Communication device, communication method, program, and communication system

Abstract

To reduce the amount of data for transmitting data indicating time.SOLUTION: A communication device includes an acquisition control unit and a communication control unit. The acquisition control unit acquires output data output from one or more electronic apparatuses from the electronic apparatuses. The communication control unit communicates with a server device by a communication method that synchronizes numbers indicating communication timing, and transmits output data associated with a first number indicating timing at which the output data was acquired among the numbers to the server device as a destination.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] Embodiments of the present invention relate to a communication device, a communication method, a program, and a communication system.

Background Art

[0002] A communication system has been proposed that collects sensor data acquired by sensors connected to each communication device from a plurality of communication devices (nodes) on a network. The sensor data may be collected via a data logger that records the sensor data acquired from the connected sensors.

[0003] The sensor data is managed in association with the acquired time. For example, the communication device can be configured to acquire the sensing time from the data logger, or determine the time when data is acquired from the data logger using the clock in the device itself, and associate the acquired or determined time with the sensor data and transmit it to the wireless network.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the above-described technology, there is a problem that the amount of data required for transmission increases because the data itself indicating the time is transmitted.

Means for Solving the Problems

[0006] The communication device according to the embodiment includes an acquisition control unit and a communication control unit. The acquisition control unit acquires output data output from one or more electronic devices from the electronic devices. The communication control unit communicates with the server device by a communication method that synchronizes numbers indicating communication timings, and transmits the output data associated with a first number indicating the timing at which the output data was acquired among the numbers to the server device as the destination.

Brief Description of the Drawings

[0007]

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Embodiments for Carrying Out the Invention

[0008] With reference to the accompanying drawings below, preferred embodiments of a communication device, a communication method, a program, and a communication system according to the present invention will be described in detail.

[0009] As described above, in the technique of transmitting while associating time with sensor data, there has been a problem of an increase in data volume. Further, for example, since the time managed by the data logger may deviate, the sensing time notified by the data logger may be inaccurate. It is possible to configure the data logger to correct the time based on the reception function of GPS (Global Positioning System). However, with such a configuration, the function becomes complicated and the power consumption may increase.

[0010] The communication system according to the present embodiment communicates with a server device (collection device) by a communication method that synchronizes numbers indicating communication timings, and uses the number when sensor data is acquired among the numbers indicating communication timings instead of the time when the sensor data is generated.

[0011] Hereinafter, an example of a communication system that collects sensor data (an example of output data) output from a data logger (an example of an electronic device) will be mainly described. The applicable communication system is not limited to this, and the electronic device and the output data may be any device and data. For example, the communication system may be configured to collect sensor data output from a sensor (an example of an electronic device) without passing through a data logger. Also, for example, the following output data may be used. · Voltage data indicating the voltage of a battery built in or connected to an electronic device · Latitude data and longitude data obtained by a GPS reception function of an electronic device · Warning data indicating that the variation of a certain data (sensor data) has become large

[0012] FIG. 1 is a diagram showing a configuration example of the communication system of the present embodiment. As shown in FIG. 1, the communication system of the present embodiment includes a concentrator 200 (an example of a server device) and a plurality of nodes 1001 to 100 13 (an example of a communication device).

[0013] The plurality of nodes 1001 to 100 13 each transmit sensor data acquired by a sensor (or a built-in sensor) connected via a data logger to the concentrator 200. Since the plurality of nodes 1001 to 100 13 can have the same configuration, they may simply be referred to as nodes 100 when there is no need to distinguish them. The number of nodes 100 is not limited to 13 and may be any number.

[0014] The concentrator 200 is a device (aggregation device) that aggregates sensor data transmitted from each of the plurality of nodes 100.

[0015] The concentrator 200 and the nodes 1001 to 100 13 constitute a wireless multi-hop network. Communication within the wireless multi-hop network is controlled, for example, by a time-division multiplexing method. The wireless communication method may be any method, and for example, wireless communication methods such as IEEE 802.11 and IEEE 802.15.4 can be applied.

[0016] In addition to the wireless multi-hop network, the concentrator 200 may be connected to a network 300. The network 300 may be in any network form, and for example, it may be a wide-area network such as the Internet, a wide-area closed network, or a local network such as an enterprise internal network.

[0017] The connection between the concentrator 200 and the network 300 may be a wired connection using an Ethernet (registered trademark) cable, an optical fiber, or the like, or a wireless connection using a mobile phone network or a satellite line. The connection to the network 300 is not essential, and the communication system may be configured with only the wireless multi-hop network composed of the concentrator 200 and the nodes 1001 to 100 13 and the communication system may be configured with only the wireless multi-hop network composed of the concentrator 200 and the nodes 1001 to 100

[0018] Note that the network 300 may be connected to, for example, a server device that collects sensor data from a plurality of concentrators 200 and executes processing using the collected sensor data.

[0019] Here, an outline of the sensor data collection process by the communication system of the present embodiment will be described.

[0020] A data logger is connected to the node 100. A sensor is further connected to the data logger. The node 100 obtains new sensor data from the data logger by a method such as polling. At this time, the node 100 obtains the sensor data itself and the data of the sensing time of the sensor data. The sensing time is, for example, the time when the sensor data is recorded in the data logger, but is not limited thereto. For example, when preheating of the sensor is performed, the sensing time may be the time when the preheating is started. Preheating is, for example, a process of warming the sensor for a certain period of time while supplying power to the sensor before obtaining data from the sensor. For example, assume that the start of preheating is 10:00:00, the completion of preheating is 10:00:20, and the time when the sensor data is recorded in the data logger is 10:00:20. In this case, 10:00:00 is recorded in the data logger as the sensing time.

[0021] Node 100 needs to wirelessly transmit data corresponding to these two pieces of data (sensor data, sensing time), but it is desirable to reduce the amount of data as much as possible. For example, it is desirable to reduce the amount of data indicating the sensing time. Note that hereinafter, data in a format representing the time used in daily life (real time described later), such as "2021 / 08 / 23 11:30:00.000", may be referred to as time data in some cases.

[0022] Instead of time data, the node 100 of this embodiment transmits, as data indicating the sensing time, a number (a number indicating communication timing) that is already used in the wireless multi-hop network to realize time-division multiplexing communication.

[0023] As the time-division multiplexing method, for example, TSCH (Time-Slotted Channel Hopping) can be applied. The number indicating the communication timing is, for example, a time slot number (ASN: Absolute Slot Number), a slot frame number, and a superframe number.

[0024] For example, node 100 polls the data logger at the start of each time slot to check whether new sensor data has been obtained. If new data exists, node 100 wirelessly transmits the obtained sensor data together with the current time slot number.

[0025] Also, when relaying sensor data transmitted from another node 100 (an example of an external communication device) to the concentrator 200, node 100 may transmit the sensor data with the same time slot number together. Specifically, the time slot number is put only once in the message transmitted wirelessly, and a message associating a plurality of sensor data with that time slot number is generated. Thereby, the amount of data to be transmitted can be further reduced.

[0026] If the time of the data logger is significantly off for some reason, in a configuration where the time data is transmitted as is, the correct time when the sensor data was recorded may become unclear. If, like in this embodiment, the configuration is such that the time slot number is transmitted as data representing the sensing time, then by converting the received time slot number into time, the correct time when the sensor data was recorded can be known.

[0027] For example, assume that the data logger is set to perform sensing at every hour on the hour and at 30 minutes past the hour, and record the sensing data in a storage medium (hereinafter, internal memory) provided inside. Even if the time managed by the data logger is off by 2 minutes and it is actually sensing at 2 minutes past the hour and 32 minutes past the hour, the data logger cannot know that the time is off. Therefore, the data logger transmits time data indicating every hour on the hour or 30 minutes past the hour in association with the sensor data. The device that receives the sensor data associated with the time data indicating every hour on the hour or 30 minutes past the hour cannot know that the actual sensing time is 2 minutes past the hour or 32 minutes past the hour.

[0028] On the other hand, according to this embodiment, a number indicating the communication timing by the communication method used in the wireless multi-hop network is transmitted instead of the time data. Therefore, if the polling interval (an example of a specified time interval), or the time interval represented by the number indicating the communication timing (for example, the time slot length) is appropriately set, the error between the time corresponding to the number and the actual sensing time can be minimized. For example, when the polling interval or the time interval represented by the number indicating the communication timing is 30 seconds, the error of the transmitted sensing time with respect to the actual sensing time can be within 30 seconds.

[0029] Next, an example of the functional configuration of the concentrator 200 will be described. FIG. 2 is a block diagram showing an example of the functional configuration of the concentrator 200. As shown in FIG. 2, the concentrator 200 includes a time management unit 201, a communication control unit 202, communication units 211, 212, and a storage unit 221.

[0030] The storage unit 221 stores various data used in the concentrator 200. For example, the storage unit 221 stores sensor data transmitted from each node 100 and data to be sent to each node, such as control information. When storing and managing sensor data in an external storage device or the like outside the concentrator 200, the storage unit 221 may not be provided.

[0031] The storage unit 221 can be configured by any generally used storage medium such as a flash memory, a memory card, a RAM (Random Access Memory), an HDD (Hard Disk Drive), and an optical disk.

[0032] The communication unit 211 communicates with each node 100 to form a wireless multi-hop network. Since the wireless multi-hop network is communication-controlled in a time-division multiplexing system as described above, the communication unit 211 operates by switching processing for each time slot. That is, in a time slot in which it can transmit data, the communication unit 211 performs transmission processing, and in a time slot in which it should wait for data reception, the communication unit 211 performs reception processing. If there is no data to be transmitted even though it is a time slot in which it can transmit data, and if it is a time slot in which neither transmission nor reception is possible, the communication unit 211 does not perform any operation. In a time slot in which neither transmission processing nor reception processing is performed, the communication unit 211 can transition to an ultra-low power consumption mode, a power-off mode, etc., and stop operating. During a period in which the communication unit 211 does not perform any operation, the entire concentrator 200 may also operate in an ultra-low power consumption mode.

[0033] The communication unit 212 is used for communication with the network 300. When not connected to the network 300, the communication unit 212 may not be provided.

[0034] The time management unit 201 manages the current time in real time. The real time means the time used in daily life with 24 hours in a day. The time management unit 201 may obtain the current time by any means, for example, the following means can be applied. · Obtain the current time information from the time server on the network 300. · Use GPS to obtain the current time information. · Obtain the current time information from the base station of the mobile phone. · Manually input the current time by a person.

[0035] The time management unit 201 obtains the current time information at an appropriate frequency according to the accuracy of the crystal oscillator (clock) of the concentrator 200, and it is assumed that the current time can always be held within an error range that is not a problem in practice during the operations described later.

[0036] For example, immediately after factory shipment and immediately after power-on, the concentrator 200 may not have an accurate current time, but it is assumed that the time management unit 201 can recognize that it is in such a state without the current time. While it does not have the current time information, the concentrator 200 does not perform the operations described later. For example, when it obtains the current time information, it is assumed that the concentrator 200 starts the operations described later. Once it has obtained the current time information, the concentrator 200 may continue to obtain the current time information at a predetermined timing (such as after a certain period of time) or may not obtain it. When continuing to obtain the current time information at a predetermined timing and if the acquisition fails, the concentrator 200 may operate in the state of "not having the current time information" or may continue to operate in the state of "having the time information".

[0037] The communication control unit 202 controls the communication between the node 100 and the network 300. For example, the communication control unit 202 switches the operation of the communication unit 211 as described above according to the schedule of the time-division multiplexing system. In addition, the communication control unit 202 constructs and maintains a wireless multi-hop network, and performs reception and transfer processing of sensor data transmitted via the wireless multi-hop network. When the concentrator 200 is connected to the network 300, the communication control unit 202 may or may not transfer the sensor data received via the communication unit 212 to the network 300. In addition, the communication control unit 202 may or may not store the sensor data in the storage unit 221. Further, the communication control unit 202 may or may not transfer the sensor data stored in the storage unit 221 to the network 300. In addition, the communication control unit 202 performs transmission processing of control information to the node 100 and the like.

[0038] FIG. 3 is a diagram showing an example of the data structure of the sensor data stored in the storage unit 221. The sensor data is stored in association with a node identifier and a generation time. The node identifier is an example of identification information for identifying the node 100 that is the transmission source of the sensor data. The generation time is the time when the sensor data is acquired (generated).

[0039] In addition to the value (read value) acquired from the sensor, the sensor data is transmitted to the concentrator 200 together with a number (for example, a time slot number) indicating the communication timing when the value is acquired. The concentrator 200 calculates the corresponding real time from the time slot number included in the sensor data using the time management unit 201 and the communication control unit 202. By such processing, the sensor data can be managed together with the generation time. The concentrator 200 may treat the time slot number as the generation time as it is without converting the generation time into the real time. In addition, the time when the concentrator 200 receives each sensor data can also be managed in the same way, but the associated reception time may or may not be recorded in the storage unit 221.

[0040] Each of the above units (the time management unit 201 and the communication control unit 202) is realized by, for example, one or more processors. For example, each of the above units may be realized by causing a processor such as a CPU (Central Processing Unit) to execute a program, that is, by software. Each of the above units may be realized by a processor such as a dedicated IC (Integrated Circuit), that is, by hardware. Each of the above units may be realized by using software and hardware in combination. When using a plurality of processors, each processor may realize one of the units, or may realize two or more of the units.

[0041] Here, an example of communication control of the time-division multiplexing method by the communication control unit 202 will be described. FIG. 4 is a diagram showing the relationship between real time and time slots of the time-division multiplexing method. As shown in FIG. 4, it is assumed that the concentrator 200 starts a wireless multi-hop network at 19:38:15. One time slot has a length of 250 milliseconds, and four time slots are used as a time-division multiplexing schedule unit 401. That is, after 19:38:15, if the schedule does not change, the same communication schedule is repeated every second. A, B, C, and D represent four schedules executed every second.

[0042] Each time slot is assigned a time slot number. In the example of FIG. 4, if the time slot number of the time slot immediately after the concentrator 200 starts the wireless multi-hop network is an integer n, the time slot number n + 5 is assigned to the sixth time slot 402 from the beginning. For example, if the time slot number n of the first time slot (the time slot corresponding to A at the left end in FIG. 4) is 0, the time slot number of the time slot 402 is 5. Basically, the time slot number increases monotonically. When there is an upper limit value of the time slot number, after reaching the upper limit value, the time slot number returns to 0 and increases monotonically again.

[0043] Such a time-division multiplexed communication schedule and time slot number are managed by the communication control unit 202 of the concentrator 200. By obtaining the current time from the time management unit 201, the communication control unit 202 can establish the correspondence between the real time and the time slot number. In the example of FIG. 4, the communication control unit 202 can determine that the time slot 403 with the time slot number n + 8 starts at 19:38:17.

[0044] Next, the configuration of the node 100 will be described. FIG. 5 is a block diagram showing an example of the functional configuration of the node 100. As shown in FIG. 5, the node 100 includes a data logger control unit 101 (an example of an acquisition control unit), a communication control unit 110, a communication unit 121, and one or more data logger interfaces 1221 to 122 m (where m is an integer of 1 or more).

[0045] Each of the data logger interfaces 1221 to 122 m is connected to the data loggers 1311 to 131 m respectively. A plurality of sensors 1411 to 141 m are connected to the data loggers 1311 to 131 m2 respectively.

[0046] When there is no need to distinguish, the data logger interfaces 1221 to 122 m are simply referred to as the data logger interface 122. Similarly, when there is no need to distinguish, the data loggers 1311 to 131 m are simply referred to as the data logger 131. Similarly, when there is no need to distinguish, the sensors 1411 to 141 m2 are simply referred to as the sensor 141.

[0047] The sensor 141 is an electronic device that outputs the detection result of a predetermined physical quantity as sensor data. The physical quantity to be detected can be any physical quantity. The data logger 131 operates as an electronic device that records the sensor data detected by the sensor 141 in a storage medium (internal memory).

[0048] One or more sensors 141 are connected to each of the data loggers 131. In FIG. 5, one sensor 141 (sensor 1411, sensor 1412) is connected to each of the data loggers 1311 and 1312, and two sensors 141 m are connected to the data logger 131 m1 , 141 m2 are shown as an example, but it is not limited to this.

[0049] The communication unit 121 performs the same operation as the communication unit 211 of the concentrator 200.

[0050] The communication control unit 110 switches the operation of the communication unit 121 according to a time-division multiplexed communication schedule in the same manner as the communication control unit 202 of the concentrator 200. Further, the communication control unit 110 discovers and connects to a wireless multi-hop network started by the concentrator 200, and sets and changes a communication path and a communication schedule. The communication control unit 110 transmits and receives a control frame including a beacon to and from other nodes 100 via the communication unit 121 for these operations.

[0051] In addition, the communication control unit 110 controls communication with other nodes 100 constituting the wireless multi-hop network. For example, the communication control unit 110 receives sensor data acquired by other nodes 100 from other nodes 100. Further, the communication control unit 110 manages data to be transmitted to other nodes 100 or the concentrator 200 and generates a transmission message. For example, when the communication control unit 110 acquires sensor data, it transmits the sensor data associated with the time slot number (an example of the first number indicating the timing at which the data was acquired) to the concentrator 200 as the destination.

[0052] Nodes 100 other than the nodes 100 (nodes 1001 to 1004 in FIG. 1) directly connected to the concentrator 200 transmit sensor data to the concentrator 200 via other nodes 100 that serve as relay devices for relaying communication with the concentrator 200.

[0053] The data logger control unit 101 functions as an acquisition control unit that acquires sensor data output from the data logger 131. For example, the data logger control unit 101 reads the number of the latest sensor data recorded in the internal memory of the data logger 131 or the latest sensor data itself via the data logger interface 122. This process is called polling.

[0054] For example, when recording sensor data in the internal memory, the data logger 131 may record the sensor data by assigning a number as information for identifying the sensor data. FIG. 6 is a diagram showing an example of a recording method of sensor data recorded by assigning a number in this way. FIG. 6 shows an example in which N (N is an integer of 1 or more) sensors 141 are connected to a certain data logger 131, and sensor data SN is acquired from each sensor 141. Each time the data logger 131 obtains sensor data, it obtains a number obtained by adding 1, assigns the obtained number to the sensor data, and records it in the internal memory.

[0055] An upper limit value may be set for the number, and when the value obtained by adding 1 reaches the upper limit value, the existing number may be overwritten thereafter. For example, after reaching the upper limit value, the number may be overwritten by returning to 1 which is the initial value. The number may be overwritten so as to be a value obtained by subtracting 1 from the upper limit value toward 1 which is the initial value.

[0056] The data logger 131 manages the number of the latest sensor data in this way, and may be configured to notify the number in response to a request from the outside.

[0057] The data structure in FIG. 6 is an example, and other information may be further recorded. For example, information such as the generation time (year, month, and day) may be further recorded. When a GPS is connected, for example, position information obtained by the GPS may be further recorded.

[0058] The data logger control unit 101 may set a polling interval for each data logger interface 122, and perform polling at the set polling interval via the corresponding data logger interface 122. The data logger control unit 101 may perform polling in response to an instruction from the concentrator 200. The polling interval may be changed during operation. When so-called preliminary power-on or preheating is required to acquire sensor data, the data logger control unit 101 starts the preliminary power-on in advance by calculating backward from the time slot for acquiring sensor data. The preliminary power-on and preheating may be controlled by the data logger 131 itself. Also, the preliminary power-on and preheating do not necessarily have to start at the time calculated backward from the time slot for acquiring sensor data. For example, the preliminary power-on and preheating may be started from the time slot for acquiring sensor data.

[0059] Returning to FIG. 5, the data logger interface 122 can communicate with the data logger 131 in accordance with a request from the data logger control unit 101 to acquire data such as sensor data, or can perform settings for the data logger 131. For example, at the time of polling, the data logger interface 122 acquires the number of the latest sensor data recorded in the internal memory of the data logger 131, or the latest sensor data itself.

[0060] Each of the above units (data logger control unit 101, communication control unit 110) is realized by, for example, one or a plurality of processors. For example, each of the above units may be realized by causing a processor such as a CPU to execute a program, that is, by software. Each of the above units may be realized by a processor such as a dedicated IC, that is, by hardware. Each of the above units may be realized by using a combination of software and hardware. When using a plurality of processors, each processor may realize one of the units, or may realize two or more of the units.

[0061] Next, the details of polling will be described. FIG. 7 is a diagram for explaining an example of polling.

[0062] Node 100 (data logger control unit 101) performs polling at each polling interval to check whether new sensor data has been recorded in data logger 131. In the example of FIG. 7, data logger control unit 101 performs polling on data logger 131 every 240 time slots (assuming the length of a time slot is 250 milliseconds) and requests the number of the latest sensor data from data logger 131. For example, the latest number obtained is 10 until before 13:00, but the latest number obtained is 11 between 13:00 and 13:10.

[0063] When the number of the sensor data obtained from data logger 131 is different from the previously acquired number, node 100 can determine that new sensor data has been recorded (generated) in data logger 131. When it is determined that new sensor data has been generated, node 100 (data logger control unit 101) further requests the sensor data corresponding to the obtained number from data logger 131. Node 100 transmits the obtained sensor data to concentrator 200 with the current time slot number as the destination.

[0064] The method for determining whether new sensor data has been generated is not limited to this. For example, data logger control unit 101 may apply a determination method using the generation time associated with the sensor data. For example, data logger control unit 101 requests the latest sensor data from data logger 131. When the generation time associated with the latest sensor data obtained from data logger 131 is different from the generation time of the previously acquired sensor data, node 100 determines that new sensor data has been generated. When the change in the physical quantity to be measured is small, a determination method using the change in the measured physical quantity may be applied. For example, data logger control unit 101 requests the latest sensor data from data logger 131. When the latest measured physical quantity obtained from data logger 131 is different from the previously acquired measured physical quantity, node 100 determines that new sensor data has been generated. Thereby, the number of transmissions can be suppressed to the minimum necessary.

[0065] Note that, for example, at the first polling after Node 100 is activated, Node 100 may or may not send sensor data to the concentrator 200.

[0066] As described above, Node 100 may send a plurality of pieces of sensor data to the concentrator 200 in a lump. That is, the communication control unit 110 sends the sensor data received from other Node 100s and the sensor data generated by itself to the concentrator 200 in a lump. Specifically, the communication control unit 110 associates a plurality of pieces of sensor data having the same time slot number among the sensor data received from other Node 100s and the sensor data acquired from the data logger 131 with the time slot number (the same time slot number), and sends them to the concentrator 200 as the destination.

[0067] FIG. 8 is a diagram for explaining an example of the process of sending sensor data in a lump. FIG. 8 is an example in which Node 1003 sends the sensor data received from 1007 and 100 12 to the concentrator 200 in a lump.

[0068] Node 1003 relays the sensor data received from Node 1007 and Node 100 12 and sends it to the concentrator 200. If the time data itself is notified as the generation time of the sensor data, it is conceivable that the times of the sensor data generated by Node 1007 and Node 100 12 are slightly different. In such a case, since Node 1003 cannot lump the received sensor data, it sends the generation time corresponding to each piece of sensor data to the concentrator 200.

[0069] On the other hand, in the configuration using the time slot number as the data indicating the generation time as in the present embodiment, between Node 1007 and Node 100 12Even if the generation times of the sensor data are slightly different, the same time slot number may be associated. In such a case, node 1003 can notify the concentrator 200 of the generation time by simply including in the transmission message the time slot number corresponding to the generation time of the sensor data of node 1007 and node 100 12 This makes it possible to reduce the data volume of the transmission message.

[0070] Note that the communication control unit 110 may group all the sensor data with the same time slot number into one, or may further divide and group them into a plurality of groups. For example, the communication control unit 110 may group the sensor data obtained from the same data logger interface 122 among the sensor data with the same time slot number. The communication control unit 110 may group the sensor data obtained from the same type of sensor 141 among the sensor data with the same time slot number. The communication control unit 110 may group the preset sensor data among the sensor data with the same time slot number.

[0071] Each data logger 131 may be managed such that the connected sensors 141 are identified according to a common rule. For example, for a plurality of data loggers 131, the same identification information such as IF1, IF2,... may be assigned to one or more interfaces (including virtual interfaces) connecting one or more sensors 141. In such a case, the communication control unit 110 may group the sensor data obtained from the sensors 141 corresponding to the interfaces assigned the same identification information.

[0072] Even if the sensor data transmitted from a plurality of other nodes 100 are associated with the same time slot number, they may be received at different timings. Considering such a case, the communication control unit 110 may not immediately transmit the received sensor data to the concentrator 200, but may wait for a certain period of time and transmit the sensor data in a grouped manner as much as possible.

[0073] By collecting and transmitting as much sensor data as possible in the manner described above, it becomes possible to reduce the data volume of the transmission message and improve the battery life by increasing the sleep time (time in the power-saving mode) of the node 100 by reducing the number of transmissions.

[0074] Although not shown in FIG. 8, identification information for identifying the sensor data is attached to each sensor data. This identification information is individually set by each node 100, for example. The identification information may be information that can identify from which sensor 141 of which node 100 the data was obtained.

[0075] Next, the data acquisition process by the node 100 according to this embodiment configured as described above will be described. FIG. 9 is a flowchart showing an example of the data acquisition process in this embodiment.

[0076] The data logger control unit 101 acquires the number of the latest sensor data from each data logger 131, for example, when the polling timing arrives (step S101). The data logger control unit 101 determines whether new sensor data has been generated, for example, based on whether the acquired number is different from the number acquired last time (step S102).

[0077] When it is determined that new sensor data has been generated (step S102: Yes), the data logger control unit 101 acquires the sensor data corresponding to the acquired number from each data logger 131 (step S103). Note that the determination of whether new sensor data has been generated and the acquisition of new sensor data are executed for each data logger 131.

[0078] The communication control unit 110 generates a transmission message in which the time slot number at which the sensor data was acquired is associated with the acquired sensor data, and transmits the transmission message to the concentrator 200 as the destination (step S104).

[0079] The communication control unit 110 may transmit a transmission message that directly contains the acquired sensor data, or may change the format of the sensor data before transmission. For example, the sensor data may be transmitted after being converted to offset binary. To reduce the amount of data, only a part of the sensor data may be transmitted. For example, if the acquired sensor data is represented by a count value that increases by one each time, only a predetermined number of lower digits of the sensor data may be transmitted.

[0080] As described above, the communication control unit 110 may generate and transmit a transmission message that combines a plurality of sensor data. Also, when receiving a transmission message relayed from another node 100 to the concentrator 200, the communication control unit 110 may transmit the sensor data included in the transmission message received from the other node 100 together with the sensor data acquired in step S103.

[0081] After transmitting the sensor data, or when no new sensor data has been generated (step S102: No), the data acquisition process ends.

[0082] As described above, according to this embodiment, each node 100 can notify the concentrator 200 of the generation time of the sensor data by transmitting the time slot number corresponding to the time instead of transmitting the time data itself. Thereby, it is possible to transmit data indicating the time with a smaller amount of data than transmitting the time data itself. Since the node 100 can reduce the time required for wireless transmission and increase the sleep time, it is possible to suppress power consumption.

[0083] (Modification 1) The communication system may include a relay node (relay device). The relay node is a node that has a function of relaying (transferring) the sensor data transmitted from another node 100. The relay node may not include some or all of the functions (data logger interface 122, data logger control unit 101) for acquiring sensor data among the respective components of the node 100 in FIG. 5, for example.

[0084] The node 100 configured as shown in FIG. 5 may operate as a relay node. For example, the node 100 may operate as a relay node when it detects that the data logger 131 is not connected at startup. Also, the node 100 may operate as a relay node when the operation mode is set in advance to operate as a relay node.

[0085] (Modification Example 2) The node 100 (data logger control unit 101) may perform polling only near the timing when the data logger 131 records sensor data in the internal memory. That is, the data logger control unit 101 may set the polling interval according to the interval at which the data logger 131 records sensor data in the internal memory. FIG. 10 is a diagram for explaining an example of polling by the node 100 of Modification Example 2 configured as described above.

[0086] For example, when the data logger 131 records sensor data in the internal memory every 10 minutes, the data logger control unit 101 performs polling only near this recording timing. Thereby, the sleep time of the node 100 and the data logger 131 can be increased, and the power consumption can be further reduced. The interval at which the data logger 131 records sensor data in the internal memory is, for example, set in advance in the node 100.

[0087] The data logger control unit 101 may be configured to learn the interval (timing) at which the data logger 131 records sensor data in the internal memory, for example, using information on the timing when new sensor data is obtained. In this case, for example, immediately after startup, the data logger control unit 101 operates in a state where the number of polling timings is increased as described with reference to FIG. 7. When the interval at which sensor data is recorded in the internal memory is obtained by learning, the data logger control unit 101 decreases the polling timing to correspond to the learned interval.

[0088] Learning the interval (timing) at which the data logger 131 records sensor data in the internal memory can also be interpreted as learning the start time to initiate the transmission (polling) of the sensor data acquisition request.

[0089] Also, when new sensor data cannot be obtained from the data logger 131 during operation, etc., the data logger control unit 101 may return to the same state as immediately after startup, increase the timing for polling, and perform timing learning again.

[0090] (Modification Example 3) The node 100 may shorten the polling interval near the timing at which the data logger 131 records sensor data in the internal memory. Thereby, a time slot number closer to the generation time of the sensor data can be obtained. FIG. 11 is a diagram for explaining an example of polling by the node 100 of the modification example 3 configured in this way.

[0091] For example, the data logger control unit 101 initially operates with a relatively long polling interval set, and learns the timing at which the data logger 131 records sensor data in the internal memory in the same manner as in modification example 2. After learning this timing, the data logger control unit 101 shortens the polling interval and performs polling only near the learned timing.

[0092] Similar to modification example 2, when new sensor data cannot be obtained from the data logger 131 during operation, etc., the data logger control unit 101 may return to the same state as immediately after startup and perform timing learning again.

[0093] (Modification Example 4) Node 100 (data logger control unit 101) may be configured to obtain not only the sensor data recorded in the internal memory of data logger 131 but also the current sensor data of sensor 141 connected to data logger 131. For example, data logger control unit 101 requests data logger 131 to obtain the current sensor data, and obtains the current sensor data that data logger 131 has obtained from sensor 141 and transmitted without recording it in the internal memory. Node 100 (communication control unit 110) transmits the time slot number as the generation time of the obtained current sensor data.

[0094] (Modification Example 5) Node 100 may be configured to obtain the sensor data transmitted to Node 100 via data logger interface 122 when data logger 131 records the sensor data in the internal memory without performing polling. Node 100 transmits the current time slot number as the generation time for the received sensor data. At this time, if a plurality of sensor data with the same generation time is transmitted from data logger 131 for some reason, Node 100 (communication control unit 110) may transmit the sensor data to concentrator 200 only once.

[0095] For example, communication control unit 110 refers to the generation time assigned to the sensor data, determines whether a plurality of sensor data is generated at the same generation time, and transmits any one of the plurality of sensor data generated at the same generation time to concentrator 200.

[0096] When data logger 131 records the sensor data in the internal memory, only the information indicating that new sensor data has been recorded may be transmitted to Node 100 via data logger interface 122. In this case, for example, Node 100 may obtain new sensor data from data logger 131 by polling when it receives the information indicating that new sensor data has been recorded.

[0097] (Modification Example 6) The data logger 131 may have its internally managed time go back due to reasons such as time correction. In such a case, there may be a situation where sensor data is recorded multiple times in the internal memory of the data logger 131 at almost the same timing. However, since the multiple sets of sensor data are recorded at almost the same timing, it may not be necessary to transmit all of them via the wireless multi-hop network. Therefore, the node 100 checks the generation time of the sensor data obtained by polling, and if it is the same as the generation time of the sensor data transmitted immediately before, it may not be necessary to transmit the sensor data.

[0098] (Modification Example 7) So far, an example using the time slot number as the number mainly indicating the communication timing has been described. It may be configured to use the slot frame number as the number indicating the communication timing.

[0099] FIG. 12 is a diagram showing the relationship between real time and the slot frame of the time-division multiplexing system. The slot frame is a unit of schedule including a fixed number of time slots. In FIG. 12, an example of slot frames 701 n , 701 n+1 each including four time slots is shown. Similar to the time slot, a slot frame number is assigned to the slot frame. By using the slot frame number, it becomes possible to transmit more sensor data in a batch.

[0100] (Modification Example 8) Depending on the time-division multiplexing system, one or more channels (frequencies) may be used. For example, in TSCH, the channel to be used is changed every time data is transmitted and received. The method of the above-described embodiment can also be applied to such a time-division multiplexing system. FIG. 13 is a diagram showing the relationship between real time and the slot frame of the time-division multiplexing system when two channels 8111 and 8112 are used.

[0101] In such a time-division multiplexed communication schedule, in addition to the time slot number, the channel used for communication is specified. The channel may be specified by a channel offset. The concentrator 200 and the node 100 transmit and receive sensor data using the specified channel.

[0102] (Modification Example 9) It may be configured to use the superframe number as the number indicating the communication timing.

[0103] FIG. 14 is a diagram showing the relationship between real time and the superframe of the time-division multiplexing system. The superframe is a unit of a schedule including a fixed number of slot frames. In FIG. 14, superframes 901 n , 901 n+1 each including two slot frames are shown as examples. A superframe number is assigned to the superframe. By using the superframe number, it becomes possible to transmit a larger amount of sensor data in a lump.

[0104] The superframe has a longer period than the time slot. For this reason, in order to notify the time with higher accuracy, the node 100 may transmit, in addition to the superframe number, the offset of the time slot within the superframe. The offset of the time slot is, for example, the offset with respect to the first time slot of the superframe. For example, the communication control unit 110 transmits sensor data in which the superframe number and the offset of the time slot within the superframe are associated as data indicating the time to the concentrator 200.

[0105] (Modification Example 10) Node 100 (communication control unit 110) may transmit the difference between the time slot number, slot frame number, or superframe number at which the sensor data was acquired and the current time slot number, slot frame number, or superframe number (an example of the second number) (i.e., not the time slot number, slot frame number, or superframe number itself at the time when the message is being processed).

[0106] For example, among the messages transmitted and received in a wireless multi-hop network, there may already be the current time slot number, slot frame number, or superframe number included. In such a case, the communication control unit 110 transmits only the difference with respect to the already included number as data indicating the time. Thereby, the amount of data to be transmitted can be further reduced.

[0107] As described above, in the communication system according to the present embodiment, a number indicating the communication timing used in a communication method such as a time-division multiplexing method is used instead of the time when output data such as sensor data was generated. Thereby, it becomes possible to reduce the amount of data required when transmitting the output data.

[0108] Next, the hardware configuration of the devices (concentrator, node) according to the embodiment will be described with reference to FIG. 15. FIG. 15 is an explanatory diagram showing an example of the hardware configuration of the devices according to the embodiment.

[0109] The device according to the embodiment includes a control device such as a CPU 51, a storage device such as a ROM (Read Only Memory) 52 and a RAM (Random Access Memory) 53, a communication I / F 54 that connects to the network to perform communication, and a bus 61 that connects each part.

[0110] The program executed by the device according to the embodiment is provided by being pre-embedded in the ROM 52 or the like.

[0111] The program executed by the device according to the embodiment may be recorded on a computer-readable recording medium such as a CD-ROM (Compact Disk Read Only Memory), a flexible disk (FD), a CD-R (Compact Disk Recordable), a DVD (Digital Versatile Disk) in an installable format or an executable format file, and provided as a computer program product.

[0112] Furthermore, the program executed by the device according to the embodiment may be stored on a computer connected to a network such as the Internet, and provided by being downloaded via the network. Also, the program executed by the device according to the embodiment may be configured to be provided or distributed via a network such as the Internet.

[0113] The program executed by the device according to the embodiment can cause a computer to function as each part of the above-described device. This computer can read a program from a computer-readable storage medium into the main storage device and execute it by the CPU 51.

[0114] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and its equivalent scope.

Explanation of Signs

[0115] 1001~100 13 Node 101 Data Logger Control Unit 110 Communication Control Unit 121 Communication Unit 1221~122m Data Logger Interface 1311~131 m Data Logger 1411~141 m Sensor 200 Concentrator 201 Time Management Unit 202 Communication Control Unit 211, 212 Communication Unit 221 Memory Unit 300 Network

Claims

[

1. ] An acquisition control unit that requests output data output from a plurality of electronic devices at time intervals set according to intervals at which the electronic devices output the output data, and acquires the output data transmitted in response to the request from the electronic devices; A communication control unit that communicates with a server device by a communication method that synchronizes numbers indicating communication timings, and transmits the output data associated with a first number indicating the timing at which the output data was acquired among the numbers to the server device as a destination; The communication control unit transmits, to the server device as a destination, a plurality of the output data that have the same first number and are output from the same type of the electronic devices or a plurality of the electronic devices set in advance, in association with the same first number. A communication device. [

2. ] The communication control unit groups a plurality of the output data that have the same first number and are output from the same type of the electronic devices or a plurality of the electronic devices set in advance, associates the same first number with the grouped plurality of the output data, and transmits the output data to the server device as a destination. The communication device according to claim 1. [

3. ] The communication control unit receives the output data associated with the first number from an external communication device that communicates by the communication method. The communication control unit transmits, to the server device as a destination, a plurality of the output data that have the same first number and are output from the same type of the electronic devices or a plurality of the electronic devices set in advance, among the output data received from the external communication device and the output data acquired from the electronic devices, in association with the same first number. The communication device according to claim 1. [

4. ] The communication control unit transmits the output data to the server device as a destination via a relay device that relays communication between the communication device and the server device. The communication device according to claim 1. [

5. ] The communication control unit transmits, to the server device as a destination via the relay device, a plurality of the output data that have the same first number among a plurality of the output data received from a plurality of devices including the electronic devices and an external communication device that communicates by the communication method, in association with the same first number. The communication device according to claim 4. [

6. ] The acquisition control unit acquires the output data transmitted by the electronic device regardless of the request for the output data. The communication device according to claim 1.

7. When the acquisition control unit receives information indicating that new output data has been recorded from the electronic device, the acquisition control unit requests the electronic device for the output data and acquires the output data transmitted in response to the request. The communication device according to claim 1.

8. Based on the generation time assigned to the output data, the communication control unit determines whether a plurality of the output data have been generated at the same generation time, and transmits any one of the plurality of the output data generated at the same generation time to the server device as a destination. The communication device according to claim 1.

9. The electronic device is at least one of a sensor that outputs a detection result of a predetermined physical quantity as the output data and a data recording device that records the output data detected by the sensor in a storage medium. The communication device according to claim 1.

10. The communication method is a time-division multiplexing method. The communication device according to claim 1.

11. The number is a time slot number, a slot frame number, or a superframe number managed by the time-division multiplexing method. The communication device according to claim 10.

12. The number is a superframe number managed by the time-division multiplexing method, and the communication control unit transmits the output data in which the superframe number and the offset of the time slot within the superframe are associated as the first number to the server device as a destination. The communication device according to claim 10.

13. A communication method executed by a communication device, including: an acquisition control step of requesting output data output from a plurality of electronic devices at time intervals set according to intervals at which the electronic devices output the output data, and acquiring the output data transmitted in response to the request from the electronic devices; and a communication control step of communicating with a server device by a communication method that synchronizes numbers indicating communication timings, and transmitting the output data in which a first number indicating a timing at which the output data was acquired among the numbers is associated to the server device as a destination. A communication method executed by a communication device. An acquisition control step of requesting output data output from a plurality of electronic devices at time intervals set according to intervals at which the electronic devices output the output data, and acquiring the output data transmitted in response to the request from the electronic devices. A communication control step of communicating with a server device by a communication method that synchronizes numbers indicating communication timings, and transmitting the output data in which a first number indicating a timing at which the output data was acquired among the numbers is associated to the server device as a destination. The communication control step transmits, to the server device as a destination, a plurality of pieces of the output data output from the same type of the electronic devices or a plurality of the preset electronic devices, with the first numbers being the same, in association with the same first number. Communication method.

14. A computer causes an acquisition control step of requesting output data output from a plurality of electronic devices at time intervals set according to intervals at which the electronic devices output the output data, and acquiring the output data transmitted in response to the request from the electronic devices; a communication control step of communicating with a server device by a communication method that synchronizes numbers indicating communication timings, and transmitting, to the server device as a destination, the output data associated with a first number indicating a timing at which the output data is acquired among the numbers; to be executed, wherein the communication control step transmits, to the server device as a destination, a plurality of pieces of the output data output from the same type of the electronic devices or a plurality of the preset electronic devices, with the first numbers being the same, in association with the same first number. Program.

15. A communication system including a server device and one or more communication devices, wherein the server device communicates with one or more of the communication devices by a communication method that synchronizes numbers indicating communication timings, each of the one or more communication devices includes an acquisition control unit that requests output data output from a plurality of electronic devices at time intervals set according to intervals at which the electronic devices output the output data, and acquires the output data transmitted in response to the request from the electronic devices; and a communication control unit that communicates with the server device by the communication method, and transmits, to the server device as a destination, the output data associated with a first number indicating a timing at which the output data is acquired among the numbers, wherein the communication control unit transmits, to the server device as a destination, a plurality of pieces of the output data output from the same type of the electronic devices or a plurality of the preset electronic devices, with the first numbers being the same, in association with the same first number. Communication system.

16. The electronic device further includes a data recording device that records the output data detected by a sensor that outputs the detection result of a preset physical quantity as the output data in a storage medium. The communication system according to claim 15.

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