Device, method and program for determining arrangement of reflector

Abstract

The present invention easily determines an installation position of a reflection plate for allowing radio waves to reach a dead zone. A device 100 for determining an arrangement of reflectors comprises: an acquisition unit 11 for acquiring arrangement information 21 of a plurality of partitions partitioning a space, a transmission start point 22 and a target reception point 23 of radio waves, the points being set inside the space, and a transmission start direction 24 of radio waves; and a determination unit 12 for determining an arrangement of a plurality of reflectors for the partitions on the basis of the arrangement information 21 of the partitions, the transmission start point 22, the target reception point 23, the transmission start direction 24 of radio waves, and reflection conditions 25 of radio waves in the respective reflectors. The reflection conditions include the following first reflection condition. First reflection condition: Reflection in the reflector satisfies incident angle θ1 = reflection angle θ2.

Description

Apparatus, method and program for determining the placement of reflectors

[0001] The present invention relates to an apparatus, a method, and a program for determining the placement of a reflector.

[0002] In recent years, radio waves in high frequency bands of approximately 2 GHz to 300 GHz, known as centimeter waves or millimeter waves, have been used in wireless communications that make up mobile phone networks and the like. Such short-wavelength radio waves tend to travel in a straight line, and if there is an obstacle in the path of the radio waves, they are likely to create dead zones where the radio waves cannot reach. Various efforts have been made to eliminate such dead zones.

[0003] For example, Non-Patent Document 1 below discloses an embodiment using a reflector as a countermeasure for radio wave blind zones. The technology in Non-Patent Document 1 controls a reflector placed on the roof of a building to allow radio waves to reach blind zones that occur behind obstacles such as canyons between buildings. Patent Document 1 below discloses a reflector that can control the direction of reflected waves.

[0004] JP 2010-226695 A

[0005] Tamami Maruyama, Tatsuo Furuno, Shinji Kamibayashi, "Research on Directional Reflectors to Eliminate Areas Where Radio Waves Do Not Reach," NTT DoCoMo Technical Journal, Vol. 17, No. 3, pp. 70-73, October 1, 2009.

[0006] When using a reflector as a countermeasure for radio wave dead zones, it is necessary to appropriately set the direction in which the radio waves are reflected so that the radio waves sent from the base station that transmits the radio waves reach the dead zone, and so that the radio waves sent from a terminal device located in the dead zone reach the base station.

[0007] On the other hand, radio wave dead zones are not limited to canyons between buildings, but also exist inside buildings such as offices, factories, etc. Various structures exist inside such buildings that can act as obstacles to radio waves, and in order to allow radio waves to reach the dead zones inside the building from the radio wave source inside the building, it is necessary to place multiple reflectors inside the building to reflect the radio waves multiple times.

[0008] In the technology of Non-Patent Document 1, in order to determine the installation positions of reflectors so that radio waves can be transmitted and received, it is necessary to obtain detailed data such as propagation loss and radio wave strength. However, if multiple reflectors are placed to reflect radio waves multiple times and make them reach dead zones, it is necessary to obtain detailed data on propagation loss and radio wave strength for each of multiple candidate locations for installing the reflectors, which creates problems in terms of labor and cost. In a mode in which multiple reflectors are used as a countermeasure for radio wave dead zones, it is desired to easily determine the installation positions of the reflectors.

[0009] An object of the present invention is to easily determine the installation position of a reflector to allow radio waves to reach blind areas.

[0010] The present invention for solving the above problems includes, for example, the following aspects. (Item 1) A device for determining the placement of reflectors, comprising: an acquisition unit that acquires placement information of a plurality of partitions that partition a space, a transmission start point and a target reception point of radio waves set within the space, and a transmission start direction of the radio waves; and a determination unit that determines the placement of the plurality of reflectors on the partitions based on the placement information of the partitions, the transmission start point, the target reception point, the radio wave transmission start direction, and a radio wave reflection condition at each reflector, wherein the reflection conditions include the following first reflection condition: First reflection condition: Reflection at the reflector satisfies incident angle θ1 = reflection angle θ2. (Item 2) The device according to item 1, wherein the reflection conditions further include the following second reflection condition: Second reflection condition: Reflection at the reflector satisfies incident angle θ1 ≠ reflection angle θ2. (Item 3) The device according to Item 2, wherein, when an object blocking the radio wave is present on a line connecting the transmission start point and the target reception point, the determination unit determines the reflection condition of a first reflector, which is the first reflector to be placed, to be the second reflection condition, and determines an interior angle of reflection on the first reflector based on an angle formed between the partition and a traveling direction of a reflected wave that satisfies the second reflection condition at a first contact point on the partition where the first reflector is placed. (Item 4) The device according to Item 3, wherein the determination unit determines the interior angle of reflection on the first reflector so as to minimize an angle formed between the partition and a traveling direction of the reflected wave that satisfies the second reflection condition at the first contact point. (Item 5) The device according to Item 3 or 4, wherein the determination unit selects the interior angle from a predetermined plurality of candidate angles. (Item 6) The device according to Item 3 or 4, wherein the determination unit selects the interior angle by presenting a predetermined plurality of candidate angles to an operator and receiving input regarding the candidate angle from the operator. (Item 7) The device described in any one of Items 3 to 6, wherein the determination unit determines the reflection condition of the mth reflector, which is the reflector to be placed in the mth position (m is a natural number of 2 or more), depending on whether or not an object blocking the radio waves exists on a straight line connecting the mth junction on the partition body where the mth reflector is placed and the target receiving point.(Item 8) The device according to Item 7, wherein, when an object blocking the radio wave is present on the straight line, the determination unit determines the reflection condition of the mth reflector to be placed to be the first reflection condition. (Item 9) The device according to Item 7, wherein, when an object blocking the radio wave is not present on the straight line, the determination unit determines the reflection condition of the mth reflector to be placed to be the second reflection condition, and determines an interior angle of reflection at the mth reflector so that a reflected wave that satisfies the second reflection condition at the mth junction reaches the target reception point. (Item 10) The device according to Item 9, wherein the determination unit selects the interior angle from a predetermined plurality of candidate angles. (Item 11) The device according to any one of Items 1 to 10, wherein, when the radio wave does not reach the target reception point, the determination unit changes at least one of the transmission start direction of the radio wave from the transmission start point and the interior angle of reflection. (Item 12) The device according to any one of Items 1 to 11, wherein the partition includes a wall. (Item 13) The device according to any one of items 1 to 11, wherein the partitions include a ceiling, a floor, and a wall. (Item 14) A method for determining the placement of reflectors, the method comprising the steps of: acquiring placement information of a plurality of partitions that partition a space, a transmission start point and a target reception point of radio waves set within the space, and a transmission start direction of the radio waves; and determining the placement of the plurality of reflectors on the partitions based on the placement information of the partitions, the transmission start point, the target reception point, the radio wave transmission start direction, and the radio wave reflection conditions at each reflector, wherein the reflection conditions include the following first reflection condition: First reflection condition: reflection at the reflector satisfies incident angle θ1 = reflection angle θ2. (Item 15) The method according to item 14, wherein the partitions include walls. (Item 16) The method according to item 14, wherein the partitions include a ceiling, a floor, and a wall. (Item 17) A program for causing a computer to function as each part of the device according to any one of items 1 to 13.

[0011] According to the present invention, it is possible to easily determine the installation position of a reflector to allow radio waves to reach blind areas.

[0012] 1 is a block diagram illustrating the function of a reflector arrangement determination device according to an embodiment of the present invention; FIG. 2 is a diagram illustrating types of reflectors to be arranged on walls in a space; FIG. 3 is a flowchart illustrating the steps of a method for determining the arrangement of reflectors according to an embodiment of the present invention; FIG. 4 is a flowchart illustrating the steps of a method for determining the arrangement of reflectors according to an embodiment of the present invention; FIG. 5 is a plan view of a target space for which the arrangement of reflectors is to be determined using a method according to an embodiment of the present invention; FIG. 6 is a plan view of a target space for which the arrangement of reflectors is to be determined using a method according to an embodiment of the present invention; FIG. 7 is a plan view of a target space for which the arrangement of reflectors is to be determined using a method according to an embodiment of the present invention; FIG. 8 is a plan view of a target space for which the arrangement of reflectors is to be determined using a method according to an embodiment of the present invention; FIG. 9 is a plan view of a target space for which the arrangement of reflectors is to be determined using a method according to an embodiment of the present invention; FIG. 10 is a plan view of a target space for which the arrangement of reflectors is to be determined using a method according to an embodiment of the present invention; 1A and 1B are schematic perspective and side views of a space of an object for which a location of a reflector is to be determined by a method according to another embodiment of the present invention;

[0013] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description and drawings, the same reference numerals will denote the same or similar components, and therefore, redundant descriptions of the same or similar components will be omitted.

[0014] In this embodiment, a case where the partitions that separate the space are walls will be described as an example. That is, in the following description of this embodiment, the word "wall" can be read as "partition."

[0015] [Configuration of the Apparatus] FIG. 1 is a block diagram for explaining the functions of a reflector arrangement determination apparatus according to an embodiment of the present invention.

[0016] A reflector arrangement determination device 100 (hereinafter also simply referred to as device 100) according to one embodiment includes a data processing unit 10, an auxiliary storage device 20, an input unit 31, a display unit 32, and a communication interface unit (communication I / F unit) 33. The data processing unit 10 is configured as software, while the auxiliary storage device 20, the input unit 31, the display unit 32, and the communication I / F unit 33 are configured as hardware. The device 100 can be configured using, for example, a general-purpose computer such as a personal computer, a tablet terminal, a smartphone, or the like. Although not shown in the figure, the device 100 further includes, as hardware components, a processor such as a CPU that performs data processing, and memory that the processor uses as a work area for data processing.

[0017] The data processing unit 10 is a functional block that is realized by a processor executing a reflector placement determination program 29 (hereinafter also simply referred to as program 29), which will be described later. In this embodiment, the data processing unit 10 is provided as a software functional block. Each functional block in the data processing unit 10 will be described later.

[0018] The auxiliary storage device 20 is a non-volatile storage device that stores an operating system (OS), various control programs, data generated by the programs, etc., and is configured, for example, by a flash memory, an eMMC (embedded multi media card), an SSD (solid state drive), etc. The various types of data stored in the auxiliary storage device 20 will be described later.

[0019] The input unit 31 may be configured with, for example, a mouse or a keyboard, and the display unit 32 may be configured with, for example, a liquid crystal display or an organic EL display. The communication I / F unit 33 transmits and receives data to and from external devices via a wired or wireless network. The communication I / F unit 33 may be configured with various wired or wireless connections such as Ethernet (registered trademark), Wi-Fi (registered trademark), and Bluetooth (registered trademark). The input unit 31 and the display unit 32 may be integrated into a touch panel display device.

[0020] <Data Processing Unit> The following describes each functional block in the data processing unit 10. In this embodiment, the data processing unit includes a data acquisition unit 11, an arrangement determination unit 12, and an arrangement display unit 13. To facilitate understanding of the data processing, in the following description of each of these functional blocks, correspondence with the procedures illustrated in Figures 6 to 14 is indicated in parentheses.

[0021] The data acquisition unit 11 acquires various data used to determine the placement of the reflectors. In this embodiment, the data acquisition unit 11 acquires placement information for the multiple walls that partition the space, radio wave transmission start points (S1, S2) and target reception points (G1, G2) set within the space, and the radio wave transmission start direction. The placement information for the multiple walls that partition the space is wall placement data 21, which will be described later.

[0022] The placement determination unit 12 determines the placement of multiple reflectors on the wall based on the wall placement information, the transmission start points (S1, S2), the target reception points (G1, G2), the radio wave transmission start direction, and the radio wave reflection conditions at each reflector. The reflection conditions of the reflectors are specular reflection and polarized reflection shown in FIG. 2, which will be described later. In this embodiment, specular reflection is referred to as the first reflection condition, and polarized reflection is referred to as the second reflection condition.

[0023] Regarding the reflector to be placed on the first sheet, the placement determination unit 12 determines the reflection conditions of the first reflector, which is the reflector to be placed on the first sheet, depending on whether or not there is an object blocking the radio waves on the straight line connecting the transmission start point (S1, S2) and the target receiving point (G1, G2).

[0024] Preferably, when a radio wave obstruction exists on a line connecting the transmission start point (S1, S2) and the target reception point (G1, G2), the placement determination unit 12 determines the reflection condition of the first reflector, which is the first reflector to be placed, to be the second reflection condition (polarized reflection).The placement determination unit 12 then determines the interior angle (α1) of reflection at the first reflector based on the angle (B1) between the wall and the traveling direction of the reflected wave (vector B) that satisfies the second reflection condition at a first contact point (F1, F2) on the wall on which the first reflector is placed.

[0025] More preferably, the arrangement determination unit 12 determines the interior angle (α1) of reflection at the first reflector so as to minimize the angle (B1) formed between the wall and the traveling direction of the reflected wave (vector B) that satisfies the second reflection condition at the first contact point (F1, F2). In this case, the arrangement determination unit 12 can select the interior angle (α1) from a predetermined number of candidate angles. Alternatively, the arrangement determination unit 12 can select the interior angle (α1) by presenting a predetermined number of candidate angles to an operator and receiving input regarding the candidate angles from the operator.

[0026] For reflectors to be placed after the second one, the placement determination unit 12 determines the reflection condition of the mth reflector (m is a natural number greater than or equal to 2), which is the reflector to be placed as the mth one (m is a natural number greater than or equal to 2), depending on whether or not a radio wave obstruction exists on the line connecting the mth junction on the wall on which the mth reflector is placed and the target reception point (G1, G2). If a radio wave obstruction exists on the line, the placement determination unit 12 determines the reflection condition of the mth reflector to be placed as the first reflection condition (specular reflection). If no radio wave obstruction exists on the line, the placement determination unit 12 determines the reflection condition of the mth reflector to be placed as the second reflection condition (polarized reflection) and determines the interior angle (α2) of reflection at the mth reflector so that the reflected wave that satisfies the second reflection condition at the mth junction reaches the target reception point (G1, G2). In this case, the placement determination unit 12 can select the interior angle (α2) from a predetermined number of candidate angles. Alternatively, the arrangement determination unit 12 can select the interior angle (α2) by presenting a predetermined number of candidate angles to the operator and receiving input regarding the candidate angles from the operator.

[0027] If the radio waves do not reach the target reception point (G1, G2), the placement determination unit 12 can change at least one of the transmission start direction of the radio waves from the transmission start point and the inner angle of reflection (α1, α2).

[0028] The arrangement display unit 13 displays the determined arrangement of the plurality of reflectors on the wall, for example, on the display unit 32 of the device 100. An example of the display is shown in Fig. 15. The coordinates of the contact points shown in the figure are the coordinates at which the reflectors are arranged.

[0029] <Auxiliary Storage Device> A description will be given of various data stored in the auxiliary storage device 20. In this embodiment, the auxiliary storage device 20 stores wall arrangement data 21, radio wave transmission start point data 22, radio wave target reception point data 23, radio wave transmission start direction data 24, reflector data 25, and a reflector arrangement determination program 29.

[0030] The wall arrangement data 21 is arrangement information of multiple walls that divide a space. The target space in this embodiment is, for example, a space inside a building such as an office or a factory. The wall arrangement data 21 is provided, for example, as two-dimensional or three-dimensional coordinate data. The radio wave transmission start point data 22 is information on a radio wave transmission start point (S1, S2) set inside the space. The radio wave target reception point data 23 is information on a radio wave target reception point (G1, G2) set inside the space. The radio wave transmission start direction data 24 is information on the radio wave transmission start direction.

[0031] In this embodiment, the data 21, 22, and 23 are provided as two-dimensional coordinate data, and the data 24 is provided as vector information using the two-dimensional coordinate data.

[0032] The reflector data 25 is data related to a reflector to be placed on a wall in the space. The reflector data 25 includes data related to the type of reflector and data related to the interior angle of reflection. The data related to the type of reflector is information that distinguishes between specular reflection and polarized reflection, which are shown in FIG. 2 to be described later, as the manner in which radio waves are reflected on the surface of the reflector. The data related to the interior angle of reflection is data related to variations in the interior angle α of reflection when the type of reflector is polarized reflection. An example of the data related to the interior angle α of reflection is shown in Table 1. In this embodiment, when a reflector whose reflection condition is polarized reflection is placed on a wall in the space, six types of interior angle α of reflection shown in Table 1 can be selected.

[0033]

[0034] The wall arrangement data 21, radio wave transmission start point data 22, radio wave target reception point data 23, radio wave transmission start direction data 24, and reflector data 25 are acquired, for example, via the input unit 31 or the communication I / F unit 33, and stored in the auxiliary storage device 20. In this embodiment, the wall arrangement data 21 is acquired from an external server device 90 via the communication I / F unit 33 and the network 99. The radio wave transmission start point data 22, radio wave target reception point data 23, and radio wave transmission start direction data 24 are input by the operator of the device 100 via the input unit 31. The reflector data 25 is stored in advance in the auxiliary storage device 20.

[0035] FIG. 2 is a diagram illustrating the types of reflectors to be placed on walls in a space. (A) shows the case where radio waves are specularly reflected (also called regular reflection) on the surface of the reflector, and (B) shows the case where radio waves are polarizedly reflected on the surface of the reflector. The internal angle of reflection α is given by the sum of the angle of incidence θ1 and the angle of reflection θ2. The symbol n in the figure indicates the normal to the surface of the reflector. As shown in (A), when a reflector that specularly reflects radio waves on its surface is used, the angle of incidence θ1 and the angle of reflection θ2 are equal. In contrast, as shown in (B), when a reflector that polarizedly reflects radio waves on its surface is used, the angle of incidence θ1 and the angle of reflection θ2 can be made different. For example, a radio wave reflector described in International Publication No. 2023 / 127710 can be used as a reflector that specularly reflects radio waves on its surface as shown in (A). For example, a reflector that polarizedly reflects radio waves on its surface as shown in (B) can be used as a reflector described in Patent Document 1.

[0036] With reference to Figure 2, the reason for adopting not only specular reflection but also polarized reflection as the type of reflectors placed on the walls of a space in one embodiment of the present invention will be explained. As shown in Figure 2, the larger the reflection angle θ2, the fewer the number of times the radio waves are reflected within the space, allowing the radio waves to travel farther. In other words, by selectively using specular reflection and polarized reflection depending on the magnitude of the incident angle θ1, it is possible to reduce the number of reflectors placed on the walls of the space and allow the radio waves to travel farther while maintaining the strength of the radio waves.

[0037] The reflector placement determination program 29 is a computer program for implementing the respective functional blocks 11 to 13 in the data processing unit 10 by software. The program 29 can be installed in the device 100 via a network 99 such as the Internet connected by the communication I / F unit 33. Alternatively, the program 29 can be installed in the device 100 by having the device 100 read a computer-readable, non-transitory, tangible recording medium, such as a memory card, on which the program 29 is recorded.

[0038] [Processing Procedure] Figures 3 to 5 are flowcharts for explaining the procedure of a method for determining the placement of reflectors according to one embodiment of the present invention. Figures 6 to 14 are plan views of a target space for which the placement of reflectors is to be determined using a method according to one embodiment of the present invention. These plan views show how radio waves are reflected within the space in accordance with each step of the flowchart.

[0039] Hereinafter, a procedure for determining the placement of reflectors by a method according to one embodiment of the present invention will be described with reference to the flowcharts of FIGS. 3 to 5 and the plan views of FIGS.

[0040] In step S1, the arrangement information of the multiple walls that divide the space, the radio wave transmission start points (S1, S2) and target reception points (G1, G2) set within the space, and the radio wave transmission start direction are acquired.

[0041] As shown in FIG. 6 , in this embodiment, coordinates (J1, J2), (K1, K2), (L1, L2), (M1, M2), (N1, N2), (O1, O2), and (P1, P2) are given as arrangement information for multiple walls that partition a space. The coordinates (0, 0) shown in the corner of the figure are the origin of the coordinates. Multiple line segments connecting the coordinates (0, 0), (J1, J2), (P1, P2), and (O1, O2) represent multiple walls that partition the space within the building. Similarly, multiple line segments connecting the coordinates (K1, K2), (L1, L2), (N1, N2), and (M1, M2) represent multiple walls that partition the space within the building.

[0042] In this embodiment, the space enclosed by the four coordinates (0,0), (J1,J2), (P1,P2), and (O1,O2) is an office space, and radio waves propagate unobstructed within this space, except for obstructions described below. The space enclosed by the four coordinates (K1,K2), (L1,L2), (N1,N2), and (M1,M2) is a building structure such as a pillar, which blocks radio wave propagation.

[0043] 6 illustrates the coordinates (S1, S2) of the radio wave transmission start point and the coordinates (G1, G2) of the radio wave target reception point. In the figure, the radio wave transmission start direction is indicated by an arrow from the coordinates (S1, S2). When viewed from the transmission start point (S1, S2), the target reception point (G1, G2) is blocked by a radio wave shield, and the target reception point (G1, G2) is located in a radio wave blind zone. In this embodiment, location information of multiple walls that partition the space is acquired from an external server device 90, and the coordinates (S1, S2) of the radio wave transmission start point, the coordinates (G1, G2) of the radio wave target reception point, and the radio wave transmission start direction are input by an operator of the device 100 via the input unit 31.

[0044] In step S2, the reflection conditions of the first reflector, which is the first reflector to be arranged, are determined. Fig. 4 is a flowchart showing the details of step S2 shown in Fig. 3.

[0045] As shown in FIG. 7, in step S21, a straight line (shown as a dashed line in the figure) is drawn between the transmission start point (S1, S2) and the target reception point (G1, G2), and in step S22, it is determined whether or not there is an object blocking the radio waves on this straight line (dashed line).

[0046] If a radio wave shield is present in step S22 (Yes), the reflection condition of the first reflector, which is the first reflector to be placed, is determined to be the second reflection condition (polarized reflection) in step S23. Subsequently, as shown in Fig. 8, the first contact points (F1, F2) on the wall on which the first reflector is to be placed are determined in step S24, and the interior angle (α1) of reflection at the first reflector is determined in step S25, as shown in Fig. 9.

[0047] The interior angle (α1) of reflection at the first reflector is determined based on the angle (B1) formed between the wall and the traveling direction of the reflected wave (vector B) that satisfies the second reflection condition at the first contact point (F1, F2) on the wall where the first reflector is located, as shown in Fig. 9. More preferably, the interior angle (α1) of reflection at the first reflector is determined so as to minimize the angle (B1) formed between the wall and the traveling direction of the reflected wave (vector B) that satisfies the second reflection condition at the first contact point (F1, F2).

[0048] In this case, the interior angle (α1) of reflection at the first reflector can be selected from a predetermined plurality of candidate angles exemplified in Table 1. Alternatively, the interior angle (α1) can be selected by presenting a predetermined plurality of candidate angles exemplified in Table 1 to an operator and receiving input regarding the candidate angles from the operator.

[0049] If no radio wave obstruction exists in step S22 (No), the series of procedures shown in the flowcharts of Figures 3 to 5 ends. If no radio wave obstruction exists on the line connecting the transmission start point (S1, S2) and the target reception point (G1, G2), radio waves can be transmitted and received directly between the transmission start point (S1, S2) and the target reception point (G1, G2), and there is no need to determine the placement of a reflector.

[0050] In steps S3 and S4, for the second and subsequent reflectors, the contact point on the wall where the reflector is to be placed and the reflection conditions of the reflector are determined. Hereinafter, the second reflector to be placed is referred to as the second reflector, and the contact point on the wall where the second reflector is to be placed is referred to as the second contact point. Similarly, the mth reflector (m is a natural number of 2 or greater) is referred to as the mth reflector, and the contact point on the wall where the mth reflector is to be placed is referred to as the mth contact point.

[0051] In step S3, the m-th tangent point on the wall of the m-th reflector is determined. As shown in Fig. 9, the second tangent point (R1, R2) on the wall where the second reflector is disposed is determined from the traveling direction of the reflected wave (vector B) that satisfies the second reflection condition at the first tangent point (F1, F2) on the wall, which was referenced in step S25, and the arrangement information of the walls that partition the space. The m-th tangent point on the wall where the m-th reflector is disposed is determined in the same manner as the second tangent point on the wall where the second reflector is disposed.

[0052] In step S4, the reflection conditions of the m-th reflector are determined. Fig. 5 is a flowchart showing the details of step S4 shown in Fig. 3. Note that Figs. 10 to 13, which will be described later, show an example in which the second reflector is disposed at the second contact point (R1, R2). When the m-th reflector is disposed at the m-th contact point, the reflection conditions are determined in the same way as when the second reflector is disposed at the second contact point.

[0053] As shown in FIG. 10, in step S41, the mth contact point on the wall of the mth reflector is connected to the target receiving point (G1, G2) by a straight line (shown by a dashed line in the figure), and in step S42, it is determined whether or not there is an object blocking the radio waves on this straight line (dashed line).

[0054] If no radio wave obstruction is present in step S42 (No), the reflection condition of the mth reflector located at the mth junction is determined to be the second reflection condition (polarized reflection) in step S43A. Subsequently, as shown in FIG. 11 , the interior angle of reflection (α2) at the mth reflector is determined in step S44A so that the reflected wave that satisfies the second reflection condition at the mth junction reaches the target receiving point (G1, G2). The interior angle of reflection (α2) is selected from a predetermined number of candidate angles shown in Table 1.

[0055] On the other hand, as shown in Fig. 12, if a radio wave obstruction is present in step S42 (Yes), in step S43B, the reflection condition of the mth reflector to be placed at the mth junction is determined to be the first reflection condition (specular reflection). Note that in Fig. 12, for the sake of explanation, the positions of the target reception points (G1, G2) are shifted from the positions shown in Fig. 11. In other words, if a radio wave obstruction is present between the mth junction on the wall of the mth reflector and the target reception point (G1, G2), a specular reflection reflector is placed at the mth junction instead of a polarized reflection reflector, as shown in Fig. 13, and radio waves are propagated to the target reception point (G1, G2).

[0056] 13 , because there are radio wave obstructions between the second junction (R1, R2) and the third junction (T1, T2) and the target reception point (G1, G2), specular reflectors are placed at the second junction (R1, R2) and the third junction (T1, T2). In contrast, there is no radio wave obstruction between the fourth junction (U1, U2) and the target reception point (G1, G2). Therefore, a polarized reflector is placed at the fourth junction (U1, U2), and the interior angle (α2) of polarized reflection at the fourth junction (U1, U2) is determined so that the signal reaches the target reception point (G1, G2).

[0057] Regarding the angle of the interior angle of the polarized reflection to be set at the fourth contact point (U1, U2), if there is no suitable angle among the multiple candidate interior angles exemplified in Table 1 and the radio waves do not reach the target receiving point (G1, G2), a recalculation can be performed, for example, as outlined in Figure 14.

[0058] In the recalculation example shown in FIG. 14 , by changing at least one of the radio wave transmission start direction and the reflection interior angle (α1, α2), the position of the reflector is recalculated so that the radio waves reach the target reception point (G1, G2). In FIG. 14 , the dashed lines indicate the contact points on the wall and the reflection conditions before recalculation, when the radio waves do not reach the target reception point (G1, G2). The solid lines indicate the contact points on the wall and the reflection conditions when the radio waves reach the target reception point (G1, G2) after recalculation. In the example shown in FIG. 14 , the radio wave transmission start direction is changed and the coordinates of the first contact point (F1, F2) are offset by (0, γ), so that the radio waves reach the target reception point (G1, G2). Note that in the recalculation described above, the reflection interior angle may have multiple angles. That is, for each of the reflection interior angles α1 and α2 shown in FIG. 14 and FIG. 13 , six types of reflection interior angles α as exemplified in Table 1 can be selected for recalculation.

[0059] In step S5, it is determined whether the radio waves have reached the target reception points (G1, G2). If the radio waves have reached the target reception points (G1, G2) (Yes in S5), in step S6, the contact points on the walls where the determined reflectors will be placed and the reflection conditions are displayed, as shown in Figure 15, and the series of procedures is terminated.

[0060] If the radio waves have not reached the target reception points (G1, G2) (No in S5), the process proceeds to step S7, where preparations are made to execute the procedure shown in the flowchart for the (m+1)th reflector to be placed next, and the process is repeated from step S3. Thereafter, the process is repeated from step S3 until the radio waves reach the target reception points (G1, G2) or until a predetermined upper limit number of times is reached.

[0061] As described above, according to one embodiment of the present invention, it is possible to easily determine the installation position of the reflector to allow radio waves to reach blind areas.

[0062] [Other Embodiments] Although the present invention has been described above with reference to specific embodiments, the present invention is not limited to the above-described embodiments.

[0063] 16 and 17 are diagrams illustrating a target space for which a reflector arrangement is to be determined by a method according to another embodiment of the present invention, in which Fig. 16 is a schematic perspective view of the target space, and Fig. 17 is a side view of the target space.

[0064] In the above-described embodiment, the partitions that divide the space are walls, but the type of partition is not limited to walls. In other embodiments, as described with reference to Figures 16 and 17, the installation position of the reflector can also be determined assuming that the partitions that divide the space include a ceiling, floor, and walls. In the above-described embodiment, the radio wave transmission start points (S1, S2) and the target reception points (G1, G2) are set on the same floor (e.g., the first floor) of the building illustrated in Figure 16. However, in other embodiments, the radio wave transmission start points (S1, S2) and the target reception points (G1, G2) can be set on multiple floors (e.g., the first and second floors) within the building illustrated in Figure 16. In this case, the space for which the placement of the reflector is to be determined can be a plane that includes the height direction (Z-axis direction) within the building, as illustrated in Figure 17.

[0065] The arrangement information of the multiple partitions that partition the space in the example shown in Figure 17 will be described. The coordinate (0,0) shown in the corner of the figure is the origin of the coordinate system. The space surrounded by the four coordinates (0,0), (O1, O2), (P1, P2), and (J1, J2) is a space within a building with multiple floors, and radio waves propagate unobstructed within this space except for the partitions described below.

[0066] The line segment connecting the coordinates (0,0) and (O1,O2) represents the first floor, which divides the space within the building. The line segment connecting the coordinates (J1,J2) and (P1,P2) represents the second floor ceiling, which divides the space within the building. The line segment connecting the coordinates (C1,C2) and (D1,D2) represents the first floor ceiling or second floor floor, which divides the space within the building. The line segment connecting the coordinates (0,0) and (C1,C2), the line segment connecting the coordinates (C1,C2) and (J1,J2), the line segment connecting the coordinates (O1,O2) and (E1,E2), and the line segment connecting the coordinates (E1,E2) and (P1,P2) each represent a wall, which divides the space within the building. The line segment connecting the coordinates (D1, D2) and (E1, E2) represents an area where there is no ceiling on the first floor or no floor on the second floor (for example, an atrium or staircase), and radio waves propagate between the first and second floors without being obstructed through this area.

[0067] In the above embodiment, as exemplified in Figures 6 to 14, both specular reflection and polarized reflection shown in Figure 2 can be selected as the manner in which radio waves are reflected from the surface of a reflector, but it is not necessarily necessary to use both of these manners when determining the placement of a reflector. The placement of a reflector can also be determined using only specular reflection, without using polarized reflection, as the manner in which radio waves are reflected from the surface of a reflector. In this case, the recalculation step outlined in Figure 14 is applied as appropriate.

[0068] The coordinates of the radio wave transmission start point (S1, S2) and the target reception point (G1, G2) do not necessarily have to be treated as the coordinates of a single point; these coordinates can be treated as coordinates having an area of ​​a predetermined size around them.

[0069] Areas in the space where radio waves should not be received may be set as pseudo walls in the wall placement information (wall placement data 21). For example, if it is desired to intentionally set a radio wave blind area in an area on a line connecting the radio wave transmission start point (S1, S2) and the target reception point (G1, G2), it is advisable to set such pseudo wall information. This makes it possible to set, for example, a secret area in the space where data can be transmitted and received.

[0070] The wall layout information (wall layout data 21) may be reduced according to a predetermined scale, and the layout of the reflectors may be determined using such reduced wall layout information, thereby reducing the computational load on the device 100.

[0071] In the above-described embodiment, the placement of reflectors on walls in a space is determined for a space inside a building such as an office or a factory, but the target space is not limited to the inside of a building. For example, if wall placement information (wall placement data 21) is created so as to place pseudo walls, the placement of reflectors can also be determined for an outdoor space.

[0072] In the above embodiment, the reflector arrangement determination device 100 is realized as an integrated device, but the device 100 does not need to be an integrated device, and the processor, memory, auxiliary storage device 20, etc. may be located in different locations and connected to each other via a network. The input unit 31 and the display unit 32 also do not necessarily need to be located in one place, and may be located in different locations and connected to each other so as to be able to communicate with each other via a network.

[0073] In the above embodiment, the functional blocks 11 to 13 constituting the data processing unit 10 are realized by software, but some or all of these functional blocks 11 to 13 may be realized as hardware. The processing of the functional blocks 11 to 13 constituting the data processing unit 10 does not need to be performed by a single processor, but may be distributed among multiple processors. Some or all of the functions of the data processing unit 10 and the data items in the auxiliary storage device 20 may be cloud-based on an external server device 90 connected via the communication I / F unit 33.

[0074] 10 Data processing unit 11 Data acquisition unit 12 Placement determination unit 13 Placement display unit 13 Functional block 20 Auxiliary storage device 21 Wall placement data 22 Radio wave transmission start point data 23 Radio wave target reception point data 24 Radio wave transmission start direction data 25 Reflector data 29 Reflector placement determination program 31 Input unit 32 Display unit 33 Communication interface unit (communication I / F unit) 90 Server device 99 Network 100 Reflector placement determination device

Claims

1. A device for determining the placement of reflectors, comprising: an acquisition unit that acquires placement information of a plurality of partitions that partition a space, a transmission start point and a target reception point of a radio wave set within the space, and a transmission start direction of the radio wave, and a determination unit that determines the placement of the plurality of reflectors on the partitions based on the placement information of the partitions, the transmission start point, the target reception point, the transmission start direction of the radio wave, and the reflection conditions of the radio wave at each reflector, wherein the reflection conditions include the following first reflection condition: First reflection condition: Reflection at the reflector satisfies the incidence angle θ1 = reflection angle θ2.

2. The device according to claim 1, wherein the reflection conditions further include the following second reflection condition: Second reflection condition: reflection at the reflector satisfies an angle of incidence θ1≠an angle of reflection θ2.

3. The device described in claim 2, wherein, when an object blocking the radio waves is present on a straight line connecting the transmission start point and the target receiving point, the determination unit determines the reflection condition of the first reflector, which is the first reflector to be placed, to be the second reflection condition, and determines the interior angle of reflection at the first reflector based on the angle between the partition and the traveling direction of the reflected wave that satisfies the second reflection condition at a first contact point on the partition on which the first reflector is placed.

4. The device described in claim 3, wherein the determination unit determines the interior angle of the reflection at the first reflector so as to minimize the angle between the direction of travel of the reflected wave that satisfies the second reflection condition at the first contact point and the partition body.

5. The apparatus of claim 3, wherein the determining unit selects the interior angle from a predetermined plurality of candidate angles.

6. The device of claim 3, wherein the determination unit selects the interior angle by presenting a predetermined number of candidate angles to an operator and accepting input regarding the candidate angles from the operator.

7. The device described in claim 3, wherein the determination unit determines the reflection condition of the mth reflector (m is a natural number equal to or greater than 2), which is the reflector to be arranged mth, depending on whether or not an object blocking the radio waves is present on a straight line connecting the mth junction on the partition body on which the mth reflector is arranged and the target receiving point.

8. The device according to claim 7, wherein, when an object blocking the radio waves is present on the straight line, the determination unit determines the reflection condition of the mth reflector to be placed to be the first reflection condition.

9. The device described in claim 7, wherein, when there is no obstruction to the radio wave on the straight line, the determination unit determines the reflection condition of the mth reflector to be placed to be the second reflection condition, and determines the interior angle of reflection at the mth reflector so that a reflected wave that satisfies the second reflection condition at the mth junction reaches the target receiving point.

10. The apparatus of claim 9, wherein the determiner selects the interior angle from a predetermined plurality of candidate angles.

11. The device according to claim 1, wherein the determination unit changes at least one of the transmission start direction of the radio wave from the transmission start point and the inner angle of the reflection if the radio wave does not reach the target reception point.

12. The apparatus of claim 1, wherein the compartment includes a wall.

13. The apparatus of claim 1, wherein the compartment includes a ceiling, a floor and walls.

14. A method for determining the arrangement of reflectors, comprising the steps of: acquiring arrangement information of a plurality of partitions that divide a space, a transmission start point and a target reception point of a radio wave set within the space, and a transmission start direction of the radio wave; and determining the arrangement of the plurality of reflectors on the partitions based on the arrangement information of the partitions, the transmission start point, the target reception point, the transmission start direction of the radio wave, and the reflection conditions of the radio wave at each reflector, wherein the reflection conditions include the following first reflection condition: First reflection condition: reflection at the reflector satisfies the incidence angle θ1 = reflection angle θ2.

15. The method of claim 14, wherein the compartment comprises a wall.

16. The method of claim 14, wherein the compartment includes a ceiling, a floor and walls.

17. A program for causing a computer to function as each part of the device according to any one of claims 1 to 13.

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