JP7577495B2 - Wireless communication device, information processing device, wireless communication method, and program - Google Patents

Description

The present invention relates to wireless communication technology.

Sensor data collection systems are known that use wired communication to collect sensor data from multiple sensor devices to a gateway, such as systems that monitor the voltage of battery cells and systems that monitor the operating status of equipment in a factory.

In recent years, there has been an increasing demand to replace wired communication with wireless communication in sensor data collection systems. Among these, the use of Bluetooth (registered trademark) LE (Low Energy), a low-power wireless communication, has been attracting attention.

When collecting sensor data from multiple sensor devices using Bluetooth LE, a method is adopted in which a connection is established between a gateway (Master) that receives the sensor data and a sensor device (Slave) that transmits the sensor data, and communication is carried out. With this method, the maximum number of sensor devices that can be connected to one gateway is several dozen. To collect sensor data from a greater number of sensor devices, multiple gateways must be used.

In an environment where multiple gateways are installed, due to the specifications of Bluetooth LE, a situation may arise in which communication between one gateway and its subordinate sensor devices and communication between another gateway and its subordinate sensor devices are carried out at the same time and on the same channel. In this situation, radio wave interference occurs, disrupting communication, which may result in the loss of sensor data.

Bluetooth LE uses frequency hopping to change the channel used for communication over time. This makes it possible to avoid interference over time, even if the above-mentioned interference does occur.

In a sensor data collection system, it may be necessary to continuously obtain sensor data from a large number of sensor devices at short time intervals without any loss. In other words, there are cases where the loss of sensor data cannot be ignored as a system. The frequency hopping of Bluetooth LE does not ensure that radio interference can be avoided, and in an environment where multiple gateways using Bluetooth LE are in close proximity, loss of sensor data due to radio interference will occur.

Patent Document 1 discloses a technology that prevents packet errors caused by radio interference even when multiple voice links of frequency hopping spread spectrum short-distance wireless communication exist in a short distance space. The technology of Patent Document 1 prepares multiple non-overlapping AFH (Adaptive Frequency Hopping) channel maps in advance, and the main unit assigns different channel maps to the base unit according to the base unit's TEN number (extension terminal number). In the technology of Patent Document 1, the number of selectable channel maps is limited, so the number of base units must be known. For example, if the number of channel maps is smaller than the number of base units, radio interference will occur, and if the number of channel maps is greater than the number of base units, the communication bandwidth will be unnecessarily narrowed.

JP 2006-270609 A

The technology in Patent Document 1 uses the AFH function that is standard on Bluetooth (Classic) to determine the initial channel used by the parent device, so no radio interference occurs at first, but the effect disappears over time.

Bluetooth LE does not implement the AFH function. For this reason, the technology of Patent Document 1 cannot be applied to a sensor data collection system that uses Bluetooth LE.

In sensor data collection systems that use wireless communication such as Bluetooth LE, there is a demand for interference to not occur from the start and for interference to be permanently avoided.

In one embodiment of the present invention, a wireless communication device corresponding to a single master node in a network including the master node and at least one slave node includes a scanning unit that performs a scanning process to receive beacon signals from other wireless communication devices, a determination unit that determines the number of master nodes present in the surrounding environment of the wireless communication device and the order of the wireless communication devices based on the result of the scanning process, a selection unit that selects one channel map from a plurality of predetermined channel maps based on the determined number of master nodes and the determined order, and a first communication unit that communicates with the at least one slave node according to the selected channel map.

The present invention provides technology to avoid radio interference between networks.

FIG. 1 is a diagram showing a communication system according to an embodiment of the present invention. FIG. 2 is a functional block diagram of the gateway shown in FIG. FIG. 3 is a diagram showing channel information stored in the storage unit shown in FIG. FIG. 4 is a diagram for explaining channel setting in the communication system shown in FIG. FIG. 5 is a block diagram illustrating an example of a hardware configuration of the gateway illustrated in FIG. FIG. 6 is a functional block diagram of the sensor device shown in FIG. FIG. 7 is a block diagram illustrating an example of a hardware configuration of the sensor device illustrated in FIG. FIG. 8 is a flowchart showing a process for setting a channel by the gateway shown in FIG.

The following describes an embodiment of the present invention with reference to the drawings.

[composition]
Fig. 1 is a schematic diagram of a communication system 100 according to an embodiment of the present invention. As shown in Fig. 1, the communication system 100 includes a plurality of gateways 110, a plurality of sensor devices 120, and a server device 130. The communication system 100 is an IoT network in which the server device 130 collects sensor data from the sensor devices 120 via the gateways 110.

The sensor device 120 measures the state of the location or equipment in which the sensor device 120 is installed and generates sensor data including the state measurement results.

The gateway 110 relays signals between the sensor device 120 and the server device 130. For example, the gateway 110 receives sensor data from the sensor device 120 and transmits the sensor data to the server device 130.

For communication between the gateway 110 and the sensor device 120, wireless communication such as Bluetooth LE is used. In this embodiment, Bluetooth LE is used. In Bluetooth LE, a network is formed by a single master node and at least one slave node connected to the master node. The master node controls communication in the network. For example, the master node notifies the slave node of the frequency channel to be used. The gateway 110 is equipped with a wireless communication device used as the master node, and the sensor device 120 is equipped with a wireless communication device used as the slave node.

Communication between the server device 130 and the gateway 110 may be performed using wireless communication or wired communication. When using wireless communication, wireless communication using a frequency band different from the frequency band (2.4 GHz band) used for communication between the gateway 110 and the sensor device 120 may be used. In this embodiment, 5 GHz band Wi-Fi is used.

The wireless communication device of the gateway 110 has an individual communication area 112. The communication area 112 corresponds to the range where the wireless signal transmitted by the wireless communication device of the gateway 110 can reach. The communication areas 112 partially overlap each other. The gateways 110 are placed within the range where each other's wireless radio waves can reach. Preferably, the gateways 110 are placed in an environment where they are less susceptible to the influence of wireless radio waves from other systems.

In the example shown in FIG. 1, the communication system 100 has three gateways 110-1, 110-2, and 110-3. The gateways 110-1, 110-2, and 110-3 have communication areas 112-1, 112-2, and 112-3, respectively. The communication areas 112-1, 112-2, and 112-3 partially overlap each other. The gateway 110-1 communicates with sensor devices 120-1 to 120-6, and the gateway 110-1 and the sensor devices 120-1 to 120-6 form a network. The gateway 110-2 communicates with sensor devices 120-7 to 120-12, and the gateway 110-2 and the sensor devices 120-7 to 120-12 form another network. Gateway 110-3 communicates with sensor devices 120-13 to 120-18, and gateway 110-3 and sensor devices 120-13 to 120-18 form yet another network.

In the area surrounded by the dashed line in FIG. 1, radio interference between networks using Bluetooth LE may occur. Radio interference may cause loss of sensor data. In this embodiment, the communication system 100 controls the networks to use different frequency channels in order to avoid radio interference between the networks. A method for controlling the networks to use different channels will be described later.

FIG. 2 shows an example of a schematic functional configuration of a gateway 110. The gateway 110 shown in FIG. 2 corresponds to one of the gateways 110 shown in FIG. 1. The remaining gateways 110 shown in FIG. 1 may have the same functional configuration as the gateway 110 shown in FIG. 2.

As shown in FIG. 2, the gateway 110 includes a first communication unit 202, an advertising unit 204, a scanning unit 206, a second communication unit 208, a control unit 210, and a memory unit 220. The control unit 210 controls the first communication unit 202, the advertising unit 204, the scanning unit 206, the second communication unit 208, and the memory unit 220. The first communication unit 202, the advertising unit 204, the scanning unit 206, and the control unit 210 correspond to the wireless communication device of the present invention.

The first communication unit 202 wirelessly communicates with the sensor device 120. As described above, Bluetooth LE is used for communication between the gateway 110 and the sensor device 120. Therefore, the first communication unit 202 performs communication processing that complies with Bluetooth LE. The first communication unit 202 receives sensor data from the sensor device 120.

The advertising unit 204 performs advertising processing at a predetermined time interval, broadcasting an advertisement packet including a Bluetooth device address (BD address) and a universally unique identifier (UUID). This time interval is called an advertising interval. The advertising processing includes broadcasting an advertisement packet on 37ch (channel with ID=37), broadcasting an advertisement packet on 38ch, and broadcasting an advertisement packet on 39ch. The advertisement packet corresponds to a beacon signal. The Bluetooth address is device-specific information, and more specifically, is identification information uniquely assigned to a Bluetooth device. The UUID is, for example, a service UUID.

The scanning unit 206 performs a scanning process to receive advertisement packets from other gateways 110 at a predetermined time interval. This time interval is called a scan interval. The scanning process is performed over a time period called a scan window. When the scanning unit 206 receives an advertisement packet from another gateway 110, it sends the received advertisement packet to the control unit 210.

The control unit 210 performs channel setting. Channel setting is a process for setting a channel to be used for communication with the sensor device 120. The control unit 210 refers to the channel information stored in the storage unit 220 to perform channel setting. The channel information is information that associates multiple channel maps with a set of the number of master nodes and an order. Each channel map indicates a set of channels. The control unit 210 includes a determination unit 212 and a selection unit 214.

The determination unit 212 determines the number of master nodes present in the surrounding environment of itself (wireless communication device of the gateway 110) and its own order (ranking) based on the result of the scan process by the scan unit 206. The surrounding environment of the gateway 110 indicates the environment in which the gateway 110 is installed. The determination unit 212 determines the number of master nodes based on the number of wireless communication devices that transmit advertisement packets including predetermined information (UUID in this embodiment). Specifically, the determination unit 212 sets the number of master nodes to a value obtained by adding 1 to the number of wireless communication devices that transmit advertisement packets including UUID. The determination unit 212 determines the order based on a comparison between its own BD address and the BD address included in the received advertisement packet. For example, the determination unit 212 determines the order according to the order in which its own BD address is the largest among multiple BD addresses including its own BD address and the BD address included in the received advertisement packet.

The selection unit 214 selects one channel map from among the multiple channel maps based on the number and order of master nodes determined by the determination unit 212. Specifically, the selection unit 214 refers to the channel information stored in the storage unit 220, and selects a channel map associated with the determined combination of the number and order of master nodes from among the multiple channel maps included in the channel information.

The first communication unit 202 communicates with the sensor device 120 according to the channel map selected by the selection unit 214. The first communication unit 202 communicates while changing (hopping) the frequency between the channels of the selected channel map.

The second communication unit 208 communicates with the server device 130. As described above, Wi-Fi is used for communication between the gateway 110 and the server device 130. Therefore, the second communication unit 208 performs communication processing that complies with Wi-Fi. The second communication unit 208 receives sensor data from the first communication unit 202 via the control unit 210 and transmits the sensor data to the server device 130.

Figure 3 shows an example of channel information stored in the storage unit 220. As described above, the channel information is information that associates multiple channel maps with a set of master node numbers and orders. In the example shown in Figure 3, the channel map {0ch, 2ch, 4ch, ..., 34ch, 36ch} is associated with a set of two master node numbers and the first order. The channel map {1ch, 3ch, 5ch, ..., 33ch, 35ch} is associated with a set of two master node numbers and the second order. These two channel maps associated with two master node numbers do not overlap.

The channel map {0ch, 3ch, 6ch, ..., 33ch, 36ch} is associated with the set of three master node numbers and the first order. The channel map {1ch, 4ch, 7ch, ..., 31ch, 34ch} is associated with the set of three master node numbers and the second order. The channel map {2ch, 5ch, 8ch, ..., 32ch, 35ch} is associated with the set of three master node numbers and the third order. These three channel maps associated with three master node numbers do not overlap.

The channel setting will be described with reference to FIG. 4. Here, it is assumed that the channel information shown in FIG. 3 is used. As shown in FIG. 4, gateways 110-1, 110-2, and 110-3 equipped with wireless communication devices used as master nodes are arranged in close proximity. Gateway 110-1 broadcasts an advertisement packet including a BD address "XX:XX:XX:...". Gateway 110-2 broadcasts an advertisement packet including a BD address "YY:YY:YY:...". Gateway 110-1 broadcasts an advertisement packet including a BD address "ZZ:ZZ:ZZ:...".

Gateway 110-1 performs a scan process and discovers gateways 110-2 and 110-3 as a result. In other words, gateway 110-1 recognizes that there are two devices nearby that emit radio waves that cause interference. Gateway 110-1 recognizes that there are three master nodes in its surrounding environment (specifically, the master nodes of gateways 110-1, 110-2, and 110-3). Gateways 110-2 and 110-3 similarly recognize that there are three master nodes in their surrounding environment.

Let us assume that BD address "XX:XX:XX:..." is greater than BD address "YY:YY:YY:...", which is greater than BD address "ZZ:ZZ:ZZ:...". In this case, gateway 110-1 recognizes its own turn as first, gateway 110-2 recognizes its own turn as second, and gateway 110-3 recognizes its own turn as third.

Gateway 110-1 determines that the number of master nodes is three and that it is first in order. Gateway 110-1 determines to use channel map {0ch, 3ch, 6ch, ..., 33ch, 36ch} for communication with sensor device 120. Similarly, gateway 110-2 determines to use channel map {1ch, 4ch, 7ch, ..., 31ch, 34ch}, and gateway 110-3 determines to use channel map {2ch, 5ch, 8ch, ..., 32ch, 35ch}.

In this way, gateways 110-1, 110-2, and 110-3 use different channels, which avoids interference between the networks.

Figure 5 shows an outline of an example of a hardware configuration for realizing the gateway 110 shown in Figure 2. As shown in Figure 5, the gateway 110 includes a processor 502, a RAM (Random Access Memory) 504, a program memory 506, a storage device 508, a communication interface 510, and a bus 516. The processor 502 exchanges signals with the RAM 504, the program memory 506, the storage device 508, and the communication interface 510 via the bus 516.

The processor 502 typically includes general-purpose circuits such as a CPU (Central Processing Unit) and a GPU (Graphics Processing Unit). The RAM 504 is used by the processor 502 as a working memory. The RAM 504 includes a volatile memory such as an SDRAM (Synchronous Dynamic Random Access Memory). The program memory 506 stores programs executed by the processor 502, such as a channel setting program. The programs include computer-executable instructions. For example, a ROM (Read-Only Memory) is used as the program memory 506. The processor 502 loads the program stored in the program memory 506 into the RAM 504, and interprets and executes the program. When the channel setting program is executed by the processor 502, it causes the processor 502 to execute the processes described with respect to the determination unit 212 and the selection unit 214.

Programs such as the communication control program may be provided to the gateway 110 in a state where they are stored in a computer-readable storage medium. In this case, for example, the gateway 110 is provided with a drive that reads data from the storage medium, and acquires the program from the storage medium. Examples of storage media include magnetic disks, optical disks (CD-ROM, CD-R, DVD-ROM, DVD-R, etc.), magneto-optical disks (MO, etc.), and semiconductor memories. The program may also be stored on a server on the network, and the gateway 110 may download the program from the server.

The storage device 508 stores data such as channel information. The storage device 508 includes a non-volatile memory such as a hard disk drive (HDD) or a solid state drive (SSD). A portion of the storage device 508 may be used as the program memory 506.

The communication interface 510 is an interface for communicating with an external device. The communication interface 510 includes a Bluetooth LE module 512 for communicating with the sensor device 120. The Bluetooth LE module 512 includes a processing circuit including a processor and a memory, an RF (Radio Frequency) circuit, and an antenna. The Bluetooth LE module 512 may be provided as a chip (LSI chip). A BD address is assigned to the Bluetooth LE module 512.

The communication interface 510 further includes a Wi-Fi module 514 for communicating with the server device 130. In an embodiment in which the communication between the gateway 110 and the server device 130 is wired communication, the communication interface 510 includes a wired module instead of the Wi-Fi module 514.

In the example hardware configuration shown in FIG. 4, the first communication unit 202, advertising unit 204, and scanning unit 206 are realized by a Bluetooth LE module 512. The second communication unit 208 is realized by a Wi-Fi module 514. The control unit 210 is realized by a processor 502. The memory unit 220 is realized by a storage device 508.

The control unit 210 may be implemented as a dedicated circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array). The decision unit 212 and selection unit 214 included in the control unit 210 and the storage unit 220 may be realized by a Bluetooth LE module 512.

Figure 6 shows an example of a schematic functional configuration of a sensor device 120. The sensor device 120 shown in Figure 6 corresponds to one of the sensor devices 120 shown in Figure 1. The remaining sensor devices 120 shown in Figure 1 can have the same functional configuration as the sensor device 120 shown in Figure 6.

As shown in FIG. 6, the sensor device 120 includes a sensor unit 602, a communication unit 604, and a control unit 606. The control unit 606 controls the sensor unit 602 and the communication unit 604.

The sensor unit 602 measures the state of the location or equipment in which the sensor device 120 is installed, and generates sensor data indicating the state measurement results. The sensor unit 602 sends the sensor data to the communication unit 604 via the control unit 606.

The communication unit 604 communicates with the gateway 110. As described above, Bluetooth LE is used for communication between the gateway 110 and the sensor device 120. Therefore, the communication unit 604 performs communication processing that complies with Bluetooth LE. The communication unit 604 transmits sensor data to the gateway 110.

Figure 7 shows an outline of an example of a hardware configuration for implementing the sensor device 120 shown in Figure 6. As shown in Figure 7, the sensor device 120 includes a processor 702, a RAM 704, a program memory 706, a storage device 708, a Bluetooth LE module 710, a sensor 712, and a bus 714. The processor 702 exchanges signals with the RAM 704, the program memory 706, the storage device 708, the Bluetooth LE module 710, and the sensor 712 via the bus 714.

The processor 702 typically includes general-purpose circuits such as a CPU and a GPU. The RAM 704 is used by the processor 702 as a working memory. The RAM 704 includes a volatile memory such as an SDRAM. The program memory 706 stores programs executed by the processor 702, such as a control program. For example, a ROM is used as the program memory 706. The processor 702 expands the program stored in the program memory 706 into the RAM 704, and interprets and executes the program. When the control program is executed by the processor 702, it causes the processor 702 to execute the processing described with respect to the control unit 606.

The storage device 708 stores data such as sensor data. The storage device 708 includes a non-volatile memory such as a flash memory. A portion of the storage device 708 may be used as the program memory 706.

The Bluetooth LE module 710 is an interface for communicating with the gateway 110. The Bluetooth LE module 710 includes a processing circuit including a processor and a memory, an RF circuit, and an antenna. The Bluetooth LE module 710 may be provided as a chip (LSI chip).

The sensor 712 measures the state of the location or equipment in which the sensor device 120 is installed and generates sensor data. Examples of the sensor 712 include a temperature sensor, an acceleration sensor, and an angular velocity sensor.

In the example hardware configuration shown in FIG. 7, the communication unit 604 is realized by a Bluetooth LE module 710. The control unit 606 is realized by a processor 702.

The control unit 606 may be implemented as a dedicated circuit such as an ASIC or FPGA.

[Action]
FIG. 8 illustrates an example of a channel setup procedure performed by the gateway 110.

In step S801 of FIG. 8, the gateway 110 is started. Accordingly, the Bluetooth LE module 512 of the gateway 110 becomes active.

In step S802, the gateway 110 performs advertising and scanning processes for a certain period of time. For example, the advertising unit 204 periodically broadcasts an advertisement packet including a BD address and a UUID, and the scanning unit 206 performs scanning to receive the advertisement packet.

In step S803, the determination unit 212 determines the number of master nodes present in the surrounding environment of the gateway 110 based on the results of the scan process. For example, the determination unit 212 determines the number of master nodes to be the number of wireless communication devices that transmit advertisement packets including UUIDs plus 1. If N master nodes are discovered as a result of the scan process, the determination unit 212 determines the number of master nodes to be (N+1).

In step S804, the determination unit 212 determines the order of the gateways 110 based on the results of the scan process. Specifically, the determination unit 212 determines the order based on a comparison between its own BD address and the BD address included in the advertisement packet received by the scan unit 206. The N master nodes discovered as a result of the scan process are referred to as the first to Nth master nodes. First, the determination unit 212 initializes the variable Order (e.g., Order = 1). The determination unit 212 compares its own BD address with the BD address of the first master node. If its own BD address is larger than the BD address of the first master node, the determination unit 212 does not change the variable Order and compares its own BD address with the BD address of the second master node. If the BD address of the node itself is smaller than the BD address of the first master node, the determination unit 212 increments the variable Order by 1, and then compares the BD address of the node itself with the BD address of the second master node. By repeating this operation, the determination unit 212 compares the BD address of the node itself with the BD addresses of the first to Nth master nodes. The determination unit 212 sets the value of the variable Order at the end of the comparison as the ranking.

In step S805, the selection unit 214 selects one channel map from among a plurality of predetermined channel maps based on the number and order of master nodes determined by the determination unit 212. Specifically, the selection unit 214 refers to the channel information stored in the storage unit 220 and selects a channel map associated with the number and order of master nodes determined by the determination unit 212. In the channel information shown in FIG. 3, if the determination unit 212 determines that the number of master nodes is four and that the order is second, the selection unit 214 selects the channel map {1ch, 5ch, 9ch, ..., 29ch, 33ch}.

In step S806, the control unit 210 applies the channel map selected by the selection unit 214 to the first communication unit 202. The first communication unit 202 communicates according to the selected channel map. The gateway 110 establishes a connection with the sensor device 120. When the connection is established, the gateway 110 notifies the sensor device 120 of the channel map, and the gateway 110 and the sensor device 120 communicate according to the channel map.

In this way, the gateway 110 autonomously sets the channel map to be used for communication with the sensor device 120.

In the example shown in FIG. 8, the channel configuration is performed when the gateway 110 starts up. The channel configuration may also be performed at other times.

If the number of networks does not change dynamically, channel setting may be performed when the gateway 110 is started or when the network starts communication. In this case, the network continues to use the channel map determined at that time.

When the number of networks changes dynamically, channel setting may be performed at any time while the network is in operation. The gateway 110 may perform channel setting periodically. The gateway 110 may also perform channel setting when it detects a deterioration in communication quality. The gateway 110 may also perform channel setting according to instructions from the server device 130.

For example, if gateway 110 performs channel setting after a new network is added, gateway 110 will discover a new master node and, as a result, will use a new channel map. This allows communication to be performed without causing interference with communication of the new network. Also, if any network is removed (the number of networks is reduced), the channel map may be changed by performing channel setting. Gateway 110 can perform channel setting independently even in response to dynamic increases and decreases in networks.

[effect]
As described above, each of the gateways 110 included in the communication system 100 performs a scan process to receive advertisement packets, and determines the number of master nodes present in the surrounding environment of the gateway 110 and its own order based on the result of the scan process, selects one channel map from a plurality of predetermined channel maps based on the determined number of master nodes and the determined order, and communicates with the sensor device 120 according to the selected channel map. In this configuration, the gateway 110 communicates with the sensor device 120 on channels different from each other. Thereby, radio interference between networks is avoided in the communication system 100 including a plurality of gateways 110, and loss of sensor data due to radio interference is prevented. As a result, the sensor data generated by the sensor device 120 can reliably reach the server device 130. The gateway 110 is suitable for a system in which data loss due to radio interference is not allowed. In addition, the channel setting can be implemented without modifying the program constituting the wireless communication specification of Bluetooth LE of the communication LSI equipped with Bluetooth LE.

The multiple channel maps are associated with a combination of the number of master nodes and an order, and the gateway 110 selects from the multiple channel maps a channel map associated with the determined number of master nodes and the determined order. This allows all available channels to be used by the gateway 110. For example, if there are two gateways 110, one gateway 110 uses the channel map {0ch, 2ch, 4ch, ..., 34ch, 36ch}, and the other gateway 110 uses the channel map {1ch, 3ch, 5ch, ..., 33ch, 35ch}, and all channels 0ch to 35ch are used. The channels can be used effectively.

The gateway 110 determines the order based on a comparison between the identification information uniquely assigned to the wireless communication device (Bluetooth LE module 512) and the identification information uniquely assigned to the wireless communication device discovered as a result of the scanning process. In this embodiment, the identification information is the BD address. In other embodiments, the identification information may be the serial number of the wireless communication device. This ensures that the gateways 110 are in a different order from each other.

The gateway 110 receives sensor data from the sensor device 120 and transmits the sensor data to the server device 130. The gateway 110 uses a channel different from that of the other gateways 110. Therefore, no radio interference occurs, and the gateway 110 can reliably receive the sensor data from the sensor device 120. As a result, the sensor data can be aggregated in the server device 130 without data loss.

[Modification]
In the above-described embodiment, the gateway 110 is a repeater that transfers sensor data from the sensor device 120 to the server device 130. The gateway 110 is an example of a master device (information processing device) that includes a wireless communication device used as a master node. In other embodiments, the master device may process the sensor data received from the sensor device 120. In this case, the master device may not include the second communication unit 208.

The sensor device 120 is an example of a slave device including a wireless communication device used as a slave node. The slave device may be a control device that controls the location where the slave device is installed or the state of the device. For example, the control device receives control data from the server device 130 via the gateway 110 and performs control according to the received control data. The control data may be generated by the gateway 110. For example, the control device includes a sensor unit 602, and the gateway 110 compares the measurement value included in the sensor data received from the control device with a predetermined threshold value. If the measurement value exceeds the predetermined threshold value, the gateway 110 generates control data for performing a predetermined operation (for example, closing a valve) and transmits the control data to the control device.

Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims.

100...communication system, 110...gateway, 112...communication area, 120...sensor device, 130...server device, 202...first communication unit, 204...advertising unit, 206...scanning unit, 208...second communication unit, 210...control unit, 212...determination unit, 214...selection unit, 220...storage unit, 502...processor, 504...RAM, 506...program memory, 508...storage device, 510...communication interface, 512...Bluetooth LE module, 514...Wi-Fi module, 516...bus, 602...sensor unit, 604...communication unit, 606...control unit, 702...processor, 704...RAM, 706...program memory, 708...storage device, 710...Bluetooth LE module, 712...sensor, 714...bus.

Claims (9)

A wireless communication device corresponding to a master node in a network including a single master node and at least one slave node,
a scanning unit that performs a scanning process to receive a beacon signal from another wireless communication device;
a determination unit that determines, based on a result of the scanning process, the number of master nodes present in a surrounding environment of the wireless communication device and an order of the master nodes corresponding to the wireless communication device among the master nodes present in the surrounding environment of the wireless communication device;
A selection unit that selects one channel map from a plurality of predetermined channel maps based on the determined number of master nodes and the determined order;
a first communication unit for communicating with the at least one slave node according to the selected channel map;
A wireless communication device comprising: The plurality of channel maps are associated with a set of a master node number and an order;
The selection unit selects a channel map associated with the determined number of master nodes and the determined order from among the plurality of channel maps.
The wireless communication device of claim 1 . The determination unit determines the number of master nodes present in a surrounding environment of the wireless communication device based on the number of wireless communication devices that transmit beacon signals including predetermined information.
3. The wireless communication device according to claim 1 or 2. The wireless communication device according to any one of claims 1 to 3, wherein the determination unit determines the order based on a comparison between identification information uniquely assigned to the wireless communication device and identification information uniquely assigned to a wireless communication device discovered as a result of the scanning process. The wireless communication device according to claim 4, wherein the identification information is a BD address. A wireless communication device according to any one of claims 1 to 5,
The at least one slave node is provided in at least one sensor device,
The first communication unit receives sensor data obtained by the at least one sensor device from the at least one slave node.
Information processing device. A second communication unit that communicates with a server device different from the at least one slave node,
The second communication unit transmits the received sensor data to the server device.
The information processing device according to claim 6. A wireless communication method executed by a wireless communication device corresponding to a master node in a network including a single master node and at least one slave node, comprising:
performing a scanning process for receiving a beacon signal from another wireless communication device;
Determining the number of master nodes present in the surrounding environment of the wireless communication device and an order of the master nodes corresponding to the wireless communication device among the master nodes present in the surrounding environment of the wireless communication device based on a result of the scanning process;
selecting one channel map from a plurality of predetermined channel maps based on the determined number of master nodes and the determined order;
communicating with the at least one slave node according to the selected channel map;
A wireless communication method comprising: A computer included in a wireless communication device corresponding to a master node in a network including a single master node and at least one slave node,
A scanning means for performing a process of receiving a beacon signal from another wireless communication device;
A means for determining, based on a result of the scanning process, the number of master nodes present in the surrounding environment of the wireless communication device and an order of the master nodes corresponding to the wireless communication device among the master nodes present in the surrounding environment of the wireless communication device ;
A program for causing the device to function as a means for selecting one channel map from a plurality of predetermined channel maps based on the determined number of master nodes and the determined order, and a means for communicating with the at least one slave node according to the selected channel map.