A control device, base station, control method, and program for managing the status of a reflector.

Abstract

To provide a technique for efficiently detecting defective elements in a wireless communication system that uses a reflector.SOLUTION: A control device that controls a reflecting device that reflects radio waves transmitted from a base station using a reflector composed of a plurality of reflecting elements performs a monitoring process to monitor the presence of defective elements, which are reflecting elements that do not operate normally, performs a reporting process to report information about the defective elements, and obtains setting information from the base station for performing at least one of the monitoring process and the reporting process.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a technique for managing the state of a reflector.

Background Art

[0002] In mobile communication, a wireless communication service is provided to a terminal existing at a position where radio waves transmitted by a base station can be received. Therefore, it is important to appropriately reach the radio waves transmitted by the base station to the position of the terminal. In particular, in recent wireless communication environments that tend to use high-frequency bands, the wireless quality is likely to deteriorate due to the influence of obstacles and the like. Therefore, the use of a reflector that reflects radio waves between the base station and the terminal has been considered. Note that the reflector can change the direction in which radio waves are reflected by changing its physical orientation. However, by using a metasurface reflector, radio waves can be reflected in various directions by electrical control without changing the physical orientation. Non-Patent Document 1 describes a technique for controlling the radio wave reflection pattern in a reflector by a base station transmitting control information to a control device of the reflector.

Prior Art Documents

Non-Patent Documents

[0003]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present invention provides a technique for efficiently detecting defective elements in a wireless communication system using a reflector. [Means for solving the problem]

[0005] A control device according to one aspect of the present invention is a control device for controlling a reflecting device that reflects radio waves transmitted from a base station using a reflector comprising a plurality of reflecting elements, and comprises: a monitoring means that performs a monitoring process to monitor for the presence of a faulty element, which is a reflecting element that does not operate properly; a reporting means that performs a reporting process to report information about the faulty element; and an acquisition means that acquires setting information from the base station for performing at least one of the monitoring process and the reporting process.

[0006] A base station according to one aspect of the present invention is a base station that communicates with a control device that controls a reflecting device that reflects radio waves using a reflector comprising a plurality of reflecting elements, and comprises a generation means for generating setting information for performing at least one of the following: a monitoring process for monitoring the presence of a faulty element which is a reflecting element that does not operate properly, and a reporting process for reporting information on the faulty element, and a notification means for notifying the control device of the setting information. [Effects of the Invention]

[0007] According to the present invention, a faulty element can be efficiently detected in a wireless communication system using a reflector. [Brief explanation of the drawing]

[0008] [Figure 1] This is a diagram showing an example configuration of a wireless communication system. [Figure 2] This figure shows an example of a reflective element configuration. [Figure 3] This figure shows an example of the hardware configuration of a base station and a control device. [Figure 4] This figure shows an example of the functional configuration of a control device. [Figure 5] This figure shows an example of the functional configuration of a base station. [Figure 6]This diagram shows the processing flow when a control device reports information about a faulty element to a base station, and the base station notifies the control device of the reflective element settings. [Figure 7] This diagram shows the processing flow when a control device performs monitoring and reporting of defective elements. [Figure 8] This diagram shows the processing flow when the control device stops reporting defective elements or stops controlling the reflector. [Modes for carrying out the invention]

[0009] The embodiments will be described in detail below with reference to the attached drawings. Note that the following embodiments do not limit the invention as defined in the claims, and not all combinations of features described in the embodiments are essential to the invention. Two or more of the features described in the embodiments may be combined in any way. Furthermore, identical or similar configurations will be given the same reference numeral, and redundant descriptions will be omitted.

[0010] (System Configuration) Figure 1 shows an example of the configuration of a wireless communication system according to this embodiment. The wireless communication system is, for example, a cellular communication system compliant with the 3GPP® cellular communication standard. However, it is not limited to this, and the following discussion can be applied to a wireless communication system compliant with any wireless communication standard. The wireless communication system is composed of, for example, base stations 101, 102 and 103, terminals 111 and 112, reflectors 121 and 122, and control devices 131 and 132. In this embodiment, base stations 101 to 103 may each be referred to as base station 100 without distinction. Also, terminals 111 and 112 may be referred to as terminal 110 without distinction, reflectors 121 and 122 may be referred to as reflector 120 without distinction, and control devices 131 and 132 may be referred to as control device 130 without distinction. Here, base station 103 is assumed to be a base station that constitutes cell 143 with greater coverage than the other base stations. For example, base station 103 can communicate with other communication devices such as terminal 110 over an area ranging from several hundred meters to several tens of kilometers in radius from its own center. Base station 103 may also be called a macrocell base station. On the other hand, base stations 101 and 102 constitute cells 141 and 142, respectively, which have smaller coverage compared to base station 103. Base stations 101 and 102 may also be called small cell base stations. In this embodiment, terminals 111 and 112 communicate with base stations 101 and 102, respectively. Terminal 110 may also be called User Equipment (UE).

[0011] Here, for example, suppose there is an obstruction between the base station 101 and the terminal 111, and the radio waves transmitted from the base station 101 are not received at terminal 111 with sufficient strength. In this case, there is a possibility that the radio waves transmitted from terminal 111 are also not received at base station 101 with sufficient strength. Within the cell of base station 100, areas where radio waves transmitted from base station 100 are not received at sufficient strength are sometimes called dead zones. In particular, when using high-frequency radio waves, the likelihood of dead zones occurring increases. In such situations, by placing the reflector 121 in a position where it can transmit and receive radio waves at sufficient strength to both base station 101 and terminal 111, the reflector 121 can relay communication between base station 101 and terminal 111. The reflector 121 reflects the radio waves transmitted from base station 101 in a predetermined reflection pattern. The reflector 121 also reflects the radio waves transmitted from 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 towards the terminal 111, and radio waves transmitted from the terminal 111 can be reflected towards the base station 101. As a result, radio waves transmitted from the base station 101 can be received by the terminal 111 with sufficient strength, and radio waves transmitted from the terminal 111 can be received by the base station 101 with sufficient strength. Here, the reflection pattern is a pattern that shows the gain of the reflector in each direction, and is determined by the reflection phase set in the reflective elements that make up the reflector of the reflector 120. For example, a pattern in which radio waves incident from a predetermined incident direction are almost not attenuated, and radio waves incident from another incident direction are attenuated to almost zero. Also, radio waves emitted in a predetermined direction are emitted with high power, and radio waves are hardly emitted in other directions. Thus, the reflection pattern is expressed by a combination of patterns that show the gain of the incident and emitted directions, respectively.

[0012] The control device 131 is connected to the reflector 121 and controls the reflection pattern of the reflector 121. The control device 131 and the reflector 121 may be implemented as an integrated unit or as separate units. The control device 131 may control the reflector 121 so that a predetermined fixed reflection pattern is formed. Furthermore, by wirelessly connecting the control device 131 to the base station 101, the base station 101 can remotely control the reflector 121 via the control device 131. In addition, if the base station 103 and the control device 131 are wirelessly connected, the base station 103 can remotely control the reflector 121 via the control device 131. For example, base station 103 may include a wide area within its cell 143 that includes cells 141 and 142 of base stations 101 and 102, respectively, and base stations 101 to 103 may belong to the same network domain and be able to cooperate with each other. In this case, when the base station 101 and the terminal 111 are wirelessly connected via the reflector 121, and the control device 131 is wirelessly connected to the base station 103, the reflector 121, which relays between the base station 101 and the terminal 111, can be controlled by the base station 103 via the control device 131. In this way, a base station covering a wide area can centrally control the reflector via the control device, enabling integrated management of the entire wireless communication system and the elimination of more dead zones.

[0013] The same discussion can be applied to communication between the base station 102 and the terminal 112. For example, if sufficient radio wave strength cannot be transmitted or received between them due to obstacles, a reflector 122 can be installed, and the control device 132 can control the reflector 122 to enable communication between the base station 102 and the terminal 112. Note that the configuration in Figure 1 is merely an example. For example, the number of reflectors relaying communication between the base station 100 and the terminal 110 may be one or two or more. Also, a large number of terminals may be connected to the base station 100. In this case, some terminals may communicate directly with the base station 100 without going through the reflector 120, while other terminals may communicate with the base station 100 via the reflector 120.

[0014] The reflector 120 includes a reflector that reflects radio waves incident on the reflector 120 in a predetermined direction, and is configured to allow the reflection pattern of the reflector to be changed. For example, the reflector 120 changes the reflection direction of radio waves transmitted from the base station 100 or terminal 110 by physically controlling the orientation of the reflector so that it faces a desired direction. The reflector 120 may also be configured to include a reflector made of an Intelligent Reflecting Surface (IRS) using a metasurface. The IRS may be composed of, for example, multiple reflective elements, and a reflection pattern can be formed by controlling the reflection phase of each reflective element. As an example, a metasurface reflector using liquid crystal may have a reflector with a liquid crystal layer provided between the reflective element and the ground (ground plate). In this reflector, the reflective element is used as an electrode, and a voltage is applied to the reflective element. By changing the voltage applied to the reflective element, the electrical properties (dielectric constant) of the liquid crystal change, and the reflection phase of the reflective element changes in accordance with the change in the dielectric constant of the liquid crystal. In this way, by changing the voltage applied to the reflecting element, it is possible to finely control the reflection phase of the reflecting element. Therefore, by adjusting the voltage applied to each of the reflecting elements constituting the reflector, the reflector can be controlled to form a desired reflection pattern. In this way, by using a metasurface, the direction of reflection of radio waves can be changed without physically changing the orientation or posture of the reflector. The reflector 120 may have other reflection mechanisms. For example, the reflector 120 may include a reflector using an IRS with diodes. In a metasurface reflector using diodes, the reflecting element and the circuit element are connected by a diode, and when a voltage is applied to the diode, current flows in the circuit, and as a result the reflection phase of the reflecting element changes. In this way, the reflection pattern of the reflector 120 can be controlled by the voltage applied to the diode. In this embodiment, the explanation will be given assuming that the reflector 120 has a metasurface reflector using liquid crystal.

[0015] The control device 130 controls the reflection pattern of the reflecting device 120. For example, the control device 130 has setting information (reflecting element setting) that specifies the reflection phase to be set for each reflecting element. The control device 130 controls the reflection phase of each reflecting element according to this reflecting element setting. As an example, the reflecting element setting includes information for identifying each reflecting element and information for identifying 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 it may be an identifier for the reflecting element. Also, the information for identifying the reflection phase of each reflecting element may be the absolute value of the reflection phase, or it may be a relative value of the reflection phase with respect to a reference value. 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 identifying the reflection phase of each reflecting element are not limited to these. The reflecting element setting may exist for each reflection pattern formed by the reflecting device 120. For example, if a pattern ID is assigned to each reflection pattern as an identifier that uniquely identifies that reflection pattern, the control device 130 may set the reflection phase of each reflecting element on the reflector according to the reflecting element setting associated with each pattern ID.

[0016] The reflection pattern set in the reflector 120 may be notified to the control device 130 by the base station 100. For example, the base station 100 generates the reflector settings for each reflector element constituting the reflector of the reflector 120 and notifies the control device 130. Note that devices other than the base station 100 may generate the reflector settings, and devices other than the base station 100 may notify the control device 130 of the reflector settings. If the reflection pattern and reflector settings are pre-associated and shared between the base station 100 and the control device 130, the control device 130 can control the reflection pattern of the reflector 120 by notifying the control device 130 of the pattern ID from the base station 100. That is, the control device 130 sets the reflection phase of each reflector element of the reflector 120 according to the reflector settings associated with the notified pattern ID. Note that the information notified by the base station 100 to the control device 130 is not limited to the pattern ID. For example, the reflector settings themselves may be notified.

[0017] If there is a defective element among the reflecting elements that make up the reflector, a desired reflection pattern may not be formed. In the present embodiment, a reflecting element that does not operate normally is called a defective element. As an example, a defective element may occur due to damage to the reflecting element itself, deterioration of the electrical characteristics of the liquid crystal that makes up the reflector, a failure of the circuit that applies a voltage to the reflecting element, etc. Note that the factors causing the defective element are not limited to those described above. For example, even if a predetermined voltage according to the reflecting element setting is applied to a reflecting element whose electrical characteristics of the liquid crystal have deteriorated, the liquid crystal may not reach the desired dielectric constant, and as a result, the reflection phase of the reflecting element may not become the desired phase. If the reflection phase of the defective element is different from the desired reflection phase, a desired reflection pattern is not formed as the reflection pattern of the reflection device 120. Thus, when a desired reflection pattern is not formed due to the presence of a defective element, for example, radio waves transmitted by the base station 100 and reflected by the reflection device 120 may not be received at sufficient intensity at the terminal 110. If sufficient power is not received, the dead zone is not eliminated, and the area coverage deteriorates. Also, if a peak of the reflection pattern is formed in a direction different from the desired direction, a decrease in the accuracy of azimuth estimation or beam training may occur.

[0018] In order to grasp the presence of a defective element, for example, at the terminal 110, the reception intensity of radio waves transmitted by the base station 100 and reflected by the reflection device 120 can be measured. In this case, it is necessary to dispatch a worker or the like to the site to perform regular measurements and the like. Also, the performance degradation of the reflector of the reflection device 120 may be grasped by receiving a report on the radio wave reception status from the user who uses the terminal 110. In the present embodiment, in view of such a situation, a control device 130 connected to the reflection device 120 provides a method of monitoring the presence of a defective element and autonomously reporting it to the base station 100. As a result, it is possible to grasp the presence of a defective element at an early stage without dispatching a worker or the like to the site, and to efficiently maintain and operate the reflection device 120. Hereinafter, the processing related to the detection and reporting of a defective element in the present embodiment will be described.

[0019] (Detection and Reporting of Defective Elements) The control device 130 monitors the states of each reflection element on the reflector of the reflection device 120. As an example, in order to determine whether each reflection element is operating normally, the control device 130 periodically applies a predetermined voltage to each reflection element to determine whether the liquid crystal of each reflection element is controlled to a desired dielectric constant. For example, each reflection element may have an electrode for measuring the dielectric constant of the liquid crystal. Note that the method for measuring the dielectric constant of the reflection element is not limited to this. The control device 130 calculates, for example, the difference between the measured dielectric constant of the liquid crystal and a predetermined reference value, and if the difference exceeds a threshold value, determines that the reflection element is not operating normally. Note that the method for determining whether each reflection element is operating normally is not limited to this method, and an appropriate method may be used according to the configuration of the reflector of each reflection device 120. The control device 130 monitors the states of each reflection element by periodically executing such determination processing for each reflection element.

[0020] The control device 130 reports the states of each reflection element on the reflector of the reflection device 120 to the base station 100. For example, the control device 130 reports the detection information of the detected defective element to the base station 100. As an example, the detection information is specific information that can identify the defective element. The specific information can be the position of the defective element on the reflector. For example, when the reflector is composed of M rows × N columns of reflection elements, the position of the defective element can be specified by the combination of its row number and column number. Also, when each reflection element is given an identifier that can uniquely identify the reflection element on the reflector, the control device 130 can identify the defective element using the identifier. Note that the method for identifying the defective element is not limited to these. Further, the control device 130 may report the number of detected defective elements and the defective rate to the base station 100 as the detection information. In this embodiment, the ratio of defective elements to the reflection elements constituting the reflector is referred to as the defective rate. By using the number of defective elements and the defective rate, the control device 130 can report the states of the reflection elements in the reflection device 120 to the base station 100 with a smaller amount of information compared to the case of notifying the information of each individual defective element.

[0021] (Change in reflection phase) When the base station 100 receives a report of faulty element information from the control device 130, it may change the reflection phase set for each reflector based on the reported faulty element information. For example, if the base station 100 and the control device 130 have shared in advance a set of reflector settings that anticipate the occurrence of faulty elements, the base station 100 may notify the control device 130 of information that identifies this set of reflector settings. The control device 130 may then change the reflection phase of each reflector according to the notified information.

[0022] The base station 100 may generate a new reflector element configuration that takes into account the effects of the reported faulty elements. Alternatively, a device other than the base station 100 may generate the reflector element configuration. For example, the control device 130 may generate the reflector element configuration. As an example, the base station 100 may generate a new reflector element configuration using a genetic algorithm. An example of a method for generating a reflector element configuration using a genetic algorithm is described below. First, if the reflector is composed of M rows × N columns of reflector elements, and the reflection phase of each reflector element is represented by R bits, then an M × N × R rows, P columns matrix is ​​generated in which each element of the matrix is ​​randomly assigned a value of 0 or 1. P is an arbitrary integer. Here, in the matrix, the value of the element corresponding to a faulty element is set to zero. Next, an objective function is calculated for each row, assuming that the components of each row correspond to the reflection phase of each reflector element. For example, the objective function is the transmit power in the direction in which a peak is formed in the desired reflection pattern. Once the calculation of the objective function for all rows is complete, the rows are sorted based on the values ​​of the objective functions. For example, the rows are sorted in descending order of the transmit power in the objective function. Then, the top 50% of the objective function is retained, the remaining 50% is discarded, and a new row is generated using the remaining top 50% to form column P again. The generated matrix is ​​used to calculate the objective function for each row. This process is repeated until the convergence condition is met, and the surviving components are selected as the reflection phase of each reflecting element. In this way, by using a genetic algorithm, it is possible to generate a reflecting element configuration that forms a desired reflection pattern even in the presence of defective elements.

[0023] The method for generating the reflector element settings is not limited to methods using genetic algorithms. For example, the base station 100 may generate a new reflector element setting by adding a predetermined common phase to the reflection phase of each reflector element in the current reflector element setting. For example, the effect of a reflector element not functioning properly may arise from the difference between the phase that should be set for that reflector element according to the reflector element setting and the reflection phase of the actual faulty element. Assuming that the reflection phase of the actual faulty element is zero, the effect of the faulty element can be reduced while maintaining the current reflection pattern by adding a common phase to the reflection phase of all reflector elements so that the reflection phase of the faulty element in the reflector element setting becomes zero. In this case, the base station 100 may notify the control device 130 of the amount of change in the common reflection phase to be added to the reflection phase of each current reflector element. When the reflector element setting generated by the base station 100 is notified to the control device 130, the control device 130 controls the reflection phase of each reflector element of the reflector device 120 according to the reflector element setting.

[0024] (Notification of reflection phase) When the base station 100 notifies the control device 130 of the reflective element settings it has generated, the amount of information to be notified can be enormous. For example, assuming that a reflector of 100 wavelengths is composed of approximately 40,000 reflective elements, the information of the reflection phase to be set for each of the 40,000 reflective elements will be notified. In addition, the reflective element settings may contain redundant information. The method for efficiently notifying the reflection phase in this embodiment will be explained using an example of reflective element settings shown in Figure 2. In Figure 2(A), the base station 100 extracts the difference between the reflective element settings before and after the change, based on the generated reflective element settings and the current reflective element settings of the reflecting device 120, and notifies the control device 130 only of the settings for the reflective elements with differences. For example, if the number of reflective elements with differences is D, and the reflector is composed of reflective elements in an M row × N column configuration, by notifying only the settings for the reflective elements with differences, the amount of information notified from the base station 100 to the control device 130 can be reduced to D / (M × N). In Figure 2(B), if the base station 100 has a common reflection phase for some of the reflection elements in the generated reflection element settings, it aggregates the reflection elements for which this common value is set and notifies the control device 130. For example, the base station 100 associates the common reflection phase with information identifying the reflection elements for which this reflection phase is set and notifies the control device 130. This reduces the amount of reflection phase information corresponding to the number of aggregated reflection elements. In Figure 2(C), if the base station 100 has a common regularity in the reflection phases set for some of the reflection elements in the generated reflection element information, it notifies the control device 130 of this common regularity. For example, the base station 100 associates information identifying the common regularity with information identifying the reflection elements to be set and notifies the control device 130. One example of a common regularity is to set the reflection phase sequentially for a predetermined range of reflection elements, using a faulty element as a reference, while increasing the phase by the same amount. Figure 2(C) shows a rule for setting the reflection phase of each reflection element while increasing it by 10 [deg] in the Y direction. The base station 100 may also notify the control device 130 of information specifying which of the above-described methods to use to notify the reflective element settings.For example, an identifier may be assigned to each notification method, and during the connection process between the base station 100 and the control device 130, the base station 100 may notify the control device 130, or the control device 130 may notify the base station 100. Alternatively, each time 100 notifies the control device 130 of the reflective element information, it may notify the control device 130 of the notification method to be used. The base station 100 may also generate a new reflective element setting for each reflection pattern and notify the control device 130 of it.

[0025] (Control of monitoring and reporting processes by base stations) The control device 130 connected to the reflector 120 monitors for the presence of faulty elements in the reflector 120 and autonomously reports this to the base station 100, enabling efficient maintenance and operation of the reflector 120. On the other hand, if faulty elements are frequently reported from a large number of control devices 130, the amount of information required for these reports will increase, potentially affecting data communication. For example, if faulty element reports are made using a portion of the control channel or header on the wireless frame, similar to other control information, the reporting of faulty elements may strain the transmission of other control information, potentially causing delays in data communication. Also, if the failure rate is low, the impact of faulty elements on the reflection pattern may be small. In this embodiment, as an example, a method is provided in which the base station 100 controls the monitoring of faulty elements and the reporting of faulty element information performed by each control station 130.

[0026] The base station 100 generates monitoring settings to control the monitoring of faulty elements performed by the control device 130, and notifies the control device 130. For example, if the control device 130 is to periodically determine the state of each reflective element and report the determination result, the base station 100 notifies the control device 130 of monitoring settings that include the period during which the determination is performed. Also, for example, if the control device 130 is to perform monitoring processing semi-permanently, the base station 100 notifies the control device 130 of monitoring settings that include the period during which the determination is performed and the period during which the determination is performed within that period. The base station 100 may also request that the control device 130 perform the determination at a time instructed by the base station 100. In this case, the base station 100 may notify the control device 130 of monitoring settings that include the time at which the determination is to be performed. Furthermore, the base station 100 may notify the control device 130 of monitoring settings that include conditions for changing the period during which the determination is performed. For example, the period during which the determination is performed may be changed on the condition that the failure rate exceeds a threshold. In this case, the base station 100 notifies the control processing unit 130 of the monitoring settings, which include a threshold for the failure rate as a condition for changing the judgment period, and the judgment periods before and after the condition is met.

[0027] Furthermore, the base station 100 may generate a report setting to control the reporting of defective element information performed by the control device 130 and notify the control device 130. For example, if the base station 100 controls the control device 130 to make a report when a predetermined condition is met, the base station 100 notifies the control device 130 of a report setting that includes that condition. For example, if the condition is that the failure rate exceeds a threshold, the base station 100 notifies the control device 130 of a report setting that includes the failure rate threshold. Also, if the control device 130 is to make a report after the failure rate has exceeded a threshold, the report setting may include multiple failure rate thresholds. For example, if the first to third thresholds in the report setting are set to 0.1, 0.2, and 0.3 respectively, the control device 130, upon receiving this, will make a report to the base station 100 if the failure rate exceeds any of 0.1, 0.2, or 0.3. The control device 130 may report to the base station 100 information that identifies each defective element, the failure rate, the failure rate threshold for which the condition was met in the current report, etc. Furthermore, the base station 100 may instruct the control device 130 to periodically report information on defective elements. In this case, the base station 100 may notify the control device 130 of the reporting settings, including the reporting cycle. If the control device 130 is to report semi-permanently, the base station 100 may notify the control device 130 of the reporting settings, including the reporting period and the reporting cycle within that period. If the base station 100 requests the control device 130 to report at a specified time, the base station 100 may notify the control device 130 of the reporting settings, including the time for reporting. The base station 100 may notify the control device 130 of the reporting settings, including conditions for changing the reporting cycle. For example, the cycle for making a determination may be changed on the condition that the failure rate exceeds a threshold.

[0028] The control device 130 monitors for faulty elements or reports information about faulty elements based on the monitoring settings or reporting settings notified by the base station 100. The base station 100 may request the control device 130 to perform monitoring or reporting processing to check the status of the reflective elements, regardless of whether or not there are monitoring or reporting settings. When the control device 130 receives a request from the base station to perform monitoring or reporting processing, it makes a determination about the status of each reflective element and reports the result to the base station 100. The period included in the monitoring or reporting settings may also be a frequency. If the unit time is shared between the base station 100 and the control device 130, notification can be made with less information if the frequency is used than if the period is used. The base station 100 may also notify the monitoring settings and reporting settings in the same message. Notifying in the same message reduces the amount of information due to overhead compared to notifying in multiple messages.

[0029] (Stop notification when the defect rate exceeds the threshold) If the failure rate in the reflector 120 is high, there is a high probability that the desired reflection pattern will not be formed even if the reflection phase of the normally functioning reflector elements is changed. For example, it may be necessary to replace the reflector or the reflector 120 itself. In this embodiment, in such a situation, the control device 130 may stop reporting information about the defective elements. The control device 130 may also stop controlling the reflector 120. The control device 130 may also turn off the power to the reflector 120. By stopping the reporting process or stopping the control of the reflector 120, the power consumption can be reduced. In addition, by stopping the reporting process, the control device 130 can efficiently utilize wireless resources. In particular, if the control device 130 is performing connection processing with the base station 100 for reporting purposes, stopping the reporting process has the advantage of eliminating the need to perform connection processing.

[0030] The control device 130 may autonomously stop the reporting process if predetermined conditions are met. The control device 130 may also notify the base station 100 that the predetermined conditions have been met or that its device has stopped the reporting process. Furthermore, if predetermined conditions are met, the control device 130 may autonomously stop controlling the reflector 120 or turn off the reflector 120. The control device 130 may also notify the base station 100 that the predetermined conditions have been met, that it has stopped controlling the reflector 120, or that it has turned off the power to the reflector 120. When the power to the reflector 120 is turned off, the reflector of the reflector 120 becomes a reflector that performs, for example, specular reflection or mirror reflection, depending on the physical state of the surface of the reflector with respect to the incident radio waves.

[0031] The conditions under which the control device 130 stops reporting or stops controlling the reflector may be notified to the control device 130 from the base station 100. For example, the base station 100 may notify the control device 130 of reporting settings that include the conditions for stopping reporting. The base station 100 may also notify the control device 130 of reporting settings that include the conditions for stopping the control of the reflector. The conditions for stopping reporting and the conditions for stopping the control of the reflector may be the same or different. An example of a predetermined condition may be that the defect rate exceeds a predetermined threshold. The predetermined condition may be other conditions, such as the number of defective elements exceeding a threshold, or the defect rate in some of the regions of the reflector exceeding a threshold when the reflector is divided into multiple regions. The base station 100 may also notify the control device 130 of the conditions for stopping the control of the reflector as an instruction, and the control device 130 may notify this instruction and the conditions for stopping reporting in the same message. Notifications that the control device 130 stops reporting processing, stops controlling the reflector 120, or turns off the power to the reflector 120 may be called stop notifications.

[0032] (Method of notification from base station 100 to control device 130) The base station 100 can transmit configuration information such as reflector element settings, monitoring settings, and reporting settings, or the aforementioned notifications and instructions, to the control device 130 using procedures and frames defined in the 3GPP cellular communication standard. For example, the base station 100 notifies the control device 130 of configuration information using Radio Resource Control (RRC) messages. In this case, for example, a new type of message for notifying configuration information may be defined in the RRC Reconfiguration message. When the control device 130 receives an RRC message, it extracts the configuration information contained in the message. Then, according to the extracted configuration information, the control device 130 performs settings such as controlling the reflection phase of each reflector element, monitoring the reflector elements, and reporting faulty elements.

[0033] The base station 100 may notify the control device 130 of configuration information, etc., using a media access control (MAC) subheader. In this case, a new MAC subheader format for notifying configuration information may be defined. Alternatively, some fields of an existing MAC subheader may be repurposed for notifying configuration information. For example, a field of a predetermined number of bits may be provided in the MAC subheader to indicate configuration information. The control device 130 analyzes the MAC subheader included in the signal addressed to its device and obtains the configuration information. Then, according to the acquired reflective element settings, the control device 130 performs settings such as controlling the reflection phase of each reflective element, monitoring the reflective elements, and reporting defective elements.

[0034] In order to use RRC messages or MAC subheaders, an RRC connection must be established between the base station 100 and the control device 130. Therefore, when using RRC messages or MAC subheaders, a processing load such as connection establishment occurs between the base station 100 and the control device 130 each time configuration information is notified. On the other hand, the control device 130 sends an acknowledgment notification indicating that it has successfully received the RRC message or MAC subheader. This acknowledgment notification allows the base station 100 to confirm that the reflection pattern of the reflector 120 has been changed or that the control device 130 has set up monitoring or reporting processing, enabling highly reliable control. Furthermore, since the reflective element settings set on the reflector 120 can be reliably shared between the base station 100 and the reflector 120, it is also possible to control the reflector 120 by notifying only the difference in the reflective element settings for the changed reflective elements. Note that since RRC messages can contain a lot of information, when using RRC messages, the base station 100 can notify the control device 130 of the reflective element settings by any of the methods described above.

[0035] Furthermore, the base station 100 may notify the control device 130 of the configuration information using downlink control information (DCI) as defined in the 3GPP cellular communication standard. In this case, a new DCI format for notifying the configuration information may be defined. Alternatively, a part of an existing DCI format may be repurposed for notifying the configuration information. In the DCI, for example, a field of a predetermined number of bits may be provided to indicate the reflector element settings. The control device 130 decodes the physical downlink control channel (PDCCH). In one example, a radio network temporary identifier (RNTI) may be assigned to the control device 130 in advance. In this case, the control device 130 can obtain information from the DCI addressed to itself by decoding the PDCCH using the RNTI. If an RNTI is assigned in advance, the control device 130 can decode the PDCCH simply by observing the synchronization signal to establish time synchronization of the downlink (the link from the base station 100 to the control device 130). In other words, in this case, the control device 130 does not need to perform a random access procedure to establish uplink synchronization with the base station 100, nor does it need to establish a connection at the RRC layer. Therefore, the connection establishment process and other related processes can be omitted, and the processing load can be reduced.

[0036] The base station 100 may notify the control device 130 of the configuration information using system information transmitted by broadcast or multicast. An example of system information is a Master Information Block (MIB) or a System Information Block (SIB). In this case, a new type of information block for notifying the reflective element configuration may be defined. Alternatively, some elements of an existing SIB or MIB may be repurposed to notify the configuration information. In the SIB or MIB, for example, a field of a predetermined number of bits may be provided to indicate the configuration information. When using system information transmitted by broadcast or the like, the information transmitted from the base station 100 is received by all control devices 130 and terminals 110. Therefore, the control device 130 needs to determine whether the received information is relevant to the reflective device 120 that it controls and monitors. When the base station 100 notifies the configuration information using broadcast or the like, it may include information that identifies the target control device 130 or reflective device 120. The control device 130 extracts the configuration information for its own device or the reflective device 120 connected to its device from the received system information. The control device 130 then performs the following actions according to the extracted setting information: control of the reflection phase of each reflective element, monitoring of the reflective elements, and setting up the reporting process for defective elements.

[0037] Furthermore, a signaling protocol layer may be defined for notifying reflective element settings, monitoring settings, or reporting settings. For example, the protocol used in this layer may be called the Intelligent Reflecting Surface protocol (IRS protocol). Alternatively, this layer may be called the IRS protocol layer. For example, the control device 130 receives a message from the IRS protocol layer and, based on the setting information contained in the message, sets the control of the reflection phase of each reflective element, the monitoring process for reflective elements, the reporting process for defective elements, etc. By defining an IRS protocol layer, it becomes possible to use a message format suitable for notifying setting information. Note that the above-mentioned methods for notifying setting information may be used in combination.

[0038] (Method of notification from control device 130 to base station 100) The control device 130 can report information about faulty elements, notify the base station 100 of the cessation of reporting processing, and notify the base station 100 of the cessation of control of the reflector 120, using procedures and frames specified in the 3GPP cellular communication standard. As an example, the control device 130 can perform the above-mentioned reports and notifications using UE Capability Signaling. UE Capability Signaling is a signaling method for notifying the base station 100 of the UE's capabilities and is used after an RRC connection is established with the base station 100. Therefore, it can include more information compared to, for example, when reporting or notifying using a control channel. For example, by using UE Capability Signaling, the control device 130 can report information about faulty elements to the base station 100 in any of the above-mentioned ways. In addition, by using UE Capability Signaling, the base station 130 can receive an acknowledgment that it has received the report or notification, thus enabling highly reliable control. In this case, a new field may be defined in UE Capability Signaling for the control device 130 to perform reports and notifications. The base station 100 extracts information about each reflecting element included in the UE Capability Signaling, notifications of the cessation of reporting processing, notifications of the cessation of control of the reflecting device 120, and so on.

[0039] The control device 130 may use random access procedure message 1 or message 3 to make the above-mentioned reports and notifications. For example, when using random access procedure message 1, the control device 130 can report information about faulty elements to the base station 100 by utilizing the fact that multiple preamble patterns are available. For example, by pre-determining preamble patterns corresponding to the information about faulty elements that the control device 130 will report, the control device 130 can select a pattern corresponding to the information about faulty elements to report and perform random access. The base station 100 identifies the information about faulty elements based on the pattern selected by the control device 130. A combination of multiple preamble patterns may be used to notify information about faulty elements. The base station 100 extracts information about the corresponding faulty element based on the preamble pattern received from the control device 130 in the random access channel. Furthermore, when the control device 130 notifies the cessation of reporting processing or the cessation of control of the reflector 120, for example, preamble patterns corresponding to the information to be notified may be pre-determined between the base station 100 and the control device 130. The control device 130 can notify the base station 100 of the cessation of reporting processing or the cessation of control of the reflector 120 by selecting and transmitting a preamble pattern according to the information to be notified. On the other hand, when using random access procedure message 3, a new field may be defined for the control device 130 to report and notify. Alternatively, some fields of an existing message may be repurposed for reporting or notification by the control device 130. The base station 100 extracts information from the fields in the message, such as reporting information on each reflector, notification of the cessation of reporting processing, and notification of the cessation of control of the reflector 120.

[0040] The control device 130 may use uplink control information (UCI) to perform the above-mentioned reports and notifications. In this case, a new UCI format may be defined for the control device 130 to perform reports and notifications. Alternatively, an existing UCI format may be repurposed for reports or notifications by the control device 130. In the UCI, for example, a field of a predetermined number of bits may be provided to indicate the information of each reflector, the cessation of reporting processing, or the cessation of control of the reflector 120. The base station 100 extracts from the UCI the reports of information of each reflector, the notifications of the cessation of reporting processing, the notifications of the cessation of control of the reflector 120, etc.

[0041] When using Random Access Procedure messages or UCI, it is not necessary for an RRC connection to be established between the base station 100 and the control device 130, so reports or notifications can be made without performing connection establishment or other processing. For example, if reporting of faulty element information is frequently required, the control device 130 can make the report without imposing a large processing load.

[0042] Furthermore, reporting of information on each reflector, notification of the cessation of reporting processing, and notification of the cessation of control of the reflector 120 may be performed at the IRS protocol layer. The base station 100 receives messages at the IRS protocol layer and acquires information such as information on each reflector, the cessation of reporting processing, and the cessation of control of the reflector 120 contained in the message. By defining a protocol layer for IRS, it becomes possible to use a message format suitable for reporting or notification by the control device 130. Note that the above-mentioned reporting or notification methods may be used in combination.

[0043] (Device configuration) Next, an example configuration of the base station 100 and control device 130 described above will be explained. Figure 3 is a diagram showing the hardware configuration of the base station 100 and control device 130. In one example, the base station 100 and control device 130 are configured to include a processor 301, ROM 302, RAM 303, storage device 304, and communication circuit 305. The processor 301 is a computer configured to include one or more processing circuits, such as a general-purpose CPU (Central Processing Unit) or ASIC (Application-Specific Integrated Circuit). The processor 301 performs the overall processing of the device and the individual processing described above by reading and executing programs stored in the ROM 302 and storage device 304. The ROM 302 is a read-only memory in which information such as programs and various parameters related to the processing performed by the base station 100 and control device 130 is recorded. The RAM 303 functions as a workspace when the processor 301 executes programs and is a random access memory in which temporary information is recorded. The storage device 304 is configured, for example, by a removable external storage device. The communication circuit 305 is configured to include, for example, a circuit for wired or wireless communication between the base station 100 and the control device 130. For example, the base station 100 may communicate with the control device 130 using a communication circuit 305 for LTE or 5G for communication with the terminal device 110. However, this is just an example, and the base station 100 may be configured to communicate with the control device 130 using a communication circuit 305 for wired or wireless communication, which is provided separately from the communication circuit 305 for LTE or 5G. The control device 130 has a communication circuit 305 for wireless or wired communication for communication with the base station 100. The control device 130 may also have a communication circuit 305 for (for example, wired) communication with the reflector 120. Although one communication circuit 305 is shown in Figure 3, the base station 100 and the control device 130 may have multiple communication circuits. Multiple communication functions may be implemented by a single communication circuit 305.

[0044] Figure 4 shows an example of the functional configuration of the control device 130. The control device 130 has, for example, a monitoring unit 401, a reporting unit 402, an acquisition unit 403, a reflection device control unit 404, and a notification unit 405. These functional units can be realized, for example, by the processor 301 executing a program stored in the ROM 302 or storage device 304 and controlling the communication circuit 305 as needed. However, it is not limited to this, and for example, dedicated hardware may be provided to realize each function.

[0045] The monitoring unit 401 monitors for the presence of defective elements in the reflector 120. The monitoring unit 401 may also monitor for the presence of defective elements by periodically determining the state of each reflector based on the monitoring settings notified by the base station 100. The monitoring settings include information such as the period during which the monitoring unit 401 determines the state of each reflector. The monitoring device 401 may autonomously determine the state of each reflector regardless of whether or not there are monitoring settings. Alternatively, it may determine the state of each reflector aperiodically based on instructions from the base station 100. If the monitoring unit 401 detects a defective element, it notifies the reporting unit 402.

[0046] The reporting unit 402 reports information about defective elements to the base station 100. The reporting unit 402 may also make a report when the set conditions are met, based on the reporting settings notified by the base station 100. The reporting settings may include, for example, a threshold for the failure rate as a condition for performing a report. As an example, the reporting unit 402 aggregates the number of defective elements notified by the monitoring unit 401 and determines whether the failure rate exceeds the threshold. If the failure rate exceeds the threshold, the reporting unit 402 reports to the base station 100, for example, information that identifies the defective elements. The information that identifies the failure rate may be information indicating the location of the defective elements on the reflector. The acquisition unit 403 acquires information necessary for the operation of the control unit 130 from the base station 100. The information necessary for the operation of the control unit 130 includes, for example, reflector settings, monitoring settings, reporting settings, etc. The acquisition unit 403 notifies each function of the information acquired from the base station 100. For example, the acquisition unit 403 notifies the reflector control unit 404 of the reflector element settings, the monitoring unit 401 of the monitoring settings, and the reporting unit 402 of the reporting settings. The reflector control unit 404 controls the reflection phase of each reflector element of the reflector device 120. The reflector control unit 404 may set the reflection phase of each reflector element based on the reflector element settings notified by the base station 100. The reflector element settings include information that identifies the reflector element whose reflection phase is to be set and information that identifies the reflection phase to be set.

[0047] The notification unit 405 notifies the base station 100 of the cessation of reporting, the cessation of control of the reflector, etc. For example, if the reporting settings notified by the base station 100 include a condition to stop reporting information on defective elements, the reporting unit 402 notifies the notification unit 405 that this condition has been met. Based on this notification, the notification unit 405 notifies the base station 100 that the condition to stop reporting has been met. Note that if the reporting cessation condition has been met, the reporting unit 402 will not report to the base station 100 even if the conditions for reporting information on defective elements are met thereafter. On the other hand, for example, if the reporting settings notified by the base station 100 include a condition to stop control of the reflector, the reporting unit 402 notifies the notification unit 405 and the reflector control unit 404 that this condition has been met. Upon receiving this notification, the reflector control unit 404 stops control of the reflector 120. Upon receiving this notification, the notification unit 405 notifies the base station 100 that the condition to stop control of the reflector has been met. The condition for stopping control of the reflector may also be the condition for turning off the power to the reflector. In this case, the reflector control unit 404 may turn off the power to the reflector 120 when this condition is met, and the notification unit 405 may notify the base station 100 that the condition for turning off the power to the reflector has been met.

[0048] Figure 5 shows an example of the functional configuration of the base station 100. The base station 100 has, for example, an acquisition unit 501, a reflector element setting unit 502, a monitoring setting unit 503, and a reporting setting unit 504. These functional units can be realized, for example, by a processor 301 executing a program stored in the ROM 302 or storage device 304 and controlling the communication circuit 305 as needed. However, it is not limited to this, and for example, dedicated hardware may be provided to realize each function.

[0049] The acquisition unit 501 acquires information about defective elements from the control device 130. This information includes, for example, information that identifies the defective element. The acquisition unit 501 notifies the reflective element setting unit 502 of the acquired information about defective elements. The reflective element setting unit 502 determines the reflection phase to be set for each reflective element of the reflecting device 120. The reflective element setting unit 502 may also determine the reflection phase to be set for each reflective element for each reflection pattern. Upon receiving information about defective elements from the acquisition unit 501, the reflective element setting unit 502 determines whether or not to change the reflection phase. For example, the reflective element setting unit 502 identifies the reflection pattern when the reflection phase of the defective element is set to zero, and compares the difference between the peak of the identified reflection pattern and the peak of the reflection pattern when all reflective elements were operating normally. The reflective element setting unit 502 may determine to change the reflection phase if the difference exceeds a threshold. The reflective element setting unit 502 notifies the control device 130 of the changed reflective element settings.

[0050] The monitoring setting unit 503 and the reporting setting unit 504 generate monitoring settings and reporting settings to control the monitoring and reporting processes performed by the control device 130, respectively, and notify the control device 130. The monitoring settings may include the period for which the control device 130 determines the state of the reflecting elements. The reporting settings may include the conditions under which the control device 130 reports defective elements. The reporting settings may also include conditions under which the control device 130 stops the reporting process or stops controlling the reflecting device. When the conditions for stopping the reporting process or stopping the control of the reflecting device are met, the acquisition unit 501 receives a notification from the control device 130 of the report stop or the reflecting device control stop. When the base station 100 receives these notifications, it may execute a procedure or process to communicate with the terminal 110 without going through the reflecting device 120.

[0051] (Process flow) Next, we will explain an example of the processing flow performed in a wireless communication system. Since the details of the processing are as described above, we will only provide an overview of the processing flow here and will not repeat the details.

[0052] Figure 6 shows an example of the processing flow when the control device 130 reports a detected faulty element to the base station 100, and the base station 100 notifies the control device 130 of the reflective element settings to be set in the reflector 120. It is assumed that the pattern ID and reflective element settings are shared in advance between the base station 100 and the control device 130 for each reflection pattern. First, the base station 100 determines the reflection pattern for communication with the terminal 110 (S601) and notifies the control device 130 of the pattern ID corresponding to this reflection pattern (S602). The control device 130 determines the reflection phase of each reflective element in the reflector 120 according to the notified pattern ID (S603). For example, the control device 130 may have a table showing the reflection phase of each reflective element for each pattern ID. The control device 130 sets each reflective element in the reflector 120 using the determined reflection phase (S604). Now, suppose a faulty element has occurred in the reflector 120 (S605). The control device 130 periodically monitors the reflective elements (S606) and detects faulty elements by determining the state of each reflective element (S607). The control device 130 reports information about the detected faulty elements to the base station 100 (S608). As described above, the control device 130 may also report information about faulty elements when the conditions are met, according to the reporting settings notified in advance by the base station 100. Based on the reported information about faulty elements, the base station 100 generates new reflective element settings (S609). Any method described above may be used to generate the reflective element settings, or other methods may be used. The base station 100 notifies the control device 130 of the generated reflective element settings (S610). The control device 130 determines the reflection phase to be set for each reflective element of the reflecting device 120 according to the notified reflective element settings (S611). The control device 130 sets each reflective element of the reflecting device 120 using the determined reflection phase (S612). In this way, the control device 130 can detect defective elements in the reflector 120 and notify the base station 100 of the information about the defective elements, and the base station 100 can control the reflector to change the reflection phase of the reflector elements based on the notified information about the defective elements.

[0053] Figure 7 shows an example of the processing flow when the control device 130 performs monitoring and reporting processing for defective elements according to the monitoring settings and reporting settings generated by the base station 100. First, the base station 100 determines the period during which the control device 130 will monitor the reflector 120 and the conditions for the control device 130 to report defective elements, and generates the monitoring settings and reporting settings (S701). For example, suppose the reporting setting indicates that the condition for reporting defective elements is when the defect rate exceeds a first threshold of 0.1 or a second threshold of 0.2. The base station 100 notifies the control device 130 of the generated monitoring settings and reporting settings (S702). Now, suppose a defective element has occurred in the reflector 120 (S703). The control device 130 periodically determines the state of each reflector element of the reflector 120 according to the monitoring settings notified by the base station 100 and detects the defective element (S704). Here, for example, if the failure rate calculated by the control device 130 exceeds the first threshold, the conditions shown in the reporting settings are satisfied (S705), and the control device 130 reports information about the faulty element to the base station 100 (S706). The processing flow from S707 to S710 is the same as S609 to S612 in Figure 6, so the explanation is omitted. Next, suppose that another faulty element occurs in the reflector 120 (S711). The control device 130 continues to monitor for faulty elements even after changing the reflection phase of each reflector element. The control device 130 detects a faulty element (S712), and for example, if the failure rate calculated by the control device 130 exceeds the second threshold of 0.2 shown in the reporting settings (S713), the control device 130 reports information about the faulty element to the base station 100 (S714). In this way, it is possible to control the monitoring of reflector elements and reporting of faulty elements by the control device 130 based on the monitoring setup and reporting settings generated by the base station 100.

[0054] Figure 8 shows an example of the processing flow when the control device 130 stops reporting information about defective elements or stops controlling the reflector 120. First, the base station 100 determines the conditions for the control device 130 to stop reporting information about defective elements or the conditions for the control device 130 to stop controlling the reflector 120 (S801). These conditions may be the same or different from each other. For example, the base station 100 determines that the defect rate has exceeded a predetermined threshold as the same condition and notifies the control device 130 (S802). Notification of the conditions may be included in the reporting settings notified from the base station 100 to the control device 130. Now, suppose a defective element has occurred in the reflector 120 (S803). The control device 130 periodically determines the state of each reflector and detects a defective element (S804). For example, if the defect rate calculated by the control device 130 exceeds a predetermined threshold, the set condition is satisfied (S805), and the control device 130 notifies the base station 100 that the condition has been met (S806). The control device 130 also stops controlling the reflector 120 and controls the reflector 120 to turn off its power (S807). The control device 130 then notifies the base station 100 that it has stopped controlling the reflector 120 or that it has turned off its power (S808). The reflector 120 turns off its own power in accordance with the control from the control device 130 (S809). In this way, the control device 130 can report information about defective elements and stop controlling the reflector 120 based on the conditions set by the base station 100.

[0055] As described above, according to this embodiment, the control device 130 autonomously monitors the state of the reflective elements of the reflector 120 and reports information about defective elements to the base station. The base station then identifies the reflection phase to be set for the reflective elements based on the reported information about defective elements and notifies the reflector 120. The reflector 120 controls the reflective elements of the reflector 120 according to the notified reflection phase. This makes it possible to efficiently detect defective elements in a wireless communication system using a reflector.

[0056] The invention is not limited to the embodiments described above, and various modifications and changes are possible within the scope of the gist of the invention. [Explanation of symbols]

[0057] 100: Base station, 110: Terminal, 120: Reflector, 130: Control device

Claims

1. A control device for controlling a reflecting device that reflects radio waves transmitted from a base station using a reflector composed of multiple reflecting elements, A monitoring means that performs a monitoring process to monitor for the presence of a defective element, which is a reflective element that does not function properly, A reporting means that performs a reporting process to report information about the defective element, The system includes an acquisition means for acquiring configuration information from the base station for performing at least one of the monitoring process and the reporting process. A control device characterized by the following features.

2. The aforementioned configuration information includes the period or frequency at which the monitoring process is performed. The control device according to feature 1.

3. The setting information includes the period or frequency for executing the monitoring process when the defect rate, which is the ratio of defective elements to the reflective elements constituting the reflector, exceeds a predetermined threshold. The control device according to feature 1.

4. The aforementioned configuration information includes one or more of the following: the period, frequency, and conditions for executing the reporting process. The control device according to feature 1.

5. The reporting means notifies the base station of the configuration information using at least one of the following: UE Capability Signaling in the cellular communication standard of the Third Generation Partnership Project (3GPP), message 1 or message 3 of the random access procedure, uplink control information, and the Intelligent Reflecting Surface protocol. The control device according to feature 1.

6. A base station that communicates with a control device that controls a reflective device that reflects radio waves using a reflector composed of multiple reflective elements, A generation means for generating setting information for performing at least one of the following processes: a monitoring process for monitoring the presence of a faulty element, which is a reflective element that does not function properly, and a reporting process for reporting information about the faulty element. The system includes a notification means for notifying the control device of the aforementioned setting information. A base station characterized by the following features.

7. The aforementioned configuration information includes the period or frequency at which the monitoring process is performed. The base station described in commodity statement 6.

8. The setting information includes the period or frequency for executing the monitoring process when the defect rate, which is the ratio of defective elements to the reflective elements constituting the reflector, exceeds a predetermined threshold. The base station described in commodity statement 6.

9. The aforementioned configuration information includes one or more of the following: the period, frequency, and conditions for executing the reporting process. The base station described in commodity statement 6.

10. The notification means notifies the control device of the configuration information using at least one of the following: a Radio Resource Control (RRC) message in the Third Generation Partnership Project (3GPP) cellular communication standard, downlink control information or a media access control (MAC) subheader, a system information block and a master information block, and an Intelligent Reflecting Surface protocol. The base station described in commodity statement 6.

11. A control method performed by a control device that controls a reflecting device that reflects radio waves transmitted from a base station using a reflector composed of multiple reflecting elements, A monitoring step includes performing a monitoring process to detect the presence of a defective element, which is a reflective element that does not function properly, A reporting step which involves performing a reporting process to report information about the defective element, The process includes an acquisition step of acquiring setting information from the base station for performing at least one of the monitoring process and the reporting process. A control method characterized by the following:

12. A control method performed by a base station that communicates with a control device that controls a reflective device that reflects radio waves using a reflector composed of multiple reflective elements, A generation step that generates setting information for performing at least one of the following processes: a monitoring process that monitors for the presence of a faulty element, which is a reflective element that does not function properly, and a reporting process that reports information about the faulty element. The process includes a notification step of notifying the control device of the aforementioned setting information. A control method characterized by the following:

13. A control device that controls a reflecting device that reflects radio waves transmitted from a base station using a reflector composed of multiple reflecting elements has a computer equipped with it. A monitoring process is executed to detect the presence of a faulty element, which is a reflective element that does not function properly. The system then executes a reporting process to report information about the defective element. The base station is used to obtain configuration information for performing at least one of the monitoring process and the reporting process. A program for that purpose.

14. A computer in a base station that communicates with a control device that controls a reflective device that reflects radio waves using a reflector composed of multiple reflective elements, The system generates configuration information for performing at least one of the following processes: a monitoring process that monitors for the presence of a faulty element, which is a reflective element that does not function properly, and a reporting process that reports information about the faulty element. The setting information is notified to the control device. A program for that purpose.

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