Base station device, control device, control method, and program for using reflective plate divided into plurality of regions

Abstract

This base station device is capable of communicating with a terminal device via a reflection device that reflects radio waves, and is configured such that: control of a reflection pattern of the reflection device is performed by a control device that communicates with the base station device; capability information indicating whether or not a reflection surface of the reflection device can be divided into a plurality of regions for which mutually different reflection patterns can be set is acquired from the control device; a determination as to whether or not to divide the reflection surface is made on the basis of the capability information; the reflection pattern to be set on the reflection surface is selected on the basis of the determination; and the result of the determination and the result of the selection are notified to the control device.

Description

Base station device, control device, control method, and program using a reflector divided into multiple areas

[0001] The present invention relates to a technique for controlling the reflection pattern of a reflector.

[0002] In mobile communications, wireless communication services are provided to terminals located in positions where they can receive radio waves transmitted from base stations. Therefore, it is important that the radio waves transmitted by the base station reach the terminal's location appropriately. In particular, in recent wireless communication environments that tend to use high-frequency bands, wireless quality is easily degraded due to the influence of obstructions, etc., so the use of reflectors that reflect radio waves between the base station and the terminal has been considered. While reflectors can change the direction in which radio waves are reflected by changing their physical orientation, metasurface reflectors can reflect radio waves in various directions through electrical control without changing their physical orientation. Non-Patent Document 1 describes a technology in which a base station controls the reflection pattern of radio waves from a reflector by transmitting control information to a reflector control device.

[0003] Wu Qingqing, Rui Zhang, “Intelligent reflecting surface enhanced wireless network: Joint active and passive beamforming design”, 2018 IEEE Global Communication Conference, 2018

[0004] The present invention provides a technology that enables a greater number of terminals in blind zones of a cell to communicate with a base station via a single reflector in a wireless communication system that uses a reflector.

[0005] A base station device according to one aspect of the present invention is a base station device capable of communicating with a terminal device via a reflecting device that reflects radio waves, wherein control of the reflection pattern of the reflecting device is performed by a control device that communicates with the base station device, and the base station device has an acquisition means that acquires capability information from the control device indicating whether the reflection surface of the reflecting device can be divided into multiple areas in which different reflection patterns can be set, a selection means that decides whether to divide the reflection surface based on the capability information and selects a reflection pattern to be set on the reflection surface based on the decision, and a notification means that notifies the control device of the results of the decision and the selection.

[0006] According to the present invention, in a wireless communication system using a reflector, it is possible to enable a greater number of terminals in blind zones of a cell to communicate with a base station via a single reflector.

[0007] Other features and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings, in which the same or similar elements are designated by the same reference numerals.

[0008] The accompanying drawings are incorporated into and constitute a part of the specification, illustrate embodiments of the present invention, and together with the description are used to explain the principles of the present invention. Figure 1 is a diagram showing an example of the configuration of a wireless communication system. Figure 2 is a diagram showing an example of the configuration of a wireless communication system. Figure 3 is a diagram showing an example of the reflecting surface of a reflecting device. Figure 4 is a diagram showing an example of the configuration of a wireless communication system. Figure 5 is a diagram showing an example of the hardware configuration of a base station and a control device. Figure 6 is a diagram showing an example of the functional configuration of a base station. Figure 7 is a diagram showing an example of the functional configuration of a control device. Figure 8 is a diagram showing the processing flow when a base station instructs a reflection pattern of a reflector. Figure 9 is a diagram showing an example of the sequence between a base station and a control device.

[0009] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention as claimed, and not all combinations of features described in the embodiments are necessarily essential to the invention. Two or more of the features described in the embodiments may be combined in any desired manner. Furthermore, the same reference numerals are used to designate identical or similar components, and redundant descriptions will be omitted.

[0010] (System Configuration) FIG. 1 shows an example configuration of a wireless communication system according to this embodiment. The wireless communication system is, for example, a cellular communication system conforming to the cellular communication standard of the Third Generation Partnership Project (3GPP (registered trademark)). However, this is not limited to this, and the following discussion can be applied to a wireless communication system conforming to any wireless communication standard. The wireless communication system includes, for example, a base station 101, a terminal 111, a reflecting device 121, and a control device 131. The terminal 111 is wirelessly connected to the base station 101 via the reflecting device 121. The control device 131 is wiredly connected to the reflecting device 121. Note that the control device 131 may also be wirelessly connected to the reflecting device 121. The control device 131 is also wirelessly connected to the base station 101. A range within which communication with a base station is possible is called a cell, and a terminal can wirelessly communicate with the base station within the range of the cell. For example, the base station 101 constitutes cell 141. Here, if there is an obstacle or the like between the base station and the terminal, radio waves transmitted from the base station may not be received with sufficient strength by the terminal even within the cell. Such an area where the direct waves of radio waves transmitted from a base station are not received by a terminal with sufficient power (or where the direct waves of radio waves transmitted from a terminal are not received by a base station with sufficient power) can be called a blind zone. That is, if a terminal is in a blind zone, there is a high possibility that normal communication with the base station cannot be performed. Particularly when radio waves in a high-frequency band are used, the presence of many obstacles around the base station and the terminal increases the possibility of a blind zone occurring. In FIG. 1 , it is assumed that a blind zone 161 is created by an obstacle 151. That is, it is assumed that a terminal 111 in the blind zone 161 is in a situation where it cannot receive the direct waves of radio waves transmitted from the base station 101 with sufficient power. In such a situation, by providing a reflecting device that reflects radio waves between the base station and the terminal, the radio waves transmitted by the base station can be received by the terminal with sufficient power. That is, in FIG. 1 , even though the terminal 111 is in the blind zone 161, it can communicate normally with the base station 101 due to the waves reflected by the reflecting device 121. Although FIG. 1 shows an example in which the terminal 111 is wirelessly connected to the base station 101, the number of terminals connected to the base station 101 may be two or more.Furthermore, two or more base stations 101 may be included in the wireless communication system. Similarly, two or more control devices 131 may be connected to the base station 101, and the control device 131 may be connected to two or more reflecting devices 121. Furthermore, the number of reflecting devices that relay communication between the base station 101 and the terminal 111 may be two or more. There may be a case where multiple obstacles 151 exist within the range of the cell 141, thereby causing multiple blind zones 161. Furthermore, the blind zones 161 may have various shapes.

[0011] The terminal 111 is a terminal used by a user, and exchanges radio signals with the base station 101 via a wireless medium. The terminal 111 may be referred to as User Equipment (UE). The terminal 111 includes, for example, a smartphone, a mobile phone, a personal computer, a tablet terminal, a wearable terminal, an IoT (Internet of Things) terminal, etc. The base station 101 exchanges radio signals with the terminal 111 via a wireless medium. The base station 101 includes, for example, a gNB (next generation Node B), an eNB (evolved Node B), etc.

[0012] The reflector 121 reflects radio waves transmitted from the base station 101 in a predetermined reflection pattern. The reflector 121 also reflects radio waves transmitted from the terminal 111 in a predetermined reflection pattern. By appropriately setting the reflection pattern of the reflector 121, radio waves transmitted from the base station 101 can be reflected toward the terminal 111, and radio waves transmitted from the terminal 111 can be reflected toward the base station 101. This allows radio waves transmitted from the base station 101 to be received by the terminal 111 with sufficient strength, and radio waves transmitted from the terminal 111 to be received by the base station 101 with sufficient strength. Here, the reflection pattern is a pattern that indicates the gain of the reflector for each direction, and is determined by the reflection phase set in the reflecting elements that constitute the reflector of the reflector 121. For example, this pattern may be such that radio waves incident from a predetermined incident direction are hardly attenuated, and radio waves incident from another incident direction are attenuated to almost zero. Furthermore, radio waves emitted in a predetermined direction are emitted with high power, while radio waves are hardly emitted in other directions. In this way, the reflection pattern is expressed by a combination of patterns that indicate the gains of the incident and emitted light.

[0013] The reflecting device 121 includes a reflector that reflects radio waves incident on the reflecting device 121 in a predetermined direction and is configured to be able to change the reflection pattern of the reflector. For example, the reflecting device 121 can change the reflection direction of radio waves transmitted from the base station 101 or the terminal 111 by physically controlling the attitude of the reflector so that it faces a desired direction. The reflecting device 121 may also be configured to include an Intelligent Reflecting Surface (IRS) reflector using a metasurface. The IRS reflector is, for example, composed of multiple reflecting elements, and the reflection phase of each reflecting element can be electrically controlled to form a reflection pattern for the entire reflector. As an example, a metasurface reflecting device using a liquid crystal may have a reflector with a liquid crystal layer provided between the reflecting element and a ground (ground plate). In this reflecting device, the reflecting element is used as an electrode, and a voltage is applied to the reflecting element. By changing the voltage applied to the reflecting element, the electrical characteristics (dielectric constant) of the liquid crystal change, and the reflection phase of the reflecting element changes in response to the change in the dielectric constant of the liquid crystal. In this way, the reflection phase of the reflecting element can be precisely controlled by changing the voltage applied to the reflecting element. Therefore, by adjusting the voltage applied to each of the reflecting elements that make up the reflecting plate, the reflecting plate can be controlled to form a desired reflection pattern. In this way, by using a metasurface, the reflection direction of radio waves can be changed without physically changing the orientation or posture of the reflecting device. The reflecting device 121 may also have other reflection mechanisms. For example, the reflecting device 121 may include an IRS reflecting plate using a diode. In a metasurface reflecting plate using a diode, the reflecting element and the circuit element are connected by a diode. When a voltage is applied to the diode, a current flows in the circuit, resulting in a change in the reflection phase of the reflecting element. In this way, the reflection pattern of the reflecting device 121 can be controlled by the voltage applied to the diode. In this embodiment, the reflecting device 121 is described as having a metasurface reflecting plate using a liquid crystal.

[0014] The control device 131 is connected to the reflecting device 121 and controls the reflection pattern of the reflecting device 121. The control device 131 and the reflecting device 121 may be implemented as an integrated unit or as separate units. Furthermore, by wirelessly connecting the control device 131 and the base station 101, the base station 101 can remotely control the reflecting device 121 via the control device 131. For example, the control device 131 may have setting information (reflecting element setting) indicating the reflection phase to be set for each reflecting element of the reflecting device 121. The reflecting element setting includes information for identifying each reflecting element and information specifying the reflection phase to be set for each reflecting element. The information for identifying each reflecting element may be the position of each reflecting element on the reflector, or may be an identifier that can uniquely identify a specific reflecting element on the entire reflector. Furthermore, the information for specifying the reflection phase of each reflecting element may be the absolute value of the reflection phase or a relative value with respect to a reference value of the reflection phase. The information included in the reflecting element setting is not limited to these, and the information for identifying each reflecting element and the information for specifying the reflection phase of each reflecting element are also not limited to these. The control device 131 then controls the reflection phase of each reflecting element of the reflecting device 121 according to this reflection element setting. For example, if the reflecting device 121 has an IRS-based reflector, the control device 131 may adjust the voltage applied to each reflecting element according to the reflection setting to be set for each reflecting element indicated in the reflection element setting. Furthermore, one reflection element setting may be associated with one reflection pattern formed by the reflecting device 121. For example, reflection element settings corresponding to each reflection pattern may be generated and associated and stored in the control device 131. Furthermore, a reflection pattern ID may be assigned to each reflection pattern as an identifier that uniquely identifies the reflection pattern. In other words, by specifying one reflection pattern ID, one reflection element setting associated with the reflection pattern corresponding to that reflection pattern ID may be identified. For example, when a reflection pattern ID is specified, the control device 131 may set the reflection phase of each reflecting element of the reflecting device 121 according to the reflection element setting corresponding to that reflection pattern ID.

[0015] The reflection pattern to be set in the reflecting device 121 can be notified to the control device 131 by the base station 101. For example, if a reflection pattern and a reflection pattern ID are associated in advance and shared between the base station 101 and the control device 131, the base station 101 can notify the control device 131 of the reflection pattern ID, and the control device 131 can acquire the reflection pattern to be set in the reflecting device 121. Note that the information that the base station 101 notifies the control device 131 is not limited to the reflection pattern ID. For example, the reflection element setting itself may be notified. In this embodiment, an example will be described in which the base station 101 notifies the reflection pattern of the reflecting device 121 using the reflection pattern ID. Note that the base station 101 can generate reflection element settings corresponding to each reflection pattern and provide them to the control device 131. Note that a device other than the base station 101 may generate reflection element settings and provide them to the base station 101, and the base station 101 may provide the reflection element settings to the control device 131.

[0016] As described above, providing the reflector 121 allows the terminal device 111 in the blind zone to communicate with the base station 101 with sufficient power. In particular, when using a reflector 121 including an IRS reflector, the reflection pattern can be dynamically controlled depending on the location of the terminal 111, thereby improving the continuity of communication between the base station 101 and the terminal 111. However, if the blind zone 161 is large and multiple terminals are distributed far apart within it, a single reflector may not be able to cover the entire area. For example, as shown in FIG. 2 , if the blind zone 161 includes a terminal 112 in addition to the terminal 111 and the terminals 111 and 112 are far apart, the reflected waves from the reflector 121, which is set with a predetermined reflection pattern, may not be received by the terminal 112 with sufficient reception power. In other words, if the area in which communication with the base station 101 is possible using the reflected waves from the reflector 121 is defined as the extended area 171, the terminal 111 within the extended area can communicate with the base station 101, while the terminal 112 outside the extended area cannot communicate with the base station 101.

[0017] In consideration of these circumstances, the base station 101 in this embodiment divides the reflective surface of the reflector of the reflector 121 connected to the control device 131 into multiple regions in which different reflection patterns can be set, and sets a separate reflection pattern for each region. For example, the base station 101 acquires capability information from the control device 131 indicating whether the reflective surface of the reflector 121 can be divided into multiple regions, and determines whether to divide the reflective surface based on the capability information. The base station 101 can then select the reflection pattern to be set for each region based on that decision. The base station 101 notifies the control device 131 of the results of its decision on whether to divide the reflective surface and the selection of the reflection pattern to be set on the reflective surface. The control device 131 controls the reflection pattern of the reflector 121 based on the notified decision and selection results. With this configuration, a number of expansion areas corresponding to the number of regions on the reflective surface are formed. As a result, even when using a single reflector 121, multiple terminals located far apart in a blind zone can communicate with the base station 101.

[0018] As described above, the base station 101 may determine whether to divide the reflecting surface based on the capability information of the reflecting device 121. For example, when acquiring information about the reflecting device 121 from the control device 131, the base station 101 may acquire capability information regarding whether the reflecting surface of the reflecting device 121 can be divided. The base station 101 may decide to divide the reflecting surface if the reflecting device 121 is capable of being divided, and not to divide the reflecting surface if the reflecting device 121 is not capable of being divided. Furthermore, if the reflecting surface of the reflecting device 121 can be divided, the base station 101 may determine whether to divide the reflecting surface based on the number of terminals. For example, the base station 101 may decide to divide the reflecting surface if there are two or more terminals in the blind zone, or if the number of terminals in the blind zone exceeds a threshold. On the other hand, the base station 101 may decide not to divide the reflecting surface if the number of terminals in the blind zone is one, or if the number of terminals in the blind zone is below a threshold. Furthermore, the base station 101 may decide whether to divide the reflecting surface based on the distribution of terminal locations. For example, the base station 101 may decide to divide the blind zone when the distance between multiple terminals in the blind zone exceeds a predetermined threshold, or when all of the terminals in the blind zone cannot be included in a single extended area that can be formed without dividing the reflecting surface of the reflecting device 121. On the other hand, the base station 101 may decide not to divide the blind zone when none of the distances between multiple terminals in the blind zone exceed a predetermined threshold, or when all of the terminals in the blind zone are included in a single extended area that can be formed without dividing the reflecting surface of the reflecting device 121. The base station 101 may decide to divide the blind zone when multiple extended areas need to be formed regardless of the number or locations of the terminals. For example, when there are multiple areas within the blind zone where users or terminals tend to gather due to the layout of buildings or the use of space, the base station 101 may decide to divide the reflecting surface so that each area is included in a respective extended area. Furthermore, when the areas where users or terminals tend to gather change depending on the time of day, the base station 101 may decide whether to divide the blind zone depending on the time of day. For example, in the case of an event venue, where the use of the space and the location where many users and terminals gather vary depending on the time of day depending on the content of the event, the base station 101 can decide whether or not to divide the space for each time period.The base station 101 may use the history and trends in the distribution of terminal locations in the past to determine whether or not multiple extended areas should be formed for each time period, and may then decide whether or not to divide the area based on the results of that determination. In this way, the base station 101 determines whether or not to divide the area based on the capacity of the reflecting surface of the reflecting device 121, the status of the blind zone, and the like, so that even when a single reflecting device 121 is used, blind zones can be eliminated more efficiently depending on the situation.

[0019] The base station 101 may determine a division pattern for the reflecting surface of the reflecting device 121. For example, the division pattern may be represented by one or more of the number of regions to be formed on the reflecting surface by division, the area ratio of the regions, and the range of each of the regions. For example, the base station 101 may determine to form the same number of regions on the reflecting surface as the number of terminals in the blind zone. By forming the same number of regions on the reflecting surface as the number of terminals, it is possible to set a reflection pattern in each region so that an extended area is formed for each terminal. The base station 101 may also determine the area ratio of multiple regions based on the number of terminals. For example, the base station 101 may set the area ratio between the regions so that the larger the number of terminals included in an extended area formed by a region on the reflecting surface, the larger the area. The base station 101 may also set the area ratio between the regions so that the region on the reflecting surface that forms an extended area including a terminal performing communication that should be handled with priority has a larger area. This makes it possible to improve the continuity of communication that should be handled with priority. The base station 101 may also determine the range of each region on the reflecting surface based on the number of terminals. For example, the base station 101 may determine the boundaries of each region so that the reflective surface is divided vertically or horizontally based on the area ratio between the regions determined based on the number of terminals. In other words, by determining the boundaries of each region on the reflective surface, the range of each region may be determined.

[0020] The base station 101 may determine the division pattern based on the distribution of terminal locations. For example, the base station 101 may determine the extended area to be formed by the reflecting device 121 to include each terminal based on its location in the blind zone. For example, if there are two terminals communicating with the base station 101 in the blind zone and they are geographically separated by more than a predetermined distance, the base station 101 may divide the reflecting surface into two to form two extended areas that include the locations of the respective terminals. The base station 101 may also determine the area ratio of each area so that the greater the distance between the terminal and the reflecting device 121, the larger the area on the reflecting surface that forms the extended area that includes the terminal's location. The size of the extended area may be correlated with the size of the area on the reflector used to form the extended area. For example, the larger the area on the reflector, the farther the reflected wave will reach, and the larger the extended area will be. Therefore, the base station 101 may determine the area ratio of each region on the reflecting surface so that the region on the reflecting surface that forms an extended area including the location of terminals close to the reflecting device 121 is small and the region on the reflecting surface that forms an extended area including the location of terminals far from the reflecting device 121 is large. If a terminal is performing communication that should be handled preferentially, the base station 101 may determine the area ratio of each region so that the region on the reflecting surface that forms an extended area including the location of that terminal is large. Furthermore, the base station 101 may determine the range of each region by identifying the boundaries of each region to be formed on the reflecting surface based on the determined area ratio. The base station 101 may also group multiple terminals that are geographically close to each other. If there are a large number of terminals in a blind zone, grouping multiple terminals that are geographically close to each other can reduce the number of regions to be formed on the reflecting surface. In this case, the base station 101 may form the same number of regions on the reflecting surface as the number of groups so that each group corresponds to its respective extended area. The base station 101 may also determine the area ratio of each region on the reflecting surface based on the characteristics of each group. For example, the base station 101 can determine the area ratio so that the area of ​​the region on the reflective surface that forms the extended area associated with a group increases as the number of terminals included in the group increases.The base station 101 may determine the area ratio of each region such that the area on the reflecting surface that forms the extended area including the group increases as the distance between the group and the reflecting device 121 increases. Furthermore, the base station 101 may determine the range of each region by identifying the boundaries of each region to be formed on the reflecting surface based on the determined area ratio. The base station 101 may acquire the geographical distribution of terminals based on the location information of each terminal 110. For example, if each terminal 110 has a function that can identify location information, such as a global positioning system (GPS) or a global navigation satellite system (GNSS), the location information of the terminal 110 may be notified to the base station 101 by each terminal 110. The method by which the base station 101 acquires the location information of each terminal 110 is not limited to this, and other methods that allow the base station 101 to identify the location of each terminal 110 may be used. For example, if a specific terminal 110 is a stationary terminal that does not move, the operator may input the location information of the terminal 110 to the base station 101 in advance.

[0021] The base station 101 may also determine the division pattern based on the expansion areas to be formed in the blind zone. For example, the base station 101 may determine the division pattern based on the layout of buildings within the blind zone, the use of the space, and the like. For example, the base station 101 may determine the number of expansion areas to be formed in the blind zone and determine to form the same number of regions on the reflective surface. The base station 101 may also determine the range of the expansion area to be formed and determine the area ratio of each region so that the larger the area, the larger the area on the reflective surface that forms the expansion area. Furthermore, the base station 101 may determine the range of each region by identifying the boundaries of each region to be formed on the reflective surface based on the determined area ratio between each region. Note that if the expansion area to be formed varies depending on the time of day, the base station 101 may determine the division pattern for each time of day.

[0022] In this way, by having the base station 101 determine the division pattern according to the number and location distribution of terminals, the layout of buildings in the blind zone, the use of the space, etc., the number and size of the extended areas can be adjusted according to the conditions of the blind zone, thereby making it possible to more flexibly eliminate blind zones using a single reflecting device 121. Note that, in the above description, the number of regions to be formed on the reflecting surface by division, the area ratio of those regions, and the range of each of those regions are used as the division pattern, but the division pattern may be a combination of these or may be expressed in other ways. The division pattern may be any information that allows the base station 101 to uniquely specify to the control device 131 how to divide the reflecting surface of the reflecting device 121.

[0023] After determining whether to divide the reflecting surface and the division pattern, the base station 101 may notify the control device 131 of the determination and divide the reflecting surface. When the control device 131 is notified by the base station 101 of the number of regions to be formed by division, the control device 131 may divide the reflecting surface using any division method that can be set on the reflecting surface of the reflecting device 121 so that the notified number of regions are formed. For example, the control device 131 may divide the reflecting surface so that each region has an equal area. On the other hand, when the control device 131 is notified by the base station 101 of the number of regions and the area ratio of the regions, the control device 131 may divide the reflecting surface using any division method that can be set on the reflecting surface so that the area ratio of each region matches the notified area ratio. Furthermore, when the control device 131 is notified by the base station 101 of the range of each region to be formed on the reflecting surface, the control device 131 may divide the reflecting surface so that each region is formed within that range. In this way, the degree of freedom in the method of dividing the reflecting surface by the control device 131 may vary depending on the granularity of the information notified by the base station 101. FIG. 3 shows an example of a division method for dividing the reflecting surface of the reflecting device 121. The control device 131 can flexibly divide the reflecting surface to form multiple regions based on a division pattern notified to the base station 101. For example, the base station 101 can divide the reflecting surface along the X-axis or Y-axis direction shown in FIG. 3. Here, the X-axis is assumed to be horizontal with the ground where the reflecting device 121 is installed, and the Y-axis is assumed to be perpendicular to the ground. In this case, the reflecting surface can be divided into a left region and a right region along a dotted line 301 parallel to the Y-axis. The reflecting surface can also be divided into an upper region and a lower region along a dotted line 302 parallel to the X-axis. Note that the number of divisions of the reflecting surface may be three or more. For example, the reflecting surface can be divided into four regions along the dotted lines 301 and 302. Each region may have various shapes other than a rectangle. The boundaries of each region may be straight or curved. In this way, the reflecting surface is not limited to the above and can be divided into any number of regions and any shapes. Furthermore, the control device 131 may notify the base station 101 in advance of division patterns that can be formed on the reflective surface. The base station 101 can select a division pattern for the area to be formed on the reflective surface from the division patterns notified by the control device 131.In this way, base station 101 notifies control device 131 of the division pattern and reflection pattern so as to divide the reflecting surface of reflecting device 121, and control device 131 divides the reflecting surface of reflecting device 121 and sets the reflection pattern in accordance with the notification, so that, for example, as shown in Fig. 4, extended areas 171 and 172 are formed by the reflector of reflecting device 121, and terminals 111 and 112 can communicate with base station 101 in each extended area. An example configuration of such base station 101 and control device 131 will be described below.

[0024] (Device Configuration) FIG. 5 is a diagram showing the hardware configuration of the base station 101 and the control device 131. In one example, the base station 101 and the control device 131 are configured to include a processor 501, a ROM 502, a RAM 503, a storage device 504, and a communication circuit 505. The processor 501 is a computer configured to include one or more processing circuits, such as a general-purpose CPU (Central Processing Unit) or an ASIC (Application Specific Integrated Circuit). The processor 501 reads and executes programs stored in the ROM 502 or the storage device 504 to perform the overall processing of the device and each of the above-mentioned processes. The ROM 502 is a read-only memory that stores programs related to the processing executed by the base station 101 and the control device 131, various parameters, and other information. The RAM 503 functions as a workspace when the processor 501 executes a program, and is also a random access memory that stores temporary information. The storage device 504 is configured, for example, by a removable external storage device. The communication circuit 505 includes, for example, a circuit for wired or wireless communication between the base station 101 and the control device 131 .

[0025] FIG. 6 is a diagram illustrating an example of the functional configuration of the base station 101. The base station 101 has, as its functions, for example, an information acquisition unit 601, a division pattern selection unit 602, a reflection pattern selection unit 603, and an information notification unit 604. These functional units may be realized, for example, by the processor 501 executing a program stored in the ROM 502 or the storage device 504 and controlling the communication circuit 505 as necessary. However, this is not limited to this, and, for example, dedicated hardware may be provided to realize each function. The information acquisition unit 601 acquires information about the reflecting device 121 from the control device 131. For example, the information acquisition unit 601 may acquire capability information indicating whether the reflecting surface of the reflecting device 121 can be divided into multiple regions in which different reflection patterns can be set. Furthermore, the information acquisition unit 601 may acquire, from the control device 131, division patterns that can be formed on the reflecting surface and reflection patterns that can be set in each region formed by the division. The division pattern selection unit 602 determines whether to divide the reflecting surface of the reflecting device 121 and the division pattern. For example, the division pattern selection unit 602 may make a decision based on the capability information of the reflection device 121, the distribution of terminal positions, etc. The reflection pattern selection unit 603 may select a reflection pattern to be set in each area on the reflection surface. The reflection pattern selection unit 603 may select a reflection pattern based on the geographical range of an extended area to be formed in the blind zone, for example. The information notification unit 604 notifies the control device 131 of the determined presence or absence of division, the division pattern, the reflection pattern, etc.

[0026] FIG. 7 is a diagram illustrating an example of the functional configuration of the control device 131. The control device 131 has, as its functions, for example, an information notification unit 701, an information receiving unit 702, and a reflection device control unit 703. These functional units may be realized, for example, by the processor 501 executing a program stored in the ROM 502 or the storage device 504 and controlling the communication circuit 505 as necessary. However, this is not limited to this, and, for example, dedicated hardware may be provided to realize each function. The information notification unit 701 notifies the base station 101 of information related to the reflection device 121. For example, the information notification unit 701 may notify capability information indicating whether the reflection surface of the reflection device 121 can be divided into multiple regions in which different reflection patterns can be set. The information notification unit 701 may also notify the base station 101 of division patterns that can be formed on the reflection surface and reflection patterns that can be set in each region formed by the division. The information receiving unit 702 receives information from the base station 101 that can identify the division pattern and the reflection pattern. The reflection device control unit 703 controls the reflection device 121 in accordance with the division pattern and reflection pattern acquired by the information receiving unit 702 .

[0027] (Processing Flow) An example of the operation when the base station 101 sets the reflection pattern of the reflecting device 121 via the control device 131 will be described. Fig. 8 shows an example of a processing flow when the base station 101 in the wireless communication system shown in Fig. 4 sets the reflection pattern of the reflecting device 121 via the control device 131. In this example, the base station 101 uses the wireless connection established with the control device 131 to set the division pattern and reflection pattern of the reflecting device 121 connected to the control device 131 via the control device 131.

[0028] First, the base station 101 acquires information about the reflecting device 121 from the control device 131 (S801). For example, the base station 101 may acquire capability information indicating whether the reflecting surface of the reflector of the reflecting device 121 can be divided into multiple areas in which different reflection patterns can be set. The base station 101 may also acquire information from the control device 131 that identifies the division patterns and reflection patterns that can be set on the reflecting surface of the reflecting device 121. Based on this information, the base station 101 determines whether to divide the reflecting surface (S802). For example, the base station 101 may determine whether to divide the reflecting surface based on the capability information acquired from the control device 131. The base station 101 may also determine whether to divide the reflecting surface based on the distribution of terminals, etc. In this example, the terminals communicating with the base station 101 are collectively referred to as terminals 110. 6, the base station 101 may decide to divide the reflecting surface in cases such as when the distance between the terminal 111 and the terminal 112 exceeds a predetermined threshold, or when a large number of terminals 110 are included in the blind zone 161 and there is no reflection pattern that can form an extended area that includes all the terminals 110 without dividing the reflecting surface. In this example, it is assumed that the base station 101 decides to divide the reflecting surface based on the capability information of the reflecting device 121, the distribution of the terminals, etc.

[0029] The base station 101 determines a division pattern for the reflecting surface (S803). For example, the base station 101 may determine the division pattern for the reflecting surface of the reflector of the reflecting device 121 based on the geographical distribution of the terminals 110. For example, if the number of terminals 110 in the blind zone 161 is small and they are geographically distant from each other, the base station 101 may determine a division pattern such that the number of regions formed is equal to the number of terminals 110. On the other hand, if the number of terminals 110 in the blind zone 161 is large, the base station 101 may group multiple terminals 110 that are geographically close to each other and determine a division pattern such that the number of regions formed is equal to the number of groups. The base station 101 may also determine the area ratio of each region formed on the reflecting surface based on the geographical range of the extended area to be formed. Note that the base station 110 may select a combination of extended areas that includes the location of each terminal and use the number of extended areas included in that combination as the number of regions to be formed on the reflecting surface. In this case, the area ratio of the geographical ranges of the extended areas included in that combination may be used as the area ratio of the regions formed on the reflecting surface.

[0030] The base station 101 may determine the range of each region on the reflective surface based on the number of determined regions and the area ratio of the regions. For example, the base station 101 may determine the range of each region on the reflective surface along the X-axis and Y-axis shown in FIG. 3 . As an example, the base station 101 may determine the range of each region on the reflective surface by setting multiple boundary lines parallel to the Y-axis, such as dotted line 301. In this case, the area ratio determined for each region is expressed as the length of each region on the X-axis. The base station 101 may also determine the range of each region on the reflective surface by setting multiple boundary lines parallel to the X-axis, such as dotted line 302. In this case, the area ratio determined for each region is expressed as the length of each region on the Y-axis. The base station 101 may also divide the reflective surface two-dimensionally. For example, the base station 101 may form (M+1)×(N+1) regions by combining M boundary lines parallel to the X-axis and N boundary lines parallel to the Y-axis. The range of each region may be expressed as a range on the X-axis and the Y-axis. For example, the range of a specific region may be expressed as (X_1 to X_2, Y_1 to Y_2). Here, X_1 and X_2 may indicate the start point and end point of the specific region on the X-axis, respectively. Furthermore, Y_1 and Y_2 may indicate the start point and end point of the specific region on the Y-axis, respectively. Note that X_1, X_2, Y_1, and Y_2 may correspond to the identifiers of the respective reflective elements constituting the reflector.

[0031] The base station 101 determines a reflection pattern to be set for each region formed on the reflecting surface (S804). For example, the base station 101 determines a reflection pattern to be set for each region on the reflecting surface so that the expanded area formed by reflection from each region includes the locations of the terminals or groups to be covered by that expanded area. For example, the base station 101 may select a reflection pattern to be set from among the reflection patterns that can be set for the reflecting device 121 notified by the control device 131. As an example, a reflection pattern may be selected such that, when a specific reflection pattern is set for the reflecting device 121, the direction of reflected waves travels toward the desired expanded area. Note that the direction of travel of the reflected waves may be a direction in which the received power of the reflected waves is enhanced. Furthermore, a reflection pattern may be selected such that, when a specific reflection pattern is set for the reflecting device 121, an expanded area is formed in the desired direction and the largest number of terminals is included in that expanded area. Note that the method by which the base station 101 assigns reflection patterns to each region on the reflecting surface is not limited to the above, as long as the desired expanded area is formed using the reflection patterns set for each region.

[0032] The base station 101 may previously identify the correspondence between the reflection pattern set in the reflector 121 and the extended area formed by that reflection pattern. For example, the base station 101 may estimate the geographical extent of the extended area based on the geographical arrangement of the base station 101 and the reflection pattern set in the reflector 121. As an example, the base station 101 may estimate the geographical extent in which the received power of the reflected wave is enhanced based on the incident angle at the reflector 121 of the radio wave transmitted from the base station 101 toward the reflector 121 and the emission direction in which the radio wave is enhanced in the reflection pattern set in the reflector 121. The base station 101 may also identify the geographical extent of the extended area based on the actually measured received signal strength. For example, the received signal strength for each reflection pattern is measured in advance at each predetermined location in the blind zone. For example, when a specific reflection pattern is set, a location where a received signal strength exceeding a predetermined threshold is measured may be included in the extended area formed by that specific reflection pattern. The base station 101 may store the correspondence between such reflection patterns and the received signal strength at each point within the blind zone. The base station 101 may determine the reflection pattern based on the correspondence between the reflection pattern and the geographical range of the extended area obtained in advance. Thus, once the desired geographical range to be covered is identified, the base station 101 can determine an extended area that includes that geographical range and identify a reflection pattern corresponding to that extended area. The base station 101 may also identify the extended area by actually measuring the received signal strength for combinations of the division patterns of the reflective surface and the reflection patterns set in each region of each division pattern, and store the correspondence between them. In this case, once the desired geographical range to be covered is identified, the base station 101 can determine the extended area that includes that geographical range and identify the division patterns associated with the extended area and the reflection patterns to be set in each region.

[0033] The base station 101 may determine the reflection pattern to be set in each region based on the expanded area formed when a single predetermined reflection pattern is set on the reflecting device 121 without dividing the reflection surface. That is, when a reflecting element setting corresponding to each reflection pattern is set in each region, each region may form a reflection pattern similar to that formed when the reflection surface is not divided. In this case, the base station 101 may perform a correction using a predetermined phase shift on the reflection phase of the reflecting elements constituting each region. When different reflection patterns are set in each region on the reflection surface, the reflection phase may become discontinuous at the boundary between the regions. This discontinuity may result in a reflection pattern different from that formed when a single reflection pattern is set on the entire reflection surface. In this case, adding a common offset to the reflection phases of all reflecting elements constituting a specific region does not change the reflection pattern formed by reflection in that region. Therefore, the reflection pattern may be shaped by setting a common offset to all reflecting elements constituting at least one of the regions so that the reflection phase becomes continuous at the boundary between adjacent regions on the reflection surface. In this way, the base station 101 can determine the reflection pattern and the offset value of the reflection phase, and notify the control device 131 of this together with information that can identify the area where the offset correction should be performed. In this case, the control device 131 can add the offset value when setting the reflection phase for the identified area.

[0034] The base station 101 notifies the control device 131 of the division pattern and the reflection pattern (S805). For example, the base station 101 may notify one or more of the number of regions to be formed on the reflecting surface by division, the area ratio of the regions, and the range of each of the regions as the division pattern. If the base station 101 and the control device 131 share configurable division patterns along with identification information associated with each division pattern, the base station 101 may use the identification information to notify the number of regions to be formed on the reflecting surface by division, the area ratio of the regions, the range of each of the regions, and the like. Such identification information may be referred to as a division pattern ID. The division pattern ID may be notified to the base station 101 by the control device 131 along with a division pattern that can be set on the reflecting surface of the reflecting device 121. When the base station 101 forms a division pattern and notifies the control device 131, the base station 101 may notify the control device 131 of the division pattern and the division pattern ID. When the range of each region on the reflecting surface is notified as the division pattern, each region may be notified in association with identifying identification information. By being notified of information that can identify each area, the base station 101 can specify the reflection pattern to be set on the reflection surface and the area in which to set that reflection pattern, thereby enabling the desired expansion area to be formed with high accuracy.

[0035] The base station 101 notifies the control device 131 of the reflection patterns to be set on the reflecting surface of the reflecting device 121. For example, the base station 101 may notify the control device 131 of the reflection patterns to be set on each region of the reflecting surface using a reflection pattern ID as information for identifying each reflection pattern. When the base station 101 notifies the control device 131 of the number of regions as a division pattern, the base station 101 may notify the control device 131 of the same number of reflection patterns. If the radio waves transmitted from the base station 101 are uniformly received by the reflecting surface, a similar extended area can be formed regardless of which region on the reflecting surface each reflection pattern is placed in. Therefore, the base station 101 does not need to notify the control device 131 of the region in which each reflection pattern should be set. Furthermore, when the base station 101 notifies the control device 131 of the area ratios of the regions as a division pattern, the base station 101 may associate the reflection patterns in order of the area size. In this case, for example, the base station 101 may notify the control device 131 of the reflection patterns in order so that the reflection patterns are set in the regions with the largest or smallest areas. On the other hand, when notifying the range of an area as a division pattern, the base station 101 can notify the control device 131 of information that can identify each reflection pattern and information that can identify the area in which the reflection pattern should be set.

[0036] As described above, the base station 101 notifies the control device 131 of a combination of a division pattern and a reflection pattern, allowing the control device 131 to set a reflection pattern in each region on the reflective surface. In this case, the division pattern and the reflection pattern may be independent of each other, or may be associated with each other. For example, if the division pattern and the reflection pattern are independent, any reflection pattern can be set in each region formed by the division. In this case, the base station 101 can freely select a combination of a division pattern and a reflection pattern, but the amount of information to be notified to the control device 131 may be large. On the other hand, to reduce the amount of information communicated between the base station 101 and the control device 131, the selection of a division pattern may determine options for reflection patterns that can be set in each region. For example, separate identification information may be set that uniquely identifies the combination of a division pattern and a reflection pattern set in each region. In this case, the base station 101 notifies the control device 131 of one identification information, allowing the division pattern and reflection pattern to be identified at the same time. For example, a value of 1 in the identification information may indicate at a glance that two regions should be formed on the reflective surface and that a first reflection pattern and a second reflection pattern should be set in the first and second regions, respectively. Alternatively, the division pattern and the reflection pattern may be uniquely identified by a combination of a division pattern ID and a reflection pattern ID. In this case, different division pattern IDs may result in different reflection patterns being set in the regions associated with the reflection pattern IDs. For example, a division pattern ID of 1 and a reflection pattern ID of 1 may indicate that two regions should be formed on the reflective surface and that a first reflection pattern and a second reflection pattern should be set in the first and second regions, respectively. Alternatively, a division pattern ID of 1 and a reflection pattern ID of 2 may indicate that two regions should be formed on the reflective surface and that a third reflection pattern and a fourth reflection pattern should be set in the first and second regions, respectively.On the other hand, if the division pattern ID is 2 and the reflection pattern ID is 1, it may indicate that three regions are formed on the reflection surface, and that a third reflection pattern, a fourth reflection pattern, and a fifth reflection pattern should be set in the first region, the second region, and the third region, respectively. In this way, different division pattern IDs may be used so that the same reflection pattern ID indicates different reflection patterns.

[0037] When changing the reflection pattern of a portion of the area on the reflecting surface, the base station 101 may notify the control device 131 of information that can identify the area and the reflection pattern. The control device 131 sets a reflection pattern for the identified area. This allows for notification with a small amount of information when changing the reflection pattern of only a portion of the area without changing the division pattern of the reflecting surface. For example, if the reflecting surface of the reflector of the reflector device 121 is divided into four areas and 32 reflection patterns (5 bits) are set, the amount of information notified from the base station 101 to the control device 131 of the reflection patterns for all the areas may be 20 bits (= 4 areas × 5 bits). On the other hand, when notifying only information about the area where the reflection pattern should be set, it is only necessary to notify the area identification information (2 bits for four areas) and the reflection pattern (5 bits), so the amount of information notified from the base station 101 to the control device 131 may be 7 bits.

[0038] Furthermore, if the location where information for identifying a reflection pattern is stored in a message format used to notify all areas formed on the reflective surface and the reflection pattern to be set in each area is associated with the area where the reflection pattern should be set, the base station 101 may notify the area where each reflection pattern should be set without including information for identifying each area. For example, if the order in which the reflection patterns are stored in the message format is associated with each area in a predetermined division pattern, the base station 101 may include information for identifying the reflection pattern in the message according to that order. This may reduce the amount of information in the message corresponding to the information for identifying each area. For example, in the above case, notifying the information for identifying each area and the reflection pattern requires 28 bits (= 7 bits × 4). On the other hand, not notifying the information for identifying each area requires 20 bits (= 5 bits × 4).

[0039] (Sequence Between Base Station and Control Device) A sequence between the base station 101 and the control device 131 performed based on the above operation by the base station 101 will be described. FIG. 9 shows an example of a sequence when the base station 101 sets the reflection pattern of the reflecting device 121 via the control device 131. First, the base station 101 establishes a wireless connection with the control device 131. For example, when the control device 131 is powered on, it performs a cell search to search for a cell that can be used as a connection destination, and may establish an RRC (Radio Resource Control) connection with the base station 101 by performing a random access procedure. The control device 131 may notify the base station 101 of capability information and the like regarding the reflecting device 121 using the RRC connection established with the base station 101. For example, the control device 131 may notify the base station 101 of division patterns and reflection patterns that can be set in the reflecting device 121 connected to the base station 101 (S901). In this case, information that can identify each division pattern and reflection pattern may also be notified to the base station 101. The base station 101 stores the division patterns, reflection patterns, and identification information of the reflecting device 121 that can be set from the control device 131. The base station 101 determines the division pattern of the reflecting surface of the reflecting device 121 (S902). For example, the base station 101 may determine whether to divide the reflecting surface and the division pattern based on the capability information of the reflecting surface of the reflecting device 121, the distribution of the positions of the terminals 110, etc. The base station 101 notifies the control device 131 of an instruction including the determined division pattern of the reflecting surface (S903). Next, the base station 101 determines the reflection patterns to be set for each region on the reflecting surface (S904). For example, the base station 101 may determine the reflection pattern so that the extended area formed by reflection from each region on the reflecting surface covers the desired area. The base station 101 notifies the control device 131 of information that can identify the determined reflection pattern (S905). The notification of the division pattern of the reflective surface (S903) and the notification of the information that can identify the reflection pattern (S905) by the base station 101 may be performed together or separately. For example, the base station 101 may change only the reflection pattern of a specific area on the reflective surface without changing the division pattern.In this case, the base station 101 can only notify information that can identify the reflection pattern and information that identifies the area on the reflection surface where the reflection pattern should be set.

[0040] The control device 131 controls the reflecting device 121 based on the notification received from the base station 101. For example, the control device 131 divides the reflecting surface of the reflector of the reflecting device 121 and sets a reflection pattern. The control device 131 specifies the division pattern to be set on the reflecting surface based on the number of regions to be formed, the area ratio of each region on the reflector, information capable of identifying the range of each region on the reflector, and the like, notified by the base station 101. Note that when the base station 101 provides information capable of identifying a division pattern, the control device 131 can specify the corresponding division pattern based on that information. Furthermore, the control device 131 specifies the region on the reflecting surface where the reflection pattern should be set and the reflection pattern to be set based on the reflection pattern identification information notified by the base station 101, divides the reflecting surface of the reflector of the reflecting device 121 into multiple regions, and sets a reflection pattern in each region. That is, the control device 131 controls the reflection phase of the reflecting elements included in each region using the reflection element settings corresponding to each reflection pattern.

[0041] The base station 101 may transmit instructions to the control device 131, including the division pattern and reflection pattern of the reflecting surface of the reflector of the reflector of the reflector 121, using procedures and frames specified in the 3GPP cellular communication standard. As an example, the base station 101 may use a radio resource control (RRC) message to instruct the control device 131. In this case, for example, a new type of message for notifying the division pattern, reflection pattern, etc. may be defined in the RRC Reconfiguration message. Upon receiving the RRC message, the control device 131 extracts information contained in the message and identifies the division pattern, reflection pattern, etc. The base station 101 may include a large amount of information in the RRC message. In addition, the control device 131 sends an acknowledgement notification indicating that the RRC message was successfully received. This acknowledgement notification allows the base station 101 to confirm that the division and reflection pattern of the reflector 121 have been changed, thereby enabling reliable control. When an RRC message is used, the base station 101 may have a higher degree of freedom in notifying division patterns, reflection patterns, and the like.

[0042] The base station 101 may also notify the control device 131 of the division pattern, reflection pattern, etc. using a medium access control (MAC) subheader. In this case, a new MAC subheader format may be defined for notifying such information. Also, some fields of an existing MAC subheader may be diverted to notify such information. For example, a field with a predetermined number of bits for indicating such information may be provided in the MAC subheader. The control device 131 analyzes the MAC subheader included in a signal addressed to the base station 101 to identify the division pattern, reflection pattern, etc. to be set. The base station 101 may also notify the control device 131 of the division pattern, reflection pattern, etc. using downlink control information (DCI) defined in the 3GPP cellular communication standard. In this case, a new DCI format for notifying such information may be defined. Also, some of the existing DCI formats may be diverted to notify such information. For example, a field with a predetermined number of bits for indicating the division pattern, reflection pattern, etc. may be provided in the DCI. The control device 131 decodes the physical downlink control channel (PDCCH). In one example, a radio network temporary identifier (RNTI) can be assigned to the control device 131 in advance. In this case, the control device 131 can obtain information from the DCI addressed to the control device 131 by decoding the PDCCH using the RNTI. When the RNTI is assigned in advance, the control device 131 can decode the PDCCH simply by establishing time synchronization of the downlink (the link from the base station 101 to the control device 131) by observing a synchronization signal. That is, in this case, the control device 131 does not need to perform a random access procedure with the base station 101 to establish uplink synchronization or to establish a connection in the RRC layer. Therefore, the connection establishment process and the like can be omitted, thereby reducing the processing load.

[0043] The control device 131 can notify the base station 101 of information such as division patterns that can be set in the reflecting device 121 connected to the control device 131 and reflection patterns to be shared with the base station 101, using procedures and frames specified in the 3GPP cellular communication standard. As an example, the control device 131 can notify the base station 101 of this information using UE Capability Signaling. UE Capability Signaling is signaling for notifying the base station 101 of the UE's capabilities, and is used after an RRC connection is established with the base station 101. For this reason, the signaling can include more information than when reporting or notifying using, for example, a control channel. For example, the control device 131 can notify the base station 101 of various information such as information on division patterns that can be set in the reflecting device 121 described above, reflection patterns and their identifiers, by using UE Capability Signaling. Furthermore, by using UE Capability Signaling, an acknowledgment is sent indicating that the base station 131 has received information, thereby enabling highly reliable control. In this case, a new field may be defined in the UE Capability Signaling for the control device 131 to send information. The base station 101 extracts information included in the UE Capability Signaling and identifies information such as a division pattern and a reflection pattern that can be set in the reflection device 121.

[0044] Furthermore, the control device 131 may notify the above-mentioned information using random access procedure message 1 or message 3. For example, when using random access procedure message 1, the control device 131 may report information such as a division pattern and a reflection pattern to the base station 101 by utilizing the availability of multiple preamble patterns. For example, by predetermining preamble patterns according to the capability information, etc., to be notified by the control device 131, the control device 131 selects a pattern according to the capability information of the reflecting device 121 and performs random access. The base station 101 identifies the capability information, etc., of the reflecting device 121 based on the pattern selected by the control device 131. A combination of multiple preamble patterns may be used to notify the capability information of the reflecting device 121. On the other hand, when using random access procedure message 3, a new field may be defined for the control device 131 to notify information. Furthermore, some fields of an existing message may be diverted for notification by the control device 131. The base station 101 identifies information regarding configurable division patterns and reflection patterns from the fields in the message. The control device 131 may notify the above-mentioned information using uplink control information (UCI). In this case, a new UCI format may be defined for the control device 131 to perform the notification. Alternatively, an existing UCI format may be adapted for use in the notification by the control device 131. In the UCI, for example, a field with a predetermined number of bits may be prepared to indicate capability information, etc. of the reflector device 121. The base station 101 extracts, from the UCI, information on the capability information, configurable division patterns, reflection patterns, etc.

[0045] Furthermore, a signaling protocol layer may be defined for communication of capability information, division patterns, reflection patterns, and the like between the base station 101 and the control device 131. For example, the protocol used in this layer may be called an Intelligent Reflecting Surface protocol (IRS protocol). This layer may also be called an IRS protocol layer. For example, the control device 131 receives a message of the IRS protocol layer and identifies the division pattern, reflection pattern, and the like to be set based on the division pattern, reflection pattern, and the like included in the message. By defining the IRS protocol layer, it becomes possible to use a message format suitable for notifying the division pattern, reflection pattern, and the like. Furthermore, this method does not require an RRC connection, and therefore does not require the processing load for the RRC connection. Note that the above-described methods of notifying the division pattern, reflection pattern, and the like may be used in combination. For example, the division pattern may be notified by an RRC message, and the reflection pattern may be notified by another method.

[0046] As described above, according to this embodiment, the base station 101 divides the reflecting surface of the reflecting device 121 connected to the control device 131 into multiple regions and communicates with the terminal 111 while controlling the reflection pattern of each region. For example, the base station 101 determines the division pattern of the reflecting surface and the reflection pattern of each region based on the geographical distribution of terminals in the blind zone 161. With this configuration, even if only one reflecting device can be used in a situation where terminals are widely distributed in the blind zone, it is possible to increase the number of terminals that can communicate with the base station 101. This makes it possible to eliminate more blind zones in the cell formed by the base station 101. Therefore, it is possible to contribute to Goal 9 of the Sustainable Development Goals (SDGs) led by the United Nations, which is to "Develop resilient infrastructure, promote sustainable industrialization and foster innovation."

[0047] The invention is not limited to the above-described embodiment, and various modifications and variations are possible within the scope of the gist of the invention.

[0048] This application claims priority based on Japanese Patent Application No. 2024-049214, filed March 26, 2024, the entire contents of which are incorporated herein by reference.

Claims

1. A base station device capable of communicating with a terminal device via a reflecting device that reflects radio waves, wherein the reflection pattern of the reflecting device is controlled by a control device that communicates with the base station device, and the base station device has: an acquisition means that acquires from the control device capability information indicating whether the reflection surface of the reflecting device can be divided into multiple areas in which different reflection patterns can be set; a selection means that decides whether to divide the reflection surface based on the capability information and selects a reflection pattern to be set on the reflection surface based on the decision; and a notification means that notifies the control device of the results of the decision and the selection.

2. The base station device according to claim 1, wherein the selection means further selects a division pattern indicated by one or more of the number of regions to be formed on the reflective surface by division, the range of each of the regions, or the area ratio of the regions, and the notification means issues the notification including information that can identify the selected division pattern.

3. The base station device according to claim 2, wherein the acquisition means further acquires information from the control device that can identify the division pattern that can be formed on the reflecting surface, and the selection means selects the division pattern to be set on the reflecting surface from the acquired division patterns.

4. The base station device according to claim 2 or 3, wherein the selection means selects the division pattern based on the number of terminal devices.

5. The base station device according to claim 2 or 3, wherein the selection means selects the division pattern based on the distribution of positions of the terminal devices.

6. The base station device according to claim 1, wherein the notification means issues the notification including information capable of specifying a reflection pattern to be set for each of a plurality of areas formed by division.

7. The base station device according to claim 6, wherein identification information for identifying each of the plurality of areas is assigned to each of the plurality of areas, and the notification means issues the notification to at least some of the areas included in the plurality of areas, in which the identification information assigned to each of the partial areas is associated with information that can specify the reflection pattern to be set for each of the partial areas.

8. The base station device according to claim 6, wherein, in a notification of reflection pattern settings that targets all areas formed by division, if the areas in which each of the reflection patterns to be set is to be set are identified based on the order of the reflection patterns to be set indicated in the notification, the notification means issues the notification including information that can identify each of the reflection patterns to be set but not including information that identifies the areas in which each of the reflection patterns to be set is to be set.

9. The base station device according to claim 1, wherein the notification means notifies the control device using at least one of a Radio Resource Control (RRC) message in a cellular communication standard of the Third Generation Partnership Project (3GPP), a Downlink Control Information (DCI) or a Medium Access Control (MAC) subheader, and an Intelligent Reflecting Surface protocol.

10. A control device that controls the reflection pattern of a reflecting device that reflects radio waves, wherein communication is performed between a base station device and a terminal device via the reflecting device, and the control device has: a notification means that notifies the base station device of capability information indicating whether the reflection surface of the reflecting device can be divided into multiple areas in which different reflection patterns can be set; a receiving means that receives from the base station device a notification indicating a decision on whether to divide the reflection surface based on the capability information and a selection of a reflection pattern to be set on the reflection surface based on the decision; and a control means that controls the reflection pattern of the reflecting device based on the notification.

11. The control device according to claim 10, wherein the notification means notifies the base station device of information that can identify a division pattern indicated by one or more of the number of areas that can be formed on the reflecting surface by division, the range of each of the areas, or the area ratio of the areas, as the capability information.

12. The control device according to claim 10, wherein the notification means performs the notification using at least one of UE Capability Signaling in the cellular communication standard of the Third Generation Partnership Project (3GPP), message 1 or message 3 of a random access procedure, uplink control information, and a protocol for Intelligent Reflecting Surface.

13. A control method executed by a base station device capable of communicating with a terminal device via a reflecting device that reflects radio waves, wherein control of the reflection pattern of the reflecting device is performed by a control device communicating with the base station device, the control method comprising: acquiring capability information from the control device indicating whether the reflection surface of the reflecting device can be divided into multiple areas in which different reflection patterns can be set; determining whether to divide the reflection surface based on the capability information, and selecting a reflection pattern to be set on the reflection surface based on the decision; and notifying the control device of the results of the decision and the selection.

14. A control method executed by a control device that controls the reflection pattern of a reflecting device that reflects radio waves, wherein communication is performed between a base station device and a terminal device via the reflecting device, the control method including: notifying the base station device of capability information indicating whether the reflection surface of the reflecting device can be divided into multiple areas in which different reflection patterns can be set; receiving a notification from the base station device indicating a decision on whether to divide the reflection surface based on the capability information and a selection of a reflection pattern to be set on the reflection surface based on the decision; and controlling the reflection pattern of the reflecting device based on the notification.

15. A program for causing a computer to function as each of the means possessed by the base station device according to any one of claims 1 to 9.

16. A program for causing a computer to function as each of the means possessed by the control device according to any one of claims 10 to 12.

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