Wireless Communication Characteristics Prediction System and IoT Wireless Monitoring System

Abstract

To provide a wireless communication characteristic prediction system that reduces man-hours for estimating electromagnetic field strength in a communication service provision area, and an IoT wireless monitoring system using the system.SOLUTION: A wireless communication characteristic prediction system 100 includes an electromagnetic field computation device and an output device. The electromagnetic field computation device includes a calculation device that performs predetermined processing and a storage device that can be accessed by the calculation device, repeatedly performs ray tracing calculations to estimate electromagnetic field distribution, changes generation states of reflected waves, diffracted waves, and scattered waves in ray tracing calculations from acquired position data of a structure in a communication service provision area, and transmits the estimated electromagnetic field distribution to the output device. The output device outputs the estimated electromagnetic field distribution.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a wireless communication characteristic prediction system in which a structure that scatters radio waves analyzes the radio wave environment in a service area.

Background Art

[0002] Due to the worldwide spread of mobile wireless information terminals, there is an increasing demand to enjoy wireless communication services such as wireless calls and wireless data transfer regardless of the surrounding environment. When a radio wave scatterer (structure) exists in a communication service providing area, the electromagnetic wave of the wireless communication medium is scattered by the scatterer, the power of the electromagnetic wave radiated from the transmitter and reaching the receiver fluctuates, and in many cases the received power decreases, making it difficult to have good-quality wireless communication in a certain area within the communication service providing area. Such a weak electric field area is caused by the arrangement relationship of the electromagnetic wave scatterers in the communication service providing area and the positional relationship of the transmitters and receivers for wireless communication. Therefore, when forming a wireless communication network in the communication service providing area, prediction of the communication situation based on the arrangement states of various transmitters and receivers is important for forming the wireless communication network. In order to know the communication situation in a specific transmitter and receiver arrangement in the communication service providing area, it is necessary to actually arrange transmitters and receivers in the area and measure the received power at multiple points. However, since wireless communication is affected by radio wave scatterers around the transmitters and receivers, entry prohibition measures in the measurement target area are required to minimize the variation factors during measurement, and it is necessary to secure personnel and measurement time for the measurement, which incurs costs.

[0003] To solve such a problem, a technique has been proposed in which an electromagnetic field model for analyzing the wireless communication characteristics in a communication service providing area is constructed in a computer to virtually realize the electromagnetic field distribution in the arrangement state of transmitters and receivers in the communication service providing area.

[0004] As background art in this technical field, there is the following prior art. For example, Patent Document 1 (Japanese Patent Application Laid-Open No. 2015-800616) describes a wireless network station design method in which a digital camera generates image data obtained by photographing a target area from a plurality of directions. An image processing apparatus extracts features of a structure in the target area from the image data and the photographing conditions to obtain structure feature data. A numerical model creation apparatus for analysis generates numerical model data from the structure feature data. A received power analysis apparatus performs electromagnetic field analysis on the numerical model data based on radio equipment conditions and outputs the received power of the radio equipment as a calculation result, and a display displays this (see the abstract).

[0005] Further, Patent Document 2 (Japanese Patent Application Laid-Open No. 2010-74729) describes a ray launching method calculation unit 6 that calculates first radio wave propagation characteristic estimation data from a transmission point to a building at a reception point using plane data by the ray launching method, and an imaging method calculation unit 7 that calculates second radio wave propagation characteristic estimation data from the transmission point to the building at the reception point using vertical cross-sectional data by the imaging method, and calculates indoor penetration data to a radio wave reception point inside the building for each of the first radio wave propagation characteristic estimation data and the second radio wave propagation characteristic estimation data, and a synthesizing unit 8 that synthesizes the indoor penetration data. A radio wave propagation characteristic estimation apparatus including the same is described (see the abstract).

[0006] In addition, Patent Document 3 (Japanese Patent Application Laid-Open No. 9-33584) stores information on the positions of the start and end points of a road through which radio waves can pass and the wall surfaces of buildings near the road as element information 60. Further, information on the position of an intersection through which radio waves can pass, the position of the road with respect to the intersection, and the diffraction points due to buildings near the intersection is stored as node information 50. Using the positions of the start and end points stored as element information 60 and the positional relationship between the position of the intersection stored as node information 50 and the road with respect to the intersection, a route of the road and the intersection from the transmission point to the reception point is searched. Using the element information of the road and the node information of the intersection included in the searched route, the wall surface and the diffraction point near the route are configured. There is described an electric field strength calculation device that performs ray tracing of radio waves from the transmission point using the wall surface and the diffraction point, and calculates the electric field strength by adding the powers of the rays that have reached the reception point (see the abstract).

[0007] In addition, Patent Document 4 (Japanese Patent Application Laid-Open No. 3-235013) discloses, in a scattering cross-section calculation device that calculates the scattering cross-section of a target, a virtual line that divides the target into a plurality of individuals is set on the surface of the target, points are set at substantially wavelength intervals of the radio wave used on the circumference of the cross-section of each individual when the target is divided by the virtual line, the points set for each individual are connected by straight lines, a plurality of triangles are formed for each surface of the target divided into individuals by the virtual line to form a plurality of triangles on the surface of the target, a polyhedron approximation means for approximating the target with a polyhedron, an edge search means for searching for all the edges visible from the incident direction of the polyhedron approximated by the polyhedron approximation means, a unit vector calculation means for obtaining a unit vector whose angles formed with the incident direction and the observation direction existing in the respective planes of the two surfaces sharing the edge are equal for each edge searched by the edge search means, an equivalent wave source calculation means for obtaining an equivalent wave source having the direction of the unit vector to be provided on each edge, a diffracted wave calculation means for obtaining a diffracted wave in the observation direction radiated from the equivalent wave source, and a scattering cross-section calculation means for obtaining the scattering cross-section from the sum of the diffracted waves (see Claim 1).

Prior Art Documents

Patent Documents

[0008] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2015 - 800616 [Patent Document 2] Japanese Unexamined Patent Application Publication No. 2010 - 74729 [Patent Document 3] Japanese Unexamined Patent Application Publication No. Hei 9 - 33584 [Patent Document 4] Japanese Unexamined Patent Application Publication No. Sho 3 - 235013 [Summary of the Invention] [Problems to be Solved by the Invention]

[0009] The above - mentioned prior art uses the measured values of the exact physical dimensions of the radio wave scatterer and the specifications of the radio wave scatterer to reproduce the distribution of the radio wave scatterer in the communication service - providing area on computer resources, determines the electrical characteristics of the reproduced electromagnetic wave scatterer, uses the electromagnetic wave scatterer virtually constructed on the computer resources as the object of electromagnetic field calculation, and estimates the electromagnetic field distribution in the communication service - providing area by ray - tracing calculation performed with rays approximating the electromagnetic waves used for communication. This conventional method requires a huge amount of man - hours to reproduce the distribution of the electromagnetic wave scatterer with accurate physical dimensions on computer resources, and in the ray - tracing calculation, in order to calculate the electromagnetic wave distribution in the area where the ray is shielded by the electromagnetic wave scatterer, there is a problem that another calculation process requiring more computer resources than the calculation process in the area where the ray is not blocked is necessary. [Means for Solving the Problems]

[0010] A typical example of the invention disclosed in the present application is as follows. That is, a radio communication characteristic prediction system, A model generation device, comprising an electromagnetic field calculation device and an output device, The model generation device calculates dimensional information of the structure from point cloud data representing positions on the surface of the structure within a communication service provision area and the wavelength of radio waves used for communication, wherein the electromagnetic field calculation device has an arithmetic device that executes predetermined processing and a storage device accessible by the arithmetic device, repeatedly executes ray - tracing calculation to estimate the electromagnetic field distribution, Using the position data of the structure and the calculated dimensional information of the structure,Changing the generation states of reflected waves, diffracted waves, and scattered waves in the ray tracing calculation, transmitting the estimated electromagnetic field distribution to the output device, and the output device outputs the estimated electromagnetic field distribution.

Effect of the Invention

[0011] According to one aspect of the present invention, the man-hours for estimating the electromagnetic field strength within the communication service providing area can be reduced. Problems, configurations, and effects other than those described above will be clarified by the description of the following embodiments.

Brief Description of the Drawings

[0012]

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Mode for Carrying Out the Invention

[0013] Hereinafter, examples will be described with reference to the drawings.

[0014] <Example 1> An example of the wireless communication characteristic prediction system according to an embodiment of the present invention will be described with reference to FIGS. 1 and 11 to 20. The wireless communication characteristic prediction system of this embodiment reduces the realization cost of a wireless system that provides a communication service.

[0015] FIG. 1 is a diagram showing the configuration of the wireless communication characteristic prediction system 101 of Example 1, FIG. 11 is a diagram showing the data structure of various tables used by the wireless communication characteristic prediction system, FIGS. 12 to 14 are diagrams showing the operation flow of the wireless communication characteristic prediction system, FIGS. 15 and 16 are diagrams showing the radiation of diffracted waves and scattered waves other than reflected waves, and FIGS. 17 to 20 are diagrams showing an example of the process of creating a polygon group from point cloud data.

[0016] The wireless communication characteristic prediction system 100 shown in FIG. 1 includes a measurement radio 1, a communication radio 4, a calculation model generation device 110 that receives data from each of the measurement radio 1 and the communication radio 4, a structure data storage device 140 that transfers data with the calculation model generation device 110, an electromagnetic field calculation device 150 that receives data from the structure data storage device 140, and a display device 180 that receives data from the electromagnetic field calculation device 150.

[0017] The measurement radio 1 is a ranging device having a measurement high-frequency signal source 2 and a measurement antenna 3. The measurement radio 1 transmits and receives high-frequency electromagnetic waves generated by the measurement high-frequency signal source 2 from the measurement antenna 3, and adds information on the measurement location in the communication service providing area to the distance from the measurement radio 1 to each point on the surface of the electromagnetic wave scatterer existing in the communication service providing area and the direction from the measurement radio 1 to each point as vector data, and sends it to the calculation model generation device 110.

[0018] The communication radio 4 has a communication high-frequency signal source 5 and a communication antenna 6. The communication radio 4 transmits and receives high-frequency electromagnetic waves generated by the communication high-frequency signal source 5 from the communication antenna 6, and adds the spatial coordinates related to the measurement location in the communication service providing area to the information on the received electromagnetic wave, and sends it to the calculation model generation device 110. When the frequency of the radio wave used by the communication radio 4 for communication is lower than one-fourth (preferably one-tenth or less) of the frequency of the radio wave used by the measurement radio 1 for measurement, the detailed shape of the electromagnetic wave scatterer in the communication service providing area can be obtained, and the calculation accuracy of the electromagnetic field distribution can be improved.

[0019] The calculation model generation device 110 stores the data received from the measurement radio 1 and the communication radio 4 in the point cloud storage circuit 111. The point cloud coordinate generation circuit 112 calculates the coordinates of a plurality of points on the electromagnetic wave scatterer measured using the data on the electromagnetic wave scatterer stored in the point cloud storage circuit 111. The point cloud filter circuit 113 determines the isolated points from all the points using the coordinates calculated by the point cloud coordinate generation circuit 112, and deletes the data related to the determined points. The polygon generation circuit 114 generates a polygon, which is a polygonal element, using the data related to the points determined by the point cloud filter circuit 113. The polygon group formation circuit 115 classifies the plurality of polygons generated by the polygon generation circuit 114 into a plurality of polygon groups using the positional relationship with adjacent polygons. The adjacent polygon connection state data generation circuit 116 calculates the connection relationship of each polygon group generated by the polygon group formation circuit 115 using the connection relationship with adjacent polygons. The polygon attribute determination circuit 117 adds attributes to each polygon within the polygon group using the connection relationship between the polygon groups calculated by the adjacent polygon connection state data generation circuit 116 and the communication wavelength of the communication wavelength data 143 held by the structure data storage device 140, and sends the point cloud data related to the determined plurality of points, the data related to the polygon group, the information on the electromagnetic field of the measurement location with the spatial coordinates related to the measurement location within the communication service providing area added thereto, and the data of the polygon with attributes added thereto to the structure data storage device 140.

[0020] In the structure data storage device 140, the point cloud table 141 stores point cloud data regarding a plurality of determined points sent by the calculation model generation device 110. The communication area data 142 stores information regarding the electromagnetic field of the measurement location with the data regarding the polygon group and the spatial coordinates regarding the measured location in the communication service providing area added thereto. The content stored in the communication area data 142 is output to the communication area storage circuit 160 of the electromagnetic field calculation device 150. The communication wavelength data 143 stores the wavelength used for wireless communication. The polygon table 144 stores data of polygons with attributes added thereto. The electrical property table 145 stores information regarding electrical constants such as permittivity, permeability, and conductivity. The data stored in the polygon table 144 has the information regarding the electrical constants stored in the electrical property table 145 added thereto and is output to the polygon table storage circuit 161 of the electromagnetic field calculation device 150. As shown in FIG. 11, the data structures of the point cloud table 141, the communication area data 142, and the polygon table 144 are arrays of spatial coordinates.

[0021] In the electromagnetic field calculation device 150, the iteration condition setting circuit 151 sets iteration conditions for controlling the number of ray emissions. The transmission point generation circuit 152 generates a transmission point within the communication service providing area using the content of the communication area storage circuit 160. The reception point generation circuit 153 generates a plurality of reception points within the communication service providing area using the content of the communication area storage circuit 160. The ray emission circuit 154 uses the information of the transmission point generated by the transmission point generation circuit 152 and the reception points generated by the reception point generation circuit 153, and according to the content of the iteration condition setting circuit 151 that the electromagnetic field calculation device 150 has in advance, generates a plurality of rays from the transmission point in different directions. The received power integration circuit 155 determines whether the rays generated by the ray emission circuit 154 pass through a predetermined finite area around the reception point using the content of the communication area storage circuit 160. If they pass through, it integrates the energy of the rays at the points where the rays collide with the finite area considering the phase, and sets the ray arrival flag for the reception point. The ray - polygon collision determination circuit 156 determines whether the rays generated by the ray emission circuit 154 collide with each polygon existing within the communication service providing area using the content of the polygon table storage circuit 161. The re - emission ray selection circuit 157 collates the polygon information from the ray - polygon collision determination circuit 156 with the content of the polygon table storage circuit 161 to select the type of ray to be re - emitted. The re - emission ray generation circuit 158 re - emits rays using the information of the re - emission ray selection circuit 157. The iteration condition determination circuit 159 monitors the number of re - generations of the re - emission ray generation circuit 158. If the number of re - generations is within the number predetermined by the iteration condition setting circuit 151, it continues the operation of the ray emission circuit 154. If the number is exceeded, it terminates the operation of the ray emission circuit 154. Then, the electromagnetic field calculation device 150 sends the content of the communication area storage circuit 160, the content of the polygon table storage circuit 161, the information regarding all the rays generated by the ray emission circuit 154, and the result of integration considering the energy and phase of the rays at the points where they collide with each finite area of the received power integration circuit 155 to the display device 180.

[0022] The above-described calculation model generation device 110, structure data storage device 140, and electromagnetic field calculation device 150 are configured by a computer having a processor (CPU), a memory, an auxiliary storage device, and a communication interface.

[0023] The processor is an arithmetic unit that executes a program stored in the memory. By the processor executing various programs, the functions of each device are realized. Note that a part of the processing performed by the processor when executing a program may be executed by another arithmetic unit (for example, hardware such as an ASIC or FPGA).

[0024] The memory includes a ROM which is a non-volatile memory element and a RAM which is a volatile memory element. The ROM stores unchanging programs (for example, BIOS). The RAM is a high-speed and volatile memory element such as a DRAM (Dynamic Random Access Memory), and temporarily stores the programs executed by the processor and the data used during program execution.

[0025] The auxiliary storage device is, for example, a large-capacity and non-volatile storage device such as a magnetic storage device (HDD) or a flash memory (SSD). Also, the auxiliary storage device stores the data used by the processor during program execution and the programs executed by the processor. That is, the programs are read from the auxiliary storage device, loaded into the memory, and executed by the processor, thereby realizing the functions of each device.

[0026] The communication interface is a network interface device that controls communication with other devices according to a predetermined protocol.

[0027] The computer may have an input interface and an output interface. The input interface is an interface to which an input device such as a keyboard or a mouse is connected to receive input from the user. The output interface is an interface to which an output device such as the display device 180 or a printer described later is connected to output the execution result of the program in a form visible to the user.

[0028] The program executed by the processor is provided to each device via a removable medium (such as a CD-ROM or a flash memory) or a network and stored in a non-volatile auxiliary storage device which is a non-transitory storage medium. Therefore, the computer may have an interface for reading data from the removable medium.

[0029] Each device is a computer system configured on one physical computer or on a plurality of computers configured logically or physically, and may operate on a virtual computer constructed on a plurality of physical computer resources. The functional parts of each device may operate on separate physical or logical computers, or a plurality of them may be combined to operate on one physical or logical computer.

[0030] The display device 180 has a structure display circuit 181, a ray display circuit 182, an electromagnetic field display circuit 183, and a polygon display circuit 184. The structure display circuit 181 displays the stored content of the communication area storage circuit 160 input from the electromagnetic field calculation device 150 on the display. The ray display circuit 182 displays information about all the rays generated by the ray emission circuit 154 on the display. The electromagnetic field display circuit 183 displays on the display the result of integrating the energy of the rays at the points where they collided with each finite region of the receiver incoming power integration circuit 155, taking into account the phase. The polygon display circuit 184 displays the content of the polygon table storage circuit 161 on the display.

[0031] Note that the display device 180 may be a terminal connected to the electromagnetic field calculation device 150 via a network. In this case, the electromagnetic field calculation device 150 has the function of a web server, the display device 180 accesses the electromagnetic field calculation device 150 using a predetermined protocol (e.g., http), and the web browser of the display device 180 realizes the display function. Also, the display device 180 may execute a dedicated application to realize the display function. Further, an interface for outputting the radio communication characteristic prediction result to another computer system may be provided together with or instead of the display device 180. Thus, various forms can be adopted for the output device that outputs the radio communication characteristic prediction result.

[0032] FIG. 12 is a flowchart of an example of the calculation model generation process executed by the calculation model generation device 110.

[0033] After assigning spatial coordinates to the points indicating each point on the surface of the electromagnetic wave scatterer in the communication service providing area, the maximum value l of the distance between points max and the minimum value l min are set as thresholds (200), a first wavelength for calculating the electromagnetic wave characteristics of the electromagnetic wave scatterer and a second wavelength of the electromagnetic wave used for communication are set (201), the resolution of the spatial coordinates of the points is reset with a first wavelength shorter than the second wavelength, the distance between the two closest points in the point group having the reset spatial coordinates is calculated (203), and if the distance between these two points is smaller than the set minimum value l of the distance between points min (no in 204), these two points are replaced with one point having the intermediate coordinates of the two points (205). Then, the points in the point group are transformed so that the distance between all points in the point group is equal to or greater than the minimum value, a triangular polygon is generated from the three closest points d1, d2, and d3 in the transformed point group (206), and using the positional relationship information and connection relationship information of the generated polygon, if adjacent polygons are considered to continuously exist on the same plane within a predetermined error range, the polygons are grouped into the same group (207). After the grouping is completed, the plurality of polygon groups formed are classified (208), and the same electrical characteristics are assigned to the polygons belonging to each group, and the calculation model generation process is terminated (209).

[0034] FIG. 13 is a flowchart of an example of the polygon group generation process 206 in the process of FIG. 12.

[0035] Set a threshold for the outer dimension of a polygon group composed of a plurality of consecutive polygons, a threshold L for the connection angle allowed between adjacent polygons in the polygon group, and a threshold δ for curvature (210, 211). Select one central polygon P0 from all the polygons (212), and extract up to three polygons P1, P2, P3 adjacent to the central polygon P0 (213). Calculate the connection angles q1, q2, q3 between the central polygon P0 and the maximum three adjacent polygons (214). If the connection angles q1, q2, q3 are smaller than the threshold δ (yes in 216), these four polygons are grouped into the same group (217). If the outer shape G i of the formed polygon group is larger than the threshold L (yes in 218), this group is classified as the polygon group G that generates reflected waves R (219). After finishing the above-mentioned process for all the polygons (yes in 220), select one polygon from all the polygons as the new central polygon P0 (221), and extract the polygons P1, P2, P3 adjacent to the central polygon (222). If the groups to which the central polygon and the adjacent polygons belong are the same (yes in 223), these groups are classified as the polygon group G that generates reflected waves R (225). If the groups to which the central polygon and the adjacent polygons belong are different and neither group is a polygon group that forms reflected waves (no in 223, no in 224), these groups are classified as the polygon group G that generates scattered waves S (226). If the groups to which the central polygon and the adjacent polygons belong are different and only one of the groups is not a polygon group that forms reflected waves (no in 223, yes in 225), these groups are classified as the polygon group G that generates diffracted waves D (227). After finishing the process related to the classification of polygon groups for all the polygons (yes in 223), assign electrical characteristics to each polygon (229), and end the polygon group generation process.

[0036] FIG. 14 is a flowchart of an example of the electromagnetic field calculation process performed by the electromagnetic field calculation device.

[0037] Threshold l for the maximum ray propagation path used in ray tracing calculations min , l max A transmission point and a reception point are set within the communication service area (231), and a ray accumulation space is set around the reception point (232). max is set (233). Rays are emitted from the transmission point in all directions in three dimensions with a set resolution (234). Polygons that collide with each ray emitted from the transmission point are searched for (235), and reflected wave rays are generated from the searched polygons and re-emitted (236).

[0038] If the searched polygon belongs to a polygon group that generates diffracted waves (yes in 237), a ray of diffracted waves is generated from the polygon and re-radiated (238). As an example of the radiation direction of the diffracted waves, as shown in Fig. 15, a side corresponding to the outer shape of a polygon forming the outer shape of each polygon group is set as an edge line, and the re-radiation direction of the ray of the diffracted waves is determined so as to be linearly symmetrical with respect to the ray colliding with the polygon and the vector perpendicular to the edge line in a virtual plane formed by a vector perpendicular to the edge line that bisects the connection angle of two polygons belonging to other adjacent polygon groups that share the same edge line and the ray colliding with the polygon.

[0039] If the explored polygon belongs to a polygon group that generates scattered waves (yes in 239), rays of scattered waves are generated from the polygon and re-emitted (240). An example of the radiation direction of the scattered waves is, as shown in FIG. 16, with the side corresponding to the outer shape of the polygon forming the outer shape of each polygon group as an edge line, and the re-radiation direction of the rays of the scattered waves is determined so as to be in the opposite direction to the vector orthogonal to the edge line that bisects the connection angle of two polygons belonging to other adjacent polygon groups sharing the edge line and the ray colliding with the polygon within the virtual plane formed by the ray colliding within the virtual plane. Therefore, unlike the rays of the diffracted waves, the rays of the scattered waves have freedom in the re-radiation direction, and as an example, a plurality of rays may be re-emitted at regular intervals. Also, the rays of the scattered waves that are re-emitted a plurality of times may cancel the re-emission depending on the situation where the rays collide with the polygon again. When the number of times of re-emission of the rays is monitored and the number of re-emission times exceeds the threshold value, the emission of the rays is terminated (no in 241). For all the rays formed within the communication service providing area, the power of all the rays that have passed through one of the ray integration spaces is added considering the phase (242).

[0040] From FIGS. 17 to 20, the process of generating a plurality of polygons from a large number of points on each surface of a plurality of electromagnetic wave scatterers existing within the communication service providing area and classifying these plurality of polygons into various polygon groups having different attributes is shown. For the object arranged in the communication service providing area which is the electromagnetic field characteristic calculation target space shown in FIG. 17, the point group shown in FIG. 18 can be obtained. Using the obtained point group, the polygon shown in FIG. 19 is generated, and as shown in FIG. 20, the generated polygons are classified to form an attribute group.

[0041] According to this embodiment, the spatial coordinates of each point on the surface of the electromagnetic wave scatterer in the communication service providing area are obtained by measurement using electromagnetic waves at frequencies higher than the communication frequency, and the ray tracing calculation of the electromagnetic field distribution in the communication service providing area can be performed on computer resources using the obtained spatial coordinates. Moreover, since the ray tracing calculation can be performed only by collision verification between the ray and the polygon modeling the electromagnetic wave scatterer and re-radiation of the ray at the time of collision, model construction for calculating the electromagnetic field distribution in the communication service providing area and electromagnetic field calculation using the constructed model can be executed at high speed. Also, the man-hours and required time necessary for constructing a wireless communication system in the communication service providing area can be reduced, and the cost required for constructing the wireless communication system can be reduced.

[0042] <Example 2> Another example of the wireless communication characteristic prediction system according to the present invention will be described with reference to FIG. 2. Example 2 is different from Example 1 in that an electromagnetic field calculation device 170 having a reflected ray generation circuit 162, a secondary ray determination circuit 163, and a secondary ray generation circuit 164 is used instead of the electromagnetic field calculation device 150 of Example 1. In Example 2, mainly the differences from Example 1 will be described, and the same components as those in Example 1 will be denoted by the same reference numerals, and their descriptions will be omitted.

[0043] FIG. 2 is a diagram showing the configuration of the wireless communication characteristic prediction system 101 of Example 2.

[0044] In the electromagnetic field calculation device 170 of this embodiment, the ray polygon collision determination circuit 156 determines whether the ray generated by the ray emission circuit 154 collides with the polygon within the communication service providing area, with reference to the polygon table storage circuit 161. The reflected ray generation circuit 162 generates reflected waves re-emitted from all the polygons with which the ray collides. The secondary ray determination circuit 163 determines, using the information in the polygon table storage circuit 161, whether the polygon with which the ray collides re-emits a secondary ray of a diffracted wave or a scattered wave different from reflection. The secondary ray generation circuit 164 generates a secondary ray re-emitted from the polygon according to the determination result of the secondary ray determination circuit 163. The reflected wave generated by the reflection of the ray by the polygon reflects the macroscopic characteristics of the structure, and the diffracted wave generated by the ray bending around the polygon at the corner of the structure and the scattered wave generated by the scattering of the ray by the polygon reflect the microscopic characteristics of the structure. The secondary ray generation circuit 164 of Embodiment 2 generates a secondary ray in consideration of both such microscopic and macroscopic characteristics of the structure. Therefore, the electromagnetic field characteristics can be accurately calculated regardless of the size of the structure and the range irradiated by the structure radio wave (i.e., whether the entire structure is irradiated with radio waves or only a part is irradiated).

[0045] The iteration condition determination circuit 159 monitors the number of times the ray is regenerated by the re-emitted ray generation circuit 158. If the number of times of regeneration is within a predetermined number of times, the operation of the ray emission circuit 154 is continued. If the number of times of regeneration exceeds the predetermined number of times, the operation of the ray emission circuit 154 is terminated. Then, the electromagnetic field calculation device 170 sends to the display device 180 the content of the communication area storage circuit 160, the content of the polygon table storage circuit 161, information on all the rays generated by the ray emission circuit 154, and the result integrated in consideration of the energy and phase of the ray at the point where each finite area of the received signal power integration circuit 155 collides.

[0046] According to this embodiment, in the process of re-radiating rays from the polygon where the rays collided, the generation of reflected waves, diffracted waves, and scattered waves is realized by different elements. Therefore, the generation operation of reflected waves that can be accelerated in ray tracing calculations can be executed by a dedicated routine, and the electromagnetic field analysis by ray tracing calculations can be accelerated. As a result, the man-hours and required time necessary for constructing a wireless communication system within a communication service providing area can be reduced, and the cost necessary for constructing a wireless communication system can be reduced.

[0047] <Example 3> Another example of the wireless communication characteristic prediction system according to the present invention will be described with reference to FIG. 3. Example 3 is different from Example 2 in that an electromagnetic field calculation device 171 having a secondary ray pseudo-generation circuit 176 and a second ray-polygon collision determination circuit 177 is used instead of the electromagnetic field calculation device 170 of Example 2. In Example 3, mainly the differences from Example 2 will be described, and the same components as those in Example 2 will be denoted by the same reference numerals, and their descriptions will be omitted.

[0048] FIG. 3 is a diagram showing the configuration of the wireless communication characteristic prediction system 102 of Example 3.

[0049] In the electromagnetic field calculation device 171 of this embodiment, the secondary ray determination circuit 163 determines whether the polygon with which the ray has collided re-radiates a secondary ray different from reflection using the information in the polygon table storage circuit 161. The secondary ray temporary generation circuit 176 generates a secondary ray temporarily radiated from the polygon according to the determination result of the secondary ray determination circuit 163. The second ray-polygon collision determination circuit 177 determines, using the information in the polygon table storage circuit 161, with which polygon belonging to which polygon group the temporarily radiated ray collides. The secondary ray generation circuit 164 re-radiates a secondary ray from the polygon when the temporarily radiated ray does not collide with a polygon in the polygon group that causes the secondary ray to be generated again based on the determination result of the second ray-polygon collision determination circuit 177. The iteration condition determination circuit 159 monitors the number of re-occurrences of the re-radiated ray generation circuit 158, continues the operation of the ray emission circuit 154 if the number of re-occurrences is within a predetermined number, and ends the operation of the ray emission circuit 154 if the number of re-occurrences exceeds the predetermined number. For this number of re-occurrences, different upper limit numbers may be used depending on the cause of the generation of the secondary ray. For example, since the reflected wave is stronger than the diffracted wave and the scattered wave, it is advisable to increase the upper limit number. Then, the electromagnetic field calculation device 171 sends to the display device 180 the content of the communication area storage circuit 160, the content of the polygon table storage circuit 161, information regarding all the rays generated by the ray emission circuit 154, and the result of integration considering the energy and phase of the ray at the point where it collided with each finite area of the received power integration circuit 155.

[0050] According to this embodiment, in order to prohibit a non-reflected secondary ray from re-radiating a secondary ray again, for a reflected wave whose influence can be ignored in the electromagnetic field calculation result, the processing of a ray that is even weaker in order due to a reflected wave with a weaker intensity in order can be omitted. Therefore, the electromagnetic field analysis by ray tracing calculation can be speeded up. As a result, the man-hours and the required time necessary for constructing a wireless communication system within the communication service providing area can be reduced, and the cost necessary for constructing the wireless communication system can be reduced.

[0051] <Example 4> Another example of the wireless communication characteristic prediction system according to the present invention will be described with reference to FIG. 4. Example 4 is different from Example 1 in that a camera 8 is used as a ranging device instead of the measurement radio 1, and a video data conversion device 7 for acquiring video data from the camera 8 is provided. In Example 4, mainly the differences from Example 1 will be described, and the same components as those in Example 1 are denoted by the same reference numerals, and their descriptions are omitted.

[0052] FIG. 4 is a diagram showing the configuration of the wireless communication characteristic prediction system 103 of Example 4.

[0053] The video data conversion device 7 uses image diagnosis technology to calculate the coordinates of each point on the surface of the electromagnetic wave scatterer in the communication service providing area from the video data acquired by the camera 8, and outputs the calculation result to the calculation model generation device 110.

[0054] According to this embodiment, the electromagnetic wave emitted by this system in order to acquire the data required by the calculation model generation device 110 is only the communication radio 4, and the amount of the electromagnetic wave emitted by this system can be reduced compared with the embodiment of FIG. 1, so that the electromagnetic wave interference given by this system to other systems can be reduced.

[0055] <Example 5> Another example of the wireless communication characteristic prediction system according to the present invention will be described with reference to FIG. 5. Example 5 is different from Example 1 in that a calculation model generation device 130 having a new polygon coupling circuit 118 is used instead of the calculation model generation device 110. In Example 5, mainly the differences from Example 1 will be described, and the same components as those in Example 1 are denoted by the same reference numerals, and their descriptions are omitted.

[0056] FIG. 5 is a diagram showing the configuration of the wireless communication characteristic prediction system 104 of Example 5.

[0057] In the calculation model generation device 130 of this embodiment, the polygon group formation circuit 115 classifies a plurality of polygons generated by the polygon generation circuit 114 into a plurality of polygon groups using the positional relationship with adjacent polygons. The polygon combination circuit 118 combines a plurality of adjacent polygons into one polygon for each of the plurality of polygon groups using the positional relationship with adjacent polygons among the plurality of polygons generated by the polygon generation circuit 114. The polygon combination circuit 118 may combine polygons with reference to the communication wavelength data 143. For example, polygons having a size of 1 / 4 or less of the wavelength of the electromagnetic wave for communication may be combined. Also, the central part of the electromagnetic wave scatterer may have larger polygons, and the corner part of the electromagnetic wave scatterer may have smaller polygons. In the central part of the electromagnetic wave scatterer, secondary rays are mainly generated by reflection, and it is necessary to consider the secondary rays generated by scattering and diffraction at the corner part of the electromagnetic wave scatterer. Therefore, it is advisable to enlarge the polygons in the central part of the electromagnetic wave scatterer to consider macro features, and to reduce the polygons in the corner part of the electromagnetic wave scatterer to consider micro features. The adjacent polygon junction state data generation circuit 116 calculates the connection relationship of each polygon group generated by the polygon group formation circuit 115 using the connection relationship of the plurality of polygons with adjacent polygons.

[0058] According to this embodiment, since the total number of polygons in the calculation model used by the electromagnetic field calculation device 150 can be reduced, the collision determination between rays and polygons that are frequently repeated in the ray tracing calculation can be reduced, and the electromagnetic field analysis by the ray tracing calculation can be accelerated. As a result, the man-hours and required time necessary for constructing the wireless communication system within the communication service providing area can be reduced, and the cost necessary for constructing the wireless communication system can be reduced.

[0059] <Example 6> Another example of the wireless communication characteristic prediction system according to the present invention will be described with reference to FIG. 6. Example 6 is different from Example 1 in that a calculation model generation device 131 having an adjacent polygon junction state determination / data generation circuit 119 is used instead of the adjacent polygon junction state data generation circuit 116. In Example 6, mainly the differences from Example 1 will be described, and the same components as those in Example 1 are denoted by the same reference numerals, and their descriptions are omitted.

[0060] FIG. 6 is a diagram showing the configuration of the wireless communication characteristic prediction system 105 of Example 6.

[0061] In the calculation model generation device 131 of the present embodiment, the adjacent polygon connection state determination / data generation circuit 119 calculates the connection relationship of each polygon group generated by the polygon group formation circuit 115 using the connection relationship between a plurality of polygons and adjacent polygons. When the polygon is connected to another polygon, the polygon attribute determination circuit 117 adds an attribute to each polygon in the polygon group using the connection relationship between the polygon groups calculated by the adjacent polygon connection state determination / data generation circuit 119. When the polygon is not connected to another polygon, the process returns to the point cloud filter circuit 113 to remove each point in the point cloud that forms the polygon.

[0062] According to the present embodiment, in the ray tracing calculation performed by the electromagnetic field calculation device 150, polygons having a size that does not affect the electromagnetic field analysis result, that is, polygons smaller than the wavelength of the electromagnetic wave for communication, can be removed from the calculation target, and the electromagnetic field analysis by the ray tracing calculation can be accelerated. As a result, the man-hours and time required for constructing the wireless communication system within the communication service providing area can be reduced, and the cost required for constructing the wireless communication system can be reduced.

[0063] <Example 7> Another example of the wireless communication characteristic prediction system according to the present invention will be described with reference to FIG. 7. Example 7 is different from Example 1 in that a structure data storage device 190 having structure property data 146 is used instead of the structure data storage device 140 of Example 1. In Example 7, the differences from Example 1 will be mainly described, and the same components as those in Example 1 will be denoted by the same reference numerals, and their descriptions will be omitted.

[0064] FIG. 7 is a diagram showing the configuration of the wireless communication characteristic prediction system 106 of Example 7.

[0065] The structural property data 146 of the structural data storage device 190 provides the electrical characteristics of the electromagnetic wave scatterers within the communication service providing area to the polygon attribute determination circuit 117 of the calculation model generation device 110. The polygon attribute determination circuit 117 changes in correspondence with the scatterer structure determined from the structure of the polygon group.

[0066] According to this embodiment, since the properties of the rays re-radiated when the rays collide with the polygons can be changed according to the differences in the electrical characteristics of the electromagnetic wave scatterers, the accuracy of the electromagnetic field analysis by ray tracing calculation can be improved, and the electromagnetic field distribution within the communication service providing area estimated by this system can be made closer to reality. As a result, the man-hours and required time necessary for constructing the wireless communication system within the communication service providing area can be reduced, and the cost necessary for constructing the wireless communication system can be reduced.

[0067] <Example 8> Another example of the wireless communication characteristic prediction system according to the present invention will be described with reference to FIG. 8. Example 8 is different from Example 1 in that an electromagnetic field calculation device 172 having a reflected ray generation circuit 162, a secondary ray determination circuit 163, a diffracted ray generation circuit 167, and a scattered ray generation circuit 166 is used instead of the electromagnetic field calculation device 150 of Example 1. In Example 8, mainly the differences from Example 1 will be described, and the same components as those in Example 1 will be denoted by the same reference numerals, and their descriptions will be omitted.

[0068] FIG. 8 is a diagram showing the configuration of the wireless communication characteristic prediction system 107 of Example 8.

[0069] In the electromagnetic field calculation device 172 of this embodiment, the ray polygon collision determination circuit 156 determines whether the ray generated by the ray emission circuit 154 collides with a polygon within the communication service providing area, with reference to the polygon table storage circuit 161. The reflected ray generation circuit 162 generates reflected waves re-emitted from all the polygons with which the ray has collided. The secondary ray determination circuit 163 determines, using the information in the polygon table storage circuit 161, whether the polygon with which the ray has collided re-emits secondary rays of diffracted waves or scattered waves different from reflection. The diffracted ray generation circuit 167 generates diffracted rays re-emitted from the polygon according to the determination result of the secondary ray determination circuit 163. The scattered ray generation circuit 166 generates scattered rays re-emitted from the polygon according to the determination result of the secondary ray determination circuit 163. The iteration condition determination circuit 159 monitors the number of times the rays are regenerated by the diffracted ray generation circuit 167 and the scattered ray generation circuit 166. If the number of times of regeneration is within a predetermined number of times, the operation of the ray emission circuit 154 is continued. If the number of times of regeneration exceeds the predetermined number of times, the operation of the ray emission circuit 154 is terminated. Then, the electromagnetic field calculation device 172 sends to the display device 180 the content of the communication area storage circuit 160, the content of the polygon table storage circuit 161, information on all the rays generated by the ray emission circuit 154, and the result of integration considering the energy and phase of the rays at the points where they collided with each finite area of the received power integration circuit 155.

[0070] According to this embodiment, in the process of re-emitting rays from the polygon with which the ray has collided, the generation of reflected waves, diffracted waves, and scattered waves is realized by different elements. Therefore, the generation operation of reflected waves, which can be accelerated in ray tracing calculations, can be executed by a dedicated routine, and the electromagnetic field analysis by ray tracing calculations can be accelerated. Also, since the calculation processing related to scattered waves and the calculation processing related to diffracted waves can be independently executed with the same calculation processing as that for reflected waves, the electromagnetic field analysis by ray tracing calculations can be further accelerated. As a result, the man-hours and required time necessary for constructing a wireless communication system within the communication service providing area can be reduced, and the cost necessary for constructing a wireless communication system can be reduced.

[0071] <Example 9> Another example of the wireless communication characteristic prediction system according to the present invention will be described with reference to FIG. 9. Example 9 is different from Example 8 in that an electromagnetic field calculation device 173 having a polygon table history circuit 168 is used instead of the electromagnetic field calculation device 172 of Example 8. In Example 9, mainly the differences from Example 8 will be described, and the same components as those in Example 8 will be denoted by the same reference numerals, and their descriptions will be omitted.

[0072] FIG. 9 is a diagram showing the configuration of the wireless communication characteristic prediction system of Example 9.

[0073] In the electromagnetic field calculation device 173 of this embodiment, the polygon table history circuit 168 sequentially stores the contents of the polygon table storage circuit 161, and instead of the polygon table storage circuit 161, it sends data to the ray - polygon collision determination circuit 156, the reflected ray generation circuit 162, the secondary ray determination circuit 163, and the polygon display circuit 184 of the display device 180.

[0074] According to this embodiment, in the ray tracing calculation and polygon display when the spatial arrangement of the electromagnetic wave scatterers in the communication service providing area changes, past polygon data can be used. Therefore, the dynamic fluctuation of the electromagnetic field distribution when a moving body is included in the communication service providing area can be evaluated, and the application of the wireless communication characteristic prediction system of the present invention can be expanded.

[0075] <Example 10> Another example of the wireless communication characteristic prediction system according to the present invention will be described with reference to FIG. 10. Example 10 is different from Example 1 in that an electromagnetic field calculation device 174 having a received power determination circuit 169 is used instead of the electromagnetic field calculation device 150 of Example 1. In Example 10, mainly the differences from Example 1 will be described, and the same components as those in Example 1 will be denoted by the same reference numerals, and their descriptions will be omitted.

[0076] FIG. 10 is a diagram showing the configuration of the wireless communication characteristic prediction system of Example 10.

[0077] In the electromagnetic field calculation device 174 of this embodiment, the iteration condition determination circuit 159 monitors the number of regenerations of the re-radiation ray generation circuit 158. If the number of regenerations is within a predetermined number, the operation of the ray emission circuit 154 is continued. If the number of regenerations exceeds the predetermined number, the operation of the ray emission circuit 154 is terminated. The received power determination circuit 169 checks the ray arrival flags for all reception points of the receiver incoming power integration circuit 155. If there is a reception point where the flag is not set, the content of the iteration condition setting circuit 151 is changed and a series of processes starting from the transmission point generation circuit 152 are repeated. On the other hand, if the flag is set at all reception points, the electromagnetic field calculation device 174 sends the content of the communication area storage circuit 160, the content of the polygon table storage circuit 161, information on all the rays generated by the ray emission circuit 154, and the result obtained by integrating considering the energy and phase of the rays at the points where the rays collided with each finite area of the receiver incoming power integration circuit 155 to the display device 180.

[0078] According to this embodiment, the processing of the electromagnetic field calculation device 174 can be optimized according to the display resolution of the electromagnetic field distribution, and the electromagnetic field distribution can be displayed with the minimum calculation time for the required resolution of the electromagnetic field distribution. As a result, the man-hours and time required for constructing the wireless communication system within the communication service providing area can be reduced, and the cost required for constructing the wireless communication system can be reduced.

[0079] <Example 11> In this embodiment, an example of engineering by a wireless monitoring system that estimates the electromagnetic field environment within a communication service providing area and predicts the communication quality within the area using the wireless communication characteristic prediction system of any of the above-described embodiments will be described with reference to FIG. 21. Since the wireless communication characteristic prediction system of any of the above-described embodiments can be used for the wireless monitoring system, the description thereof will be omitted.

[0080] FIG. 21 is a diagram showing an example of engineering by the IoT wireless monitoring system 1101 using the wireless communication characteristic prediction system of the present invention.

[0081] The IoT wireless monitoring system 1101 has a plurality of fixed structures 1012 and movable structures 1013 inside the building 1011 which is a communication service providing area, and a plurality of wireless communication devices 1021 are installed. A mobile environment measuring device 1003 having a communication wireless device 4 and a measurement wireless device 1 moves along a measurement route 1004 inside the building 1011, and at each point on the measurement route 1004, the measurement wireless device 1 acquires the coordinates of each point on the surfaces of the plurality of fixed structures 1012 and the movable structures 1013 which are electromagnetic wave scatterers in the building 1011 serving as a communication service providing area, and the communication wireless device 4 receives transmitted radio waves from the plurality of wireless communication devices 1021. The spatial positional relationship between the building 1011 and the measurement route 1004 is acquired in advance. The wireless communication characteristic prediction system can estimate the electromagnetic field distribution at each point required in the building 1011 which is within the communication service providing area using the electromagnetic field intensity within the communication service providing area obtained from the acquired positional relationship and the spatial coordinates of the acquired electromagnetic wave scatterers by electromagnetic field analysis using computer resources.

[0082] According to this embodiment, at the site of the communication service providing area where the wireless communication system is to be constructed, a model for calculating the radio wave environment for the electromagnetic waves used by the wireless communication system is generated, and various characteristics of the wireless communication system within the area can be predicted using this model. Thus, an appropriate wireless communication environment within the communication service providing area can be constructed, and various wireless communication performances in the appropriate environment can be displayed. For this reason, the personnel and working hours required for wireless engineering for constructing the wireless communication system can be reduced, and the cost of wireless engineering can be cut.

[0083] <Example 12> In this embodiment, another example of engineering by a wireless monitoring system that estimates the electromagnetic field environment within a communication service providing area and predicts the communication quality within the area using the wireless communication characteristic prediction system of any of the foregoing embodiments will be described with reference to FIG. 22. In Embodiment 12, instead of the movable structure 1013, a plurality of moving bodies 1015 serving as electromagnetic wave scatterers are present within the building 1011, and a plurality of measurement radios 1 are fixedly and dispersedly arranged within the building 1011 instead of the mobile environment measurement device 1003, which is different from Embodiment 11. In Embodiment 12, mainly the differences from Embodiment 11 will be described, and the same components as those in Embodiment 11 will be denoted by the same reference numerals, and their descriptions will be omitted. Also, since any of the wireless communication characteristic prediction systems of Embodiments 1 to 10 described above can be used for the wireless monitoring system, its description will be omitted.

[0084] FIG. 22 is a diagram showing an example of engineering by an IoT wireless monitoring system 1101 using the wireless communication characteristic prediction system of the present invention.

[0085] The positions of the measurement radios 1 within the building 1001 can be acquired in advance. In Embodiment 12, similar to Embodiment 11, the coordinates of each point on the surfaces of the plurality of fixed structures 1012 and the moving bodies 1015 serving as electromagnetic wave scatterers can be acquired. Particularly, even when the spatial arrangement of the electromagnetic wave scatterers within the building 1011 changes, the coordinates of each point on the surface of the electromagnetic wave scatterers can be acquired in real time without running the mobile environment measurement device 1003.

[0086] According to this embodiment, even when there are electromagnetic wave scatterers moving within the communication service providing area, similar to Embodiment 11, by performing electromagnetic field analysis using computer resources, the electromagnetic field distribution at each point required within the building 1011 that becomes the communication service providing area can be estimated. At the site of the communication service providing area where the wireless communication system is to be constructed, a model for calculating the radio wave environment for the electromagnetic waves used by the wireless communication system is generated, and various characteristics of the wireless communication system within the area can be predicted using this model. Thus, an appropriate wireless communication environment within the communication service providing area can be constructed, and various wireless communication performances in the appropriate environment can be displayed. Therefore, the number of personnel and working hours required for wireless engineering for constructing the wireless communication system can be reduced, and the cost of wireless engineering can be cut down.

[0087] Note that the present invention is not limited to the embodiments described above, and includes various modifications and equivalent configurations within the scope of the appended claims. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and the present invention is not necessarily limited to those having all the configurations described. Also, a part of the configuration of one embodiment may be replaced with the configuration of another embodiment. Further, the configuration of another embodiment may be added to the configuration of one embodiment. Also, for a part of the configuration of each embodiment, addition, deletion, or replacement with other configurations may be made.

[0088] Also, each of the above-described configurations, functions, processing units, processing means, etc. may be realized in hardware, for example, by designing a part or all of them with an integrated circuit, or may be realized in software by a processor interpreting and executing a program for realizing each function.

[0089] Information such as programs, tables, files, etc. for realizing each function can be stored in a storage device such as a memory, a hard disk, an SSD (Solid State Drive), or a recording medium such as an IC card, an SD card, or a DVD.

[0090] Also, the control lines and information lines show those considered necessary for explanation, and do not necessarily show all the control lines and information lines required for implementation. In reality, it is reasonable to consider that almost all components are interconnected.

Explanation of Signs

[0091] 1 Wireless device for measurement 2 High-frequency signal source for measurement 3 Antenna for measurement 4 Wireless device for communication 5 High-frequency signal source for communication 6 Antenna for communication 7 Video data conversion device 8 Camera 100~107 Wireless communication characteristic prediction system 110 Calculation model generation device 111 Point group memory circuit 112 Point group coordinate generation circuit 113 Point group filter circuit 114 Polygon generation circuit 115 Polygon group formation circuit 116 Adjacent polygon joining state data generation circuit 117 Polygon attribute determination circuit 118 Polygon combination circuit 119 Data generation circuit 130 Calculation model generation device 131 Calculation model generation device 140 Structure data storage device 141 Point group table 142 Communication area data 143 Communication wavelength data 144 Polygon table 145 Electrical characteristic table 146 Structure property data 150 Electromagnetic field calculation device 151 Iterative condition setting circuit 152 Transmission point generation circuit 153 Reception point generation circuit 154 Ray emission circuit 155 Received power integration circuit for receiver 156 Polygon collision determination circuit 157 Re - emission ray selection circuit 158 Re - emission ray generation circuit 159 Iteration condition determination circuit 160 Communication area memory circuit 161 Polygon table memory circuit 162 Reflection ray generation circuit 163 Secondary ray determination circuit 164 Secondary ray generation circuit 166 Scattered ray generation circuit 167 Diffraction ray generation circuit 168 Polygon table history circuit 169 Received power determination circuit 170, 171, 172, 173, 174 Electromagnetic field calculation device 176 Secondary ray temporary generation circuit 177 Polygon collision determination circuit 180 Display device 181 Structure display circuit 182 Ray display circuit 183 Electromagnetic field display circuit 184 Polygon display circuit 190 Structure data storage device 1001, 1011 Buildings 1003 Mobile environment measurement device 1004 Measurement route 1006 Polygon group generation process 1012, 1013 Structures 1015 Mobile object 1021 Wireless communication device 1101 IoT Wireless monitoring system

Claims

1. A wireless communication characteristic prediction system, comprising: a model generation device, an electromagnetic field calculation device, and an output device; the model generation device calculates dimension information of the structure from point cloud data representing positions on the surface of the structure within the communication service providing area and the wavelength of radio waves used for communication; the electromagnetic field calculation device has an arithmetic device that executes predetermined processing and a storage device accessible by the arithmetic device, repeatedly executes ray tracing calculation to estimate the electromagnetic field distribution, uses the position data of the structure and the calculated dimension information of the structure to change the generation states of reflected waves, diffracted waves, and scattered waves in the ray tracing calculation, transmits the estimated electromagnetic field distribution to the output device, the output device outputs the estimated electromagnetic field distribution, characterized in that it is a wireless communication characteristic prediction system.

2. A wireless communication characteristic prediction system, comprising: a measurement device, an electromagnetic field calculation device, and an output device; the measurement device measures the distance and direction to a point on the surface of a structure within the communication service providing area using electromagnetic waves; the electromagnetic field calculation device has an arithmetic device that executes predetermined processing and a storage device accessible by the arithmetic device, repeatedly executes ray tracing calculation to estimate the electromagnetic field distribution, changes the generation states of reflected waves, diffracted waves, and scattered waves in the ray tracing calculation from the position data of the structure, transmits the estimated electromagnetic field distribution to the output device, the output device outputs the estimated electromagnetic field distribution, wherein the frequency of the electromagnetic wave used by the wireless communication device arranged within the communication service providing area for communication is 1 / 10 or less of the frequency of the electromagnetic wave used by the measurement device for measurement, characterized in that it is a wireless communication characteristic prediction system.

3. A wireless communication characteristic prediction system, comprising: a mobile measurement device, a model generation device, a structure data storage device, an electromagnetic field calculation device, and an output device; the mobile measurement device is equipped with a measurement device that measures the distance and direction to a point on the surface of an electromagnetic wave scatterer existing within the communication service providing area, and an electromagnetic field measurement device that measures the electromagnetic field strength at the communication frequency; the model generation device generates a polygon representing the structure within the communication service providing area from the data measured by the measurement device; the structure data storage device stores data necessary for ray tracing calculation; the electromagnetic field calculation device An arithmetic unit that executes a predetermined process, and a storage device accessible to the arithmetic unit, Repeatedly execute the ray tracing calculation to estimate the electromagnetic field distribution, Change the generation states of reflected waves, diffracted waves, and scattered waves in the ray tracing calculation from the position data of the structure, Transmit the estimated electromagnetic field distribution to the output device, The output device outputs the estimated electromagnetic field distribution. A wireless communication characteristic prediction system characterized by this.

4. A wireless communication characteristic prediction system, Comprising a measurement device, a mobile measurement device, a model generation device, a structure data storage device, an electromagnetic field calculation device, and an output device, The measurement device measures the distance and direction to a point on the surface of an electromagnetic wave scatterer existing within a communication service providing area, The mobile measurement device is equipped with an electromagnetic field measurement device that measures the electromagnetic field intensity at a communication frequency, The model generation device generates a polygon representing a structure within the communication service providing area from the data measured by the measurement device, The structure data storage device stores data necessary for ray tracing calculation, The electromagnetic field calculation device, An arithmetic unit that executes a predetermined process, and a storage device accessible to the arithmetic unit, Repeatedly execute the ray tracing calculation to estimate the electromagnetic field distribution, Change the generation states of reflected waves, diffracted waves, and scattered waves in the ray tracing calculation from the position data of the structure, Transmit the estimated electromagnetic field distribution to the output device, The output device outputs the estimated electromagnetic field distribution. A wireless communication characteristic prediction system characterized by this.

5. The wireless communication characteristic prediction system according to claim 1, The point cloud data is generated from the measured data of the distance to the surface of the structure, The electromagnetic field calculation device acquires the point cloud data as the position data of the structure. A wireless communication characteristic prediction system characterized by this.

6. The wireless communication characteristic prediction system according to claim 1, The model generation device groups the polygons generated from the point cloud data according to the positional relationship with adjacent polygons, The electromagnetic field calculation device determines whether diffracted waves in the ray tracing calculation occur using the information of the grouped polygons. A wireless communication characteristic prediction system characterized by this.

7. The wireless communication characteristic prediction system according to claim 1, The model generation device groups the polygons generated from the point cloud data according to the positional relationship with adjacent polygons and the communication wavelength, The electromagnetic field calculation device uses the information of the grouped polygons to determine whether diffracted waves and scattered waves in the ray tracing calculation occur. A wireless communication characteristic prediction system characterized by this.

8. The wireless communication characteristic prediction system according to claim 1, Comprising an electromagnetic field measurement device that measures the electromagnetic field intensity measured at a plurality of locations within the communication service providing area where the wireless communication device is disposed, The electromagnetic field calculation device changes the position and direction of the polygon generated from the point cloud data so that the difference between the electromagnetic field distribution within the area obtained by the ray tracing calculation and the measured electromagnetic field intensity decreases, and re-executes the ray tracing calculation. A wireless communication characteristic prediction system characterized by this.

9. The wireless communication characteristic prediction system according to claim 6 or 7, The electromagnetic field calculation device, Stores data with information regarding electrical characteristics added to the generated polygon, Referring to the information regarding the electrical characteristics, determining the radiation direction and initial intensity of the ray re-radiated when the ray collides with the polygon in the ray tracing calculation. A wireless communication characteristic prediction system characterized by this.

10. The wireless communication characteristic prediction system according to claim 1, The output device generates display data for displaying the result of the electromagnetic field calculation using the polygons within the communication service providing area and the information regarding the group of polygons used in the electromagnetic field calculation. A wireless communication characteristic prediction system characterized by this.

11. An IoT wireless monitoring system using the wireless communication characteristic prediction system according to claim 3 or 4.

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