JP2012095159A - Relay device, wireless communication device, control method and communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent disconnection between a server and a client in a temporary non-communicable situation.SOLUTION: A relay device 200 relays communication between a first electronic device that performs communication via wireless communication and a second electronic device that sends a request to the first electronic device. The relay device 200 includes a communication unit 201 for receiving a connection confirmation message that is transmitted from the second electronic device confirming whether the communication with the first electronic device is possible or not, and a control unit 204 for transmitting a response to the second electronic device to the effect that the communication with the first electronic device is possible, instead of the first electronic device, when the connection confirmation message is received by the communication unit 201.

Description

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

  In a communication system including a wireless communication section in which wireless communication is performed, communication may be temporarily disabled in the wireless communication section due to a change in radio wave conditions or the like. If communication is temporarily disabled, the connection between the server and the client included in the communication system is cut off, and information exchanged so far may be wasted.

  In Patent Document 1, a plurality of communication paths are prepared in advance between a server and a client, and when communication on a communication path in use becomes impossible, the server and the client are used by using another communication path. A technique for maintaining the connection between the two has been proposed.

JP 2000-122947 A

  However, even if another communication path is used when communication is not possible as in the prior art described above, if it takes time to detect communication failure or switch communication paths, a timeout occurs and the server and client The connection between them may be broken.

  The present invention has been made in view of the above, and provides a relay device, a wireless communication device, a control method, and a communication system that can prevent a connection between a server and a client from being disconnected due to temporary inability to communicate The purpose is to do.

  In order to solve the above-described problems and achieve the object, the present invention provides a relay device that relays communication between a first electronic device and a second electronic device that transmits a request to the first electronic device. And receiving means for receiving a connection confirmation message transmitted to confirm that the second electronic device can communicate with the first electronic device; and the connection confirmation message by the receiving means. A relay control means for transmitting, to the second electronic device, a response to the effect that communication with the first electronic device is possible instead of the first electronic device. It is characterized by.

  Here, the communication apparatus further includes a communication state confirmation unit that determines whether communication with the first electronic device is possible, and the relay control unit cannot communicate with the first electronic device by the communication state confirmation unit. Is determined, the request from the second electronic device to the first electronic device is stored in the storage unit, and communication with the first electronic device is enabled by the communication state confirmation unit. It is preferable that the request stored in the storage unit is transmitted to the first electronic device after it has been determined.

  The request transmitted from the second electronic device may be a user operation performed in the second electronic device.

  In addition, the relay control unit may change the communication status confirmation unit from the second electronic device to the first electronic device while it is determined that communication with the first electronic device is impossible. When a request is received, it is preferable to transmit a message requesting to pause transmission of the request to the second electronic device.

  In addition, the relay control unit resumes transmission of a request to the second electronic device after it is determined by the communication state confirmation unit that communication with the first electronic device is possible. It is preferable to send a message requesting.

  The relay control unit pauses transmission of a request to the second electronic device when the communication state confirmation unit determines that communication with the first electronic device is impossible. It is also possible to send a message requesting that.

  In order to solve the above-described problems and achieve the object, the present invention provides a first electronic device, a second electronic device that transmits a request to the first electronic device, and the first electronic device. A connection confirmation message is received that relays communication between the device and the second electronic device, and the second electronic device transmits to confirm that communication with the first electronic device is possible. In a communication system including a relay device that transmits a response indicating that communication with the first electronic device is possible instead of the first electronic device to the second electronic device, It is a wireless communication device used as the first electronic device.

  In order to solve the above-described problems and achieve the object, the present invention relays communication between the first electronic device and the second electronic device that transmits a request to the first electronic device. A control method in a relay device, wherein the relay device receives a connection confirmation message transmitted to confirm that the second electronic device can communicate with the first electronic device; When the connection confirmation message is received, the relay device sends a response indicating that communication with the first electronic device is possible instead of the first electronic device. Transmitting to the network.

  In order to solve the above-described problems and achieve the object, the present invention provides a first electronic device, a second electronic device that transmits a request to the first electronic device, and the first electronic device. A communication system having a relay device that relays communication between a device and the second electronic device, wherein the relay device enables the second electronic device to communicate with the first electronic device A reception means for receiving a connection confirmation message to be transmitted to confirm that the first electronic device is replaced with the first electronic device when the connection confirmation message is received by the reception means; And a relay control means for transmitting a response to the effect that communication with the device is possible to the second electronic device.

  The relay device, the wireless communication device, the control method, and the communication system according to the present invention have an effect that the connection between the server and the client can be prevented from being disconnected due to temporary communication failure.

FIG. 1 is a diagram showing a schematic configuration of a communication system. FIG. 2 is a diagram illustrating an example of control when a connection confirmation message is received. FIG. 3 is a diagram illustrating an example of control when communication is temporarily disabled. FIG. 4 is a block diagram showing a functional configuration of the mobile phone terminal. FIG. 5 is a block diagram illustrating a functional configuration of the relay apparatus. FIG. 6 is a diagram illustrating an example of server management data. FIG. 7 is a flowchart showing the processing procedure of the communication status confirmation unit. FIG. 8 is a flowchart showing the processing procedure of the relay control unit.

  Hereinafter, the present invention will be described in detail with reference to the drawings. The present invention is not limited to the following description. In addition, constituent elements in the following description include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those in a so-called equivalent range. In the following, a mobile phone terminal will be described as an example of a wireless communication device. However, an application target of the present invention related to a wireless communication device is not limited to a mobile phone terminal. For example, PHS (Personal Handyphone System), PDA, The present invention can also be applied to portable navigation devices, personal computers, game machines, and the like.

(Embodiment)
First, a communication system 100 according to the present embodiment will be described with reference to FIG. FIG. 1 is a diagram illustrating a schematic configuration of a communication system 100. As shown in FIG. 1, the communication system 100 includes a mobile phone terminal 1, a relay device 200, an electronic device 300, and a base station 400.

  The mobile phone terminal 1 establishes a radio signal line with the base station 400 and performs telephone communication and information communication with the base station 400. In the present embodiment, the mobile phone terminal 1 functions as a server that provides services to clients. The service here is, for example, a remote desktop service such as VNC (Virtual Network Computing). When the mobile phone terminal 1 provides a remote desktop service, a support person of a mobile phone company or the like can remotely operate the mobile phone terminal 1 via a client.

  The base station 400 transfers the message received from the mobile phone terminal 1 to the relay device 200 side through the radio signal line established with the mobile phone terminal 1 and also receives the message from the mobile phone terminal 1 received from the relay device 200 side. The message is transferred to the mobile phone terminal 1.

  The electronic device 300 functions as a client that transmits a request to the mobile phone terminal 1 and receives a service from the mobile phone terminal 1. The electronic device 300 may be any device that can perform communication as a client. For example, a personal computer having a communication function can be used as the electronic device 300.

  The relay device 200 is connected to the base station 400 and the electronic device 300 via a wired line, and relays messages exchanged between the mobile phone terminal 1 and the electronic device 300. The relay device 200 does not disconnect the connection between the mobile phone terminal 1 and the electronic device 300 even when wireless communication between the mobile phone terminal 1 and the base station 400 is temporarily disabled due to a change in radio wave condition or the like. As described above, various controls are executed.

  Note that the relay device 200 may be a device such as an HTTP (HyperText Transfer Protocol) proxy device that requires a client to explicitly specify the address of the relay device 200 in order to relay a message. Further, the relay device 200 may be a device that does not require the client to explicitly specify the address of the relay device 200 in order to relay a message, such as a router device or a gateway device.

  Further, although FIG. 1 shows an example in which one mobile phone terminal 1, relay device 200, electronic device 300, and base station 400 exist, a plurality of these devices may exist. For example, the relay device 200 may relay a message between the plurality of mobile phone terminals 1 and the plurality of electronic devices 300.

  Next, control executed by the relay device 200 to maintain the connection between the mobile phone terminal 1 and the electronic device 300 will be described with reference to FIGS. 2 and 3. Hereinafter, in order to simplify the description, description of the base station 400 is omitted.

  FIG. 2 is a diagram illustrating an example of control when a connection confirmation message is received. As shown in FIG. 2, when the electronic device 300 transmits a connection request message to the mobile phone terminal 1 as a server in step S11, the relay device 200 sends the connection request message to the mobile phone terminal 1 in step S12. Forward to. Then, the cellular phone terminal 1 that has received the connection request message performs processing for establishing a connection and returns a connection response message to the relay device 200 in step S13. The relay apparatus 200 transfers a connection response message to the electronic device 300 as step S14.

  As described above, the connection between the electronic device 300 and the mobile phone terminal 1 is established by transmitting and receiving the connection request message and the connection response message between the electronic device 300 and the mobile phone terminal 1 via the relay device 200. Is done.

  After the connection is established, the electronic device 300 transmits a connection confirmation message to the mobile phone terminal 1 in step S15. The connection confirmation message is also called a “keep alive” message, and is periodically transmitted to confirm whether communication with the connection destination is possible. Upon receiving the connection confirmation message, the destination device of the connection confirmation message responds to the transmission source with a connection confirmation response message to indicate that communication is possible. If there is no response to the connection confirmation message, the transmission source device determines that communication with the connection destination is disabled.

  When the relay apparatus 200 receives the connection confirmation message transmitted from the electronic device 300 to the mobile phone terminal 1, the relay apparatus 200 transmits the connection confirmation response message as an electronic message in step S16 without transferring the connection confirmation message to the mobile phone terminal 1. It responds to the device 300. As a result, the electronic device 300 determines that communication with the mobile phone terminal 1 is possible.

  Further, after establishing the connection, the relay device 200 periodically transmits a connection confirmation message to the mobile phone terminal 1 that is a server, and checks whether communication with the mobile phone terminal 1 is possible. When the relay device 200 transmits a connection confirmation message to the mobile phone terminal 1 in step S17, the mobile phone terminal 1 responds to the relay device 200 with a connection confirmation response message in step S18. As a result, the relay device 200 determines that communication with the mobile phone terminal 1 is possible.

  Here, it is assumed that the wireless communication of the mobile phone terminal 1 is temporarily disabled for some reason. As described above, when the wireless communication is temporarily disabled, when the relay device 200 transmits a connection confirmation message to the mobile phone terminal 1 in step S19, a connection confirmation response message is received from the mobile phone terminal 1. Not responding. As a result, the relay device 200 determines that communication with the mobile phone terminal 1 is temporarily disabled.

  At this time, when the electronic device 300 transmits a connection confirmation message to the mobile phone terminal 1 in step S20, the relay apparatus 200 does not transfer the connection confirmation message to the mobile phone terminal 1 and connects in step S21. The confirmation response message is returned to the electronic device 300. As a result, the electronic device 300 determines that the state in which communication with the mobile phone terminal 1 is possible continues, and maintains the connection with the mobile phone terminal 1.

  After the temporary communication failure is resolved, when the relay device 200 transmits a connection confirmation message to the mobile phone terminal 1 in step S22, the mobile phone terminal 1 sends a connection confirmation response message to the relay device 200 in step S23. To respond. As a result, the relay device 200 determines that communication with the mobile phone terminal 1 has been restored.

  Thereafter, when the provision of the service is completed, the electronic device 300 transmits a disconnection request message to the mobile phone terminal 1 in step S24 in order to disconnect the connection with the mobile phone terminal 1. The relay apparatus 200 transfers a disconnection request message to the mobile phone terminal 1 as step S25. Then, the cellular phone terminal 1 that has received the disconnection request message performs processing for disconnecting the connection in step S <b> 26 and returns a disconnection response message to the relay device 200. The relay apparatus 200 transfers a disconnection response message to the electronic device 300 as step S27.

  After the connection is disconnected, the periodic transmission of the connection confirmation message by the electronic device 300 and the relay device 200 is stopped.

  As described above, when the connection confirmation message is transmitted from the electronic device 300 that is the client to the mobile phone terminal 1 that is the server, the relay device 200 connects without connecting the connection confirmation message to the mobile phone terminal 1. The confirmation response message is returned to the electronic device 300. For this reason, even when wireless communication of the mobile phone terminal 1 is temporarily disabled, the electronic device 300 determines that communication with the mobile phone terminal 1 is still possible, and the electronic device 300 The connection with the mobile phone terminal 1 is maintained.

  Note that the relay device 200 periodically transmits a connection confirmation message to the mobile phone terminal 1 to check the communication state with the mobile phone terminal 1, and the state where communication with the mobile phone terminal 1 is impossible is longer than a predetermined time. If it continues for a long time, the response of the connection confirmation response message to the electronic device 300 is stopped. As a result, the electronic device 300 can execute necessary processing when the connection is disconnected.

  FIG. 3 is a diagram illustrating an example of control when wireless communication of the cellular phone terminal 1 is temporarily disabled. Although not shown in FIG. 2, while the connection between the electronic device 300 and the mobile phone terminal 1 is established, the electronic device 300 is a server as step S41 in order to receive the provision of services. A service request message is transmitted to the mobile phone terminal 1. The relay device 200 transfers the service request message to the mobile phone terminal 1 as step S42.

  When the mobile phone terminal 1 receives the service request message, in step S43, the mobile phone terminal 1 executes a process for providing the service, and transmits the execution result to the relay device 200 as a service response message. The relay device 200 transfers the service response message to the electronic device 300 as step S44.

  Thus, the service is provided from the mobile phone terminal 1 to the electronic device 300 by the electronic device 300 and the mobile phone terminal 1 transmitting and receiving the service request message and the service response message via the relay device 200.

  Here, it is assumed that the wireless communication of the mobile phone terminal 1 is temporarily disabled for some reason. If the relay apparatus 200 transmits a connection confirmation message to the mobile phone terminal 1 in step S45 when wireless communication is temporarily disabled, the connection confirmation response message is not responded from the mobile phone terminal 1. As a result, the relay device 200 determines that communication with the mobile phone terminal 1 is temporarily disabled.

  At this time, when the electronic device 300 transmits a service request message (request) to the mobile phone terminal 1 as step S46, the relay device 200 does not transfer the service request message to the mobile phone terminal 1, and step S47. As a service request message. Then, the relay device 200 transmits a BUSY message to the electronic device 300 as step S48.

  Here, the BUSY message is a message used for flow control, and there is a possibility that the message on the receiving side will not catch up and the message may be missed. Therefore, in order to request the transmitting side to pause the message transmission. Used. When electronic device 300 receives the BUSY message, electronic device 300 determines that mobile phone terminal 1 is in a high-load state, and pauses transmission of a new service request message while maintaining connection with mobile phone terminal 1.

  Thereafter, the relay device 200 periodically transmits a connection confirmation message to the mobile phone terminal 1 to check the status of communication with the mobile phone terminal 1 in steps S49 to S51. Then, when the wireless communication of the mobile phone terminal 1 is restored and the mobile phone terminal 1 responds with a connection confirmation response message in step S52, the relay device 200 determines that the wireless communication of the mobile phone terminal 1 has been restored.

  If it is determined that the wireless communication of the mobile phone terminal 1 has been restored, the relay device 200 transmits the stored service request message to the mobile phone terminal 1 in step S53. In addition, the relay device 200 transmits a recovery notification message to the electronic device 300 as step S54.

  Here, the recovery notification message is a message used for flow control, and since there is no possibility that the processing on the receiving side catches up and the message is lost, etc., so that the sending side is requested to resume the transmission of the message. Used for. When receiving the recovery notification message, the electronic device 300 transmits a new service request message.

  When the mobile phone terminal 1 receives the service request message stored in the relay device 200, the mobile phone terminal 1 executes processing for providing the service in step S55, and transmits the execution result to the relay device 200 as a service response message. The relay device 200 transfers the service response message to the electronic device 300 as step S56.

  As described above, when the service request message is transmitted from the electronic device 300 to the mobile phone terminal 1 while the wireless communication of the mobile phone terminal 1 is temporarily disabled, the relay device 200 transmits the BUSY message. The message is transmitted to the electronic device 300 and the message transmission is suspended. For this reason, when wireless communication of the mobile phone terminal 1 is temporarily disabled, a new message is sent from the electronic device 300 to the mobile phone terminal 1 while maintaining the connection between the electronic device 300 and the mobile phone terminal 1. It is possible to prevent a communication error from occurring.

  The relay device 200 stores a message transmitted from the electronic device 300 while the wireless communication of the mobile phone terminal 1 is temporarily disabled, and transfers the message to the mobile phone terminal 1 after the wireless communication is restored. To do. For this reason, it is possible to prevent the message transmitted while the wireless communication of the mobile phone terminal 1 is temporarily disabled from being lost.

  Here, an example of the service request message stored in the relay device 200 in step S47 is shown. For example, the service request message includes a script indicating an operation performed by the user of the electronic device 300 with respect to a graphical user interface (GUI) based on data transmitted from the mobile phone terminal 1. That is, the relay device 200 stores the operation performed by the user of the electronic device 300 in step S47. When communication between the mobile phone terminal 1 and the relay device 200 becomes possible, the relay device 200 transmits a service request message including the script described above to the mobile phone terminal 1 (step S53). Then, the cellular phone terminal 1 transmits response data for the script to the electronic device 300 via the relay device 200 (steps S55 and S56).

  According to such a configuration, the user of the electronic device 300 can operate the GUI provided by the mobile phone terminal 1 without being aware that the communication with the mobile phone terminal 1 has been temporarily disabled. It becomes possible.

  Next, the functional configuration of the mobile phone terminal 1 shown in FIG. 1 will be described with reference to FIG. FIG. 4 is a block diagram showing a functional configuration of the mobile phone terminal 1. As shown in FIG. 4, the mobile phone terminal 1 includes a control unit 22, a storage unit 24, a communication unit 26, an operation unit 13, an audio processing unit 30, and a display unit 2.

  The storage unit 24 is a storage device that stores various types of information. The storage unit 24 may store information in a semiconductor such as a flash memory that is fixedly provided in the mobile phone terminal 1, a removable storage medium such as a memory card, and read / write of the storage medium You may comprise as a combination with an apparatus.

  The storage unit 24 stores data and programs used for processing in the control unit 22. The data and programs stored in the storage unit 24 include a communication control program 24a and a service program 24b. The communication control program 24a is a program for realizing various controls related to message transmission / reception. The service program 24b is a program for realizing a service provided by the mobile phone terminal 1 as a server.

  The communication unit 26 functions as a transmission unit and a reception unit. The communication unit 26 includes an antenna 26 a, establishes a radio signal line using the CDMA method or the like with the base station 400 via a channel assigned by the base station 400, and performs telephone communication and information with the base station 400. Communicate. The operation unit 13 includes operation keys, direction keys, a determination button, and the like. When these keys and buttons are operated by the user, a signal corresponding to the operation content is generated. The generated signal is input to the control unit 22 as a user instruction.

  The audio processing unit 30 executes processing of an audio signal input to the microphone 15 and an audio signal output from the receiver 16. The display unit 2 includes a display panel constituted by a liquid crystal display (LCD), an organic EL (Organic Electro-Luminescence) panel, and the like, and a standby screen and various functions based on the control of the control unit 22. Display the screen on the display panel.

  The control unit 22 comprehensively controls the overall operation of the mobile phone terminal 1. That is, the control unit 22 performs communication so that various processes of the mobile phone terminal 1 are executed in an appropriate procedure according to the operation of the operation unit 13 and the software stored in the storage unit 24 of the mobile phone terminal 1. The operation of the unit 26, the voice processing unit 30, the display unit 2, and the like are controlled.

  The control unit 22 executes processing based on a computer program (for example, an operating system program, application program, etc.) stored in the storage unit 24. The control unit 22 is constituted by, for example, a microprocessor unit (MPU: Micro Processing Unit), and executes various processes of the mobile phone terminal 1 according to procedures defined in the computer program. In other words, the control unit 22 sequentially reads instruction sequences from the computer program stored in the storage unit 24 and executes processing. Note that the control unit 22 can download and execute not only the computer program stored in the storage unit 24 but also a computer program stored in another device.

  As part of the control of the mobile phone terminal 1, the control unit 22 sequentially reads instruction sequences included in the communication control program 24 a and executes the read instruction sequences to execute processing related to message transmission / reception. In addition, the control unit 22 sequentially reads instruction sequences included in the service program 24b and executes the read instruction sequences, thereby realizing a service provided by the mobile phone terminal 1 as a server.

  Next, a functional configuration of the relay apparatus 200 illustrated in FIG. 1 will be described with reference to FIG. FIG. 5 is a block diagram illustrating a functional configuration of the relay apparatus 200. As illustrated in FIG. 5, the relay device 200 includes a communication unit 201, a communication unit 202, a storage unit 203, and a control unit 204.

  The communication unit 201 functions as a transmission unit and a reception unit for exchanging messages with a client such as the electronic device 300. The communication unit 202 functions as a transmission unit and a reception unit for exchanging messages with a server such as the mobile phone terminal 1. Note that the communication unit 201 and the communication unit 202 may be, for example, an interface device for connecting to a network such as Ethernet (registered trademark) or a modem for performing communication through a public line.

  The storage unit 203 is a storage device that stores various types of information, and is, for example, a magnetic storage device or a semiconductor storage device. The storage unit 203 stores data and programs used for processing in the control unit 204. The data and programs stored in the storage unit 203 include a relay program 203a and server management data 203b. Further, the storage unit 203 is provided with a message buffer 203c that is an area for temporarily storing messages.

  The relay program 203a is a program for realizing the functions related to message relay as described above. The server management data 203b is data for managing the state of the server that is the message transfer destination. Note that the addition of data to the server management data 203b and the deletion of data from the server management data 203b are executed by the control unit 204 according to the connection establishment status.

  An example of the server management data 203b is shown in FIG. As shown in FIG. 6, the server management data 203b has items such as an address, a connection confirmation time, and a state, and data is stored for each server. The address item stores the server address. The connection confirmation time item stores the date and time when the connection response message was last received from the server.

  In the status item, a value indicating “connected”, “temporarily disconnected”, or “disconnected” is stored as a value indicating the communication status with the server. “Connecting” indicates that communication with the server is possible. “Temporarily disconnected” indicates that communication with the server is temporarily disconnected. “Disconnecting” indicates that communication with the server has been disconnected for a certain period of time.

  The control unit 204 controls the overall operation of the relay apparatus 200 in an integrated manner. That is, the control unit 204 controls the operations of the communication unit 201, the communication unit 202, and the like so that various processes of the relay device 200 are executed in an appropriate procedure according to software stored in the storage unit 203. .

  The control unit 204 executes processing based on a computer program (for example, an operating system program, an application program, etc.) stored in the storage unit 203. The control unit 204 is configured by, for example, a microprocessor unit (MPU: Micro Processing Unit), and executes various processes of the mobile phone terminal 1 according to procedures defined in the computer program. That is, the control unit 204 sequentially reads instruction sequences from the computer program stored in the storage unit 203 and executes processing.

  Note that the control unit 204 can download and execute not only the computer program stored in the storage unit 203 but also a computer program stored in another device. The control unit 204 can also read and execute a computer program stored in a storage medium such as a CD-ROM that can be read by a medium reading device (not shown).

  When the control unit 204 sequentially reads the instruction sequence included in the relay program 203a and executes the read instruction sequence, the communication state confirmation unit 204a and the relay control unit 204b are realized. The communication state confirmation unit 204a periodically confirms the communication state with the transfer destination server. The relay control unit 204b controls the relay of various messages so that the connection between the server and the client is not disconnected even if the wireless communication of the server is temporarily disabled.

  Next, a processing procedure of processing executed by the control unit 204 based on the relay program 203a will be described with reference to FIGS.

  FIG. 7 is a flowchart showing a processing procedure of the communication state confirmation unit 204a realized by the control unit 204 executing the relay program 203a. The processing procedure shown in FIG. 7 is periodically executed.

  In step S101, the communication status confirmation unit 204a acquires one piece of data that has not been acquired from the server management data 203b. If unacquired data can be obtained (No at Step S102), the communication state confirmation unit 204a transmits a connection confirmation message to the address set in the obtained data and waits for a response at Step S103.

  When a response is received within the predetermined time (No at Step S104), the communication status confirmation unit 204a sets “Connecting” to the item of the acquired data status as Step S105. Then, in step S106, the communication state confirmation unit 204a sets the date and time when the response is received in the item of the connection confirmation time of the acquired data. Thereafter, the communication state confirmation unit 204a re-executes Step S101 and the subsequent steps.

  If a response is not received within a predetermined time and a timeout occurs (step S104, Yes), the communication status confirmation unit 204a starts from the date and time set in the item of connection confirmation time of the acquired data as step S107. The elapsed time of is calculated.

  If the elapsed time is within the threshold (No in step S108), the communication state confirmation unit 204a sets “temporarily disconnected” in the acquired data state item in step S109. On the other hand, if the elapsed time exceeds the threshold value (step S108, Yes), the communication state confirmation unit 204a sets “disconnected” to the item of the acquired data state as step S110. Thereafter, the communication state confirmation unit 204a re-executes Step S101 and the subsequent steps.

  If unacquired data cannot be acquired in step S101, that is, if all the data has been acquired (step S102, Yes), the communication state confirmation unit 204a ends the process.

  FIG. 8 is a flowchart showing the processing procedure of the relay control unit 204b realized by the control unit 204 executing the relay program 203a. The processing procedure illustrated in FIG. 8 is executed every time a message is received by the communication unit 201.

  When a message is received by the communication unit 201 as step S201, the relay control unit 204b determines whether the received message is a connection confirmation message as step S202. When the received message is a connection confirmation message (step S202, Yes), the relay control unit 204b acquires the state of the server that is the transmission destination of the connection confirmation message from the server management data 203b as step S203. .

  When the acquired state is not “disconnected”, that is, when the acquired state is “connected” or “temporarily disconnected” (No in step S204), the relay control unit 204b sets a connection confirmation response as step S205. Send a message to the sending client.

  On the other hand, when the acquired state is “disconnecting” (step S204, Yes), the relay control unit 204b does not transmit the connection confirmation response message. Note that if the protocol allows the sender of the connection confirmation response message to notify other devices that communication with the destination is impossible, the client is notified that communication is not possible. May be.

  When the received message is not a connection confirmation message (No at Step S202), the relay control unit 204b acquires the state of the server that is the message transmission destination from the server management data 203b as Step S206. Note that the case where the received message is not a connection confirmation message means that the received message is, for example, a connection request message, a service request message, or a disconnection request message.

  When the acquired state is “connected” (step S207, Yes), the relay control unit 204b executes step S215 and the subsequent steps. When the acquired state is not “connected”, that is, when the acquired state is “disconnecting” or “temporarily disconnecting” (No in step S207), the relay control unit 204b sends a BUSY message as step S208. Send to the sending client. In step S209, the relay control unit 204b stores the received message in the message buffer 203c.

  Subsequently, in step S210, the relay control unit 204b acquires the state of the server that is the message transmission destination from the server management data 203b. If the acquired state is not changed to “connected” (No in step S211), the relay control unit 204b determines whether a timeout has occurred in step S212. The timeout here occurs when a predetermined time has elapsed since the message was received.

  When the timeout has not occurred (No at Step S212), the relay control unit 204b re-executes Step S210 and subsequent steps, and re-determines the server state. When a timeout occurs (step S212, Yes), the relay control unit 204b deletes the message stored in the message buffer 203c as step S213. Note that if the protocol allows the other party to notify the message source that communication with the destination is impossible, the client will indicate that communication is not possible when a timeout occurs. May be notified.

  If the state acquired in step S210 has changed to “connected” (step S211, Yes), the relay control unit 204b acquires the message stored in the message buffer 203c as step S214. At this time, the message is deleted from the message buffer 203c. Subsequently, the relay control unit 204b executes step S215 and the subsequent steps.

  Note that after the server communication is restored, the relay control unit 204b may execute a process of restoring the connection between the server and the client. This is to cope with the case where the server has disconnected from the client for a long time because communication has been impossible. In this case, since the connection is maintained on the client side, it is only necessary to recover the connection on the server side.

  The connection recovery can be realized, for example, by causing the relay control unit 204b to transmit a connection request message set with the client as a transmission source to the server. Even if a response to the connection request message is transmitted from the server, it is not necessary to transfer the response to the client. In addition, the message sent from the client after the connection is established is stored in the relay device 200 so that the state before the disconnection can be restored, and the stored message is received after the connection is restored. You may transmit to a server in order.

  In step S215, the relay control unit 204b transfers the message to the server that is the message transmission destination. And the relay control part 204b determines whether the response from the server was received as step S216. When a response has not been received (step S216, No), the relay control unit 204b determines whether a timeout has occurred as step S217. The timeout here occurs when a predetermined time elapses after the message is transferred.

  When a timeout has not occurred (No at Step S217), the relay control unit 204b re-executes Step S216 and the subsequent steps, and re-determines whether there is a response. When a timeout occurs (step S217, Yes), the relay control unit 204b does nothing particularly. If the protocol allows the message source to notify other devices that communication with the destination is not possible, relay that communication is not possible when a timeout occurs. The control unit 204b may be transmitted to the client.

  When the response is received (step S216, Yes), the relay control unit 204b transmits the received response to the client as step S218.

  As described above, in this embodiment, since the relay apparatus 200 transmits a response to the connection confirmation message transmitted by the client to confirm the communication state with the server, the server temporarily Even if communication is disabled, the client can maintain the connection. Further, in this embodiment, when the client transmits a request to the server when the server is temporarily unable to communicate, the relay apparatus 200 transmits a BUSY message to the client, so that the connection is maintained. You can make the client stand by.

  In addition, the aspect of this invention shown by said each embodiment can be arbitrarily changed in the range which does not deviate from the summary of this invention. For example, a program such as the relay program 203a may be divided into a plurality of modules or may be integrated with other programs. Further, the mobile phone terminal 1 and the relay device 200 may download and execute a program such as the relay program 203a from another device through a communication line. Further, the mobile phone terminal 1 and the relay device 200 may read and execute a program such as the relay program 203a stored in a portable storage medium such as a CD-ROM.

  In the above embodiment, there is a section where wireless communication is performed on the communication path between the server and the relay apparatus 200. However, there is no section where wireless communication is performed on the communication path between the server and the relay apparatus 200. Also good. That is, the present invention can also be applied to a communication system that does not include a wireless communication section in which wireless communication is performed.

  In the above embodiment, when a request from a client is received when the server is temporarily incapable of communication, the client is made to wait while maintaining the connection by using a flow control mechanism. However, other mechanisms that can obtain the same effect may be used. That is, in response to a request transmitted from the client when the server is temporarily unable to communicate, the relay apparatus 200 may transmit a message other than the BUSY message to suspend the message transmission to the client.

  In the above embodiment, the BUSY message is transmitted to the client when a request is received from the client. However, after detecting that the server cannot communicate, the BUSY message is immediately transmitted to the client. It is good to do. In this case, based on the connection request message, the disconnection request message, etc., it is possible to grasp which server and which client are connected, and send a BUSY message to the server that is connected to the server that cannot communicate. Good. With this configuration, a request is not transmitted from the client while the server is unable to communicate, and the message buffer 203c need not be provided.

  As described above, the relay device, the wireless communication device, the control method, and the communication system according to the present invention are suitable for suppressing the disconnection between the server and the client due to temporary inability to communicate.

DESCRIPTION OF SYMBOLS 1 Mobile phone terminal 2 Display part 13 Operation part 15 Microphone 16 Receiver 22 Control part 24 Storage part 24a Communication control program 24b Service program 26 Communication part 30 Voice processing part 100 Communication system 200 Relay device
201 communication unit 202 communication unit 203 storage unit 203a relay program 203b server management data 203c message buffer 204 control unit 204a communication state confirmation unit 204b relay control unit 300 electronic device 400 base station

Claims (9)

A relay device that relays communication between a first electronic device and a second electronic device that transmits a request to the first electronic device,
Receiving means for receiving a connection confirmation message transmitted to confirm that the second electronic device can communicate with the first electronic device;
When the connection confirmation message is received by the receiving unit, a response indicating that communication with the first electronic device is possible is sent to the second electronic device instead of the first electronic device. And a relay control means. A communication state confirmation unit for determining whether communication with the first electronic device is possible;
The relay control unit makes a request from the second electronic device to the first electronic device while the communication state confirmation unit determines that communication with the first electronic device is impossible. The request stored in the storage unit is transmitted to the first electronic device after it is determined that communication with the first electronic device is enabled by the communication state confirmation unit. The relay apparatus according to claim 1.   The relay device according to claim 2, wherein the request transmitted from the second electronic device is a user operation performed in the second electronic device.   The relay control unit receives a request from the second electronic device to the first electronic device while the communication state confirmation unit determines that communication with the first electronic device is impossible. The relay apparatus according to claim 2, wherein when received, the relay apparatus transmits a message requesting to pause transmission of the request to the second electronic device.   The relay control unit requests the second electronic device to resume request transmission after it is determined by the communication state confirmation unit that communication with the first electronic device is possible. 5. The relay apparatus according to claim 4, wherein the message is transmitted.   The relay control unit pauses transmission of a request to the second electronic device when the communication state confirmation unit determines that communication with the first electronic device is impossible. The relay apparatus according to claim 2, wherein the message to be requested is transmitted.   Relaying communication between the first electronic device, the second electronic device that transmits a request to the first electronic device, the first electronic device, and the second electronic device, and the second electronic device. When the connection confirmation message transmitted to confirm that the electronic device can communicate with the first electronic device is received, the first electronic device is used instead of the first electronic device. A wireless communication device used as the first electronic device in a communication system including a relay device that transmits a response to the effect that communication with the second electronic device is possible. A control method in a relay device that relays communication between a first electronic device and a second electronic device that transmits a request to the first electronic device,
Receiving a connection confirmation message sent by the relay device to confirm that the second electronic device can communicate with the first electronic device;
When the connection confirmation message is received, the relay device sends a response to the second electronic device that it can communicate with the first electronic device instead of the first electronic device. And a transmitting method. A first electronic device;
A second electronic device that transmits a request to the first electronic device;
A communication system having a relay device that relays communication between the first electronic device and the second electronic device,
The relay device is
Receiving means for receiving a connection confirmation message transmitted to confirm that the second electronic device can communicate with the first electronic device;
When the connection confirmation message is received by the receiving unit, a response indicating that communication with the first electronic device is possible is sent to the second electronic device instead of the first electronic device. And a relay control means.

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