JP5874499B2 - COMMUNICATION SYSTEM, RELAY DEVICE, COMMUNICATION DEVICE, AND COMMUNICATION CONTROL METHOD - Google Patents

Description

  The present invention relates to a communication system, a relay device, a call device, and a communication control method.

  In recent years, the number of communication devices such as mobile phones has increased rapidly, and along with this, the amount of communication on the communication network side that relays communication between the communication device and other communication devices has also increased. In such a situation, when a call request is transmitted from a call device (hereinafter referred to as “call”) in a certain amount of time, such as when a disaster occurs, the communication network side including the relay device is connected to the communication line. It becomes difficult to establish a call due to a congestion state where there is no free space. Calls at the time of a disaster, etc. are often made mainly for the purpose of confirming safety. Therefore, the user of the call device must call another call device that is the destination of the call until the congestion state is resolved. On the other hand, unnecessary calls are repeated, and as a result, there is a possibility that the congestion of the communication line will be prolonged.

  Accordingly, various techniques for preventing unnecessary calls have been studied. As such a technique, for example, when a communication line is congested, a call is reserved from the communication device to the relay device on the communication network side, and the waiting time required for securing the communication line from the relay device to the communication device. Something that knows the time is known. In this technology, the call device that has received the notification of the waiting time stops calling again until the waiting time arrives after receiving the notification, and when the waiting time arrives, the calling device is re-executed and the calling is accepted. The relay device secures a communication line. As a result, it is possible to prompt the user of the communication device to hesitate to repeat unnecessary calls until the waiting time comes.

JP 2001-251424 A

  However, the above-described prior art has a problem that communication line congestion may not be appropriately eliminated.

  Specifically, in the prior art, a communication line is secured before the waiting time arrives, but if there is no communication line available when the waiting time arrives, a call that has already been established is forced. The communication line was secured by disconnecting it. The call time should be left to the free will of the user who is making the call, and it is not always appropriate to forcibly disconnect the established call. For this reason, in the prior art, it was difficult to say that the congestion of the communication line can be appropriately eliminated.

  The disclosed technology has been made in view of the above, and it is possible to appropriately eliminate congestion of a communication line without disconnecting an established call, a communication system, a relay device, a call device, and a communication control method. The purpose is to provide.

  In one aspect, a communication system disclosed in the present application relays a call device and a call request transmitted from the call device to a destination device that is another call device that is the destination of the call request using a communication line. Including a relay device. The relay device includes a reservation instruction unit, a registration unit, and a call permission unit. The reservation instructing unit rejects relaying of a call request transmitted from the call device when the communication line is congested, and transmits a call reservation including identification information of the call device and identification information of the destination device. A reservation instruction is sent to the call device. When receiving a call reservation transmitted from the call device, the registration unit registers a correspondence relationship between the identification information of the call device and the identification information of the destination device included in the call reservation. The call permission unit, when detecting the release of a part of the communication lines, permits the call device whose identification information is registered by the registration unit to retransmit the call request, and A call permission including identification information of the corresponding destination device is transmitted to the call device. The call device includes a reservation management unit and a call control unit. When receiving a reservation instruction transmitted from the relay device, the reservation management unit transmits the call reservation to the relay device and manages the identification information of the destination device included in the call reservation as reservation data. . When the call control unit receives a call permission transmitted from the relay device, the call control unit retransmits the call request including the identification information of the destination device included in the call permission as a destination to the relay device. The identification information of the destination device is deleted from the reservation data. When the call permission is not received, the call control unit stops transmitting the call request including the identification information of the destination device that matches the reservation data as a destination.

  According to one aspect of the communication system disclosed in the present application, there is an effect that congestion of the communication line can be appropriately eliminated without disconnecting the established call.

FIG. 1 is a diagram illustrating a configuration of a communication system according to the present embodiment. FIG. 2 is a functional block diagram showing the configuration of the relay device in this embodiment. FIG. 3 is a functional block diagram showing the configuration of the reservation status management server in the present embodiment. FIG. 4 is a diagram illustrating an example of the data structure of the reservation information DB. FIG. 5 is a functional block diagram showing the configuration of the call device in the present embodiment. FIG. 6 is a diagram illustrating an example of a data structure of reservation data. FIG. 7 is a flowchart illustrating a processing procedure of reservation registration processing by the relay device according to the present embodiment. FIG. 8 is a flowchart illustrating a processing procedure of a call permission process by the relay device according to the present embodiment. FIG. 9 is a flowchart showing a processing procedure of reservation information registration processing by the reservation status management server in the present embodiment. FIG. 10 is a flowchart showing a processing procedure of reservation information transmission processing by the reservation status management server in the present embodiment. FIG. 11 is a flowchart showing the processing procedure of the reservation postponement process by the reservation status management server in the present embodiment. FIG. 12 is a flowchart illustrating a processing procedure of reservation cancellation processing by the reservation status management server in the present embodiment. FIG. 13 is a flowchart showing a processing procedure of call reservation processing by the call device in the present embodiment. FIG. 14 is a flowchart illustrating a processing procedure of a call request retransmission process performed by the call device according to the present embodiment. FIG. 15 is a flowchart illustrating a processing procedure of a call request transmission stop process by the call device according to the present embodiment. FIG. 16 is a sequence diagram illustrating an example of a processing procedure in which the communication system according to the present embodiment registers reservation information. FIG. 17 is a diagram (part 1) illustrating a transition of reservation data of the communication device 300a. FIG. 18 is a diagram (part 1) illustrating a transition of the reservation information DB of the reservation status management server 200a. FIG. 19 is a sequence diagram illustrating an example of a processing procedure for establishing a call by the communication system according to the present embodiment. FIG. 20 is a diagram (part 2) illustrating a transition of the reservation information DB of the reservation status management server 200a. FIG. 21 is a diagram (part 2) illustrating a transition of reservation data of the communication device 300a. FIG. 22 is a sequence diagram illustrating an example of a processing procedure in which the communication system according to the present embodiment requests postponement of retransmission of a call request. FIG. 23 is a diagram (part 3) illustrating a transition of the reservation information DB of the reservation status management server 200a. FIG. 24 is a sequence diagram illustrating an example of a processing procedure in which the communication system according to the present embodiment requests cancellation of retransmission of a call request. FIG. 25 is a diagram (part 3) illustrating a transition of reservation data of the communication device 300a. FIG. 26 is a diagram (part 4) illustrating a transition of the reservation information DB of the reservation status management server 200a. FIG. 27 is a sequence diagram illustrating an example of a processing procedure in which the communication system according to the present embodiment deletes reservation information. FIG. 28 is a diagram (part 5) illustrating a transition of the reservation information DB of the reservation status management server 200a.

  Hereinafter, embodiments of a communication system, a relay device, a communication device, and a communication control method disclosed in the present application will be described in detail with reference to the drawings. The disclosed technology is not limited by this embodiment.

  First, the structure of the communication system of a present Example is demonstrated. FIG. 1 is a diagram illustrating a configuration of a communication system according to the present embodiment. As shown in FIG. 1, this communication system includes a congestion monitoring device 10, relay devices 20a and 20b, relay devices 100a and 100b, reservation status management servers 200a and 200b, and communication devices 300a and 300b. In the following description, the relay devices 20a and 20b are referred to as the relay device 20 unless otherwise distinguished. In the following description, the relay devices 100a and 100b are referred to as the relay device 100 unless they are particularly distinguished. In the following description, the reservation status management servers 200a and 200b are referred to as the reservation status management server 200 unless otherwise distinguished. In the following description, the call devices 300a and 300b are referred to as the call device 300 unless they are particularly distinguished.

  The congestion monitoring device 10 is communicably connected to the relay device 20 and the relay device 100. The congestion monitoring device 10 monitors the congestion state of communication lines set in the relay device 20 and the relay device 100. The congestion state is a state in which a call request exceeding the line capacity is received by the relay device 20 and the relay device 100, or all the communication lines set in the relay device 20 and the relay device 100 are free. This refers to the state where there is no line. When the congestion monitoring device 10 detects that a congestion state of the communication line has occurred, the congestion monitoring device 10 notifies the relay device 20 and the relay device 100 of a congestion occurrence notification that reports that fact. When the congestion monitoring device 10 detects that the congestion state of the communication line has been released, the congestion monitoring device 10 notifies the relay device 20 and the relay device 100 of a congestion release notification for reporting the fact.

  The relay device 20 and the relay device 100 are connected so as to communicate with each other. The relay device 100 is communicably connected to the call device 300. The relay device 20 and the relay device 100 relay the call request transmitted from the call device 300 to another call device that is the destination of the call request (hereinafter referred to as “destination device”) using a communication line. For example, the relay device 20 and the relay device 100 relay a call request transmitted from the call device 300a to the call device 300b as a destination device using a communication line. Also, the relay device 20 and the relay device 100 relay a call response returned from the destination device that has received the call request to the call device 300 using a communication line. For example, the relay device 20 and the relay device 100 relay a call response returned from the call device 300b as the destination device that has received the call request to the call device 300a using a communication line.

  The reservation status management server 200 is communicably connected to the relay device 100. Reservation status management server 200 receives a request from relay device 100 and manages the correspondence between the telephone number of caller device 300 of the caller included in the call reservation and the phone number of the destination device. For example, the reservation status management server 200 manages the correspondence between the telephone number of the telephone device 300a and the telephone number of the telephone device 300b as the destination device. The telephone number is an example of identification information.

  The call device 300 is a communication device such as a mobile phone or a fixed phone. The call device 300 receives an operation from the user of the call device 300 and transmits a call request including the telephone number of another call device 300 as a destination to the relay device 100. For example, the call device 300a transmits a call request including the telephone number of the call device 300b as the destination device as the destination to the relay device 100. Further, the call device 300 establishes a call by receiving a call response relayed by the relay device 100. For example, the call device 300a establishes a call by receiving a call response from the call device 300b relayed by the relay device 100a.

  In this embodiment, the relay device 100 rejects the relay of the call request transmitted from the call device 300 when the communication line is congested, and the telephone number of the call device 300 that is the call request source and the phone number of the destination device. The call device 300 is instructed to transmit a call reservation including For example, when receiving the congestion occurrence notification from the congestion monitoring device 10, the relay device 100 a rejects the relay of the call request from the call device 300 a, and determines the telephone number of the call device 300 a and the phone number of the call device 300 b as the destination device. Instruct the call device 300a to transmit the call reservation including the call reservation.

  When the call device 300 is instructed to transmit a call reservation, the call device 300 transmits to the relay device 100 a call reservation including the telephone number of the caller device 300 of the call originator and the telephone number of the destination device, and also makes a call reservation. The telephone number of the included destination device is managed as reservation data. For example, the call device 300a transmits a call reservation including its own phone number and the phone number of the call device 300b as the destination device to the relay device 100a, and also uses the phone number of the call device 300b included in the call reservation as reservation data. to manage.

  Then, when receiving the call reservation, the relay apparatus 100 registers the correspondence relationship between the telephone number of the call apparatus 300 and the telephone number of the destination apparatus included in the call reservation in the reservation status management server 200. For example, the relay device 100a transmits to the reservation status management server 200a a registration request including the correspondence between the telephone number of the communication device 300a included in the call reservation and the telephone number of the communication device 300b as the destination device. Receiving the registration request, the reservation status management server 200a stores the correspondence included in the registration request in a predetermined storage area.

  Then, the relay device 100 monitors the release of the communication line. When the relay device 100 detects the release of some of the communication lines, the relay device 100 permits the call device 300 whose telephone number is registered in the reservation status management server 200 to retransmit the call request, and the corresponding destination device. The call permission including the telephone number is transmitted to the call device 300. In the following, some of the released communication lines are referred to as “free lines”. For example, when detecting a free line, the relay device 100a permits the call device 300a whose phone number is registered in the reservation status management server 200a to retransmit the call request, and the phone number of the call device 300b as the destination device. Is transmitted to the call device 300a.

  When the call device 300 receives the call permission transmitted from the relay device 100, the call device 300 retransmits the call request including the telephone number of the destination device included in the call permission as a destination to the relay device 100, and Delete the phone number of the device from the reservation data. For example, when receiving a call permission, the call device 300a retransmits a call request including the telephone number of the call device 300b as a destination device included in the call permission as a destination to the relay device 100a, and sets the phone number of the call device 300b. Delete from reservation data.

  On the other hand, when the call permission is not received, the call device 300 stops the transmission of the call request including the destination device telephone number that matches the reservation data as the destination. For example, when the call device 300a has not received the call permission, the call device 300a stops the transmission of the call request including the telephone number of the call device 300b as the destination device that matches the reservation data as the destination.

  As described above, in the communication system of this embodiment, when the communication line is congested, the telephone apparatus 300 manages the telephone number of the destination apparatus included in the telephone call reservation to the relay apparatus 100 as reservation data. The call device 300 stops transmitting a call request including a phone number that matches the reservation data until the call permission from the relay device 100 is received after the call reservation is made. Thereby, in the communication system of a present Example, the congestion of a communication line can be eliminated appropriately, without disconnecting the call in establishment.

  Next, the configuration of relay device 100 shown in FIG. 1 will be described. FIG. 2 is a functional block diagram showing the configuration of the relay device in this embodiment. As shown in FIG. 2, this relay apparatus 100 includes a congestion monitoring IF (Interface) unit 101, a relay IF unit 102, a call IF unit 103, a reservation status management IF unit 104, a relay control unit 105, a reservation status. A registration unit 106 and a call permission unit 107 are included.

  The congestion monitoring IF unit 101 is a device that performs data communication with the congestion monitoring device 10. For example, the congestion monitoring IF unit 101 corresponds to an interface module or the like. The relay device 100 receives a congestion occurrence notification, a congestion release notification, and the like from the congestion monitoring device 10 via the congestion monitoring IF unit 101.

  The relay IF unit 102 is a device that performs data communication with the relay device 20. For example, the relay IF unit 102 corresponds to an interface module or the like. The relay device 100 transmits / receives a call request, a call response, and the like to / from the relay device 20 via the relay IF unit 102.

  The call IF unit 103 is a device that performs data communication with the call device 300. For example, the call IF unit 103 corresponds to an interface module or the like. The relay device 100 transmits / receives a call request, a call response, a reservation instruction (to be described later), a call reservation, a call permission, and the like to / from the call device 300 via the call IF unit 103.

  The reservation status management IF unit 104 is a device that performs data communication with the reservation status management server 200. For example, the reservation status management IF unit 104 corresponds to an interface module or the like. The relay device 100 communicates with the reservation status management server 200 via the reservation status management IF unit 104 between the telephone number of the caller device 300 of the caller included in the call reservation and the phone number of the destination device. Etc.

  The relay control unit 105 relays the call request transmitted from the call device 300 to the destination device that is the destination of the call request using the communication line. Specifically, when receiving a call request from the call device 300 via the call IF unit 103, the relay control unit 105 secures a communication line to another relay device connected to the destination device and performs the relay request. Set in the IF unit 102. Then, the relay control unit 105 transfers the call request to the adjacent relay device via the relay IF unit 102. On the other hand, the relay control unit 105 establishes a call by receiving a call response returned from the destination apparatus that has received the call request. Specifically, the relay control unit 105 establishes a call by receiving a call response via the relay IF unit 102.

  Further, the relay control unit 105 rejects relaying of the call request transmitted from the call device 300 when the communication line is congested, and sets the telephone number of the call device 300 of the call request source and the phone number of the destination device. Instructs call device 300 to transmit a call reservation including the call reservation. Specifically, the relay control unit 105 performs the following processing when triggered by the reception of the congestion occurrence notification from the congestion monitoring device 10 via the congestion monitoring IF unit 101. That is, even if the relay control unit 105 receives a call request from the call device 300 via the call IF unit 103, the relay control unit 105 rejects the relay of the received call request. At the same time, relay control unit 105 transmits a reservation instruction for instructing transmission of a call reservation including the telephone number of call device 300 and the telephone number of the destination device to call device 300 via call IF unit 103. . The relay control unit 105 is an example of a reservation instruction unit.

  When the relay control unit 105 receives a congestion release notification from the congestion monitoring device 10 via the congestion monitoring IF unit 101, the relay control unit 105 transfers the received congestion release notification to the call permission unit 107.

  The reservation status registration unit 106 receives a call reservation transmitted from the call device 300 in response to the reservation instruction via the call IF unit 103. When receiving a call reservation, the reservation status registration unit 106 registers the correspondence relationship between the telephone number of the call device 300 and the telephone number of the destination device included in the call reservation as reservation information in the reservation status management server 200. In the following, it is assumed that the correspondence between the telephone number of the caller device 300 of the transmission source included in the call reservation and the telephone number of the destination device is simply expressed as “correspondence”. The reservation status registration unit 106 is an example of a registration unit.

  A process in which the reservation status registration unit 106 registers the correspondence as reservation information will be described. The reservation status registration unit 106 specifies the priority order of the correspondence relationship based on the order in which the call reservations are received. For example, the reservation status registration unit 106 specifies the priority of the correspondence relationship by assigning values in ascending order from the correspondence relationship in which the order of receiving the call reservation is early. The reservation status registration unit 106 receives a registration request for registering the correspondence and priority between the telephone number of the communication device 300 and the telephone number of the destination device via the reservation status management IF unit 104. Transmit to server 200. The reservation status management server 200 that has received the registration request stores a combination of correspondence and priority included in the registration request in a reservation information DB (Database) 203 described later.

  The reservation status registration unit 106 receives the postponement request transmitted from the call device 300 via the call IF unit 103. The postponement request is a signal for requesting postponement of the retransmission of the call request by the call device 300 that has received the call permission. The postponement request includes the telephone number of the communication device 300 that is the transmission source. When the reservation status registration unit 106 receives the postponement request, the reservation status registration unit 106 updates the correspondence relationship corresponding to the telephone number of the call device 300 that is the transmission source of the postponement request so as to be lower than the current priority order.

  A process in which the reservation status registration unit 106 updates the priority order of the correspondence relationship will be described. The reservation status registration unit 106 adds, to the postponement request, instruction information that instructs to update the correspondence corresponding to the telephone number of the call device 300 that is the transmission source of the postponement request so that the correspondence is lower than the current priority. Then, the postponement request with the instruction information added is transferred to the reservation status management IF unit 104. The reservation status management server 200 that has received the postponement request updates the reservation information DB 203 based on the instruction information included in the postponement request.

  In addition, the reservation status registration unit 106 receives a cancellation request transmitted from the call device 300 via the call IF unit 103. The cancel request is a signal for the call device 300 that has received the call request to request cancellation of the retransmission of the call request. The cancellation request includes the telephone number of the communication device 300 that is the transmission source. When the reservation status registration unit 106 receives the cancellation request, the reservation status registration unit 106 deletes the correspondence relationship corresponding to the telephone number of the communication device 300 that is the transmission source of the cancellation request.

  A process in which the reservation status registration unit 106 deletes the correspondence will be described. The reservation status registration unit 106 adds instruction information instructing to delete the correspondence corresponding to the telephone number of the communication device 300 that is the transmission source of the cancellation request to the cancellation request, and reserves the cancellation request to which the instruction information is added. Transfer to the situation management IF unit 104. The reservation status management server 200 that has received the cancel request updates the reservation information DB 203 based on the instruction information included in the cancel request.

  The call permission unit 107 monitors a free line when the communication line is congested. When the call permission unit 107 detects a free line, the call permission unit 107 permits the call device 300 whose telephone number is registered by the reservation status registration unit 106 to retransmit the call request and sets the phone number of the corresponding destination device. The call permission including the call is transmitted to the call device 300.

  A process in which the call permission unit 107 transmits a call permission when the communication line is congested will be described. The call permission unit 107 detects a free line from the communication line set in the relay IF unit 102 by the relay control unit 105. When the call permission unit 107 detects a free line, the call permission unit 107 transmits a reservation information request for transmitting a correspondence relationship having a priority of 1 to the reservation status management server 200 via the reservation status management IF unit 104. . The call permission unit 107 receives a correspondence relationship with a priority of 1, which is returned from the reservation status management server 200 in response to the reservation information request. The call permission unit 107 determines a call device 300 that is permitted to retransmit a call request based on the received correspondence, and includes a phone number of a destination device corresponding to the determined phone number of the call device 300 Is transmitted to the call device 300 via the call IF unit 103.

  In addition, when the congestion is released, the call permission unit 107 permits all call devices 300 whose telephone numbers are registered by the reservation status registration unit 106 to retransmit the call request, and sets all the corresponding destination devices. A call permission including a telephone number is transmitted to the call device 300.

  A process in which the call permission unit 107 transmits a call permission when the congestion is released will be described. The call permission unit 107 receives the congestion release notification transferred from the relay control unit 105. When the call permission unit 107 accepts the congestion release notification, the call permission unit 107 transmits a reservation information request for transmitting all correspondences to the reservation status management server 200 via the reservation status management IF unit 104. The call permission unit 107 receives all the correspondences returned from the reservation status management server 200 in response to the reservation information request. The call permission unit 107 transmits a call permission including the telephone number of the corresponding destination device to the call device 300 via the call IF unit 103 based on the received correspondence.

  The relay control unit 105, the reservation status registration unit 106, and the call permission unit 107 described above correspond to, for example, an integrated device such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array). The relay control unit 105, the reservation status registration unit 106, and the call permission unit 107 correspond to electronic circuits such as a CPU (Central Processing Unit) and an MPU (Micro Processing Unit), for example.

  Next, the configuration of the reservation status management server 200 shown in FIG. 1 will be described. FIG. 3 is a functional block diagram showing the configuration of the reservation status management server in the present embodiment. As illustrated in FIG. 3, the reservation status management server 200 includes a reservation status management IF unit 201, a reservation status management unit 202, and a reservation information DB 203.

  The reservation status management IF unit 201 is a device that performs data communication with the relay device 100. For example, the reservation status management IF unit 201 corresponds to an interface module or the like. The reservation status management server 200 communicates with the relay device 100 via the reservation status management IF unit 201 between the telephone number of the caller device 300 that is included in the call reservation and the phone number of the destination device. Send / receive registration request, reservation information request, postponement request, cancellation request, etc.

  When the reservation status management unit 202 receives a registration request from the relay device 100, the reservation status management unit 202 associates the correspondence between the telephone number of the communication device 300 and the telephone number of the destination device and the priority order included in the registration request, and stores the reservation information. Store in the DB 203.

  In addition, when the reservation status management unit 202 receives a reservation information request from the relay apparatus 100, the reservation status management unit 202 extracts a correspondence relationship having a priority of 1 from the reservation information DB 203. The reservation status management unit 202 transmits the correspondence extracted from the reservation information DB 203 to the relay device 100. The reservation status management unit 202 updates the priority order of the reservation information DB 203.

  When the reservation status management unit 202 receives a postponement request from the relay device 100, the reservation status management unit 202 refers to the reservation information DB 203 to set the priority of the entry corresponding to the telephone number of the communication device 300 that is the transmission source of the postponement request. Update to the bottom. The reservation status management unit 202 updates the priority order of the remaining entries in the reservation information DB 203. The reservation status management unit 202 returns a postponement completion reporting that the postponement of retransmission of the call reservation has been completed to the relay apparatus 100.

  When the reservation status management unit 202 receives a cancel request from the relay device 100, the reservation status management unit 202 refers to the reservation information DB 203 and deletes the entry corresponding to the telephone number of the call device 300 that is the transmission source of the cancel request. The reservation status management unit 202 updates the priority order of the remaining entries in the reservation information DB 203. The reservation status management unit 202 replies to the relay apparatus 100 with the completion of cancellation reporting that the cancellation of the retransmission of the call reservation has been completed.

  The reservation information DB 203 stores the correspondence between the telephone number of the call device 300 and the telephone number of the destination device included in the call reservation as reservation information. FIG. 4 is a diagram illustrating an example of the data structure of the reservation information DB. As shown in FIG. 4, the reservation information DB 203 stores the calling number, called number, and priority in association with each other.

  The calling number stores the telephone number of the call device 300 of the transmission source included in the call reservation. The called number stores the telephone number of the destination device included in the call reservation. The priority is the order of the call devices 300 that should preferentially permit retransmission of the call request among the call devices 300 having the call number of each corresponding relationship when there are a plurality of corresponding relationships between the calling number and the called number. Indicates. For example, in FIG. 4, there are five correspondence relationships. Specifically, there is a correspondence relationship in which the calling number is “08011112222” in the entry on the first line. There is a correspondence relationship in which the calling number is “0447777111” in the entry on the second line. There is a correspondence relationship in which the calling number is “05033445566” in the entry on the third line. There is a correspondence relationship in which the calling number is “08011112222” in the entry on the fourth line. There is a correspondence relationship in which the calling number is “09088888888” in the entry on the fifth line. Here, since the priority of the entry in the first row is “1”, the call device 300 having the calling number “08011112222” in the entry in the first row permits re-transmission of the call request with the highest priority. It becomes a call device.

  Note that the reservation status management unit 202 described above corresponds to, for example, an integrated device such as an ASIC or FPGA. The reservation status management unit 202 corresponds to an electronic circuit such as a CPU or MPU, for example.

  The reservation information DB 203 described above corresponds to, for example, a semiconductor memory device such as a RAM (Random Access Memory), a ROM (Read Only Memory), and a flash memory (Flash Memory), or a storage device such as a hard disk or an optical disk.

  Next, the configuration of the communication device 300 shown in FIG. 1 will be described. FIG. 5 is a functional block diagram showing the configuration of the call device in the present embodiment. As shown in FIG. 5, the call device 300 includes a call IF unit 301, a user IF unit 302, a storage unit 303, a reservation management unit 304, and a call control unit 305.

  The call IF unit 301 is a device that performs data communication with the relay device 100. For example, the call IF unit 301 corresponds to an interface module or the like. The call device 300 transmits / receives a call request, a call response, a reservation instruction, a call reservation, a call permission, and the like to / from the relay device 100 via the call IF unit 301.

  The user IF unit 302 is a device that accepts various types of information from the user of the call device 300 and displays various types of information to the user of the call device 300. For example, the user IF unit 302 corresponds to a keyboard, a display, a touch panel, and the like.

  The storage unit 303 stores reservation data 331. The reservation data 331 stores the telephone number of the destination device included in the call reservation transmitted to the relay device 100. FIG. 6 is a diagram illustrating an example of a data structure of reservation data. As shown in FIG. 6, the reservation data 331 stores the called number. The called number stores the telephone number of the destination device included in the call reservation transmitted to the relay device 100. The first line in the example of FIG. 6 indicates that a call reservation for reserving a call request for a destination apparatus having the telephone number “044777711” is transmitted to the relay apparatus 100. The second line in the example of FIG. 6 indicates that a call reservation for reserving a call request for a destination apparatus having the telephone number “090125345678” has been transmitted to the relay apparatus 100.

  When receiving a reservation instruction transmitted from the relay device 100, the reservation management unit 304 transmits a call reservation to the relay device 100 and manages the telephone number of the destination device included in the call reservation as reservation data 331. Specifically, when the reservation management unit 304 receives a reservation instruction from the relay device 100 via the call IF unit 301, the reservation management unit 304 first determines whether or not to make a call reservation via the user IF unit 302. Accept from 300 users. When making a call reservation, the reservation management unit 304 transmits a call reservation including the phone number of the call device 300 and the phone number of the destination device to the relay device 100 via the call IF unit 301. Furthermore, the reservation management unit 304 stores the telephone number of the destination device included in the call reservation in the reservation data 331.

  When the telephone number of the destination apparatus is received from the user of the telephone apparatus 300, the telephone call control unit 305 generates a telephone call request including the received telephone number of the destination apparatus and transmits it to the relay apparatus 100. On the other hand, the call control unit 305 performs a call process for receiving a call response relayed by the relay device 100.

  Further, the call control unit 305 monitors whether or not a call permission transmitted from the relay device 100 is received when a call reservation is transmitted from the reservation management unit 304. Specifically, when a call reservation is transmitted, the call control unit 305 monitors whether or not a call permission transmitted from the relay device 100 via the call IF unit 301 is received.

  When the call control unit 305 receives the call permission, the call control unit 305 retransmits the call request including the telephone number of the destination device included in the call permission to the relay device 100 via the call IF unit 301. The telephone number of the destination device included in the reservation data 331 is deleted. On the other hand, if the call control unit 305 has not received the call permission, the call control unit 305 stops transmitting the call request including the telephone number of the destination device that matches the reservation data 331.

  A process in which the call control unit 305 retransmits a call request will be described. When receiving a call permission, the call control unit 305 receives a postponement request or a cancel request from the user via the user IF unit 302. When the call control unit 305 receives the cancel request, the call control unit 305 transfers the cancel request instead of the call request to the relay device 100 via the call IF unit 301, and the telephone number of the destination device included in the call permission The matching telephone number is deleted from the reservation data 331.

  On the other hand, when the call control unit 305 receives the postponement request, the call control unit 305 transfers the postponement request instead of the call request to the relay device 100 via the call IF unit 301 and transmits the call permission transmitted from the relay device 100. Monitors whether or not it is received.

  If neither the cancellation request nor the postponement request is received, the call control unit 305 acquires a telephone number that matches the telephone number of the destination device included in the call permission from the reservation data 331. The call control unit 305 retransmits the call request including the acquired telephone number as the destination to the relay apparatus 100 via the call IF unit 301 and deletes the telephone number included in the call request destination from the reservation data 331. To do. The call control unit 305 performs normal call processing for receiving a call response relayed by the relay device 100 after retransmitting the call request.

  A process in which the call control unit 305 stops sending a call request will be described. When the call control unit 305 generates a call request during a period when the call permission is not received, whether the telephone number of the destination device included in the generated call request matches the telephone number of the reservation data 331 or not. Determine. If the call control unit 305 does not match, the telephone number of the destination device included in the call request is not yet the target of call reservation, and the call request is sent to the relay device 100 via the call IF unit 301. Send. On the other hand, if they match, the call control unit 305 stops sending the call request and discards the call request because the telephone number of the destination device included in the call request has already been subject to call reservation. To do. As a result, it is possible to avoid a situation in which an unnecessary call request is transmitted and congestion of the communication line deteriorates.

  Note that the reservation management unit 304 and the call control unit 305 described above correspond to, for example, an integrated device such as an ASIC or FPGA. The reservation status management unit 202 corresponds to an electronic circuit such as a CPU or MPU, for example.

  The storage unit 303 described above corresponds to, for example, a semiconductor memory device such as a RAM, a ROM, or a flash memory, or a storage device such as a hard disk or an optical disk.

  Next, a processing procedure of the communication system according to the present embodiment will be described. FIG. 7 is a flowchart illustrating a processing procedure of reservation registration processing by the relay device according to the present embodiment.

  As illustrated in FIG. 7, when the relay apparatus 100 has not received the congestion occurrence notification from the congestion monitoring apparatus 10 (step S101; No), the relay apparatus 100 ends the process. On the other hand, when receiving the congestion occurrence notification (step S101; Yes), the relay device 100 determines whether a call request is received (step S102). When the relay apparatus 100 has not received a call request (step S102; No), the relay apparatus 100 ends the process.

  When receiving the call request (step S102; Yes), the relay device 100 rejects the call request relay (step S103), and transmits a reservation instruction to the call device 300 (step S104). The relay device 100 determines whether a call reservation has been received (step S105). When the relay apparatus 100 does not receive the call reservation (step S105; No), the relay apparatus 100 ends the process.

  On the other hand, when the call reservation is received (step S105; Yes), the relay device 100 specifies the priority order based on the call reservation reception order (step S106). The relay device 100 transmits a registration request including the correspondence between the calling number and the called number included in the call reservation and the priority order to the reservation status management server 200 (step S107), and the process returns to step S102.

  Next, a processing procedure of call permission processing by the relay device 100 in the present embodiment will be described. FIG. 8 is a flowchart illustrating a processing procedure of a call permission process by the relay device according to the present embodiment.

  As illustrated in FIG. 8, when the relay apparatus 100 has not detected a free line (step S111; No), the relay apparatus 100 proceeds to step S111 again. On the other hand, when the relay apparatus 100 detects an empty line (step S111; Yes), the relay apparatus 100 transmits a reservation information request for requesting transmission of a correspondence relationship having a priority of 1 to the reservation status management server 200 ( Step S112).

  The relay device 100 receives a correspondence relationship having a priority of 1 from the reservation status management server 200 (step S113), and determines the call device 300 having the received calling number of the correspondence relationship as a target for which a call request is permitted. (Step S114). The relay device 100 generates a call permission including the called number corresponding to the determined calling number of the call device 300 and transmits it to the call device (step S115).

  Relay device 100 receives a response to call permission from call device 300 (step S116). When the response is a call request (step S117; Yes), the relay device 100 transfers the call request to another relay device 100 (step S118). When the response is a postponement request (step S117; No, step S119; Yes), the relay device 100 transfers the postponement request to the reservation status management server 200 (step S120), and returns the process to step S112. When the response is a cancel request (step S119; No), the relay device 100 transfers the cancel request to the reservation status management server 200 (step S121), and returns the process to step S112.

  Next, a processing procedure of reservation information registration processing by the reservation status management server 200 in the present embodiment will be described. FIG. 9 is a flowchart showing a processing procedure of reservation information registration processing by the reservation status management server in the present embodiment.

  As illustrated in FIG. 9, the reservation status management server 200 ends the process when the registration request is not received from the relay device 100 (step S131; No). On the other hand, when the reservation status management server 200 receives a registration request from the relay apparatus 100 (step S131; Yes), the reservation information DB 203 indicates the correspondence between the calling party number and the called party number and the priority order included in the registration request. (Step S132).

  Next, a processing procedure of reservation information transmission processing by the reservation status management server 200 in the present embodiment will be described. FIG. 10 is a flowchart showing a processing procedure of reservation information transmission processing by the reservation status management server in the present embodiment.

  As illustrated in FIG. 10, when the reservation status management server 200 has not received a reservation information request from the relay device 100 (step S141; No), the processing ends. When the reservation status management server 200 receives a reservation information request from the relay device 100 (step S141; Yes), the reservation status management server 200 extracts a correspondence relationship having a priority of 1 from the reservation information DB 203 (step S142). The reservation status management server 200 transmits the extracted correspondence relationship to the relay device 100 (step S143), and updates the priority of the reservation information DB 203 (step S144).

  Next, the processing procedure of the reservation postponement process by the reservation status management server 200 in the present embodiment will be described. FIG. 11 is a flowchart showing the processing procedure of the reservation postponement process by the reservation status management server in the present embodiment.

  As illustrated in FIG. 11, if the reservation status management server 200 has not received a postponement request from the relay device 100 (step S151; No), the processing ends. On the other hand, when the reservation status management server 200 receives a postponement request from the relay device 100 (step S151; Yes), the reservation status management server 200 performs the following processing. That is, the reservation status management server 200 refers to the reservation information DB 203 and updates the priority of the entry corresponding to the telephone number of the communication device 300 that is the transmission source of the postponement request to the lowest level (step S152).

  The reservation status management server 200 updates the priority order of the remaining entries in the reservation information DB 203 (step S153). The reservation status management server 200 returns postponement completion to the relay device 100 (step S154).

  Next, a processing procedure of reservation cancellation processing by the reservation status management server 200 in the present embodiment will be described. FIG. 12 is a flowchart illustrating a processing procedure of reservation cancellation processing by the reservation status management server in the present embodiment.

  As illustrated in FIG. 12, when the reservation status management server 200 has not received a cancellation request from the relay device 100 (step S161; No), the processing ends. On the other hand, when the reservation status management server 200 receives the cancellation process from the relay device 100 (step S161; Yes), the reservation status management server 200 refers to the reservation information DB 203 and sets the telephone number of the communication device 300 that is the transmission source of the cancellation request. The corresponding entry is deleted (step S162).

  The reservation status management server 200 updates the priority order of the remaining entries in the reservation information DB 203 (step S163). The reservation status management server 200 returns the completion of cancellation to the relay device 100 (step S164).

  Next, a processing procedure of call reservation processing by the call device 300 in the present embodiment will be described. FIG. 13 is a flowchart showing a processing procedure of call reservation processing by the call device in the present embodiment.

  As shown in FIG. 13, the call device 300 receives a telephone number of the destination device from the user (hereinafter referred to as “called number”), generates a call request including the received called number, and transmits the call request to the relay device 100 (see FIG. 13). Step S171). Call device 300 determines whether or not a reservation instruction has been received from relay device 100 (step S172). If no reservation instruction has been received from the relay device 100 (step S172; No), the call device 300 performs a call process for receiving a call response (step S173).

  On the other hand, when receiving a reservation instruction from the relay device 100 (step S172; Yes), the call device 300 receives from the user whether or not to make a call reservation (step S174). If no call reservation is made (step S175; No), the call device 300 ends the process. On the other hand, when making a call reservation (step S175; Yes), the call device 300 transmits a call reservation including the telephone number of the call device 300 (hereinafter referred to as “calling number”) and the called number to the relay device 100. (Step S176). The call device 300 stores the called number included in the call reservation in the reservation data 331 (step S177).

  Next, a processing procedure of a call request retransmission process by the call device 300 in the present embodiment will be described. FIG. 14 is a flowchart illustrating a processing procedure of a call request retransmission process performed by the call device according to the present embodiment. The process shown in FIG. 14 is executed when a call reservation is transmitted from the call device 300, for example.

  As shown in FIG. 14, the call device 300 monitors whether or not a call permission has been received from the relay device 100 (step S181). If the call device 300 has not received the call permission (step S181; No), the call device 300 executes a call request transmission stop process (step S182). The call request transmission stop process will be described in detail later.

  On the other hand, when receiving a call permission from the relay device 100 (step S181; Yes), the call device 300 receives a postponement request or a cancel request from the user (step S183). When receiving a cancel request (step S184; Yes), the communication device 300 transfers the cancel request to the relay device 100 in place of the call request (step S185), and receives a call that matches the called number included in the call permission. The number is deleted from the reservation data 331 (step S186).

  When receiving the postponement request (step S184; No, step S187; Yes), the communication device 300 transfers the postponement request to the relay device 100 instead of the call request (step S188), and returns the process to step S181. .

  When neither the cancellation request nor the postponement request is received (step S187; No), the call device 300 acquires the called number that matches the called number included in the call permission from the reservation data 331 (step S189). The call device 300 resends the call request including the acquired called number as the destination to the relay device 100 (step S190), and deletes the called number included in the call request destination from the reservation data 331 (step S191). Thereafter, the call device 300 performs a call process for receiving a call response (step S192).

  Next, a processing procedure of call request transmission stop processing by the call device 300 in the present embodiment will be described. FIG. 15 is a flowchart illustrating a processing procedure of a call request transmission stop process by the call device according to the present embodiment. The call request transmission stop process shown in FIG. 15 corresponds to step S182 shown in FIG.

  As illustrated in FIG. 15, when the call device 300 has not generated a call request (step S201; No), the process ends. On the other hand, when the call device 300 generates a call request (step S201; Yes), the call device 300 determines whether or not the called number included in the generated call request matches the called number in the reservation data 331 (step S201). S202).

  If they do not match (step S202; No), the call device 300 transmits a call request to the relay device 100 (step S203). Thereafter, the call device 300 executes normal call processing for receiving a call response (step S204).

  On the other hand, if they match (step S202; Yes), the call device 300 stops sending the call request and discards the call request (step S205).

  Next, an example of a series of processing from when the communication system according to the present embodiment detects occurrence of a congestion state of a communication line until registration of reservation information will be described. FIG. 16 is a sequence diagram illustrating an example of a processing procedure in which the communication system according to the present embodiment registers reservation information.

  As shown in FIG. 16, the congestion monitoring device 10 detects that a communication line congestion has occurred (step S211), and transmits a congestion occurrence notification to the relay device 100a (step S212). The relay device 100 a receives the congestion occurrence notification from the congestion monitoring device 10.

  The call device 300a generates a call request including the telephone number of the call device 300a as the transmission source and the telephone number of the call device 300b as the destination device, and transmits the generated call request to the relay device 100a (step S213). . In the present embodiment, the telephone number of the call device 300a as the transmission source, that is, the calling number is “08011112222”, and the phone number of the call device 300b as the destination device, that is, the called number is “044771111”. To do.

  Since the relay device 100a has received the congestion occurrence notification, the relay device 100a rejects the relay of the call request transmitted from the call device 300a (step S214), and makes a reservation instructing transmission of the call reservation including the called number and the calling number. The instruction is transmitted to the communication device 300a (step S215).

  Call device 300a receives the reservation instruction from relay device 100a. Then, the call device 300a transmits a call reservation including the calling number and the called number to the relay device 100a (step S216), and stores the called number included in the call reservation in the reservation data 331 (step S217). For example, as shown in FIG. 17, the call device 300 a stores the called number “044777711” included in the call reservation in the reservation data 331. FIG. 17 is a diagram (part 1) illustrating a transition of reservation data of the communication device 300a.

  When the relay device 100a receives the call reservation transmitted from the call device 300a, the relay device 100a specifies the priority order of the correspondence relationship included in the call reservation based on the order of receiving the call reservation (step S218). Here, it is assumed that the relay device 100a receives the first call reservation and specifies the priority of the correspondence relationship included in this call reservation as “1”. The relay device 100a transmits a registration request including the correspondence relationship included in the call reservation and the specified priority as reservation information to the reservation status management server 200a (step S219).

  Upon receiving the registration request transmitted from the relay device 100a, the reservation status management server 200a stores the correspondence between the calling number and called number included in the registration request and the priority order in the reservation information DB 203 as reservation information (step S220). . For example, as illustrated in FIG. 18, the reservation status management server 200 a stores the correspondence between the calling number “08011112222” and the called number “044777711” included in the registration request and the priority “1” in the reservation information DB 203. FIG. 18 is a diagram (part 1) illustrating a transition of the reservation information DB of the reservation status management server 200a.

  Thereafter, the reservation status management server 200a transmits, to the relay device 100a, reservation registration completion reporting that the registration of registration information has been completed (step S221). When receiving the reservation registration completion from the reservation status management server 200a, the relay device 100a transfers the reservation registration completion to the call device 300a as necessary (step S222).

  Next, an example of a series of processing from when the communication system according to the present embodiment detects a free line to when a call is established will be described. FIG. 19 is a sequence diagram illustrating an example of a processing procedure for establishing a call by the communication system according to the present embodiment.

  As illustrated in FIG. 19, the relay device 100a detects a free line (step S231), and transmits a reservation information request for requesting transmission of a correspondence relationship having a priority of “1” to the reservation status management server 200a ( Step S232).

  When the reservation status management server 200a receives the reservation information request from the relay device 100a, the reservation status management server 200a extracts, from the reservation information DB 203, a correspondence relationship in which the priority is “1” (step S233). For example, as shown in the middle part of FIG. 20, the reservation status management server 200a extracts from the reservation information DB 203 the correspondence relationship between the calling number “08011112222” and the called number “047771111” having the priority “1”. FIG. 20 is a diagram (part 2) illustrating a transition of the reservation information DB of the reservation status management server 200a. The reservation status management server 200a transmits the extracted correspondence relationship to the relay device 100a (step S234). The reservation status management server 200a updates the priority order of the reservation information DB 203 (step S235). For example, as shown in the lower part of FIG. 20, the reservation status management server 200a updates the priority by reassigning values to the remaining correspondences other than the extracted correspondences in ascending order.

  When the relay device 100a receives the correspondence from the reservation status management server 200a, the relay device 100a permits re-transmission of the call request of the call device 300a having the calling number of the correspondence (step S236). The relay device 100a transmits a call permission including the called number corresponding to the permitted calling number to the call device 300a (step S237).

  When receiving the call permission transmitted from the relay device 100a, the call device 300a obtains the called number that matches the called number included in the call permission from the reservation data 331 (step S238). The call device 300a transmits a call request including the acquired called number as a destination to the relay device 100a (step S239). The call device 300a deletes the called number included in the call request from the reservation data 331 (step S240). For example, as shown in FIG. 21, the call device 300 a deletes the called number “044777711” included in the call request from the reservation data 331. FIG. 21 is a diagram (part 2) illustrating a transition of reservation data of the communication device 300a.

  When receiving the call request transmitted from the call device 300a, the relay device 100a transfers the received call request to the adjacent relay device 20a (step S241). When the relay device 20a receives the call request transferred from the relay device 100a, the relay device 20a performs predetermined routing with the destination number included in the call request as a destination. When receiving the call response returned from the destination device that has received the call request, the relay device 20a transfers the received call response to the relay device 100a (step S242). The relay device 100a transfers the call response transmitted from the relay device 20a to the call device 300a (step S243).

  The call device 300a establishes a call by receiving the call response transferred by the relay device 100a (step S244).

  Next, an example of a series of processes in which the communication system according to the present embodiment detects an idle line and requests postponement of a call request retransmission will be described. FIG. 22 is a sequence diagram illustrating an example of a processing procedure in which the communication system according to the present embodiment requests postponement of retransmission of a call request. In FIG. 22, the processing from step S251 to step S257 corresponds to the processing from step S231 to step S237 shown in FIG. 19, and thus detailed description thereof is omitted.

  As shown in FIG. 22, when receiving a call permission transmitted from the relay device 100a, the call device 300a accepts a user operation and transfers a postponement request to the relay device 100a instead of the call request (step S258).

  When the relay device 100a receives the postponement request transmitted from the call device 300a, the relay device 100a transfers the received postponement request to the reservation status management server 200a (step S259).

  When receiving the postponement request transferred by the relay device 100a, the reservation status management server 200a performs the following processing. That is, the reservation status management server 200a refers to the reservation information DB 203 and updates the telephone number of the call device 300a that is the transmission source of the postponement request, that is, the priority of the entry corresponding to the calling number to the lowest order (step S260). For example, as shown in the middle part of FIG. 23, the reservation status management server 200a updates the priority of the entry corresponding to the postponement request origination number “08011112222” to the lowest order “6”. FIG. 23 is a diagram (part 3) illustrating a transition of the reservation information DB 203 of the reservation status management server 200a.

  The reservation status management server 200a updates the priority order of the reservation information DB 203 (step S261). For example, as shown in the lower part of FIG. 23, the reservation status management server 200a updates the priority order by reassigning values in ascending order to all the correspondence relationships in the reservation information DB 203. The reservation status management server 200a returns a postponement completion to the relay device 100a (step S262). When the relay device 100a receives the postponement completion returned from the reservation status management server 200a, the relay device 100a transfers the received postponement completion to the call device 300a as necessary (step S263).

  Next, an example of a series of processes in which the communication system according to the present embodiment detects an idle line and requests cancellation of retransmission of a call request will be described. FIG. 24 is a sequence diagram illustrating an example of a processing procedure in which the communication system according to the present embodiment requests cancellation of retransmission of a call request. In FIG. 24, the processing of step S271 to step S277 corresponds to the processing of step S231 to step S237 shown in FIG.

  As shown in FIG. 24, when receiving a call permission transmitted from the relay device 100a, the call device 300a accepts the user's operation and transfers a stop request instead of the call request to the relay device 100a (step S278). The call device 300a deletes the called number that matches the called number included in the call permission from the reservation data 331 (step S279). For example, as shown in FIG. 25, the call device 300 a deletes the called number that matches the called number “044777711” included in the call permission from the reservation data 331. FIG. 25 is a diagram (part 3) illustrating a transition of reservation data of the communication device 300a.

  The reservation status management server 200a receives the cancellation request transferred by the relay device 100a (step S280). Then, the reservation status management server 200a refers to the reservation information DB 203 and deletes the telephone number of the communication device 300a that is the transmission source of the cancellation request, that is, the entry corresponding to the calling number (step S281). For example, the reservation status management server 200a deletes the entry corresponding to the call origination number “08011112222” of the cancellation request, as shown in the middle part of FIG. FIG. 26 is a diagram (part 4) illustrating a transition of the reservation information DB 203 of the reservation status management server 200a.

  The reservation status management server 200a updates the priority order of the remaining entries in the reservation information DB 203 (step S282). For example, as shown in the lower part of FIG. 26, the reservation status management server 200a updates the priority order by reassigning values to the remaining correspondences in the reservation information DB 203 in ascending order. The reservation status management server 200a returns a cancellation completion to the relay device 100a (step S283). When the relay device 100a receives the cancellation completion returned from the reservation status management server 200a, the relay device 100a transfers the received cancellation completion to the call device 300a as necessary (step S284).

  Next, an example of a series of processes in which the communication system according to the present embodiment detects the release of the congestion state of the communication line and deletes reservation information will be described. FIG. 27 is a sequence diagram illustrating an example of a processing procedure in which the communication system according to the present embodiment deletes reservation information.

  As shown in FIG. 27, the congestion monitoring device 10 detects the release of the congestion state of the communication line (step S291), and transmits a congestion release notification to the relay device 100a (step S292).

  When the relay apparatus 100a receives the congestion release notification transmitted from the congestion monitoring apparatus 10, the relay apparatus 100a transmits a reservation information request for requesting transmission of all correspondences to the reservation status management server 200a (step S293).

  When the reservation status management server 200a receives the reservation information request transmitted from the relay device 100a, the reservation status management server 200a refers to the reservation information DB 203 and returns all correspondences to the relay device 100a (step S295). The reservation status management server 200a deletes all entries in the reservation information DB 203 (step S294). For example, the reservation status management server 200a deletes all entries in the reservation information DB 203 as shown in FIG. FIG. 28 is a diagram (part 5) illustrating a transition of the reservation information DB 203 of the reservation status management server 200a.

  When the relay apparatus 100a receives all the correspondences from the reservation status management server 200a, the relay apparatus 100a permits the re-transmission of the call request of the call device 300a having the corresponding calling party number (step S296). The relay device 100a transmits a call permission including the called number corresponding to the permitted calling number to the call device 300a (step S297).

  When receiving the call permission transmitted from the relay device 100a, the call device 300a deletes all called numbers in the reservation data 331 (step S298).

  As described above, in the communication system according to the present embodiment, when the communication line is congested, the call device 300 manages the telephone number of the destination device included in the call reservation to the relay device 100 as reservation data. The call device 300 stops transmitting a call request including a phone number that matches the reservation data until the call permission from the relay device 100 is received after the call reservation is made. For this reason, in the communication system of the present embodiment, congestion of the communication line can be appropriately eliminated without disconnecting the established call.

  Further, in the communication system of the present embodiment, when an idle line is detected, the relay device 100 specifies the priority order of the correspondence relationship between the calling number and the called number based on the reception order of the call reservation from the calling device 300. Then, a call permission is transmitted to the call device 300 based on the identified priority order. For this reason, in the communication system of the present embodiment, it is possible to permit the call device 300 to retransmit the call request fairly in the order in which the call reservations are executed, avoiding unnecessary repetition of calling, and as a result The communication line congestion can be quickly resolved.

  Further, in the communication system according to the present embodiment, when the relay device 100 receives the postponement request from the call device 300, the call permission priority corresponding to the transmission source of the postponement request becomes lower than the current priority. Update as follows. For this reason, in the communication system of the present embodiment, even when the user of the call device 300 cannot make a call immediately, even when the call device 300 receives a call permission, it is possible to flexibly cope with it.

  Further, in the communication system of the present embodiment, when the relay device 100 receives a cancel request from the call device 300, the reservation information corresponding to the transmission source of the cancel request is deleted from the reservation information DB 203 of the reservation status management server 200. To do. For this reason, in the communication system of the present embodiment, even when the user of the call device 300 does not want to retransmit the call request, even when the call device 300 receives a call permission, it can flexibly cope with it.

100 relay device 101 congestion monitoring IF unit 102 relay IF unit 103 call IF unit 104 reservation status management IF unit 105 relay control unit 106 reservation status registration unit 107 call permission unit 200 reservation status management server 201 reservation status management IF Unit 202 reservation status management unit 203 reservation information DB
300 Call device 301 Call IF unit 302 User IF unit 303 Storage unit 304 Reservation management unit 305 Call control unit 331 Reservation data

Claims (6)

A communication system including a call device and a relay device that relays a call request transmitted from the call device to a destination device that is another call device that is a destination of the call request using a communication line,
The relay device is
Reservation instruction for refusing to relay a call request transmitted from the call device when the communication line is congested and instructing to transmit a call reservation including identification information of the call device and identification information of the destination device A reservation instructing unit for transmitting to the call device;
When a call reservation transmitted from the call device is received, a correspondence relationship between the identification information of the call device and the identification information of the destination device included in the call reservation based on the order of receiving the call reservation A registration unit that identifies the priority order of the registered information, and registers the identified priority order in association with the correspondence relationship ;
When the release of a part of the communication lines is detected, the destination device corresponding to the identification information is permitted while allowing the call device in which the identification information is registered by the registration unit to retransmit the call request. A call permission unit that transmits a call permission including the identification information to the calling device,
The communication device is:
A reservation management unit that, when receiving a reservation instruction transmitted from the relay device, transmits the call reservation to the relay device and manages identification information of the destination device included in the call reservation as reservation data;
When a call permission transmitted from the relay device is received, the call request including the identification information of the destination device included in the call permission as a destination is retransmitted to the relay device, and the destination device is identified. A call control unit that deletes information from the reservation data and stops transmission of the call request including, as a destination, identification information of the destination device that matches the reservation data when the call permission is not received; Prepared ,
The call permission unit determines the call device that is permitted to retransmit the call request based on the priority when the release of some of the communication lines is detected, and Send the call permission,
When the call control unit receives the call permission, the call control unit receives a postponement request for requesting postponement of retransmission of the call request from the user of the call device, and if the postponement request is received, Instead, transfer the accepted postponement request to the relay device,
When the registration unit receives the postponement request from the call device, the registration unit updates the priority corresponding to the identification information of the call device that is the transmission source of the postponement request to be lower than the current priority. A communication system characterized by the above . When the call control unit receives the call permission, the call control unit receives a stop request for requesting the stop of retransmission of the call request from the user of the call device, and if the stop request is received, Instead, the received cancellation request is transferred to the relay device, and the identification information of the destination device included in the call permission is deleted from the reservation data,
When the registration unit receives the cancellation request from the call device, the registration unit deletes a correspondence relationship between the identification information of the call device that is a transmission source of the cancellation request and the identification information of the destination device. The communication system according to claim 1 . The call permission unit permits retransmission of the call request to all the call devices whose identification information is registered by the registration unit at the time of release of the congestion, and all the corresponding to the identification information communication system according to claim 1 or 2, characterized in that sending a call grant including the identification information of the destination device to the communication device. The relay device in a communication system including a call device and a relay device that relays a call request transmitted from the call device to a destination device, which is another call device that is a destination of the call request, using a communication line. And
Reservation instruction for refusing to relay a call request transmitted from the call device when the communication line is congested and instructing to transmit a call reservation including identification information of the call device and identification information of the destination device A reservation instructing unit for transmitting to the call device;
When a call reservation transmitted from the call device is received, a correspondence relationship between the identification information of the call device and the identification information of the destination device included in the call reservation based on the order of receiving the call reservation A registration unit that identifies the priority order of the registered information, and registers the identified priority order in association with the correspondence relationship ;
When the release of a part of the communication lines is detected, the destination device corresponding to the identification information is permitted while allowing the call device in which the identification information is registered by the registration unit to retransmit the call request. A call permission unit that transmits a call permission including the identification information to the calling device,
The call permission unit determines the call device that is permitted to retransmit the call request based on the priority when the release of some of the communication lines is detected, and Send the call permission,
When the call device receives the call permission, the call device accepts a postponement request for requesting postponement of retransmission of the call request from the user of the call device. If the postponement request is accepted, the call request is replaced with the call request. Then, in a situation where the accepted postponement request is transferred to the relay device, the registration unit, when receiving the postponement request from the telephone device, includes the identification information of the telephone device that is the transmission source of the postponement request. A relay apparatus, wherein the corresponding priority is updated so as to be lower than the current priority . The call device in a communication system including a call device and a relay device that relays a call request transmitted from the call device to a destination device that is another call device that is a destination of the call request using a communication line. And
Instructed to transmit a call reservation including identification information of the communication device and identification information of the destination device from the relay device that refuses to relay a call request transmitted from the communication device when the communication line is congested A reservation management unit that transmits the call reservation to the relay device when the reservation instruction is received, and manages the identification information of the destination device included in the transmitted call reservation as reservation data;
When the call reservation is received , the priority order of the correspondence relationship between the identification information of the call device and the identification information of the destination device included in the call reservation is specified based on the order of receiving the call reservation. The relay device that registers the specified priority in association with the correspondence relationship permits the call device in which the identification information is registered to retransmit the call request, and corresponds to the identification information. When the call permission including the identification information of the destination device is received, the call request including the identification information of the destination device included in the call permission as a destination is retransmitted to the relay device, and the identification of the destination device is performed. If the information is deleted from the reservation data and the call permission has not been received, transmission of the call request including the destination device identification information that matches the reservation data as a destination is stopped. And a call control section which,
When the relay device detects the release of some of the communication lines , the relay device determines the call device that is permitted to retransmit the call request based on the priority, and the determined call device When the call permission is transmitted and a deferral request is received from the call device, the priority corresponding to the identification information of the call device that is the transmission source of the deferral request is updated to be lower than the current priority When the call control unit receives the call permission, the call control unit receives the postponement request for requesting postponement of retransmission of the call request from the user of the call device, and receives the postponement request. A call device that transfers the accepted postponement request to the relay device instead of the call request . Communication control executed by a communication system including a call device and a relay device that relays a call request transmitted from the call device to a destination device that is another call device that is a destination of the call request using a communication line A method,
The relay device rejects relaying of a call request transmitted from the call device when the communication line is congested, and transmits a call reservation including identification information of the call device and identification information of the destination device. Send a reservation instruction to instruct the call device,
When the call device receives a reservation instruction transmitted from the relay device, the call device transmits the call reservation to the relay device, and the identification information of the destination device included in the transmitted call reservation is used as reservation data. Manage,
When the relay device receives a call reservation transmitted from the call device , based on the order of receiving the call reservation, the call device identification information and the destination device identification included in the call reservation Identify the priority of the correspondence relationship with the information, register the identified priority in association with the correspondence relationship ,
When the relay device detects the release of a part of the communication lines, the relay device permits retransmission of the call request to the call device in which the identification information is registered, and the destination corresponding to the identification information Transmitting a call permission including the identification information of the device to the call device;
When the call device receives a call permission transmitted from the relay device, the call device including the identification information of the destination device included in the call permission as a destination is retransmitted to the relay device; If the identification information of the destination device is deleted from the reservation data and the call permission has not been received, transmission of the call request including the destination device identification information that matches the reservation data as a destination is stopped. look at including it,
The process of transmitting the call permission determines the call device that is permitted to retransmit the call request based on the priority when the release of some of the communication lines is detected, and determines the determined call Including transmitting the call permission to a device,
When the call permission is received, the process of stopping transmission of the call request accepts a postponement request for postponing retransmission of the call request from the user of the call device, and accepts the postponement request. , In place of the call request, including a process of transferring the accepted postponement request to the relay device,
In the process of registering the priority, when the postponement request is received from the call device, the priority corresponding to the identification information of the call device that is the transmission source of the postponement request becomes lower than the current priority. The communication control method characterized by including the process updated as follows .

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