JP2015122572A - Radio communication system, radio communication terminal, radio communication method, and radio communication program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio communication system and the like for suppressing power consumption of a radio communication terminal having a small power generation amount.SOLUTION: A radio communication system S comprises: radio communication terminals 11 to 19 for performing ad hoc radio communication; a base station 20 for directly or indirectly performing radio communication with the radio communication terminals 11 to 19; and a server 30 for processing a signal transmitted through the base station 20. Each of the radio communication terminals 11 to 19 comprises: a reception circuit for receiving a signal; a transmission circuit for transmitting a signal; a power generation circuit which is connected to at least the reception circuit; and a control unit. When a power storage amount of a power storage element is equal to or more than a predetermined value, the control unit drives the reception circuit by power supply from the power generation circuit and stands by for a signal from another radio communication terminal.

Description

  The present invention relates to a wireless communication system that performs ad hoc wireless communication.

  As infrastructure facilities such as bridges, tunnels, and water and sewage systems are aging, it is possible to install a large number of sensors in these infrastructure facilities and monitor the status of the infrastructure facilities to determine the priority of repair and replacement. It is being considered. If data from the sensor group described above can be acquired by wireless communication, many advantages such as an increase in the degree of freedom of sensor installation locations and a reduction in equipment costs can be obtained.

  By the way, when constructing a wireless sensor network, the number of required wireless communication terminals becomes very large. In addition, the installation and replacement of wireless communication terminals may have a significant impact on the surrounding area. Therefore, when operating a wireless sensor network, it is desired to operate the wireless communication terminal continuously for a long period of time and reduce the number of battery replacements.

  For example, Patent Document 1 discloses a communication unit, a self-supporting power supply unit that converts natural energy into electric energy, a time measuring unit having an atomic clock, and a start time setting that outputs a start signal based on an output signal of the time measuring unit. And a power supply controller that activates the communication unit in response to the activation signal described above.

JP 2007-295057 A

  Usually, the power generated by natural energy varies greatly depending on the installation environment of the terminal device. For example, when the “self-supporting power supply unit” described in Patent Document 1 is a solar cell, the amount of solar radiation (time average) on the solar cell varies greatly depending on the installation position of the terminal device. Further, when ad hoc wireless communication is performed using a wireless terminal, the wireless terminal used for relay has a higher communication frequency than other wireless terminals. If it does so, in the radio | wireless terminal with a small amount of solar radiation to a self-supporting power supply part, and the radio | wireless terminal which relays frequently, a battery remaining charge becomes easy to reduce.

  In the technique described in Patent Document 1, since the wireless terminals are operated uniformly regardless of the amount of power generated by the self-supporting power supply unit, there is a possibility that the remaining battery level varies among the wireless terminals. For example, when relaying is performed using a wireless terminal with a small amount of power generated by the independent power supply unit, the power consumption may be larger than that of other wireless terminals. As a result, the battery replacement time of each wireless terminal varies, and the burden required for battery replacement work increases.

  Then, this invention makes it a subject to provide the radio | wireless communications system etc. which suppress the power consumption of the radio | wireless communication terminal with small electric power generation amount.

In order to solve the above problems, the present invention includes a plurality of wireless communication terminals that perform ad hoc wireless communication, a base station that performs direct or indirect wireless communication with the plurality of wireless communication terminals, and a plurality of the wireless communication terminals. A server for processing a signal transmitted via the base station, each of the plurality of wireless communication terminals receiving a signal, a transmitting circuit transmitting the signal, and at least the receiving circuit A power generation circuit connected to the power generation circuit, and a control unit, wherein the power generation circuit includes a power generation element and a power storage element that stores power generated by the power generation element, and the control unit includes: When the charged amount is equal to or larger than a predetermined value, the receiving circuit is driven by supplying power from the power generation circuit, and a signal from another wireless communication terminal is waited for.
Details will be described in an embodiment for carrying out the invention.

  ADVANTAGE OF THE INVENTION According to this invention, the radio | wireless communications system etc. which suppress the power consumption of the radio | wireless communication terminal with small electric power generation amount can be provided.

1 is a configuration diagram of a radio communication system according to a first embodiment of the present invention. It is a functional block diagram of a radio | wireless communication terminal. It is a functional block diagram of the electric power generation circuit with which a radio | wireless communication terminal is provided. It is a functional block diagram which shows the structure of a base station. It is explanatory drawing regarding the uplink communication in a radio | wireless communications system. It is a message sequence in uplink communication. It is a message sequence when communication of a data signal is not completed in uplink communication. FIG. 6 is an explanatory diagram illustrating a power state of a wireless communication terminal on a transmission side / reception side when performing signal relay processing. It is a flowchart which shows the operation | movement of the transmission process by a radio | wireless communication terminal. It is a flowchart which shows the operation | movement of the relay process by a radio | wireless communication terminal. It is explanatory drawing of the terminal management table for managing a radio | wireless communication terminal. It is explanatory drawing which shows the position block of each radio | wireless communication terminal. It is a message sequence of the process which transmits a command instruction | indication signal from a server to a wireless terminal device. 6 is a flowchart illustrating an operation of relay processing by a wireless communication terminal in a wireless communication system according to a second embodiment of the present invention. It is a flowchart which shows the operation | movement of the relay process by a radio | wireless communication terminal. It is a flowchart which shows operation | movement of a server in the radio | wireless communications system which concerns on 3rd Embodiment of this invention. It is a flowchart which shows operation | movement of the radio | wireless communication terminal used as a duty terminal. It is a flowchart which shows the operation | movement of the relay process by a radio | wireless communication terminal in the radio | wireless communications system which concerns on 4th Embodiment of this invention.

  Embodiments of the present invention will be described in detail with reference to the drawings as appropriate. Hereinafter, as an example, a case where the wireless communication system S (see FIG. 1) performs device operation monitoring and abnormality detection based on the detection value of the sensor 1 (see FIG. 2) will be described.

<< First Embodiment >>
<Configuration of wireless communication system>
FIG. 1 is a configuration diagram of a wireless communication system according to the present embodiment. The wireless communication system S is a system that detects a physical quantity representing the state of equipment or equipment (for example, distortion of a bridge) with a sensor 1 (see FIG. 2) and transmits the detection result to the server 30 via the base station 20. is there. As shown in FIG. 1, the wireless communication system S includes a plurality of wireless communication terminals 11 to 19, a base station 20, and a server 30.

(Wireless communication terminal)
The wireless communication terminals 11 to 19 have a function of constructing a network by autonomously recognizing other surrounding wireless communication terminals by performing ad hoc wireless communication. In the wireless communication system S, information exchange between the wireless communication terminals 14 to 19 and the base station 20 is relayed by the other wireless communication terminals 11 to 13 (multi-hop communication). The wireless communication terminals 11 to 19 are classified into a plurality of ranks according to the number of hops until the information transmitted by the wireless communication terminals 11 to 19 reaches the base station 20. Hereinafter, a wireless communication terminal that can be connected to the base station 20 with M hops is referred to as a “rank M wireless communication terminal”.

For example, information from the wireless communication terminal 11 illustrated in FIG. 1 is directly transmitted to the base station 20. Therefore, the wireless communication terminal 11 is a rank 1 wireless communication terminal. Information from the wireless communication terminal 14 is indirectly transmitted to the base station 20 via the rank 1 wireless communication terminal 11. Therefore, the wireless communication terminal 14 is a rank 2 wireless communication terminal.
In FIG. 1, the rank 1 or rank 2 wireless communication terminals 11 to 19 are illustrated, but actually, rank 3 or higher wireless communication terminals also exist.

  FIG. 2 is a functional block diagram of the wireless communication terminal. The wireless communication terminal 11 includes a sensor 1, a control unit 2, a memory 3, a transmission circuit 4, an antenna 5, a reception circuit 6, a switch circuit 7, a battery 8, and a power generation circuit 9. Yes. In FIG. 2, the bus B is shown in a simplified manner with a single line, but actually, a plurality of buses such as a data bus (not shown) and an address bus (not shown) are connected to the control unit 2. Yes.

  The sensor 1 detects a physical quantity representing the state of equipment (for example, the degree of bridge distortion). As the sensor 1, various types of sensors such as a strain sensor, a break sensor, a temperature sensor, and a tilt sensor can be used. Information (detection value) acquired by the sensor 1 is transmitted toward the base station 20 via the transmission circuit 4 and the antenna 5.

The control unit 2 is, for example, a microcomputer (not shown), reads a program stored in a ROM (Read Only Memory), develops it in a RAM (Random Access Memory), and a CPU (Central Processing Unit) performs various processes. Is supposed to run.
The control unit 2 has a function of comprehensively controlling the operation of the wireless communication terminal 11, and the sensor 1, the memory 3, the transmission circuit 4, the reception circuit 6, the switch circuit 7, the battery 8, and the power generation circuit 9 via the bus B. It is connected to the. Details of the processing executed by the control unit 2 will be described later.

  The memory 3 stores the terminal ID / rank of the wireless communication terminal 11, the detection value of the sensor 1, the remaining amount of the battery 8, a command instruction from the server 30, information received from other wireless terminal devices, and the like. As the memory 3, for example, a semiconductor memory element is used.

  The transmission circuit 4 is a circuit that transmits a signal read from the memory 3 by the control unit 2. The transmission circuit 4 includes an oscillation circuit (not shown) that generates a high frequency, a modulation circuit (not shown) that modulates the amplitude or frequency of a carrier wave, and the like. The input side of the transmission circuit 4 is connected to the control unit 2, and the output side is connected to the switch circuit 7.

The antenna 5 converts an electric signal input from the transmission circuit 4 into an electromagnetic wave and emits it (transmits), or converts an electromagnetic wave propagated through space into an electric signal (receives). The antenna 5 is connected to the switch circuit 7.
The receiving circuit 6 is a circuit that receives an electrical signal input from the antenna 5. The receiving circuit 6 has a demodulating circuit (not shown) for demodulating the above-described electric signal to obtain the original signal. The input side of the receiving circuit 6 is connected to the switch circuit 7, and the output side is connected to the control unit 2.

  The switch circuit 7 is a circuit that switches the connection between the transmission circuit 4 and the antenna 5 and the connection between the antenna 5 and the reception circuit 6 in accordance with a command from the control unit 2. That is, the switch circuit 7 connects the transmission circuit 4 and the antenna 5 and disconnects the antenna 5 and the reception circuit 6 during signal transmission. On the other hand, at the time of signal reception, the switch circuit 7 connects the antenna 5 and the reception circuit 6 and cuts off the transmission circuit 4 and the antenna 5.

  The switch circuit 7 may be omitted, and a transmitting antenna (not shown) and a receiving antenna (not shown) may be provided separately. In this case, the transmission antenna is connected to the transmission circuit 4 and the reception antenna is connected to the reception circuit 6.

  The battery 8 is, for example, a primary battery, and is installed so that power can be supplied to the sensor 1, the control unit 2, the memory 3, the transmission circuit 4, and the reception circuit 6. In addition, as the battery 8, a chargeable / dischargeable secondary battery may be used.

The power generation circuit 9 is a circuit that feeds power generated by the power generation element 9a (see FIG. 3) to the reception circuit 6 in accordance with a command from the control unit 2.
FIG. 3 is a functional block diagram of a power generation circuit included in the wireless communication terminal. As shown in FIG. 3, the power generation circuit 9 includes a power generation element 9a, a boosting unit 9b, a capacitor 9c, and a power supply control unit 9d.

The power generation element 9a is, for example, a solar battery that converts light energy of sunlight into electrical energy, and includes one or a plurality of solar battery cells (not shown). The power generating element 9a is connected to the booster 9b via the wiring K1.
The booster 9b has a function of boosting the voltage input from the power generation element 9a to a voltage suitable for the storage of the capacitor 9c. The step-up part 9b is connected to the capacitor 9c via the lines K2 and K3, and is connected to the power supply control part 9d via the line K2.

  The capacitor 9c (storage element) is an element that stores and discharges the electric charge generated by the power generation element 9a, and is connected to the wiring K2 via the wiring K3. The capacitor 9c stores the generated power from the power generation element 9a. Further, the power supply control unit 9d described later discharges from the capacitor 9c toward the receiving circuit 6. As the capacitor 9c, for example, an electric double layer capacitor can be used.

  The power supply control unit 9d controls power supply to the receiving circuit 6 via the wiring K4 in accordance with a command from the control unit 2. When the charged amount (voltage value) of the capacitor 9c is equal to or greater than a predetermined value, the power supply control unit 9d supplies power to the receiving circuit 6 by discharging the capacitor 9c. The electric power supplied from the power generation circuit 9 to the reception circuit 6 is used for transfer waiting described later.

On the other hand, when the charged amount (voltage value) of the capacitor 9c is less than the predetermined value, the power supply control unit 9d does not supply power to the reception circuit 6. That is, the transfer circuit 6 does not wait for transfer while a sufficient amount of generated power is not obtained from the power generation element 9a. As described above, in the present embodiment, signals from other wireless communication terminals are relayed using only the wireless communication terminals in which the amount of power generated by the power generation element 9a is sufficient.
Note that the wireless communication terminals 12 to 19 shown in FIG. 1 also have the same configuration (see FIGS. 2 and 3) as the wireless communication terminal 11 described above.

(base station)
The base station 20 illustrated in FIG. 1 directly performs wireless communication with the rank 1 wireless communication terminals 11 to 13 or indirectly with the rank 2 or higher wireless communication terminals 14 to 19 (that is, Wireless communication (via the rank 1 wireless communication terminals 11 to 13). The base station 20 transmits information acquired by itself to the server 30 via the network N. In addition, the base station 20 also has a function of transmitting command instructions received from the server 30 via the network N to the wireless communication terminals 11 to 19.

FIG. 4 is a functional block diagram showing the configuration of the base station. As shown in FIG. 4, the base station 20 includes an antenna 21, a switch circuit 22, a transmission circuit 23 that transmits a signal, a reception circuit 24 that receives a signal, and a control unit that controls the operation of the entire base station 20. 25 and a memory 26 in which various information is stored. The base station 20 is supplied with power from an external power source E (for example, a commercial power system).
Note that the switch circuit 22 may be omitted, and a transmitting antenna (not shown) and a receiving antenna (not shown) may be provided separately. Description of the details of each component of the base station 20 is omitted.

(server)
The server 30 illustrated in FIG. 1 has a function of processing a signal transmitted from the base station 20 via the network N. The server 30 also has a function of transmitting command instructions to the wireless communication terminals 11 to 19 via the base station 20. The server 30 is connected to a computer (not shown) of an administrator of the wireless communication system S.

<Operation of wireless communication terminal>
First, an outline of operations of the wireless communication terminals 11 to 19 will be described with reference to FIG. 5, and then each operation of the wireless communication terminals 11 to 19 will be described in detail with reference to FIGS. 6 to 13.
FIG. 5 is an explanatory diagram regarding uplink communication in a wireless communication system. In the wireless communication terminals 11, 13, 15, 17, and 18 (open triangles) shown in FIG. 5, the power generation amount of the power generation element 9 a (see FIG. 3) is sufficient. Has been done. On the other hand, in the wireless communication terminals 12, 14, 16, 19 (triangles with diagonal lines), the amount of power generated by the power generation element 9a is not sufficient, and data signals are not relayed.

Below, the case where the radio | wireless communication terminal 17 shown in FIG. 5 transmits a data signal toward the base station 20 as an example is demonstrated. The wireless communication terminal 17 periodically transmits a data signal including the detection value of the sensor 1 (see FIG. 2) to the base station 20.
First, the wireless communication terminal 17 broadcasts a transmission notice signal including its own rank (= 2) to the surrounding wireless communication terminals 12, 13, 16, and 18. The transmission notice signal is received by the wireless communication terminals 13 and 18 that are supplied with power from the power generation circuit 9 (see FIG. 2) to the reception circuit 6 among the surrounding wireless communication terminals 12, 13, 16, and 18. . Note that the wireless communication terminals 12 and 16 cannot receive the transmission notice signal because the power generation amount of the power generation element 9a is not sufficient and the reception circuit 6 is not operating.

  A connection with the wireless communication terminal 17 is established by the wireless communication terminal 13 having a higher rank than the wireless communication terminal 17 that is the transmission source among the wireless communication terminals 13 and 18 that have received the transmission notice signal. The wireless communication terminal 13 that is rank 1 transmits the data signal received from the wireless communication terminal 17 that is rank 2 to the base station 20. The data signal transmitted to the base station 20 is transmitted to the server 30 via the network N.

(Transmission process)
FIG. 6 is a message sequence in uplink communication. In the following description, it is assumed that the wireless communication terminal 13 shown in FIG. 5 is a “higher rank terminal” and the wireless communication terminal 17 is a “lower rank terminal”.
The lower rank wireless communication terminal 17 periodically transmits a data signal including the detection value of the sensor 1 (see FIG. 2) to the base station 20. In step S101, the wireless communication terminal 17 broadcasts a transmission notice signal to surrounding wireless communication terminals 12, 13, 16, 18 (see FIG. 5). This transmission notice signal includes the terminal ID of the wireless communication terminal 17 and the rank (= 2). In step S102, the wireless communication terminal 17 waits for a reception notification signal to be described later.

On the other hand, the higher rank wireless communication terminal 13 waits for a transmission notice signal (waits for transfer) in step S201. The power of the power generation circuit 9 (see FIG. 3) is used for waiting for transfer.
When the transmission notice signal is received from the wireless communication terminal 17, the wireless communication terminal 13 transmits a reception notification signal to the wireless communication terminal 17 in step S 202. As a result, a connection is established between the wireless communication terminals 13 and 17.

  Incidentally, when there are a plurality of wireless communication terminals that transmit reception notification signals, it is preferable to prevent collision of reception notification signals in the wireless communication terminal 17 by shifting the transmission timing. For example, a value inversely proportional to the signal strength of the received transmission advance notice signal can be used as the delay time from when the transmission advance notice signal is received until the reception notification signal is transmitted. As a result, the reception notification signal from the wireless communication terminal 13 with the best signal reception state reaches the wireless communication terminal 17 first.

In addition, when performing the process of step S202, the control part 2 (refer FIG. 2) of the radio | wireless communication terminal 13 switches the electric power supply source from the electric power generation circuit 9 to the battery 8. FIG. That is, the power of the power generation circuit 9 is used for the process of step S201, and the power of the battery 8 is used for the processes of steps S202, S203, and S204. Details of the power supply switching will be described later.
In step S203, the wireless communication terminal 13 executes data signal standby (data standby).

  When the reception notification signal is received from the wireless communication terminal 13, the wireless communication terminal 17 transmits a data signal to the wireless communication terminal 13 in step S <b> 103. This data signal includes the terminal ID of the wireless communication terminal 17, the rank (= 2), the remaining battery level, and the detection value of the sensor 1. After transmitting the data signal, in step S104, the wireless communication terminal 17 waits for an Ack signal.

  When the data signal is received from the wireless communication terminal 17, the wireless communication terminal 13 transmits an Ack signal to the wireless communication terminal 17 in step S <b> 204. Thereby, the reception process of the wireless communication terminal 13 is completed. Moreover, the transmission process of the wireless communication terminal 17 is completed by receiving the Ack signal transmitted in step S204.

  FIG. 7 is a message sequence when data signal communication is not completed in uplink communication. After transmitting the data signal (S1031), the lower rank wireless communication terminal 17 (see FIG. 5) waits for an Ack signal from the wireless communication terminal 13 in step S1041. If the Ack signal is not received even after the predetermined time has elapsed, the wireless communication terminal 17 retransmits the data signal in step S1032.

  In this way, the wireless communication terminal 17 retransmits the data signal until a predetermined maximum number of retransmissions (for example, 3 times) is reached until an Ack signal is received. If the Ack signal is not obtained within the maximum number of retransmissions, the wireless communication terminal 17 records a communication failure and stops the transmission process. The data signal missed in the communication is transmitted together with the next signal transmission.

  FIG. 8 is an explanatory diagram showing the power state of the wireless communication terminal on the transmission side / reception side when performing signal relay processing. In FIG. 8, the process performed with the power of the power generation circuit 9 (see FIG. 2) is shown by hatching, and the process performed with the power of the battery 8 (see FIG. 2) is shown in white. The step numbers shown in parentheses correspond to those in FIG.

The transmitting-side wireless communication terminal 17 (see FIG. 5) transmits a transmission notice signal (S101), waits for a reception notification signal (S102), transmits a data signal (S103), and waits for an Ack signal (S104). At that time, the power of the battery 8 is used.
On the other hand, the radio communication terminal 13 on the receiving side (see FIG. 5) waits for a transfer signal with the power of the power generation circuit 9 (S201: shaded portion). At this time, the components other than the receiving circuit 6 are operated by the power of the battery 8, and the control unit 2 is set in the sleep state to suppress the consumption of the battery 8 to a minimum.

  After receiving the transmission notice signal (S101) from the wireless communication terminal 17 on the transmission side, the control unit 2 (see FIG. 2) of the wireless communication terminal 13 switches the power source of each component including the reception circuit 6 to the battery 8. Then, the control unit 2 uses the power of the battery 8 to transmit a reception notification signal (S202), wait for a data signal (S203), and transmit an Ack signal (S204). By using the power of the battery 8 in this way, the processes in steps S202 to S204 can be performed reliably.

FIG. 9 is a flowchart showing an operation of transmission processing by the wireless communication terminal. Below, the case where a data signal is transferred via the radio | wireless communication terminal 13 from the radio | wireless communication terminal 17 shown in FIG. 5 as an example is demonstrated.
In step S301, the wireless communication terminal 17 determines whether data to be transmitted has occurred. Generation of data to be transmitted includes regular arrival of signal transmission time and reception of data signals from other wireless communication terminals.

  If there is no data to be transmitted (S301 → No), the wireless communication terminal 17 repeats the process of step S301. On the other hand, when data to be transmitted is generated (S301 → Yes), in step S302, the wireless communication terminal 17 broadcasts a transmission advance notice signal to surrounding wireless communication terminals 12, 13, 16, 18 (see FIG. 5). Next, in step S303, the wireless communication terminal 17 determines whether a reception notification signal has been received within a predetermined time after transmitting the transmission advance notice signal.

If the reception notification signal has not been received (S303 → No), in step S304, the wireless communication terminal 17 determines whether or not the number of retransmissions of the transmission notice signal has reached a predetermined number (maximum number of retransmissions). When the number of retransmissions of the transmission announcement signal reaches the predetermined number (S304 → Yes), the wireless communication terminal 17 stops the transmission process in step S310.
On the other hand, when the number of retransmissions of the transmission announcement signal has not reached the predetermined number (S304 → No), the processing of the wireless communication terminal 17 proceeds to step S305. In step S305, the wireless communication terminal 17 broadcasts a transmission notice signal again, and returns to the process of step S303.

When the reception notification signal is received in step S303 (S303 → Yes), in step S306, the wireless communication terminal 17 refers to the terminal ID and the rank included in the reception notification signal, and the wireless communication terminal 13 (see FIG. 5). Send a data signal.
When reception notification signals are received from a plurality of wireless communication terminals, the wireless communication terminal 17 preferably transmits a data signal to the wireless communication terminal 13 that is the transmission source of the reception notification signal received first. . As described above, the reception notification signal from the wireless communication terminal 13 having the best signal reception state arrives at the wireless communication terminal 17 at the earliest timing.

In step S307, the wireless communication terminal 17 determines whether or not an Ack signal is received from the wireless communication terminal 13 within a predetermined time after transmitting the data signal.
When the Ack signal is not received (S307 → No), in step S308, the wireless communication terminal 17 determines whether the number of retransmissions of the data signal has reached a predetermined number (maximum number of retransmissions).

If the number of retransmissions of the data signal has not reached the predetermined number (S308 → No), the processing of the wireless communication terminal 17 proceeds to step S309. In step S309, the wireless communication terminal 17 retransmits the data signal to the wireless communication terminal 13, and returns to the process of step S307.
On the other hand, when the number of retransmissions of the data signal reaches a predetermined number (S308 → Yes), the wireless communication terminal 17 stops the transmission process in step S310. Note that data that could not be transmitted this time is sent together in the next communication.

  If the Ack signal is received in step S307 (S307 → Yes), the wireless communication terminal 17 ends the transmission process (END). As described above, the power of the battery 8 is used for a series of processes from Steps S301 to S310 (see FIG. 8).

(Relay processing)
FIG. 10 is a flowchart showing the operation of relay processing by the wireless communication terminal. Note that at the time of “START”, the wireless communication terminal 13 is in a standby state in which standby is not performed.
In step S401, the wireless communication terminal 13 determines whether or not the amount of power generated by the power generation element 9a (that is, the amount of power stored in the capacitor 9c) is greater than or equal to a predetermined value by the power supply control unit 9d (see FIG. 3). The above-mentioned “predetermined value” is a threshold value that serves as a criterion for determining whether or not waiting for transfer can be continuously performed for a predetermined time.

  When the power generation amount of the power generation element 9a is less than the predetermined value (S401 → No), the wireless communication terminal 13 repeats the process of step S401. That is, the wireless communication terminal 13 stands by until the generated power reaches a predetermined value or data to be transmitted is generated. When data to be transmitted is generated, the wireless communication terminal 13 executes the above-described transmission process (see FIG. 9).

  If the amount of power generated by the power generation element 9a is equal to or greater than a predetermined value (S401 → Yes), the wireless communication terminal 13 starts waiting for a transmission notice signal (waiting for transfer) in step S402. That is, the wireless communication terminal 13 operates the reception circuit 6 with the power from the power generation circuit 9 (see FIG. 3), and waits for a transmission advance notice signal from another wireless communication terminal.

  In step S403, the wireless communication terminal 13 determines whether or not the transmission notice signal is received from the lower rank wireless communication terminal by the control unit 2 (see FIG. 3). When the transmission notice signal has not been received (S403 → No), the processing of the wireless communication terminal 13 returns to step S401. On the other hand, when the transmission notice signal is received (S403 → Yes), in step S404, the wireless communication terminal 13 switches the power supply of the receiving circuit 6 from the power generating element 9a to the battery 8 by the power supply control unit 9d (see FIG. 3). .

In step S405, the wireless communication terminal 13 transmits a reception notification signal to the wireless communication terminal 17 that is the transmission source of the transmission notice signal.
In step S <b> 406, the wireless communication terminal 13 determines whether a data signal has been received from the wireless communication terminal 17. When the data signal is received (S406 → Yes), the wireless communication terminal 13 transmits an Ack signal to the wireless communication terminal 17 in step S407.

  Next, in step S408, the wireless communication terminal 13 transfers (relays) the data signal. That is, the wireless communication terminal 13 adds its own terminal ID and the like to the data signal received from the wireless communication terminal 17, and transmits this data signal to the base station 20 (see FIG. 1). As a result, it is possible for the server 30 to grasp what route the data signal has reached. Note that the processing content of step S408 is the same as the transmission processing described in FIG.

  On the other hand, when no data signal is received in step S406 (S406 → No), in step S409, the wireless communication terminal 13 determines whether or not a predetermined time has elapsed since the reception notification signal was transmitted. When the predetermined time has not elapsed (S409 → No), the processing of the wireless communication terminal 13 returns to step S406. On the other hand, when the predetermined time has elapsed (S409 → Yes), in step S410, the wireless communication terminal 13 stops waiting for the data signal.

  In step S411, the wireless communication terminal 13 switches the power supply of the reception circuit 6 (see FIG. 3) from the battery 8 to the power generation element 9a. Next, the processing of the wireless communication terminal 13 returns to START (RETURN) and waits until the power generation circuit 9 obtains sufficient power for waiting for transfer.

(About terminal management table)
FIG. 11 is an explanatory diagram of a terminal management table for managing wireless communication terminals.
The server 30 (see FIG. 1) creates the terminal management table T using the data signal transmitted to itself. The terminal management table T includes a terminal ID / rank / position block of a wireless communication terminal that is a transmission source, a transmission route of a signal received in the past, a data cycle, a previous data reception time, a battery remaining amount, Information including is recorded.
For example, the server 30 estimates the remaining battery level of the wireless communication terminal based on the voltage value of the battery 8 (see FIG. 2). The remaining battery level may be estimated based on the total activation time of the wireless communication terminal or the total number of signal transmission / reception.

  In the terminal management table T shown in FIG. 11, the terminal ID, rank, past transmission route, and remaining battery level are included in the data signal transmitted from the wireless communication terminal. Further, the data cycle (for example, 300 sec) is set in advance. Based on the “data cycle” and “previous data reception time” in the terminal management table T, the server 30 monitors whether the periodic data communication from the wireless communication terminals 11 to 19 is interrupted.

Moreover, the server 30 estimates the position of the radio | wireless communication terminals 11-19 based on the transmission route of the signal received in the past, and records it as a position block.
FIG. 12 is an explanatory diagram showing a position block of each wireless communication terminal. In the example shown in FIG. 12, the wireless communication terminals 11, 14, 15 are classified as the position block A, the wireless communication terminals 12, 15, 16, 17 are classified as the position block B, and the wireless communication terminals 13, 17, 18, 19 is classified as a position block C.
As shown in FIG. 12, one wireless communication terminal may be registered in a plurality of position blocks in an overlapping manner depending on the installation position. Further, one position block is not always assigned to each rank 1 wireless communication terminal.

(Command instructions from the server)
FIG. 13 is a message sequence of a process for transmitting a command instruction signal from the server to the wireless terminal device. Hereinafter, a case where a command instruction is transmitted from the server 30 illustrated in FIG. 12 to the wireless communication terminal 17 (lower rank terminal) via the wireless communication terminal 13 (higher rank terminal) will be described.
In step S <b> 501, the server 30 transmits a command instruction signal to the base station 20. The command instruction signal includes the terminal ID and position block of the wireless communication terminal 13 to be instructed in addition to the contents of the command instruction (for example, change of the data cycle).

When the base station 20 receives a transmission notice signal from the wireless communication terminal 13 whose rank is higher than that of the wireless communication terminal 17 among the position blocks to which the wireless communication terminal 17 belongs (S502), the base station 20 issues a command instruction to the reception notification signal. The content of the signal is transmitted to the wireless communication terminal 13 (S503). Incidentally, the process of step S502 uses the power of the battery 8 in order to transmit the data (including the detection value of the sensor 1; see FIG. 2) acquired by the higher rank wireless communication terminal 13 itself to the base station 20. Performed regularly.
After receiving the data signal from the higher rank wireless communication terminal 13 (S504), the base station 20 transmits an Ack signal to the wireless communication terminal 13 (S505).

Next, when the wireless communication terminal 13 that is the higher rank receives the transmission notice signal from the wireless communication terminal 17 that is the lower rank (S506), the reception notification signal includes the content of the command instruction signal and transmits it to the wireless communication terminal 17. (S507).
The wireless communication terminal 17 reads a command instruction from the signal received by itself, and transmits a data signal including the command instruction Ack to the command instruction to the wireless communication terminal 13 (S508). In response to this, an Ack signal is transmitted from the wireless communication terminal 13 to the wireless communication terminal 17 (S509).

  The data signal including the command instruction Ack is transferred to the base station 20 in the same procedure as the normal data signal exchange (S510 to S513). When the base station 20 receives a data signal including the instruction Ack signal from the wireless communication terminal 13 (S512), the base station 20 transmits the Ack signal to the wireless communication terminal 13 (S513) and transmits the instruction Ack signal to the server 30. (S514).

  The wireless communication terminal 13 that has received the data signal including the instruction Ack signal from the wireless communication terminal 17 (S508) stops the subsequent broadcast and stores the command instruction signal stored in its own memory 3 (see FIG. 2). Erase. Other wireless communication terminals used for relaying the command instruction signal broadcast the downlink signal to a wireless communication terminal lower than itself for a certain period, and then delete this signal and stop broadcasting.

<Effect>
In the present embodiment, signals are relayed using only the wireless communication terminals in which the power generation amount of the power generation element 9a (the amount of electricity stored in the capacitor 9c) is equal to or greater than a predetermined value among the wireless communication terminals 11 to 19. As described above, the receiving circuit 6 waits for the transfer with the electric power from the power generation circuit 9, so that the consumption of the battery 8 during the relay process can be suppressed.
In this embodiment, the wireless communication terminal whose generated power is less than a predetermined value does not wait for transfer. Thus, since it is not necessary to use the power of the battery 8 for waiting for transfer when relaying, it is possible to suppress the power consumption of the wireless communication terminal with a small amount of generated power.

  If a wireless communication terminal whose power generation amount of the power generation element 9a is insufficient is also relayed by the power of the battery 8, the remaining amount of the battery 8 is rapidly increased in a specific wireless communication terminal depending on the installation environment and the presence / absence of the relay. May decrease. For example, the remaining amount of the battery 8 is rapidly reduced in a wireless communication terminal that is installed in a place with poor sunlight and relays frequently, compared to other wireless communication terminals. As a result, a large difference occurs in the power consumption of the battery 8 between the wireless communication terminals, and the time for replacement of the battery 8 varies.

  On the other hand, in the present embodiment, relaying is performed using only wireless communication terminals that can wait for transfer with the power of the power generation circuit 9 (otherwise, relaying is not performed). Therefore, the difference in power consumption of the battery 8 between the wireless communication terminals is reduced, and the remaining amount of the battery 8 can be made uniform. As a result, the variation in the replacement time of the battery 8 is reduced, and the replacement work of the battery 8 can be performed collectively for each of the wireless communication terminals 11-19. Therefore, the cost required for the replacement work of the battery 8 can be reduced and the replacement work can be completed in a short period of time.

  In addition, the wireless communication terminals 11 to 19 wait for transfer with the power of the power generation circuit 9, and then perform transmission of a reception notification signal, standby for a data signal, and transmission of an Ack signal with the power of the battery 8. Thus, the signal relay process can be reliably executed without interruption.

<< Second Embodiment >>
The second embodiment is different from the first embodiment in that a plurality of data signals received from other wireless communication terminals are transferred together, but the configuration of each of the wireless communication terminals 11 to 19 (see FIGS. 2 and 3). Is the same as in the first embodiment. Therefore, a different part from 1st Embodiment is demonstrated and description is abbreviate | omitted about the overlapping part.
Below, the case where a signal is relayed by the radio | wireless communication terminal 13 shown in FIG. 1 as an example is demonstrated.

  14 and 15 are flowcharts showing the operation of the relay process by the wireless communication terminal. Note that the processing in steps S401 to S404 in FIG. 14 and steps S405 to S407 and S409 to S411 in FIG. 15 are the same as the relay processing (see FIG. 10) described in the first embodiment.

  When a data signal is received in step S406 of FIG. 15 (S406 → Yes), the wireless communication terminal 13 transmits an Ack signal (S407), and then determines whether the number of data has reached a predetermined value in step S601. . The number of data described above is an upper limit value of the number of data received from the lower rank wireless communication terminals and temporarily stored in the memory 3 (see FIG. 2). That is, the wireless communication terminal 13 stores the data signal received from the lower rank wireless communication terminal in the memory 3 until the number of data reaches a predetermined value (for example, 3) without immediately transferring the data signal.

If the number of data has not reached the predetermined value (S601 → No), the processing of the wireless communication terminal 13 returns to step S401 in FIG. On the other hand, when the number of data reaches a predetermined value (S601 → Yes), the processing of the wireless communication terminal 13 proceeds to step S602.
In step S602, the wireless communication terminal 13 determines whether or not the data signal transmission time has come. The cycle of this transmission time (for example, 300 sec: see FIG. 11) is set in advance. If it is not the transmission time of the data signal (S602 → No), the wireless communication terminal 13 repeats the process of step S602. On the other hand, when the transmission time of the data signal comes (S602 → Yes), the processing of the wireless communication terminal 13 proceeds to step S603.

In step S603, the wireless communication terminal 13 reads the data stored in the memory 3 (see FIG. 2), transfers the data to the higher rank wireless communication terminal, and its own data (terminal ID, rank, remaining battery level, Combined data including the detection value of the sensor 1) is generated.
In step S604, the wireless communication terminal 13 transmits (transfers) the joint data signal generated in step S603 to the base station 20.

<Effect>
According to this embodiment, the number of data signal transmissions (relays) can be reduced as compared with the case where signals from other wireless communication terminals are transferred each time. Therefore, the power consumption of the battery 8 can be further reduced than in the first embodiment.

«Third embodiment»
The third embodiment differs from the first embodiment in that when there is no other wireless communication terminal that can be relayed around the wireless communication terminal, relay is performed using the wireless communication terminal specified by the server 30. This is the same as in the first embodiment. Therefore, a different part from 1st Embodiment is demonstrated and description is abbreviate | omitted about the overlapping part.

<Server operation>
FIG. 16 is a flowchart showing the operation of the server.
In step S <b> 701, the server 30 determines whether there is a wireless communication terminal in which periodic data communication (regular data communication) is interrupted. That is, the server 30 refers to the terminal management table T (see FIG. 11), and based on the data cycle and the previous data reception time, whether or not data communication is performed for each data cycle (predetermined period). Is determined for each wireless communication terminal.

When there is no wireless communication terminal in which the scheduled data communication is interrupted (S701 → No), the server 30 ends the process (END). On the other hand, when there is a wireless communication terminal in which the scheduled data communication is interrupted (S701 → Yes), the processing of the server 30 proceeds to step S702.
In the following description, it is assumed that the scheduled data communication is interrupted in the wireless communication terminal 17 (rank 2, position block C) shown in FIG.

  In step S702, the server 30 determines whether or not the data signal is interrupted for the wireless communication terminals of the same rank located around the wireless communication terminal 17 specified in step S701. That is, the server 30 refers to the terminal management table T (see FIG. 11), belongs to the same position block C as the wireless communication terminal 17, and has the same rank as the wireless communication terminal 17, the wireless communication terminals 18 and 19 (see FIG. 11). 12), it is determined whether or not the data signal is interrupted.

If there are wireless data terminals 18 and 19 of the same rank located around the wireless communication terminal 17 in which the data signal is interrupted (S702 → Yes), the processing of the server 30 proceeds to step S703. In this case, there is a high possibility that the higher rank wireless communication terminal is not relaying.
In step S <b> 703, the server 30 extracts wireless communication terminals that can cover a terminal group that has not reached the signal from the wireless communication terminals 11 to 13 that are one rank higher than the wireless communication terminal 17. In other words, the server 30 has a smaller number of hops to the base station 20 than a wireless communication terminal that has not reached a signal, and a wireless communication terminal that has relayed a signal in the past via the wireless communication terminal that has not reached the signal ( (Candidate terminal on duty). This process is performed by referring to the rank of the terminal management table T (see FIG. 11) and the past transmission route.

In step S704, the server 30 determines the duty terminal from the candidates extracted in step S703. Here, the “duty terminal” is a wireless communication terminal that has been instructed to temporarily perform relaying with the power of the battery 8 (see FIG. 1) among wireless communication terminals that have not been relayed (waiting) until then. is there.
For example, among the candidates extracted in step S703, the server 30 sets the one with the maximum remaining battery power as the duty terminal. That is, the server 30 compares the remaining battery capacity with reference to the terminal management table T (see FIG. 11), and designates the terminal with the maximum remaining battery charge as the duty terminal. A plurality of wireless communication terminals may be designated as duty terminals hierarchically from the upper side.

In step S705, the server 30 transmits a command instruction signal to wait for transfer with the power of the battery 8 to the duty terminal determined in step S704 (for example, the wireless communication terminal 13: see FIG. 12).
The command instruction signal described above is transmitted according to the procedure described in FIG. That is, when the wireless communication terminal 13 that has not been relayed until then transmits data with the power of the battery 8, the command signal (designation of the duty terminal) is included in the reception notification signal from the base station 20.
If the arrival status of the data signal does not improve even after specifying the duty terminal, it is preferable that the server 30 designates another wireless communication terminal as the duty terminal.

On the other hand, in step S702, when there is no data signal interruption among the wireless communication terminals 18 and 19 of the same rank located around the wireless communication terminal 17 (S702 → No), the processing of the server 30 is as follows. The process proceeds to step S706.
In step S706, the server 30 determines whether or not the connection destination of the wireless communication terminal 17 specified in step S701 is included in a transmission route via another wireless communication terminal that is one rank higher. The aforementioned “connection destination” means another wireless communication terminal that has exchanged data with the wireless communication terminal 17 in the past.

  When the connection destination of the wireless communication terminal 17 is included in a transmission route via another wireless communication terminal that is one rank higher (S706 → Yes), the processing of the server 30 proceeds to step S707. In step S707, the server 30 determines whether or not the transmission route specified in step S706 (for example, the wireless communication terminal 18 → the wireless communication terminal 13 → the base station 20) is still used after the data communication of the wireless communication terminal 17 is interrupted. To do.

  When the transmission route specified in step S706 is still used after the data interruption of the wireless communication terminal 17 (S707 → Yes), the processing of the server 30 proceeds to step S708. In this case, since the higher rank wireless communication terminal 13 is normal, there is a high possibility that the wireless communication terminal 17 itself that has not reached the signal has an abnormality. In step S708, the server 30 transmits information indicating that the wireless communication terminal 17 should be checked to the administrator's computer (not shown).

On the other hand, when the connection destination of the wireless communication terminal 17 is not included in the transmission route via another wireless communication terminal (S706 → No), the processing of the server 30 proceeds to step S709. In this case, there is a high possibility that the upper radio communication terminal 13 is not relaying.
In step S <b> 709, the server 30 instructs the wireless communication terminal 13 of higher rank, which is the connection destination of the wireless communication terminal 17, to start relaying. In this case, the wireless communication terminal 13 of the higher rank relays (waits for reception of transfer) with the power of the battery 8 in the same manner as the above-mentioned “turn terminal”.
Further, also when the transmission route specified in step S706 is not used after the data interruption of the wireless communication terminal 17 (S707 → No), the server 30 executes the process of step S709.

<Operation of duty terminal>
FIG. 17 is a flowchart showing the operation of the wireless communication terminal serving as the duty terminal. In the following description, it is assumed that the wireless communication terminal 13 (see FIG. 12) is designated as the duty terminal.
In step S801, the wireless communication terminal 13 determines whether or not the wireless communication terminal 13 is designated as the duty terminal. That is, the wireless communication terminal 13 determines whether or not a command instruction for operating the wireless communication terminal 13 as a duty terminal is included in the reception notification signal (S503: see FIG. 13) when performing periodic data communication. judge.
The reception notification signal described above transmitted a periodic transmission notice signal using the power of the battery 8 in order to transmit data (including the detection value of the sensor 1; see FIG. 2) acquired by the wireless communication terminal 13 itself. At this time (S502: see FIG. 13), it is a signal returned from the base station 20.

If the designated terminal is not designated (S801 → No), the wireless communication terminal 13 repeats the process of step S801. On the other hand, when it is designated as the duty terminal (S801 → Yes), the processing of the wireless communication terminal 13 proceeds to step S802.
In step S802, the wireless communication terminal 13 switches the power supply of the receiving circuit 6 from the power generation element 9a (see FIG. 3) to the battery 8.
In step S803, the wireless communication terminal 13 uses the reception circuit 6 to start waiting for a transmission notice signal (waiting for transfer).

In step S804, the wireless communication terminal 13 determines whether a transmission advance notice signal has been received from another wireless communication terminal. When the transmission notice signal has not been received (S804 → No), the processing of the wireless communication terminal 13 proceeds to step S805.
In step S805, the wireless communication terminal 13 determines whether or not a predetermined time has elapsed since the wireless communication terminal 13 was designated as the duty terminal. If the predetermined time has not elapsed (S805 → No), the process of the wireless communication terminal 13 returns to step S804. On the other hand, when the predetermined time has elapsed (S805 → Yes), the processing of the wireless communication terminal 13 proceeds to step S808.

On the other hand, when the transmission advance notice signal is received in step S804 (S804 → Yes), in step S405, the wireless communication terminal 13 transmits a reception notification signal to the lower rank wireless communication terminal.
Note that it is preferable that the delay time from when the transmission notice signal is received to when the reception notification signal is transmitted is longer than that during normal relay processing (that is, time is earned). This is because there is a possibility that another wireless communication terminal that spontaneously starts relaying with the electric power of the power generation element 9a exists near the wireless communication terminal 13. If the reception notification signal from another wireless communication terminal is delivered to the lower rank wireless communication terminal first, it is not necessary for the wireless communication terminal 13 to perform relaying, and the consumption of the battery 8 can be suppressed.

After transmitting the reception notification signal (S405), if the predetermined time has elapsed without receiving the data signal (S406 → No) (S806 → Yes), the processing of the wireless communication terminal 13 proceeds to step S808.
In step S808, the wireless communication terminal 13 notifies the server 30 that the operation as the duty terminal is finished. As a result, it is possible to avoid waiting for transfer reception unnecessarily for a long time and to suppress the consumption of the battery 8.
In step S809, the wireless communication terminal 13 switches the power supply of the reception circuit 6 from the battery 8 to the power generation element 9a. That is, the wireless communication terminal 13 finishes the role as the duty terminal and stands by.

  The processing in steps S405 to S408 illustrated in FIG. 17 is the same as the relay processing (see FIG. 10) described in the first embodiment, and thus description thereof is omitted. When the wireless communication terminal 13 relays as the duty terminal, the data signal of the wireless communication terminal 17 or the like that has not reached the signal is transmitted to the server 30 via the base station 20.

In step S810, the wireless communication terminal 13 determines whether or not the amount of power generated by the power generation element 9a is equal to or greater than a predetermined value. The above-mentioned “predetermined value” is a threshold value that serves as a criterion for determining whether or not standby for transfer can be continued for a predetermined time.
If the amount of generated power is less than the predetermined value (S810 → No), the processing of the wireless communication terminal 13 returns to step S804. On the other hand, when the generated power amount is equal to or greater than the predetermined value (S810 → Yes), the processing of the wireless communication terminal 13 proceeds to step S811.

  In step S811, the wireless communication terminal 13 switches the power supply of the reception circuit 6 from the battery 8 to the power generation element 9a. In this case, the wireless communication terminal 13 performs a relay process (see FIG. 10) using the power generated by the power generation element 9a.

<Effect>
According to the present embodiment, when there is no wireless communication terminal that can be relayed around the wireless communication terminal 17, the wireless communication terminal 13 (the duty terminal) designated by the server 30 relays using the power of the battery 8. Do. As described above, the data signal from each wireless communication terminal is periodically transmitted by temporarily using the wireless communication terminal 13 that has not been relayed until then (the power generation amount of the power generation element 9a is not sufficient). Can be obtained.

In addition, when there are a plurality of wireless communication terminals that are candidates for the duty terminal, the server 30 designates the one with the largest remaining battery charge as the duty terminal. As a result, the battery remaining amount of the wireless communication terminals 11 to 19 is promoted to be uniform.
Further, the server 30 determines whether or not there is a high possibility that the wireless communication terminal 17 in which the scheduled data communication is interrupted is broken by checking the past transmission route. Thereby, the administrator of the wireless communication system S can easily grasp the wireless communication terminal to be repaired or replaced.

<< Fourth Embodiment >>
The fourth embodiment is different from the first embodiment in that all operations related to relaying are performed by the power of the power generation circuit 9, but the other points are the same as in the first embodiment. Therefore, a different part from 1st Embodiment is demonstrated and description is abbreviate | omitted about the overlapping part.
In addition, although illustration is abbreviate | omitted, in this embodiment, the electric power generation circuit 9 (refer FIG. 2) of the radio | wireless communication terminals 11-19 is connected to the transmission circuit 4 while being connected to the receiving circuit 6. FIG. That is, power can be supplied from the power generation circuit 9 to the transmission circuit 4 in response to a command from the control unit 2.

  FIG. 18 is a flowchart showing an operation of relay processing by the wireless communication terminal. In the flowchart shown in FIG. 18, the processing of steps S <b> 404 and S <b> 411 (power supply switching of the receiving circuit 6) is omitted from the flowchart of the relay processing (see FIG. 10), and the power source used for the relay processing is all the power generation circuit 9. Below, the case where a relay process is performed by the radio | wireless communication terminal 13 (refer FIG. 12) is demonstrated as an example.

If the amount of power generated by the power generation element 9a is greater than or equal to a predetermined value in step S401 (S401 → Yes), the wireless communication terminal 13 starts waiting for transfer with the power from the power generation circuit 9 in step S402a. Note that the power of the battery 8 is not supplied to the receiving circuit 6 while waiting for transfer.
When a transmission advance notice signal is received in step S403 (S403 → Yes), the wireless communication terminal 13 transmits a reception notification signal with power from the power generation circuit 9 in step S405a.

When the data signal is received in step S406 (S406 → Yes), the wireless communication terminal 13 transmits the Ack signal with the power from the power generation circuit 9 (S407a), and further transmits the data signal with the power from the power generation circuit 9. Transfer (S408a). After transferring the data signal, the processing of the wireless communication terminal 13 returns to START (RETURN) and waits until the power necessary for the relay processing is obtained from the power generation circuit 9.
When data to be transmitted occurs during standby, the wireless communication terminal 13 stops standby and transmits a data signal using the power of the battery 8.

<Effect>
According to this embodiment, not only waiting for transfer when relay processing is performed, but also transmission of a reception notification signal, transmission of an Ack signal, and transfer of a data signal performed thereafter are performed by the power of the power generation circuit 9. Thus, since the power of the power generation circuit 9 is used for a series of relay processes, the power consumption of the battery 8 can be further reduced as compared with the first embodiment.

≪Modification≫
As described above, the wireless communication system S according to the present invention has been described by each embodiment. However, the present invention is not limited to these descriptions, and various modifications can be made.
For example, although each embodiment demonstrated the case where the electric power generation element 9a was a solar cell, it is not restricted to this. That is, a vibration power generation element that converts energy associated with vibration (change in pressure) into electrical energy may be used as the power generation element 9a. The vibration power generation element has, for example, a plate shape in which piezoelectric elements are spread, and is installed in a device such as a motor.

Further, as the power generation element 9a, a thermoelectric element that obtains electric power from a temperature difference between devices may be used. The thermoelectric element is formed by joining two kinds of metals (or a p-type semiconductor and an n-type semiconductor), and generates an electromotive force with a temperature difference (Seebeck effect). For example, the thermoelectric element is installed in a server that is a heating element, or installed in a pipe through which high-temperature water flows.
Moreover, you may comprise the electric power generation element 9a by combining two types or three types among the above-mentioned solar cell, a vibration electric power generation element, and a thermoelectric element (it connects in parallel).

  Moreover, although each embodiment demonstrated the case where the radio | wireless communications system S was used as a sensor network system which manages the operating condition of an apparatus based on the detected value of the sensor 1 (refer FIG. 2), it is not restricted to this. For example, you may use the radio | wireless communications system S as an energy management system which measures the power consumption of an apparatus and controls the output. As an example of the energy management system, it is conceivable to measure the power consumption of a plurality of air conditioners and change the set temperature or the like according to the measurement result.

  In the third embodiment, the case where the data signal from the rank-2 wireless communication terminal 17 (see FIG. 12) does not reach the server 30 has been described. However, the present invention is not limited to this. That is, for wireless communication terminals of rank 3 or higher, one or a plurality of higher-ranked wireless communication terminals (candidate terminal terminals: S703) that can cover a terminal group that has not reached a signal can be extracted by examining past transmission routes. .

  Further, for example, the third embodiment and the fourth embodiment may be combined. That is, when there is a radio communication terminal that has not reached the signal (S702: see FIG. 16), a radio communication terminal different from the radio communication terminal that has not reached the signal is designated as the duty terminal (S704: see FIG. 16). The relay processing may be performed with the power of the battery 8 by the duty terminal. When the power generation amount of the power generation element 9a becomes equal to or greater than a predetermined value (S810 → Yes: see FIG. 17), the wireless communication terminal that was the duty terminal until then uses a series of relays using the power generation power of the power generation element 9a. Processing is performed (see FIG. 18).

  Each of the configurations shown in FIGS. 2 and 3 may be realized by hardware by designing a part or all of them with, for example, an integrated circuit. In addition, each of the above-described configurations may be realized by software by interpreting and executing a program that realizes each function by the processor. Information such as programs, tapes, and files that realize each function can be stored in a recording device such as a memory, a hard disk, or an SSD (Solid State Drive), or a recording medium such as an IC card, an SD card, or a DVD. .

  Further, the control lines and information lines indicate what is considered necessary for the explanation, and not all the control lines and information lines on the product are necessarily shown. Actually, it may be considered that almost all the components are connected to each other.

S wireless communication system 11, 12, 13, 14, 15, 16, 17, 18, 19 wireless communication terminal 1 sensor 2 control unit 4 transmission circuit 6 reception circuit 8 battery 9 power generation circuit 9a power generation element (solar cell, vibration power generation element) , Thermoelectric generator)
9b Booster 9c Capacitor (storage element)
9d Power supply control unit (control unit)
20 base station 30 server N network T terminal management table

Claims (10)

A plurality of wireless communication terminals that perform ad hoc wireless communication, a base station that directly or indirectly performs wireless communication with the plurality of wireless communication terminals, and a signal that is transmitted from the plurality of wireless communication terminals via the base station And a server to
Each of the plurality of wireless communication terminals includes a reception circuit that receives a signal, a transmission circuit that transmits a signal, a power generation circuit connected to at least the reception circuit, and a control unit,
The power generation circuit includes a power generation element and a power storage element that stores power generated by the power generation element,
The control unit drives the reception circuit by supplying power from the power generation circuit and waits for a signal from another wireless communication terminal when the storage amount of the power storage element is equal to or greater than a predetermined value. Wireless communication system. The power generation circuit is also connected to the transmission circuit,
The control unit drives the transmission circuit by power supply from the power generation circuit, and transfers a signal received by the standby of the reception circuit to another wireless communication terminal by the transmission circuit. The wireless communication system according to claim 1. The server, when there is a wireless communication terminal that has not reached the signal within a predetermined period, among the plurality of wireless communication terminals that are signal sources, the wireless communication that has not reached the signal A wireless communication terminal different from the terminal is designated as a duty terminal to be temporarily relayed, and a command instruction for relaying with battery power is transmitted to the duty terminal,
The wireless communication system according to claim 1, wherein the duty terminal that has received the command instruction performs the relay with battery power. The server has a less number of hops to the base station than a wireless communication terminal that has not reached the signal, and a wireless communication terminal that has relayed a signal in the past via the wireless communication terminal that has not reached the signal. The radio communication system according to claim 3, wherein a radio communication terminal having the maximum remaining battery power among the candidates is designated as the duty terminal. Wireless communication is performed directly or indirectly by ad hoc wireless communication with a base station connected to a server, and a reception circuit that receives a signal, a transmission circuit that transmits a signal, and a connection to at least the reception circuit A power generation circuit and a control unit,
The power generation circuit includes a power generation element and a power storage element that stores power generated by the power generation element,
The control unit drives the reception circuit by supplying power from the power generation circuit and waits for a signal from another wireless communication terminal when the storage amount of the power storage element is equal to or greater than a predetermined value. Wireless communication terminal. The power generation circuit is also connected to the transmission circuit,
The controller is
6. The transmission circuit is driven by power supply from the power generation circuit, and a signal received by the standby of the reception circuit is transferred to another wireless communication terminal by the transmission circuit. Wireless communication terminal. The wireless communication terminal according to claim 5 or 6, wherein the power generation element is any one of a solar battery, a vibration power generation element, and a thermoelectric generation element. The wireless communication terminal according to claim 5, wherein the power generation element is a combination of a plurality of types among a solar cell, a vibration power generation element, and a thermoelectric generation element. A wireless communication method executed by a wireless communication terminal that performs direct or indirect wireless communication by ad hoc wireless communication with a base station connected to a server,
The wireless communication terminal includes a reception circuit that receives a signal, a transmission circuit that transmits a signal, a power generation circuit connected to at least the reception circuit, and a control unit.
The power generation circuit includes a power generation element and a power storage element that stores power generated by the power generation element,
The control unit drives the reception circuit by supplying power from the power generation circuit and waits for a signal from another wireless communication terminal when the storage amount of the power storage element is equal to or greater than a predetermined value. Wireless communication method.   A wireless communication program for causing the wireless communication terminal, which is a computer, to execute the wireless communication method according to claim 9.

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