JP7489666B2 - Wireless communication device - Google Patents

Description

The present invention relates to a wireless communication device having communication channels with different communication speeds in multiple frequency bands.

Technologies have been developed to suppress the degradation of wireless transmission quality caused by interference from other systems.

For example, the wireless communication system of Patent Document 1 is composed of two wireless devices that communicate with each other wirelessly and perform point-to-point communication, and each wireless device has a (1+1) redundant configuration with first and second wireless transmission systems and first and second wireless reception systems. It is possible to configure one of the first and second wireless transmission systems to be in active use and perform wireless transmission operations to the other wireless device using a specific wireless frequency assigned in advance, while the other wireless transmission system is in standby as a backup system for equipment redundancy. In addition, the second wireless transmission system and the second wireless reception system have the characteristic of being able to operate according to independent frequency control, occupied bandwidth control, and modulation method control for transmission and reception, respectively.

JP 2017-034373 A

However, in conventional technology, when interference occurs, another device with a different wireless system is used, so a spare radio needs to be placed. Also, a control circuit may be required to change the modulation system and wireless occupied band for the other device.

The present invention has been made in consideration of the problems inherent in such conventional technology. The object of the present invention is to provide a wireless communication device that can maintain wireless communication starting with high-priority communication data while avoiding interference, without disposing a spare device with a different wireless method in the event that the radio waves being used are subject to interference, and without controlling changes to the modulation method and occupied wireless band.

A wireless communication device having communication channels with different communication speeds in multiple frequency bands according to an aspect of the present invention includes a high-speed receiving unit that receives reception information for a high-speed communication channel in a first frequency band, a low-speed receiving unit that receives reception information for a low-speed communication channel in a second frequency band, a control unit that, when there is transmission data, assigns a priority to the transmission data, determines the reception strength of the reception information, and, when the reception strength of the high-speed communication channel is equal to or greater than a predetermined reception strength threshold, determines the availability of the low-speed communication channel, and a low-speed transmitting unit that transmits transmission data with a high priority assigned by the control unit using a low-speed communication channel determined to be available in the second frequency band, and it is preferable that the priority is preset according to the type of application of the transmission data.

According to the present invention, it is possible to provide a wireless communication device that can avoid interference and maintain wireless communication starting with high-priority communication data, without deploying a spare device with a different wireless method in case the radio waves being used are subject to interference, and without controlling changes to the modulation method and occupied wireless band.

4 is a flowchart for explaining an overview of a transmission process of the wireless communication device according to the present embodiment. 1 is a block diagram showing an outline of the configuration of a wireless communication device according to an embodiment of the present invention; 1A is a block diagram showing an example of details of a control unit of a wireless communication device according to the present embodiment, and FIG. 1B is a block diagram showing an example of details of a storage unit of a wireless communication device according to the present embodiment. FIG. 11 is a schematic diagram for explaining an example of priority according to the embodiment. 5 is a flowchart showing an example of an operation of a transmission/reception process of the wireless communication device according to the present embodiment.

Below, an example of a wireless communication device according to the present embodiment will be described in detail with reference to the drawings. Note that the embodiments described below are comprehensive or specific examples. The numerical values, shapes, materials, components, installation positions and connection forms of the components, steps, and order of steps shown in the following embodiments are merely examples and are not intended to limit the scope of the present disclosure. Furthermore, among the components in the following embodiments, components that are not described in an independent claim that indicates a top-level concept will be described as optional components. Furthermore, the dimensional ratios in the drawings are exaggerated for the convenience of explanation and may differ from the actual ratios.

(1) Overview of Operation of Wireless Communication Device FIG. 1 is a flow chart showing a schematic overview of a transmission operation of a wireless communication device according to this embodiment.

The control unit of the wireless communication device, which includes a CPU (Central Processing Unit) not shown, is configured to be able to execute the operations of steps S101, S102, S103, S104, and S105.

In step S101, the control unit monitors the usage status of multiple communication channels that are set up in advance as available. The multiple communication channels that are set up in advance as available are communication channels that belong to at least two or more frequency bands, and the communication channels include at least a high-speed communication channel capable of high-speed transmission and a low-speed communication channel that transmits at a low speed. The high-speed communication channel has a communication speed of a maximum of several Gbps to several tens of Gbps or more, and the low-speed communication channel has a communication speed of a maximum of about several hundred kbps. In addition, there are at least two high-speed communication channels, which belong to a first frequency band. There is at least one low-speed communication channel, which belongs to a second frequency band. The first frequency band and the second frequency band have different frequencies, and it is preferable that the first frequency band is a higher frequency band than the second frequency band, but the first frequency band may be a lower frequency band than the second frequency band. In addition, the low-speed communication channel may have a time during which continuous transmission is possible or a total transmission time that can be transmitted per unit time. By setting such a restriction, interference is reduced in the low-speed communication channel, and wireless communication may be performed stably. It is also preferable that the high-speed communication channel has no restrictions on the continuous transmission time or the total transmission time per unit time. The high-speed communication channel may be a CSMA/CA (Carrier Sense Multiple Access/Collision Avoidance) system. In this system, before transmitting communication data, it is checked whether there is interference on the same communication channel, and if there is interference, the transmission is temporarily suspended. If there is no interference, a random time is waited and the communication data is transmitted to avoid collision with the interfering signal. Next, the wireless communication device proceeds to step S102.

In step S102, the control unit selects an available communication channel. In step S101, if no interference waves are received on at least some of the high-speed communication channels, the control unit determines that the high-speed communication channels that are not receiving interference waves are available. Also, if no interference waves are received on a low-speed communication channel and the constraints on the low-speed communication channel are met, the control unit determines that the low-speed communication channel is available. Therefore, the communication channels that the control unit determines to be available may be, at most, all of the multiple communication channels that have been set up as available in advance. Also, there may be cases where the control unit determines that no communication channels are available. Next, the wireless communication device proceeds to step S103.

In step S103, the control unit determines whether or not there is an available communication channel. If there is an available communication channel (step S103: YES), the wireless communication device proceeds to step S104. If there is no available communication channel (step S103: NO), the wireless communication device returns to step S101.

In step S104, the control unit assigns a priority to the communication data to be transmitted, and in principle transmits communication data with a higher priority on an available communication channel. Note that the step of assigning a priority to the communication data to be transmitted can be performed each time communication data to be transmitted is generated.

Details about priority will be given later, but for example, priority is based on the priority value, and the lower the priority value, the higher the priority. Priority is determined in principle based on the type of application of the transmitted data. In particular, transmitted data from control-related applications has a high priority. For example, if the transmitted data related to a transmission request is data from an entertainment-related application, it is likely to have a low priority.

However, the priority may be determined based on the length of the allowable delay time as the delay time allowed for the communication data to be transmitted. For example, it is possible to set the highest priority to communication data with the shortest allowable delay time among the communication data to be transmitted. Also, for example, it is possible to set the lowest priority to communication data with the longest allowable delay time among the communication data to be transmitted. Note that the above priority may be used when classifying priorities within the same application. Also, each time communication data to be transmitted is generated, if there are multiple pieces of communication data to be transmitted, the control unit can repeat the operation of reassigning the priority.

If a high-speed communication channel is available among the available communication channels, the control unit transmits communication data on the high-speed communication channel starting with the communication data with the highest priority. Also, if there are multiple available high-speed communication channels, the control unit transmits communication data with the highest priority using the faster high-speed communication channel. It is also possible to transmit communication data with the second highest priority using the high-speed communication channel with the second fastest communication speed while transmitting communication data with the first highest priority using the high-speed communication channel with the highest communication speed.

For example, when there is communication data with a higher priority that will complete transmission sooner if transmitted over a low-speed communication channel than if transmitted over a high-speed communication channel, the control unit may transmit the communication data over the low-speed communication channel. In this case, communication data with a higher priority than the communication data may be transmitted over the high-speed communication channel. In this way, a high-speed communication channel and a low-speed communication channel may be used simultaneously. Also, there may be cases where multiple high-speed communication channels are used simultaneously while a low-speed communication channel is used simultaneously, or where a low-speed communication channel is not used simultaneously. Details of these cases will be described in the modified examples.

Furthermore, for example, if the transmission completion time of high priority communication data is later than the transmission completion time of communication data with a lower priority, it is also possible to divide the high priority communication data and transmit it first from multiple communication channels. In this way, depending on the situation, it may be possible to transmit all of the high priority communication data by dividing it and shortening the transmission time. The details of this case will also be described in the modified example.

In step S105, the control unit determines whether there is any communication data to be transmitted. If there is no communication data to be transmitted (step S105: YES), the control unit ends the transmission process. If there is still communication data to be transmitted (step S105: NO), the control unit returns to step S101 and continues the transmission process.

The high-speed communication channel may be a communication channel in a wireless band defined by Wi-Fi (registered trademark). For example, the high-speed communication channel may be a communication channel in the 2.4 GHz band and the 5 GHz band. A so-called narrow-sense wireless LAN using the 2.4 GHz band or the 5 GHz band is capable of large-capacity communication with a maximum communication speed of several Gbps, and can be used without a license under the Radio Law, and is therefore used in various electronic devices. However, interference from other electronic devices is also a problem.

The low-speed communication channel may be a communication channel of a radio band defined by Wi-SUN (registered trademark). Wireless communication methods such as Wi-SUN using the 920 MHz band can be used without a license under the Radio Law, just like the wireless LAN. However, the communication speed is only a few hundred kbps at most, and is not suitable for large-volume communication. However, due to various constraints, wireless communication tends to be stable and with less interference compared to wireless LAN. In addition, the 920 MHz band has the advantage of being able to cover a wider area because it has a longer communication distance and can extend farther than the 2.4 GHz and 5 GHz bands.

As such, interference is likely to occur in the 2.4 GHz and 5 GHz bands, and when interference occurs, communication latency occurs due to the CSMA/CA method. Therefore, by assigning priority to communication data that should be transmitted in the 2.4 GHz band, etc., and allowing transmission in the 920 MHz band when interference is occurring but there is high-priority communication data, it may be possible to reduce the delay time of high-priority communication data. Details will be described later.

(2) Details of the Wireless Communication Device An example of the configuration of the wireless communication device 100 will be described in detail with reference to Fig. 2 and Fig. 3. Fig. 2 is a block diagram showing an example of the overall configuration of the wireless communication device 100. Fig. 3 is a block diagram showing an example of the detailed configuration of the control unit 130 of the wireless communication device 100 in Fig. 2.

Referring to FIG. 2, the wireless communication device 100 includes a high-speed communication unit 110, a low-speed communication unit 120, a control unit 130, an external I/F unit 150, a memory unit 160, a high-speed communication antenna unit ANTH, and a low-speed communication antenna unit ANTL.

The optional transmission/reception control unit 132, which will be described later, has a function of switching between the connection between the high-speed communication antenna unit ANTH and the high-speed receiving unit 111 and the connection between the high-speed communication antenna unit ANTH and the high-speed transmitting unit 112. In other words, the transmission/reception control unit 132 has a function of connecting the high-speed communication antenna unit ANTH and the high-speed receiving unit 111 when receiving communication data, and connecting the high-speed communication antenna unit ANTH and the high-speed transmitting unit 112 when transmitting communication data.
Similarly, the optional transmission/reception control unit 132, which will be described later, has a function of switching between the connection between the low-speed communication antenna unit ANTL and the low-speed receiving unit 121 and between the low-speed communication antenna unit ANTL and the low-speed transmitting unit 122. That is, the transmission/reception control unit 132 has a function of connecting the low-speed communication antenna unit ANTL and the low-speed receiving unit 121 when receiving low-speed communication data, and connecting the low-speed communication antenna unit ANTL and the low-speed transmitting unit 122 when transmitting low-speed communication data. Note that the transmission/reception control unit 132 switches the wireless communication device 100 to a transmission mode when transmitting communication data, ACK (ACKnowledgement), NACK (Negative ACKnowledgement), control information, etc. At other times, the transmission/reception control unit 132 switches the wireless communication device 100 to a reception mode.

In addition, if the optional transmission/reception control unit 132 is not provided, the required number of antennas (not shown) can be fixedly connected to the receiving unit, and the required number of antennas (not shown) can be fixedly connected to the transmitting unit. The above antennas, including the high-speed communication antenna unit ANTH and the low-speed communication antenna unit ANTL, can be placed inside or outside the wireless communication device 100. In the following description, the wireless communication device 100 may be referred to as a node.

The high-speed receiving unit 111 and the low-speed receiving unit 121 have a function of receiving control information including communication data, ACK, or NACK transmitted from other nodes. They also have a function of distinguishing communication data addressed to the node itself from communication data addressed to other nodes by referring to the destination information of the received communication data. As an example, the destination information is node identification information, and is information that can be referred to as information included in the header. The communication data may be communication data whose final destination is the node itself, or communication data whose final destination is not the node itself. If the communication data is communication data whose final destination is the node itself, the communication data is output to the external I/F unit 150. If the communication data is communication data whose final destination is not the node itself and the communication data does not include communication path information, the communication data may be discarded. If the communication data is communication data whose final destination is not the node itself and the communication path information may include the node itself, the wireless communication device 100 can also function as a relay terminal.

The high-speed transmission unit 112 and the low-speed transmission unit 122 have the function of transmitting communication data. They also have the function of transmitting control information including an ACK, which is a positive response to communication data received from another node, or an NAC, which is a negative response, etc.

The control unit 130 can be realized using a microcomputer equipped with a CPU (Central Processing Unit) and the like. A computer program (wireless communication program) for making the microcomputer function as the control unit 130 is installed in the microcomputer and executed. As a result, the microcomputer functions as a plurality of information processing units equipped in the control unit 130. In this specification, an example of realizing the control unit 130 by software is shown, but it is of course possible to configure the control unit 130 by preparing dedicated hardware for executing each information processing. The dedicated hardware includes devices such as application specific integrated circuits (ASICs) and conventional circuit components arranged to execute the functions described in the embodiment. In addition, the plurality of information processing units included in the control unit 130 may be configured by individual hardware. Furthermore, the control unit 130 may also be used as an electronic control device used to control the electronic device that is the target of wireless communication.

For example, when the wireless communication device 100 is provided in a moving body, the wireless communication function of the wireless communication device 100 may be included in the function of an electronic control device that controls a configuration that is not related to the movement of the moving body. In this case, a wireless communication program that realizes the wireless communication function of the wireless communication device 100 may be added to the electronic control program of the electronic control device. Also, a hardware that realizes the wireless communication function of the wireless communication device 100 may be added to the hardware of the electronic control device. Furthermore, at least a part of the electronic control program of the electronic control device may be configured to include at least a part of the wireless communication program of the wireless communication device 100. Furthermore, at least a part of the hardware of the electronic control device may be configured to include at least a part of the hardware of the wireless communication device 100. Also, the wireless communication function of the wireless communication device 100 may be included in the function of an electronic control device that has any function of moving in the internal space of a building such as a house or office, or a structure such as a factory, or in some cases, in the external space.

Figure 3 (A) shows multiple information processing units of the control unit 130. The control unit 130 includes, as multiple information processing units, a priority assignment unit 131, a transmission/reception control unit 132, a reception strength determination unit 133, a communication channel condition determination unit 134, a communication channel selection unit 135, a transmission data selection unit 136, and a transmission delay time calculation unit 137.

The priority setting unit 131 has a function of setting a priority according to the type of application to which the transmission data is used when transmission data occurs, and indicating whether the priority is high or not. If the application is a control application, the transmission data of the control application is given a priority of "1", indicating that the priority is high. For example, in the case of monitor data and control data, the priority of the control data is high. Even in the case of sensor data, the priority of sensor data of an in-vehicle vehicle control device is higher than that of transmission data of image information by an imaging device such as a camera. Furthermore, in the case of transmission data of entertainment-related music information or video information, the lowest priority value among the transmission data is given, indicating that the priority is low. In this way, a high priority is set for applications that pose a high risk to human life, such as driving control. In addition, the priority may be associated with an allowable delay time and a data amount of the transmission data as the maximum delay time allowed for the transmission data to which the priority is assigned. It is also possible to calculate whether the allowable delay time is met from the data amount of the transmission data and the transmission speed of the communication channel.

The transmission data to which the priority is assigned by the priority assignment unit 131 can be stored in the priority storage unit 162 of the storage unit 160 in FIG. 3B (described later) in association with the allowable delay time and the amount of transmission data. FIG. 4 shows an example of transmission data stored in the priority storage unit 162. The lower the priority, the higher the priority, and the shorter the allowable time, the less time there is until the transmission of the transmission data is completed. When transmission data related to the same application is generated, there are cases where the total traffic can be reduced by increasing the priority of data with a small amount of transmission data. It is also possible to configure the transmission data with a short allowable delay time to be assigned a high priority if it is the same application. Data A in FIG. 4 has a priority level of "1", which indicates that the priority is high, and the allowable delay time is 1 ms. In addition, not only the contents of "Data A" but also the data amount information of "Data A" may be stored in the part displayed as "Data A".

The transmission/reception control unit 132 has the function of setting the wireless communication device 100 to a reception mode or a transmission mode (or both). The transmission/reception control unit 132 normally sets the wireless communication device 100 to a reception mode, and is capable of switching the wireless communication device 100 from the reception mode to the transmission mode when transmitting transmission data.

The reception strength determination unit 133 has a function of monitoring the received reception power when the wireless communication device 100 is in the reception mode and determining whether it exceeds a predetermined reception strength threshold. When the received power is equal to or less than the predetermined reception strength threshold, the reception strength determination unit 133 determines the received reception power as noise, and when the received power is equal to or more than the predetermined reception strength threshold, the reception strength determination unit 133 analyzes the received reception data. When the destination of the received reception data is the node itself, the reception strength determination unit 133 transmits the received data to the high-speed reception unit 111 or the low-speed reception unit 121 in order to execute reception processing of the received data. When the destination of the received reception data is not the node itself, the reception strength determination unit 133 transmits identification information of the communication channel through which the received signal was transmitted and interference information indicating that interference is occurring in the communication channel to the communication channel selection unit 135.

When transmission data occurs, the communication channel condition determination unit 134 has the function of determining whether a communication channel with restricted communication conditions can be used based on the past usage status of the communication channel stored in the communication channel usage status storage unit 163. For example, the restricted communication conditions may include restrictions on the available time for a communication channel per unit time, communication pause periods, and the continuous available communication time. For example, the above conditions are set when using Wi-SUN (registered trademark). The communication channel condition determination unit 134 transmits communication channel information indicating communication channels that do not meet the above conditions and have a reception strength below a predetermined reception strength threshold to the communication channel selection unit 135.

The communication channel selection unit 135 has a function of selecting a communication channel for transmitting transmission data when transmission data is generated. For example, when the communication channels include a high-speed communication channel group and a low-speed communication channel group, if any of the high-speed communication channels in the high-speed communication channel group is available, the high-speed communication channel is selected to be used. Also, when all of the high-speed communication channels in the high-speed communication channel group are unavailable, an available low-speed communication channel is selected. Note that an available communication channel is a communication channel whose reception strength is equal to or less than a predetermined reception strength threshold and does not fall under the above-mentioned communication condition restrictions. For example, the high-speed communication channel group may mean all communication channels in the 2.4 GHz band and 5 GHz band specified in Wi-Fi (registered trademark). Also, for example, the low-speed communication channel group may mean all communication channels in the 920 MHz band specified in Wi-SUN (registered trademark).

When transmission data occurs, the transmission data selection unit 136 selects the transmission data to be transmitted using the communication channel selected by the communication channel selection unit 135. Since a priority order is set for the transmission data, the transmission data selection unit 136 selects the transmission data so that the transmission data with the highest priority is transmitted first. For example, when multiple communication channels with different transmission speeds are selected for communication, the principle is that the transmission data with the highest priority is transmitted by the communication channel with the highest transmission speed. However, there may be cases where the transmission data with the second highest priority cannot be transmitted by the communication channel with the second fastest transmission time within the allowable delay time, but can be transmitted by the communication channel with the first fastest transmission time. In this case, there may be cases where the transmission data with the first highest priority can be transmitted by the communication channel with the second fastest transmission time within the allowable delay time. In such a case, the transmission data selection unit 136 can perform a selection operation so that the transmission data with the first highest priority is transmitted by the communication channel with the second fastest transmission time, and the transmission data with the second highest priority is transmitted by the communication channel with the first fastest transmission time. In other words, the transmission data selection unit 136 can also assign the transmission data and the communication channel taking into account the allowable delay time of the transmission data. Such processing operations can also be performed by the transmission data selection unit 136 when warning information is received from the transmission delay time calculation unit 137, which will be described later.

The transmission delay time calculation unit 137 has a function of calculating the transmission delay time until the transmission of the transmission data selected by the transmission data selection unit 136 is completed when the transmission data selected by the transmission channel selection unit 135 is transmitted using the communication channel selected by the communication channel selection unit 135. For example, if the transmission of the transmission data is not completed within the allowable delay time range of the transmission data, it is possible to transmit warning information to the transmission data selection unit 136.

The external I/F unit 150 is an input/output interface for communication data and various data to be transmitted and received, and may be an interface with devices such as sensors connected to the wireless communication device 100, or with electronic devices. An ECU (Electronic Control Unit) may be configured by the devices or electronic devices connected to the external I/F unit 150. The electronic devices may include electronic devices such as vehicle control devices, vehicle sensing devices, vehicle surrounding information acquisition devices, and entertainment devices as in-vehicle devices. The vehicle control devices may include navigation devices and autonomous driving control devices.

The storage unit 160 is a computer-readable storage medium. For example, the storage unit 160 may be a Read Only Memory (ROM) or an Erasable Programmable ROM (EPROM). The storage unit 160 may also be an Electrically Erasable Programmable ROM (EEPROM), a Random Access Memory (RAM), a hard disk, etc. The storage unit 160 may also be called a register, a cache, a main memory (primary storage device), etc. The storage unit 160 may store executable programs (program codes), software modules, etc. for implementing autonomous movement according to one embodiment of the present disclosure.

As shown in FIG. 3(A), the memory unit 160 includes a parameter memory unit 161, a priority memory unit 162, and a communication channel usage status memory unit 163.

The parameter storage unit 161 stores identification information such as the ID of the wireless communication device 100, and parameter information such as modulation/demodulation parameter information for the communication channel. As described above, the identification information such as the ID of the wireless communication device 100 can be used when determining whether or not received data is addressed to the node itself. In addition, the modulation/demodulation parameter information is determined corresponding to the communication channel. Therefore, unlike the conventional technology, the control unit 130, the high-speed communication unit 110, and the low-speed communication unit 120 do not require a dedicated configuration for changing the modulation/demodulation method or occupied band, and modules of a specified method can be used, making it possible to configure the wireless communication device 100 simply.

The priority information storage unit 162 stores priority information related to the priority of the transmission data shown in FIG. 4. As described above, the lower the priority, the higher the priority, and the shorter the allowable time, the less time there is until the transmission of the transmission data is completed. When transmission data related to the same application is generated, there are cases where the total traffic can be reduced by increasing the priority of data with a small amount of transmission data. In addition, if it is the same application, it is possible to configure the transmission data with a short allowable delay time to be assigned a high priority. Data A in FIG. 4 has a priority level of "1", which indicates that it has a high priority, and the allowable delay time is 1 ms. In addition, not only the contents of "Data A" but also the data volume information of "Data A" may be stored in the portion displayed as "Data A".

The communication channel usage status storage unit 163 can store communication channel usage history information. The usage history information can store information such as the usage time per unit time immediately before the communication channel, the order of use of the communication channel, etc. The unit time is based on the specifications such as the standard for the communication channel, but it is also possible to set the unit time to one hour, for example. For example, the time during which communication data was transmitted and received using a communication channel restricted by the standard in the hour before the time when the transmission data is to be transmitted can be stored. In addition, the identification information of the communication channel used can be stored in order in the order in which the transmission data was transmitted. If there is a bias in the communication channel that transmits the transmission data, there is a possibility that interference will occur frequently throughout the entire system. Therefore, it may be possible to transmit the next transmission data using a communication channel different from the communication channel used immediately before, thereby reducing the delay time of the entire system.

(3) Example of Operation of Wireless Communication Device Next, a basic example of operation of the wireless communication device 100 will be described using a flowchart with reference to Fig. 5. In this flow, a method of transmitting high-priority data when interference occurs in all high-speed communication channels will be described.

In step S501, the reception strength determination unit 133 of the control unit 130 determines the reception strength of the reception power received in the high-speed communication channel. If the reception strength of the received reception power is equal to or greater than a predetermined reception strength threshold (step S501: YES), the wireless communication device 100 proceeds to step S502, assuming that reception data has been received. If the reception strength of the received reception power is lower than the predetermined reception strength threshold (step S501: NO), the wireless communication device 100 proceeds to step S505.

In step S502, the reception strength determination unit 133 of the control unit 130 detects whether the destination of the received data is the own node. For example, it is possible to determine whether the received data is addressed to the own node based on whether identification information such as the ID of the own node is present in the destination information area of the header area of the received data. If the destination of the received data is the own node (step S502: YES), the wireless communication device 100 proceeds to step S503. If the destination of the received data is not the own node (step S502: NO), the wireless communication device 100 proceeds to step S508.

In step S503, since the received data is addressed to the node itself, the high-speed receiver 111 of the wireless communication device 100 performs reception processing including demodulation of the received data. The received data may be transmitted to an external electronic device via the external I/F unit 150. Next, the wireless communication device 100 proceeds to step S504.

In step S504, since the wireless communication device 100 was able to successfully receive the received data in step S503, the wireless communication device 100 transmits an ACK, which is a positive response, from the high-speed transmission unit 112 to the other wireless communication device that transmitted the received data. The wireless communication device 100 executes the above processing and ends the transmission and reception processing.

In step S505, since the wireless communication device 100 is not receiving a reception signal, it determines whether or not there is a transmission request for transmission data for the own node. Transmission data may be received from an external electronic device via the external I/F unit 150. If there is a transmission request for transmission data for the own node (step S505: YES), the wireless communication device 100 proceeds to step S506. If there is no transmission request for transmission data for the own node (step S505: NO), the wireless communication device 100 returns to step S501.

In step S506, since no interference is occurring in the communication channels, the communication channel selection unit 135 of the control unit 130 uses the fastest high-speed communication channel to transmit the transmission data related to the transmission request from the high-speed transmission unit 112. As described above, there are cases where the fastest high-speed communication channel is not used, but details will be described in a modified example. Next, the wireless communication device 100 proceeds to step S507.

In step S507, if an ACK, which is positive response information to the transmission data sent in step S506, is received, the control unit 130 ends the transmission/reception process. In addition, if an ACK is not received even after a predetermined time has elapsed, step S506 may be repeated a predetermined number of times until an ACK is received.

In step S508, even if interference is occurring in at least one of the communication channels, it is determined whether or not there is a request to transmit transmission data for the own node. If there is a request to transmit transmission data for the own node (step S508: YES), the wireless communication device 100 proceeds to step S509. If there is no request to transmit transmission data for the own node (step S508: NO), the wireless communication device 100 returns to step S501.

In step S509, even if interference occurs in at least one of the communication channels, if there is a transmission request in the own node, the priority of the transmission data related to the transmission request is determined. As described above, the priority is based on the priority value, and the smaller the priority value, the higher the priority. In particular, the priority of the transmission data is high when the application is related to the control system. If there is a transmission request in the own node and the priority of the transmission data related to the transmission request is high (step S509: YES), the wireless communication device 100 proceeds to step S510. For example, it is highly likely that the transmission data related to the transmission request is data of a control system application. If there is a transmission request in the own node and the priority of the transmission data related to the transmission request is low (step S509: NO), the wireless communication device 100 returns to step S501 and waits until the situation changes, such as the interference being eliminated. For example, it is highly likely that the transmission data related to the transmission request is data of an entertainment system application.

In step S510, the communication channel selection unit 135 determines whether a low-speed communication channel that is expected to be less likely to cause interference is available. If a low-speed communication channel is available (step S510: YES), the wireless communication device 100 proceeds to step S511. If a low-speed communication channel is also not available (step S510: NO), the wireless communication device 100 returns to step S501.

In step S511, the wireless communication device 100 uses a low-speed communication channel to transmit high-priority transmission data from the low-speed transmission unit 122, and then temporarily ends the transmission and reception process.

By performing the above operations, it is possible to avoid interference and maintain wireless communication starting with high-priority communication data without deploying spare devices with different wireless methods and without controlling changes to the modulation method and wireless occupied band.

(Variation 1)
In the above embodiment, the 2.4 GHz band and the 5 GHz band are mainly described as the high-speed communication channel, and the 920 MHz band is mainly described as the low-speed communication channel, but the high-speed communication channel and the low-speed communication channel are not limited to these frequency bands. The frequency band of the high-speed communication channel may be a frequency band of a mobile wireless communication system such as 4G or 5G. That is, the frequency band usable as the high-speed communication channel may be equal to or lower than the 2.4 GHz band and the 5 GHz band or higher. In addition, the 920 MHz band is mainly described as the low-speed communication channel, but the frequency band is not limited to the 920 MHz band as long as it is slower than the high-speed communication channel. For example, the frequency band of the low-speed communication channel may be a frequency band with a higher frequency than the frequency band of the high-speed communication channel. The high-speed communication channel and the low-speed communication channel may be a frequency band that is available without a license under the Radio Law.

(Variation 2)
In the above embodiment, the explanation has been centered on the aspect in which high-priority data is actively transmitted using a high-speed communication channel, and when the high-speed communication channel cannot be used due to interference or the like, a low-speed communication channel is also used for transmission. However, when a high-speed communication channel can be used for high-priority transmission data, a low-speed communication channel can also be used. However, it is preferable that the transmission of the transmission data is completed using the low-speed communication channel within the range of the allowable delay time for the transmission data. In this way, when a high-speed communication channel can be used, it may be possible to transmit data efficiently by utilizing the low-speed communication channel.

(Variation 3)
In the above embodiment, the case where the transmission data is not divided has been mainly described, but the transmission data can also be divided and transmitted. For example, when the transmission data is imaging information obtained by an imaging device such as a CCD camera, if the imaging information cannot be transmitted in one packet, the imaging information can be divided into multiple packets and transmitted. In this case, the wireless communication device 100 can operate so that each of the divided packets is given a priority. In addition, the divided packets do not need to be transmitted on the same communication channel, and for example, an operation can be performed in which the first packet is transmitted on a high-speed communication channel in the 2.4 GHz band and the second packet is transmitted on a high-speed communication channel in the 5 GHz band. In addition, the division of the transmission data can also be performed when the communication volume of the transmission data is large. For example, when the transmission completion time of the communication data exceeds the allowable delay time, the communication data can be divided into multiple pieces, and the divided communication data can be transmitted within the allowable delay time using different communication channels. In any of the above cases, it is assumed that each of the independent transmission data is given a priority.

(Variation 4)
Although some description has been given in the above embodiment, when the wireless communication device 100 can select multiple communication channels, it may be preferable to select a communication channel different from the communication channel used by the immediately preceding transmission data. For example, when multiple wireless communication devices belong to the same system, if one wireless communication device continues to use a high-speed communication channel, other wireless communication devices may not be able to use the high-speed communication channel, and the performance of the system may be suppressed. In order to avoid such interference situations, it is also possible to configure the wireless communication device 100 to use a different communication channel for each transmission of transmission data.

(Variation 5)
Contrary to the above description, when the wireless communication device 100 can select multiple communication channels, it may be preferable to select the same communication channel as the communication channel used by the immediately preceding transmission data, because by actively using an effective communication channel, it may be possible to reduce search time and improve system efficiency.

(Variation 6)
In the above embodiment, the priority and the method of selecting a communication channel when transmitting data information such as transmission data are mainly described, but the processing in this embodiment is not limited to data information, and can be applied to control data. For example, it is also possible to configure the wireless communication device 100 so that a priority is given to response information such as ACK and NACK, and a communication channel for transmitting the response information such as ACK and NACK is selected in consideration of the priority.

The following describes the features of the wireless communication device 100 according to this embodiment.

The wireless communication device 100 having communication channels with different communication speeds in multiple frequency bands according to the first aspect of the present disclosure preferably includes a high-speed receiving unit 111, a low-speed receiving unit 121, a control unit 130, and a low-speed transmitting unit 122, as described below. The high-speed receiving unit 111 preferably receives reception information for a high-speed communication channel in a first frequency band, and the low-speed receiving unit 121 preferably receives reception information for a low-speed communication channel in a second frequency band. When there is transmission data, the control unit 130 preferably assigns a priority to the transmission data, determines the reception strength of the reception information, and determines the availability of the low-speed communication channel when the reception strength of the high-speed communication channel is equal to or greater than a predetermined reception strength threshold. The low-speed transmitting unit 122 preferably transmits the transmission data with the highest priority assigned by the control unit 130 using a low-speed communication channel determined to be available in the second frequency band. The priority is preferably set in advance according to the type of application of the transmission data.

According to the present disclosure, it is possible to avoid interference and maintain wireless communication starting with high-priority communication data without deploying spare devices with different wireless methods and without controlling changes to the modulation method and occupied wireless band.

The high-speed communication channel in the first frequency band in the wireless communication device 100 according to the second aspect of the present disclosure preferably includes multiple sub-high-speed communication channels. The low-speed communication channel in the second frequency band also preferably includes multiple sub-low-speed communication channels. When the control unit 130 receives reception information with a reception strength equal to or greater than a predetermined reception strength threshold in all of the multiple sub-high-speed communication channels, it is preferable that the control unit 130 causes the low-speed transmission unit 122 to transmit transmission data with a higher priority using the low-speed communication channels.

According to the present disclosure, even if interference occurs in all of the multiple sub-high-speed communication channels included in the high-speed communication channel, it is possible to immediately transmit high-priority transmission data via a low-speed communication channel where interference is less likely to occur. Therefore, even if high-priority transmission data for a control system or the like occurs, it may be possible to reduce the situation in which the transmission data cannot be transmitted.

The control unit 130 of the wireless communication device 100 according to the third aspect of the present disclosure preferably executes the following process. That is, the control unit 130 preferably refers to the allowable delay time included in the priority order of the transmission data, and transmits the transmission data to the low-speed transmission unit 122 if the transmission data can be completed within the allowable delay time range when the transmission data is transmitted via a low-speed communication channel.

According to the present disclosure, even if interference occurs in all high-speed communication channels, it is possible to transmit high-priority transmission data within the allowable delay time via low-speed communication channels where interference is less likely to occur. Therefore, even if high-priority transmission data such as control system transmission data occurs, it may be possible to reduce the situation in which the transmission data cannot be transmitted.

It is preferable that the control unit 130 of the wireless communication device 100 according to the fourth aspect of the present disclosure executes the following process. That is, it is preferable that the control unit 130 refers to the remaining time of a predetermined allowable cumulative usage time in units of a predetermined time in the low-speed communication channel, and transmits the transmission data to the low-speed transmission unit 122 if the transmission of the transmission data can be completed within the remaining time.

According to the present disclosure, when restrictions are placed on the use of low-speed communication channels, the restrictions can be complied with by checking the usage history related to the restrictions, thereby improving the availability of low-speed communication channels.

The control unit 130 of the wireless communication device 100 according to the fifth aspect of the present disclosure preferably executes the following process. When the low-speed communication channel falls within a predetermined idle period, or when the reception strength of the low-speed communication channel is equal to or greater than a predetermined reception strength threshold, the control unit 130 preferably does not allow the low-speed transmission unit 122 to transmit transmission data via the low-speed communication channel.

According to the present disclosure, when restrictions are placed on the use of low-speed communication channels, the restrictions can be observed by checking the conditions related to the restrictions, thereby improving the availability of low-speed communication channels. In addition, by checking the reception strength of low-speed communication channels, it is possible to check for interference occurring in the low-speed communication channels.

The control unit 130 of the wireless communication device 100 according to the sixth aspect of the present disclosure preferably executes the following process when a low-speed communication channel is available while transmitting transmission data via a high-speed communication channel. First, the control unit 130 refers to the allowable delay time included in the priority order of the transmission data. Then, when the transmission data is transmitted via the low-speed communication channel, if the transmission of the transmission data can be completed within the range of the allowable delay time, it is preferable to transmit the transmission data that is experiencing a waiting time among the transmission data that can be completed using the low-speed communication channel.

According to the present disclosure, not only is interference occurring in a high-speed communication channel, but latency is also occurring, but by transmitting data that can be transmitted within the allowable delay time via a low-speed communication channel, it is possible to improve the utilization efficiency of the entire system.

The control unit 130 of the wireless communication device 100 according to the seventh aspect of the present disclosure preferably executes the following process. That is, the control unit 130 preferably divides the transmission data, and reassigns priorities to each of the divided transmission data into which the transmission data is divided, and to all the transmission data including the other transmission data if there is other transmission data. In addition, the control unit 130 preferably uses a high-speed communication channel or a low-speed communication channel in the order of priority of the transmission data.

According to the present disclosure, even if the amount of data to be transmitted is large, the data can be divided into appropriate amounts and the priority can be reassigned, making it possible to transmit the large amount of data with an appropriate priority.

When there is an available sub-high-speed communication channel among the multiple sub-high-speed communication channels, the control unit 130 of the wireless communication device 100 according to the eighth aspect of the present disclosure preferably transmits transmission data in the order of priority using the available sub-high-speed communication channel. Alternatively, when the control unit 130 has transmitted the immediately preceding transmission data using an available sub-high-speed communication channel, it is preferable to transmit the transmission data using the sub-high-speed communication channel, or to execute the following process. That is, it is preferable to transmit the transmission data using another available sub-high-speed communication channel or a low-speed communication channel, or to wait until an unavailable sub-high-speed communication channel becomes available. Also, when there is an available sub-low-speed communication channel among the multiple sub-low-speed communication channels, it is preferable to transmit the transmission data in the order of priority using the available sub-low-speed communication channel. Alternatively, when there is an available sub-low-speed communication channel among the multiple sub-low-speed communication channels, it is preferable to transmit the transmission data using the sub-low-speed communication channel, or to execute the following process. That is, it is preferable to transmit the transmission data using another available sub-low-speed communication channel, or to wait until an unavailable sub-low-speed communication channel becomes available.

According to the present disclosure, even if there is a sub-high-speed communication channel where interference or the like is occurring, it is possible to transmit high-priority transmission data using other available sub-high-speed communication channels. Furthermore, by configuring the available sub-high-speed communication channels so that there is no bias, it is possible to improve the utilization efficiency of resources throughout the system. Or, it may become possible to efficiently use valid sub-high-speed communication channels.

Furthermore, according to the present disclosure, even if there is a sub-low-speed communication channel where interference or the like is occurring, it is possible to transmit high-priority transmission data using other available sub-low-speed communication channels. Also, by configuring the available sub-low-speed communication channels so that there is no bias, it is possible to improve the utilization efficiency of resources throughout the system. Or, it may become possible to efficiently use valid sub-low-speed communication channels.

The control unit 130 of the wireless communication device 100 according to the ninth aspect of the present disclosure preferably processes the response data in the same manner as the transmission data in the above aspect, even when the transmission data is response data including an ACK or NACK. Specifically, it is preferable to determine the reception strength of the received information, and if the reception strength of the high-speed communication channel is equal to or greater than a predetermined reception strength threshold and response data is present, to execute the following process. That is, it is preferable to assign priorities to the response data, and transmit the response data in the order of the assigned priorities using available low-speed communication channels in the second frequency band.

According to the present disclosure, not only when the transmission data is data information, but also when the transmission data is control information, it is possible to maintain wireless communication while avoiding interference from control information with high priority.

The first frequency band of the wireless communication device 100 according to the tenth aspect of the present disclosure preferably includes at least two sub-frequency bands, each of which preferably includes a plurality of sub-high-speed communication channels. The sub-high-speed communication channels preferably include a communication channel defined by Wi-Fi (registered trademark). The low-speed communication channels in the second frequency band preferably include a plurality of sub-low-speed communication channels, each of which preferably includes a communication channel defined by Wi-SUN (registered trademark).

According to the present disclosure, it is possible to avoid interference and maintain wireless communication starting with high-priority communication data without deploying spare devices with different wireless methods and without controlling changes to the modulation method and occupied wireless band.

(Supplementary description of the embodiment)
The block diagrams used in the description of the above-mentioned embodiments show functional blocks. The method of realizing each functional block is not particularly limited. For example, each functional block may be realized using one device that is physically or logically coupled, or may be realized using two or more devices that are physically or logically separated and directly or indirectly connected to each other.

When the wireless communication device 100 is configured with multiple hardware elements, the control unit 130 and/or the functional blocks of the control unit 130 (not shown) are realized by any hardware element or a combination of the hardware elements. Examples of hardware elements include a processor, memory, storage, a communication device, an input device, an output device, a bus, etc.

In this case, each function of the control unit 130 is realized by loading a specific software or program onto hardware such as a processor and memory. Specifically, each function is realized by loading specific software onto the hardware, causing the processor to perform calculations and control the reading and writing of data in the memory and storage.

In this disclosure, the judgment or decision may be made based on a value represented by one bit (0 or 1), a Boolean value (true or false), or a comparison of numerical values (e.g., a comparison with a predetermined value).

The processing steps, sequences, flow charts, etc. of each aspect, variation, or embodiment described herein may be reordered unless inconsistent. For example, the methods described in this disclosure present elements of various steps using an example order and are not limited to the particular order presented.

In addition, the information, parameters, etc. described in this disclosure may be expressed using absolute values, may be expressed using relative values from a predetermined value, or may be expressed using other corresponding information.

The names used for the parameters described above are not limiting in any way. Furthermore, the formulas etc. using these parameters may differ from those explicitly disclosed in this disclosure. The various names are not limiting in any way.

As used in this disclosure, the phrase "based on" does not mean "based only on," unless expressly stated otherwise. In other words, the phrase "based on" means both "based only on" and "based at least on."

In this disclosure, the term "A and B are different" may mean "A and B are different from each other." The term may also mean "A and B are each different from C." Terms such as "separate" and "combined" may also be interpreted in the same way as "different."

Each aspect/embodiment described in this disclosure may be used alone, in combination, or switched depending on the implementation.

Although the embodiments have been described in detail with reference to the drawings, the present invention is not limited to the contents described in the above embodiments. Furthermore, the components described above include those that a person skilled in the art would easily imagine and those that are substantially the same. Furthermore, the configurations described above can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of the configuration can be made without departing from the spirit of the present invention.

REFERENCE SIGNS LIST 100 Wireless communication device 110 High-speed communication unit 120 Low-speed communication unit 130 Control unit 150 External I/F unit 160 Storage unit

Claims (9)

A wireless communication device having communication channels with different communication speeds in a plurality of frequency bands,
a high speed receiving unit for receiving reception information for a high speed communication channel in a first frequency band;
a low-speed receiving unit for receiving reception information for a low-speed communication channel in a second frequency band;
a control unit which, when there is transmission data, assigns a priority to the transmission data, determines a reception strength of the reception information, and, when the reception strength of the high-speed communication channel is equal to or greater than a predetermined reception strength threshold, determines availability of the low-speed communication channel;
a low-speed transmission unit that transmits data having a high priority level assigned by the control unit using a low-speed communication channel determined to be available in a second frequency band,
the control unit refers to an allowable delay time included in the priority order of the transmission data, and when the transmission data can be completed within the allowable delay time range when the transmission data is transmitted through the low-speed communication channel, transmits the transmission data to the low-speed transmission unit;
A wireless communication device, wherein the priority order is preset depending on the type of application of the transmission data. The wireless communication device according to claim 1, wherein the high-speed communication channel in the first frequency band includes a plurality of sub-high-speed communication channels, and the low-speed communication channel in the second frequency band also includes a plurality of sub-low-speed communication channels, and when the control unit receives reception data that is reception information with a reception strength equal to or greater than a predetermined reception strength threshold in all of the plurality of sub-high-speed communication channels, the control unit causes the low-speed transmission unit to transmit the transmission data with the highest priority using the low-speed communication channels. The wireless communication device according to claim 1 or 2, wherein the control unit refers to the remaining time of a predetermined allowable cumulative usage time in units of a predetermined time in the low-speed communication channel, and transmits the transmission data to the low-speed transmission unit if the transmission of the transmission data can be completed within the remaining time. A wireless communication device as described in any one of claims 1 to 3, wherein when the low-speed communication channel corresponds to a pause period according to a predetermined rule, or when the receiving strength of the low-speed communication channel is equal to or greater than a predetermined receiving strength threshold, the control unit does not cause the low-speed transmitting unit to transmit the transmission data via the low-speed communication channel. The wireless communication device of any one of claims 1 to 4, wherein the control unit, when the low-speed communication channel is available while transmitting the transmission data via the high-speed communication channel, refers to the allowable delay time included in the priority order of the transmission data, and when the transmission data is transmitted via the low-speed communication channel, if the transmission data can be completed within the range of the allowable delay time, transmits the transmission data that is experiencing a waiting time among the transmission data that can be completed from the low-speed transmission unit using the low-speed communication channel. The wireless communication device according to any one of claims 1 to 5, wherein the control unit divides the transmission data, reassigns a priority to each of the divided transmission data into which the transmission data is divided, and to all of the transmission data including the other transmission data if there is other transmission data, and utilizes the high-speed communication channel or the low-speed communication channel in the order of the priority. When there is an available sub-high speed communication channel among the plurality of sub-high speed communication channels, the control unit
Transmitting transmission data in the order of priority using the available sub-high-speed communication channels; or
When the immediately preceding transmission data is being transmitted using the available sub-high-speed communication channel,
Using the sub-high-speed communication channel, or
Transmitting transmission data using another available sub-high-speed communication channel or the low-speed communication channel, or by waiting until the unavailable sub-high-speed communication channel becomes available;
When there is an available sub-low speed communication channel among the plurality of sub-low speed communication channels, the control unit
Transmitting transmission data in the order of priority using the available sub-low-speed communication channels; or
When the immediately preceding transmission data is being transmitted using the available sub-low-speed communication channel,
Using the sub-low-speed communication channel, or
3. The wireless communication device according to claim 2, wherein the transmission data is transmitted by using another available sub-low-rate communication channel or by waiting until the unavailable sub-low-rate communication channel becomes available. The wireless communication device according to any one of claims 1 to 7, wherein the control unit determines the receiving strength of the received information even when the transmission data is response data including an ACK or a NACK, and when the receiving strength of the high-speed communication channel is equal to or greater than a predetermined receiving strength threshold and the response data is present, assigns a priority to the response data, and transmits the response data using an available low-speed communication channel in a second frequency band in the order of the assigned priority. 2. The wireless communication device of claim 1, wherein the first frequency band includes at least two sub-frequency bands, each of which includes a plurality of sub-high-speed communication channels, the sub-high-speed communication channels including a communication channel defined by Wi-Fi (registered trademark), and the low-speed communication channels in the second frequency band include a plurality of sub-low-speed communication channels, the sub-low-speed communication channels including a communication channel defined by Wi- SUN (registered trademark).

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