JP2018042022A - Communication control device, relay, communication control program, and relay program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a state where data addressed to a terminal are not delivered to the terminal, from being continued after a communication control device transmits the data addressed to the terminal.SOLUTION: After a communication control device 1 transmits data addressed to a terminal to a relay 2, even after the lapse of a predetermined time, an acknowledgement signal may not be received from the relay 2. In such a case, a buffer success/failure determination part 13 of the communication control device 1 determines that it can be recognized that a transmission processing part 17 of the relay 2 performs a different operation after the data addressed to the terminal are transmitted from the transmission processing part 17. Thus, the buffer success/failure determination part 13 determines that the relay 2 cannot buffer the data addressed to the terminal. As a result, the communication control device 1 causes a buffer 14 for retransmission to buffer the data addressed to the terminal and, in a case where a condition that becomes a retransmission trigger is satisfied, transmits the data addressed to the terminal again.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a communication system including a communication control device that transmits data addressed to a terminal, a relay that receives data addressed to the terminal from the communication control device, and a terminal that receives data addressed to the terminal from the relay.

  In the indirect transmission procedure specified in IEEE 802.15.4, the communication control device that is the data transmission source sets the data addressed to the terminal to be transmitted to the terminal that is the data transmission destination. Time buffering. Thereafter, if the communication control apparatus receives a data request command from the terminal while buffering the data addressed to the terminal, the communication control apparatus returns a receipt confirmation signal (ACK) to the terminal, and then the terminal Send data to the terminal to the terminal.

  For example, in the case of indirect transmission in which data is directly transmitted from a HEMS (Home Energy Management System) controller as an example of a communication control device to a battery-powered terminal as an example of a terminal, the HEMS controller buffers the data. . On the other hand, in the case of indirect transmission in which the communication control device transmits the data addressed to the terminal to the terminal via the relay, the relay that directly transmits the data to the terminal buffers the data addressed to the terminal. As a technology related to this, there is a technology disclosed in the following Patent Document 1.

JP 2006-101148 A

  The repeater erases the data destined to the terminal when the data destined for the terminal cannot be buffered because the data buffer addressed to the terminal is insufficient. Conventionally, when data addressed to a terminal is transmitted from a communication control device to a terminal via a repeater, the communication control device cannot grasp the buffering status of the repeater. For this reason, even if the communication control device has finished transmitting the data addressed to the terminal, the repeater erases the data addressed to the terminal because the data buffer addressed to the terminal of the repeater is insufficient. There may be. In this case, the state where the data addressed to the terminal is erased in the repeater continues. Therefore, the state in which the communication control device cannot make the data addressed to the terminal reach the terminal continues.

  The present invention has been made in view of such problems of the prior art. An object of the present invention is to provide a repeater and a communication control apparatus capable of preventing a situation in which the data addressed to the terminal does not reach the terminal after the communication control apparatus transmits the data addressed to the terminal. Is to provide.

  Another object of the present invention is to provide a relay program and communication capable of preventing a situation in which the data addressed to the terminal does not reach the terminal after the communication control device transmits the data addressed to the terminal. It is to provide a control program.

  In order to solve the above problems, a repeater according to a first aspect of the present invention includes a communication control device that transmits data addressed to a terminal, a repeater that receives the data addressed to the terminal from the communication control device, and A repeater used in a communication system including a terminal that receives the data addressed to the terminal from the repeater by transmitting a data request for transmitting the data addressed to the terminal to the repeater, A transmission processing unit that transmits to the communication control device a reception confirmation signal that can specify that the terminal-addressed data has been received; a reception processing unit that receives the terminal-addressed data from the communication control device; and the reception processing The terminal-addressed data buffer for buffering the terminal-addressed data received by the communication unit, and the terminal-addressed data buffered in the terminal-addressed data buffer. A buffer availability determination unit that determines whether or not the terminal data is buffered, and the buffer availability determination unit determines that the data addressed to the terminal can be buffered in the data buffer addressed to the terminal. A buffer success / failure response processing unit to be transmitted to the terminal, wherein the buffer success / failure response processing unit determines that the data addressed to the terminal cannot be buffered in the data buffer addressed to the terminal. Causes the transmission processing unit to perform an operation different from the operation of transmitting the receipt confirmation signal.

  A communication control apparatus according to a second aspect of the present invention includes a communication control apparatus that transmits data addressed to a terminal, a repeater that receives the data addressed to the terminal from the communication control apparatus, and the terminal to the repeater. A communication control device used in a communication system including a terminal that receives the data addressed to the terminal from the repeater by transmitting a data request for transmission of the addressed data, wherein the data addressed to the terminal is A transmission processing unit for transmitting to the repeater; a reception processing unit for receiving from the repeater a reception confirmation signal capable of specifying that the relay unit has buffered the data addressed to the terminal; and The repeater can buffer the data addressed to the terminal based on whether or not it has recognized that it has performed an operation different from the operation of transmitting an acknowledgment signal to the communication control device. A buffer success / failure determination unit that determines whether or not the terminal-addressed data is buffered when the buffer success / failure determination unit determines that the repeater cannot buffer the data addressed to the terminal. It is buffered in the retransmission buffer by determining whether or not a retransmission buffer for buffering the data addressed to the terminal and a condition serving as a retransmission trigger are satisfied on condition that the terminal has capacity. A retransmission determination unit that determines whether or not the timing for retransmitting the data addressed to the terminal has arrived, and the transmission processing unit receives the timing for retransmitting the data addressed to the terminal When the retransmission determination unit determines, the terminal-addressed data buffered in the retransmission buffer is retransmitted to the repeater.

  A communication control apparatus according to a third aspect of the present invention includes a communication control apparatus that transmits data addressed to a terminal, a relay that receives the data addressed to the terminal from the communication control apparatus, and the terminal that is connected to the relay. By transmitting a data request for transmission of addressed data, it is possible to specify that the data addressed to the terminal can be received via the relay when the data addressed to the terminal is received from the relay A communication control device used in a communication system including a terminal that transmits a reception confirmation message addressed to the communication control device to the communication control device, a transmission processing unit that transmits the data addressed to the terminal to the repeater, A reception processing unit that receives from the repeater the reception confirmation message addressed to the communication control device transmitted by the terminal; and the reception processing unit receives the confirmation message addressed to the communication control device. A buffer success / failure determination unit that determines whether the relay device can buffer the data addressed to the terminal based on whether or not the relay device has buffered the terminal-addressed data. When the buffer success / failure determination unit determines, the retransmission buffer for buffering the terminal-addressed data, on the condition that the terminal-addressed data has a free capacity that can be buffered, a retransmission trigger, A retransmission determination unit that determines whether or not the timing for retransmitting the data addressed to the terminal buffered in the retransmission buffer has arrived by determining whether or not the following condition is satisfied. The transmission processing unit, when the retransmission determination unit determines that the timing for retransmitting the data addressed to the terminal has arrived, File to send the terminal addressed data buffered again to the repeater.

  A communication control device according to a fourth aspect of the present invention includes a communication control device as a wireless device that transmits terminal-addressed data as radio waves, and a relay as a wireless device that receives the terminal-addressed data from the communication control device. And a terminal that receives the data destined for the terminal from the repeater by transmitting a data request for requesting transmission of the data destined for the terminal to the repeater. The transmission processing unit for transmitting the data addressed to the terminal to the repeater, the reception processing unit for intercepting the data addressed to the terminal transmitted by the relay to the terminal, and the reception processing unit Based on whether or not the data addressed to the terminal transmitted by the repeater is intercepted, it is determined whether or not the repeater can buffer the data addressed to the terminal. A buffer success / failure determination unit, and when the buffer success / failure determination unit determines that the repeater cannot buffer the data addressed to the terminal, the buffer success / failure determination unit has a free capacity to buffer the data addressed to the terminal. The terminal buffered in the retransmission buffer by determining whether or not a retransmission trigger condition is satisfied, and a retransmission buffer for buffering the data addressed to the terminal. A retransmission determination unit that determines whether or not the timing for retransmitting the destination data has arrived, and the transmission determination unit determines that the timing for retransmitting the data destined for the terminal has arrived In this case, the terminal-addressed data buffered in the retransmission buffer is transmitted again to the repeater.

  A relay program according to a fifth aspect of the present invention includes a communication control device that transmits data addressed to a terminal, a relay device that receives the data addressed to the terminal device from the communication control device, and the relay device that is addressed to the terminal device. A relay program incorporated in a computer that operates a repeater used in a communication system including a terminal that receives data destined for the terminal from the repeater by transmitting a data request for data transmission. A transmission processing unit that transmits to the communication control device a reception confirmation signal that can specify that the computer has received the data addressed to the terminal, and a reception processing unit that receives the data addressed to the terminal from the communication control device. A terminal-addressed data buffer for buffering the terminal-addressed data received by the reception processing unit; and the terminal-addressed data A buffer availability determination unit that determines whether or not the terminal-addressed data buffer can be buffered, and the buffer availability determination unit determines that the terminal-addressed data can be buffered in the terminal-addressed data buffer. , A program for functioning as a buffer success / failure response processing unit for transmitting the receipt confirmation signal to the transmission processing unit, wherein the buffer success / failure response processing unit stores the data addressed to the terminal in the data buffer addressed to the terminal. When the buffer availability determination unit determines that buffering cannot be performed, the transmission processing unit is caused to perform an operation different from the operation of transmitting the receipt confirmation signal.

  A communication control program according to a sixth aspect of the present invention includes a communication control device that transmits data addressed to a terminal, a repeater that receives the data addressed to the terminal from the communication control device, and the terminal to the repeater Communication control incorporated in a computer for operating a communication control device used in a communication system including a terminal that receives the data addressed to the terminal from the repeater by transmitting a data request for transmission of the addressed data A transmission processing unit for transmitting the data addressed to the terminal to the repeater; and a reception confirmation signal for specifying that the relay has buffered the data addressed to the terminal. A reception processing unit that receives from the receiver, and that the repeater has performed an operation different from the operation of transmitting the receipt confirmation signal to the communication control device. A buffer success / failure determining unit that determines whether the relay device has buffered the data addressed to the terminal based on whether or not the relay device has buffered the data addressed to the terminal device; If the success / failure determination unit determines that the terminal-addressed data has sufficient free space to buffer the data destined for the terminal, a retransmission buffer for buffering the data addressed to the terminal, and a condition serving as a retransmission trigger By functioning as a retransmission determination unit that determines whether it is time to retransmit the data addressed to the terminal that is buffered in the retransmission buffer, The transmission processing unit, when the retransmission determination unit determines that the timing for retransmitting the data addressed to the terminal has arrived, Retransmits the terminal addressed data buffered in the buffer to the repeater.

  A communication control program according to a seventh aspect of the present invention includes a communication control device that transmits data addressed to a terminal, a repeater that receives the data addressed to the terminal from the communication control device, and the terminal to the repeater By transmitting a data request for transmission of addressed data, it is possible to specify that the data addressed to the terminal can be received via the relay when the data addressed to the terminal is received from the relay A communication control program incorporated in a computer for operating a communication control device used in a communication system including a terminal that transmits a receipt confirmation message addressed to the communication control device to the communication control device, the computer being the terminal A transmission processing unit for transmitting data addressed to the machine to the repeater, and a receipt confirmation message addressed to the communication control apparatus transmitted by the terminal. A reception processing unit that receives the message, a buffer that determines whether or not the repeater has buffered the data addressed to the terminal based on whether the reception processing unit has received the receipt confirmation message addressed to the communication control device Success / failure determination unit, and when the buffer success / failure determination unit determines that the data destined for the terminal could not be buffered, has a free capacity that can buffer the data destined for the terminal. As conditions, a retransmission buffer for buffering the data destined for the terminal, and by determining whether a condition serving as a retransmission trigger is satisfied, the data destined for the terminal buffered in the retransmission buffer is determined again. Functioning as a retransmission determination unit that determines whether or not the timing for transmission has arrived, and the transmission processing unit includes the data addressed to the terminal When the timing of transmitting again determines that the retransmission judging unit that arrives, transmits again the terminal addressed data buffered in the retransmission buffer to the repeater.

  A communication control program according to an eighth aspect of the present invention includes a communication control device as a wireless device that transmits terminal-addressed data as radio waves, and a relay as a wireless device that receives the terminal-addressed data from the communication control device. And a terminal that receives the data destined for the terminal from the repeater by transmitting a data request for requesting transmission of the data destined for the terminal to the repeater. A communication control program incorporated in a computer for operating the terminal, wherein the computer transmits a data to the terminal, a transmission processing unit that transmits the data to the terminal, and the data to the terminal that the relay transmits to the terminal A reception processing unit that intercepts the terminal, whether the reception processing unit intercepts the data addressed to the terminal transmitted to the terminal by the repeater And a buffer success / failure determination unit for determining whether the repeater was able to buffer the data addressed to the terminal, and the buffer success / failure determination unit determines that the repeater was not able to buffer the data addressed to the terminal. In such a case, a retransmission buffer for buffering the data destined for the terminal and whether a condition serving as a retransmission trigger is satisfied, provided that the terminal has sufficient free space for buffering the data destined for the terminal. By determining whether or not the timing for retransmitting the data addressed to the terminal buffered in the retransmission buffer has arrived, and the transmission processing unit, When the retransmission determination unit determines that the timing for retransmitting the data addressed to the terminal has arrived, a buffer is stored in the retransmission buffer. Retransmits the terminal addressed data files being ring to the repeater.

  According to each of the repeater, the communication control device, the relay program, and the communication control program of the present invention, after the communication control device transmits the data addressed to the terminal, the state where the data addressed to the terminal does not reach the terminal continues. Can be prevented.

It is a figure for demonstrating the whole structure of the communication system of embodiment of this invention. It is a block diagram for demonstrating the structure of the communication control apparatus of Embodiment 1-3 of this invention and a repeater. It is a sequence diagram for demonstrating the communication procedure performed in the communication system of Embodiment 1 of this invention. It is a sequence diagram of the modification of the communication system of Embodiment 1 of this invention. It is a flowchart for demonstrating the control which the communication control program integrated in the communication control apparatus of Embodiment 1 of this invention performs. It is a flowchart for demonstrating the control which the relay program integrated in the repeater of Embodiment 1 of this invention performs. It is a sequence diagram for demonstrating the communication procedure performed in the communication system of Embodiment 2 of this invention. It is a sequence diagram of the modification of the communication system of Embodiment 2 of this invention. It is a flowchart for demonstrating the control which the communication control program integrated in the communication control apparatus of Embodiment 2 of this invention performs. It is a flowchart for demonstrating the control which the relay program incorporated in the repeater of Embodiment 2 of this invention performs. It is a sequence diagram for demonstrating the communication procedure performed in the communication system of Embodiment 3 of this invention. It is a sequence diagram of the modification of the communication system of Embodiment 3 of this invention. It is a flowchart for demonstrating the control which the communication control program integrated in the communication control apparatus of Embodiment 3 of this invention performs. It is a flowchart for demonstrating the control which the relay program incorporated in the repeater of Embodiment 3 of this invention performs. It is a block diagram for demonstrating the structure of the communication control apparatus of Embodiment 4 of this invention, and a repeater. It is a sequence diagram for demonstrating the communication procedure performed in the communication system of Embodiment 4 of this invention. It is a sequence diagram of the modification of the communication system of Embodiment 4 of this invention. It is a flowchart for demonstrating the control which the communication control program integrated in the communication control apparatus of Embodiment 4 of this invention performs. It is a flowchart for demonstrating the control which the relay program incorporated in the repeater of Embodiment 4 of this invention performs. It is a flowchart for demonstrating the control which the communication control program incorporated in the communication control apparatus of the modification of Embodiment 4 of this invention performs. It is a sequence diagram for demonstrating the 1st specific example of the retransmission trigger of each communication control apparatus of Embodiment 1-4 of this invention. It is a flowchart of the communication control apparatus for demonstrating the 1st specific example of the retransmission trigger of each communication control apparatus of Embodiment 1-4 of this invention. It is a sequence diagram for demonstrating the 2nd specific example of the retransmission trigger of each communication control apparatus of Embodiment 1-4 of this invention. It is a sequence diagram for demonstrating the modification of the 2nd specific example of the retransmission trigger of each communication control apparatus of Embodiment 1-4 of this invention. It is a flowchart of the communication control apparatus for demonstrating the 2nd specific example of the retransmission trigger of each communication control apparatus of Embodiment 1-4 of this invention. It is a block diagram for demonstrating the 3rd specific example of the retransmission trigger of each communication control apparatus of Embodiment 1-3 of this invention. It is a block diagram for demonstrating the 3rd specific example of the retransmission trigger of each communication control apparatus of Embodiment 4 of this invention. It is a sequence diagram for demonstrating the 3rd specific example of the retransmission trigger of each communication control apparatus of Embodiment 1-4 of this invention. It is a flowchart of the communication control apparatus for demonstrating the 3rd specific example of the retransmission trigger of each communication control apparatus of Embodiment 1-4 of this invention. It is a flowchart of the repeater for demonstrating the 3rd specific example of the retransmission trigger of each communication control apparatus of Embodiment 1-4 of this invention. It is a sequence diagram for demonstrating the modification of the 3rd specific example of the retransmission trigger of each communication control apparatus of Embodiment 1-4 of this invention. It is a block diagram of a communication control apparatus in case each communication control apparatus of Embodiment 1-4 of this invention has a function which estimates the free capacity of the data buffer addressed to the terminal of a repeater. The schematic diagram for demonstrating the free capacity of a repeater estimated when each communication control apparatus of Embodiment 1-4 of this invention has the function to predict the free capacity of the data buffer addressed to the terminal of a repeater It is. Control executed by the communication control program incorporated in the communication control device when each communication control device of the first to fourth embodiments of the present invention has a function of predicting the free capacity of the data buffer addressed to the terminal of the repeater It is a flowchart for demonstrating. Control executed by the communication control program incorporated in the communication control device when each communication control device of the first to fourth embodiments of the present invention has a function of predicting the free capacity of the data buffer addressed to the terminal of the repeater It is a flowchart for demonstrating.

  Hereinafter, a communication control device, a repeater, a communication control program, and a relay program according to embodiments will be described with reference to the drawings. In the description of the embodiments and the drawings, the same reference numerals are assigned to the same configurations. The description of the same configuration given the same reference numeral is not repeated in the following embodiments unless otherwise required. In the drawings of the respective embodiments, the same configuration given the same reference numeral has the same function unless otherwise specified.

(Overall configuration of communication system)
The overall configuration of a communication system common to the first to fourth embodiments will be described with reference to FIG.

  The communication system 100 includes one communication control device 1, a plurality of, for example, three repeaters 2, and a plurality of types, for example, six types of terminals 3.

  The communication control device 1 is, for example, a HEMS controller. The plural types of terminals 3 are, for example, a lighting fixture 31, a power meter 32, a solar power generation system 33, an air conditioner 34, a storage battery system 35, a sensor group 36, and the like installed in a building. The sensor group 36 includes a plurality of, for example, three heat detection sensors for fire notification. The first repeater 2 relays communication between the communication control device 1 and each of the lighting fixture 31, the power meter 32, and the solar power generation system 33. The second repeater 2 relays communication between the communication control device 1 and each of the air conditioner 34 and the storage battery system 35. The third repeater 2 relays communication between the communication control device 1 and each of the plurality of sensors 36A, 36B, 36C.

  The communication control device 1, the repeater 2, and the terminal 3 according to the present embodiment are wireless communication devices that transmit and receive terminal-addressed data as radio waves, respectively. However, the communication control device 1, the repeater 2, and the terminal 3 may be wired communication devices that are communicably connected to each other via wiring.

  In the present embodiment, the communication control device 1 is operated by an operator or transmits terminal-addressed data according to a communication control program stored in a storage unit. The communication control program is readable by a computer built in the communication control device 1 and can be recorded on a recording medium as an external device of the communication control device 1. The terminal-addressed data transmitted by the communication control device 1 is a command signal for causing the terminal 3 to execute some control.

  The repeater 2 receives terminal-addressed data from the communication control device 1 and transmits the received terminal-addressed data to the terminal 3. The repeater 2 buffers the data addressed to the terminal, and transmits the data addressed to the terminal 3 to the terminal 3 when receiving a data request for the data addressed to the terminal from the terminal 3.

  In the present embodiment, the repeater 2 receives, buffers, and transmits data addressed to the terminal according to the relay program stored in the storage unit. The relay program is readable by a computer built in the repeater 2 and can be recorded on a recording medium as an external device of the repeater 2.

  The terminal 3 receives the data addressed to the terminal from the repeater 2 by transmitting a data request for requesting transmission of the data addressed to the terminal to the repeater 2. Thereby, the terminal 3 executes control instructed by the data addressed to the terminal. For example, when the lighting fixture 31 receives the data addressed to the terminal, the control for turning on or off the lighting fixture 31 is executed in the control unit of the lighting fixture 31.

  The sensor groups 36 constituting a part of the terminal 3 according to the present embodiment are battery-driven terminals that are driven by electric power stored in the battery. For this reason, the communication unit of the terminal 3 is activated at the timing when the data request is transmitted to the repeater 2, and is stopped after executing control according to the instruction by the received data addressed to the terminal. That is, the communication unit of the terminal 3 is not always driven, but alternately repeats the drive state and the stop state every predetermined time. Therefore, the lifetime of the battery can be extended by reducing the amount of power used in the battery.

  On the other hand, the luminaire 31, the power meter 32, the solar power generation system 33, the air conditioner 34, and the storage battery system 35 that constitute another part of the terminal 3 of the present embodiment are devices that are driven by system power. It is. The communication unit of the luminaire 31, the power meter 32, the solar power generation system 33, the air conditioner 34, and the storage battery system 35 is also activated at the timing of transmitting the data request to the repeater 2, and the received instruction to the terminal addressed data After executing the control according to the above, it is stopped. Therefore, the power consumed by the lighting fixture 31, the power meter 32, the solar power generation system 33, the air conditioner 34, and the storage battery system 35 for communication can be reduced.

  In the communication system 100, the communication control device 1 can transmit a plurality of terminal-addressed data corresponding to each of the plurality of terminals 3. In addition, when one repeater 2 has jurisdiction over a large number of terminals 3, it receives various types of terminal-addressed data respectively corresponding to the large number of terminals 3 from the communication control device 1, and the received various types Each terminal-addressed data is transmitted to a large number of terminals 3. That is, one repeater 2 sorts out various types of terminal-addressed data and transmits it to many terminals 3. In this case, one repeater 2 may buffer various types of terminal-addressed data corresponding to each of a large number of terminals 3. As a result, there is also a repeater 2 in which the free space of the buffer for data addressed to the terminal is small.

(Outline of configurations of communication control device and repeater of first to third embodiments)
The outline | summary of the structure of the communication control apparatus of Embodiment 1-3 and a repeater is demonstrated using FIG.

<Communication control device>
Each communication control device 1 of the first to third embodiments includes an antenna 11, a reception processing unit 12, a buffer success / failure determination unit 13, a retransmission buffer 14, a retransmission determination unit 15, an application processing unit 16, and a transmission processing unit 17. It is equipped with.

  The antenna 11 converts an electric signal into a radio wave, and converts the radio wave into an electric signal. The reception processing unit 12 receives the radio signal transmitted from the repeater 2. For example, a reception confirmation signal that can specify that the repeater 2 can buffer the data addressed to the terminal is received from the repeater 2.

  The buffer success / failure determination unit 13 determines that the repeater 2 has buffered the data addressed to the terminal based on whether or not the repeater 2 has recognized an operation different from the operation of transmitting the receipt confirmation signal to the communication control device 1. It is determined whether or not the ring has been completed. Details of this different operation will be described later.

  The application processing unit 16 determines which terminal-addressed data is to be transmitted to which terminal 3 in accordance with a communication control program incorporated in advance or by an operation of the operator. The application processing unit 16 causes the transmission processing unit 17 to transmit the terminal addressed data to the repeater 2, and then temporarily stores the same terminal addressed data as the transmitted terminal addressed data.

  When the buffer success / failure determination unit 13 determines that the repeater 2 has not been able to buffer the data addressed to the terminal, the application processing unit 16 retransmits the temporarily stored terminal addressed data to the relay 2 again. Determine whether it is necessary. In the present embodiment, when the application processing unit 16 determines that the data destined for the terminal needs to be transmitted again to the repeater 2, in order to buffer the data destined for the terminal in the retransmission buffer 14, The terminal addressed data is transmitted to the buffer success / failure determination unit 13. When the application processing unit 16 determines that there is no need to retransmit the data addressed to the terminal to the repeater 2, the application processing unit 16 deletes the data addressed to the terminal.

  However, in the present embodiment, the application processing unit 16 does not have to determine whether it is necessary to transmit the data addressed to the terminal to the repeater 2 again. In this case, the application processing unit 16 only determines that the data destined for the terminal to be retransmitted to the buffer success / failure determination unit 13 only when the buffer success / failure determination unit 13 determines that the data addressed to the terminal is not buffered by the repeater 2. Send.

  The retransmission buffer 14 receives the data addressed to the terminal transmitted from the application processing unit 16 via the buffer success / failure determination unit 13 on the condition that the terminal has sufficient free space to buffer the data addressed to the terminal. Buffer. In the present embodiment, the retransmission buffer 14 buffers the terminal-addressed data when the buffer success / failure determination unit 13 determines that the repeater 2 cannot buffer the data addressed to the terminal.

  The retransmission determination unit 15 determines whether or not it is time to retransmit the data addressed to the terminal buffered in the retransmission buffer 14 by determining whether or not a condition serving as a retransmission trigger is satisfied. To do. Details of this retransmission trigger will be described later.

  The transmission processing unit 17 transmits the data addressed to the terminal to the repeater 2. In addition, when the retransmission determination unit 15 determines that it is time to retransmit the data addressed to the terminal, the transmission processing unit 17 transfers the data addressed to the terminal buffered in the retransmission buffer 14 to the repeater 2. Send again.

  According to said structure, the communication control apparatus 1 can transmit again the data addressed to the terminal which the repeater 2 could not buffer to the repeater 2. Therefore, it is possible to prevent the state where the data addressed to the terminal does not reach the terminal device 3 after the communication control device 1 has transmitted the data addressed to the terminal device.

<Repeater>
Each repeater 2 of the first to third embodiments includes an antenna 21, a reception processing unit 22, a buffering data transmission management unit 23, a terminal-addressed data buffer 24, a buffer availability determination unit 25, a buffer success / failure response processing unit 26, And a transmission processing unit 27.

  The antenna 21 converts an electric signal into a radio wave, and converts the radio wave into an electric signal. The reception processing unit 22 receives terminal-addressed data from the communication control device 1. Further, the reception processing unit 22 receives a data request from the terminal 3.

  When the reception processing unit 22 receives a data request from the terminal 3, the buffering data transmission management unit 23 transmits data addressed to the terminal to the terminal 3. The terminal-addressed data buffer 24 buffers the data addressed to the terminal received by the reception processing unit 22 until a data request is received from the terminal.

  The buffer availability determination unit 25 temporarily stores the data addressed to the terminal transmitted from the communication control device 1, and the terminal addressed data stored temporarily can be buffered in the data buffer 24 addressed to the terminal. It is determined whether or not. The buffer availability determination unit 25 compares the data amount of the data destined for the terminal and the free capacity of the data buffer 24 destined for the terminal to determine whether the data destined for the terminal can be buffered in the data buffer 24 destined for the terminal. judge.

  When it is determined that the data addressed to the terminal cannot be buffered in the data buffer 24 addressed to the terminal, the buffer availability determination unit 25 deletes the data addressed to the terminal. When it is determined that the data addressed to the terminal can be buffered in the data buffer 24 addressed to the terminal, the buffer availability determining unit 25 causes the data addressed to the terminal to be buffered in the data buffer 24 addressed to the terminal.

  The buffer success / failure response processing unit 26 can identify that the data addressed to the terminal has been received when the buffer availability determination unit 25 determines that the data addressed to the terminal can be buffered in the data buffer 24 addressed to the terminal. The signal is transmitted to the transmission processing unit 27. On the other hand, the buffer success / failure response processing unit 26 is different from the operation of transmitting the receipt confirmation signal when the buffer availability determination unit 25 determines that the data addressed to the terminal cannot be buffered in the data buffer 24 addressed to the terminal. The transmission processing unit 27 performs the operation. This different operation will be described in detail later.

  According to the above configuration, it is possible to notify the communication control device 1 that the repeater 2 has not been able to buffer the data addressed to the terminal. For this reason, the communication control device 1 can again transmit the data addressed to the terminal that the repeater 2 could not buffer to the repeater 2. As a result, it is possible to prevent a state in which the data addressed to the terminal does not reach the terminal 3 after the communication control device 1 transmits the data addressed to the terminal.

(Embodiment 1)
The configuration of the repeater and the communication control device according to the first embodiment will be described.

<Repeater>
The buffer success / failure response processing unit 26 of the repeater 2 according to the first embodiment causes the transmission processing unit 27 to continue the state in which the reception confirmation signal is not transmitted as the different operation described above. According to this, different operations can be realized by simple control.

<Communication control device>
The communication control apparatus 1 according to the first embodiment may not receive a receipt confirmation signal from the repeater 2 even after a predetermined time has elapsed after transmitting the data addressed to the terminal to the repeater 2. In this case, the buffer success / failure determination unit 13 of the communication control apparatus 1 according to the present embodiment confirms that the transmission processing unit 27 of the repeater 2 has performed different operations after the data addressed to the terminal is transmitted from the transmission processing unit 17. It is considered to have been recognized. Thereby, the buffer success / failure determination unit 13 determines that the repeater 2 could not buffer the data addressed to the terminal. According to this, the communication control device 1 can grasp that the repeater 2 could not buffer the data addressed to the terminal by simple control.

  A sequence for describing a communication procedure executed in the communication system according to the first embodiment will be described with reference to FIG.

  First, in step S1, a data request signal is transmitted from the application processor of the communication control apparatus 1 to the transmission / reception processor. The application processor corresponds to the application processing unit 16, and the transmission / reception processor corresponds to the reception processing unit 12, the buffer success / failure determination unit 13, the retransmission buffer 14, the retransmission determination unit 15, and the transmission processing unit 17. The application processor and the transmission / reception processor may be mounted on different CPUs.

  In step S2, the transmission / reception processor causes the transmission processor 17 to transmit the data addressed to the terminal included in the data transmission request signal to the repeater 2. In step S3, an acknowledgment signal (ACK) that can specify that the repeater 2 has buffered the data addressed to the terminal has not been received from the repeater 2. Therefore, the communication control device 1 transmits the data addressed to the terminal to the repeater 2 a plurality of times, for example, three times.

  The application processor 16 of the application processor temporarily stores data addressed to the terminal included in the data request signal transmitted to the transmission / reception processor. Thereafter, after the data addressed to the terminal is transmitted to the repeater 2, the data request signal including the data addressed to the terminal is deleted from the application processing unit 16. At that time, the application processing unit 16 may determine that buffering of the data addressed to the terminal in the retransmission buffer 14 is necessary. In this case, the application processing unit 16 notifies the buffer success / failure determination unit 13 of the transmission / reception processor. Accordingly, the buffer success / failure determination unit 13 causes the retransmission buffer 14 to buffer the data addressed to the terminal included in the data transmission request signal.

  Next, consider a case where the buffer availability determination unit 25 of the repeater 2 determines in step S3 that the terminal-addressed data buffer 24 cannot buffer the terminal-addressed data. In this case, the buffer success / failure response processing unit 26 of the repeater 2 does not cause the transmission processing unit 27 to transmit an acknowledgment signal (ACK) that was scheduled to be returned to the communication control device 1 if the data addressed to the terminal has been buffered. .

  Therefore, for example, the communication control device 1 does not receive the receipt confirmation signal (ACK) from the repeater 2 even if a predetermined time has elapsed after transmitting the data addressed to the terminal. Therefore, the buffer success / failure determination unit 13 of the communication control device 1 recognizes that the repeater 2 cannot buffer the data addressed to the terminal. In this case, in step S 4, the buffer success / failure determination unit 13 of the transmission / reception processor of the communication control device 1 buffers the data addressed to the terminal transmitted to the repeater 2 in the retransmission buffer 14.

  Thereafter, in step S5, the terminal 3 transmits a data request to the repeater 2. As a result, in step S6, the repeater 2 transmits the data destined for the terminal that has already been buffered in the terminal-destined data buffer 24 of the repeater 2 to the terminal 3 that has transmitted the data request. As a result, the free capacity of the terminal-addressed data buffer 24 of the repeater 2B increases, and the terminal 3 acquires the data destined for the terminal.

  The retransmission determination unit 15 of the communication control device 1 determines that a retransmission trigger has been established. For example, the retransmission determination unit 15 determines that a predetermined time has elapsed since the data addressed to the terminal is buffered in the retransmission buffer 14. As a result, the transmission processing unit 17 retransmits the terminal-addressed data buffered in the retransmission buffer 14 to the repeater 2 in step S7.

  After receiving the data addressed to the terminal, the repeater 2 determines that the buffer availability determination unit 25 can buffer the data addressed to the terminal. Thereby, the repeater 2 returns an acknowledgment signal (ACK) to the communication control device 1 in step S8. This receipt confirmation signal has the same meaning as a signal that can specify that the repeater 2 has buffered the data addressed to the terminal. Therefore, the communication control apparatus 1 can recognize that the repeater 2 can buffer the data addressed to the terminal. At this time, since the repeater 2 has already transmitted to the terminal 3 the data destined for the terminal that has already been buffered in the data buffer 24 destined for the terminal, the free capacity of the data buffer 24 destined for the terminal increases. doing. Accordingly, in step S9, the terminal-addressed data transmitted again from the communication control device 1 to the repeater 2 is buffered in the terminal-addressed data buffer 24 of the repeater 2.

  A modification of the communication system according to the first embodiment will be described with reference to FIG. In the modification of the communication system of the first embodiment, a repeater 2A and a repeater 2B are connected in series between the communication control device 1 and the terminal 3. Accordingly, the data addressed to the terminal is transmitted from the communication control device 1 to the terminal 3 via the repeater 2A and the repeater 2B in this order.

  The repeater 2B exhibits only the same function as the function of the repeater 2 described above. Therefore, the repeater 2B has a configuration similar to the configuration of the repeater 2 described above. On the other hand, the repeater 2A also exhibits the function of the transmission / reception processor of the communication control device 1 in addition to the function of the repeater 2 described above. Therefore, the repeater 2A has a configuration of a transmission / reception processor of the communication control device 1 in addition to the configuration of the repeater 2 described above.

  First, in step SA1, a data request signal is transmitted from the application processor of the communication control device 1 to the transmission / reception processor. Also in this case, the application processor corresponds to the application processing unit 16, and the transmission / reception processor corresponds to the reception processing unit 12, the buffer success / failure determination unit 13, the retransmission buffer 14, the retransmission determination unit 15, and the transmission processing unit 17. To do.

  In step SA2, the transmission processing unit 17 of the transmission / reception processor transmits the data addressed to the terminal identified by the data transmission request signal to the repeater 2A. Since transmission from the repeater 2A to the repeater 2B is not indirect transmission, the repeater 2A receives the data addressed to the terminal regardless of whether or not the data buffer 24 addressed to the terminal has a free capacity, and receives an acknowledgment signal (ACK ) To the communication control device 1. As a result, the communication control apparatus 1 recognizes that the repeater 2A has successfully received the data addressed to the terminal by receiving the receipt confirmation signal (ACK).

  Next, in step SA4, the repeater 2A transmits the data addressed to the terminal received from the communication control device 1 to the repeater 2B. In step SA5, it is assumed that the repeater 2B cannot buffer the data addressed to the terminal. In this case, the repeater 2B does not return an acknowledgment signal (ACK) that was scheduled to be returned to the repeater 2A to the repeater 2A if the data addressed to the terminal has been buffered. Therefore, in step SA4, the repeater S2A transmits a plurality of pieces of data addressed to the terminal to the repeater 2B, for example, only three times. For example, the communication control device 1 determines that the repeater 2B does not receive an acknowledgment signal (ACK) from the repeater 2B even after a predetermined time has elapsed after transmitting the data addressed to the terminal. Recognize that is not buffered.

  If the repeater 2A recognizes that the repeater 2B could not buffer the data addressed to the terminal, the repeater 2B buffers the data addressed to the terminal transmitted to the repeater 2B in the retransmission buffer 14 in step SA6. ing.

  Thereafter, in step SA7, the terminal 3 transmits a data request to the repeater 2B. As a result, in step SA8, the repeater 2B transmits the data destined for the terminal that has already been buffered in the terminal-destined data buffer 24 of the repeater 2 to the terminal 3 that has transmitted the data request. As a result, the free capacity of the terminal-addressed data buffer 24 of the repeater 2B increases, and the terminal 3 acquires the above-mentioned data addressed to the terminal.

  Thereafter, in step SA9, for example, the repeater 2A, after buffering the data destined for the terminal in the retransmission buffer 14, passes the data destined for the terminal buffered in the retransmission buffer 14 after a predetermined time has elapsed. It transmits again to the repeater 2B. At this time, since the repeater 2B has already transmitted to the terminal 3 the data destined for the terminal that has already been buffered in the data buffer 24 destined for the terminal, the free capacity of the data buffer 24 destined for the terminal increases. doing. Therefore, the buffer availability determination unit of the repeater 2B determines that the terminal-addressed data transmitted again can be buffered. Therefore, in step SA10, the repeater 2B returns an acknowledgment signal (ACK) that can specify that the data addressed to the terminal can be buffered in the data buffer 24 for the terminal to the repeater 2A. Thereby, the repeater 2A recognizes that the repeater 2B has buffered the data addressed to the terminal. Thereafter, in step SA11, the data destined for the terminal after being transmitted again from the communication control device 1 to the repeater 2 is buffered in the terminal-destined data buffer 24 of the repeater 2.

  Control executed by the communication control program incorporated in the communication control apparatus according to the first embodiment will be described with reference to FIG.

  In step S111, the communication control device 1 transmits a transmission request signal including data addressed to the terminal from the application processing unit 16 of the application processor to the transmission processing unit 17 of the transmission / reception processor. Thereby, in step S112, the transmission processing unit 17 transmits the data addressed to the terminal to the repeater 2.

  Thereafter, in step S113, the buffer success / failure determination unit 13 determines whether or not the reception processing unit 12 has not received the receipt confirmation signal (ACK). Thereby, the buffer success / failure determination unit 13 determines whether or not the repeater 2 could not buffer the data addressed to the terminal.

  If the buffer success / failure determination unit 13 determines in step S113 that the reception processing unit 12 has received an acknowledgment signal (ACK), it is not necessary to buffer the data addressed to the terminal in the retransmission buffer 14. Therefore, in step S111, the application processing unit 16 of the application processor transmits a next data transmission request including data addressed to the next terminal to the transmission processing unit 17 of the transmission / reception processor. As a result, the transmission processing unit 17 transmits the next terminal-addressed data to the repeater 2.

  On the other hand, in step S113, the buffer success / failure determination unit 13 may determine that the reception confirmation signal (ACK) has not been received by the reception processing unit 12 even after a predetermined time elapses after transmission of data addressed to the terminal, for example. . In this case, in step S114, the buffer success / failure determination unit 13 determines whether or not the retransmission buffer 14 has a free capacity capable of buffering data destined for the terminal to be transmitted. If it is not determined in step S114 that the retransmission buffer 14 has free space, the buffer success / failure determination unit 13 notifies the application processing unit 16 of the fact in step S115. Thereby, the application processing unit 16 erases the data stored in the terminal that is temporarily stored. Thereafter, the process of step S111 is executed again.

  If it is determined in step S114 that the retransmission buffer 14 has free space, the buffer success / failure determination unit 13 notifies the application processing unit 16 of the fact. Thereby, in step S116, the application processing unit 16 determines whether or not the data addressed to the terminal needs to be transmitted to the repeater 2 again. If the application processing unit 16 determines in step S116 that there is no need to retransmit the data destined for the terminal to the repeater 2, it erases the data destined for the terminal in step S115.

  In step S116, when the application processing unit 16 determines that the data addressed to the terminal needs to be transmitted to the repeater 2 again, the application processing unit 16 notifies the buffer success / failure determination unit 13 to that effect. Thereby, in step S117, the buffer success / failure determination unit 13 causes the retransmission buffer 14 to buffer the data addressed to the terminal temporarily stored in the application processing unit 16.

  Thereafter, in step S118, the retransmission determination unit 15 determines whether or not a condition serving as a predetermined retransmission trigger is satisfied. In step S118, if the condition for a predetermined retransmission trigger is not satisfied, the process of step S118 is repeated. On the other hand, in step S118, if a condition that becomes a predetermined retransmission trigger is satisfied, in step S112, the transmission processing unit 17 sends the terminal-addressed data buffered in the retransmission buffer 14 to the repeater 2 again. Send.

  Control executed by the relay program incorporated in the repeater according to the first embodiment will be described with reference to FIG.

  In step S <b> 121, the reception processing unit 22 of the repeater 2 receives terminal-addressed data from the communication control device 1. Thereafter, in step S122, the buffer availability determination unit 25 compares the data amount of the data addressed to the terminal with the free capacity of the data buffer 24 addressed to the terminal. Based on the comparison result, the buffer availability determination unit 25 determines whether or not the terminal-addressed data can be buffered in the terminal-addressed data buffer 24.

  In step S122, the buffer availability determination unit 25 may determine that the data addressed to the terminal can be buffered in the data buffer 24 addressed to the terminal. In this case, in step S123, the transmission processing unit 27 returns a receipt confirmation signal (ACK) that can specify that the buffering can be performed to the communication control apparatus 1. Thereafter, in step S124, the buffer availability determination unit 25 causes the terminal-addressed data buffer 24 to buffer the terminal-addressed data.

  On the other hand, in step S122, the buffer availability determination unit 25 may determine that the data addressed to the terminal cannot be buffered in the data buffer 24 addressed to the terminal. In this case, in step S125, the state where the acknowledgment signal (ACK) is not returned to the communication control device 1 is continued. Thereafter, in step S126, the buffer availability determination unit 25 erases the data addressed to the terminal received by the reception processing unit 22.

  In step S127, the buffering data transmission management unit 23 of the repeater 2 determines whether a data request is received from the terminal 3. If it is not determined in step S127 that the data request has been received from the terminal 3, the buffering data transmission management unit 23 causes the reception processing unit 12 of the repeater 2 to receive a new terminal from the communication control device 1 in step S129. It is determined whether or not data has been received. If it is not determined in step 129 that the reception processing unit 12 of the repeater 2 has received new data addressed to the terminal, the processes in steps S127 and S129 are repeated. In step S129, when the repeater 2 receives new terminal-addressed data, the repeater 2 executes step S122 on the new terminal-addressed data. On the other hand, in step S127, the buffering data transmission management unit 23 may determine that a data request has been received from the terminal 3. In this case, in step S128, the buffering data transmission management unit 23 causes the terminal addressed data buffered in the terminal addressed data buffer 24 to be transmitted from the transmission processing unit 27 to the terminal 3.

(Embodiment 2)
A communication control device, a repeater, a communication control program, and a relay program according to the second embodiment will be described with reference to FIGS.

<Communication control device>
The reception processing unit 12 of the communication control apparatus 1 according to the present embodiment sends an acknowledgment signal from the repeater 2 to which the unbufferable information that can specify that the repeater 2 cannot buffer the data addressed to the terminal is added. May receive. In this case, it is considered that the buffer success / failure determination unit 13 of the communication control device 1 according to the present embodiment has recognized that the repeater 2 has performed a different operation. Thereby, the buffer success / failure determination unit 13 determines that the repeater 2 could not buffer the data addressed to the terminal. According to this, the communication control device 1 can surely grasp that the repeater 2 could not buffer the data addressed to the terminal.

<Repeater>
The buffer success / failure response processing unit 26 of the repeater 2 according to the present embodiment receives, as different operations described above, the addition of unbufferable information that can specify that the repeater 2 cannot buffer the data addressed to the terminal. The confirmation signal is transmitted to the transmission processing unit 27. According to this, it is possible to reliably notify the communication control apparatus 1 that the repeater 2 cannot buffer the data addressed to the terminal.

  A communication procedure executed in the communication system according to the second embodiment will be described with reference to FIG.

  The communication procedure of the communication system of the second embodiment shown in FIG. 7 is similar to the communication procedure of the communication system of the first embodiment shown in FIG. However, the repeater 2 performs the process of step S3A when the buffer availability determination unit 25 determines in step S3 that the terminal-addressed data buffer cannot be buffered in the terminal-addressed data buffer 24. This is different from the embodiment. Further, the repeater 2 performs the above-described implementation in that the process of step S8A is performed instead of step S8 when the buffer availability determination unit 25 determines that the data addressed to the terminal can be buffered in the data buffer 24 addressed to the terminal. The form is different.

  In S3A, repeater 2 of the present embodiment returns a receipt confirmation signal (ACK) to which unbufferable information is added to communication control device 1. The unbufferable information is information that can specify that the repeater 2 could not be buffered. In step S8A, the repeater 2 of the present embodiment returns a receipt confirmation signal (ACK) to which bufferable information is added to the communication control apparatus 1. The bufferable information is information that can specify that the repeater 2 has been buffered.

  In the present embodiment, the reception confirmation signal (ACK) is also added with buffer information including information that can identify the current free capacity of the terminal-addressed data buffer 24. However, the buffer information may be information on the free capacity of the data buffer 24 addressed to the terminal itself, or information on the current usage amount and the total capacity. Further, only the above-described buffer incapable information or bufferable information is added to the receipt confirmation signal (ACK), and the above-described buffer information may not be added. When the buffer information is transmitted to the communication control device 1, the communication control device 1 can grasp the free capacity of the data buffer 24 addressed to the terminal of the repeater 2. As a result, the communication control device 1 can grasp, based on the buffer information, what data amount of data destined for the terminal can be transmitted to the repeater 2 so that the repeater 2 can buffer the data destined for the terminal. it can.

  In the communication control device 1, the reception processing unit 12 receives the reception confirmation signal (ACK) to which the unbufferable information is added. As a result, in step S4, the buffer success / failure determination unit 13 of the communication control device 1 recognizes that the repeater 2 cannot buffer the data addressed to the terminal, and buffers the data addressed to the terminal in the retransmission buffer 14. Let

  A modification of the communication system according to the second embodiment will be described with reference to FIG.

  The communication procedure of the communication system of the modification of the second embodiment shown in FIG. 8 is similar to the communication procedure of the communication system of the modification of the first embodiment shown in FIG. However, the relay 2B performs the process of step SA5A when the buffer availability determination unit 25 determines that the data destined for the terminal cannot be buffered in the data buffer 24 destined for the terminal. This is different from the repeater 2 of FIG. The repeater 2B, when the buffer availability determination unit 25 determines that the data addressed to the terminal can be buffered in the data buffer 24 addressed to the terminal, executes the process of step SA10A instead of step SA10. It differs from the repeater 2 of a modification.

  In step SA5A, the repeater 2B returns a receipt confirmation signal (ACK) to which unbufferable information is added to the repeater 2A. The unbufferable information is information that can specify that the repeater 2 could not buffer the data addressed to the terminal. In step SA10A, repeater 2B returns a receipt confirmation signal (ACK) to which bufferable information is added to repeater 2A. The bufferable information is information that can specify that the repeater 2 has buffered the data addressed to the terminal.

  In the present embodiment, the reception confirmation signal (ACK) is also added with buffer information including information that can specify the free capacity of the data buffer 24 addressed to the terminal. The repeater 2A recognizes that the repeater 2B has not been able to buffer the data addressed to the terminal by receiving the acknowledgment signal (ACK) to which the unbufferable information is added. In step SA6, the repeater 2A is addressed to the terminal. Buffer data. Further, since the buffer information includes information capable of specifying the free capacity of the terminal-addressed data buffer 24, the communication control device 1 can grasp the free capacity of the terminal-addressed data buffer 24 of the repeater 2B. As a result, the repeater 2A can know how much data amount of data addressed to the terminal is transmitted to the repeater 2B so that the repeater 2B can buffer the data addressed to the terminal. Furthermore, only the above-described buffer incapable information or bufferable information is added to the receipt confirmation signal (ACK), and the buffer information may not be added.

  The control executed by the communication control program incorporated in the communication control apparatus according to the second embodiment will be described with reference to FIG.

  The control of the communication control apparatus 1 of the second embodiment shown in FIG. 9 is similar to the control of the communication control apparatus 1 of the first embodiment shown in FIG. However, the buffer success / failure determination unit 13 of the communication control device 1 according to the present embodiment determines whether or not the reception confirmation signal (ACK) to which the buffer unavailable information is added is received from the repeater 2 in step S113A. However, it differs from the communication control apparatus 1 of Embodiment 1. The unbufferable information is information that can specify that the repeater 2 could not buffer the data addressed to the terminal.

  Also by this, the buffer success / failure determination unit 13 of the communication control device 1 can determine whether or not the repeater 2 could not buffer the data addressed to the terminal, as in the first embodiment. As a result, also in the present embodiment, after the repeater 2 has buffered the data destined for the terminal, the data destined for the terminal cannot be buffered in the retransmission buffer 14, the repeater 2 again sends the data to the repeater 2. Can be sent.

  The control executed by the relay program incorporated in the repeater according to the second embodiment will be described with reference to FIG.

  The control of the repeater 2 of the second embodiment shown in FIG. 10 is similar to the control of the repeater 2 of the first embodiment shown in FIG. However, the buffer success / failure response processing unit 26 of the repeater 2 according to the present embodiment causes the transmission processing unit 27 to transmit the reception confirmation signal (ACK) to which the buffer enable information is added to the communication control device 1 in step S123A. 3 differs from the repeater 2 of the first embodiment. The bufferable information is information that can specify that the repeater 2 has buffered the data addressed to the terminal. Further, the buffer success / failure response processing unit 26 of the repeater 2 according to the present embodiment causes the transmission processing unit 27 to transmit the reception confirmation signal (ACK) to which the buffer unavailable information is added to the communication control device 1 in step S125A. 3 differs from the repeater 2 of the first embodiment. The unbufferable information is information that can specify that the repeater 2 could not buffer the data addressed to the terminal. Also by this, as in the first embodiment, it is possible to notify the communication control apparatus 1 that the repeater 2 has not been able to buffer the data addressed to the terminal.

(Embodiment 3)
A communication control device, a repeater, a communication control program, and a relay program according to the third embodiment will be described with reference to FIGS.

<Repeater>
The buffer success / failure response processing unit 26 of the repeater 2 according to the present embodiment, as a different operation as described above, can specify that the repeater 2 has not buffered the data addressed to the terminal, separately from the receipt confirmation signal. The impossible message is transmitted to the transmission processing unit 27. Therefore, it is possible to reliably notify the communication control device 1 that the repeater 2 cannot buffer the data addressed to the terminal.

<Communication control device>
In some cases, the reception processing unit 12 of the communication control apparatus 1 receives a non-bufferable message from the repeater 2 that can specify that the repeater 2 could not buffer the data addressed to the terminal, separately from the receipt confirmation signal. . In this case, the buffer success / failure determination unit 13 considers that the repeater 2 has recognized that the above-described different operations have been performed. Thereby, the buffer success / failure determination unit 13 determines that the repeater 2 could not buffer the data addressed to the terminal. Therefore, the communication control device 1 can reliably grasp that the repeater 2 has not been able to buffer the data addressed to the terminal.

  A communication procedure executed in the communication system according to the third embodiment will be described with reference to FIG.

  The communication procedure of the communication system of the third embodiment shown in FIG. 11 is similar to the communication procedure of the communication system of the first embodiment shown in FIG. However, the repeater 2 of the present embodiment is the same as that of the first embodiment in that the process of step S3B is executed when the data addressed to the terminal cannot be buffered in the data buffer 24 addressed to the terminal in step S3. Different from the repeater 2.

  In step S3B, the repeater 2 according to the present embodiment returns, to the communication control device 1, a non-bufferable message that can specify that the buffering could not be performed, separately from the receipt confirmation signal (ACK). When the reception processing unit 12 of the communication control device 1 receives the buffer unavailable message, it transmits an acknowledgment signal (ACK) to the repeater 2 in step S4A. Thereby, the repeater 2 recognizes that the buffer unavailable message has reached the communication control device 1.

  In addition, when the buffer success / failure determination unit 13 of the communication control device 1 receives the non-bufferable message, it recognizes that the repeater 2 could not buffer the data addressed to the terminal.

  Next, the application processing unit 16 of the communication control device 1 determines whether or not it is necessary to buffer the data addressed to the terminal in the retransmission buffer 14. For example, there is a case where data destined for a terminal that causes a problem in place of the control of the terminal 3 is used if it is not sent to the terminal 3 within a certain fixed time. In this case, the application processing unit 16 determines that retransmission of data addressed to the terminal is unnecessary after a certain period of time has elapsed.

  In step S7A1, the transmission / reception processor of the communication control device 1 transmits an inquiry signal to the application processor. In step S <b> 7 </ b> A <b> 2, when the application processor receives the inquiry signal, the application processor transmits an answer signal that can specify whether or not the buffering is necessary to the transmission / reception processor. When the response signal is a signal that can specify that there is a need for buffering, the transmission / reception processor causes the retransmission buffer 14 to buffer the data addressed to the terminal that could not be buffered by the repeater 2.

  Thereafter, in step S7A3, the application processor of the communication control device 1 transmits a data transmission request signal to the transmission / reception processor. As a result, in step S7, the data addressed to the terminal that is buffered in the retransmission buffer 14 is transmitted to the repeater 2 again. Thereafter, in step S8, the repeater 2 returns an acknowledgment signal (ACK) to the communication control apparatus 1, and in step S9, the terminal-addressed data buffer 24 is buffered in the terminal-addressed data buffer 24. In this case, since the buffering has succeeded, the repeater 2 does not transmit the unbufferable message transmitted in step S3B. As a result, in the communication control device 1, since the reception processing unit 12 does not receive a non-bufferable message even after a predetermined time has elapsed after receiving the receipt confirmation signal (ACK), the buffer success / failure determination unit 13 and the repeater 2 are the terminals. It is determined that the data addressed to the machine has been buffered.

  A modification of the communication system according to the third embodiment will be described with reference to FIG.

  The communication procedure of the communication system of the modification of the second embodiment shown in FIG. 12 is similar to the communication procedure of the communication system of the modification of the first embodiment shown in FIG. However, the communication procedure of the communication system of the modification of the second embodiment shown in FIG. 12 is different from the communication procedure of the communication system of the modification of the first embodiment shown in FIG.

  The repeater 2B of the present embodiment transmits an acknowledgment signal (ACK) to the repeater 2A at step SA4A. In addition, in repeater 2B of the present embodiment, in step SA5, buffer availability determination unit 25 may determine that data destined for the terminal cannot be buffered in data buffer 24 destined for the terminal. In this case, the buffer availability determination unit 25 returns a buffer unavailable message to the repeater 2A separately from the receipt confirmation signal (ACK) in SA5A. The unbufferable message is a signal that can specify that the repeater 2B could not buffer the data addressed to the terminal.

  When the repeater 2A receives the buffer unavailable message, in step SA5B, the repeater 2A transmits an acknowledgment signal (ACK) notifying that the buffer unavailable message has been received to the repeater 2B. In addition, the repeater 2A transfers the buffer impossible message to the communication control device 1 in step SA5C.

  The reception processing unit 12 of the communication control device 1 receives the buffer unavailable message from the repeater 2A. Thereby, the communication control device 1 recognizes that the repeater 2B could not buffer the data addressed to the terminal. In step SA5D, the communication control device 1 transmits an acknowledgment signal (ACK) that can specify that the buffer unavailable message has been received to the repeater 2A.

  In the present embodiment, in step SA5E, an inquiry signal for requesting an answer as to whether it is necessary to buffer data addressed to the terminal is transmitted from the transmission / reception processor to the application processor. When the application processor receives the inquiry signal in step SA5F, the application processor transmits an answer signal that can specify whether or not the buffering is necessary to the transmission / reception processor. When the answer signal is a signal that can specify that there is a need for buffering, the transmission / reception processor of the communication control apparatus 1 buffers the data addressed to the terminal that could not be buffered by the repeater 2 in the retransmission buffer 14. Ring.

  Thereafter, in step SA5G, the application processor of the communication control device 1 transmits a data transmission request signal to the transmission / reception processor. As a result, in step SA5H, the communication control device 1 transmits the terminal-addressed data buffered in the retransmission buffer 14 again to the repeater 2A.

  Thereafter, in step SA5I, repeater 2A transmits an acknowledgment signal (ACK) that can specify that the data addressed to the terminal has been received to communication control device 1, and then relays the data addressed to the terminal in step SA9. Transfer again to the device 2B. The repeater 2B returns an acknowledgment signal (ACK) to the repeater 2A in step SA10, and buffers the terminal-addressed data in the terminal-addressed data buffer 24 in step SA11. Thereafter, since the buffering has succeeded, the repeater 2B does not transmit the unbufferable message transmitted in step SA5A. As a result, since the reception processing unit of the repeater 2A does not receive the unbufferable message even after a predetermined time has elapsed after receiving the receipt confirmation signal (ACK), the repeater 2B determines that the data addressed to the terminal has been buffered.

  The control executed by the communication control program incorporated in the communication control apparatus according to the third embodiment will be described with reference to FIG.

  The control of the communication control apparatus 1 of the third embodiment shown in FIG. 13 is similar to the control of the communication control apparatus 1 of the first embodiment shown in FIG. However, the communication control apparatus 1 according to the present embodiment is different from the communication control apparatus 1 in that the buffer success / failure determination unit 13 determines whether or not the reception processing unit 12 has received the unbufferable message from the repeater 2 in step S113B. 1 communication control device 1. The unbufferable message is a signal that can specify that the repeater 2 could not buffer the data addressed to the terminal. This also allows the communication control device 1 to recognize that the repeater 2 has not been able to buffer the data addressed to the terminal, as in the first embodiment. As a result, also in this embodiment, the communication control apparatus 1 causes the retransmission data to be buffered in the retransmission buffer 14 and then retransmits the data addressed to the terminal that could not be buffered by the repeater 2 to the repeater 2. Can do.

  The control executed by the relay program incorporated in the repeater according to the third embodiment will be described with reference to FIG.

  The control of the repeater 2 of the third embodiment shown in FIG. 14 is similar to the control of the repeater 2 of the first embodiment shown in FIG. However, the control of the repeater 2 according to the present embodiment does not execute step S123, but performs transmission of an acknowledgment signal (ACK) in step S123B regardless of whether or not the data addressed to the terminal is buffered. This is different from the repeater 2 of the first embodiment. Step S123B is executed after step S121 and before step S122. Further, the control of the repeater 2 of the present embodiment is that the buffer success / failure response processing unit 26 of the repeater 2 causes the transmission processing unit 27 to transmit the buffer unavailable message to the communication control device 1 in step S125B. This is different from the repeater 2 of the first embodiment. The unbufferable message is a signal that can specify that the data addressed to the terminal could not be buffered. This also allows the repeater 2 to notify the communication control device 1 that the data addressed to the terminal could not be buffered, as in the first embodiment.

(Embodiment 4)
The configuration of the communication control apparatus and the repeater according to the fourth embodiment will be described with reference to FIG.

  As a premise, the communication system of the present embodiment is different from the communication control apparatus 1 of the first to third embodiments in the following points.

  As shown in FIG. 15, the repeater 2 of the present embodiment is different from the repeater 2 of the first to third embodiments shown in FIG. 2 in that the buffer success / failure response processing unit 26 is not included. Yes.

  In the communication system according to the present embodiment, when the terminal 3 receives the data addressed to the terminal from the repeater 2, the communication control device-addressed receipt confirmation message is transmitted to the repeater 2. When the repeater 2 of the present embodiment receives a confirmation message addressed to the communication control device instead of having the buffer success / failure response processing unit 26, the repeater 2 receives the confirmation message addressed to the communication control device. Transfer to terminal 3. The communication control device address confirmation message is a signal that can specify that the terminal 3 has received the data addressed to the terminal.

<Communication control device>
In the communication control device 1 according to the present embodiment, the reception processing unit 12 receives from the repeater 2 the receipt confirmation message addressed to the communication control device transmitted by the terminal 3. The buffer success / failure determination unit 13 of the communication control device 1 determines whether or not the repeater 2 has buffered the data addressed to the terminal based on whether or not the reception processing unit 12 has received the receipt confirmation message addressed to the communication control device. judge. For this reason, the communication control device 1 can again transmit the data addressed to the terminal that the repeater 2 could not buffer to the repeater 2.

  In the present embodiment, the transmission processing unit 17 of the communication control apparatus 1 transmits the data addressed to the terminal device to the terminal device 3 via the relay device 2 and then to the other terminal device via the relay device 2. Data is transmitted to the terminal 3. When the terminal 3 receives the data addressed to the terminal from the repeater 2, the terminal 3 transmits a receipt confirmation message addressed to the communication control device to the communication control device 1 via the repeater 2. When the terminal 3 receives data addressed to another terminal from the repeater 2, the terminal 3 transmits a receipt confirmation message addressed to another communication control device to the communication control device 1 via the repeater 2.

  The reception processing unit 12 may receive a receipt confirmation message addressed to another communication control device without receiving the receipt confirmation message addressed to the communication control device. In this case, the buffer success / failure determination unit 13 determines that the repeater 2 could not buffer the data addressed to the terminal. Therefore, the communication control device 1 can reliably grasp that the repeater 2 has not been able to buffer the data addressed to the terminal.

  Also in the present embodiment, after the data addressed to the terminal is transmitted to the repeater 2, a condition that becomes a retransmission trigger described later may be satisfied. In this case, if the reception processing unit 12 has not received the communication control device reception confirmation message, the buffer success / failure determination unit 13 determines that the repeater 2 could not buffer the data destined for the terminal. Thereby, the data addressed to the terminal is buffered in the retransmission buffer 14 and immediately transmitted again from the transmission processing unit 17 to the repeater 2.

  A communication procedure executed in the communication system according to the fourth embodiment will be described with reference to FIG.

  The communication procedure of the communication system of the fourth embodiment shown in FIG. 16 is similar to the communication procedure of the communication system of the first embodiment shown in FIG. However, the communication procedure of the communication system of the fourth embodiment shown in FIG. 16 differs from the communication procedure of the communication system of the first embodiment shown in FIG.

  When the repeater 2 receives the data addressed to the terminal from the communication control device 1 in step S2, the repeater 2 confirms the receipt in step S2A regardless of whether the data addressed to the terminal can be buffered in the data buffer 24 addressed to the terminal. A signal is returned to the communication control device 1. In this case, the acknowledgment signal (ACK) is simply a signal that can specify that the data addressed to the terminal has been received, and is a signal that can specify whether or not the repeater 2 has buffered the data addressed to the terminal. Absent. Therefore, at this stage, the communication control device 1 cannot determine whether or not the repeater 2 can buffer the data addressed to the terminal.

  In the present embodiment, in step S6A, after receiving the data addressed to the terminal, the terminal 3 transmits a receipt confirmation message addressed to the communication control device to the repeater 2. This receipt confirmation message addressed to the communication control device is a receipt confirmation message for the data addressed to the terminal that has been buffered by the repeater 2 before.

  Thereafter, the repeater 2 transfers a receipt confirmation message addressed to the communication control device to the communication control device 1 in step S6B. When the transmission / reception processor of the communication control device 1 receives the receipt confirmation message addressed to the communication control device, in step S6C, the transmission / reception processor transmits an inquiry signal asking for an answer as to whether or not the application processor needs to be buffered.

  When the application processing unit 16 receives the inquiry signal, the application processing unit 16 determines which terminal addressed data corresponds to the reception confirmation message addressed to the communication control device. In this determination, the communication control device receipt confirmation message corresponding to the terminal data transmitted later is received even though the communication control device receipt confirmation message corresponding to the terminal data sent earlier is not received. May be received. In this case, the application processing unit 16 recognizes that the data addressed to the terminal previously transmitted by the repeater 2 could not be buffered.

  Next, the application processor 16 of the application processor determines whether or not there is a need to buffer the data addressed to the terminal in the retransmission buffer 14. For example, there is a case in which terminal-addressed data that causes a problem in the control of the terminal 3 is used if the terminal 3 is not reached within a certain time from a certain point of time. In this case, the application processing unit 16 determines that retransmission of data destined for the terminal is unnecessary after a certain period of time has elapsed from a certain point in time.

  In step S6D, the application processor transmits an answer signal that can specify whether or not there is a necessity for buffering in the retransmission buffer 14 for the data addressed to the terminal, to the transmission / reception processor. If the response signal is a signal that can specify that there is a need for buffering, the transmission / reception processor causes the retransmission buffer 14 to buffer the data addressed to the terminal that could not be buffered by the repeater 2.

  Next, in step S6E, the application processor of the communication control device 1 transmits a data transmission request signal to the transmission / reception processor. Thereby, in step S7, the transmission / reception processor transmits the data addressed to the terminal, which has been buffered in the retransmission buffer 14, to the repeater 2.

  In step S8, the repeater 2 returns an acknowledgment signal (ACK) that can specify that the data addressed to the terminal has been received, to the communication control apparatus 1. Thereafter, in step S9, the repeater 2 buffers the terminal-addressed data in the terminal-addressed data buffer 24. Thereafter, when the reception processing unit 22 of the repeater 2 receives the same data request as in step S5, the buffering data transmission management unit 23 receives the terminal-addressed data buffered in the terminal-addressed data buffer 24. The data is transmitted to the transmission processing unit 27. As a result, as in step S6A, the terminal 3 that has received the transmitted data addressed to the terminal device transmits a communication control device address receipt confirmation message to the communication control device 1 via the repeater 2. By receiving this receipt confirmation message addressed to the communication control device, the buffer success / failure determination unit 13 of the communication control device 1 determines that the repeater 2 has buffered the data addressed to the terminal.

  A modification of the communication system according to the fourth embodiment will be described with reference to FIG.

  The communication procedure of the communication system of the fourth embodiment shown in FIG. 17 is similar to the communication procedure of the communication system of the first embodiment shown in FIG. However, the communication procedure of the communication system of the fourth embodiment shown in FIG. 17 differs from the communication procedure of the communication system of the first embodiment shown in FIG. 4 in the following points.

  Regardless of whether or not the repeater 2B has buffered the data addressed to the terminal, in step SA4A, the repeater 2B returns a receipt confirmation signal to the repeater 2A. In this case, the reception confirmation signal (ACK) is a signal that can simply specify that the data addressed to the terminal has been received, and is a signal that can specify whether or not the repeater 2B has buffered the data addressed to the terminal. Absent. Therefore, at this stage, the repeater 2A cannot determine whether or not the repeater 2B has buffered the data addressed to the terminal.

  In the present embodiment, after the terminal 3 receives the data addressed to the terminal in step SA8, in step S8B, the communication controller receiving receipt confirmation message is transmitted to the repeater 2B. The reception confirmation message addressed to the communication control device is a signal that can specify that the terminal device 3 has received the data addressed to the terminal device, and is a signal for informing the communication control device 1 to that effect. Next, in step S8C, the repeater 2B transfers the receipt confirmation message addressed to the communication control apparatus to the repeater 2A. Thereafter, in step S8D, the repeater 2A transfers the communication control device address receipt confirmation message to the communication control device 1.

  In the present embodiment, steps SA5E, SA5F, SA5G, SA5H, SA5I, SA9, SA10, and SA11 in FIG. 17 are the same as steps SA5E, SA5F, SA5G, SA5H, SA5I, SA9, SA10, and SA11 in FIG. is there.

  Also by the above communication procedure, the repeater 2B can notify the communication control device 1 that the data addressed to the terminal could not be buffered. Further, the communication control device 1 can transmit the buffered terminal addressed data to the repeater 2B again.

  The control executed by the communication control program incorporated in the communication control apparatus according to the fourth embodiment will be described with reference to FIG.

  The control of the communication control apparatus 1 of the fourth embodiment shown in FIG. 18 is similar to the control of the communication control apparatus 1 of the first embodiment shown in FIG. However, in step S113X, the communication control device 1 according to the present embodiment determines whether or not the communication control device address receipt confirmation message transmitted from the terminal 3 has been received from the repeater 2 within a predetermined time, for example. However, it differs from the communication control apparatus 1 of Embodiment 1. The predetermined time is measured immediately after the communication control device 1 transmits the data addressed to the terminal.

  According to this, by determining whether or not the terminal 3 has received the data addressed to the terminal within a predetermined time, it is possible to determine whether or not the repeater 2 could not buffer the data addressed to the terminal. it can. As a result, also in the present embodiment, after the repeater 2 has buffered the data destined for the terminal, the data destined for the terminal cannot be buffered in the retransmission buffer 14, the repeater 2 again sends the data to the repeater 2. Can be sent.

  The control executed by the relay program incorporated in the repeater according to the fourth embodiment will be described with reference to FIG.

  The control of the repeater 2 of the fourth embodiment shown in FIG. 19 is similar to the control of the repeater 2 of the first embodiment shown in FIG. However, the repeater 2 of the present embodiment is different from the repeater 2 of the first embodiment in that step S123 and step S125 are not executed and step S123C is executed instead. That is, in step S123C, the repeater 2 transmits a reception confirmation signal to the communication control apparatus 1 regardless of whether or not the data addressed to the terminal can be buffered in the data buffer addressed to the terminal. Step S123C is executed after step S121 and before step S122. Thereafter, when it is determined in step S122 that the buffer availability determination unit 25 can buffer the data addressed to the terminal in the data buffer 24 addressed to the terminal, the data addressed to the terminal is converted to the data buffer 24 addressed to the terminal in step S124. To buffer.

  On the other hand, if the buffer availability determination unit 25 determines in step S122 that the terminal addressed data cannot be buffered in the terminal addressed data buffer 24, the terminal addressed data is deleted in step S126. In other words, in the present embodiment, the communication control device 1 itself does not notify the communication control device receipt confirmation message transmitted from the terminal 3 instead of notifying whether or not the repeater 2 has made the data addressed to the terminal. Based on this, it is determined whether or not the repeater 2 has created data addressed to the terminal.

  Control executed by the communication control apparatus 1 according to the modification of the fourth embodiment will be described with reference to FIG.

  The control executed by the communication control apparatus 1 according to the modification of the fourth embodiment shown in FIG. 20 is similar to the control executed by the communication control apparatus 1 according to the fourth embodiment described above with reference to FIG. Yes. The control executed by the communication control apparatus 1 of the modification of the fourth embodiment shown in FIG. 20 is only the control executed by the communication control apparatus 1 of the above-described fourth embodiment described with reference to FIG. 18 and step S113Y. Is different. In step S113Y, the buffer success / failure determination unit 13 of the communication control apparatus 1 determines whether or not the data addressed to the terminal transmitted from the repeater 2 to the terminal 3 can be intercepted by the antenna 11 and the reception processing unit 12 within a predetermined time. judge.

  In some cases, the terminal-addressed data transmitted from the repeater 2 to the terminal 3 can be intercepted by the antenna 11 and the reception processing unit 12. In this case, the buffer success / failure determination unit 13 determines that the repeater 2 has buffered the data addressed to the terminal. On the other hand, the antenna 11 and the reception processing unit 12 cannot intercept the data addressed to the terminal device transmitted from the repeater 2 to the terminal device 3, and the second data transmitted later than the first data addressed to the terminal device transmitted earlier. There is a case to intercept the data addressed to the terminal. In this case, the buffer success / failure determination unit 13 determines that the repeater 2 has not been able to buffer the data transmitted to the first terminal previously transmitted.

  According to this, the communication control apparatus 1 determines whether or not the repeater 2 has transmitted the data addressed to the terminal to the terminal 3 within a predetermined time after transmitting the data addressed to the terminal. 2 can determine whether the data addressed to the terminal could not be buffered. As a result, also in the present embodiment, the communication control apparatus 1 causes the repeater 2 to buffer the data destined for the terminal that could not buffer the data destined for the terminal in the retransmission buffer 14, and then the transmission processing unit 17 Can be transmitted to the repeater 2 again.

  In step S113Y, if the reception processing unit 12 has not intercepted the data addressed to the terminal when the predetermined time has elapsed, the buffer success / failure determination unit 13 cannot buffer the data addressed to the terminal by the repeater 2 It is judged that. However, when the reception processing unit 12 intercepts data transmitted to another terminal transmitted later without intercepting the data transmitted to the terminal previously transmitted, the buffer success / failure determination unit 13 determines the repeater 2 May determine that the data addressed to the terminal could not be buffered. Also by this control, the communication control device 1 can grasp that the repeater 2 could not buffer the data addressed to the terminal.

(First specific example of retransmission trigger)
A first specific example of the retransmission trigger described in each of Embodiments 1 to 4 will be described with reference to FIGS. 21 and 22.

  In this specification, it is assumed that the retransmission trigger is an opportunity to retransmit the data addressed to the terminal that is buffered in the retransmission buffer 14 of the communication control device 1.

  In the communication control device 1 according to the first to fourth embodiments, the condition serving as a retransmission trigger is established when a predetermined time has elapsed after the data addressed to the terminal is transmitted to the repeater 2. According to this, the communication control apparatus 1 can transmit the data addressed to the terminal to the repeater 2 again with simple control.

  A first specific example of a retransmission trigger of each communication control apparatus according to the first to fourth embodiments will be described with reference to FIG.

  The communication procedure of the communication system shown in FIG. 21 is similar to the communication procedure of the communication system shown in FIG. However, the communication control device 1 according to the present embodiment repeats the terminal-addressed data buffered in the retransmission buffer 14 when a predetermined time has elapsed after transmitting the data addressed to the terminal in step S2. 2 to send again. That is, whether or not a condition for triggering retransmission is satisfied is determined by whether or not a predetermined time has elapsed since the transmission of data addressed to the terminal.

  Whether the above-mentioned conditions for triggering retransmission are satisfied is determined by whether or not a predetermined time has elapsed since the transmission of data destined for the terminal, as shown in FIG. 7 of the second embodiment and FIG. 11 of the third embodiment. The present invention can also be applied to the communication system shown in FIG.

  A first specific example of the retransmission trigger of each communication control apparatus according to the first to fourth embodiments will be described with reference to FIG.

  The control of the communication control device 1 shown in FIG. 22 is similar to the control of the communication control device 1 shown in FIG. However, the communication control apparatus 1 according to the present embodiment is different from the communication according to the first embodiment in that, in step S118A, it is determined whether or not a predetermined time has elapsed since the data addressed to the terminal is transmitted to the repeater 2. It is different from the control device 1. According to this, the communication control apparatus 1 can transmit the data addressed to the terminal to the repeater 2 again with simple control.

  In FIG. 9 according to the second embodiment, FIG. 13 according to the third embodiment, and FIG. 4 can also be applied in step S118 shown in FIG.

(Second specific example of retransmission trigger)
A second specific example of the retransmission trigger described in each of Embodiments 1 to 4 will be described with reference to FIGS.

  In each of the first to fourth embodiments, consider a case where each of the communication control device 1 and the repeater 2 is a wireless device that transmits and receives terminal-addressed data as radio waves. In this case, in the communication control device 1 according to the first to fourth embodiments, the condition serving as a retransmission trigger is that after the data addressed to the terminal is transmitted to the repeater 2, the reception processing unit 12 is connected to the terminal by the repeater 2. This is established when the radio waves of the data addressed to the terminal transmitted to 3 are intercepted.

  According to this, the communication control apparatus 1 buffers the retransmission buffer 14 in response to the transmission of the terminal-addressed data buffered in the terminal-addressed data buffer 24 by the repeater 2 to the terminal 3. Send the data addressed to the terminal again. For this reason, the communication control device 1 retransmits the data destined for the terminal to the repeater 2 at a timing when the probability that the repeater 2 can be buffered is increased due to the increase in the free capacity of the data buffer 24 destined for the terminal. be able to.

  A second specific example of the retransmission trigger of each communication control apparatus according to the first to fourth embodiments will be described with reference to FIG.

  The communication procedure of the communication system shown in FIG. 23 is similar to the communication procedure of the communication system shown in FIG. However, in FIG. 23, the communication control apparatus 1 may be able to intercept the terminal-addressed data transmitted from the repeater 2 to the terminal 3 in step S6A. In this case, the communication control apparatus 1 considers that the repeater 2 has buffered the data addressed to the terminal, and retransmits the data addressed to the terminal buffered in the retransmission buffer 14 to the repeater 2. . That is, it is determined whether or not a condition for triggering retransmission has been satisfied based on whether or not the repeater 2 has transmitted data addressed to the terminal to the terminal 3.

  Whether or not the condition that becomes the retransmission trigger is satisfied is determined by whether or not the repeater 2 transmits the data addressed to the terminal to the terminal 3 as shown in FIG. 7 and Embodiment 3 of the second embodiment. The present invention can also be applied to the communication system shown in FIG. 11 and FIG. 16 of the fourth embodiment.

  A modification of the second specific example of the retransmission trigger of each communication control device 1 according to the first to fourth embodiments will be described with reference to FIG.

  The communication procedure of the communication system shown in FIG. 24 is similar to the communication procedure of the communication system shown in FIG. However, in FIG. 24, in step SA8A, the repeater 2A may be able to intercept the data addressed to the terminal transmitted from the repeater 2B to the terminal 3. In this case, the repeater 2A considers that the repeater 2 has buffered the data addressed to the terminal, and retransmits the data addressed to the terminal buffered in the retransmission buffer 14 to the repeater 2B. That is, it is determined whether or not a condition for triggering retransmission has been established, depending on whether or not the repeater 2B has transmitted data addressed to the terminal to the terminal 3. Therefore, the communication control apparatus 1 can transmit the data addressed to the terminal device to the repeater 2 again at a timing at which the repeater 2 can be buffered.

  Whether or not the condition that becomes the retransmission trigger is satisfied is determined by whether or not the repeater 2B transmits the data addressed to the terminal to the terminal 3 in FIG. 8 of the second embodiment and the third embodiment. The present invention can also be applied to the communication system shown in FIG.

  A second specific example of the retransmission trigger of each communication control device 1 according to the first to fourth embodiments will be described with reference to FIG.

  The control of the communication control apparatus 1 shown in FIG. 25 is similar to the control of the communication control apparatus 1 shown in FIG. However, the communication control device 1 according to the present embodiment is different from the first embodiment in that it determines whether or not the data addressed to the terminal transmitted from the repeater 2 to the terminal 3 is received (intercepted) in step S118B. Is different from the communication control apparatus 1 of FIG. According to this, it can be reliably determined whether or not the repeater 2 could not buffer the data addressed to the terminal.

  Receiving the data addressed to the terminal transmitted from the repeater 2 to the terminal 3 in step S118B is set as a retransmission trigger in FIG. 9 of the second embodiment, FIG. 13 of the third embodiment, and the fourth embodiment. This can also be applied in step S118 shown in FIG.

(Third specific example of retransmission trigger)
A third specific example of the retransmission trigger described in each of Embodiments 1 to 4 will be described with reference to FIGS.

  In each of the communication control apparatuses 1 according to the first to fourth embodiments, the condition that becomes a retransmission trigger is that after the data addressed to the terminal is transmitted to the repeater 2, the reception processing unit 12 passes from the terminal 3 via the repeater 2. This is true when a data request is received. Therefore, the communication control device 1 transmits the data addressed to the terminal buffered in the retransmission buffer 14 to the repeater 2 again when the data request is received.

  Based on the data request received from the terminal 3, the repeater 2 transmits the terminal addressed data buffered in the terminal addressed data buffer 24 to the terminal 3. Therefore, in the repeater 2, the free capacity of the terminal-addressed data buffer 24 has increased. Therefore, the communication control apparatus 1 according to the present embodiment can transmit the data addressed to the terminal device to the repeater 2 again at a timing at which the repeater 2 is likely to be buffered.

  A third specific example of the retransmission trigger of each communication control apparatus according to the first to third embodiments will be described with reference to FIG.

  As shown in FIG. 26, the repeater 2 applied to each of the first to third embodiments transfers the data request received from the terminal 3 to the communication control device 1. It differs from each repeater 2 of the forms 1-3. The repeater 2 shown in FIG. 26 further includes a data request transfer processing unit 28 in addition to the configuration of each repeater 2 of the first to third embodiments shown in FIG.

  With reference to FIG. 27, a third specific example of the retransmission trigger of each communication control apparatus according to the fourth embodiment will be described.

  As shown in FIG. 27, the repeater 2 applied to the fourth embodiment transfers the data request received from the terminal 3 to the communication control device 1 in the fourth embodiment shown in FIG. It is different from the repeater 2. The repeater 2 shown in FIG. 27 further includes a data request transfer processing unit 28 in addition to the configuration of the repeater 2 of the fourth embodiment shown in FIG.

  FIG. 29 is a sequence diagram for explaining a third specific example of a retransmission trigger of each communication control apparatus according to the first to fourth embodiments using FIG.

  The communication procedure of the communication system shown in FIG. 28 is similar to the communication procedure of the communication system shown in FIG. However, in FIG. 28, when the communication control device 1 receives the data request transmitted from the terminal 3 from the repeater 2, the data addressed to the terminal that has been buffered in the retransmission buffer 14 is transmitted to the repeater 2. Sending again. As a result, whether or not a condition serving as a retransmission trigger is satisfied is determined based on whether or not a data request is received. Therefore, also in the present embodiment, the communication control apparatus 1 can retransmit the data addressed to the terminal device to the repeater 2 at a timing with a high probability that the repeater 2 can be buffered.

  Specifically, in step S6A, the repeater 2 transfers the data request received from the terminal 3 in step S5 to the communication control device 1. When receiving a data request from the repeater 2, the communication control device 1 returns a receipt confirmation signal to the repeater 2 in step S6B.

  Whether or not the above-described conditions for triggering retransmission are satisfied is determined based on whether or not a data request is received, as shown in FIG. 7 of the second embodiment, FIG. 11 of the third embodiment, and FIG. 16 of the fourth embodiment. The communication system shown in FIG.

  A third specific example of the retransmission trigger of each communication control apparatus 1 according to the first to fourth embodiments will be described with reference to FIG.

  The control of the communication control device 1 shown in FIG. 29 is similar to the control of the communication control device 1 shown in FIG. However, the communication control apparatus 1 according to the first embodiment is different in that the communication control apparatus 1 according to the first embodiment determines whether or not the data request transmitted from the terminal 3 is received from the repeater 2 in step S118C. Is different. In other words, whether or not a condition for triggering retransmission is satisfied is determined by whether or not a data request is received. Therefore, also in the present embodiment, the communication control apparatus 1 can retransmit the data addressed to the terminal device to the repeater 2 at a timing with a high probability that the repeater 2 can be buffered.

  Executing the process of determining whether or not the terminal 3 has received the data request transmitted to the repeater 2 in step S118C is illustrated in FIG. 9 of the second embodiment, FIG. 13 of the third embodiment, and The present invention can also be applied in step S118 shown in FIG.

  A third specific example of the retransmission trigger of each repeater 2 according to the first to fourth embodiments will be described with reference to FIG.

  The control of the repeater 2 shown in FIG. 30 is similar to the control of the repeater 2 shown in FIG. However, the repeater 2 of the present embodiment is that the repeater 2 of the first embodiment transfers the data request to the communication control apparatus 1 after receiving the data request transmitted by the terminal 3 in step S129. Is different.

  According to this, the communication control apparatus 1 can regard the reception of the data request as the establishment of a condition that becomes a retransmission trigger, and can transmit the data addressed to the terminal to the repeater 2 again. In this case, the repeater 2 transmits the terminal-addressed data buffered in the terminal-addressed data buffer 24 to the terminal 3 based on the data request, and then the terminal transmitted again from the communication control device 1. Receive the addressed data. Accordingly, the repeater 2 receives the data addressed to the terminal at the timing when the free capacity of the data buffer 24 addressed to the terminal increases. As a result, the probability that the data addressed to the terminal that has been transmitted again by the repeater 2 can be buffered is increased.

  A modification of the third specific example of the retransmission trigger of each communication control device 1 according to the first to fourth embodiments will be described with reference to FIG.

  The communication procedure of the communication system shown in FIG. 31 is similar to the communication procedure of the communication system shown in FIG. However, in FIG. 31, when the communication control device 1 receives a data request transmitted from the terminal 3 from the repeater 2, the communication addressed to the terminal that has been buffered in the retransmission buffer 14 is transmitted to the repeater 2. Sending again. That is, it is determined whether or not a condition for triggering retransmission has been satisfied based on whether or not the reception processing unit 12 of the communication control device 1 has received a data request.

  Specifically, in step SA8A, the repeater 2B transfers the data request received from the terminal 3 in step SA7 to the repeater 2A. When receiving a data request from the repeater 2B, the communication control device 1 returns a receipt confirmation signal to the repeater 2A in step SA8B.

  Whether or not the above-mentioned conditions for triggering retransmission are satisfied is determined by whether or not a data request is received, as shown in FIG. 8 of the second embodiment, FIG. 12 of the third embodiment, and FIG. 17 of the fourth embodiment. The communication system shown in FIG.

(Estimation of free space)
The free capacity prediction function added to the communication control apparatus 1 according to the first to fourth embodiments will be described with reference to FIGS.

  Configuration of communication control device 1 when each communication control device 1 according to the first to fourth embodiments has a function of predicting the free capacity of the data buffer 24 addressed to the terminal of the repeater 2 with reference to FIGS. 32 and 33 Will be explained.

  32 is further provided with a data size storage unit 19 and a transmission destination buffer capacity prediction unit 18 in comparison with each communication control device 1 of the first to third embodiments shown in FIG. ing. However, the communication control apparatus 1 according to the fourth embodiment shown in FIG. 15 may further include a data size storage unit 19 and a transmission destination buffer capacity prediction unit 18.

  The data size storage unit 19 stores a reference indirect transmission size M indicating an upper limit value of the size of data addressed to the terminal that is expected to be buffered by the repeater 2 shown in FIG. The transmission destination buffer capacity prediction unit 18 predicts an average free capacity of the terminal-addressed data buffer 24 of the repeater 2.

  The transmission destination buffer capacity prediction unit 18 executes the following processing for the first transmission of data addressed to the terminal. In this specification, the data destined for the terminal that is transmitted to the repeater 2 for the first time based on the data transmission request from the application processor is referred to as the first data destined for the terminal.

  The data size of the first data addressed to the terminal may be less than or equal to the reference indirect transmission size M. In this case, the transmission destination buffer capacity prediction unit 18 causes the transmission processing unit 17 to transmit the first terminal addressed data without buffering in the retransmission buffer 14. After the first terminal addressed data is transmitted to the repeater 2, the buffer success / failure determination unit 13 may determine that the repeater 2 could not buffer the first terminal addressed data. In this case, the transmission destination buffer capacity prediction unit 18 decreases the reference indirect transmission size M by a predetermined size.

  On the other hand, the data size of the first terminal-addressed data may be larger than the reference indirect transmission size M. In this case, the transmission destination buffer capacity prediction unit 18 does not transmit the first terminal addressed data to the repeater 2, and the first terminal addressed data is provided on the condition that there is a free capacity in the retransmission buffer. The re-transmission buffer 14 is buffered. The buffer success / failure determination unit 13 may determine that the repeater 2 has successfully buffered the first terminal-addressed data buffered in the retransmission buffer 14 a predetermined number of times. In this case, the transmission destination buffer capacity prediction unit 18 increases the reference indirect transmission size M by a specific size.

  According to the above configuration, by predicting the free capacity of the repeater 2, the retransmission buffer can be transmitted without transmitting to the repeater 2 the first terminal-addressed data with a relatively low probability that the repeater 2 can be buffered. 14 for buffering. Accordingly, it is possible to omit unauthorized transmission processing of data addressed to a terminal with a relatively low probability that the repeater 2 can be buffered.

  34 and FIG. 35, communication incorporated in the communication control device when each communication control device of the first to fourth embodiments has a function of predicting the free capacity of the data buffer 24 addressed to the terminal of the repeater. The control executed by the control program will be described.

  As shown in FIG. 34, in step S151, the communication control apparatus 1 transmits a terminal-addressed data transmission request signal from the application processor to the transmission / reception processor. In step S152, the transmission destination buffer capacity prediction unit 18 determines whether or not the data size of the first terminal-addressed data determined to be transmitted by the application processing unit 16 is larger than the reference indirect transmission size M.

  In some cases, the data size of the data addressed to the terminal is equal to or smaller than the reference indirect transmission size M. In this case, the transmission destination buffer capacity prediction unit 18 causes the transmission processing unit 17 to transmit the data addressed to the terminal to the repeater 2 in step S162 of FIG. 35 without buffering the data in the retransmission buffer 14. On the other hand, the data size of the first terminal-addressed data may be larger than the reference indirect transmission size M. In this case, the transmission destination buffer capacity prediction unit 18 determines whether or not the transmission processing unit 17 transmits data to the repeater 2 after buffering the first terminal addressed data in the retransmission buffer 14. . Therefore, the process of step S153 in FIG. 34 is executed.

  As shown in FIG. 34, in step S153, the transmission destination buffer capacity prediction unit 18 determines whether or not there is a free capacity capable of buffering the first terminal addressed data to be transmitted to the retransmission buffer 14. judge. If it is not determined in step S153 that the retransmission buffer 14 has free space, the transmission destination buffer capacity prediction unit 18 notifies the application processing unit 16 of the fact. Accordingly, in step S154, the application processing unit 16 deletes the first data addressed to the terminal. Thereafter, the application processing unit 16 executes the process of step S151 again.

  In step S153, it may be determined that the retransmission buffer 14 has free space. In this case, the transmission destination buffer capacity prediction unit 18 causes the retransmission buffer 14 to buffer the first terminal addressed data received from the application processing unit 16 in step S155. Thereafter, in step S156, the retransmission determination unit 15 determines whether or not a condition that becomes a predetermined retransmission trigger is satisfied. In step S156, if the condition for a predetermined retransmission trigger is not satisfied, the process of step S156 is repeated. On the other hand, if a predetermined condition for triggering retransmission is satisfied in step S156, the first terminal-addressed data buffered in the retransmission buffer 14 is transmitted from the transmission processing unit 17 to the repeater 2 in step S157. Will be sent again.

  Thereafter, in step S158, the buffer success / failure determination unit 13 determines whether or not the reception processing unit 12 has not received the receipt confirmation signal (ACK). Thereby, the buffer success / failure determination unit 13 determines whether or not the repeater 2 could not buffer the first terminal addressed data.

  In step S158, when the reception confirmation signal (ACK) is received by the reception processing unit 12, the transmission destination buffer capacity prediction unit 18 adds 1 to the buffering success count C in step S159. The buffering success count C starts from zero. Next, in step S160, the transmission destination buffer capacity prediction unit 18 determines whether or not the buffering success count C is a predetermined number of times, for example, 5 times or more. If the buffering success count C is not 5 or more, the process of step S151 is executed. On the other hand, the buffering success count C may be 5 or more. In this case, in step S162, the transmission destination buffer capacity prediction unit 18 increases the reference indirect transmission size M by a predetermined size (constant), and returns the buffering success count C to zero. Thereafter, the process of step S151 is executed.

  In step S162 shown in FIG. 35, the communication control apparatus 1 considers the case where the data addressed to the terminal is transmitted to the repeater 2. In this case, in step S163, the buffer success / failure determination unit 13 determines whether or not the reception processing unit 12 has not received the receipt confirmation signal (ACK). Thereby, the buffer success / failure determination unit 13 determines whether or not the repeater 2 could not buffer the first terminal addressed data. In step S163, when a reception confirmation signal (ACK) is received by the reception processing unit 12, the process of step S151 is executed. On the other hand, if the reception confirmation signal (ACK) is not received in the reception processing unit 12 in step S163, the transmission destination buffer capacity prediction unit 18 sets the reference indirect transmission size M to the specific size (constant) in step S164. ) Only.

  In step S165, the transmission destination buffer capacity prediction unit 18 determines whether or not the retransmission buffer 14 has a free capacity capable of buffering data destined for the terminal to be transmitted. If it is not determined in step S165 that the retransmission buffer 14 has free space, the transmission destination buffer capacity prediction unit 18 notifies the application processing unit 16 of the fact in step S166. Thereby, the application processing unit 16 erases the first data addressed to the terminal. Thereafter, the process of step S151 in FIG. 34 is executed again.

  On the other hand, if it is determined in step S165 that the retransmission buffer 14 has free space, the transmission destination buffer capacity prediction unit 18 buffers the data addressed to the second and subsequent terminals in the retransmission buffer 14 in step S167. Let When the data addressed to the terminal previously transmitted to the repeater 2 based on the data transmission request is transmitted again to the repeater 2, the data addressed to the terminal is referred to as the data addressed to the second and subsequent terminals.

  Thereafter, in step S168, the retransmission determination unit 15 determines whether or not a condition for triggering retransmission is satisfied. In step S168, if the conditions for triggering retransmission are not satisfied, the process of step S168 is repeated. On the other hand, in step S168, if a predetermined condition for triggering retransmission is satisfied, in step S169, the second and subsequent terminal-addressed data buffered in retransmission buffer 14 is transmitted from transmission processing unit 17 to the repeater. 2 is sent again.

  Thereafter, in step S <b> 170, the buffer success / failure determination unit 13 determines whether or not the reception processing unit 12 has received an acknowledgment signal (ACK). As a result, the buffer success / failure determination unit 13 determines whether or not the repeater 2 has not been able to buffer the data addressed to the terminal for the second time or later.

  In step S170, if the buffer success / failure determination unit 13 determines that the reception confirmation signal (ACK) has not been received in the reception processing unit 12, the processing in steps S165 to S170 is repeated. On the other hand, if the buffer success / failure determination unit 13 determines that the reception processing unit 12 has received the receipt confirmation signal (ACK), the process of step S151 in FIG. 34 is executed.

  In steps S158, S163, and S170, the buffer success / failure determination unit 13 only needs to determine whether or not the repeater 2 has received the data addressed to the terminal. Therefore, in steps S158, S163, and S170, whether the buffer success / failure determination unit 13 has received the receipt confirmation signal with the buffer unusable information added from the repeater 2, as in step S113A of FIG. 9 of the second embodiment. It may be determined whether or not. Further, in steps S158, S163, and S170, the buffer success / failure determination unit 13 determines whether or not a buffer unusable message has been received from the repeater 2 as in step S113B of FIG. 13 of the third embodiment. Good. Further, in steps S158, S163, and S170, the buffer success / failure determination unit 13 performs the communication control device from the terminal 3 via the repeater 2 within a predetermined time, similarly to step S113X of FIG. 18 of the fourth embodiment. It may be determined whether a receipt confirmation signal has been received. Also, in steps S158, S163, and S170, the buffer success / failure determination unit 13 receives the data addressed to the terminal from the repeater 2 within a predetermined time, as in step S113Y of FIG. 20 of the modification of the fourth embodiment. Or you may determine whether it intercepted.

  In the above description, the transmission destination buffer capacity prediction unit 18 increases or decreases the transmission data size as described above for the first transmission of data addressed to the terminal. However, the second and subsequent controls are also described above. The transmission data size may be increased or decreased.

  Hereinafter, characteristic configurations of the repeater 2 and the communication control device 1 according to the embodiment and effects obtained thereby will be described.

  (1) The communication system 100 includes a communication control device 1, a repeater 2, and a terminal 3. The communication control device 1 transmits terminal addressed data. The repeater 2 receives terminal-addressed data from the communication control device 1. The terminal 3 receives the data addressed to the terminal from the repeater 2 by transmitting a data request for requesting transmission of the data addressed to the terminal to the repeater 2.

  The repeater 2 includes a transmission processing unit 27, a reception processing unit 22, a terminal-addressed data buffer 24, a buffer availability determination unit 25, and a buffer success / failure response processing unit 26.

  The transmission processing unit 27 transmits to the communication control device 1 a receipt confirmation signal that can specify that the terminal-addressed data has been received. The reception processing unit 22 receives terminal-addressed data from the communication control device 1. The terminal-addressed data buffer 24 buffers terminal-addressed data received by the reception processing unit 22. The buffer availability determination unit 25 determines whether the data destined for the terminal can be buffered in the data buffer 24 destined for the terminal. The buffer success / failure response processing unit 26 causes the transmission processing unit 27 to transmit a receipt confirmation signal when the buffer availability determination unit 25 determines that the data addressed to the terminal can be buffered in the data buffer 24 addressed to the terminal. The buffer success / failure response processing unit 26 performs an operation different from the operation of transmitting the receipt confirmation signal when the buffer availability determination unit 25 determines that the data addressed to the terminal cannot be buffered in the data buffer 24 addressed to the terminal. The transmission processing unit 27 performs the processing. According to this configuration, it is possible to notify the communication control device 1 that the repeater 2 has not been able to buffer the data addressed to the terminal.

  (2) The buffer success / failure response processing unit 26 may cause the transmission processing unit 27 to continue the state in which the receipt confirmation signal is not transmitted as the different operation described above. According to this, different operations can be realized by simple control.

  (3) The buffer success / failure response processing unit 26 transmits, as a different operation as described above, a reception confirmation signal to which the unbufferable information that can specify that the repeater 2 cannot buffer the data addressed to the terminal is added. 27 may be transmitted. According to this, it is possible to reliably notify the communication control apparatus 1 that the repeater 2 cannot buffer the data addressed to the terminal.

  (4) The buffer success / failure response processing unit 26 transmits, as a different operation as described above, a non-bufferable message capable of specifying that the repeater 2 cannot buffer the data addressed to the terminal, separately from the reception confirmation signal. 27 may be transmitted. According to this, it is possible to reliably notify the communication control apparatus 1 that the repeater 2 cannot buffer the data addressed to the terminal.

  (5) The communication system 100 includes a communication control device 1, a repeater 2, and a terminal 3. The communication control device 1 transmits terminal addressed data. The repeater 2 receives terminal-addressed data from the communication control device 1. The terminal 3 receives the data addressed to the terminal from the repeater 2 by transmitting a data request for requesting transmission of the data addressed to the terminal to the repeater 2.

  The communication control device 1 includes a transmission processing unit 17, a reception processing unit 12, a buffer success / failure determination unit 13, a retransmission buffer 14, and a retransmission determination unit 15. The transmission processing unit 17 transmits the data addressed to the terminal to the repeater 2. The reception processing unit 12 receives an acknowledgment signal from the repeater 2 that can specify that the repeater 2 has buffered the data addressed to the terminal. The buffer success / failure determination unit 13 determines that the repeater 2 has buffered the data addressed to the terminal based on whether or not the repeater 2 has recognized an operation different from the operation of transmitting the receipt confirmation signal to the communication control device 1. It is determined whether or not the ring has been completed. The retransmission buffer 14 has a free capacity that can buffer the data destined for the terminal when the buffer success / failure determination unit 13 determines that the repeater 2 has not been able to buffer the data destined for the terminal. As a condition, terminal-addressed data is buffered. The retransmission determination unit 15 determines whether or not it is time to retransmit the data addressed to the terminal buffered in the retransmission buffer 14 by determining whether or not a condition serving as a retransmission trigger is satisfied. To do. When the retransmission determination unit 15 determines that the timing for retransmitting the data destined for the terminal has arrived, the transmission processing unit 17 retransmits the data destined for the terminal buffered in the retransmission buffer 14 to the repeater 2. To do. Also with this configuration, the data addressed to the terminal that could not be buffered by the repeater 2 can be transmitted to the repeater 2 again.

  (6) The buffer success / failure determination unit 13 may not receive the receipt confirmation signal from the repeater 2 even if a predetermined time has elapsed after the data addressed to the terminal is transmitted from the transmission processing unit 17. In this case, the buffer success / failure determination unit 13 determines that the transmission processing unit 17 of the repeater 2 has recognized a different operation, and determines that the repeater 2 has not been able to buffer the data addressed to the terminal. May be. According to this configuration, the communication control device 1 can grasp that the repeater 2 could not buffer the data addressed to the terminal by simple control.

  (7) In the buffer success / failure determination unit 13, the reception processing unit 12 receives from the repeater 2 the receipt confirmation signal to which the unbufferable information that can specify that the repeater 2 cannot buffer the data addressed to the terminal is added. There is a case. In this case, the buffer success / failure determination unit 13 may determine that the repeater 2 has not been able to buffer the data addressed to the terminal, assuming that the repeater 2 has recognized a different operation. According to this configuration, the communication control apparatus 1 can reliably grasp that the repeater 2 cannot buffer the data addressed to the terminal.

  (8) The buffer success / failure determination unit 13 may receive, from the repeater 2, an unbufferable message that can specify that the repeater 2 could not buffer the data addressed to the terminal, separately from the receipt confirmation signal. In this case, the buffer success / failure determination unit 13 regards that the repeater 2 can recognize that the above-described different operations have been performed, and determines that the repeater 2 could not buffer the data addressed to the terminal. Good. According to this configuration, the communication control apparatus 1 can reliably grasp that the repeater 2 cannot buffer the data addressed to the terminal.

  (9) The communication system 100 includes a communication control device 1, a repeater 2, and a terminal 3. The communication control device 1 transmits terminal addressed data. The repeater 2 receives terminal-addressed data from the communication control device 1. The terminal 3 transmits a data request for requesting transmission of data addressed to the terminal to the repeater 2. As a result, when the terminal 3 receives the data addressed to the terminal from the repeater 2, the terminal 3 sends a receipt confirmation message to the communication control device that can specify that the data addressed to the terminal has been received via the repeater 2. Transmit to the communication control device 1.

  The communication control device 1 includes a transmission processing unit 17, a reception processing unit 12, a buffer success / failure determination unit 13, a retransmission buffer 14, and a retransmission determination unit 15. The transmission processing unit 17 transmits the data addressed to the terminal to the repeater 2. The reception processing unit 12 receives from the repeater 2 the receipt confirmation message addressed to the communication control apparatus transmitted by the terminal 3. The buffer success / failure determination unit 13 determines whether or not the repeater 2 has buffered the data addressed to the terminal, based on whether or not the reception processing unit 12 has received the receipt confirmation message addressed to the communication control device. The retransmission buffer 14 has a free capacity that can buffer the data destined for the terminal when the buffer success / failure determination unit 13 determines that the repeater 2 has not been able to buffer the data destined for the terminal. As a condition, terminal-addressed data is buffered. The retransmission determination unit 15 determines whether or not it is time to retransmit the data addressed to the terminal buffered in the retransmission buffer 14 by determining whether or not a condition serving as a retransmission trigger is satisfied. To do. When the retransmission determination unit 15 determines that the timing for retransmitting the data destined for the terminal has arrived, the transmission processing unit 17 retransmits the data destined for the terminal buffered in the retransmission buffer 14 to the repeater 2. To do. Also with this configuration, the data addressed to the terminal that could not be buffered by the repeater 2 can be transmitted to the repeater 2 again.

  (10) After the data addressed to the terminal is transmitted to the repeater 2, a condition that becomes a retransmission trigger may be satisfied. In this case, if the reception processing unit 12 has not received the receipt confirmation message addressed to the communication control device, the buffer success / failure determination unit 13 may determine that the repeater 2 could not buffer the data addressed to the terminal.

  (11) The transmission processing unit 17 transmits the data addressed to the terminal device to the terminal device 3 via the relay device 2, and then transmits the data addressed to another terminal device to the terminal device 3 via the relay device 2. When the terminal 3 receives the data addressed to the terminal from the repeater 2, the terminal 3 transmits a receipt confirmation message addressed to the communication control device to the communication control device 1 via the repeater 2. When the terminal 3 receives data addressed to another terminal from the repeater 2, the terminal 3 transmits a receipt confirmation message addressed to another communication control device to the communication control device 1 via the repeater 2. The reception processing unit 12 may receive a receipt confirmation message addressed to another communication control device without receiving the receipt confirmation message addressed to the communication control device. In this case, the buffer success / failure determination unit 13 may determine that the repeater 2 could not buffer the data addressed to the terminal. According to this configuration, the communication control apparatus 1 can reliably grasp that the repeater 2 cannot buffer the data addressed to the terminal.

  (12) The communication system 100 includes a communication control device 1, a repeater 2, and a terminal 3. The communication control device 1 transmits terminal addressed data. The repeater 2 receives terminal-addressed data from the communication control device 1. The terminal 3 transmits a data request for requesting transmission of data addressed to the terminal to the repeater 2. As a result, the terminal 3 receives the data addressed to the terminal from the repeater 2.

  The communication control device 1 includes a transmission processing unit 17, a reception processing unit 12, a buffer success / failure determination unit 13, a retransmission buffer 14, and a retransmission determination unit 15. The transmission processing unit 17 transmits the data addressed to the terminal to the repeater 2. The reception processing unit 12 intercepts the data addressed to the terminal transmitted from the repeater 2 to the terminal 3. Whether or not the buffer success / failure determination unit 13 was able to buffer the data addressed to the terminal based on whether or not the reception processing unit 12 intercepted the data addressed to the terminal transmitted to the terminal 3 by the relay 2. Determine whether or not. The retransmission buffer 14 has a free capacity that can buffer the data destined for the terminal when the buffer success / failure determination unit 13 determines that the repeater 2 has not been able to buffer the data destined for the terminal. As a condition, terminal-addressed data is buffered. The retransmission determination unit 15 determines whether or not it is time to retransmit the data addressed to the terminal buffered in the retransmission buffer 14 by determining whether or not a condition serving as a retransmission trigger is satisfied. To do. When the retransmission determination unit 15 determines that the timing for retransmitting the data destined for the terminal has arrived, the transmission processing unit 17 retransmits the data destined for the terminal buffered in the retransmission buffer 14 to the repeater 2. To do. Also with this configuration, the data addressed to the terminal that could not be buffered by the repeater 2 can be transmitted to the repeater 2 again.

  (13) After the data addressed to the terminal is transmitted to the repeater 2, a condition that becomes a retransmission trigger may be satisfied. In this case, if the reception processing unit 12 does not intercept the data addressed to the terminal, the buffer success / failure determination unit 13 may determine that the repeater 2 could not buffer the data addressed to the terminal.

  (14) The transmission processing unit 17 transmits the data addressed to the terminal device to the terminal device 3 via the relay device 2 and then transmits the data addressed to another terminal device to the terminal device 3 via the relay device 2. The reception processing unit 12 may intercept other terminal-addressed data without intercepting the terminal-addressed data. In this case, the buffer success / failure determination unit 13 may determine that the repeater 2 could not buffer the data addressed to the terminal. According to this configuration, the communication control apparatus 1 can reliably grasp that the repeater 2 cannot buffer the data addressed to the terminal.

  (15) The condition serving as a retransmission trigger may be satisfied when a predetermined time elapses after the data addressed to the terminal is transmitted to the repeater 2. According to this configuration, the data addressed to the terminal can be transmitted again to the repeater 2 with simple control.

  (16) Each of the communication control device 1 and the repeater 2 may be a wireless device that transmits and receives terminal-addressed data as radio waves. In this case, the condition that becomes a retransmission trigger is that, after the data addressed to the terminal is transmitted to the repeater 2, the reception processing unit 12 intercepts the radio wave of the data addressed to the terminal transmitted to the terminal 3 by the repeater 2. May be satisfied. According to this configuration, when the repeater 2 transmits the data addressed to the terminal device to the terminal device 3 again, the data addressed to the terminal device is transmitted again, so that the terminal device has a high probability that the relay device 2 can be buffered. The data addressed to the machine can be transmitted to the repeater 2 again.

  (17) The condition that becomes a retransmission trigger is established when the reception processing unit 12 receives a data request from the terminal 3 via the repeater 2 after the data addressed to the terminal is transmitted to the repeater 2. Also good. According to this configuration, when the communication control device 1 receives the data request, the terminal-addressed data is transmitted again, so that the data addressed to the terminal is relayed with a high probability that the repeater 2 can be buffered. Can be sent to the device 2 again.

  (18) The communication control device 1 preferably further includes a data size storage unit 19 and a transmission destination buffer capacity prediction unit 18. The data size storage unit 19 stores a reference indirect transmission size M indicating the upper limit value of the size of data destined for the terminal that is expected to be buffered by the repeater 2. The transmission destination buffer capacity prediction unit 18 predicts the free capacity of the terminal-addressed data buffer 24 of the repeater 2.

  The destination buffer capacity prediction unit 18 controls the transmission of the first data addressed to the terminal that is transmitted to the repeater 2 for the first time based on the data transmission request as follows.

  If the data size of the data destined for the first terminal is equal to or smaller than the reference indirect transmission size M, the transmission destination buffer capacity prediction unit 18 does not buffer the data for the first terminal without buffering in the retransmission buffer 14. The data is transmitted to the transmission processing unit 17. Thereafter, the buffer success / failure determination unit 13 may determine that the repeater 2 has not been able to buffer the data addressed to the first terminal. In this case, the transmission destination buffer capacity prediction unit 18 decreases the reference indirect transmission size M by a predetermined size.

  On the other hand, the data size of the first terminal-addressed data may be larger than the reference indirect transmission size M. In this case, the transmission destination buffer capacity prediction unit 18 does not transmit the data addressed to the terminal to the repeater 2 and retransmits the first data addressed to the terminal on the condition that there is a free capacity in the retransmission buffer. The buffer 14 is buffered. The buffer success / failure determination unit 13 may determine that the repeater 2 has successfully buffered the first terminal-addressed data buffered in the retransmission buffer 14 a predetermined number of times. In this case, the transmission destination buffer capacity prediction unit 18 increases the reference indirect transmission size M by a specific size.

  According to this configuration, by predicting the free space of the repeater 2, the retransmission terminal 14 can transmit the first terminal-addressed data with a relatively low probability that the repeater 2 can be buffered to the repeater 2. It is buffered with. Therefore, it is possible to omit a wasteful transmission process of the first terminal-addressed data with a relatively low probability that the repeater 2 can be buffered.

  (19) The relay program is incorporated in a computer that operates the repeater, and is for causing the computer to function as the above-described units of the repeater.

  (20) to (22) The communication control program is incorporated in a computer that operates the communication control apparatus, and is for causing the computer to function as the above-described units of the communication control apparatus.

DESCRIPTION OF SYMBOLS 1 Communication control apparatus 2 Repeater 3 Terminal 12 Reception processing part 13 Buffer success / failure determination part 14 Retransmission buffer 15 Retransmission determination part 17 Transmission processing part 18 Destination buffer capacity prediction part 19 Data size memory | storage part 22 Reception processing part 24 Terminal Address data buffer 25 Buffer availability determination unit 26 Buffer success / failure response processing unit 27 Transmission processing unit 100 Communication system

Claims (22)

A communication control device that transmits data addressed to the terminal;
A repeater for receiving the data addressed to the terminal from the communication control device;
A terminal that receives the data addressed to the terminal from the repeater by transmitting a data request for transmission of the data addressed to the terminal to the repeater;
A repeater used in a communication system including:
A transmission processing unit for transmitting to the communication control device a receipt confirmation signal capable of specifying that the terminal-addressed data has been received;
A reception processing unit for receiving the data addressed to the terminal from the communication control device;
A terminal-addressed data buffer that buffers the terminal-addressed data received by the reception processing unit;
A buffer availability determination unit that determines whether the data addressed to the terminal can be buffered in the data buffer addressed to the terminal;
A buffer success / failure response processing unit that transmits the reception confirmation signal to the transmission processing unit when the buffer availability determination unit determines that the data addressed to the terminal can be buffered in the data buffer addressed to the terminal. ,
The buffer success / failure response processing unit is different from the operation of transmitting the receipt confirmation signal when the buffer availability determination unit determines that the data addressed to the terminal cannot be buffered in the data buffer addressed to the terminal. A repeater that causes the transmission processing unit to perform an operation.   The repeater according to claim 1, wherein the buffer success / failure response processing unit causes the transmission processing unit to continue a state in which the reception confirmation signal is not transmitted as the different operation.   As the different operation, the buffer success / failure response processing unit sends the transmission confirmation unit with the reception confirmation signal to which the non-bufferable information that can specify that the repeater cannot buffer the data addressed to the terminal is added. The repeater according to claim 1, wherein transmission is performed.   As the different operation, the buffer success / failure response processing unit sends, to the transmission processing unit, a non-bufferable message capable of specifying that the repeater has not buffered the data addressed to the terminal, separately from the receipt confirmation signal. The repeater according to claim 1, wherein transmission is performed. A communication control device that transmits data addressed to the terminal;
A repeater for receiving the data addressed to the terminal from the communication control device;
A terminal that receives the data addressed to the terminal from the repeater by transmitting a data request for transmission of the data addressed to the terminal to the repeater;
A communication control device used in a communication system including:
A transmission processing unit for transmitting the data addressed to the terminal to the repeater;
A reception processing unit that receives from the repeater an acknowledgment signal that can specify that the repeater has buffered the data addressed to the terminal;
Whether or not the repeater can buffer the data addressed to the terminal based on whether or not the repeater has recognized that the operation has been different from the operation of transmitting the receipt confirmation signal to the communication control device. A buffer success / failure determination unit for determining
If the buffer success / failure determination unit determines that the repeater has not been able to buffer the data addressed to the terminal, on the condition that the terminal has a free capacity enough to buffer the data addressed to the terminal. A retransmission buffer for buffering data addressed to the terminal,
A retransmission determination unit that determines whether or not the timing for retransmitting the data addressed to the terminal that is buffered in the retransmission buffer has arrived by determining whether or not a condition serving as a retransmission trigger is satisfied; With
The transmission processing unit, when the retransmission determination unit determines that it is time to retransmit the data addressed to the terminal, transmits the data addressed to the terminal buffered in the retransmission buffer to the repeater The communication control device that transmits again.   The buffer success / failure determination unit is configured to transmit the repeater when the reception confirmation signal is not received from the repeater even after a predetermined time has elapsed after the data addressed to the terminal is transmitted from the transmission processing unit. The communication control apparatus according to claim 5, wherein it is determined that the processing unit has recognized that the different operation has been performed, and the repeater determines that the data addressed to the terminal has not been buffered.   The buffer success / failure determination unit has received the reception confirmation signal from the repeater to which the non-bufferable information that can specify that the repeater has not been able to buffer the data addressed to the terminal has been added. 6. The communication control device according to claim 5, wherein the relay controller determines that the relay has failed to buffer the data addressed to the terminal, assuming that the relay has recognized the different operation.   The buffer success / failure determination unit, when receiving a non-bufferable message from the repeater that can specify that the repeater could not buffer the data addressed to the terminal, separately from the receipt confirmation signal, 6. The communication control apparatus according to claim 5, wherein it is determined that the terminal has recognized the different operation, and the relay determines that the data addressed to the terminal has not been buffered. A communication control device that transmits data addressed to the terminal;
A repeater for receiving the data addressed to the terminal from the communication control device;
When the data addressed to the terminal is received from the repeater by transmitting a data request for transmitting the data addressed to the terminal to the repeater, the data addressed to the terminal is received via the repeater. A communication control device used in a communication system including a terminal that transmits a receipt confirmation message addressed to a communication control device that can be identified to the communication control device,
A transmission processing unit for transmitting the data addressed to the terminal to the repeater;
A reception processing unit that receives from the repeater the receipt confirmation message addressed to the communication control device transmitted by the terminal;
A buffer success / failure determination unit that determines whether or not the repeater has buffered the data addressed to the terminal, based on whether or not the reception processing unit has received the receipt confirmation message addressed to the communication control device;
If the buffer success / failure determination unit determines that the repeater has not been able to buffer the data addressed to the terminal, on the condition that the terminal has a free capacity enough to buffer the data addressed to the terminal. A retransmission buffer for buffering data addressed to the terminal,
A retransmission determination unit that determines whether or not the timing for retransmitting the data addressed to the terminal that is buffered in the retransmission buffer has arrived by determining whether or not a condition serving as a retransmission trigger is satisfied; With
The transmission processing unit, when the retransmission determination unit determines that it is time to retransmit the data addressed to the terminal, transmits the data addressed to the terminal buffered in the retransmission buffer to the repeater The communication control device that transmits again.   After the data addressed to the terminal is transmitted to the repeater, if the condition that becomes the retransmission trigger is satisfied and the reception processing unit has not received the receipt confirmation message addressed to the communication control device, the success or failure of the buffer The communication control apparatus according to claim 9, wherein the determination unit determines that the repeater has not been able to buffer the data addressed to the terminal. The transmission processing unit transmits the data addressed to the terminal to the terminal via the repeater, and then transmits data addressed to another terminal to the terminal via the relay.
When the terminal receives the data addressed to the terminal from the repeater, the terminal transmits a receipt confirmation message addressed to the communication control device to the communication control device via the repeater, and the other from the repeater When receiving the data addressed to the terminal of the terminal, the receipt confirmation message addressed to another communication control device is transmitted to the communication control device via the repeater,
When the reception processing unit receives the receipt confirmation message addressed to the other communication control device without receiving the receipt confirmation message addressed to the communication control device, the buffer success / failure determination unit indicates that the repeater is connected to the terminal. The communication control device according to claim 9, wherein it is determined that the destination data could not be buffered. A communication control device as a wireless device that transmits data addressed to the terminal as radio waves;
A repeater as a wireless device for receiving the data addressed to the terminal from the communication control device;
A communication control device used in a communication system including a terminal that receives data destined for the terminal from the repeater by transmitting a data request for transmitting the data addressed to the terminal to the repeater. ,
A transmission processing unit for transmitting the data addressed to the terminal to the repeater;
A reception processing unit for intercepting the data addressed to the terminal transmitted by the repeater to the terminal;
Based on whether the reception processing unit intercepts the data addressed to the terminal transmitted by the repeater to the terminal, it determines whether the repeater has buffered the data addressed to the terminal. A buffer success / failure determination unit;
If the buffer success / failure determination unit determines that the repeater has not been able to buffer the data addressed to the terminal, on the condition that the terminal has a free capacity enough to buffer the data addressed to the terminal. A retransmission buffer for buffering data addressed to the terminal,
A retransmission determination unit that determines whether or not the timing for retransmitting the data addressed to the terminal that is buffered in the retransmission buffer has arrived by determining whether or not a condition serving as a retransmission trigger is satisfied; With
The transmission processing unit, when the retransmission determination unit determines that it is time to retransmit the data addressed to the terminal, transmits the data addressed to the terminal buffered in the retransmission buffer to the repeater The communication control device that transmits again.   After the data addressed to the terminal is transmitted to the repeater, when the condition that becomes the retransmission trigger is satisfied, if the reception processing unit does not intercept the data addressed to the terminal, the buffer success / failure determination unit is The communication control device according to claim 12, wherein the repeater determines that the data addressed to the terminal has not been buffered. The transmission processing unit transmits the data addressed to the terminal to the terminal via the repeater, and then transmits data addressed to another terminal to the terminal via the relay.
When the reception processing unit intercepts the data addressed to the other terminal without intercepting the data addressed to the terminal, the buffer success / failure determination unit allows the repeater to buffer the data addressed to the terminal. The communication control device according to claim 12, wherein the communication control device determines that there is not.   The communication control device according to claim 5, wherein the condition serving as a retransmission trigger is satisfied when a predetermined time has elapsed after the data addressed to the terminal is transmitted to the repeater. Each of the communication control device and the repeater is a wireless device that transmits and receives the data addressed to the terminal as a radio wave,
The condition that becomes the retransmission trigger is that, after the data addressed to the terminal is transmitted to the repeater, the reception processing unit intercepts the radio wave of the data addressed to the terminal transmitted to the terminal by the repeater The communication control device according to claim 5, wherein   The condition for the retransmission trigger is satisfied when the data addressed to the terminal is transmitted to the repeater, and then the reception processing unit receives the data request from the terminal via the repeater. The communication control device according to claim 5. A data size storage unit for storing a reference indirect transmission size indicating an upper limit value of the size of the data addressed to the terminal that is expected to be buffered by the repeater;
A destination buffer capacity prediction unit that predicts a free capacity of the data buffer addressed to the terminal of the repeater, further comprising:
The destination buffer capacity prediction unit
For the first transmission of data addressed to the terminal that is transmitted to the repeater for the first time based on a data transmission request,
If the data size of the data destined for the first terminal is equal to or smaller than the reference indirect transmission size, the data destined for the first terminal is transmitted to the transmission processing unit without buffering in the retransmission buffer. Then, if the buffer success / failure determination unit determines that the repeater could not buffer the first terminal addressed data, the reference indirect transmission size is reduced by a predetermined size,
If the data size of the data addressed to the first terminal is larger than the reference indirect transmission size, the retransmission buffer has a free space without transmitting the data addressed to the terminal to the repeater. As a condition, the first terminal addressed data is buffered in the retransmission buffer, and then the first terminal addressed data buffered in the retransmission buffer is continuously buffered by the repeater a predetermined number of times. 18. The communication control device according to claim 5, wherein when the buffer success / failure determination unit determines that ringing has been completed, the reference indirect transmission size is increased by a specific size. A communication control device that transmits data addressed to the terminal;
A terminal that receives the data addressed to the terminal from the repeater by transmitting a data request for transmitting the data addressed to the terminal to the repeater and the relay that receives the data addressed to the terminal from the communication control device Machine,
A relay program incorporated in a computer for operating a repeater used in a communication system including:
The computer,
A transmission processing unit for transmitting a receipt confirmation signal capable of specifying that the terminal-addressed data has been received to the communication control device;
A reception processing unit for receiving the data addressed to the terminal from the communication control device;
A terminal-addressed data buffer for buffering the terminal-addressed data received by the reception processing unit;
A buffer availability determination unit for determining whether the data addressed to the terminal can be buffered in the data buffer addressed to the terminal;
When the buffer availability determination unit determines that the data addressed to the terminal can be buffered in the data buffer addressed to the terminal, it functions as a buffer success / failure response processing unit that causes the transmission processing unit to transmit the receipt confirmation signal. ,
The buffer success / failure response processing unit is different from the operation of transmitting the receipt confirmation signal when the buffer availability determination unit determines that the data addressed to the terminal cannot be buffered in the data buffer addressed to the terminal. A relay program that causes the transmission processing unit to perform an operation. A communication control device that transmits data addressed to the terminal;
A repeater for receiving the data addressed to the terminal from the communication control device;
A terminal that receives the data addressed to the terminal from the repeater by transmitting a data request for transmission of the data addressed to the terminal to the repeater;
A communication control program incorporated in a computer for operating a communication control device used in a communication system including:
The computer,
A transmission processing unit for transmitting the data addressed to the terminal to the repeater;
A reception processing unit that receives from the repeater an acknowledgment signal that can specify that the repeater has buffered the data addressed to the terminal;
Whether or not the repeater can buffer the data addressed to the terminal based on whether or not the repeater has recognized that the operation has been different from the operation of transmitting the receipt confirmation signal to the communication control device. A buffer success / failure determination unit for determining
If the buffer success / failure determination unit determines that the repeater has not been able to buffer the data addressed to the terminal, on the condition that the terminal has a free capacity enough to buffer the data addressed to the terminal. Retransmission buffer that buffers data addressed to the terminal,
A retransmission determination unit that determines whether it is time to retransmit the data addressed to the terminal that is buffered in the retransmission buffer by determining whether a condition that becomes a retransmission trigger is satisfied; Function as
The transmission processing unit, when the retransmission determination unit determines that it is time to retransmit the data addressed to the terminal, transmits the data addressed to the terminal buffered in the retransmission buffer to the repeater A communication control program to send again. A communication control device that transmits data addressed to the terminal;
A repeater for receiving the data addressed to the terminal from the communication control device;
When the data addressed to the terminal is received from the repeater by transmitting a data request for transmitting the data addressed to the terminal to the repeater, the data addressed to the terminal is received via the repeater. A communication control program incorporated in a computer for operating a communication control device used in a communication system including a terminal that transmits a receipt confirmation message addressed to the communication control device that can be identified to the communication control device. ,
The computer,
A transmission processing unit for transmitting the data addressed to the terminal to the repeater;
A reception processing unit for receiving from the repeater the receipt confirmation message addressed to the communication control device transmitted by the terminal;
A buffer success / failure determination unit that determines whether or not the repeater has buffered the data addressed to the terminal, based on whether the reception processing unit has received the receipt confirmation message addressed to the communication control device;
If the buffer success / failure determination unit determines that the repeater has not been able to buffer the data addressed to the terminal, on the condition that the terminal has a free capacity enough to buffer the data addressed to the terminal. Retransmission buffer that buffers data addressed to the terminal,
A retransmission determination unit that determines whether it is time to retransmit the data addressed to the terminal that is buffered in the retransmission buffer by determining whether a condition that becomes a retransmission trigger is satisfied; Function as
The transmission processing unit, when the retransmission determination unit determines that it is time to retransmit the data addressed to the terminal, transmits the data addressed to the terminal buffered in the retransmission buffer to the repeater A communication control program to send again. A communication control device as a wireless device that transmits data addressed to the terminal as radio waves;
A repeater as a wireless device for receiving the data addressed to the terminal from the communication control device;
By transmitting a data request for requesting transmission of the data addressed to the terminal to the repeater, a communication control device used in a communication system including a terminal that receives the data addressed to the terminal from the repeater is operated. A communication control program incorporated in a computer,
The computer,
A transmission processing unit for transmitting the data addressed to the terminal to the repeater;
A reception processing unit for intercepting the data addressed to the terminal transmitted by the repeater to the terminal;
Based on whether the reception processing unit intercepts the data addressed to the terminal transmitted by the repeater to the terminal, it determines whether the repeater has buffered the data addressed to the terminal. Buffer success / failure determination unit,
If the buffer success / failure determination unit determines that the repeater has not been able to buffer the data addressed to the terminal, on the condition that the terminal has a free capacity enough to buffer the data addressed to the terminal. Retransmission buffer that buffers data addressed to the terminal,
A retransmission determination unit that determines whether it is time to retransmit the data addressed to the terminal that is buffered in the retransmission buffer by determining whether a condition that becomes a retransmission trigger is satisfied; Function as
The transmission processing unit, when the retransmission determination unit determines that it is time to retransmit the data addressed to the terminal, transmits the data addressed to the terminal buffered in the retransmission buffer to the repeater A communication control program to send again.

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