Control device, control method, and program

Abstract

An acquisition unit (11) in this control device (10) acquires information relating to interference received, from a signal transmitted from a non-terrestrial network (50), by a signal directly transmitted from a non-terrestrial network (20) to a terminal device (40). A path control unit (12) selects a usage communication path from among a direct path and an indirect path on the basis of information pertaining to the interference. The "direct path" refers to a path through which a signal is directly transmitted from the non-terrestrial network (20) to the terminal device (40). The "indirect path" refers to a path through which the signal transmitted from the non-terrestrial network 20 reaches the terminal device (40) indirectly via the reconfigurable intelligent surface (RIS) (31) of a terrestrial relay device (30).

Description

[Technical Field]

[0001] The present disclosure relates to a control device, a control method, and a non-transitory computer-readable medium. [Background technology]

[0002] Various technologies relating to non-terrestrial networks (NTNs) have been proposed (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-168898 Summary of the Invention [Problem to be solved by the invention]

[0004] The inventor has discovered that there is a possibility that the communication quality of one non-terrestrial network may be degraded due to interference of a signal from a first non-terrestrial network device (e.g., a satellite) included in one non-terrestrial network to a terrestrial terminal device, caused by a signal from a second non-terrestrial network device included in another non-terrestrial network.

[0005] An object of the present disclosure is to provide a control device, a control method, and a non-transitory computer-readable medium that can reduce degradation in communication quality between a non-terrestrial network and a terminal device. [Means for solving the problem]

[0006] A control device according to a first aspect is a control device that controls a communication path used to transmit a signal to a terminal device in a communication system including a non-terrestrial network device included in a first non-terrestrial network and a terrestrial relay device including a RIS (Reconfigurable Intelligent Surface), a first acquisition means for acquiring information about interference that a signal transmitted directly from the non-terrestrial network device to the terminal device receives from a signal transmitted from a second non-terrestrial network; a route control means for selecting the communication route to be used from a direct route for transmitting directly from the non-terrestrial network device to the terminal device and an indirect route through which a signal transmitted from the non-terrestrial network device indirectly reaches the terminal device via the terrestrial repeater, based on the information regarding the interference; It is equipped with:

[0007] A control method according to a second aspect is a control method executed by a control device in a communication system, the communication system includes a non-terrestrial network device included in a first non-terrestrial network and a terrestrial relay device including a RIS (Reconfigurable Intelligent Surface); The control method includes: acquiring information about interference that a signal transmitted directly from the non-terrestrial network device to a terminal device receives from a signal transmitted from a second non-terrestrial network; selecting a communication path to be used for transmitting a signal to the terminal device in the communication system from a direct path for transmitting directly from the non-terrestrial network device to the terminal device and an indirect path for transmitting indirectly from the non-terrestrial network device to the terminal device via the terrestrial repeater based on the information regarding the interference; Includes:

[0008] A non-transitory computer-readable medium according to a third aspect is a non-transitory computer-readable medium storing a program for causing a control device in a communication system to execute a process, the communication system includes a non-terrestrial network device included in a first non-terrestrial network and a terrestrial relay device including a RIS (Reconfigurable Intelligent Surface); The process comprises: acquiring information about interference that a signal transmitted directly from the non-terrestrial network device to a terminal device receives from a signal transmitted from a second non-terrestrial network; selecting a communication path to be used for transmitting a signal to the terminal device in the communication system from a direct path for transmitting directly from the non-terrestrial network device to the terminal device and an indirect path for transmitting indirectly from the non-terrestrial network device to the terminal device via the terrestrial repeater based on the information regarding the interference; Includes: [Effects of the Invention]

[0009] The present disclosure makes it possible to provide a control device, a control method, and a non-transitory computer-readable medium that can reduce degradation in communication quality between a non-terrestrial network and a terminal device. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram illustrating an example of a communication system according to a first embodiment. [Figure 2] FIG. 2 is a block diagram showing an example of a control device in the first embodiment. [Figure 3] FIG. 10 is a diagram illustrating an example of a communication system according to a second embodiment. [Figure 4] 10A and 10B are diagrams illustrating an example of a method for acquiring information about interference. [Figure 5] FIG. 10 is a block diagram showing an example of a control device in a second embodiment. [Figure 6]FIG. 10 is a diagram illustrating an example of a communication system according to a third embodiment. [Figure 7] FIG. 11 is a block diagram showing an example of a control device according to a third embodiment. [Figure 8] FIG. 10 is a diagram illustrating an example of a communication system according to a fourth embodiment. [Figure 9] FIG. 10 is a block diagram showing an example of a control device in a fourth embodiment. [Figure 10] FIG. 13 is a diagram illustrating another method for selecting a communication path to be used in the fourth embodiment. [Figure 11] FIG. 10 is a diagram illustrating an example of a communication system according to a fifth embodiment. [Figure 12] FIG. 13 is a block diagram showing an example of a control device in a fifth embodiment. [Figure 13] FIG. 2 is a diagram illustrating an example of a hardware configuration of a control device. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the following description and drawings have been omitted or simplified as appropriate for clarity of explanation. Furthermore, in the following drawings, the same elements are given the same reference numerals, and duplicate explanations are omitted as necessary. Furthermore, in this disclosure, unless otherwise specified, "at least one of A or B (A / B)" may mean any one of A or B, or both A and B. Similarly, when "at least one" is used with respect to three or more elements, it may mean any one of these elements, or any multiple elements (including all elements).

[0012] First Embodiment <Communication System Overview> Fig. 1 is a diagram showing an example of a communication system in the first embodiment. In Fig. 1, the communication system 1 includes a control device 10, a non-terrestrial network device 20, a terrestrial repeater device 30 including a RIS (Reconfigurable Intelligent Surface) 31, and a terminal device 40. Note that, for simplicity of explanation, one each of the non-terrestrial network device 20, the terrestrial repeater device 30, and the terminal device 40 is shown here, but the number of these is not limited to one. Furthermore, the RIS (Reconfigurable Intelligent Surface) is sometimes called an IRS (Intelligent Reflecting Surface).

[0013] The non-terrestrial network device 20 is included in a first non-terrestrial network (NTN).

[0014] 1 shows a non-terrestrial network device 50. This non-terrestrial network device 50 is included in a second non-terrestrial network that is different from a first non-terrestrial network. For example, the operator that provides the first non-terrestrial network is different from the operator that provides the second non-terrestrial network. This makes it difficult for the first non-terrestrial network and the second non-terrestrial network to operate in cooperation with each other.

[0015] 1 also shows a terminal device 60. This terminal device 60 is, for example, a terminal of a carrier that provides a second non-terrestrial network, and is capable of communicating with the second non-terrestrial network but is incapable of communicating with the first non-terrestrial network.

[0016] In such a situation, a signal transmitted directly from the non-terrestrial network device 20 to the terminal device 40 may be interfered with by a signal transmitted from the non-terrestrial network device 50 to the terminal device 60. Hereinafter, this interference may be simply referred to as "interference." This is because the frequency bands allocated to non-terrestrial networks are limited, and therefore the frequencies of the first non-terrestrial network and the second non-terrestrial network are likely to be close to or overlap with each other.

[0017] 1, the route through which a signal from the non-terrestrial network device 20 to the terminal device 40 passes includes a "direct route" in which the signal is transmitted directly from the non-terrestrial network device 20 to the terminal device 40, and an "indirect route" (hereinafter sometimes referred to as a "first indirect route") in which the signal transmitted from the non-terrestrial network device 20 indirectly reaches the terminal device 40 via the RIS 31 of the terrestrial repeater 30. In other words, the candidates for the route through which a signal from the non-terrestrial network device 20 to the terminal device 40 passes (i.e., the route candidates) include the direct route and the first indirect route.

[0018] <Example of control device configuration> 2 is a block diagram showing an example of a control device in the first embodiment. In FIG. 2, the control device 10 includes an acquisition unit 11 and a route control unit 12.

[0019] The acquisition unit 11 acquires information relating to interference that a signal transmitted directly from the non-terrestrial network device 20 to the terminal device 40 receives from a signal transmitted from the non-terrestrial network device 50 .

[0020] The route control unit 12 selects a "used communication route" from the direct route and the first indirect route based on the information about interference. This "used communication route" is a route through which a signal from the non-terrestrial network device 20 to the terminal device 40 actually passes.

[0021] For example, if the route control unit 12 determines that "interference" is occurring based on the above-mentioned information on interference, it may select the above-mentioned first indirect route as the communication route to be used. The above-mentioned first indirect route can transmit a signal to the terminal device 40 with pinpoint accuracy using a sharp beam from the RIS 31. This makes it possible to avoid interference. On the other hand, if the route control unit 12 determines that "interference" is not occurring based on the above-mentioned information on interference, it may select the above-mentioned direct route as the communication route to be used.

[0022] Here, an example of a method for acquiring information about interference will be described. FIG. 3 is a diagram illustrating an example of a method for acquiring information about interference. In FIG. 3, the control device 10 is connected to, for example, radio wave monitoring antennas 70-1, 70-2, and 70-3. The control device 10 acquires the reception power of radio waves received by the radio wave monitoring antennas 70-1, 70-2, and 70-3 during non-transmission periods of the frequency of the communication system 1. The reception power of radio waves during non-transmission periods of the frequency of the communication system 1 is considered to be the reception power of radio waves of a communication system corresponding to the second non-terrestrial network. In other words, the reception power of radio waves received by the radio wave monitoring antennas 70-1, 70-2, and 70-3 during non-transmission periods of the frequency of the communication system 1 can be used as information about interference.

[0023] In this case, the route control unit 12 may determine that the above-mentioned "interference" is occurring if the received power indicated by the information on interference is equal to or greater than a predetermined threshold, and may determine that "interference" is not occurring if the received power indicated by the information on interference is less than the predetermined threshold. Note that radio waves emitted from the non-terrestrial network device 20 on the direct route may cause interference with other communication systems. For this reason, the control device 10 may cause the non-terrestrial network device 20 to start communication on the direct route only when the received power of radio waves in the vicinity of the frequency of the communication system 1 is not observed. This makes it possible to reduce interference from the communication system 1 to other communication systems.

[0024] The control device 10 may acquire information about the location of the terminal device 40. The control device 10 may have a RIS control unit (not shown) that controls the beam radiation direction of the RIS 31 so that the radiation direction of the beam emitted from the RIS 31 is directed toward the terminal device 40. For example, the RIS control unit (not shown) forms a phase control signal that controls the phase of the signal emitted from the RIS 31 so that the beam radiation direction of the RIS 31 is directed toward the terminal device 40. The control device 10 passes this phase control signal to the terrestrial repeater device 30, and the RIS 31 adjusts the phase of the signal output from each element. Here, when communication between the terminal device 40 and the non-terrestrial network device 20 is possible, the information about the location of the terminal device 40 may be acquired by the control device 10 from the terminal device 40 via the non-terrestrial network device 20. Furthermore, when communication between the terminal device 40 and the non-terrestrial network device 20 is impossible due to "interference," the information about the location of the terminal device 40 may be acquired by the control device 10 from the terminal device 40 via the terrestrial communication network.

[0025] The control device 10 may also have a beam control unit (not shown) that controls the radiation direction of the beam radiated from the non-terrestrial network device 20 depending on the communication path to be used. For example, when the above-mentioned direct path is selected as the communication path to be used, the beam control unit (not shown) generates a phase control signal that controls the phase of the signal radiated from each antenna element of the array antenna so that the radiation direction of the beam radiated from the array antenna of the non-terrestrial network device 20 is directed toward the area where the terminal device 40 is located. When the above-mentioned first indirect path is selected as the communication path to be used, the beam control unit (not shown) generates a phase control signal that controls the phase of the signal radiated from each antenna element of the array antenna so that the radiation direction of the beam radiated from the array antenna of the non-terrestrial network device 20 is directed toward the RIS 31. The control device 10 passes this phase control signal to the non-terrestrial network device 20, and the non-terrestrial network device 20 adjusts the phase of the signal output from each element.

[0026] The terminal device 40 may also control the directivity of the reception beam depending on the communication path to be used. That is, for example, when the above-mentioned direct path is selected as the communication path to be used, the terminal device 40 controls the phase of the signal received by each antenna element of the array antenna of the terminal device 40 so that the direction of the reception beam is directed toward the non-terrestrial network device 20. When the above-mentioned first indirect path is selected as the communication path to be used, the terminal device 40 controls the phase of the signal received by each antenna element of the array antenna of the terminal device 40 so that the direction of the reception beam is directed toward the RIS 31.

[0027] As described above, according to the first embodiment, the acquisition unit 11 in the control device 10 acquires information regarding interference that a signal transmitted directly from the non-terrestrial network device 20 to the terminal device 40 receives from a signal transmitted from the non-terrestrial network device 50. The route control unit 12 selects a "communication route to use" from the above direct route and the above first indirect route based on the information regarding interference.

[0028] This configuration of the control device 10 makes it possible to suppress degradation of communication quality between the non-terrestrial network and the terminal device.

[0029] Second Embodiment The second embodiment relates to an embodiment in which a communication path to be used is selected from among a plurality of indirect path candidates.

[0030] Fig. 4 is a diagram showing an example of a communication system in the second embodiment. In Fig. 4, the communication system 1 includes a control device 10, non-terrestrial network devices 20-1 and 20-2, a terrestrial repeater device 30 including a RIS 31, and a terminal device 40. The non-terrestrial network devices 20-1 and 20-2 are included in the first non-terrestrial network.

[0031] Fig. 5 is a block diagram showing an example of a control device in the second embodiment. In Fig. 5, the control device 10 has an acquisition unit 11 and a route control unit 12. The acquisition unit 11 has an acquisition unit 11A and an acquisition unit 11B.

[0032] Similar to the acquisition unit 11 described in the first embodiment, the acquisition unit 11A acquires information regarding interference that a signal transmitted directly from a non-terrestrial network device 20 to a terminal device 40 receives from a signal transmitted from a non-terrestrial network device 50.

[0033] The acquisition unit 11B acquires information (hereinafter, sometimes referred to as "first information") about the reception gain of the signal that has passed through the first indirect path at the terminal device 40. For example, the terminal device 40 may calculate the reception gain based on the reference signal that has been transmitted from the non-terrestrial network device 20-1 and received via the RIS 31, and transmit the calculated reception gain to the control device 10 as the "first information."

[0034] Furthermore, the acquisition unit 11B acquires information (hereinafter, sometimes referred to as "second information") regarding the reception gain at the terminal device 40 of a signal that has passed through the "second indirect path." The "second indirect path" is an indirect path through which a signal transmitted from the non-terrestrial network device 20-2 indirectly reaches the terminal device 40 via the RIS 31 of the terrestrial repeater device 30. For example, the terminal device 40 may calculate a reception gain based on a reference signal transmitted from the non-terrestrial network device 20-2 and received via the RIS 31, and transmit the calculated reception gain to the control device 10 as the "second information."

[0035] The route control unit 12 of the second embodiment selects a communication route to be used from the first indirect route and the second indirect route based on the first information and the second information. This selection may be performed when a communication route to be used is selected from a direct route and an indirect route as described in the first embodiment, and a plurality of indirect route candidates are included in the indirect route.

[0036] For example, the route control unit 12 may select, as the communication route to be used, an indirect route corresponding to the first information or the second information, whichever indicates a better reception gain. That is, depending on the positional relationship (distance between the non-terrestrial network device 20-1 and the RIS 31, incident angle of radio waves, etc.), there may be cases where transmitting a signal from the non-terrestrial network device 20-2 is more advantageous in terms of reception gain. In this case, it is more advantageous to select the second indirect route as the communication route to be used than the first indirect route.

[0037] As described above, according to the second embodiment, the acquisition unit 11 in the control device 10 acquires first information regarding the reception gain in the terminal device 40 of a signal that has passed through the first indirect path. The acquisition unit 11 acquires second information regarding the reception gain in the terminal device 40 of a signal that has passed through the second indirect path. The path control unit 12 selects a communication path to use from the first indirect path and the second indirect path based on the first information and the second information.

[0038] This configuration of the control device 10 makes it possible to select an indirect path with better reception quality.

[0039] If the non-terrestrial network device 20 is an artificial satellite, the orbit of the non-terrestrial network device 20 is fixed. Therefore, if the position on the orbit of the non-terrestrial network device 20-1 is associated with the selection record of the communication route to be used and the corresponding relationship is stored first, the route control unit 12 can select the communication route to be used by using this correspondence relationship and information on the position on the orbit of the non-terrestrial network device 20-1.

[0040] Third Embodiment The third embodiment relates to an embodiment in which a communication path to be used is selected from among a plurality of indirect path candidates.

[0041] Fig. 6 is a diagram illustrating an example of a communication system according to the third embodiment. In Fig. 6, the communication system 1 includes a control device 10, a non-terrestrial network device 20, a terrestrial repeater device 30-1 including a RIS 31-1, a terrestrial repeater device 30-2 including a RIS 31-2, and a terminal device 40.

[0042] Fig. 7 is a block diagram showing an example of a control device in the third embodiment. In Fig. 7, the control device 10 has an acquisition unit 11 and a route control unit 12. The acquisition unit 11 has an acquisition unit 11A and an acquisition unit 11C.

[0043] Similar to the acquisition unit 11 described in the first embodiment, the acquisition unit 11A acquires information regarding interference that a signal transmitted directly from a non-terrestrial network device 20 to a terminal device 40 receives from a signal transmitted from a non-terrestrial network device 50.

[0044] The acquisition unit 11C acquires first information related to the reception gain of the signal that has passed through the first indirect path at the terminal device 40. For example, the terminal device 40 may calculate the reception gain based on a reference signal that has been transmitted from the non-terrestrial network device 20 and received via the RIS 31-1, and transmit the reception gain to the control device 10 as the "first information."

[0045] The acquisition unit 11C also acquires information (hereinafter, sometimes referred to as "third information") regarding the reception gain at the terminal device 40 of a signal that has passed through the "third indirect path." The "third indirect path" is an indirect path through which a signal transmitted from the non-terrestrial network device 20 indirectly reaches the terminal device 40 via the RIS 31-2 of the terrestrial repeater 30-2. For example, the terminal device 40 may calculate a reception gain based on a reference signal transmitted from the non-terrestrial network device 20 and received via the RIS 31-2, and transmit the calculated reception gain to the control device 10 as the "third information."

[0046] The route control unit 12 of the third embodiment selects a communication route to be used from the first indirect route and the third indirect route based on the first information and the third information. This selection may be performed when a communication route to be used is selected from a direct route and an indirect route as described in the first embodiment, and a plurality of indirect route candidates are included in the indirect route.

[0047] For example, the route control unit 12 may select, as the communication route to be used, an indirect route corresponding to one of the first information and the third information that shows a better reception gain.

[0048] As described above, according to the third embodiment, the acquisition unit 11 in the control device 10 acquires first information regarding the reception gain in the terminal device 40 of a signal that has passed through the first indirect path. The acquisition unit 11 acquires third information regarding the reception gain in the terminal device 40 of a signal that has passed through the third indirect path. The route control unit 12 selects a communication route to use from the first indirect path and the third indirect path based on the first information and the third information.

[0049] This configuration of the control device 10 makes it possible to select an indirect path with better reception quality.

[0050] <Fourth embodiment> The fourth embodiment relates to an embodiment in which a communication path to be used is selected from among a plurality of indirect path candidates.

[0051] Fig. 8 is a diagram showing an example of a communication system in the fourth embodiment. In Fig. 8, the communication system 1 includes a control device 10, non-terrestrial network devices 20-1 and 20-2, a terrestrial repeater device 30-1 including a RIS 31-1, a terrestrial repeater device 30-2 including a RIS 31-2, and a terminal device 40. The non-terrestrial network devices 20-1 and 20-2 are included in the first non-terrestrial network.

[0052] Fig. 9 is a block diagram showing an example of a control device in the fourth embodiment. In Fig. 9, the control device 10 has an acquisition unit 11 and a route control unit 12. The acquisition unit 11 has an acquisition unit 11A and an acquisition unit 11D.

[0053] Similar to the acquisition unit 11 described in the first embodiment, the acquisition unit 11A acquires information regarding interference that a signal transmitted directly from a non-terrestrial network device 20 to a terminal device 40 receives from a signal transmitted from a non-terrestrial network device 50.

[0054] The acquisition unit 11D acquires first information regarding the reception gain of the signal that has passed through the first indirect path at the terminal device 40. For example, the terminal device 40 may calculate the reception gain based on a reference signal that has been transmitted from the non-terrestrial network device 20-1 and received via the RIS 31-1, and transmit the reception gain to the control device 10 as the "first information."

[0055] Furthermore, the acquisition unit 11D acquires information (hereinafter, sometimes referred to as "fourth information") regarding the reception gain at the terminal device 40 of a signal that has passed through the "fourth indirect path." The "fourth indirect path" is an indirect path through which a signal transmitted from the non-terrestrial network device 20-2 indirectly reaches the terminal device 40 via the RIS 31-2 of the terrestrial repeater 30-2. For example, the terminal device 40 may calculate a reception gain based on a reference signal transmitted from the non-terrestrial network device 20-2 and received via the RIS 31-2, and transmit the calculated reception gain to the control device 10 as the "fourth information."

[0056] The route control unit 12 of the fourth embodiment selects a communication route to be used from the first indirect route and the fourth indirect route based on the first information and the fourth information. This selection may be performed when a communication route to be used is selected from a direct route and an indirect route as described in the first embodiment, and a plurality of indirect route candidates are included in the indirect route.

[0057] For example, the route control unit 12 may select, as the communication route to be used, an indirect route corresponding to one of the first information and the fourth information that shows a better reception gain.

[0058] As described above, according to the fourth embodiment, the acquisition unit 11 in the control device 10 acquires first information regarding the reception gain in the terminal device 40 of a signal that has passed through the first indirect path. The acquisition unit 11 acquires fourth information regarding the reception gain in the terminal device 40 of a signal that has passed through the fourth indirect path. The path control unit 12 selects a communication path to use from the first indirect path and the fourth indirect path based on the first information and the fourth information.

[0059] This configuration of the control device 10 makes it possible to select an indirect path with better reception quality.

[0060] <Modification> The route control unit 12 of the fourth embodiment may select a communication route to be used based on the position of the terminal device 40, the position of the RIS 31, and the orbital position of the non-terrestrial network device 20. That is, for example, if the non-terrestrial network device 20 is an artificial satellite, the orbit of the non-terrestrial network device 20 is predetermined. Therefore, once the position of the non-terrestrial network device 20 and the target position (target area) are determined, a RIS 31 suitable for the combination of the non-terrestrial network device 20 and the target position (target area) is determined. A suitable RIS is, for example, a RIS that can see the target position (target area). For example, as shown in FIG. 10, RIS 31-1 cannot see the position of the terminal device 40, while RIS 31-2 can see the position of the terminal device 40. In such a situation, the route control unit 12 may select the "fourth indirect route" as the communication route to be used. FIG. 10 is a diagram illustrating another method for selecting a communication route to be used in the fourth embodiment. This method is also applicable to the second and third embodiments.

[0061] Fifth Embodiment The fifth embodiment relates to an embodiment in which the communication route to be used is selected from a direct route, or either a terrestrial route and an indirect route for transmission to a terminal device via a land network.

[0062] Fig. 11 is a diagram illustrating an example of a communication system according to the fifth embodiment. In Fig. 11, a communication system 1 includes a control device 10, a non-terrestrial network device 20, a terrestrial repeater device 30 including a RIS 31, a terminal device 40, and a terrestrial base station 80 of a terrestrial network.

[0063] 12 is a block diagram showing an example of a control device in the fifth embodiment. In FIG. 12, the control device 10 includes an acquisition unit 11 and a route control unit 12.

[0064] The acquisition unit 11 in the control device 10 of the fifth embodiment acquires information regarding interference that a signal transmitted directly from a non-terrestrial network device 20 to a terminal device 40 receives from a signal transmitted from a non-terrestrial network device 50.

[0065] In the control device 10 of the fifth embodiment, the route control unit 12 selects, based on information about interference, either the above-mentioned direct route or the above-mentioned first indirect route, as the communication route to be used. In Fig. 11, the "terrestrial route" is a route that passes through a terrestrial base station 80.

[0066] For example, when the route control unit 12 determines that "interference" is occurring based on the above-mentioned information on interference, it may select either the "terrestrial route" or the above-mentioned first indirect route as the communication route to be used. On the other hand, when the route control unit 12 determines that "interference" is not occurring based on the above-mentioned information on interference, it may select the above-mentioned direct route as the communication route to be used.

[0067] Furthermore, the route control unit 12 may select a communication route to be used from the "terrestrial route" and the first indirect route described above based on the characteristics of data included in a signal transmitted to the terminal device 40 (for example, the amount of data or the type of data). For example, the route control unit 12 may select the terrestrial route as the communication route to be used when the amount of data transmitted to the terminal device 40 is equal to or greater than a predetermined level, and may select the first indirect route as the communication route to be used when the amount of data transmitted to the terminal device 40 is less than the predetermined level. Alternatively, for example, the route control unit 12 may select the first indirect route as the communication route to be used when the type of data requires low latency, and may select the terrestrial route as the communication route to be used when the type of data is a type that tolerates latency. Note that the information regarding the characteristics of the data may be acquired by the acquisition unit 11.

[0068] <Other embodiments> <1> When selecting a communication path to use from among a plurality of indirect paths, an indirect path corresponding to a better reception gain may be selected as the communication path to use from any combination of the first to fourth indirect paths described in the first to fifth embodiments.

[0069] <2> FIG. 13 is a diagram illustrating an example of the hardware configuration of a control device. In FIG. 13, the control device 100 has a processor 101 and a memory 102. The processor 101 may be, for example, a microprocessor, an MPU (Micro Processing Unit), or a CPU (Central Processing Unit). The processor 101 may include multiple processors. The memory 102 is configured by a combination of a volatile memory and a non-volatile memory. The memory 102 may include storage located away from the processor 101. In this case, the processor 101 may access the memory 102 via an I / O interface (not shown).

[0070] The control device 10 of the first to fifth embodiments may each have the hardware configuration shown in FIG. 13. The acquisition unit 11 and the route control unit 12 of the control device 10 of the first to fifth embodiments may be realized by the processor 101 reading and executing a program stored in the memory 102. The program can be stored using various types of non-transitory computer-readable media and supplied to the control device 10. Examples of non-transitory computer-readable media include magnetic recording media (e.g., flexible disks, magnetic tapes, hard disk drives) and magneto-optical recording media (e.g., magneto-optical disks). Further examples of non-transitory computer-readable media include CD-ROMs (Read Only Memory), CD-Rs, and CD-R / Ws. Further examples of non-transitory computer-readable media include semiconductor memories. Examples of semiconductor memories include mask ROMs, programmable ROMs (PROMs), erasable PROMs (EPROMs), flash ROMs, and random access memories (RAMs). The program may also be supplied to the control device 10 by various types of transitory computer-readable media. Examples of transitory computer-readable media include electrical signals, optical signals, and electromagnetic waves. The transitory computer-readable media can supply the program to the control device 10 via a wired communication path such as an electrical wire or optical fiber, or via a wireless communication path.

[0071] Although the present invention has been described above with reference to the embodiments, the present invention is not limited to the above. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the invention.

[0072] A part or all of the above-described embodiments can be described as, but not limited to, the following supplementary notes. (Appendix 1) A control device for controlling a communication path used to transmit a signal to a terminal device in a communication system including a non-terrestrial network device included in a first non-terrestrial network and a terrestrial relay device including a RIS (Reconfigurable Intelligent Surface), a first acquisition means for acquiring information about interference that a signal transmitted directly from the non-terrestrial network device to the terminal device receives from a signal transmitted from a second non-terrestrial network; a route control means for selecting the communication route to be used from a direct route for transmitting directly from the non-terrestrial network device to the terminal device and an indirect route through which a signal transmitted from the non-terrestrial network device indirectly reaches the terminal device via the terrestrial repeater, based on the information regarding the interference; A control device comprising: (Appendix 2) the first non-terrestrial network includes a first non-terrestrial network device and a second non-terrestrial network device; the indirect path includes a first indirect path through which a signal transmitted from the first non-terrestrial network device indirectly reaches the terminal device via the terrestrial repeater, and a second indirect path for indirectly transmitting the signal from the second non-terrestrial network device to the terminal device via the terrestrial repeater; the control device includes a second acquisition means for acquiring first information on a reception gain in the terminal device of a signal that has passed through the first indirect path and second information on a reception gain in the terminal device of a signal that has passed through the second indirect path; the route control means selects the communication route to be used from the first indirect route and the second indirect route based on the first information and the second information. 10. The control device of claim 1. (Appendix 3) the communication system includes a second terrestrial repeater; the indirect path includes a first indirect path through which a signal transmitted from the non-terrestrial network device indirectly reaches the terminal device via the terrestrial repeater, and a third indirect path for indirectly transmitting the signal from the non-terrestrial network device to the terminal device via the second terrestrial repeater, the control device includes a third acquisition means for acquiring first information regarding a reception gain in the terminal device of a signal that has passed through the first indirect path and third information regarding a reception gain in the terminal device of a signal that has passed through the third indirect path; the route control means selects the communication route to be used from the first indirect route and the third indirect route based on the first information and the third information. 10. The control device of claim 1. (Appendix 4) the first non-terrestrial network includes a first non-terrestrial network device, a second non-terrestrial network device, and a second terrestrial repeater device; the indirect path includes a first indirect path through which a signal transmitted from the first non-terrestrial network device indirectly reaches the terminal device via the terrestrial repeater, and a fourth indirect path for indirectly transmitting the signal from the second non-terrestrial network device to the terminal device via the second terrestrial repeater; the control device includes a fourth acquisition means for acquiring first information on a reception gain in the terminal device of a signal that has passed through the first indirect path and fourth information on a reception gain in the terminal device of a signal that has passed through the fourth indirect path; the route control means selects the communication route to be used from the first indirect route and the fourth indirect route based on the first information and the fourth information. 10. The control device of claim 1. (Appendix 5) the communication system includes a land network; the route control means selects, as the communication route to be used, either the direct route or one of a terrestrial route for transmitting to the terminal device via the land network and the indirect route; 10. The control device of claim 1. (Appendix 6) the route control means selects the communication route to be used from the terrestrial route and the indirect route based on characteristics of data included in the signal. 6. The control device of claim 5. (Appendix 7) the first non-terrestrial network includes a first non-terrestrial network device and a second non-terrestrial network device; the indirect path includes a first indirect path through which a signal transmitted from the first non-terrestrial network device indirectly reaches the terminal device via the terrestrial repeater, and a second indirect path for indirectly transmitting the signal from the second non-terrestrial network device to the terminal device via the terrestrial repeater; the route control means selects the communication route to be used from the first indirect route and the second indirect route based on the location of the first non-terrestrial network device, the location of the second non-terrestrial network device, and the location of the terminal device; 10. The control device of claim 1. (Appendix 8) the communication system includes a second terrestrial repeater; the indirect path includes a first indirect path through which a signal transmitted from the non-terrestrial network device indirectly reaches the terminal device via the terrestrial repeater, and a third indirect path for indirectly transmitting the signal from the non-terrestrial network device to the terminal device via the second terrestrial repeater, the route control means selects the communication route to be used from the first indirect route and the third indirect route based on the location of the non-terrestrial network device and the location of the terminal device. 10. The control device of claim 1. (Appendix 9) the first non-terrestrial network includes a first non-terrestrial network device, a second non-terrestrial network device, and a second terrestrial repeater device; the indirect path includes a first indirect path through which a signal transmitted from the first non-terrestrial network device indirectly reaches the terminal device via the terrestrial repeater, and a fourth indirect path for indirectly transmitting the signal from the second non-terrestrial network device to the terminal device via the second terrestrial repeater; the route control means selects the communication route to be used from the first indirect route and the fourth indirect route based on the location of the first non-terrestrial network device, the location of the second non-terrestrial network device, and the location of the terminal device. 10. The control device of claim 1. (Appendix 10) A control method executed by a control device in a communication system, comprising: the communication system includes a non-terrestrial network device included in a first non-terrestrial network and a terrestrial relay device including a RIS (Reconfigurable Intelligent Surface); The control method includes: acquiring information about interference that a signal transmitted directly from the non-terrestrial network device to a terminal device receives from a signal transmitted from a second non-terrestrial network; selecting a communication path to be used for transmitting a signal to the terminal device in the communication system from a direct path for transmitting directly from the non-terrestrial network device to the terminal device and an indirect path for transmitting indirectly from the non-terrestrial network device to the terminal device via the terrestrial repeater based on the information regarding the interference; A control method comprising: (Appendix 11) the first non-terrestrial network includes a first non-terrestrial network device and a second non-terrestrial network device; the indirect path includes a first indirect path through which a signal transmitted from the first non-terrestrial network device indirectly reaches the terminal device via the terrestrial repeater, and a second indirect path for indirectly transmitting the signal from the second non-terrestrial network device to the terminal device via the terrestrial repeater; The control method includes acquiring first information on a reception gain in the terminal device of a signal that has passed through the first indirect path and second information on a reception gain in the terminal device of a signal that has passed through the second indirect path; switching the use communication path includes selecting the use communication path from the first indirect path and the second indirect path based on the first information and the second information. 11. The control method of claim 10. (Appendix 12) A non-transitory computer-readable medium storing a program for causing a control device in a communication system to execute a process, the communication system includes a non-terrestrial network device included in a first non-terrestrial network and a terrestrial relay device including a RIS (Reconfigurable Intelligent Surface); The process comprises: acquiring information about interference that a signal transmitted directly from the non-terrestrial network device to a terminal device receives from a signal transmitted from a second non-terrestrial network; selecting a communication path to be used for transmitting a signal to the terminal device in the communication system from a direct path for transmitting directly from the non-terrestrial network device to the terminal device and an indirect path for transmitting indirectly from the non-terrestrial network device to the terminal device via the terrestrial repeater based on the information regarding the interference; Including, Non-transitory computer-readable medium. [Explanation of symbols]

[0073] 1. Communication Systems 10 Control device 11 Acquisition Department 12 Route control section 20 Non-terrestrial network equipment 30 Ground repeater 40 Terminal Equipment 50 Non-terrestrial network equipment 60 Terminal Equipment 70 Radio wave monitoring antenna 80 terrestrial base stations

Claims

1. A control device for controlling a communication path used to transmit a signal to a terminal device in a communication system including a non-terrestrial network device included in a first non-terrestrial network and a terrestrial relay device including a RIS (Reconfigurable Intelligent Surface), a first acquisition means for acquiring information about interference that a signal transmitted directly from the non-terrestrial network device to the terminal device receives from a signal transmitted from a second non-terrestrial network; a route control means for selecting the communication route to be used from a direct route for transmitting directly from the non-terrestrial network device to the terminal device and an indirect route through which a signal transmitted from the non-terrestrial network device indirectly reaches the terminal device via the terrestrial repeater, based on the information regarding the interference; A control device comprising:

2. the first non-terrestrial network includes a first non-terrestrial network device and a second non-terrestrial network device; the indirect path includes a first indirect path through which a signal transmitted from the first non-terrestrial network device indirectly reaches the terminal device via the terrestrial repeater, and a second indirect path for indirectly transmitting the signal from the second non-terrestrial network device to the terminal device via the terrestrial repeater, the control device includes a second acquisition means for acquiring first information on a reception gain in the terminal device of a signal that has passed through the first indirect path and second information on a reception gain in the terminal device of a signal that has passed through the second indirect path; the route control means selects the communication route to be used from the first indirect route and the second indirect route based on the first information and the second information. The control device according to claim 1 .

3. the communication system includes a second terrestrial repeater; the indirect path includes a first indirect path through which a signal transmitted from the non-terrestrial network device indirectly reaches the terminal device via the terrestrial repeater, and a third indirect path for indirectly transmitting the signal from the non-terrestrial network device to the terminal device via the second terrestrial repeater, the control device includes third acquisition means for acquiring first information on a reception gain in the terminal device of a signal that has passed through the first indirect path and third information on a reception gain in the terminal device of a signal that has passed through the third indirect path; the route control means selects the communication route to be used from the first indirect route and the third indirect route based on the first information and the third information. The control device according to claim 1 .

4. the first non-terrestrial network includes a first non-terrestrial network device, a second non-terrestrial network device, and a second terrestrial repeater device; the indirect paths include a first indirect path through which a signal transmitted from the first non-terrestrial network device indirectly reaches the terminal device via the terrestrial repeater, and a fourth indirect path for indirectly transmitting the signal from the second non-terrestrial network device to the terminal device via the second terrestrial repeater, the control device includes a fourth acquisition means for acquiring first information on a reception gain in the terminal device of a signal that has passed through the first indirect path and fourth information on a reception gain in the terminal device of a signal that has passed through the fourth indirect path; the route control means selects the communication route to be used from the first indirect route and the fourth indirect route based on the first information and the fourth information. The control device according to claim 1 .

5. the communication system includes a land network; the route control means selects, as the communication route to be used, either the direct route or one of a terrestrial route for transmitting to the terminal device via the land network and the indirect route; The control device according to claim 1 .

6. the route control means selects the communication route to be used from the terrestrial route and the indirect route based on characteristics of data included in the signal. The control device according to claim 5.

7. the first non-terrestrial network includes a first non-terrestrial network device and a second non-terrestrial network device; the indirect path includes a first indirect path through which a signal transmitted from the first non-terrestrial network device indirectly reaches the terminal device via the terrestrial repeater, and a second indirect path for indirectly transmitting the signal from the second non-terrestrial network device to the terminal device via the terrestrial repeater, the route control means selects the communication route to be used from the first indirect route and the second indirect route based on the location of the first non-terrestrial network device, the location of the second non-terrestrial network device, and the location of the terminal device; The control device according to claim 1 .

8. the communication system includes a second terrestrial repeater; the indirect path includes a first indirect path through which a signal transmitted from the non-terrestrial network device indirectly reaches the terminal device via the terrestrial repeater, and a third indirect path for indirectly transmitting the signal from the non-terrestrial network device to the terminal device via the second terrestrial repeater, the route control means selects the communication route to be used from the first indirect route and the third indirect route based on the location of the non-terrestrial network device and the location of the terminal device. The control device according to claim 1 .

9. the first non-terrestrial network includes a first non-terrestrial network device, a second non-terrestrial network device, and a second terrestrial repeater device; the indirect paths include a first indirect path through which a signal transmitted from the first non-terrestrial network device indirectly reaches the terminal device via the terrestrial repeater, and a fourth indirect path for indirectly transmitting the signal from the second non-terrestrial network device to the terminal device via the second terrestrial repeater, the route control means selects the communication route to be used from the first indirect route and the fourth indirect route based on a position of the first non-terrestrial network device, a position of the second non-terrestrial network device, and a position of the terminal device. The control device according to claim 1 .

10. A control method executed by a control device in a communication system, comprising: the communication system includes a non-terrestrial network device included in a first non-terrestrial network and a terrestrial relay device including a RIS (Reconfigurable Intelligent Surface); The control method includes: acquiring information about interference that a signal transmitted directly from the non-terrestrial network device to a terminal device receives from a signal transmitted from a second non-terrestrial network; selecting a communication path to be used for transmitting a signal to the terminal device in the communication system from a direct path for transmitting directly from the non-terrestrial network device to the terminal device and an indirect path for transmitting indirectly from the non-terrestrial network device to the terminal device via the terrestrial repeater based on the information regarding the interference; A control method comprising:

11. the first non-terrestrial network includes a first non-terrestrial network device and a second non-terrestrial network device; the indirect path includes a first indirect path through which a signal transmitted from the first non-terrestrial network device indirectly reaches the terminal device via the terrestrial repeater, and a second indirect path for indirectly transmitting the signal from the second non-terrestrial network device to the terminal device via the terrestrial repeater, The control method includes acquiring first information on a reception gain in the terminal device of a signal that has passed through the first indirect path and second information on a reception gain in the terminal device of a signal that has passed through the second indirect path; switching the use communication path includes selecting the use communication path from the first indirect path and the second indirect path based on the first information and the second information. The control method according to claim 10.

12. A program for causing a control device in a communication system to execute processing, the communication system includes a non-terrestrial network device included in a first non-terrestrial network and a terrestrial relay device including a RIS (Reconfigurable Intelligent Surface); The process comprises: acquiring information about interference that a signal transmitted directly from the non-terrestrial network device to a terminal device receives from a signal transmitted from a second non-terrestrial network; selecting a communication path to be used for transmitting a signal to the terminal device in the communication system from a direct path for transmitting directly from the non-terrestrial network device to the terminal device and an indirect path for transmitting indirectly from the non-terrestrial network device to the terminal device via the terrestrial repeater based on the information regarding the interference; Includes:

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