Communication system, communication path control device, communication service provision method, and program

Abstract

To estimate the time when observation data of a satellite station become available.SOLUTION: A communication system comprises: an acquisition part which acquires communication path information capable of identifying a part of a communication path associated with a satellite, wherein the communication path from the satellite distributing observation data to a user of the observation data includes a ground station corresponding to the satellite and a ground system network connecting with the ground station; and a computation processing part which computes the time when the observation data of the satellite is provided for the user by the use of the communication path based upon the response in the case of the use of the communication path corresponding to the communication path information.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a communication system, a communication path control device, a communication service providing method, and a program. [Background technology]

[0002] Satellite constellations (mega-constellations) formed using multiple small satellites (artificial satellites) are increasing. Each small satellite captures or acquires high-resolution images as observation data (mission data, etc.) and distributes the observation data during its flight. The amount of observation data held by such small satellites, and the associated amount of communication data, are increasing.

[0003] In order to provide observation data held by satellites to users U in various locations, the following communication paths (1) to (4) are generally used.

[0004] (1) Satellite → (2) Ground station → (3) Ground network → (4) User U

[0005] An IP network (e.g., a packet network such as the Internet) may be used as such a terrestrial network. By using this IP network, the user U can obtain observation data at a desired location. On the other hand, it is difficult to predict the time it will take to complete the transfer of the observation data, and it is sometimes impossible to predict when the user U will be able to use the observation data.

[0006] In the above circumstances, it was necessary for a user U to be able to identify when observation data becomes available. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] International Publication No. 2018 / 142539 Summary of the Invention [Problem to be solved by the invention]

[0008] However, in the case of the technology of Patent Document 1, although the knowledge of the transmission path from the satellite station to the ground station that minimizes the time required to complete data transmission when data is sent from the satellite station to the ground station is shown, the knowledge does not include the terrestrial network, which makes it difficult to estimate the time when the observation data from the satellite station becomes available.

[0009] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide a communication system, a communication path control device, a communication service providing method, and a program that can solve the above-mentioned problems. [Means for solving the problem]

[0010] According to a first aspect of the invention, a communication system includes a communication path from a satellite that distributes observation data to a user of the observation data, which includes a ground station corresponding to the satellite and a ground network connected to the ground station, and is equipped with an acquisition unit that acquires communication path information capable of identifying a portion of the communication path to the satellite, and a calculation processing unit that calculates the time it takes to provide the satellite's observation data to the user using the communication path, based on responsiveness when the communication path corresponding to the communication path information is used.

[0011] According to a second aspect of the invention, a communication path control device includes a communication path from a satellite that distributes observation data to a user of the observation data, which includes a ground station corresponding to the satellite and a ground network connected to the ground station, and is equipped with an acquisition unit that acquires communication path information capable of identifying a portion of the communication path to the satellite, and a calculation processing unit that calculates a time required for providing the satellite's observation data to the user using the communication path based on responsiveness when the communication path corresponding to the communication path information is used.

[0012] According to a third aspect of the invention, a communication service providing method includes a communication path from a satellite that distributes observation data to a user of the observation data, which includes a ground station corresponding to the satellite and a ground network connected to the ground station, and includes a step of acquiring communication path information capable of identifying a portion of the communication path to the satellite, and calculating a time required for providing the observation data of the satellite to the user using the communication path based on responsiveness when the communication path corresponding to the communication path information is used.

[0013] According to a fourth aspect of the invention, the program causes a computer to execute a process of: acquiring communication route information capable of identifying a portion of the communication route to the satellite; and calculating a time required for providing the observation data of the satellite to the user using the communication route based on responsiveness when the communication route corresponding to the communication route information is used, the communication route including a ground station corresponding to the satellite and a ground network connected to the ground station. Effect of the Invention

[0014] According to the present invention, it is possible to estimate the time when observation data from a satellite station will become available. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a diagram illustrating an example of a configuration of a communication system according to an embodiment. [Diagram 2] FIG. 2 is a diagram for explaining a mission processing system of the communication system 1 according to the embodiment. [Diagram 3] FIG. 2 is a diagram for explaining a mission processing system of the communication system 1 according to the embodiment. [Figure 4] 11 is a flowchart of a load information collection process by a routing control server 8 of the embodiment. [Diagram 5] 11 is a flowchart of an analysis process by the routing control server 8 of the embodiment. [Figure 6A]10 is a diagram for explaining a sequence of processing by the routing control server 8 of the embodiment. FIG. [Figure 6B] FIG. 6B is a diagram for explaining the distribution process of the observation data shown in FIG. 6A. [Figure 7A] FIG. 11 is a diagram for explaining a distribution process of observation data according to an embodiment. [Figure 7B] FIG. 11 is a diagram for explaining a distribution process of observation data according to an embodiment. [Figure 8A] FIG. 1 is a diagram for explaining generation of an observation plan according to an embodiment. [Figure 8B] FIG. 1 is a diagram for explaining generation of an observation plan according to an embodiment. [Figure 9] FIG. 13 is a diagram for explaining an application example of the embodiment. [Figure 10] 11 is a flowchart of a communication process according to an embodiment. [Figure 11] FIG. 2 is a schematic block diagram illustrating an example of the configuration of a computer according to the embodiment. [Figure 12] 1 is a diagram illustrating an example of the configuration of a communication path control device 100 according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] The following describes embodiments of the present invention, but the following embodiments do not limit the scope of the invention. Furthermore, not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention. Fig. 1 is a diagram showing an example of the configuration of a communication system according to an embodiment. In the configuration shown in Fig. 1, the communication system 1 includes a satellite station 2 that flies in an orbit and a geostationary orbit satellite station 3 that flies in a geostationary orbit. In the following description, the satellite station 2 and the geostationary orbit satellite station 3 may be collectively referred to as a "satellite."

[0017] The communication system 1 includes a wireless communication system from a satellite to a ground station 4, and a ground system GS that uses terrestrial communication lines. For example, the ground system GS in the communication system 1 includes a ground station 4, a control device 5, a planning server 6, a data processing server 7, and a route control server 8.

[0018] The ground station 4 includes a ground station 41 and a ground station 42. There may be a plurality of ground stations 41 and a plurality of ground stations 42. The ground stations 41A and 41B are an example of a plurality of ground stations 41. When there is no need to distinguish between the ground stations 41A and 41B, they may be collectively referred to as the ground station 41.

[0019] For example, the ground station 41 communicates with the satellite station 2. The ground station 41 transmits various commands to the satellite station 2. The ground station 41 receives predetermined mission information and the like from the satellite station 2 and distributes it to a relay station, which will be described later. The ground station 42 communicates with the geostationary orbit satellite station 3. The ground station 42 transmits various commands to the geostationary orbit satellite station 3. The ground station 42 receives signals from the geostationary orbit satellite station 3 and distributes predetermined mission information to a relay station, which will be described later.

[0020] The control device 5 communicates with the planning server 6 and the ground station 4. In response to instructions from the planning server 6, the control device 5 sends various commands addressed to the satellite to the ground station 4, and causes the ground station 4 to transmit various commands addressed to the satellite. The various commands mentioned above include information such as a plan to have the satellite transmit observation data, in addition to controlling the operation of the satellite. The control device 5 of the embodiment transmits various commands addressed to the satellite station 2 via, for example, the ground station 41. The control device 5 transmits various commands addressed to the geostationary orbit satellite station 3 via the ground station 42.

[0021] The planning server 6 communicates with the control device 5, the data processing server 7, the route control server 8, and the terminal device 9. The planning server 6 creates a plan for executing a mission based on a request from a user U obtained from the terminal device 9 or the like. The planning server 6 holds and manages basic information on resources available in the communication system 1. For example, the planning server 6 holds information on the configuration of the ground system GS, available communication lines, connection destinations, and the like (connection destination information). The planning server 6 sends information on available resources to the data processing server 7 or the like, and causes communication to be performed using the resources.

[0022] The planning server 6 receives a request from the user U via the terminal device 9 used by the user U, and based on the request, collects information for making a plan for executing the mission. The planning server 6 instructs the route control server 8 to collect information for planning the mission execution, and acquires route information generated by the route control server 8. The planning server 6 creates a plan for the mission execution based on this route information, notifies the control device 5 of the plan information of the plan, and causes the control device 5 to generate a command addressed to the satellite.

[0023] The data processing server 7 is an example of a relay station. The data processing server 7 acquires observation data (mission data) from the ground station 4 using a ground communication line, and provides the observation data as a product to the terminal device 9 of the user U. The data processing server 7 may be configured by dividing it into relay devices 71, 72, 73, etc. The relay devices 71, 72, 73 each perform the above-mentioned processing in parallel. The relay devices 71, 72, 73 may be configured in the same way, or may be changed depending on the processing load. In the following explanation, the relay device 71 is illustrated, but the explanation of the relay device 71 may be referred to for the relay devices 72 and 73.

[0024] The route control server 8 controls the communication route for collecting observation data from satellites via the ground station 4, the network NW which is a ground-based communication line, and the data processing server 7.

[0025] The terminal device 9 is an information and communication device such as a so-called personal computer, a tablet terminal device, etc. The terminal device 9 accepts an operation by the user U and transmits information corresponding to the operation.

[0026] 2 and 3 are diagrams for explaining a mission processing system of the communication system 1 according to the embodiment. The ground station 4 includes an antenna 401, a modulation / demodulation unit 402, an antenna control unit 403, a reception processing unit 404, a storage unit 405, a distribution processing unit 406, a communication processing unit 407, a station control unit 409, a command / telemeter communication processing unit 410, and a station control unit 411. Each of the above configurations shows an example of a general configuration, and the present invention is not limited to this.

[0027] The command and telemetry communication processing unit 410 executes processing to send commands to the satellite station 2 and acquire telemetry data (observation data) in response to a request from the control device 5. The satellite station 2 receives commands according to a plan that specifies the execution of imaging and generates observation data.

[0028] In response to a request from the control device 5, the station control unit 411 performs processing related to control of the ground station 4 regarding satellite operation processing.

[0029] The ground station 4 of the embodiment further includes a load test control unit 420 . The load test control unit 420 performs a process for testing the load of the communication line for delivering the mission information in response to a request from the route control server 8. The details will be described later. Note that the storage unit 405 may be provided with an area for holding data 405D for the load test.

[0030] The planning server 6 is a computer including a CPU capable of executing a program, a semiconductor memory, and the like. For example, the planning server 6 includes a control unit 61, an interface unit 64, and a storage unit 67. The planning server 6 executes the main processing of the planning server 6 by causing the control unit 61 (CPU) to execute a program, and stores the results of the processing in the storage unit 67. The interface unit 64 is communicably connected to an external device. The control unit 61 communicates with the external device via the interface unit 64 through its processing. In the following description, the processing by the control unit 61 may be described as the processing by the planning server 6. For example, the planning server 6 (request processing unit) may acquire and output the time for providing the satellite observation data to the user via the communication path in response to a request from the user of the satellite observation data.

[0031] The route control server 8 (communication route control device) is a computer including a CPU capable of executing a program, a semiconductor memory, and the like. For example, the route control server 8 includes a control unit 81, an interface unit 84, and a storage unit 87. The route control server 8 executes the main processing of the route control server 8 by causing the control unit 81 (CPU) to execute a program, and stores the processing results in the storage unit 87. The interface unit 84 is communicably connected to an external device. The control unit 81 communicates with the external device via the interface unit 84 through its processing. In the following description, the processing by the control unit 81 may be described as the processing of the route control server 8.

[0032] For example, the interface unit 84 (acquisition unit) acquires communication path information from the planning server 6 that indicates that the communication path from the satellite that distributes the observation data to the user of the observation data includes a ground station 4 corresponding to the satellite and a network NW (terrestrial network) connected to the ground station 4, and that this information can identify a portion of the communication path to the satellite. The control unit 81 (arithmetic processing unit) calculates the time required to provide satellite observation data to a user using a communication path, based on the responsiveness when a communication path corresponding to the communication path information is used.

[0033] The control unit 81 performs a responsiveness test to detect responsiveness when communication is performed using a communication path corresponding to the communication path information. Using the result of the responsiveness test, the control unit 81 calculates the time required to provide the satellite observation data to the user using the communication path. The control unit 81 may calculate the time required to provide satellite observation data to a user using the communication path based on the communication path information identifying the ground station 4 and the results of the response test identifying the ground station 4. The control unit 81 may detect the responsiveness by detecting the communication load status on the communication path corresponding to the communication path information. The control unit 81 may test the responsiveness of the network NW from the data processing server 7 (responsiveness test unit) to the ground station 4 by applying a predetermined communication load to the communication path. The control unit 81 may use a model indicating the responsiveness when a communication path corresponding to the communication path information is used to calculate the time required to provide satellite observation data to a user using the communication path. The above will now be described in more detail.

[0034] The relay device 71 of the data processing server 7 includes a communication processing unit 701, a collection processing unit 702, a memory unit 703, a high-order processing unit 704, a memory unit 705, a distribution processing unit 706, a communication processing unit 707, and a relay control unit 709. Each of the above configurations shows an example, and the present invention is not limited to this. The data processing server 7 of the embodiment further includes a load test control unit 720.

[0035] For example, the communication processing unit 701 is connected to a network NW. The communication processing unit 701 communicates with the communication processing unit 407 of the ground station 4 via the network NW. When the configuration within the data processing server 7 described below is configured to enable parallel processing, the communication processing unit 701 may perform processing for load distribution.

[0036] The collection processing unit 702 communicates with the distribution processing unit 406 of the ground station 4, receives information from the distribution processing unit 406, and stores the information in the storage unit 703. This storage unit 703 includes a semiconductor memory, a magnetic recording device, etc., and is used as a buffer for temporarily storing the received information, etc.

[0037] The high-order processing unit 704 performs high-order processing on the mission information stored in the storage unit 703, and stores the results in the storage unit 705. This storage unit 705 includes a semiconductor memory, a magnetic recording device, etc., and is used as a buffer for temporarily storing the results of the high-order processing, etc.

[0038] The distribution processing unit 706 distributes the results of the high-level processing stored in the storage unit 705 to the terminal device 9 via the communication processing unit 707 .

[0039] The relay control unit 709 communicates with the station control unit 409 of the ground station 4 and monitors the status of command and telemetry processing in the ground station 4. The relay control unit 709 allocates resources in the relay device 71 according to instructions from the planning server 6. The relay control unit 709 monitors the operation status of the collection processing unit 702, memory unit 703, high-order processing unit 704, memory unit 705, and distribution processing unit 706 to collect the load status. For example, this load status includes the CPU operation rate, memory usage, and the standby status of processing scheduled to be executed.

[0040] In response to a request from the routing control server 8 , the load test control unit 720 notifies the routing control server 8 of the load status of the relay device 71 collected by the relay control unit 709 .

[0041] Next, the transfer time required to deliver the observation data held by the satellite station 2 to the terminal device 9 of the user U is divided into the following items, and a communication route that minimizes the total time is considered.

[0042] (1) T1: Time from when the satellite station 2 communicates with either the ground station 41 or the geostationary orbit satellite station 3 until the transfer is completed (2) T2: Time from when the geostationary orbit satellite station 3 communicates with the ground station 42 until the transfer is completed (only when the geostationary orbit satellite station 3 is used). (3) T3: Processing time of ground station 4 (4) T4: Time required for transmission from ground station 4 to the relay station (including time for regenerating the signal from ground station 4) (5) T5: Processing time of relay station (6) T6: Time required for transfer from the relay station to the terminal device 9 (communication device) of user U

[0043] These issues will be discussed below. The time estimation method for "item (1)" and "item (2)" may be derived using a known method as appropriate. This time T1 includes the time it takes for the satellite station 2 to fly into a specified area and become able to communicate with the ground station 4 or the geostationary orbit satellite station 3. For example, if no time is allocated to communication with the ground station 4 even after reaching that area, the time until allocation at the next orbit, etc. will be included here.

[0044] “Item (3) Processing time (T3) of ground station 4” includes the following times: (3-1) The time required for the process of converting information from the satellite station 2 into information that can be distributed to the relay station. For example, observation data (images) from satellite station 2 are distributed after being adapted to the characteristics of the network NW from ground station 4 to the relay station. The image conversion process involved in this includes image division processing, image encoding processing, etc. If the image data distributed from satellite station 2 can be transferred to the relay station as is, this processing may be omitted.

[0045] (3-2) The time required for the process of converting information to be delivered to a relay station into a form that matches the characteristics of the transmission path. For example, this includes processing to add information for detecting errors or packet loss during transmission, or information for compensating for these on the receiving side, before transmission.

[0046] "Item (4) Time required for transmission from ground station 4 to relay station (T4)" includes the following times: For example, it corresponds to the time required for processing from the start of processing in response to a communication processing request until reception is completed. This time includes the time required for retransmission control (layer 4 of the OSI reference model, TCP layer, etc.), routing (layer 3 of the OSI reference model, IP layer, etc.), link establishment control (layer 2 of the OSI reference model, MAC layer, etc.) at both the ground station 4 and the relay station. The above transfer time includes a transmission delay time due to the length of the transmission path from the ground station 4 to the relay station. Note that the transfer time increases as the length of the transmission path increases.

[0047] "Item (5) Relay station processing time (T5)" includes the following times: (5-1) The time required for the process of converting information extracted from the signal received from the ground station 4 into information that can be distributed to the terminal device 9 of the user U. For example, this corresponds to the processing in (3-1) above, and includes information decryption processing. More specific examples in the case where the information is an image include image compounding, synthesis of divided images, etc. If the image data distributed from the ground station 4 can be used as the image to be distributed as is, this process may be omitted.

[0048] (5-2) The time required for the process of converting information to be distributed to a relay station into a form that matches the characteristics of the transmission path. For example, this includes processing to add information for detecting errors or packet loss during transmission, or information for compensating for these on the receiving side, before transmission.

[0049] "Item (6) Transfer time (T6) from the relay station to the terminal device 9 of the user U includes the following times: For example, it corresponds to the time required for processing from the start of processing in response to a communication processing request until reception is completed.

[0050] In the application exemplified in this embodiment, it is preferable to use communication services with lower latency and wider bandwidth, and therefore it is advisable to implement communication control based on the required quality level of the network to be used.

[0051] (Relationship between transmission distance and available transmission bandwidth) Protocols suitable for ensuring the reliability of communication services include those that recover from communication errors, packet loss, and other problems by retransmission. TCP is an example of such a protocol. FTP, which also uses TCP, can achieve the same effect. In protocols that implement retransmission control, the receiving station sends a response to the communication request back to the sending station. In the case of TCP, the sending of the next packet is delayed until the response is detected. As the physical distance of the available transmission path increases, the transmission delay increases, and as a result, the RTT can become relatively long.

[0052] In this way, in the case of a usage pattern that requires both increasing reliability through retransmission control and reducing the time required for communication, there is a limit to how much these requirements can be met using a single communication channel.

[0053] (Broadband when using transmission lines with relatively long transmission distances) When the range that can be realized by a single communication channel is exceeded, it is a good idea to assign multiple communication channels to one communication service and use each communication channel in parallel. By applying TCP to each communication channel, it becomes possible to increase the apparent bandwidth of the communication that uses that transmission path according to the number of communication channels used.

[0054] (Priority Control) Priority levels that classify the quality levels of communication services may be assigned to the information to be distributed, and priority control may be implemented that determines the order of processing, the required quality of the network to be used, and so on, based on these priorities.

[0055] For example, the order of processing may be controlled by managing the order of reading from a buffer in which each data is stored, and when a high-priority process occurs, the read order may be adjusted so that the data is read first. To achieve this process, the read order from the buffer may be managed using a queue, and based on the priority information of the processes arranged in the queue, the order may be determined to be the order sorted when the queue is updated.

[0056] Also, for example, it is advisable to use a network that classifies the quality levels of communication services to reduce increases in communication delays.

[0057] The load information collection process by the routing control server 8 of the embodiment will be described with reference to Fig. 4 and Fig. 6A. Fig. 4 is a flowchart of the load information collection process by the routing control server 8 of the embodiment. Fig. 6A is a diagram for explaining the sequence of the process by the routing control server 8 of the embodiment.

[0058] The routing control server 8 performs each process from S12 to S18 below, and adds the results as time-series information to the storage unit 87. For example, the routing control server 8 repeats these processes at a predetermined cycle using a timer interrupt or the like.

[0059] First, the routing control server 8 detects the communication load status of the ground station 4 (S12). For example, the route control server 8 sends a packet (e.g., ping) to the ground station 4 to check the responsiveness of lower levels of the communication hierarchy, detects the response time, and identifies abnormal states such as a state in which communication is not possible or a state in which the response is abnormally slow. Furthermore, the routing control server 8 sends an inquiry packet to the ground station 4 to check the status of the waiting for distribution processing. In response to the request from the routing control server 8, the ground station 4 may respond to the routing control server 8 with the status of the waiting for distribution processing at the ground station 4 as the load status.

[0060] The routing control server 8 inquires of the data processing server 7 about the load status of the land line (S14). For example, the data processing server 7 receives a request from the route control server 8, requests the ground station 4 to transmit load test data 405D (a predetermined amount of data) in response to the request, and receives the load test data 405D from the ground station 4. The data processing server 7 detects the time required for this communication. The data processing server 7 may respond to the route control server 8 with the time required for the communication to obtain the load test data 405D as the load status of the ground line.

[0061] The routing control server 8 inquires of the data processing server 7 about the load status of the reception processing (S16). For example, some of the data processing servers 7 have receiving equipment such as a load balancer. If the receiving process from the ground station 4 is backed up due to some reason caused by the configuration of the data processing server 7, the situation can be shared with the route control server 8 to improve the accuracy of the analysis of the load situation of the receiving process. Therefore, the routing control server 8 may inquire of the data processing server 7 about the backlog of the reception process from the ground station 4 as the load status of the reception process. By sharing the backlog status of the reception process from the ground station 4 with the routing control server 8, the accuracy of the analysis can be improved. Note that if the above-mentioned receiving equipment is not installed, the processing of this step can be omitted.

[0062] The routing control server 8 inquires of the data processing server 7 about the load status of the conversion processing (S18). For example, some of the data processing servers 7 perform conversion processing on the data received from the ground station 4 so that the data can be distributed. If this conversion process is stalled for some reason, such as due to the configuration of the data processing server 7, then by sharing this situation with the route control server 8, it is possible to improve the accuracy of the analysis of the load status of the conversion process. Therefore, the routing control server 8 may inquire of the data processing server 7 about the backlog status of the conversion process for generating distribution data as the load status of the above conversion process. By sharing the backlog status of this conversion process with the routing control server 8, the accuracy of the analysis can be improved. Note that if the above conversion process is not being performed, the processing of this step can be omitted.

[0063] The routing control server 8 collects data on the load status through the above series of processes and stores it in the storage unit as time-series data. The routing control server 8 repeats these processes at a predetermined cycle, such as by a timer interrupt. The above-mentioned processes of S14, S16, and S18 may be carried out together as one process. The routing control server 8 may make an inquiry to the data processing server 7 for each relay device.

[0064] The analysis process by the routing control server 8 will be described with reference to Fig. 5 and Fig. 6A. Fig. 5 is a flowchart of the analysis process by the routing control server 8 of the embodiment. The routing control server 8 performs the following processes from S22 to S26 to analyze the time required to distribute the observation data.

[0065] The planning server 6 receives a request for information on the scheduled delivery time of the desired product from the terminal device 9, etc. In response to this, the planning server 6 requests the route control server 8 for route information for shortening the scheduled delivery time of the desired product. This "scheduled time to provide the desired product" refers to the estimated time from when the satellite 2 acquires observation data corresponding to the "desired product" until when this observation data is downlinked to one of the ground stations 4 and begins to be distributed to terminal devices 9, etc., using the network NW, which is a terrestrial line.

[0066] The route control server 8 receives a request for appropriate route information from the planning server 6 (S22).

[0067] The routing control server 8 acquires historical information on the load conditions of the ground stations 4, communication lines, data processing server 7, etc., and a standard value table including data on predetermined standard values ​​(S24).

[0068] The routing control server 8 calculates the time required for delivery based on the history information of the load status information, and derives a recommended route (S26). The routing control server 8 adds the result to the storage unit as time-series information.

[0069] As a result of the above analysis, the route control server 8 notifies the planning server 6 of route information on the recommended route (S28). Through the above processing, the route control server 8 can notify the planning server 6 of route information of a recommended route in response to a request from the planning server 6. The planning server 6 determines the route to be actually used based on the route information of the recommended route.

[0070] The distribution of observation data by satellite station 2 will be described with reference to Figures 6A and 6B. Figure 6B is a diagram for explaining the distribution process of the observation data shown in Figure 6A. The example shown here is one in which the ground station 41 is used as a communication path for the satellite station 2 to transmit observation data.

[0071] After the planning server 6 has determined the route to be actually used, it notifies each device of the distribution plan.

[0072] The planning server 6 notifies the control device 5 of the distribution plan (S32). The control device 5 acquires the distribution plan from the planning server 6, and notifies the acquired distribution plan to the ground station 4 (S34).

[0073] The ground station 4 notifies the satellite station 2 of the distribution plan (S38). The satellite station 2 acquires the distribution plan from the ground station 4, waits for distribution until the date and time of the acquired distribution plan arrives, and continues flying.

[0074] The planning server 6 notifies the data processing server 7 of the distribution plan (S36). The data processing server 7 acquires the distribution plan from the planning server 6, and adds the date and time according to the acquired distribution plan to the processing schedule.

[0075] At the scheduled date and time according to the distribution plan, the satellite station 2 starts transmitting the observation data to the ground station 4 (S42). The ground station 4 receives this observation data, and places the observation data that has been made deliverable in the storage unit 405. At the scheduled date and time according to the distribution plan, the data processing server 7 requests the ground station 4 to distribute observation data and acquires the observation data stored in the storage unit 405 (S52). The data processing server 7 stores the received observation data in the storage unit 77 and starts distribution to the terminal device 9 (S54). As a result, the terminal device 9 acquires the observation data.

[0076] The distribution of observation data by satellite station 2 will be described with reference to FIGS. 7A and 7B. 7A and 7B are diagrams for explaining the observation data distribution process according to the embodiment. The example shown here is one in which a geostationary orbit satellite station 3 and a ground station 42 are used as a communication path for a satellite station 2 to transmit observation data.

[0077] After the planning server 6 has determined the route to be actually used, it notifies each device of the distribution plan.

[0078] The planning server 6 notifies the control device 5 of the distribution plan (S32). The control device 5 acquires the distribution plan from the planning server 6, and notifies both the ground station 41 and the ground station 42 of the acquired distribution plan (S34).

[0079] The ground station 41 notifies the satellite station 2 of the distribution plan (S38A). The satellite station 2 acquires the distribution plan from the ground station 41, waits for distribution until the date and time of the acquired distribution plan arrives, and continues flying. The ground station 42 notifies the geostationary orbit satellite station 3 of the distribution plan (S38B). The geostationary orbit satellite station 3 acquires the distribution plan from the ground station 42, waits until the date and time of the acquired distribution plan arrives, and continues flying.

[0080] The planning server 6 notifies the data processing server 7 of the distribution plan (S36). The data processing server 7 acquires the distribution plan from the planning server 6, and adds the date and time according to the acquired distribution plan to the processing schedule. This distribution plan includes the use of the geostationary orbit satellite station 3 and the ground station 42.

[0081] At the scheduled date and time according to the distribution plan, the satellite station 2 starts transmitting the observation data to the geostationary orbit satellite station 3 (S42A). The geostationary orbit satellite station 3 receives the observation data from the satellite station 2 and waits. At the scheduled date and time according to the distribution plan, the geostationary orbit satellite station 3 starts transmitting the observation data to the ground station 42 (S44). The ground station 42 receives this observation data and stores the observation data that has been made available for distribution in the storage unit 405 . At the scheduled date and time according to the distribution plan, the data processing server 7 requests the ground station 42 to distribute observation data and acquires the observation data stored in the storage unit 405 (S52). The data processing server 7 stores the received observation data in the storage unit 77 and starts distribution to the terminal device 9 (S54). As a result, the terminal device 9 acquires the observation data.

[0082] A part of the generation of an observation plan according to the embodiment will be described with reference to FIGS. 8A and 8B. 8A and 8B are diagrams for explaining generation of an observation plan according to an embodiment. The table shown in Fig. 8A lists, for each candidate communication route, the time it takes for observation data from satellite station 2 to reach ground station 4. This table includes items such as conditions, satellite station identification information, geostationary orbit satellite station identification information, ground station identification information, processing server identification information, travel time, transmission speed and distance between the satellite station and ground station, and transmission speed and distance between satellite stations. A record in this table is created for each communication path under consideration. The "condition" is identification information for a communication path. The “satellite station identification information” and the “geostationary orbit satellite station identification information” are identification information for the satellite station 2 and the geostationary orbit satellite station 3 . “Ground station identification information” is identification information of the ground station 4 . The “processing server identification information” is identification information of the data processing server 7 . "Moving time" is the time it takes for satellite station 2 to move to a position where it can transmit observation data. The “transmission speed and distance between the satellite station and the ground station” is the transmission speed between the satellite station 2 and the ground station 41 and the distance from the ground station 41 to the data processing server 7 . The “transmission speed and distance between satellite stations” refers to the transmission speed between the satellite station 2 and the geostationary orbit satellite station 3 and the distance from the ground station 42 to the data processing server 7 .

[0083] Using the above table, the route control server 8 determines "time T1: time until satellite station 2 communicates with either the ground station 41 or the geostationary orbit satellite station 3 and completes transfer" and "time T2: time until geostationary orbit satellite station 3 communicates with the ground station 42 and completes transfer" based on the travel time required for satellite station 2 to move to a position where it can communicate with the ground station 41 or the geostationary orbit satellite station 3, the expected transmission speed for communication between satellite station 2 and ground station 41 or between satellite station 2 and geostationary orbit satellite station 3, and the volume of observation data.

[0084] The table shown in Fig. 8B lists the time required for relaying observation data distributed from the ground station 4 to the data processing server 7 for each candidate ground communication path. This table includes items such as conditions, the geographical distance between the ground station and the processing server, the load status of the WAN line, and the standby time for parallel processing. A record in this table is created for each terrestrial communication path under consideration.

[0085] The "condition" is identification information for a terrestrial communication path. "Geographical distance between ground station and processing server and load status of WAN line" refers to the geographical distance between the ground station 4 and the data processing server 7 and the load status of the WAN line (network NW) used for communication between the ground station 4 and the data processing server 7. The "parallel processing waiting time" is the time that the relay device 71 and the like constituting the data processing server 7 wait for the start of parallel processing.

[0086] The route control server 8 uses the above table to calculate the expected time for communication from the ground station 4 to the data processing server 7 and for processing by the data processing server 7 for each communication route set for comparison. For example, the route control server 8 calculates the time required for communication for some or all of the communication routes set for comparison. The route control server 8 may predetermine the transmission speed between satellites, the transmission speed between the satellite and the ground, the processing capacity of the data processing server 7 (data registration load), and a margin time modeling the delay in communication processing as fixed values ​​and store them in a table.

[0087] An application example of the embodiment will be described with reference to FIG. FIG. 9 is a diagram for explaining an application example of the embodiment.

[0088] A part of the orbit of satellite station 2 is modeled and drawn in the vertical direction of Figure 9. Satellite station 2 flies along its orbit from the top to the bottom of the page. Earth stations 41A and 41B exist near this orbit. Earth station 41A and earth station 41B are far away from each other, and it takes time for satellite station 2 to move between the respective earth stations. The data processing server 7 is located relatively close to the ground station 41B, and is located far from the ground station 41A due to the above relationship.

[0089] First, a comparison will be made between sending observation data from the satellite station 2 to the data processing server 7 via the ground station 41A and sending it to the data processing server 7 via the ground station 41B.

[0090] A time chart is shown on the right side of Figure 9. The starting point of the horizontal axis is set at the time when the satellite station 2 starts transmitting observation data to the ground station 41 A. Each arrow indicates a communication process.

[0091] The upper time chart is an example in which ground station 41A is used. In the upper part, arrows are drawn in order for times T1, T3, T4, T5, and T6. Time T4 is the time from when ground station 41A receives the observation data to when it transmits it to data processing server 7. The sum of times T1, T3, T4, T5, and T6 is the time it takes to transmit the observation data of satellite station 2 to data processing server 7 via ground station 41A.

[0092] The middle time chart is an example in which ground station 41B is used. In the middle section, arrows of times T1a, T3a, T4a, T5a, and T6a are drawn in order. The time from when the ground station 41B receives the observation data to when it sends it to the data processing server 7 is time T4a. Note that it takes time for the satellite station 2 to approach the ground station 41B, so the starting point of the arrow of time T1a is delayed compared to the upper section. The sum of times T1a, T3a, T4a, T5a, and T6a is the time when the observation data of the satellite station 2 is sent to the data processing server 7 via the ground station 41B. Adding the time when the satellite station 2 approaches the ground station 41B to the above times is the time when the observation data of the satellite station 2 is sent to the data processing server 7 via the ground station 41B from a given point in time.

[0093] Comparing the times in the upper and middle rows, no significant differences are apparent apart from the delay in the start of communication due to the "time it takes to approach ground station 41B" mentioned above, and the difference in length between time T4 in the upper row and time T4a in the middle row.

[0094] As shown in this figure, if the length of time T4 in the upper row is longer than the sum of the "time until approaching ground station 41B" and time T4a in the middle row, by using ground station 41B, the time until the data processing server 7 receives the observation data will be shortened even if the satellite station 2 starts to transmit the observation data late.

[0095] Furthermore, this orbit is located above a geostationary orbit satellite station 3. When satellite station 2 approaches geostationary orbit satellite station 3, communication becomes possible.

[0096] The lower time chart is an example in which a geostationary orbit satellite station 3 and a ground station 42 are used. In the lower row, arrows are drawn in order for times T1b, T2b, T3b, T4b, T5b, and T6b. Time T1b when satellite station 2 transmits observation data to geostationary orbit satellite station 3 and time T2b when geostationary orbit satellite station 3 transmits observation data to ground station 42 are different from the case where ground stations 41A and 41B are used. If the times from time T3b when ground station 42 receives and transmits the observation data are not significantly different from time T3a in the middle row, then the length obtained by adding together time T1b and time T2b will be different from time T1a in the middle row.

[0097] The communication speed at which the geostationary orbit satellite station 3 sends observation data to the ground station 42 is slower than the communication speed at which the satellite station 2 sends observation data to the ground station 41B. Therefore, in a simple comparison, using the geostationary orbit satellite station 3, which requires time T2b, is at a disadvantage. However, if ground stations 41A and 41B are reserved for use, they cannot be used even if they approach during flight, and must wait until the next orbit.

[0098] In contrast, if observation data can be sent to the geostationary orbit satellite station 3, the geostationary orbit satellite station 3 will appear to be stationary in a position where it can always communicate with the ground station 42. Therefore, unlike the satellite station 2, if communication with the ground station 42 becomes possible, the geostationary orbit satellite station 3 will be able to communicate with the ground station 42 without having to wait for an orbital period. Therefore, even if a communication route includes a communication route with an increased number of relay stages or a communication route with a relatively slow communication speed, it may be effective if the conditions of the other communication routes are not favorable.

[0099] The route control server 8 may notify the planning server 6 of all the communication routes compared and considered as described above as route information, or alternatively, may notify several routes with relatively short communication times.

[0100] According to this embodiment, the communication path between the satellite and the ground station 4 is determined by taking into consideration the state of the ground system GS. For example, even if the communication route between the satellite and the ground station 4 is optimal, if the communication time in the range of the terrestrial system GS is long, other conditions may result in an optimal communication route. Therefore, in this embodiment, the state of the terrestrial system GS is included in the conditions for consideration, so that the optimal communication route can be selected even in the above-mentioned case.

[0101] By using this routing control server 8, the accuracy of estimating the time when the user U will acquire the observation data is improved. By mechanizing the execution of this estimation process using the routing control server 8, it is possible to quantify the time without relying on human experience.

[0102] In addition, when obtaining observation data from each satellite station 2 of a satellite constellation (megaconstellation), processing is required more frequently. However, as described above, the execution of the processing is mechanized by using the route control server 8, making it possible to meet such requests.

[0103] Second embodiment A second embodiment will be described with reference to FIGS. In the second embodiment, a case will be described in which processing similar to that in the first embodiment is performed by processing using a processor such as a CPU and a program.

[0104] FIG. 10 is a flowchart of a communication process according to the embodiment. In addition, when the control unit 81 including the acquisition unit and the calculation processing unit of the embodiment is implemented in a computer, for example, the computer shown in Fig. 11 can be applied. This will be described later.

[0105] The above-mentioned FIG. 11 also serves as a schematic block diagram showing an example of the configuration of a computer according to at least one embodiment. In the configuration shown in FIG. 11, a computer 800 includes a CPU 810, a main memory device 820, an auxiliary memory device 830, an interface 840, and a non-volatile recording medium 850.

[0106] The route control server 8, the computer of the ground station 4, the planning server 6, the data processing server 7, or a part thereof of the communication system 1 may be implemented in the computer 800. In this case, the operation of each of the above-mentioned processing units is stored in the auxiliary storage device 830 in the form of a program. The CPU 810 reads the program from the auxiliary storage device 830, develops it in the main storage device 820, and executes the above-mentioned processing according to the program. The CPU 810 also secures a storage area corresponding to each of the above-mentioned storage units in the main storage device 820 according to the program. Communication between each device and other devices is executed by the interface 840 having a communication function and performing communication according to the control of the CPU 810. The interface 840 also has a port for the non-volatile recording medium 850, and reads information from the non-volatile recording medium 850 and writes information to the non-volatile recording medium 850.

[0107] For example, when the routing control server 8 is implemented in a computer 800, the operations of each part of the control unit 81, including the acquisition unit and the calculation processing unit, are stored in the form of a program in the auxiliary storage device 830. The CPU 810 reads the program from the auxiliary storage device 830, loads it in the main storage device 820, and executes the above-mentioned processing according to the program. Furthermore, the CPU 810 reserves a memory area in the main memory device 820 in accordance with the program. Communications with other devices such as the computer of the ground station 4, the planning server 6, the data processing server 7, etc. are performed by the interface 840, which has a communication function and operates under the control of the CPU 810.

[0108] When the computer of the ground station 4 is implemented in the computer 800, the operation of each unit of the ground station 4 is stored in the form of a program in the auxiliary storage device 830. The CPU 810 reads the program from the auxiliary storage device 830, loads it into the main storage device 820, and executes the above-mentioned processing according to the program. Furthermore, the CPU 810 reserves a memory area in the main memory device 820 in accordance with the program. Communications with other devices such as the control device 5, the data processing server 7, and the route control server 8 are performed by the interface 840 having a communication function and operating under the control of the CPU 810.

[0109] When the planning server 6 is implemented in the computer 800, the operation of each part of the planning server 6 is stored in the form of a program in the auxiliary storage device 830. The CPU 810 reads the program from the auxiliary storage device 830, loads it into the main storage device 820, and executes the above-mentioned processing according to the program. Furthermore, the CPU 810 reserves a memory area in the main memory device 820 in accordance with the program. Communications with other devices such as the data processing server 7, the route control server 8, and the terminal device 9 are performed by an interface 840 having a communication function and operating under the control of the CPU 810.

[0110] When the data processing server 7 is implemented in the computer 800, the operation of each part of the data processing server 7 is stored in the form of a program in the auxiliary storage device 830. The CPU 810 reads the program from the auxiliary storage device 830, loads it in the main storage device 820, and executes the above-mentioned processing according to the program. Furthermore, the CPU 810 reserves a memory area in the main memory device 820 in accordance with the program. Communications with other devices such as the computer in the ground station 4, the planning server 6, the route control server 8, and the terminal device 9 are performed by the interface 840 having a communication function and operating under the control of the CPU 810.

[0111] Any one or more of the above-mentioned programs may be recorded in the non-volatile recording medium 850. In this case, the interface 840 may read the program from the non-volatile recording medium 850. Then, the CPU 810 may directly execute the program read by the interface 840, or may temporarily store the program in the main storage device 820 or the auxiliary storage device 830 and execute it.

[0112] It should be noted that a program for executing all or part of the processing performed by any of the computers in the communication system 1 may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read into a computer system and executed to perform processing of each part. Note that the term "computer system" as used herein includes the OS (Operating System) and hardware such as peripheral devices. Furthermore, the term "computer-readable recording medium" refers to portable media such as flexible disks, optical magnetic disks, ROMs (Read Only Memory), and CD-ROMs (Compact Disc Read Only Memory), as well as storage devices such as hard disks built into computer systems. The above-mentioned program may be for realizing part of the above-mentioned functions, or may be capable of realizing the above-mentioned functions in combination with a program already recorded in the computer system.

[0113] Although an embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and designs that do not deviate from the gist of the present invention are also included.

[0114] As described in the above embodiment, the communication system 1 includes a calculation processing unit 110 and an acquisition unit 140. The acquisition unit 140 acquires communication path information that identifies a part of the communication path from a satellite that distributes observation data to a user of the observation data, the communication path including a ground station corresponding to the satellite and a ground network connected to the ground station. The calculation processing unit 110 calculates the time required to provide the observation data of the satellite to the user by using the communication path, based on the responsiveness when the communication path corresponding to the communication path information is used. This allows the communication system 1 to estimate the time when the observation data of the satellite station will be available.

[0115] 12 is a diagram showing an example of the configuration of the communication path control device 100 according to the embodiment. In the configuration shown in FIG. The acquisition unit 140 acquires communication path information that identifies a part of the communication path from a satellite that distributes observation data to a user of the observation data, the communication path including a ground station corresponding to the satellite and a ground network connected to the ground station. The calculation processing unit 110 calculates the time required to provide the observation data of the satellite to the user using the communication path based on the responsiveness when the communication path corresponding to the communication path information is used. This enables the communication path control device 100 to estimate the time when the observation data from the satellite station will become available. [Explanation of symbols]

[0116] 1. Communication Systems 2 satellite stations 3 Geostationary orbit satellite station 4, 41, 41A, 41B, 42 ground station 5 Control equipment 6 Planning Server 7 Data Processing Server 8 Routing Server 9 Terminal Equipment 71, 71, 73 Relay device 420, 720 Load test control section

Claims

1. an acquisition unit that acquires communication path information that can identify a part of the communication path from a satellite that distributes observation data to a user of the observation data, the communication path including a ground station corresponding to the satellite and a ground network connected to the ground station; and a processing unit that calculates a time required for providing the satellite observation data to a user using a communication route corresponding to the communication route information, based on a responsiveness when the communication route is used; A communication system comprising:

2. The arithmetic processing unit is A response test is carried out to detect the response when communication is performed using a communication path corresponding to the communication path information, and a result of the response test is used to calculate a time required for providing the satellite observation data to a user using the communication path. The communication system according to claim 1 .

3. The arithmetic processing unit is Based on the communication route information that identifies the ground station and the result of the response test that identifies the ground station, a time required for providing the observation data of the satellite to a user using the communication route is calculated. The communication system according to claim 2 .

4. The arithmetic processing unit is The responsiveness is detected by detecting a communication load state in a communication path corresponding to the communication path information. The communication system according to claim 2 .

5. The arithmetic processing unit is A predetermined communication load is applied to the communication path to test the response of the ground network from a response test unit to the ground station. The communication system according to claim 2 .

6. The arithmetic processing unit is Using a model indicating the responsiveness when a communication route corresponding to the communication route information is used, a time required for providing the observation data of the satellite to a user using the communication route is calculated. The communication system according to claim 1 .

7. a request processing unit that, in response to a request from a user of the observation data of the satellite, acquires and outputs a time period during which the observation data of the satellite is to be provided to the user using the communication path; The communication system of claim 1 .

8. an acquisition unit that acquires communication path information that can identify a part of the communication path from a satellite that distributes observation data to a user of the observation data, the communication path including a ground station corresponding to the satellite and a ground network connected to the ground station; and a processing unit that calculates a time required for providing the satellite observation data to a user using a communication route corresponding to the communication route information, based on a responsiveness when the communication route is used; A communication path control device comprising:

9. A communication path from a satellite that distributes observation data to a user of the observation data includes a ground station corresponding to the satellite and a ground network connected to the ground station, and communication path information capable of identifying a part of the communication path across the satellite is acquired; A process of calculating a time required for providing the satellite observation data to a user using the communication route based on a responsiveness when the communication route corresponding to the communication route information is used. A method for providing a communication service comprising:

10. On the computer, A communication path from a satellite that distributes observation data to a user of the observation data includes a ground station corresponding to the satellite and a ground network connected to the ground station, and communication path information capable of identifying a part of the communication path across the satellite is acquired; A process of calculating a time required for providing the satellite observation data to a user using the communication route based on a responsiveness when the communication route corresponding to the communication route information is used. A program for executing the above.

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