Communication control devices, communication control methods, communication control programs, communication control systems, relay satellites and satellite systems

Abstract

A communication control device controls optical communication between a communication relay satellite and multiple user satellites, such that when the communication relay satellite relays communication between the multiple user satellites and other devices, the sum of the data rates representing the communication rates per unit time between the multiple user satellites and the communication relay satellite does not exceed a limit value for the data rates between the communication relay satellite and other devices.

Description

[0001] This application is a divisional application of the original application filed on November 12, 2021, with application number 2021800756799 and invention title "Communication Control Equipment, Communication Control Method, Communication Control Program, Communication Control System, Communication Relay Satellite and Satellite System". Technical Field

[0002] This disclosure relates to communication control equipment, communication control methods, communication control programs, communication control systems, communication relay satellites, and satellite systems. Background Technology

[0003] A known optical downlink system exists between a remote terminal and a ground terminal. The remote terminal comprises n optical communication terminals (OT1 to OTn), and the ground terminal comprises a cluster of n optical ground base stations (OGS1 to OGSn), which are connected via either n optical downlink channels (DL1 to DLn) or n optical uplink channels (UC1 to UCn) (e.g., Patent Document 1). The optical downlink system is configured such that the n optical ground base stations (OGS1 to OGSn) are synchronized. This is because the optical ground base stations (OGS1 to OGSn) are positioned at a specific distance from each other for each of the n optical downlink channels, thus ensuring spatial separation, and because the optical uplink channels (UC1 to UCn) utilize time-division multiplexing, thus ensuring temporal separation. This makes it possible to avoid time overlap between the optical uplink channels (UC1 to UCn) (e.g., claims 1 and 8 of Patent Document 1).

[0004] There are also known free-space optical communication systems comprising constellations of multiple satellites (e.g., Patent Document 2). This free-space optical communication system includes a satellite constellation, each satellite comprising multiple uplink / downlink optical telescopes for optical communication with multiple ground stations. When a given satellite passes a predetermined ground station, one or more of the uplink / downlink telescopes of the given satellite track at least two ground optical telescopes at the predetermined ground station, and the given satellite transmits data to the ground optical telescope with the clearest line of sight relative to the given satellite (e.g., claim 1 in Patent Document 2).

[0005] There is also a known mobile satellite communication system capable of flexibly handling, for example, sudden and temporary increases in communication demand (e.g., patent document 3). In this system, flying relay stations are deployed at altitudes ranging from several kilometers to tens of kilometers above the communication area of ​​the low-Earth orbit (LEO) communication satellite to relay communication between the LEO satellite and ground-based or maritime mobile communication terminals. The flying relay stations include the ability to communicate with mobile communication terminals via radio waves and with the LEO communication satellite via laser. In this system, when a single flying relay station cannot handle an increase in communication volume from multiple mobile communication terminals within the same communication area, multiple flying relay stations are deployed above the communication area, allowing communication between the LEO communication satellite and mobile communication terminals to be segmented and relayed through these multiple flying relay stations.

[0006] Note that Patent Document 3 discloses that, in order to enable a near-Earth orbit communication satellite to conduct simultaneous optical communication with multiple flight relay stations in parallel, it can be equipped with multiple optical antennas for communicating with multiple flight relay stations, corresponding to the number of flight relay stations that can be processed (e.g., paragraph

[0034] in Patent Document 3).

[0007] Citation List Patent documents Patent Document 1: Japanese Patent Application Publication (JP-A) No. 2013-132045 Patent Document 2: Japanese National Phase Publication No. 2015-524629 Patent document 3: JP-A No. 2007-13513 Summary of the Invention The problem the invention aims to solve However, when considering the scenario of multiple artificial satellites (hereinafter referred to as "satellites") existing in outer space, it is impractical for each of these satellites to communicate independently with ground stations. Therefore, as Figure 17 As shown, a scenario can be envisioned where a communication relay satellite SR is provided to relay communication between satellite SU and ground station G on Earth E, and each of the multiple satellites SU1, SU2, and SU3 communicates with ground station G via the communication relay satellite SR. Figure 17 As shown, the communication relay satellite SR receives data D1, D2, and D3 transmitted from multiple satellites SU1, SU2, and SU3 respectively, and transmits the data DR to the ground station G.

[0008] In this scenario, the data communication rate per unit time (hereinafter referred to as the "data rate") on the communication line between the communication relay satellite SR and the ground station G is physically limited. Therefore, the data rate on the communication line between the communication relay satellite SR and the ground station G must not exceed a predetermined value. Thus, for example, even if the communication relay satellite SR receives data from each of the multiple satellites SU1, SU2, and SU3, the data aggregated across SU1, SU2, and SU3 cannot always be transmitted to the ground station G within a certain time period.

[0009] On the other hand, sometimes the communication line between the communication relay satellite SR and the ground station G has a high data rate, and a large amount of data can be transmitted simultaneously from the communication relay satellite SR to the ground station G. In this case, the communication relay satellite SR may sometimes transmit data received from two or more satellites to the ground station G within a certain time period. In this situation, if the satellite used for communication with the ground station G within a certain time period is limited to a single satellite SU1, other satellites SU2 and SU3 will not be able to communicate with the ground station G within that time period. This will result in low utilization of the communication line, even though the communication line between the communication relay satellite SR and the ground station G has spare capacity.

[0010] Note that the above problems are not limited to the case where the data transmitted from the communication relay satellite SR is destined for the ground station G. Similar problems may arise, for example, when the communication relay satellite SR transmits data to other equipment such as flying objects deployed in the stratosphere or troposphere.

[0011] In the technologies described in Patent Documents 1 to 3, limitations on the data rate between the communication relay satellite and other equipment such as ground stations are not considered. For example, although Patent Document 3 describes a low-Earth orbit communication satellite that conducts simultaneous optical communication in parallel with multiple flying relay stations, limitations on the data rate between these communication relay satellites and other equipment are not considered.

[0012] Therefore, in traditional technologies, when a communication relay satellite relays communication between multiple satellites and other devices such as ground stations, there is a problem that while meeting the data rate limits between the communication relay satellite and other devices, it is impossible to transmit data from a greater number of satellites to other devices.

[0013] In view of the above, this disclosure provides a communication control device, a communication control method, a communication control program, a communication control system, a communication relay satellite, and a satellite system. When the communication relay satellite relays communication between multiple satellites and other devices, it can transmit data from a greater number of satellites to other devices while meeting the data rate limits between the communication relay satellite and other devices.

[0014] means for solving problems The first aspect of this disclosure is a communication control device configured to relay communication between multiple satellites and other devices. The communication control device includes: multiple optical communication sections capable of parallel optical communication with multiple satellites; a device communication section configured to communicate with other devices; a setting section configured to: set a first data rate, the first data rate being the sum of limit values ​​for data communication rates per unit time between the multiple satellites and the multiple optical communication sections; and set a second data rate, the second data rate being a limit value for data communication rates per unit time between the communication control device and other devices; and a control section configured to control the multiple optical communication sections and the device communication section such that data received by the multiple optical communication sections from the multiple satellites at the first data rate is relayed in parallel to the other devices at the second data rate.

[0015] The second aspect of this disclosure is a communication control device including a control section configured to control communication between a communication relay satellite and multiple satellites, such that when the communication relay satellite relays communication between the multiple satellites and other devices, the sum of the data rates representing the communication rate per unit time between the multiple satellites and the communication relay satellite does not exceed a limit value for the data rate between the communication relay satellite and other devices.

[0016] The effects of the invention This disclosure achieves the beneficial effect that, when a communication relay satellite relays communication between multiple satellites and other devices, it enables data from a greater number of satellites to be transmitted to other devices while meeting the data rate limits between the communication relay satellite and other equipment. Attached Figure Description

[0017] Figure 1 This is a diagram illustrating an example of a schematic configuration of a satellite system according to an exemplary implementation.

[0018] Figure 2This is a diagram illustrating an example of a schematic configuration of a communication control system according to a first exemplary embodiment and a second exemplary embodiment.

[0019] Figure 3 This is a diagram used to illustrate communication periods.

[0020] Figure 4 This is a diagram used to illustrate communication periods.

[0021] Figure 5 This is a schematic diagram used to illustrate a signal switching circuit.

[0022] Figure 6 This is a schematic diagram used to illustrate a signal switching circuit.

[0023] Figure 7 This is a schematic diagram used to illustrate a signal switching circuit.

[0024] Figure 8A This is a schematic diagram used to illustrate a signal switching circuit.

[0025] Figure 8B This is a diagram illustrating a configuration example of a communication control system in which a relay communication unit is configured by an optical communication unit.

[0026] Figure 8C This is a diagram illustrating an example configuration of a communication control system in which optical communication units in multiple optical communication units are configured to relay communication units.

[0027] Figure 9 This is a schematic block diagram of a computer used as a communication control device.

[0028] Figure 10 This is a diagram used to illustrate the processes performed by the communication control device.

[0029] Figure 11 This is a schematic diagram used to illustrate satellite acquisition.

[0030] Figure 12 This is a schematic diagram used to illustrate satellite acquisition.

[0031] Figure 13 This is a schematic diagram used to illustrate satellite acquisition.

[0032] Figure 14 This is a schematic diagram used to illustrate satellite acquisition.

[0033] Figure 15 This is a diagram used to illustrate the processes performed by the communication control device.

[0034] Figure 16 This is a diagram used to illustrate a modified example of communication.

[0035] Figure 17 It is a diagram used to illustrate the technical problem to be solved.

[0036] Explanation of reference numerals in the attached figures 1 Satellite System 2 Communication Relay Satellites 3A, 3B, and 3C user satellites 4 ground stations 12 Communication Control System 14a, 14b, 14c optical communication units 16 Communication Control Devices 18 signal switching circuit 20 high-frequency wireless communication units 70 computers. Detailed Implementation

[0037] Exemplary embodiments will now be described in detail with reference to the accompanying drawings.

[0038] Satellite system of the first exemplary embodiment Figure 1 This is a schematic diagram of a satellite system 1 according to an exemplary embodiment. (As shown) Figure 1 As shown, the satellite system 1 of this exemplary embodiment includes a communication relay satellite 2, other satellites 3A, 3B, and 3C (hereinafter referred to as "user satellites") different from the communication relay satellite 2, and a ground station 4, which is a wireless communication station on Earth. The communication relay satellite 2 and the user satellites 3A, 3B, and 3C are all satellites. The ground station 4 is an example of other equipment. The ground station 4 installed on the ground is an example of an earth station performing radio or optical communication. In the case of multiple ground stations installed, ground station 4 can be a collective term for these ground stations.

[0039] Each of the user satellites 3A, 3B, and 3C operates in a first orbit in outer space. The communications relay satellite 2 operates in a second orbit in outer space. Both the first and second orbits are at a lower altitude than the geostationary orbit (approximately 36,000 km). Note that geostationary orbit (GEO) is an example of a geostationary orbit. The second orbit is at a higher altitude than the first orbit. The first orbit could be, for example, a low Earth orbit (LEO). The apogee of a LEO could be, for example, between 20 km and 2,000 km above the Earth's surface. The second orbit could be, for example, a medium Earth orbit (MEO). The apogee of a MEO could be, for example, between 1,000 km and approximately 360,000 km above the Earth's surface.

[0040] Each of the multiple user satellites 3A, 3B, and 3C wirelessly communicates with the communication relay satellite 2 and, via the communication relay satellite 2, data communicates with the ground station 4. The communication relay satellite 2 relays data communication in real time between the multiple user satellites 3A, 3B, and 3C and the ground station 4 by simultaneously conducting data communication with the multiple user satellites 3A, 3B, and 3C and concurrently with the ground station 4. The ground station 4 is connected to a server 6 via a network 5 such as the Internet, and the server 6 receives data acquired by the user satellites 3A, 3B, and 3C via the ground station 4. This allows the server 6 to acquire data from the user satellites 3A, 3B, and 3C while located on the ground. The server 6 also includes operational... Figure 1 The required functions of the satellite system. Note that when referring to any one of the multiple user satellites 3A, 3B, and 3C, that user satellite is simply referred to as "User Satellite 3".

[0041] Figure 2 This is a diagram illustrating a detailed example of the configuration of a communication control system 12 according to an exemplary embodiment. (See diagram for reference.) Figure 2 As shown, the communication control system 12 includes multiple optical communication units 14A, 14B, and 14C, a communication control device 16, a signal switching circuit 18, a data multiplexer circuit 19A, a data demultiplexer circuit 19B, and a high-frequency wireless communication unit 20. The communication control system 12 is installed on the communication relay satellite 2. Note that when referring to any one of the multiple optical communication units 14A, 14B, and 14C, that optical communication unit is simply referred to as "optical communication unit 14". Note that the number of user satellites 3 is not limited to... Figure 2 The example has three, but can have more than three. Furthermore, the number of user satellites 3 does not need to be the same as the number of optical communication units 14, and can be greater than the number of optical communication units. User satellite 3 can be part of a satellite constellation system that coordinates with multiple other satellites to achieve a specific function or service.

[0042] Optical communication unit like Figure 2 As shown in the optical communication unit 14A, the optical communication unit 14A includes an optical telescope 140A, an optical receiver 142A, and an optical transmitter 144A. Note that... Figure 2 The configurations of optical communication units 14B and 14C shown are similar to those of optical communication unit 14A. Therefore, only the configuration of optical communication unit 14A will be described. Note that the optical communication unit is an example of the optical communication portion of this disclosure.

[0043] Optical telescope 140A receives laser light from user satellites 3A, 3B, and 3C, and transmits laser light to user satellites 3A, 3B, and 3C. Note that the user satellite with which optical communication unit 14A communicates optically is not limited to user satellite 3A. Optical communication unit 14A can also communicate optically with user satellites 3B and 3C. Optical telescope 140A includes apertures (not shown) serving as the entry and exit points for the laser light. Optical telescope 140A also includes a beam steering mirror (not shown). The path of the light is adjusted via the beam steering mirror.

[0044] Optical telescope 140A outputs laser light received from another satellite to optical receiver 142A via a beam deflector. Optical telescope 140A also outputs laser light from optical transmitter 144A (described below) to another satellite via a beam deflector.

[0045] The optical receiver 142A acquires a digital electrical signal corresponding to the laser received by the optical telescope 140A by optically demodulating the laser output from the optical telescope 140A. The optical receiver 142A then outputs the digital electrical signal to the high-frequency wireless communication unit 20, which will be described later.

[0046] The optical transmitter 144A acquires a laser corresponding to a digital electrical signal by optically modulating the digital electrical signal output from the high-frequency wireless communication unit 20, which will be described later. The optical transmitter 144A then outputs the laser to the optical telescope 140A.

[0047] Communication control device like Figure 2 As shown, the communication control device 16 includes a setting part 160 and a control part 162.

[0048] The data rate at which communication relay satellite 2 transmits data to ground station 4 is physically limited. Specifically, the data rate at which communication relay satellite 2 transmits data to ground station 4 must not exceed a predetermined limit. Therefore, even if communication relay satellite 2 receives data in parallel from each of the multiple user satellites 3A, 3B, and 3C, it cannot always transmit the data to ground station 4 within a specific time period.

[0049] On the other hand, when the communication line between communication relay satellite 2 and ground station 4 has spare capacity relative to the data rate limit, data transmitted from two or more user satellites 3 can sometimes be transmitted to ground station 4 within a specific time period. In this case, if the target for relaying data from communication relay satellite 2 to ground station 4 is limited to a single user satellite 3 and a single optical communication unit 14, the communication line between communication relay satellite 2 and ground station 4 will have low utilization, which is not optimal.

[0050] Furthermore, if the number of optical communication units 14 that relay data to ground station 4 is limited to, for example, a single optical communication unit 14 communicating with user satellite 3A, then other user satellites 3B and 3C will be unable to transmit data to ground station 4 until communication between user satellite 3A and communication relay satellite 2 is completed.

[0051] To address this issue, the communication control device 16 of this exemplary embodiment controls the communication between multiple optical communication units 14A, 14B, 14C and multiple user satellites 3A, 3B, 3C, ensuring that when the communication relay satellite 2 relays communication between the multiple user satellites 3A, 3B, 3C and the ground station 4, the sum of the data rates between the multiple user satellites 3A, 3B, 3C and the multiple optical communication units 14A, 14B, 14C does not exceed the data rate limit between the high-frequency wireless communication unit 20 and the ground station 4. Specifically, the communication control device 16 of this exemplary embodiment controls the communication such that when data transmitted from the multiple user satellites 3A, 3B, 3C is received by the multiple optical communication units 14A, 14B, 14C, the sum of the data rates between the multiple user satellites 3A, 3B, 3C and the multiple optical communication units 14A, 14B, 14C does not exceed the data rate limit between the high-frequency wireless communication unit 20 and the ground station 4.

[0052] More specifically, firstly, the communication control device 16 sets the number of user satellites 3 used for simultaneous or parallel optical communication with the communication relay satellite 2, so as not to exceed the data rate limit between the communication relay satellite 2 and the ground station 4. Then, the communication control device 16 controls each device so that data received from the optical communication target user satellite 3 is transmitted to the ground station 4 during the time period of optical communication to receive data from the optical communication target user satellite 3.

[0053] The details are as follows.

[0054] Consider a scenario where the total number of optical communication units installed on communication relay satellite 2 is N. U The data rate limit value for the data communication line between a single user satellite 3 and a single optical communication unit 14 is R. U (bps: bits per second), the time span required for a single optical communication unit 14 to establish a communication line for data communication with a single user satellite 3 is X. aq (s: seconds), and the data rate limit during data communication when transmitting data from communication relay satellite 2 to ground station 4 is R. G (bps). In this case, R G With R UThe conditions between them are expressed by the following formula (1). Note that the data rate limit mentioned here is not limited to the data rate limit specified in the design specification of the optical communication unit 14, and can also be a data rate limit determined based on operational reasons. When the data rate limit values ​​of each optical communication unit 14 are different, a fixed value not greater than the maximum value among these data rate limit values ​​can be set as R. G .

[0055] [Mathematical Expression 1] (1) The maximum number N of optical communication units used for simultaneous optical communication is determined by the following formula (2). op Configure the settings.

[0056] [Mathematical Expression 2] (2) When N op <N U When, the communication time span T is determined according to the following formula (3). co (s) is configured such that the communication time span represents the time span used for data communication on the communication line between a single user satellite 3 and a single optical communication unit 14. This allows data from a greater number of possible user satellites 3 to be transmitted to the ground station 4.

[0057] [Mathematical Expression 3] (3) For example, consider calculating the maximum number of optical communication units that can perform simultaneous optical communication as N according to formula (2). op = 1. In this case, the communication control device 16 can, for example, control multiple optical communication units 14A, 14B, 14C, so that during the communication time span T co (s) Intrinsic optical communication is conducted between user satellite 3A and optical communication unit 14A, followed by communication over a time span T. co (s) Optical communication is conducted between the internal user satellite 3B and the optical communication unit 14B.

[0058] As another example, consider calculating the maximum number of optical communication units performing simultaneous optical communication as N according to formula (2). op = 2. In this case, the communication control device 16 can, for example, control multiple optical communication units 14A, 14B, 14C, so that during the communication time span T co (s) When optical communication is conducted between the internal user satellite 3A and the optical communication unit 14A, during the communication time span T co(s) also conducts optical communication between user satellite 3B and optical communication unit 14B.

[0059] According to formula (2), the maximum number N of optical communication units that can perform simultaneous optical communication is... op Calculations are performed to ensure that the sum of the data rates between multiple user satellites 3A, 3B, and 3C and multiple optical communication units 14A, 14B, and 14C does not exceed the data rate limit between communication relay satellite 2 and ground station 4. This allows data from a greater number of possible user satellites 3 to be transmitted to ground station 4 in a single transmission while meeting the data rate limit between communication relay satellite 2 and ground station 4. Furthermore, the utilization rate of the communication line between communication relay satellite 2 and ground station 4 can be improved. Note that the sum of the data rates between multiple user satellites 3A, 3B, and 3C and multiple optical communication units 14A, 14B, and 14C is an example of the first data rate of this disclosure. Additionally, the data communication rate limit R per unit time between communication control device 16 and ground station 4 is... G (bps) is an example of the second data rate in this disclosure.

[0060] Note that the communication control device 16 also performs control such that the timing of each optical communication between the individual optical communication unit 14 and the individual user satellite 3 is offset from each other by a time span T calculated according to the following formula (4). dif (s). Therefore, the communication time span T co (s) are allocated to each optical communication unit 14.

[0061] [Mathematical Expression 4] (4) Figure 3 The number of optical communication units installed on communication relay satellite 2 is 3 (i.e., N). U = 3), and the maximum number of optical communication units that can perform optical communication simultaneously is calculated as N. op An example of the control sequence when = 1. Figure 3 In the example shown, the number of optical communication units used for optical communication is N. op = 1, therefore, T dif = T co Therefore, as Figure 3 As shown, for example, the communication start timing of optical communication unit 14B is after optical communication unit 14A has ended its optical communication.

[0062] like Figure 3As shown, the high-frequency wireless communication unit 20 of the communication relay satellite 2 transmits data to the ground station 4 and the optical communication unit 14 receives data from the user satellite 3 in parallel to enable real-time data relay. That is, when the communication time span T... co During (s) when the optical communication unit 14 of the communication relay satellite 2 receives data from the user satellite 3, the high-frequency wireless communication unit 20 begins to transmit the received data to the ground station 4.

[0063] For example, such as Figure 3 As shown, data received from user satellite 3 by optical communication unit 14A between time t0 and time t1 begins to be transmitted to ground station 4 by high-frequency wireless communication unit 20 between time t0 and time t1. Furthermore, data received from user satellite 3 by optical communication unit 14B between time t1 and time t2 begins to be transmitted to ground station 4 by high-frequency wireless communication unit 20 between time t1 and time t2. Additionally, data received from user satellite 3 by optical communication unit 14C between time t2 and time t3 begins to be transmitted to ground station 4 by high-frequency wireless communication unit 20 between time t2 and time t3. Note that there is a slight delay between the time period during which optical communication unit 14 receives data and the timing at which high-frequency wireless communication unit 20 begins transmitting data to ground station 4. Furthermore, the user satellite 3 with which optical communication unit 14 communicates is not fixed. For example, the user satellite 3 with which optical communication unit 14A communicates is not fixed to user satellite 3A. For example, optical communication unit 14A can also communicate with user satellite 3B or user satellite 3C. Optical communication unit 14A can, for example, communicate optically with a first user satellite between time t0 and time t1, and communicate optically with a second user satellite between time t3 and time t4.

[0064] Figure 4 This is an example of a control sequence where the maximum number of optical communication units performing simultaneous optical communication is calculated as Nop = 2. Figure 4 In the example shown, the number of optical communication units performing optical communication is N. op = 2, therefore, T dif = T co / 2. Therefore, for example, the communication start timing of optical communication unit 14B is T after the start of optical communication from optical communication unit 14A. dif = T co / 2 after.

[0065] For example, such as Figure 4As shown, data received from user satellite 3 by optical communication unit 14A between time t0 and time t1, and data received from user satellite 3 by optical communication unit 14C between time t0 and time t1, are all transmitted to ground station 4 by high-frequency wireless communication unit 20 between time t0 and time t1. Furthermore, data received from user satellite 3 by optical communication unit 14A between time t1 and time t2, and data received from user satellite 3 by optical communication unit 14B between time t1 and time t2, are all transmitted to ground station 4 by high-frequency wireless communication unit 20 between time t1 and time t2. Additionally, data received from user satellite 3 by optical communication unit 14B between time t2 and time t3, and data received from user satellite 3 by optical communication unit 14C between time t2 and time t3, are all transmitted to ground station 4 by high-frequency wireless communication unit 20 between time t2 and time t3.

[0066] Note that the maximum number of optical communication units performing simultaneous optical communication is calculated as N. op When N = 3, U =N op =3, therefore formula (3) cannot be applied. In this case, the control section 162, described later, is able to control all optical communication units 14A, 14B, 14C installed in the communication control system 12 to perform optical communication simultaneously or at a desired timing.

[0067] The setting section 160 sets the first data rate, which is a limit value R of the data communication rate per unit time between multiple user satellites 3A, 3B, 3C and multiple optical communication units 14A, 14B, 14C. U The sum of all data points. Furthermore, setting section 160 sets a second data rate, which is a limit value R of the data communication rate per unit time between the communication relay satellite 2 and the ground station 4. G Next, the settings section 160 configures various control information based on these data rates.

[0068] First, set section 160, based on the data rate limit value R of optical communication unit 14. U and the data rate limit R of the communication line from communication relay satellite 2 to ground station 4 G According to formula (2), the maximum number N of optical communication units used for simultaneous optical communication is determined. op Configure the settings.

[0069] Next, in section 160, the time span X required for the optical communication unit 14 to establish a communication line with the user satellite 3 is set. aq The total number N of optical communication unitsU And the maximum number N of optical communication units used for synchronous optical communication. op According to formula (3), the communication time span T is calculated. co Configure the settings. Note that the time span X required for the optical communication unit 14 to establish a communication line with the user satellite 3 is preset. aq The time span X required for optical communication unit 14 to establish a communication line with user satellite 3 is calculated based on the time span required for communication relay satellite 2 to acquire user satellite 3. aq Note that when the time span required for optical communication unit 14 to establish a communication line with user satellite 3 is different for each of the multiple user satellites 3, the maximum value (time span) of these time spans can be set to X. aq .

[0070] Next, set part 160, based on the communication time span T. co The maximum number N of optical communication units that can perform simultaneous optical communication. op According to formula (4), the control time span T is determined. dif Configure settings to control the timing of communication initiation. Note that the time information used as reference time information for Satellite System 1 is obtained from a measurement satellite such as GPS (Global Positioning System). Specifically, the communication relay satellite 2 and user satellite 3 of Satellite System 1 use timing information obtained from a measurement satellite such as GPS as common reference time information in Satellite System 1 for various control purposes.

[0071] The control unit 162 controls the plurality of optical communication units 14A, 14B, 14C and the high-frequency wireless communication unit 20, described later, such that data received by the plurality of optical communication units 14A, 14B, 14C from the plurality of user satellites 3A, 3B, 3C at a first data rate is relayed in parallel to the ground station 4 at a second data rate. Therefore, for N op Each optical communication unit 14 is controlled to enable N op Each optical communication unit 14 performs parallel optical communication with multiple user satellites 3. Specifically, the control section 162, based on the communication time span T set by the setting section 160, performs parallel optical communication with multiple user satellites 3. co and control time span T dif The control unit 162 controls multiple optical communication units 14A, 14B, and 14C to perform control. More specifically, the control unit 162 controls the communication time span between one user satellite 3 (among multiple user satellites 3A, 3B, and 3C) and one optical communication unit 14 (among multiple optical communication units 14A, 14B, and 14C) to be a communication time span T. coThe control unit 162 also performs control such that a control time span T elapses from the start of communication between the user satellite 3 and the optical communication unit 14. dif After that, communication between the other user satellite 3 among the multiple user satellites 3A, 3B, and 3C and the other optical communication unit 14 among the multiple optical communication units 14A, 14B, and 14C begins.

[0072] Note that the maximum number of optical communication units that can perform optical communication simultaneously is calculated as N. op When the value is 3, the control unit 162 can control all optical communication units 14A, 14B, and 14C installed on the communication control system 12 to simultaneously or at desired timing communicate with multiple user satellites 3.

[0073] The control unit 162 controls the optical communication of multiple optical communication units 14A, 14B, and 14C by outputting control signals, so as to realize the above-mentioned control processing of multiple optical communication units 14A, 14B, and 14C and the control processing of the signal switching circuit 18 described below.

[0074] Signal switching circuit The signal switching circuit 18 responds to the control signal output from the communication control device 16 to switch the signal path among the plurality of optical communication units 14A, 14B, 14C, and to switch the signal path between the plurality of optical communication units 14A, 14B, 14C and the high-frequency wireless communication unit 20, which will be described later.

[0075] Figures 5 to 8A This is a schematic diagram illustrating the signal switching circuit 18. The signal switching circuit 18 switches the electrical signal path by changing its internal circuit path in response to a control signal output by the communication control device 16. The signal paths between the plurality of optical communication units 14A, 14B, 14C and the high-frequency wireless communication unit 20, described later, are thus switched. For example, as... Figure 5 As shown, the signal switching circuit 18 can set the internal circuit path and switch the signal path, so that the optical communication units 14A and 14B are electrically connected to the high-frequency wireless communication unit 20. Note that in Figure 5 In the example shown, data is multiplexed by data multiplexer circuit 19A, and the multiplexed data is demultiplexed by data demultiplexer circuit 19B, so that optical communication unit 14A and optical communication unit 14B can communicate with each other in parallel.

[0076] Alternative locations, such as Figure 6 As shown, the signal switching circuit 18 can switch the signal path, so that optical communication units 14A and 14C are electrically connected to the high-frequency wireless communication unit 20. Note that in Figure 6In the example shown, data is multiplexed by data multiplexer circuit 19A, and the multiplexed data is demultiplexed by data demultiplexer circuit 19B, so that optical communication unit 14A and optical communication unit 14C can communicate with each other in parallel.

[0077] Alternative locations, such as Figure 7 As shown, the signal switching circuit 18 can switch the signal path, so that optical communication units 14A, 14B, and 14C are electrically connected to the high-frequency wireless communication unit 20. Note that in Figure 7 In the example shown, data is multiplexed by data multiplexer circuit 19A, and the multiplexed data is demultiplexed by data demultiplexer circuit 19B, so that optical communication units 14A, 14B and 14C can communicate with each other in parallel.

[0078] Alternative locations, such as Figure 8A As shown, the signal switching circuit 18 can switch the signal path, enabling optical communication unit 14A and optical communication unit 14B to be electrically connected to each other. Note that... Figure 8A The example shown is an illustration of data communication between user satellites relayed by communication relay satellite 2. For instance, a scenario can be envisioned where optical communication occurs between optical communication unit 14A and user satellite 3A, and also between optical communication unit 14B and user satellite 3B. In this case, as... Figure 8A As shown, optical communication unit 14A receives data from user satellite 3A, and this data is transmitted to user satellite 3B via optical communication unit 14B. Furthermore, optical communication unit 14B receives data from user satellite 3B, and this data is transmitted to user satellite 3A via optical communication unit 14A. Communication relay satellite 2 can relay data communication between user satellites in this manner.

[0079] Data multiplexer circuit and data demultiplexer circuit like Figures 5 to 8A As shown, the data multiplexer circuit 19A multiplexes data to enable optical communication through multiple optical communication units. Figures 5 to 8A As shown, the data demultiplexer circuit 19B demultiplexes the multiplexed data so that optical communication can be realized through multiple optical communication units.

[0080] High-frequency wireless communication unit Figures 5 to 8A The high-frequency wireless communication unit 20 shown is an example of a relay communication unit that enables the communication relay satellite 2 to communicate with the ground station 4, etc. Note that the relay communication unit is an example of the device communication portion of this disclosure. The high-frequency wireless communication unit 20 includes a high-frequency modulator circuit 200, a high-frequency transmission antenna 201 (see [link to documentation]). Figure 2 : Figures 5 to 8A (not shown in the image), high-frequency transmitter 202, high-frequency receiving antenna 203 (see [reference]). Figure 2 : Figures 5 to 8A The system includes a high-frequency receiver 204 (not shown) and a high-frequency demodulator circuit 206. The high-frequency wireless communication unit 20 modulates data acquired by multiple optical communication units 14A, 14B, and 14C, and transmits this data to the ground station 4. The high-frequency wireless communication unit 20 also demodulates data transmitted from the ground station 4 and transmits this data to the multiple optical communication units 14A, 14B, and 14C.

[0081] The high-frequency modulator circuit 200 modulates the digital electrical signal output from the optical communication unit 14 and outputs it to the high-frequency transmitter 202.

[0082] The high-frequency transmitter 202 converts the signal modulated by the high-frequency modulator circuit 200 into a high-frequency signal and amplifies the signal.

[0083] The high-frequency transmitting antenna 201 transmits high-frequency signals output by the high-frequency transmitter 202 toward the ground station 4.

[0084] The high-frequency receiving antenna 203 receives the high frequency transmitted by the ground station 4.

[0085] The high-frequency receiver 204 extracts the modulation signal from the high frequency received by the high-frequency receiving antenna 203 and outputs the modulation signal.

[0086] The high-frequency demodulator circuit 206 demodulates the modulated signal output by the high-frequency receiver 204 and converts it into a digital electrical signal.

[0087] Note that although the example described in this exemplary embodiment is that of using the high-frequency wireless communication unit 20 as a relay communication unit, the optical communication unit can also be used as a relay communication unit for wireless communication with the ground station 4. When the relay communication unit is configured with an optical communication unit, optical communication occurs between the communication relay satellite 2 and the ground station 4. In this case, data communication occurs in parallel between multiple user satellites 3A, 3B, and 3C and multiple optical communication units 14, data received by each of the multiple optical communication units 14 is multiplexed, and optical communication occurs between the optical communication unit used as a relay communication unit and the ground station 4.

[0088] Figure 8B An example configuration of a communication control system is shown when an optical communication unit is configured as a relay communication unit. Figure 8BIn some cases, for example, data multiplexer circuit 19A multiplexes data received from user satellite 3A by optical communication unit 14A and data received from user satellite 3B by optical communication unit 14B. Then, the optical transmitter 201 and optical telescope 203 of relay optical communication unit 21 use optical communication to transmit the data multiplexed by data multiplexer circuit 19A to ground station 4.

[0089] Furthermore, the optical telescope 205 and optical receiver 207 of the relay optical communication unit 21 use optical communication to receive data transmitted from the ground station 4. The data demultiplexer circuit 19B demultiplexes the data transmitted from the ground station 4. Then, for example, optical communication units 14A and 14B can transmit the data, which has been demultiplexed by the data demultiplexer circuit 19B, to user satellite 3A and user satellite 3B, respectively.

[0090] Note that the relay communication unit that communicates with the ground station 4 can be configured by at least one optical communication device among multiple optical communication units 14. Figure 8C An example configuration of a communication control system is shown where optical communication unit 14C, one of multiple optical communication units 14A, 14B, and 14C, is configured as a relay communication unit. Figure 8C In this case, the optical communication unit 14C is used as a relay communication unit, and therefore optical communication is performed between the optical communication unit 14C configured as a relay communication unit and the ground station 4. Note that in Figure 8C In this case, since optical communication unit 14C among the multiple optical communication units 14A, 14B, and 14C is configured as a relay communication unit, the number of optical communication units used for data communication with user satellite 3 is reduced by one. Therefore, in Figure 8C In the case where multiple user satellites 3 and multiple optical communication units 14 are communicating in parallel, 1 needs to be subtracted from the total number of optical communication units to obtain N in formula (3). U .

[0091] The communication control device 16 of the communication control system 12 can be, for example, made by a means such as Figure 9The computer 70 shown is an implementation of this system. The computer 70 includes a central processing unit (CPU) 71, a memory 72 serving as a temporary storage area, and a non-volatile storage section 73. The computer 70 also includes an input / output interface (I / F) 74 and a read / write (R / W) section 75, to which input / output devices (not shown) are connected (I / F 74), and the read / write (R / W) section 75 controls the reading and writing of data with respect to a recording medium. The computer 70 also includes a network interface (I / F) 76, which enables the communication control system 12 to connect to a terrestrial communication system such as the Internet. The CPU 71, memory 72, storage section 73, I / F 74, R / W section 75, and network I / F 76 are interconnected via a bus 77.

[0092] The storage section 73 can be implemented using a hard disk drive (HDD), a solid-state drive (SSD), flash memory, or the like. The program used to make the computer 70 work is stored in the storage section 73, which serves as the storage medium. The CPU 71 reads the program from the storage section 73, expands the program in the memory 72, and executes the processing included in the program sequentially.

[0093] Functionality implemented by a program can be achieved, for example, through semiconductor integrated circuits such as application-specific integrated circuits (ASICs).

[0094] Furthermore, the various devices included in the communication control system 12 can be manufactured by... Figure 9 The computer 70 shown is implemented.

[0095] Operation of communication control system 12 Next, the operation of the communication control system 12 of this exemplary embodiment will be described. When the communication control system 12 is started and receives a command signal, the communication control device 16 performs... Figure 10 The communication control processing routine shown indicates the start of optical communication between multiple user satellites 3A, 3B, and 3C and communication relay satellite 2.

[0096] In step S100, setting part 160, based on the data rate limit value R of optical communication unit 14. U and the data rate limit R of the communication line from communication relay satellite 2 to ground station 4 G According to formula (2), the maximum number N of optical communication units that can perform simultaneous optical communication is... op Configure the settings. Note that the configuration section 160 reads the data rate limit value R from a predetermined storage section within the communication control device 16 or from the memory 72. U and data rate limit value R G To obtain this data.

[0097] In step S102, setting part 160, based on the time span X required for optical communication unit 14 to establish a communication line with user satellite 3. aq The total number N of optical communication units U and the maximum number N of optical communication units set in step S100 op According to formula (3), for the communication time span T co Configure the settings. Note that the configuration section 160 can obtain the time span X from a predetermined storage section within the communication control device 16 or from the memory 72. aq .

[0098] In step S104, setting part 160 is based on the communication time span T set in step S102. co and the maximum number N of optical communication units set in step S100 op According to formula (4), the control time span T dif Configure settings to control the timing of communication initiation.

[0099] In step S106, the control unit 162, based on the communication time span T set in step S102... co and the control time span T set in step S104 dif This is used to control multiple optical communication units 14A, 14B, and 14C.

[0100] Specifically, the control unit 162 controls the communication time span between the user satellite 3A (used as the first satellite example) and the optical communication unit 14A (used as the first optical communication unit example) to be a communication time span T. co The control section 162 also performs control so that, from the start of communication between user satellite 3A and optical communication unit 14A, a control time span T elapses. dif Subsequently, communication was initiated between user satellite 3B, used as an example of a second satellite, and optical communication unit 14B, used as an example of a second optical communication unit.

[0101] This allows the relay satellite 2 to relay data from a larger number of user satellites 3 to ground station 4 while meeting the data rate limits between the relay satellite 2 and ground station 4 when relaying communication between multiple user satellites 3A, 3B, 3C and ground station 4.

[0102] As described above, the communication control device 16 of the communication control system 12 according to the first exemplary embodiment controls the communication between the communication relay satellite and multiple user satellites, such that when the communication relay satellite relays communication between multiple satellites and ground stations, the sum of the data rates representing the communication rate per unit time between the multiple user satellites and the communication relay satellite does not exceed a data rate limit between the communication relay satellite and the ground station. This enables the transmission of data from a larger number of user satellites to the ground station while satisfying the data rate limit between the communication relay satellite and the ground station when the communication relay satellite relays communication between multiple user satellites and the ground station.

[0103] In addition, increasing the number of user satellites communicating simultaneously enables the utilization rate of communication lines between communication relay satellites and ground stations.

[0104] Satellite system of the second exemplary embodiment Next, a second exemplary embodiment will be described. Note that the configuration of the satellite system and communication control system in the second exemplary embodiment is similar to that in the first exemplary embodiment, therefore the same reference numerals are assigned and their description is omitted.

[0105] The communication control system in the second exemplary embodiment differs from that in the first exemplary embodiment in that the communication relay satellite 2 acquires X based on the time span X. aq Calculations are performed, and the communication time span T between user satellite 3 and optical communication unit 14 is calculated accordingly. co The setting specifies that the acquisition time span X represents the time span required for the communication relay satellite 2 to acquire the user satellite 3.

[0106] As shown in formula (3), the communication time span T between user satellite 3 and optical communication unit 14 is... co Based on the time span X required to establish a communication line between user satellite 3 and optical communication unit 14 aq To perform the calculations.

[0107] The communication control system in the second exemplary embodiment calculates the acquisition time span X, which represents the time span required for the optical communication unit 14 to acquire the user satellite 3. This includes the time span X required to establish a communication line between the user satellite 3 and the optical communication unit 14. aq In the second exemplary embodiment, the communication control system then responds to the acquisition of the time span X. aq And regarding the communication time span T co Configure the settings.

[0108] When establishing a communication line between user satellite 3 and optical communication unit 14, most of the required time is spent acquiring data over a time span X, during which optical communication unit 14 acquires data from user satellite 3. Therefore, the communication control system of the second exemplary embodiment calculates this acquisition time span and, in response to this acquisition time span X, adjusts the communication time span T. co Configure the settings.

[0109] The following is a detailed explanation.

[0110] Note that in the second exemplary embodiment, the following description pertains to the case where the communication relay satellite 2 is the satellite that transmits the beacon laser signal and the user satellite 3 is the satellite that receives the beacon laser signal. Therefore, the following description pertains to the case where the communication relay satellite 2 acquires the user satellite 3 as its communication partner.

[0111] First, the setting section 160 of the communication control device 16 of the communication relay satellite 2 calculates the uncertain region that the user satellite 3, which is the communication target of the optical communication unit 14, may exist in. Specifically, the setting section 160 calculates the uncertain region that the user satellite 3 may exist in using known methods, based on the calculated orbit of the user satellite 3, the prediction error of the user satellite 3's orbit, the attitude determination accuracy information of the user satellite 3, and the attitude control accuracy. Note that the possible location of the user satellite 3 is predicted based on the calculated orbit of the user satellite 3, the prediction error of the user satellite 3's orbit, the attitude determination accuracy of the user satellite 3, and the attitude control accuracy.

[0112] Figures 11 to 13 This diagram illustrates the acquisition of user satellite 3 by communication relay satellite 2. As described below, the acquisition of user satellite by communication relay satellite 2 consists of a satellite tracking step, a coarse acquisition step of user satellite 3 by communication relay satellite 2, a coarse acquisition step of user satellite 3 from communication relay satellite 2, and a fine acquisition step. Note that... Figures 11 to 13 The acquisition method shown is a spiral scanning method. In a second exemplary embodiment, an example of configuring the satellite acquisition method with this spiral scanning method will be described below.

[0113] Satellite tracking steps First, in section 160, based on the calculated orbit results of user satellite 3, the prediction error of user satellite 3's orbit, the attitude accuracy of user satellite 3, and the attitude control accuracy of user satellite 3, known methods are used to calculate the possible uncertainty region F of user satellite 3, such as... Figure 11 As shown.

[0114] Rough steps for communication relay satellite 2 to acquire user satellite 3 Next, the control unit 162 controls the optical telescope of the optical communication unit 14 to point in the direction of the uncertain region F set by the setting unit 160, and controls it so that the beam of the beacon laser signal L1 is output from the optical communication unit 14. Note that the beam divergence angle of the beacon laser signal L1 is typically smaller than that of the uncertain region F. Therefore, the control unit 162 of the communication control device 16 of the communication relay satellite 2 controls the optical communication unit 14 so that the beacon laser signal L1 scans within the uncertain region F, and scans the entire range of the uncertain region F.

[0115] Next, as Figure 12 As shown, an optical receiving sensor (not shown) mounted on user satellite 3 receives the beacon laser signal L1. The optical receiving sensor (not shown) is implemented using a sensor such as a known quadrant photodiode detector or a CCD. Then, the control unit of user satellite 3 (not shown) identifies the direction of communication relay satellite 2 based on the output value of the optical receiving sensor.

[0116] Rough steps for user satellite 3 to acquire communication relay satellite 2 Next, as Figure 13 As shown, user satellite 3 transmits a beacon laser signal L2 along the identified direction of communication relay satellite 2. The optical communication unit 14 of communication relay satellite 2 receives the beacon laser signal L2 output by user satellite 3. Note that the optical receiving sensor (not shown) used in this operation can be similarly implemented using a sensor such as a quadrant photodiode detector or a CCD. The control section 162 of the communication control device 16 of communication relay satellite 2 identifies the direction of user satellite 3 based on the output value of the optical receiving sensor.

[0117] Detailed acquisition steps Next, the control section 162 of the communication control device 16 of the communication relay satellite 2 controls the transmission of the beacon laser signal L1 from the optical communication unit 14 to stop. For example... Figure 13 As shown, the control section 162 of the communication control device 16 then transmits a beacon laser signal L3 along the direction of the identified user satellite 3. The user satellite 3 receives the beacon laser signal L3. This completes the acquisition of user satellite 3 by the communication relay satellite 2.

[0118] Then, communication relay satellite 2 and user satellite 3 use known technologies to suppress external interference that may affect the vibration of the satellite itself and the optical communication lines between satellites by adjusting the pointing mechanism (not shown in the figure), such as the coarse pointing mechanism and the fine pointing (mechanism or reflector), in order to achieve stable tracking.

[0119] Next, we will illustrate an example of how to calculate the time span X when using the spiral scanning method.

[0120] like Figure 11 As shown, in the spiral scanning method, the beacon laser signal L1 is scanned in a spiral shape within the uncertain region F. The polar coordinates used for acquisition by spiral scanning are represented by the following formula (5). Note that in the following formula (5), ρ corresponds to the distance r from the origin in polar coordinates. Furthermore, in the following formula (5), θ corresponds to the angle in polar coordinates.

[0121] [Mathematical Expression 5] (5) Figure 14 This shows the view from the M direction. Figure 11 A view of signal light L1 in the image. (See image for example.) Figure 14 As shown, I in formula (5) θ This indicates the distance between a beacon laser signal emitted at a first timing indicating a given time and a signal laser signal emitted at a second timing indicating the next subsequent time.

[0122] To ensure that the trajectory of the beacon laser signal beam covers the entire uncertain region F, the following formula (6) must be satisfied. Note that θ in the following formula... b The beam divergence angle of the indicator beacon laser signal beam.

[0123] [Mathematical Expression 6] (6) like Figure 11 As shown, in the uncertain region F, the size is θ μ (Note that θ) μ The spiral angle θ is also formed by the time series of beacon laser signals. μ In the case where the time interval between the scans of two adjacent beams representing the beacon laser signal is assumed to be Δt, the time span t required to complete the scan of the entire uncertain region F is... μ It is represented by the following formula (7).

[0124] [Mathematical Expression 7] (7) Formula (8) provides an example of a method for setting the time interval Δt. Note that L represents the communication distance between relay satellite 2 and user satellite 3, c represents the speed of light, and t... s Let F represent the response time of the optical receiving sensor included in communication relay satellite 2, and let F represent the bandwidth of the steering mirror used to scan the signal light. The communication distance L between communication relay satellite 2 and user satellite 3 is obtained by calculating the uncertainty region F.

[0125] [Mathematical Expression 8] (8) Note that the calculation formulas (5) to (8) for the spiral scanning method are described in the references cited below.

[0126] References cited "Beaconless acquisition tracking and pointing scheme of satellite opticalcommunication in multi-layer satellite networks, by Weiqi Chen, Qi Zhang, Xiangjun Xin, Qinghua Tian, ​​Ying Tao, Yufei Shen, Guixing Cao, Rui Ding, and Yifan Zhang in Proceedings SPIE 11023, Fifth Symposium on Novel Optoelectronic Detection Technology and Application, 110231E (March 12, 2019); https: / / doi.org / 10.1117 / 12.2521600" (https: / / doi.org / 10.1117 / 12.2521600).

[0127] In this manner, the setting section 160 of the second exemplary embodiment calculates the first time span required for the beacon laser signal L1 to be received by the user satellite 3, the beacon laser signal L1 being an example of a first beacon laser signal output from the communication relay satellite 2.

[0128] The setting portion 160 of the second exemplary embodiment also calculates the second time span required for the beacon laser signal L2 output by the user satellite 3 to be received by the communication relay satellite 2 in response to the user satellite 3 receiving the beacon laser signal L1.

[0129] The setting section 160 of the second exemplary embodiment also calculates the third time span required for the beacon laser signal L3 output by the communication relay satellite 2 to be received by the user satellite 3 in response to the communication relay satellite 2 receiving the beacon laser signal L2.

[0130] Then, the setting section 160 of the second exemplary embodiment calculates the time span X as the sum of the first time span, the second time span, and the third time span.

[0131] Note that in the second exemplary embodiment, the first time span corresponds to the scan time span t obtained in formula (7). μ .

[0132] Therefore, the setting portion 160 of the second exemplary embodiment is first based on the speed of light c, the communication distance L between the communication relay satellite 2 and the user satellite 3, the bandwidth F of the steering mirror used to scan the beacon laser signal, and the response time t of the light receiving sensor included in the communication relay satellite 2. s The time interval Δt is calculated according to formula (8).

[0133] Next, in the setting section 160 of the second exemplary embodiment, based on the calculated time interval Δt, the spiral angle θ formed by the time sequence of the emitted beacon laser signal... μ and the distance I between the beacon laser signal emitted at the first timing and the beacon laser signal emitted at the second timing. θ According to formula (7), for the scanning time span t μ The calculation is performed on the scanning time span t. μ This is an example of the first time span.

[0134] The setting section 160 of the second exemplary embodiment also calculates the second and third time spans based on the possible location of the user satellite 3. Note that information regarding the possible location of the user satellite 3 at a given time can be pre-transmitted to the communication relay satellite 2 by the ground station 4 or the like.

[0135] In the second exemplary embodiment, the setting section 160 sets the acquisition time span X as the time span X required for the optical communication unit 14 to establish a communication line with the user satellite 3. aq The time span X represents the calculated scanning time span t. μ The sum of the second and third time spans, the scanning time span t μ This is an example of the first time span. Note that setting section 160 allows further addition of a predetermined time span to the scan time span t. μ The sum of the second and third time spans is used to define the time span X. aq Configure the settings.

[0136] Operation of communication control system 12 Next, the operation of the communication control system 12 according to the second exemplary embodiment will be described. When the communication control system 12 is activated and receives a command signal, the communication control device 16 performs... Figure 15 The acquisition time span setting processing routine shown indicates the start of optical communication between multiple user satellites 3A, 3B, and 3C and communication relay satellite 2.

[0137] In step S200, the setting part 160 identifies the uncertain region F, in which the user satellite 3, which may be the communication target of the optical communication unit 14, may exist.

[0138] In step S202, the setting section 160 calculates the time interval Δt, which represents the time interval between the transmission of the beacon laser signal when scanning the beacon laser signal within the uncertain region F using a spiral scanning method to acquire the user satellite 3. Specifically, the setting section 160 calculates the time interval based on the speed of light c, the communication distance L between the communication relay satellite 2 and the user satellite 3, the bandwidth F of the steering mirror used to scan the beacon laser signal, and the response time t of the optical receiving sensor included in the communication relay satellite 2. s The time interval Δt is calculated according to formula (8).

[0139] In step S204, setting part 160, based on the time interval Δt calculated in step S202, the angle θ of the spiral formed by the time sequence of the emitted beacon laser signal. μ and the distance I between the beacon laser signal emitted at the first timing and the beacon laser signal emitted at the second timing. θ According to formula (7), the scanning time span t is calculated. μ Perform the calculation.

[0140] In step S205, the setting part 160 calculates the second time span and the third time span based on the possible location of user satellite 3.

[0141] In step S206, setting part 160 sets the calculated scan time span t calculated in step S204. μ The sum of the second and third time spans set in step S205 is used as the time span X required for the optical communication unit 14 to establish a communication line with the user satellite 3. aq .

[0142] After completion Figure 15 When the time span setting processing routine shown is executed, the communication control device 16 executes... Figure 10 The communication control processing routine is shown. During this processing, the communication time span T is adjusted according to formula (3). coWhen performing calculations, the time span X set by the setting section 160 of the second exemplary embodiment is used. aq To the communication time span T co Calculations are performed. Therefore, the communication time span T is calculated in response to the time required to acquire user satellite 3. co Configure the settings.

[0143] Since the other configurations and operations of the satellite system and communication control system of the second exemplary embodiment are similar to those of the satellite system and communication control system of the first exemplary embodiment, their description is omitted.

[0144] As described above, the communication control device 16 of the communication control system 12 according to the second exemplary embodiment calculates the first time span required for the beacon laser signal L1 to be received by the user satellite 3, where the beacon laser signal L1 is an example of a first beacon laser signal output by the communication relay satellite 2. The communication control device 16 also calculates the second time span required for the beacon laser signal L2, output by the user satellite 3 in response to the user satellite 3 receiving the beacon laser signal L1, to be received by the communication relay satellite 2. The communication control device 16 also calculates the third time span required for the beacon laser signal L3, output by the communication relay satellite 2 in response to the communication relay satellite 2 receiving the beacon laser signal L2, to be received by the user satellite 3. The communication control device 16 calculates the acquisition time span X as the sum of the first time span, the second time span, and the third time span. Then, the communication control device 16 sets the acquisition time span X as the time span X required for the optical communication unit 14 to establish a communication line with the user satellite 3. aq This enables adjustments to the communication time span T in response to the time required to acquire user satellite 3. co Configure the settings.

[0145] Note that the communication control device 16 identifies potential uncertainties surrounding the user satellite 3, which serves as the communication target for the optical communication unit. The communication control device 16 also considers the time interval Δt (representing the time interval between beacon laser signal transmissions) calculated when scanning beacon laser signals within the uncertain region using a spiral scanning method to acquire the user satellite, and the spiral angle θ formed by the time sequence of the transmitted beacon laser signals. μ and the distance I between the beacon laser signal emitted at the first timing and the beacon laser signal emitted at the second timing. θ The scanning time span t represents the time required to scan beacon laser signals to acquire user satellite data. μ Calculations are performed. Then, the communication control device 16 uses a scanning time span t. μAs the first time span required for beacon laser signal L1 to be received by user satellite 3, beacon laser signal L1 is an example of the first beacon laser signal output by communication relay satellite 2. This enables the use of a spiral scanning method to target the time span X required by user satellite 3. aq Perform the calculation.

[0146] The size of the uncertain region F is the range within which user satellite 3 might exist at a given point in time, and is determined taking into account factors such as the prediction accuracy of user satellite 3's orbit for optical communication, attitude control accuracy, and the characteristics of the optical communication unit. The actual accuracy of the uncertain region F depends on the entire system and therefore varies depending on user satellite 3. Therefore, considering poor accuracy and errors, the uncertain region F can be set as a large region at the initial point of actual operation. Then, as operation progresses, it can be expected that the characteristics of the optical communication unit 14 and the accuracy of acquiring user satellite 3 will improve, thus the size of the uncertain region F can be reduced.

[0147] Alternatively, relay satellite 2 can continuously record the acquisition time span X for optical communication with user satellite 3. Therefore, when planning the next communication, relay satellite 2 can reduce the predicted acquisition time span X by updating the uncertain region F that user satellite 3 may have, taking into account the difference between the previously existing and acquired location of user satellite 3 and its predicted location. In this case, the number of communications with user satellite 3 per unit time can be increased.

[0148] Note that this disclosure is not limited to the exemplary embodiments described above, and various modifications can be applied without departing from the spirit of the invention.

[0149] For example, in the exemplary embodiments described above, some examples have been described: the communication control device 16 controls multiple optical communication units 14A, 14B, and 14C such that when an optical communication unit 14 receives data from a user satellite 3, which is the target of the optical communication, the received data is transmitted in parallel from the communication relay satellite 2 to the ground station 4. However, it is not limited to this. For example, the communication control device 16 may temporarily store the data received from the user satellite 3 in a storage section. For example, if the total rate of data received from multiple user satellites 3 exceeds the data rate limit of the communication line between the communication relay satellite 2 and the ground station 4, the communication control device 16 may temporarily store the data received from multiple user satellites 3 in a storage section. Alternatively, for example, if formula (1) is not satisfied, the communication control device 16 may temporarily store the data received from the user satellite 3 in a storage section. Then, when there is spare capacity in the communication line between the communication relay satellite 2 and the ground station 4, the communication control device 16 may transmit the data stored in the storage section to the ground station 4.

[0150] Furthermore, in the above exemplary embodiments, it has been described that the data rate limit value of the communication line between user satellite 3 and optical communication unit 14 is a uniform R. U Examples are provided. However, this is not the only one. For example, for each optical communication unit 14, the data rate limit value R... U These can be different values.

[0151] Note that although the exemplary embodiments described above illustrate an example with only one high-frequency wireless communication unit, which is an example of a relay communication unit, the invention is not limited thereto. Multiple high-frequency wireless communication units can be provided as examples of relay communication units. Furthermore, the relay communication unit can be an optical communication unit as described above.

[0152] Furthermore, in the above exemplary embodiments, an example was described in which the setting section 160 of the communication control device 16 sets various data, and the control section 162 performs various controls to execute a control sequence for communication of the optical communication unit 14 based on the data set by the setting section 160, but this is not limited to this. For example, the control sequence information of the optical communication unit 14 and the relay communication unit determined by the ground server 6 can be pre-transmitted to the operators of the communication relay satellite 2 and the user satellite 3 via the ground station 4 or the server 6 connected to the ground station 4. Then, the communication control device 16 of the communication relay satellite 2 can execute based on the received control sequence information. Figure 10 or Figure 15 Various settings and controls are involved. In this case, the control sequence information can be determined based on scheduling information that specifies the timing of optical communication between communication relay satellite 2 and user satellite 3, and is calculated by the operator of communication relay satellite 2 based on information obtained from the operator of user satellite 3, such as the location information of user satellite 3.

[0153] Furthermore, in the above exemplary embodiments, the communication time span T has been described according to formula (3). co Perform calculations and based on the communication time span T co An example of controlling multiple optical communication units 14A, 14B, and 14C. However, it is not limited to this. For example, in response to a user request, a predetermined time span T can be... ur Add to communication time span T co In this case, for example, as Figure 16 As shown, it can respond to user requests by extending the time span T. ur The communication time span T added to the optical communication unit 14A co So that the communication time span T is offset relative to the communication of optical communication unit 14B and the optical communication time span of optical communication unit 14C.ur .

[0154] Although the second exemplary embodiment describes an example of using a spiral scanning method as a method for acquiring satellites, it is not limited thereto. Another method may be used as a method for acquiring satellites. Note that in this case, the acquisition time span X can be calculated by calculating at least the first time span and the second time span among the various time spans calculated in the second exemplary embodiment, wherein the acquisition time span X represents the time required for the communication relay satellite 2 (or optical communication unit 14) to acquire the user satellite 3.

[0155] Therefore, for example, the communication control device 16 can calculate the acquisition time span X in response to a first time span required for the first beacon laser signal L1 output by the communication relay satellite 2 to be received by the user satellite 3, and a second time span required for the second beacon laser signal L2 output by the user satellite 3 in response to the first beacon laser signal L1 being received by the user satellite 3 to be received by the communication relay satellite 2. For example, the communication control device 16 can calculate the acquisition time span X as the sum of the first time span and the second time span.

[0156] Alternatively, for example, the communication control device 16 can calculate the acquisition time span X in response to a first time span required for the first beacon laser signal L1 output by the user satellite 3 to be received by the communication relay satellite 2, and a second time span required for the second beacon laser signal L2 output by the communication relay satellite 2 in response to the first beacon laser signal L1 being received by the communication relay satellite 2 to be received by the user satellite 3. For example, the communication control device 16 can calculate the acquisition time span X as the sum of the first time span and the second time span.

[0157] While the example described above illustrates multiple satellites as user satellites, it is not limited thereto. For example, at least one of the multiple satellites may be an additional communications relay satellite.

[0158] Although the exemplary embodiments described above illustrate an example of communication relay satellite 2 relaying communication between multiple user satellites 3 and ground station 4, the method is not limited thereto. An additional earth station (e.g., a mobile wireless station established on the ground or in the Earth's atmosphere) that wirelessly communicates with the communication relay satellite can be used instead of ground station 4. In this case, communication relay satellite 2 relays communication between multiple user satellites 3 and the earth station. For example, using an earth station established in the stratosphere has the advantage of reliably ensuring the time span of optical communication from communication relay satellite 2 to the earth station, unaffected by ground-based communication environments (e.g., weather). Alternatively, another user satellite or another communication relay satellite can be used instead of ground station 4. In this case, communication relay satellite 2 relays communication between multiple user satellites 3 and other user satellites or other communication relay satellites. Note that this communication can be conducted via optical communication, in which case the relay communication unit is an optical communication unit.

[0159] This specification has described an exemplary embodiment in which a program is pre-installed in the storage portion 73 of the computer 70. However, the program can be provided as stored on a computer-readable recording medium. For example, the program can be provided in a format stored on a non-transitory storage medium such as an optical disc read-only memory (CD-ROM), a digital universal disc read-only memory (DVD-ROM), or a universal serial bus (USB) memory. Alternatively, the program can be provided in a format downloadable from an external device via a network.

[0160] Note that the various processes performed by the CPU in the exemplary embodiments described above, which are read and executed by the software (program), can be performed by various types of processors other than the CPU. Such processors include programmable logic devices (PLDs) that allow post-manufacturing modification of circuit configurations, such as field-programmable gate arrays (FPGAs), and application-specific integrated circuits (ASICs), which are processors with circuit configurations custom-designed for performing specific processes. Alternatively, a general-purpose graphics processing unit (GPGPU) can also be used as the processor. The corresponding processes can be performed by any of these different types of processors, or by a combination of two or more processors of the same or different types (such as multiple FPGAs, or a combination of a CPU and an FPGA). The hardware architecture of these various types of processors is more specifically a circuit incorporating circuit elements such as semiconductor elements.

[0161] Furthermore, the various processes in the exemplary embodiments can be configured by computers, servers, etc., including general computing processing devices, storage devices, etc., and executed by programs. Such programs can be stored in storage devices, recorded on recording media such as magneto-optical disks, optical disks, or semiconductor memories, or provided via a network. Obviously, other various configuration elements do not necessarily have to be implemented by a single computer or server, but can also be shared and implemented by multiple independent computers connected together via a network.

[0162] The disclosures of Japanese Patent Application No. 2020-189818, filed November 13, 2020, and Japanese Patent Application No. 2021-121038, filed July 21, 2021, are incorporated herein by reference in their entirety. All referenced documents, patent applications, and technical standards mentioned in this specification are incorporated by reference to the same extent that each individually referenced document, patent application, or technical standard is specifically and individually indicated to be incorporated by reference.

[0163] Note that in the exemplary embodiments described above, the absence of terms such as "only," "only based on," "only in response to," and "only in the case of," implies that additional information may also be considered in this specification. As an example, in addition to the described situations, "execute B when A occurs" does not necessarily mean that B is always performed when A occurs.

[0164] In any method, program, terminal, apparatus, server, or system (hereinafter referred to as "method, etc."), even if there are operational aspects that differ from those described in this specification, the various aspects of the technology disclosed herein are applicable to any operation that is the same as that described in this specification, and the existence of operations that differ from those described in this specification does not mean that the method, etc., is outside the scope of the various aspects of the technology disclosed herein.

[0165] The following supplementary information has been released.

[0166] Supplement 1 A communication control device, the communication control device comprising: The control section is configured to control communication between the communication relay satellite and multiple satellites such that when the communication relay satellite relays communication between the multiple satellites and other devices, the sum of the data rates representing the communication rates per unit time between the multiple satellites and the communication relay satellite does not exceed a limit value for the data rate between the communication relay satellite and the other devices.

[0167] Supplement 2 According to the communication control device described in Supplement 1, wherein: The communication relay satellite includes: multiple optical communication units that communicate optically with the multiple satellites; and a device communication unit that communicates with the other devices; and The control unit controls the communication between the plurality of optical communication units and the plurality of satellites, ensuring that the sum of the data rates between the plurality of satellites and the plurality of optical communication units does not exceed the data rate limit between the device communication unit and other devices.

[0168] Supplement 3 According to the communication control device described in Supplement 2, the communication control device further includes: The setting section is configured to: based on a data rate limit value R of the communication line between one of the satellites and one of the optical communication units. U And the data rate limit R of the communication line between the device communication unit and the other devices. G According to the following formula (1), the number N of optical communication units that perform simultaneous optical communication among the plurality of optical communication units is... op Configure settings. The control section is configured to handle N op The optical communication units are controlled so that in N op Each optical communication unit communicates with the plurality of satellites.

[0169] [Mathematical Expression 9] (1) Supplement 4 According to the communication control device described in Supplement 3, wherein: The settings section is also configured to: The number N of the optical communication units op Less than the total number N of the optical communication units u In the case of the number N of the optical communication units, op The time span X required to establish a communication line between one of the satellites and one of the optical communication units. aq and the total number N of the optical communication units. u According to formula (2), for the communication time span T co Configure the communication time span T. co This indicates the time span of communication between the satellite and the optical communication unit. Based on the communication time span T co and the number N of the optical communication units op According to the following formula (3), the control time span Tdif Configure the control time span T. dif Used to control the timing of communication initiation; and The control unit is configured to: Based on the communication time span T co and the control time span T dif Control is performed such that the data communication time span between the first satellite among the plurality of satellites and the first optical communication unit among the plurality of optical communication units is the communication time span T. co ,as well as Control is performed such that: when the control time span T has elapsed since the start of communication between the first satellite and the first optical communication unit... dif At that time, data communication between the second satellite among the plurality of satellites and the second optical communication unit among the plurality of optical communication units begins.

[0170] [Mathematical Expression 10] (2) [Mathematical Expression 11] (3) Supplement 5 According to the communication control device described in Supplement 4, wherein: The acquisition time span X represents the time span required for one optical communication unit to acquire information from one of the satellites, including the time span X required to establish a communication line between the satellite and the optical communication unit. aq China; and The setting portion is configured to: respond to a time span X including the acquisition time span X aq For the communication time span T co Configure the settings.

[0171] Supplement 6 According to the communication control device described in Supplement 5, the setting portion is configured to: In response to a first time span required for a first beacon laser signal output from the communication relay satellite to be received by one of the satellites, and a second time span required for a second beacon laser signal output by the satellite in response to the first beacon laser signal being received by the satellite to be received by the communication relay satellite, the acquisition time span X is calculated; and In response to the time span X including obtaining the time span X aq For the communication time span T co Configure the settings.

[0172] Supplement 7 According to the communication control device described in Supplement 5, the setting portion is configured to: In response to a first time span required for a first beacon laser signal output from one of the satellites to be received by the communication relay satellite, and a second time span required for a second beacon laser signal output by the communication relay satellite in response to the first beacon laser signal being received by the communication relay satellite to be received by the one satellite, the acquisition time span X is calculated; and In response to including obtaining the time span X aq For the communication time span T co Configure the settings.

[0173] Supplement 8 According to any one of Supplements 1 to 7, in the communication control device, at least one of the plurality of satellites is an additional communication relay satellite.

[0174] Supplement 9 The communication control device according to any one of Supplements 2 to 8, wherein the other device is at least one of an earth station or ground station configured to communicate wirelessly with the communication relay satellite.

[0175] Supplement 10 The communication control device according to any one of Supplements 2 to 8, wherein: The device communication unit configured to communicate with the other devices is an optical communication unit; and The other equipment is at least one of an earth station, ground station, satellite, or other communication relay satellite configured to communicate optically with the communication relay satellite.

[0176] Supplement 11 A communication control method comprising various processes performed by a communication control device according to any one of Supplements 1 to 10.

[0177] Supplement 12 A communication control program for enabling a computer to function as a component of a communication control device according to any one of Supplements 1 to 10.

[0178] Supplement 13 A communication control system, the communication control system comprising: Multiple optical communication units, wherein the multiple optical communication units are configured to perform optical communication with multiple satellites; A ground communication unit, configured to communicate with a ground station; and Communication control device according to any one of Supplements 1 to 10.

[0179] Supplement 14 A communication relay satellite, said communication relay satellite being equipped with a communication control system according to Supplement 13.

[0180] Supplement 15 A satellite system comprising: Multiple satellites; Communication relay satellite; Ground station; and Communication control device according to any one of Supplements 1 to 10.

Claims

1. A communication control device, characterized in that, The system has a control unit that, when a relay satellite relays communication between multiple satellites and other devices, controls the communication between the relay satellite and the multiple satellites such that the sum of the data rates representing the communication rates between the multiple satellites and the relay satellite per unit time is below a limit value for the data rates between the relay satellite and the other devices.

2. The communication control device according to claim 1, characterized in that, The relay satellite has multiple optical communication devices for optical communication with the multiple satellites, as well as communication devices for communication between the other devices. The control unit controls the communication between the plurality of optical communication devices and the plurality of satellites, so that the sum of the data rates between the plurality of satellites and the plurality of optical communication devices is below the data rate limit between the device communication device and the other devices.

3. The communication control device according to claim 2, characterized in that, The communication control device further includes a setting unit, which is based on the data rate limit R of the communication line between the satellite and the optical communication device. U And the data rate limit R in the communication line between the device's communication unit and the other devices. G According to the following formula (1), the number N of the multiple optical communication devices that can perform optical communication simultaneously is set. op , The control unit controls N op Taiwan's optical communication equipment, to be used in N op Taiwan's optical communication equipment communicates with multiple satellites. （1）。 4. The communication control device according to claim 3, characterized in that, The setting unit also considers the number N of the optical communication devices. op The number of optical communication devices is less than the total number N. U In the case of the number N of the optical communication devices, op The time X required for the satellite to establish a communication line with the optical communication device aq And the total number N of the optical communication devices U According to the following formula (2), the communication time T, which represents the time for communication between the satellite and the optical communication device, is set. co , The setting unit also bases the communication time T on co and the number N of the optical communication devices op According to the following formula (3), the control time T for controlling the start timing of communication is set. dif , The control unit is based on the communication time T co and the control time T dif The communication time between the first satellite among the plurality of satellites and the first optical communication device among the plurality of optical communication devices is controlled to the communication time T. co After the first satellite and the first optical communication device begin communication, the control time T elapses. dif At that time, communication between the second satellite among the plurality of satellites and the second optical communication device among the plurality of optical communication devices begins. （2） （3）。 5. The communication control device according to claim 4, characterized in that, The time X required for the satellite to establish a communication line with the optical communication device aq Includes acquisition time X, which represents the time required for the optical communication device to acquire information from the satellite. The setting unit determines the time X based on the acquisition time X. aq Set the communication time T co .

6. The communication control device according to claim 5, characterized in that, The setting unit calculates the acquisition time X based on a first time required for the first acquisition signal light output from the relay satellite to be received by the satellite, and a second time required for the second acquisition signal light output from the satellite to be received by the relay satellite in response to the reception of the first acquisition signal light by the satellite. The setting unit determines the time X based on the acquisition time X. aq Set the communication time T co .

7. The communication control device according to claim 5, characterized in that, The setting unit calculates the acquisition time X based on a first time required for the relay satellite to receive the first acquisition signal light output from the satellite, and a second time required for the satellite to receive the second acquisition signal light output from the relay satellite in response to the reception of the first acquisition signal light by the relay satellite. The setting unit determines the time X based on the acquisition time X. aq Set the communication time T co .

8. The communication control device according to any one of claims 1 to 7, characterized in that, At least one of the multiple satellites is another relay satellite.

9. The communication control device according to any one of claims 2 to 7, characterized in that, The other equipment is at least one of an earth station and a ground station that communicates wirelessly with the relay satellite.

10. The communication control device according to any one of claims 2 to 7, characterized in that, The communication device used for communication between the other devices is an optical communication device. The other equipment is at least one of an earth station, ground station, satellite, and other relay satellites that communicate optically with the relay satellite.

11. A communication control method, characterized in that, It includes the various processes performed by the communication control device according to any one of claims 1 to 7.

12. A communication control program, characterized in that, The communication control program is used to enable the computer to function as a part of the communication control device according to any one of claims 1 to 7.

13. A communication control system, characterized in that, include: Multiple optical communication devices communicate with multiple satellites. Ground communication equipment is used for communication between ground stations; as well as The communication control device according to any one of claims 1 to 7.

14. A relay satellite, characterized in that, It is equipped with the communication control system as described in claim 13.

15. A satellite system, characterized in that, It includes multiple satellites, relay satellites, ground stations, and the communication control device according to any one of claims 1 to 7.

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