Call system, call terminal, communication control device, call program, communication control program, and call method

Abstract

To provide a communication system capable of continuing communication without disconnecting a call even when a network of a communication terminal is changed.SOLUTION: In a call system 9 in which a call control signal is exchanged between a call terminal 10 and a call control device 3 via a communication control device 2, the call terminal 10 includes change notification means for notifying the call control device 3 of the network information change on the basis of the operating state of a softphone operating on the call terminal when the connected network information is changed. The communication control device 2 includes control means that transfers the change notification to the call control device 3, and performs control to continue communication with the call terminal 10 on the basis of the operating state when the communication control device 2 receives the change notification from the call terminal 10.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a calling system, a calling terminal, a communication control device, a calling program, a communication control program, and a calling method, and can be applied to, for example, a terminal and a system that installs a calling program that is a calling application and makes calls. [Background technology]

[0002] In recent years, with the spread of flat-rate data communication services for smartphones, there has been an increase in cases where IP-PBX IP telephone applications (hereafter referred to as "softphones") are installed on smartphones and internal calls are made using softphones via an Internet connection not only in the office but also when on the go.

[0003] Generally, softphones are call-controlled by "SIP (RFC2361)", and the IP-PBX manages the registration information of the softphones by using the REGISTER function of SIP. In addition, as an example of a configuration of a communication system including a softphone, there is a communication system described in Patent Document 1. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2013-90288 A Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, in smartphones and the like, temporary disconnections due to network changes, such as switching from LTE (Long Term Evolution) to wireless LAN, frequently occur.

[0006] Conventionally, when a smartphone's network is switched and its IP address is changed, the softphone on the smartphone sends information to the IP-PBX to clear its registration information to avoid a state mismatch with before the network change. The softphone then requests the IP-PBX to re-register with the registration information that includes the new IP address.

[0007] However, there was a problem in that if a call was coming in or in progress on the softphone on the smartphone at the time the registration information was cleared, the call would be forcibly disconnected.

[0008] Therefore, there is a demand for a call system, a call terminal, a communication control device, a call program, a communication control program, and a call method that can continue communication without disconnecting a call even if the network of the call terminal is changed. [Means for solving the problem]

[0009] The first aspect of the present invention is a call system in which a call terminal and a call control device exchange call control signals via a communication control device, comprising: (1) the call terminal, The call terminal; Connected Network has been switched from an LTE network to a wireless LAN or from a wireless LAN to an LTE network. If changed If, The operating state of the softphone operating on the call terminal When you are on a call or receiving a call, The network With the change of IP address (2) when the communication control device receives the change notification from the call terminal, the communication control device transfers the change notification to the call control device, The softphone Operating Status When you are on a call or receiving a call The present invention is characterized by comprising a control means for controlling the continuation of communication with the call terminal.

[0010] The second aspect of the present invention is a call terminal that transmits and receives a call control signal to and from a call control device via a communication control device, The call terminal; Connected Network has been switched from an LTE network to a wireless LAN or from a wireless LAN to an LTE network. If changed , the above The operating status of the softphone running on the terminal When you are on a call or receiving a call , the call control device, With the change of IP address The present invention is characterized by comprising a change notification means for notifying the change.

[0011] The third aspect of the present invention is a communication control device that relays a call control signal between a communication terminal and a call control device, In the call terminal, Connected Network When the communication network is changed from an LTE communication network to a wireless LAN or vice versa, when the operation state of the softphone operating on the communication terminal is in a call or in an incoming call, a new IP address having a new IP address due to the change of the network is notified to the call control device. Upon receiving a change notification, the change notification is transferred to the call control device, The above Softphone operational status When you are on a call or receiving a call, The communication device further comprises a control means for controlling the continuation of communication with the communication terminal.

[0012] A fourth aspect of the present invention provides a call program for a call terminal that transmits and receives a call control signal to and from a call control device via a communication control device, comprising: The call terminal; Connected Network has been switched from an LTE network to a wireless LAN or from a wireless LAN to an LTE network. If changed 、 The operating state of the softphone operating on the call terminal When you are on a call or receiving a call , the call control device, With the change of IP address The present invention is characterized in that it functions as a change notification means for notifying changes.

[0013] A communication control program according to a fifth aspect of the present invention includes a computer that is mounted on a communication control device that relays a call control signal between a call terminal and a call control device, the computer controlling the communication terminal, In the call terminal, Connected Network When the communication network is changed from an LTE communication network to a wireless LAN or vice versa, when the operation state of the softphone operating on the communication terminal is in a call or in an incoming call, a new IP address having a new IP address due to the change of the network is notified to the call control device. Upon receiving a change notification, the change notification is transferred to the call control device, The above Softphone operational status When you are on a call or receiving a call, The communication device is characterized in that it functions as a control means for controlling the continuation of communication with the call terminal.

[0014] The sixth aspect of the present invention is a communication method in which a communication terminal and a call control device exchange a call control signal via a communication control device, the communication terminal comprising: The call terminal; Connected Network has been switched from an LTE network to a wireless LAN or from a wireless LAN to an LTE network. When changed, the operating state of the softphone operating on the call terminal When you are on a call or receiving a call, The network With the change of IP address When the communication control device receives the change notification from the call terminal, the communication control device transfers the change notification to the call control device and updates the operation state When you are on a call or receiving a call, The communication terminal is characterized in that it controls to continue communication with the communication terminal. Effect of the Invention

[0015] According to the present invention, even if the network of a call terminal is changed, communication can be continued without disconnecting the call. [Brief description of the drawings]

[0016] [Figure 1] 1 is an overall configuration diagram showing the overall configuration of a call system (audio communication system) according to an embodiment. [Diagram 2] FIG. 2 is an internal configuration diagram showing the internal configuration of a mobile terminal according to the embodiment. [Diagram 3] FIG. 2 is an internal configuration diagram showing the internal configuration of a VoIP-GW according to an embodiment. [Figure 4] FIG. 4 is a sequence diagram showing the operation of a call process (a call process when a network switch occurs during an incoming call) according to the embodiment. [Diagram 5] FIG. 4 is a sequence diagram showing the operation of a call process (a call process when a network switching occurs during a call) according to the embodiment. [Figure 6] FIG. 1 is a sequence diagram showing an operation of a conventional call processing. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] (A) Main embodiment Hereinafter, an embodiment of a call system, a call terminal, a communication control device, a call program, a communication control program, and a call method according to the present invention will be described in detail with reference to the drawings.

[0018] (A-1) Configuration of the embodiment [Overall configuration of the call system] FIG. 1 is a diagram showing the overall configuration of a call system (audio communication system) according to an embodiment.

[0019] In FIG. 1, a telephone system 9 according to the embodiment includes an in-house system 20 including a VoIP (Voice over IP)-GW 2 as a communication control device, an IP-PBX 3, an IP telephone 4, a router 5, etc., and a mobile terminal 10 as a telephone terminal.

[0020] Although only one IP telephone 4 is shown in FIG. 1, a plurality of IP telephones 4 may be used.

[0021] The mobile terminal 10 is a telephone terminal having a communication function, a microphone, a speaker, etc., and may be, for example, a smartphone, a tablet terminal, a wearable terminal, a personal computer, a game terminal, etc. The mobile terminal 10 is connected to, for example, an LTE communication network 6-2, a wireless LAN 6-3, and the Internet 6-1, etc., and transmits and receives information to and from the components that make up the in-house system 20.

[0022] Although the hardware configuration of the mobile terminal 10 is not shown, it can be a device equipped with a CPU, ROM, RAM, EEPROM, an input / output interface, a communication device (communication unit), and the like, similar to existing calling terminals. The CPU executes processing programs (e.g., calling program 1, etc.) stored in the ROM to perform various processes. Also, the calling program 1 for making calls on the mobile terminal 10 is installed in the mobile terminal 10.

[0023] The call program 1 is an application for making a call on a call terminal such as a mobile terminal 10, and is a so-called softphone. The call program 1 holds the global IP address of the destination device to which the call control signal is sent, and sends the call control signal to the global IP address. For example, the destination global IP address is the IP address of a router 5 connected to the Internet 6-1.

[0024] The VoIP-GW2 is a device that relays call control signals and RTP packets. Although the hardware configuration of the VoIP-GW2 is not shown, it can be a device equipped with a CPU, ROM, RAM, EEPROM, an input / output interface, a communication device (communication unit), and the like, similar to existing network devices. The CPU executes a processing program (a call control program 25, described later) stored in the ROM, thereby carrying out various processes. The VoIP-GW2 also has a function of encrypting communication contents by configuring a VPN with the mobile terminal 10 in order to ensure security with an external network section (such as the Internet 6-1).

[0025] The IP-PBX 3 is a call control device that controls call processing between the IP telephone 4 and the call program 1 (mobile terminal 10). The IP-PBX 3 performs call control according to, for example, a predetermined call control protocol. The call control protocol is not particularly limited, and in this embodiment, for example, the case where SIP (Session Initiation Protocol) is applied is illustrated.

[0026] The IP telephone 4 is a telephone connected to the LAN of the local area system 20 , and communication processing is controlled by the IP-PBX 3 .

[0027] The router 5 is a network device that is connected to the Internet 6-1 via a global IP address. This global IP address is a fixed IP address that is always connected according to a contract with an Internet connection service provider.

[0028] The router 5 transfers (NAT connection) the communication packet received at a specific communication port of this global IP address to the local IP address of the VoIP-GW2 on the LAN side. This operation (setting) by the router 5 allows the call program 1 running on the mobile terminal 10 connected via LTE to connect to the router 5 via the Internet 6-1 and communicate with the VoIP-GW2 connected to the LAN of the local area system 20.

[0029] [Mobile terminal and calling program] FIG. 2 is a diagram showing the internal configuration of the mobile terminal according to the embodiment.

[0030] In FIG. 2, a mobile terminal 10 according to the embodiment includes a control unit 11, a communication unit 12, and a storage unit 13, and a calling program 1 is installed in the storage unit 13.

[0031] The control unit 11 controls the processing of the mobile terminal 10.

[0032] The communication unit 12 is an interface for transmitting and receiving information. In this embodiment, the communication unit 12 is connectable to the LTE communication network 6-2 or the wireless LAN 6-3 by a user's selection or a predetermined setting.

[0033] The call program 1 establishes a call by sending and receiving a call control signal in accordance with a call control protocol, and performs voice communication. The call program 1 has a network switch detection unit 101, an encryption communication processing unit 102, and a change information notification unit 103.

[0034] The network switching detection unit 101 detects that the network to which the communication unit 12 connects has been switched from the LTE communication network 6-2 or the wireless LAN 6-3 to either one of them.

[0035] The encryption communication processing unit 102 enables encrypted communication (VPN connection) for communication data of a network (Internet 6-1, etc.) between the mobile terminal 10 and the VoIP-GW2. Specifically, the encryption communication processing unit 102 transmits authentication information, such as an ID and password for a VPN connection, to the VoIP-GW2 and requests the establishment of a VPN connection. Then, the VoIP-GW2 performs authentication using the ID and password for the VPN connection, and if the authentication is successful, the VPN connection is established.

[0036] When the change information notification unit 103 receives an event from the network switching detection unit 101 that the network information has been changed, it notifies the VoIP-GW2 of the update of the network information (for example, notification of a new IP address associated with the network change) based on the state of the call program 1 itself (standby state, incoming call state, or in-call state).

[0037] [VoIP-GW] FIG. 3 is a diagram showing the internal configuration of the VoIP-GW according to the embodiment.

[0038] In FIG. 3, the VoIP-GW 2 according to the embodiment includes a control unit 21, a communication unit 22, and a storage unit .

[0039] The control unit 21 controls the processing performed by the VoIP-GW 2. The communication unit 22 transmits and receives information to and from the LAN in the local area system 20.

[0040] The storage unit 23 stores a call control program 25 that controls call processing with the call program 1 installed in the mobile terminal 10. Note that the processing unit implemented by the control unit 21 executing the call control program 25 is also referred to as a "communication control unit."

[0041] The call control program 25 relays a call control signal exchanged between the call program 1 installed in the mobile terminal 10 and the IP-PBX 3 .

[0042] Furthermore, when the call control program 25 receives a request to establish a VPN connection via the Internet 6-1, it authenticates the request source (the call program 1 of the mobile terminal 10) and then establishes the VPN connection. For this authentication, for example, a VPN connection ID and password sent from the request source are used.

[0043] Furthermore, the call control program 25 has a function of changing the communication destination of the call program 1 while maintaining the call state with the IP-PBX 3, even if a network update notification is received from the call program 1 (change information notification unit 103) of the mobile terminal 10.

[0044] (A-2) Operation of the embodiment Next, the operation of the call processing in the call system 9 according to the embodiment will be described in detail with reference to the drawings. First, problems with the conventional operation will be pointed out, and then the operation of the call system 9 according to the present embodiment that solves the problems will be described.

[0045] (A-2-1) Conventional call processing operation FIG. 6 is a sequence diagram showing the operation of conventional call processing.

[0046] The conventional call system in FIG. 6 differs from the call system 9 of this embodiment in that a VoIP-GW200 (a conventional VoIP-GW) is applied instead of the VoIP-GW2, and a mobile terminal 300 (a mobile terminal equipped with a conventional call program 301) is applied instead of the mobile terminal 10.

[0047] [S1, S2] The call program 301 of the mobile terminal 300 performs call control processing with the IP telephone 4. After this, calls using RTP packets are possible between the IP telephone 4 and the mobile terminal 300 (call program 301).

[0048] [S3, S4] When a network switch is performed during a call, the call program 301 establishes a VPN connection with the VoIP-GW 200 via the new network.

[0049] [S5, S6] Next, the call program 301 notifies the IP-PBX 3 to clear its own registration information (notifies the IP-PBX 3 of deregistration information) in order to avoid a state mismatch with before the network change.

[0050] [S7, S8] When the IP-PBX 3 clears the registration information of the call program 301, it notifies the IP telephone 4 that the call destination (call program 301) of the IP telephone 4 is absent. In other words, the call between the call program 301 and the IP-PBX 3 is terminated.

[0051] [S9, S10] The call program 301 notifies the IP-PBX 3 of the registration information including the new network information.

[0052] As described above, the conventional call processing has a problem that the call is terminated when the mobile terminal 300 switches networks.

[0053] (A-2-2) Call processing according to the embodiment (call processing when network switching occurs during incoming call) FIG. 4 is a sequence diagram showing the operation of a call process (a call process when a network switch occurs during an incoming call) according to the embodiment.

[0054] [S101] The IP telephone 4 transmits a call request (INVITE) to the call program 1 via the IP-PBX 3 etc. When the call program 1 of the mobile terminal 10 receives the call request, it stores the caller information (IP address and audio media information) of the IP telephone 4 internally until the call is released.

[0055] [S102] When the mobile terminal 10 receiving a call from the call program 1 undergoes network switching (for example, when a network change occurs from LTE to wireless LAN), the mobile terminal 10 starts a VPN connection in the new network (under a wireless LAN environment).

[0056] [S103] The VoIP-GW2 authenticates the VPN connection request from the call program 1 and then permits the connection.

[0057] [S104] When the call program 1 receives the connection permission from the VoIP-GW 2, it transmits information for continuing the registration to the IP-PBX 3. Note that the VoIP-GW 2 continues to use the connection (TCP connection or UDP port) that was used for communication with the IP-PBX 3 before the network change of the mobile terminal 10.

[0058] [S105] The IP-PBX 3 transmits a response to the re-registration to the telephone program 1. After this, call control of the VoIP-GW 2 is performed for the telephone program 1 after the network change.

[0059] [S106] The call program 1 transmits a response to the call request in step S101. The responder information (IP address and voice media information) transmitted is the information after the network is switched. After this, a call using RTP packets is possible between the IP telephone 4 and the mobile terminal 10 (call program 1).

[0060] [S107] The call program 1 requests the IP telephone 4 to end the call.

[0061] [S108] The IP telephone 4 transmits a response to the call termination in step S107 described above. The call is released in the entire call system 9.

[0062] [S109] The call program 1 requests the IP-PBX 3 to cancel registration (sends information about canceling registration) in order to resolve the discrepancy in status before the network change.

[0063] [S110] After processing the deregistration request, the IP-PBX 3 transmits a response to the deregistration request from the calling program 1.

[0064] [S111] The call program 1 sends a registration request to the IP-PBX 3 .

[0065] [S112] The IP-PBX 3 transitions the call program 1 to a registration state, and returns a response to the call program 1.

[0066] (A-2-3) Call processing according to the embodiment (call processing when network switching occurs during a call) FIG. 5 is a sequence diagram showing the operation of call processing (call processing when network switching occurs during a call) according to the embodiment.

[0067] [S201] The call program 1 transmits a call request to the IP telephone 4 via the IP-PBX 3 or the like.

[0068] [S202] The IP telephone 4 performs a response process for the call program 1. After this, a call using RTP packets is possible between the IP telephone 4 and the mobile terminal 10 (call program 1).

[0069] [S203, S204] When a network change (eg, change from LTE to wireless LAN) occurs during a call, the mobile terminal 10 (call program 1) establishes a VPN connection in the new network environment, similar to steps S102 and S103 described above.

[0070] [S205, S206] As in step S104, the call program 1 transmits information about continuation of registration (re-registration) to the IP-PBX 3. Then, as in step S105, the IP-PBX 3 responds to the re-registration to the call program 1.

[0071] [S207] The call program 1 updates the caller information (IP address and voice media information) in the VoIP-GW 2 .

[0072] [S208] The VoIP-GW2 responds to the update of the caller information to the call program 1. After this, the voice communication of the VoIP-GW2 is performed for the mobile terminal 10 after the network change.

[0073] [S209~S214] The process after the call ends is similar to steps S107 to S112 described above, and therefore the description will be omitted.

[0074] (A-3) Effects of the embodiment According to the above embodiment, a user of the call program 1 (softphone) can move between networks without disconnecting a call even when a call is incoming or in progress.

[0075] (B) Other embodiments Although various modified embodiments have been mentioned in the above-described embodiment, the present invention can also be applied to the following modified embodiments.

[0076] (B-1) In the above-described embodiment, the network switching between LTE and wireless LAN has been described. However, as long as it is possible for the OS of the mobile terminal 10 to notify the call program 1 of a network change, the present invention can also be applied to networks such as public LTE and private LTE.

[0077] (B-2) In addition, in the above-mentioned call system 9, LTE has been used as an example of a wireless communication system, but this is not limited to this, and wireless communication systems such as 3G, 4G, and 5G can also be applied in the same manner.

[0078] (B-3) When the mobile terminal 10 switches networks, the communication ports for call control and voice traffic temporarily become free on the VoIP-GW2. In step S104 described above, if the telephone number included in REGISTER matches the telephone number before the network switch, the VoIP-GW2 reallocates the free communication ports to continue the communication. After the call is completed, the port information reallocated in step S109 described above is released. This is based on the idea that it is better to clear the information once to prevent communication ports from becoming free when a problem occurs in the communication port allocation.

[0079] As a modified example, the VoIP-GW2 may continue to use the reallocated port without releasing the port information. In this case, the processes of steps S109 to S114 can be omitted. Note that the REGISTER information in the above-mentioned step S104 and the above-mentioned step S111 is the same. [Explanation of symbols]

[0080] 1...call program, 4...IP telephone, 5...router, 6-1...Internet, 6-2...LTE communication network, 6-3...wireless LAN, 9...call system, 10...mobile terminal, 11, 21...control unit, 12, 22...communication unit, 13, 23...memory unit, 20...in-house system, 25...call control program, 101...network switching detection unit, 102...encryption communication processing unit, 103...change information notification unit.

Claims

1. In a call system in which a call terminal and a call control device transmit and receive a call control signal via a communication control device, The call terminal includes a change notification means for notifying the call control device of a change having a new IP address associated with the change of the network when the network connected to the call terminal is changed from an LTE communication network to a wireless LAN or from a wireless LAN to an LTE communication network and the operation state of a softphone operating on the call terminal is in a call or in an incoming call; The communication control device includes a control means for transferring the change notification to the call control device when the change notification is received from the call terminal, and for controlling the continuation of communication with the call terminal when the operating state of the softphone is in a call or receiving an incoming call. A communication system comprising:

2. The communication system according to claim 1, further comprising an encryption communication processing means for establishing an encryption communication path between the communication terminal and the communication control device when the network is changed from an LTE communication network to a wireless LAN or from a wireless LAN to an LTE communication network.

3. 3. The communication system according to claim 2, wherein the change notification means performs the change notification after the encryption communication path is established by the encryption communication processing means.

4. A call terminal that transmits and receives a call control signal to and from a call control device via a communication control device, A change notification means for notifying the call control device of a change having a new IP address associated with the change of the network when the network connected to the call terminal is changed from an LTE communication network to a wireless LAN or from a wireless LAN to an LTE communication network and the operating state of a softphone operating on the call terminal is in a call or in an incoming call. A call terminal comprising:

5. A communication control device that relays a call control signal between a call terminal and a call control device, A control means for receiving, from the call terminal, a change notification having a new IP address associated with the change of the network when the operation state of a softphone operating on the call terminal is in a call or receiving an incoming call, when the network connected to the call terminal is changed from an LTE communication network to a wireless LAN or from a wireless LAN to an LTE communication network, and transferring the change notification to the call control device and performing control to continue communication with the call terminal when the operation state of the softphone is in a call or receiving an incoming call. A communication control device comprising:

6. A computer installed in a call terminal that transmits and receives call control signals to and from a call control device via a communication control device, a change notification means for notifying the call control device of a change having a new IP address associated with the change of the network when the network connected to the call terminal is changed from an LTE communication network to a wireless LAN or from a wireless LAN to an LTE communication network and the operation state of a softphone operating on the call terminal is in a call or in an incoming call; A telephone call program characterized by causing the telephone call program to function as a telephone call.

7. A computer mounted on a communication control device that relays call control signals between a call terminal and a call control device, a control means for receiving, from the call terminal, a change notification having a new IP address associated with the change of the network when the operation state of a softphone running on the call terminal is in a call or receiving an incoming call, when the network connected to the call terminal is changed from an LTE communication network to a wireless LAN or from a wireless LAN to an LTE communication network, the change notification having a new IP address associated with the change of the network from the call terminal and the softphone is in a call or receiving an incoming call, the control means for transferring the change notification to the call control device and performing control to continue communication with the call terminal when the operation state of the softphone is in a call or receiving an incoming call; A communication control program characterized by causing the communication control program to function as a

8. A communication method in which a call terminal and a call control device exchange a call control signal via a communication control device, When a network connected to the call terminal is changed from an LTE communication network to a wireless LAN or from a wireless LAN to an LTE communication network, the call terminal notifies the call control device of a change having a new IP address associated with the change in the network when an operation state of a softphone running on the call terminal is in a call or in an incoming call; When the communication control device receives the change notification from the call terminal, the communication control device transfers the change notification to the call control device, and when the operation state is a call in progress or an incoming call, controls to continue communication with the call terminal. A calling method comprising:

Images