Wireless communication device, wireless communication system, and wireless communication method

Abstract

To provide a wireless communication device that can efficiently transmit and receive sensor information in a network that transmits sensor information acquired by a sensor.SOLUTION: A wireless communication device 10 includes a received data acquisition unit 113a, a terminal determination unit 114, a timing calculation unit 111, a self-terminal radar wave generation unit, and a sensor information acquisition unit 112, and the received data acquisition unit 113a acquires other terminal radar waves and other terminal sensor information. The terminal determination unit 114 determines the source terminal of the other terminal radar wave on the basis of a chirp signal of the other terminal radar wave and terminal information. The timing calculation unit 111 calculates the communication timing of the self-terminal on the basis of the reception time of the other terminal radar wave and the other terminal sensor information transmitted from the previous other terminal. The self-terminal radar wave generation unit generates a self-terminal radar wave of a predetermined chirp signal. The sensor information acquisition unit 112 emits the self-terminal radar waves at communication timing and acquires the self-terminal sensor information.SELECTED DRAWING: Figure 5A

Description

Technical Field

[0001] The present invention relates to a wireless communication device, a wireless communication system, and a wireless communication method.

Background Art

[0002] Conventionally, a communication system has been proposed for relaying data acquired by sensors and transmitting it to a target location. Patent Document 1 discloses a wireless communication system including a parent node and a plurality of child nodes each having a sensor unit. The wireless communication system disclosed in Patent Document 1 specifies the measurement time at each node with high accuracy without implementing a clock function at each node.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the wireless communication system disclosed in Patent Document 1, the parent node transmits a parent beacon signal to the child nodes at a fixed period, and the child nodes recognize the communication available period by receiving the parent beacon signal. Further, when the child nodes measure with the sensor unit, they transmit to the parent node information necessary to specify the measurement time counter value received from the parent node and the measurement elapsed time from the transmission time of the parent beacon signal from the parent node to the measurement time. Based on the information transmitted from this child node, the parent node synchronizes the measurement time. That is, in the wireless communication system disclosed in Patent Document 1, since it is necessary to additionally provide a beacon device for each node to know the measurement time, the scale of the device increases, and the communication efficiency decreases due to beacon communication.

[0005] This invention has been made in view of the problems of the prior art described above. The object of this invention is to provide a wireless communication device that can efficiently transmit and receive sensor information in a network that transmits sensor information acquired by a sensor. [Means for solving the problem]

[0006] A wireless communication device according to an embodiment of the present invention is a wireless communication device that constitutes a communication system that transmits data to a target destination in accordance with a predetermined relay sequence, comprising: a received data acquisition unit that acquires other terminal radar waves radiated from other terminals and other terminal sensor information transmitted from the other terminal immediately preceding the local terminal in the relay sequence as received data; a terminal determination unit that determines the source terminal of the other terminal radar waves based on the chirp signal of the other terminal radar waves and terminal information stored in a storage unit in advance; and the other terminal radar waves and other terminal sensor information that the terminal determination unit has determined to have been transmitted from the other terminal immediately preceding the local terminal in the relay sequence. The system comprises: a timing calculation unit that calculates a first reception interval based on the reception time of the signal information and calculates the communication timing of the terminal based on the first reception interval; a terminal radar wave generation unit that generates a terminal radar wave of a predetermined chirp signal based on terminal information; a sensor information acquisition unit that emits a terminal radar wave at the communication timing, acquires terminal sensor information based on the reflected waves of the terminal radar wave, and stores it in a storage unit; a sensor information generation unit that generates transmission data including at least the terminal sensor information; and a transmission data transmission unit that emits a terminal radar wave and transmits the transmission data to the next other terminal in the relay sequence.

[0007] Another aspect of the present invention relates to a wireless communication system that transmits data according to a predetermined relay sequence, comprising: a plurality of wireless communication devices; and a collection module which is the final destination of the data transmitted by the plurality of wireless communication devices according to the relay sequence, wherein the wireless communication device includes: a received data acquisition unit that acquires other terminal radar waves radiated from other terminals and other terminal sensor information transmitted from another terminal one step ahead of the own terminal in the relay sequence as received data; a terminal determination unit that determines the source terminal of the other terminal radar waves based on the chirp signal of the other terminal radar waves and terminal information stored in a storage unit in advance; and the terminal determination unit determines the source terminal of the other terminal radar waves in the relay sequence The system includes: a timing calculation unit that calculates a first reception interval based on the reception time of radar waves and sensor information from another terminal determined to have been transmitted from the previous other terminal, and calculates the communication timing of the own terminal based on the first reception interval; a self-terminal radar wave generation unit that generates a self-terminal radar wave of a predetermined chirp signal based on terminal information; a sensor information acquisition unit that emits a self-terminal radar wave at the communication timing, acquires self-terminal sensor information based on the reflected waves of the self-terminal radar wave, and stores it in a storage unit; a sensor information generation unit that generates transmission data that includes at least self-terminal sensor information; and a transmission data transmission unit that transmits the transmission data to the next other terminal in the relay sequence.

[0008] Another aspect of the present invention is a wireless communication method performed by a computer, which acquires as received data a radar wave from another terminal radiated from another terminal and sensor information from another terminal transmitted from the terminal immediately preceding the local terminal in the relay sequence; determines the source terminal of the radar wave based on the chirp signal of the radar wave and terminal information stored in a memory unit in advance; calculates a first reception interval based on the reception time of the radar wave and sensor information from the other terminal determined to have been transmitted from the terminal immediately preceding the local terminal in the relay sequence; calculates the local terminal's communication timing based on the first reception interval; generates a local terminal radar wave with a predetermined chirp signal based on the terminal information; radiates the local terminal radar wave at the communication timing; acquires local terminal sensor information based on the reflected wave of the local terminal radar wave; generates transmission data including at least the local terminal sensor information; and transmits the transmission data to the next other terminal in the relay sequence. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a wireless communication device that can efficiently transmit and receive sensor information in a network that transmits sensor information acquired by a sensor. [Brief explanation of the drawing]

[0010] [Figure 1] This figure shows the configuration of the wireless communication system according to this embodiment. [Figure 2] This diagram shows the configuration of the wireless communication device according to this embodiment. [Figure 3A] This is a diagram illustrating the radio waves emitted from an antenna. [Figure 3B] This diagram illustrates the radio waves emitted from the antenna according to this embodiment. [Figure 3C] This diagram illustrates the radio waves emitted from the antenna according to this embodiment. [Figure 4] This block diagram shows the configuration of the sensor communication terminal according to this embodiment. [Figure 5A]It is a block diagram showing the functional configuration of the sensor communication terminal according to this embodiment. [Figure 5B] It is a block diagram for explaining the functional configuration of the transmission data generation unit according to this embodiment. [Figure 6] It is a diagram for explaining the configuration of the storage unit of the sensor communication terminal according to this embodiment. [Figure 7A] It is a diagram for explaining the terminal determination using the chirp signal according to this embodiment. [Figure 7B] It is a diagram for explaining the terminal determination using the chirp signal according to this embodiment. [Figure 8A] It is a diagram for explaining the terminal determination using the chirp signal according to this embodiment. [Figure 8B] It is a diagram for explaining the terminal determination using the chirp signal according to this embodiment. [Figure 9] It is a diagram showing an example of the data format of a communication packet in the wireless communication system according to this embodiment. [Figure 10] It is a diagram showing an example of the data format of received data and transmitted data in the wireless communication system according to this embodiment. [Figure 11] It is a diagram for explaining the data flow in the wireless communication system according to this embodiment. [Figure 12] It is a flowchart showing an example of the processing of the wireless communication device according to this embodiment. [Figure 13] It is a flowchart showing an example of the processing of the wireless communication device according to this embodiment. [Figure 14] It is a flowchart showing an example of the processing of the wireless communication device according to this embodiment. [Figure 15] It is a flowchart showing an example of the processing of the wireless communication device according to this embodiment. [Figure 16] It is a flowchart showing an example of the processing of the wireless communication device according to this embodiment.

Embodiments for Carrying Out the Invention

[0011] Hereinafter, the wireless communication system 1 according to this embodiment will be described in detail with reference to the drawings. Note that the dimensional ratios in the drawings are exaggerated for convenience of explanation and may differ from the actual ratios. Also, in the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals.

[0012] (Wireless Communication System 1) FIG. 1 is a diagram showing the configuration of the wireless communication system 1 according to this embodiment. The wireless communication system 1 is installed, for example, inside a bus in an environment where many people flow in and out, and detects the flow of people and lost items. Further, the detected data is notified to a monitor that can be viewed by the driver and a data center of an operating company, a management company, or the like.

[0013] The wireless communication system 1 includes a plurality of wireless communication devices 10a to 10d and a collection module 20. When it is not necessary to distinguish and describe each of the wireless communication devices 10a to 10d, they are simply referred to as "wireless communication device 10". Also, in the example shown in FIG. 1, an example in which the number of wireless communication devices 10 in the wireless communication system 1 is four is shown, but the number of wireless communication devices 10 does not limit the configuration of the embodiment. For example, the number of wireless communication devices 10 in the wireless communication system 1 may be more than four or less than four.

[0014] Also, in this embodiment, the wireless communication system 1 is a communication system that transmits data to a target destination according to a predetermined relay order by relaying the data with the wireless communication device 10.

[0015] For example, the predetermined relay order corresponds to the ascending order of the numbers assigned to each of the wireless communication devices 10a to 10d in the example shown in FIG. 1, and corresponds to the order of the wireless communication device 10a, the wireless communication device 10b, the wireless communication device 10c, and the wireless communication device 10d. That is, in the example shown in FIG. 1, the wireless communication device 10a is the start terminal of the communication. Also, in the example shown in FIG. 1, the final target destination in the relay order corresponds to the collection module 20.

[0016] The wireless communication device 10 includes a sensor communication terminal 100, which will be described later. The wireless communication device 10 also transmits the sensor information acquired (sensed) by the sensor communication terminal 100 to the next wireless communication device 10 in a predetermined relay sequence.

[0017] In the example shown in Figure 1, wireless communication device 10a transmits sensor information to wireless communication device 10b via path R12. Wireless communication device 10b then transmits the sensor information transmitted from wireless communication device 10a and the sensor information acquired by wireless communication device 10b to wireless communication device 10c via path R23. Wireless communication device 10c then transmits the sensor information transmitted from wireless communication device 10b and the sensor information acquired by wireless communication device 10c to wireless communication device 10d via path R34. Furthermore, wireless communication device 10d transmits the sensor information transmitted from wireless communication device 10c and the sensor information acquired by wireless communication device 10d to the collection module 20 via path R4c. As a result, the collection module 20 collects all sensor information acquired by wireless communication devices 10a to 10d.

[0018] Furthermore, data is received by each wireless communication device 10 if the sum of the value obtained by the radio wave propagation loss calculation formula shown in equation (1) below and the transmission power is equal to or greater than the value required for reception. For example, if the radio wave frequency is 60 GHz and there are no obstacles between terminals, the data will be received if the distance between the wireless communication devices 10 is less than 4 m. Here, r represents the distance between devices, and λ represents the wavelength of the radio wave. Propagation loss (dB) = 20log((4πr) / λ) ... (1)

[0019] Furthermore, the radar waves emitted for sensing from the sensor communication terminal 100 of the wireless communication device 10 may or may not reach other wireless communication devices 10, depending on the distance between the installed wireless communication devices 10. For example, in the example shown in Figure 1, the radar waves emitted from wireless communication device 10a reach wireless communication devices 10b and 10c, but not reach wireless communication device 10d. On the other hand, in the example shown in Figure 1, the radar waves emitted from wireless communication devices 10b and 10c reach other wireless communication devices 10.

[0020] (Wireless communication device 10) Figure 2 is a block diagram showing the configuration of the wireless communication device 10 according to this embodiment. As shown in Figure 2, the wireless communication device 10 is composed of a sensor communication terminal 100, a solar panel 200, and an antenna 300. Details of the sensor communication terminal 100 will be described later.

[0021] The solar panel 200 is a device that converts ambient light into electricity and supplies power to the sensor communication terminal 100. In this embodiment, the wireless communication device 10 operates based on the electricity generated by the solar panel 200. When the wireless communication system 1 according to this embodiment is installed inside a bus, the wireless communication device 10 is installed, for example, on the ceiling inside the bus. In this case, the solar panel 200 of the sensor communication terminal 100 is powered by the ambient light entering the bus during the day. Also, at night or in dark places such as tunnels, the solar panel 200 of the sensor communication terminal 100 is powered by the lighting inside the bus, such as fluorescent lights or LEDs. Therefore, since the sensor communication terminal 100 operates with the electricity supplied from the solar panel 200, it is possible to install it so that sensor information is transmitted according to a predetermined relay sequence in the wireless communication system 1 shown in Figure 1.

[0022] Antenna 300 is used for transmitting and receiving radio waves for wireless communication. In this embodiment, antenna 300 is used for data transmission and reception between wireless communication device 10 and other wireless communication devices 10. Specifically, antenna 300 transmits transmission data and receives reception data. Antenna 300 may also be used to emit radar waves for detecting objects. In this embodiment, antenna 300 acquires sensing data (sensor information) sensed by radar waves. When the sensor communication terminal 100 shares wireless communication and radar waves, a predetermined standard such as IEEE802.11ay is applied. When this standard is applied, sensing and communication use the same 60GHz, so the sensor and communication operate independently. In Figure 2, an example is shown where there is only one antenna 300, but antennas 300 corresponding to wireless communication and radar waves may be provided.

[0023] Figure 3A is a diagram illustrating the illumination area radiated from antenna 300. Generally, radar waves are radiated (irradiated) in one direction for detection. For example, Figure 3A shows an example where radar waves are radiated from antenna 300 in the upward direction of the figure.

[0024] On the other hand, as shown in Figure 3B, the illumination area can be expanded by electrically sweeping the antenna direction. Also, as shown in Figure 3C, the illumination area can be expanded by mechanically sweeping the antenna direction. In this embodiment, the sensor communication terminal 100 expands the radar wave illumination area by electrically and / or mechanically sweeping the antenna direction.

[0025] Furthermore, in this embodiment, the radar waves emitted from the sensor communication terminal 100 are FMCW (Frequency Modulated Continuous Wave radar) radars. Also, in this embodiment, the radar waves emitted from the sensor communication terminal 100 have different chirp values ​​(chirp signals) for each wireless communication device 10. The chirp signal is a signal whose frequency increases over time. The chirp signals of the radar waves will be described later with reference to Figures 7A, 7B, 8A, and 8B.

[0026] In this specification, radar waves emitted from the wireless communication device 10's own terminal may be referred to as "local terminal radar waves," and radar waves emitted from other terminals of the wireless communication device 10 may be referred to as "other terminal radar waves" to distinguish between them. Furthermore, sensor information acquired by the local terminal may be referred to as "local terminal sensor information," and sensor information transmitted from other terminals may be referred to as "other terminal sensor information" to distinguish between them.

[0027] (Sensor communication terminal 100) Figure 4 is a block diagram showing the configuration of the sensor communication terminal 100. In this embodiment, the sensor communication terminal 100 is a device to which the above-mentioned IEEE802.11ay or the like applies, and is a device in which the function of a sensor utilizing 60GHz and the function of wireless communication are realized in an integrated manner.

[0028] Furthermore, in this embodiment, when the sensor communication terminal 100 transmits its own acquired sensor data to the information collection module 20, if the next destination in the predetermined relay sequence is not the information collection module 20, it transmits the data to another wireless communication device 10. In addition, the sensor communication terminal 100 of the wireless communication device 10 relays the data from the previous wireless communication device 10 in the predetermined relay sequence and transmits it to the next destination in the predetermined relay sequence. That is, the sensor communication terminal 100 transmits its own acquired sensor data, and if it has also received other terminal sensor data transmitted from another terminal, it transmits this data together with the own acquired sensor data to the next destination in the predetermined relay sequence.

[0029] The sensor communication terminal 100 may be configured as a general-purpose computer, as shown in Figure 4, comprising a control unit 110, a storage unit 120, a communication interface 130, and an input / output interface 140.

[0030] The control unit 110 is a component that controls the functions of the sensor communication terminal 100. Specifically, the control unit 110 has multiple functions as shown in Figure 5A. Details of each of these functions will be described later.

[0031] Furthermore, the control unit 110 may be configured as, for example, a general-purpose microcomputer. In this case, the microcomputer may have a computer program installed that allows it to function as a sensor communication terminal 100. By executing the computer program, the microcomputer functions as one of the multiple information processing circuits provided by the sensor communication terminal 100. In this embodiment, an example is shown in which the multiple information processing circuits provided by the sensor communication terminal 100 are realized by software, but of course, it is also possible to configure the information processing circuits by preparing dedicated hardware to perform each of the information processing operations shown below. Alternatively, the multiple information processing circuits may be configured using separate hardware.

[0032] Furthermore, the control unit 110 operates based on a program (not shown) stored in the memory unit 120 and executes each of the functions provided by the control unit 110 as described above. Note that the program is not limited to being stored in the memory unit 120, but may also be stored in a ROM (not shown) or the like within the sensor communication terminal 100, for example.

[0033] As shown in Figure 5A, the storage unit 120 includes a sensor information DB121 (DB: Database), a received information DB122, a transmitted information DB123, and a terminal information DB124.

[0034] Furthermore, as described above, the storage unit 120 may store programs for each function executed by the control unit 110. The data and programs stored in the storage unit 120 may be configured as areas physically or logically separated within a single storage device. Alternatively, the storage unit 120 for each data may be provided in multiple physically different storage devices.

[0035] The communication IF 130 is an interface for exchanging data transmitted and received via the antenna 300. In this embodiment, data received via the antenna 300 is sent to the received data acquisition unit 113a provided in the communication unit 113. Also, the transmission data transmission unit 113b provided in the communication unit 113 sends transmission data to the antenna 300 via the communication IF 130 and transmits it to another terminal (wireless communication device 10 or collection module 20).

[0036] The input / output IF140 is, for example, a component (interface) for exchanging data between the sensor unit 400 or external device 500 and the sensor communication terminal 100. The input / output IF140 is also used as an interface when a user operates the sensor communication terminal 100. In this embodiment, the sensor unit 400 is different from a radar sensor transmitted via the antenna 300, and may be, for example, an image sensor such as a camera or an ultrasonic sensor capable of detecting objects. The sensor unit 400 sends sensing data sensed by the applicable sensor to the input / output IF140.

[0037] In this embodiment, if the sensor is a radar that acquires information via the antenna 300, the sensor information acquired by the antenna 300 is sent to the sensor information acquisition unit 112 via the communication IF 130.

[0038] (Functions and configuration of sensor communication terminal 100) Figure 5A is a block diagram showing the functional configuration of the sensor communication terminal 100. The control unit 110 includes a timing calculation unit 111, a sensor information acquisition unit 112, a communication unit 113, a terminal determination unit 114, and a transmission data generation unit 115. As shown in Figure 5B, the transmission data generation unit 115 also includes a self-terminal radar wave generation unit 115a and a sensor information generation unit 115b.

[0039] The timing calculation unit 111 calculates the communication timing of its own terminal. Specifically, the timing calculation unit 111 calculates a first reception interval based on the reception time of the radar wave emitted from the other terminal immediately preceding the own terminal in the relay sequence and the transmitted sensor information of the other terminal, and calculates the communication timing based on the first reception interval. In this embodiment, the communication timing is the timing at which the wireless communication device 10 begins to emit radar waves. In this embodiment, the first reception interval is the emission time of the other terminal's radar wave and the transmission time of the other terminal's sensor information. The timing calculation unit 111 may also calculate the first reception interval based on the emission time of the own terminal's radar wave and the transmission time of the own terminal's sensor information. In this case, if there are multiple first reception intervals, the old first reception interval is updated with the new first reception interval, and the new first reception interval is applied to the calculation of the communication timing.

[0040] Furthermore, the timing calculation unit 111 calculates the next communication timing for its own terminal based on the first reception interval and the number of terminals constituting the wireless communication system 1. For example, if the number of terminals constituting the wireless communication system 1 is N, the time from the emission of the terminal's radar wave to the emission of the next terminal's radar wave, which is the next communication timing for the terminal, can be calculated by multiplying the first reception interval by the number of terminals N. In this embodiment, the terminals constituting the wireless communication system 1 correspond to the wireless communication devices 10.

[0041] Furthermore, the timing calculation unit 111 calculates a second reception interval based on the time interval between radar waves transmitted from two different other terminals. Specifically, the second reception interval is calculated from the difference between the radiation start time of the radar wave transmitted from one terminal and the radiation start time of the radar wave transmitted from another terminal.

[0042] Furthermore, if the second reception interval is greater than the first reception interval, the timing calculation unit 111 calculates the communication timing based on the second reception interval. The magnitude (time interval) of the communication timing may change depending on the installation conditions of the device and the radio wave communication environment. In other words, by calculating the communication timing using a larger interval, the timing calculation unit 111 enables the transmission and reception of sensor information that is suitable for the installation conditions of the device and the communication environment.

[0043] The sensor information acquisition unit 112 acquires local terminal sensor information from the sensor at the communication timing calculated by the timing calculation unit 111. Specifically, the sensor information acquisition unit 112 emits a local terminal radar wave of a predetermined chirp signal generated by the local terminal radar wave generation unit 115a based on terminal information stored in the terminal information DB 124, and acquires local terminal sensor information based on the reflected wave. In this embodiment, the predetermined chirp signal value in the local terminal radar wave is a predetermined slope value of the chirp signal for each wireless communication device 10.

[0044] Furthermore, the sensor information acquisition unit 112 stores the acquired local terminal sensor information in the sensor information DB 121. Specifically, the sensor information acquisition unit 112 acquires radar information acquired by the antenna 300 as sensor information via the communication IF 130. In this embodiment, the sensor information acquisition unit 112 emits local terminal radar waves at the communication timing calculated by the timing calculation unit 111, acquires local terminal sensor information based on the reflected waves of the local terminal radar waves, and stores it in the sensor information DB 121 of the storage unit 120. Alternatively, the sensor information acquisition unit 112 may acquire data acquired by emitting local terminal radar waves from the sensor unit 400 via the input / output IF 140 as local terminal sensor information.

[0045] Regarding the acquisition of local terminal sensor information by the sensor information acquisition unit 112, a configuration may be used in which the user can set whether to acquire local terminal sensor information from the communication IF 130 or the input / output IF 140. In this case, the user sets whether to acquire local terminal sensor information from the communication IF 130 or the input / output IF 140 via the input / output IF 140. Alternatively, the wireless communication device 10 may be configured to pre-set information in the storage unit 120 regarding whether to acquire local terminal sensor information from the communication IF 130 or the input / output IF 140.

[0046] The local terminal sensor information acquired by the sensor information acquisition unit 112 is stored in the sensor information DB 121, as shown in Figure 6.

[0047] The communication unit 113 includes a received data acquisition unit 113a and a transmitted data transmission unit 113b.

[0048] The received data acquisition unit 113a acquires received data when there are radar waves emitted from other terminals and sensor information from other terminals transmitted from other terminals that are ahead of its own terminal in the relay sequence.

[0049] Furthermore, when the received data acquisition unit 113a receives radar waves transmitted from another terminal, it transmits the reflected waves to the terminal that transmitted the radar waves via the transmitted data transmission unit 113b.

[0050] Furthermore, if the received data acquisition unit 113a receives radar waves transmitted from another terminal, the terminal determination unit 114 determines the source terminal (radiating terminal) of the radar waves.

[0051] The terminal determination unit 114 determines the source terminal of the other terminal's radar wave based on the chirp signal of the other terminal's radar wave and terminal information previously stored in the terminal information DB 124 of the storage unit 120.

[0052] In this embodiment, the terminal information is a value predetermined by the slope of the chirp signal as shown in Figures 7A and 7B. For example, in the example shown in Figure 7A, the slope (fb-fa) / Tα becomes the terminal information (IDα) of a certain wireless communication device 10. In the example shown in Figure 7B, (fb-fa) / Tβ, which has a gentler slope than in Figure 7A, becomes the terminal information (IDβ) of a certain wireless communication device 10.

[0053] The terminal determination unit 114 may determine a terminal based on the number of radar wave periods (Tα, Tβ) measured over a predetermined sampling period (Tc), as shown in Figure 8A. Furthermore, this sampling interval (Tc) is not limited to a single configuration in the wireless communication system 1; for example, as shown in Figure 8B, a configuration may be used in which the sampling period is determined for each terminal, such as Tcα and Tcβ.

[0054] Furthermore, when the received data acquisition unit 113a receives received data, it stores the acquired received data in the received information DB 122, as shown in Figure 6. In the example shown in Figure 6, the storage areas for the sensor information of the wireless communication devices 10a to 10d shown in Figure 1 are assigned to "A" to "D" in the received information DB 122, respectively. Similarly, for the transmitted information DB 123, which will be described later, the areas for the sensor information of the wireless communication devices 10a to 10d are assigned to "A" to "D" in the received information DB 122, respectively. Note that the received information DB 122 and transmitted information DB 123 shown in Figure 6 are schematic representations of the sensor information storage areas, and the received information DB 122 and transmitted information DB 123 also store header information and other information besides sensor information.

[0055] Figure 9 shows an example of the data format of a communication packet applied to sensor information according to this embodiment. As shown in Figure 9, the communication packet includes a "Preamble", "Destination Terminal ID", "Source Terminal ID", "Header", "Data Section", and "FCS" (Frame Check Sequence).

[0056] Figure 10 is a diagram illustrating an example of the configuration of the "data section" of the communication packet shown in Figure 9. As shown in Figure 10, the data format of the "data section" stores "Terminal 1 Valid" to "Terminal 4 Valid" and "Terminal 1 Data" to "Terminal 4 Data" related to wireless communication devices 10a to 10d. Note that "Terminal 1 Valid" to "Terminal 4 Valid" may also be stored in the "header" of the communication packet shown in Figure 9.

[0057] The fields "Terminal 1 Valid" to "Terminal 4 Valid" contain information indicating which terminal (wireless communication device 10) acquired the sensor information for the data included in the transmitted or received data. For example, in the wireless communication device 10 according to this embodiment, if the value "1" is stored in "Terminal 1 Valid" to "Terminal 4 Valid", it indicates that the sensor information of the terminal to which "1" is assigned is stored. Conversely, if the value "0" is stored in "Terminal 1 Valid" to "Terminal 4 Valid", it indicates that the sensor information of the terminal to which "0" is assigned is not stored.

[0058] "Terminal 1 Data" to "Terminal 4 Data" include sensor information acquired by the terminal (wireless communication device 10) regarding the data contained in the transmitted or received data. In this embodiment, the data size of "Terminal 1 Data" to "Terminal 4 Data" is the same.

[0059] The data transmission unit 113b transmits the data to the next terminal in a predetermined relay sequence. Furthermore, as described above, when the data transmission unit 113b receives radar waves from another terminal, it transmits the reflected waves to the terminal that transmitted those radar waves.

[0060] The terminal determination unit 114 determines the destination, which is the destination of the sensor information of another terminal acquired as received data. Furthermore, if the identification number stored in the "destination terminal ID" of the received data indicates the local terminal, the terminal determination unit 114 outputs the received data to the external device 500 via the input / output IF 140.

[0061] The self-terminal radar wave generation unit 115a of the transmission data generation unit 115 generates a self-terminal radar wave of a predetermined chirp signal based on terminal information stored in the terminal information DB 124. In this embodiment, the self-terminal radar wave of the predetermined chirp signal is the slope value of the chirp signal determined for each wireless communication device 10.

[0062] Furthermore, the sensor information generation unit 115b of the transmission data generation unit 115 generates transmission data to be sent to the next other terminal in a predetermined relay sequence. Specifically, the sensor information generation unit 115b stores the local terminal sensor information acquired by the local terminal and stored in the sensor information DB 121 in the transmission information DB 123. In addition, the sensor information generation unit 115b stores the received data, which is other terminal sensor information acquired by the received data acquisition unit 113a and stored in the received information DB 122, in the transmission information DB 123.

[0063] (Transmission and reception of radar waves and sensor information) Figure 11 illustrates the transmission and reception of radar waves and sensor information in the wireless communication system 1 shown in Figure 1. In the example shown in Figure 11, the emission of radar waves from the own terminal is indicated by solid circles, and the reception of radar waves from other terminals is indicated by dashed circles. Also in the example shown in Figure 11, the data transmission of sensor information from the own terminal is indicated by solid rectangles, and the data reception of sensor information from other terminals is indicated by dashed rectangles.

[0064] At the timing of point P1 in Figure 11, the wireless communication device 10a emits its own terminal radar wave. In the configuration shown in Figure 1, the wireless communication device 10a is the starting terminal and emits its own terminal radar wave at a predetermined timing. In the example shown in Figure 11, the terminal radar wave emitted from the wireless communication device 10a is received by the wireless communication devices 10b and 10c. In the wireless communication device 10a, the emission of its own terminal radar wave ends upon receipt of the reflected wave. In the wireless communication devices 10b and 10c, the reception of other terminal radar waves ends when the emission of other terminal radar waves from the wireless communication device 10a ends.

[0065] Next, the wireless communication device 10a transmits the sensor information acquired by emitting and receiving its own terminal radar waves to the next terminal in the relay sequence, the wireless communication device 10b. Subsequently, the wireless communication device 10a terminates the transmission of its own terminal sensor information upon receiving response information from the wireless communication device 10b. The wireless communication device 10b recognizes the timing of the end of receiving the other terminal's sensor information based on the amount of data transmitted from the wireless communication device 10a, and transmits response information to the wireless communication device 10a after the end of receiving the other terminal's sensor information.

[0066] At the timing of point P2, the wireless communication device 10a can calculate (recognize) time t1, which is the time from the start of the emission of its own terminal radar waves to the end of the transmission of its own terminal sensor information. In Figure 11, time t1 corresponds to point P2 - point P1. Furthermore, the wireless communication device 10a can calculate (recognize) the next emission timing (communication timing) of its own terminal radar waves using time t1 and the number of terminals N of the wireless communication device 10 provided in the wireless communication system 1. In the example shown in Figure 11, since the number of terminals N is 4, the time T1 until the next emission of its own terminal radar waves is T1 = time t1 × N = time t1 × 4.

[0067] Furthermore, at the timing of point P2, the wireless communication device 10b recognizes the communication timing of its own terminal and begins emitting its own terminal radar waves. In the example shown in Figure 11, the terminal radar waves emitted from the wireless communication device 10b are received as other terminal radar waves by wireless communication devices 10a, 10c, and 10d.

[0068] At the timing of point P2, the wireless communication device 10c recognizes the time t3 from the start of its own terminal radar wave emission to the end of its own terminal sensor information transmission, based on the interval between receiving radar waves from other terminals from wireless communication devices 10a and 10b. Furthermore, the wireless communication device 10c can calculate (recognize) the emission timing (communication timing) of the next radar wave emission from the wireless communication device 10c, based on time t3 and the number of terminals N.

[0069] The timing of point P4 is the communication timing of the wireless communication device 10d, at which point the wireless communication device 10d emits its own terminal radar waves. The timing of point P5 returns to the wireless communication device 10a, at which point the wireless communication device 10a emits its own terminal radar waves. The wireless communication device 10a can recognize the timing to emit its own terminal radar waves at the aforementioned time T1.

[0070] Furthermore, in the example shown in Figure 11, times t1a to t4a are time intervals updated by the first or second reception interval calculated by the timing calculation unit 111. Also, in the example shown in Figure 11, times T2a and T3a are times calculated by times t2a and t3a.

[0071] As described above, the wireless communication system 1 according to this embodiment calculates the communication timing based on the time required for actual radar wave emission and sensor information transmission. In other words, the wireless communication system 1 can communicate at an appropriate communication timing according to the communication time conditions, such as the set positions of each wireless communication device 10 constituting the wireless communication system 1 and the presence or absence of obstacles between devices. Therefore, the wireless communication system 1 can efficiently transmit and receive sensor information in a network that transmits sensor information acquired by sensors.

[0072] (Outline of the processing flow of wireless communication system 1) Next, the processing flow in the wireless communication device 10 is shown using the flowcharts in Figures 12 to 16. The series of operations of the wireless communication device 10 shown in the flowcharts in Figures 12 to 16 begin when the wireless communication device 10 is powered on and end when the task is completed. Furthermore, the flowcharts in Figures 12 to 16 also end when the power is turned off or when an interrupt occurs indicating the end of processing. In addition, in the following explanation of the flowcharts, the same content as described in the above-mentioned explanation of the wireless communication system 1 and wireless communication device 10 will be omitted or simplified.

[0073] The flowcharts shown in Figures 13 to 16 are flowcharts of the subroutine processing steps S1202 to S1205 shown in Figure 12. First, the processing flow in the wireless communication device 10 will be explained based on the flowchart shown in Figure 12.

[0074] In step S1201, the control unit 110 determines whether its own terminal is the start terminal and whether it is the first communication process. In this embodiment, the start terminal is the initiating terminal in the wireless communication system 1, and in the example shown in Figure 1, for example, it corresponds to the wireless communication device 10a. In step S1201, if the control unit 110 determines that its own terminal is the start terminal and it is the first communication process (step S1201: YES), the process proceeds to step S1205. On the other hand, in step S1201, if the control unit 110 determines that its own terminal is not the start terminal or it is not the first communication process (step S1201: NO), the process proceeds to step S1202.

[0075] In step S1202, the received data acquisition unit 113a performs radar wave reception processing. Specifically, the "radar wave reception processing" subroutine shown in Figure 13 is executed. Next, we will explain using the "radar wave reception processing" subroutine shown in Figure 13.

[0076] In step S1301, the received data acquisition unit 113a determines whether or not it has received radar waves emitted from another terminal. If the received data acquisition unit 113a determines in step S1301 that it has received radar waves emitted from another terminal (step S1301: YES), the process proceeds to step S1302. On the other hand, if the received data acquisition unit 113a determines in step S1301 that it has not received radar waves emitted from another terminal (step S1301: NO), the process returns to step S1202 in the flowchart shown in Figure 12.

[0077] In step S1302, the terminal determination unit 114 determines the source terminal of the other terminal's radar wave based on the chirp signal of the other terminal's radar wave and terminal information previously stored in the storage unit 120. Also in step S1302, the received data acquisition unit 113a stores the radar wave reception start time, which is the time when reception of the other terminal's radar wave began, in the storage unit 120. After that, the process proceeds to step S1303.

[0078] In step S1303, the received data acquisition unit 113a determines whether or not the reception of the radar waves from the other terminal has ended. In this embodiment, whether or not the reception of the radar waves from the other terminal has ended is determined by whether or not the radio waves of the radar waves emitted from the other terminal have disappeared (can no longer be received). In step S1303, if the received data acquisition unit 113a determines that the reception of the radar waves from the other terminal has ended (step S1303: YES), the process proceeds to step S1304. On the other hand, in step S1303, if the received data acquisition unit 113a determines that the reception of the radar waves from the other terminal has not ended (step S1303: NO), the process returns to step S1303 and the process of step S1303 is repeated.

[0079] In step S1304, the received data acquisition unit 113a stores the radar wave reception end time, which is the time indicating that the reception of radar waves from another terminal has ended, in the storage unit 120. After that, the process returns to step S1202 in the flowchart of Figure 12.

[0080] In step S1203 of Figure 12, the received data acquisition unit 113a performs data reception processing for other terminal sensor information. Specifically, the "sensor information reception processing" subroutine shown in Figure 14 is executed. Next, we will explain using the "sensor information reception processing" subroutine shown in Figure 14.

[0081] In step S1401, the received data acquisition unit 113a determines whether or not it has received other terminal sensor information from another terminal. If the received data acquisition unit 113a determines in step S1401 that it has received other terminal sensor information data from another terminal (step S1401: YES), the process proceeds to step S1402. On the other hand, if the received data acquisition unit 113a determines in step S1401 that it has not received other terminal sensor information from another terminal (step S1401: NO), the process returns to step S1202 in the flowchart of Figure 12.

[0082] In step S1402, the received data acquisition unit 113a stores the start time of reception of other terminal sensor information in the storage unit 120. The process then proceeds to step S1403.

[0083] In step S1403, the received data acquisition unit 113a stores the received information from other terminal sensors in the received information DB 122. The process then proceeds to step S1404.

[0084] In step S1404, the received data acquisition unit 113a determines whether or not the reception of other terminal sensor information has finished. If the received data acquisition unit 113a determines in step S1404 that the reception of other terminal sensor information has finished (step S1404: YES), the process proceeds to step S1405. On the other hand, if the received data acquisition unit 113a determines in step S1404 that the reception of other terminal sensor information has not finished (step S1404: NO), the process returns to step S1403, and the process from step S1403 is repeated.

[0085] In step S1405, the received data acquisition unit 113a stores the completion time of reception of other terminal sensor information in the storage unit 120. After that, the process returns to step S1203 in the flowchart of Figure 12.

[0086] In step S1204 of Figure 12, the timing calculation unit 111 and the terminal determination unit 114 perform communication interval calculation processing. Specifically, the "communication interval calculation processing" subroutine shown in Figure 15 is executed. Next, we will explain using the "communication interval calculation processing" subroutine shown in Figure 15.

[0087] In step S1501, the timing calculation unit 111 performs a communication interval calculation process. Specifically, the timing calculation unit 111 calculates a first reception interval based on the reception time of the radar wave emitted from the other terminal immediately preceding its own terminal in the relay sequence and the transmitted sensor information of the other terminal.

[0088] In this embodiment, if no received data (other terminal sensor information) is received, the process returns to step S1202 due to the branching at step S1401 in Figure 14, and therefore the processing in step S1204 is not performed. Also, if the received data acquisition unit 113a has received received data (other terminal sensor information), as shown in Figure 11, the received data acquisition unit 113a receives the other terminal radar wave before the other terminal sensor information.

[0089] In this embodiment, the reception interval for radar waves from other terminals is calculated by subtracting the radar wave reception start time from the radar wave reception end time. Similarly, the reception interval for sensor information from other terminals is calculated by subtracting the reception start time for sensor information from sensor information from sensor information from sensor information from sensor information from sensor from other terminals. In this embodiment, the first reception interval is the radiation time of radar waves from other terminals and the transmission time of sensor information from other terminals. Next, the process proceeds to step S1502.

[0090] In step S1502, the timing calculation unit 111 calculates the next communication timing for its own terminal based on the first reception interval and the number of terminals constituting the wireless communication system 1. For example, if the number of terminals constituting the wireless communication system 1 is N, the time from the emission of the terminal's radar wave to the emission of the next terminal's radar wave, which is the next communication timing for the terminal, can be calculated by multiplying the first reception interval by the number of terminals N. In this embodiment, the terminals constituting the wireless communication system 1 correspond to the wireless communication devices 10. The process then proceeds to step S1503.

[0091] In step S1503, the terminal determination unit 114 determines whether or not there is reception of other terminal radar waves from two different other terminals. If the terminal determination unit 114 determines in step S1503 that there is reception of other terminal radar waves from two different other terminals (step S1503: YES), the process proceeds to step S1504. On the other hand, if the terminal determination unit 114 determines in step S1503 that there is no reception of other terminal radar waves from two different other terminals (step S1503: NO), the process returns to step S1204 in the flowchart of Figure 12.

[0092] In step S1504, if the timing calculation unit 111 receives radar waves transmitted from two different other terminals, it calculates a second reception interval based on the time interval of the other terminal radar waves. Specifically, the second reception interval is calculated from the difference between the start time of reception of the other terminal radar wave transmitted from one terminal and the start time of reception of the other terminal radar wave transmitted from another other terminal. After that, the process returns to step S1204.

[0093] In step S1205 of Figure 12, the control unit 110, sensor information acquisition unit 112, transmission data generation unit 115, and transmission data transmission unit 113b perform self-terminal communication processing. Specifically, the "self-terminal communication processing" subroutine shown in Figure 16 is executed. Next, we will explain using the "self-terminal communication processing" subroutine shown in Figure 16.

[0094] In step S1601, the control unit 110 determines whether or not it is the communication timing for its own terminal. Specifically, the communication timing for its own terminal is the timing calculated in step S1502. The communication timing for its own terminal also applies when its own terminal is the starting terminal and it is the first communication process. If the control unit 110 determines in step S1601 that it is the communication timing for its own terminal (step S1601: YES), the process proceeds to step S1602. On the other hand, if the control unit 110 determines in step S1601 that it is not the communication timing for its own terminal (step S1601: NO), the process returns to step S1202, and the process from step S1202 is repeated.

[0095] In step S1602, the self-terminal radar wave generation unit 115a generates a self-terminal radar wave with a predetermined chirp signal based on the terminal information stored in the terminal information DB 124. In this embodiment, the predetermined chirp signal of the self-terminal radar wave is generated based on the slope value of the chirp signal determined for each wireless communication device 10. Also in step S1602, the sensor information acquisition unit 112 emits a self-terminal radar wave, acquires self-terminal sensor information from the sensor according to the reflection of the self-terminal radar wave, and stores it in the sensor information DB 121. Specifically, the sensor information acquisition unit 112 acquires radar information acquired by the antenna 300 as sensor information via the communication IF 130. Alternatively, the sensor information acquisition unit 112 may acquire data acquired by the sensor unit 400 as sensor information via the input / output IF 140. After that, the process proceeds to step S1603.

[0096] In step S1603, the sensor information generation unit 115b generates transmission data to be sent to the next other terminal in a predetermined relay sequence. In this embodiment, the transmission data includes the local terminal sensor information acquired by the local terminal's sensor information acquisition unit 112. The transmission data may also include other terminal sensor information transmitted from the terminal immediately preceding the local terminal in a predetermined relay sequence. The process then proceeds to step S1604.

[0097] In step S1604, the transmission data transmission unit 113b transmits transmission data containing its own terminal's sensor information to the next other terminal in a predetermined relay sequence. As described above, the transmission data may include other terminal sensor information transmitted from the terminal immediately preceding its own terminal in a predetermined relay sequence. The process then proceeds to step S1605.

[0098] In step S1605, the control unit 110 determines whether the processing related to acquiring local terminal sensor information and relaying other terminal sensor information in the wireless communication device 10 has been completed. In this embodiment, the processing related to acquiring local terminal sensor information and relaying other terminal sensor information is terminated, for example, by turning off the power of the wireless communication device 10. Alternatively, the processing related to acquiring local terminal sensor information and relaying other terminal sensor information may be terminated when a predetermined number of processing steps have been performed or when a predetermined time for processing to be performed by a timer has elapsed.

[0099] In step S1605, if the control unit 110 determines that processing in the wireless communication device 10 has finished (step S1605: YES), the process returns to step S1205 and terminates. On the other hand, in step S1605, if the control unit 110 determines that processing in the wireless communication device 10 has not finished (step S1605: NO), the process returns to step S1202, and the process from step S1202 is repeated.

[0100] As described above, the wireless communication device 10 according to this embodiment is a wireless communication device that constitutes a communication system that transmits data to a target destination according to a predetermined relay sequence. The wireless communication device 10 includes a received data acquisition unit 113a that acquires other terminal radar waves radiated from other terminals and other terminal sensor information transmitted from the other terminal immediately preceding the local terminal in the relay sequence as received data. The wireless communication device 10 also includes a terminal determination unit 114 that determines the source terminal of the other terminal radar waves based on the chirp signal of the other terminal radar waves and terminal information stored in a storage unit in advance. The wireless communication device 10 also calculates a first reception interval based on the reception time of the other terminal radar waves and other terminal sensor information determined by the terminal determination unit 114 to have been transmitted from the other terminal immediately preceding the local terminal in the relay sequence. The wireless communication device 10 also includes a timing calculation unit 111 that calculates the communication timing of the local terminal based on the first reception interval. The wireless communication device 10 also includes a local terminal radar wave generation unit 115a that generates a local terminal radar wave with a predetermined chirp signal based on the terminal information. Furthermore, the wireless communication device 10 includes a sensor information acquisition unit 112 that emits its own terminal radar waves at the communication timing, acquires its own terminal sensor information based on the reflected waves of its own terminal radar waves, and stores it in the storage unit 120. The wireless communication device 10 also includes a sensor information generation unit 115b that generates transmission data which includes at least its own terminal sensor information. Furthermore, the wireless communication device 10 includes a transmission data transmission unit 113b that transmits the transmission data to the next other terminal in the relay sequence.

[0101] As a result, the wireless communication device 10 calculates the communication timing based on the actual time required for radar wave emission and sensor information transmission. In other words, the wireless communication device 10 can communicate at an appropriate communication timing according to the communication time conditions, such as the set positions of each wireless communication device 10 constituting the wireless communication system 1 and the presence or absence of obstacles between devices. Furthermore, the wireless communication device 10 can calculate the communication timing without using devices such as beacons by determining the source terminal of other terminal radar waves using chirp signals. Therefore, the wireless communication device 10 can efficiently send and receive sensor information in a network that transmits sensor information acquired by sensors.

[0102] Furthermore, the timing calculation unit 111 of the wireless communication device 10 may calculate the next communication timing of its own terminal based on the first reception interval and the predetermined number of terminals constituting the communication system. This makes it possible for the wireless communication device 10 to calculate an appropriate communication timing based on the actual communication interval between each wireless communication device 10 without using predetermined data regarding the communication cycle. In this embodiment, the terminals constituting the wireless communication system 1 correspond to the wireless communication devices 10.

[0103] Furthermore, the timing calculation unit 111 of the wireless communication device 10 may calculate a second reception interval based on the time intervals between radar waves transmitted from two different other terminals. In addition, if the second reception interval is greater than the first reception interval, the timing calculation unit 111 may calculate the communication timing based on the second reception interval. For example, the magnitude of the communication timing in a communication system may change depending on the communication environment. That is, by calculating the communication timing using the larger of the calculated first and second reception intervals, the wireless communication device 10 can send and receive sensor information that is suitable for the communication environment.

[0104] Furthermore, the wireless communication device 10 according to this embodiment may be equipped with a solar panel 200 that generates electricity and may operate based on the electricity generated by the solar panel 200. As a result, since the wireless communication device 10 according to this embodiment operates on electricity supplied from the solar panel 200, it is possible to install it so that sensor information is transmitted according to a predetermined relay sequence in the wireless communication system 1 shown in Figure 1. In addition, since the wireless communication system 1 transmits sensor information according to a predetermined relay sequence, it is not necessary to directly transmit sensor information from all wireless communication devices 10 to the collection module 20. In other words, in the wireless communication system 1, it is sufficient to relay sensor information using electricity generated by the solar panel 200, thus realizing a system with reduced power consumption.

[0105] (Other embodiments) While embodiments have been described in detail with reference to the drawings, these embodiments are not limited to those described above. Furthermore, the components described above include those easily conceivable by those skilled in the art, and those that are substantially the same. Moreover, the configurations described above can be combined as appropriate. In addition, various omissions, substitutions, or modifications of the configurations can be made without departing from the spirit of the embodiments.

[0106] Furthermore, a computer program (wireless communication program) that causes a computer to execute the processing (wireless communication method) in the wireless communication device 10 described above, and a computer-readable recording medium on which the program is stored, are included within the scope of this embodiment. Here, the type of computer-readable recording medium is arbitrary. Also, the computer program is not limited to one stored on the recording medium, but may be transmitted via telecommunication lines, wireless or wired communication lines, networks such as the Internet, etc.

[0107] The following describes the features of the wireless communication device 10, the wireless communication system 1, and the wireless communication method.

[0108] The wireless communication device 10 according to the first embodiment is a wireless communication device that constitutes a communication system that transmits data to a target destination according to a predetermined relay sequence. The wireless communication device 10 includes a received data acquisition unit 113a that acquires other terminal radar waves radiated from other terminals and other terminal sensor information transmitted from the other terminal immediately preceding the local terminal in the relay sequence as received data. The wireless communication device 10 also includes a terminal determination unit 114 that determines the source terminal of the other terminal radar waves based on the chirp signal of the other terminal radar waves and terminal information stored in a storage unit in advance. The wireless communication device 10 also calculates a first reception interval based on the reception time of the other terminal radar waves and other terminal sensor information determined by the terminal determination unit 114 to have been transmitted from the other terminal immediately preceding the local terminal in the relay sequence. The wireless communication device 10 also includes a timing calculation unit 111 that calculates the communication timing of the local terminal based on the first reception interval. The wireless communication device 10 also includes a local terminal radar wave generation unit 115a that generates a local terminal radar wave with a predetermined chirp signal based on the terminal information. Furthermore, the wireless communication device 10 includes a sensor information acquisition unit 112 that emits its own terminal radar waves at the communication timing, acquires its own terminal sensor information based on the reflected waves of its own terminal radar waves, and stores it in the storage unit 120. The wireless communication device 10 also includes a sensor information generation unit 115b that generates transmission data which includes at least its own terminal sensor information. Furthermore, the wireless communication device 10 includes a transmission data transmission unit 113b that transmits the transmission data to the next other terminal in the relay sequence.

[0109] According to the above configuration, the wireless communication device 10 calculates the communication timing based on the time required for actual radar wave emission and sensor information transmission. In other words, the wireless communication device 10 can communicate at an appropriate communication timing according to the communication time conditions, such as the set positions of each wireless communication device 10 constituting the wireless communication system 1 and the presence or absence of obstacles between devices. Furthermore, the wireless communication device 10 can calculate the communication timing without using devices such as beacons by determining the source terminal of other terminal radar waves using a chirp signal. Therefore, the wireless communication device 10 can efficiently send and receive sensor information in a network that transmits sensor information acquired by sensors.

[0110] The timing calculation unit 111 of the wireless communication device 10 according to the second embodiment may calculate the next communication timing of its own terminal based on the first reception interval and the predetermined number of terminals constituting the communication system.

[0111] With the above configuration, the wireless communication device 10 can calculate an appropriate communication timing based on the actual communication interval between each wireless communication device 10, without using predetermined data regarding the communication cycle.

[0112] In the third embodiment, the timing calculation unit 111 of the wireless communication device 10 may calculate a second reception interval based on the time interval between radar waves transmitted from two different other terminals. Furthermore, if the second reception interval is greater than the first reception interval, the timing calculation unit 111 may calculate the communication timing based on the second reception interval.

[0113] In a communication system to which the wireless communication device 10 is applied, the size (interval) of the communication timing may change depending on the communication environment, for example. That is, the wireless communication device 10 can send and receive sensor information suitable for the communication environment by calculating the communication timing using the larger of the calculated first reception interval and second reception interval.

[0114] The wireless communication device 10 according to the fourth embodiment may include a solar panel 200 that generates electricity and may operate based on the electricity generated by the solar panel 200.

[0115] According to the above configuration, the wireless communication device 10 is powered by electricity supplied from the solar panel 200, making it possible to install it so that sensor information is transmitted according to a predetermined relay sequence in the wireless communication system 1 shown in Figure 1. Furthermore, in the wireless communication system 1, since sensor information is transmitted according to a predetermined relay sequence, it is not necessary to directly transmit sensor information from all wireless communication devices 10 to the collection module 20. In other words, in the wireless communication system 1, it is sufficient to relay sensor information using electricity generated by the solar panel 200, thus realizing a system with reduced power consumption.

[0116] The fifth embodiment of the wireless communication system 1 is a wireless communication system that transmits data according to a predetermined relay order, and comprises a plurality of wireless communication devices and a collection module which is the final destination of the data transmitted by the plurality of wireless communication devices according to the relay order. The wireless communication device 10 includes a received data acquisition unit 113a that acquires other terminal radar waves radiated from other terminals and other terminal sensor information transmitted from the other terminal immediately preceding the own terminal in the relay order as received data. The wireless communication device 10 also has a terminal determination unit 114 that determines the source terminal of the other terminal radar waves based on the chirp signal of the other terminal radar waves and terminal information stored in a storage unit in advance. The wireless communication device 10 also calculates a first reception interval based on the reception time of the other terminal radar waves and other terminal sensor information determined by the terminal determination unit 114 to have been transmitted from the other terminal immediately preceding the own terminal in the relay order. The wireless communication device 10 also has a timing calculation unit 111 that calculates the communication timing of the own terminal based on the first reception interval. Furthermore, the wireless communication device 10 has a self-terminal radar wave generation unit 115a that generates a self-terminal radar wave of a predetermined chirp signal based on terminal information. The wireless communication device 10 also has a sensor information acquisition unit 112 that emits a self-terminal radar wave at the communication timing, acquires self-terminal sensor information based on the reflected waves of the self-terminal radar wave, and stores it in the storage unit 120. The wireless communication device 10 also has a sensor information generation unit 115b that generates transmission data that includes at least self-terminal sensor information. Furthermore, the wireless communication device 10 has a transmission data transmission unit 113b that transmits the transmission data to the next other terminal in the relay sequence.

[0117] According to the above configuration, the wireless communication device 10 of the wireless communication system 1 calculates the communication timing based on the time required for actual radar wave emission and sensor information transmission. In other words, the wireless communication system 1 can communicate at an appropriate communication timing according to the communication time conditions, such as the set positions of each wireless communication device 10 constituting the wireless communication system 1 and the presence or absence of obstacles between devices. Furthermore, the wireless communication device 10 of the wireless communication system 1 can calculate the communication timing without using devices such as beacons by determining the source terminal of the radar waves of other terminals using a chirp signal. Therefore, the wireless communication system 1 can efficiently send and receive sensor information in a network that transmits sensor information acquired by sensors.

[0118] The wireless communication method according to the sixth embodiment is a wireless communication method executed by a computer. The wireless communication method acquires other terminal radar waves radiated from other terminals and other terminal sensor information transmitted from the other terminal immediately preceding the local terminal in the relay sequence as received data. The wireless communication method also determines the source terminal of the other terminal radar waves based on the chirp signal of the other terminal radar waves and terminal information stored in a memory unit in advance. The wireless communication method also calculates a first reception interval based on the reception time of the other terminal radar waves and other terminal sensor information determined to have been transmitted from the other terminal immediately preceding the local terminal in the relay sequence. The wireless communication method also calculates the local terminal's communication timing based on the first reception interval. The wireless communication method also generates a local terminal radar wave with a predetermined chirp signal based on the terminal information. The wireless communication method also radiates the local terminal radar wave at the communication timing. The wireless communication method also acquires local terminal sensor information based on the reflected wave of the local terminal radar wave. The wireless communication method also generates transmission data that includes at least the local terminal sensor information. Furthermore, the wireless communication method transmits the transmission data to the next other terminal in the relay sequence.

[0119] According to the above configuration, the wireless communication method calculates the communication timing based on the time required for actual radar wave emission and sensor information transmission. In other words, the wireless communication method enables communication at an appropriate timing according to the communication time conditions, such as the set position of each wireless communication device 10 constituting the wireless communication system 1 and the presence or absence of obstacles between devices. Furthermore, the wireless communication method can calculate the communication timing without using devices such as beacons by determining the source terminal of the radar waves of other terminals using a chirp signal. Therefore, the wireless communication method enables efficient transmission and reception of sensor information acquired by sensors in a network that transmits sensor information. [Explanation of Symbols]

[0120] 1. Wireless communication system 10, 10a~10d Wireless communication equipment 20 Collection Modules 100 Sensor Communication Terminals 110 Control Unit 111 Timing calculation unit 112 Sensor Information Acquisition Unit 113 Communication Unit 113a Received data acquisition unit 113b Transmission Data Transmission Section 114 Terminal detection unit 115 Transmission data generation unit 115a Self-terminal radar wave generation unit 115b Sensor information generation unit 120 Storage section 121 Sensor Information Database 122 Receiving Information DB 123 Transmission Information DB 124 Terminal Information Database 200 solar panels 300 Antenna 400 Sensor Unit 500 External device

Claims

1. A wireless communication device that constitutes a communication system that transmits data to a destination according to a predetermined relay sequence, A received data acquisition unit that acquires received data including radar waves emitted from other terminals and sensor information from other terminals transmitted from the terminal immediately preceding the local terminal in the relay sequence, A terminal determination unit that determines the source terminal of the other terminal's radar wave based on the chirp signal of the other terminal's radar wave and terminal information stored in the storage unit in advance, The terminal determination unit calculates a first reception interval based on the reception time of the radar wave and sensor information of the other terminal that are determined to have been transmitted from the terminal immediately preceding the local terminal in the relay sequence, and the timing calculation unit calculates the communication timing of the local terminal based on the first reception interval, A terminal radar wave generation unit generates a terminal radar wave of a predetermined chirp signal based on the terminal information, A sensor information acquisition unit that emits the terminal's radar waves at the aforementioned communication timing, acquires terminal sensor information based on the reflected waves of the terminal's radar waves, and stores it in a storage unit, A sensor information generation unit that generates transmission data including at least the aforementioned self-terminal sensor information, A wireless communication device comprising a transmission data transmission unit that transmits the transmission data to the next terminal in the relay sequence.

2. The wireless communication device according to claim 1, wherein the timing calculation unit calculates the next communication timing of its own terminal based on the first reception interval and a predetermined number of terminals constituting the communication system.

3. The timing calculation unit calculates a second reception interval based on the time interval between the radar waves transmitted from two different other terminals. The wireless communication device according to claim 2, wherein the timing calculation unit calculates the communication timing based on the second reception interval if the second reception interval is greater than the first reception interval.

4. It is further equipped with solar panels to generate electricity, A wireless communication device according to any one of claims 1 to 3, which operates based on the power generated by the solar panel.

5. A wireless communication system that transmits data according to a predetermined relay sequence, Multiple wireless communication devices, The system comprises a collection module which is the final destination of the data transmitted by multiple wireless communication devices in accordance with the relay sequence, The aforementioned wireless communication device is A received data acquisition unit that acquires received data including radar waves emitted from other terminals and sensor information from other terminals transmitted from the terminal immediately preceding the local terminal in the relay sequence, A terminal determination unit that determines the source terminal of the other terminal's radar wave based on the chirp signal of the other terminal's radar wave and terminal information stored in the storage unit in advance, The terminal determination unit calculates a first reception interval based on the reception time of the radar wave and sensor information of the other terminal that are determined to have been transmitted from the terminal immediately preceding the local terminal in the relay sequence, and the timing calculation unit calculates the communication timing of the local terminal based on the first reception interval, A terminal radar wave generation unit generates a terminal radar wave of a predetermined chirp signal based on the terminal information, A sensor information acquisition unit that emits the terminal's radar waves at the aforementioned communication timing, acquires terminal sensor information based on the reflected waves of the terminal's radar waves, and stores it in a storage unit, A sensor information generation unit that generates transmission data including at least the aforementioned self-terminal sensor information, A transmission data transmission unit that transmits the transmission data to the next other terminal in the relay sequence, A wireless communication system having

6. A wireless communication method performed by a computer, The system acquires radar waves emitted from other terminals and sensor information from other terminals transmitted from the terminal immediately preceding the current terminal in the relay sequence as received data. Based on the chirp signal of the other terminal's radar wave and terminal information stored in the memory unit beforehand, the source terminal of the other terminal's radar wave is determined. Based on the reception time of the radar wave and sensor information of the other terminal that were determined to have been transmitted from the other terminal immediately preceding the local terminal in the relay sequence, the first reception interval is calculated. Based on the first reception interval, the communication timing of the terminal is calculated. Based on the terminal information, a predetermined chirp signal local radar wave is generated. At the aforementioned communication timing, the terminal emits radar waves. Based on the reflected waves of the aforementioned radar waves of the terminal, sensor information of the terminal is acquired. Generate transmission data that includes at least the aforementioned self-terminal sensor information, A wireless communication method for transmitting the transmission data to the next other terminal in the relay sequence.

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