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

Technical Field

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

Background Art

[0002] Techniques related to beamforming in which a device transmits and receives radio waves in a specific direction are known.

[0003] Patent Document 1 discloses a space communication system including a satellite that detects the electromagnetic wave radiation state of each observation region on the earth with a plurality of antenna elements and transmits framed data generated based on the detected electromagnetic wave radiation state to a communication terminal. In the space communication system described in Patent Document 1, a communication terminal performs processing related to beamforming in the satellite.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the technique described in Patent Document 1, it is not assumed that a communication terminal has a beamforming function. Therefore, in the technique described in Patent Document 1, for example, when a communication terminal executes handover, beamforming cannot be performed in an appropriate direction for the communication terminal, the connection is disconnected, and rescan is required again, or when the communication terminal starts communication, the communication terminal cannot be scanned in an appropriate direction, and the scan may take a long time.

[0006] This disclosure has been made in view of the above-mentioned problems, and one exemplary objective is to provide a technology that enables a communication terminal to beamform in an appropriate direction. [Means for solving the problem]

[0007] A communication terminal control device relating to an exemplary aspect of this disclosure includes a beamforming function and an indicating means for indicating a beamforming direction to be used by a communication terminal capable of communicating with both terrestrial base stations and non-terrestrial network base stations in order to initiate communication with a base station with which the communication terminal is not currently communicating.

[0008] An exemplary aspect of the present disclosure of a communication terminal control method includes a communication terminal control device instructing a communication terminal having a beamforming function and capable of communicating with terrestrial base stations and non-terrestrial network base stations on the beamforming direction to be used to initiate communication with a base station with which the communication terminal is not currently communicating.

[0009] A program relating to an exemplary aspect of this disclosure is a program that causes a computer to function as a communication terminal control device, wherein the computer functions as an instruction means for instructing a communication terminal having beamforming capabilities and capable of communicating with terrestrial base stations and non-terrestrial network base stations on the beamforming direction to be used to initiate communication with a base station with which the communication terminal is not currently communicating. [Effects of the Invention]

[0010] According to an illustrative aspect of this disclosure, one exemplary effect is that it enables communication terminals to beamform in the appropriate direction. [Brief explanation of the drawing]

[0011] [Figure 1] Block diagram showing the configuration of the communication terminal control device related to this disclosure. [Figure 2] This flowchart shows the flow of the communication terminal control method related to this disclosure. [Figure 3] This is a block diagram showing the configuration of the communication system related to this disclosure. [Figure 4] This figure shows an example of a heatmap in this disclosure. [Figure 5] This figure shows an example of the format of trajectory information in this disclosure. [Figure 6] This figure shows another example of a heatmap in this disclosure. [Figure 7] This figure shows an example of processing in the communication system related to this disclosure. [Figure 8] This figure shows another example of processing in the communication system related to this disclosure. [Figure 9] This block diagram shows an example of the hardware configuration of a communication terminal control device and a communication terminal related to this disclosure. [Modes for carrying out the invention]

[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 each of 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 each of the exemplary embodiments shown below may also be included in the scope of the present invention. In addition, the effects mentioned in each of the exemplary embodiments shown below are examples of effects that can be expected in that exemplary embodiment and do not define the scope of the present invention. That is, embodiments that do not produce the effects mentioned in each of 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 later. 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 be employed in other exemplary embodiments included in the present disclosure as long as there are no particular technical obstacles. In addition, each technical means shown in the drawings referred to for explaining this exemplary embodiment can also be employed in other exemplary embodiments included in the present disclosure as long as there are no particular technical obstacles.

[0014] (Overview of Communication Terminal Control Device 1) The communication terminal control device 1 according to this exemplary embodiment has a beamforming function and is a device that controls a communication terminal capable of communicating with a terrestrial base station and a non-terrestrial network (NTN: Non-Terrestrial Network) base station. Specifically, the communication terminal control device 1 is a device that instructs a communication terminal of a beamforming direction used to start 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 not installed on the ground and is a base station for a communication terminal existing on the ground, sea, or air to communicate. The non-terrestrial network base station is, for example, one or more low-earth orbit satellites. When the 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 configuration that realizes an instruction means in this exemplary embodiment.

[0017] The instruction unit 11 has a beamforming function and instructs a beamforming direction used to start communication with a base station with which the communication terminal is not communicating, for a communication terminal capable of communicating with a terrestrial base station and a non-terrestrial network base station. The base station with which the communication terminal is not communicating may be a handover destination base station when the communication terminal performs handover, or may be a connection destination base station when the communication terminal starts communication. Further, the beamforming direction 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 handover destination base station, or may be a beamforming direction used for scanning for communication start.

[0018] As described above, in the communication terminal control device 1 according to this exemplary embodiment, a configuration is adopted that includes an instruction unit 11 having a beamforming function and instructing a beamforming direction used to start communication with a base station with which the communication terminal is not communicating, for a communication terminal capable of communicating with a terrestrial base station and a non-terrestrial network base station. Therefore, according to the communication terminal control device 1 according to this exemplary embodiment, when starting communication with a base station with which the communication terminal is not communicating, for example, at the time of handover execution or at the time of communication start, the beamforming direction is instructed, so that the effect of being able to perform beamforming in an appropriate direction on the communication terminal can be obtained.

[0019] (Flow of the 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 flowchart 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 has a beamforming function and instructs a beamforming direction used to start communication with a base station with which the communication terminal is not communicating, for a communication terminal capable of communicating with a terrestrial base station and a non-terrestrial network base station.

[0021] As described above, in the communication terminal control method S1 according to this exemplary embodiment, in step S11, the instruction unit 11 is configured to instruct a communication terminal that has a beamforming function and is capable of communicating with a ground base station and a non-terrestrial network base station on the beamforming direction to be used to initiate communication with a base station with which the communication terminal is not currently 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 function as those described in Exemplary Embodiment 1 are denoted by the same reference numerals, and their descriptions are omitted as appropriate. The scope of application of each technical means employed in this exemplary embodiment is not limited to this embodiment. That is, each technical means employed in this exemplary embodiment can also be employed in other exemplary embodiments included in this disclosure, to the extent that no particular technical hindrance occurs. Furthermore, each technical means shown in the drawings referenced to describe this exemplary embodiment can also be employed in other exemplary embodiments included in this 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 Figure 3. Figure 3 is a block diagram showing the configuration of the communication system 100 according to this exemplary embodiment. As shown in Figure 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 can send and receive data via wireless communication. Although the communication system 100 shown in Figure 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 beamforming capabilities and can communicate with ground 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 beamforming direction to be used by the communication terminal 4 to initiate communication with a base station with which it is not currently communicating. As an example, the communication terminal control device 3 instructs the beamforming direction according to the location 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 that associates the location of the communication terminal 4 with the beamforming direction to be instructed. Details of the heat map will be described later.

[0026] (Configuration of the communication terminal control device 3) As shown in Figure 3, the communication terminal control device 3 comprises 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 for storing data. The device storage unit 36 ​​stores data that the device control unit 31 references. 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. For example, the device communication unit 37 receives BF direction information indicating the beamforming direction of the communication terminal 4 and position information indicating the location of the communication terminal 4 from the communication terminal 4, and transmits information indicating the beamforming direction of the communication terminal 4 to the communication terminal 4.

[0029] (Functions of the device control unit 31) The device control unit 31 controls each component of the communication terminal control device 3. Furthermore, as shown in Figure 3, the device control unit 31 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 implement the instruction means, acquisition means, and generation means, respectively.

[0030] The instruction unit 11 provides instructions to the communication terminal 4 via the device communication unit 37. As an example, the instruction unit 11 instructs the beamforming direction according to the location and time of the communication terminal 4. As another example, the instruction unit 11 instructs the beamforming direction by referring to a heat map that associates the location of the communication terminal 4 with the beamforming direction to be instructed. The instruction unit 11 also instructs the communication terminal 4 on the beamforming direction, including the azimuth and elevation angles.

[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 attitude information indicating the attitude of each of the multiple communication terminals 4 from each 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 refers to the BF direction information and position information stored in the device storage unit 36 ​​to generate a heat map indicating the beamforming direction indicated by the instruction unit 11. The generation unit 33 also refers to the attitude information stored in the device storage unit 36 ​​to generate a heat map indicating the beamforming direction indicated by the instruction unit 11. The method by which the generation unit 33 generates the heat map will be described later.

[0033] The learning unit 34 trains a pre-trained model. For example, the learning unit 34 takes information about the communication terminal 4 as input and trains the pre-trained model to output the direction in which the signal strength is estimated to be high at the communication terminal 4. Examples of information about the communication terminal 4 include the location information of the communication terminal 4, information about the surroundings of the communication terminal 4, the locations of ground base stations around the communication terminal 4, the orbits of non-terrestrial network base stations that can communicate with the communication terminal 4, time information, and the attitude of the communication terminal 4. An example of a pre-trained model is a CNN (Convolutional Neural Network).

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

[0035] The terminal communication unit 51 communicates with the communication terminal control device 3 via wireless communication. For example, the terminal communication unit 51 receives information from the communication terminal control device 3 indicating the beamforming direction of the communication terminal 4, 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 GPS signals as location information based on a satellite positioning system. The GPS signal receiving unit 52 supplies the received GPS signals to the terminal control unit 41.

[0037] Sensor 53 is comprised of one or more various sensors. For example, sensor 53 may include an accelerometer and a gyroscope. Sensor 53 supplies the detected information to the terminal control unit 41.

[0038] Camera 54 is a device that photographs subjects included in the field of view. Camera 54 supplies the image including the subject to the terminal control unit 41.

[0039] (Functions of the terminal control unit 41) The terminal control unit 41 controls each component of the communication terminal 4. As shown in Figure 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. For 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 the direction of the ground base station or non-terrestrial network base station with which the communication terminal 4 is communicating as BF direction information. 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. For example, the location information acquisition unit 45 acquires the GPS signal supplied from the GPS signal receiving unit 52 as location information. 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. For example, the posture information acquisition unit 46 acquires information supplied from the sensor 53 as 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. For 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 how to create a heatmap) An example of how the generation unit 33 of the communication terminal control device 3 creates a heat map will be described with reference to Figure 4. Figure 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 multiple communication terminals 4 transmit the BF direction information and position information, respectively, to the communication terminal control device 3 via the terminal communication unit 51.

[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 usage frequency information from each of the multiple communication terminals 4. The acquisition unit 32 may also further acquire time information. The acquisition unit 32 supplies the acquired BF direction information and location information (and usage frequency information and time information as needed) to the generation unit 33.

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

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

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

[0052] Next, the generation unit 33 refers to the location information to identify the mesh in which each of the multiple communication terminals 4 resides. Then, the generation unit 33 refers to the BF direction information to generate a heatmap that associates the beamforming direction indicated by the BF direction information with the mesh in which each communication terminal 4 resides. Although Figure 4 shows meshes divided into x and y directions, the mesh may also be divided in the z direction. In other words, the generation unit 33 may generate a three-dimensional heatmap.

[0053] Here, since the heatmap differs with time and frequency, the generation unit 33 may create heatmaps for each time and each frequency. In Figure 4, the heatmap on the left is the heatmap for time t0 and frequency f1, and the heatmap on the right is the heatmap for time t2 and frequency f1.

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

[0055] Similarly, the generation unit 33 refers to the BF direction information and position information and, as shown on the right side of Figure 4, associates that, at time t2 and frequency f1, for the mesh 9 where communication terminal 4b exists, the most numerous communication terminals 4 in mesh 9 are communicating in the direction of angle ag3 (BF direction 2). Furthermore, the generation unit 33 associates that, for the mesh 9 where communication terminal 4b exists, the next most numerous communication terminals 4 in mesh 9 are communicating in the direction of angle ag4.

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

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

[0058] (Example 2 of how to create a heatmap) Another example of how the generation unit 33 of the communication terminal control device 3 creates a heat map will be described.

[0059] The generation unit 33 may acquire information indicating the direction of the highest radio wave intensity for each mesh, time, and frequency of the heatmap, and generate a heatmap based on the acquired information.

[0060] As an example, the acquisition unit 32 acquires information from a device capable of measuring received power (not shown in Figure 3) that indicates the direction (azimuth and elevation) where the received power is highest, for each mesh, time, and frequency of the heatmap. The generation unit 33 then generates a heatmap by referring to the information acquired by the acquisition unit 32. For example, the generation unit 33 associates the received power and the direction with the highest radio wave intensity as the beamforming direction for each mesh indicated by the acquired information, for each time and frequency.

[0061] In this way, the generation unit 33 acquires information indicating the direction with the highest radio wave intensity for each mesh, time, and frequency of the heatmap, and generates a heatmap based on the acquired information. The instruction unit 11 then refers to the heatmap and instructs the beamforming direction to be used by the communication terminal 4 to initiate communication with a base station with which it is not currently communicating.

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

[0063] (Example 3 of how to create a heatmap) Further examples of how the generation unit 33 of the communication terminal control device 3 creates a heatmap will be described.

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

[0065] An example of the trajectory information format is shown in Figure 5. Figure 5 is a diagram showing an example of the trajectory information format in this exemplary embodiment. The format shown in Figure 5 is a format called a two-row trajectory element format. The generation unit 33 generates a heat map by referring to the trajectory information represented in the format shown in Figure 5 as an example.

[0066] Low Earth orbit satellites orbit the same orbit at predetermined intervals. Therefore, when the generation unit 33 creates a heatmap by referring to orbital information, it may generate a heatmap for the period until the low Earth orbit satellite orbits the same orbit again, and predict future heatmaps. For example, if a low Earth orbit satellite orbits the same orbit every 15 hours, the generation unit 33 may predict and generate a heatmap for the next 15 hours in advance based on the heatmap for the past 15 hours.

[0067] Furthermore, in the case of a satellite constellation in which multiple low Earth orbit satellites operate in coordination, the generation unit 33 may generate a heatmap by referring to the orbital information of each of the multiple low Earth orbit satellites.

[0068] In this way, the generation unit 33 refers to orbital information showing the orbit of the low Earth orbit satellite and generates a heat map. Then, the instruction unit 11 refers to the heat map and instructs the beamforming direction to be used by the communication terminal 4 to initiate communication with a base station with which it is not currently communicating. Therefore, the instruction unit 11 can instruct the communication terminal 4 on the beamforming direction corresponding to the position of the low Earth orbit satellite.

[0069] Furthermore, the instruction unit 11 may refer to orbital information instead of a heatmap to instruct the communication terminal 4 on the beamforming direction corresponding to the position of the low Earth orbit satellite. In other words, the instruction unit 11 is not necessarily configured to refer to a heatmap; it may refer to orbital information instead of a heatmap and instruct the communication terminal 4 on the beamforming direction corresponding to the position of the low Earth orbit satellite. Specifically, the instruction unit 11 may refer to orbital information and instruct the communication terminal 4, which can communicate with the low Earth orbit satellite, on the direction of the low Earth orbit satellite as the beamforming direction.

[0070] (Example 4 of how to create a heatmap) Further examples of how the generation unit 33 of the communication terminal control device 3 creates a heatmap will be described.

[0071] The generation unit 33 may generate a heatmap by further referencing attitude information indicating the attitude of the communication terminal 4, in addition to BF direction information and position information.

[0072] In this case, the attitude information acquisition unit 46 in each of the multiple 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 attitude 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 attitude information to the generation unit 33.

[0074] The generation unit 33 generates a heatmap 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 heatmap. The generation unit 33 then generates a three-dimensional heatmap for each attitude of the communication terminal 4, based on time, frequency, azimuth angle, elevation angle, and time. For example, the generation unit 33 generates a heatmap that associates mesh 1, time t2, frequency f1, and the state in which the communication terminal 4 is facing the positive x-axis with the azimuth angle and elevation angle (beamforming direction).

[0075] In this way, the generation unit 33 refers to attitude information indicating the attitude of the communication terminal 4 and generates a heat map. The instruction unit 11 then refers to the heat map and instructs the beamforming direction to be used by the communication terminal 4 to initiate communication with a base station with which it is not currently communicating. Therefore, the instruction unit 11 can prevent instructing the communication terminal 4 to beamform in a certain direction if its attitude makes beamforming in that direction impossible. In other words, the instruction unit 11 can instruct the communication terminal 4 to beamforming in a direction that is appropriate to its attitude.

[0076] (Example 5 of how to create a heatmap) Further examples of how the generation unit 33 of the communication terminal control device 3 creates a heatmap will be described.

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

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

[0079] Examples of information about the communication terminal 4 to be input into the trained model include the location information of the communication terminal 4, information about the surroundings of the communication terminal 4, the locations of ground base stations around the communication terminal 4, the orbits of non-terrestrial network base stations that can communicate with the communication terminal 4, and the attitude of the communication terminal 4. The location information of the communication terminal 4 may be obtained from the location information acquisition unit of the communication terminal 4. The information about the surroundings of the communication terminal 4 may be obtained from a device that generates a 3D map of the surroundings of the communication terminal 4, aerial photographs, or images obtained from the image acquisition unit 47 of the communication terminal 4. The orbits of non-terrestrial network base stations may be obtained from the orbit information of non-terrestrial network base stations. The attitude of the communication terminal 4 may be obtained from the attitude information acquisition unit 46 of the communication terminal 4.

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

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

[0082] (Example 6 of how to create a heatmap) Another example of how the generation unit 33 of the communication terminal control device 3 creates a heat map will be described with reference to Figure 6. Figure 6 shows another example of a heat map in this exemplary embodiment.

[0083] The generation unit 33 cannot associate a beamforming direction with a mesh from which data could not be acquired. Therefore, the generation unit 33 determines the beamforming direction for a mesh in which no beamforming direction has been set by referring to the beamforming direction of a neighboring mesh. Here, "neighboring mesh" refers to, for example, a mesh located at the same x, y, or z coordinates as a mesh in which no beamforming direction has been set, or a mesh adjacent to or diagonally adjacent to a mesh in which no beamforming direction has been set.

[0084] For example, in the diagram shown on the left side of Figure 6, mesh 3, mesh 11, and mesh 15 are associated with the same beamforming direction. In this case, the generation unit 33 determines the beamforming direction of mesh 7, which has the same y-coordinate as mesh 3, mesh 11, and mesh 15 and for which no beamforming direction has been set, to the 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 Figure 6, meshes 1, 3, 5, and 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, 3, 5, and 7, to BF direction 2, which is the same beamforming direction toward mesh 6 as meshes 1, 3, 5, and 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 adjacent or diagonally adjacent meshes and are the beamforming directions toward mesh 10.

[0086] In the diagram on the right side of Figure 6, one example of a method for determining the beamforming method for meshes 2, 9, and 11 is a configuration that calculates the number of beamforming directions directed towards each mesh. For example, in the diagram on the right side of Figure 6, mesh 6 has four beamforming directions directed towards it: mesh 1, mesh 3, mesh 5, and mesh 7. For example, if the number of beamforming directions directed towards a mesh is three or more, the generation unit 33 determines the beamforming direction of a mesh adjacent to or diagonally adjacent to the mesh in question (mesh 2), for which no beamforming direction has been set, to BF direction 2 directed towards 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 given mesh, the difference in the beamforming direction angles of a given mesh and multiple adjacent or diagonally adjacent meshes is equal to the difference in angle between the given mesh and each of the adjacent or diagonally adjacent meshes.

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

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

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

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

[0092] (Example of processing in communication system 100) An example of processing in the communication system 100 will be explained with reference to Figure 7. Figure 7 is a diagram showing an example of processing in the communication system 100 according to this exemplary embodiment.

[0093] In the diagram shown on the left side of Figure 7, communication terminal 4 cannot communicate with the ground base station B2 and the non-terrestrial network base station S1 because it is blocked by a building. Therefore, communication terminal 4 is beamforming in direction BF 1 toward the ground base station B1, which is far away and has low received power.

[0094] As shown in the left side of Figure 7, after a predetermined time has elapsed, the instruction unit 11 refers to at least one of the heatmap and orbital information to instruct the communication terminal 4 on the beamforming direction to use to initiate communication with a base station with which the communication terminal 4 is not currently 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, so the instruction unit 11 instructs the communication terminal 4 to beamform in the BF direction 2 to initiate communication with the base station with which the communication terminal 4 is not currently communicating, as shown on the right side of Figure 7. Specifically, the instruction unit 11 transmits instruction information to the communication terminal 4 indicating that it is instructed to beamform in the BF direction 2.

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

[0096] (Example of processing in communication system 100, part 2) Another example of processing in the communication system 100 will be described with reference to Figure 8. Figure 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 Figure 8, communication terminal 4 is beamforming to the right in Figure 8, based on the orientation of communication terminal 4. In other words, communication terminal 4 shown on the left side of Figure 8 is in an orientation where it cannot beamform to the left in Figure 8. Therefore, communication terminal 4 is beamforming in the BF direction 1 toward the non-terrestrial network base station S1.

[0098] After a predetermined time has elapsed from the diagram shown on the left side of Figure 8, the instruction unit 11 refers to at least one of the heatmap and orbital information to instruct the communication terminal 4 on the beamforming direction to be used to initiate communication with a base station with which the communication terminal 4 is not currently 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 beamform. Therefore, as shown on the right side of Figure 8, the instruction unit 11 instructs the communication terminal 4 to beamform in the BF direction 2, which is the direction in which the communication terminal 4 can beamform and in which the terrestrial base station B2 is located. Specifically, the instruction unit 11 transmits instruction information to the communication terminal 4 indicating that it is instructed to beamform in the BF direction 2.

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

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

[0101] (Effects of Embodiment 2) As described above, in the communication system 100 according to this exemplary embodiment, the instruction unit 11 refers to the heatmap, trajectory information, and attitude information to instruct the communication terminal 4 on the beamforming direction to be used to initiate communication with a base station with which the communication terminal 4 is not currently communicating. Therefore, the instruction unit 11 can cause the communication terminal 4 to beamform in the appropriate direction when the communication terminal 4 performs a handover or initiates communication. As a result, for example, when the communication terminal 4 performs a handover, the instruction unit 11 can instruct the communication terminal 4 on the beamforming direction toward the handover destination base station, so the communication terminal 4 knows the handover destination in advance and can communicate without interruption. This eliminates the need for rescanning to initiate communication when the connection is interrupted. Also, for example, when the communication terminal 4 initiates communication, the instruction unit 11 can instruct the communication terminal 4 on the beamforming direction to shorten the scan time for initiating communication. This shortens the scan time.

[0102] [Examples of implementation using software] 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 integrated circuits (IC chips) or by software.

[0103] In the latter case, the communication terminal control devices 1 and 3 and the communication terminal 4 are implemented by a computer that executes instructions for a program, which is software that implements each function. An example of such a computer (hereinafter referred to as computer C) is shown in Figure 9. Computer C comprises at least one processor C1 and at least one memory C2. The memory C2 stores a program P that causes computer C to operate as the communication terminal control devices 1 and 3 and the communication terminal 4. In computer C, the processor C1 reads the program P from the memory C2 and executes it, thereby implementing the functions of the communication terminal control devices 1 and 3 and the communication terminal 4.

[0104] Processor C1 can include, for example, a CPU (Central Processing Unit), GPU (Graphic Processing Unit), DSP (Digital Signal Processor), MPU (Micro Processing Unit), FPU (Floating Point Number Processing Unit), PPU (Physics Processing Unit), microcontroller, or a combination thereof. Memory C2 can include, for example, flash memory, HDD (Hard Disk Drive), SSD (Solid State Drive), or a combination thereof.

[0105] Computer C may also be equipped with RAM (Random Access Memory) for loading program P at runtime and for temporarily storing various data. Furthermore, computer C may be equipped with communication interfaces for sending and receiving data with other devices. Additionally, computer C may be equipped with input / output interfaces for connecting input / output devices such as keyboards, mice, displays, and printers.

[0106] Furthermore, program P can be recorded on a non-temporary, tangible recording medium M that is readable by computer C. Such a recording medium M could be, for example, tape, disk, card, semiconductor memory, or programmable logic circuitry. Computer C can acquire program P via such a recording medium M. Program P can also be transmitted via a transmission medium. Such a transmission medium could be, for example, a communication network or broadcast waves. Computer C can also acquire program P via such a transmission medium.

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

[0108] (Note 1) A communication terminal control device comprising a beamforming function and an instruction means for indicating the beamforming direction to be used by a communication terminal capable of communicating with a ground base station and a non-terrestrial network base station to initiate communication with a base station with which the communication terminal is not currently communicating.

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

[0110] (Note 3) The communication terminal control device according to Appendix 1 or 2, wherein the indicating means indicates the beamforming direction by referring to a heat map which associates the position of the communication terminal with the beamforming direction to be indicated.

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

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

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

[0114] (Note 7) The communication terminal control device according to appendices 4 to 6, wherein the generation means divides the region included in the heatmap into a plurality of meshes, and determines the beamforming direction in a mesh from which the acquisition means could not acquire BF direction information and position information by referring to the beamforming direction in a neighboring mesh of the mesh.

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

[0116] (Note 9) The instruction means provides the communication terminal with a beamforming direction including an azimuth angle and an elevation angle, as described in any one of the appendices 1 to 8, as a communication terminal control device.

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

[0118] (Note 11) A program that causes a computer to function as a communication terminal control device, wherein the computer functions as an instruction means for instructing a communication terminal having beamforming capabilities and capable of communicating with terrestrial base stations and non-terrestrial network base stations on the beamforming direction to be used to initiate communication with a base station with which the communication terminal is not currently communicating.

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

[0120] Furthermore, this communication terminal control device may also be equipped with memory, and this memory may store a program for causing the processor to execute the instruction processing. This program may also be recorded on a computer-readable, non-temporary, tangible recording medium.

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

[0122] (Note 1) A communication terminal control device comprising at least one processor, wherein the at least one processor has a beamforming function and performs an instruction process that instructs a communication terminal capable of communicating with a terrestrial base station and a non-terrestrial network base station on the beamforming direction to be used to initiate communication with a base station with which the communication terminal is not currently communicating.

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

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

[0125] (Note 4) The communication terminal control device described in Appendix 3, wherein the at least one processor performs an acquisition process to acquire BF direction information indicating the beamforming direction of each of the plurality of communication terminals that can communicate with the ground base station and the non-terrestrial network base station, and position information indicating the position of each of the plurality of communication terminals, and a generation process that generates the heat map by referring to the BF direction information and the position information.

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

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

[0128] (Note 7) The communication terminal control device according to any one of the appendices 4 to 6, wherein the at least one processor divides the region included in the heatmap into a plurality of meshes in the generation process, and determines the beamforming direction in a mesh from which the acquisition means could not acquire BF direction information and position information by referring to the beamforming direction in a neighboring mesh of the mesh.

[0129] (Note 8) The communication terminal control device according to any one of the appendices 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 processing, refers to orbital information indicating the orbit of the low Earth orbit satellite and instructs the beamforming direction of the communication terminal.

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

[0131] 1, 3 Communication terminal control device 4. Communication terminals 11 Instruction part 32 Acquisition Department 33 Generation part 34. Learning Department 42 Acquisition Department 43 BF Control Unit 44 BF direction acquisition section 45 Location information acquisition section 46 Attitude information acquisition unit 47 Image acquisition unit 100 Communication Systems

Claims

1. Acquisition means for acquiring BF direction information indicating the beamforming direction of each of a plurality of communication terminals capable of communicating with a ground base station and a non-terrestrial network base station, and position information indicating the position of each of the plurality of communication terminals, A generation means that generates a heat map in which the position of the communication terminal and the beamforming direction to be indicated are associated by referring to the BF direction information and the position information, A communication terminal having beamforming capabilities and capable of communicating with the ground base station and the non-terrestrial network base station, provides an instruction means for indicating a beamforming direction to be used by the communication terminal to initiate communication with a base station with which it is not currently communicating, by referring to a heat map which associates the location of the communication terminal with the indicated beamforming direction. A communication terminal control device equipped with the following features.

2. The indicating means indicates the beamforming direction according to the location and time of the communication terminal. The communication terminal control device according to claim 1.

3. The acquisition means further acquires attitude information indicating the attitude of each of the plurality of communication terminals from each of the plurality of communication terminals, The generation means further references the posture information and generates the heat map. The communication terminal control device according to claim 1.

4. The generation means takes information about the communication terminal as input and generates the heatmap using a trained model that has been trained to output directions where the radio wave intensity is estimated to be high at the communication terminal. The communication terminal control device according to claim 1.

5. The generation means divides the region included in the heatmap into a plurality of meshes, and determines the beamforming direction in a mesh from which the acquisition means could not obtain BF direction information and position information by referring to the beamforming direction in a neighboring mesh of that mesh. The communication terminal control device according to claim 1.

6. The aforementioned non-terrestrial network base station is a low Earth orbit satellite. The indicating means refers to orbital information indicating the orbit of the low Earth orbit satellite and indicates the beamforming direction of the communication terminal. A communication terminal control device according to claim 1 or 2.

7. By a communication terminal control device, The system acquires beamforming direction information for each of the multiple communication terminals capable of communicating with a terrestrial base station and a non-terrestrial network base station, and location information for each of the multiple communication terminals. Referencing the BF direction information and the position information, a heatmap is generated that associates the position of the communication terminal with the indicated beamforming direction. For a communication terminal having beamforming capabilities and capable of communicating with the ground base station and the non-terrestrial network base station, the system refers to a heatmap that associates the location of the communication terminal with the beamforming direction to be indicated, and instructs the communication terminal to use a beamforming direction to initiate communication with a base station with which it is not currently communicating. A method for controlling communication terminals.

8. Obtain BF direction information indicating the beamforming direction of each of a plurality of communication terminals capable of communicating with a ground base station and a non-terrestrial network base station, and location information indicating the position of each of the plurality of communication terminals, Referencing the BF direction information and the position information, a heatmap is generated that associates the position of the communication terminal with the indicated beamforming direction. A program that causes a computer to perform the following actions for a communication terminal having beamforming capabilities and capable of communicating with the ground base station and the non-terrestrial network base station: referencing a heatmap that associates the location of the communication terminal with the beamforming direction to be indicated, and instructing the communication terminal to use a beamforming direction to initiate communication with a base station with which it is not currently communicating.

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