Optical space communication management device, optical space communication system, and optical space communication management method

Abstract

[Problem] To control according to the requirements of various communication services and transmit information via an appropriate communication network. [Solution] The present invention comprises: a line measurement unit 11 which measures line measurement information when performing line control based on line route information and line parameters for transmitting and receiving communication service data to and from an optical space communication device 2 which performs optical space communication via one or a plurality of lines mounted on a non-terrestrial node group and an optical ground station, on the basis of a service request and line measurement information on a plurality of lines, received from the non-terrestrial node group; a position calculation unit 13 which calculates position information on the non-terrestrial node group; a line parameter calculation unit 10 which calculates line route information and line parameters on the basis of the position information, a service request, and line measurement information; a line control unit 12 which controls a line on the basis of the line route information and the line parameters, for the optical space communication device 2; and a line information communication unit 14 which communicates the service request, the line measurement information, the line route information, and the line parameters with the non-terrestrial node group.

Description

[Technical Field]

[0001] The present invention relates to an optical space communication management device, an optical space communication system, and an optical space communication management method. [Background technology]

[0002] In recent years, satellite optical communication networks with various circuit types have begun to appear, such as those between geostationary orbit satellites and low earth orbit satellites, between ground and geostationary orbit satellites / low earth orbit satellites, and between low earth orbit satellites. Optically modulated signals with various modulation methods and communication rates are also beginning to appear. Therefore, it is predicted that future satellite optical communication networks will be a mixture of various circuit types and optically modulated signals, and that the increase in the number of satellites will make ground-based system operations more complicated. Accordingly, it is expected that operational expenses (OPEX), including communication needs, line quality, and dealing with failures, will increase rapidly.

[0003] Under these circumstances, it is expected that the demand for automated and unmanned system operation will increase in the future. In terrestrial trunk optical communication networks, there is a concept of adaptive optical communication networks that can realize automated and unmanned system operation. As an example, technology related to elastic optical communication networks (hereinafter, this may be referred to as EON: Elastic Optical Network) is disclosed in, for example, Non-Patent Document 1. If the concept of this adaptive optical communication network is applied to satellite optical communication networks, automation of satellite optical communication networks can be realized. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] M. Jinno et al., “Virtualization in optical networks from network level to hardware level”, Journal of Optical Communication Networking, Vol. 5, No. 10, pp. A46-A56, 2012. Summary of the Invention [Problem to be solved by the invention]

[0005] In terrestrial backbone optical communication networks, conventional methods such as those described in Non-Patent Document 1 separate and control each communication network layer, such as an intercity communication network, an intracity communication network, and a communication network for corporate and individual lines. Note that intercity communication networks may be called core communication networks, intracity communication networks may be called metropolitan communication networks, and communication networks for corporate and individual lines may be called access communication networks. Separate control for each layer involves independent control of each communication network, which prevents effective use of each network. In satellite optical communication networks, as mentioned in the background art, various layered circuits are beginning to be operated independently. Furthermore, multiple satellite communication operators are also beginning to operate their satellite optical communication networks independently.

[0006] On the other hand, in addition to the existing high-capacity communication services, a wide variety of communication services are beginning to appear, including low-latency services for telemedicine and autonomous driving, device connection services for IoT data communication, and confidential communication services for national security and top-secret private information. In satellite communications, in addition to satellite broadcasting, high-capacity communication services and satellite image distribution services using Earth observation satellites are beginning to expand. Therefore, assuming that satellite optical communication networks will become widespread in suburban areas, it will be necessary to respond to new service requirements, such as time delay, reliability, and security, in addition to the existing communication capacity. However, depending on the service requirements, there is a risk that they will not be able to be met due to the characteristics of each line configuration.

[0007] An object of one aspect of the present invention is to provide an optical space communication management device that effectively utilizes various line types and satellite optical communication networks of multiple satellite communication operators, rather than each individual line type or each satellite optical communication network of each satellite communication operator, to perform control in response to requests for a wide variety of communication services and transmit optically modulated signals via an appropriate communication network. [Means for solving the problem]

[0008] The optical free space communication management device according to the present invention is an optical free space communication management device that performs optical free space communication over one or more lines mounted on at least one of a satellite and an airborne vehicle of a non-terrestrial node group and an optical ground station, and performs line control based on line route information and line parameters for transmitting and receiving communication service data based on service requests over multiple lines and line measurement information over multiple lines received from at least one of the satellite and the airborne vehicle of a non-terrestrial node group and the optical ground station, and performs line control based on line route information and line parameters for transmitting and receiving communication service data over multiple lines between the optical free space communication devices over which the communication service data is transmitted and received. Line measurement information including delay time a line measurement unit for measuring the Indicates the predetermined value of the line a service request collection unit that collects the service requests; a position calculation unit that calculates position information of at least one of the satellite and the flying object; and the position information calculated by the position calculation unit. a line parameter calculation unit that calculates the line path information including the number of relays in the free space optical communication based on the delay time measured by the line measurement unit and the predetermined value of the service request collected by the service request collection unit, and calculates the line parameters indicating parameters of the optical modulated signal in the free space optical communication based on the predetermined value of the service request; a line control unit that performs line control for the optical space communications device based on the line path information and the line parameters calculated by the line parameter calculation unit; at least one of the satellite and the airborne vehicle of a non-terrestrial node group, the optical ground station; and and before The communication device further includes a line information communication unit that communicates the line measurement information, the line path information, and the line parameters.

[0009] The optical free space communication system according to the present invention includes an optical free space communication device that performs optical free space communication over one or more lines mounted on at least one of a satellite and an airborne vehicle of a non-terrestrial node group and an optical ground station, and an optical free space communication management device that performs line control based on line path information and line parameters for transmitting and receiving communication service data based on service requests over the multiple lines and line measurement information over the multiple lines received from the at least one of the satellite and the airborne vehicle of the non-terrestrial node group and the optical ground station. space A communication system, comprising: Indicates the predetermined value of the line A service request collection unit that collects the service requests and a plurality of lines between the optical space communications device through which the communication service data is transmitted and received. Line measurement information including delay time a position calculation unit that calculates position information of at least one of the satellite and the flying object; and the position information calculated by the position calculation unit. a line parameter calculation unit that calculates the line path information including the number of relays in the free space optical communication based on the delay time measured by the line measurement unit and the predetermined value of the service request collected by the service request collection unit, and calculates the line parameters indicating parameters of the optical modulated signal in the free space optical communication based on the predetermined value of the service request; The optical space communications device is provided with a line control unit that performs line control based on the line path information and the line parameters calculated by the line parameter calculation unit, and a line information communication unit that communicates the service request, the line measurement information, the line path information, and the line parameters with at least one of the satellite, the airborne vehicle, and the optical ground station of the non-terrestrial node group, and the optical space communications device is controlled by line control based on the line path information and the line parameters from the optical space communications management device, and transmits and receives an optically modulated signal including the communication service data.

[0010] The optical free space communication management method according to the present invention is an optical free space communication management method in an optical free space communication management device that performs optical free space communication over one or more lines mounted on at least one of a satellite and an airborne vehicle of a non-terrestrial node group and an optical ground station, and that performs line control based on line route information and line parameters for transmitting and receiving communication service data based on service requests over multiple lines and line measurement information over multiple lines received from at least one of the satellite and the airborne vehicle of a non-terrestrial node group and the optical ground station, and Line measurement information including delay time The first step is to measure Indicates the predetermined value of the line a second step of collecting the service requests; a third step of calculating position information of at least one of the satellite and the flying object; and and calculating the line path information including the number of relays of the free space optical communication based on the delay time measured in the first step and the predetermined value of the service request collected in the second step, and calculating the line parameters indicating parameters of the optical modulated signal of the free space optical communication based on the predetermined value of the service request. a fourth step, a fifth step of performing line control on the optical space communications device based on the line path information and the line parameters calculated in the fourth step, and a fifth step of performing line control on the optical space communications device based on the line path information and the line parameters calculated in the fourth step, and a fifth step of performing line control on the optical space communications device based on the line path information and the line parameters calculated in the fourth step, and a fifth step of performing line control on the optical space communications device based on the line path information and the line parameters calculated in the fourth step, Ta's and a sixth step of performing communication. [Effects of the Invention]

[0011] According to one aspect of the embodiment of the present invention, an optical space communication management device can be realized that effectively utilizes various line types and satellite optical communication networks of multiple satellite communication operators, rather than for each individual line type or each satellite optical communication network of each satellite communication operator, to perform control in response to the requirements of a wide variety of communication services and transmit optically modulated signals via an appropriate line satellite optical communication network. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic diagram showing an example of the configuration of an optical space communication system according to this embodiment. [Figure 2] FIG. 2 is a block diagram showing an example of the configuration of an optical space communication system according to this embodiment. [Figure 3] FIG. 3 is a diagram illustrating a detailed block configuration example of the optical space communications device. [Figure 4] FIG. 4 is a diagram illustrating a detailed block configuration example of the optical space communication management device. [Figure 5] FIG. 5 is a block diagram showing an example of the configuration of the optical communication unit according to this embodiment. [Figure 6] FIG. 6 is a diagram showing a detailed block configuration example of an optical transmitter that employs a digital coherent optical communication system. [Figure 7] FIG. 7 is a diagram showing an example of the configuration of a transmission-side digital signal processing unit when the optical communication unit employs a wavelength division multiplexing system and a digital coherent optical communication system. [Figure 8] FIG. 8 is a diagram showing an example of the configuration of a transmission-side digital signal processing unit when the Nyquist wavelength division multiplexing system and the digital coherent optical communication system are adopted. [Figure 9] FIG. 9 is a diagram showing an example of the configuration of a transmitting-side digital signal processing unit that employs the Nyquist frequency division multiplexing method. [Figure 10] FIG. 10 is a diagram showing a specific example of the configuration of a transmission-side digital signal processing unit when an orthogonal frequency division multiplexing system and a digital coherent optical communication system are adopted. [Figure 11] FIG. 11 is a diagram showing an example of the configuration of an optical transmitter that employs an optical intensity modulation method. [Figure 12] FIG. 12 is a diagram showing an example of the configuration of a transmission-side digital signal processing unit that employs the optical intensity modulation method. [Figure 13] FIG. 13 is a diagram showing a detailed block configuration example of an optical transmitter that employs an optical phase modulation method. [Figure 14] FIG. 14 is a diagram showing an example of the configuration of a transmission-side digital signal processing unit that employs the optical phase modulation method. [Figure 15] FIG. 15 is a diagram showing a detailed block configuration example of an optical receiver that employs a digital coherent optical communication system. [Figure 16] FIG. 16 is a diagram showing a specific example of the configuration of a receiving-side digital signal processing unit when the optical communication unit employs wavelength division multiplexing. [Figure 17] FIG. 17 is a diagram showing an example of the configuration of a receiving-side digital signal processing unit when the optical communication unit employs the Nyquist wavelength division multiplexing system. [Figure 18] FIG. 18 is a diagram showing an example of the configuration of a receiving-side digital signal processing unit that employs the Nyquist frequency division multiplexing method. [Figure 19] FIG. 19 is a diagram showing an example of the configuration of a receiving-side digital signal processing unit that employs the orthogonal frequency division multiplexing method. [Figure 20]FIG. 20 is a diagram showing a detailed block configuration example of an optical receiver that employs the optical intensity modulation method. [Figure 21] FIG. 21 is a diagram showing an example of the configuration of a receiving-side digital signal processing unit that employs the optical intensity modulation method. [Figure 22] FIG. 22 is a diagram showing a detailed block configuration example of a first embodiment of an optical receiver employing an optical phase modulation method. [Figure 23] FIG. 23 is a diagram showing an example of the configuration of a receiving-side digital signal processing unit that employs the optical phase modulation method. [Figure 24] FIG. 24 is a diagram showing a detailed block configuration example of a second embodiment of an optical receiver employing an optical phase modulation method. [Figure 25] FIG. 25 is a diagram showing an example of a sequence for explaining the optical space communication management function according to this embodiment. [Figure 26] FIG. 26 is a diagram showing an example of a line measurement information database etc. according to this embodiment. [Figure 27] FIG. 27 is a diagram showing an example of a location information database according to this embodiment. [Figure 28] FIG. 28 is an example of a flowchart showing the processing procedure of the optical space communication management function according to this embodiment. [Figure 29] FIG. 29 is an example of a flowchart showing the processing procedure of the line parameter calculation processing according to this embodiment. [Figure 30] 10A and 10B are diagrams illustrating examples of effects according to the present embodiment; DETAILED DESCRIPTION OF THE INVENTION

[0013] An embodiment of the present invention will be described in detail below with reference to the drawings.

[0014] This embodiment is particularly concerned with optical space communications between satellites in which multiple circuit configurations exist, such as between a geostationary orbit satellite and a low-earth orbit satellite, between two low-earth orbit satellites, or between equipment installed on the ground and a geostationary orbit satellite or a low-earth orbit satellite.

[0015] (Embodiment 1) 1 shows an example of the configuration of an optical free space communications system according to this embodiment. The optical free space communications system to which the present invention is applied comprises a non-terrestrial node group consisting of a geostationary orbit satellite 5 in a geostationary orbit, low-earth orbit satellites 6A-6C in a low orbit, and flying objects 7A-7D flying in the air, as well as optical ground stations 3A-3D and radio ground stations 4A and 4B installed on the ground. The geostationary orbit satellite 5, low-earth orbit satellites 6A-6C, flying objects 7A-7D, optical ground stations 3A-3D, and radio ground stations 4A and 4B are each channel-controlled by an optical free space communications management device 1 (1A, 1B).

[0016] FIG. 2 is a block diagram showing an example of the configuration of an optical free-space communication system to which the present invention is applied. As shown in FIG. 2 , the optical free-space communication system includes one or more optical free-space communication devices 2 mounted on at least one of a geostationary orbit satellite 5, a low-earth orbit satellite 6, and an air vehicle 7 as a non-terrestrial node group and an optical ground station 3; and an optical free-space communication management device 1 that performs line control based on line path information and line parameters for transmitting and receiving communication service data based on service requests and line measurement information received from the geostationary orbit satellite 5, the low-earth orbit satellite 6, and the air vehicle 7 as non-terrestrial node group. The pair of optical free-space communication devices 2 transmit and receive communication service data via an optical free-space communication line, and the wireless ground station 4 transmits and receives line information related to the communication service data via a wireless control line such as radio waves. The optical free-space communication management device 1 may also perform line control based on environmental information and weather information received from an environmental and weather information collection device 8. The line information includes service requests, line measurement information, line route information, and line parameters for each of the multiple lines related to the geostationary orbit satellite 5, low earth orbit satellite 6, and spacecraft 7 of the non-terrestrial node group and the optical ground station 3.

[0017] For example, a geostationary orbit satellite 5 is a satellite located in a geostationary orbit, and includes one or more optical space communications devices 2, a geostationary orbit satellite control unit 51 that controls the geostationary orbit satellite 5, and a geostationary orbit satellite communication unit 52. Also, for example, a low-orbit satellite 6 (6A to 6C) is a satellite located in a low orbit, and includes one or more optical space communications devices 2, a low-orbit satellite control unit 61 that controls the low-orbit satellite 6, and a low-orbit satellite communication unit 62.

[0018] Furthermore, the air vehicle 7 (7A to 7D) may be, for example, an aircraft, a drone, a high altitude platform station (HAPS), a helicopter, or an unmanned aerial vehicle (UAV), and includes one or more optical space communications devices 2, an air vehicle control unit 71 that controls the air vehicle 7, and an air vehicle communication unit 72. The geostationary orbit satellite control unit 51, the low earth orbit satellite control unit 61, and the air vehicle control unit 71 are electronic circuits configured with electronic devices that can be mounted on board, such as a field programmable gated array (FPGA) or a central processing unit (CPU).

[0019] The geostationary orbit satellite control unit 51 controls the attitude of the geostationary orbit satellite 5 in its orbit. The low-earth orbit satellite control unit 61 controls the attitude of the low-earth orbit satellite 6 in its orbit. The flying object control unit 71 controls the attitude of the flying object 7 in flight.

[0020] Note that a group including at least one of one or more geostationary orbit satellites 5, one or more low-orbit satellites 6, and one or more flying objects 7 may also be referred to as a non-terrestrial node group, and the optical communication system in this embodiment can be said to include an optical space communication device 2 that is provided in each of the non-terrestrial node groups.

[0021] The optical ground stations 3 (3A to 3D) are devices installed on the ground. Unlike the non-terrestrial node group, they are directly connected to the optical free-space communication management device 1 via control lines such as a wired or wireless LAN (Local Area Network), a terrestrial mobile line, or an RF feeder link. Each optical ground station 3 (3A to 3D) includes an optical free-space communication device 2, an optical ground station control unit 31 that controls the directivity angles (azimuth angle and elevation angle) required for optical free-space communication at the optical ground station 3, and an optical ground station communication unit 32 that communicates line information with the optical free-space communication management device 1. The line information includes service requests, line measurement information, line path information, and line parameters for each of the multiple lines related to the geostationary orbit satellite 5, low-earth orbit satellite 6, and flying object 7 of the non-terrestrial node group and the optical ground station 3. The optical ground stations 3 (3A to 3D) may be installed not only on the ground but also on ships at sea, celestial bodies, planets, etc.

[0022] The environmental information collection device 8 (8A, 8B) includes an environmental information collection unit 801 that collects environmental information related to the environment in which the optical ground station 3 and the air vehicle 7 are located, a weather information collection unit 802 that collects weather information for the area in which the optical ground station 3 and the air vehicle 7 are located, an environmental information database DB6 that stores the environmental information collected by the environmental information collection unit 801, and a weather information database DB7 that stores the weather information collected by the weather information collection unit 802. The environmental information collection device 8 (8A, 8B) communicates the collected environmental information and weather information to the optical space communication management device 1. The environmental information collection unit 801 may be installed on a ship on land or at sea, a celestial body, a planet, or the like, or may be installed on an air vehicle such as an unmanned aerial vehicle or a satellite in outer space. The weather information collection unit 802 may collect weather information from the cloud, the Internet, or the like, or may determine weather information from the environmental information acquired by the environmental information collection unit 801. The environmental information includes, for example, environmental information such as temperature, humidity, wind speed, wind direction, cloud cover, cloud height, rainfall, atmospheric pressure, illuminance, and panoramic camera images. The environmental information may also include weather information. The environmental information includes information collected by environmental sensors such as panoramic cameras, nebulometers, ceilometers, thermometers, hygrometers, barometers, illuminometers, anemometers, wind vanes, and rain gauges. The weather information includes past and current weather conditions in each region, such as sunny, rainy, or cloudy weather, as well as weather forecasts for each region. The environmental information database DB6 and the weather information database DB7 are stored in storage devices such as read-only memory (ROM) and hard disks.

[0023] The optical free-space communications management device 1 includes a line measurement unit 11 that measures line measurement information of multiple lines between the optical free-space communications devices 2 through which communication service data is transmitted and received; a line control unit 12 that performs line control for the optical free-space communications devices 2 based on line path information and line parameters; a line parameter calculation unit 10 that calculates line path information and line parameters based on a service request and line measurement information to perform line control; a line information communication unit 14 that communicates line information with the optical ground station 3 and the radio ground station 4; a position calculation unit 13 that calculates the position of at least one of the geostationary orbit satellite 5, the low-earth orbit satellite 6, and the airborne vehicle 7; and a service request collection unit 17 connected to the line information communication unit 14. The line information includes service requests, line measurement information, line path information, and line parameters of each of multiple lines related to the geostationary orbit satellite 5, the low-earth orbit satellite 6, and the airborne vehicle 7 of the non-terrestrial node group and the optical ground station 3. The optical free-space communications management device 1 (1A, 1B) may be installed not only on the ground but also on a ship at sea, a celestial body, a planet, etc.

[0024] The line information communication unit 14 receives service requests and line measurement information from the geostationary orbit satellites 5, low earth orbit satellites 6, and flying objects 7 of the non-terrestrial node group and the optical ground station 3 via the optical ground station communication unit 32 of the optical ground station 3 and the wireless ground station communication unit 42 (described later) of the wireless ground station 4. The line information communication unit 14 transmits the received line measurement information to the line measurement unit 11. The service requests received by the line information communication unit 14 are collected by the service request collection unit 17. The service request collection unit 17 stores the collected service requests in a service request information database DB3. The line measurement unit 11 stores the line measurement information in a line measurement information database DB2 (described later). The position calculation unit 13 transmits position information calculated based on orbit information stored in a position information database DB5 (described later) to the line parameter calculation unit 10. The line parameter calculation unit 10 refers to the information stored in the line path information database DB1, the information stored in the line parameter information database DB4, the information stored in the service request information database DB3, the line measurement information database DB2, and the location information transmitted from the location calculation unit 13, calculates the line path information and line parameters, and then transmits them to the line control unit 12. The line parameter calculation unit 10 may also refer to the environmental information stored in the environmental information database DB6 and the weather information stored in the weather information database DB7 to calculate the line path information and line parameters. The line control unit 12 transmits the line path information and line parameters to the line information communication unit 14, and performs line control for the optical free-space communications device 2 included in the non-terrestrial node group via the wireless ground station wireless communication unit 41 of the wireless ground station 4 described below, and for the optical free-space communications device 2 included in the optical ground station 3 via the optical ground station communication unit 32. The line control unit 12 also stores the line path information and line parameters in the line path information database DB1 and the line parameter information database DB4. The line path information database DB1, line measurement information database DB2, service request information database DB3, line parameter information database DB4, and location information database DB5 are stored in a storage device such as a ROM (Read Only Memory) or a hard disk.The line parameter calculation unit 10, line measurement unit 11, line control unit 12, line information communication unit, and position calculation unit 13 may be electronic circuits configured with on-board electronic devices such as an FPGA (Field Programmable Gated Array) or a CPU (Central Processing Unit), or may be servers or PCs capable of AI (Artificial Intelligence), machine learning, etc. Furthermore, the line parameter calculation unit 10, line measurement unit 11, line control unit 12, line information communication unit, and position calculation unit 13 may be collectively configured as an SDN (Software Defined Network) controller.

[0025] The line control unit 12 of the optical free space communication management device 1 transmits line path information and line parameters to the optical ground station communication unit 32 of the optical ground station 3 via the line information communication unit 14. The line control unit 12 of the optical free space communication management device 1 also transmits line path information and line parameters to a radio ground station communication unit 42 (described later) of the radio ground station 4 via the line information communication unit 14.

[0026] The wireless ground station 4 (4A, 4B) is a device that communicates line information of each line between the wireless ground station 4 and the multiple optical space communication devices 2, between which communication service data is transmitted and received, via the satellite communication control line, such as the radio waves, and includes a wireless ground station wireless communication unit 41, a wireless ground station communication unit 42, and a wireless ground station control unit 43. The wireless ground station communication unit 42 may be configured with an electronic circuit, such as an FPGA (Field Programmable Gated Array) or a CPU (Central Processing Unit), which can be mounted on an electronic device, or may be a communication device for wired data transmission and reception compatible with Ethernet used in terrestrial networks, or a communication device for wireless data transmission and reception. The wireless ground station wireless communication unit 41 includes a communication device for transmitting and receiving data via radio waves for satellite communication, and a satellite communication antenna, which may be configured with an electronic circuit, such as an FPGA (Field Programmable Gated Array) or a CPU (Central Processing Unit), which can be mounted on an electronic device, or may be a communication device for transmitting and receiving data via radio waves for satellite communication. The line information includes service requests, line measurement information, line path information, and line parameters for each of the multiple lines related to the non-terrestrial node group's geostationary orbit satellites 5, low-earth orbit satellites 6, and flying bodies 7 and the optical ground station 3. The wireless ground stations 4 (4A, 4B) may be installed not only on the ground but also on ships at sea, or on celestial bodies, planets, etc.

[0027] The wireless ground station wireless communication unit 41 communicates line information with the geostationary orbit satellite communication unit 52 of the geostationary orbit satellite 5, the low-earth orbit satellite communication unit 62 of the low-earth orbit satellite 6, or the air vehicle communication unit 72 of the air vehicle 7. The wireless ground station control unit 43 controls the directivity angles (azimuth and elevation) required for optical space communication in the wireless ground station 4. The wireless ground station communication unit 42 communicates line information with the line information communication unit 14 of the optical space communication management device 1. The line information includes service requests, line measurement information, line path information, and line parameters for each of multiple lines related to the geostationary orbit satellite 5, the low-earth orbit satellite 6, and the air vehicle 7 of the non-terrestrial node group, and the optical ground station 3. For example, the wireless ground station 4 and the optical space communication management device 1 are connected by control lines such as a wired or wireless LAN (Local Area Network), a terrestrial mobile line, or an RF feeder link.

[0028] The optical space communications device 2 is controlled and processes based on line control from the optical space communications management device 1, and includes optical units 21_1, ..., 21_n, an optical space communications device control unit 22, a communication service processing unit 23, and optical communications units 202_1, ..., 202_n. The optical space communications device control unit 22 and the communication service processing unit 23 are configured with electronic circuits that are configured with electronic devices that can be mounted on board, such as an FPGA (Field Programmable Gated Array) or a CPU (Central Processing Unit), and the optical unit 21 is configured with optical elements, such as an optical antenna such as a lens, a mirror, an optical sensor, and an optical filter.

[0029] The optical unit 21 uses an optical antenna to shape or focus a light beam transmitted from a satellite, flying object, or the like, and further performs capture, tracking, and directivity control of the light beam in accordance with the satellite, flying object, or the like.

[0030] When the optical free space communications device 2 is provided in the optical ground station 3, the optical free space communications device control unit 22 acquires line path information and line parameters from the line control unit 12 of the optical free space communications management device 1 via the optical ground station communication unit 32 and the line information communication unit 14 of the optical free space communications management device 1, and accepts line control. Having acquired the line path information and line parameters, the optical free space communications device control unit 22 controls the parameters and path information of the optical units 21_1, . . . 21_n, the optical communication units 202_1, . . . 202_n, and the communication service processing unit 23 of the optical free space communications device 2.

[0031] Furthermore, when the optical free-space communications device 2 is provided in the optical ground station 3, the optical free-space communications device control unit 22 transmits a service request and line measurement information for the line via the optical ground station 3 to the optical ground station communication unit 32 and the line information communication unit 14 of the optical free-space communications management device 1. The line information communication unit 14 transmits the line measurement information to the line measurement unit 11 of the optical free-space communications management device 1 and stores the service request for the line via the optical ground station 3 in the service request DB. Note that when the optical free-space communications device 2 is provided in a non-terrestrial node group, the optical free-space communications device control unit 22 transmits the service request and line measurement information to the optical free-space communications management device 1 via the geostationary orbit satellite communication unit 52 of the geostationary orbit satellite 5, the low-earth orbit satellite communication unit 62 of the low-earth orbit satellite 6, or the air vehicle communication unit 72 of the air vehicle 7, the wireless ground station wireless communication unit 41 of the wireless ground station 4, and the wireless ground station communication unit 42 of the wireless ground station 4.

[0032] Furthermore, when the optical free-space communications device 2 is provided in the optical ground station 3, the optical free-space communications device control unit 22 receives line path information and line parameters of the line passing through the optical ground station 3 from the line control unit 12 of the optical free-space communications management device 1 via the optical ground station communication unit 32 and the line information communication unit 14 of the optical free-space communications management device 1. Note that when the optical free-space communications device 2 is provided in a non-terrestrial node group, the optical free-space communications device control unit 22 receives line path information and line parameters from the line control unit 12 of the optical free-space communications management device 1 via the geostationary orbit satellite communication unit 52 of the geostationary orbit satellite 5 or the low-orbit satellite communication unit 62 of the low-orbit satellite 6 or the airborne vehicle communication unit 72 of the airborne vehicle 7, the wireless ground station wireless communication unit 41 of the wireless ground station 4, and the wireless ground station communication unit 42 of the wireless ground station 4.

[0033] The communication service processing unit 23 processes communication service data transmitted and received via the line, sets routing, allocates communication bandwidth, and sets whether encryption is enabled or disabled. When the optical free space communications device 2 is provided in the optical ground station 3, the communication service processing unit 23 transmits a service request to the optical free space communications device control unit 22 based on communication service data from a terrestrial network including a mobile communication network of a business company connected to the cloud or an optical backbone communication network. When the optical free space communications device 2 is provided in the optical ground station 3 and the optical ground station 3 is installed on a ship or the like, the communication service processing unit 23 transmits a service request to the optical free space communications device control unit 22 based on communication service data generated by a user on board the ship or marine resource exploration images acquired by user equipment installed on the ship. When the optical space communications device 2 is provided in an optical ground station 3 and the optical ground station 3 is installed on a planet or a celestial body, the communications service processing unit 23 transmits a service request to the optical space communications device control unit 22 based on communications service data generated by a user residing near the planet or celestial body or a planetary image or celestial body image acquired by a user device installed near the planet or celestial body. The optical space communications device control unit 22 transmits the service request to the optical space communications management device 1 via a control line such as a wired or wireless LAN.

[0034] Furthermore, when the optical space communications device 2 is provided in a geostationary orbit satellite 5, a low-earth orbit satellite 6, or an air vehicle 7 of a non-terrestrial node group, the optical space communications device control unit 22 may transmit service requests and line measurement information for one or more lines from the geostationary orbit satellite 5, the low-earth orbit satellite 6, or the air vehicle 7 of the non-terrestrial node group via the communications service processing unit 23, including the communication service data as packets, pilot signals, etc., to the optical ground station 3 or the geostationary orbit satellite 5, the low-earth orbit satellite 6, or the air vehicle 7 of another non-terrestrial node group.

[0035] Furthermore, when the optical free-space communications device 2 is provided in the optical ground station 3, the optical free-space communications device control unit 22 may receive service requests and line measurement information for one or more lines from the geostationary orbit satellites 5, low-earth orbit satellites 6, and flying bodies 7 of the non-terrestrial node group, together with communication service data, as packets, pilot signals, or the like, via the communication service processing unit 23. The optical free-space communications device control unit 22 transmits the received service requests and line measurement information to the optical free-space communications management device 1 via the optical ground station communication unit 32.

[0036] Furthermore, when the optical free-space communications device 2 is provided in the optical ground station 3, the optical free-space communications device control unit 22 may transmit line path information and line parameters of one or more lines to the geostationary orbit satellite 5, low-earth orbit satellite 6, and airborne vehicle 7 of the non-terrestrial node group, together with communication service data, as a packet, a pilot signal, or the like, via the communication service processing unit 23. The optical free-space communications device control unit 22 receives the line path information and line parameters from the optical free-space communications management device 1 via the optical ground station communication unit 32.

[0037] Furthermore, when the optical space communications device 2 is provided in a geostationary orbit satellite 5, a low-earth orbit satellite 6, or an airborne vehicle 7 of the non-terrestrial node group, the optical space communications device control unit 22 may receive line route information and line parameters of one or more lines from the geostationary orbit satellite 5, the low-earth orbit satellite 6, or the airborne vehicle 7 of the non-terrestrial node group via the communications service processing unit 23, including the communication service data as packets, pilot signals, etc., at the optical ground station 3 or the geostationary orbit satellite 5, the low-earth orbit satellite 6, or the airborne vehicle 7 of the non-terrestrial node group.

[0038] When the optical free space communications device 2 is provided in the geostationary orbit satellite 5, the low-earth orbit satellite 6, and the air vehicle 7 of the non-terrestrial node group, the communications service processing unit 23 transmits a service request to the optical free space communications device control unit 22 based on user data such as Earth observation images obtained by user equipment such as an optical sensor or a synthetic aperture radar (SAR) (not shown) provided in the non-terrestrial node group, communications service data from a terrestrial network including a mobile communications network and an optical backbone communications network of a business company connected to a cloud, or communications service data generated by a user aboard the air vehicle 7. The optical free space communications device control unit 22 transmits the transmitted service request to the optical free space communications management device 1 via the geostationary orbit satellite communications unit 52 of the geostationary orbit satellite 5, the low-earth orbit satellite communications unit 62 of the low-earth orbit satellite 6, or the air vehicle communications unit 72 of the air vehicle 7, the wireless ground station wireless communications unit 41 of the wireless ground station 4, and the wireless ground station communications unit 42 of the wireless ground station 4.

[0039] The geostationary orbit satellites 5, low-earth orbit satellites 6 (6A to 6C), and air vehicles 7 (7A to 7D) may be equipped with RF communication equipment (not shown) that aggregates communication service data from users connected to the terrestrial network and communication service data from the air vehicles 7, such as aircraft, drones, high-altitude pseudo satellites, helicopters, and unmanned aerial vehicles. The communication service data aggregated by the RF communication equipment (not shown) may be transmitted to a communication service processing unit 23, where it may be processed.

[0040] Based on line control from the optical space communications device control unit 22, the optical communication units 202_1, ..., 202_n convert communication service data from the communication service processing unit 23 into an optical modulation signal. Note that, as shown in the detailed block configuration example in Fig. 3, when there are multiple lines, the optical space communications device 2 may be provided with an optical communication unit 201 and an optical unit 21 corresponding to each line. For example, when there are n lines, n optical communication units 202_1, ..., 202_n and optical units 21_1, ..., 21_n may be provided. On the other hand, when there is one line, for example, one optical communication unit 202_1 and one optical unit 21_1 are provided.

[0041] The optical communication units 202_1, ..., 202_n amplify the optical power of the optical modulated signals on the transmitting side and the receiving side via the optical units 21_1, ..., 21_n. The optical communication units 202_1, ..., 202_n are configured to set the modulation method, the number of wavelengths, the optical output power of a high-power optical amplifier 92 (described later), the type of error correction code, the coding rate, and the like. The optical communication unit 202 may be configured with a digital coherent optical transceiver, an optical phase-modulation optical transceiver, an optical intensity-modulation optical transceiver, or the like, which are capable of adaptively switching line parameters. The optical communication unit 202 can perform optical amplification and adaptive switching and setting of line parameters for each line. Furthermore, the optical unit 21 may also adaptively switch and set line parameters specific to the optical unit 21, such as the beam divergence angle, for each line.

[0042] The optical space communications device 2 in the embodiment of FIG. 3 further includes a communication service processing unit 201 and an optical space communications device control unit 205.

[0043] The communication service processing unit 201 is connected to optical communication units 202_1, ..., 202_n assigned to each line, and performs routing settings, communication band allocation, encryption / non-encryption settings, etc. There is one communication service processing unit 201 so that it can process a plurality of lines, but if there are n lines, for example, n communication service processing units 201_1, ..., 201_n (not shown) may be provided.

[0044] The communication service processing unit 201 may be configured with a reconfigurable hardware SDN (Software Defined Network) switch or the like. The communication service processing unit 201 may also be equipped with communication protocols such as IP (Internet Protocol), TCP (Transmission Control Protocol), and UDP (User Datagram Protocol), and routing control technologies such as RIP (Routing Information Protocol), OSPF (Open Shortest Path First), MPLS (Multi-Protocol Label Switching), GMPLS (Generalized Multi-Protocol Label Switching), and DTN (Delay Tolerant Networking). The communication service processing unit 201 may also be configured to handle data of communication standards known as Ethernet, such as 1GbE (1G Ethernet), 10GbE (10G Ethernet), 100GbE (100G Ethernet), and 400GbE (400G Ethernet), data of optical transmission standards such as OTN (Optical Transport Network), and data of mobile networks such as 5G (5th Generation).

[0045] Furthermore, when the optical free space communications device 2 is provided in a geostationary orbit satellite 5, a low earth orbit satellite 6, or an air vehicle 7 of the non-terrestrial node group, the communications service processing unit 201 may transmit service requests and line measurement information to the optical ground station 3 or the geostationary orbit satellite 5, the low earth orbit satellite 6, or an air vehicle 7 of the non-terrestrial node group, and may receive line path information and line parameters from the optical ground station 3 as packets, pilot signals, or the like along with the communications service data. Note that the communications service processing unit 201 and the optical free space communications device control unit 205 transmit and receive service requests, line measurement information, line path information, and line parameters.

[0046] Furthermore, when the optical free space communications device 2 is provided in the optical ground station 3, the communications service processing unit 201 may transmit line path information and line parameters to the geostationary orbit satellites 5, low earth orbit satellites 6, and air vehicles 7 of the non-terrestrial node group, and may receive service requests and line measurement information from the geostationary orbit satellites 5, low earth orbit satellites 6, and air vehicles 7 of the non-terrestrial node group, including these as packet signals together with communications service data. Note that the communications service processing unit 201 and the optical free space communications device control unit 205 transmit and receive service requests, line measurement information, line path information, and line parameters.

[0047] The optical space communications device control unit 205 performs various controls such as collecting line measurement information from the optical unit 21 and the optical communications unit 202, controlling line parameters, and setting line path information.

[0048] Furthermore, as shown in the diagram showing an example of a detailed block configuration in Figure 4, the optical space communication management device 1 may receive line measurement information and service requests from one or more lines related to the geostationary orbit satellites 5, low orbit satellites 6, and airborne vehicles 7 of the non-terrestrial node group and the optical ground station 3, and may also transmit line path information and line parameters to one or more lines related to the geostationary orbit satellites 5, low orbit satellites 6, and airborne vehicles 7 of the non-terrestrial node group and the optical ground station 3.

[0049] 4, the optical space communication management device 1 is configured by connecting a line path information database DB1, a line measurement information database DB2, a service request information database DB3, a line parameter information database DB4, and a position information database DB5 to a line parameter calculation unit 10, and connecting a line control unit 12 to the line path information database DB1 and the line parameter information database DB4. Also, a line information communication unit 14 is connected to the line control unit 12, and a line measurement unit 11 is connected to the line measurement information database DB2. Also, a position calculation unit 13 is connected to the position information database DB5.

[0050] In this case, the line measurement unit 11 can receive and measure line measurement information for each of the multiple lines of the geostationary orbit satellites 5, the low-earth orbit satellites 6, and the airborne vehicle 7. Similarly, with regard to service requests, the service request information database DB3 can acquire service requests for each of the multiple lines of the geostationary orbit satellites 5, the low-earth orbit satellites 6, and the airborne vehicle 7. Furthermore, the line control unit 12 and the line information communication unit 14 can transmit line path information and line parameters for each of the multiple lines related to the optical ground station 3, the geostationary orbit satellites 5, the low-earth orbit satellites 6, and the airborne vehicle 7.

[0051] 4, the optical space communication management device 1 is configured by connecting a line path information database DB1, a line measurement information database DB2, a service request information database DB3, a line parameter information database DB4, a location information database DB5, and an environment information database DB6 and a weather information database DB7 of the environment and weather information collection device 8 to a line parameter calculation unit 10, and connecting a line control unit 12 to the line path information database DB1 and the line parameter information database DB4. Also, a line information communication unit 14 is connected to the line control unit 12, and a line measurement unit 11 is connected to the line measurement information database DB2. Also, a position calculation unit 13 is connected to the location information database DB5.

[0052] Next, a case will be described with reference to Fig. 5 where the optical communication unit 202 converts one piece of communication service data from the communication service processing unit 23 into an optical modulation signal of one wavelength and outputs it to the optical unit 21. Also, Fig. 5 describes a case where the optical communication unit 202 converts the optical modulation signal of one wavelength input from the optical unit 21 into one piece of communication service data and transmits it to the communication service processing unit.

[0053] 5 is a block diagram showing an example of the configuration of an optical communication unit according to this embodiment. The optical communication unit 202 includes an optical transmitter 81 that converts communication service data into an optical modulated signal and transmits it, an optical receiver 82 that converts the optical modulated signal into communication service data and receives it, and an optical amplifier 83 that amplifies the optical modulated signal received from the optical unit 21 and the optical modulated signal to be transmitted to the optical unit 21.

[0054] First, we will explain the case where there is no optical transmitter 81B and optical receiver 82B, and details will be described later.However, when the optical communication unit 202 is equipped with an optical multiplexing / demultiplexing device 101, an optical transmitter 81B, and an optical receiver 82B, the optical communication unit 202 can handle wavelength division multiplexing (WDM) optical modulated signals in which optical modulated signals of multiple wavelengths are multiplexed.

[0055] The optical transmitter 81 generates an optical modulated signal of one wavelength from one communication service data from the communication service processing unit 23. For example, a high-power optical amplifier 92 included in the optical amplifying device 83 amplifies the optical modulated signal to high power.

[0056] Furthermore, for example, the low-noise optical amplifier 100 provided in the optical amplifying device 83 performs low-noise amplification of an optical modulated signal of one wavelength. The low-noise amplified optical modulated signal of one wavelength is converted into one piece of communication service data by the optical receiver 82. Note that the high-power optical amplifier 92 and the low-noise optical amplifier 100 may be integrated into one device.

[0057] Furthermore, the optical amplifying device 83 may be omitted, or may be configured with at least one of a high-power optical amplifier 92 and a low-noise optical amplifier 100 included in the optical amplifying device 83. Also, a configuration may be adopted in which switching is performed directly from the optical unit 21 to the optical multiplexing / demultiplexing device 101, or a configuration may be adopted in which switching is performed directly from the optical unit 21 to the optical transmitter 81 and the optical receiver 82.

[0058] Also, the optical transmitter 81, the optical receiver 82, and the communication service processing unit 23 may be omitted or switched. In this case, the demultiplexing unit 103 of the optical multiplexing and demultiplexing device 101 included in the optical communication unit 202_1 and the multiplexing unit 102 of the optical multiplexing and demultiplexing device 101 included in the optical communication unit 202_2 are connected to each other.

[0059] Next, the optical transmitter 81 and the optical receiver 82 will be described in detail. Fig. 6 is a diagram showing a detailed block configuration example of the optical transmitter 81 when, for example, a digital coherent optical communication system is adopted. As shown in Fig. 6, when the digital coherent optical communication system is adopted, the optical transmitter 81 includes a transmission-side digital signal processing unit 84, an I-phase digital-to-analog conversion unit 85, a Q-phase digital-to-analog conversion unit 87, a transmission light source 86, and an IQ optical modulator 121. The IQ optical modulator 121 includes an I-phase optical modulator 88, an optical branching unit 89, a Q-phase optical modulator 90, a π / 2 phase shift unit 131, and an optical combining unit 91.

[0060] The transmitting-side digital signal processing unit 84 generates a modulated signal based on one piece of communication service data. The modulated signal consists of an I-phase digital signal and a Q-phase digital signal, which are separately input to the IQ optical modulator 121. Note that one piece of communication service data may be subjected to error correction coding, and digital processing such as digital filtering, signal degradation compensation, modulator nonlinear compensation, and linear equalization processing may also be performed.

[0061] The transmitter digital signal processing unit 84 uses a digital multiplexing method such as Orthogonal Frequency Division Multiplexing (OFDM) or Nyquist-Frequency Division Multiplexing (N-FDM) to convert a modulated signal generated based on one piece of communication service data into one subcarrier signal, multiplex multiple subcarrier signals, and then separates them into an I-phase digital signal and a Q-phase digital signal, which are input to the IQ optical modulator 121. This allows the optical transmitter 81 to generate an optical modulated signal containing multiple pieces of communication service data for one wavelength. Note that one piece of communication service data may be subjected to error correction coding, and digital processing such as digital filtering, signal degradation compensation, modulator nonlinear compensation, and linear equalization may be performed.

[0062] The I-phase communication service data is converted from an I-phase digital signal to an I-phase electrical signal by the I-phase digital-to-analog converter 85, and the I-phase electrical signal is converted into an I-phase optical modulated signal by the I-phase optical modulator 88 of the IQ optical modulator 121.

[0063] The Q-phase communication service data is converted from a Q-phase digital signal to a Q-phase electrical signal by the Q-phase digital-to-analog converter 87, and the Q-phase electrical signal becomes a Q-phase optical modulated signal by the Q-phase optical modulator 90 of the IQ optical modulator 121 and the π / 2 phase shifter 131 that shifts the optical phase by π / 2.

[0064] The optical combiner 91 combines the I-phase optical modulated signal input from the I-phase optical modulator 88 and the Q-phase optical modulated signal input from the Q-phase modulator 90 to generate an optical modulated signal of one wavelength.

[0065] When modulating by the I-phase optical modulator 88 of the IQ optical modulator 121 and the Q-phase optical modulator 90 of the IQ optical modulator 121, two unmodulated lights are used, which are obtained by branching the unmodulated light output from the transmitting light source 86 by the optical branching unit 89.

[0066] Next, the detailed configuration of the transmitting-side digital signal processing unit 84 will be described. FIG. 7 is a diagram showing a specific example configuration of the transmitting-side digital signal processing unit 84 when the optical communication unit employs wavelength division multiplexing and digital coherent optical communication. The transmitting-side digital signal processing unit 84 includes an error correction coding unit 841, a multi-level modulation unit 842, and a resampling unit 843. The error correction coding unit 841 performs error correction coding processing on the communication service data. The multi-level modulation unit 842 performs so-called multi-level modulation on the communication service data that has been error correction coded by the error correction coding unit 841, modulating the data so that one modulation symbol can take two or more signal points. The multi-level modulation unit 842 may also perform differential coding processing. The resampling unit 843 outputs I-phase digital signals and Q-phase digital signals obtained by performing various resampling processing on the multi-level modulated signal that has been multi-level modulated by the multi-level modulation unit 842. Furthermore, an interleaver unit (not shown) that performs a process of changing the order of bit data included in the communication service data may be provided after the error correction coding unit 841.

[0067] Such a transmitting-side digital signal processing unit 84 may be embodied in the form shown in Fig. 8. Fig. 8 is a diagram showing an example of the configuration of the transmitting-side digital signal processing unit 84 when the optical communication unit employs a Nyquist wavelength division multiplexing system and a digital coherent optical communication system.

[0068] The transmitting-side digital signal processing unit 84 shown in FIG. 8 includes an error correction coding unit 841, a multi-level modulation unit 842, a Nyquist filter unit 844, a modulator nonlinear compensation unit 845, and a resampling unit 843.

[0069] The configurations of the error correction coding unit 841, the multi-level modulation unit 842, and the resampling unit 843 are the same as those in FIG. 8, so they are denoted by the same reference numerals and the description thereof will be omitted below.

[0070] The Nyquist filter unit 844 is a filter that performs waveform shaping for Nyquist wavelength division multiplexing on the multi-level modulated signal that has been multi-level modulated in the multi-level modulation unit 842. The modulator nonlinearity compensation unit 845 compensates for the nonlinearity of the I-phase optical modulator 88 and the Q-phase optical modulator 90 of the IQ optical modulator 121. Furthermore, an interleaver unit (not shown) that changes the order of bit data included in the communication service data may be provided after the error correction coding unit 841.

[0071] The transmitting-side digital signal processing unit 84 may also be embodied in the form shown in Fig. 9. Fig. 9 is a diagram showing an example of the configuration of the transmitting-side digital signal processing unit 84 that employs the Nyquist frequency division multiplexing method. In the form shown in Fig. 9, the Nyquist FDM (frequency division multiplexing) method is employed to multiplex communication service data, separate it into an I-phase digital signal and a Q-phase digital signal, and output them.

[0072] The transmitting-side digital signal processing unit 84 receives one to a maximum of n pieces of communication service data. An error correction coding unit 841, a multi-level modulation unit 842, a frequency conversion unit 847, and a Nyquist filter unit 844 are assigned to each of the supplied communication service data. For example, when communication service data SD_1 is supplied, various processes are performed by the error correction coding unit 841_1, the multi-level modulation unit 842_1, the frequency conversion unit 847_1, and the Nyquist filter unit 844_1. When communication service data SD_2 is supplied, various processes are performed by the error correction coding unit 841_2, the multi-level modulation unit 842_2, the frequency conversion unit 847_2, and the Nyquist filter unit 844_2. Similarly, when communication service data SD_n is supplied, various processes are performed by the error correction coding unit 841_n, the multi-level modulation unit 842_n, the frequency conversion unit 847_n, and the Nyquist filter unit 844_n. Furthermore, an interleaver unit (not shown) that performs a process of changing the order of bit data included in the communication service data may be provided after the error correction coding unit 841.

[0073] Frequency conversion sections 847 _ 1 , 847 _ 2 , . . . 847 _n perform frequency conversion on the subcarrier multi-level modulated signals output from the multi-level modulation sections, and output the converted signals to Nyquist filter section 844 .

[0074] The transmitting-side digital signal processing unit 84 that employs the Nyquist FDM method further comprises a power allocation unit 848 , a subcarrier multiplexing unit 849 , an inverse frequency conversion unit 850 , and a resampling unit 843 .

[0075] Power allocation section 848 allocates power to each subcarrier M-ary modulated signal output from Nyquist filter section 844 in accordance with the power ratio of the subcarrier M-ary modulated signal to the overall power of the plurality of subcarrier M-ary modulated signals.

[0076] The subcarrier multiplexing unit 849 subcarriers multiplexes the subcarrier multilevel modulated signal supplied from the power allocating unit 848 .

[0077] The inverse frequency conversion unit 850 performs an inverse frequency conversion on the subcarrier-multiplexed signal, which is the inverse of that performed by the frequency conversion unit 847. The signal that has undergone the inverse frequency conversion in this way is subjected to various resampling processes in the resampling unit 843, and is output as an I-phase digital signal and a Q-phase digital signal.

[0078] The transmitting-side digital signal processing unit 84 may also be embodied in the form shown in Fig. 10. Fig. 10 is a diagram showing an example of the configuration of the transmitting-side digital signal processing unit 84 that employs an orthogonal frequency division multiplexing system and a digital coherent optical communication system. In the form shown in Fig. 10, the OFDM system is employed, communication service data is multiplexed, and the data is separated into an I-phase digital signal and a Q-phase digital signal for output.

[0079] A transmitter digital signal processing unit 84 employing the OFDM system is supplied with 1 to a maximum of n pieces of communication service data. An error correction coding unit 841, a multi-level modulation unit 842, and a frequency conversion unit 847 are assigned to each of the supplied communication service data. The transmitter digital signal processing unit 84 employing the OFDM system also includes a subcarrier multiplexing unit 849, a CP adding unit 851, and a resampling unit 843. An interleaver unit (not shown) that rearranges the order of bit data included in the communication service data may be provided after the error correction coding unit 841.

[0080] In the embodiment shown in FIG. 10, the same components and members as those in the Nyquist FDM system shown in FIG. 9 are denoted by the same reference numerals, and the description thereof will be omitted below.

[0081] The CP adding unit 851 adds a cyclic prefix (CP) to the subcarriers obtained by inverse frequency conversion of the multi-level modulated signal output from the multi-level modulation unit 842 in the inverse frequency conversion unit 850. This makes it possible to provide resistance to delayed waves. The signals to which the CPs have been added in this way are subjected to various resampling processes in the resampling unit 843 and are output as I-phase digital signals and Q-phase digital signals.

[0082] Although the optical transmitter 81 shown in Fig. 6 and the transmission-side digital signal processing unit 84 shown in Figs. 7 to 10 show a case where the optical modulated signal is single-polarized, they may also be configured to have polarization-multiplexed optical modulated signals. In this case, the optical modulated signal from the optical transmitter 81 for the X polarization and the optical modulated signal from the optical transmitter 81 for the Y polarization are polarization-multiplexed in a polarization combiner, and a polarization-multiplexed optical modulated signal is output. Similarly, the transmission-side digital signal processing unit 93 is configured to generate I-phase and Q-phase digital signals for the X polarization and I-phase and Q-phase digital signals for the Y polarization.

[0083] 11 is a diagram showing a detailed block configuration example of the optical transmitter 81 when the optical intensity modulation method is adopted. As shown in FIG. 11, when the optical intensity modulation method is adopted, the optical transmitter 81 includes a transmission-side digital signal processing unit 84, a digital-to-analog conversion unit 870, a transmission light source 86, and an optical intensity modulator 900.

[0084] When the optical intensity modulation method is adopted, the digital-to-analog converter 870 converts the digital signal of the communication service data output from the transmitting-side digital signal processor 84 into an electrical signal. The optical intensity modulator 900 modulates the intensity of the communication service data converted into an electrical signal by the digital-to-analog converter 87, to generate an optically modulated signal.

[0085] FIG. 12 illustrates a configuration example of a transmitting-side digital signal processing unit 84 employing optical intensity modulation. When optical intensity modulation is employed, the transmitting-side digital signal processing unit 84 includes an error correction coding unit 841, a multi-level modulation unit 842, a digital filter unit 846, and a resampling unit 843, as shown in FIG. 12. When optical intensity modulation is employed, the transmitting-side digital signal processing unit 84 generates a modulated signal based on one piece of communication service data. The modulated signal is a digital signal and is input to an optical intensity modulator. Note that one piece of communication service data may be subjected to error correction coding, or digital processing such as digital filtering, signal degradation compensation, modulator nonlinear compensation, and linear equalization may be performed. An interleaver unit (not shown) may be provided after the error correction coding unit 841 to rearrange the order of bit data included in the communication service data.

[0086] 13 is a diagram showing a detailed block configuration example of the optical transmitter 81 when, for example, optical phase modulation is employed. As shown in Fig. 13, when optical phase modulation is employed, the optical transmitter 81 includes a transmission-side digital signal processing unit 84, a digital-to-analog conversion unit 870, a transmission light source 86, and an optical phase modulator 901. The optical phase modulator 901 modulates the phase of the communication service data converted into an electrical signal by the digital-to-analog conversion unit 87, to generate an optically modulated signal.

[0087] FIG. 14 illustrates a configuration example of a transmitting-side digital signal processing unit 84 employing optical phase modulation. For example, when optical phase modulation is employed, the transmitting-side digital signal processing unit 84 includes, as shown in FIG. 14, an error correction encoder 841, a phase modulator 852 that phase-modulates the communication service data that has been error-correction-encoded by the error-correction encoder 841 so that one modulation symbol corresponds to two signal points, a digital filter 846, and a resampler 843. The phase modulator 852 may perform differential encoding. When optical phase modulation is employed, the transmitting-side digital signal processing unit 84 generates a modulated signal based on one communication service data. The modulated signal is a digital signal and is input to an optical intensity modulator. Note that one communication service data may be subjected to error-correction encoding, or digital processing such as digital filtering, signal degradation compensation, modulator nonlinear compensation, and linear equalization may be performed. An interleaver (not shown) that rearranges the order of bit data included in the communication service data may be provided after the error-correction encoder 841.

[0088] Next, the optical receiver 82 will be described. Fig. 15 is a diagram showing a detailed block configuration example of the optical receiver 82 that employs the digital coherent optical communication system. As shown in Fig. 15, the optical receiver 82 when employing the digital coherent optical communication system includes a receiving-side digital signal processing unit 93, an I-phase analog-to-digital conversion unit 94, a Q-phase analog-to-digital conversion unit 95, a local light source 97, and a coherent optical detection unit 122. The coherent optical detection unit 122 includes an I-phase balanced photodetector 96, a Q-phase balanced photodetector 98, and an optical frequency mixer 99.

[0089] The optical frequency mixer 99 uses the unmodulated light output from the local light source 97, interferes with the low-noise amplified optical modulated signal, and separates it into an I-phase optical modulated signal and a Q-phase optical modulated signal. The I-phase optical modulated signal is detected by an I-phase balanced photodetector 96 and converted into an I-phase electrical signal. The I-phase electrical signal is then converted into an I-phase digital signal by an I-phase analog-to-digital converter 94.

[0090] The Q-phase optical modulated signal is detected by the Q-phase balanced photodetector 98 and becomes a Q-phase electrical signal. The Q-phase electrical signal is then converted into a Q-phase digital signal by the Q-phase balanced photodetector 98. The receiving-side digital signal processing unit 93 converts the modulated signal, which is synthesized from the I-phase digital signal and the Q-phase digital signal, into one piece of communication service data. The I-phase digital signal and the Q-phase digital signal are output from the I-phase balanced photodetector 96 and the Q-phase balanced photodetector 98 of the coherent optical detection unit 122. Note that one piece of communication service data may be subjected to error correction decoding, and digital processing such as digital filtering, frequency estimation, phase estimation, and signal degradation compensation such as adaptive equalization may also be performed.

[0091] The receiving-side digital signal processing unit 93 can separate the digitally multiplexed I-phase digital signal and Q-phase digital signal into multiple subcarriers, for example, using an Orthogonal Frequency Division Multiplexing (OFDM) system or a Nyquist-Frequency Division Multiplexing (N-FDM) system, and convert the modulated signal as one subcarrier into one piece of communication service data. The I-phase digital signal and Q-phase digital signal are output from the I-phase balanced photodetector 96 and the Q-phase balanced photodetector 98 of the coherent optical detection unit 122. This allows the optical receiver 82 to convert one wavelength of optical modulated signal into multiple pieces of communication service data. Note that one piece of communication service data may be subjected to error correction decoding, and digital processing such as digital filtering, frequency estimation, phase estimation, and signal degradation compensation such as adaptive equalization may be performed.

[0092] 16 is a diagram showing a specific example of the configuration of the receiving-side digital signal processing unit 93 when the optical communication unit employs wavelength division multiplexing. This receiving-side digital signal processing unit 93 includes a resampling unit 931, a clock extraction unit 932, an adaptive equalization unit 934, a frequency estimation unit 935, a phase estimation unit 936, a multi-level demodulation unit 937, and an error correction decoding unit 938.

[0093] The resampling unit 931 receives the I-phase digital signal and the Q-phase digital signal and performs various resampling processes on each of them. The clock extraction unit 932 extracts clocks from the I-phase digital signal and the Q-phase digital signal resampled by the resampling unit 931. The adaptive equalization unit 934 performs equalization processing on the input I-phase digital signal and the Q-phase digital signal, respectively, and detects power fluctuation information to be stored in a power fluctuation information table TB4 (described later). The frequency estimation unit 935 performs frequency estimation required for demodulation of the input I-phase digital signal and the Q-phase digital signal, and detects frequency fluctuation information to be stored in a frequency fluctuation information table TB3 (described later). The phase estimation unit 936 performs phase estimation required for demodulation of the I-phase digital signal and the Q-phase digital signal, and detects phase fluctuation information to be stored in a phase fluctuation information table TB5 (described later). The multi-level demodulation unit 937 demodulates the I-phase digital signal and the Q-phase digital signal, which are multi-level modulated signals, to generate a single communication service data. The multi-level demodulation unit 937 may perform differential decoding processing. The error correction decoding unit 938 performs error correction decoding processing on the communication service data obtained by the multi-level demodulation unit 937. Furthermore, before the error correction decoding unit 938, there may be a deinterleaver unit (not shown) that performs processing inversely to the bit data rearrangement processing on the communication service data that has been subjected to processing for rearranging the order of bit data by an interleaver unit (not shown).

[0094] Such a receiving-side digital signal processing unit 93 may be embodied in the form shown in FIG. 17. FIG. 17 is a diagram showing an example of the configuration of the receiving-side digital signal processing unit 93 when the optical communication unit employs Nyquist wavelength division multiplexing. The receiving-side digital signal processing unit 93 shown in FIG. 17 includes a resampling unit 931, a clock extraction unit 932, a matched filter unit 933, an adaptive equalization unit 934, a frequency estimation unit 935, a phase estimation unit 936, a multi-level demodulation unit 937, and an error correction decoding unit 938. The matched filter unit 933 is a filter necessary for demodulation. The configurations of the resampling unit 931, the clock extraction unit 932, the adaptive equalization unit 934, the frequency estimation unit 935, the phase estimation unit 936, the multi-level demodulation unit 937, and the error correction decoding unit 938 are the same as those in FIG. 16, and therefore the same reference numerals are used and their description will be omitted below. In addition, before the error correction decoding unit 938, there may be a deinterleaver unit (not shown) that performs the reverse operation of the bit data rearrangement on the communication service data that has been processed by an interleaver unit (not shown) to rearrange the order of the bit data.

[0095] Furthermore, the receiving-side digital signal processing unit 93 may be embodied in the form shown in Fig. 18. Fig. 18 is a diagram showing an example of the configuration of the receiving-side digital signal processing unit 93 that employs the Nyquist frequency division multiplexing method. In the form shown in Fig. 18, the transmitting-side digital signal processing unit 84 multiplexes communication service data under the Nyquist FDM (frequency division multiplexing) method, and separates the data as an I-phase digital signal and a Q-phase digital signal into the original communication service data and outputs it.

[0096] The receiving side digital signal processor 93 can separate and output from 1 to a maximum of n pieces of communication service data.

[0097] The multiplexed signal input to the receiving-side digital signal processing unit 93 passes through a resampling unit 931 and a frequency estimation unit 935 and reaches a frequency conversion unit 939. The frequency conversion unit 939 performs frequency conversion and supplies an I-phase digital signal and a Q-phase digital signal for each of the multiplexed communication service data to matched filter units 933_1 to 933_n, respectively.

[0098] The I-phase digital signal and the Q-phase digital signal for each communication service data to be separated and output are assigned to a matched filter unit 933, an inverse frequency conversion unit 941, a clock extraction unit 932, an adaptive equalization unit 934, a phase estimation unit 936, a multi-level demodulation unit 937, and an error correction decoding unit 938. For example, when communication service data SD_1 is output, various processes are performed by a matched filter unit 933_1, an inverse frequency conversion unit 941_1, a clock extraction unit 932_1, an adaptive equalization unit 934_1, a phase estimation unit 936_1, a multi-level demodulation unit 937_1, and an error correction decoding unit 938_1. Furthermore, when communication service data SD_2 is output, various processes are performed by a matched filter unit 933_2, an inverse frequency conversion unit 941_2, a clock extraction unit 932_2, an adaptive equalization unit 934_2, a phase estimation unit 936_2, a multi-level demodulation unit 937_2, and an error correction decoding unit 938_2. When communication service data SD_n is output, various processes are performed by a matched filter unit 933_n, an inverse frequency conversion unit 941_n, a clock extraction unit 932_n, an adaptive equalization unit 934_n, a phase estimation unit 936_n, a multi-level demodulation unit 937_n, and an error correction decoding unit 938_n. Furthermore, a deinterleaver unit (not shown) may be provided before the error correction decoding unit 938_n to reverse the bit data rearrangement process performed by an interleaver unit (not shown) on the communication service data whose order has been rearranged.

[0099] The I-phase digital signal and Q-phase digital signal that have passed through the matched filter unit 933 are converted to inverse frequencies in an inverse frequency conversion unit 941. The same processing as described above is also performed in a clock extraction unit 932, an adaptive equalization unit 934, a phase estimation unit 936, a multi-level demodulation unit 937, and an error correction decoding unit 938, and the signals are output as communication service data.

[0100] The receiving-side digital signal processing unit 93 may also be embodied in the form shown in Fig. 19. Fig. 19 is a diagram showing an example of the configuration of a receiving-side digital signal processing unit 93 that employs orthogonal frequency division multiplexing. In the form shown in Fig. 19, an I-phase digital signal and a Q-phase digital signal, into which communication service data has been multiplexed under the OFDM system, are separated into the original communication service data and output. The receiving-side digital signal processing unit 93 can separate and output from 1 to a maximum of n pieces of communication service data.

[0101] The multiplexed signal input to the receiving-side digital signal processing unit 93 is sent to a CP removal unit 944 via a resampling unit 931, a frequency estimation unit 935, and a phase estimation unit 936. The CP removal unit 944 removes the CP added by the CP addition unit 851. The I-phase digital signal and the Q-phase digital signal output from the CP removal unit 944 are sent to a subcarrier separation unit 945, which separates them into subcarriers in the digital domain. The separated individual communication service data undergoes frequency conversion in frequency conversion units 939_1 to 939_n, multi-level demodulation in multi-level demodulation units 937_1 to 937_n, and error correction decoding in error correction decoding units 938_1 to 938_n. Furthermore, a deinterleaver unit (not shown) may be provided before the error correction decoding unit 938_n to reverse the bit data rearrangement process on the communication service data that has undergone bit data rearrangement processing in an interleaver unit (not shown).

[0102] When the optical communication unit 202 includes the optical multiplexing / demultiplexing device 101, the optical communication unit 202 can handle a plurality of optically modulated signals. For example, when the optical communication unit 202 includes the optical multiplexing / demultiplexing device 101 and the optical multiplexing / demultiplexing device 101 includes the multiplexing unit 102, the optical communication unit 202 can handle a plurality of optically modulated signals by performing multiplexing processing to combine optically modulated signals multiplexed at a plurality of wavelengths output from a plurality of optical transmitters 81A and 81B, for example.

[0103] Furthermore, by using the aforementioned Nyquist frequency division multiplexing or orthogonal frequency division multiplexing, it becomes possible to handle cases where multiple communication service data are included in an optical modulated signal for one wavelength. For example, when the transmitting-side digital signal processing unit 84 uses the Nyquist frequency division multiplexing or orthogonal frequency division multiplexing, it becomes possible to generate a single optical modulated signal based on multiple communication service data. As a result, when the optical communication unit 202 includes the optical multiplexing / demultiplexing device 101 and the optical multiplexing / demultiplexing device 101 includes the multiplexing unit 102, the optical communication unit 202 can handle optical modulated signals based on multiple communication service data multiplexed over multiple wavelengths by performing multiplexing processing to combine optical modulated signals multiplexed over multiple wavelengths output from multiple optical transmitters 81A and 81B, for example.

[0104] Furthermore, for example, if the optical communication unit 202 is equipped with an optical multiplexing / demultiplexing device 101 and the optical multiplexing / demultiplexing device 101 is equipped with a demultiplexing unit 103, the optical communication unit 202 can handle multiple optical modulated signals by performing a demultiplexing process to demultiplex optical modulated signals multiplexed at multiple wavelengths to, for example, multiple optical receivers 82A, 82B.

[0105] Furthermore, by using the above-mentioned Nyquist frequency division multiplexing method or orthogonal frequency division multiplexing method, it becomes possible to handle the case where multiple communication service data are included in an optical modulated signal of one wavelength. As a result, when the optical communication unit 202 includes the optical multiplexing / demultiplexing device 101 and the optical multiplexing / demultiplexing device 101 includes the demultiplexing unit 103, the optical communication unit 202 can handle optical modulated signals based on multiple communication service data separated into multiple wavelengths by performing demultiplexing processing to demultiplex optical modulated signals multiplexed at multiple wavelengths to, for example, multiple optical receivers 82A, 82B.

[0106] Although the optical receiver 82 shown in Fig. 15 and the receiving-side digital signal processing unit 93 shown in Figs. 16 to 19 show a case where the optical modulated signal is single-polarized, they may also be configured to have a case where the optical modulated signal is polarization multiplexed. In that case, the polarization-multiplexed optical modulated signal is polarization-separated by a polarization separator, and the polarization-separated X-polarized optical modulated signal is input to the X-polarized optical receiver 82, and the polarization-separated Y-polarized optical modulated signal is input to the Y-polarized optical receiver 82. The receiving-side digital signal processing unit 93 is also configured to process and receive the I-phase digital signal and Q-phase digital signal of the X-polarized wave and the I-phase digital signal and Q-phase digital signal of the Y-polarized wave.

[0107] Fig. 20 is a diagram showing a detailed block configuration example of an optical receiver 82 that employs optical intensity modulation. As shown in Fig. 20, the optical receiver 82 when employing optical intensity modulation includes an opto-electrical converter 821, an electric filter unit 822, an analog-to-digital conversion unit 870, and a receiving-side digital signal processing unit 93. Furthermore, the optical receiver 82 does not necessarily need to include at least one of the electric filter unit 822 and the analog-to-digital conversion unit 870.

[0108] The photoelectric converter 821 performs photoelectric conversion on the low-noise amplified optical modulated signal, converting it into an electric signal. The converted electric signal passes through an electric filter unit 822 and is converted into an electric signal having a predetermined band. The electric signal that has passed through the electric filter unit 822 is converted into a digital signal by an analog-to-digital converter 870. The function of the electric filter unit 822 may be incorporated into the receiving-side digital signal processor 93, and digital filtering may be performed.

[0109] FIG. 21 is a diagram illustrating a configuration example of a receiving-side digital signal processing unit 93 that employs optical intensity modulation. When optical intensity modulation is employed, the receiving-side digital signal processing unit 93 includes, as shown in FIG. 21, a resampling unit 931, a digital filter unit 846, a clock extraction unit 932, a multi-level demodulation unit 937, and an error correction decoding unit 938. The receiving-side digital signal processing unit 93 converts a modulated digital signal into one piece of communication service data. The digital signal is output from an optical-to-electrical converter 821. Note that one piece of communication service data may be subjected to error correction decoding, or digital processing such as digital filtering, linear equalization, and signal degradation compensation. Furthermore, a deinterleaver unit (not shown) may be provided before the error correction decoding unit 938 to reverse the bit data rearrangement process performed by an interleaver unit (not shown) on the communication service data.

[0110] Fig. 22 is a diagram showing a detailed block configuration example of a first embodiment of an optical receiver employing optical phase modulation. For example, an optical receiver 82 of the first embodiment employing optical phase modulation includes a local light source 97, an optical frequency mixer 99, a balanced photodetector 823, a digital-to-analog converter 870, and a receiving-side digital signal processor 93, as shown in Fig. 22. Furthermore, the optical receiver 82 does not necessarily need to include at least one of the electrical filter 822 and the analog-to-digital converter 870.

[0111] The optical frequency mixer 99 uses the unmodulated light output from the local light source 97 to interfere with the low-noise amplified optical modulated signal. The interfered optical modulated signal is detected by a balanced photodetector 823 and converted into an electric signal. The electric signal is then converted into a digital signal by an analog-to-digital converter 870. The function of the electric filter 822 may be incorporated into the receiving-side digital signal processor 93, and digital filtering may be performed.

[0112] FIG. 23 is a diagram showing an example of the configuration of a receiving-side digital signal processing unit 93 that employs optical phase modulation. When optical phase modulation is employed, the receiving-side digital signal processing unit 93 includes, as shown in FIG. 23, a resampling unit 931, a digital filter unit 846, a clock extraction unit 932, a phase demodulation unit 940 that converts one modulation symbol into two signal points and converts them into one communication service data, and an error correction decoding unit 938. The phase demodulation unit 940 may perform differential decoding processing. The receiving-side digital signal processing unit 93 converts a modulated signal consisting of a digital signal into one communication service data. The digital signal is output from a balanced photodetector 823. Note that error correction decoding may be performed on one communication service data, and digital processing such as a digital filter, frequency estimation, phase estimation, and signal degradation compensation such as adaptive equalization may also be performed. In addition, before the error correction decoding unit 938, there may be a deinterleaver unit (not shown) that performs the reverse operation of the bit data rearrangement on the communication service data that has been processed by an interleaver unit (not shown) to rearrange the order of the bit data.

[0113] 24 is a diagram showing a detailed block configuration example of a second embodiment of an optical receiver 82 that employs optical phase modulation. For example, the second embodiment of the optical receiver 82 that employs optical phase modulation includes, as shown in FIG. 24, an optical delay interference unit 824, a balanced photodetector 823, an electric filter unit 822, a digital-to-analog conversion unit 870, and a receiving-side digital signal processing unit 93. The optical receiver 82 does not necessarily need to include at least one of the electric filter unit 822 and the analog-to-digital conversion unit 870.

[0114] The optical delay interference unit 824 interferes with the low-noise amplified optical modulated signal. The interfered optical modulated signal is detected by a balanced photodetector 823 and converted into an electric signal. The electric signal is then converted into a digital signal by an analog-to-digital conversion unit 870. The function of the electric filter unit 822 may be incorporated into the receiving-side digital signal processing unit 93, and digital filtering may be performed. Furthermore, a deinterleaver unit (not shown) may be provided before the error correction decoding unit 938 to reverse the bit data shuffling process on communication service data that has been shuffled in an interleaver unit (not shown).

[0115] Next, information regarding the control line transmitted and received between the optical space communication management device 1, the wireless ground station 4, the optical ground station 3, and the non-terrestrial node group will be described with reference to Fig. 25. Fig. 25 is a diagram showing an example of a sequence for explaining the optical space communication management function according to this embodiment. In the figure, dotted lines indicate communication via a wireless control line such as radio waves, and solid lines indicate communication via a control line such as a wired or wireless LAN.

[0116] As shown in Figure 25, the wireless ground station 4 receives a service request based on communication service data from a group of non-terrestrial nodes via a wireless control line such as radio waves (S1-1), and transmits the received service request to the optical space communication management device 1 via a control line such as a wired or wireless LAN (S2).

[0117] When a service request from a non-terrestrial node group is transmitted together with communication service data, it is received by the optical ground station 3 via an optical line (S1-2). The communication service processing unit 23 of the optical free space communications device 2 of the optical ground station 3 transmits the service request of the optical ground station 3 to the optical free space communications management device 1 via a control line such as a wired or wireless LAN based on the communication service data from the terrestrial network, which includes a mobile communications network of a business company connected to the cloud or the like and an optical backbone communications network, and if there is also a service request from the non-terrestrial node group received by the optical ground station 3, the service request from the non-terrestrial node group is also transmitted (S3).

[0118] In addition, the non-terrestrial node group transmits line measurement information to the wireless ground station 4 via a wireless control line such as radio waves (S4-1), and the wireless ground station 4 transmits the line measurement information to the optical space communication management device 1 via a control line such as a wired or wireless LAN (S5).

[0119] When a service request from a non-terrestrial node group is transmitted together with communication service data, it is received by the optical ground station 3 via an optical line (S4-2). The optical ground station 3 transmits its line measurement information to the optical free space communications management device 1 via a control line such as a wired or wireless LAN, and if the optical ground station 3 has received line measurement information from the non-terrestrial node group, it also transmits the line measurement information from the non-terrestrial node group (S6). Furthermore, when the optical free space communications management device 1 is connected to the environmental weather information collection device 8, the environmental weather information collection device 8 transmits environmental weather information (S10) in addition to transmitting the line measurement information (S5, S6).

[0120] Next, the optical space communications management device 1 transmits the line route information and line parameters of the optical ground station 3 for transmitting and receiving communication service data based on the service request, line measurement information, and environmental weather information to the optical ground station 3 via a control line such as a wired or wireless LAN, and when transmitting the line route information and line parameters from the non-terrestrial node group together with the communication service data, it transmits the line route information and line parameters from the non-terrestrial node group to the optical ground station 3 (S7).When transmitting the line route information and line parameters from the non-terrestrial node group together with the communication service data, it transmits the line route information and line parameters from the non-terrestrial node group from the optical ground station 3 to the non-terrestrial node group via the optical line (S9-1).

[0121] The optical space communication management device 1 also transmits line path information and line parameters for transmitting and receiving communication service data based on the service request and line measurement information to the wireless ground station 4 via a control line such as a wired or wireless LAN (S8).The wireless ground station 4 transmits the line path information and line parameters to the non-terrestrial node group via a wireless control line such as radio waves (S9-2).

[0122] Next, details of the line information will be explained using FIG. 26. FIG. 26 is a diagram showing examples of the line route information database DB1, line measurement information database DB2, service request information database DB3, and line parameter information database DB4 according to this embodiment. The line route information database DB1 includes, for example, a line route information table TB1 and an optical signal route information table TB2. The line measurement information database DB2 includes, for example, a frequency fluctuation information table TB3, a power fluctuation information table TB4, and a phase fluctuation information table TB5. The service request information database DB3 includes a service request table TB6. The line parameter information database DB4 includes an optical signal parameter table TB7-1 and a high-power optical amplifier parameter table TB8-1. Note that when the aforementioned Nyquist frequency division multiplexing method or orthogonal frequency division multiplexing method is used, the line parameter information database DB4 includes an optical signal / subcarrier signal parameter table TB7-2 and a high-power optical amplifier parameter table TB8-2.

[0123] The line route information table TB1 stores route information for each line. The line route information table TB1 stores a line number, which is a number for each line, a transmitting optical free space communications device number, a transmitting optical free space communications device type, a receiving optical free space communications device number, a receiving optical free space communications device type, a propagation delay, and an optical signal number, all of which are associated with each other. The line route information stored in the line route information table TB2 is not limited to this.

[0124] The transmitting optical free space communications device number is the number of the optical free space communications device 2 that transmits the optical modulated signal handled by the line, and the transmitting optical free space communications device type is the type of the optical free space communications device 2 that transmits the optical modulated signal handled by the line. The receiving optical free space communications device number is the number of the optical free space communications device 2 that receives the optical modulated signal handled by the line, and the receiving optical free space communications device type is the type of the optical free space communications device 2 that receives the optical modulated signal handled by the line. The propagation delay indicates how many seconds propagation in the line is delayed, and the optical signal number is the number of the optical modulated signal transmitted and received via the line. The propagation delay may be the end-to-end time delay on the network.

[0125] The optical signal path information table TB2 records path information for each optical modulated signal. For each optical modulated signal, the optical signal number, the transmitting optical free space communications device number, the receiving optical free space communications device number, and the relay optical free space communications device number are stored in association with each other. The relay optical free space communications device number is the number of the optical free space communications device 2 that relays the optical modulated signal as it passes through the ground or a satellite. However, the optical signal path information stored in the optical signal path information table TB2 is not limited to this.

[0126] The frequency fluctuation information table TB3 stores information on fluctuations in the frequency of the optical modulated signal transmitted by the optical space communications device 2 for each line and for each time. The frequency fluctuation information table TB3 stores a line number, which is the number for each line, time information, which is time information, the transmitting side frequency fluctuation speed, the transmitting side frequency fluctuation start value, and the transmitting side frequency fluctuation amount, all linked together. However, the frequency fluctuation information stored in the frequency fluctuation information table TB3 is not limited to this.

[0127] The fluctuation rate is the amount of change per second in the frequency of the optically modulated signal. The fluctuation rate is in units such as Hz / second. The start value is the frequency value of the optically modulated signal when the optically modulated signal is transmitted. The start value is in units such as Hz. The fluctuation amount is the amount of change in the frequency of the optically modulated signal. The fluctuation amount is in units such as Hz.

[0128] The power fluctuation information table TB4 stores information on the output of the optical modulation signal transmitted by the optical space communications device 2 for each line. The power fluctuation information table TB4 stores a line number, which is the number for each line, time information, which is time information, a scintillation index, an optical signal-to-noise ratio, and a signal-to-noise ratio, all of which are linked together. The power fluctuation information stored in the power fluctuation information table TB4 is not limited to this.

[0129] The scintillation index indicates the normalized variance of the received optical power in the line, and indicates the degree of atmospheric turbulence in ground-to-satellite optical communications. The optical signal-to-noise ratio (OSNR) is the optical signal-to-noise ratio of the optically modulated signal in the line, and the signal-to-noise ratio (SNR) is the signal-to-noise ratio of the electrical signal in the line. The optical signal-to-noise ratio and signal-to-noise ratio are expressed in dB.

[0130] The phase fluctuation information table TB5 stores information on the phase dispersion value of the optical modulated signal transmitted by the optical space communications device 2 for each line and for each time. The phase fluctuation information table TB5 stores a line number, which is the number for each line, time information, which is information on the time, and the phase dispersion value of the optical modulated signal, all linked together. Furthermore, the phase fluctuation information stored in the phase fluctuation information table TB5 is not limited to this.

[0131] The service request table TB6 stores service requests for each service. The service request table TB6 stores, in association with one another, a service number, which is a number for each service, a service type, a transmitting side optical free space communications device number, a receiving side optical free space communications device number, a desired communication rate, an allowable delay time, an allowable bit error rate (BER), and whether or not encryption is required. The service request table TB6 may also contain an allowable packet error rate (PER), an allowable system margin, an allowable throughput, and the like. The service request information stored in the service request table TB6 is not limited to this.

[0132] The transmitting optical space communications device number is the number of the optical space communications device 2 that transmits the service. The receiving optical space communications device number is the number of the optical space communications device 2 that is the destination of the service. The desired communication rate is the communication rate required for the service, and is expressed in Gbit / s.

[0133] The allowable delay time is the delay time allowed for the service, measured in seconds. The bit error rate is the bit error rate allowed for the service. The packet error rate is the packet error rate allowed for the service. The allowable system margin is the system margin allowed for the service, and the allowable throughput is the throughput allowed for the service. The encryption requirement indicates whether encryption is required for the service.

[0134] The optical signal parameter table TB7-1 stores parameters for each optical modulated signal. The optical signal parameter table TB7-1 stores, in association with each other, an optical signal number, a service number, a transmission wavelength, a communication rate, a symbol rate, a modulation method, a multi-level number, an error correction code type, a coding rate, a repetition rate of the error correction code, whether encryption is performed, and whether polarization multiplexing is performed. However, the information on the optical signal parameters stored in the optical signal parameter table TB7-1 is not limited to this.

[0135] The optical signal number is the optical signal number assigned to each optical modulation signal. The transmission wavelength is the wavelength of the optical modulation signal to be transmitted, measured in nm. The communication rate is the communication rate of the optical modulation signal, measured in Gbit / s.

[0136] The symbol rate is the modulation speed per unit time of the optically modulated signal, measured in gigabits per second. The modulation method is a digital signal processing method for the digital information contained in the optically modulated signal, such as M-PSK (Multilevel-Phase Shift Keying), M-QAM (Multilevel-Quadrature Amplitude Modulation), OOK (On-Off Keying), M-PAM (Multilevel-Pulse Amplitude Modulation), M-PPM (Multilevel-Pulse Position Modulation), and M-PAPM (Multilevel-Pulse Amplitude Position Modulation). The number of multilevels is the number of multilevels used in multilevel modulation of the digital information contained in the optically modulated signal.

[0137] The error correction code type indicates the type of error correction code of the communication service data contained in the optical modulated signal. The coding rate is the coding rate of the error correction code of the communication service data contained in the optical modulated signal. The number of repetitions is the number of repetitions of the error correction code. The presence or absence of encryption indicates whether the communication service data contained in the optical modulated signal is encrypted or not. The presence or absence of polarization multiplexing indicates whether the optical modulated signal is polarization multiplexed or not.

[0138] The optical transmission system parameter table TB8-1 stores parameters for each high-power optical amplifier 92. The high-power optical amplifier parameter table TB8-1 stores, in association with each other, the transmitted optical free space communications device number, transmitted optical output, transmitted wavelength, optical signal number, optical signal power ratio, and beam divergence angle for each high-power optical amplifier 92. The transmitted optical output is the output of the high-power optical amplifier 92, measured in watts. The optical signal power ratio is the ratio of the optical output power of the optical modulated signal to the overall optical power of the wavelength-multiplexed optical modulated signal multiplexed at multiple wavelengths after the high-power optical amplifier 92. The beam divergence angle is the beam divergence angle on the transmitting side of the optical unit 21.

[0139] When the aforementioned Nyquist frequency division multiplexing method or orthogonal frequency division multiplexing method is used, the optical signal / subcarrier signal parameter table TB7-2 stores parameters for each optical modulation signal. The optical signal / subcarrier signal parameter table TB7-2 stores, in association with each other, the optical signal number, subcarrier signal number, service number, transmission wavelength, subcarrier signal frequency allocation information, communication rate, symbol rate, modulation method, multi-level number, error correction code type, coding rate, error correction code repetition rate, encryption enable / disable, subcarrier signal power ratio, and polarization multiplexing enable / disable.

[0140] The optical signal number is the optical signal number assigned to each optical modulated signal. The subcarrier signal number is the number of the subcarrier modulated signal in the digital frequency domain included in the optical modulated signal. The service number is the number assigned to each service. The transmission wavelength is the wavelength of the optical modulated signal to be transmitted, expressed in nm. The frequency allocation information of the subcarrier signal is the frequency allocation information of the subcarrier modulated signal in the digital frequency domain. The communication rate is the communication rate of the subcarrier modulated signal, expressed in Gbit / s.

[0141] The symbol rate is the modulation speed per unit time of the subcarrier modulation signal, measured in gigabits per second. The modulation method is the digital modulation method for the digital information contained in the subcarrier modulation signal, such as M-PSK (Multilevel-Phase Shift Keying), M-QAM (Multilevel-Quadrature Amplitude Modulation), OOK (On-Off Keying), M-PAM (Multilevel-Pulse Amplitude Modulation), M-PPM (Multilevel-Pulse Position Modulation), and M-PAPM (Multilevel-Pulse Amplitude Position Modulation). The number of multilevels is the number of multilevels used in multilevel modulation of the digital information contained in the subcarrier modulation signal.

[0142] The error correction code type indicates the type of error correction code for the communication service data contained in the subcarrier modulated signal. The coding rate is the coding rate of the error correction code for the communication service data contained in the subcarrier modulated signal. The number of repetitions is the number of repetitions of the error correction code. The encryption status indicates whether the communication service data contained in the subcarrier modulated signal is encrypted or not. The subcarrier signal power ratio is the power ratio of the subcarrier modulated signal to the total power of multiple subcarrier modulated signals contained in the optical modulated signal. The polarization multiplexing status indicates whether the subcarrier modulated signal is polarization multiplexed or not.

[0143] The optical transmission system parameter table TB8-2 stores parameters for each high-power optical amplifier 92. The high-power optical amplifier parameter table TB8-2 stores, in association with each other, the transmitted optical free space communications device number, transmitted optical output power, transmitted wavelength, optical signal number, optical signal power ratio, subcarrier signal number, and beam divergence angle for each high-power optical amplifier 92. The transmitted optical output power is the output of the high-power optical amplifier 92, and is expressed in watts. The beam divergence angle is the beam divergence angle on the transmitting side of the optical unit 21.

[0144] Next, details of the location information will be explained using Fig. 27. Fig. 27 is a diagram showing an example of the location information database DB5 according to this embodiment. The location information database DB5 includes, for example, a satellite orbit parameter table TB9, an airborne object movement parameter table TB10, a satellite / airborne object location information table TB11, and an optical free space communications device information table TB12.

[0145] Parameters related to the non-terrestrial node group are stored in a satellite orbit parameter table TB9 and an airborne object movement parameter table TB10. The position calculation unit 13 of the optical free space communications management device in Figure 2 calculates position information from the satellite orbit parameter table TB9 and the airborne object movement parameter table TB10. The calculated position information may be stored in a position information database as a satellite / airborne object position information table TB11.

[0146] The satellite orbit parameter table TB9 stores satellite orbit parameters for each geostationary orbit satellite 5 and low-earth orbit satellite 6. The satellite orbit parameter table TB9 stores the satellite number, which is the number of the geostationary orbit satellite 5 or low-earth orbit satellite 6, the orbital inclination (°), the right ascension of the ascending node (°), the eccentricity, the mean argument of anomaly (°), the mean anomaly angle (°), the mean motion (number of rotations per day), and the number of orbital revolutions in an epoch, all linked together. These satellite orbit parameters are based on, for example, two-line orbital element (TLE) format, which is a text format of Keplerian orbital elements in the geocentric coordinate system of the artificial satellite, or GPS data acquired by a GPS receiver (not shown) mounted on the satellite. However, the satellite orbit parameter information stored in the satellite orbit parameter table TB9 is not limited to this.

[0147] The flying object movement parameter table TB10 stores movement parameters for each flying object 7. The flying object movement parameter table TB10 stores the flying object number, which is the number of the flying object 7, longitude (°), latitude (°), horizontal speed (m / s), ascent speed (m / s), altitude (m), movement direction vector, and trajectory form. These flying object movement parameters are based on, for example, GPS data acquired by a GPS receiver (not shown) mounted on the flying object. However, the information on the flying object movement parameters stored in the flying object movement parameter table TB10 is not limited to this.

[0148] The satellite and airborne object position information table TB11 stores position information for each geostationary orbit satellite 5, low-earth orbit satellite 6, and airborne object 7 by time. The satellite and airborne object position information table TB11 stores the satellite and airborne object number, which is the number of the geostationary orbit satellite 5, low-earth orbit satellite 6, and airborne object 7, the type of satellite and airborne object, time, X-coordinate position, Y-coordinate position, Z-coordinate position, movement speed (m / s), and movement direction vector, all linked together. The type refers to the type of medium, such as a low-earth orbit satellite, a geostationary orbit satellite, or an airborne object. However, the satellite and airborne object position information stored in the satellite and airborne object position information table TB11 is not limited to this.

[0149] The optical free space communications device information table TB12 stores the optical free space communications device number and optical free space communications device type as information held by the optical free space communications device for each satellite / aircraft number. The optical free space communications device number is the number of the optical free space communications device 2 that transmits the optical modulated signal handled by the line. The optical free space communications device type is the type of the optical free space communications device 2 that transmits the optical modulated signal handled by the line. However, the information on the optical free space communications devices stored in the optical free space communications device information table TB12 is not limited to this.

[0150] Next, the processing procedure of the optical space communication management function performed by the optical space communication management device 1 will be described with reference to Fig. 28. Fig. 28 is an example of a flowchart showing the processing procedure of the optical space communication management function according to this embodiment. The line parameter calculation unit 10 determines whether or not the line parameter calculation unit 10 has received a service request (S11).

[0151] The line information communication unit 14 stores the received service request in the service request table TB6. If it is determined that the line parameter calculation unit 10 did not refer to a new service request in the service request table TB6 (S11: NO), the line parameter calculation unit 10 temporarily terminates and then restarts to execute step S11.

[0152] If it is determined that the line parameter calculation unit 10 has referenced a new service request from the service request table TB6 (S11: YES), the line measurement unit 11 acquires line measurement information from the radio earth station 4 via the line information communication unit (S12). The line measurement unit 11 stores the acquired line measurement information in a frequency fluctuation information table TB3, a power fluctuation information table TB4, and a phase fluctuation information table TB5.

[0153] Next, the line parameter calculation unit 10 acquires position information for each of the geostationary orbit satellites 5, low earth orbit satellites 6, and airborne object 7, calculated by the position calculation unit 13 from the information stored in the satellite orbit parameter table TB9, airborne object movement parameter table TB10, satellite / airborne object position information table TB11, and optical free space communications device information table TB12 (S13). The line parameter calculation unit 10 may also acquire environmental information and weather information stored in the environmental information database DB6 and weather information database DB7, respectively.

[0154] Next, the line parameter calculation unit 10 determines a topology indicating the position of each node of the non-terrestrial node group, such as the geostationary orbit satellite 5, the low-earth orbit satellite 6, the flying object 7, and the optical ground station 3, and the connection points of each node (S14). The geostationary orbit satellite 5, the low-earth orbit satellites 6A-6C, the flying objects 7A-7D, and the optical ground stations 3A-3D equipped with the optical space communications device 2 may also be called nodes 3A-3D, 5, 6A-6C, 7A-7D.

[0155] Next, the line parameter calculation unit 10 checks each communication service request to be transmitted (S15). Next, the line parameter calculation unit 10 calculates line route information and line parameters by line parameter calculation processing S20, which will be described later. The line parameter calculation unit 10 transmits the calculated line route information and line parameters to the line control unit 12, and the line control unit 12 performs line control based on the calculated line parameters (S16). The line parameter calculation unit 10 stores the line route information in line route information table TB1 and optical signal route information table TB2, and the line parameters in optical signal parameter table TB7-1 and high-power optical amplifier parameter table TB8-1. When the above-mentioned Nyquist frequency division multiplexing method or orthogonal frequency division multiplexing method is used, the line parameter calculation unit 10 stores the line route information in line route information table TB1 and optical signal route information table TB2, and the line parameters in optical signal / subcarrier signal parameter table TB7-2 and high-power optical amplifier parameter table TB8-2.

[0156] Next, the line parameters will be described in detail using Fig. 29. Fig. 29 is an example of a flowchart showing the processing steps of line parameter calculation processing S20 according to this embodiment. The line path information and line parameters are calculated by the line parameter calculation unit 10 based on the location information calculated by the location calculation unit 13, and the line measurement information stored in the service request table TB6, the line path information table TB1, the frequency fluctuation information table TB3, and the power fluctuation information table TB4. The line path information and line parameters may also be calculated by the line parameter calculation unit 10 based on the location information calculated by the location calculation unit 13, the line measurement information stored in the service request table TB6, the line path information table TB1, the frequency fluctuation information table TB3, and the power fluctuation information table TB4, and the environmental information and weather information stored in the environmental information database DB6 and the weather information database DB7, respectively. When updating the line path information and line parameters, the line path information stored in the line path information database DB1 before the update and the line parameters stored in the line parameter information database DB4 may be used.

[0157] The line parameter calculation unit 10 records the calculated line route information and line parameters in, for example, the optical signal parameter table TB7-1, the high-power optical amplifier parameter table TB8-1, the line route information table TB1, and the optical signal route information table TB2. When the above-mentioned Nyquist frequency division multiplexing method or the orthogonal frequency division multiplexing method is used, the line parameter calculation unit 10 records the calculated line route information and line parameters in, for example, the optical signal / subcarrier signal parameter table TB7-2, the high-power optical amplifier parameter table TB8-2, the line route information table TB1, and the optical signal route information table TB2.

[0158] The line parameter calculation process S20 includes a priority order selection process S30 and an error correction code selection process S40. The priority order selection process S30 is a process for selecting a priority order of paths for each optically modulated signal based on the propagation delay time. The error correction code selection process S40 is a process for selecting an error correction code for each optically modulated signal and for selecting whether or not to encrypt each optically modulated signal. The priority order selection process S30 and the error correction code selection process S40 may be reversed.

[0159] First, the priority selection process S30 will be described. The line parameter calculation unit 10 determines whether the propagation delay time for the target service is shorter than a predetermined time (S31). Here, the predetermined time refers to a value corresponding to the allowable delay time in the service request, for example, in the service request table TB6. The propagation delay time is determined by referring to the propagation delay in the line path information table TB1, for example.

[0160] If it is determined that the propagation delay time is shorter than the predetermined time (S31: YES), a line between a geostationary orbit satellite 5 or a low-earth orbit satellite 6 will be selected. In this case, the line parameter calculation unit 10 determines whether the communication distance is shorter than a first predetermined distance (S32). Here, the communication distance is calculated by referring to the location information, and the first predetermined distance is calculated by referring to the service request.

[0161] If it is determined that the communication distance is shorter than the first predetermined distance (S32: YES), the line parameter calculation unit 10 selects a first priority order (S34). For example, the first priority order may be a line including a geostationary orbit satellite 5, a line including a low-orbit satellite 6 and having fewer relays than a predetermined number, a line including a geostationary orbit satellite 5 providing a service different from the target service, and a line including a low-orbit satellite 6 providing a service different from the target service and having fewer relays than a predetermined number.

[0162] If it is determined that the communication distance is equal to or greater than the first predetermined distance (S32: NO), the line parameter calculation unit 10 selects a second priority order (S35). For example, the second priority order may be in the order of a line including a low-earth orbit satellite 6 and having fewer relays than a predetermined number, a line including a geostationary orbit satellite 5, a line including a low-earth orbit satellite 6 providing a service different from the target service and having fewer relays than a predetermined number, and a line including a geostationary orbit satellite 5 providing a service different from the target service.

[0163] If it is determined that the propagation delay time is equal to or longer than the predetermined time (S31: NO), a line between the low-earth orbit satellite 6, the flying object 7, the optical ground station 3, etc. will be selected. In this case, the line parameter calculation unit 10 determines whether the communication distance is shorter than a second predetermined distance (S33). The second predetermined distance is calculated by referring to the service request.

[0164] If it is determined that the communication distance is shorter than the second predetermined distance (S33: YES), the line parameter calculation unit 10 selects a third priority order (S36). For example, the third priority order may be a line that includes a low-orbit satellite 6 and has a predetermined number of relays or more, a line that includes a low-orbit satellite 6 that provides a service different from the target service and has a predetermined number of relays or more, a line that includes an airborne vehicle 7, and a line that includes an airborne vehicle 7 that provides a service different from the target service.

[0165] If it is determined that the communication distance is equal to or greater than the second predetermined distance (S33: NO), the line parameter calculation unit 10 selects a fourth priority order (S37). For example, the fourth priority order may be in the following order: a line including an airborne vehicle 7, a line including an airborne vehicle 7 that provides a service different from the target service, a line including a low-earth orbit satellite 6 with a predetermined number of relays or more, and a line including a low-earth orbit satellite 6 that provides a service different from the target service. By determining the priority order, the line parameter calculation unit 10 determines line parameters corresponding to values ​​to be stored in the optical signal routing information table TB2.

[0166] Next, the error correction code selection process S40 will be explained. The line parameter calculation unit 10 determines whether the propagation delay time for the target service is shorter than a predetermined time (S41). Here, the predetermined time refers to a value corresponding to the allowable delay time in the service request, for example, in the service request table TB6. The propagation delay time is determined by referring to the propagation delay in the line path information table TB1, for example.

[0167] If it is determined that the propagation delay time is shorter than the predetermined time (S41: YES), a line between a geostationary orbit satellite 5 or a low-earth orbit satellite 6 is selected. In this case, the line parameter calculation unit 10 determines whether the request for the allowable bit error rate is smaller than a first predetermined value (S42). The first predetermined value refers to a value corresponding to the allowable bit error rate in the service request, for example, in the service request table TB6. The request for the allowable bit error rate is, for example, linked one-to-one with the service, and is determined when the service type is decided.

[0168] If it is determined that the required allowable bit error rate is smaller than the first predetermined value (S42: YES), the line parameter calculation unit 10 selects a first error correction code (S44). For example, the first error correction code is an error correction code with high reliability and a high coding rate, such as a low density parity-check code with a high number of repetitions and a high coding rate.

[0169] If it is determined that the required allowable bit error rate is equal to or greater than the first predetermined value (S42: NO), the line parameter calculation unit 10 selects a second error correction code (S45). For example, the second error correction code is a highly reliable error correction code with a low coding rate, such as a low density parity check code (LDPC) with a small number of repetitions and a low coding rate.

[0170] If it is determined that the propagation delay time is equal to or longer than a predetermined time (S41: NO), a line between the low-earth orbit satellite 6, the flying object 7, the optical ground station 3, etc. will be selected. In this case, the line parameter calculation unit 10 determines whether the request for the allowable bit error rate is smaller than a second predetermined value (S43). The second predetermined value indicates a value corresponding to the allowable bit error rate in the service request, for example, in the service request table TB6.

[0171] If it is determined that the required allowable bit error rate is smaller than the second predetermined value (S43: YES), the line parameter calculation unit 10 selects a third error correction code (S46). For example, the third error correction code is an error correction code with little processing delay and a high coding rate, such as a polar code with little processing delay and high error correction capability.

[0172] If it is determined that the required allowable bit error rate is equal to or greater than the second predetermined value (S43: NO), the line parameter calculation unit 10 selects a fourth error correction code (S47). For example, the fourth error correction code may be an error correction code with low processing delay and a low coding rate, such as a Reed-Solomon code (RS) with low processing delay and low error correction capability. By selecting the error correction code, the line parameter calculation unit 10 determines the line parameters corresponding to the values ​​stored in the error correction code type field of the optical signal parameter table TB7-1. Although not shown in the flowchart of FIG. 29, a process for selecting no error correction code may also be performed. Note that although the allowable bit error rate is given as an example, the determination may also be based on the allowable packet error rate (PER), allowable system margin, allowable throughput, etc.

[0173] Next, the line parameter calculation unit 10 determines whether or not confidential communication is required for the target service (S48). If it is determined that confidential communication is required (S48: YES), the line parameter calculation unit 10 performs encryption for the service (S49), and the line parameter calculation process S20 ends.

[0174] If it is determined that confidential communication is not necessary (S48: NO), the line parameter calculation process S20 ends. Note that the line parameter calculation unit 10 determines whether to encrypt or not, and thereby determines the line parameters corresponding to the values ​​stored in the encryption / non-encryption field of the optical signal parameter table TB7-1.

[0175] The flowchart showing the processing procedure of the optical space communication management function according to this embodiment explained using Figure 28 and the flowchart showing the processing procedure of the line parameter calculation process S20 according to this embodiment explained using Figure 29 are examples and are not limited to these.

[0176] Next, the effects of this embodiment will be described with reference to Fig. 30. Fig. 30 is an example diagram used to explain the effects of this embodiment. For example, route 111 shown by the dotted arrow is a route used for transmitting low-capacity, low-latency information, and is used for a service in which optically modulated signals are transmitted and received over long distances at a low communication rate with low latency over a line including a low-earth orbit satellite.

[0177] The route 112 shown by the dashed arrow is a route used for transmitting large volumes of information such as video content and satellite-acquired images, and is used for services in which optically modulated signals are transmitted and received at high speeds, in multiple values, over short distances via lines including low-orbit satellites.

[0178] The route 113 shown by the solid arrow is a route used for transmitting information such as IoT (Internet of Things), which has low latency requirements, and is used for services that use wavelength division multiplexing and transmit and receive optically modulated signals over a line including a geostationary orbit satellite 5.

[0179] The route 114 shown with a diagonal arrow is a route used for transmitting large amounts of information that require low latency, and is used for services in which optically modulated signals are transmitted and received over short distances at high communication rates using lines including an ultra-low latency flying object 7.

[0180] In this manner, in this embodiment, a line is selected according to the service based on the line parameters. Furthermore, two optically modulated signals, the optically modulated signal on path 111 and the optically modulated signal on path 112, are transmitted from node 3D to node 6C as a single combined optically modulated signal, and therefore multiplexed in the optical domain. Furthermore, one optically modulated signal transmitted from node 3C to node 5 contains two pieces of digital information, and is multiplexed in the digital domain.

[0181] As described above, the optical space communication management device 1 in this embodiment can control across layers without dividing into layers, and transmit information via an appropriate communication network. Note that in this embodiment, even when there is only one node, it is possible to control the timing of transmitting an optical modulation signal.

[0182] Furthermore, the optical space communication management device 1 in this embodiment is capable of calculating line parameters and line route information based on environmental information and weather information as well as line measurement information and service requests, and therefore can realize an optical space communication management device that can perform appropriate routing and transmit optically modulated signals to a satellite optical communication network, such as site diversity, which selects a line with an optical ground station depending on the environment and weather.

[0183] In the above description, optical space communication nodes on the ground, on air vehicles in the sky, in low orbit, and in geostationary orbit are given as examples, but this embodiment is not limited to these and may also be applied to optical space communication in outer space, including the sky and outer space such as medium orbit, transfer orbit, near the moon, and deep space.

[0184] In the above description, optical space communication nodes of various circuit types on the ground, on airborne vehicles, low orbit, and geostationary orbit have been described as examples, but this embodiment is not limited to this and may be applied to satellite optical communication networks of various circuit types in the sky or outer space, such as on the ground, on airborne vehicles, low orbit, geostationary orbit, medium orbit, transfer orbit, near the moon, deep space, etc., operated by multiple satellite communication operators.

[0185] In the above description, nodes in optical communications between satellites or between terrestrial satellites have been described as examples, but the present embodiment is not limited to this and may be applied to optical communications in terrestrial mobile bodies such as automobiles and trains, or optical space communications stations, or may be applied to indoor optical communications stations or mobile bodies, or may be applied to optical communications in surface mobile bodies such as ships, underwater mobile bodies, or undersea mobile bodies.

[0186] The above description deals with the case where the line parameter calculation unit 10, line measurement unit 11, line control unit 12, position calculation unit 13, service request collection unit 17, wireless communication unit 20, optical space communication device control unit 22, communication service processing unit 23, wireless ground station wireless communication unit 41, wireless ground station communication unit 42, wireless ground station control unit 43, geostationary orbit satellite control unit 51, low orbit satellite control unit 61, and flying object control unit 71, communication service processing unit 201, etc. are electronic circuits configured with electronic devices that can be mounted on-board, such as an FPGA (Field Programmable Gated Array) or a CPU (Central Processing Unit), but the present embodiment is not limited to this.

[0187] For example, the line parameter calculation unit 10, line measurement unit 11, line control unit 12, position calculation unit 13, service request collection unit 17, wireless communication unit 20, optical space communication device control unit 22, communication service processing unit 23, wireless ground station wireless communication unit 41, wireless ground station communication unit 42, wireless ground station control unit 43, geostationary orbit satellite control unit 51, low orbit satellite control unit 61, and flying object control unit 71, communication service processing unit 201, etc. may be configured as programs or protocols recorded in RAM (Random Access Memory) that are called by a CPU (Central Processing Unit). [Explanation of symbols]

[0188] 1 Optical space communication management device 2 Optical space communication device 3 Optical ground station 4 Radio Ground Station 5 Geostationary orbit satellite 6 Low orbit satellite 7 Projectile 8. Environmental weather information collection device 10 Line parameter calculation unit 11 Line Measurement Section 12 Line control section 13 Position calculation section 14 Line Information and Communications Department 17 Service Request Collection Unit 20 Radio Communication Department 21 Optics Department 22 Optical space communication device control section 23 Communication Service Processing Unit 31 Optical ground station control unit 32 Optical Ground Station Communications Unit 41 Radio Ground Station Radio Communication Section 42 Radio Ground Station Communications Department 43 Radio Ground Station Control Unit 51 Geostationary Orbit Satellite Control Unit 52 Geostationary orbit satellite communications department 61 Low Earth Orbit Satellite Control Unit 62 Low Earth Orbit Satellite Communication Department 71 Projectile control unit 72 Airborne Communications Department 81 Optical transmitter 82 Optical receiver 83 Optical Amplifier 84 Transmitting side digital signal processing unit 85 I-phase digital-to-analog converter 86 Transmitting light source 87 Q-phase digital-to-analog converter 88 I-phase optical modulator 89 Optical branching section 90 Q-phase optical modulator 91 Light convergence section 92 High-power optical amplifier 93 Receiving side digital signal processing unit 94 I-phase analog-to-digital converter 95 Q-phase analog-to-digital converter 96 I-phase balanced photodetector 97 Local light source 98 Q-phase balanced photodetector 99 Optical frequency mixing section 100 Low noise optical amplifier 101 Optical multiplexer / demultiplexer 102 Multiplexing section 103 Demultiplexer Routes 111-114 121 Optical Modulator 122 Coherent light detector 131 Phase shift section 201 Communication Service Processing Unit 202 Optical communication unit 205 Terminal control unit 206 Terminal Communication Device 801 Environmental Information Collection Department 802 Weather Information Collection Department 821 Photoelectric Converter 822 Electrical filter section 823 Balanced Photodetector 824 Optical Delay Interference Unit 841 Error correction coding unit 842 Multi-level modulation section 843 Resampler 844 Nyquist filter section 845 Modulator nonlinear compensation section 846 Digital filter section 847 Frequency conversion unit 848 Power Allocation Unit 849 Subcarrier Multiplexing Unit 850 Inverse frequency conversion section 851 CP addition part 852 Phase modulation section 870 Digital to Analog Converter 900 Optical Intensity Modulator 901 Optical Phase Modulator 931 Resampler 932 Clock Extraction Unit 933 Matched filter section 934 Adaptive Equalization Unit 935 Frequency Estimation Unit 936 Phase estimation section 937 Multi-level demodulation section 938 Error Correction Decoding Unit 939 Frequency conversion unit 940 Phase demodulation section 941 Inverse frequency conversion unit 944 CP removal section 945 Subcarrier Separation Unit DB1 Line Route Information Database DB2 line measurement information database DB3 service request information database DB4 Line parameter information database DB5 Location Database DB6 Environmental Information Database DB7 Weather Information Database TB1 Line Route Information Table TB2 Optical signal route information table TB3 Frequency Fluctuation Information Table TB4 Power Fluctuation Information Table TB5 Phase Variation Information Table TB6 Service Request Table TB7-1 Optical Signal Parameter Table TB7-2 Optical Signal and Subcarrier Signal Parameter Table TB8-1 High Power Optical Amplifier Parameter Table TB8-2 High Power Optical Amplifier Parameter Table TB9 Satellite Orbit Parameter Table TB10 Projectile Movement Parameter Table TB11 Missile Position Information Table TB12 Optical Space Communication Device Information Table

Claims

1. An optical space communication management device that performs line control based on line path information and line parameters for transmitting and receiving communication service data based on service requests for multiple lines and line measurement information for multiple lines received from at least one of the satellites and flying objects of a non-terrestrial node group and the optical ground station, in an optical space communication device that performs optical space communication over one or more lines mounted on at least one of the satellites and flying objects of a non-terrestrial node group and the optical ground station, a line measurement unit that measures line measurement information including delay times of a plurality of lines between the optical space communications devices through which the communication service data is transmitted and received; a service request collection unit that collects the service requests indicating predetermined values ​​of the line; a position calculation unit that calculates position information of at least one of the satellite and the flying object; a line parameter calculation unit that calculates the line path information including the number of relays of the free space optical communication based on the position information calculated by the position calculation unit, the delay time measured by the line measurement unit, and a predetermined value of the service request collected by the service request collection unit, and calculates the line parameters indicating parameters of an optically modulated signal of the free space optical communication based on the predetermined value of the service request; a line control unit that performs line control on the optical space communications device based on the line path information and the line parameters calculated by the line parameter calculation unit; An optical space communication management device comprising: at least one of the satellites and the airborne vehicles of a non-terrestrial node group; the optical ground station; and a line information communication unit that communicates the service request, the line measurement information, the line path information, and the line parameters.

2. An optical free space communication system including an optical free space communication device that performs optical free space communication over one or more lines mounted on at least one of a satellite and an airborne vehicle of a non-terrestrial node group and an optical ground station, and an optical free space communication management device that performs line control based on line path information and line parameters for transmitting and receiving communication service data based on service requests for the multiple lines and line measurement information for the multiple lines received from the at least one of the satellite and the airborne vehicle of the non-terrestrial node group and the optical ground station, The optical space communication management device includes: a service request collection unit that collects the service requests indicating predetermined values ​​of the line; a line measurement unit that measures line measurement information including delay times of a plurality of lines between the optical space communications devices through which the communication service data is transmitted and received; a position calculation unit that calculates position information of at least one of the satellite and the flying object; a line parameter calculation unit that calculates the line path information including the number of relays of the free space optical communication based on the position information calculated by the position calculation unit, the delay time measured by the line measurement unit, and a predetermined value of the service request collected by the service request collection unit, and calculates the line parameters indicating parameters of an optically modulated signal of the free space optical communication based on the predetermined value of the service request; a line control unit that performs line control on the optical space communications device based on the line path information and the line parameters calculated by the line parameter calculation unit; a line information communication unit that communicates the service request, the line measurement information, the line path information, and the line parameters; and The optical space communications device is controlled by line control based on the line path information and the line parameters from the optical space communications management device, and transmits and receives an optical modulated signal including the communication service data. Optical space communication system.

3. The optical space communications device performs at least one of the following processes: transmitting the optical modulation signal for one wavelength based on one or more of the communication service data when performing frequency multiplexing processing in the digital domain in the digital signal processing in the optical communication unit of the optical space communications device; and receiving the one or more of the communication service data based on the optical modulation signal for one wavelength when performing frequency separation processing in the digital domain in the digital signal processing in the optical communication unit of the optical space communications device. The optical free space communication system according to claim 2 .

4. The optical space communications device performs at least one of the following processes: transmitting one wavelength-multiplexed optically modulated signal obtained by multiplexing the optically modulated signal of one wavelength based on one communication service data; and receiving one communication service data based on the optically modulated signal of one wavelength obtained by demultiplexing the one wavelength-multiplexed optically modulated signal into the optically modulated signals of multiple wavelengths. The optical free space communication system according to claim 2 .

5. The optical free space communications device performs at least one of the following processes when performing frequency multiplexing processing in the digital domain in digital signal processing in the optical communication unit of the optical free space communications device: transmitting one wavelength multiplexed optical modulated signal in which one wavelength of the optical modulated signal based on one or more of the communication service data is multiplexed with multiple wavelengths; and receiving one or more of the communication service data based on one wavelength of the optical modulated signal in frequency separation processing in the digital domain in digital signal processing in the optical communication unit of the optical free space communications device, in which one wavelength of the optical modulated signal is demultiplexed into optical modulated signals of multiple wavelengths. The optical free space communication system according to claim 2 .

6. an environmental information collecting unit that collects environmental information related to an environment in which at least one of the satellite and the air vehicle is located; and a weather information collecting unit that collects weather information related to a weather in which at least one of the satellite and the air vehicle is located; the line parameter calculation unit calculates the line path information and the line parameters based on the location information calculated by the location calculation unit, the service requests collected by the service request collection unit, the line measurement information measured by the line measurement unit, environmental information collected by the environmental information collection unit, and weather information collected by the weather information collection unit.

6. The optical space communication system according to claim 2.

7. An optical free space communication management method in an optical free space communication management device that performs optical free space communication over one or more lines mounted on at least one of a satellite and an airborne vehicle of a non-terrestrial node group and an optical ground station, the method performing line control based on line path information and line parameters for transmitting and receiving communication service data based on service requests over multiple lines and line measurement information over multiple lines received from at least one of the satellite and the airborne vehicle of a non-terrestrial node group and the optical ground station, a first step of measuring line measurement information including delay times of a plurality of lines between the optical space communications devices through which the communication service data is transmitted and received; a second step of collecting said service requests indicating predetermined values ​​of said lines; a third step of calculating position information of at least one of the satellite and the flying object; a fourth step of calculating the line path information including the number of relays of the free space optical communication based on the location information calculated in the third step, the delay time measured in the first step, and the predetermined value of the service request collected in the second step, and calculating the line parameters indicating parameters of the optical modulated signal of the free space optical communication based on the predetermined value of the service request; a fifth step of performing line control on the optical space communications device based on the line path information and the line parameters calculated in the fourth step; a sixth step of communicating the service request, the line measurement information, the line path information, and the line parameters between at least one of the satellite and the airborne vehicle of the non-terrestrial node group and the optical ground station; Optical space communication management method.

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