JP7097769B2 - Wireless communication system - Google Patents

Description

The present application relates to a wireless communication system that enhances the reliability of a wireless network between high priority points that require continuous communication.

In recent years, wireless communication has become widespread in communication systems for consumer devices such as mobile phones and smartphones. In recent years, the application of wireless has expanded to industrial equipment such as remote I / O (input / output), sensors, and robots due to the advantages of miniaturization and cost reduction of wireless equipment and reduction of wiring and cable costs. There is. Furthermore, as represented by the IoT (Internet of Things), wireless is attracting more attention than ever as a means of connecting everything to the Internet.

On the other hand, in communication systems of industrial equipment that require high reliability, wireless communication is still avoided and wired communication is widespread. Behind the fact that wireless communication is not widespread as a communication system for industrial equipment that requires high reliability, communication becomes impossible if the communication environment deteriorates due to the surrounding weather conditions or if an obstacle enters the propagation path between the transmitting side and the receiving side. For example, it is an unstable system that is not guaranteed to be able to communicate.

In addition, as mobile Wifi routers, smartphones with tethering functions, and radio-controlled unmanned vehicle drones become widespread, the communication environment is deteriorating due to their radio wave interference, and the fact that they can move is the communication environment. It is difficult to grasp and predict the radio wave, which is a factor that hinders the spread of radio waves in highly reliable applications. Furthermore, if jamming radio waves are intentionally transmitted, there is a concern that radio interference may occur, which is also one of the factors.

In order to solve these radio problems, in Patent Document 1, wireless relay between a base station and a plurality of mobile stations is performed by a small flying object, and the mobile station and the mobile station are changed according to changes in the position and distribution of the mobile station. Stable communication is realized by changing the position and route of small flying objects and flexibly changing the network configuration so that the distance from the relay station is less than a predetermined value. Further, since the flying objects are located in the air, it is possible to secure a propagation path without obstacles in the middle, and it is possible to suppress the attenuation of the signal strength. Further, when a small flying object breaks down, a method of continuous communication is disclosed by substituting for another small flying object.

Patent Document 2 discloses a method of ensuring a sufficient communication capacity without delay by appropriately arranging a flight relay station for support when a rapid increase in communication demand is expected due to seasonal fluctuations, sudden accidents, or the like. .. Further, when the communication by the laser beam is interrupted due to the failure of the optical communication function or the like and it is difficult to recapture, the method of switching to the communication by the radio wave and avoiding the interruption of the communication is disclosed.

In Patent Document 3, the position information and the electric field strength of the ground station and the aerial node device are detected, the position information and the electric field strength are acquired by mutual communication, the position information that enables the required communication is calculated, and the position is moved to a predetermined position. A method of replacing a network node damaged in the event of a disaster by moving is disclosed.

In Patent Document 4, when a communication failure occurs in a wireless mesh network, the reference value of the amount of forward traffic and the number of wireless links for each normal time zone is statistically calculated, and the most usable is based on the reference value. Reconstruct with priority given to high transmission paths and nodes. Further, when a wireless node fails, a method of dispatching a mobile base station to the position of a high-priority wireless node, forming a wireless link with a peripheral wireless node, and functioning as a relay node is disclosed based on the above reference value. ing.

Japanese Unexamined Patent Publication No. 2004-336408 Japanese Unexamined Patent Publication No. 2007-13513 Japanese Unexamined Patent Publication No. 2008-236438 Japanese Unexamined Patent Publication No. 2013-239827

However, in the method of Patent Document 1, when the weather condition deteriorates or an obstacle moves to the radio propagation path, it is necessary to reduce the distance between the mobile station and the relay station. There was a problem that continuous communication could not be performed because the distance between the mobile station and the relay station could not be dynamically optimized only by changing the position of the squadron accordingly. Further, there is no mechanism for predicting the failure of a small flying object, and since the alternative small flying object moves after the small flying object fails, there is a problem that it takes time to recover from the communication failure.

Although the method of Patent Document 2 can cope with a rapid increase in communication demand, since the position of the relay station cannot be dynamically changed, continuous communication cannot be performed when the weather conditions deteriorate or an obstacle moves to the radio propagation path. There was a problem at last.

In the method of Patent Document 3, it takes time to find a position where the electric field strength becomes a predetermined state when the radio wave environment changes suddenly, such as when the weather condition deteriorates or an obstacle moves to the radio wave propagation path. As a result, there was a problem that continuous communication was not possible. Further, even if the electric field strength is high, there is a problem that continuous communication cannot be performed when the interference wave is large.

In the method of Patent Document 4, the dispatch destination of the mobile base station is determined based on the amount of forward traffic and the number of wireless links, and the weather conditions at the dispatch destination deteriorate and there are obstacles in the radio wave propagation path at the dispatch destination. There was a problem that continuous communication could not be performed when dispatched to an environment with poor radio wave environment. In addition, there is a problem that continuous communication cannot be performed when a mobile base station breaks down.

This application has been made to solve the above-mentioned problems, avoiding the influence of the deterioration of the radio wave environment, and improving the reliability of the wireless network between the points where continuous communication is required. The purpose is to obtain a wireless communication system.

The wireless communication system according to the present application is a wireless communication system in which communication is performed via a wireless relay device that can move between wireless devices, and the wireless relay device monitors obstacles that cause radio interference. The unit, the obstacle position identification unit that identifies the position of the obstacle based on the output from the obstacle monitoring unit, the antenna unit that receives the desired wave to be received and the interference wave of the obstacle, and the output from the antenna unit. The interference wave level detection unit that detects the reception level of the interference wave, the desired wave level detection unit that detects the reception level of the desired wave by the output from the antenna unit, and the position of the obstacle and the reception level of the interference wave are monitored. Obstacle interference wave monitoring unit, monitoring information unit that stores the position of the obstacle and the reception level of the interference wave, which is the output from the obstacle interference wave monitoring unit, and the position of the obstacle and the reception level of the interference wave. Therefore, when the obstacle interference wave identification unit that identifies whether the obstacle is generating the interference wave and the obstacle interference wave identification unit identify that the obstacle is generating the interference wave, the obstacle is generated. The location of the abnormality determination unit that determines whether the reception level of the interference wave to be performed is an abnormality level that interferes with the wireless communication of the wireless relay device that is the own device, and the position where the wireless relay device that is the own device may move. When the movable range information unit that manages the movable / non-movable information shown for each and the abnormality determination unit determines that the level is abnormal, the destination of the wireless relay device, which is the own device, is determined based on the movable / non-movable information, and the own device determines the destination. It is equipped with a self-device position control unit that controls the position of a certain wireless relay device.

According to the present application, when there is an obstacle that causes radio wave interference, the wireless relay device autonomously moves to a place with a good radio wave environment so as to identify the position of the obstacle and avoid the influence of the obstacle. By increasing the utilization efficiency of the spatial radio wave environment, it is possible to obtain a wireless communication system capable of increasing the reliability of the wireless network between high-priority wireless devices that require continuous communication.

It is a block diagram of the wireless relay device used in the wireless communication system which concerns on Embodiment 1. FIG. It is a figure which shows the flowchart which identifies the obstacle which generates the interference wave in the wireless communication system of Embodiment 1. FIG. It is a figure which shows the flowchart which avoids the influence of the obstacle which becomes the radio wave interference in the wireless communication system of Embodiment 1. FIG. It is a figure which shows an example of the movable / non-movable information for each coordinate managed by the movable range information part in the wireless communication system of Embodiment 1. FIG. It is a figure which shows the flowchart which determines the coordinate which limits the movement destination in the wireless communication system of Embodiment 1. FIG. It is a conceptual diagram which avoids an obstacle by the wireless relay device of own device in the wireless communication system of Embodiment 1. FIG. It is a block diagram of the wireless relay device used in the wireless communication system which concerns on Embodiment 2. FIG. It is a figure which shows the flowchart which requests the help from the wireless relay device of another device in the wireless communication system of Embodiment 2. FIG. 5 is a conceptual diagram for requesting help from a wireless relay device of another device in the wireless communication system of the second embodiment. In the wireless communication system of the third embodiment, it is a conceptual diagram which avoids an obstacle by the wireless relay device of the own device and another device. In the wireless communication system of the third embodiment, it is a conceptual diagram which determines the movement destination candidate of the wireless relay apparatus of own apparatus and other apparatus. In the wireless communication system of the third embodiment, it is a figure which shows the flowchart which determines the moving destination route of the wireless relay apparatus of own apparatus and other apparatus. In the wireless communication system of the fourth embodiment, it is a conceptual diagram which avoids an obstacle by the wireless relay device of the own device and another device. It is a figure which shows the flowchart which requests the help from the wireless relay device of another device in the wireless communication system of Embodiment 4. FIG. 5 is a conceptual diagram for warning an obstacle that generates an interference wave in the wireless communication system of the fifth embodiment.

Embodiment 1.
Hereinafter, the wireless communication system according to the first embodiment of the present application will be described with reference to FIGS. 1 to 6.
In a wireless communication system, for example, a wireless device located at a distance from each other and a wireless device communicate with each other via a movable wireless relay device.
FIG. 1 is a configuration diagram of a wireless relay device used in the wireless communication system according to the first embodiment. When the wireless relay device communicates between wireless devices fixedly arranged at two points, for example, radio waves are used. Used as a mobile wireless relay device to improve the reliability of wireless networks between high-priority points that require continuous communication even when the environment deteriorates, and to avoid the effects of deterioration of the radio wave environment. It is a thing. This wireless relay device can be mounted on an unmanned flying object such as a drone and move in space.

In FIG. 1, the wireless relay device of the wireless communication system includes an obstacle monitoring unit 101, an obstacle position specifying unit 102, an antenna unit 103, an interference wave level detecting unit 104, a desired wave level detecting unit 105, and an obstacle. It is composed of an object interference wave monitoring unit 107, a monitoring information unit 108, an obstacle interference wave identification unit 109, an abnormality determination unit 110, a movable range information unit 111, and a self-device position control unit 112.
The obstacle monitoring unit 101 monitors obstacles such as people and objects that cause radio wave obstacles, and is a camera for identifying the position of the obstacle, a millimeter-wave radar, an infrared sensor, LiDAR, an ultrasonic distance meter, and a position. Specific GPS, altitude sensor, etc. are used. The obstacle position specifying unit 102 identifies the position of the obstacle by the output from the obstacle monitoring unit 101.

The antenna unit 103 receives the interference wave generated from an obstacle or the like, and the interference wave level detection unit 104 detects the reception level of the interference wave. Further, the antenna unit 103 receives the desired wave to be received, and the desired wave level detection unit 105 detects the reception level of the desired wave. The obstacle interference wave monitoring unit 107 has the distance Di (position of the obstacle) between the wireless relay device, which is its own device calculated by the obstacle position identification unit 102, and the obstacle, and the interference measured by the interference wave level detection unit 104. The wave level PNi is monitored, and the distance Di with the obstacle and the interference wave level PNi are stored in the monitoring information unit 108 in chronological order.

The obstacle interference wave identification unit 109 identifies whether or not an interference wave is emitted from the obstacle, based on the fluctuation of the distance between the wireless relay device, which is its own device, and the obstacle, and the fluctuation of the interference wave level. And the interference wave correlation is obtained. If there is a correlation, it is identified that the interference wave is generated from the obstacle.
The correlation coefficient Cn is a coefficient calculated from the positional relationship of obstacles and the level of interference waves. The obstacle interference wave identification unit 109 stores the calculated correlation coefficient Cn in the monitoring information unit 108.

障害物が干渉波を発生していた場合、一般的に干渉波レベルＰＮｉは障害物との距離Ｄｉの二乗に反比例するため、相関が有る場合の相関係数は－１≦Ｃｎ＜０の間をとる。 Here, for example, the correlation coefficient Cn is expressed by the following equation (1) using the equation of the general Pearson's correlation coefficient.

When an obstacle generates an interference wave, the interference wave level PNi is generally inversely proportional to the square of the distance Di with the obstacle, so the correlation coefficient when there is a correlation is between -1≤Cn <0. Take.

Based on the information from the obstacle interference wave identification unit 109 and the monitoring information unit 108, the abnormality determination unit 110 wirelessly relays the radio relay device in which the interference wave generated by the obstacle detected by the interference wave level detection unit 104 is its own device. Determine if it is a level that interferes with communication. The determination method may be determined as an abnormal level when the level of the interference wave exceeds a predetermined threshold, or the SN ratio of the reception level of the desired wave and the interference wave is monitored, and the SN ratio sets the predetermined threshold. If it exceeds the level, it may be determined to be an abnormal level.

The movable range information unit 111 stores and manages the movable / non-movable information indicating whether or not the wireless relay device, which is the own device, may move, for each three-dimensional place.
The own device position control unit 112 determines the destination of the wireless relay device, which is the own device, based on the movable / non-movable information from the movable range information unit 111, and moves the position of the wireless relay device, which is the own device, to the move destination. Control to do.

A method of identifying the position of an obstacle that generates an interference wave will be described with reference to the flowchart of FIG.
In FIG. 2, in step S1, the correlation coefficient Cn is calculated by the obstacle interference wave identification unit 109, and the process proceeds to step S2. In step S2, it is determined whether or not the correlation coefficient Cn is 0 or more, and if there is a positive correlation with the correlation coefficient Cn of 0 or more (No), there is no correlation between the obstacle and the interference wave, so step S3 is performed. Proceed and determine that the obstacle is not generating an interference wave. After that, the process proceeds to step S4, and after a certain period of time Ta has elapsed (Yes), the process returns to step S1 to obtain the correlation coefficient Cn again, and it is determined again whether or not there is a correlation.

If there is a negative correlation with a correlation coefficient Cn of 0 or less in step S2 (Yes), the process proceeds to step S5 to determine whether or not the correlation coefficient is α or less. Here, α is a threshold value for determining that an obstacle is generating an interference wave. If the correlation coefficient is α <Cn <0 in step S5 (No), the process proceeds to step S6, and it is determined that the correlation is weak. After that, the process proceeds to step S7, and after a certain period of time Tb has elapsed (Yes), the process returns to step S1 to obtain the correlation coefficient Cn again, and it is determined again whether or not there is a correlation.

In step S5, when the correlation coefficient is Cn ≦ α (Yes), the process proceeds to step S8, it is determined that there is a correlation, and it is determined that the obstacle is generating the interference wave. After that, the process proceeds to step S9, and after a certain period of time Tc has elapsed (Yes), the process returns to step S1 to obtain the correlation coefficient Cn, and it is determined again whether or not there is a correlation. Here, the relationship between Ta, Tb, and Tc for a certain period of time is, for example, Tc <Tb <Ta. When there are a plurality of obstacles, the correlation coefficient is obtained for each obstacle, and it is identified whether each obstacle generates an interference wave.

For simplification, the correlation coefficient Cn is, for example, the difference between the interference wave level PNn and the interference wave level PNn + 1, the square of the distance Dn + 1 to the obstacle, and the obstacle, as shown in the following equation (2). It may be obtained by the quotient with the difference from the square of the distance Dn.
Cn = {(PNn) ― (PNn + 1)} / {(Dn + 1) ^2- (Dn) ² } ・ ・ ・ (2)
Here, the level PNn + 1 of the interference wave at the time Tn + 1, the distance Dn + 1 with the obstacle, the level PNn of the interference wave at the time Tn, and the distance Dn with the obstacle. In order to eliminate temporary sudden fluctuations and errors due to fading, an equalizer may be used or averaging may be performed.

Further, the correlation coefficient Cn is the quotient of the product of the interference wave levels PNn + 1 and PNn at the time Tn + 1 and the time Tn and the square of the distances Dn + 1 and Dn to the obstacle as shown in the following equation (3). You may ask.
Cn = {(PNn + 1) * (Dn + 1) ² } / {(PNn) * (Dn) ² } ・ ・ ・ (3)
Since the correlation coefficient Cn is a coefficient calculated from the positional relationship of obstacles and the level of the interference wave, a calculation method other than the above-mentioned formula may be used.

A method of avoiding an obstacle that generates an interference wave will be described with reference to the flowchart of FIG. 3 and the conceptual diagram of the movable range information unit 111 of FIG.
In FIG. 3, in step S11, the obstacle monitoring unit 101 detects the presence or absence of movement of the obstacle. If there is an obstacle movement in step S11 (Yes), step S12 specifies the position of the obstacle by the obstacle position specifying unit 102.

In the movable range information unit 111, the movable / non-movable information indicating whether or not the own device may move for each place, for example, as shown in FIG. 4, [obstacle <presence / absence>, movement <possible / impossible>, The order of move destination candidates <i (numbers from i = 1 to n ³ are entered)> and interference wave generation <yes / no>] are managed.
The moveability information is managed by, for example, three-dimensional coordinate axes (Xi, Yi, Zi) and i = 1 to n, and the position (Source Coorinate) of the wireless relay device 200-1 which is the own device before the move is determined. (Xsc, Ysc, _Zsc ), the moved position of the obstacle 230 (Xa, Y1, Zc), and the position (Destination Coordinate) of the wireless relay device 200-2, which is the own device after the movement (Xdc, Ydc,). Zdc).

In step S13 following step S12, the own device position control unit 112 maps the position of the obstacle in the movable range information unit 111 based on the information from the obstacle position identification unit 102 and the abnormality determination unit 110. do. Here, the mapping is the movable / non-movable information [obstacle <yes / no>, movement <possible / impossible> of the moved position (Xa, Y1, Zc) of the obstacle acquired by the obstacle position specifying unit ₁₀₂ . , The order of move destination candidates <i (numbers from i = 1 to n ³ are entered)>, interference wave generation <yes / no>] is updated.
The information _on whether or not the obstacle can be moved at the moved position (Xa, Y1, Zc) is as follows: [Obstacle <None>, Movement <possible>, Order of move destination candidate <i (i =) before the obstacle moves. A unique number from 1 to n ³ is entered)>, interference wave generation <no>], but after the obstacle has moved, [obstacle <yes>, movement <impossible>, destination candidate The order is <-(blank)>, interference wave generation <yes>].

In step S14, the obstacle interference wave identification unit 109 confirms whether there is an obstacle for which the identification of the obstacle and the interference wave has been completed, and if there is an obstacle for which the identification has been completed (Yes), the step S15 is performed. Proceedingly, the movable / non-movable information of the position where the obstacle exists in the movable range information unit 111 is updated.
The information _on whether or not the obstacle can be moved at the moved position (Xa, Y1, Zc) is [obstacle <Yes>, movement <impossible>, destination until the identification by the obstacle interference wave identification unit 109 is completed. The order of candidates <-(blank)>, interference wave generation <none>], but when identification is completed, [obstacle <presence>, movement <impossible>, order of destination candidates <-(movement) It is updated to (synonymous with no precedent)> and interference wave generation <yes>].

Here, if the movement prohibited area is known in advance from the three-dimensional map information or the like, the movable range information unit 111 corresponds to the movement prohibited area based on the obstacle information of the three-dimensional map information or the like. The coordinates may be set in advance as [obstacle <presence>, movement <impossible>, order of movement destination candidates <-(blank)>, interference wave generation <-(blank)>].

Next, in the abnormality determination unit 110,

In step S16, when the SN ratio obtained by the abnormality determination unit 110 is lower than the predetermined threshold value β (Yes), it is determined that the abnormality level is determined, and the process proceeds to step S17, and the movable range information is determined by the own device position control unit 112. The moveability information of the unit 111 is updated. As for the coordinates for updating the mobility information, the position control unit 112 of the own device determines the position (Xa, Ysc, _Zsc ) of the wireless relay device which is the own device and the position (Xa, Y1) of the source (obstacle) of the interference wave. , Zc) and communication deteriorates due to interference waves, so by forcibly updating the moveability information to move <impossible> (the order of move destination candidates is also executed at the same time <->), all at once. Limit the destination.

A method of determining the coordinates that limit the movement destination will be described with reference to the flowchart of FIG. To determine the region of coordinates that limits the destination, for example, the directivity of the radio wave of the interference wave is determined by sequentially monitoring the fluctuation of the interference wave level or the SN ratio with the movement of the wireless relay device or the obstacle which is the own device. It is done by predicting.
In FIG. 5, step S21 determines whether or not the wireless relay device, which is the own device, has moved, and if there is movement (Yes), the process proceeds to step S22, and the SN ratio of the previous value and the SN ratio of the current value are obtained. Make a comparison. In step S22, if the SN ratio of the current value is lower than the SN ratio of the previous value (No), the process proceeds to step S23, and the area that limits the destination of the wireless relay device, which is the own device, is expanded according to the moving direction. Let me.
For example, when moving from (Xsc, Ysc, Zsc) to (Xsc + 1, Ysc + 1, Zsc) and the SN ratio is lower than the previous value, the position of the wireless relay device (Xsc + 1, Ysc + 1, Zsc) The area that limits the destination between the object and the obstacle (Xa, Y1, Zc) is expanded by ₊₁ minute in the X and Y directions, or by multiplying the ratio according to the change in the SN ratio.

In step S18 of FIG. 3, when the own device position control unit 112 determines that the abnormality is found by the abnormality determination unit 110, the movable range information unit 111 searches for the coordinates of movement <possible>, or moves destination candidates. Searches for the coordinates to which the order of is assigned, and if there is a move destination (Yes), the process proceeds to step S19 to move to the move destination. Here, if the SN ratio does not improve in the movement to the movement destination, the movement destination is autonomously reviewed according to the order of the movement destination candidates. After that, the process proceeds to step S20, and after a certain period of time Td has elapsed (Yes), the process returns to step S11.

Here, when the obstacle itself that generates the interference wave also moves, the movement destination is adjusted according to the positional relationship between the obstacle and the wireless relay device which is the own device, as in the case where the wireless relay device which is the own device moves. Update the area that limits. When the obstacle goes away, the restricted area is reduced according to the distance traveled and the improvement of the signal-to-noise ratio.
Further, the SN ratio, which is a determination value determined by the abnormality determination unit 110 to be abnormal, and the SN ratio measured to limit the destination when an obstacle generates an interference wave are determined by Shannon-Hartley's theorem. It can be an expression. Further, the determination value by the abnormality determination unit 110 may be limited to the abnormality determination and the movement destination simply by the level of the interference wave, not by the SN ratio.

Further, when the monitoring information unit 108 described above calculates the distance between the wireless relay device which is its own device and an obstacle, it may be obtained from the coordinates of the movable range information unit 111.
In addition, since it is possible that obstacles move sequentially, the coordinates that limit the movement destination may be appropriately determined based on the coordinates of the obstacle estimated using a Kalman filter or the like, and the movement possibility information may be updated as appropriate. do not have.

In addition, the candidate site for the destination of the wireless relay device, which is the own device, coordinates the radio wave environment (for example, SN ratio or desired wave level) within the movable range, for example, in advance or in a time zone when communication is not required. It may be determined by monitoring each time, or the radio wave environment (for example, SN ratio or desired wave level) that changes with the movement of the wireless relay device, which is the own device, is managed for each coordinate, and the SN ratio is set. A location that exceeds a predetermined threshold may be autonomously learned, and a location that has many coordinates that exceed the threshold may be autonomously set as a candidate site for movement.
Further, even when there are a plurality of obstacles, the position of the obstacle generating the disturbing wave is specified by identifying each obstacle by the methods of FIGS. 2, 3 and 4.

FIG. 6 is an example of a conceptual diagram for avoiding the influence of obstacles in the wireless communication system according to the first embodiment. The wireless relay device 200-1 (generally referred to as 200), which is a self-device that relays the radio between the wireless device 210 and the wireless device 220 whose position is fixed, is shown in the figure when an obstacle 230 approaches. 1. In order to identify the position of the obstacle 230 generating the interference wave by the method described in FIGS. 2 and 3 and avoid the influence of the interference wave, the method described in FIGS. 3, 4 and 5 is used. , The optimum destination is found in the movable range 250, and the position of the wireless relay device 200-1 (broken line) is moved to the position of the wireless relay device 200-2 (solid line).

In this way, the position of the wireless relay device 200, which is the own device, can be spatially controlled according to the position of the obstacle 230 that generates the interference wave so as to avoid the influence of the interference wave. Stable continuous communication is possible between the device 210 and the wireless device 220. Further, as the position of the wireless relay device 200, which is the own device, or the obstacle 230 that generates the interference wave moves, the candidate values of the destination of the wireless relay device 200 can be sequentially reviewed, so that the surrounding radio wave environment can be changed. It can respond to changes and maintain a stable radio communication environment.
Furthermore, since it is determined whether the interference wave is at a level that interferes with wireless communication, even if an obstacle that does not generate an interference wave approaches, the position of the wireless relay device 200, which is the own device, can be set to the optimum radio wave environment. Since it can be moved to a position, it is possible to maintain a stable radio communication environment.

According to the first embodiment of the present application, even if an obstacle 230 such as a person or an object that causes a radio wave obstruction moves, the obstacle is timely and obstructed so that the wireless network between high-priority points can be autonomously operated continuously. The wireless relay device 200 autonomously moves to a place with a good radio wave environment so as to identify the position of the object 230, monitor the influence of the obstacle, and avoid the influence of the obstacle, and use the spatial radio wave environment. By increasing the efficiency, it is possible to obtain a wireless communication system capable of increasing the reliability of the wireless network between the high-priority wireless devices 210 and 220 that require continuous communication. As a result, the installation work time of the wireless relay device 200 can be significantly shortened, the installation work cost can be reduced, the manual maintenance of the network administrator can be eliminated, and the maintainability can be improved.

Embodiment 2.
Next, the wireless communication system according to the second embodiment of the present application will be described with reference to FIGS. 7 to 9.
In the second embodiment, the priority is such that continuous communication needs to be performed by using another wireless relay device 201 (hereinafter referred to as a wireless relay device of another device) without moving the position of the wireless relay device 200 which is the own device. It is intended to improve the reliability of wireless networks between high points.
Since the method of identifying an obstacle that generates an interference wave and the method of identifying a candidate site for a destination are the same as those in the first embodiment, the description thereof will be omitted.

FIG. 7 is a configuration diagram for requesting relief from the wireless relay device of another device of the wireless communication system according to the second embodiment, and the configuration other than the addition of the other device rescue request determination unit 113 and the other device rescue request unit 114 is implemented. The configuration is the same as that shown in FIG. 1 of the first embodiment, and the drawings are omitted.
In FIG. 7, the abnormality determination unit 110 uses the same method as in the first embodiment, for example, by monitoring the SN ratio, the interference wave generated by the obstacle 230 detected by the interference wave level detection unit 104 is its own device. It is determined whether or not the level interferes with the wireless communication of the wireless relay device 200. The other device rescue request determination unit 113 is the same as the first embodiment when the abnormality determination unit 110 determines the abnormality level, or when the abnormality determination unit of the other device rescue request determination unit 113 itself determines the abnormality level. In the above method, the movable range information unit 111 is updated, and when the movable range information unit 111 has a destination of the wireless relay device 201 of another device, a rescue request is made to the other device rescue request unit 114.

FIG. 8 is a diagram showing a flowchart for requesting help from a wireless relay device 201 of another device in the wireless communication system according to the second embodiment. In FIG. 8, in step S31, when the SN ratio obtained by the abnormality determination unit 110 in the other device rescue request determination unit 113 is equal to or less than the predetermined threshold value β, or the abnormality determination possessed by the other device rescue request determination unit 113 itself is performed. When the SN ratio is lower than the predetermined threshold value γ in the unit (Yes), it is determined that there is an abnormality, and the process proceeds to step S32. In step S32, the own device position control unit 112 updates the movable / non-movable information of the movable range information unit 111 in the same manner as in the first embodiment. Step S33 determines whether or not the movable range information unit 111 has a destination for the wireless relay device 201 of the other device, and if there is a destination (Yes), proceeds to step S34 and proceeds to step S34 to request rescue of the other device 114. Request for help from the wireless relay device 201 of another device.

On the other hand, if the abnormality determination unit 110 does not determine an abnormality in step S31, or if the SN ratio is equal to or higher than the predetermined threshold value γ possessed by the other device rescue request determination unit 113 itself (No), the process proceeds to step S35. The rescue request determination unit 113 of the other device cancels the rescue request to the wireless relay device 201 of the other device, and instructs the wireless relay device 201 of the other device to return to the original place.

Here, the candidate site for the destination of the wireless relay device 201 of the other device may be notified from the wireless relay device 200 of the own device, or the wireless relay device 201 of the other device itself has been described in the first embodiment. It may be determined by the same method as the wireless relay device 200 of the own device, or may be a wireless relay device different from the wireless relay device 201 of the other device. In addition, in order to avoid the influence of interference due to the close proximity of the own device and the wireless relay device of another device, even if a method of selecting the optimum wireless method or radio frequency is used together using technology such as cognitive radio. I do not care. Further, the abnormality determination unit 110 monitors the state of the wireless relay device 200 of the own device such as failure prediction information (decrease in transmission output, deterioration of reception sensitivity, etc.) of the wireless relay device 200 of the own device, and if it is about to fail, an abnormality occurs. It may be determined that, and a rescue request may be made to the wireless relay device 201 of another device.

FIG. 9 is an example of a conceptual diagram for avoiding the influence of obstacles in the wireless communication system according to the second embodiment. The wireless relay device 200 of its own device that relays the radio between the wireless device 210 and the wireless device 220 generates an interference wave by the method described with reference to FIGS. 1, 2, and 3 when an obstacle 230 approaches. In order to identify the position of the obstacle 230 and avoid the influence of the interference wave, the optimum destination is found in the movable range 250 by the method described in FIGS. 3, 4, and 5, and FIG. 7, FIG. By the method shown in FIG. 8, a rescue request is made to the wireless relay device 201, which is another device, and the wireless relay device 201 is moved.

In this way, when the obstacle 230 that generates the interference wave approaches the radio relay device 200 between the wireless devices 210 and 220 having high priority for continuous communication, it is another device in order to avoid the influence of the interference wave. By requesting help from the wireless relay device 201, moving it to a position where the optimum radio wave environment can be obtained, and performing wireless relay by the wireless relay device 201 of another device, continuous communication of the network between high-priority points is realized. do.
Furthermore, since radio wave abnormalities can be detected by the SN ratio, even if an obstacle that does not generate interference waves approaches, the wireless relay device 201 of another device can be moved to the optimum radio wave environment position, resulting in a stable radio wave communication environment. Can be maintained.
With such a highly reliable wireless communication system, it is possible to construct a highly reliable wireless network with the minimum number required even in places where a large number of wireless devices cannot be placed (depopulated areas, space), so the wireless network is low. You can reduce the cost.

Embodiment 3.
Next, the wireless communication system according to the third embodiment of the present application will be described with reference to FIGS. 10 to 12.
In the third embodiment, the positions of the wireless relay devices 200 and 201 of the own device and the other device are moved, and both the own device and the other device are used as the wireless relay device, so that a high priority point where continuous communication is required is required. It is intended to increase the reliability of the wireless network between them.
The configuration of the wireless communication system in the third embodiment is the same as that in FIG. 7 of the second embodiment, and the drawings are omitted. Since the method of identifying an obstacle that generates an interference wave, the method of determining an abnormality, and the method of requesting relief are the same as those of the first and second embodiments, the description thereof will be omitted. Here, a method of determining the optimum moving destination based on the radio wave environment of a plurality of devices will be described.

FIG. 10 is an example of a conceptual diagram for avoiding the influence of obstacles in the wireless communication system according to the third embodiment. In FIG. 10, the wireless relay device 200-1 of the own device that relays the radio between the wireless device 210 and the wireless device 220 is the method described with reference to FIGS. 1, 2, and 3 when the obstacle 230 approaches. In order to identify the position of the obstacle generating the interference wave and avoid the influence of the interference wave, the movable range 251 of the wireless relay device 200 of the own device is 251 by the method described with reference to FIGS. 3, 4, and 5. Find the best destination in. On the other hand, by the method shown in FIGS. 7 and 8, a rescue request is made to the wireless relay device 201 of the other device, and the optimum destination is found within the movable range 252 of the wireless relay device 201 of the other device. The destination of the wireless relay device 200 of the own device and the wireless relay device 201 of the other device is determined by the method shown in FIG. 11 and moved.

FIG. 11 is a conceptual diagram in which the movable range information unit 111 is used to determine candidates for moving destinations of the wireless relay device 200 of the own device and the wireless relay device 201 of the other device. The coordinates of the wireless device 210 are shown in 211, and the coordinates of the wireless device 220 are shown in 221.
The wireless relay device 200 of the own device and the wireless relay device 201 of the other device need to be arranged at a spatial position having the best radio wave environment in the space between the wireless device 210 and the wireless device 220. There are innumerable propagation paths of radio waves of the wireless device 210 and the wireless device 220 as shown by, for example, R1, R2, R3, R4, and R5, but it is not possible to select the optimum propagation path from all the propagation paths. Since it is not possible, narrow down the number of candidate propagation routes and select the propagation route from them.

FIG. 12 shows a flowchart for determining the destination route of the wireless relay device 200 of the own device of the wireless communication system and the wireless relay device 201 of the other device, and a method of selecting a propagation route will be described based on this flowchart.
In FIG. 12, in step S41, in order to select the optimum propagation path from all the propagation paths, the number of candidate propagation paths is narrowed down and the propagation path is selected from them. Here, for example, R1, R2, R3, R4, and R5 are defined as propagation paths. In order to efficiently select the optimum propagation path, each propagation path R1 to R5 shall be a path that is not spatially biased. In step S42, in the own device position control unit 112, the number of non-movable coordinates of the movable range information unit 111 of the movable range information unit 111 is totaled for each propagation path R1 to R5.

In step S43, a path having the minimum number of immovable paths is selected from the propagation paths R1 to R5. Step S44 determines whether or not there is a 0 route having the minimum number of immovable items, and if the minimum value is 0 (Yes), the process proceeds to step S45 to determine the route. In step S44, if there is no route having a minimum value of 0 (No), the process proceeds to step S46, and it is determined whether or not there is a route having the minimum value among the routes without obstacles. In step S46, if there is a route having the minimum value (Yes), the route is determined by proceeding to step S47. If there is no obstacle-free route in step S46 (No), the process proceeds to step S48 to review the route, return to step S41, and determine the route again by the same flow.
As shown in the route determination example of FIG. 11, the propagation path R5 having the minimum number of immovable coordinates of “1” and the number of impaired coordinates of “0” is selected.

Here, when there are a plurality of minimum routes without obstacles (hereinafter referred to as candidate routes), for example, the one farthest from the obstacle may be selected as the propagation route, or the candidate route may be spatially in the middle. The propagation path in is predicted to have the best radio wave environment and is selected. If the optimum route cannot be selected from the candidate routes, or if the selection is uncertain, select a route near the candidate route where the optimum propagation route is likely to exist, and increase the number of propagation routes to be investigated. , The propagation path that is most positioned in the middle may be selected.

After determining the propagation path, as shown in FIG. 11, for example, two points 290 and 291 in the middle of the path length of the wireless relay device 200 of the own device and the wireless relay device 201 of the other device divided into three equal parts. Is selected as the destination of the wireless relay device 200 of the own device and the wireless relay device 201 of the other device. Whether to move the wireless relay device 200 of the own device or the wireless relay device 201 of the other device to the location 290 or 291 is determined by the wireless relay device 200 of the own device, for example, the location 290 first, and the other device. Notify the wireless relay device 201 of, for example, the destination of the location 291.

Here, a method of improving the reliability of the wireless network with a total of two wireless relay devices, one for each of the wireless relay device 200 of the own device and the wireless relay device 201 of the other device, has been shown. The number of devices may be two or more.
In this way, when an obstacle that generates an interference wave approaches a wireless network between high-priority points for continuous communication, the radio waves of the own device and other devices are autonomously used to avoid the influence of the interference wave. By moving the position of the relay device to a position where the optimum radio wave environment can be obtained and performing wireless relay between the own device and the wireless relay device of another device, continuous communication of the network between high-priority points is realized.
Furthermore, since radio wave abnormalities can be detected by the SN ratio, even if an obstacle that does not generate interference waves approaches, the wireless relay device of another device can be moved to the position of the optimum radio wave environment, so a stable radio wave communication environment can be created. It will be sustainable.

Embodiment 4.
Next, the wireless communication system according to the fourth embodiment of the present application will be described with reference to FIGS. 13 and 14.
In the fourth embodiment, the reliability of the wireless network between high-priority points where continuous communication is required is improved even when there is a lot of humidity or rain such as during the rainy season, which causes radio interference.
As shown in FIG. 13, the wireless communication system according to the fourth embodiment includes a humidity sensor 271 in the wireless relay device 200, which is its own device. The abnormality determination unit 110 appropriately monitors the humidity by the humidity sensor 271. Other configurations are the same as those in FIG. 7 of the second embodiment, and the drawings are omitted.
The method of determining the radio wave abnormality, the method of requesting help from the wireless relay device of another device, and the method of determining the optimum destination of the plurality of wireless relay devices are the same as those of the first, second, and third embodiments. Is omitted. Here, a method of determining the destination of a plurality of wireless relay devices will be described.

FIG. 13 is an example of a conceptual diagram for avoiding the influence of obstacles in the wireless communication system according to the fourth embodiment.
In FIG. 13, the wireless relay device 200-1 of the own device that relays the radio between the wireless device 210 and the wireless device 220 is the method described with reference to FIGS. 1, 2, and 3 when the obstacle 231 approaches. In order to identify the position of the obstacle generating the interference wave and avoid the influence of the interference wave, the movable range 251 of the wireless relay device 200 of the own device is 251 by the method described with reference to FIGS. 3, 4, and 5. Find the best destination in. On the other hand, by the method shown in FIGS. 7 and 8, a rescue request is made to the wireless relay device 201 of the other device, and the optimum destination is found within the movable range 252 of the wireless relay device 201 of the other device. The destinations of the wireless relay device 200 of the own device and the wireless relay device 201 of the other device are determined by the methods shown in FIGS. 11 and 12, and are moved.

FIG. 14 is a diagram showing a flowchart for requesting help from a wireless relay device 201 of another device in the wireless communication system of the fourth embodiment.
In FIG. 14, in step S51, the abnormality determination unit 110 determines whether or not the humidity in the wireless network environment is abnormal. When the humidity is determined to be abnormal when the humidity is equal to or higher than the predetermined threshold value RHα (Yes), the process proceeds to step S52, and the other device rescue request determination unit 113 updates the movable range information unit 111 by the same method as in the second embodiment. do. Step S53 determines whether or not the movable range information unit 111 has a moving destination of the wireless relay device 200 of the own device and the wireless relay device 201 of another device, and if there is a moving destination (Yes), step S54. Proceed and make a rescue request to the movable range information unit 111 to the wireless relay device 201 of another device.

In step S51, if the abnormality determination unit 110 does not determine an abnormality, or if the abnormality determination unit possessed by the other device rescue request determination unit 113 itself has a humidity of RHα or less (No), the step S55 is performed. Proceeding, the rescue request determination unit 113 of the other device cancels the rescue request to the wireless relay device 201 of the other device, and instructs the other device to return to the place based on the wireless relay device 201 of the other device.

Here, the humidity may be managed for each coordinate as a part of the parameter of the movable / non-movable information managed by the movable range information unit 111, and may be used as a parameter when determining the optimum propagation path. By using the humidity as a parameter and using the methods described in the first to third embodiments, it is possible to move the wireless relay device 200 of the own device to a position where the humidity is low.

In this way, even when there is a lot of humidity or rain, such as during the rainy season, which causes radio wave interference, by monitoring the humidity, in order to avoid the influence of humidity, the position of the wireless relay device 200 of the own device can be moved. By requesting help from the wireless relay device 201 of another device, moving it to a position where the optimum radio wave environment can be obtained, and performing wireless relay by the wireless relay device 201 of the other device, a network between high-priority points can be obtained. Achieve continuous communication.
Furthermore, by using humidity as a parameter, it is possible to move the wireless relay device to a position where the humidity is low, so it is possible to reduce the effects of deterioration of life due to humidity, and the life of the wireless relay device can be extended. The effect is also obtained.

Embodiment 5.
Next, the wireless communication system according to the fifth embodiment of the present application will be described with reference to FIG.
In the fifth embodiment, even if the interference wave generated by an obstacle is large and it is difficult to relay by the wireless relay device of the own device, the reliability of the wireless network between high-priority points where continuous communication is required is improved. It is something like that.
In the wireless communication system of the fifth embodiment, as shown in FIG. 15, the wireless relay device 200 of the own device includes a warning device 281 that warns against an obstacle that generates an interference wave. Other configurations are the same as those in FIG. 7 of the second embodiment, and the drawings are omitted.

The method of identifying an obstacle that is generating an interference wave, the method of determining a radio wave abnormality, the method of requesting help from a wireless relay device of another device, and the method of determining the optimum destination of multiple wireless relay devices are as follows. Since it is the same as the first, second, and third embodiments, the description thereof will be omitted. Here, a method of warning an obstacle in which an interference wave is generated so as not to generate an interference wave will be described.
The obstacle 230 generating the interference wave is identified by the same method as in the first embodiment, the wireless relay device 200 of the own device moves to the position of the obstacle 230, and the warning device 281 is used to identify the obstacle 230. Warn against. On the other hand, a rescue request is made to the wireless relay device 201 of another device by the same method as in the second embodiment, and continuous communication is performed between the wireless device 210 and the wireless device 220 using the wireless relay device 201 of the other device.

In this way, the obstacle 230 that generates the interference wave is warned, the wireless relay device 201 of the other device is requested for help, the device is moved to a position where the optimum radio wave environment can be obtained, and the wireless relay device 201 of the other device is obtained. By wirelessly relaying by, continuous communication of the network between high-priority points is realized.
When an interference wave such as an object that causes radio interference, a person, an illegal radio wave, a leaked radio wave due to a construction defect, or an interfering radio wave detects movement into a wireless network between high-priority points, it interferes with the radio wave. By identifying the position of an object or person, moving to that location, and giving a warning, it is possible to maintain a stable and highly reliable wireless communication network.

The above has explained the climate such as the deterioration of the radio wave environment caused by objects and people around the wireless relay device, and the humidity that affects the radio wave environment. , Autonomously search for the optimum position according to the positional restrictions such as prohibited areas, failure prediction information of the wireless relay device of the own device (decrease in transmission output, deterioration of reception sensitivity, etc.), and search for the wireless relay device. The number of mobile or wireless relay devices may be increased or decreased.

The present disclosure describes various exemplary embodiments and examples, although the various features, embodiments, and functions described in one or more embodiments are those of a particular embodiment. It is not limited to application, but can be applied to embodiments alone or in various combinations.
Therefore, innumerable variations not illustrated are envisioned within the scope of the art disclosed in the present application. For example, it is assumed that at least one component is modified, added or omitted, and further, at least one component is extracted and combined with the components of other embodiments.

101: Obstacle monitoring unit, 102: Obstacle position identification unit, 103: Antenna unit,
104: Interference wave level detection unit, 105: Desired wave level detection unit, 107: Obstacle monitoring unit,
108: Monitoring information unit, 109: Obstacle interference wave identification unit, 110: Abnormality determination unit,
111: Movable range information unit, 112: Own device position control unit,
113: Other device rescue request judgment unit, 114: Other device rescue request unit,
200, 200-1, 200-2: Wireless relay device of own device,
201: Wireless relay device of other device, 210: Wireless device, 220: Wireless device,
230, 231: Obstacles, 250, 251, 252: Movable range,
271: Humidity sensor, 281: Warning device.

Claims (25)

In a wireless communication system that communicates via a wireless relay device that can move between wireless devices, the wireless relay device includes an obstacle monitoring unit that monitors obstacles that cause radio interference and the obstacle monitoring. The obstacle position specifying unit that identifies the position of the obstacle based on the output from the unit, the antenna unit that receives the desired wave to be received and the interference wave of the obstacle, and the interference wave due to the output from the antenna unit. The interference wave level detection unit that detects the reception level of the above, the desired wave level detection unit that detects the reception level of the desired wave by the output from the antenna unit, the position of the obstacle, and the reception level of the interference wave. An obstacle interference wave monitoring unit to be monitored, a monitoring information unit that stores the position of the obstacle and the reception level of the interference wave, which is an output from the obstacle interference wave monitoring unit, and the position of the obstacle and the interference. From the reception level of the wave, the obstacle interference wave identification unit that identifies whether the obstacle is generating the interference wave and the obstacle interference wave identification unit indicate that the obstacle is generating the interference wave. When specified, an abnormality determination unit that determines whether the reception level of the interference wave generated by the obstacle is an abnormal level that hinders the wireless communication of the wireless relay device that is the own device, and the wireless relay that is the own device. The movable range information unit that manages the movable range information that indicates whether the device can move or not for each location, and the own device based on the movable property information when the abnormality determination unit determines that the level is abnormal. A wireless communication system including a self-device position control unit that determines a destination of a certain wireless relay device and controls the position of the self-device wireless relay device. The wireless communication system according to claim 1, wherein the obstacle interference wave monitoring unit monitors a distance between the wireless relay device, which is its own device, and the obstacle. The obstacle interference wave identification unit obtains the correlation between the obstacle and the interference wave from the fluctuation of the distance between the wireless relay device which is its own device and the obstacle and the fluctuation of the reception level of the interference wave. The wireless communication system according to claim 1 or 2, wherein when there is a correlation, it is specified that the interference wave is generated from the obstacle. Any of claims 1 to 3, wherein the monitoring information unit stores the distance between the wireless relay device, which is its own device, and the obstacle, and the reception level of the interference wave in time series. The wireless communication system according to item 1. Any of claims 1 to 4, wherein the abnormality determination unit monitors the reception level of the interference wave and determines that the reception level of the interference wave exceeds a predetermined threshold value as an abnormality level. The wireless communication system according to item 1. The abnormality determination unit monitors the SN ratio of the reception level of the desired wave and the interference wave, and determines the abnormality level when the SN ratio exceeds a predetermined threshold value according to claim 1. Item 4. The wireless communication system according to any one of Item 4. The wireless communication system according to any one of claims 1 to 6, wherein the movable range information unit stores movable / non-movable information indicating whether or not the movable range is movable for each three-dimensional location. The movable range information stored in the movable range information unit includes, in addition to the movable property, the presence / absence of the obstacle, the presence / absence of the interference wave indicating whether the obstacle is generating the interference wave, and the own device. The wireless communication system according to claim 7, wherein the order of the move destination candidates representing the priority order of the move destination candidates of a certain wireless relay device and the SN ratio investigated in the past are stored. The wireless communication system according to claim 7, wherein the movable range information unit makes it impossible to move a place corresponding to a movement prohibited area from three-dimensional map information. The first aspect of the present invention is characterized in that the own device position control unit updates the movable / non-movable information of the movable range information unit each time the wireless relay device or the obstacle which is the own device moves. 9. The wireless communication system according to any one of 9. The claim is characterized in that the own device position control unit updates the movable / non-movable information of the section between the obstacle and the wireless relay device which is the own device in a batch so as not to move, and limits the move destination. The wireless communication system according to any one of claims 1 to 9. The own device position control unit estimates the directivity of the interference wave from the fluctuation amount of the reception level or the SN ratio of the interference wave with the movement of the wireless relay device which is the own device, and is the own device. The wireless communication system according to any one of claims 1 to 11, wherein the range for limiting the destination of the wireless relay device is determined from the directivity of the interference wave. The abnormality determination unit monitors the SN ratio of the reception level of the desired wave and the interference wave for each location, and the own device position control unit sets a location having an SN ratio of a predetermined value or more as a destination candidate site. The wireless communication system according to any one of claims 1 to 12. From claim 1, the wireless relay device, which is the own device, is provided with a humidity sensor, and the abnormality determination unit moves the position of the wireless relay device of the own device when the humidity is determined to be equal to or higher than a predetermined humidity. The wireless communication system according to any one of claims 13. The wireless relay device, which is the own device, has a location where the other device rescue request determination unit, which determines whether to make a rescue request to the wireless relay device of the other device, and a position where the wireless relay device of the other device may move. The movable range information unit that manages the movable / non-movable information shown for each is determined, and the destination of the wireless relay device of the other device is determined based on the movable / non-movable information. The wireless communication system according to claim 1, further comprising a rescue requesting unit for other devices for requesting relief. The other device rescue request determination unit determines that the abnormality level is determined by the abnormality determination unit, or that the reception level of the interference wave generated by the obstacle is the abnormality level of the other device rescue request determination unit itself. The wireless communication system according to claim 15, wherein the other device rescue requesting unit requests relief from the wireless relay device of the other device. 13. The wireless communication system described. In the wireless relay device which is the own device, the rescue request determination unit of the other device for determining whether to make a rescue request to the wireless relay device of the other device and the wireless relay device of the own device and the other device may move. The movable range information unit that manages the movable range information that indicates the position for each place, and the movable destination of the own device and the wireless relay device of the other device are determined based on the movable property information, and the wireless of the own device is determined. The first aspect of claim 1, wherein the position control unit of the own device that controls the position of the relay device and the rescue request unit of the other device that requests the information of the destination and the rescue to the wireless relay device of the other device are provided. Wireless communication system. When determining the destination of the wireless relay device of the own device and the other device, the own device position control unit selects a radio wave propagation path to be investigated so as not to be spatially biased, and moves for each propagation path. 18. Claim 18 is characterized in that the number of immovable items is totaled, a route is selected in which the number of immovable items is the minimum value, and the destination of the wireless relay device of the own device and the other device is determined on the selected route. The wireless communication system described in. The wireless communication system according to claim 19, wherein the own device position control unit selects a route having the least obstacles when selecting a radio wave propagation route. 13. The described wireless communication system. 19. The self-device position control unit according to claim 19, wherein when there are a plurality of radio wave propagation paths and the candidates cannot be narrowed down, the path located in the center of the space is selected from the candidates. Wireless communication system. When reviewing the propagation path to be investigated, the own device position control unit selects a space that is likely to be a candidate for the propagation path, redifferentiates the space, and re-investigates to search for the optimum propagation path. 19. The wireless communication system according to claim 19. 15. The wireless relay device, which is the own device, includes a humidity sensor, and when the abnormality determination unit determines that the humidity is equal to or higher than a predetermined humidity, the wireless relay device of the other device is requested to provide relief. Alternatively, the wireless communication system according to claim 18. When the abnormality determination unit determines an abnormality when the reception level of the interference wave exceeds a predetermined threshold value or when the SN ratio of the reception level of the desired wave and the interference wave exceeds a predetermined threshold value, the other abnormality determination unit is used. The 15th or 18th claim, wherein the device rescue requesting unit requests rescue from the wireless relay device of the other device, and the wireless relay device of the own device approaches the obstacle to give a warning. Wireless communication system.

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