JP6572136B2 - COMMUNICATION SYSTEM, COMMUNICATION DEVICE, SECOND DEVICE, COMMUNICATION METHOD, AND COMPUTER PROGRAM - Google Patents

Description

  The present invention relates to a technique for estimating information related to the time of data.

  In IoT (Internet of Things), data is collected from various devices such as sensors. Then, based on the correlation between the devices, meaning is given to the collected data. When meaning is given to the collected data, it is one of the important factors that the time when the data is acquired between the devices matches the reference.

  Various techniques for synchronizing time between apparatuses have been proposed (see, for example, Patent Document 1). One of the time synchronization techniques is NTP (Network Time Protocol). In NTP, a server and each device communicate to synchronize the time managed by each device.

JP 2011-176768 A

  However, a device that does not have a function for generating time information (so-called clock function) cannot be synchronized in the first place. In addition, even if it has a function of generating time information, there is an apparatus that does not have a function for performing time synchronization processing such as NTP. Further, even if the time synchronization processing function is provided, the generated time information may not be accurate because it is not functioning effectively or cannot be synchronized with the server. The data acquired by these devices has a problem that the time when the data is acquired cannot be given correctly. Such a problem is not a problem limited to the IoT sensor described above, but is a problem common to all technologies that use information related to the time of data.

  In view of the above circumstances, an object of the present invention is to provide a technique capable of more accurately acquiring information related to the time of data.

  One aspect of the present invention is a first estimation unit that acquires first transmission time information that is information related to a time required for data transmission between the first device and the own device, and between the second device and the own device. A second estimation unit that obtains second transmission time information, which is information relating to the time required for data transmission, and a first indicating the time at which the data is received by the device relative to the data transmitted from the first device. The reception time information, intermediate transmission time information indicating the time when the data is transmitted from the own device to the second device, the first transmission time information, and the second transmission time information are added to the first transmission time information. And a second receiving time information indicating the time when the data is received at the own device and recording the data transmitted from the communication device. A second device comprising a control unit; A communication system comprising a.

  One aspect of the present invention is the communication system, wherein the first transmission time information, the second transmission time information, and the first reception time are related to data recorded by the control unit of the second device. An estimation unit configured to estimate a time at which the data is transmitted from the first device based on the information, the second reception time information, and the intermediate transmission time information;

  One aspect of the present invention is the communication system described above, wherein the first estimation unit acquires first transmission time information at a predetermined timing, and the control unit of the communication device acquires the first estimation unit. The stored first transmission time information is stored, and the stored first transmission time information is added to the data.

One aspect of the present invention is the communication system described above, wherein the communication device further includes a communication control unit that forms a communication path between the own device and the second device, and the second estimation unit includes: When a communication path is formed between the own apparatus and the second apparatus, the second transmission time information is acquired for communication via the communication path.
One aspect of the present invention is the communication system described above, wherein the control unit of the communication device adds the first reception time information and the first transmission time information for each data transmitted from the first device, The second transmission time information and the intermediate transmission time information are added to the plurality of data to which the first reception time information and the first transmission time information are added, and transmitted to the second device.
One aspect of the present invention is the communication system described above, wherein the control unit of the communication device adds the first reception time information and the first transmission time information for each data transmitted from the first device, The intermediate transmission time information is added only to the first data and the last data that are continuously transmitted among the plurality of data to which the first reception time information and the first transmission time information are added, The second transmission time information is added to any continuously transmitted data and transmitted to the second device.

  One aspect of the present invention is a first estimation unit that acquires first transmission time information that is information related to a time required for data transmission between the first device and the own device, and between the second device and the own device. A second estimation unit that obtains second transmission time information, which is information relating to the time required for data transmission, and a first indicating the time at which the data is received by the device relative to the data transmitted from the first device. The reception time information, intermediate transmission time information indicating the time when the data is transmitted from the own device to the second device, the first transmission time information, and the second transmission time information are added to the first transmission time information. And a control unit that transmits to the two devices.

  One aspect of the present invention is a first estimation unit that acquires first transmission time information that is information related to a time required for data transmission between the first device and the own device, and between the second device and the own device. A second estimation unit that obtains second transmission time information, which is information relating to the time required for data transmission, and a first indicating the time at which the data is received by the device relative to the data transmitted from the first device. The reception time information, intermediate transmission time information indicating the time when the data is transmitted from the own device to the second device, the first transmission time information, and the second transmission time information are added to the first transmission time information. A control unit for transmitting to the second device, and a control unit for recording the data transmitted from the communication device including the second reception time information indicating the time when the data was received by the own device. Two devices.

  One aspect of the present invention is a first estimation step of acquiring first transmission time information that is information related to a time required for data transmission between the first device and the own device, and between the second device and the own device. A second estimation step of obtaining second transmission time information, which is information relating to the time required for data transmission, and a first time indicating the time at which the data is received by the device relative to the data transmitted from the first device. The reception time information, intermediate transmission time information indicating the time when the data is transmitted from the own device to the second device, the first transmission time information, and the second transmission time information are added to the first transmission time information. A second transmission time information indicating a time at which the data was received by the second device and recording the data.

  One aspect of the present invention is a first estimation unit that acquires first transmission time information that is information related to a time required for data transmission between the first device and the own device, and between the second device and the own device. A second estimation unit that obtains second transmission time information, which is information relating to the time required for data transmission, and a first indicating the time at which the data is received by the device relative to the data transmitted from the first device. The reception time information, intermediate transmission time information indicating the time when the data is transmitted from the own device to the second device, the first transmission time information, and the second transmission time information are added to the first transmission time information. A computer program for causing a computer to function as a communication device including a control unit that transmits to two devices.

  One aspect of the present invention is a first estimation unit that acquires first transmission time information that is information related to a time required for data transmission between the first device and the own device, and between the second device and the own device. A second estimation unit that obtains second transmission time information, which is information relating to the time required for data transmission, and a first indicating the time at which the data is received by the device relative to the data transmitted from the first device. The reception time information, intermediate transmission time information indicating the time when the data is transmitted from the own device to the second device, the first transmission time information, and the second transmission time information are added to the first transmission time information. A control unit for transmitting to the second device, and a control unit for recording the data transmitted from the communication device including the second reception time information indicating the time when the data was received by the own device. Computer as a second device A computer program for functioning.

  According to the present invention, it is possible to acquire information on the time of data more accurately.

1 is a system configuration diagram illustrating a system configuration of a communication system 100. FIG. 2 is a schematic block diagram showing a functional configuration of a communication device 20. FIG. 3 is a schematic block diagram showing a functional configuration of a second device 30. FIG. 4 is a sequence chart illustrating a specific example of a flow of processing when first transmission time information is generated in the operation of the communication system 100. 4 is a sequence chart showing a specific example of a processing flow until data transmitted from the first device 10 is recorded in the second device 30 in the operation of the communication system 100. 4 is a sequence chart showing a specific example of a flow of processing when data transmission estimated time information is recorded in the operation of the communication system 100. FIG. 3 is a diagram illustrating a transition of a state of data handled in the communication system 100. 1 is a diagram illustrating a system configuration of a data collection system 200 that is an application example of a communication system 100. FIG.

  FIG. 1 is a system configuration diagram illustrating a system configuration of the communication system 100. The communication system 100 estimates information regarding the time of data generated by the first device 10. For example, the communication system 100 estimates a time at which data is transmitted by the first device 10 (hereinafter referred to as “data transmission time”). When the first device 10 is configured to generate data and transmit it immediately, the time at which the data was substantially generated may be estimated by estimating the time of the transmission timing. .

  The communication system 100 includes a communication device 20 and a second device 30. The communication device 20 is communicably connected to the first device 10 via the first network 40. The communication device 20 is communicably connected to the second device 30 via the second network 50. The first network 40 and the second network 50 may be configured in any manner as long as they are networks that connect each device so that they can communicate with each other. For example, the first network 40 and the second network 50 may be configured by the Internet.

  The first device 10 generates data and transmits the generated data to the communication device 20 via the first network 40. The first device 10 is, for example, a sensor. The first device 10 may generate data including detected information (hereinafter referred to as “detection information”), for example, and may transmit the generated data to the communication device 20.

  FIG. 2 is a schematic block diagram illustrating a functional configuration of the communication device 20. For example, the communication device 20 includes a CPU (Central Processing Unit), a memory, an auxiliary storage device, and the like connected by a bus, and executes a communication program. The communication device 20 may be configured as an information processing device such as a smartphone that executes the communication program. All or some of the functions of the communication device 20 may be realized by using hardware such as an application specific integrated circuit (ASIC), a programmable logic device (PLD), and a field-programmable gate array (FPGA). . Further, the communication device 20 may be realized by dedicated hardware. The communication program may be recorded on a computer-readable recording medium. The communication program may be provided via a telecommunication line. The communication device 20 includes a first communication unit 201, a first communication control unit 202, a first estimation unit 203, a second communication unit 204, a second communication control unit 205, a second estimation unit 206, a storage unit 207, and a control unit 208. Is provided.

  The first communication unit 201 is configured using a communication device such as a communication interface. The first communication unit 201 communicates with the first device 10 via the first network 40. The first communication unit 201 may perform wired communication or wireless communication. The first communication unit 201 receives data generated by the first device 10.

  The first communication control unit 202 controls communication in the first communication unit 201. The first communication control unit 202 transmits a communication request to the first device 10 via the first communication unit 201 and the first network 40 in response to an instruction from the first estimation unit 203. The communication request is data requesting that a communication response is returned to the transmission source device (communication device 20) to the transmission destination device (first device 10). The communication request may be, for example, an ICMP (Internet Control Message Protocol) “echo request” packet. In other words, the first communication control unit 202 may be configured using ping. The first communication control unit 202 notifies the first estimation unit 203 of the time required from when the communication request is transmitted until the communication response is received (hereinafter referred to as “first response time”).

  The first estimation unit 203 instructs the first communication control unit 202 to transmit a communication request at a predetermined timing. Based on the first response time notified from the first communication control unit 202, the first estimation unit 203 is a time required until data is received by the communication device 20 after the first device 10 transmits data ( Hereinafter, it is referred to as “first transmission time”). For example, the first estimation unit 203 may estimate the time obtained by multiplying the first response time by 1/2 as the first transmission time.

  The second communication unit 204 is configured using a communication device such as a communication interface. The second communication unit 204 communicates with the second device 30 via the second network 50. The second communication unit 204 may perform wired communication or wireless communication. The second communication unit 204 transmits data in which information is added to the data generated by the first device 10.

  The second communication control unit 205 controls communication in the second communication unit 204. The second communication control unit 205 forms a communication path with the second device 30 via the second network 50 in response to an instruction from the control unit 208. The formed communication path is, for example, a highly secure communication network (for example, a closed network) provided for a corporation by a communication company. For communication paths formed in the second network 50, for example, communication using an encrypted communication method (for example, VPN: Virtual Private Network) such as SSL (Secure Sockets Layer) and TLS (Transport Layer Security) is applied. Also good.

  The second communication control unit 205 transmits a communication request to the second device 30 via the communication path formed on the second communication unit 204 and the second network 50 in response to an instruction from the second estimation unit 206. . The communication request is data requesting a device (second device 30) as a transmission destination to send a communication response back to the device (communication device 20) as a transmission source. The communication request may be, for example, an ICMP “echo request” packet. In other words, the second communication control unit 205 may be configured using ping. The second communication control unit 205 notifies the second estimation unit 206 of the time required from when the communication request is transmitted until the communication response is received (hereinafter referred to as “second response time”).

  The second estimation unit 206 instructs the second communication control unit 205 to transmit a communication request in response to an instruction from the control unit 208. Based on the second response time notified from the second communication control unit 205, the second estimation unit 206 transmits the time from when the communication device 20 transmits data until the second device 30 receives the data ( Hereinafter, it is referred to as “second transmission time”). For example, the second estimation unit 206 may estimate the time obtained by multiplying the second response time by 1/2 as the second transmission time.

The storage unit 207 is configured using a storage device such as a magnetic hard disk device or a semiconductor storage device. The storage unit 207 stores data according to the control of the control unit 208.
The control unit 208 controls communication processing in the communication device 20. The control unit 208 adds first reception time information, first transmission time information, second transmission time information, and intermediate transmission time information to the data received by the first communication unit 201. The first reception time information is information indicating the time at which data is received by the first communication unit 201. The first reception time information is generated based on a clock provided in the communication device 20. As described above, the first transmission time information is information indicating the time required from when the first device 10 transmits data until the communication device 20 receives the data. As described above, the second transmission time information is information indicating the time required from when the communication device 20 transmits data until the second device 30 receives the data. The intermediate transmission time information is information indicating the time at which data is transmitted by the second communication unit 204. The intermediate transmission time information is generated based on a clock provided in the communication device 20. When the timing for transmitting data to the second device 30 arrives, the control unit 208 instructs the second communication control unit 205 to form a communication path. When the communication path is formed, the control unit 208 instructs the second estimation unit 206 to estimate the second transmission time.

  FIG. 3 is a schematic block diagram illustrating a functional configuration of the second device 30. For example, the second device 30 includes a CPU, a memory, an auxiliary storage device, and the like connected by a bus, and executes a control program. Note that all or some of the functions of the second device 30 may be realized using hardware such as an ASIC, PLD, or FPGA. The second device 30 may be realized by dedicated hardware. The control program may be recorded on a computer-readable recording medium. The control program may be provided via a telecommunication line. The second device 30 includes a communication unit 301, a communication control unit 302, a storage unit 303, a control unit 304, and an estimation unit 305.

  The communication unit 301 is configured using a communication device such as a communication interface. The communication unit 301 communicates with the communication device 20 via the second network 50. The communication unit 301 may perform wired communication or wireless communication. The communication unit 301 receives data transmitted from the communication device 20.

  The communication control unit 302 controls communication in the communication unit 301. The communication control unit 302 forms a communication path with the communication device 20 via the second network 50. When a communication request is received from the communication device 20 via the communication path formed on the communication unit 301 and the second network 50, the communication control unit 302 transmits a communication response in response to the communication request. The communication response may be, for example, an ICMP “echo reply” packet. In other words, the communication control unit 302 may be configured using ping.

The storage unit 303 is configured using a storage device such as a magnetic hard disk device or a semiconductor storage device. The storage unit 303 stores data in accordance with the control of the control unit 304.
The control unit 304 controls processing in the second device 30. The control unit 304 adds second reception time information to the data received by the communication unit 301. The second reception time information is information indicating the time at which the data is received by the communication unit 301. The second reception time information is generated based on a clock provided in the second device 30. The control unit 304 records the data to which the second reception time is added in the storage unit 303.

  The estimation unit 305 performs data transmission on the data stored in the storage unit 303 based on the first transmission time information, the second transmission time information, the first reception time information, the second reception time information, and the intermediate transmission time information. Estimate time. The estimation unit 305 may estimate the data transmission time based on the following equation, for example.

Data transmission time = R2-T2- (S-R1) -T1
R2: second reception time T2: second transmission time S: intermediate transmission time R1: first reception time T1: first transmission time

  The estimation unit 305 adds information indicating the estimated data transmission time (hereinafter referred to as “data transmission estimation time information”) to the data. The estimation unit 305 records the data to which the data transmission estimated time information is added in the storage unit 303.

  FIG. 4 is a sequence chart showing a specific example of a processing flow when the first transmission time information is generated in the operation of the communication system 100. First, the first estimation unit 203 of the communication device 20 instructs the first communication control unit 202 to transmit a communication request when a predetermined timing arrives. The predetermined timing is determined in advance by a designer or a user so that the first transmission time is obtained with a predetermined accuracy. This predetermined timing may be a regular timing or an irregular timing. The predetermined timing may be, for example, a timing that arrives once an hour, a timing that arrives once a day, or another timing. The first communication control unit 202 transmits a communication request to the first device 10 in response to an instruction from the first estimation unit 203 (step S101).

  When receiving a communication request from the communication device 20, the first device 10 transmits a communication response to the communication device 20 in response to the received communication request (step S102). When the communication response is received, the first communication control unit 202 of the communication device 20 acquires the first response time. The first communication control unit 202 notifies the first estimation unit 203 of the acquired first response time. The first estimation unit 203 estimates the first transmission time based on the first response time (step S103). The first estimation unit 203 notifies the control unit 208 of first transmission time information that is an estimation result. The control unit 208 records the first transmission time information in the storage unit 207 (step S104).

  FIG. 5 is a sequence chart illustrating a specific example of a processing flow until data transmitted from the first device 10 is recorded in the second device 30 in the operation of the communication system 100. First, the first device 10 generates data at a predetermined timing (step S201). This predetermined timing may be a regular timing or an irregular timing. The predetermined timing may be, for example, a timing that arrives once an hour, a timing that arrives once a day, or another timing. The first device 10 transmits the generated data to the communication device 20 (step S202).

  When data is received from the first device 10, the control unit 208 of the communication device 20 adds first reception time information to the received data (step S203). Further, the control unit 208 reads the latest first transmission time information recorded in the storage unit 207, and adds the read first transmission time information to the data (step S204). The control unit 208 writes the data with the first reception time information and the first transmission time information added to the storage unit 207.

  When the predetermined timing arrives, the control unit 208 instructs the second communication control unit 205 to connect a communication path. This predetermined timing is determined in advance by a designer or a user. This predetermined timing may be a regular timing or an irregular timing. This predetermined timing may be, for example, a timing that arrives once an hour, a timing that arrives once a day, or the number or amount of data recorded in the storage unit 207 May be a timing at which reaches a predetermined threshold. The second communication control unit 205 connects a communication path to the second device 30 in response to an instruction from the control unit 208 (step S206).

  When the communication path is connected, the control unit 208 instructs the second estimation unit 206 to estimate the second transmission time. The second estimation unit 206 instructs the second communication control unit 205 to transmit a communication request in response to an instruction from the control unit 208. The second communication control unit 205 transmits a communication request to the second device 30 in response to an instruction from the second estimation unit 206 (step S207).

  When receiving the communication request from the communication device 20, the communication control unit 302 of the second device 30 transmits a communication response to the communication device 20 in response to the received communication request (step S208). When the communication response is received, the second communication control unit 205 of the communication device 20 acquires the second response time. The second communication control unit 205 notifies the second estimation unit 206 of the acquired second response time. The second estimation unit 206 estimates the second transmission time based on the second response time (step S209). The second estimation unit 206 notifies the control unit 208 of second transmission time information that is an estimation result. The control unit 208 adds the second transmission time information to the data (Step S210). In addition, the control unit 208 adds intermediate transmission time information to the data (step S211). The control unit 208 transmits data to which the first reception time information, the first transmission time information, the second transmission time information, and the intermediate transmission time information are added to the second device 30 (step S212).

  When data is received from the communication device 20, the control unit 304 of the second device 30 adds second reception time information to the received data (step S213). The control unit 304 writes the data with the second reception time information added to the storage unit 303 (step S214).

  FIG. 6 is a sequence chart illustrating a specific example of a processing flow when data transmission estimation time information is recorded in the operation of the communication system 100. First, the estimation unit 305 of the second device 30 reads data that is an object of estimation of the data transmission time from the data stored in the storage unit 303. The estimation unit 305 estimates the data transmission time based on information added to the read data (step S301). The estimation unit 305 adds data transmission estimated time information to the data (step S302). The estimation unit 305 records the data added with the data transmission estimated time information in the storage unit 303 (step S303).

  FIG. 7 is a diagram showing a transition of the state of data handled in the communication system 100. FIG. 7A shows data at a time point received from the first device 10 by the communication device 20. Although not explicitly shown in FIG. 7A, the first device 10 may add some time information or time information to the data transmitted from the first device 10. For example, when the first device 10 includes a unique clock, information indicating the data generation time or information indicating the data transmission time may be added to the data. However, since the accuracy of the generation time and the transmission time added by the first device 10 depends on the accuracy of the clock of the first device 10, it is assumed that it is not higher than the time estimated by the second device 30. .

  FIG. 7B shows data stored in the storage unit 207 of the communication device 20. The first reception time information and the first transmission time information are added to the data shown in FIG.

  FIG. 7C shows data immediately before being transmitted by the control unit 208 of the communication device 20. The second transmission time information and the intermediate transmission time information are added to the data shown in FIG. Note that a plurality of sets of data (data to which the first reception time information and the first transmission time information are added) shown in parentheses in FIG. 7C may exist. That is, one second transmission time information and intermediate transmission time information may be added to a plurality of data to which the first reception time information and the first transmission time information are added. In this case, a plurality of data is transmitted from the communication device 20 to the second device 30 in a state of being collected.

  FIG. 7D shows data at a time point when it is received by the second device 30 and recorded in the storage unit 303. A plurality of sets of data shown in parentheses in FIG. 7D may exist as in FIG. Second reception time information is added to the data shown in FIG.

  FIG. 7E shows data to which data transmission estimated time information is added by the control unit 304 of the second device 30. When a plurality of sets of data are collected together, data transmission estimated time information is acquired and added to each data.

  In the communication system 100 configured as described above, data transmission based on a reference time common to a plurality of data (in this case, the time of a clock provided in the second device 30) in the second device 30 that is a data reception destination. Time is estimated. Therefore, even if the first device 10 that is the data transmission source does not have a clock, the data transmission time can be estimated. Even if the first device 10 has a clock, the data transmission time can be estimated with the accuracy of the clock of the second device 30 regardless of the accuracy of the clock of the first device 10.

  When a plurality of first devices 10 are connected to a single communication system 100, a common reference time for each data (in this case, the first time) It is possible to estimate the data transmission time based on the time of the clock provided in the second device 30. Therefore, when processing is performed based on the transmission time of each data, it is possible to improve the accuracy of the processing.

  In the communication system 100, the transmission time in a network (for example, the second network 50) where the communication path is not always connected is estimated when the communication path is formed. Therefore, even when the transmission time is different each time a communication path is formed, the data transmission time can be estimated with higher accuracy.

  In the communication system 100, the communication device 20 does not correct the time information added to the data but adds information necessary for estimating the data transmission time. For this reason, the communication device 20 does not need to calculate the correct time in the course of communication, and simply adds information, so that the processing can be realized with less resources.

  In the communication system 100, the second device 30 converts the information necessary for estimating the data transmission time into data and records it in the storage unit 303. The process of actually estimating the data transmission time (the process shown in FIG. 6) can be executed at an arbitrary timing. For this reason, the second device 30 does not need to calculate the correct time in the course of communication, and simply adds information, so that the processing can be realized with less resources.

In the communication system 100, information indicating the time when data is received by the communication device 20 (first reception time information) and information indicating the time when data is transmitted from the communication device 20 (intermediate transmission time information) are included in the data. Added. Therefore, even if data is temporarily stored in the communication device 20, it is possible to estimate a more accurate data transmission time based on the time. Further, by using these pieces of information, it is possible to detect a failure on the network based on the residence time in the communication device 20 on the data path.
Similarly, it is possible to detect a failure in the first network 40 through which data is transmitted by using the first transmission time information. For example, when the first transmission time information is a value significantly different from the previous value, it may be determined that some kind of failure has occurred.
Similarly, it is possible to detect a failure in the second network 50 through which data is transmitted by using the second transmission time information. For example, when the first transmission time information is a value significantly different from the previous value, it may be determined that some kind of failure has occurred.
When the order of information added to data (for example, first reception time, intermediate transmission time, and second reception time) is different between data, data is retransmitted due to congestion in any of the intermediate paths It may be determined that network processing is being performed.

  In the communication system 100, the first transmission time information is acquired in advance as shown in FIG. Therefore, the communication device 20 does not need to acquire the first transmission time information in the course of communication, and can realize processing with fewer resources.

  In the communication system 100, communication may be performed between the communication device 20 and the second device 30 by setting a plurality of data as one set. In this case, second transmission time information, intermediate transmission time information, and second reception time information are added to a plurality of data sets. Therefore, it is possible to improve the efficiency of data communication and recording in the storage unit 303.

<Application example>
FIG. 8 is a diagram illustrating a system configuration of a data collection system 200 that is an application example of the communication system 100. The data collection system 200 includes a plurality of gateways 21, a collection server 31, a database 32, and a time synchronization server 33. A plurality of sensors 11 are connected to the data collection system 200. The data collection system 200 collects data transmitted from each sensor 11 and estimates the time (data transmission time) when each data is transmitted by the sensor 11. The gateway 21 is communicably connected to the plurality of sensors 11 via the first network 41. The gateway 21 is communicably connected to the collection server 31 via the second network 51. As long as the 1st network 41 and the 2nd network 51 are networks which connect each apparatus so that communication is possible, they may be comprised by what kind of aspect. For example, the first network 41 and the second network 51 may be configured by the Internet.

  The sensor 11 is a specific example of the first device 10. The gateway 21 is a specific example of the communication device 20. The collection server 31 is a specific example of the second device 30. The first network 41 is a specific example of the first network 40. The second network 51 is a specific example of the second network 50. A database 32 and a time synchronization server 33 are connected to the collection server 31. The database 32 corresponds to the storage unit 303 of the second device 30.

  The sensor 11 generates sensor information (including information detected by the sensor 11 and identification information of the sensor 11) as data. The sensor 11 transmits the generated data to the gateway 21 via the first network 41. Any type of sensor may be applied to the sensor 11. A plurality of types of sensors may be applied to the sensor 11. The sensor 11 may be, for example, a sensor that measures temperature, a sensor that measures atmospheric pressure, a sensor that measures volume, or a sensor that measures wind speed. Good.

  The gateway 21 adds first reception time information, first transmission time information, second transmission time information, and intermediate transmission time information to sensor information received via the first network 41. The gateway 21 transmits the sensor information added with each information to the collection server 31 via the second network 51.

  The collection server 31 adds second reception time information to the sensor information received via the second network 51. The collection server 31 records the sensor information to which the second reception time information is added in the database 32. The collection server 31 executes time synchronization processing with the time synchronization server 33. Therefore, the time of the clock that the collection server 31 has (for example, the time that is the reference of the second reception time information) is accurate.

The database 32 is a database device including a storage device such as a magnetic hard disk device or a semiconductor storage device. The database 32 stores sensor information collected by the collection server 31.
The time synchronization server 33 synchronizes the time of other devices by operating based on NTP.

  In the data collection system 200 configured as described above, the transmission time of the sensor information detected by the plurality of sensors 11 can be estimated based on a common reference time in the collection server 31. Therefore, it is possible to improve the accuracy of processing using each sensor information. Further, it is not necessary to have a function (for example, a clock function or an NTP client function) for acquiring accurate time in each sensor 11 or gateway 21. Therefore, the cost for constructing the data collection system 200 can be reduced.

[Modification]
The first network 40 may be constructed as a closed network that is always connected. The second network 50 may also be constructed as a closed network that is always connected.

A communication path may always be formed in the second network 50. In this case, the process of step S206 shown in FIG. 5 is unnecessary. Further, the processes in steps S207 to S209 shown in FIG. 5 may be executed at a predetermined timing as a pre-process as in the process shown in FIG. In this case, information indicating the estimated second transmission time (second transmission time information) may be recorded in the storage unit 207.
A communication path may be formed in the first network 40 similarly to the second network 50 described above. In this case, the first communication control unit 202 operates in the same manner as the second communication control unit 205 described above. That is, the first communication control unit 202 forms a communication path with the first device 10 via the first network 40 in accordance with an instruction from the control unit 208. The formed communication path is, for example, a highly secure communication network (for example, a closed network) provided for a corporation by a communication company. For the communication path formed in the first network 40, communication (for example, VPN) using an encrypted communication method such as SSL or TLS may be applied. In this case, the measurement of the first response time and the estimation of the first transmission time are performed for the communication path formed on the first network 40. Data transmission from the first device 10 to the communication device 20 is also performed on a communication path formed on the first network 40.

The process of estimating the data transmission time may be performed not by the second device 30 but by another device (not shown). That is, the function as the estimation unit 305 may be implemented in another device (not shown) instead of the second device 30. For example, the function as the estimation unit 305 in the application example described above may be implemented in a device different from the collection server 31. In this case, the function as the estimation unit 305 reads data from the database 32 and executes processing.
When transmitting a plurality of data continuously (continuously), the communication device 20 may add the intermediate transmission time information only to the data transmitted first and the data transmitted last. In this case, the second transmission time information is added to at least one of the continuously transmitted data. In this case, the control unit 304 of the second device 30 adds the second reception time information only to the first transmitted data and the last transmitted data, and records them in the storage unit 303 in the order received. . When estimating the data transmission time, the control unit 304 transmits the second and subsequent data based on the data transmission estimated time of the first transmitted data and the data transmission estimated time of the last transmitted data. Estimate the data transmission estimated time of each data. For example, the time obtained by dividing the difference between the data transmission estimated time of the first transmitted data and the data transmission estimated time of the last transmitted data by the number of data transmitted in the meantime, The data transmission time of each data may be estimated by cumulatively adding to the second and subsequent data.

  The number of communication devices 20 installed in the communication path from the first device 10 to the second device 30 need not be limited to one. For example, data may be transmitted from the first device 10 to the second device 30 via two or more communication devices 20. In this case, in each communication device 20, the first reception time information, the first transmission time information, the second transmission time information, and the intermediate transmission time information are added. In addition, the first transmission time information may indicate a time required for transmission between the communication device 20 positioned immediately before in the communication path and the own device. Similarly, the second transmission time information may represent a time required for transmission between the communication device 20 located immediately after the communication route and the own device.

The control unit 208 of the communication device 20 changes the first transmission time information and the second transmission time information into information indicating the first response time (hereinafter referred to as “first response time information”) and the second response time. Information (hereinafter referred to as “second response time information”) may be added to the data. In this case, the control unit 304 of the second device may estimate the first transmission time and the second transmission time based on the first response time information and the second response time information, respectively.
When transmitting the “echo request”, the first communication control unit 202 may specify the size of data to be transmitted (the data size in FIG. 7A). With this configuration, the first response time can be acquired more accurately.
When transmitting the “echo request”, the second communication control unit 205 may specify the size of data to be transmitted (the data size in FIG. 7C). With this configuration, the second response time can be acquired more accurately.
The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes designs and the like that do not depart from the gist of the present invention.

DESCRIPTION OF SYMBOLS 100 ... Communication system, 10 ... 1st apparatus, 20 ... Communication apparatus, 201 ... 1st communication part, 202 ... 1st communication control part, 203 ... 1st estimation part, 204 ... 2nd communication part, 205 ... 2nd communication Control unit, 206 ... second estimation unit, 207 ... storage unit, 208 ... control unit, 30 ... second device, 301 ... communication unit, 302 ... communication control unit, 303 ... storage unit, 304 ... control unit, 305 ... estimation Part

Claims (11)

A first estimation unit that obtains first transmission time information that is information related to a time required for data transmission between the first device and the own device;
A second estimator for acquiring second transmission time information, which is information related to the time required for data transmission between the second device and the own device;
For the data transmitted from the first device, first reception time information indicating the time at which the data is received at the own device, and intermediate transmission time indicating the time at which the data is transmitted from the own device to the second device. A control unit that adds information, the first transmission time information, and the second transmission time information to the second device, and
A communication device comprising:
A second device comprising a control unit for recording the data transmitted from the communication device by adding second reception time information indicating a time at which the data is received by the device;
Equipped with a,
The second apparatus is a communication system that is not a data relay apparatus but an apparatus that communicates data with the first apparatus as a communication end device . A first estimation unit that obtains first transmission time information that is information related to a time required for data transmission between the first device and the own device;
A second estimator for acquiring second transmission time information, which is information related to the time required for data transmission between the second device and the own device;
For the data transmitted from the first device, first reception time information indicating the time at which the data is received at the own device, and intermediate transmission time indicating the time at which the data is transmitted from the own device to the second device. A control unit that adds information, the first transmission time information, and the second transmission time information to the second device, and
A communication device comprising:
A second device comprising a control unit for recording the data transmitted from the communication device by adding second reception time information indicating a time at which the data is received by the device;
Regarding the data recorded by the control unit of the second device, the first transmission time information, the second transmission time information, the first reception time information, the second reception time information, and the intermediate transmission time communication system comprising a data, based on, and an estimation unit for estimating a time sent the data from the first device. A first estimation unit that obtains first transmission time information that is information related to a time required for data transmission between the first device and the own device;
A second estimator for acquiring second transmission time information, which is information related to the time required for data transmission between the second device and the own device;
For the data transmitted from the first device, first reception time information indicating the time at which the data is received at the own device, and intermediate transmission time indicating the time at which the data is transmitted from the own device to the second device. A control unit that adds information, the first transmission time information, and the second transmission time information to the second device, and
A communication device comprising:
A second device comprising a control unit that records the data transmitted from the communication device by adding second reception time information indicating the time at which the data was received by the device, and
The control unit of the communication device adds the first reception time information and the first transmission time information to each data transmitted from the first device, and adds the first reception time information and the first transmission time information. A communication system, wherein one piece of the second transmission time information and intermediate transmission time information is added to the plurality of pieces of data and transmitted to the second device. A first estimation unit that obtains first transmission time information that is information related to a time required for data transmission between the first device and the own device;
A second estimator for acquiring second transmission time information, which is information related to the time required for data transmission between the second device and the own device;
For the data transmitted from the first device, first reception time information indicating the time at which the data is received at the own device, and intermediate transmission time indicating the time at which the data is transmitted from the own device to the second device. A control unit that adds information, the first transmission time information, and the second transmission time information to the second device, and
A communication device comprising:
A second device comprising a control unit that records the data transmitted from the communication device by adding second reception time information indicating the time at which the data was received by the device, and
The control unit of the communication device adds the first reception time information and the first transmission time information to each data transmitted from the first device, and adds the first reception time information and the first transmission time information. The intermediate transmission time information is added only to the first data and the last data that are continuously transmitted among the plurality of data that have been transmitted, and the second transmission is performed on any of the continuously transmitted data A communication system that adds time information to the second device and transmits the time information. The first estimation unit acquires first transmission time information at a predetermined timing,
The control unit of the communication device stores the first transmission time information acquired by the first estimation unit, and adds the stored first transmission time information to the data . The communication system as described in any one . The communication device further includes a communication control unit that forms a communication path between the device and the second device,
The second estimation unit, when the communication path is formed between the the own device the second device to obtain the second transmission time information about the communication through the communication path, of claims 1 to 5 The communication system as described in any one. A first estimation unit that obtains first transmission time information that is information related to a time required for data transmission between the first device and the own device;
A second estimator for acquiring second transmission time information, which is information related to the time required for data transmission between the second device and the own device;
For the data transmitted from the first device, first reception time information indicating the time at which the data is received at the own device, and intermediate transmission time indicating the time at which the data is transmitted from the own device to the second device. A control unit that adds information, the first transmission time information, and the second transmission time information to the second device, and
The first transmission time information, the second transmission time information, and the first reception time information regarding the data to which the second reception time information indicating the time when the data was received by the second device is added. Based on the second reception time information and the intermediate transmission time information, an estimation unit that estimates a time at which the data is transmitted from the first device;
A communication device comprising: A first estimation unit that obtains first transmission time information that is information related to a time required for data transmission between the first device and the own device;
A second estimator for acquiring second transmission time information, which is information related to the time required for data transmission between the second device and the own device;
For the data transmitted from the first device, first reception time information indicating the time at which the data is received at the own device, and intermediate transmission time indicating the time at which the data is transmitted from the own device to the second device. A control unit that adds information, the first transmission time information, and the second transmission time information to the second device, and
A controller for adding and recording second reception time information indicating a time at which the data is received by the device relative to the data transmitted from the communication device .
Regarding the data recorded by the control unit of the second device, the first transmission time information, the second transmission time information, the first reception time information, the second reception time information, and the intermediate transmission time A second device comprising: an estimation unit configured to estimate a time when the data is transmitted from the first device based on the information . )
A first estimation step of obtaining first transmission time information, which is information relating to time required for data transmission between the first device and the own device;
A second estimation step of obtaining second transmission time information, which is information relating to the time required for data transmission between the second device and the own device;
For the data transmitted from the first device, first reception time information indicating the time at which the data is received at the own device, and intermediate transmission time indicating the time at which the data is transmitted from the own device to the second device. Adding information, the first transmission time information, and the second transmission time information, and transmitting to the second device;
Adding the second reception time information indicating the time when the data was received by the second device to the data, and recording the data;
The first transmission time information, the second transmission time information, and the first reception time information regarding the data to which the second reception time information indicating the time when the data was received by the second device is added. A method of estimating a time at which the data is transmitted from the first device based on the second reception time information and the intermediate transmission time information . A computer program for causing a computer to function as the communication device according to claim 7 . A computer program for causing a computer to function as the second device according to claim 8 .

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