Control device and control method for suppressing network power consumption in cellular communication system

Abstract

This control device operates as a base station device of a first-generation first cellular communication system, and shares a plurality of antennas with another control device that operates as a base station device of a second-generation second cellular communication system, and the control device receives, from the other control device, information indicating the state of communications executed by the other control device, and determines whether or not to stop the operation of one or more antennas among the plurality of antennas on the basis of the state of communications executed by the control device and the information. If it is determined that the operation of one or more antennas is to be stopped, the control device controls the plurality of antennas to stop the operation of the one or more antennas, and notifies the other control device that the operation of the one or more antennas has been stopped.

Description

Control device and control method for suppressing power consumption of a network in a cellular communication system 【0001】 The present invention relates to a power-saving technology for a network in a cellular communication system. 【0002】 Currently, the fifth-generation (5G) cellular communication system is widely used, and in the future, it is expected that the sixth-generation (6G) cellular communication system will be standardized and widely deployed. It is assumed that the 5G wireless communication system and the 6G wireless communication system will coexist for a certain period from the start of the introduction of 6G. Non-Patent Document 1 describes a base station device that includes antennas and communication circuits with different configurations for 5G and 6G, respectively, in one housing and executes communication for each of 5G and 6G. 【0003】 When the base station device has different antennas and communication circuits for executing communication of a plurality of wireless communication systems of different generations, it is assumed that the scale of the device becomes too large. In contrast, the base station device can suppress the device scale by using a configuration that shares a part of the device configuration. 【0004】 M. E. Leinonen, M. Jokinen, N. Tervo, O. Kursu, A. Parssininen, "Radio interoperability in 5G and 6G multi-radio base station" 【0005】 In recent years, in a cellular communication system, it has been required to suppress not only the power consumption of terminal devices but also the power consumption of the network. 【0006】 The present invention provides a power-saving control technology for a network in an environment where a part of the device configuration for a plurality of wireless communication systems is shared. 【0007】A control device according to one aspect of the present invention is a control device that operates as a base station device for a first generation first cellular communication system and shares a plurality of antennas with another control device that operates as a base station device for a second generation second cellular communication system different from the first generation, and includes receiving means for receiving information from the other control device indicating the state of communication performed by the other control device; determination means for determining whether or not to stop the operation of one or more of the plurality of antennas based on the state of communication performed by the control device and the information; control means for controlling the plurality of antennas to stop the operation of one or more antennas when it is determined that the operation of one or more antennas should be stopped; and notification means for notifying the other control device of the cessation of the operation of one or more antennas when it is determined that the operation of one or more antennas should be stopped. 【0008】 A control device according to another aspect of the present invention is a control device operating as a base station device of a second cellular communication system of a second generation different from the first generation, which shares a plurality of antennas with another control device operating as a base station device of a first generation first cellular communication system, and comprises: notification means for notifying the other control device of information indicating the status of communication performed by the control device; receiving means for receiving a notification from the other control device indicating the cessation of operation of one or more of the plurality of antennas; and communication means for performing communication using an antenna among the plurality of antennas that is not included in the one or more of the plurality of antennas. 【0009】 According to the present invention, power consumption can be reduced in a network environment where some of the device configurations for multiple wireless communication systems are shared. 【0010】 Other features and advantages of the present invention will become apparent from the following description with reference to the accompanying drawings. In the accompanying drawings, the same or similar components are given the same reference numeral. 【0011】The attached drawings are included in the specification and constitute a part thereof, illustrating embodiments of the present invention and are used to explain the principles of the present invention together with the description thereof. Figure 1 is a diagram showing an example configuration of a wireless communication system. Figure 2 is a diagram showing an example hardware configuration of a control device. Figure 3 is a diagram showing an example of the functional configuration of a first control device. Figure 4 is a diagram showing an example of the functional configuration of a second control device. Figure 5 is a diagram showing an example of the processing flow executed in a wireless communication system. 【0012】 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. 【0013】(System Configuration) Figure 1 shows an example of the configuration of the wireless communication system according to this embodiment. This wireless communication system includes a 5G DU / CU 101 that functions as a base station device for a wireless communication system compliant with the fifth-generation (5G) cellular communication standard, and a 6G DU / CU 102 that functions as a base station device for a wireless communication system compliant with the sixth-generation (6G) cellular communication standard. DU stands for Distributed Unit, and CU stands for Central Unit. A DU / CU is a control device that implements the functions of a base station device. That is, the 5G DU / CU 101 is a first control device that performs control for 5G communication, and the 6G DU / CU 102 is a second control device that performs control for 6G communication. The 5G DU / CU 101 and the 6G DU / CU 102 share a Radio Unit (RU 103). Specifically, the 5G DU / CU 101 communicates with the 5G terminal device 111 via the RU 103, and the 6G DU / CU 102 communicates with the 6G terminal device 112 via the RU 103. The 5G DU / CU 101 and the 6G DU / CU 102 may be housed in a single enclosure, or they may be implemented as separate devices located in different locations. The RU 103 includes at least multiple antennas and may include frequency converters, amplifiers, etc., as needed. In this way, by sharing antennas, etc. (RU) among control devices (DU / CU) of multiple generations of wireless communication systems, the size of the devices can be reduced compared to the case where separate antennas, etc. are provided for each of those control devices. In Figure 1, one 5G DU / CU 101, one 6G DU / CU 102, and one RU 103 are shown, but of course, many of these devices exist. Furthermore, the number of terminal devices shown in Figure 1 is just an example, and there may be more or, in some cases, fewer terminal devices than those shown. Also, 5G and 6G are examples of different generations of cellular communication standards, and other different generations of cellular communication standards, such as 6G and 7th generation (7G), or 4G and 6G, may be used. 【0014】In recent years, cellular communication systems have required power saving not only for terminal devices but also for the network. Therefore, in this embodiment, it is possible to stop using one or more antennas, which are part of the multiple antennas (antenna ports) included in RU103. This allows all antennas to be used when the volume of communication or the number of terminal devices is large, while power supply to some antennas is stopped when the volume of communication or the number of terminal devices is small, thereby suppressing power consumption. Alternatively, RU103 may suppress power consumption by turning off the communication function while maintaining power supply to the antennas. In one example, RU103 may disconnect the connection between the antenna and the frequency converter and the amplifier. Furthermore, RU103 may use a specific antenna for transmitting a predetermined signal such as a reference signal, but not for communicating user data. Also, RU103 may use a specific antenna for transmitting downlink signals but not for receiving uplink signals. Conversely, RU103 may use a specific antenna for receiving uplink signals but not for transmitting downlink signals. 【0015】 Power saving control in RU103 is performed by sending an instruction signal to RU103 from either the 5G DU / CU101 or the 6G DU / CU102. Here, the 5G DU / CU101 or the 6G DU / CU102 can independently control RU103 based on, for example, the number of connected terminal devices or the total data rate. For example, the 6G DU / CU102 may perform control to turn off the power to some of the antennas included in RU103 based on the fact that there are few connected 6G terminal devices 112. In this case, even if there are many connected 5G terminal devices 111 and it is necessary to use all of the antennas, the RU103 may stop using some of the antennas due to the control of the 6G DU / CU102. 【0016】In this embodiment, in view of these circumstances, the control functions of the RU 103 are integrated into a first control device, which is either a 5G DU / CU 101 or a 6G DU / CU 102. The second control device, which is the other device, notifies the first control device, which has the control functions of the RU 103, of information indicating the status of the communication performed by the second control device. Based on this information, the first control device can decide whether or not to stop using one or more of the multiple antennas provided on the RU 103. 【0017】 Information indicating the communication status notified by the second control device includes, for example, the timing for the second control device to request that one or more antennas among the multiple antennas included in RU103 be stopped. The first control device may control the first control device to stop the operation of an antenna if the timing for the second control device to request that the antenna be stopped arrives while the antenna should be stopped in its own device. The second control device may also notify the first control device of the number of antennas to be requested to be used (or the number of antennas to be stopped) as information indicating the communication status. The first control device may, for example, control RU103 to use the antenna that is greater than the number of antennas to be used for communication in its own device and the number of antennas notified by the second control device, and to stop the use of the other antennas. 【0018】Furthermore, the information indicating the communication status notified from the second control device may be the number of terminal devices connected to the second control device. The first control device may determine the number of antennas to be used based on the number of terminal devices connected to itself and the number of terminal devices connected to the second control device, and may decide to use that number of antennas and stop the operation of the remaining antennas. The number of connected terminal devices and the number of antennas to be used may be associated, for example, based on past communication history. For example, a table may be prepared that records the relationship between the number of terminal devices connected to the first control device and the second control device in the past and the number of antennas used when communicating with those terminal devices. Then, when the first control device identifies the number of terminal devices connected to itself and the number of terminal devices connected to the second control device, it may refer to the table and identify the number of antennas to be used that are associated with those numbers. Alternatively, the first control device may input the number of terminal devices connected to itself and the number of terminal devices connected to the second control device into a predetermined function to identify the number of antennas to be used. The predetermined function may be identified, for example, based on artificial intelligence (AI) / machine learning (ML). For example, a trained model obtained through machine learning, using the number of terminal devices connected to the first control device and the second control device respectively as input, and the number of antennas used to provide communication to those terminal devices as training data, can be generated as a predetermined function. 【0019】Furthermore, the information indicating the communication status notified from the second control device may include the radio quality of the terminal device connected to the second control device. The first control device may determine the number of antennas to be used based on the radio quality of the terminal device connected to itself and the radio quality of the terminal device connected to the second control device, and decide to use that number of antennas and stop the operation of the remaining antennas. The information indicating radio quality may be, for example, a Channel Quality Indicator (CQI). However, it is not limited to this, and any information indicating quality (such as reference signal received power (RSRP), reference signal received quality (RSRQ), signal-to-interference noise ratio (SINR), etc.) may be used as information indicating radio quality. The radio quality of the connected terminal device and the number of antennas to be used may be associated, for example, based on the history of past communications. For example, a table may be prepared that records the relationship between the radio quality of terminal devices connected to the first control device and the second control device respectively in the past and the number of antennas used when communicating with those terminal devices. The first control device may, upon identifying the wireless quality of terminal devices connected to itself and the wireless quality of terminal devices connected to the second control device, refer to a table to determine the number of antennas to be used associated with those wireless quality levels. Alternatively, the first control device may input the wireless quality of terminal devices connected to itself and the wireless quality of terminal devices connected to the second control device into a predetermined function to determine the number of antennas to be used. This predetermined function may be determined, for example, based on artificial intelligence (AI) / machine learning (ML). For example, a trained model obtained by machine learning, using the wireless quality of terminal devices connected to the first and second control devices respectively as input and the number of antennas used to provide communication to those terminal devices as training data, may be generated as the predetermined function. Alternatively, the first control device may determine the number of antennas necessary for communication with terminal devices based on the wireless quality and number of terminal devices. 【0020】Furthermore, the first control device may decide to restart the operation of an antenna that has stopped working, based on the information described above. For example, it may decide to restart the antenna's operation if the number of terminal devices connected to the first or second control device increases. 【0021】 The first control unit controls the RU 103 to stop or restart the operation of an antenna based on the decision described above, and at the same time may notify the second control unit of information regarding the antenna to be stopped or restarted. This allows the second control unit to determine the number of antennas available in the RU 103 and to perform communication control according to that number of antennas. The first control unit may also notify the second control unit of information indicating the number of antennas that will be used or stopped from being used. Furthermore, the first control unit may notify the second control unit of information identifying which of the antennas in the RU 103 will be stopped (or used). That is, the first control unit may specify which antenna to operate or stop, or it may not specify which antenna to operate and notify the number of antennas. 【0022】 The first control device may send a message to the second control device requesting information and receive the above-mentioned information in response. The first control device may periodically send the request and periodically acquire the information, or it may send the request message when, for example, the amount of traffic handled by the first control device decreases or increases. The second control device may also periodically notify the first control device of the above-mentioned information without receiving a request, or when the amount of traffic handled by the second control device decreases or increases. 【0023】Furthermore, the first control device may instruct the second control device to control the signal transmission power. For example, the first control device may transmit information to the second control device requesting a reduction in the signal transmission power. This reduces the geographical range over which the second control device provides communication services and decreases the number of terminal devices connected to the second control device. As a result, power saving can be achieved by reducing the number of antennas that the second control device needs to use for communication and increasing the number of antennas that are deactivated. The first control device may also transmit information to the second control device requesting that it hand over connected terminal devices to other control devices. By handing over connected terminal devices in response to this request, the second control device can reduce the number of antennas required for communication and increase the number of antennas that are deactivated, thereby saving power. In one example, the first control device may request the second control device to hand over terminal devices with low wireless quality from among the terminal devices connected to the second control device. 【0024】Next, an example of the configuration of the control device (DU / CU 101 for 5G and DU / CU 102 for 6G) according to this embodiment will be described with reference to Figure 2. In one example, the control device is configured to include a processor 201, ROM 202, RAM 203, storage device 204, and communication circuit 205. The processor 201 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), and executes the overall processing of the device and the above-mentioned processing by reading and executing programs stored in the ROM 202 and storage device 204. The ROM 202 is a read-only memory that stores information such as programs and various parameters related to the processing executed by the control device. The RAM 203 functions as a workspace when the processor 201 executes programs and is a random access memory that stores temporary information. The storage device 204 is configured to include, for example, a removable external storage device. The communication circuit 205 is configured to include, for example, a circuit for 5G / 6G wireless communication. Although Figure 2 shows one communication circuit 205, the control device may have multiple communication circuits. For example, the control device may have wireless communication circuits that support 5G / 6G or earlier or later generations of communication standards. The control device may have separate communication circuits 205 for each of the multiple usable frequency bands, or it may have a common communication circuit 205 for at least a portion of those frequency bands. Furthermore, the control device may have communication circuits 205 for wired communication with other control devices. 【0025】Figure 3 shows an example of the functional configuration of the first control device. The first control device is configured to include an information receiving unit 301, a communication status identification unit 302, an antenna usage identification unit 303, an RU control unit 304, and a control information notification unit 305. Note that Figure 3 shows only the functions particularly relevant to this embodiment, and various other functions that the first control device may have are omitted from the illustration. For example, the first control device naturally has other functions that a DU / CU that controls 5G or 6G communication generally has. Also, the functional blocks in Figure 3 are shown schematically, and each functional block may be implemented as an integrated unit or further subdivided. Furthermore, each function in Figure 3 may be implemented, for example, by the processor 201 executing a program stored in the ROM 202 or storage device 204, or by a processor located inside the communication circuit 205 executing predetermined software. Note that the details of the processing performed by each functional unit will not be explained in detail here, and only the general functions will be outlined. 【0026】The information receiving unit 301 receives information indicating the communication status from the second control device. The details of this information are as described above and will not be repeated here. The communication status identification unit 302 identifies the communication status in both the first and second control devices from the communication status of the first control device itself and the information receiving unit 301 indicating the communication status of the second control device. The antenna usage identification unit 303 determines the number of antennas to be used from among the multiple antennas included in the RU 103, based on the communication status in both the first and second control devices identified by the communication status identification unit 302. The antenna usage identification unit 303 may also specify which of the multiple antennas to use. That is, the antenna usage identification unit 303 may specify the antennas to be used individually, or it may specify only the number of antennas to be used without specifying which antennas to use. The RU control unit 304 outputs a control signal to the RU 103 to operate the number of antennas identified by the antenna usage identification unit 303 and stop the operation of the other antennas. Furthermore, if a specific antenna to be operated is specified by the antenna specification unit 303, the RU control unit 304 outputs a control signal to the RU 103 to operate that specific antenna and stop the operation of other antennas. In addition, if an antenna to be stopped is specified by the antenna specification unit 303, the RU control unit 304 may output a control signal to the RU 103 to stop the operation of the specified antenna and operate other antennas. The control information notification unit 305 notifies the second control device of information indicating how the RU 103 was controlled. For example, the control information notification unit 305 notifies the second control device of information indicating the number of antennas to be used (operated) or stopped in the RU 103, or information specifying the antennas to be used (operated) or stopped in the RU 103. In addition, information regarding both the antennas to be used (operated) and the antennas to be stopped in the RU 103 (information indicating the number of each antenna and information specifying the antennas) may be notified to the second control device.The control information notification unit 305 may further notify the second control device of information requesting that the second control device reduce the signal transmission power, or information requesting that terminal devices connected to the second control device be handed over to other control devices. The control information notification unit 305 may also notify the second control device of information requesting that the transmission power be increased, for example, when the suppression of transmission power in the second control device should be released. 【0027】 Figure 4 shows an example of the functional configuration of the second control device. The second control device is configured to include an information notification unit 401, a control information receiving unit 402, and a communication control unit 403. Note that Figure 4 shows only the functions particularly relevant to this embodiment, and various other functions that the second control device may have are not shown. For example, the second control device naturally has other functions that a DU / CU that controls 5G or 6G communication generally has. Also, the functional blocks in Figure 4 are shown schematically, and each functional block may be implemented as an integrated unit or further subdivided. Furthermore, each function in Figure 4 may be implemented, for example, by the processor 201 executing a program stored in the ROM 202 or storage device 204, or by a processor located inside the communication circuit 205 executing predetermined software. Note that the details of the processing performed by each functional unit will not be explained in detail here, and only the general functions will be outlined. 【0028】The information notification unit 401 notifies the first control device of information indicating the communication status of the second control device itself. The control information receiving unit 402 receives from the first control device information indicating the number of antennas among the multiple antennas of the RU 103 that will be used or stopped, or information specifying a particular antenna to be used or stopped. The control information receiving unit 402 may also, depending on the circumstances, receive from the first control device information requesting a reduction in the signal transmission power of the second control device, or information requesting a handover of a terminal device connected to the second control device to another control device. The communication control unit 403 controls communication with terminal devices connected to itself based on the information received by the control information receiving unit 402. For example, the communication control unit 403 uses an operating (not stopped) antenna to perform communication with the connected terminal device. In one example, if the communication control unit 403 is notified of an antenna to be stopped, it uses an antenna among the multiple antennas of the RU 103 that is not included in the notified antenna to perform communication with the terminal device. Furthermore, the communication control unit 403 may determine whether to accept a request to reduce or increase the transmission power when it receives information requesting that the transmission power be reduced or increased. If the communication control unit 403 accepts the request, it reduces or increases the transmission power of the signal according to the request. The communication control unit 403 may also determine whether to accept a request when it receives information requesting that the connected terminal device be handed over to another control device. If the communication control unit 403 accepts the request, it hands over the connected terminal device to another control device. The communication control unit 403 may also be configured to always accept the above-mentioned requests when it receives them. In other words, it may not be necessary to determine whether to accept or not to accept the request. 【0029】(Processing Flow) Next, an example of the processing flow performed in a wireless communication system will be explained using Figure 5. In Figure 5, the explanation assumes that the first control device is a 6G DU / CU 102 and the second control device is a 5G DU / CU 101. However, this is just one example, and the 5G DU / CU 101 may be the first control device and the 6G DU / CU 102 may be the second control device. Furthermore, the details of each processing step are as described above, so they will not be repeated here. 【0030】 First, the 6G DU / CU 102 collects information indicating the communication status of the 5G DU / CU 101 (S501). Then, based on the collected information, the 6G DU / CU 102 determines whether to stop the operation of one or more of the multiple antennas of the RU 103, and whether to restart the operation of the antennas that have stopped operating (S502). At this time, the 6G DU / CU 102 may also determine whether to request the 5G DU / CU 101 to reduce the transmission power or to hand over the connected terminal device. Then, depending on the result of the determination, the 6G DU / CU 102 sends a control instruction to the RU 103 (S503) and notifies the 5G DU / CU 101 of the result of the determination in S502 (S504). 【0031】 In this embodiment, as described above, power consumption can be reduced by stopping the operation of the antenna in an environment where base station equipment (control devices, network nodes, DU / CU) of multiple wireless communication systems share the RU103. Furthermore, since the stopping of operation can be shared among the base station equipment of multiple wireless communication systems, when control is performed by one base station equipment, the other base station equipment can appropriately perform communication based on that control. Thus, it becomes possible to contribute to Goal 9 of the United Nations-led Sustainable Development Goals (SDGs), "Build resilient infrastructure, promote sustainable industrialization and foster innovation." 【0032】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. 【0033】 This application claims priority based on Japanese Patent Application No. 2024-215498, filed on December 10, 2024, and all of its contents are incorporated herein by reference.

Claims

1. A control device that operates as a base station device for a first generation first cellular communication system and shares a plurality of antennas with another control device that operates as a base station device for a second generation second cellular communication system different from the first generation, comprising: receiving means for receiving information from the other control device indicating the state of communication performed by the other control device; determination means for determining whether or not to stop the operation of one or more of the plurality of antennas based on the state of communication performed by the control device and the information; control means for controlling the plurality of antennas to stop the operation of one or more antennas when it is determined that the operation of one or more antennas should be stopped; and notification means for notifying the other control device of the cessation of the operation of one or more antennas when it is determined that the operation of one or more antennas should be stopped.

2. The control device according to claim 1, further comprising a means for requesting the provision of the information to the other control device.

3. The control device according to claim 1 or 2, wherein the receiving means periodically receives the information from the other control device.

4. The control device according to any one of claims 1 to 3, wherein the state of communication performed by the control device is represented by whether or not the operation of one or more antennas should be stopped, the information includes information indicating the timing at which the other control device requests the operation of one or more antennas to be stopped, and the determination means determines to stop the operation of one or more antennas when the timing arrives during the period in which the control device should stop the operation of one or more antennas.

5. The control device according to any one of claims 1 to 3, wherein the state of communication performed by the control device is represented by the number of terminal devices connected to the control device, the information includes information indicating the number of terminal devices connected to the other control device, and the determination means determines the number of antennas to be used from the plurality of antennas based on the number of terminal devices connected to the control device and the number of terminal devices connected to the other control device, and determines to stop the operation of the remaining antennas.

6. The control device according to any one of claims 1 to 3, wherein the state of communication performed by the control device is represented by the wireless quality of a terminal device connected to the control device, the information includes information indicating the wireless quality of a terminal device connected to the other control device, and the determination means determines the number of antennas to be used from the plurality of antennas based on the wireless quality of the terminal device connected to the control device and the wireless quality of the terminal device connected to the other control device, and determines to stop the operation of the remaining antennas.

7. The control device according to any one of claims 1 to 6, wherein the notification means notifies the other control device of information identifying one or more antennas whose operation is to be stopped.

8. The control device according to any one of claims 1 to 6, wherein the notification means notifies the other control device of information indicating the number of antennas whose operation is stopped.

9. The control device according to any one of claims 1 to 8, wherein the notification means further notifies the other control device of information requesting a reduction in the signal transmission power.

10. The control device according to any one of claims 1 to 8, wherein the notification means further notifies the other control device of information requesting that it hand over a terminal device currently connected to the other control device.

11. A control device operating as a base station device of a second cellular communication system of a second generation different from the first generation, sharing a plurality of antennas with another control device operating as a base station device of a first generation cellular communication system, the control device comprising: notification means for notifying the other control device of information indicating the status of communication performed by the control device; receiving means for receiving a notification from the other control device indicating the cessation of operation of one or more of the plurality of antennas; and communication means for performing communication using antennas that are not included in the one or more of the plurality of antennas.

12. The control device according to claim 9, wherein the notification means notifies the other control device of the information when it receives a request for the provision of the information from the other control device.

13. The control device according to claim 9 or 10, wherein the notification means periodically notifies the other control device of the information.

14. A control method performed by a control device that operates as a base station device for a first generation first cellular communication system and shares a plurality of antennas with another control device that operates as a base station device for a second generation second cellular communication system different from the first generation, the control method comprising: receiving information from the other control device indicating the state of communication performed by the other control device; determining whether or not to stop the operation of one or more of the plurality of antennas based on the state of communication performed by the control device and the information; controlling the plurality of antennas to stop the operation of one or more antennas if it is determined that the operation of one or more antennas should be stopped; and notifying the other control device of the cessation of the operation of one or more antennas if it is determined that the operation of one or more antennas should be stopped.

15. A control method performed by a control device operating as a base station device of a second cellular communication system of a second generation different from the first generation, which shares a plurality of antennas with another control device operating as a base station device of a first generation cellular communication system, the control method comprising: notifying the other control device of information indicating the status of communication performed by the control device; receiving a notification from the other control device indicating the cessation of operation of one or more of the plurality of antennas; and performing communication using an antenna among the plurality of antennas that is not included in the one or more of the plurality of antennas.

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