KR20150026212A - Abnormal call control method and apparatus - Google Patents

Abstract

A method for processing an abnormal call of the present invention comprises the steps of: when a call connection request is received from an originating terminal, determining whether the call is an abnormally cut old call; and deleting the old call if it is determined the call is the old call and executing a connection request for call connection with a terminating terminal.

Description

[0001] ABNORMAL CALL CONTROL METHOD AND APPARATUS [0002]

The present invention relates to a technique for processing an abnormal call of a communication terminal for mobile communication, and more particularly, to a technique for handling an abnormal call of a communication terminal for mobile communication by processing a corresponding call as a garbage call when an abnormal call is disconnected due to entry into a weak electric field area To an abnormal call processing method and apparatus which are suitable for executing call processing without fail.

As is well known, the ALL-IP network can provide interworking services with an Internet network using IP (Internet Protocol), and can provide solutions suitable for integrated multimedia services including voice, data, and real- ), The cost reduction effect can be obtained through the packet transmission.

As a core technology for providing a new service in the All-IP based communication environment, an IP Multimedia Subsystem (hereinafter referred to as " IP Multimedia Subsystem ") defined as a core technology for providing various services to subscribers based on the ALL- Quot; IMS "). Such an IMS can provide IP services over a packet network regardless of the access network format, and can provide services that require transmission of multimedia data such as one-to-one video calls as well as general call services.

In 3GPP Release 8, EPC (Evolved Packet Core), which is a network architecture, is described as one of mobile communication systems. EPC is a set of network nodes for 3GPP LTE (Long Term Evolution) to be.

This EPC evolves the core network of the existing 3GPP system architecture to support Evolved-UMTS Terrestrial Radio Access Network (E-UTRAN), which is an evolved RAN, It has an efficient network structure in which the network node is simplified. A wireless communication system including an EPC and an E-UTRAN may be referred to as an evolved packet system (EPS), and an LTE mobile communication system currently in service in Korea can be regarded as such.

Accordingly, in the communication environment in which the LTE mobile communication system is constructed, subscribers can receive various types of mobile communication related services through the communication terminal. Such mobile communication related services are provided in such a manner that each communication terminal is connected to a weak electric field area (Area), but not in a communication service area (area).

Meanwhile, if a call termination button is pressed while talking to two communication terminals, the communication terminal generates a call end (BYE) message and transmits the message to the mobile communication network through a base station (eNodeB, for example) (Terminates) the call connection between the called terminal and the called terminal.

However, when the mobile subscriber enters the weak electric field area during the call, the communication terminal can not transmit the call end message to the base station, and the call is disconnected.

In this case, in the mobile communication network, since the communication terminal has abnormally cut off the call but has not received the call termination message for the communication terminal, it is impossible to transmit the call termination message to the related node (e.g., the base station or the mobility management node) The call connection is regarded as being in the call state until it is discriminated by call truncation.

When the communication terminal maintains the busy state due to the abnormal call disconnection and the communication terminal increases the connection request (INVITE) through the base station or the like, the call connection request signal The user of the corresponding communication terminal recognizes abnormal call truncation in the mobile communication network and recognizes the normal call service (connection request service) until the call is released (deleted) There is a problem in that it is not provided.

Korean Registered Patent No. 10-1007200, publication date January 12, 2011. Korean Patent Publication No. 2007-0060655, published on June 13, 2007.

When a connection request is received from a calling terminal in a situation where a call is interrupted after an abnormal call is truncated, a deletion process of an existing call is forced regardless of reception of a call termination message, We propose a new call processing scheme.

The problems to be solved by the present invention are not limited to those mentioned above, and another problem to be solved by the present invention can be clearly understood by those skilled in the art from the following description will be.

According to one aspect of the present invention, there is provided a method for determining whether a call is an existing call in which a call is disconnected when a call connection request is received from a calling terminal, And executing a connection request for a call connection with the mobile terminal.

According to another aspect of the present invention, there is provided a method for controlling a call connection method, comprising the steps of: determining, when a call connection request is received from a calling terminal, whether the call is an existing call maintained in a call state through searching for previously stored terminal information; And executing a connection request process for a call connection between the calling terminal and the called terminal after the completion of the deletion processing.

According to another aspect of the present invention, there is provided a communication system including a message receiver for receiving a call connection request from a calling party, a call status detector for determining whether the call received through the search for stored terminal information is an existing call A terminal information management unit for deleting the existing call when it is determined that the call is an existing call; and a control unit for generating a connection request for a call connection between the calling terminal and the called terminal when the deletion of the existing call is completed, And a call processing unit for transmitting the call processing unit to the call processing unit.

In the present invention, when a connection request for a call is received from a calling terminal, it is determined whether or not the call is an existing call that is abnormally truncated, and a garbage call is determined in the existing call, By executing the connection request for the call connection, it is possible to effectively prevent the occurrence of the call drop phenomenon for the new call due to the abnormal call termination.

FIG. 1 is a network configuration diagram of a mobile communication system to which an abnormal call processing technique according to the present invention is applicable,
FIG. 2 is a block diagram of a node device suitable for applying the abnormal call processing technique according to the present invention;
3 is a block diagram of an abnormal call processing apparatus according to the present invention;
FIG. 4 is a flowchart for explaining a process of deleting an existing call disconnected from an abnormal call and requesting a connection of a new call when a connection request is received in a situation where a call is abnormally cut according to the present invention;
FIG. 5 is a flowchart showing a main procedure of executing connection request processing of a new call after deleting an existing call that has been truncated according to the present invention; FIG.

First, the advantages and features of the present invention, and how to accomplish them, will be clarified with reference to the embodiments to be described in detail with reference to the accompanying drawings. While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

In the following description of the present invention, detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. It is to be understood that the following terms are defined in consideration of the functions of the present invention, and may be changed according to intentions or customs of a user, an operator, and the like. Therefore, the definition should be based on the technical idea described throughout this specification.

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

FIG. 1 is a network configuration diagram of a mobile communication system to which an abnormal call processing technique according to the present invention can be applied. Referring to FIG. 1, communication terminals (UEs) 110/1 and 110/2 and base stations (eNodeBs) 120/1, 120, a mobile communication network 130, an IP multimedia subsystem 140, and an IP multimedia subsystem (IMS) 150.

1, when the communication terminal UE-A 110/1 is a calling terminal, the communication terminal UE-B 110/2 may be defined as a called terminal or vice versa, Each of the communication terminals 110/1 and 110/2 provides a packet-based voice call service, a packet-based video call service, a packet-based data communication service, etc. from each of the corresponding base stations 120/1 and 120/2 For example, an LTE subscriber terminal, a VoLTE subscriber terminal supporting HD voice, and the like. Between each of the communication terminals UE-A and UE-B and each of the base stations 120/1 and 120/2, a cell or a radio unit including a mobile communication antenna, a mobile communication repeater, RU: radio unit) can be installed.

Next, when the base station 120/1 is the base station of the calling party (for the calling terminal), the base station 120/2 can be defined as the base station of the called party (for the called terminal) or vice versa, The base stations 120/1 and 120/2 may be defined as a base station, base station equipment, or base station device for supporting next generation technologies and services such as LTE (or VoLTE). Radio bearer control A radio resource management function such as radio admission control, connection mobility control, dynamic resource allocation to a communication terminal (or a user terminal) .

In addition, each of the base stations 120/1 and 120/2 can perform IP header compression and encryption of user data streams, routing of user plane data to the signal processing node 134, scheduling of paging messages Scheduling and transmission of broadcast and broadcast information, and measurement and measurement reporting for mobility and scheduling.

Further, each of the base stations 120/1 and 120/2 detects (abnormal processing of an abnormal call) when the communication terminal in the busy state enters the weak electric field area (communication shaded area with weak radio wave) and the call is abnormally cut, (For example, an end message including an abnormal call disconnection state code) indicating termination of a call due to a call disconnection and transmitting the generated end message to the mobility management node 132 in the mobile communication network 130 can do.

Here, the abnormal call exception process may be performed, for example, by monitoring a packet exchanged between the calling terminal and the called terminal. For example, when the called terminal is an LTE terminal, it may take about 10 seconds or so, When the terminal is a legacy terminal (a 3G terminal, a 2G terminal, or the like), it may take several tens of seconds.

Although only two base stations are illustrated in FIG. 1 for the sake of convenience and ease of explanation, it is also possible to provide communication services (for example, voice call service, video call service, group video A plurality of multimedia services including a call service, a supplementary information service, and the like can be managed (controlled) by the mobility management node 132 in the mobile communication network 130, and dozens of base stations can be managed in one TA (Tracking Area) Or a group).

The mobile communication network 130 may be, for example, an LTE mobile communication system (or LTE network), and includes a mobility management node (MME) 132, a signal processing node A Serving Gateway 134, a packet processing node (e.g., a PGW: PDN Gateway) 136, and a policy management node (e.g., PCRF: Policy and Charging Rule Function (PCRF) 138). Here, the SGW 134 and the PGW 136 may be defined as separate user plane nodes or integrated user plane nodes, and each node (e.g., MME, SGW, PGW, PCRF) constituting the mobile communication network 130 Etc.) may be partially or selectively incorporated or replaced with other components depending on the network environment of the mobile communication network system and the like.

The mobility management node 132 may be a node that manages the mobility of the communication terminal through the signal control between the base station and the signal processing node 134. The mobility management node 132 may be a session management server, Paging, subscriber authentication, and so on. In other words, each base station can receive a control plane, such as processing a control signal when there is a request for association from a communication terminal or another network node, such as signal processing node 134 or packet processing node 136, and control plane, and receives subscriber profile information, authentication and location related data from an HLR (Home Location Register) (not shown), and sets up an EPS bearer or an IP tunnel and performs mobility management (mobility management) and the like. Here, the HLR can store and manage subscriber profile information, authentication, location-related data of the terminal, and the like.

Here, as in the above-described base station, the mobility management node 132 performs processing when the communication terminal in the call enters the weak electric field area (communication shadow area where the radio wave is weak) and the call is abnormally cut ). When an exception process is executed, an abnormal termination message (for example, a termination message including an abnormal call termination code) indicating termination of a call due to an abnormal call termination is generated, (134), and so on. Here, the abnormal call exception process can be performed in the same or similar manner as the above-described base station depending on the type (network type) of the called terminal.

The signal processing node 134 processes the payload traffic according to a predetermined session based on a communication policy in the network provided from the policy management node 138 via a packet processing node 136 A user plane node which performs session control and the like and interworks with a base station through an S1-U interface, supports handoff in an LTE mobile communication system and a 3GPP network, And an ESP bearer (Evolved Packet System bearer) 136 and a PDU (Packet Data Unit) using tunneling.

Next, the packet processing node 136 allocates the IP of the terminal apparatus according to the communication and charging policy provided from the policy management node 138, and allocates the IP of the terminal apparatus to the user plane Node, it maintains routing information with the signal processing node 134 and the external network for packet service, provides tunneling and IP routing functions through organic linkage with the intelligent network, and provides the functions of the signal processing node 134 and the external network PDU to the signal processing node 134, and may provide a function of transmitting policy priority information provided from the policy management node 138 to the signal processing node 134.

The policy management node 138 also provides dynamic QoS and billing rules according to the service data flow and manages and processes communication policies and billing policies in the mobile communication network Can be performed.

The first IN network 140 may be an IP Multimedia Subsystem (IMS), which may be defined as an intelligent network node, for example. The first IN network 140 may include an Originating-Call Session Control Function (O-CSCF) 142 A home location register (HLR) 144, and an originating-application server (O-AS) 146, for example.

First, an outgoing call session control node (O-CSCF) 142 is an infrastructure system performing call processing and performing a basic function for multimedia session control based on SIP (Session Initiation Protocol) The control node 142 handles subscriber registration, authentication, billing, service triggering and routing, caller location inquiry, and decompression and release of SIP messages. The control node 142 is divided into Proxy_CSCF, Interogating-CSCF, and Serving- .

The subscriber information node (HLR) 144 refers to a server node including a database storing subscriber information and the like for a mobile communication network (e.g., LTE network). The subscriber profile information, authentication, Data and the like can be provided. Here, the HLR 144 may be defined (collectively) as an HSS (Home Subscriber Server) that can provide the same or similar functions.

The originating application service node (O-AS) 146 then sends a message for additional service operations such as caller indication, outgoing / incoming call prohibition, call forwarding, group video call, and call processing, call connection management, Fields, etc., and can perform functions such as billing and interworking with various nodes for performing call session control node (CSCF), subscriber information node (HLR), multimedia resource node (MRF) The originating application service node 146 may have a function of processing the application, the operation, the administration, the maintenance, and the like. For this purpose, the originating application service node 146 may have, for example, Details of the functions provided by the originating application service node 146 will be described in detail later with reference to FIG. Here, the originating application service node (O-AS) may be defined as an originating-telephony application server (O-TAS).

In addition, when the call connection request (SIP INVITE message) is received from the originating call session control node 142 side, the originating application service node 146 determines whether or not the call is an existing call in which an abnormal call is truncated, It is judged that the call is an existing call, and when the call is judged to be an existing call, it is regarded that the call is a garbage call which is truncated, and a connection request for call connection with the called terminal is executed , Which will be described later in detail with reference to FIG. 5 attached hereto.

On the other hand, the second intelligent network 150 may mean an IMS (IP Multimedia Subsystem) similar to the first intelligent network 140 described above. The second intelligent network 150 includes a terminating-call session control (T-CSCF) Function 152, a home location register (HLR) 154, and a terminating-application server (T-AS) 156. The overall function and each node The functions at the first intelligent network 140 and the corresponding respective nodes 142, 144 and 146 are substantially the same.

Therefore, in order to avoid unnecessary redundant description for the sake of simplification of the specification, detailed description of the function of each node 152, 154, 156 constituting the second intelligent network 150 is omitted here.

FIG. 2 is a block diagram of a node device suitable for applying the abnormal call processing technique according to the present invention, and includes a call processing block 202, a subscriber DB 204, a billing block 206, an interworking interface block 208, Block 210, and the like.

Referring to FIG. 2, the call processing block 202 performs additional service operations such as caller indication, call / incoming call prohibition, call forwarding, group video call, and call processing, call connection management, and message field change for call processing For this purpose, the call processing block 202 may include an abnormal call processing device having a configuration as shown in FIG.

FIG. 3 is a block diagram of an abnormal call processing apparatus according to the present invention. The apparatus includes a message receiving unit 302, a call state determining unit 304, a terminal information managing unit 306, and a call processing unit 308.

3, when a call connection request (for example, a SIP INVITE message) is received from a caller, that is, when a call connection request is received from an outgoing call session control node 142, And transferring it to the storage unit 304, for example.

In addition, the message receiver 302 receives a normal call termination (BYE) message (i.e., a call termination message transmitted from the calling terminal to the mobile communication network when the call terminates normally between the calling terminal and the called terminal) from the call session control node 142 When receiving an abnormal termination message indicating termination of the call due to the abnormal call termination from the call session control node 142, transmits the abnormal termination message to the terminal information managing unit 306 and the call processing unit 308, To the management unit 306 and the call processing unit 308, respectively.

Next, when the SIP INVITE message (connection request message) is delivered from the message receiving unit 302, the call state determining unit 304 searches for a call connection request message transmitted from the subscriber DB 204 of FIG. (I.e., an existing call maintaining the call state after the abnormal call is disconnected) or a new call, and transmits the determination result to the terminal information management unit 306 and the call processing unit 308. [ And the like can be provided.

To this end, the subscriber DB 204 of FIG. 2 stores registration state information including subscriber's supplementary service state and terminal information (i.e., terminal information related to call connection of each communication terminal).

When notified that the call that transmitted the connection request from the call state determination unit 304 is an existing call disconnected from the abnormal call, the terminal information management unit 306 determines that the existing call is a garbage call that has been truncated in abnormal call, (Deletion of the terminal information for the call connection of the corresponding communication terminal) of the corresponding terminal information stored in the terminal 204.

The terminal information management unit 306 may also provide a function of deleting the corresponding terminal information stored in the subscriber DB 204 when a normal call termination (BYE) message or an abnormal termination message is delivered from the message receiving unit 302 have.

Next, the call processing unit 308 generates a call end (BYE) message when the deletion of the existing call (that is, the existing call maintaining the call state after the abnormal call termination) is completed according to the present invention, To the outgoing call session control node 142 for transmission of the call destina- tion process (i.e., execution of the existing call deletion process) to the called terminal (the incoming intelligent network side) (SIP INVITE message) for connection of a new call to the called party (to the called intelligent network) (that is, to execute the connection request processing of the new call) to the outgoing call session control node 142 Can be provided.

Also, the call processing unit 308 generates a call end (BYE) message when a normal call end (BYE) message or an abnormal end end message is transmitted from the message receiving unit 302 and transmits the call end (BYE) message to the called party To the outgoing call session control node 142 for execution of call deletion processing).

2, the charging block 206 may provide a function of performing a related charging process when the communication terminals are provided with an additional service or the like performed in the intelligent network, and the interlocking interface block 208 may perform a call session control (CSCF), subscriber information node (HLR), application service node (OS), and various nodes necessary for performing various additional services.

The operation management maintenance (OAM) block 210 may provide a function of handling operation, management, maintenance, etc. of the originating application service node 146 in the intelligent network 140 have.

Next, a series of processes for processing an abnormal call according to the present invention will be described in detail using a mobile communication system having the above-described configuration.

FIG. 4 is a flowchart illustrating a process of deleting an existing call that is disconnected when an access request is received and requesting a connection of a new call when a call is abnormally disconnected according to the present invention.

4, if the calling terminal UE-A is in a weak electric field area (a communication shadow area where the radio waves are weak in a weak communication area) while a call is connected between the calling terminal UE-A and the called terminal UE- The call of the calling terminal UE-A is abnormally disconnected without transmitting a call termination (BYE) message to the base station 120/1 (step 401).

The base station 120/1 or the mobility management node 132 in the mobile communication network 130 detects an abnormal call disconnection in the state where the call of the calling terminal UE-A is abnormally cut off, The UE-A transmits a connection request (SIP INVITE message) for re-calling before detection of an abnormal call disconnection. In this case, The connection request message is transmitted to the originating application service node 146 via a path via the base station 120/1, the mobile communication network 130 and the outgoing call session control node 142 in the first intelligent network 140 (Steps 402 and 403).

Next, at the originating application service node 146, it is determined whether or not the call that transmitted the connection request is a new call or an existing call (i.e., an existing call in which the call state is maintained after the abnormal call is disconnected) (Step 404), which will be described later in detail with reference to FIG.

FIG. 5 is a flowchart illustrating a main procedure for executing connection request processing of a new call after deleting an existing call that has been truncated according to the present invention.

5, the message receiver 302 receives a call connection request (for example, a SIP INVITE message) from the origination call session control node 142, and transmits the request to the call state determiner 304 (step 502).

When a connection request message (SIP INVITE message) is received through the message reception unit 302 (step 502), the call state determination unit 304 determines whether the terminal information in the subscriber DB 204 (Step 504), it is determined whether the corresponding call that transmitted the connection request is a new call or an existing call in which the call state is maintained, that is, whether the call is an existing call that remains in the call state after the abnormal call termination (Steps 506 and 508).

As a result of the determination in step 506, when the call that transmitted the connection request is a new call, the call state determination unit 304 notifies the call processing unit 308 of the call, and the process then proceeds to step 512 , The call processing unit 308 generates a connection request (SIP INVITE message) for a new call connection between the calling terminal and the called terminal according to a normal call processing procedure and transmits it to the called party (incoming intelligent network) The request processing will be executed.

As a result of the determination in step 508, if it is determined that the call transmitted the connection request is an existing call maintained in a call state after the abnormal call termination, the terminal information management unit 306 transmits the existing call to the non- garbage), and deletes the corresponding terminal information stored in the subscriber DB 204 (deletes terminal information for call connection of the corresponding communication terminal) (step 510).

Next, when the deletion of the existing call maintained in the communication state after the abnormal call termination is completed, the call processing unit 308 generates and transmits a call end (BYE) message to the called party (incoming intelligent network side) (Step 512) and complete the call connection for the new call (step 514), as shown in FIG. 4, Explain.

4, the originating application service node 146 generates a call termination (BYE) message when a deletion process for an existing call is completed, and transmits a call termination (BYE) message through an outgoing call session control node 142 To the call session control node 152 (steps 405, 406).

As a result, after the incoming call session control node 152 has communicated (transmitted / received) a call termination message with the terminating application service node 156 (steps 407 and 408), the call termination message is transmitted to the called terminal UE- (Step 409) and processes the call termination for the called terminal.

After the call origination application end node 146 completes the call termination process, the originating application service node 146 generates a connection request (SIP INVITE message) for a new call connection between the calling terminal and the called terminal, (Step 410), and the outgoing call session control node 142 transmits the connection request to the called session control node 152 (step 411).

Thereafter, after the incoming call session control node 152 communicates (transmits and receives) a connection request message with the incoming application service node 156 (steps 412 and 413), the connection request message is transmitted to the called terminal UE-B via the mobile communication network By sending a message (step 414), the call between the calling terminal and the called terminal is connected.

On the other hand, in the embodiment of the present invention, the deletion processing for the existing call (i.e., the existing call for raising the connection request in the state of disconnecting the abnormal call) from which the connection request is received from the existing call maintained in the call state is transmitted to the application service node However, the present invention is not necessarily limited to this. By applying the constituent elements capable of performing a related function to a call session control node (outgoing call session control node) It is of course possible to design the deletion processing for the existing call to raise the connection request at the call session control node.

On the other hand, in the embodiment of the present invention, the deletion processing of the existing call and the connection request processing of the new call are performed by separating the intelligent network of the calling side and the intelligent network of the called party, but the present invention is not limited thereto, It is also possible to construct the integrated intelligent network of the new call and perform the deletion processing of the existing call and the connection request processing of the new call. In this case, it may be designed to configure only one call session control node and an application service node.

Furthermore, although the receiving terminal is an LTE terminal in the embodiment of the present invention, the present invention is not necessarily limited to this, and the same applies to a case where the called terminal is a legacy terminal. In this case, the originating application service node in the first intelligent network generates a CALL RELEASE message to perform signaling conversion between ISDN User Part (ISUP) used in the media gateway control node, i.e., SIP and circuit (circuit) (E.g., 3G mobile communication network) side through a media gateway control function (MGCF) supporting the media gateway control function (MGCF).

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims. It is easy to see that this is possible. That is, the embodiments disclosed in the present invention are not intended to limit the scope of the present invention but to limit the scope of the present invention.

Therefore, the scope of protection of the present invention should be construed in accordance with the following claims, and all technical ideas within the scope of equivalents should be interpreted as being included in the scope of the present invention.

According to the embodiment of the present invention, when a connection request of a call is received from a calling terminal, it is determined whether or not the call is an existing call that is abnormally truncated, and a garbage call is detected in the existing call, A connection request for a new call connection with the terminal is executed, thereby providing an abnormal call processing model that can effectively prevent a call drop phenomenon for a new call due to abnormal call termination.

The present invention including such a technical configuration can be applied to a VoLTE (or LTE) mobile communication network or a heterogeneous mixed mobile communication network, thereby improving the service quality in VoLTE (or LTE) communication service or heterogeneous communication service.

302: message reception unit 304: call state determination unit
306: terminal information management unit 308:

Claims (7)

Determining whether the call is an existing call disconnected when the call connection request is received from the calling terminal;
If it is determined that the call is an existing call, deleting the existing call and executing a connection request for making a call connection with the called terminal
And an unvoiced call processing method. The method according to claim 1,
The deletion of the existing call may include,
Lt; RTI ID = 0.0 > application service node or call session control node in the intelligent network
Abnormal call processing method. When the call connection request is received from the calling terminal, determining whether the call is an existing call in which the call state is maintained through searching for stored terminal information;
If it is determined that the call is an existing call, executing deletion processing of the existing call;
Performing a connection request process for a call connection between the calling terminal and the called terminal after completion of the deletion process
And an unvoiced call processing method. The method of claim 3,
The deletion processing of the existing call includes:
Is executed through an originating application service node in an intelligent network or an outgoing call session control node
Abnormal call processing method. A message receiving unit for receiving a call connection request from a calling side;
A call state determination unit for determining whether the call received through searching for the stored terminal information is an existing call in which the call state is maintained;
A terminal information management unit for deleting the existing call if it is determined as the existing call;
When a deletion of the existing call is completed, a call request for a call connection between the calling terminal and the called terminal is generated and transmitted to the called party,
And an unvoiced call processing device. 6. The method of claim 5,
The terminal information management unit,
When an abnormal termination message indicating termination of a call due to an abnormal call termination is received from the mobile communication network, the corresponding terminal information for the call connection stored in the subscriber DB is deleted
Abnormal call processing device. The method according to claim 6,
The abnormal termination message includes:
Generated and transmitted from the base station or the mobility management node in the mobile communication network
Abnormal call processing device.

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