a diagram illustrating an incoming call processing procedure according to a separate routing processing method for providing an efficient incoming call according to an embodiment of the present invention. FIG. 3 illustrates a procedure for processing an outgoing call originated in the CS network to an IMS network.

As shown in FIG. 3, the calling terminal 110 transmits a call in the CS network and requests a call connection to the MSC 120 (S301).

(MSC) 120 transmits information related to the called terminal 210 to a home location register (HLR) 130 according to a call connection request of the calling terminal 110, such as a routing number, And requests the number and other information necessary for processing and routing (S303).

The home location register (HLR) 130 determines whether the destination terminal received from the IMRN, that is, the S-CSCF or TAS, is registered with the telephone number of the destination terminal 210 to which the calling terminal 110 desires to make a call connection S-CSCF address to the exchange (MSC) 120 (S305).

At this time, the address of the S-CSCF to which the called terminal is registered from the S-CSCF 225 or the TAS 240 is transferred and stored in the HLR 130, and the IMRN of the call for each S- Can be set differently. 4, the home location register (HLR) 130 receives and stores the address information of the S-CSCF of the called terminal 210 registered in the IMS network, and the IMRN That is, routing numbers can be assigned differently and stored in a table form.

Then, the MSC 120 transmits the received information, for example, the telephone number of the called terminal and corresponding IMRN information to the MGCF 140, and the MGCF 140 transmits an identification number matching the IMRN The S-CSCF 225 transmits the session connection message to the S-CSCF 225 (S307) (S309). In this case, the plurality of S-CSCFs 225 are provided with identification numbers for identifying S-CSCFs in order to perform efficient routing, so that separate routing for providing efficient incoming calls according to the present invention is possible.

In detail, information transmitted from the MGCF 140 to the MGCF 140 at the MSC 120 and transmitted from the MGCF 140 to the S-CSCF 225 is transmitted to the location registration destination terminal 210, When the call connection is requested from the calling terminal 110 to the called terminal 210 as the IMRN information of the call mapped to the S-CSCF address of the terminal 210, that is, the routing number information, CSCF < / RTI > 225 with a matching identification number.

The TAS 240 receives the service request message from the S-CSCF 225 and forwards the information related to the called subscriber service to the S-CSCF 225 A call is made to the called terminal 210 and a call is established between the calling terminal 110 and the called terminal 210 in step S313.

As described above, the home location register (HLR) 130 receives the address of the S-CSCF where the called terminal 210 registers the location from the S-CSCF 225 or the TAS 240 and sets the IMRN of the call differently It is possible to directly connect to the S-CSCF when processing an incoming call of the terminal, thereby preventing unnecessary traffic from occurring in the IMS network.

In addition, it is possible to process the incoming call even when the home subscriber server (HSS) 230 in the IMS network fails, and it is possible to minimize the time required to connect the incoming call by minimizing the passage of unnecessary nodes.

While the specification contains many features, such features should not be construed as limiting the scope of the invention or the scope of the claims. In addition, the features described in the individual embodiments herein may be combined and implemented in a single embodiment. On the contrary, the various features described in the singular embodiments may be individually implemented in various embodiments or properly combined.

Although the operations are described in a particular order in the figures, it should be understood that such operations are performed in a particular order as shown, or that all described operations are performed in a series of sequential orders, or to obtain the desired result. In certain circumstances, multitasking and parallel processing may be advantageous. It should also be understood that the division of various system components in the above embodiments does not require such distinction in all embodiments. The above-described program components and systems can generally be implemented as a single software product or as a package in multiple software products.

The method of the present invention as described above can be implemented by a program and stored in a computer-readable recording medium (CD-ROM, RAM, ROM, floppy disk, hard disk, magneto optical disk, etc.). Such a process can be easily carried out by those skilled in the art and will not be described in detail.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. The present invention is not limited to the drawings.

110: UE # 1 (called terminal)
120: MSC (exchange)
130: HLR (home location register)
140: MGCF
210: UE # 2 (calling terminal)
220: CSCF
225: S-CSCF
230: HSS (Home Subscriber Server)
240: TAS

Claims (8)

A method for receiving an outgoing call originated from a circuit-switched network to a destination terminal registered in an IMS (IP Multimedia Subsystem) network,
The Home Location Register of the circuit-switched network receives Serving-Call Session Control Function (S-CSCF) information registered by the called terminal from the IMS network and allocates an Internet Protocol Multimedia Routing Number (IMRN) for each S- Storing in a subscriber profile of a called terminal;
The home location register of the circuit-switched network receiving a routing information request for an incoming call of the outgoing call from an exchange of the circuit-switched network;
Transmitting, by the home location register of the circuit-switched network, the stored S-CSCF information to the switch of the circuit-switched network in response to the routing information request;
Transmitting a call connection request including the S-CSCF information to an MGCF (Media Gateway Control Function) for interworking between the circuit-switched network and the IMS network; And
Wherein the MGCF directly sends a signaling message for call connection to the S-CSCF based on the S-CSCF information without passing through an Interrogating-Call Session Control Function (I-CSCF). delete The method according to claim 1,
Wherein the home location register receives the S-CSCF information registered by the called terminal from the S-CSCF or TAS (Telephony Application Server) of the IMS network in the storing in the subscriber profile. The method according to claim 1,
Wherein the S-CSCF information transmitted to the exchange of the circuit-switched network includes the routing number (IMRN) of the called terminal and the telephone number information of the called terminal. A system for processing an outgoing call originated from a circuit-switched network to an IMS (IP Multimedia Subsystem) network,
Transmission means for transmitting information of the S-CSCF in which the called terminal registered in the IMS network is registered as the equipment of the IMS network to the home location register of the circuit-switched network;
Storing information of the S-CSCF transmitted from the transmission means in the subscriber profile of the called terminal and responding the information of the S-CSCF when receiving a routing information request for an incoming process of the outgoing call from an exchange of the circuit-switched network A home location register of the circuit-switched network; And
And a Media Gateway Control Subsystem (MGCF) for interworking between the circuit-switched network and the IMS network,
Upon receipt of a call connection request including the S-CSCF information from the exchange of the circuit-switching network, the MGCF directly transmits a signaling message for call connection to the S-CSCF based on the S-CSCF information without passing through the I-CSCF To-be-received. delete 6. The method of claim 5,
Wherein the transmission means is an S-CSCF or a TAS. 6. The method of claim 5,
Wherein the S-CSCF information transmitted to the exchange of the circuit-switched network includes the routing number (IMRN) of the called terminal and the telephone number information of the called terminal.

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