Communication terminal control device, communication terminal control method, and program

Abstract

This communication terminal control device comprises an instruction unit that provides, to a communication terminal which has a beam-forming function and which is capable of communication with a ground base station and a non-ground network base station, instruction regarding a beam-forming direction to be used for initiating communication with a base station with which the communication terminal is not currently communicating.

Description

Communication terminal control device, communication terminal control method, and program

[0001] The present disclosure relates to a communication terminal control device, a communication terminal control method, and a program.

[0002] 2. Description of the Related Art Beamforming technology is known, in which a device transmits and receives radio waves in a specific direction.

[0003] Patent Document 1 discloses a space communication system including an artificial satellite that detects electromagnetic wave radiation conditions in each observation area on Earth using multiple antenna elements and transmits framed data generated based on the detected electromagnetic wave radiation conditions to a communication terminal. In the space communication system described in Patent Document 1, processing related to beamforming in the artificial satellite is performed by the communication terminal.

[0004] Japanese Patent Application Publication No. 2010-16485

[0005] The technology described in Patent Literature 1 does not take into account cases where the communication terminal has a beamforming function. Therefore, with the technology described in Patent Literature 1, for example, when the communication terminal executes handover, the communication terminal may not be able to form beams in an appropriate direction, causing the connection to be cut off and the need to scan again, or when the communication terminal starts communication, the communication terminal may not be able to scan in an appropriate direction, causing scanning to take a long time.

[0006] The present disclosure has been made in view of the above problems, and an exemplary purpose thereof is to provide a technology that allows a communication terminal to perform beamforming in an appropriate direction.

[0007] A communication terminal control device according to an exemplary aspect of the present disclosure includes an instruction means for instructing a communication terminal that has a beamforming function and is capable of communicating with both terrestrial base stations and non-terrestrial network base stations of a beamforming direction to be used to start communication with a base station with which the communication terminal is not communicating.

[0008] A communication terminal control method according to an exemplary aspect of the present disclosure includes a communication terminal control device instructing a communication terminal that has a beamforming function and is capable of communicating with a terrestrial base station and a non-terrestrial network base station of a beamforming direction to be used to initiate communication with a base station with which the communication terminal is not communicating.

[0009] A program according to an exemplary aspect of the present disclosure is a program that causes a computer to function as a communication terminal control device, and causes the computer to function as an instruction means that instructs a communication terminal that has a beamforming function and is capable of communicating with terrestrial base stations and non-terrestrial network base stations on a beamforming direction to be used to start communication with a base station with which the communication terminal is not communicating.

[0010] According to an exemplary aspect of the present disclosure, an exemplary effect is achieved in which a communication terminal can perform beamforming in an appropriate direction.

[0011] FIG. 1 is a block diagram showing a configuration of a communication terminal control device according to the present disclosure. FIG. 2 is a flow diagram showing a flow of a communication terminal control method according to the present disclosure. FIG. 3 is a block diagram showing a configuration of a communication system according to the present disclosure. FIG. 4 is a diagram showing an example of a heat map according to the present disclosure. FIG. 5 is a diagram showing an example of a format of trajectory information according to the present disclosure. FIG. 6 is a diagram showing another example of a heat map according to the present disclosure. FIG. 7 is a diagram showing an example of processing in a communication system according to the present disclosure. FIG. 8 is a diagram showing another example of processing in a communication system according to the present disclosure. FIG. 9 is a block diagram showing an example of a hardware configuration of a communication terminal control device and a communication terminal according to the present disclosure.

[0012] The following are examples of embodiments of the present invention. However, the present invention is not limited to the exemplary embodiments shown below, and various modifications are possible within the scope of the claims. For example, embodiments obtained by appropriately combining the technical means employed in the exemplary embodiments shown below may also be included in the scope of the present invention. Furthermore, embodiments obtained by appropriately omitting some of the technical means employed in the exemplary embodiments shown below may also be included in the scope of the present invention. Furthermore, the effects mentioned in the exemplary embodiments shown below are examples of effects expected in the exemplary embodiments, and do not define the scope of the present invention. In other words, embodiments that do not exhibit the effects mentioned in the exemplary embodiments shown below may also be included in the scope of the present invention.

[0013] [Exemplary Embodiment 1] A first exemplary embodiment of the present invention will be described in detail with reference to the drawings. This exemplary embodiment is a basic form of the exemplary embodiments described below. Note that the scope of application of each technical means employed in this exemplary embodiment is not limited to this exemplary embodiment. That is, each technical means employed in this exemplary embodiment can also be employed in other exemplary embodiments included in the present disclosure to the extent that no particular technical obstacles arise. Furthermore, each technical means shown in the drawings referenced to explain this exemplary embodiment can also be employed in other exemplary embodiments included in the present disclosure to the extent that no particular technical obstacles arise.

[0014] (Overview of Communication Terminal Control Device 1) The communication terminal control device 1 according to this exemplary embodiment is a device that has a beamforming function and controls a communication terminal that can communicate with terrestrial base stations and non-terrestrial network (NTN) base stations. Specifically, the communication terminal control device 1 is a device that instructs a communication terminal on a beamforming direction to be used for starting communication with a base station with which the communication terminal is not communicating.

[0015] A terrestrial base station is a base station installed on the ground. A non-terrestrial network base station is a base station that is not installed on the ground and is a base station for communication between communication terminals located on the ground, at sea, or in the sky. An example of a non-terrestrial network base station is one or more low-orbit satellites. Furthermore, when a non-terrestrial network base station orbits a predetermined orbit, information indicating the predetermined orbit is referred to as orbit information.

[0016] (Configuration of communication terminal control device 1) The configuration of the communication terminal control device 1 according to this exemplary embodiment will be described with reference to Fig. 1. Fig. 1 is a block diagram showing the configuration of the communication terminal control device 1 according to this exemplary embodiment. As shown in Fig. 1, the communication terminal control device 1 includes an instruction unit 11. The instruction unit 11 is a component that realizes instruction means in this exemplary embodiment.

[0017] The instruction unit 11 has a beamforming function and instructs a communication terminal that can communicate with terrestrial base stations and non-terrestrial network base stations of a beamforming direction to be used to start communication with a base station with which the communication terminal is not communicating. The base station with which the communication terminal is not communicating may be a base station to which the communication terminal is to hand over when the communication terminal executes handover, or may be a base station to which the communication terminal is to connect when starting communication. Furthermore, the beamforming direction to be used to start communication with a base station with which the communication terminal is not communicating may be, for example, a beamforming direction toward the base station to which the communication terminal is to hand over, or a beamforming direction to be used for scanning to start communication.

[0018] As described above, the communication terminal control device 1 according to this exemplary embodiment employs a configuration including an instruction unit 11 that instructs a communication terminal that has a beamforming function and is capable of communicating with terrestrial base stations and non-terrestrial network base stations, of a beamforming direction to be used to start communication with a base station with which the communication terminal is not communicating. Therefore, according to the communication terminal control device 1 according to this exemplary embodiment, when the communication terminal starts communication with a base station with which it is not communicating, for example, when executing handover or when starting communication, the beamforming direction is instructed, thereby achieving the effect of enabling the communication terminal to perform beamforming in an appropriate direction.

[0019] (Flow of communication terminal control method S1) The flow of the communication terminal control method S1 according to this exemplary embodiment will be described with reference to Fig. 2. Fig. 2 is a flow diagram showing the flow of the communication terminal control method S1 according to this exemplary embodiment.

[0020] (Step S11) In step S11, the instruction unit 11 instructs a communication terminal that has a beamforming function and is capable of communicating with a terrestrial base station and a non-terrestrial network base station of a beamforming direction to be used to start communication with a base station with which the communication terminal is not communicating.

[0021] As described above, the communication terminal control method S1 according to this exemplary embodiment employs a configuration in which, in step S11, the instruction unit 11 instructs a communication terminal that has a beamforming function and is capable of communicating with a terrestrial base station and a non-terrestrial network base station of a beamforming direction to be used to start communication with a base station with which the communication terminal is not communicating. Therefore, the communication control method S1 according to this exemplary embodiment provides the same effects as the communication terminal control device 1 described above.

[0022] [Exemplary Embodiment 2] A second exemplary embodiment of the present invention will be described in detail with reference to the drawings. Components having the same functions as those described in exemplary embodiment 1 are denoted by the same reference numerals, and their description will be omitted as appropriate. The scope of application of each technical means employed in this exemplary embodiment is not limited to this exemplary embodiment. That is, each technical means employed in this exemplary embodiment can also be employed in other exemplary embodiments included in the present disclosure, to the extent that no particular technical hindrance occurs. Furthermore, each technical means shown in each drawing referenced to describe this exemplary embodiment can also be employed in other exemplary embodiments included in the present disclosure, to the extent that no particular technical hindrance occurs.

[0023] (Configuration of communication system 100) The configuration of the communication system 100 according to this exemplary embodiment will be described with reference to Fig. 3. Fig. 3 is a block diagram showing the configuration of the communication system 100 according to this exemplary embodiment. As shown in Fig. 3, the communication system 100 is configured to include a communication terminal control device 3 and a communication terminal 4. In the communication system 100, the communication terminal control device 3 and the communication terminal 4 are capable of transmitting and receiving data via wireless communication. Note that although the communication system 100 shown in Fig. 3 includes only one communication terminal 4, it may include multiple communication terminals 4.

[0024] In the communication system 100, the communication terminal 4 has a beamforming function and can communicate with terrestrial base stations and non-terrestrial network base stations. Examples of non-terrestrial network base stations include low earth orbit satellites (LEO) and LEO constellation systems.

[0025] Furthermore, in the communication system 100, the communication terminal control device 3 instructs the communication terminal 4 on a beamforming direction to be used to start communication with a base station with which the communication terminal 4 is not communicating. As one example, the communication terminal control device 3 instructs the beamforming direction according to the position and time of the communication terminal 4. As another example, the communication terminal control device 3 instructs the beamforming direction by referring to a heat map in which the position of the communication terminal 4 is associated with the instructed beamforming direction. Details of the heat map will be described later.

[0026] (Configuration of Communication Terminal Control Device 3) As shown in FIG. 3, the communication terminal control device 3 includes a device control unit 31, a device storage unit 36, and a device communication unit 37.

[0027] The device storage unit 36 ​​is a storage device that stores data. The device storage unit 36 ​​stores data referenced by the device control unit 31. An example of data stored in the device storage unit 36 ​​is a heat map.

[0028] The device communication unit 37 communicates with the communication terminal 4 via wireless communication. As an example, the device communication unit 37 receives, from the communication terminal 4, BF direction information indicating the beamforming direction of the communication terminal 4 and position information indicating the position of the communication terminal 4, and transmits information indicating the beamforming direction of the communication terminal 4 to the communication terminal 4.

[0029] (Functions of device control unit 31) The device control unit 31 controls each component included in the communication terminal control device 3. As shown in Fig. 3, the device control unit 31 also includes an instruction unit 11, an acquisition unit 32, a generation unit 33, and a learning unit 34. In this exemplary embodiment, the instruction unit 11, the acquisition unit 32, and the generation unit 33 are configured to respectively realize an instruction means, an acquisition means, and a generation means.

[0030] The instruction unit 11 instructs the communication terminal 4 via the device communication unit 37. As one example, the instruction unit 11 instructs the beamforming direction according to the position and time of the communication terminal 4. As another example, the instruction unit 11 instructs the beamforming direction by referring to a heat map in which the position of the communication terminal 4 is associated with the instructed beamforming direction. Furthermore, the instruction unit 11 instructs the communication terminal 4 on the beamforming direction including the azimuth angle and the elevation angle.

[0031] The acquisition unit 32 acquires data via the device communication unit 37. The acquisition unit 32 stores the acquired data in the device storage unit 36. As an example, the acquisition unit 32 acquires BF direction information indicating the beamforming direction of each of the multiple communication terminals 4 and position information indicating the position of each of the multiple communication terminals 4. The acquisition unit 32 also acquires, from each of the multiple communication terminals 4, attitude information indicating the attitude of the multiple communication terminals 4. The acquisition unit 32 may also acquire the time and the frequency used by each of the multiple communication terminals 4.

[0032] The generation unit 33 generates a heat map. The generation unit 33 stores the generated heat map in the device storage unit 36. As an example, the generation unit 33 references the BF direction information and position information stored in the device storage unit 36 ​​to generate a heat map indicating the beamforming direction instructed by the instruction unit 11. The generation unit 33 also references the attitude information stored in the device storage unit 36 ​​to generate a heat map indicating the beamforming direction instructed by the instruction unit 11. A method by which the generation unit 33 generates a heat map will be described later.

[0033] The learning unit 34 trains the trained model. As an example, the learning unit 34 trains the trained model so that, using information about the communication terminal 4 as input, it outputs a direction in which radio wave intensity is estimated to be high at the communication terminal 4. Examples of the information about the communication terminal 4 include location information of the communication terminal 4, information about the surroundings of the communication terminal 4, the positions of terrestrial base stations around the communication terminal 4, the trajectories of non-terrestrial network base stations that can communicate with the communication terminal 4, information about time, and the attitude of the communication terminal 4. An example of the trained model is a convolutional neural network (CNN).

[0034] (Configuration of Communication Terminal 4) As shown in FIG. 3, the communication terminal 4 includes a terminal control unit 41, a terminal communication unit 51, a GPS (Global Positioning System) signal receiving unit 52, a sensor 53, and a camera 54.

[0035] The terminal communication unit 51 communicates via wireless communication with the communication terminal control device 3. As an example, the terminal communication unit 51 receives information indicating the beamforming direction of the communication terminal 4 from the communication terminal control device 3, and transmits BF direction information indicating the beamforming direction of the communication terminal 4 and position information indicating the position of the communication terminal 4 to the communication terminal control device 3.

[0036] The GPS signal receiving unit 52 receives a GPS signal as position information based on a satellite positioning system, and supplies the received GPS signal to the terminal control unit 41.

[0037] The sensor 53 includes one or more sensors. For example, the sensor 53 includes an acceleration sensor and a gyro sensor. The sensor 53 supplies detected information to the terminal control unit 41.

[0038] The camera 54 is a device that captures an image of a subject included in its angle of view. The camera 54 supplies an image including the subject to the terminal control unit 41.

[0039] (Functions of Terminal Control Unit 41) The terminal control unit 41 controls each component included in the communication terminal 4. As shown in FIG. 3 , the terminal control unit 41 also includes an acquisition unit 42, a BF control unit 43, a BF direction acquisition unit 44, a position information acquisition unit 45, an attitude information acquisition unit 46, and an image acquisition unit 47.

[0040] The acquisition unit 42 acquires data via the terminal communication unit 51. An example of the data acquired by the acquisition unit 42 is information indicating the beamforming direction.

[0041] The BF control unit 43 controls the beamforming direction of the communication terminal 4. As an example, the BF control unit 43 changes the beamforming direction to the direction indicated by the information indicating the beamforming direction acquired by the acquisition unit 42.

[0042] The BF direction acquisition unit 44 acquires BF direction information indicating the direction in which the communication terminal 4 is beamforming. As an example, the BF direction acquisition unit 44 acquires, as the BF direction information, the direction of a terrestrial base station or a non-terrestrial network base station with which the communication terminal 4 is communicating. The BF direction acquisition unit 44 transmits the acquired BF direction information to the communication terminal control device 3 via the terminal communication unit 51.

[0043] The location information acquisition unit 45 acquires location information indicating the location of the communication terminal 4. As an example, the location information acquisition unit 45 acquires, as location information, a GPS signal supplied from the GPS signal receiving unit 52. The location information acquisition unit 45 transmits the acquired location information to the communication terminal control device 3 via the terminal communication unit 51.

[0044] The posture information acquisition unit 46 acquires posture information indicating the posture of the communication terminal 4. As an example, the posture information acquisition unit 46 acquires information supplied from the sensor 53 as the posture information. The posture information acquisition unit 46 transmits the acquired posture information to the communication terminal control device 3 via the terminal communication unit 51.

[0045] The image acquisition unit 47 acquires an image. As an example, the image acquisition unit 47 acquires an image supplied from the camera 54. The image acquisition unit 47 transmits the acquired image to the communication terminal control device 3 via the terminal communication unit 51.

[0046] (Example 1 of Method for Creating Heat Map) An example of a method for the generation unit 33 of the communication terminal control device 3 to create a heat map will be described with reference to Fig. 4. Fig. 4 is a diagram showing an example of a heat map in this exemplary embodiment.

[0047] First, the BF direction acquisition unit 44 and the position information acquisition unit 45 in each of the plurality of communication terminals 4 transmit the BF direction information and the position information to the communication terminal control device 3 via the terminal communication unit 51 , respectively.

[0048] The acquisition unit 32 of the communication terminal control device 3 acquires BF direction information and location information from each of the multiple communication terminals 4. The acquisition unit 32 may further acquire operating frequency information from each of the multiple communication terminals 4. The acquisition unit 32 may also acquire time information. The acquisition unit 32 supplies the acquired BF direction information and location information (and, if necessary, operating frequency information and time information) to the generation unit 33.

[0049] The acquisition unit 32 may acquire BF direction information and location information (and, if necessary, operating frequency information) from the terrestrial base station and the non-terrestrial network base station. In this case, the terrestrial base station and the non-terrestrial network base station acquire location information (and, if necessary, operating frequency information) from each of the multiple communication terminals 4. Next, the terrestrial base station and the non-terrestrial network base station identify the beamforming direction of the communication terminal 4 from the location of the communication terminal 4 indicated by the location information and the locations of the terrestrial base station and the non-terrestrial network base station, and generate BF direction information indicating the identified beamforming direction. Then, the terrestrial base station and the non-terrestrial network base station transmit the generated BF direction information and the acquired location information (and, if necessary, operating frequency information) to the communication terminal control device 3.

[0050] The generation unit 33 references the BF direction information and position information supplied from the acquisition unit 32 and generates a heat map indicating the beamforming direction of the communication terminal 4 .

[0051] As an example, the generation unit 33 first divides an area in which multiple communication terminals 4 exist into multiple meshes, as shown on the left side of Fig. 4. The generation unit 33 may assign an identification number to each mesh to distinguish it from other meshes.

[0052] Next, the generation unit 33 refers to the location information and identifies the meshes in which each of the multiple communication terminals 4 exists. Then, the generation unit 33 refers to the BF direction information and generates a heat map in which the meshes in which each communication terminal 4 exists are associated with the beamforming direction indicated by the BF direction information. Note that while FIG. 4 depicts meshes divided in the x and y directions, the meshes may also be divided in the z direction. That is, the generation unit 33 may generate a three-dimensional heat map.

[0053] Here, since the heat map varies depending on time and frequency, the generation unit 33 may generate a heat map for each time and frequency. In Fig. 4, the heat map on the left is a heat map for time t0 and frequency f1, and the heat map on the right is a heat map for time t2 and frequency f1.

[0054] For example, the generation unit 33 refers to the BF direction information and the position information and associates, as shown on the right side of Fig. 4, that at time t2 and frequency f1, for mesh 1 in which communication terminal 4a exists, there are the most communication terminals 4 communicating in the direction of angle ag1 (BF direction 1) in mesh 1. Furthermore, the generation unit 33 associates, for mesh 1 in which communication terminal 4a exists, there are the next most communication terminals 4 communicating in the direction of angle ag2 in mesh 1.

[0055] Similarly, the generation unit 33 refers to the BF direction information and the position information, and associates, with respect to the mesh 9 in which communication terminal 4b exists, at time t2 and frequency f1, the largest number of communication terminals 4 communicating in the direction of angle ag3 (BF direction 2) in the mesh 9, as shown on the right side of Fig. 4. Furthermore, the generation unit 33 associates, with respect to the mesh 9 in which communication terminal 4b exists, the next largest number of communication terminals 4 communicating in the direction of angle ag4 in the mesh 9.

[0056] In this way, the generation unit 33 acquires BF direction information and location information (and, if necessary, operating frequency information and time information) from each of the multiple communication terminals, and generates a heat map by referring to the BF direction information and location information (and, if necessary, operating frequency information and time information). Furthermore, the generation unit 33 may generate a three-dimensional heat map for each time, frequency, azimuth angle, and elevation angle, as shown in FIG. 4 . Then, the instruction unit 11 refers to the heat map and instructs the communication terminal 4 on a beamforming direction to be used to start communication with a base station with which it is not communicating.

[0057] Therefore, when communication terminal 4 is communicating using a certain frequency at a certain time, instruction unit 11 can determine an appropriate beamforming direction at the location where communication terminal 4 is located by referring to the heat map.

[0058] (Second Example of Method for Creating Heat Map) Another example of the method for the generation unit 33 of the communication terminal control device 3 to create a heat map will be described.

[0059] The generation unit 33 may acquire information indicating the direction in which the received power has the highest radio wave intensity for each mesh, time, and frequency of the heat map, and generate the heat map based on the acquired information.

[0060] As an example, the acquisition unit 32 acquires information indicating the direction (azimuth angle and elevation angle) in which the received power is strongest for each mesh, time, and frequency of the heat map from a device (not shown in FIG. 3) capable of measuring received power. The generation unit 33 then generates a heat map by referring to the information acquired by the acquisition unit 32. For example, the generation unit 33 associates the received power and the direction in which the radio wave strength is strongest as the beamforming direction for each time and frequency with the mesh indicated by the acquired information.

[0061] In this way, the generation unit 33 acquires information indicating the direction with the strongest radio wave received power for each mesh, time, and frequency of the heat map, and generates a heat map based on the acquired information. The instruction unit 11 then refers to the heat map and instructs the communication terminal 4 on the beamforming direction to use for starting communication with a base station with which it is not communicating.

[0062] Therefore, when communication terminal 4 is communicating using a certain frequency at a certain time, instruction unit 11 can determine an appropriate beamforming direction at the location where communication terminal 4 is located by referring to the heat map.

[0063] (Third Example of Method for Creating Heat Map) Still another example of a method for the generation unit 33 of the communication terminal control device 3 to create a heat map will be described.

[0064] If the non-terrestrial network base station is a low-orbit satellite, the generation unit 33 may refer to orbit information indicating the orbit of the low-orbit satellite to generate the heat map. As an example, the generation unit 33 refers to the orbit information, and if the low-orbit satellite is in a position where it can communicate with the communication terminal 4, sets the beamforming direction in the direction in which the low-orbit satellite is located.

[0065] An example of the format of the orbit information is shown in Fig. 5. Fig. 5 is a diagram showing an example of the format of the orbit information in this exemplary embodiment. The format shown in Fig. 5 is a format called two-row orbit elements. As an example, the generation unit 33 references the orbit information expressed in the format shown in Fig. 5 and generates a heat map.

[0066] Low-earth orbit satellites orbit the same orbit every predetermined time. Therefore, when creating a heat map by referring to orbit information, the generation unit 33 may generate a heat map for a period until the low-earth orbit satellite orbits the same orbit and predict a future heat map. For example, if a low-earth orbit satellite orbits the same orbit every 15 hours, the generation unit 33 may predict a heat map for the future 15 hours based on the heat map for the past 15 hours and generate it in advance.

[0067] In addition, in the case of a satellite constellation in which multiple low-orbit satellites operate in coordination, the generation unit 33 may generate a heat map by referring to the orbit information of each of the multiple low-orbit satellites.

[0068] In this way, the generation unit 33 generates a heat map by referring to orbit information indicating the orbits of low-earth orbit satellites. Then, the instruction unit 11 refers to the heat map and instructs the communication terminal 4 on a beamforming direction to be used to start communication with a base station with which the communication terminal 4 is not communicating. Therefore, the instruction unit 11 can instruct the communication terminal 4 on a beamforming direction according to the position of the low-earth orbit satellite.

[0069] Note that the instruction unit 11 may refer to orbit information instead of a heat map and instruct the communication terminal 4 on a beamforming direction according to the position of the low-orbit satellite. That is, the instruction unit 11 is not necessarily configured to refer to a heat map, but may refer to orbit information instead of a heat map and instruct the communication terminal 4 on a beamforming direction according to the position of the low-orbit satellite. Specifically, the instruction unit 11 may refer to the orbit information and instruct the communication terminal 4, which is capable of communicating with the low-orbit satellite, on the direction of the low-orbit satellite as the beamforming direction.

[0070] (Fourth Example of Method for Creating Heat Map) Still another example of the method for the generation unit 33 of the communication terminal control device 3 to create a heat map will be described.

[0071] The generation unit 33 may generate a heat map by further referring to posture information indicating the posture of the communication terminal 4 in addition to the BF direction information and the position information.

[0072] In this case, the attitude information acquisition unit 46 in each of the plurality of communication terminals 4 transmits the attitude information to the communication terminal control device 3 via the terminal communication unit 51 .

[0073] The acquisition unit 32 of the communication terminal control device 3 acquires posture information in addition to BF direction information and position information from each of the multiple communication terminals 4. The acquisition unit 32 supplies the acquired BF direction information, position information, and posture information to the generation unit 33.

[0074] The generation unit 33 generates a heat map by referring to the BF direction information and position information using the method described above. Similarly, the generation unit 33 refers to the acquired attitude information and associates the attitude information with each mesh in the heat map. The generation unit 33 then generates a three-dimensional heat map for each time, frequency, azimuth angle, elevation angle, and attitude of the communication terminal 4. For example, the generation unit 33 generates a heat map that associates mesh 1, time t2, frequency f1, and a state in which the communication terminal 4 is facing in the positive direction of the x-axis with the azimuth angle and elevation angle (beamforming direction).

[0075] In this way, the generation unit 33 generates a heat map by referring to the attitude information indicating the attitude of the communication terminal 4. Then, the instruction unit 11 refers to the heat map and instructs the beamforming direction to be used to start communication with a base station with which the communication terminal 4 is not communicating. Therefore, when the communication terminal 4 is in an attitude that does not allow beamforming in a certain direction, the instruction unit 11 can prevent the instruction to beamform in that certain direction. In other words, the instruction unit 11 can instruct the communication terminal 4 on a beamforming direction that corresponds to the attitude of the communication terminal 4.

[0076] (Fifth Example of Method for Creating Heat Map) Still another example of the method for the generation unit 33 of the communication terminal control device 3 to create a heat map will be described.

[0077] The generation unit 33 may generate a heat map using a learned model that takes information about the communication terminal 4 as input instead of information obtained from the communication terminal 4, terrestrial base stations, and non-terrestrial network base stations, and outputs directions in which the radio wave strength is estimated to be high at the communication terminal 4.

[0078] In this case, the learning unit 34 first trains a trained model using as training data multiple pairs of information about the communication terminal 4 and directions of high radio wave intensity for the communication terminal 4. Then, the generation unit 33 inputs information about the communication terminal 4 into the trained model trained by the learning unit 34, and generates a heat map by referring to the beamforming directions output from the trained model.

[0079] Examples of information about the communication terminal 4 to be input into the trained model include location information of the communication terminal 4, information about the surroundings of the communication terminal 4, the locations of terrestrial base stations around the communication terminal 4, the trajectories of non-terrestrial network base stations that can communicate with the communication terminal 4, and the attitude of the communication terminal 4. For the location information of the communication terminal 4, location information acquired by a location information acquisition unit of the communication terminal 4 may be used. For the information about the surroundings of the communication terminal 4, a device that generates a three-dimensional map of the surroundings of the communication terminal 4, aerial photographs, or images acquired by an image acquisition unit 47 of the communication terminal 4 may be used. For the trajectories of the non-terrestrial network base stations, trajectory information of the non-terrestrial network base stations may be used. For the attitude of the communication terminal 4, attitude information acquired by an attitude information acquisition unit 46 of the communication terminal 4 may be used.

[0080] The trained model outputs information indicating the azimuth angle and elevation angle (beamforming direction) as the direction in which the radio wave intensity is estimated to be high at the communication terminal 4. The trained model may also output the azimuth angle and elevation angle for each position of the non-terrestrial network base station.

[0081] In this way, the generation unit 33 receives information about the communication terminal 4 as input and generates a heat map using a trained model that has been trained to output a direction (beamforming direction) estimated to have high radio wave intensity at the communication terminal 4. The instruction unit 11 refers to the heat map and instructs the communication terminal 4 on a beamforming direction to be used to start communication with a base station with which the communication terminal 4 is not communicating. Therefore, even if the instruction unit 11 is unable to obtain information in advance, such as if it is unable to obtain BF direction information from the communication terminal 4 indicating the direction in which the communication terminal 4 is beamforming, the instruction unit 11 can instruct the communication terminal 4 on an appropriate beamforming direction.

[0082] (Example 6 of Method for Creating Heat Map) Another example of a method for the generation unit 33 of the communication terminal control device 3 to create a heat map will be described with reference to Fig. 6. Fig. 6 is a diagram showing another example of a heat map in this exemplary embodiment.

[0083] For example, the generation unit 33 cannot associate a beamforming direction with a mesh for which data could not be acquired. Therefore, the generation unit 33 determines the beamforming direction for a mesh for which a beamforming direction is not set by referring to the beamforming directions for meshes neighboring the mesh. Here, "neighboring meshes" include, for example, meshes that are located at the same x-coordinate, y-coordinate, or z-coordinate as a mesh for which a beamforming direction is not set, and meshes that are adjacent or diagonally adjacent to a mesh for which a beamforming direction is not set.

[0084] For example, in the diagram shown on the left side of Fig. 6, the same beamforming direction is associated with mesh 3, mesh 11, and mesh 15. In this case, the generation unit 33 determines the beamforming direction of mesh 7, which is a mesh with the same y coordinate as mesh 3, mesh 11, and mesh 15 and for which no beamforming direction is set, to be BF direction 7, which is the same beamforming direction as mesh 3, mesh 11, and mesh 15.

[0085] As another example, in the diagram shown on the right side of Fig. 6, mesh 1, mesh 3, mesh 5, and mesh 7 are associated with a beamforming direction toward mesh 6. In this case, the generation unit 33 determines the beamforming direction of mesh 2, which is adjacent or diagonally adjacent to meshes 1, mesh 3, mesh 5, and mesh 7, to be BF direction 2, which is the beamforming direction toward mesh 6, just like meshes 1, mesh 3, mesh 5, and mesh 7. Similarly, for meshes 9 and 11, the generation unit 33 determines BF direction 9 and BF direction 11, respectively, which are beamforming directions associated with the adjacent or diagonally adjacent meshes and are beamforming directions toward mesh 10.

[0086] In the diagram shown on the right side of Fig. 6, an example of a method for determining the beamforming methods for mesh 2, mesh 9, and mesh 11 is a configuration in which the number of beamforming directions directed to each mesh is calculated. For example, in the diagram shown on the right side of Fig. 6, four beamforming directions, namely mesh 1, mesh 3, mesh 5, and mesh 7, are directed to mesh 6. For example, when there are three or more beamforming directions directed to a mesh, the generation unit 33 determines the beamforming direction of a mesh (mesh 2) that is adjacent or diagonally adjacent to the mesh and has no beamforming direction set to be BF direction 2 directed to mesh 6.

[0087] In the diagram shown on the right side of Figure 6, as another example of a method for determining the beamforming method for mesh 2, mesh 9, and mesh 11, the generation unit 33 determines whether, for a certain mesh, the difference in angle of the beamforming direction between the mesh and each of multiple meshes adjacent or diagonally adjacent to the mesh is equal to the difference in angle between the mesh and each of the multiple meshes adjacent or diagonally adjacent to the mesh.

[0088] For example, in the diagram shown on the right side of Fig. 6, the generation unit 33 calculates the angle (-45°, with the y-axis direction being 0°) between mesh 6 and mesh 1, which is diagonally adjacent to mesh 6, in mesh 6. The generation unit 33 also calculates the angle (135°) of the beamforming direction in mesh 1.

[0089] Next, the generation unit 33 calculates the angle (-135°) between the mesh 6 and the mesh 3 that is diagonally adjacent to the mesh 6. The generation unit 33 also calculates the angle (45°) of the beamforming direction in the mesh 3.

[0090] The generation unit 33 then calculates the difference (90°) between the angle (−45°) between mesh 6 and mesh 1 and the angle (−135°) between mesh 6 and mesh 3, and the difference (90°) between the angle of the beamforming direction in mesh 1 (135°) and the angle of the beamforming direction in mesh 3 (45°).Since the calculated differences are equal, the generation unit 33 determines the beamforming direction of mesh 2 (angle −90°) adjacent to mesh 6 to be 135°−45°=90° from the angle (−45°) between mesh 6 and mesh 1 and the angle (135°) of the beamforming direction in mesh 1.

[0091] In this way, the generation unit 33 determines the beamforming direction in a mesh for which information could not be acquired by referring to the beamforming direction in a mesh neighboring the mesh. Therefore, even if the instructing unit 11 could not acquire information in advance, such as when BF direction information indicating the direction in which the communication terminal 4 is beamforming cannot be acquired from the communication terminal 4, the instructing unit 11 can instruct the communication terminal 4 of an appropriate beamforming direction.

[0092] (Processing Example 1 in Communication System 100) An example of processing in the communication system 100 will be described with reference to Fig. 7. Fig. 7 is a diagram showing an example of processing in the communication system 100 according to this exemplary embodiment.

[0093] 7, the communication terminal 4 is unable to communicate with the terrestrial base station B2 and the non-terrestrial network base station S1 because the communication terminal 4 is blocked by a building. Therefore, the communication terminal 4 performs beamforming in the BF direction 1 toward the terrestrial base station B1, which is far away and has low reception power.

[0094] When a predetermined time has elapsed from the diagram shown on the left side of Fig. 7 , the instruction unit 11 refers to at least one of the heat map and the trajectory information to instruct the communication terminal 4 on the beamforming direction to be used to start communication with a base station with which the communication terminal 4 is not communicating. After the predetermined time has elapsed, the non-terrestrial network base station S1 has moved to a position where it can communicate with the communication terminal 4, and therefore the instruction unit 11 instructs the communication terminal 4 to perform beamforming in the BF direction 2 to start communication with a base station with which the communication terminal 4 is not communicating, as shown on the right side of Fig. 7 . Specifically, the instruction unit 11 transmits instruction information to the communication terminal 4 indicating that it instructs the communication terminal 4 to perform beamforming in the BF direction 2.

[0095] When the acquisition unit 42 of the communication terminal 4 acquires the instruction information from the communication terminal control device 3, it supplies the instruction information to the BF control unit 43. The BF control unit 43 performs beamforming in the BF direction 2 based on the instruction information.

[0096] (Processing Example 2 in Communication System 100) Another example of processing in the communication system 100 will be described with reference to Fig. 8. Fig. 8 is a diagram showing another example of processing in the communication system 100 according to this exemplary embodiment.

[0097] In the diagram shown on the left side of Fig. 8, the communication terminal 4 performs beamforming in the right direction of Fig. 8 based on the attitude of the communication terminal 4. In other words, the communication terminal 4 shown on the left side of Fig. 8 is in an attitude that does not allow beamforming in the left direction of Fig. 8. Therefore, the communication terminal 4 performs beamforming in BF direction 1 toward the non-terrestrial network base station S1.

[0098] When a predetermined time has elapsed from the diagram shown on the left side of Fig. 8 , the instruction unit 11 refers to at least one of the heat map and the trajectory information to instruct the communication terminal 4 on the beamforming direction to be used to start communication with a base station with which the communication terminal 4 is not communicating. After the predetermined time has elapsed, the non-terrestrial network base station S1 has moved to a position where the communication terminal 4 cannot perform beamforming, so the instruction unit 11 instructs the communication terminal 4 to perform beamforming in BF direction 2, which is a direction in which the communication terminal 4 can perform beamforming and in which terrestrial base station B2 is located, as shown on the right side of Fig. 8 . Specifically, the instruction unit 11 transmits instruction information to the communication terminal 4 indicating that the instruction instructs the communication terminal 4 to perform beamforming in BF direction 2.

[0099] When the acquisition unit 42 of the communication terminal 4 acquires the instruction information from the communication terminal control device 3, it supplies the instruction information to the BF control unit 43. The BF control unit 43 performs beamforming in the BF direction 2 based on the instruction information.

[0100] In processing examples 1 and 2, the case where communication terminal 4 starts communication with a base station with which communication terminal 4 is not communicating when handover is executed is described; however, this embodiment is not limited to this, and can be similarly applied to the case where communication terminal 4 starts communication from a state in which it is not communicating (for example, a power-off state or a communication-off state such as a so-called airplane mode).

[0101] Effect of Second Embodiment As described above, in the communication system 100 according to this exemplary embodiment, the instruction unit 11 refers to the heat map, trajectory information, and attitude information to instruct the communication terminal 4 on the beamforming direction to be used to start communication with a base station with which the communication terminal 4 is not communicating. Therefore, when the communication terminal 4 starts handover or communication, the instruction unit 11 can cause the communication terminal 4 to perform beamforming in an appropriate direction. As a result, for example, when the communication terminal 4 executes handover, the instruction unit 11 can instruct the communication terminal 4 on the beamforming direction toward the handover destination base station. Therefore, the communication terminal 4 knows the handover destination in advance and can communicate without losing connection. This eliminates the need for rescanning to start communication after a connection is lost. Furthermore, for example, when the communication terminal 4 starts communication, the instruction unit 11 can instruct the communication terminal 4 on the beamforming direction to shorten the scanning time required to start communication. This shortens the scanning time.

[0102] [Example of Software Implementation] Some or all of the functions of the communication terminal control devices 1 and 3 and the communication terminal 4 may be implemented by hardware such as an integrated circuit (IC chip), or may be implemented by software.

[0103] In the latter case, the communication terminal control devices 1, 3, and communication terminal 4 are realized, for example, by a computer that executes instructions of a program, which is software that realizes each function. An example of such a computer (hereinafter referred to as computer C) is shown in Figure 9. Computer C includes at least one processor C1 and at least one memory C2. Memory C2 stores a program P for operating computer C as communication terminal control devices 1, 3, and communication terminal 4. In computer C, processor C1 reads and executes program P from memory C2, thereby realizing each function of communication terminal control devices 1, 3, and communication terminal 4.

[0104] The processor C1 may be, for example, a central processing unit (CPU), a graphics processing unit (GPU), a digital signal processor (DSP), a micro processing unit (MPU), a floating point number processing unit (FPU), a physics processing unit (PPU), a microcontroller, or a combination thereof. The memory C2 may be, for example, a flash memory, a hard disk drive (HDD), a solid state drive (SSD), or a combination thereof.

[0105] The computer C may further include a RAM (Random Access Memory) for expanding the program P during execution and for temporarily storing various data. The computer C may also include a communication interface for transmitting and receiving data to and from other devices. The computer C may also include an input / output interface for connecting input / output devices such as a keyboard, a mouse, a display, and a printer.

[0106] The program P can also be recorded on a non-transitory, tangible recording medium M that can be read by the computer C. Such a recording medium M can be, for example, a tape, a disk, a card, a semiconductor memory, or a programmable logic circuit. The computer C can acquire the program P via such a recording medium M. The program P can also be transmitted via a transmission medium. Such a transmission medium can be, for example, a communication network or broadcast waves. The computer C can also acquire the program P via such a transmission medium.

[0107] [Appendix 1] This disclosure includes the techniques described in the following appendices. However, the present invention is not limited to the techniques described in the following appendices, and various modifications are possible within the scope of the claims.

[0108] (Supplementary Note 1) A communication terminal control device having a beamforming function and including an instruction means for instructing a communication terminal capable of communicating with a terrestrial base station and a non-terrestrial network base station of a beamforming direction to be used to start communication with a base station with which the communication terminal is not communicating.

[0109] (Supplementary Note 2) The communication terminal control device according to Supplementary Note 1, wherein the instruction means instructs the beamforming direction depending on a position of the communication terminal and a time.

[0110] (Supplementary Note 3) The communication terminal control device according to Supplementary Note 1 or 2, wherein the instruction means instructs the beamforming direction by referring to a heat map in which positions of the communication terminals are associated with beamforming directions to be instructed.

[0111] (Supplementary Note 4) The communication terminal control device according to Supplementary Note 3, comprising: an acquisition means for acquiring beamforming direction information indicating a beamforming direction of each of the plurality of communication terminals capable of communicating with the terrestrial base station and the non-terrestrial network base station, and location information indicating a location of each of the plurality of communication terminals; and a generation means for generating the heat map by referring to the beamforming direction information and the location information.

[0112] (Supplementary Note 5) The communication terminal control device according to Supplementary Note 4, wherein the acquisition means further acquires, from each of the plurality of communication terminals, posture information indicating the posture of the plurality of communication terminals, and the generation means further refers to the posture information to generate the heat map.

[0113] (Supplementary Note 6) The communication terminal control device according to Supplementary Note 4 or 5, wherein the generation means generates the heat map using a trained model that has been trained to input information about the communication terminal and output directions in which radio wave intensity is estimated to be high at the communication terminal.

[0114] (Supplementary Note 7) The communication terminal control device according to Supplementary Notes 4 to 6, wherein the generation means divides an area included in the heat map into a plurality of meshes, and determines the beamforming direction in a mesh for which the acquisition means was unable to acquire BF direction information and position information, by referring to the beamforming direction in a mesh neighboring the mesh.

[0115] (Supplementary Note 8) The communication terminal control device according to any one of Supplementary Notes 1 to 7, wherein the non-terrestrial network base station is a low-earth orbit satellite, and the instruction means refers to orbit information indicating the orbit of the low-earth orbit satellite and instructs the beamforming direction of the communication terminal.

[0116] (Supplementary Note 9) The communication terminal control device according to any one of Supplementary notes 1 to 8, wherein the instruction means instructs the communication terminal of a beamforming direction including an azimuth angle and an elevation angle.

[0117] (Supplementary Note 10) A communication terminal control method, comprising: a communication terminal control device instructing a communication terminal, which has a beamforming function and is capable of communicating with a terrestrial base station and a non-terrestrial network base station, of a beamforming direction to be used to start communication with a base station with which the communication terminal is not communicating.

[0118] (Supplementary Note 11) A program that causes a computer to function as a communication terminal control device, the program causing the computer to function as an instruction means that instructs a communication terminal that has a beamforming function and is capable of communicating with terrestrial base stations and non-terrestrial network base stations on a beamforming direction to be used to start communication with a base station with which the communication terminal is not communicating.

[0119] (Supplementary Note 12) A communication terminal control device comprising at least one processor, the processor having a beamforming function, and executing instruction processing to instruct a communication terminal capable of communicating with a terrestrial base station and a non-terrestrial network base station of a beamforming direction to be used to start communication with a base station with which the communication terminal is not communicating.

[0120] The communication terminal control device may further include a memory that stores a program for causing the processor to execute the instruction process. The program may be recorded on a computer-readable, non-transitory, tangible recording medium.

[0121] [Appendix 2] This disclosure includes the techniques described in the following appendices. However, the present invention is not limited to the techniques described in the following appendices, and various modifications are possible within the scope of the claims.

[0122] (Supplementary Note 1) A communication terminal control device comprising at least one processor, the at least one processor having a beamforming function, and executing an instruction process to instruct a communication terminal capable of communicating with a terrestrial base station and a non-terrestrial network base station of a beamforming direction to be used to start communication with a base station with which the communication terminal is not communicating.

[0123] (Supplementary Note 2) The communication terminal control device according to Supplementary Note 1, wherein the at least one processor instructs the beamforming direction in accordance with a position of the communication terminal and a time in the instruction process.

[0124] (Supplementary Note 3) The communication terminal control device according to Supplementary Note 1 or 2, wherein, in the instruction process, the at least one processor instructs the beamforming direction by referring to a heat map in which a position of the communication terminal is associated with a beamforming direction to be instructed.

[0125] (Supplementary Note 4) The communication terminal control device according to Supplementary Note 3, wherein the at least one processor executes an acquisition process to acquire beamforming direction information indicating a beamforming direction of each of the plurality of communication terminals capable of communicating with the terrestrial base station and the non-terrestrial network base station, and location information indicating a location of each of the plurality of communication terminals, and a generation process to generate the heat map by referring to the beamforming direction information and the location information.

[0126] (Supplementary Note 5) The communication terminal control device according to Supplementary Note 4, wherein the at least one processor further acquires, from each of the plurality of communication terminals in the acquisition process, posture information indicating the postures of the plurality of communication terminals, and further refers to the posture information in the generation process to generate the heat map.

[0127] (Supplementary Note 6) The communication terminal control device according to Supplementary Note 4 or 5, wherein in the generation process, the at least one processor generates the heat map using a trained model that has been trained to input information about the communication terminal and output directions in which radio wave intensity is estimated to be high at the communication terminal.

[0128] (Supplementary Note 7) The communication terminal control device according to any one of Supplementary Notes 4 to 6, wherein in the generation process, the at least one processor divides an area included in the heat map into a plurality of meshes, and determines the beamforming direction in a mesh for which the acquisition means was unable to acquire BF direction information and position information by referring to the beamforming direction in a mesh neighboring the mesh.

[0129] (Supplementary Note 8) The communication terminal control device according to any one of Supplementary Notes 1 to 7, wherein the non-terrestrial network base station is a low-earth orbit satellite, and the at least one processor, in the instruction process, refers to orbit information indicating an orbit of the low-earth orbit satellite and instructs the communication terminal on a beamforming direction.

[0130] (Supplementary Note 9) The communication terminal control device according to any one of Supplementary notes 1 to 8, wherein the at least one processor instructs the communication terminal of a beamforming direction including an azimuth angle and an elevation angle in the instruction process.

[0131] REFERENCE SIGNS LIST 1, 3 Communication terminal control device 4 Communication terminal 11 Instruction unit 32 Acquisition unit 33 Generation unit 34 Learning unit 42 Acquisition unit 43 BF control unit 44 BF direction acquisition unit 45 Position information acquisition unit 46 Attitude information acquisition unit 47 Image acquisition unit 100 Communication system

Claims

1. An instruction means for instructing a communication terminal having a beamforming function and capable of communicating with a terrestrial base station and a non-terrestrial network base station of a beamforming direction to be used for starting communication with a base station with which the communication terminal is not in communication; A communication terminal control device comprising:

2. The instruction means instructs the beamforming direction according to a position and a time of the communication terminal. The communication terminal control device according to claim 1.

3. The instruction means instructs the beamforming direction by referring to a heat map in which the position of the communication terminal is associated with the instructed beamforming direction.

3. The communication terminal control device according to claim 1 or 2.

4. An acquisition means for acquiring beamforming direction information indicating a beamforming direction of each of the plurality of communication terminals capable of communicating with the terrestrial base station and the non-terrestrial network base station, and location information indicating a location of each of the plurality of communication terminals; A generating means for generating the heat map by referring to the BF direction information and the position information; The communication terminal control device according to claim 3 , comprising:

5. the acquiring means further acquires, from each of the plurality of communication terminals, posture information indicating postures of the plurality of communication terminals; The generating means further refers to the posture information to generate the heat map. The communication terminal control device according to claim 4.

6. The generation means generates the heat map using a trained model that has been trained to receive information about the communication terminal and output a direction in which radio wave intensity is estimated to be high in the communication terminal. The communication terminal control device according to claim 4.

7. The generating means divides an area included in the heat map into a plurality of meshes, and determines a beamforming direction in a mesh for which the acquiring means was unable to acquire BF direction information and position information by referring to a beamforming direction in a mesh adjacent to the mesh. The communication terminal control device according to claim 4.

8. the non-terrestrial network base station is a low earth orbit satellite; The instruction means refers to orbit information indicating an orbit of the low-earth orbit satellite and instructs the communication terminal on a beamforming direction.

3. The communication terminal control device according to claim 1 or 2.

9. A communication terminal control device Instructing a communication terminal having a beamforming function and capable of communicating with a terrestrial base station and a non-terrestrial network base station of a beamforming direction to be used for starting communication with a base station with which the communication terminal is not communicating; A communication terminal control method comprising:

10. A program for causing a computer to function as a communication terminal control device, The computer, An instruction means for instructing a communication terminal having a beamforming function and capable of communicating with a terrestrial base station and a non-terrestrial network base station of a beamforming direction to be used for starting communication with a base station with which the communication terminal is not in communication; A program that functions as a