Wireless communication system, management device therefor, relay device, communication control method, and communication control program

Abstract

[Problem] To provide a wireless communication system with which, even when a movable terminal device enters a radio wave dead zone, it is possible to enable a radio wave beam to reach the terminal device. [Solution] A wireless communication system 1 comprising: a movable terminal device 100; an antenna 201 for transmitting a radio wave beam that includes a communication signal to the terminal device 100; a relay device (reflection plate 202) for relaying, to the terminal device 100, the radio wave beam that is transmitted from the antenna 201; and a radio wave management server 300 for acquiring position information pertaining to the terminal device 100 and / or the relay device and controlling the antenna 201 on the basis of the position information so that the radio wave beam is transmitted toward the relay device.

Description

[Technical Field]

[0001] The present invention relates to a wireless communication system, a management device therefor, a relay device, a communication control method, and a communication control program. [Background technology]

[0002] In recent years, in the field of wireless communications, there has been a demand for the use of short wavelength radio waves such as millimeter waves and terahertz waves due to the increasing speed and capacity of wireless communications and the shortage of available frequency bands.

[0003] However, radio waves have short wavelengths, and blind spots can occur when there are obstacles or other obstacles in the way. To eliminate blind spots, there is a conventional technology that uses a reflector to reflect communication signals between a base station and a mobile terminal (Patent Document 1). This technology measures and compares the received power of a mobile terminal when the reflector reflects radio waves in a first direction and when the reflector reflects radio waves in a second direction. The direction of the reflector with the highest reception strength is then determined. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-57723 Summary of the Invention [Problem to be solved by the invention]

[0005] However, conventional technologies have the problem that it takes time to try switching the reflection direction. Furthermore, conventional technologies have the problem that the reflection direction is limited because the position of the reflector is fixed. Furthermore, conventional technologies have the problem that they cannot determine the appropriate reflection direction when the received power is close to zero and cannot be measured.

[0006] Therefore, an object of the present invention is to provide a wireless communication system, a management device, a relay device, a communication control method, and a communication control program therefor, which are capable of transmitting a radio wave beam to a mobile terminal device even if the terminal device is in a radio wave blind spot. [Means for solving the problem]

[0007] The above object of the present invention can be achieved by the following means.

[0008] (1) A mobile terminal device, an antenna that transmits a radio wave beam including a communication signal to the terminal device, a relay device that relays the radio wave beam transmitted from the antenna to the terminal device, and a management device that acquires location information of at least one of the terminal device and the relay device and controls the antenna to transmit the radio wave beam toward the relay device based on the acquired location information. the relay device is a reflector, a plurality of the reflectors are arranged in an array, and the management device selects at least one of the plurality of reflectors and causes the radio wave beam to be transmitted toward the selected reflector. Wireless communication system.

[0009] (2) The wireless communication system described in (1) above, wherein the management device acquires location information of the terminal device and location information of the relay device, moves the relay device based on the location information of the terminal device, and controls the antenna to transmit the radio wave beam toward the relay device based on the location information of the relay device.

[0010] (3) The relay device is provided in plurality, The wireless communication system described in (1) above, wherein the management device acquires location information of the terminal device, selects a relay device from among the multiple relay devices to relay the radio wave beam based on the location information of the terminal device, and controls the antenna to transmit the radio wave beam toward the selected relay device.

[0011] (4) The relay device acquires location information of the terminal device, and is capable of moving to a position where it can transmit the radio beam to the terminal device based on the location information of the terminal device and the antenna, The wireless communication system described in (1) above, wherein the management device acquires location information of the relay device and controls the antenna to transmit the radio wave beam toward the relay device based on the location information of the relay device.

[0013] ( 5 ) The management device changes the orientation of the reflector based on the position information of the terminal device. 1 ) A wireless communication system according to the present invention.

[0016] ( 6 a management device that acquires location information of at least one of a mobile terminal device and a relay device that relays a radio wave beam transmitted from an antenna to the terminal device, and controls the antenna to transmit the radio wave beam toward the relay device based on the acquired location information. The relay device is a reflector, and multiple reflectors are arranged in an array, and a management device selects at least one of the multiple reflectors and transmits the radio wave beam toward the selected reflector.

[0017] ( 7 ) acquiring location information of the terminal device and location information of the relay device, moving the relay device based on the location information of the terminal device, and controlling the antenna to transmit the radio wave beam toward the relay device based on the location information of the relay device, 6 ) A management device according to the present invention.

[0018] ( 8 ) a plurality of relay devices are provided, selecting a relay device for relaying the radio wave beam from among a plurality of relay devices based on the acquired location information of the terminal device, and controlling the antenna so as to transmit the radio wave beam toward the selected relay device ( 6 ) A management device according to the present invention.

[0019] ( 9 ) the relay device acquires location information of the terminal device, and is capable of moving to a position where it can transmit the radio wave beam to the terminal device based on the location information of the terminal device and the antenna, acquiring location information of the relay device, and controlling the antenna to transmit the radio wave beam toward the relay device based on the location information of the relay device. 6 ) A management device according to the present invention.

[0021] ( 10 ) changing the orientation of the reflector based on the position information of the terminal device, 9 ) A management device according to the present invention.

[0024] ( 11 ) A relay device that relays a radio wave beam transmitted from an antenna to a mobile terminal device, The relay device is a reflector, and a plurality of the reflectors are arranged in an array, and acquires position information of the terminal device, and moves to a position from which the radio wave beam can be transmitted to the terminal device based on the position information of the terminal device and the antenna, and transmits the radio wave beam toward at least one of the reflectors selected from the plurality of reflectors. Relay device.

[0026] ( 12 ) The orientation of the reflector is changed based on the position information of the terminal device. 1 ) The relay device described in

[0029] ( 13 ) a step (a) of acquiring location information of at least one of a mobile terminal device and a relay device that relays a radio wave beam transmitted from an antenna to the terminal device; and (b) controlling the antenna so as to transmit the radio wave beam toward the relay device based on the acquired location information. death, the relay device is a reflector, and a plurality of the reflectors are arranged in an array; In the step (b), at least one of the plurality of reflectors is selected, and the radio wave beam is transmitted toward the selected reflector. Communication control method.

[0030] ( 14 ) a plurality of relay devices are provided, The step (b) selects a relay device for relaying the radio wave beam from among a plurality of relay devices based on the acquired location information of the terminal device, and controls the antenna so as to transmit the radio wave beam toward the selected relay device. 13 ) A communication control method according to the present invention.

[0031] ( 15) the relay device acquires location information of the terminal device, and is capable of moving to a position where it can transmit the radio wave beam to the terminal device based on the location information of the terminal device and the antenna, The step (a) includes acquiring location information of the relay device; The step (b) controls the antenna so as to transmit the radio wave beam toward the relay device based on the position information of the relay device. 13 ) A communication control method according to the present invention.

[0033] ( 16 ) The step (b) changes the orientation of the reflector based on the position information of the terminal device. 13 ) A communication control method according to the present invention.

[0036] ( 17 )the above( 13 )~( 16 10. A communication control program for causing a computer to execute the communication control method according to any one of the preceding claims. [Effects of the Invention]

[0037] The present invention can change the direction of the radio wave beam to provide an optimal radio wave path based on the location information of at least one of a mobile terminal device and a relay device that relays the radio wave beam from the antenna. Therefore, according to the present invention, even if the mobile terminal device is in a radio wave blind spot, the radio wave beam can reach the terminal device. [Brief explanation of the drawings]

[0038] [Figure 1] 1 is a schematic diagram illustrating a wireless communication system according to a first embodiment. [Figure 2] 10 is a flowchart showing a procedure for implementing a communication control method by a radio wave management server. [Figure 3] 1 is a schematic diagram for explaining an incident angle and a reflection angle on a reflector. FIG. [Figure 4] FIG. 10 is a schematic diagram illustrating a wireless communication system according to a second embodiment. [Figure 5] FIG. 10 is a schematic diagram illustrating a wireless communication system according to a third embodiment. [Figure 6] FIG. 10 is a schematic diagram illustrating a wireless communication system according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0039] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the description of the drawings, the same elements are designated by the same reference numerals, and duplicate explanations will be omitted. Furthermore, the dimensional proportions in the drawings are exaggerated for the convenience of explanation and may differ from the actual proportions.

[0040] (Embodiment 1) FIG. 1 is a schematic diagram illustrating a wireless communication system according to the first embodiment.

[0041] 1, the wireless communication system 1 according to the first embodiment includes a terminal device 100, an antenna 201, a reflector 202, and a radio wave management server 300. Note that a radio unit (RU) that performs wireless communication with the terminal device 100, base station equipment, and the like are connected to the antenna 201, but are not shown here.

[0042] The terminal device 100 is mobile. The terminal device 100 is capable of wireless communication with a wireless unit, a base station facility, etc. For this purpose, the terminal device 100 has a wireless unit required for communication with a wireless unit, a base station facility, etc.

[0043] The terminal device 100 is, for example, an automatic guided vehicle (AGV), a mobile robot, an air drone, an underwater or surface drone, etc. These terminal devices 100 may be autonomously moving devices or remotely controlled devices. In addition, the terminal device 100 may be a smartphone or a tablet computer. The device may be a portable device such as a computer that can be carried by a person.

[0044] The antenna 201 transmits a beamformed radio wave beam. The radio wave beam includes a communication signal to the terminal device 100. The radio wave beam is, for example, a radio wave with a short wavelength such as a millimeter wave or a terahertz wave. Beamforming is a technology that forms a directional pattern on the antenna 201 by controlling the phase of multiple antenna elements, for example, and increases or decreases the gain of the antenna 201 in a specific direction. Therefore, even if the antenna 201 is fixed, it can transmit a directional radio wave beam in a specific (arbitrary) direction. Note that the antenna 201 may be movable or rotatable. By making the antenna 201 movable or rotatable, the beamformed radio wave beam can be transmitted more efficiently in a specific (arbitrary) direction.

[0045] The reflector 202 is a relay device. The reflector 202 in the first embodiment is movable and rotatable. In the first embodiment, there is only one reflector 202.

[0046] The reflector 202 relays the radio wave beam transmitted from the antenna 201 toward the terminal device 100. The reflector 202 of the first embodiment is movable and rotatable. By moving and rotating, the reflector 202 reflects the radio wave beam emitted from the antenna 201 toward the terminal device 100.

[0047] The radio wave management server 300 is a management device. The radio wave management server 300 transmits a radio wave beam from the antenna 201 to the terminal device 100 based on the position information of the terminal device 100 and the reflector 202. The radio wave management server 300 is a computer, and controls the antenna 201 by executing a program created according to the procedure described below.

[0048] (Communication control method) FIG. 2 is a flowchart showing the procedure for implementing a communication control method by radio wave management server 300.

[0049] First, the radio wave management server 300 measures the position of the terminal device 100 (S101). For example, a positioning technique using ultra-wideband wireless communication (UWB (Ultra Wide Band)) is used to measure the position of the terminal device 100. In addition to this, a number of other existing techniques can also be used to measure the position of the terminal device 100, such as identifying the position by analyzing video from a surveillance camera.

[0050] Next, the radio wave management server 300 checks whether or not there is an obstacle 500 on the path of the radio wave beam between the antenna 201 and the terminal device 100 (S102). If there is an obstacle 500, a radio wave blind spot 510 occurs as seen from the antenna 201, as shown in Fig. 1. If such a radio wave blind spot 510 exists, the millimeter waves or terahertz waves transmitted from the antenna 201 do not directly reach the terminal device 100.

[0051] To check for the obstacle 500, a positioning technology such as LiDAR (Laser Imaging Detection and Ranging) is used. When LiDAR is used, the radio wave management server 300 compares the distance from the antenna 201 to the positioned object with the distance from the antenna 201 to the terminal device 100 to determine whether or not there is an obstacle 500. The distance from the antenna 201 to the terminal device 100 is obtained from the position information of the terminal device 100 acquired in step S101. A camera may also be used to check for the obstacle 500. When a camera is used, the camera is installed at the position of (or in the vicinity of) the antenna 201. The radio wave management server 300 determines whether or not there is an obstacle 500 based on whether or not the terminal device 100 is visible from the antenna 201 from the camera image (which may be a still image). To determine whether or not there is an obstacle 500 from the camera image, object detection using AI (Artificial Intelligence), for example, may be used.

[0052] If it is determined in step S102 that no obstacle 500 exists (S102: NO), the radio wave management server 300 then calculates the emission direction and focal length of the radio wave beam transmitted from the antenna 201 (S103). At this stage, no obstacle 500 exists between the antenna 201 and the terminal device 100. This state is sometimes referred to as a line of sight (LOS) being ensured from the antenna 201 to the terminal device 100.

[0053] The radio wave management server 300 calculates the emission direction and focal length of the radio wave beam to the terminal device 100 based on the location information of the terminal device 100 acquired in S101. The emission direction and focal length of the radio wave beam to the terminal device 100 can be found, for example, by mapping the positions of the antenna 201 and the terminal device 100 onto a two-dimensional or three-dimensional coordinate system. The emission direction of the radio wave beam is the direction of the terminal device 100 as seen from the antenna 201 in the mapped coordinate system. The focal length of the radio wave beam is the distance from the antenna 201 to the terminal device 100 in the mapped coordinate system.

[0054] The emission direction and focal length of the radio wave beam may be calculated taking into account the radio wave conditions, as will be described later.

[0055] Next, the radio wave management server 300 causes the antenna 201 to transmit (emit) the radio wave beam that has been beamformed to have the calculated emission direction and focal length (S105).

[0056] Thereafter, the radio wave management server 300 determines whether or not the processing has ended (S106). If the processing has not ended (S106: NO), the radio wave management server 300 returns to S101 and continues the processing. This makes it possible to track the position of the moving terminal device 100 and always transmit the radio wave beam in the optimal direction. On the other hand, if the processing has ended (S106: YES), the radio wave management server 300 ends the processing. The processing is ended, for example, in response to an end instruction from the user.

[0057] On the other hand, if it is determined in step S102 that an obstacle 500 is present (S102: YES), the radio wave management server 300 then calculates the position and orientation of the reflector 202, and the emission direction and focal length of the radio wave beam to the reflector 202, based on the position information acquired in S101 and the position information of the obstacle 500 (S104).

[0058] At this stage (S104), an obstacle 500 exists between the antenna 201 and the terminal device 100. Therefore, the radio wave management server 300 first calculates the position and orientation of the reflector 202 so that the radio wave beam from the antenna 201 is relayed by the reflector 202 and reaches the terminal device 100. The position and orientation of the reflector 202 are calculated, for example, using a two-dimensional or three-dimensional coordinate system as follows.

[0059] The radio wave management server 300 first maps the positions of the antenna 201, the terminal device 100, and the obstacle 500 in a two-dimensional or three-dimensional coordinate system. Next, from the mapped positions of the antenna 201, the terminal device 100, and the obstacle 500, the radio wave management server 300 calculates the position of the reflector 202 such that the obstacle 500 does not exist on either the path from the antenna 201 to the reflector 202 or on the path from the reflector 202 to the terminal device 100.

[0060] There are many positions of the reflector 202 where no obstacle 500 exists on either the path from the antenna 201 to the reflector 202 or on the path from the reflector 202 to the terminal device 100. Therefore, the position of the reflector 202 that is actually determined may be, for example, the position that minimizes the moving distance from the current position of the reflector 202. This reduces the time required for the reflector 202 to move. Alternatively, the position of the reflector 202 that is determined may be, for example, the position that minimizes the total distance between the distance from the antenna 201 to the reflector 202 and the distance from the reflector 202 to the terminal device 100 (the position that provides the shortest distance).

[0061] Next, the radio wave management server 300 calculates the orientation of the reflector 202, whose position has been determined, at which the angle of incidence and the angle of reflection of the radio wave beam are the same.

[0062] 3 is a schematic diagram for explaining the angle of incidence and the angle of reflection on the reflector 202. The angle of incidence α and the angle of reflection β are angles relative to the normal h of the reflector 202, as shown in FIG.

[0063] Radio wave beams with short wavelengths, such as millimeter waves and terahertz waves, tend to travel in a straight line (they hardly diverge). For this reason, as shown in Fig. 3, the radio wave beam can reach the terminal device 100 most efficiently when the relationship of incident angle α = reflection angle β holds.

[0064] Next, the radio wave management server 300 calculates the emission direction of the radio wave beam. The emission direction of the radio wave beam is the direction of the positioned reflector 202 as viewed from the antenna 201.

[0065] Next, the radio wave management server 300 calculates the focal length of the radio wave beam, which is the sum (a+b) of the distance a from the antenna 201 to the positioned reflector 202 and the distance b from the reflector 202 to the terminal device 100, as shown in Fig. 3 .

[0066] Also at this stage (S104), the emission direction and focal length of the radio wave beam may be calculated taking into account the radio wave conditions.

[0067] Next, the radio wave management server 300 causes the antenna 201 to transmit a radio wave beam that has been beamformed to have the calculated emission direction and focal length (S105).

[0068] Thereafter, the radio wave management server 300 determines whether or not the processing has ended (S106). If the processing has not ended (S106: NO), the radio wave management server 300 returns to S101 and continues processing. This makes it possible to track the position of the moving terminal device 100 and always transmit the radio wave beam in the optimal direction. On the other hand, if the processing has ended (S106: YES), the radio wave management server 300 ends the processing.

[0069] In the first embodiment, by using the reflector 202, it is possible to ensure that the radio wave beam reaches the terminal device 100 via an optimal route that avoids the obstacle 500. In particular, in the first embodiment, it is possible to move the reflector 202 and change the orientation and focal length of the reflector 202. Therefore, in the first embodiment, even if the terminal device 100 moves, it is possible to avoid the obstacle 500, if any, and ensure that the radio wave beam reaches the terminal device 100.

[0070] Here, a method for checking the radio wave conditions will be described.

[0071] The radio wave strength of the radio wave beam may decrease due to interference between the beams. In addition, the radio wave conditions may also change due to the movement of the radio wave beam emitted from the antenna 201 itself. For this reason, the radio wave conditions are constantly changing. When determining the direction and focal length, it is preferable to take into consideration the surrounding radio wave conditions when the radio wave beam is emitted from the antenna 201 during calculation.

[0072] A relatively simple method for checking the radio wave conditions is, for example, to simply estimate the radio wave conditions around the target terminal device 100 or reflector 202 using only information such as the emission direction and focal length of the multiple beams emitted by the antenna 201 itself.

[0073] Another method for checking radio wave conditions is to estimate them based on radio wave strength information obtained by placing multiple measuring devices in the target wireless area. In this method, for example, radio wave beams are emitted into the wireless area with different emission directions and focal lengths, and the measuring devices measure the radio wave strength. The measurement results are used to create a radio wave heat map. Heat maps are created for each change in the radio wave beam emission direction and focal length. Machine learning is then performed using the multiple heat maps created to create an AI model. Then, when actually estimating radio wave conditions, the radio wave strength obtained from the measuring devices at that time is input into the AI ​​model to estimate the current radio wave conditions.

[0074] (Embodiment 2) FIG. 4 is a schematic diagram illustrating a wireless communication system 1 according to the second embodiment.

[0075] As shown in Fig. 4, the wireless communication system 1 according to the second embodiment has a reflector array 204 in which a plurality of reflectors 2021 to 2035 are arranged in an array. The reflector array 204 is a relay device. The individual reflectors 2021 to 2035 are rotatable. The reflector array 204 of the second embodiment does not move. The configuration other than the reflector array 204 is the same as that of the wireless communication system 1 of the first embodiment, and therefore a description thereof will be omitted.

[0076] The basic operation of the radio wave management server 300 in the second embodiment is the same as that in the first embodiment. Therefore, the communication control method by the radio wave management server 300 is the same as the control procedure shown in Fig. 2. However, step S104 is a control corresponding to the reflector array 204. Therefore, only step S104 in the second embodiment will be described here, and descriptions of the other steps will be omitted.

[0077] Furthermore, in the second embodiment, the position of the reflector array 204 is fixed. Therefore, the position of the reflector array 204 and the positions of the individual reflectors 2021 to 2035 are stored in advance in the radio wave management server 300. Therefore, it is not necessary to measure the positions of the reflectors 2021 to 2035, which are relay devices.

[0078] In step S104 in the second embodiment, the radio wave management server 300 first maps the positions of the antenna 201, the terminal device 100, and the obstacle 500 onto a two-dimensional or three-dimensional coordinate system, as in the first embodiment.

[0079] Next, based on the positions of the antenna 201, the terminal device 100, and the obstacle 500, the radio wave management server 300 selects one reflector from the reflector array 204 that is located in a position where there is no obstacle 500 on either the path from the antenna 201 to the reflectors 2021 to 2035, or on the path from the reflectors 2021 to 2035 to the terminal device 100.

[0080] There may be a plurality of reflectors that do not have an obstacle 500 on either the path from the antenna 201 to the reflectors 2021 to 2035 or from the reflectors 2021 to 2035 to the terminal device 100. In such a case, the one reflector that is selected is, for example, the reflector that has the shortest total distance (shortest distance) between the distance from the antenna 201 to the reflectors 2021 to 2035 and the distance from the reflectors 2021 to 2035 to the terminal device 100. One reflector that can be selected may be, for example, a reflector that does not require any change in orientation from a previously used reflector, or one that requires a smaller rotation angle.

[0081] Thereafter, similarly to the first embodiment, the radio wave management server 300 calculates the orientation and focal length of the selected reflector.

[0082] Here, a case will be described where the terminal device 100 has moved. Here, it is assumed that the terminal device 100 has moved from position A to position B in FIG.

[0083] First, when the terminal device 100 is at position A, the radio wave management server 300 selects one reflector 2028 from the reflector array 204. The reflector 2028 is located in a position where it can avoid the obstacle 500 and relay the radio wave beam to the terminal device 100 at position A. Then, the radio wave management server 300 adjusts the orientation and focal length of the reflector 2028 and transmits the radio wave beam so that the radio wave beam from the antenna 201 reaches the terminal device 100 at position A.

[0084] Thereafter, when the terminal device 100 moves to position B, the radio wave management server 300 selects one reflector 2035 from the reflector array 204. The reflector 2035 is positioned so that it can avoid the obstacle 500 and relay the radio wave beam to the terminal device 100 at position B. The radio wave management server 300 then adjusts the orientation and focal length of the reflector 2035 and transmits the radio wave beam so that the radio wave beam from the antenna 201 reaches the terminal device 100 at position B.

[0085] In the second embodiment, by using the reflector array 204, it is possible to ensure that the radio wave beam reaches the terminal device 100 via an optimal route that avoids the obstacle 500. Furthermore, in the second embodiment, when the terminal device 100 moves, the radio wave beam can be reliably relayed to the terminal device 100 by selecting a reflector in accordance with the movement of the terminal device 100. Furthermore, in the second embodiment, since a plurality of reflectors 2021 to 2035 are arranged in an array, it is not necessary to move the reflectors. Therefore, in the second embodiment, it is possible to ensure that the radio wave beam reaches the terminal device 100 faster than in the case where the reflectors are moved.

[0086] In the second embodiment, the position of the reflector array 204 is fixed (does not move), but the present invention is not limited to this and the reflector array 204 may be movable. Also, in FIG. 4, the plurality of reflectors 2021 to 2035 are shown as being substantially spaced apart from one another, but there may be gaps between the individual reflectors that allow rotation. Also, the present invention is not limited to this and the gaps between the individual reflectors may be larger than the gap that allows rotation of the individual reflectors. Furthermore, the number of the plurality of reflectors is not limited to the 3 rows and 5 columns shown in FIG. 4 . Furthermore, the structure of the array does not have to be rectangular overall. For example, the array may have a different number of reflectors in each row.

[0087] (Embodiment 3) FIG. 5 is a schematic diagram illustrating a wireless communication system 1 according to the third embodiment.

[0088] As shown in Fig. 5, the wireless communication system 1 according to the third embodiment has a plurality of repeaters 211 and 212. The repeaters 211 and 212 are relay devices. Each of the repeaters 211 and 212 has an antenna capable of beamforming radio waves. However, the repeaters 211 and 212 according to the third embodiment are stationary. The configuration other than the repeaters 211 and 212 is the same as that of the wireless communication system 1 according to the first embodiment, and therefore a description thereof will be omitted.

[0089] Furthermore, in the third embodiment, the positions of the repeaters 211 and 212 are fixed. Therefore, the positions of the repeaters 211 and 212 are stored in advance in the radio wave management server 300. Therefore, it is not necessary to measure the positions of the repeaters 211 and 212, which are relay devices.

[0090] The basic operation of the radio wave management server 300 of the third embodiment is the same as that of the second embodiment. Therefore, the procedure for communication control by the radio wave management server 300 is also the same as the control procedure shown in Fig. 2. Therefore, in the third embodiment, in step S104, instead of selecting a reflector, the repeater 211 or 212 that can avoid the obstacles 501 and 502 and allow the radio wave beam to reach the terminal device 100 is selected.

[0091] Here, a case will be described where the terminal device 100 has moved. Here, it is assumed that the terminal device 100 has moved from position A to position B in FIG.

[0092] First, when the terminal device 100 is at position A, the radio wave management server 300 selects one repeater 211 from the multiple repeaters 211 and 212. The repeater 211 is located in a position where it can transmit a radio wave beam to the terminal device 100 at position A while avoiding the obstacle 501. The radio wave management server 300 then adjusts the emission direction and focal length of the radio wave beam transmitted from the repeater 211 so that the radio wave beam from the antenna 201 reaches the terminal device 100 at position A, and transmits the radio wave beam. The radio wave beam from the antenna 201 is beamformed so that the direction and focal length are to the repeater 211. Furthermore, the radio wave beam from the repeater 211 is beamformed so that the direction and focal length are to the terminal device 100.

[0093] Thereafter, when the terminal device 100 moves to position B, the radio wave management server 300 selects the repeater 212. The repeater 212 is located in a position where it can transmit the radio wave beam to the terminal device 100 at position B, avoiding the obstacle 502. The radio wave management server 300 then adjusts the emission direction and focal length of the radio wave beam transmitted from the repeater 212 so that the radio wave beam from the antenna 201 reaches the terminal device 100 at position B, and transmits the radio wave beam. The radio wave beam from the antenna 201 is beamformed so that the direction and focal length are to the repeater 212. In addition, the radio wave beam from the repeater 212 is beamformed so that the direction and focal length are to the terminal device 100.

[0094] In this embodiment 3, by using the repeaters 211 and 212, it is possible to ensure that the radio wave beam reaches the terminal device 100 via the optimal route that avoids obstacles. Also, in this embodiment 3, when the terminal device 100 moves, the repeaters 211 and 212 that are suitable for relaying are selected in accordance with the movement of the terminal device 100.

[0095] Furthermore, in the third embodiment, by using the repeaters 211 and 212, it is possible to make the radio wave beam reach the terminal device 100 without mechanical operations such as moving or rotating the reflector. The repeaters 211 and 212 have a higher degree of freedom in the emission direction of the radio wave beam compared to the reflector 202, and are also advantageous in terms of radio wave intensity. Therefore, the number of repeaters 211 and 212 that can be installed can be fewer than when multiple reflectors are installed.

[0096] In the third embodiment, multiple stationary repeaters 211 and 212 are used, but the present invention is not limited to this, and the multiple repeaters 211 and 212 may be movable. Also, there may be only one repeater. If there is only one repeater, it is preferable that the repeater is movable. Also, the repeaters 211 and 212 may have an omnidirectional antenna that does not support beamforming. If it does not support beamforming, the efficiency is lower than that of a radio wave beam, but it is still possible for radio waves to reach the terminal device 100. In the case of a repeater with an omnidirectional antenna, the number of repeaters to be installed may be one or more.

[0097] (Embodiment 4) FIG. 6 is a schematic diagram illustrating a wireless communication system 1 according to the fourth embodiment.

[0098] As shown in FIG. 6, the wireless communication system 1 according to the fourth embodiment has a repeater-equipped drone 220. The repeater-equipped drone 220 is a relay device. The repeater-equipped drone 220 has an antenna 201 capable of beamforming radio waves. The repeater-equipped drone 220 moves (flies) in the air. The repeater-equipped drone 220 transmits its own position to the radio wave management server 300. Therefore, the radio wave management server 300 can always grasp the position of the repeater-equipped drone 220. The configuration other than the repeater-equipped drone 220 is the same as that of the wireless communication system 1 according to the first embodiment, and therefore a description thereof will be omitted.

[0099] The basic operation of the radio wave management server 300 of embodiment 4 is the same as that of embodiment 3. Furthermore, in the procedure of the communication control method by the radio wave management server 300, in step S104, instead of selecting a repeater, the repeater-equipped drone 220 is moved to a position where the radio wave beam can reach the terminal device 100 while avoiding the moving obstacle 520. Therefore, the repeater-equipped drone 220 is moved to a position where LOS can be secured from the antenna 201 and LOS can be secured from the repeater-equipped drone 220 to the terminal device 100.

[0100] For this reason, it is preferable that the repeater-equipped drone 220 be equipped with a device for determining the positions of both the antenna 201 and the terminal device 100. The positions are determined using, for example, UWB positioning technology.

[0101] The repeater-equipped drone 220 may be equipped with a camera. The camera is used to complement UWB positioning to confirm that there are no radio wave obstructions between the antenna 201 and the drone, and between the drone and the terminal device 100 (that LOS is ensured). When a camera is equipped on the repeater-equipped drone 220, the radio wave management server 300 analyzes the video data acquired by the camera and moves the repeater-equipped drone 220 to a position where LOS can be ensured from both the antenna 201 to the repeater-equipped drone 220 and from the repeater-equipped drone 220 to the terminal device 100. This allows the repeater-equipped drone 220 to adjust its position while checking LOS for both the antenna 201 and the terminal device 100, thereby improving the accuracy and time of position adjustment compared to when using UWB alone.

[0102] The position adjustment of the repeater-equipped drone 220 is performed by the radio wave management server 300. That is, the radio wave management server 300 acquires, from the repeater-equipped drone 220, position information of the antenna 201 and the terminal device 100, and further, if an obstacle is present, position information of the obstacle. Then, similar to the first embodiment, the radio wave management server 300 moves the repeater-equipped drone 220 to a position where the radio wave beam can be relayed from the antenna 201 to the terminal device 100 while avoiding the obstacle, based on the position information of the antenna 201, the terminal device 100, and the obstacle. If the repeater-equipped drone 220 is an autonomous mobile drone, the radio wave management server 300 instructs the repeater-equipped drone 220 to move to that position by specifying the coordinates of a position where the radio wave beam can be relayed from the antenna 201 to the terminal device 100 while avoiding the obstacle.

[0103] Then, the radio wave management server 300 emits a radio wave beam from the antenna 201 in a direction and at a focal length to the repeater-equipped drone 220, and also emits (relays) a radio wave beam from the repeater-equipped drone 220 in a direction and at a focal length to the terminal device 100.

[0104] Note that some or all of the functions of the radio wave management server 300 may be performed by the repeater-equipped drone 220. For example, in order to make the radio wave beam reach the repeater-equipped drone 220, the radio wave management server 300 determines the position of the repeater-equipped drone 220 and causes the antenna 201 to emit the radio wave beam to the repeater-equipped drone 220. Meanwhile, in order to make the radio wave beam reach the terminal device 100, the repeater-equipped drone 220 determines the position of the terminal device 100 and adjusts its own position to make the radio wave beam reach the terminal device 100.

[0105] Here, as shown in FIG. 6, an example of communication with the terminal device 100 within a tunnel construction site will be described.

[0106] The terminal device 100 is attached to a construction machine working at a tunnel construction site. A repeater-equipped drone 220 flies inside the tunnel. A moving obstacle 520 also exists inside the tunnel.

[0107] The radio wave management server 300 uses UWB to determine the position of the terminal device 100 from the repeater-equipped drone 220. As a result, the radio wave management server 300 moves the repeater-equipped drone 220 to a position where it can relay a radio wave beam from the antenna 201 to the terminal device 100, avoiding obstacles. The radio wave management server 300 also checks, from the video of the camera mounted on the repeater-equipped drone 220, whether line of sight (LOS) is ensured for both the antenna 201 and the terminal device 100. If LOS is not ensured, the radio wave management server 300 analyzes the camera video and further adjusts the position of the repeater-equipped drone 220.

[0108] Positioning of the terminal device 100 by UWB is always performed, and the radio wave management server 300 moves the repeater-equipped drone 220 in accordance with the movement of the obstacle 520. As for the subsequent emission of the radio wave beam, the radio wave beam is emitted from the antenna 201 to the repeater-equipped drone 220, and the radio wave beam is then emitted (relayed) from the repeater-equipped drone 220 to the terminal device 100, as in the third embodiment.

[0109] In the fourth embodiment, by using the repeater-equipped drone 220, it is possible to ensure that the radio wave beam reaches the terminal device 100 via an optimal route that avoids obstacles. Furthermore, the repeater-equipped drone 220 can change its position more freely compared to the reflectors, reflector arrays, fixed repeaters, and the like in the other embodiments. For this reason, the fourth embodiment is suitable when a moving obstacle 520 is present.

[0110] In addition, in the fourth embodiment, one repeater-equipped drone 220 is used, but this is not limited to this, and multiple repeater-equipped drones 220 may be used.

[0111] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments.

[0112] For example, the relay device may use a combination of the reflector 202, the reflector array 204, the repeater 211 and / or 212, and the repeater-equipped drone 220. When these are used in combination, the source and destination are the repeater 211 and / or 212 and the repeater-equipped drone 220 instead of the antenna 201 and the terminal device 100, and the communication control method can be implemented in the same way as in any of the first to fourth embodiments.

[0113] The present invention is also effectively applicable to terahertz waves, which have a strong tendency to propagate in a straight line (are less likely to be diffracted).The present invention is also effectively applicable to Sub-6 5G and Wi-Fi, and is also effectively applicable to microwaves.

[0114] The program according to the present invention can also be realized by a dedicated hardware circuit. The program can also be provided on a computer-readable recording medium such as a Universal Serial Bus (USB) memory or a Digital Versatile Disc (DVD)-Read Only Memory (ROM), or it can be provided online via a network such as the Internet, regardless of the recording medium. When provided online, the program is recorded on a recording medium such as a magnetic disk in a computer connected to the network.

[0115] Furthermore, the present invention can be modified in various ways based on the configurations described in the claims, and these modifications are also within the scope of the present invention.

[0116] This application is based on Japanese Patent Application No. 2022-005451, filed on January 18, 2022, the disclosure of which is incorporated by reference in its entirety.

[0117] The following embodiments are also within the scope of the present invention: a wireless communication system as claimed in claim 1 having the features of claim 2; a wireless communication system as claimed in claim 1 having the features of claim 3; a wireless communication system as claimed in claim 1 having the features of claim 4; a wireless communication system as claimed in any one of claims 1 to 4 having the features of claim 5; a wireless communication system as claimed in claim 5 having the features of claim 6; a wireless communication system as claimed in claim 5 or 6 having the features of claim 7; a wireless communication system as claimed in any one of claims 1 to 4 having the features of claim 8; a wireless communication system as claimed in claim 9 having the features of claim 10; a wireless communication system as claimed in claim 9 having the features of claim 11; a management device as claimed in claim 9 having the features of claim 12; a management device as claimed in any one of claims 9 to 12 having the features of claim 13; a management device as claimed in claim 13 having the features of claim 14; a management device as claimed in claim 15. a management device according to claim 13 or 14; a management device according to any one of claims 9 to 12 having the features of claim 16; a management device according to claim 17 having the features of claim 18; a management device according to claim 18 having the features of claim 19; a management device according to claim 18 or 19 having the features of claim 20; a management device according to claim 17 having the features of claim 21; a communication control method according to claim 22 having the features of claim 23; a communication control method according to claim 22 having the features of claim 24; a communication control method according to any one of claims 22 to 24 having the features of claim 25; a communication control method according to claim 25 having the features of claim 26; a communication control method according to claim 25 or 26 having the features of claim 27; a communication control method according to any one of claims 22 to 24 having the features of claim 28; a communication control program according to any one of claims 22 to 28 having the features of claim 29. [Explanation of symbols]

[0118] 1 wireless communication system, 100 terminal devices, 201 antenna, 202 Reflector, 204 reflector array, 211, 212 repeaters, 220 repeater-equipped drones, 300 Radio wave management server.

Claims

1. a mobile terminal device; an antenna for transmitting a radio wave beam including a communication signal to the terminal device; a relay device that relays the radio wave beam transmitted from the antenna to the terminal device; a management device that acquires location information of at least one of the terminal device and the relay device, and controls the antenna to transmit the radio beam toward the relay device based on the acquired location information, the relay device is a reflector, and a plurality of the reflectors are arranged in an array; The management device selects at least one of the plurality of reflectors and transmits the radio wave beam toward the selected reflector.

2. 2. The wireless communication system of claim 1, wherein the management device acquires location information of the terminal device and location information of the relay device, moves the relay device based on the location information of the terminal device, and controls the antenna to transmit the radio wave beam toward the relay device based on the location information of the relay device.

3. The relay device is provided in plurality, The wireless communication system described in claim 1, wherein the management device acquires location information of the terminal device, selects a relay device from among the multiple relay devices to relay the radio wave beam based on the location information of the terminal device, and controls the antenna to transmit the radio wave beam toward the selected relay device.

4. the relay device acquires location information of the terminal device, and is capable of moving to a position from which the radio beam can be transmitted to the terminal device based on the location information of the terminal device and the antenna; The wireless communication system according to claim 1 , wherein the management device acquires location information of the relay device and controls the antenna to transmit the radio beam toward the relay device based on the location information of the relay device.

5. The wireless communication system according to claim 1 , wherein the management device changes the orientation of the reflector based on location information of the terminal device.

6. A management device that acquires location information of at least one of a mobile terminal device and a relay device that relays a radio wave beam transmitted from an antenna to the terminal device, and controls the antenna to transmit the radio wave beam toward the relay device based on the acquired location information, the relay device is a reflector, and a plurality of the reflectors are arranged in an array; A management device that selects at least one of the plurality of reflectors and transmits the radio wave beam toward the selected reflector.

7. 7. The management device of claim 6, further comprising: a control unit configured to control the antenna to transmit the radio wave beam toward the relay device based on the location information of the relay device; a control unit configured to control the antenna to transmit the radio wave beam toward the relay device based on the location information of the relay device; and a control unit configured to control the antenna to transmit the radio wave beam toward the relay device based on the location information of the relay device.

8. The relay device is provided in plurality, The management device described in claim 6, which selects a relay device from among a plurality of relay devices to relay the radio wave beam based on the acquired location information of the terminal device, and controls the antenna to transmit the radio wave beam toward the selected relay device.

9. the relay device acquires location information of the terminal device, and is capable of moving to a position from which the radio beam can be transmitted to the terminal device based on the location information of the terminal device and the antenna; The management device according to claim 6 , further comprising: a control unit configured to acquire location information of the relay device; and control the antenna to transmit the radio beam toward the relay device based on the location information of the relay device.

10. The management device according to claim 6 , wherein the orientation of the reflector is changed based on position information of the terminal device.

11. A relay device that relays a radio wave beam transmitted from an antenna to a mobile terminal device, The relay device is a reflector, and multiple reflectors are arranged in an array. The relay device acquires location information of the terminal device, moves to a position where it can transmit the radio wave beam to the terminal device based on the location information of the terminal device and the antenna, and transmits the radio wave beam toward at least one reflector selected from the multiple reflectors.

12. The relay device according to claim 11 , wherein the orientation of the reflector is changed based on position information of the terminal device.

13. a step (a) of acquiring location information of at least one of a mobile terminal device and a relay device that relays a radio wave beam transmitted from an antenna to the terminal device; and (b) controlling the antenna to transmit the radio wave beam toward the relay device based on the acquired location information, the relay device is a reflector, and a plurality of the reflectors are arranged in an array; A communication control method, wherein step (b) selects at least one of the plurality of reflectors and transmits the radio wave beam toward the selected reflector.

14. The relay device is provided in plurality, The communication control method according to claim 13, wherein step (b) selects a relay device for relaying the radio wave beam from among a plurality of relay devices based on the acquired location information of the terminal device, and controls the antenna to transmit the radio wave beam toward the selected relay device.

15. the relay device acquires location information of the terminal device, and is capable of moving to a position from which the radio beam can be transmitted to the terminal device based on the location information of the terminal device and the antenna; The step (a) includes acquiring location information of the relay device; The communication control method according to claim 13 , wherein said step (b) comprises controlling said antenna to transmit said radio wave beam toward said relay device based on location information of said relay device.

16. The communication control method according to claim 13 , wherein the step (b) changes the orientation of the reflector based on location information of the terminal device.

17. A communication control program for causing a computer to execute the communication control method according to any one of claims 13 to 16.

Images