Radio device and wireless communication system

Abstract

To provide a radio device capable of promptly executing a FOTA operation.SOLUTION: A radio device 20 is capable of transmitting and receiving data of firmware with another radio device over a multi-hop communication network including a plurality of radio devices, and the radio device comprises a control device 21 and a communication device. When receiving data other than firmware from another radio device by the communication device, while transmitting a beacon in a first cycle, the control device receives the data in a first reception waiting state after the transmission of the beacon. When receiving the data of firmware from another radio device by the communication device, while transmitting the beacon in a second cycle which is shorter than the first cycle, the control device transmits a data request and receives the data of firmware in the first reception waiting state after the transmission of the beacon.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a radio and a wireless communication system capable of transmitting and receiving firmware data. [Background technology]

[0002] As a conventional wireless device, for example, a wireless communication device shown in Patent Document 1 is known. A parent device, which is a wireless communication device, transmits a notification regarding firmware to be updated via a second communication method to a child device, which is a wireless communication device connected downstream of the parent device. In response to this notification, the child device attempts to establish communication with the server via a first communication method. Here, if this communication is not established, the child device downloads and updates the firmware via communication with the parent device via the second communication method. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-200620 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned patent document 1, when the child device cannot receive the firmware from the server, the child device receives the firmware from the parent device. Since the amount of firmware data is larger than the amount of data that can be transmitted from the parent device to the child device in one transmission operation, the parent device must divide the firmware and transmit the divided data to the child device multiple times, which poses the problem that it takes a long time to transmit the firmware.

[0005] The present disclosure has been made to solve such problems, and aims to provide a radio and a radio communication system that can quickly perform FOTA operations. [Means for solving the problem]

[0006] A radio device according to one embodiment of the present disclosure is a radio device capable of transmitting and receiving firmware data to and from other radio devices in a multi-hop communication network including multiple radio devices, and is equipped with a control device and a communication device, wherein when receiving data other than the firmware from another radio device using the communication device, the control device transmits a beacon at a first period while receiving the data in a first wait state after transmitting the beacon, and when receiving the firmware data from the other radio device using the communication device, the control device transmits a data request while transmitting the beacon at a second period shorter than the first period, and receives the firmware data in the first wait state after transmitting the beacon.

[0007] A wireless communication system according to one aspect of the present disclosure includes a plurality of radio devices included in a multi-hop communication network, and the radio devices receiving data other than the radio device firmware transmit a beacon at a first period while receiving the data in a first waiting state after the transmission of the beacon, and the radio devices receiving the firmware data transmit a data request while transmitting the beacon at a second period shorter than the first period while receiving the firmware data in the first waiting state after the transmission of the beacon. Effect of the Invention

[0008] According to the present disclosure, for example, when the amount of firmware data is larger than the amount of data that the wireless device can transmit at one time, the wireless device divides and transmits the firmware data. In this case, the wireless device transmits beacons at a second cycle shorter than the first cycle in the FOTA operation for transmitting and receiving firmware data, thereby shortening the time interval for receiving firmware data in the first reception waiting state following the transmission of the beacon, and thus enabling the FOTA operation to be performed quickly.

[0009] The above and other objects, features, and advantages of the present disclosure will become apparent from the following detailed description of preferred embodiments, taken in conjunction with the drawings. [Brief description of the drawings]

[0010] [Figure 1] 1 is a diagram illustrating a wireless communication system according to an embodiment and a modification of the present disclosure. [Diagram 2] FIG. 2 is a block diagram showing an example of the configuration of a center device and a wireless device; [Diagram 3] FIG. 13 is a diagram for explaining a periodic operation. [Figure 4] FIG. 11 is a diagram for explaining a second FOTA operation. [Diagram 5] 4 is a flowchart showing an example of an operation of the wireless device. [Figure 6] 10 is a flowchart showing an example of an operation of the wireless device according to the first modification. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] <Wireless communication system> 1, a wireless communication system 10 according to an embodiment of the present disclosure includes a plurality of wireless devices 20 and a center device 30. In the wireless communication system 10, data such as data related to a meter 11 that reads the amount of gas used by a consumer, such as city gas, LP gas, and hydrogen gas, is transmitted from the wireless device 20 to the center device 30, and data is collected in the center device 30. In the following description, the meter 11 is described as reading gas, but the meter reading target is not limited to gas and may be electricity, water, or the like.

[0012] The wireless device 20 is communicatively connected to a meter 11 of a consumer and performs data communication with the meter 11. The wireless device 20 also has a communication function using a first communication network 12 and a communication function using a second communication network 13. As a result, the wireless device 20 is communicatively connected to a center device 30 using the first communication network 12 or the second communication network 13 and performs data communication with the center device 30.

[0013] This data includes data related to the meter 11 and the wireless device 20. The data related to the meter 11 includes a meter reading value indicating the amount of gas usage read by the meter 11, and an alarm indicating an abnormality in the amount of gas usage read by the meter 11, and is transmitted from the wireless device 20 to the center device 30. The data related to the wireless device 20 includes time data of the wireless device 20, and firmware version number and data, and is transmitted from the center device 30 to the wireless device 20.

[0014] The first communication network 12 may be a communication network such as a WAN (Wide Area Network), which has communication facilities such as a base station 12a, an exchange, and cables, and may be connected to the Internet. The second communication network 13 is a communication network different from the first communication network 12, such as a FAN (Field Area Network), which is a wireless multi-hop network in which multiple wireless devices 20 transmit data in a relay manner. For example, when the meter 11 is to read gas, the second communication network 13 may be WISUN-JUTA, which is a communication method standardized by the WI-SUN Alliance.

[0015] The center device 30 has a server function of collecting data from the wireless devices 20, and provides services and information based on the collected data to consumers and businesses that manage the meters 11. For example, the center device 30 collects meter readings from the meter 11, calculates gas usage based on the readings, and transmits the calculated amount to consumers and businesses. The center device 30 also collects alarms from the meter 11, and transmits an instruction to the meter 11 to shut off the gas flow path of the meter 11 in response to the alarms, causing the meter 11 to shut off the gas flow path.

[0016] The center device 30 also has a management function for managing the wireless device 20, and transmits data related to the management of the wireless device 20 to the wireless device 20. For example, the center device 30 transmits time data to the wireless device 20 and causes the wireless device 20 to perform a time correction operation based on the time data. The center device 30 also transmits firmware data to the wireless device 20 and causes the wireless device 20 to perform a FOTA operation based on the firmware data.

[0017] <Center device> As shown in FIG. 2, the center device 30 includes a center control device 31 and a center communication interface 32 electrically connected to the center control device 31. The center communication interface 32 is a communication interface for wired communication and is connected to the first communication network 12 by a cable or the like. As a result, the center communication interface 32 receives data transmitted from the wireless device 20 via the first communication network 12 and inputs the data to the center control device 31, or transmits data to the wireless device 20 via the first communication network 12 under the control of the center control device 31. The center communication interface 32 may be a communication interface for wireless communication and may be connected to the first communication network 12 by wireless communication. The center communication interface 32 may be connected to the Internet by wireless communication or wired communication, and may be capable of communicating with the wireless device 20 via the Internet and the first communication network 12.

[0018] The center control device 31 is a computer, and has a center calculation unit 33 and a center storage unit 34. The center storage unit 34 is a memory accessible from the center calculation unit 33, and is composed of RAM, ROM, etc. The center storage unit 34 stores programs for executing various processes such as data collection of the center device 30 and management of the wireless device 20, and data used in these programs. The center storage unit 34 also stores data received from the wireless device 20 and data to be transmitted to the wireless device 20.

[0019] The center calculation unit 33 is composed of, for example, a processor such as a CPU, and executes a program stored in the center storage unit 34. As a result, the center control device 31 controls the operation of the components of the center device 30 based on input data from the center communication interface 32, and executes various processes related to data collection and management of the wireless device 20. The center control device 31 may be composed of a single device, or may be configured such that multiple devices are distributed and arranged to operate the center control device 31 in cooperation with each other.

[0020] <Radio> The wireless device 20 includes a control device 21, a battery 22, and a communication device and a third communication interface 25 that are electrically connected to the control device 21. The battery 22 is a power source for the wireless device 20, and is connected to the control device 21, the communication device, and the third communication interface 25 to supply power thereto.

[0021] The control device 21 is a computer, and has a calculation unit 26 and a storage unit 27. The storage unit 27 is a memory accessible from the calculation unit 26, and is composed of RAM, ROM, etc. The storage unit 27 stores programs for executing various operations such as FOTA operations of the wireless device 20, and data used in these programs. The storage unit 27 also stores data received from the meter 11, the center device 30, and other wireless devices 20, and data to be transmitted to these devices.

[0022] The calculation unit 26 is configured with processors such as a CPU and an MPU, and executes a program stored in the storage unit 27. As a result, the control device 21 controls the operation of the components of the wireless device 20 based on input data from the communication device and the third communication interface 25, and executes various processes such as FOTA operations. Note that the control device 21 may be configured with a single device, or may be configured with multiple devices distributed and configured to operate the control device 21 in cooperation with each other.

[0023] The communication device has a first communication interface 23 and a second communication interface 24. The first communication interface 23 is a communication interface for wireless communication for the first communication network 12, and is electrically connected to a first antenna 28. As a result, the first communication interface 23 is connected to a base station 12a of the first communication network 12 by wireless communication via the first antenna 28. The first communication interface 23 receives data transmitted from the center device 30 via the first communication network 12 by the first antenna 28 and inputs the data to the control device 21, or transmits data to the center device 30 via the first communication network 12 by the first antenna 28 under the control of the control device 21.

[0024] Moreover, the second communication interface 24 is a communication interface for wireless communication for the second communication network 13, and is electrically connected to the second antenna 29. As a result, the second communication interface 24 is connected by wireless communication to the second antenna 29 of the other wireless device 20 that can communicate via the second antenna 29. The second communication interface 24 receives data transmitted from the other wireless device 20 via the second antenna 29 and inputs the data to the control device 21, and transmits data to the other wireless device 20 via the second antenna 29 under the control of the control device 21.

[0025] Moreover, the third communication interface 25 is a communication interface for wired communication, and is connected to the meter 11 by a cable. As a result, the third communication interface 25 receives data from the meter 11 and inputs the data to the control device 21, and transmits data to the meter 11 under the control of the control device 21. Note that the wireless device 20 may be connected to the meter 11 by wireless communication via a wireless communication interface.

[0026] <Communication functions> 1, multiple wireless devices 20 in a wireless communication system 10 belong to a second communication network 13 and include a wireless slave device 20a and a wireless master device 20b that relays data transmission between the wireless slave device 20a and a center device 30. The communication functions of the wireless slave device 20a and the wireless master device 20b include a first communication function for communicating using the first communication network 12 via a first communication interface 23, and a second communication function for communicating using the second communication network 13 via a second communication interface 24.

[0027] The wireless master device 20b enables a first communication function by the first communication interface 23 and a second communication function by the second communication interface 24 in order to relay communication between the wireless slave device 20a and the center device 30. As a result, the wireless master device 20b transmits and receives data to and from the center device 30 via the first communication network 12, and transmits and receives data to and from other wireless slave devices 20a with which it can communicate via the second communication network 13.

[0028] When communicating with the center device 30 using the first communication network 12, the wireless slave device 20a enables the first communication function. As a result, the wireless slave device 20a transmits and receives data to and from the center device 30 directly via the first communication network 12 without going through the wireless master device 20b. In this case, the wireless slave device 20a may disable the second communication function. Also, the wireless slave device 20a may enable the second communication function, and in this case, the first communication function may be prioritized over the second communication function.

[0029] When the wireless slave unit 20a communicates with other wireless slave units 20a and the wireless master unit 20b that can communicate using the second communication network 13, it disables the first communication function and enables the second communication function. As a result, the wireless slave unit 20a transmits and receives data with other communicable wireless slave units 20a or the wireless master unit 20b in the second communication network 13, and relays the data transmission between the other wireless slave units 20a and the wireless master unit 20b. In this way, the wireless slave unit 20a transmits and receives data with the wireless master unit 20b directly without passing through other wireless slave units 20a, or via one or more other wireless slave units 20a, and transmits and receives data with the center device 30 via the wireless master unit 20b.

[0030] <Second communication network> In the second communication network 13, the data transmitted from the wireless slave unit 20a is transmitted from the wireless slave unit 20a to the wireless master unit 20b based on the rank. This rank is the minimum number of hops from the wireless slave unit 20a to the wireless master unit 20b and is stored in the storage unit 27. The rank of the wireless master unit 20b is the minimum value of 0, and the rank of the wireless slave unit 20a that can communicate directly with the wireless master unit 20b without passing through other wireless slave units 20a is 1. And as the number of wireless slave units 20a relaying between the wireless master unit 20b increases, the rank of the wireless slave unit 20a increases. The wireless devices 20 (wireless master unit 20b and wireless slave units 20a) in the second communication network 13 are updated by the exchange process of the hop count table.

[0031] Note that in the example of FIG. 1, there is one wireless master unit 20b in the second communication network 13, but the number of wireless master units 20b is not limited to this. A plurality of wireless master units 20b may belong to the same second communication network 13. In this case, the wireless slave unit 20a belonging to this second communication network 13 has a hop count for each of the plurality of wireless master units 20b, and the smallest of these plurality of hop counts is the rank of the wireless slave unit 20a.

[0032] <FOTA operation> In this way, the wireless device 20 can communicate with the center device 30 via the first communication network 12, and can communicate with other wireless devices 20 via the second communication network 13. Therefore, the FOTA operation in which the wireless device 20 receives firmware data includes a first FOTA operation using the first communication network 12 and a second FOTA operation using the second communication network 13.

[0033] The communication speed of the first communication network 12 is faster than the communication speed of the second communication network 13, and the amount of data that can be transmitted at one time by the first communication network 12 is greater than the amount of data that can be transmitted at one time by the second communication network 13. Therefore, when transmitting the same amount of data, it is faster to use the first communication network 12 than to use the second communication network 13. Therefore, the wireless device 20 attempts a first FOTA operation using the first communication network 12, and if the first FOTA operation cannot be performed, performs a second FOTA operation using the second communication network 13.

[0034] In this second FOTA operation, when the wireless device 20 receives firmware data from another wireless device 20 through the second communication network 13, the wireless device 20 receives data from a higher-ranked wireless device 20 that is lower in rank than the wireless device 20 in the second communication network 13. In this case, since the firmware version of the higher-ranked wireless device 20 is newer than the version of the wireless device 20, the wireless master device 20b that is the wireless device 20 with the lowest rank in the second communication network 13 does not receive firmware data from the other wireless device 20. Therefore, in the FOTA operation, the wireless master device 20b does not execute the second FOTA operation but executes the first FOTA operation. In contrast, the wireless slave device 20a can execute the first FOTA operation and the second FOTA operation, and in the second FOTA operation, receives data from a higher-ranked wireless slave device 20a or a wireless master device 20b that is lower in rank than the wireless device in the second communication network 13.

[0035] Therefore, in the FOTA operation, when the center device 30 acquires a new version of firmware, it transmits a FOTA instruction to the wireless master device 20b via the first communication network 12. The wireless master device 20b executes the first FOTA operation in accordance with the FOTA instruction, receives and stores firmware data from the center device 30 via the first communication network 12, and updates the firmware to the new version.

[0036] Also, the wireless master device 20b transmits a FOTA instruction to the wireless slave device 20a via the second communication network 13. In response to this, the wireless slave device 20a executes a first FOTA operation in accordance with the FOTA instruction, receives and stores firmware data from the center device 30 via the first communication network 12, and updates the firmware to a new version. However, there are cases where the first FOTA operation cannot be executed, such as when the wireless slave device 20a cannot connect to the first communication network 12, and when the wireless slave device 20a cannot start receiving firmware data within a predetermined time even if it connects to the first communication network 12. In this case, the wireless slave device 20a executes a second FOTA operation, receives and stores firmware data from the upper wireless slave device 20a or the wireless master device 20b via the second communication network 13, and updates the firmware to a new version.

[0037] <Cyclic operation> 3, the wireless device 20 communicates with other wireless devices 20 intermittently via the second communication network 13 using, for example, a Receiver Initiated Transmission (RIT) method from the viewpoint of low power consumption. This intermittent operation includes transmission of a beacon, a first reception waiting state after transmission of the beacon, and a pause state after the first reception waiting state. In the periodic operation, the intermittent operation is executed periodically.

[0038] In this intermittent operation, power is consumed by transmitting beacons and waiting for the first reception. Therefore, when the frequency of communication of the wireless device 20 is low, such as when no data other than beacons is transmitted or received, or when the amount of data is small and the number of times data is transmitted or received is small, if the transmission period of the beacons is set to the shortest period at which the wireless device 20 can transmit, for example, every second, the power consumption becomes large. Therefore, if the beacons are always transmitted every second, the life of the battery 22 cannot be extended for 10 years.

[0039] Therefore, when the communication frequency is low as in the example of Fig. 3, the wireless device 20 can reduce power consumption due to beacon transmission and first reception waiting by transmitting a beacon at a first period longer than the shortest period, for example, every 5 seconds. For example, in the case of gas meter reading, 5 seconds is adopted as the first period, which is the beacon transmission period that minimizes power consumption over 10 years, depending on the frequency of transmission of meter reading values ​​and alarms to the center device 30 and the frequency of reception of maintenance communication from the center device 30.

[0040] On the other hand, when the wireless device 20 communicates frequently because of a large amount of data such as firmware data, the wireless device 20 transmits beacons at a second cycle that is shorter than the first cycle. This allows the wireless device 20 to keep the overall power consumption low on average.

[0041] In the periodic operation shown in Fig. 3, the transmission of beacons is indicated by dotted lines, and the transmission of data other than beacons is indicated by solid lines. In the following, the operation when a trigger for transmitting data (data transmission trigger) occurs in the lower-level wireless device 20 in the second communication network 13 will be described, but the operation when a trigger for data transmission occurs in the upper-level wireless device 20 may be performed in a similar manner.

[0042] 3, all wireless devices 20 constituting the second communication network 13 transmit beacons including an RIT Data Request identifier, identification information of the second communication network 13 to which the wireless device belongs, identification information of the wireless device itself, and a rank in a first period via the second communication network 13. Since the wireless device 20 is asynchronous with the other wireless devices 20, it transmits the beacon at its own timing.

[0043] In this case, the wireless device 20 enters a first reception waiting state in which communication such as data transmission and reception is possible for a first time period shorter than the first period from the transmission of the beacon. Furthermore, after the first reception waiting state, the wireless device 20 enters a sleep state in which this communication operation is paused for a second time period longer than the first time. In this way, the wireless device 20 executes a cyclic operation in which an intermittent operation including the transmission of the beacon, the first reception waiting state, and the sleep state is repeated in a first period. This sleep state reduces power consumption.

[0044] For example, when a lower-level wireless device 20 transmits data such as a meter reading value at a fixed time, a trigger (data transmission trigger) occurs that requires the lower-level wireless device 20 to transmit the data such as the meter reading value at this fixed time. Then, from the occurrence of this data transmission trigger, the lower-level wireless device 20 enters a second reception waiting state in which communication such as sending and receiving data is possible for a third time that is longer than the first reception waiting state time. Then, when the lower-level wireless device 20 receives a beacon from another wireless device 20 in the second reception waiting state, it transmits a link request to the higher-level wireless device 20 that is the wireless device 20 that transmitted the beacon.

[0045] When the upper radio device 20 receives a link request in the first reception waiting state after transmitting a beacon, it checks the identification information of the second communication network 13 and the destination information included in the link request against the identification information of the second communication network 13 stored in the upper radio device 20 and its own identification information. If the check is successful, the upper radio device 20 transmits a link acknowledgement in response to the link request to the lower radio device 20. As a result, when the lower radio device 20 receives the link acknowledgement, a link between the lower radio device 20 and the upper radio device 20 is established.

[0046] Furthermore, when the higher-level radio device 20 transmits a link acknowledgement, it extends the time of the first reception waiting state longer than the first time so as to be able to receive data from the lower-level radio device 20. In response to this, when the lower-level radio device 20 receives a link acknowledgement from the higher-level radio device 20 in the second reception waiting state, it transmits the data to the higher-level radio device 20. In response to this, when the higher-level radio device 20 receives data in the first reception waiting state, it transmits a reception response to the data to the lower-level radio device 20, then releases the link with the lower-level radio device 20, ends the first reception waiting state, and goes into a dormant state. When the lower-level radio device 20 receives a reception response in the second reception waiting state, it releases the link with the higher-level radio device 20, ends the second reception waiting state, and goes into a dormant state until the transmission of the next beacon.

[0047] The upper and lower wireless devices 20 transmit beacons in the first cycle even during such link establishment and data transmission / reception. However, these wireless devices 20 skip transmitting the beacon if the timing of transmitting the beacon is during a communication state such as a second reception waiting state.

[0048] <Second FOTA operation> In this way, when the data to be transmitted is larger than the amount of data that can be transmitted at one time, the wireless device 20 divides the data into multiple pieces and repeats the transmission of the divided data until all the divided data has been transmitted. Therefore, when transmitting data such as firmware that is much larger than the amount of data that can be transmitted at one time, it takes a very long time for the wireless device 20 to transmit all the data. For example, the amount of transmittable data is 100 bytes, while the amount of firmware data is 1 megabyte.

[0049] While transmitting this data, the wireless device 20 cannot communicate with other wireless devices 20. This may cause problems such as the wireless device 20 being unable to transmit data such as meter readings at a scheduled time. In addition, in the second communication network 13 formed by the wireless device 20, data is transmitted by the wireless device 20 relaying the data transmission, which may cause problems in the transmission of data such as meter readings of other wireless devices 20.

[0050] For this reason, as shown in Fig. 4, when the wireless device 20 transmits and receives firmware data via the second communication network 13 in the second FOTA operation, the wireless device 20 transmits beacons in a second cycle that is shorter than the first cycle. For example, the first cycle is 5 seconds, whereas the second cycle is the shortest cycle of 1 second. The wireless device 20 transmits beacons in the second cycle while transmitting and receiving data such as firmware data, but skips the transmission of the beacons if the timing of the transmission of the beacons is during a communication state such as a second reception waiting state. Also, in Fig. 4, as in Fig. 3, the transmission of beacons is indicated by dotted lines, and the transmission of data other than beacons is indicated by solid lines.

[0051] Specifically, when the lower-level radio device 20 executes the second FOTA operation in response to the FOTA instruction, a data transmission trigger for a first data request that requests the first data, which is the first data among the firmware data, occurs. As a result, the lower-level radio device 20 enters the second reception waiting state for a third time, which is longer than the first time, from the occurrence of the data transmission trigger for the first data request. Then, when the lower-level radio device 20 receives a beacon from the higher-level radio device 20, which is another radio device 20, in this second reception waiting state, it transmits a link request to the higher-level radio device 20. In response to this, when the higher-level radio device 20 receives a link request in the first reception waiting state immediately after transmitting the beacon, it checks the identification information and destination information of the second communication network 13 included in this link request against the identification information of the second communication network 13 stored in the device and its own identification information, and if the check is successful, it transmits a link acknowledgement for the link request. As a result, when the lower-level radio device 20 receives the link acknowledgement in the second reception waiting state, a link between the lower-level radio device 20 and the higher-level radio device 20 is established. Furthermore, when the higher-level wireless device 20 transmits the link acknowledgement, the higher-level wireless device 20 extends the first reception waiting state beyond the first time period so that the higher-level wireless device 20 can receive data from the lower-level wireless device 20.

[0052] Then, when the lower radio device 20 receives a link acknowledgement in the second reception waiting state, it cancels the first cycle for the subsequent beacon transmission cycle and sets it to the second cycle, and transmits beacons in the second cycle. Then, the lower radio device 20 transmits a first data request, which is a firmware data request, to the higher radio device 20. Note that the lower radio device 20 may change the beacon transmission cycle from the first cycle to the second cycle when a data transmission trigger for the first data request occurs.

[0053] When the upper-level radio device 20 receives a first data request for firmware in the first reception waiting state, a data transmission trigger occurs to transmit the first data of the firmware in response to the first data request. Therefore, the upper-level radio device 20 cancels the first cycle for the transmission cycle of subsequent beacons and sets it to the second cycle, and transmits beacons in the second cycle. In addition, when the upper-level radio device 20 receives the first data request, it transmits a reception response to the first data request to the lower-level radio device 20, and then ends the first reception waiting state and enters a second reception waiting state triggered by the occurrence of the data transmission trigger for the first data.

[0054] In response to this, when the lower-level wireless device 20 receives a reception response to the first data request in the second reception waiting state, it ends the second reception waiting state and goes into a hibernation state. Then, the lower-level wireless device 20 ends the hibernation state at the timing of the second period, transmits a beacon, and goes into the first reception waiting state after transmitting the beacon.

[0055] The higher-level radio device 20 receives this beacon in the second reception waiting state, and if the source data of the beacon matches the source data of the first data request, it transmits a link request to the lower-level radio device 20. When the lower-level radio device 20 receives the link request in the first reception waiting state, it checks the identification information and destination information of the second communication network 13 included in the link request against data stored in the device, and if the check is successful, it transmits a link acknowledgement to the higher-level radio device 20. As a result, when the higher-level radio device 20 receives the link acknowledgement in the second reception waiting state, a link between these radio devices 20 is established. Furthermore, when the lower-level radio device 20 transmits the link acknowledgement, it extends the time of the first reception waiting state to be longer than the first time so that it can receive data from the higher-level radio device 20.

[0056] Then, the upper radio device 20 acquires firmware data from the storage unit 27, divides the data, and acquires first data, which is divided data including the first data of the firmware, in response to the first data request of the firmware. Furthermore, when there is divided data remaining in the firmware data to be transmitted next to the first data, the upper radio device 20 attaches a flag indicating that next data is present to the first data and transmits it to the lower radio device 20.

[0057] In response to this, when the lower-level radio device 20 receives the first data from the upper-level radio device 20 in the first reception waiting state, the lower-level radio device 20 stores the first data in the storage unit 27. Furthermore, when a flag indicating that next data is present is added to the first data, the lower-level radio device 20 generates a data transmission trigger for a second data request that requests the second data, which is the next divided data of the first data among the divided data of the firmware. Therefore, when the lower-level radio device 20 transmits a reception response of the first data to the upper-level radio device 20, the lower-level radio device 20 ends the first reception waiting state and then enters a second reception waiting state, which is triggered by the occurrence of the data transmission trigger for the second data request.

[0058] Furthermore, the higher-level wireless device 20 receives a reception response to the first data from the lower-level wireless device 20 in the second reception waiting state. This allows the lower-level wireless device 20 and the higher-level wireless device 20 to confirm that the divided data has been transmitted and received. Then, when the higher-level wireless device 20 receives the reception response to the first data, it ends the second reception waiting state and goes into a pause state until the next beacon transmission.

[0059] In this way, the upper radio device 20 and the lower radio device 20 repeat a series of operations from transmitting a data request for divided data of firmware, to transmitting the divided data in response to the data request, and further receiving a reception response to the divided data. As a result, the lower radio device 20 sequentially receives the divided data of firmware and stores it in the storage unit 27. Then, when there is no divided data to be transmitted next among the divided data of firmware, the upper radio device 20 attaches a flag of the final data to the final divided data and transmits it. In response to this, when the lower radio device 20 receives the final divided data and stores it in the storage unit 27, it transmits a reception response to the final divided data. Also, since the lower radio device 20 does not generate a data transmission request for the next data request due to the flag of the final data, the lower radio device 20 and the upper radio device 20 end the second FOTA operation and change the transmission period of the beacon from the second period to the first period.

[0060] Then, the lower-level radio device 20 performs a verify check on the acquired firmware, and if the firmware has been acquired correctly, updates the firmware currently being used to the firmware acquired in this second FOTA operation.The lower-level radio device 20 then changes (updates) the version number of the firmware stored in the storage unit 27 to the version number of the updated firmware.

[0061] <Radio operation> The lower radio device 20 is controlled by the control device 21, for example, in accordance with a flowchart showing an example of a control method for the radio device 20 in Fig. 5. First, the lower radio device 20 monitors whether or not it acquires a FOTA command from the upper radio device 20 (step S1). When the lower radio device 20 acquires a FOTA command (step S1: YES), it determines whether or not it is possible to acquire firmware data via the first communication network 12 (step S2). Here, if the lower radio device 20 is able to acquire firmware data via the first communication network 12 (step S2: YES), it executes a first FOTA operation and acquires the firmware data via the first communication network 12 (step S3).

[0062] On the other hand, if the lower radio device 20 cannot acquire firmware data via the first communication network 12 (step S2: No), it transmits a request for the firmware version to the upper radio device 20 (step S4). When the upper radio device 20 receives the request for the version, it acquires its own firmware version and transmits it to the lower radio device 20. When the lower radio device 20 receives the version from the upper radio device 20, it determines whether the received version of the upper radio device 20 is newer than the firmware version of the lower radio device (step S5). When the version of the upper radio device 20 is the same as or older than the version of the upper radio device 20, that is, when the version of the upper radio device 20 is not newer than the version of the lower radio device (step S5: No), there is no need to update the firmware, and the process ends.

[0063] On the other hand, if the version number of the upper radio device 20 is newer than that of the lower radio device 20 (step S5: YES), a firmware data request is generated as transmission data. Therefore, the lower radio device 20 executes the second FOTA operation and establishes a link with the upper radio device 20. Then, the lower radio device 20 changes the transmission period of the beacon from the first period to a second period that is shorter than the first period (step S6), and transmits the beacon at the second period.

[0064] Then, the lower radio device 20 transmits a firmware data request (step S7), and the upper radio device 20 transmits the divided data of the firmware in response to the data request. In response to this, the lower radio device 20 receives the divided data of the firmware from the upper radio device 20 in the first reception waiting state and stores it in the storage unit 27 (step S8). Then, the lower radio device 20 determines whether the divided data received from the upper radio device 20 is the final data of the divided data of the firmware (step S9).

[0065] Here, if a flag indicating that next data is present is added to the divided data received in step S8, the lower-level radio device 20 determines that the divided data is not the last one (step S9: NO).Then, the lower-level radio device 20 repeats the processes of steps S7 to S9 until it receives the last divided data.Therefore, the lower-level radio device 20 sequentially receives the divided data of the firmware and stores it in the storage unit 27.

[0066] If the final data flag is added to the divided data received in step S8, the lower-level wireless device 20 determines that the divided data is final (step S9: YES). As a result, the lower-level wireless device 20 has received all the divided data of the firmware, so it ends the second FOTA operation, returns the beacon period from the second period to the first period (step S10), and transmits beacons at the first period.

[0067] In this way, the lower-level radio device 20 receives the firmware data by the first FOTA operation in step S3 or the second FOTA operation in steps S8 to S9. As a result, the lower-level radio device 20 updates the firmware to this firmware, and changes the version number stored in the storage unit 27 to the version number of this updated firmware.

[0068] According to the above configuration, when the lower-level radio device 20 cannot acquire firmware data via the first communication network 12, the lower-level radio device 20 acquires the firmware data via the second communication network 13. This enables the lower-level radio device 20 to more reliably receive firmware data and update the firmware.

[0069] Furthermore, the lower-level radio device 20 and the upper-level radio device 20 transmit beacons at a second period shorter than the first period while transmitting and receiving the divided data of the firmware via the second communication network 13. Then, the lower-level radio device 20 receives the divided data of the firmware in the first reception waiting state immediately after transmitting the beacon. This shortens the time interval at which the lower-level radio device 20 receives the divided data, and the second FOTA operation of transmitting and receiving the firmware data can be performed quickly.

[0070] Furthermore, when a data transmission event occurs, the wireless device 20 enters a second reception waiting state triggered by the occurrence of the event. In this second reception waiting state, the wireless device 20 transmits and receives data, such as waiting to receive a beacon from another wireless device 20, transmitting a link request after receiving a beacon, receiving a link acknowledgement in response to the link request, transmitting data, and receiving a reception response to the data.

[0071] On average, the beacon reception waiting time is half the beacon transmission cycle, and the data transmission / reception time is 0.1 seconds. Therefore, when the beacon transmission cycle is the first cycle, for example, 5 seconds, the beacon reception waiting time is 2.5 seconds. In this case, the time in the second reception waiting state is 2.6 seconds (data transmission / reception time 0.1 seconds + beacon reception waiting time 2.5 seconds = 2.6 seconds), and the beacon reception waiting time occupies more than 90% of the time in the second reception waiting state.

[0072] On the other hand, when the beacon transmission period is a second period shorter than the first period, for example, 1 second, the beacon reception waiting time is 0.5 seconds. In this case, the time of the second reception waiting state is 0.6 seconds (data transmission / reception time 0.1 seconds + beacon reception waiting time 0.5 seconds). In this way, by changing the beacon transmission period from the first period to the second period, the time of the second reception waiting state becomes 0.6 seconds / 2.6 seconds x 100 = 23%. In this way, the time of the second reception waiting state becomes about one-fourth, and the power consumption of the second reception waiting state also becomes about one-fourth. Therefore, the power consumption of the second reception waiting state can be kept low, and the frequency of replacing the battery 22, which is the power source of the wireless device 20, can be reduced.

[0073] Furthermore, among all the wireless devices 20 included in the second communication network 13, the wireless devices 20 that transmit and receive firmware data in the second FOTA operation transmit beacons in the second cycle. In this way, the beacon transmission cycle is the second cycle, which is shorter than the first cycle, so that firmware data accompanying the transmission of the beacons can be transmitted and received quickly. On the other hand, the wireless devices 20 that transmit and receive data other than firmware transmit beacons in the first cycle, which is longer than the second cycle, so that an increase in power consumption accompanying the transmission of the beacons can be suppressed.

[0074] <Variation 1> In the wireless communication system 10 according to the first modification, in the above embodiment, the control device 21 receives the time data together with the firmware version number in the first reception waiting state, and corrects the time based on the time data.

[0075] Specifically, the lower-level radio device 20 periodically requests time data from a higher-level radio device 20 than itself. Therefore, in the process of step S1 in Fig. 5, the lower-level radio device 20 may periodically request the firmware version number from the higher-level radio device 20 together with the request for time data. This time data is data for time correction of the radio device 20, and is periodically transmitted from the center device 30. In the second communication network 13, the higher-level radio device 20 transmits the time data and version number stored in the memory unit 27 to the lower-level radio device 20 in response to a request from the lower-level radio device 20.

[0076] When the lower-level radio device 20 receives the time data, it stores it in the memory unit 27 and executes a time correction operation based on this time data. In the time correction operation, the lower-level radio device 20 corrects the time it holds based on the time data. In this way, time data is transmitted sequentially from the higher-level radio device 20 to the lower-level radio device 20 in the second communication network 13, and all of the radio devices 20 in the second communication network 13 execute the time correction operation based on the same time data, so that the times are synchronized.

[0077] Furthermore, when the lower-level wireless device 20 receives the firmware version number, it executes the processes in and after step S5. In this way, by receiving the firmware version number together with the time data, the wireless device 20 can reduce the number of communications and the power consumption compared to receiving the version number and the time data separately.

[0078] Furthermore, even if the FOTA instruction is not acquired in S1 of Fig. 5, the wireless device 20 acquires the firmware version number in accordance with a periodic time request, which enables the wireless device 20 to determine by itself whether FOTA is necessary.

[0079] <Variation 2> In the wireless communication system 10 according to the second modification, in the above-mentioned embodiment and the first modification, the control device 21 transmits a beacon at a third period longer than the first period for a predetermined time after the end of the second FOTA operation, and then transmits a beacon at the first period.

[0080] For example, the wireless device 20 is controlled by the control device 21 in accordance with a flowchart showing an example of a control method of Fig. 6. In the flowchart of Fig. 6, processes of steps S11 and S12 are executed between the process of step S9 and the process of step S10 in the flowchart of Fig. 5.

[0081] Specifically, the lower-level wireless device 20 transmits beacons in the second cycle from when it starts the second FOTA operation in step S5: YES until it ends the second FOTA operation in step S9: YES. The higher-level wireless device 20 also transmits beacons in the second cycle while it is performing the second FOTA operation. Then, when these wireless devices 20 end the second FOTA operation, they change the beacon transmission cycle from the second cycle, which is shorter than the first cycle, to a third cycle, which is longer than the first cycle (step S11).

[0082] Then, these wireless devices 20 measure the time that has elapsed since the beacon transmission cycle was changed, and monitor whether or not this elapsed time reaches a predetermined time (step S12). Here, these wireless devices 20 transmit beacons in the third cycle until the elapsed time reaches the predetermined time (step S12: NO). Since the first time of the first reception waiting state in the periodic operation of the third cycle is the same as in the first cycle, the second time of the sleep state in the periodic operation of the third cycle is longer than in the periodic operation of the first cycle. In this way, since the sleep state is longer in the periodic operation of the third cycle than in the periodic operation of the first cycle, it is possible to suppress power consumption to a lower level in the periodic operation of the third cycle than in the periodic operation of the first cycle.

[0083] Then, when the elapsed time reaches a predetermined time (step S12: YES), these wireless devices 20 change the beacon transmission cycle from the third cycle to the first cycle (step S10). These wireless devices 20 transmit beacons at the first cycle in the cyclic operation.

[0084] In this way, in the second FOTA operation, the wireless device 20 transmits beacons in the second cycle, thereby shortening the time interval for receiving firmware data in the first reception waiting state immediately after transmitting the beacon, and the second FOTA operation can be performed quickly. Also, by transmitting beacons in the third cycle in the cyclic operation for a predetermined time after the second FOTA operation, the time interval for transmitting beacons is lengthened, and the power consumption due to beacon transmission can be reduced. Therefore, even if the power consumption increases in the second FOTA operation, the overall increase in power consumption can be mitigated by the reduction in power consumption thereafter.

[0085] <Other Modifications> In the wireless communication system 10 according to the above embodiment and all the modified examples, the wireless device 20 changes the beacon transmission period to the second period in the second FOTA operation for transmitting and receiving firmware data. However, the case where the beacon transmission period is changed to the second period is not limited to this. For example, the wireless device 20 may change the beacon transmission period to the second period when the second communication network 13 is constructed or updated, when polling, and when relaying data transmission. In such a case, since the number of data transmissions is large, the wireless device 20 can transmit and receive data quickly while synchronizing with the beacon by transmitting the beacon at the second period shorter than the first period.

[0086] Furthermore, when transmitting or receiving data of a predetermined amount or more, the wireless device 20 may change the transmission period of the beacon to the second period. In this way, when transmitting data of a predetermined amount or more that is larger than the amount of data that can be transmitted at one time, the wireless device 20 divides and transmits the data, so that it takes time to transmit all of the data. Even in such a case, the wireless device 20 can transmit and receive data quickly while synchronizing with the beacon by transmitting the beacon at the second period that is shorter than the first period.

[0087] In the wireless communication system 10 according to the above-described embodiment and all modified examples, firmware data is transmitted from a higher-level wireless device 20 to a lower-level wireless device 20 in the second communication network 13, but firmware data may be transmitted from a lower-level wireless device 20 to a higher-level wireless device 20 in the second communication network 13. In this case as well, when transmitting firmware data, the beacon transmission period is set to a second period that is shorter than the first period, so that the firmware data can be transmitted and received quickly.

[0088] In the wireless communication system 10 according to the above embodiment and all modified examples, the wireless device 20 sets the beacon transmission period to a second period shorter than the first period in the second FOTA operation, but the beacon transmission period may also be set to a fifth period shorter than the fourth period in the first FOTA operation.

[0089] That is, the wireless device 20 performs a periodic operation in communication with the center device 30 through the first communication network 12. This periodic operation, like the periodic operation through the second communication network 13 with other wireless devices 20 shown in the example of Fig. 3, periodically repeats an intermittent operation including transmission of a beacon, a first reception waiting state following the transmission, and a rest state thereafter. This periodic operation through the first communication network 12 is similar to the periodic operation through the second communication network 13, except for the period of the beacon. In the periodic operation through the first communication network 12, the wireless device 20 transmits a beacon at a fourth period (e.g., 15 seconds).

[0090] When transmitting / receiving data other than firmware to / from the center device 30, the wireless device 20 transmits a beacon in a fourth cycle and receives the data in a first reception waiting state after the beacon transmission. In contrast, when receiving firmware data from the center device 30, the wireless device 20 transmits a beacon in a fifth cycle, which is shorter than the fourth cycle, and transmits a data request to the center device 30. The center device 30 divides the firmware data and transmits the divided data in response to the data request to the wireless device 20. The wireless device 20 receives the divided data in response to the data request from the center device 30 in a first reception waiting state after the beacon transmission.

[0091] Except for the beacon period, this first FOTA operation is similar to the second FOTA operation in the example of Fig. 4. In this way, by transmitting a beacon at the fifth period, the wireless device 20 shortens the time interval for receiving firmware data in the first reception waiting state after the transmission of the beacon, so that the first FOTA operation for receiving firmware data can be quickly performed.

[0092] It should be noted that many improvements and other embodiments of the present disclosure will be apparent to those skilled in the art from the above description. Therefore, the above description should be construed as merely illustrative and is provided for the purpose of teaching those skilled in the art the best mode for carrying out the present disclosure. Details of the structure and / or function thereof may be substantially modified without departing from the spirit of the present disclosure.

[0093] <Additional Notes> The above description of the embodiment and modifications discloses the following techniques. Technique 1 is a radio device capable of transmitting and receiving firmware data to and from other radio devices in a multi-hop communication network including a plurality of radio devices, the radio device comprising a control device and a communication device, wherein when receiving data other than the firmware from the other radio devices using the communication device, the control device transmits a beacon at a first period and receives the data in a first reception waiting state after transmitting the beacon, and when receiving the firmware data from the other radio devices using the communication device, the control device transmits a data request while transmitting the beacon at a second period shorter than the first period and receives the firmware data in the first reception waiting state after transmitting the beacon.

[0094] According to this configuration, the firmware data is larger than the amount of data that the wireless device can transmit at one time, so the wireless device divides the data and transmits it. In this case, the wireless device transmits the beacon at a second period that is shorter than the first period, thereby shortening the time interval for receiving the firmware data in the first reception waiting state after transmitting the beacon. Therefore, the wireless device can quickly perform FOTA operations for transmitting and receiving the firmware data.

[0095] Technology 2 is the radio described in Technology 1, in which, when the control device transmits the firmware data to another radio via the communication device, while transmitting the beacon at the second period, the control device receives the data request in the first reception waiting state after transmitting the beacon, and transmits the firmware data in response to the data request.

[0096] According to this configuration, the wireless device transmits beacons at a second period shorter than the first period, thereby shortening the time interval for receiving firmware data requests in the first reception waiting state after transmitting a beacon. This shortens the time interval for the wireless device to transmit firmware data in response to a data request, enabling FOTA operations for transmitting and receiving firmware data to be performed quickly.

[0097] Technique 3 is the radio according to Technique 2, in which, when transmitting the firmware data to another radio via the communication device, the control device divides the firmware data, and in a second reception waiting state transmits the divided data of the firmware data in response to the data request, and receives a reception response to the divided data. With this configuration, the radio can confirm that it has been able to transmit the divided data to the other radio by receiving a reception response to the transmitted divided data from the other radio.

[0098] Technology 4 is the radio according to Technology 3, wherein, when the control device receives the divided data of the firmware from another radio device via the communication device, the control device receives the divided data in the first reception waiting state, and when the divided data is not the final data, transmits the data request requesting the next divided data in the second reception waiting state and receives a reception response to the data request. With this configuration, the radio device can confirm that the data request for the divided data was successfully transmitted to the other radio device by receiving a reception response to the data request for the transmitted divided data from the other radio device.

[0099] Technology 5 is the radio described in any one of Technology 1 to 4, wherein the multiple radio devices included in the communication network include a radio slave device and a radio master device that relays communication between the radio slave devices and a center device, and the control device receives the firmware data from the radio device whose rank, which is the minimum number of hops to the wireless master device in the communication network, is smaller than the rank of the control device.

[0100] According to this configuration, in the communication network, firmware data is transmitted from a higher-ranked wireless device to a lower-ranked wireless device, thereby suppressing data collisions and enabling smooth transmission of firmware data to wireless devices in the second communication network and rapid FOTA operation.

[0101] Technique 6 is a radio device according to any one of Techniques 1 to 5, wherein, if the version number of the firmware received from another radio device is newer than the version number of the firmware stored, the control device changes the transmission period of the beacon from the first period to the second period, and receives data of the firmware in the first reception waiting state after transmitting the beacon.

[0102] According to this configuration, if the firmware version number received from another wireless device is older than the firmware version number stored in the wireless device, the wireless device does not execute the FOTA operation to receive firmware data. Therefore, firmware with the same or older version number as the version number stored in the wireless device is not transmitted or received, and it is possible to avoid the execution of unnecessary FOTA operations.

[0103] Technique 7 is the wireless device according to technique 6, in which the control device receives time data together with the firmware version number, and corrects the time based on the time data.

[0104] According to this configuration, by receiving the firmware version number and the time data together, the wireless device can communicate less frequently and reduce power consumption associated with communication than if the wireless device received the firmware version number and the time data separately.

[0105] Technique 8 is a wireless communication system including a plurality of radio devices included in a multi-hop communication network, and among the plurality of radio devices, a radio device receiving data other than firmware transmits a beacon in a first period and receives the data in a first reception waiting state after the transmission of the beacon, and a radio device receiving the firmware data transmits the beacon in a second period shorter than the first period and transmits a data request, and receives the firmware data in the first reception waiting state after the transmission of the beacon.

[0106] According to this configuration, a wireless device performing FOTA operation can quickly perform FOTA operation to receive firmware data by transmitting a beacon in the second cycle, while a wireless device not performing FOTA operation can keep power consumption due to beacon transmission low by transmitting a beacon in the first cycle. [Explanation of symbols]

[0107] 10: Wireless communication systems 20: Radio 20a: Wireless adapter 20b: Wireless base station 21: Control device 23: First communication interface (communication device) 24: Second communication interface (communication device) 30: Center device

Claims

1. A wireless device capable of transmitting and receiving firmware data to and from other wireless devices in a multi-hop communication network including a plurality of wireless devices, A control device and a communication device, The control device includes: when receiving data other than the firmware from another wireless device by the communication device, transmitting a beacon in a first period while receiving the data in a first reception waiting state after transmitting the beacon; when receiving the firmware data from another wireless device by the communication device, transmitting a data request while transmitting the beacon at a second period shorter than the first period, and receiving the firmware data in the first reception waiting state after transmitting the beacon; Radio.

2. when transmitting the firmware data to another wireless device via the communication device, the control device receives the data request in the first reception waiting state after transmitting the beacon while transmitting the beacon in the second cycle, and transmits the firmware data in response to the data request.

2. A radio according to claim 1.

3. When transmitting the firmware data to another wireless device via the communication device, the control device divides the firmware data, and in a second reception waiting state, transmits the divided data of the firmware data in response to the data request, and receives a reception response to the divided data.

3. A radio according to claim 2.

4. when receiving the divided data of the firmware from another wireless device via the communication device, the control device receives the divided data in the first reception waiting state, and when the divided data is not the final data, transmits the data request requesting the next divided data in the second reception waiting state, and receives a reception response to the data request.

4. A radio according to claim 3.

5. The plurality of wireless devices included in the communication network include wireless slave devices and a wireless master device that relays communication between the wireless slave devices and a center device, the control device receives the firmware data from the wireless device having a rank, which is the minimum number of hops to the wireless master device in the communication network, that is smaller than the rank of the control device itself; 2. A radio according to claim 1.

6. when the version number of the firmware received from another wireless device is newer than the version number of the firmware stored in the memory, the control device changes the transmission cycle of the beacon from the first cycle to the second cycle, and receives data of the firmware in the first reception waiting state after the transmission of the beacon.

2. A radio according to claim 1.

7. The control device includes: receiving time data together with the firmware version number; Correcting the time based on the time data.

7. A radio according to claim 6.

8. A multi-hop communication network includes a plurality of wireless devices, Among the plurality of radio devices, the wireless device receiving data other than firmware transmits a beacon in a first period and receives the data in a first reception waiting state after transmitting the beacon; the wireless device receiving the firmware data transmits a data request while transmitting the beacon at a second period shorter than the first period, and receives the firmware data in the first reception waiting state after transmitting the beacon. Wireless communication system.

Images