Wireless management method and wireless system

Abstract

To provide a radio management method and a radio system that enable coexistence of radio signals of a plurality of radio devices which use a common frequency band to enable effective utilization of frequencies.SOLUTION: An influenced area that is influenced by radio signals from a radio device is specified on the basis of at least location information on the radio device. Among the plurality of neighboring radio devices, radio signals from interfered terminals that are interfered by the radio device are monitored. On the basis of the monitoring result, the presence or absence of a non-interfered band in which the interface with the interfered terminals does not occur is determined. When the non-interfered band is found, the radio device is enabled to use the non-interfered band. When the non-interfered band is not found, a low-influenced band is specified, which less influences the interfered terminals, on the basis of the monitoring result, and the radio device is enabled to use the low-influenced band.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present disclosure relates to a wireless management method and a wireless system, and more particularly to a wireless management method and a wireless system for managing a wireless device that uses a common frequency band with a plurality of peripheral wireless devices.

Background Art

[0002] A wireless system composed of a base station and a terminal is known. A typical example of a wireless system is a public wireless LAN (Local Area Network). In a public wireless LAN, for example, a use case of transmitting data from a base station to a public computer terminal or a smartphone terminal is assumed. On the other hand, in recent years, industrial wireless LANs have emerged. In an industrial wireless LAN, for example, a use case of transmitting data measured by an IoT (Internet of Things) terminal to a base station is assumed.

[0003] In the frequency band below 1 GHz (S1G (Sub 1 GHz) band) used for IoT, a plurality of wireless systems coexist. A passive tag system in the 920 MHz band including WPT (Wireless Power Transfer) is one of them. The passive tag system can start transmitting a signal without performing carrier sense. This is currently a licensed station and the frequency bands are also separated, but in the future, it is aimed to further expand the use cases. For example, applications to sensor use outdoors and sensor use such as inspection and monitoring are being studied. However, for this purpose, avoidance of the human body and coexistence with other wireless communications are essential. Also, in the frequency bands that will be vacated by digital MCA (845 - 660 MHz and 928 - 940 MHz), coexistence between a passive tag system with an antenna output of 1W and other LPWA (Low Power Wide Area-network) is being studied.

[0004] To achieve coexistence in a wider range of use cases for multiple wireless systems sharing the same frequency band, basic coexistence methods such as carrier sensing are essential. However, more efficient coexistence methods are needed for the effective use of frequency. In particular, passive tag systems with high EIRP (Equivalent Isotropically Radiated Power) have a wide interference range, so methods that prevent mutual interference are required. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] ARIB STD-T108 Version 1.3, "Standard Specification for Radio Equipment for Telemetry, Telecontrol, and Data Transmission in the 920MHz Band," April 12, 2019 [Non-Patent Document 2] IEEE Std 802.11ah TM-2016 (IEEE Standard for Information technology - Telecommunications and information exchange between systems Local and metropolitan area networks - Specific requirements, Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications, Amendment 2: Sub 1 GHz License Exempt Operation, IEEE Computer Society, 7 December 2016 [Overview of the project] [Problems that the invention aims to solve]

[0006] This disclosure is made in view of the above circumstances and aims to provide a technology that enables the effective use of frequency by coexisting radio signals from multiple wireless devices using a common frequency. [Means for solving the problem]

[0007] This disclosure provides a wireless management method for achieving the above objective. The wireless management method of this disclosure is a method for managing a wireless device that uses a common frequency band with multiple peripheral wireless devices. The wireless management method of this disclosure includes at least the following steps:

[0008] The first step of the wireless management method of this disclosure is to identify an affected area that is affected by the wireless signal of a wireless device, based at least on the location information of the wireless device. The second step is to monitor the wireless signals of an interfered terminal among a plurality of surrounding wireless devices that are affected by interference from the wireless device in the affected area. The third step is to determine whether there is a non-interference band in which no interference occurs with the interfered terminal, based on the monitoring results obtained by monitoring the wireless signal of the interfered terminal. The fourth step is to cause the wireless device to use the non-interference band if one exists. The fifth step is, if no non-interference band exists, to identify a low-impact band that has little impact on the interfered terminal, based on the monitoring results obtained by monitoring the wireless signal of the interfered terminal, and cause the wireless device to use the low-impact band.

[0009] This disclosure provides a wireless system for achieving the above objective. The wireless system of this disclosure is a system for managing a wireless device that uses a common frequency band with a plurality of peripheral wireless devices. The wireless system of this disclosure comprises at least one memory storing at least one control program and at least one processor coupled to the at least one memory. The at least one control program is configured to cause the at least one processor to perform at least the following processes.

[0010] The first process that the above-mentioned control program causes the above-mentioned processor to execute is to identify an affected area that is affected by the radio signal of the radio device, based on at least the location information of the radio device. The second process is to monitor the radio signals of the affected terminals among a plurality of peripheral radio devices in the affected area that are affected by the radio device. The third process is to determine whether there is a non-interference band in which no interference occurs with the affected terminal, based on the monitoring results obtained by monitoring the radio signals of the affected terminals. The fourth process is to cause the radio device to use the non-interference band if one exists. The fifth process is, if no non-interference band exists, to identify a low-impact band that has little impact on the affected terminal, based on the monitoring results obtained by monitoring the radio signals of the affected terminals, and cause the radio device to use the low-impact band. [Effects of the Invention]

[0011] According to the wireless management method and wireless system described herein, the effective use of frequency is possible through the coexistence of wireless signals from multiple wireless devices using a common frequency band. [Brief explanation of the drawing]

[0012] [Figure 1] This figure shows an example of the configuration of a wireless system according to the embodiments of this disclosure. [Figure 2] This figure shows an example of the configuration of a transmitting terminal that makes up the wireless system shown in Figure 1. [Figure 3] This figure shows an example of the configuration of a monitoring terminal that makes up the wireless system shown in Figure 1. [Figure 4] This figure shows an example of the configuration of a control terminal that makes up the wireless system shown in Figure 1. [Figure 5] This is a flowchart showing the procedure for a wireless management method according to an embodiment of this disclosure. [Figure 6] This diagram illustrates the method for determining which monitoring terminals are subject to wireless environment information acquisition. [Figure 7]It is a flowchart showing a calculation procedure for numerical evaluation of channels for selection of a low - impact band. [Figure 8] It is a diagram for explaining the arrangement of a CW signal that minimizes the impact on an OFDM signal of a wireless LAN. [Figure 9] It is a diagram showing a first modification of the configuration of a wireless system according to an embodiment of the present disclosure. [Figure 10] It is a diagram showing an example of the configuration of a transmitting terminal including a control program that constitutes the wireless system shown in FIG. 9. [Figure 11] It is a diagram showing a second modification of the configuration of a wireless system according to an embodiment of the present disclosure. [Figure 12] It is a diagram showing a second modification of the configuration of a wireless system according to an embodiment of the present disclosure. [Figure 13] It is a diagram showing an example of the configuration of a transmitting terminal including a monitoring function and a control program that constitutes the wireless system shown in FIG. 12.

Embodiments for Carrying Out the Invention

[0013] Hereinafter, embodiments of a wireless management method and a wireless system of the present disclosure will be described with reference to the drawings.

[0014] 1. Wireless System According to Embodiment of the Present Disclosure FIG. 1 shows an example of the configuration of a wireless system according to an embodiment of the present disclosure. The wireless system 10 shown in FIG. 1 includes a transmitting terminal 20 and a receiving terminal 60 that transmit and receive wireless signals. The transmitting terminal 20 and the receiving terminal 60 constitute a wireless device. The wireless device according to the present embodiment is a device having either or both of a function of notifying information by a wireless signal and a function of supplying power by a wireless signal. The transmitting terminal 20 may be a passive terminal or an active terminal such as 11ah.

[0015] The wireless system 10 includes at least one control device 30 and a plurality of monitoring terminals 40. The control device 30 and the monitoring terminals 40 are connected to a network 50 together with the transmitting terminal 20. The network 50 may be wired or wireless.

[0016] Each of the plurality of monitoring terminals 40 monitors the wireless communication of an external communication device 70 existing in the vicinity, and collects wireless communication environment information around the monitoring terminal 40 from the monitoring results. The external communication device 70 is a peripheral wireless device that performs wireless communication using the same frequency band as the transmission terminal 20. Whether a certain external communication device 70 is a monitoring target of a certain monitoring terminal 40 depends on the positional relationship between the two and the communication status of the external communication device 70. The monitoring terminal 40 transmits the collected wireless communication environment information to the control device 30 via the network 50.

[0017] The control device 30 creates control information for the transmission terminal 20 based on the wireless communication environment information transmitted from the monitoring terminal 40. However, not necessarily all the wireless communication environment information from the monitoring terminals 40 is reflected in the control information. The control device 30 selects a monitoring terminal 40 having a relationship described below with the transmission terminal 20 from among the plurality of monitoring terminals 40. Then, control information to be notified to the transmission terminal 20 is created based on the wireless communication environment information obtained from the selected monitoring terminal 40.

[0018] The control device 30 notifies the transmission terminal 20 of the created control information via the network 50. However, the network used for notifying the control information from the control device 30 to the transmission terminal 20 may be the same as or different from the network to which the monitoring terminal 40 and the control device 30 are connected. The transmission terminal 20 transmits a wireless signal in accordance with the control information notified from the control device 30.

[0019] Figure 2 shows an example of the configuration of the transmitting terminal 20. The transmitting terminal 20 includes a control circuit 201 containing a processor, a wired communication module 202 for wired communication, a wireless communication module 203 for wireless communication, a GPS 204 for estimating its own position, and a timer 205 for monitoring the operation of the control circuit 201. The transmitting terminal 20 communicates with the control device 30 using the wired communication module 202 or the wireless communication module 203, transmitting GPS information and setting information to the control device 30, and receiving control information from the control device 30. The transmitting terminal 20 also communicates wirelessly with the receiving terminal 60 using the wireless communication module 203.

[0020] Figure 3 shows an example of the configuration of the monitoring terminal 40. The monitoring terminal 40 includes a control circuit 401 containing a processor, a wired communication module 402 for wired communication, a wireless communication module 403 for wireless communication, a GPS 404 for estimating its own position, and a timer 405 for monitoring the operation of the control circuit 401. The monitoring terminal 40 uses the wireless communication module 403 to monitor the wireless signals of external communication devices 70 in the vicinity, and transmits the wireless communication environment information obtained from the monitoring results to the control device 30 using the wired communication module 202 or the wireless communication module 203.

[0021] Figure 4 shows an example of the configuration of the control device 30. The control device 30 includes a control circuit 301 containing a processor, a wired communication module 302 for wired communication, a wireless communication module 303 for wireless communication, a memory 305, and a drive 306 containing a storage medium 306a. Furthermore, the control device 30 includes a user interface 304 into which the user can input setting information, and a timer 307 for monitoring the operation of the control circuit 301.

[0022] Memory 305 stores a control program 305a and management information 305b. The control program 305a is a program for implementing the wireless management method according to the embodiment of this disclosure. The management information 305b is information used when the control program 305a is executed. The storage medium 306a stores various information, including wireless communication environment information transmitted from the monitoring terminal 30 and GPS information and setting information transmitted from the transmitting terminal 20. The storage medium 306a is also used to store the control program 305a. The control program 305a may be provided via a network.

[0023] 2. Wireless management method according to an embodiment of this disclosure The wireless management method according to the embodiment of this disclosure is implemented by the control program 305a being executed by the control circuit 301 in the control device 30. When the control device 30 controls multiple transmitting terminals 20, the control program 305a is executed for each transmitting terminal 20. Furthermore, the wireless environment changes moment by moment depending on the activity of wireless devices including external communication devices 70, the propagation environment, and the traffic load. Taking this into consideration, the control program 305a is executed at regular intervals, and the control content is updated each time. By collecting information again after a certain period of time and reviewing the control values, feedback control becomes possible. In addition, when control is performed using machine learning, more precise control can be achieved by increasing the number of control steps.

[0024] Figure 5 is a flowchart showing the procedure of the wireless management method according to this embodiment. This flowchart also represents the control flow of the control program 305a. Therefore, the main processing of each step is the control program 305a or the control device 30 that operates according to the control program 305a. The procedure of the wireless management method according to this embodiment will be described below in accordance with the flowchart.

[0025] First, in step S1, in order to determine the range affected when the transmitting terminal 20 transmits a wireless signal, the location information of the transmitting terminal 20 is obtained from a source of location-identifying information such as GPS information or configuration information.

[0026] Next, in step S2, the affected area is identified, which is impacted by the transmission of wireless signals by the transmitting terminal 20. To identify the affected area, information such as the location information of the transmitting terminal 20, the transmitting power and power density of the transmitting terminal 20, the directivity characteristics of the antenna of the transmitting terminal 20, the direction in which the antenna is pointed, and the propagation model are used. External communication devices 70 that are affected by interference from the transmitting terminal 20 in the affected area are called affected terminals. More specifically, among the external communication devices 70 observed by the monitoring terminal 40 in the affected area, those observed with a power intensity above a threshold are determined to be affected terminals. Note that the determination may also be made by power density per unit frequency band instead of power intensity.

[0027] In step S2, the affected area may be divided according to the distance from the transmitting terminal 20 and the interference power (the interference power that can be estimated to be observed from the interfered terminal). The division of the affected area can be used later when the transmitting terminal 20 selects the bandwidth to which it transmits the wireless signal. Specifically, if the distance from the interference source, which can be confirmed from the location information of the interfered terminal, is determined to be far, or if the interference power is determined to be low, these will be factors in deciding which bandwidth to prioritize.

[0028] In step S3, after the affected area has been identified, wireless communication environment information is acquired from monitoring terminals 40 located within the affected area. Here, the method for determining which monitoring terminals 40 are to be used to acquire wireless communication environment information is explained using Figure 6. Figure 6 shows a transmitting terminal 20, its affected area AA, and multiple monitoring terminals 40A to 40H arranged around the transmitting terminal 20. The affected area AA is derived from the transmitting power of the transmitting terminal 20, the antenna pattern, and the propagation model of the wireless environment, and its size and shape change depending on these parameters. For example, if the transmitting power of the transmitting terminal 20 is controlled to be smaller, the affected area AA will also be smaller.

[0029] The direction in which the affected area AA spreads depends on the antenna pattern of the transmitting terminal 20. In the example shown in Figure 6, the affected area AA spreads to the right of the paper, and monitoring terminals 40C to 40F are included in the affected area AA. Therefore, monitoring terminals 40C to 40F are included in the acquisition of information. Monitoring terminals 40G and 40H, which are far from the transmitting terminal 20, are outside the affected area AA and are therefore not included in the acquisition of information. Although monitoring terminals 40A and 40B are located close to the transmitting terminal 20, they are determined to be outside the affected area AA based on the pattern of its spread, and therefore are also not included in the acquisition of information.

[0030] Returning to Figure 5, we continue the explanation of step S3. To determine whether the monitoring terminal 40 is within the affected area, the location information of the monitoring terminal 40 is used. Since the monitoring terminal 40 is equipped with a GPS 404, just like the transmitting terminal 20, the location information acquired by the GPS 404 is transmitted to the control device 30. In the case of a terminal where it is difficult to equip with a GPS, the location information of the monitoring terminal 40 may be obtained from, for example, location setting information registered in the management information of a storage medium or memory.

[0031] In step S3, the wireless communication environment information acquired from the monitoring terminal 40 includes the frequency band and received power used by the surrounding external communication devices 70 observed by the monitoring terminal 40. If the external communication device 70 is a specific wireless device capable of demodulating wireless signals, such as a wireless LAN terminal, then in addition to the bandwidth and interference power used, the SSID (Service Set Identifier) ​​that identifies the wireless LAN cell is acquired. Furthermore, if the external communication device 70 is a wireless LAN terminal, information such as ACK (ACKnowledgement) and NACK (Negative-ACKnowledgement) information, wireless LAN transmission frequency and traffic information within a certain period of time in the past, the MCS (Modulation and Coding Scheme) mainly used, and the retransmission frame rate is acquired. The retransmission frame rate is defined as the percentage of wireless LAN data frames where the Retry bit is set to 1.

[0032] Next, in step S4, based on the bandwidth used, interference power, and SSID obtained in step S3, the system determines which frequency bands are presumed to affect the surrounding external communication devices 70, i.e., the interfering terminal, when the transmitting terminal 20 transmits a wireless signal, and which frequency bands are presumed not to affect the interfering terminal. Hereinafter, the frequency band presumed to affect the interfering terminal will be called the interference band, and the frequency band presumed not to affect the interfering terminal will be called the non-interference band. Whether a frequency band is an interference band or a non-interference band is determined for each unit frequency band according to the rules and standards of the frequency band of the wireless signal being monitored. In step S4, the system determines whether a frequency band exists within the non-interference band in which the frequency bandwidth that the transmitting terminal 20 intends to use can be continuously secured.

[0033] If it is determined in step S4 that a non-interference band exists, the wireless management procedure proceeds to step S5 and ends in step S5. In step S5, a frequency band to be used by the transmitting terminal 20 is selected within the non-interference band. In other words, if a non-interference band exists, a wireless signal is transmitted to the transmitting terminal 20 using the non-interference band.

[0034] If it is determined in step S4 that no non-interference band exists, the transmitting terminal 20 must select a frequency band from the interference band. In this case, the wireless management procedure proceeds to step S6. In step S6, it is confirmed whether a protected terminal is located within the area affected by the transmitting terminal 20. A protected terminal is an external communication device 70 that requires priority protection for wireless communication and is registered in the management information 305b of the control program 305a. The location information of the protected terminal may be obtained using the GPS installed in the protected terminal, or it may be obtained from the location setting information registered in the management information of the storage medium or memory. Alternatively, the location of the protected terminal may be determined based on the SSID obtained from the monitoring terminal 40.

[0035] Furthermore, the external communication device 70 requesting protection as a protective device needs to be made known to the monitoring terminal 40. For this reason, the external communication device 70 requesting protection will periodically transmit wireless signals even if there is no communication data. If the external communication device 70 is connected to the control device 30, similar to the transmitting terminal 20, the control program 305a will notify the external communication device 70, and upon receiving this notification, the external communication device 70 requesting protection will periodically transmit wireless signals.

[0036] For example, if the external communication device 70 requesting protection is a wireless LAN access point (AP), the AP generally transmits beacon frames at a frequency of once every 100 milliseconds, so this can be utilized. However, if this transmission frequency is insufficient, or if the external communication device 70 requesting protection is a wireless LAN terminal that is not an AP, it is necessary to transmit a dummy wireless signal. For example, a signal directed to the terminal itself, such as CTS-to-self (clear to send to self), can be transmitted, or a data frame can be transmitted to the AP at regular intervals.

[0037] If it is determined in step S6 that the protected terminal is not within the affected area, the wireless management procedure proceeds to step S8. On the other hand, if it is determined in step S6 that the protected terminal is within the affected area, the wireless management procedure proceeds to step S8 via step S7. In step S7, the frequency band used by the protected terminal is removed from the selectable frequency bands. However, if this removal results in no selectable frequency bands remaining, the frequency band used by the protected terminal is left as one of the selectable frequency bands.

[0038] In step S8, the impact of the transmission of a wireless signal by the transmitting terminal 20 is numerically evaluated based on the information obtained in step S3. Based on the results of this numerical evaluation, a low-impact band, which is considered to have a small impact, is selected as the frequency band to which the transmitting terminal 20 will transmit a wireless signal. Alternatively, machine learning is performed using the information obtained in step S3 as input, and a frequency band determined to be a low-impact band is selected based on the results of the machine learning.

[0039] One specific method for selecting a low-impact band based on numerical evaluation is shown in Figure 7. Figure 7 is a flowchart of the calculation procedure for numerical evaluation of channels for selecting a low-impact band. According to this flowchart, first, in step S81, the distance d3 between the transmitting terminal 20 and the interfered terminal is calculated. Using the distance d1 between the monitoring terminal 40 and the transmitting terminal 20, and the distance d2 between the monitoring terminal 40 and the interfered terminal, the distance d3 can be calculated using the formula “d3=|d1-d2|”. Note that the distance d1 can be calculated from GPS information or estimated information. The distance d2 can be calculated from RSSI (Received Signal Strength Indicator), the assumed transmission power of the interfered terminal, and the propagation model.

[0040] Next, in step S82, it is determined whether the radio signal from the transmitting terminal 20 reaches a received strength that can be detected by the carrier sense of the interfered terminal, based on the distance d3 between the transmitting terminal 20 and the interfered terminal, the transmission power, and the antenna characteristics. If the determination result in step S82 is positive, the calculation procedure for numerical evaluation proceeds to step S83; if the determination result in step S82 is negative, the calculation procedure for numerical evaluation proceeds to step S84.

[0041] In step S83, the probability R that the wireless signal from the transmitting terminal 20 will prevent the interfered terminal from transmitting its signal is estimated based on the predicted or set value of the traffic volume. Meanwhile, in step S84, the received power ratio between the transmitting terminal 20 and the interfered terminal is estimated when both the transmitting terminal 20 and the interfered terminal transmit simultaneously. Then, the packet error rate is calculated based on the received power ratio, and the throughput reduction rate R' is estimated from the packet error rate.

[0042] Finally, in step S85, the probability R estimated in step S83 or the throughput degradation rate R' estimated in step S84 is set as the channel evaluation value. Since both the probability R and the throughput degradation rate R' are numerical values ​​that indicate the degradation rate of the interfered terminal, the channel with the smallest evaluation value will be selected as the low-impact bandwidth as a result of the numerical evaluation of the channels. If there are multiple interfered terminals, the numerical evaluation of the channels can be performed by an overall evaluation based on the sum of the evaluation values.

[0043] Returning to Figure 5, we will now explain step S9. In step S9, we determine the interference countermeasures to be used when using the frequency band selected in step S8. One method of interference countermeasures is to select a center frequency within the selected frequency band that does not deviate from radio wave regulations and standards, so that even if the radio signal of the transmitting terminal 20 interferes with the interfered terminal, the impact will be minimized. Alternatively, reducing the transmission power or reducing the transmission frequency within a range that the transmitting terminal can set are also effective methods of interference countermeasures. In step S9, the transmitting terminal 20 starts transmitting the radio signal while implementing the determined interference countermeasures.

[0044] Figure 8 illustrates a specific example of interference countermeasures when the affected terminal is a wireless LAN terminal. Since wireless LANs use OFDM signals, multiple subchannels exist. However, if the wireless signal from transmitting terminal 20 is a continuous wave (CW) without demodulation, such as a WPT signal, its spectrum becomes very narrow relative to the OFDM signal and subchannels. Furthermore, the area near the center frequency of the OFDM signal corresponds to the DC component of the local oscillator and is a null subcarrier where no subcarriers are placed, taking into account the offsets of D / A and A / D conversion. Therefore, by placing the CW signal of transmitting terminal 20 within the null subcarrier or guard band, the impact on the wireless LAN can be minimized. Note that attempting to control the signal strength of the OFDM signal will worsen the PER due to PAPR distortion. Similarly, attempting to control the signal strength of the CW signal will cause the waveform to broaden. For these reasons, it is preferable to control the center frequency and transmission waveform in conjunction with the transmission power control.

[0045] 3. Other Embodiments The embodiments described above can be modified in various ways without departing from the gist of this disclosure. That is, where the number of elements, quantities, amounts, ranges, etc., are referred to in the embodiments above, the technology of this disclosure is not limited to the number referred to, unless otherwise explicitly stated or clearly defined in principle. Furthermore, the structures, etc., described in the embodiments above are not necessarily essential to the technology of this disclosure, unless otherwise explicitly stated or clearly defined in principle.

[0046] For example, the configuration of the wireless system according to the above embodiment can be modified as follows. Figure 9 is a diagram showing a first modified example of the configuration of the wireless system according to the above embodiment. In the first modified example of the wireless system 11 shown in Figure 9, the transmitting terminal 21 includes a control program. In other words, the transmitting terminal 21 is equivalent to the transmitting terminal 20 in Figure 1 with the functions of the control device 30 incorporated into it.

[0047] Figure 10 shows an example of the configuration of the transmitting terminal 21 shown in Figure 9. The transmitting terminal 21 includes a control circuit 211 including a processor, a wired communication module 212, a wireless communication module 213, a user interface 214, a GPS 215, and a timer 216. Furthermore, the transmitting terminal 21 includes a memory 217 and a drive 218 including a storage medium 218a.

[0048] Memory 217 stores the control program 217a and management information 217b. The control program 217a is a program for implementing the wireless management method according to the above embodiment. The management information 217b is information used when the control program 217a is executed. The storage medium 218a stores various information, including wireless communication environment information transmitted from the monitoring terminal 30. The storage medium 218a is also used to store the control program 217a. The control program 217a may be provided via a network.

[0049] Figure 11 shows a second modified example of the configuration of the wireless system according to the above embodiment. In the second modified wireless system 12 shown in Figure 11, the transmitting terminal 22 includes a monitoring function. In other words, the transmitting terminal 22 is equivalent to the transmitting terminal 20 in Figure 1 with the functions of the monitoring terminal 40 incorporated. The transmitting terminal 22 with the monitoring function collects information on the surrounding wireless communication environment and transmits it to the control device 30 via the network 50. The control device 30 notifies the transmitting terminal 22 of control information created based on the collected wireless communication environment information.

[0050] Figure 12 shows a third modified example of the configuration of the wireless system according to the above embodiment. In the third modified example of the wireless system 12 shown in Figure 12, the transmitting terminal 23 includes a monitoring function and a control program. In other words, the transmitting terminal 23 is equivalent to the transmitting terminal 20 in Figure 1 with the functions of the monitoring terminal 40 and the control device 30 incorporated into it. According to the configuration shown in Figure 12, the transmitting terminal 23 can collect surrounding wireless communication environment information independently without being connected to other networks, and can control the transmission of wireless signals itself based on the collected information.

[0051] Figure 13 shows an example of the configuration of the transmitting terminal 23 shown in Figure 12. The transmitting terminal 23 includes a control circuit 231 including a processor, a wired communication module 232, a wireless communication module 233, a user interface 234, a GPS 235, and a timer 236. Furthermore, the transmitting terminal 23 includes a memory 237 and a drive 238 including a storage medium 238a. The transmitting terminal 23 uses the wireless communication module 233 to monitor wireless signals from external communication devices 70 in the vicinity and stores the surrounding wireless communication environment information obtained from the monitoring results in the storage medium 238a.

[0052] Memory 237 stores the control program 237a and management information 237b. The control program 237a is a program for implementing the wireless management method according to the above embodiment. The management information 237b is information used when the control program 237a is executed. The storage medium 238a is used to store various information, including information about the surrounding wireless communication environment, as well as to store the control program 237a. The control program 237a may be provided via a network.

[0053] The wireless management method according to the above embodiment can be modified and implemented. For example, when repeatedly performing the steps of the wireless management method shown in Figure 5, the interference countermeasures in step S9 may be changed to take into account the influence of wireless signals that have already been transmitted.

[0054] For example, if the monitoring terminal 40 can demodulate the communication of the interfered terminal, it measures the number of ACKs or NACKs that should be sent after a predetermined time for each data frame and compares this with the number of data frames to determine the retransmission rate. If the transmitting terminal 20 has already transmitted a radio signal during the period observed by the monitoring terminal 40, it determines whether the transmission of the radio signal by the transmitting terminal 20 has worsened the retransmission rate of the interfered terminal. Whether or not the retransmission rate has worsened can be determined by comparing the values ​​before and after the transmission of the radio signal by the transmitting terminal 20. Alternatively, it can also be determined by comparing it with the retransmission rate previously stored as data from the interfered terminal.

[0055] Even if it is determined that the retransmission rate has deteriorated, the same frequency band may still be selected in step S8. In that case, in step S9, measures such as reducing the transmission power until the interference falls within an acceptable range or to the minimum power value that can be set are implemented. Alternatively, interference may be suppressed by performing power calculations that take fairness into consideration or power calculations that are determined to have a sufficiently small impact. [Explanation of symbols]

[0056] 10, 11, 12, 13 Wireless Systems 20 Sending terminal 21. Transmitting terminal (transmitting terminal including control program) 22. Transmitting terminal (transmitting terminal including monitoring function) 23. Transmitting terminal (transmitting terminal including monitoring function and control program) 30 Control device 40 monitoring terminals 50 Networks 60 Receiving terminal 70 External communication device

Claims

1. A wireless management method for managing a wireless device that uses a frequency band common to a plurality of peripheral wireless devices, comprising: Identifying an area of ​​influence affected by the wireless signal of the wireless device based on at least location information of the wireless device; monitoring a wireless signal of an interfered terminal that is subjected to interference from the wireless device in the influence area among the plurality of peripheral wireless devices; determining whether or not there is a non-interference band in which no interference occurs with the interfered terminal based on a monitoring result obtained by monitoring the wireless signal of the interfered terminal; If the non-interference band exists, causing the wireless device to use the non-interference band; If the non-interference band does not exist, a low-impact band that has a low impact on the interfered terminal is identified based on the monitoring result, and the wireless device is caused to use the low-impact band. A radio management method comprising:

2. 2. The radio management method according to claim 1, monitoring the wireless signal of the interfered terminal includes monitoring using a plurality of monitoring terminals arranged within the area of ​​influence; The monitoring results include surrounding wireless communication environment information acquired by the plurality of monitoring terminals. A radio management method comprising:

3. 3. The radio management method according to claim 1, Identifying the area of ​​influence includes identifying the area of ​​influence based on the location information of the wireless device, and a transmission power, antenna characteristics, and a propagation model of the wireless device. A radio management method comprising:

4. 4. The radio management method according to claim 1, further comprising: Identifying the less-affected band includes calculating a retransmission rate by demodulating a radio signal from the interfered terminal, and updating the less-affected band based on a change in the retransmission rate before and after wireless communication using the less-affected band by the wireless device. A radio management method comprising:

5. 5. The radio management method according to claim 1, further comprising: and further controlling at least one of a center frequency, a transmission power, a transmission frequency, and a transmission waveform of a radio signal of the radio device based on the monitoring result so as to suppress an influence on the interfered terminal in the low-influence band. A radio management method comprising:

6. 6. The radio management method according to claim 1, further comprising: Identifying the less-affected band includes excluding a band used by a protected terminal that requires priority protection among the interfered terminals from the less-affected band. A radio management method comprising:

7. 7. The radio management method according to claim 6, Monitoring the wireless signal of the interfered terminal includes receiving a wireless signal requesting protection periodically transmitted from the protected terminal. A radio management method comprising:

8. A wireless system for managing a wireless device that uses a frequency band common to a plurality of peripheral wireless devices, at least one memory storing at least one control program; at least one processor coupled to the at least one memory; The at least one control program may cause the at least one processor to: Identifying an area of ​​influence affected by the wireless signal of the wireless device based on at least location information of the wireless device; monitoring a wireless signal of an interfered terminal that is subjected to interference from the wireless device in the influence area among the plurality of peripheral wireless devices; determining whether or not there is a non-interference band in which no interference occurs with the interfered terminal based on a monitoring result obtained by monitoring the wireless signal of the interfered terminal; If the non-interference band exists, causing the wireless device to use the non-interference band; If the non-interference band does not exist, the control unit 100 identifies a low-impact band that has a low impact on the interfered terminal based on the monitoring result, and causes the wireless device to use the low-impact band. A wireless system characterized by:

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