Wireless control device, method, and program

Abstract

[Problem] To control the radio communications with terminal devices in accordance with the moving conditions of the terminal devices. [Solution] This radio control device (200, 2000) estimates the position of a terminal device and estimates the type of the terminal device. The radio control device predicts the movement of the terminal device on the basis of the estimated position, and predicts a future position of the terminal device. The radio control device estimates, for each of a plurality of communication parameters, a reception level of the radio signal at the future position on the basis of the estimated type. The radio control device determines, on the basis of the estimation result of the reception level, a communication parameter that is to be used for the terminal device at the future position.

Description

Technical Field

[0001] The present disclosure relates to a wireless control device, a method, and a recording medium.

Background Art

[0002] In order to achieve a large capacity of a mobile communication system, wireless communication technologies using radio waves in high frequency bands such as millimeter waves or terahertz waves have been studied. In the above-described wireless communication technology, there is a problem that the propagation loss depending on the frequency is large. To solve this problem, for example, a wireless control device (for example, a wireless base station) is configured to perform beamforming using an antenna array including a plurality of antenna elements.

[0003] Hereinafter, a combination of radio waves (signals) transmitted or received by a plurality of antenna elements is referred to as a "beam". Specifically, a beam obtained by combining signals transmitted by a plurality of antenna elements is referred to as a "transmission beam". A beam obtained by combining signals received by a plurality of antenna elements is referred to as a "reception beam".

[0004] Beamforming is a control for changing the direction (angle) of a beam by controlling the phases and amplitudes of wireless signals transmitted or received by a plurality of antenna elements. Such control is known and is also referred to as "directivity control". According to this technology, since a beam is formed in the direction where a communication target exists, propagation loss can be compensated.

[0005] Patent Document 1, Patent Document 2, Patent Document 3, and Non-Patent Document 1 disclose techniques related to beamforming. Patent Document 4 discloses a technique for forming a beam according to the position information of a mobile terminal. Patent Document 5 discloses a technique for performing wireless control based on the communication quality of a user device.

Prior Art Documents

Patent Documents

[0006] [Patent Document 1] Japanese Patent Translation of PCT International Publication No. 2020-507233 [Patent Document 2] Japanese Unexamined Patent Application Publication No. 2019-134217 [Patent Document 3] WO2016 / 157727 [Patent Document 4] Japanese Unexamined Patent Application Publication No. 2006-217228 [Patent Document 5] WO2019 / 155632 [Non-Patent Document]

[0007] [Non-Patent Document 1] Takashi Seyama, Tetsuhira Ooyama, Takashi Date, "A Study on Proactive Beamforming Control Using Machine Learning in 5G Mobile Communications", Institute of Electronics, Information and Communication Engineers, IEICE Technical Report, vol. 118, no. 57, SR2018-7, pp. 43-48, May 2018 [Summary of the Invention] [Problems to be Solved by the Invention]

[0008] For example, in a certain wireless communication system, it is assumed that a radio base station performs wireless communication with a terminal device while performing beamforming. There can be multiple situations regarding the movement status of the terminal device. Such multiple situations include, for example, a situation where the terminal device is moving together with a pedestrian, and a situation where the terminal device is moving together with a vehicle. Since the radio base station performs beamforming without considering the movement status of the terminal device, the reception level of the radio signal transmitted from the radio base station may significantly decrease at the terminal device. As a result, a disconnection of the wireless link (so-called Radio Link Failure) between the radio base station and the terminal device may occur.

[0009] The present disclosure provides a technology capable of controlling wireless communication with a terminal device according to the movement status of the terminal device. [Means for Solving the Problems]

[0010] In one or more embodiments, a wireless control device is provided. The wireless control device includes a position estimation unit that estimates the position of the terminal device, a type estimation unit that estimates the type of the terminal device, a movement prediction unit that predicts the movement of the terminal device based on the estimated position and predicts the future position of the terminal device, and a selection unit that estimates the reception level of a wireless signal at the future position for each communication parameter representing one or both of an antenna and a beam based on the estimated type and determines the communication parameter to be used for the terminal device at the future position based on the estimation result of the reception level.

[0011] In one or more embodiments, a method executed in a wireless control device that communicates with a terminal device is provided. The method includes estimating the position of the terminal device, estimating the type of the terminal device, predicting the movement of the terminal device based on the estimated position and predicting the future position of the terminal device, estimating the reception level of a wireless signal at the future position for each communication parameter representing one or both of an antenna and a beam based on the estimated type, and determining the communication parameter to be used for the terminal device at the future position based on the estimation result of the reception level.

[0012] In one or more embodiments, a non-transitory computer readable medium is provided. The non-transitory computer readable medium records a program that causes a processor to perform operations including estimating the position of a terminal device, estimating the type of the terminal device, predicting the movement of the terminal device based on the estimated position and predicting a future position of the terminal device, estimating the reception level of a radio signal at the future position for each communication parameter representing one or both of an antenna and a beam based on the estimated type, and determining the communication parameter to be used for the terminal device at the future position based on the estimation result of the reception level.

Effect of the Invention

[0013] According to the above configuration, the communication parameter is determined according to the type of the terminal device. Therefore, wireless communication with the terminal device can be controlled according to the movement status of the terminal device. Other problems, configurations, and effects will be clarified by the description of the following embodiments.

Brief Description of the Drawings

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Mode for Carrying Out the Invention

[0015] Hereinafter, one or more embodiments will be described with reference to the accompanying drawings. In the present specification and drawings, elements that can be similarly described are denoted by the same reference numerals, and redundant description is omitted.

[0016] The description will be given in the following order. 1. Outline of the Embodiment 2. First Embodiment 2-1. Configuration of the Wireless Communication System 2-2. Configuration of the Terminal Device 2-3. Configuration of the Base Station Device 2-4. Configuration of the Base Station Antenna 2-5. Configuration of the Main Control Device 2-6. Configuration of the Prediction Control Unit 2-7. Flow of Processing 2-8. Effects 2-9. Modification Examples 3. Second Embodiment 3-1. Configuration of the Wireless Control Device 3-2. Flow of Processing

[0017] <<1. Outline of the Embodiment>> The outline of one or more embodiments described below will be explained.

[0018] (1) Technical Problem A wireless base station performs wireless communication with a terminal device. In this case, for example, the following multiple situations can occur as the movement status of the terminal device. · A situation where the terminal device is moving together with a pedestrian · A situation where the terminal device is moving together with a vehicle (e.g., a car)

[0019] Here, assume that a pedestrian and a car exist at positions close to each other (substantially the same position). The wireless base station performs wireless communication with the terminal device of the pedestrian and the terminal device of the car using the same communication parameters (antenna and beam). The movement path and movement speed of the pedestrian are different from those of the car. In one situation, the reception level of the wireless signal may significantly decrease. Therefore, a configuration for controlling wireless communication with the terminal device according to the movement status of the terminal device (i.e., the moving object holding the terminal device) is required.

[0020] (2) Technical Features In the above embodiments, a wireless control device is provided. The wireless control device includes a position estimation unit, a type estimation unit, a movement prediction unit, and a selection unit.

[0021] The position estimation unit estimates the position of the terminal device. The type estimation unit estimates the type of the terminal device. The movement prediction unit predicts the movement of the terminal device based on the estimated position, and predicts the future position of the terminal device.

[0022] The selection unit estimates the reception level of the wireless signal at the future position for each communication parameter based on the estimated type. Here, the communication parameter is a parameter for communicating with the terminal device, and represents one or both of the antenna and the beam. The selection unit determines the communication parameter to be used for the terminal device at the future position based on the estimation result of the reception level.

[0023] <<2. First Embodiment>> Subsequently, with reference to FIGS. 1 to 19, the first embodiment and its modified examples will be described.

[0024] <2-1. Configuration of Wireless Communication System> FIG. 1 is a diagram showing an example of the configuration of a wireless communication system 10. For example, the wireless communication system 10 is a system compliant with the technical specifications of 3GPP (Third Generation Partnership Project). Specifically, the wireless communication system 10 may be a device compliant with the technical specifications of 5G (5th Generation). Of course, the wireless communication system 10 is not limited to this example.

[0025] The wireless communication system 10 includes one or more terminal devices 100 and a base station device 200.

[0026] The terminal device 100 may be referred to as a user equipment (UE) or a mobile station, etc. For example, the terminal device 100 is a mobile terminal such as a smartphone, a mobile phone, or a tablet. Note that the functions of the terminal device 100 may be directly incorporated into various vehicles (e.g., automobiles and trains, etc.).

[0027] The base station device 200 is, for example, a node of a radio access network (RAN). The base station device 200 performs wireless communication with the terminal device 100.

[0028] Note that hereinafter, the link through which a signal is transmitted from the base station device 200 to the terminal device 100 is referred to as a "downlink". The signal transmitted on the downlink is referred to as a "downlink signal". Further, the link through which a signal is transmitted from the terminal device 100 to the base station device 200 is referred to as an "uplink". The signal transmitted on the uplink is referred to as an "uplink signal".

[0029] <2-2. Configuration of the Terminal Device> FIG. 2 is a block diagram showing an example of the configuration of the terminal device 100. The terminal device 100 includes a wireless communication unit 110, a storage unit 120, and a processing unit 130.

[0030] The wireless communication unit 110 includes an antenna for wireless communication. The wireless communication unit 110 transmits a signal to the base station device 200 via the antenna and receives a signal from the base station device 200.

[0031] The storage unit 120 includes a volatile memory and a non-volatile memory. The volatile memory may include, for example, a RAM (Random Access Memory). The non-volatile memory may include, for example, one or more of a ROM (Read Only Memory), an HDD (Hard Disk Drive), and an SSD (Solid State Drive). The non-volatile memory stores program codes (instructions) for realizing various functions of the terminal device 100.

[0032] The processing unit 130 includes one or more processors. The one or more processors may include, for example, one or more of a CPU (Central Processing Unit), an MPU (Micro Processing Unit), and a microcontroller. The processing unit 130 realizes various functions of the terminal device 100 by executing program codes stored in the storage unit 120.

[0033] <2-3. Configuration of Base Station Device> FIG. 3 is a block diagram showing an example of the configuration of the base station device 200. The base station device 200 has a configuration of a distributed antenna system (DAS: Distributed Antenna Systems).

[0034] The base station device 200 includes a plurality of base station antennas 210-1, 210-2, ···, 210-N and a main control device 220. N is an integer of 2 or more. Hereinafter, when it is not necessary to distinguish the plurality of base station antennas 210-1, 210-2, ···, 210-N from each other, these are simply referred to as "the plurality of base station antennas 210". The plurality of base station antennas 210 are arranged apart from each other. Therefore, the possibility of interference with the communication between the base station device 200 and the terminal device 100 can be reduced.

[0035] RoF (Radio over Fiber) technology, CPRI (Common Public Radio Interface) technology, or eCPRI (evolved Common Public Radio Interface) technology, etc. may be used between the main control device 220 and the plurality of base station antennas 210. Note that a repeater may be arranged between the main control device 220 and the plurality of base station antennas 210.

[0036] The main control device 220 includes a network communication unit 221, a storage unit 222, and a processing unit 223.

[0037] The network communication unit 221 transmits signals to nodes (not shown) of a network (e.g., a core network) and receives signals from the nodes of the network.

[0038] The storage unit 222 includes a volatile memory and a non-volatile memory. The volatile memory may include, for example, a RAM. The non-volatile memory may include, for example, one or more of a ROM, an HDD, and an SSD. The non-volatile memory stores program codes (instructions) for realizing various functions of the main control device 220.

[0039] Furthermore, the non-volatile memory stores information (data) used in the operation of the main control device 220. The non-volatile memory stores a first database 610 and a second database 620, which will be described later.

[0040] The processing unit 223 includes one or more processors. The one or more processors may include, for example, one or more of a CPU, an MPU, and a microcontroller. The processing unit 223 realizes various functions of the main control device 220 by executing the program codes stored in the storage unit 222.

[0041] <2-4. Configuration of Base Station Antenna> The plurality of base station antennas 210-1, 210-2, ···, 210-N have the same configuration as each other. Hereinafter, the configuration of the base station antenna 210-1 will be described, and the description of the other base station antennas will be omitted.

[0042] FIG. 4 is a block diagram showing an example of the configuration of the base station antenna 210-1. The base station antenna 210-1 includes an antenna array 211, a switch unit 212, a beam control unit 213, and an RF (radio frequency) processing unit 214.

[0043] The antenna array 211 includes a plurality of antennas (antenna elements) 230-1, 230-2, ···, 230-m. m is an integer of 2 or more. Hereinafter, in order to simplify the notation, when it is not necessary to distinguish each antenna, the symbol "230" is given to one or more antennas.

[0044] Note that the antenna array 211 may include a plurality of sub-arrays. That is, the plurality of antennas 230 may be divided into a plurality of sub-arrays. In this case, the base station antenna 210-1 can simultaneously form a plurality of beams using the plurality of sub-arrays.

[0045] The switch unit 212 includes a plurality of switch elements 231-1, 231-2, ···, 231-m. The plurality of switch elements 231-1, 231-2, ···, 231-m respectively correspond to the plurality of antennas 230-1, 230-2, ···, 230-m. Hereinafter, when it is not necessary to distinguish each switch element, the symbol "231" is given to one or more switch elements. Note that the base station antenna 210-1 may not include the switch unit 212, and the plurality of antennas 230 may be directly connected to the beam control unit 213. In this case, all the antennas 230 are used for transmission or reception.

[0046] The beam control unit 213 is configured to perform beamforming. Specifically, the beam control unit 213 controls one or more switch elements 231 to select one or more antennas 230 for transmitting a radio signal. The beam control unit 213 controls the phase and amplitude of a signal (transmission signal) transmitted from the selected antenna 230 described above to form a transmission beam.

[0047] The same applies when forming a reception beam. The beam control unit 213 controls one or more switch elements 231 to select one or more antennas 230 for receiving a radio signal. The beam control unit 213 controls the phase and amplitude of a signal (reception signal) received from the selected antenna 230 described above to form a reception beam.

[0048] Note that the beam control unit 213 can change the beam (transmission beam and reception beam) within a predetermined range. Hereinafter, the above range is referred to as the "beam steering range".

[0049] The RF processing unit 214 includes an amplifier, a frequency converter, and the like. For example, the RF processing unit 214 performs processing such as modulating a baseband signal into an RF band signal (RF signal), and demodulating an RF signal into a baseband signal. The RF processing unit 214 may include other processing such as filter processing.

[0050] A part of the functions of the base station antenna 210-1 (for example, the beam control unit 213 and the RF processing unit 214) may be implemented by one or more processors and memories. The one or more processors may include, for example, one or more of a CPU, an MPU, and a microcontroller. The memory may include volatile memory and non-volatile memory. The memory may store program code (instructions). The one or more processors may realize the functions of the base station antenna 210-1 by executing the program code stored in the memory.

[0051] Note that the configuration for beamforming is not limited to the above example (antenna array 211). As the configuration for beamforming, a directive antenna such as a lens antenna or a metamaterial may be used.

[0052] Furthermore, the base station antenna 210-1 may include other components. For example, the base station antenna 210-1 may further include a camera capable of photographing an area corresponding to the beam steering range.

[0053] <2-5. Configuration of the main control device> FIG. 5 is a block diagram showing an example of the configuration of the main control device 220. The main control device 220 includes a digital processing unit 510, a radio resource control unit 520, and a prediction control unit 530. The digital processing unit 510, the radio resource control unit 520, and the prediction control unit 530 are functional modules realized by the storage unit 222 and the processing unit 223.

[0054] The digital processing unit 510 executes processing for the downlink signal and processing for the uplink signal, etc. For example, the digital processing unit 510 generates a radio signal (downlink signal) for OFDM (Orthogonal Frequency Division Multiplexing) transmission in the downlink. For example, the digital processing unit 510 demodulates the radio signal (uplink signal) received by the antenna array 211 and detects the MIMO (Multiple Input Multiple Output) signal.

[0055] The radio resource control unit 520 determines radio resources for wireless communication with the terminal device 100. The radio resources include an antenna, a beam, a frequency, a time, etc. The radio resource control unit 520 may sometimes be also referred to as a "scheduler unit".

[0056] The prediction control unit 530 predicts communication parameters suitable for wireless communication with the terminal device 100. In this example, the communication parameters represent a combination of an antenna and a beam for wireless communication with the terminal device 100.

[0057] In this example, an identifier is pre-assigned to each of the combinations of the antennas 230 that can be selected by the prediction control unit 530. Hereinafter, the identifier is referred to as an "antenna number (or antenna index)".

[0058] For example, the antenna number may be a number that identifies each of the plurality of base station antennas 210-1, 210-2, ···, 210-N. In this case, one antenna number is assigned to one antenna array 211.

[0059] In another example, a plurality of antenna numbers may be assigned to one antenna array 211. That is, a plurality of antennas 230 included in one antenna array 211 may be divided into a plurality of groups (for example, a plurality of sub-arrays), and one antenna number may be assigned to each of the plurality of groups.

[0060] Furthermore, an identifier is pre-assigned to each of the characteristics of the beam (such as the direction of the beam and the shape pattern of the beam) that can be selected by the prediction control unit 530. Hereinafter, the identifier is referred to as a "beam number (or beam index)".

[0061] Therefore, the prediction control unit 530 determines a combination of an antenna number and a beam number as communication parameters.

[0062] The prediction control unit 530 transmits the determined communication parameters to the radio resource control unit 520. The radio resource control unit 520 receives the communication parameters from the prediction control unit 530 and determines radio resources based on the communication parameters. The radio resource control unit 520 transmits information regarding the determined radio resources to the digital processing unit 510 and the beam control unit 213. The beam control unit 213 receives information regarding the radio resources (including a combination of an antenna number and a beam number) from the radio resource control unit 520 and performs beamforming based on the antenna number and the beam number.

[0063] <2-6. Configuration of Prediction Control Unit> Next, with reference to FIGS. 6 to 11, the detailed configuration of the prediction control unit 530 will be described. FIG. 6 is a block diagram showing an example of the configuration of the prediction control unit 530.

[0064] The prediction control unit 530 includes a first database (DB) 610, a second database (DB) 620, a database (DB) update unit 630, a type estimation unit 640, a position estimation unit 650, a movement prediction unit 660, and a selection unit 670.

[0065] (1) First database FIG. 7 conceptually shows an example of the data structure of a table 700 included in the first database 610. Note that the format of the first database 610 is not limited to the table format and may be other formats.

[0066] The table 700 includes, as constituent items, a terminal identifier 710, a position 720, an antenna number 730, a beam number 740, and received power information 750. Such constituent items are stored in the first database 610 in which the table 700 is included in a state associated with each other.

[0067] The terminal identifier 710 represents information for identifying the terminal device 100. The position 720 represents the position of the terminal device 100. A map is divided into a plurality of grids, and an identifier (grid number) for identifying each of the plurality of grids is assigned. In this example, the position 720 is the grid number. In another example, the position 720 may be coordinates on a map represented by latitude, longitude, altitude, etc.

[0068] The antenna number 730 represents the antenna number used for communication with the terminal device 100. The beam number 740 represents the beam number used for communication with the terminal device 100.

[0069] The received power information 750 represents information on the received power measured at the terminal device 100 when the base station device 200 transmits a downlink signal using a beam formed by a combination of the antenna number 730 and the beam number 740 (for example, RSRP (Reference Signal Received Power)). The received power is measured using, for example, a synchronization signal or a reference signal. The synchronization signal may be, for example, the SSS (Secondary Synchronization Signal) of NR (New Radio). The reference signal may be, for example, CSI-RS (Channel State Information-Reference Signal) or PBCH-DMRS (Physical Broadcast Channel-Demodulation Reference Signal) of NR. Note that, instead of the received power, information indicating the received quality such as RSRQ (Reference Signal Received Quality), SNR (Signal to Noise Ratio), SIR (Signal to Interference Ratio), or SINR (Signal to Interference plus Noise Ratio) may be used. In this specification, the term "received level" is defined as a concept including the received power and the received quality.

[0070] As described above, the table 700 stores the relationship between the position, the communication parameters (i.e., the antenna number and the beam number), and the received level (received power or received quality).

[0071] Note that, for the same position and the same communication parameters, there may be cases where two or more received powers are measured. In this case, the received power information 750 may be a representative value obtained from the two or more received powers described above. For example, the representative value may be an average value or a median value.

[0072] (2) Second database FIG. 8 conceptually shows an example of the data structure of a table 800 included in the second database 620. Note that the format of the second database 620 is not limited to the table format and may be other formats.

[0073] Table 800 is a table created based on table 700. Table 800 includes, as constituent items, a type 810, a location 820, an antenna number 830, a beam number 840, and received power information 850. Such constituent items are stored in the second database 620 in which table 800 is included in a state associated with each other.

[0074] The type 810 represents the type of the terminal device 100. The type of the terminal device 100 is estimated by the type estimation unit 640. The method for estimating the type of the terminal device 100 will be described later.

[0075] The type of the terminal device 100 represents the type of the moving object that holds the terminal device 100. For example, moving objects are classified into a plurality of types in consideration of the moving route. For example, pedestrians move on sidewalks, automobiles move on roadways, and trains move on tracks. Thus, the movable areas of pedestrians, automobiles, and trains are different from each other. The type may be set in consideration of the movable area. For example, the type may include one or more of pedestrians, bicycles, automobiles, trains, bullet trains, and unmanned aerial vehicles (UAVs). The type may include other moving objects (for example, ships and airplanes, etc.). Unmanned aerial vehicles may sometimes be referred to as "drones".

[0076] Note that the ranges of the moving speeds of pedestrians, automobiles, and trains are different from each other. Therefore, the type may be set in consideration of the moving speed. Therefore, the type may be set in consideration of at least one of the movable area and the moving speed.

[0077] The type of the terminal device 100 does not necessarily need to be managed using the name of the moving object. An identifier (type number) may be assigned to each type of the terminal device 100.

[0078] Hereinafter, for simplicity of explanation, the types include a first type, a second type, and a third type. The first type corresponds to a pedestrian, the second type corresponds to an automobile, and the third type corresponds to a train.

[0079] Since the other components of the table 800 (position 820, antenna number 830, beam number 840, and received power information 850) are the same as those of the table 700, the description thereof is omitted.

[0080] In this way, the table 800 stores the relationship between the position, communication parameters (i.e., antenna number and beam number), and received level for each type of the terminal device 100. The prediction control unit 530 can determine appropriate communication parameters (antenna number and beam number) according to the type of the terminal device 100 by using the table 800.

[0081] In another example, the table 800 may be a table that summarizes the above data for each type and each position of the terminal device 100. That is, the table 800 may be a table that associates a combination of representative communication parameters and received power with the type and position of the terminal device 100. The combination of the representative communication parameters and received power stored in the table 800 may be selected according to a predetermined criterion. The criterion may be the criterion that the received power is the maximum. Here, the received power may be a value selected or calculated from the data in which the type, position, antenna number, and beam number of the terminal device 100 are the same. For example, the received power may be an average value, a minimum value, or a maximum value, etc. in the data in which the type, position, antenna number, and beam number of the terminal device 100 are the same.

[0082] (3) Update unit The updating unit 630 updates the first database 610. Specifically, the updating unit 630 acquires terminal information from the terminal device 100. The terminal information includes a terminal identifier, a beam number, and a received power. The terminal device 100 measures the received power using a synchronization signal or a reference signal as described above in a situation where beamforming is being performed. At this time, the terminal device 100 can also acquire the beam number. The terminal device 100 transmits the beam number and the received power together with the terminal identifier to the base station device 200 as terminal information.

[0083] Furthermore, the updating unit 630 acquires the estimated position of the terminal device 100 from the position estimating unit 650 described later. The updating unit 630 acquires the antenna number currently used for the terminal device 100 from the base station device 200.

[0084] The updating unit 630 stores the terminal identifier, the position of the terminal device 100, the antenna number, the beam number, and the received power in association with each other in the table 700.

[0085] Note that the terminal information may include information representing a GPS (Global Positioning System) signal representing the position of the terminal device 100. In another example, when the terminal device 100 can acquire the antenna number, the terminal information may include the antenna number. In another example, the updating unit 630 may acquire the antenna number and the beam number currently used for the terminal device 100 from the base station device 200.

[0086] Furthermore, the updating unit 630 updates the second database 620. The updating unit 630 classifies the information included in the table 700 for each type of the terminal device 100 and aggregates it in the table 800. Specifically, the updating unit 630 acquires records from the table 700. The record includes the terminal identifier 710, the position 720, the antenna number 730, the beam number 740, and the received power information 750 as described above. The updating unit 630 acquires the type of the terminal device 100 corresponding to the terminal identifier 710 from the type estimating unit 640.

[0087] The update unit 630 stores in the table 800 by associating with each other the type of the terminal device 100, the position 720, the antenna number 730, the beam number 740, and the received power information 750.

[0088] Note that for the same type, the same position, and the same communication parameters, two or more received powers may be acquired. In this case, the received power information 850 may be a representative value obtained from the above two or more received powers. For example, the representative value may be an average value or a median value.

[0089] (4) Type estimation unit The type estimation unit 640 estimates the type of the terminal device 100. The type estimation unit 640 estimates the type of the terminal device 100 based on one or a combination of two or more of the estimated position of the terminal device 100, the time series information of the estimated position of the terminal device 100, the map information, the moving speed of the terminal device 100, and the image acquired by the camera.

[0090] In an example, the type estimation unit 640 acquires the estimated position of the terminal device 100 and the time series information of the estimated position of the terminal device 100 from the position estimation unit 650 or the table 700 described later. Further, the storage unit 222 stores two-dimensional or three-dimensional map information. The map information includes information on the positions and sizes of sidewalks, roadways, railway lines, buildings, and the like.

[0091] As described above, since the movable areas of pedestrians, automobiles, and trains are different from each other, the type estimation unit 640 determines the type of the terminal device 100 based on the estimated position of the terminal device 100, the time series information of the estimated position of the terminal device 100, and the map information. For example, when the terminal device 100 is present on the sidewalk, the type estimation unit 640 determines that the type of the terminal device 100 is the first type. When the terminal device 100 is present on the roadway, the type estimation unit 640 determines that the type of the terminal device 100 is the second type. When the terminal device 100 is present on the railway line, the type estimation unit 640 determines that the type of the terminal device 100 is the third type.

[0092] In another example, the type estimation unit 640 may acquire the moving speed of the terminal device 100 from the movement prediction unit 660. Note that the type estimation unit 640 may calculate the moving speed of the terminal device 100 based on the time-series information of the estimated position of the terminal device 100. The type estimation unit 640 may further estimate the type of the terminal device 100 in consideration of the moving speed of the terminal device 100.

[0093] In another example, the type estimation unit 640 may estimate the type of the terminal device 100 using cameras mounted on each of the plurality of base station antennas 210. As described above, the camera captures an area corresponding to the beam steering range. The type estimation unit 640 estimates the type of the terminal device 100 based on the estimated position of the terminal device 100 and the image acquired by the camera. The type estimation unit 640 may execute a predetermined image analysis process (for example, pattern matching) on the image to estimate the type of the terminal device 100.

[0094] In another example, the type estimation unit 640 may estimate the type of the terminal device 100 by clustering (unsupervised learning) using one or two or more of the estimated position of the terminal device 100, the time-series information of the estimated position of the terminal device 100, and the moving speed of the terminal device 100.

[0095] In another example, the type estimation unit 640 may preset candidates for the type of the terminal device 100 for each area where the plurality of base station antennas 210 are installed or for each area on the map (for example, one or more grids). For example, the type estimation unit 640 may preset a "set of selectable types" for each area on the map. The type estimation unit 640 may select the type of the terminal device 100 from the set of selectable types using the moving speed of the terminal device 100.

[0096] For example, assume that the first area on the map includes only sidewalks and roadways. In this case, the moving objects included in the first area are only pedestrians and automobiles. Therefore, the type estimation unit 640 presets the first type (pedestrian) and the second type (automobile) as a set of selectable types in the first area.

[0097] Assume that the second area on the map includes only roadways and railway tracks. In this case, the moving objects included in the second area are only automobiles and trains. Therefore, the type estimation unit 640 presets the second type (automobile) and the third type (train) as a set of selectable types in the second area. According to this configuration, since the type estimation unit 640 selects the type of the terminal device 100 from the set of selectable types, the estimation accuracy of the type of the terminal device 100 can be improved.

[0098] The set of selectable types may be set by an input operation via a predetermined external interface (input devices such as a keyboard and a mouse). In another example, the type estimation unit 640 may set the set of selectable types by using cameras mounted on each of the plurality of base station antennas 210-1, 210-2, ···, 210-N. The type estimation unit 640 may execute image analysis processing on the image acquired in real time by the camera to set the set of selectable types. The type estimation unit 640 may accumulate the images acquired by the camera for a certain period and execute image analysis processing on the accumulated images to set the set of selectable types.

[0099] Note that the type estimation unit 640 may execute the above-described image analysis processing periodically or aperiodically to change the set of selectable types. When sidewalks and roadways are newly constructed due to construction work or the like, the type estimation unit 640 can add the necessary types to the set of selectable types.

[0100] (5) Position Estimation Unit The position estimation unit 650 estimates the position of the terminal device 100. For example, the position estimation unit 650 may estimate the position of the terminal device 100 by using the direction of the beam of a single antenna 230 communicating with the terminal device 100 and ranging. Examples of ranging methods include a method using propagation time such as RRT (Round-Trip Time), and a method of calculating the distance from the received level to the terminal device 100 based on a propagation model.

[0101] In another example, the position estimation unit 650 may estimate the position of the terminal device 100 by a triangulation method using a plurality of base station antennas 210.

[0102] In another example, the storage unit 222 may store in advance information representing the relationship between the reception levels at a plurality of antennas 230 and the position of the terminal device 100 (hereinafter referred to as "position-related information"). The position estimation unit 650 may estimate the position of the terminal device 100 from the reception levels at the plurality of antennas 230 based on the position-related information.

[0103] In another example, the position estimation unit 650 may estimate the position of the terminal device 100 by combining two or more of the above methods. For example, the position estimation unit 650 may use the beam direction and ranging to obtain a range in which the terminal device 100 may be included, and estimate the position of the terminal device 100 based on the position-related information within the obtained range.

[0104] In another example, the position estimation unit 650 may obtain information representing the position of the terminal device 100 from an external device (for example, the terminal device 100). The position estimation unit 650 may obtain information representing a GPS signal representing the position of the terminal device 100 from the terminal device 100. In yet another example, the position estimation unit 650 may obtain information representing measurement values of other sensors (for example, an acceleration sensor) mounted on the terminal device 100 from the terminal device 100 and estimate the position of the terminal device 100.

[0105] (6) Movement prediction unit The movement prediction unit 660 acquires time series information of the estimated position of the terminal device 100 from the position estimation unit 650 or the table 700.

[0106] In another example, the movement prediction unit 660 acquires the estimated position of the terminal device 100 from the position estimation unit 650 and accumulates the estimated position for a predetermined period. In this way, the movement prediction unit 660 may create time series information of the estimated position of the terminal device 100.

[0107] The movement prediction unit 660 executes interpolation processing by extrapolation (for example, linear interpolation processing) based on the time series information of the estimated position of the terminal device 100, and predicts the position of the terminal device 100 after a predetermined time Tm. Hereinafter, the position predicted in this way is referred to as the "future position Pf of the terminal device 100".

[0108] In another example, the movement prediction unit 660 may determine the movement direction and movement speed of the terminal device 100 based on the type of the terminal device 100, and predict the future position Pf of the terminal device 100. For this purpose, the movement prediction unit 660 may predict the future position Pf of the terminal device 100 using a first movement prediction model. For example, the first movement prediction model is a model that predicts the movement speed and movement direction according to the type of the terminal device 100. The movement prediction unit 660 acquires the type of the terminal device 100 from the type estimation unit 640, and acquires the estimated position of the terminal device 100 from the position estimation unit 650. The movement prediction unit 660 applies the type of the terminal device 100 and the estimated position of the terminal device 100 to the first movement prediction model. Thereby, the movement prediction unit 660 can accurately predict the future position Pf of the terminal device 100.

[0109] The movement prediction unit 660 may determine the movement direction and speed of the terminal device 100 based on the type of the terminal device 100 and the map information, and predict the future position Pf of the terminal device 100. As described above, the map information includes information representing the movement routes of various moving objects (for example, sidewalks, roadways, and railway tracks, etc.). By using the map information, the movement prediction unit 660 can accurately predict the future position Pf of the terminal device 100. Note that the movement prediction unit 660 may predict the future position Pf of the terminal device 100 by using a second movement prediction model. The second movement prediction model is a model that predicts the movement speed and direction according to the type of the terminal device 100, and is a model generated based on the type of the terminal device 100 and the map information.

[0110] The movement prediction unit 660 may predict the future position Pf of the terminal device 100 by using a third movement prediction model. The third movement prediction model is a model that predicts the movement speed and direction according to the type of the terminal device 100, and is a model generated from the past movement history of the terminal device 100. For example, the movement prediction unit 660 accumulates the past movement history of the terminal device 100 for each type. The movement prediction unit 660 may learn such a movement history by machine learning and generate a third movement prediction model.

[0111] (7) Selection unit The selection unit 670 acquires the future position Pf of the terminal device 100 from the movement prediction unit 660. The selection unit 670 acquires the type of the terminal device 100 from the type estimation unit 640.

[0112] Based on the type of the terminal device 100, the selection unit 670 estimates the received power of the radio signal at the future position Pf for each of a plurality of communication parameters (antenna number and beam number). Then, based on the estimated received power, the selection unit 670 determines the communication parameters to be used for the terminal device 100 at the future position Pf.

[0113] Hereinafter, for the sake of simplicity of notation, the communication parameters finally determined by the selection unit 670 (i.e., the communication parameters to be used for the terminal device 100 at the future position Pf) are referred to as "communication parameters prf".

[0114] Specifically, the selection unit 670 refers to the table 800 and estimates the reception power of the radio signal at the future position Pf for each of the plurality of communication parameters.

[0115] Assume that the type of the terminal device 100 is the first type and the future position Pf is P1. In this case, the selection unit 670 refers to the plurality of records in the table 800 where the type 810 is the first type and the position 820 is P1. In the example of FIG. 8, there are three records that satisfy this condition. The selection unit 670 selects the record with the maximum reception power information 850 from the three records. Here, Pw4 > Pw3 > Pw2. Therefore, the selection unit 670 selects the record whose reception power information 850 is "Pw4". The antenna number of the selected record is An1, and the beam number of the selected record is Bm1. Therefore, the selected communication parameters are the combination of An1 and Bm1.

[0116] The selected communication parameters above are candidates for the communication parameters prf to be used for the terminal device 100 at the future position Pf. Hereinafter, the communication parameters thus selected from the table 800 are referred to as "first parameters pr1".

[0117] If there is no record in the table 800 where the position 820 is P1, the selection unit 670 may refer to the record where the type 810 is the first type and the position 820 is the position closest to P1 (for example, P3).

[0118] The selection unit 670 acquires the communication parameters (antenna number and beam number) currently being used for the terminal device 100. Hereinafter, the communication parameters are referred to as the "second parameter pr2".

[0119] The selection unit 670 compares the first parameter pr1 and the second parameter pr2, and determines the communication parameter prf using the result of the comparison. When the first parameter pr1 and the second parameter pr2 are the same, the selection unit 670 determines the second parameter pr2 as the communication parameter prf. That is, the selection unit 670 maintains the current communication parameters (that is, the second parameter pr2).

[0120] On the other hand, when the first parameter pr1 and the second parameter pr2 are different, the selection unit 670 may determine the first parameter pr1 as the communication parameter prf.

[0121] In another example, the selection unit 670 may determine the communication parameter prf according to the following Case 1 and Case 2. Case 1: The antenna number of the first parameter pr1 is the same as the antenna number of the second parameter pr2, and the beam number of the first parameter pr1 is different from the beam number of the second parameter pr2. Case 2: The antenna number of the first parameter pr1 is different from the antenna number of the second parameter pr2.

[0122] ·Regarding Case 1 The selection unit 670 may determine the first parameter pr1 as the communication parameter prf.

[0123] When the configuration of the antenna corresponding to the antenna number includes a plurality of sub-arrays, the selection unit 670 may determine two of the first parameter pr1 and the second parameter pr2 as the communication parameter prf. In this case, the beam control unit 213 forms two beams, i.e., the beam corresponding to the beam number of the first parameter pr1 and the beam corresponding to the beam number of the second parameter pr2, using the plurality of sub-arrays.

[0124] In another example, the selection unit 670 may determine the communication parameter prf based on the relationship between the estimated received power in the case of the first parameter pr1, the received power in the case of the second parameter pr2, and the threshold value Pwth. Here, the estimated received power in the case of the first parameter pr1 is the value of the received power information 850 in the table 800. The received power in the case of the second parameter pr2 is the current received power (the received power obtained from the terminal information of the terminal device 100 at the current time).

[0125] FIG. 9 is a diagram for explaining an example of the operation of the selection unit 670. Both the estimated received power in the case of the first parameter pr1 and the current received power in the case of the second parameter pr2 are equal to or greater than the threshold value Pwth. In this case, there is little need to change the current communication parameter (the second parameter pr2). Therefore, the selection unit 670 determines the second parameter pr2 as the communication parameter prf.

[0126] FIG. 10 is a diagram for explaining an example of the operation of the selection unit 670. The current received power in the case of the second parameter pr2 is less than the threshold value Pwth, and the estimated received power in the case of the first parameter pr1 is equal to or greater than the threshold value Pwth. In this case, the selection unit 670 determines the first parameter pr1 as the communication parameter prf.

[0127] FIG. 11 is a diagram for explaining an example of the operation of the selection unit 670. Both the estimated received power in the case of the first parameter pr1 and the current received power in the case of the second parameter pr2 are smaller than the threshold value Pwth. However, the estimated received power in the case of the first parameter pr1 is larger than the current received power in the case of the second parameter pr2. In this case, the selection unit 670 may determine the first parameter pr1 as the communication parameter prf. Alternatively, the selection unit 670 may determine the two parameters, i.e., the first parameter pr1 and the second parameter pr2, as the communication parameter prf.

[0128] ·Regarding Case 2 The selection unit 670 may determine the first parameter pr1 as the communication parameter prf. Alternatively, the selection unit 670 may determine the two parameters, i.e., the first parameter pr1 and the second parameter pr2, as the communication parameter prf.

[0129] In another example, the selection unit 670 may refer to the table 800 and select, as the third parameter pr3, a communication parameter including the antenna number 830 that is the same as the antenna number of the second parameter pr2. If the estimated received power (received power information 850) in the case of the third parameter pr3 is equal to or greater than the threshold value Pwth, the selection unit 670 may determine the third parameter pr3 as the communication parameter prf. According to this configuration, it is possible to prevent the antenna number from being frequently changed. If the estimated received power in the case of the third parameter pr3 is smaller than the threshold value Pwth, the selection unit 670 may determine the first parameter pr1 as the communication parameter prf.

[0130] <2-7. Flow of Processing> Next, with reference to FIGS. 12 to 15, the operations of the respective components in the prediction control unit 530 will be described. FIG. 12 is a diagram showing a situation in which a plurality of terminal devices UE1 to UE4 are moving. Hereinafter, the operations of the respective components in the prediction control unit 530 will be described using the example of FIG. 12.

[0131] FIG. 13 is a flowchart showing an example of the flow of a process for updating the first database 610 (table 700).

[0132] As shown in FIG. 12, the terminal device UE1 is present inside the vehicle VA. The terminal device UE1 is present at the position P1.

[0133] The update unit 630 receives terminal information from the terminal device UE1 (1301). The terminal information includes the following information. · Terminal identifier: UE1 · Beam number: Bm1 · Received power: Pw1

[0134] The position estimation unit 650 estimates the position of the terminal device UE1 (1302). The position estimation unit 650 estimates that the terminal device UE1 is present at the position P1.

[0135] The update unit 630 acquires the estimated position of the terminal device UE1 (in this example, P1) from the position estimation unit 650 (1303). Further, the update unit 630 acquires the antenna number (An1) currently used for the terminal device UE1 from the radio resource control unit 520 (1303).

[0136] The update unit 630 updates the table 700 (1304). The update unit 630 adds a record having the following configuration items to the table 700. · Terminal identifier 710: UE1 · Position 720: P1 · Antenna number 730: An1 · Beam number 740: Bm1 · Received power information 750: Pw1

[0137] The update unit 630 executes the flowchart of FIG. 13 every time a predetermined time elapses, and accumulates a large number of records in the table 700. That is, the update unit 630 accumulates in the table 700 the relationship between the position, the communication parameters (that is, the antenna number and the beam number), and the received power.

[0138] FIG. 14 is a flowchart showing an example of the flow of a process for updating the second database 620 (table 800).

[0139] The update unit 630 acquires a record corresponding to the terminal device UE1 (terminal identifier 710 = UE1) from the table 700 (1401). In this example, the update unit 630 acquires the following information. · Terminal identifier 710: UE1 · Location 720: P1 · Antenna number 730: An1 · Beam number 740: Bm1 · Received power information 750: Pw1

[0140] The type estimation unit 640 estimates the type of the terminal device UE1 (1402). In the example of FIG. 12, since the terminal device UE1 exists on the road, the type estimation unit 640 estimates that the type of the terminal device UE1 is the second type (automobile).

[0141] The update unit 630 acquires the type of the terminal device UE1 from the type estimation unit 640 (1403).

[0142] The update unit 630 updates the table 800 (1404). The update unit 630 adds a record having the following configuration items to the table 800. · Type 810: Second type · Location 820: P1 · Antenna number 830: An1 · Beam number 840: Bm1 · Received power: Pw1

[0143] The update unit 630 executes the flowchart of FIG. 14 every time a predetermined time elapses, and accumulates a large number of records in the table 800. That is, the update unit 630 accumulates in the table 800 the relationship between the type of the terminal device 100, the location, the communication parameters (that is, the combination of the antenna number and the beam number), and the received power.

[0144] FIG. 15 is a flowchart showing an example of a process flow for determining communication parameters prf to be used for the terminal device 100 at a future position Pf.

[0145] In the example of FIG. 12, the terminal device UE2 is present at position P2. The terminal device UE2 is held by the pedestrian PE. The terminal device UE2 is attempting to enter position P1.

[0146] The selection unit 670 receives the terminal information of the terminal device UE2 (1501). The terminal information includes the following information. · Terminal identifier: UE2 · Beam number: Bm2 · Received power: Pw1

[0147] The position estimation unit 650 estimates the position of the terminal device UE2 (1502). The position estimation unit 650 estimates that the terminal device UE2 is present at position P2. The selection unit 670 acquires the estimated position (P2) of the terminal device UE2 from the position estimation unit 650.

[0148] The movement prediction unit 660 predicts the future position Pf of the terminal device UE2 (1503). The movement prediction unit 660 predicts that the terminal device UE2 will enter position P1. That is, the future position Pf is P1.

[0149] The type estimation unit 640 estimates the type of the terminal device UE2 (1504). The type estimation unit 640 estimates that the type of the terminal device UE2 is the first type (pedestrian). The selection unit 670 acquires the type (first type) of the terminal device UE2 from the type estimation unit 640.

[0150] The selection unit 670 refers to the table 800 based on the type of the terminal device UE2 and the future position Pf (1505). The selection unit 670 refers to a plurality of records in the table 800 where the type 810 is the first type and the position 820 is P1. In the example of FIG. 8, there are three records that satisfy this condition. The selection unit 670 selects the record with the maximum received power information 850 from among the three records. According to the above assumption, Pw4 > Pw3 > Pw2. The selection unit 670 selects the record where the received power information 850 is "Pw4". Therefore, the selected communication parameter (i.e., the first parameter pr1) is the combination of An1 and Bm1.

[0151] The selection unit 670 determines the communication parameter prf (1506). For example, in the current situation where the terminal device UE2 is present at the position P2, assume that the antenna number, beam number, and received power are as follows. · Antenna number: An1 · Beam number: Bm2 · Received power: Pw1

[0152] Therefore, the second parameter pr2 is the combination of An1 and Bm2. The current case corresponds to case 1 described above. Further, assume that Pw1 < Pwth < Pw4. As described with reference to FIG. 10, the selection unit 670 determines the first parameter pr1 (the combination of An1 and Bm1) as the communication parameter prf. The selection unit 670 transmits the communication parameter prf to the radio resource control unit 520.

[0153] <2-8. Effect> The above configuration has the following effects. The base station device 200 can control wireless communication with the terminal device 100 according to the movement status of the terminal device 100.

[0154] In the example of FIG. 12, the terminal device UE2 is held by the pedestrian PE, and the terminal device UE3 is present inside the vehicle VB. The pedestrian PE and the vehicle VB are trying to enter the same position P1. The movement path and speed of the pedestrian PE are different from those of the vehicle VB. Therefore, the communication parameters suitable for the terminal device UE2 at the position P1 may be different from the communication parameters suitable for the terminal device UE3 at the position P1.

[0155] The base station device 200 determines the communication parameter prf according to the estimated type. The base station device 200 can separately determine the communication parameter prf used for the terminal device UE2 and the communication parameter prf used for the terminal device UE3 with respect to the same future position P1. In this way, the base station device 200 can determine the communication parameter prf in consideration of the individual situations and environments of the moving objects. Therefore, the communication quality between the base station device 200 and the terminal device UE2 and the communication quality between the base station device 200 and the terminal device UE3 can be stabilized respectively.

[0156] Furthermore, in the example of FIG. 12, the terminal device UE4 is present inside the train TR. The radio wave from the base station device 200 can enter the inside of the train TR through the window on the side surface of the train TR, but it is difficult for the radio wave to enter the inside of the train TR from the front or rear of the train TR. In contrast, the table 800 stores the relationship between the position, the communication parameter (that is, the combination of the antenna number and the beam number), and the received power for each type of the terminal device 100. The base station device 200 can determine the communication parameter prf suitable for the train (the third type) by referring to the table 800. For example, the base station device 200 can determine the communication parameter prf such that the radio wave can enter through the window on the side surface of the train TR. In this way, since the base station device 200 can determine the communication parameter prf suitable for each type, it contributes to the stabilization of the communication quality.

[0157] Also, the communication environment varies depending on the position of the terminal device 100. For example, when the pedestrian PE is at position P2, there is an obstacle (building BL1) near the terminal device UE2. On the other hand, when the terminal device UE2 reaches position P1, there is no obstacle near the terminal device UE2. Therefore, the communication parameters suitable for the situation where the terminal device UE2 is at position P2 and the communication parameters suitable for the situation where the terminal device UE2 is at position P1 can be different. The base station device 200 can determine the communication parameter prf according to the change in the position of the terminal device UE2 (that is, the change in the environment around the terminal device UE2).

[0158] <2-9. Variation example> The technology according to the present disclosure is not limited to the above-described embodiments.

[0159] (1) First variation example The communication parameter is not limited to the combination of the antenna number and the beam number. The communication parameter may include only the beam number. In this configuration, the antenna number 730 in the table 700 is omitted, and the antenna number 830 in the table 800 is omitted. The selection unit 670 determines the beam number as the communication parameter prf to be used for the terminal device 100 at the future position Pf.

[0160] The communication parameter may include only the antenna number. In this configuration, the beam number 740 in the table 700 is omitted, and the beam number 840 in the table 800 is omitted. The selection unit 670 determines the antenna number as the communication parameter prf to be used for the terminal device 100 at the future position Pf.

[0161] (2) Second variation example The configurations of the first database 610 and the second database 620 are not limited to the above examples. The first database 610 may further include at least one of the moving direction, the moving speed, and the time as a configuration item. The second database 620 may further include at least one of the moving direction, the moving speed, and the time as a configuration item.

[0162] FIG. 16 conceptually shows an example of the data structure of table 1600 included in the first database 610. Table 1600 includes, as constituent items, a terminal identifier 710, a location 720, an antenna number 730, a beam number 740, received power information 750, and a time 760. Such constituent items are stored in the first database 610 in which table 1600 is included in a state associated with each other.

[0163] FIG. 17 conceptually shows an example of the data structure of table 1700 included in the second database 620. Table 1700 includes, as constituent items, a type 810, a location 820, an antenna number 830, a beam number 840, received power information 850, and a time 860. Such constituent items are stored in the second database 620 in which table 1700 is included in a state associated with each other.

[0164] The update unit 630 may delete old records from table 1600 based on the time 760 to reduce the amount of information. The update unit 630 may delete old records from table 1700 based on the time 860 to reduce the amount of information.

[0165] The update unit 630 may select only relatively new records in table 1600 based on the time 760 and aggregate the selected records into table 1700. For example, roads, buildings, etc. may be newly constructed, resulting in changes in the environment. The above configuration is advantageous in such a case. The update unit 630 can create and update table 1700 based on the recent environment. The selection unit 670 can determine the communication parameter prf based on the recent environment.

[0166] Furthermore, the table 1600 may further include a moving direction as a constituent item. The table 1700 may further include a moving direction as a constituent item. In the example of FIG. 12, the moving directions of the automobile VA and the automobile VB are different from each other. Communication parameters suitable for the situation where the terminal device UE1 is present at the position P1 may be different from the communication parameters suitable for the situation where the terminal device UE3 reaches the position P1. The base station device 200 can determine the communication parameter prf according to the moving direction. Similarly, the base station device 200 may determine the communication parameter prf in further consideration of the moving speed.

[0167] (3) Third Modification Example The first database 610 may include other tables instead of or in addition to the table 700. FIG. 18 is a diagram conceptually showing an example of the data structure of the table 1800 included in the first database 610.

[0168] The table 1800 includes, as constituent items, a terminal identifier 1810, a position 1820, an antenna number 1830, a beam number 1840, and received power information 1850. Such constituent items are stored in the first database 610 including the table 1800 in a state associated with each other. Since the terminal identifier 1810, the position 1820, the antenna number 1830, and the beam number 1840 are the same as the constituent items of the table 700, the description thereof is omitted. The received power information 1850 is information representing the received power measured at the base station device 200 when the base station device 200 receives an uplink signal with a beam formed by the combination of the antenna number 1830 and the beam number 1840. The received power is measured, for example, using a reference signal transmitted from the terminal device 100. The reference signal is, for example, an SRS (Sounding Reference Signal).

[0169] FIG. 19 conceptually shows an example of the data structure of table 1900 included in the second database 620. Table 1900 includes, as constituent items, type 810, position 820, antenna number 830, beam number 840, received power information 850, and link 870. Such constituent items are stored in the second database 620 in which table 1900 is included, in a state of being associated with each other. Link 870 represents whether the received power information 850 is the received power measured in the downlink (received power information 750 of table 700) or the received power measured in the uplink (i.e., received power information 1850 of table 1800).

[0170] The update unit 630 may update table 1900 based on table 700 and table 1800. The selection unit 670 may determine the communication parameter prf with reference to table 1900, taking into account both the received power measured in the downlink and the received power measured in the uplink.

[0171] (4) Fourth modification example The selection unit 670 may estimate the reception level (received power or reception quality) of a radio signal at a future position Pf for each of a plurality of communication parameters based on radio wave propagation prediction. For example, the selection unit 670 may perform a propagation simulation by ray tracing using map information. As described above, the map information includes information on the positions and sizes of sidewalks, roadways, railway lines, buildings, and the like. The selection unit 670 executes a propagation simulation for each type of the terminal device 100 on the map, and estimates the reception level of a radio signal at a future position Pf for each of a plurality of communication parameters.

[0172] For the above configuration, the selection unit 670 pre-creates a radio wave propagation prediction model for each type of the terminal device 100. The characteristics of radio wave propagation with respect to the surrounding environment differ depending on the type of the terminal device 100. As described above, when the terminal device 100 is present inside a train, radio waves cannot enter the train from a specific direction (the front or the rear of the train). Therefore, the radio wave propagation prediction model may be created taking into account the penetration loss of radio waves from a specific direction and the like.

[0173] The selection unit 670 may execute a propagation simulation in real time. In another example, the selection unit 670 may execute a propagation simulation in advance and store the simulated received power in the received power information 850 of the table 800. The selection unit 670 can estimate the received power of a radio signal at a future position Pf for each of a plurality of communication parameters by referring to the table 800. Then, the selection unit 670 can determine the communication parameter prf.

[0174] The selection unit 670 may use both the table 800 and the propagation simulation. For example, the selection unit 670 may estimate the received power of a communication parameter that does not exist in the table 800 using the propagation simulation. This configuration is advantageous when a sufficient amount of information is not accumulated in the table 800.

[0175] (5) Fifth Modification Example The selection unit 670 may evaluate the accuracy of the received power information 850 of the table 800. For example, the selection unit 670 compares the received power information 850 of the table 800 with the received power measured when the terminal device 100 actually reaches a future position Pf (hereinafter referred to as "actual received power") for the same communication parameter. Specifically, the selection unit 670 calculates the error between the received power information 850 of the table 800 and the actual received power.

[0176] When the error is equal to or less than a predetermined error threshold Eth, the selection unit 670 determines that the estimation accuracy of the received power information 850 in the table 800 is high. In this case, the selection unit 670 permits the change of the communication parameters currently used for the terminal device 100.

[0177] On the other hand, there may be a case where the environment when a record is added to the table 800 is significantly different from the current environment. For example, there may be a temporary presence of a shielding object. As such an example, a case where an automobile is temporarily parked on a road can be cited. In such a case, the above error becomes larger than a predetermined error threshold Eth. The selection unit 670 determines that the estimation accuracy of the received power information 850 in the table 800 is low. The selection unit 670 maintains the communication parameters (that is, the second parameter pr2) currently used for the terminal device 100.

[0178] In another example, the selection unit 670 may determine two of the first parameter pr1 and the second parameter pr2 as the communication parameter prf according to the accuracy of the received power information 850 in the table 800. In this case, the beam control unit 213 performs beamforming with the first parameter pr1 and also performs beamforming with the second parameter pr2. According to this configuration, the redundancy is increased and the connection between the base station device 200 and the terminal device 100 can be stabilized.

[0179] (6) Sixth modification example The selection unit 670 may determine three or more communication parameters as the communication parameter prf. In the example of FIG. 11, both the estimated received power in the case of the first parameter pr1 and the received power in the case of the second parameter pr2 are smaller than the threshold value Pwth. In such a case, the selection unit 670 may select the communication parameter with the second highest received power from the table 800 as an additional communication parameter. The selection unit 670 may determine the first parameter pr1, the second parameter pr2, and the above additional communication parameter as the communication parameter prf. According to this configuration, the redundancy is increased and the connection between the base station device 200 and the terminal device 100 can be stabilized.

[0180] (7) The 7th modification example When the base station device 200 performs wireless communication with the terminal device 100 using two or more communication parameters, the throughput of the system is limited. Considering this, the selection unit 670 may acquire information regarding the usage rate of radio resources from the radio resource control unit 520. The selection unit 670 may determine two or more communication parameters as the communication parameter prf only when the usage rate of radio resources is smaller than a predetermined usage rate threshold Uth.

[0181] (8) The 8th modification example The movement prediction unit 660 may predict a plurality of future positions Pf. The selection unit 670 refers to the table 800 for each of the plurality of future positions Pf. The selection unit 670 may determine the communication parameter prf so as to satisfy a predetermined condition in the process of the terminal device 100 passing through the plurality of future positions Pf. The predetermined condition may be a condition that the number of times the antenna number is changed in the above process is equal to or less than a predetermined number threshold Cth. According to this configuration, it is possible to prevent the antenna number from being frequently changed. This contributes to the stabilization of communication quality.

[0182] For example, the selection unit 670 extracts a communication parameter including the antenna number of the second parameter pr2 for each of the plurality of future positions Pf. At this time, the selection unit 670 may extract only communication parameters for which the received power information 850 is equal to or higher than a predetermined received power. The selection unit 670 may determine the communication parameter prf from among these extracted communication parameters. According to this configuration, in the process of the terminal device 100 passing through the plurality of future positions Pf, the antenna number is maintained without being changed.

[0183] (9) The 9th modification example The movement prediction unit 660 may determine the accuracy of the future position Pf. For example, when the number of estimated positions of the terminal device 100 is small, it is considered that the accuracy of interpolation by extrapolation is low. In such a case, the movement prediction unit 660 may determine that the accuracy of the future position Pf is low. Similarly, the position estimation unit 650 may determine the accuracy of the estimated position of the terminal device 100.

[0184] When it is determined that the accuracy of the estimated position of the terminal device 100 or the accuracy of the future position Pf is low, the selection unit 670 may select a fourth parameter pr4, which is a candidate for the communication parameter prf, for each of a plurality of positions around the future position Pf. Similar to the case where the selection unit 670 selects the first parameter pr1, the selection unit 670 selects the communication parameter of the record with the highest received power as the fourth parameter pr4.

[0185] The selection unit 670 may compare the first parameter pr1, the second parameter pr2, and the fourth parameter pr4, and determine the communication parameter prf using the result of the comparison. For example, the selection unit 670 may determine, as the communication parameter prf, the parameter with the highest received power among the first parameter pr1, the second parameter pr2, and the fourth parameter pr4.

[0186] (10) Tenth modification example In the above embodiment, the communication parameter prf determined by the selection unit 670 is used for wireless communication with the terminal device 100, but the communication parameter prf may be used for purposes other than wireless communication with the terminal device 100. As a first example, the base station device 200 may use the communication parameter prf for measuring the reception level (received power or reception quality) using a reference signal. In order to assist in determining the "antenna number and beam number" used for communication with the terminal device 100, the terminal device 100 may measure the actual received power with respect to the reference signal transmitted by beamforming from the base station antenna 210 of the base station device 200. At this time, using the antenna corresponding to the antenna number determined by the communication parameter prf and the beam corresponding to the beam number determined by the communication parameter prf, the base station device 200 transmits the reference signal. Thereby, the base station device 200 can add a signal transmitted according to the communication parameter prf as a reference signal to be measured at the terminal device 100. The terminal device 100 can measure the received power regarding a combination of an antenna and a beam promising for improving communication quality and report the received power to the base station device 200.

[0187] Also, as a second example, the base station apparatus 200 may use the communication parameter prf for estimating interference to the terminal apparatus 100. For example, the communication parameter prf can also be used as information indicating the antenna number and beam number at which the interference to the terminal apparatus 100 increases. Assume that the base station apparatus 200 determines at least one second terminal apparatus from among terminal apparatuses other than the terminal apparatus 100. Here, the second terminal apparatus is a terminal apparatus that communicates with the base station apparatus 200 at the same time (timing) as when communicating with the terminal apparatus 100 and at the same frequency as when communicating with the terminal apparatus 100. The base station apparatus 200 excludes from the candidates for the second terminal apparatus a terminal apparatus that can cause significant interference to the terminal apparatus 100. Specifically, the base station apparatus 200 uses the "antenna number and beam number" determined by the communication parameter prf among terminal apparatuses other than the terminal apparatus 100, and does not select as the second terminal apparatus a terminal apparatus that is expected to obtain a large received power (that is, a terminal apparatus for which it is desirable to use the antenna number and beam number). Thereby, significant interference to the terminal apparatus 100 can be avoided.

[0188] (11) Eleventh Modification Example Some or all of the various functional modules included in the base station antenna 210 and the main control device 220 may be implemented in any of a RU (Radio Unit), a DU (Distributed Unit), and a CU (Center Unit). Some or all of the various functional modules included in the base station antenna 210 and the main control device 220 may be implemented in a control device external to the base station apparatus 200, for example, a RIC (RAN Intelligent Controller).

[0189] (3. Second Embodiment) Subsequently, with reference to FIGS. 20 to 21, the second embodiment will be described. The above-described first embodiment is a specific embodiment, while the second embodiment is a more generalized embodiment.

[0190] (3-1. Configuration of Radio Control Device) FIG. 20 is a diagram showing an example of the configuration of the wireless control device 2000. The wireless control device 2000 is configured to perform wireless communication with the terminal device 2100. The wireless control device 2000 includes a position estimation unit 2010, a type estimation unit 2020, a movement prediction unit 2030, and a selection unit 2040.

[0191] The above functional modules 2010, 2020, 2030, and 2040 included in the wireless control device 2000 may be implemented by one or more processors and a memory. The one or more processors may include, for example, one or more of a CPU, an MPU, and a microcontroller. The memory may include a volatile memory and a non-volatile memory. The memory may store program code (instructions). The one or more processors may realize the functions of the wireless control device 2000 by executing the program code stored in the memory.

[0192] The position estimation unit 2010 estimates the position of the terminal device 2100. The position estimation unit 2010 may operate in the same manner as the above position estimation unit 650.

[0193] The type estimation unit 2020 estimates the type of the terminal device 2100. The type estimation unit 2020 may operate in the same manner as the above type estimation unit 640.

[0194] The movement prediction unit 2030 predicts the movement of the terminal device 2100 based on the position estimated by the position estimation unit 2010, and predicts the future position Pf of the terminal device 2100. The movement prediction unit 2030 may operate in the same manner as the above movement prediction unit 660.

[0195] Based on the type estimated by the type estimation unit 2020, the selection unit 2040 estimates the reception level of the wireless signal at the future position Pf for each of the plurality of communication parameters. Here, the communication parameter represents an antenna or a beam, or a combination of an antenna and a beam.

[0196] The selection unit 2040 determines communication parameters prf to be used for the terminal device 2100 at a future position Pf based on the estimated result of the reception level. The selection unit 2040 may operate in the same manner as the selection unit 670 described above.

[0197] <3-2. Process flow> FIG. 21 is a flowchart for explaining an example of the process flow of the radio control device 2000.

[0198] The position estimation unit 2010 estimates the position of the terminal device 2100 (2101). The type estimation unit 2020 estimates the type of the terminal device 2100 (2102).

[0199] The movement prediction unit 2030 predicts the movement of the terminal device 2100 based on the estimated position described above, and predicts a future position Pf of the terminal device 2100 (2103).

[0200] The selection unit 2040 estimates the reception level of the radio signal at the future position Pf for each communication parameter based on the estimated type described above (2104). The selection unit 2040 determines communication parameters prf to be used for the terminal device 2100 at the future position Pf based on the estimated result of the reception level (2105).

[0201] According to the above configuration, the radio control device 2000 can control wireless communication with the terminal device 2100 according to the movement status of the terminal device 2100.

[0202] Note that the embodiments and modifications described above are merely examples, and the scope of the technical idea of the present disclosure is not limited to the above-described configurations. Other aspects conceivable within the scope of the technical idea of the present disclosure are also included in the scope of the present disclosure.

[0203] The processing steps shown in the flowchart do not necessarily have to be executed in the order shown in the figure. The processing steps may be executed in an order different from the order shown in the figure, or two or more processing steps may be executed in parallel. Also, some of the processing steps may be deleted, and additional processing steps may be added.

[0204] The functions of the apparatuses (base station apparatus 200 and radio control apparatus 2000) described in this specification may be realized by any of software, hardware, and a combination of software and hardware. The program code (instructions) constituting the software may be stored, for example, in a computer-readable recording medium inside or outside each apparatus, and may be read into the memory and executed by the processor at the time of execution. Also, a computer-readable non-transitory recording medium storing the program code may be provided.

[0205] Some or all of the above embodiments and modifications may be described as follows in the appended claims, but are not limited thereto.

[0206] (Appended Claim 1) A position estimation unit that estimates the position of the terminal device, A type estimation unit that estimates the type of the terminal device, A movement prediction unit that predicts the movement of the terminal device based on the estimated position and predicts the future position of the terminal device, Based on the estimated type, for each communication parameter representing one or both of the antenna and the beam, estimate the reception level of the radio signal at the future position, A selection unit that determines the communication parameter to be used for the terminal device at the future position based on the estimation result of the reception level, A radio control apparatus comprising the above.

[0207] (Appended Claim 2) The type estimation unit estimates the type of the terminal device based on one or a combination of two or more of the estimated position of the terminal device, the time series information of the estimated position of the terminal device, map information, the moving speed of the terminal device, and an image acquired by a camera. The wireless control device according to Supplementary Note 1.

[0208] (Supplementary Note 3) The type estimation unit estimates the type of the terminal device based on the estimated position of the terminal device and the image. The wireless control device according to Supplementary Note 2.

[0209] (Supplementary Note 4) The type estimation unit estimates the type of the terminal device by clustering using one or two or more of the estimated position of the terminal device, the time series information of the estimated position of the terminal device, and the moving speed of the terminal device. The wireless control device according to Supplementary Note 2.

[0210] (Supplementary Note 5) The type estimation unit sets candidates for the type for each area where the antenna is installed or for each area of the map information. The wireless control device according to any one of Supplementary Notes 2 to 4.

[0211] (Supplementary Note 6) The candidates for the type are set by an input operation via an external interface or by image processing on the image. The wireless control device according to Supplementary Note 5.

[0212] (Supplementary Note 7) The movement prediction unit determines the movement direction and movement speed of the terminal device based on the type of the terminal device, and predicts the future position of the terminal device. The wireless control device according to any one of Supplementary Notes 1 to 6.

[0213] (Supplementary Note 8) The movement prediction unit determines the movement direction and the movement speed of the terminal device based further on the map information. The wireless control device according to appended note 7.

[0214] (Appended note 9) The movement prediction unit determines the movement direction and the movement speed of the terminal device by using a movement prediction model generated from the past movement history of the terminal device. The wireless control device according to appended note 7.

[0215] (Appended note 10) It further includes a database that stores, for each type, the relationship between the position, the communication parameter, and the reception level. The selection unit refers to the database and estimates the reception level of the wireless signal at the future position for each communication parameter. The wireless control device according to any one of appended notes 1 to 9.

[0216] (Appended note 11) The database further includes at least one of a movement direction, a movement speed, and time as a constituent item. The wireless control device according to appended note 10.

[0217] (Appended note 12) The selection unit estimates the reception level of the wireless signal at the future position by using a radio wave propagation prediction model created for each type. The wireless control device according to any one of appended notes 1 to 9.

[0218] (Appended note 13) The selection unit compares a first parameter, which is a candidate for the communication parameter to be used for the terminal device at the future position, with a second parameter, which is the communication parameter currently used for the terminal device, and determines the communication parameter to be used for the terminal device at the future position by using the result of the comparison. The wireless control device according to any one of appended notes 1 to 12.

[0219] (Appendix 14) The selection unit determines the communication parameter to be used for the terminal device at the future position based on the relationship between the estimated reception level in the case of the first parameter, the current reception level in the case of the second parameter, and a threshold value. The radio control device according to Appendix 13.

[0220] (Appendix 15) The selection unit selects, for each of a plurality of positions around the future position, a third parameter that is a candidate for the communication parameter to be used for the terminal device at the future position according to the accuracy of the estimated position or the future position of the terminal device, compares the first parameter, the second parameter, and the third parameter, and determines the communication parameter to be used for the terminal device at the future position using the result of the comparison. The radio control device according to Appendix 13 or 14.

[0221] (Appendix 16) The selection unit compares the estimated reception level of the terminal device at the future position with the reception level measured when the terminal device actually reaches the future position, evaluates the accuracy of the estimated reception level using the result of the comparison, and determines whether to change the communication parameter currently used for the terminal device based on the result of the evaluation. The radio control device according to any one of Appendices 1 to 15.

[0222] (Appendix 17) The selection unit determines two or more of the communication parameters to be used for the terminal device at the future position when the usage rate of radio resources is less than a predetermined usage rate threshold. The wireless control device according to any one of Supplementary Notes 1 to 16.

[0223] (Supplementary Note 18) The movement prediction unit predicts a plurality of the future positions, The selection unit determines the communication parameter used for the terminal device at the future position so that a predetermined condition is satisfied in the process in which the terminal device passes through the plurality of future positions. The wireless control device according to any one of Supplementary Notes 1 to 17.

[0224] (Supplementary Note 19) The predetermined condition is a condition that the number of times the antenna is changed in the process is equal to or less than a predetermined number threshold. The wireless control device according to Supplementary Note 18.

[0225] (Supplementary Note 20) The type is information representing the type of the moving object holding the terminal device. The wireless control device according to any one of Supplementary Notes 1 to 19.

[0226] (Supplementary Note 21) The type includes one or more of a pedestrian, a bicycle, an automobile, a train, a bullet train, and an unmanned aerial vehicle (UAV). The wireless control device according to any one of Supplementary Notes 20.

[0227] (Supplementary Note 22) The wireless control device uses the communication parameter used for the terminal device at the future position for measurement of the reception level using a reference signal or estimation of interference to the terminal device. The wireless control device according to any one of Supplementary Notes 1 to 21.

[0228] (Supplementary Note 23) A method executed in a wireless control device that communicates with a terminal device, estimating the position of the terminal device; estimating the type of the terminal device; Predict the movement of the terminal device based on the estimated position and predict the future position of the terminal device; Based on the estimated type, estimate the reception level of the radio signal at the future position for each communication parameter representing one or both of the antenna and the beam; Based on the estimation result of the reception level, determine the communication parameter used for the terminal device at the future position; A method including the above.

[0229] (Appendix 24) Estimate the position of the terminal device; Estimate the type of the terminal device; Predict the movement of the terminal device based on the estimated position and predict the future position of the terminal device; Based on the estimated type, estimate the reception level of the radio signal at the future position for each communication parameter representing one or both of the antenna and the beam; Based on the estimation result of the reception level, determine the communication parameter used for the terminal device at the future position; A computer-readable non-transitory recording medium recording a program for causing a processor to execute the above.

[0230] This application claims priority based on U.S. Provisional Application No. 63 / 193,639 filed on May 27, 2021, and incorporates all of its disclosures herein.

Industrial Applicability

[0231] Wireless communication with the terminal device can be controlled according to the movement status of the terminal device.

Explanation of Reference Numerals

[0232] 10: Wireless communication system 100: Terminal device 200: Base station device 610: First database 620: Second database 630: Update unit 640: Type estimation unit 650: Location estimation unit 660: Movement prediction unit 670: Selection unit 2000: Wireless control device 2010: Location estimation unit 2020: Type estimation unit 2030: Movement prediction unit 2040: Selection unit

Claims

1. Position estimation means for estimating the current position of the terminal device; Type estimation means for estimating the type of the terminal device, where the type is information representing the type of the moving object holding the terminal device; Movement prediction means for determining the movement direction and movement speed of the terminal device based on the estimated current position and the estimated type, predicting the movement of the terminal device, and predicting the future position of the terminal device; Based on the estimated type, estimating the reception level of the radio signal at the future position for each communication parameter representing one or both of the antenna and the beam; Selection means for determining the communication parameter to be used for the terminal device at the future position based on the estimation result of the reception level; A radio control device comprising the above.

2. Estimating the type of the terminal device based on one or a combination of two or more of the estimated current position of the terminal device, the time-series information of the estimated position of the terminal device, map information, the movement speed of the terminal device, and the image acquired by the camera. The radio control device according to claim 1.

3. Further comprising a database for storing the relationship between the position, the communication parameter, and the reception level for each type; The selection means refers to the database to estimate the reception level of the radio signal at the future position for each communication parameter. The radio control device according to any one of claims 1 to 2.

4. The selection means Compares a first parameter that is a candidate for the communication parameter to be used for the terminal device at the future position with a second parameter that is the communication parameter currently used for the terminal device, and uses the result of the comparison to determine the communication parameter to be used for the terminal device at the future position. The wireless control device according to any one of claims 1 to 3.

5. The selection means compares the estimated reception level of the terminal device at the future position with the reception level measured when the terminal device actually reaches the future position, and uses the result of the comparison to evaluate the accuracy of the estimated reception level, and determines whether to change the communication parameters currently used for the terminal device based on the result of the evaluation. The wireless control device according to any one of claims 1 to 4.

6. The selection means when the usage rate of the radio resources is less than a predetermined usage rate threshold, determines two or more communication parameters to be used for the terminal device at the future position. The wireless control device according to any one of claims 1 to 5.

7. A method executed in a wireless control device that communicates with a terminal device, the method including estimating the current position of the terminal device, estimating the type of the terminal device, where the type is information representing the type of the moving object holding the terminal device, determining the moving direction and moving speed of the terminal device based on the estimated current position and the estimated type, predicting the movement of the terminal device, and predicting the future position of the terminal device, estimating the reception level of a radio signal at the future position for each communication parameter representing one or both of an antenna and a beam based on the estimated type, determining the communication parameters to be used for the terminal device at the future position based on the estimation result of the reception level, and including the above steps.

8. Estimating the current position of the terminal device Estimating the type of the terminal device, where the type is information representing the type of the moving object holding the terminal device, Based on the estimated current position and the estimated type, determining the moving direction and moving speed of the terminal device, predicting the movement of the terminal device, and predicting the future position of the terminal device, Based on the estimated type, estimating the reception level of the radio signal at the future position for each communication parameter representing one or both of the antenna and the beam, Based on the estimation result of the reception level, determining the communication parameter used for the terminal device at the future position, A program for causing a processor to execute.

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