Communication control apparatus, communication control system, first terminal, communication control method, and communication control program

Abstract

The present invention comprises: an allocation unit that refers to the maximum communication capacity which can be provided by a relay device for communication with a first terminal and the maximum communication capacity which can be provided by the relay device for communication with a second terminal and that allocates communication resources of the relay device which are used in the communication of the relay device with the first terminal and with the second terminal; and a setting unit that sets the communication resources.

Description

Communication control device, communication control system, first terminal, communication control method, communication control program

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

[0002] Techniques for efficiently using communication resources are known. For example, Patent Document 1 discloses a method for switching the operation mode of a communication device having an antenna assembly including a plurality of antennas. In this method, a process of switching to an operation mode that provides a larger bandwidth for a specific coverage area or switching to an operation mode that provides higher reliability is disclosed.

[0003] Japanese Patent Translation of PCT International Publication No. 2023-548735

[0004] In the method described in Patent Document 1, an operation mode that takes into account both the communication capacity of a terminal performing uplink (hereinafter also referred to as "UL") communication and the communication capacity of a terminal performing downlink (hereinafter also referred to as "DL") communication is not disclosed. Therefore, in the method described in Patent Document 1, when the communication capacity of a terminal performing UL communication is different from the communication capacity of a terminal performing DL communication, there is a problem that communication resources cannot be efficiently allocated.

[0005] For example, assume a case where two terminals communicate in a private network via a relay device, and communication resources corresponding to the communication capacity are allocated to the relay device for each of the two terminals.

[0006] In this case, when the communication capacity of the terminal performing UL communication is larger than the communication capacity of the terminal performing DL communication, the amount of data that needs to be buffered in the relay device increases. Also, there is an upper limit to the buffering capacity in the relay device, and if the buffering capacity becomes large and exceeds the upper limit, relaying becomes impossible, resulting in a decrease in throughput or an increase in delay time.

[0007] On the other hand, if the communication capacity of a communication terminal performing DL communication is greater than that of a communication terminal performing UL communication, then excessive communication resources will be allocated to the relay device for the communication terminal performing DL communication.

[0008] This disclosure has been made in view of the above-mentioned issues, and one exemplary purpose thereof is to provide a technology for efficiently allocating communication resources.

[0009] A communication control device relating to an exemplary aspect of the present disclosure includes: allocation means for allocating communication resources of the relay device to be used by the relay device in communication with the first terminal and the second terminal, respectively, with reference to the maximum communication capacity that the relay device can provide in communication with a first terminal and the maximum communication capacity that the relay device can provide in communication with a second terminal; and setting means for setting the communication resources.

[0010] An exemplary aspect of the present disclosure is a communication control system comprising: a first terminal; and a communication control device that controls communication between a second terminal and a relay device that relays communication between the first terminal, the second terminal, and the first terminal and the second terminal, wherein the communication control device refers to the maximum communication capacity that the relay device can provide in communication with the first terminal and the maximum communication capacity that the relay device can provide in communication with the second terminal, and allocates the communication resources of the relay device that the relay device uses in communication with the first terminal and the second terminal, respectively. The means includes: a determination means that refers to the communication resources and determines the communication settings for communication between the first terminal and the relay device and the communication settings for communication between the second terminal and the relay device; and an instruction means that instructs the first terminal and the second terminal to communicate based on the communication settings, wherein the first terminal includes a receiving means for receiving instructions from the communication control device and a communication means for performing communication based on the communication settings indicated by the instructions, and the second terminal includes a receiving means for receiving instructions from the communication control device and a communication means for performing communication based on the communication settings indicated by the instructions.

[0011] An exemplary aspect of the present disclosure is a first terminal that communicates with a second terminal via a relay device, and comprises: a receiving means for receiving an instruction to communicate based on a communication setting for communication with the relay device, which is determined by referring to the maximum communication capacity that the relay device can provide in communication with the first terminal and the maximum communication capacity that the relay device can provide in communication with the second terminal, and the communication resources allocated by referring to the communication resources of the relay device used by the relay device in communication with the first terminal and the second terminal, respectively; and a communication means for performing communication based on the communication setting indicated by the instruction.

[0012] A communication control method relating to an exemplary aspect of the present disclosure includes an allocation process in which at least one processor allocates the communication resources of the relay device to be used by the relay device in communication with the first terminal and the second terminal, respectively, with reference to the maximum communication capacity that the relay device can provide in communication with a first terminal and the maximum communication capacity that the relay device can provide in communication with a second terminal, and a setting process in which the at least one processor sets the communication resources.

[0013] One exemplary effect of this disclosure is that it can provide a technology for efficiently allocating communication resources.

[0014] This is a block diagram showing the configuration of the communication control device relating to this disclosure. This is a flowchart showing the flow of the communication control method relating to this disclosure. This is a block diagram showing the configuration of the communication control system relating to this disclosure. This is a flowchart showing the flow of the communication control method relating to this disclosure. This is a block diagram showing the configuration of the first terminal relating to this disclosure. This is a flowchart showing the flow of the communication control method relating to this disclosure. This is a block diagram showing the configuration of the communication control system relating to this disclosure. This is a flowchart showing the flow of processing performed in the communication control system relating to this disclosure. This is a diagram showing an example This figure shows an example of processing performed in the communication control system relating to this disclosure. This figure shows an example of processing performed in the communication control system relating to this disclosure. This figure shows an example of processing performed in the communication control system relating to this disclosure. This figure shows an example of processing performed in the communication control system relating to this disclosure. This block diagram shows the configuration of the communication control device, satellite, first terminal, and computer functioning as the second terminal relating to this disclosure. This figure schematically represents an example of delay time relating to this disclosure. This figure schematically represents an example of beam irradiation from the satellite relating to this disclosure.

[0015] The following are examples of embodiments of the present invention. However, the present invention is not limited to the exemplary embodiments shown below, and various modifications are possible within the scope of the claims. For example, embodiments obtained by appropriately combining some or all of the technologies (things or methods) employed in each of the exemplary embodiments shown below may also be included in the scope of the present invention. Furthermore, embodiments obtained by appropriately omitting some of the technologies employed in each of the exemplary embodiments shown below may also be included in the scope of the present invention. In addition, the effects mentioned in each of the exemplary embodiments shown below are examples of effects that can be expected in that exemplary embodiment and do not define the scope of the present invention. That is, embodiments that do not produce the effects mentioned in each of the exemplary embodiments shown below may also be included in the scope of the present invention.

[0016] [First Exemplary Embodiment] A first exemplary embodiment, which is an example of an embodiment of the present invention, will be described in detail with reference to the drawings. This exemplary embodiment is the basic form for each of the exemplary embodiments described later. The scope of application of each technology adopted in this exemplary embodiment is not limited to this exemplary embodiment. That is, each technology adopted in this exemplary embodiment can also be adopted in other exemplary embodiments included in this disclosure, to the extent that no particular technical problems occur. Furthermore, each technology shown in the drawings referenced to explain this exemplary embodiment can also be adopted in other exemplary embodiments included in this disclosure, to the extent that no particular technical problems occur.

[0017] (Configuration of Communication Control Device 1) The configuration of the communication control device 1 will be described with reference to Figure 1. Figure 1 is a block diagram showing the configuration of the communication control device 1. As shown in Figure 1, the communication control device 1 includes an allocation unit 11 and a setting unit 12. In this exemplary embodiment, the allocation unit 11 and the setting unit 12 implement the allocation means and setting means, respectively.

[0018] (Allocation Unit 11) The allocation unit 11 refers to the maximum communication capacity that the relay device can provide in communication with the first terminal and the maximum communication capacity that the relay device can provide in communication with the second terminal, and allocates the communication resources of the relay device to be used by the relay device in communication with the first terminal and the second terminal, respectively.

[0019] "Maximum available communication capacity" refers to the maximum communication capacity that can be provided to each terminal from the communication capacity that can be set in the communication control device 1. Furthermore, "Maximum available communication capacity" changes sequentially. For example, at a certain point in time (a certain state), "Maximum available communication capacity" is A', and at a different point in time (a different state), "Maximum available communication capacity" is B', and so on, "Maximum available communication capacity" changes sequentially.

[0020] Furthermore, the number of relay devices is not limited in this disclosure. In the case of multiple relay devices, it is sufficient that each of the multiple relay devices communicates with one another to realize the function of a relay device as a group of relay devices, and that the configuration relays communication between the first terminal and the second terminal.

[0021] Furthermore, the number of first terminals and second terminals is not limited in this disclosure. There may be a configuration in which multiple first terminals (a group of first terminals) communicate with a second terminal, or a configuration in which a first terminal communicates with multiple second terminals (a group of second terminals), or a configuration in which a group of first terminals communicates with a group of second terminals. In these cases, "first terminal" and "second terminal" in this disclosure may be read as "group of first terminals" and "group of second terminals," respectively.

[0022] (Setting Unit 12) The setting unit 12 sets the communication resources that the allocation unit 11 has allocated.

[0023] (Effects of the communication control device 1) As described above, the communication control device 1 employs a configuration that includes an allocation unit 11 which refers to the maximum communication capacity that the relay device can provide in communication with the first terminal and the maximum communication capacity that the relay device can provide in communication with the second terminal and allocates the communication resources of the relay device to be used by the relay device in communication with the first terminal and the second terminal, respectively, and a setting unit 12 which sets the communication resources allocated by the allocation unit 11.

[0024] Therefore, the communication control device 1 has the effect of efficiently allocating communication resources.

[0025] (Flow of Communication Control Method S1) The flow of the communication control method S1 will be explained with reference to Figure 2. Figure 2 is a flowchart showing the flow of the communication control method S1. As shown in Figure 2, the communication control method S1 includes an allocation process S11 and a setting process S12.

[0026] (Allocation process S11) In allocation process S11, the allocation unit 11 refers to the maximum communication capacity that the relay device can provide for communication with the first terminal and the maximum communication capacity that the relay device can provide for communication with the second terminal, and allocates the communication resources of the relay device to be used by the relay device for communication with the first terminal and the second terminal, respectively.

[0027] (Setting process S12) In setting process S12, the setting unit 12 sets the communication resources allocated by the allocation unit 11.

[0028] (Effects of Communication Control Method S1) As described above, the communication control method S1 employs a configuration in which the allocation unit 11 refers to the maximum communication capacity that the relay device can provide in communication with the first terminal and the maximum communication capacity that the relay device can provide in communication with the second terminal, and allocates the relay device's communication resources to be used by the relay device in communication with the first terminal and the second terminal, respectively, in an allocation process S11, and the setting unit 12 sets the communication resources allocated by the allocation unit 11 in a setting process S12. Therefore, the same effects as the communication control device 1 described above can be obtained with the communication control method S1.

[0029] (Configuration of Communication Control System 100) The configuration of the communication control system 100 will be described with reference to Figure 3. Figure 3 is a block diagram showing the configuration of the communication control system 100. As shown in Figure 3, the communication control system 100 includes a first terminal 3, a second terminal 4, and a communication control device 2 that controls communication between the first terminal 3, the second terminal 4, and a relay device that relays communication between the first terminal 3 and the second terminal 4.

[0030] (Configuration of the communication control device 2) As shown in Figure 3, the communication control device 2 includes an allocation unit 11, a setting unit 12, a determination unit 21, and an instruction unit 22. In this exemplary embodiment, the allocation unit 11, setting unit 12, determination unit 21, and instruction unit 22 implement the allocation means, setting means, determination means, and instruction means, respectively.

[0031] (Allocation Unit 11) The allocation unit 11 refers to the maximum communication capacity that the relay device can provide in communication with the first terminal 3 and the maximum communication capacity that the relay device can provide in communication with the second terminal 4, and allocates the communication resources of the relay device to be used by the relay device in communication with the first terminal 3 and the second terminal 4, respectively.

[0032] (Setting Unit 12) The setting unit 12 sets the communication resources that the allocation unit 11 has allocated.

[0033] (Decision Unit 21) The decision unit 21 refers to the communication resources allocated by the allocation unit 11 and determines the communication settings for the first terminal 3 and the second terminal 4.

[0034] (Instruction Unit 22) The instruction unit 22 instructs the first terminal 3 and the second terminal 4 to communicate based on the communication settings determined by the decision unit 21.

[0035] (Configuration of the first terminal 3) As shown in Figure 3, the first terminal 3 includes a reception unit 31 and a communication unit 32. In this exemplary embodiment, the reception unit 31 and the communication unit 32 implement reception means and communication means, respectively.

[0036] (Reception unit 31) The reception unit 31 receives instructions from the communication control device 2.

[0037] (Communication Unit 32) The communication unit 32 performs communication based on the communication settings indicated by the instructions received by the reception unit 31.

[0038] (Configuration of the second terminal 4) As shown in Figure 3, the second terminal 4 includes a reception unit 41 and a communication unit 42. In this exemplary embodiment, the reception unit 41 and the communication unit 42 implement reception means and communication means, respectively.

[0039] (Reception Unit 41) The reception unit 41 receives instructions from the communication control device 2.

[0040] (Communication Unit 42) The communication unit 42 performs communication based on the communication settings indicated by the instructions received by the reception unit 41.

[0041] (Effects of the communication control system 100) As described above, the communication control system 100 is configured to include a first terminal 3, a second terminal 4, and a communication control device 2 that controls communication between the first terminal 3, the second terminal 4, and a relay device that relays communication between the first terminal 3 and the second terminal 4.

[0042] The communication control device 2 includes: an allocation unit 11 that refers to the maximum communication capacity that the relay device can provide in communication with the first terminal 3 and the maximum communication capacity that the relay device can provide in communication with the second terminal 4 and allocates the communication resources of the relay device to be used by the relay device in communication with the first terminal 3 and the second terminal 4, respectively; a setting unit 12 that sets the communication resources allocated by the allocation unit 11; a determination unit 21 that refers to the communication resources allocated by the allocation unit 11 and determines the communication settings for the first terminal 3 and the second terminal 4, respectively; and an instruction unit 22 that instructs the first terminal 3 and the second terminal 4 to communicate based on the communication settings determined by the determination unit 21.

[0043] The first terminal 3 includes a receiving unit 31 that receives instructions from the communication control device 2, and a communication unit 32 that performs communication based on the communication settings indicated by the instructions received by the receiving unit 31.

[0044] The second terminal 4 includes a reception unit 41 that receives an instruction from the communication control device 2, and a communication unit 42 that communicates based on the communication settings indicated by the instruction received by the reception unit 41.

[0045] Therefore, according to the communication control system 100, the same effects as those of the communication control device 1 described above can be obtained.

[0046] (Flow of the communication control method S100) The flow of the communication control method S100 will be described with reference to FIG. 4. FIG. 4 is a flowchart showing the flow of the communication control method S100. As shown in FIG. 4, the communication control method S100 includes an allocation process S11, a setting process S12, a determination process S21, an instruction process S22, a reception process S31, a communication process S32, an instruction process S23, a reception process S41, and a communication process S42.

[0047] (Allocation process S11) In the allocation process S11, the allocation unit 11 refers to the maximum communication capacity that the relay device can provide in communication with the first terminal 3 and the maximum communication capacity that the relay device can provide in communication with the second terminal 4, and allocates the communication resources of the relay device used in the communication with each of the first terminal 3 and the second terminal 4.

[0048] (Setting process S12) In the setting process S12, the setting unit 12 sets the communication resources allocated by the allocation unit 11.

[0049] (Determination process S21) In the determination process S21, the determination unit 21 refers to the communication resources allocated by the allocation unit 11 and determines the communication settings of the first terminal 3 and the respective communication settings of the second terminal 4.

[0050] (Instruction process S22) In the instruction process S22, the instruction unit 22 instructs the first terminal 3 to communicate based on the communication settings determined by the determination unit 21.

[0051] (Reception process S31) In the reception process S31, the reception unit 31 receives an instruction from the communication control device 2.

[0052] (Communication process S32) In the communication process S32, the communication unit 32 communicates based on the communication settings indicated by the instruction received by the reception unit 31.

[0053] (Instruction processing S23) In instruction processing S23, the instruction unit 22 instructs the second terminal 4 to communicate based on the communication settings determined by the decision unit 21.

[0054] (Reception processing S41) In reception processing S41, the reception unit 41 receives instructions from the communication control device 2.

[0055] (Communication processing S42) The communication unit 42 performs communication based on the communication settings indicated by the instruction received by the reception unit 41.

[0056] (Effects of communication control method S100) As described above, in the communication control method S100, the communication control device 2 is configured such that the allocation unit 11 refers to the maximum communication capacity that the relay device can provide in communication with the first terminal 3 and the maximum communication capacity that the relay device can provide in communication with the second terminal 4 and allocates the relay device's communication resources to be used by the relay device in communication with the first terminal 3 and the second terminal 4, respectively, in an allocation process S11; the setting unit 12 performs a setting process S12 to set the communication resources allocated by the allocation unit 11; the determination unit 21 refers to the communication resources allocated by the allocation unit 11 and performs a determination process S21 to determine the communication settings for the first terminal 3 and the second terminal 4, respectively; and the instruction unit 22 performs instruction processes S22 and S23 to instruct the first terminal 3 and the second terminal 4 to communicate based on the communication settings determined by the determination unit 21.

[0057] Furthermore, in the communication control method S100, the first terminal 3 is configured such that the receiving unit 31 performs a receiving process S31 in which it receives instructions from the communication control device 2, and the communication unit 32 performs a communication process S32 in which it communicates based on the communication settings indicated by the instructions received by the receiving unit 31.

[0058] Furthermore, in the communication control method S100, the second terminal 4 is configured such that the reception unit 41 performs a reception process S41 in which it receives instructions from the communication control device 2, and the communication unit 42 performs a communication process S42 in which it communicates based on the communication settings indicated by the instructions received by the reception unit 41.

[0059] Therefore, the same effects as those of the communication control device 1 described above can be obtained with the communication control method S100.

[0060] (Configuration of the First Terminal 3) The configuration of the first terminal 3 will be described with reference to Figure 5. Figure 5 is a block diagram showing the configuration of the first terminal 3. As shown in Figure 5, the first terminal 3 includes a reception unit 31 and a communication unit 32. In this exemplary embodiment, the reception unit 31 and the communication unit 32 implement a reception means and a communication means, respectively.

[0061] (Reception Unit 31) The reception unit 31 receives an instruction to communicate based on communication settings determined by referring to the communication resources of the relay device used in communication with the first terminal and the second terminal, which are allocated by referring to the maximum communication capacity that the relay device can provide in communication with the first terminal and the maximum communication capacity that the relay device can provide in communication with the second terminal.

[0062] (Communication Unit 32) The communication unit 32 performs communication based on the communication settings indicated by the instructions received by the reception unit 31.

[0063] (Effects of the first terminal 3) As described above, the first terminal 3 is configured to include a receiving unit 31 that receives instructions to communicate based on communication settings determined by referring to the communication resources of the relay device used in communication with the first terminal and the second terminal, which are allocated by referring to the maximum communication capacity that the relay device can provide in communication with the first terminal and the maximum communication capacity that the relay device can provide in communication with the second terminal, and a communication unit 32 that performs communication based on the communication settings indicated by the instructions received by the receiving unit 31. For this reason, the first terminal 3 provides the same effects as the communication control device 1 described above.

[0064] (Flow of Communication Control Method S3) The flow of the communication control method S3 will be explained with reference to Figure 6. Figure 6 is a flowchart showing the flow of the communication control method S3. As shown in Figure 6, the communication control method S3 includes reception processing S31 and communication processing S32.

[0065] (Reception processing S31) In reception processing S31, the reception unit 31 receives an instruction to communicate based on communication settings determined by referring to the communication resources of the relay device used in communication with the first terminal and the second terminal, which are allocated by referring to the maximum communication capacity that the relay device can provide in communication with the first terminal and the maximum communication capacity that the relay device can provide in communication with the second terminal.

[0066] (Communication processing S32) In communication processing S32, the communication unit 32 performs communication based on the communication settings indicated by the instruction received by the reception unit 31.

[0067] (Effects of communication control method S3) As described above, the communication control method S3 employs a configuration that includes: reception processing S31 in which the reception unit 31 receives an instruction to communicate based on communication settings determined by referring to the communication resources of the relay device used by the relay device in communication with the first terminal and the relay device in communication with the second terminal, which are allocated by referring to the maximum communication capacity that the relay device can provide in communication with the first terminal and the maximum communication capacity that the relay device can provide in communication with the second terminal; and communication processing S32 in which the communication unit 32 performs communication based on the communication settings indicated by the instruction received by the reception unit 31. For this reason, the same effects as the communication control device 1 described above can be obtained with the communication control method S3.

[0068] [Second Exemplary Embodiment] A second exemplary embodiment, which is an example of an embodiment of the present invention, will be described in detail with reference to the drawings. Components having the same function as those described in the above-described exemplary embodiment are denoted by the same reference numerals, and their descriptions are omitted as appropriate. The scope of application of each technology adopted in this exemplary embodiment is not limited to this exemplary embodiment. That is, each technology adopted in this exemplary embodiment can also be adopted in other exemplary embodiments included in this disclosure, to the extent that no particular technical problems arise. Furthermore, each technology shown in the drawings referenced to describe this exemplary embodiment can also be adopted in other exemplary embodiments included in this disclosure, to the extent that no particular technical problems arise.

[0069] (Configuration and Overview of Communication Control System 100A) The configuration and overview of the communication control system 100A will be described with reference to Figure 7. Figure 7 is a block diagram showing the configuration of the communication control system 100A. As shown in Figure 7, the communication control system 100A includes a satellite 2A, a first terminal 3A, and a second terminal 4A. As shown in Figure 7, the satellite 2A, the first terminal 3A, and the second terminal 4A can communicate via a network. The network is not particularly limited and may be a wireless communication network using radio waves, etc., or a wired communication network using optical fibers, etc.

[0070] In the communication control system 100A, the first terminal 3A and the second terminal 4A communicate via satellite 2A. That is, satellite 2A is a relay device that communicates between the first terminal 3A and the second terminal 4A. Both the first terminal 3A and the second terminal 4A can perform UL communication and DL communication, but in this disclosure, as an example, the case in which the first terminal 3A performs DL communication and the second terminal 4A performs UL communication will be described.

[0071] Furthermore, while this exemplary embodiment describes a case where the first terminal 3A and the second terminal 4A communicate via satellite 2A, the communication control system 100A is not limited to this configuration. In the communication control system 100A, instead of satellite 2A, communication between the first terminal 3A and the second terminal 4A may be conducted via a ground station equipped with the functions of satellite 2A.

[0072] Furthermore, the communication control system 100A may also include a communication control device equipped with a control unit 20A (details of which will be described later) on satellite 2A, in addition to satellite 2A, the first terminal 3A, and the second terminal 4A. In this case, the communication control device may be a ground station or a satellite other than satellite 2A.

[0073] Furthermore, in the communication control system 100A, satellite 2A refers to the maximum communication capacity CDL that can be provided in communication with the first terminal 3A and the maximum communication capacity CUL that can be communicated in communication with the second terminal 4A, and allocates communication resources to be used in communication with the first terminal 3A and the second terminal 4A, respectively. In other words, satellite 2A has the functions of the communication control device 1 or communication control device 2 in the exemplary embodiment described above.

[0074] Communication resources are resources used for communication, and examples include the transmit power, receive power, and bandwidth of satellite 2A. Furthermore, if a phased array antenna with multiple antenna elements is used for communication, the antenna elements of the phased array antenna are also considered communication resources. In other words, satellite 2A controls the beam width by changing the allocation of antenna elements, which are communication resources. For example, satellite 2A controls the beam width by changing the number of antenna elements allocated to one beam. Also, satellite 2A uses time as a communication resource, switching the beam direction in a time-division manner. For example, satellite 2A switches the beam direction time by changing the phase of each antenna element.

[0075] Furthermore, in the communication control system 100A, satellite 2A refers to the allocated communication resources and determines the communication settings for DL ​​communication between the first terminal 3A and satellite 2A, and the communication settings for UL communication between the second terminal 4A and satellite 2A. Then, satellite 2A instructs the first terminal 3A and the second terminal 4A to communicate based on the determined communication settings. In other words, satellite 2A has the functions of the communication control device 2 in the exemplary embodiment described above.

[0076] Communication settings refer to the settings for communication, and examples include the transmission power of satellite 2A, the transmission power of the second terminal 4A, the modulation scheme and coding rate for DL ​​communication between the first terminal 3A and satellite 2A, and the modulation scheme and coding rate for UL communication between the second terminal 4A and satellite 2A.

[0077] In other words, in the communication control system 100A, the first terminal 3A and the second terminal 4A communicate with satellite 2A using communication resources allocated by referring to the maximum communication capacity CDL available for communication with the first terminal 3A and the maximum communication capacity CUL available for communication with the second terminal 4A, according to the communication settings determined by satellite 2A.

[0078] (Configuration of Satellite 2A) The configuration of Satellite 2A will be explained again with reference to Figure 7. As shown in Figure 7, Satellite 2A comprises a control unit 20A, a storage unit 28A, and a satellite communication unit 29A.

[0079] (Storage Unit 28A) The storage unit 28A stores data that the control unit 20A refers to. Examples of data stored in the storage unit 28A include satellite position information (relay device position information) indicating the position of satellite 2A, and terminal position information indicating the position of terminals.

[0080] Terminal location information is information that indicates the location of a terminal. Terminal location information may be obtained from the terminal itself, or it may be obtained from a management device (not shown in Figure 7) that manages the location of the terminals. Hereinafter, the information indicating the location of the first terminal 3A will be referred to as the first terminal location information, and the information indicating the location of the second terminal 4A will be referred to as the second terminal location information.

[0081] (Satellite communication unit 29A) The satellite communication unit 29A is an antenna for sending and receiving data over the network. The satellite communication unit 29A may be a phased array antenna. For example, the satellite communication unit 29A transmits data supplied from the control unit 20A to the first terminal 3A or the second terminal 4A. The satellite communication unit 29A also supplies data transmitted from the first terminal 3A or the second terminal 4A to the control unit 20A.

[0082] (Control Unit 20A) The control unit 20A controls each component of the satellite 2A. As shown in Figure 7, the control unit 20A also includes an allocation unit 11A, a setting unit 12A, a determination unit 21A, an instruction unit 22A, and an acquisition unit 23A. In this exemplary embodiment, the allocation unit 11A, setting unit 12A, determination unit 21A, instruction unit 22A, and acquisition unit 23A implement the allocation means, setting means, determination means, instruction means, and acquisition means, respectively. Specific examples of the processing performed by each unit will be described later.

[0083] (Allocation Unit 11A) The allocation unit 11A allocates communication resources for satellite 2A. The allocation unit 11A supplies information indicating the allocated communication resources to the setting unit 12A.

[0084] As an example, the allocation unit 11A refers to the maximum communication capacity CDL that can be provided in communication with the first terminal 3A and the maximum communication capacity CUL that can be provided in communication with the second terminal 4A, and allocates the communication resources to be used in communication with the first terminal 3A and the second terminal 4A, respectively.

[0085] Furthermore, the allocation unit 11A further refers to the satellite position information, the first terminal position information, and the second terminal position information, and allocates communication resources to be used in communication with the first terminal 3A and the second terminal 4A, respectively. With this configuration, the allocation unit 11A can calculate the distance between satellite 2A and the first terminal 3A and the distance between satellite 2A and the second terminal 4A, and allocate resources according to the distance.

[0086] As an example, the allocation unit 11A first further refers to the satellite position information, the first terminal position information, and the second terminal position information to calculate the maximum communication capacity. As an example of this configuration, the allocation unit 11A may refer to a table that associates the communication distance to a terminal with the maximum possible communication capacity at that communication distance. More specifically, the allocation unit 11A calculates the communication distance between satellite 2A and the first terminal 3A and the communication distance between satellite 2A and the second terminal 4A from the satellite position information, the first terminal position information, and the second terminal position information. Then, the allocation unit 11A calculates the maximum communication capacity associated with the communication distance between satellite 2A and the first terminal 3A as the maximum communication capacity CDL and the maximum communication capacity associated with the communication distance between satellite 2A and the second terminal 4A as the maximum communication capacity CUL in the table. If satellite 2A is a low-Earth orbit satellite with a constant altitude, a table that associates elevation angle and maximum communication capacity may be referred to instead of communication distance.

[0087] Next, the allocation unit 11A refers to the maximum communication capacity CDL and the maximum communication capacity CUL and determines the communication capacity that satellite 2A will use for communication with the first terminal 3A and the second terminal 4A. As an example, the allocation unit 11A determines that the communication capacity that satellite 2A will use for communication with the first terminal 3A and the second terminal 4A is the smaller of the maximum communication capacity CDL that can be provided for communication with the first terminal 3A and the maximum communication capacity CUL that can be provided for communication with the second terminal 4A.

[0088] The allocation unit 11A then allocates communication resources to satisfy the determined communication capacity. One example is that the allocation unit 11A refers to a table in which communication capacity and communication resources are associated.

[0089] Another example of a method by which the allocation unit 11A allocates communication resources is a CSI-based method.

[0090] Furthermore, the allocation unit 11A may determine the beam frequency by referring to the first terminal location information and the second terminal location information.

[0091] For example, if the allocation unit 11A refers to the first terminal location information and the second terminal location information and determines that the position of the first terminal 3A and the position of the second terminal 4A are closer than a predetermined distance, the beam for the first terminal 3A and the beam for the second terminal 4A will be closer together. Since interference may occur when the two beams are close together, the allocation unit 11A sets the frequencies of the two beams to be different.

[0092] On the other hand, the allocation unit 11A refers to the first terminal position information and the second terminal position information, and if the position of the first terminal 3A and the position of the second terminal 4A are farther apart than a predetermined distance, the beam directed to the first terminal 3A and the beam directed to the second terminal 4A are separated. Since interference does not occur when the two beams are separated, the allocation unit 11A sets the frequencies of the two beams to be the same.

[0093] Furthermore, the allocation unit 11A may allocate communication resources while taking into account the remaining power of satellite 2A. For example, if the remaining power of satellite 2A is less than a predetermined value, the allocation unit 11A may impose a constraint on the upper limit of the transmission power to be allocated.

[0094] Furthermore, the allocation unit 11A may allocate communication resources in response to secure requests. For example, if a secure request is received from a second terminal 4A, the allocation unit 11A allocates beam widths to the first terminal 3A and the second terminal 4A to a width below a certain limit. In this case, if there are multiple first terminals 3A or second terminals 4A, and it is not possible to allocate a beam width that covers all of them, the allocation unit 11A will use a different beam or perform communication using time-division multiplexing with beams appropriate to the timing.

[0095] (Setting Unit 12A) The setting unit 12A sets the communication resources. For example, the setting unit 12A sets the communication resources allocated by the allocation unit 11A to satellite 2A. As another example, if a communication control device different from satellite 2A has a control unit 20A, the setting unit 12A instructs satellite 2A to set the communication resources allocated by the allocation unit 11A.

[0096] (Decision Unit 21A) The decision unit 21A determines the communication settings for communication with the first terminal 3A and communication with the second terminal 4A, respectively. As an example, the decision unit 21A refers to the communication resources allocated by the allocation unit 11A and determines at least one of the communication settings for DL ​​communication between the first terminal 3A and satellite 2A and the communication settings for UL communication between the second terminal 4A and satellite 2A. The decision unit 21A supplies information indicating the determined communication settings to the instruction unit 22A. As an example, the decision unit 21A determines the transmission power of the first terminal 3A or the transmission power of the second terminal 4A as a communication setting. In this exemplary embodiment, since the second terminal 4A is configured to perform UL communication, the decision unit 21A determines the transmission power of the second terminal 4A as a communication setting.

[0097] One example of a method by which the determination unit 21A determines the communication settings is to refer to a table that associates communication distance with communication settings. Another example of a method by which the determination unit 21A determines the communication settings is a method based on CSI.

[0098] (Instruction Unit 22A) The instruction unit 22A, via the satellite communication unit 29A, instructs the first terminal 3A and the second terminal 4A to communicate based on the communication settings. For example, the instruction unit 22A refers to the information supplied from the determination unit 21A and instructs at least one of the first terminal 3A and the second terminal 4A to communicate based on the communication settings determined by the determination unit 21A. The method by which the instruction unit 22A gives instructions is not limited, but for example, the instruction unit 22A instructs the first terminal 3A and the second terminal 4A to communicate based on the communication settings by transmitting information indicating the communication settings to the first terminal 3A and the second terminal 4A.

[0099] With this configuration, the instruction unit 22A can instruct the first terminal 3A and the second terminal 4A to set appropriate communication settings (e.g., transmission power) during communication between the satellite 2A and the first terminal 3A and the second terminal 4A.

[0100] (Acquisition Unit 23A) The acquisition unit 23A acquires data via the satellite communication unit 29A. The acquisition unit 23A stores the acquired data in the storage unit 28A. As an example, the acquisition unit 23A acquires first terminal location information and second terminal location information. As another example, the acquisition unit 23A acquires satellite location information. One example of how the acquisition unit 23A acquires satellite location information is a method in which satellite 2A is equipped with a GPS (Global Positioning System) communication unit, and the acquisition unit 23A acquires GPS signals acquired via the GPS communication unit as satellite location information.

[0101] The communication by the acquisition unit 23A to acquire the first terminal location information and the second terminal location information may be a different communication from the communication via the satellite communication unit 29A. In other words, the method by which the acquisition unit 23A acquires the first terminal location information and the second terminal location information is not limited.

[0102] (Configuration of the first terminal 3A) The configuration of the first terminal 3A will be explained again with reference to Figure 7. As shown in Figure 7, the first terminal 3A includes a control unit 30A, a storage unit 38A, and a terminal communication unit 39A. The second terminal 4A has the same configuration as the first terminal 3A, so its explanation will be omitted.

[0103] (Storage Unit 38A) The storage unit 38A stores data that the control unit 30A references. For example, the storage unit 38A stores the location information of the first terminal.

[0104] The method for storing the first terminal information in the memory unit 38A is not limited, but one example is a method in which the first terminal 3A is equipped with a GPS (Global Positioning System) communication unit, generates the first terminal location information based on GPS signals acquired via the GPS communication unit, and stores it in the memory unit 38A.

[0105] (Terminal Communication Unit 39A) The terminal communication unit 39A is an antenna for sending and receiving data over the network. For example, the terminal communication unit 39A transmits data supplied from the control unit 30A to the satellite 2A. The terminal communication unit 39A also supplies data transmitted from the satellite 2A to the control unit 30A.

[0106] (Control Unit 30A) The control unit 30A controls each component of the first terminal 3A. As shown in Figure 7, the control unit 30A also includes a reception unit 31A, a communication unit 32A, and an output unit 33A.

[0107] (Reception Unit 31A) The reception unit 31A receives instructions via the terminal communication unit 39A. For example, the reception unit 31A receives instructions to communicate based on the communication settings by obtaining information indicating the communication settings from satellite 2A. The reception unit 31A supplies the received instructions to the communication unit 32A.

[0108] (Communication Unit 32A) The communication unit 32A communicates with other devices via the terminal communication unit 39A. For example, the communication unit 32A communicates with a second terminal 4A via satellite 2A based on instructions received by the reception unit 31A.

[0109] (Output Unit 33A) The output unit 33A outputs data via the terminal communication unit 39A. For example, the output unit 33A outputs the first terminal location information stored in the memory unit 38A to the satellite 2A.

[0110] (Process flow executed in communication control system 100A) The process flow (communication control method) executed in communication control system 100A will be explained with reference to Figures 8 and 9A to 9D. Figure 8 is a flowchart showing the process flow executed in communication control system 100A. Figures 9A to 9D are diagrams showing an example of the process executed in communication control system 100A. In Figures 9A to 9D, satellite 2A is moving to the right.

[0111] (Step S101A) In step S101A, the output unit 43A of the second terminal 4A outputs the second terminal location information to the satellite 2A. Furthermore, the output unit 43A may output destination information indicating that the communication partner is the first terminal 3A.

[0112] (Step S102A: Acquisition process) In step S102A, the acquisition unit 23A of satellite 2A acquires the second terminal location information output from the second terminal 4A. Furthermore, the acquisition unit 23A acquires the destination information output from the second terminal 4A. The acquisition unit 23A stores the acquired second terminal location information and destination information in the storage unit 28A.

[0113] (Step S103A) In step S103A, the output unit 33A of the first terminal 3A outputs the first terminal location information to the satellite 2A.

[0114] (Step S104A: Acquisition process) In step S104A, the acquisition unit 23A of satellite 2A acquires the first terminal location information output from the first terminal 3A. The acquisition unit 23A stores the acquired first terminal location information in the storage unit 28A.

[0115] (Step S105A) In step S105A, the acquisition unit 23A of satellite 2A acquires satellite position information. The acquisition unit 23A stores the acquired satellite position information in the storage unit 28A.

[0116] (Step S11A: Allocation process) In step S11A, the allocation unit 11A allocates communication resources by referring to the maximum communication capacity CDL that can be provided in communication with the first terminal 3A and the maximum communication capacity CUL that can be provided in communication with the second terminal 4A. As an example, the allocation unit 11A allocates communication resources by referring to the first terminal location information and the second terminal location information stored in the storage unit 28A. The allocation unit 11A supplies information indicating the allocated communication resources to the setting unit 12A.

[0117] Specifically, in step S11A, the allocation unit 11A first refers to the first terminal location information, the second terminal location information, and the satellite location information acquired by the acquisition unit 23A, and calculates the distance from satellite 2A to the first terminal 3A and the distance from satellite 2A to the second terminal 4A. Then, the allocation unit 11A calculates the attenuation amount according to the distance.

[0118] Next, once UL communication between satellite 2A and the second terminal 4A and DL communication between satellite 2A and the first terminal 3A are established, the allocation unit 11A determines the maximum communication capacity CDL that can be provided in communication with the first terminal 3A and the maximum communication capacity CUL that can be provided in communication with the second terminal 4A. The method by which the allocation unit 11A determines the maximum communication capacity is not limited, and the maximum communication capacity may be determined using the method described above or a well-known method.

[0119] The allocation unit 11A then compares the maximum communication capacity CUD that can be provided in communication with the first terminal 3A with the maximum communication capacity CUL that can be provided in communication with the second terminal 4A.

[0120] Here, as shown in the upper part of Figure 9A, if the distance between satellite 2A and the first terminal 3A is shorter than the distance between satellite 2A and the second terminal 4A, the maximum communication capacity CDL that can be provided in communication with the first terminal 3A is greater than the maximum communication capacity CUL that can be provided in communication with the second terminal 4A (CDL > CUL).

[0121] In this case, the allocation unit 11A determines the communication capacity for communication with the first terminal 3A to be the minimum possible communication capacity, which is not less than the maximum communication capacity CUL that can be provided for communication with the second terminal 4A. For example, the allocation unit 11A determines the communication capacity for communication with the first terminal 3A to be the maximum communication capacity CUL. The allocation unit 11A also determines the communication capacity for the second terminal 4A, which has a smaller maximum communication capacity, to be the maximum communication capacity CUL.

[0122] The allocation unit 11A then allocates communication resources to satisfy the determined communication capacity. For example, the allocation unit 11A allocates the number of antenna elements, transmission power, and bandwidth to satisfy the determined communication capacity. As an example, the allocation unit 11A allocates bandwidth b2 for UL and bandwidth b1 for DL, as shown in Figure 9B.

[0123] In other words, the allocation unit 11A allocates communication resources based on the smaller of the maximum communication capacity CUD that can be provided in communication with the first terminal 3A and the maximum communication capacity CUL that can be provided in communication with the second terminal 4A.

[0124] (Step S12A: Setting process) In step S12A, the setting unit 12A sets the communication resources allocated by the allocation unit 11A to satellite 2A. For example, the setting unit 12A sets the number of antenna elements, transmission power, and bandwidth allocated by the allocation unit 11A.

[0125] (Step S21A: Decision Process) In step S21A, the decision unit 21 refers to the communication resources allocated by the allocation unit 11A and determines at least one of the communication settings for DL ​​communication between the first terminal 3A and satellite 2A and the communication settings for UL communication between the second terminal 4A and satellite 2A. The decision unit 21A supplies information indicating the determined communication settings to the instruction unit 22A.

[0126] For example, the determination unit 21 refers to the communication resources allocated by the allocation unit 11A and determines the modulation scheme and coding rate for UL communication and DL communication. As an example, as shown in the upper part of Figure 9A, the determination unit 21 determines the modulation scheme to be QPSK (Quadrature Phase-Shift Keying).

[0127] (Step S22A: Instruction Processing) In step S22A, the instruction unit 22A refers to the information supplied from the determination unit 21A and instructs the first terminal 3A to communicate based on the communication settings determined by the determination unit 21A.

[0128] (Step S31A: Reception processing) In step S31A, the reception unit 31A of the first terminal 3A receives instructions from satellite 2A.

[0129] (Step S32A: Communication Processing) In step S32A, the communication unit 32A communicates with the second terminal 4A via satellite 2A based on the instructions received by the reception unit 31A.

[0130] (Step S23A: Instruction Processing) The instruction unit 22A refers to the information supplied from the decision unit 21A and instructs the second terminal 4A to communicate based on the communication settings determined by the decision unit 21A.

[0131] (Step S41A: Reception processing) In step S41A, the reception unit 41A of the second terminal 4A receives instructions from satellite 2A.

[0132] (Step S42A: Communication Processing) In step S42A, the communication unit 42A communicates with the first terminal 3A via satellite 2A based on the instructions received by the reception unit 41A.

[0133] In other words, satellite 2A transmits the data sent from the second terminal 4A based on the communication settings to the first terminal 3A indicated by the destination information, based on the communication settings.

[0134] (Example 1 of processing to be executed when satellite 2A moves) An example of processing to be executed when satellite 2A moves will be explained again with reference to Figure 9A. For example, let's assume that satellite 2A moves and the distance between satellite 2A and the first terminal 3A is approximately equal to the distance between satellite 2A and the second terminal 4A, as shown in the center of Figure 9A.

[0135] In this case as well, steps S101A to S105 are executed in the communication control system 100A, similar to the example described above.

[0136] Then, in step S11A, the allocation unit 11A allocates communication resources in the same manner as in step S11A described above.

[0137] In this case, as shown in the center of Figure 9A, the distance between satellite 2A and the first terminal 3A is approximately equal to the distance between satellite 2A and the second terminal 4A. Therefore, the maximum communication capacity CDL that can be provided in communication with the first terminal 3A is equal to the maximum communication capacity CUL that can be provided in communication with the second terminal 4A (CDL = CUL).

[0138] In this case, the allocation unit 11A determines the communication capacity for communication with the first terminal 3A to be the maximum communication capacity CDL, and the communication capacity for communication with the second terminal 4A to be the maximum communication capacity CUL. Then, as shown in Figure 9C, the allocation unit 11A allocates bandwidth b1 for DL ​​and bandwidth b2 for UL.

[0139] In other words, as satellite 2A moves and the distance between satellite 2A and the second terminal 4A decreases, the maximum communication capacity CUL that can be provided in communication with the second terminal 4A improves. Therefore, the allocation unit 11A allocates wider bandwidths b1 and b2 compared to the bandwidths b1 and b2 shown in Figure 9B.

[0140] Next, in step S12A, similar to the example described above, the setting unit 12A sets the communication resources allocated by the allocation unit 11A to satellite 2A.

[0141] Next, in step S21A, the determination unit 21A, similar to the example described above, refers to the communication resources allocated by the allocation unit 11A and determines at least one of the communication settings for DL ​​communication between the first terminal 3A and satellite 2A and the communication settings for UL communication between the second terminal 4A and satellite 2A. For example, the determination unit 21A determines 16QAM (Quadrature Amplitude Modulation), which is a modulation scheme with an increased number of modulation levels compared to the case shown on the upper side of Figure 9A, and determines a high coding rate.

[0142] As in the example described above, steps S22A to S42A are executed in the communication control system 100A.

[0143] (Example 2 of processing to be executed when satellite 2A moves) An example of processing to be executed when satellite 2A moves further will be explained again with reference to Figure 9A. For example, suppose satellite 2A moves further and the distance between satellite 2A and the first terminal 3A becomes longer than the distance between satellite 2A and the second terminal 4A, as shown in the lower part of Figure 9A.

[0144] In this case as well, steps S101A to S105 are executed in the communication control system 100A, similar to the example described above.

[0145] Then, in step S11A, the allocation unit 11A allocates communication resources in the same manner as in step S11A described above.

[0146] As shown in the lower part of Figure 9A, the distance between satellite 2A and the first terminal 3A is longer than the distance between satellite 2A and the second terminal 4A. Therefore, the maximum communication capacity CDL that can be provided in communication with the first terminal 3A is smaller than the maximum communication capacity CUL that can be provided in communication with the second terminal 4A (CDL < CUL).

[0147] In this case, the allocation unit 11A determines the communication capacity for communication with the second terminal 4A to be the minimum possible communication capacity, and not less than the maximum communication capacity CDL that can be provided for communication with the first terminal 3A. For example, the allocation unit 11A determines the communication capacity for communication with the second terminal 4A to be the maximum communication capacity CDL. Alternatively, the allocation unit 11A determines the communication capacity for the first terminal 3A, which has a smaller maximum communication capacity, to be the maximum communication capacity CDL.

[0148] Then, as shown in Figure 9D, the allocation unit 11A allocates bandwidth b1 for DL ​​and bandwidth b2 for UL.

[0149] In other words, as satellite 2A moves and the distance between satellite 2A and the first terminal 3A increases, the maximum communication capacity (CDL) that can be provided in communication with the first terminal 3A decreases. Therefore, the allocation unit 11A allocates narrower bandwidths b1 and b2 compared to the bandwidths b1 and b2 shown in Figure 9C.

[0150] Next, in step S12A, similar to the example described above, the setting unit 12A sets the communication resources allocated by the allocation unit 11A to satellite 2A.

[0151] Next, in step S21A, the determination unit 21A, similar to the example described above, refers to the communication resources allocated by the allocation unit 11A and determines at least one of the communication settings for DL ​​communication between the first terminal 3A and satellite 2A and the communication settings for UL communication between the second terminal 4A and satellite 2A. For example, the determination unit 21A determines QPSK, a modulation scheme with a reduced number of modulation levels compared to the case shown in the center of Figure 9A, and determines a low coding rate.

[0152] As in the example described above, steps S22A to S42A are executed in the communication control system 100A.

[0153] (Example of Satellite 2A relaying multiple communications) The case in which Satellite 2A relays multiple communications will be explained with reference to Figures 10A to 10C. Figures 10 to 10C are diagrams showing an example of the process in which Satellite 2A relays multiple communications.

[0154] For example, as shown in Figure 10A, we can assume a case where satellite 2A relays communication via path 1 between the first terminal 3_1A and the second terminal 4_1A, and communication via path 2 between the first terminal 3_2A and the second terminal 4_2A.

[0155] In this case, the communication control system 100A executes steps S101A to S42A described above in the communication between the first terminal 3_1A and the second terminal 4_1A via path Path1. Here, in step S11A, the allocation unit 11A allocates communication resources that match the maximum communication capacity CUL for communication between satellite 2A and the second terminal 4_1A, because the distance between satellite 2A and the first terminal 3_1A is shorter than the distance between satellite 2A and the second terminal 4_1A. Specifically, as shown in Figures 10B and 10C, bandwidth b1 and bandwidth b2 and transmission power b1 are allocated.

[0156] Similarly, in the communication control system 100A, steps S101A to S42A described above are executed in the communication between the first terminal 3_2A and the second terminal 4_2A via path Path2. Here, in step S11A, the allocation unit 11A allocates communication resources that match the maximum communication capacity CDL for communication between satellite 2A and the first terminal 3_2A, because the distance between satellite 2A and the first terminal 3_2A is longer than the distance between satellite 2A and the second terminal 4_2A. Specifically, as shown in Figures 10B and 10C, bandwidth b3 and bandwidth b4 and transmission power b3 are allocated.

[0157] Here, comparing the distance between satellite 2A and the second terminal 4_1A, which is the longest distance in each path, with the distance between satellite 2A and the first terminal 3_2A, the distance between satellite 2A and the second terminal 4_1A is longer. Therefore, as shown in Figure 10B, the allocation unit 11A allocates bandwidths b3 and b4, which are wider than bandwidths b1 and b2, and allocates a transmit power b3 that is greater than transmit power b1. With this configuration, the allocation unit 11A can efficiently allocate communication resources for communication in path Path 1 and communication in path Path 2.

[0158] (Example of allocation unit 11A allocating communication resources according to terminal distribution) The case in which satellite 2A allocates communication resources according to terminal distribution will be explained with reference to Figure 11. Figure 11 is a diagram showing an example of the process by which satellite 2A allocates communication resources according to terminal distribution.

[0159] For example, as shown in Figure 11, if satellite 2A relays communications of a first terminal group 3_2A including multiple first terminals 3A, and the satellite communication unit 29A is a phased array antenna, the allocation unit 11A expands the beam width of beam b3 by controlling the phase of each antenna element. In Figure 11, the allocation unit 11A determines the beam width by clustering the first terminal group 3_2A.

[0160] Furthermore, the allocation unit 11A refers to the determined beam width, takes into account the gain reduction due to the determined beam width, and allocates communication resources.

[0161] Furthermore, the allocation unit 11A may allocate communication resources according to the number of first terminals 3A included in the first terminal group 3_2A. For example, if the number of first terminals 3A included in the first terminal group 3_2A is less than a predetermined number, the allocation unit 11A may lower the beam transmission power or reduce the bandwidth for the first terminal group 3_2A. On the other hand, if the number of first terminals 3A included in the first terminal group 3_2A is greater than a predetermined number, the allocation unit 11A may increase the beam transmission power or expand the bandwidth for the first terminal group 3_2A.

[0162] Furthermore, the allocation unit 11A may allocate the communication resources of satellite 2A according to the traffic volume of the first terminal 3_1A, the first terminal group 3_2A, the second terminal 4_1A, and the second terminal 4_2A, respectively.

[0163] As an example, if there is a lot of request traffic from the second terminal 4_1A, the allocation unit 11A increases the transmission power of the beam of the second terminal 4_1A. As another example, if there is little request traffic from the first group of terminals 3_2A, the allocation unit 11A may lower the transmission power of the beam or change at least one of the beam direction and beam width so that more first terminals 3A are included in the beam's range.

[0164] Furthermore, in this configuration, the allocation unit 11A may also allocate communication resources of satellite 2A according to the traffic buffered in the storage unit 28A of satellite 2A.

[0165] For example, if there is a large amount of traffic buffered in the memory unit 28A of satellite 2A, the allocation unit 11A may increase the transmission power or change at least one of the beam direction and beam width so that more terminals are included in the beam range.

[0166] With this configuration, the allocation unit 11A can allocate communication resources according to the amount of traffic in the communication.

[0167] Furthermore, an upper limit on the buffering capacity allocated to satellite 2A may be set for each pair of terminals performing UL communication and terminals performing DL communication. In this case, the allocation unit 11A may allocate communication resources for UL communication and DL communication so as not to exceed the set upper limit on buffering capacity.

[0168] Furthermore, if the number of terminal groups exceeds the number of beams available to satellite 2A, satellite 2A may switch the terminal groups to which it illuminates using time-division multiplexing. As an example of this configuration, satellite 2A calculates the ratio of traffic capacity to the maximum available communication capacity for each of the multiple terminals performing UL communication. Then, satellite 2A prioritizes illuminating terminals with a high ratio with its beam.

[0169] (Effects of the communication control system 100A) As described above, in the communication control system 100A, satellite 2A refers to the maximum communication capacity CDL that can be provided in communication with the first terminal 3A and the maximum communication capacity CUL that can be provided in communication with the second terminal 4A, and allocates the communication resources to be used in communication with the first terminal 3A and the second terminal 4A, respectively.

[0170] Therefore, in the communication control system 100A, satellite 2A does not allocate excessive or insufficient bandwidth for communication between the first terminal 3A and the second terminal 4A, as shown in Figures 9A to 9D, for example, thus ensuring bandwidth for other beams. In other words, the communication control system 100A can efficiently allocate communication resources.

[0171] Furthermore, in the communication control system 100A, satellite 2A allocates communication resources based on the smaller of the maximum communication capacity CDL (maximum communication capacity available for communication with the first terminal 3A) and the maximum communication capacity CUL (maximum communication capacity available for communication with the second terminal 4A). Therefore, the communication control system 100A does not excessively allocate communication resources to the second terminal 4A performing UL communication, resulting in a large amount of data being buffered by satellite 2A, nor does it excessively allocate communication resources to the first terminal 3A performing DL communication. Consequently, the communication control system 100A can allocate communication resources more efficiently and effectively.

[0172] Furthermore, satellite 2A may have an upper limit on its buffering capacity. Even in such cases, the communication control system 100A can efficiently allocate communication resources within its finite buffering capacity.

[0173] (Modification 1) The allocation unit 11A may allocate the communication resources of satellite 2A according to the traffic delay time with the first terminal 3A and the second terminal 4A, respectively.

[0174] For example, as mentioned above, if the number of terminal groups is greater than the number of beams, satellite 2A may switch the terminal groups to which the beam is directed by time-division multiplexing. In this case, since the second terminal 4A performing UL communication cannot transmit traffic while the beam is not directed, a traffic delay occurs. Therefore, the allocation unit 11A determines the beam direction so as to prioritize directing the beam to the second terminal 4A that has traffic with long transmission delays, and allocates communication resources so that traffic with long transmission delays can be transmitted.

[0175] Furthermore, in this configuration, the allocation unit 11A may also allocate communication resources of satellite 2A according to the transmission waiting time of the traffic buffered in the storage unit 28A of satellite 2A.

[0176] For example, in a configuration where the number of terminal groups exceeds the number of beams, and the terminal groups to which the beams are directed are switched by time-division multiplexing, satellite 2A cannot transmit traffic to the first terminal 3A performing DL communication while the beam is not directed, resulting in a delay in transmitting buffered traffic. Therefore, the allocation unit 11A determines the beam direction so as to prioritize directing the beam from the first terminal 3A, which is the destination of traffic with a long transmission delay, and allocates communication resources so that traffic with a long transmission delay can be transmitted.

[0177] With this configuration, the allocation unit 11A can allocate communication resources according to the delay time of the communication traffic.

[0178] (Modification 2) The allocation unit 11A may further refer to control information regarding the future status of the satellite 2A, the first terminal 3A, and the second terminal 4A, and allocate communication resources.

[0179] As an example, the allocation unit 11A refers to the control information and predicts the amount of attenuation.

[0180] As an example of this configuration, the allocation unit 11A refers to satellite orbit information indicating the orbit of satellite 2A as control information and allocates communication resources. For example, the allocation unit 11A refers to the satellite orbit information and predicts the distance between satellite 2A and the first terminal 3A and the distance between satellite 2A and the second terminal 4A after a predetermined period. Then, the allocation unit 11A predicts the amount of attenuation from the predicted distance and estimates and secures the received power after a predetermined period in advance.

[0181] As another example of this configuration, the allocation unit 11A refers to weather information indicating the weather at the respective locations of the first terminal 3A and the second terminal 4A as control information and allocates communication resources. For example, if the weather at the location of the first terminal 3A after a predetermined period is rain, the allocation unit 11A predicts the amount of attenuation of communication with the first terminal 3A, estimates the received power after the predetermined period in advance, and secures it.

[0182] As another example, the allocation unit 11A refers to control information and predicts the remaining power of satellite 2A.

[0183] As an example of this configuration, the allocation unit 11A refers to information indicating the current remaining power of satellite 2A, satellite orbit information, and information indicating the position of the sun as control information. The allocation unit 11A then predicts the remaining power of satellite 2A after a predetermined period (in other words, predicts the amount of electricity that satellite 2A will generate by solar power generation during a predetermined period) and secures transmission power so that the remaining power does not run out after the predetermined period.

[0184] As yet another example, the allocation unit 11A refers to control information and predicts the location of the terminal.

[0185] As an example of this configuration, the allocation unit 11A refers to information indicating the speed at which the first terminal 3A (and at least one of the second terminal 4A, hereinafter the same) is moving, and information indicating the route of the aircraft or ship, as control information. For example, the allocation unit 11A identifies the aircraft or ship on which the first terminal 3A is mounted from the terminal position information and control information of the first terminal 3A, and predicts the position of the first terminal 3A after a predetermined period. The allocation unit 11A then secures antenna elements so that the beam can track the position of the first terminal 3A after the predetermined period. In this case, if the speed at which the first terminal 3A is moving is greater than or equal to the predetermined speed, the allocation unit 11A may use a different beam for the position of the first terminal 3A after the predetermined period.

[0186] As yet another example, the allocation unit 11A refers to control information and predicts the amount of traffic.

[0187] As an example of this configuration, the allocation unit 11A refers to information indicating the past traffic volume from applications that the first terminal 3A and the second terminal 4A communicate with as control information. For example, if the information indicating the past traffic volume shows that the traffic volume will increase between 15:00 and 16:00, the allocation unit 11A predicts that the traffic volume in the area where the first terminal 3A and the second terminal 4A are located will increase between 15:00 and 16:00, and reserves communication resources for that period.

[0188] As another example of this configuration, the allocation unit 11A refers to information indicating the area where a disaster has occurred as control information. For example, if the information indicating the area where a disaster has occurred indicates that a disaster has occurred in a certain area, the allocation unit 11A predicts that the amount of traffic in the vicinity of that area will increase and secures communication resources to be allocated to communications in the vicinity of that area.

[0189] As another example, the allocation unit 11A refers to control information and predicts whether a secure request is necessary.

[0190] As an example of this configuration, the allocation unit 11A refers to information indicating a terminal that has previously made a secure request as control information. For example, if the information indicating a terminal that has previously made a secure request indicates a first terminal 3A (and at least one of the second terminal 4A, hereinafter the same), the allocation unit 11A predicts that a secure request will be made from the first terminal 3A and reserves communication resources (e.g., beam width). In this case, the allocation unit 11A may further refer to information indicating the speed at which the first terminal 3A is moving as control information and reserve communication resources so that the beam can track the position of the first terminal 3A after a predetermined period of time.

[0191] With this configuration, the allocation unit 11A can allocate communication resources according to the future status of the satellite 2A, the first terminal 3A, and the second terminal 4A.

[0192] [Third Exemplary Embodiment] A third exemplary embodiment, which is an example of an embodiment of the present invention, will be described in detail with reference to the drawings. Components having the same function as those described in the above-described exemplary embodiment are denoted by the same reference numerals, and their descriptions are omitted as appropriate. The scope of application of each technology adopted in this exemplary embodiment is not limited to this exemplary embodiment. That is, each technology adopted in this exemplary embodiment can also be adopted in other exemplary embodiments included in this disclosure, to the extent that no particular technical problems arise. Furthermore, each technology shown in the drawings referenced to describe this exemplary embodiment can also be adopted in other exemplary embodiments included in this disclosure, to the extent that no particular technical problems arise.

[0193] (Configuration and Overview of Communication Control System 100B) The configuration and overview of the communication control system 100B will be described with reference to Figure 12. Figure 12 is a block diagram showing the configuration of the communication control system 100B. As shown in Figure 12, the communication control system 100B includes satellite 2_1B, satellite 2_2B, a first terminal 3B, and a second terminal 4B. As shown in Figure 12, satellite 2_1B, satellite 2_2B, the first terminal 3B, and the second terminal 4B are connected to each other via a network so that they can communicate with each other.

[0194] The communication control system 100B differs from the communication control system 100A described above in that it includes multiple satellites.

[0195] In the communication control system 100B, the first terminal 3B and the second terminal 4B communicate via the first satellite 2_1B and the second satellite 2_2B. That is, the first satellite 2_1B and the second satellite 2_2B are relay devices that communicate with the first terminal 3B and the second terminal 4B, respectively. Both the first terminal 3B and the second terminal 4B can perform UL communication and DL communication, but in this disclosure, as an example, the case in which the first terminal 3B performs DL communication and the second terminal 4B performs UL communication will be described. Furthermore, the first terminal 3B communicates with the first satellite 2_1B, and the second terminal 4B communicates with the second satellite 2_2B.

[0196] Furthermore, in the communication control system 100B, similar to the communication control system 100A, the communication resources of the first satellite 2_1B and the second satellite 2_2B are allocated based on the maximum communication capacity that the first satellite 2_1B can provide in communication with the first terminal 3B and the maximum communication capacity that the second satellite 2_2B can provide in communication with the second terminal 4B.

[0197] Furthermore, the communication control system 100B may also include a communication control device that includes a control unit 20_1B (details will be described later) provided on the first satellite 2_1B and a control unit 20_2B provided on the second satellite 2_2B, similar to the communication control system 100A. In this case, the communication control device may be a ground station or may be on a different satellite than the first satellite 20_1B and the second satellite 20_2B.

[0198] The configurations of the first terminal 3B and the second terminal 4B are the same as those of the first terminal 3A and the second terminal 4A described above, so their explanation will be omitted.

[0199] (First Satellite 2_1B) The configuration of the first satellite 2_1B will be explained again with reference to Figure 12. As shown in Figure 12, the first satellite 2_1B includes a control unit 20_1B, a memory unit 28_1B, and a satellite communication unit 29_1B. The memory unit 28_1B and the satellite communication unit 29_1B have the same functions as the memory unit 28A and the satellite communication unit 29A described above, so their explanation will be omitted. The second satellite 2_2B also has the same configuration as the first satellite 2_1B, so its explanation will be omitted.

[0200] (Control Unit 20_1B) The control unit 20_1B controls each component of the first satellite 2_1B. As shown in Figure 12, the control unit 20_1B also includes an allocation unit 11_1B, a setting unit 12_1B, a determination unit 21_1B, an instruction unit 22_1B, an acquisition unit 23_1B, and an output unit 24_1B. In this exemplary embodiment, the allocation unit 11_1B, setting unit 12_1B, determination unit 21_1B, instruction unit 22_1B, and acquisition unit 23_1B each realize the allocation means, setting means, determination means, instruction means, and acquisition means, respectively.

[0201] (Allocation Unit 11_1B) The allocation unit 11_1B allocates communication resources of satellite 2_1B, similar to the allocation unit 11A described above. The allocation unit 11_1B supplies information indicating the allocated communication resources to the setting unit 12_1B.

[0202] As an example, the allocation unit 11_1B refers to the maximum communication capacity CDL that can be provided in communication with the first terminal 3B and the maximum communication capacity CUL that the second satellite 2_2B can provide in communication with the second terminal 4B, and allocates the communication resources to be used in communication with the first terminal 3B.

[0203] Furthermore, the allocation unit 11_1B further refers to the first terminal location information and allocates communication resources to be used in communication with the first terminal 3B.

[0204] (Setting Unit 12_1B) The setting unit 12_1B sets communication resources, similar to the setting unit 12A described above. For example, the setting unit 12_1B sets the communication resources allocated by the allocation unit 11_1B to satellite 2_1B. As another example, if a communication control device different from satellite 2_1B has a control unit 20_1B, the setting unit 12_1B instructs satellite 2_1B to set the communication resources allocated by the allocation unit 11_1B.

[0205] (Decision Unit 21_1B) The decision unit 21_1B determines the communication settings for the first terminal 3B, similar to the decision unit 21A described above. For example, the decision unit 21_1B refers to the communication resources allocated by the allocation unit 11_1B and determines the communication settings for the first terminal 3B. The decision unit 21_1B supplies information indicating the determined communication settings to the instruction unit 22_1B.

[0206] (Instruction Unit 22_1B) Similar to the instruction unit 22A described above, the instruction unit 22_1B instructs the first terminal 3B to communicate based on the communication settings via the satellite communication unit 29_1B. For example, the instruction unit 22_1B refers to the information supplied from the determination unit 21_1B and instructs the first terminal 3B to communicate based on the communication settings determined by the determination unit 21_1B.

[0207] (Acquisition Unit 23_1B) Similar to the acquisition unit 23A described above, the acquisition unit 23_1B acquires data via the satellite communication unit 29_1B. The acquisition unit 23_1B stores the acquired data in the storage unit 28_1B. As an example, the acquisition unit 23_1B acquires the location information of the first terminal.

[0208] Furthermore, the acquisition unit 23_1B acquires the maximum communication capacity CUL that the second satellite 2_2B can provide in communication with the second terminal 4B, which is output from the second satellite 2_2B.

[0209] Furthermore, the acquisition unit 23_1B acquires satellite position information of the first satellite 2_1B.

[0210] (Output Unit 24_1B) The output unit 24_1B outputs data via the satellite communication unit 29_1B. As an example, the output unit 24_1B outputs the maximum available communication capacity CDL to the second satellite 2_2B in communication with the first terminal 3B.

[0211] (Process flow executed in communication control system 100B) The process flow (communication control method) executed in communication control system 100B will be explained with reference to Figures 13 and 14A to 14F. Figure 13 is a flowchart showing the process flow executed in communication control system 100B. Figures 14A to 14F are diagrams showing an example of the process executed in communication control system 100B. In Figures 14A to 14F, both satellite 2_1B and satellite 2_2B are moving to the right.

[0212] (Step S101B) In step S101B, the output unit 43B of the second terminal 4B outputs the second terminal location information to satellite 2_2B. Furthermore, the output unit 43B may output destination information indicating that the communication partner is the first terminal 3B.

[0213] (Step S102B: Acquisition process) In step S102B, the acquisition unit 23_2B of satellite 2_2B acquires the second terminal location information output from the second terminal 4B. Furthermore, the acquisition unit 23_2B acquires the destination information output from the second terminal 4B. The acquisition unit 23_2B stores the acquired second terminal location information and destination information in the storage unit 28_2B.

[0214] (Step S103B) In step S103B, the output unit 33B of the first terminal 3B outputs the first terminal position information to satellite 2_1B.

[0215] (Step S104B: Acquisition process) In step S104B, the acquisition unit 23_1B of the first satellite 2_1B acquires the first terminal location information output from the first terminal 3B. The acquisition unit 23_1B stores the acquired first terminal location information in the storage unit 28_1B.

[0216] (Step S105B) In step S105B, the acquisition unit 23_1B of the first satellite 2_1B acquires satellite position information of the first satellite 2_1B. The acquisition unit 23_1B stores the acquired satellite position information in the storage unit 28_1B.

[0217] (Step S106B) In step S106B, the acquisition unit 23_2B for the second satellite 2_2B acquires satellite position information for the second satellite 2_2B. The acquisition unit 23_2B stores the acquired satellite position information in the storage unit 28_2B.

[0218] (Step S201B) In step S201B, the allocation unit 11_1B of the first satellite 2_1B determines the maximum communication capacity CDL that can be provided in communication with the first terminal 3B. The method by which the allocation unit 11_1B determines the maximum communication capacity CDL is as described in the exemplary embodiment described above. The output unit 24_1B then notifies the second satellite 2_2B of the maximum communication capacity CDL.

[0219] (Step S202B) In step S202B, the acquisition unit 23_2B of the second satellite 2_2B acquires the maximum communication capacity CDL notified from the first satellite 2_1B.

[0220] (Step S203B) In step S203B, the allocation unit 11_2B of the second satellite 2_2B determines the maximum communication capacity CUL that can be provided in communication with the second terminal 4B. The method by which the allocation unit 11_2B determines the maximum communication capacity CUL is as described in the exemplary embodiment above. The output unit 24_2B then notifies the first satellite 2_1B of the maximum communication capacity CUL.

[0221] (Step S204B) In step S204B, the acquisition unit 23_1B of the first satellite 2_1B acquires the maximum communication capacity CUL notified by the second satellite 2_2B.

[0222] (Step S11_1B: Allocation process) In step S11_1B, the allocation unit 11_1B of the first satellite 2_1B compares the determined maximum communication capacity CDL with the maximum communication capacity CUL acquired by the acquisition unit 23_1B in step S204B.

[0223] Here, as shown in Figure 14A, if the distance between satellite 2_1B and the first terminal 3B is shorter than the distance between satellite 2_2B and the second terminal 4B, the maximum communication capacity CDL will be greater than the maximum communication capacity CUL (CDL > CUL).

[0224] In this case, the allocation unit 11_1B determines the communication capacity for communication with the first terminal 3B to be the minimum communication capacity that is not less than the maximum communication capacity CUL. As an example, the allocation unit 11_1B determines the communication capacity for communication with the first terminal 3B to be the maximum communication capacity CUL.

[0225] The allocation unit 11_1B then allocates communication resources to satisfy the determined communication capacity. For example, the allocation unit 11_1B allocates the number of antenna elements, transmission power, and bandwidth to satisfy the determined communication capacity. As an example, the allocation unit 11_1B allocates bandwidth b1 for communication with the first terminal 3B, as shown in Figure 14B.

[0226] (Step S11_2B: Allocation process) In step S11_2B, the allocation unit 11_2B of the second satellite 2_2B compares the determined maximum communication capacity CUL with the maximum communication capacity CDL acquired by the acquisition unit 23_2B in step S202B.

[0227] As described above, if the maximum communication capacity CDL is greater than the maximum communication capacity CUL (CDL > CUL), the allocation unit 11_2B determines the communication capacity for communication with the second terminal 4B to be the maximum communication capacity CUL.

[0228] The allocation unit 11_2B then allocates communication resources to satisfy the determined communication capacity. For example, the allocation unit 11_2B allocates the number of antenna elements, transmission power, and bandwidth to satisfy the determined communication capacity. As an example, the allocation unit 11_2B allocates bandwidth b2 for communication with the second terminal 4B, as shown in Figure 14B.

[0229] (Step S12_1B: Setting process) In step S12_1B, the setting unit 12_1B sets the communication resources allocated by the allocation unit 11_1B to the satellite 2_1B. For example, the setting unit 12_1B sets the number of antenna elements, transmission power, and bandwidth allocated by the allocation unit 11_1B.

[0230] (Step S12_2B: Setting process) In step S12_2B, the setting unit 12_2B sets the communication resources allocated by the allocation unit 11_2B to satellite 2_2B. For example, the setting unit 12_2B sets the number of antenna elements, transmission power, and bandwidth allocated by the allocation unit 11_2B.

[0231] (Step S21_1B: Decision Process) In step S21_1B, the decision unit 21_1B refers to the communication resources allocated by the allocation unit 11_1B and determines the communication settings for DL ​​communication between the first terminal 3B and the first satellite 2_1B. The decision unit 21_1B supplies information indicating the determined communication settings to the instruction unit 22_1B.

[0232] For example, the determination unit 21_1B refers to the communication resources allocated by the allocation unit 11_1B and determines the modulation scheme and coding rate. As an example, as shown in Figure 14A, the determination unit 21_1B determines the modulation scheme to be QPSK.

[0233] (Step S21_2B: Decision Process) In step S21_2B, the decision unit 21_2B refers to the communication resources allocated by the allocation unit 11_2B and determines the communication settings for UL communication between the second terminal 4B and the second satellite 2_2B. The decision unit 21_2B supplies information indicating the determined communication settings to the instruction unit 22_2B.

[0234] For example, the determination unit 21_2B refers to the communication resources allocated by the allocation unit 11_2B and determines the modulation scheme and coding rate. As an example, as shown in Figure 14A, the determination unit 21_2B determines the modulation scheme to be QPSK.

[0235] (Step S22B: Instruction Processing) In step S22B, the instruction unit 22_1B refers to the information supplied by the determination unit 21_1B and instructs the first terminal 3B to communicate based on the communication settings determined by the determination unit 21_1B.

[0236] (Step S31B: Reception processing) In step S31B, the reception unit 31B of the first terminal 3B receives instructions from satellite 2_1B.

[0237] (Step S32B: Communication Processing) In step S32B, the communication unit 32B communicates with the second terminal 4B via the first satellite 2_1B and the second satellite 2_2B based on the instructions received by the reception unit 31B.

[0238] (Step S23B: Instruction Processing) In step S23B, the instruction unit 22_2B of the second satellite 2_2B refers to the information supplied from the decision unit 21_2B and instructs the second terminal 4B to communicate based on the communication settings determined by the decision unit 21_2B.

[0239] (Step S41B: Reception processing) In step S41B, the reception unit 41B of the second terminal 4B receives instructions from satellite 2_2B.

[0240] (Step S42B: Communication Processing) In step S42B, the communication unit 42B communicates with the first terminal 3B via the second satellite 2_2B and the first satellite 2_1B based on the instructions received by the reception unit 41B.

[0241] (Example 1 of processing to be performed when satellites 2_1B and 2_2B move) An example of processing to be performed when satellites 2_1B and 2_2B move will be explained with reference to Figure 14C. For example, let's assume that satellites 2_1B and 2_2B move, and that the distance between satellite 2_1B and the first terminal 3B and the distance between satellite 2_2B and the second terminal 4B are approximately equal, as shown in Figure 14C.

[0242] In this case as well, as in the example described above, steps S101B to S204B are executed in the communication control system 100B.

[0243] Then, in step S11_1B, the allocation unit 11_1B of the first satellite 2_1B allocates communication resources in the same manner as in step S11_1B described above.

[0244] In this case, as shown in Figure 14C, the distance between satellite 2_1B and the first terminal 3B is approximately equal to the distance between satellite 2_2B and the second terminal 4B, so the maximum communication capacity CDL and the maximum communication capacity CUL are equal (CDL = CUL).

[0245] In this case, the allocation unit 11_1B determines the communication capacity for communication with the first terminal 3B to be the maximum communication capacity CDL. Then, as shown in Figure 14D, the allocation unit 11_1B allocates the bandwidth b1 for communication with the first terminal 3B.

[0246] Similarly, in step S11_2B, the allocation unit 11_2B of the second satellite 2_2B determines the communication capacity for communication with the second terminal 4B to the maximum communication capacity CUL. Then, as shown in Figure 14D, the allocation unit 11_2B allocates the bandwidth b2 for communication with the second terminal 4B.

[0247] In other words, as satellite 2_2B moves and the distance between satellite 2_2B and the second terminal 4B decreases, the maximum communication capacity CUL that can be provided in communication between satellite 2_2B and the second terminal 4B improves. Therefore, allocation units 11_1B and 11_2B allocate wider bandwidths b1 and b2 compared to the bandwidths b1 and b2 shown in Figure 14B.

[0248] Next, in steps S12_1B and S12_2B, similar to the example described above, the setting unit 12_1B and the setting unit 12_2B set the communication resources allocated by the allocation unit 11_1B and the allocation unit 11_2B, respectively, to satellites 2_1B and 2_2B.

[0249] Next, in step S21_1B, the determination unit 21_1B, similar to the example described above, refers to the communication resources allocated by the allocation unit 11_1B and determines the communication settings for DL ​​communication between the first terminal 3B and the first satellite 2_1B. For example, as shown in Figure 14C, the determination unit 21_1B determines 16QAM, a modulation scheme with an increased number of modulation levels compared to the case shown in Figure 14A, and determines a high coding rate.

[0250] Similarly, in step S21_2B, the determination unit 21_2B determines the communication settings for UL communication between the second terminal 4B and the second satellite 2_2B to be 16QAM, which is a modulation scheme with an increased number of modulation levels, and determines a high coding rate.

[0251] In the following steps, as in the example described above, steps S22B to S42B are executed in the communication control system 100B.

[0252] (Example 2 of processing to be performed when satellites 2_1B and 2_2B move) An example of processing to be performed when satellites 2_1B and 2_2B move further will be explained with reference to Figure 14E. For example, suppose satellites 2_1B and 2_2B move, and as shown in Figure 14E, the distance between satellite 2_1B and the first terminal 3B becomes longer than the distance between satellite 2_2B and the second terminal 4B.

[0253] In this case as well, as in the example described above, steps S101B to S204B are executed in the communication control system 100B.

[0254] Then, in step S11_1B, the allocation unit 11_1B of the first satellite 2_1B allocates communication resources in the same manner as in step S11_1B described above.

[0255] In this case, as shown in Figure 14E, the distance between satellite 2_1B and the first terminal 3B is longer than the distance between satellite 2_2B and the second terminal 4B, so the maximum communication capacity CDL is smaller than the maximum communication capacity CUL (CDL < CUL).

[0256] In this case, the allocation unit 11_1B determines the communication capacity for communication with the first terminal 3B to be the maximum communication capacity CDL. Then, as shown in Figure 14F, the allocation unit 11_1B allocates the bandwidth b1 for communication with the first terminal 3B.

[0257] Similarly, in step S11_2B, the allocation unit 11_2B of the second satellite 2_2B determines the communication capacity for communication with the second terminal 4B to be the minimum communication capacity that is not less than the maximum communication capacity CDL. As an example, the allocation unit 11_1B determines the communication capacity for communication with the first terminal 3B to be the maximum communication capacity CDL. Then, as shown in Figure 14F, the allocation unit 11_1B allocates the bandwidth b2 for communication with the second terminal 4B.

[0258] In other words, as satellite 2_1B moves and the distance between satellite 2_1B and the first terminal 3B increases, the maximum communication capacity (CDL) that can be provided in communication between satellite 2_1B and the first terminal 3B decreases. Therefore, allocation units 11_1B and 11_2B allocate narrower bandwidths b1 and b2 compared to the bandwidths b1 and b2 shown in Figure 14C.

[0259] Next, in steps S12_1B and S12_2B, similar to the example described above, the setting unit 12_1B and the setting unit 12_2B set the communication resources allocated by the allocation unit 11_1B and the allocation unit 11_2B, respectively, to satellites 2_1B and 2_2B.

[0260] Next, in step S21_1B, the determination unit 21_1B, similar to the example described above, refers to the communication resources allocated by the allocation unit 11_1B and determines the communication settings for DL ​​communication between the first terminal 3B and the first satellite 2_1B. For example, as shown in Figure 14E, the determination unit 21_1B determines QPSK, which is a modulation scheme with a reduced number of modulation levels compared to the case shown in Figure 14C, and determines the coding rate.

[0261] Similarly, in step S21_2B, the determination unit 21_2B determines the communication settings for UL communication between the second terminal 4B and the second satellite 2_2B to be QPSK, which is a modulation scheme with a reduced number of modulation levels, and determines a low coding rate.

[0262] In the following steps, as in the example described above, steps S22B to S42B are executed in the communication control system 100B.

[0263] (Effects of the communication control system 100B) As described above, the communication control system 100B refers to the maximum communication capacity CDL that satellite 2_1B can provide in communication with the first terminal 3B and the maximum communication capacity CUL that satellite 2_2B can provide in communication with the second terminal 4B, and allocates communication resources to be used in communication with the first terminal 3B and the second terminal 4B, respectively.

[0264] Therefore, the communication control system 100B can efficiently allocate communication resources even when communicating through multiple relay devices.

[0265] Furthermore, even when the relay device moves, such as between satellites 2_1B and 2_2B, communication resources can be efficiently allocated according to the respective locations of satellite 2_1B, satellite 2_2B, the first terminal 3B, and the second terminal 4B.

[0266] [Fourth Exemplary Embodiment] A fourth exemplary embodiment, which is an example of an embodiment of the present invention, will be described in detail with reference to the drawings. The fourth exemplary embodiment of this disclosure is an embodiment that embodies Modification 1 of the second exemplary embodiment described above. Components having the same function as components described in the above-described exemplary embodiments are denoted by the same reference numerals, and their descriptions are omitted as appropriate. The scope of application of each technology adopted in this exemplary embodiment is not limited to this exemplary embodiment. That is, each technology adopted in this exemplary embodiment can also be adopted in other exemplary embodiments included in this disclosure to the extent that no particular technical problems occur. Furthermore, each technology shown in each drawing referenced to describe this exemplary embodiment can also be adopted in other exemplary embodiments included in this disclosure to the extent that no particular technical problems occur.

[0267] (Configuration and Overview of Communication Control System 100A) The configuration and overview of the communication control system 100A will be described with reference to Figure 7. Figure 7 is a block diagram showing the configuration of the communication control system 100A. As shown in Figure 7, the communication control system 100A includes a satellite 2A, a first terminal 3A, and a second terminal 4A. As shown in Figure 7, the satellite 2A, the first terminal 3A, and the second terminal 4A can communicate via a network. The network is not particularly limited and may be a wireless communication network using radio waves, etc., or a wired communication network using optical fibers, etc.

[0268] In the communication control system 100A, the first terminal 3A and the second terminal 4A communicate via satellite 2A. That is, satellite 2A is a relay device that communicates between the first terminal 3A and the second terminal 4A. Both the first terminal 3A and the second terminal 4A can perform UL communication and DL communication, but in this disclosure, as an example, the case in which the first terminal 3A performs DL communication and the second terminal 4A performs UL communication will be described.

[0269] Furthermore, while this exemplary embodiment describes a case where the first terminal 3A and the second terminal 4A communicate via satellite 2A, the communication control system 100A is not limited to this configuration. In the communication control system 100A, instead of satellite 2A, communication between the first terminal 3A and the second terminal 4A may be conducted via a ground station equipped with the functions of satellite 2A.

[0270] Furthermore, the communication control system 100A may also include a communication control device equipped with a control unit 20A (details of which will be described later) on satellite 2A, in addition to satellite 2A, the first terminal 3A, and the second terminal 4A. In this case, the communication control device may be a ground station or a satellite other than satellite 2A.

[0271] Furthermore, in the communication control system 100A, satellite 2A refers to the maximum communication capacity CDL that can be provided in communication with the first terminal 3A and the maximum communication capacity CUL that can be communicated in communication with the second terminal 4A, and allocates communication resources to be used in communication with the first terminal 3A and the second terminal 4A, respectively. In other words, satellite 2A has the functions of the communication control device 1 or communication control device 2 in the exemplary embodiment described above.

[0272] The communication control system 100A according to this embodiment is the same as the communication control system 100A according to the second exemplary embodiment, except for the differences described below. The first terminal 3A, the second terminal 4A, and the satellite 2A according to this exemplary embodiment are the same as the first terminal 3A, the second terminal 4A, and the satellite 2A according to the second exemplary embodiment, except for the differences described below. The components of the first terminal 3A, the second terminal 4A, and the satellite 2A are the same as the components of the first terminal 3A, the second terminal 4A, or the satellite 2A according to the second exemplary embodiment that are assigned the same name and the same reference numerals, except for the differences described below. The following description will focus on the differences between the fourth exemplary embodiment and the second exemplary embodiment.

[0273] (Allocation Unit 11A) Allocation Unit 11A has the same functions as Allocation Unit 11A in the second exemplary embodiment. Allocation Unit 11A allocates communication resources other than the time period during which the beam is irradiated onto the terminals, as described later, in the same manner as allocation by Allocation Unit 11A in the second exemplary embodiment. Allocation Unit 11A may further allocate the communication resources of satellite 2A to transmissions with the first terminal 3A and the second terminal 4A, respectively, according to the delay time of the traffic in transmissions with each of the first terminal 3A and the second terminal 4A. For example, if the number of terminals is greater than the number of beams that satellite 2A can irradiate, Allocation Unit 11A may allocate the time period during which the beam is irradiated onto the terminals by time division, using time as the communication resource. Specifically, if the number of first terminals 3A (or groups of first terminals 3A) is greater than the number of DL communication beams of satellite 2A, the allocation unit 11A uses time as a communication resource and allocates time periods in which beams are directed to each of the first terminals 3A (or groups of first terminals 3A) by time division. If the number of second terminals 4A (or groups of second terminals 4A) is greater than the number of UL communication beams of satellite 2A, the allocation unit 11A uses time as a communication resource and allocates time periods in which beams are directed to each of the second terminals 4A (or groups of second terminals 4A) by time division.

[0274] As described above, the allocation unit 11A allocates communication resources of satellite 2A. The allocation unit 11A supplies information indicating the allocated communication resources to the setting unit 12A.

[0275] As described above, the setting unit 12A sets the communication resources. For example, the setting unit 12A sets the communication resources allocated by the allocation unit 11A to satellite 2A. As another example, if a communication control device different from satellite 2A has a control unit 20A, the setting unit 12A instructs satellite 2A to set the communication resources allocated by the allocation unit 11A.

[0276] As described above, the determination unit 21A determines the communication settings for communication with the first terminal 3A and communication with the second terminal 4A, respectively. For example, the determination unit 21A refers to the communication resources allocated by the allocation unit 11A and determines at least one of the communication settings for DL ​​communication between the first terminal 3A and satellite 2A and the communication settings for UL communication between the second terminal 4A and satellite 2A. The determination unit 21A supplies information indicating the determined communication settings to the instruction unit 22A. For example, the determination unit 21A determines the transmission power of the first terminal 3A or the transmission power of the second terminal 4A as the communication setting. In this exemplary embodiment, since the second terminal 4A is configured to perform UL communication, the determination unit 21A determines the transmission power of the second terminal 4A as the communication setting.

[0277] As described above, the instruction unit 22A instructs the first terminal 3A and the second terminal 4A, respectively, via the satellite communication unit 29A to communicate based on the communication settings. For example, the instruction unit 22A refers to the information supplied from the determination unit 21A and instructs at least one of the first terminal 3A and the second terminal 4A to communicate based on the communication settings determined by the determination unit 21A. The method by which the instruction unit 22A gives instructions is not limited, but for example, the instruction unit 22A instructs the first terminal 3A and the second terminal 4A to communicate based on the communication settings by transmitting information indicating the communication settings to the first terminal 3A and the second terminal 4A.

[0278] In this way, by the allocation unit 11A making the above-described time allocations, satellite 2A switches the terminals (or groups of terminals) to which the beam is directed using time-division multiplexing, with time as the communication resource. By switching the terminals (or groups of terminals) to which the beam is directed, satellite 2A switches the terminals (or groups of terminals) to which communication takes place using time-division multiplexing. Note that this terminal is a collective term for the first terminal 3A and the second terminal 4A. The group of terminals is a collective term for the group of first terminals 3A (i.e., a group of multiple first terminals 3A) and the group of second terminals 4A (i.e., a group of multiple second terminals 4A).

[0279] The length of time that satellite 2A continuously irradiates a terminal (or group of terminals) with a beam (i.e., the length of time that satellite 2A and the terminal (or group of terminals) continuously communicate) may be a predetermined length (i.e., a fixed length determined in advance). The allocation unit 11A may, for example, determine the length of time that satellite 2A continuously irradiates a terminal (or group of terminals) with a beam so that the amount of traffic during the time that satellite 2A continuously irradiates a terminal (or group of terminals) with a beam reaches a predetermined amount (i.e., a fixed amount determined in advance). The amount of traffic may be, for example, the number of packets. In the following explanation, the time that satellite 2A continuously irradiates a terminal (or group of terminals) with a beam will also be referred to as the communication duration. The length of the communication duration will also be referred to as the communication duration length.

[0280] In time-division beam irradiation, satellite 2A communicates with a certain terminal (or group of terminals) for a predetermined time (i.e., the communication duration mentioned above), then irradiates a different group of terminals with the beam and continues communication for a predetermined time, repeating this process. Specifically, after satellite 2A and a certain terminal (or group of terminals) begin communication and the communication duration has elapsed, the allocation unit 11A assigns a time slot for communication to the next terminal (or group of terminals) to communicate. As a result, satellite 2A and the terminal (or group of terminals) to which the time slot has been assigned begin communication. Note that the allocation unit 11A does not need to select terminals that are included in the allocated time slot (i.e., terminals to which the beam is being shone at the time of time slot assignment) as terminals to which a new time slot will be assigned. In this way, the allocation unit 11A assigns a time slot for communication to a terminal (or group of terminals), and the communication between satellite 2A and the terminal (or group of terminals) to which the time slot has been assigned is repeated for the duration of the communication. The allocation unit 11A allocates communication time slots for each beam.

[0281] The following section will explain in detail how the allocation unit 11A allocates time slots according to the delay time.

[0282] Figure 16 is a schematic diagram illustrating an example of delay time related to this disclosure. Traffic delay time will be explained using Figure 16. Figure 16 shows an example of packet delay time generated as traffic relating to any terminal. Specifically, the example in Figure 16 shows an example of delay time for packets 1, 2, and 3 generated as traffic at the second terminal 4A in UL communication. The example in Figure 16 may also show an example of delay time for packets 1, 2, and 3 received by a satellite in DL communication. Packets 1, 2, and 3 are generated in the order of packets 1, 2, and 3, and transmitted in the order of packets 1, 2, and 3.

[0283] The delay time includes at least one of the processing time, waiting time, transmission time, and propagation time. The delay time may include the processing time, waiting time, transmission time, and propagation time. In this case, the delay time is, for example, the sum of the processing time, waiting time, transmission time, and propagation time. Irradiation period 1 and irradiation period 2 are the periods during which the terminal is irradiated. In the example in Figure 16, packets 1 and 2 are transmitted during irradiation period 1. Packet 3 is not irradiated during irradiation period 1, but is irradiated during irradiation period 2. The delay time d1_A for packet 1 and the delay time d2_A for packet 2 are the periods from when the packets are generated until the propagation time ends during irradiation period 1. The delay time d3_A for packet 3 is the periods from when the packets are generated until the propagation time ends during irradiation period 2.

[0284] Storing a packet in the transmission queue requires time. In UL communication, processing time is the time from when the packet is generated until it is stored in the transmission queue (i.e., until the storage of the packet in the transmission queue is complete). In DL communication, processing time is the time from when satellite 2A receives the packet until it is stored in the transmission queue. In the example in Figure 16, the storage of packet 2 in the queue begins only after the storage of packet 1 in the queue is complete. That is, the processing time for packet 2 begins only after the processing time for packet 1 has finished. Similarly, the storage of packet 3 in the queue begins only after the storage of packet 2 in the queue is complete.

[0285] Furthermore, since traffic cannot be transmitted while the beam is not illuminating, a waiting time (queuing delay) occurs between the time a packet is stored in the transmission queue and the time the beam is illuminating and packet transmission begins. This waiting time is the aforementioned waiting time included in the total delay.

[0286] When satellite 2A illuminates the beam and traffic transmission (i.e., transmission of packets stored in the transmit queue) becomes possible, packets are read from the transmit queue and transmitted (in other words, sent out into the communication channel). Reading packets from the transmit queue takes time. The time from when the reading of a packet from the transmit queue begins until the sending of that packet into the communication channel is completed (in other words, the transmission of that packet is completed) is the transmission time. The transmission time is expressed as packet size [bits] / maximum available communication capacity [bps] (bits per second).

[0287] A transmitted packet propagates along the communication channel and reaches its destination. In UL communication, the destination is satellite 2A. In DL communication, the destination is one of the terminals. It takes time for a transmitted packet to propagate along the communication channel. The time it takes for a packet to propagate along the communication channel is called the propagation time. Propagation time may be defined as, for example, the time from when the packet is finished being sent to the communication channel until the reception of that packet is finished, as shown in the example in Figure 16. Propagation time may also be defined as the time during which at least a portion of the packets' bits are propagating along the communication channel. In this case, the propagation time is the time from when the propagation of at least a portion of the packets to the communication channel begins until the reception of that packet is finished.

[0288] In some cases, the transmitting device (i.e., at least one of satellite 2A and the terminal that transmits the packet) may be configured such that while a bit of a packet is being read from the transmit queue, bits read before that bit are transmitted. In such cases, if propagation time is defined as the time from when propagation of the packet to at least a portion of the communication channels begins until the reception of that packet is completed, then the transmission time overlaps with the propagation time. In such cases, the transmission time and propagation time may be treated as a single block of time from the start of the transmission time to the end of the propagation time. That is, the delay time may include the time from the start of the transmission time to the end of the propagation time as part of the transmission time and propagation time. When the transmission of a packet (i.e., reading the packet from the transmit queue and transmitting the read packet) is completed, the transmission of the next packet to be transmitted begins.

[0289] In the example shown in Figure 16, packets are transmitted during transmission period 1 and transmission period 2. Packets that are transmitted and propagated during a transmission period (i.e., transmission period 1 or transmission period 2) are transmitted during that transmission period. However, in the case of UL communication, there is a limit to the amount of data (in other words, the traffic capacity) that satellite 2A can buffer. Therefore, in UL communication, the total amount of traffic that can be transmitted during an irradiation period is less than or equal to the available buffer capacity (i.e., transmission queue) that satellite 2A can buffer during that irradiation period. In the case of UL communication, the upper limit of the total traffic that can be transmitted during an irradiation period is the smaller of the maximum amount of traffic that is transmitted and propagated during that irradiation period and the available buffer capacity that satellite 2A can buffer during that irradiation period.

[0290] In the example shown in Figure 16, the packets whose transmission and propagation are completed during irradiation period 1 are packet 1 and packet 2. The allocation unit 11A calculates the sum of the delay times of the packets whose transmission and propagation are completed during a given irradiation period as the delay time for that irradiation period. For example, the allocation unit 11A calculates the sum of the delay times of the packets whose transmission and propagation are completed during irradiation period 1 (i.e., d1_A + d2_A, which is the sum of the delay time d1_A of packet 1 and the delay time d2_A of packet 2) as the delay time for irradiation period 1. The packet whose transmission and propagation are completed during irradiation period 2 is packet 3. In this case, the allocation unit 11A sets the delay time for irradiation period 2 to d3_A, which is the delay time of packet 3 during irradiation period 2. In this disclosure, the delay time of a packet may be referred to as packet delay time, and the sum of the delay times of the traffic that can be transmitted during a given irradiation period (in other words, packets whose transmission and propagation are completed during that irradiation period) may be referred to as total delay time.

[0291] The allocation unit 11A may determine the transmittable traffic as follows: The allocation unit 11A calculates the capacity [bit] of packets that can be transmitted within the beam irradiation period by multiplying the maximum available communication capacity [bps] by the beam irradiation period [s] (second). Next, the allocation unit 11A calculates the number of packets that can be transmitted within the beam irradiation period by dividing the capacity [bit] of packets that can be transmitted within the beam irradiation period by the packet size [bit]. The allocation unit 11A considers the number of packets that can be transmitted as transmittable traffic, in the order in which the packets are generated.

[0292] In UL communication, when the irradiation period allocated to a second terminal 4A ends, the allocation unit 11A calculates for each second terminal 4A the delay time of the traffic that can be transmitted after the predetermined irradiation time (i.e., the length of the irradiation period). The delay time of the traffic that can be transmitted after the predetermined irradiation time for a given second terminal 4A (i.e., the total delay time) is the sum of the delay times of packets generated at that second terminal 4A that complete transmission and propagation within the irradiation period (i.e., packet delay times).

[0293] This irradiation period may be, for example, a period of a predetermined length. The irradiation period, that is, the start time and end time of this irradiation period, may be predetermined. This irradiation period may be, for example, a period of length during which the second terminal 4A can transmit a predetermined number of packets (i.e., during which the transmission and propagation of a predetermined number of packets from the second terminal 4A can be completed). In this case, the allocation unit 11A allocates an available communication resource other than the irradiation period to communication with the second terminal 4A in the same manner as the method for allocating communication resources in the second exemplary embodiment, and further calculates the length of time during which the transmission and propagation of a predetermined number of packets from the second terminal 4A can be completed when the irradiation period is allocated (i.e., the beam is irradiated onto the second terminal 4A for the duration of the irradiation period). Specifically, the allocation unit 11A first allocates available communication resources to the second terminal 4A and calculates the communication capacity between the satellite 2A and the second terminal 4A, assuming that the beam is irradiated to the second terminal 4A for the duration of the irradiation period. Then, the allocation unit 11A calculates the total delay time, which is the length of time required for the transmission and propagation of a predetermined number of packets from the second terminal 4A to be completed, given that the communication capacity between the satellite 2A and the second terminal 4A is the calculated communication capacity.

[0294] The assignable communication resources may be the maximum assignable resources. The allocation unit 11A sets the calculated length of the period as the length of the irradiation period. The maximum assignable communication resources described above are, if there are other second terminals 4A communicating, the maximum assignable communication resources that can be assigned to the second terminal 4A, excluding the communication resources assigned to other second terminals 4A communicating with satellite 2A. The maximum assignable communication resources described above are, if there are no other second terminals 4A communicating, the maximum assignable communication resources that can be assigned to the second terminal 4A, excluding the communication resources assigned to other second terminals 4A communicating with satellite 2A. The assignable communication resources may be a predetermined percentage of the maximum assignable communication resources for each of the multiple types of communication resources. The assignable communication resources may be, for each of the multiple types of communication resources, the maximum assignable communication resources prorated by the number of beams that can be newly irradiated.

[0295] The assignable communication resources may be assignable communication resources calculated by other calculation methods. For example, the allocation unit 11A may allocate a predetermined fixed amount of communication resources to the second terminal 4A as communication resources other than the irradiation period, and further calculate the total delay time when the beam is irradiated to the second terminal 4A during the irradiation period. Specifically, the allocation unit 11A may calculate the communication capacity in such a case and use the calculated communication capacity to calculate the total delay time. As described above, the allocation unit 11A calculates the communication capacity of the communication between the satellite 2A and the second terminal 4A when communication resources are allocated to the second terminal 4A according to a predetermined allocation method, and uses the calculated communication capacity to calculate the total delay time of the communication between the satellite 2A and the second terminal 4A. In the following description, we will explain the case in which the predetermined allocation method is a method of allocating assignable communication resources (specifically, a method of allocating assignable communication resources other than the irradiation period and the irradiation period from among the communication resources). If a predetermined allocation method other than the method of allocating available communication resources is used as the predetermined allocation method, the term "allocable communication resources" in the following description may be read as "communication resources when communication resources are allocated according to the predetermined allocation method." When distinguishing the predetermined allocation method for allocating resources to the second terminal 4A from the predetermined allocation method for allocating resources to the first terminal 3A described later, the predetermined allocation method for allocating resources to the second terminal 4A will be referred to as the predetermined second allocation method.

[0296] The allocation unit 11A determines the beam direction so as to prioritize irradiating the beam to the second terminal 4A with the largest calculated delay time (in this case, the total delay time). In other words, the allocation unit 11A selects the same number of second terminals 4A from among the second terminals 4A, starting with those with larger delay times, as the second terminals 4A to which the beam will be irradiated (i.e., the second terminals 4A to which the irradiation period will be assigned). The allocation unit 11A determines the direction in which the selected second terminals 4A will be irradiated as the direction in which the beam will be irradiated. The allocation unit 11A further assigns the irradiation period of the beam irradiated toward the selected second terminals 4A. The allocation unit 11A further assigns communication resources other than the irradiation period to the selected second terminals 4A in the same manner as the method for allocating communication resources in the second exemplary embodiment.

[0297] In DL communication, when the irradiation period allocated to the first terminal 3A ends, the allocation unit 11A calculates the delay time for the traffic that can be transmitted within the predetermined irradiation time from the traffic buffered by satellite 2A, for each destination first terminal 3A. The delay time for the traffic that can be transmitted within the irradiation period for a given first terminal 3A (i.e., the total delay time) is the sum of the delay times for packets that have been transmitted and propagated within the predetermined irradiation period from the packets generated at that first terminal 3A (i.e., the packet delay times).

[0298] This irradiation period may be, for example, a period of a predetermined length. The irradiation period, that is, the start time and end time of this irradiation period, may be predetermined. This irradiation period may be, for example, a period of length that allows a predetermined number of packets to be transmitted to the first terminal 3A (i.e., that allows the transmission and propagation of a predetermined number of packets to the first terminal 3A to be completed). In this case, the allocation unit 11A allocates an available communication resource other than the irradiation period to communication with the first terminal 3A in the same way as the method for allocating communication resources in the second exemplary embodiment, and further calculates the length of time that allows the transmission and propagation of a predetermined number of packets to be completed when the irradiation period is allocated (i.e., the beam is irradiated onto the first terminal 3A for the duration of the irradiation period). Specifically, the allocation unit 11A first allocates available communication resources to the first terminal 3A and calculates the communication capacity between the satellite 2A and the first terminal 3A, assuming that the beam is irradiated to the first terminal 3A for the duration of the irradiation period. Then, the allocation unit 11A calculates the total delay time, which is the length of time required for the transmission and propagation of a predetermined number of packets from the first terminal 3A to be completed, given that the communication capacity between the satellite 2A and the first terminal 3A is the calculated communication capacity.

[0299] The assignable communication resources may be the maximum assignable resources. The assignment unit 11A sets the calculated length of the period as the length of the irradiation period. The maximum assignable communication resources described above are, if there are other first terminals 3A communicating, the maximum assignable communication resources that can be assigned to the first terminal 3A, excluding the communication resources assigned to other first terminals 3A communicating with satellite 2A. The maximum assignable communication resources described above are, if there are no other first terminals 3A communicating, the maximum assignable communication resources that can be assigned to the first terminal 3A, excluding the communication resources assigned to other first terminals 3A communicating with satellite 2A. The assignable communication resources may be a predetermined percentage of the maximum assignable communication resources for each of the multiple types of communication resources. The assignable communication resources may be, for each of the multiple types of communication resources, the maximum assignable communication resources prorated by the number of beams that can be newly irradiated.

[0300] The assignable communication resources may be assignable communication resources calculated by other calculation methods. For example, the allocation unit 11A may allocate a predetermined fixed amount of communication resources to the first terminal 3A as communication resources other than the irradiation period, and further calculate the total delay time when the beam is irradiated to the first terminal 3A during the irradiation period. Specifically, the allocation unit 11A may calculate the communication capacity in such a case and use the calculated communication capacity to calculate the total delay time. As described above, the allocation unit 11A calculates the communication capacity of the communication between the satellite 2A and the first terminal 3A when communication resources are allocated to the first terminal 3A according to a predetermined allocation method, and uses the calculated communication capacity to calculate the total delay time of the communication between the satellite 2A and the first terminal 3A. In the following description, we will explain the case in which the predetermined allocation method is a method of allocating assignable communication resources (specifically, a method of allocating assignable communication resources other than the irradiation period and the irradiation period from among the communication resources). If a predetermined allocation method other than the method of allocating allocatable communication resources is used as the predetermined allocation method, the term "allocatable communication resources" in the following description may be read as "communication resources when communication resources are allocated according to the predetermined allocation method." When distinguishing the predetermined allocation method for allocating resources to the first terminal 3A from the aforementioned predetermined allocation method for allocating resources to the second terminal 4A, the predetermined allocation method for allocating resources to the first terminal 3A will be referred to as the predetermined first allocation method.

[0301] The allocation unit 11A determines the beam direction so as to prioritize irradiating the beam to the first terminal 3A with the largest calculated delay time (in this case, total delay time). In other words, the allocation unit 11A selects the same number of first terminals 3A from among the first terminals 3A with larger delay times as the beams that have not been assigned an irradiation period, as the first terminals 3A to be irradiated with the beam (i.e., the first terminals 3A to which an irradiation period is assigned). The allocation unit 11A determines the direction in which the selected first terminals 3A are irradiated as the direction in which the beam is irradiated. The allocation unit 11A further assigns the irradiation period of the beam irradiated toward the selected first terminals 3A. The allocation unit 11A further assigns communication resources other than the irradiation period to the selected first terminals 3A in the same manner as the method for allocating communication resources in the second exemplary embodiment.

[0302] In the configuration of this exemplary embodiment, by referring to the delay time of the traffic that can actually be transmitted, it is possible to prevent situations where resources are wasted and traffic cannot be transmitted even when the beam is irradiated, and delay time can be efficiently reduced. This delay time is not the time that packets are delayed because they are stored in a queue, but the data relay latency from the time a packet is generated at the terminal that transmits the packet until the terminal that receives the packet receives it. An example of a situation where resources are wasted and traffic cannot be transmitted even when the beam is irradiated is, in UL communication, a situation where the second terminal 4 cannot transmit traffic because there is no free capacity in the buffer of satellite 2A, even though the beam is irradiated to the second terminal 4. Also, for example, if a beam is irradiated to a terminal whose maximum available communication capacity is smaller than that of other terminals, the amount of traffic that can be transmitted per unit time will be small. Another example of a situation where resources are wasted and traffic cannot be transmitted even when the beam is irradiated is when the length of the irradiation period is fixed, and the amount of traffic that can be transmitted within the irradiation period is small compared to other terminals when communicating with a terminal whose maximum available communication capacity is smaller than that of other terminals.

[0303] The above explanation describes an example in which the allocation unit 11A performs scheduling, i.e., allocation of irradiation periods, on a user-by-user basis (i.e., on a terminal-by-terminal basis (in other words, on a first terminal 3A or second terminal 4A) basis). The allocation unit 11A may also perform scheduling, i.e., allocation of irradiation periods, on a packet-by-packet basis. In this case, when the irradiation period for a terminal (or group of terminals) ends, the allocation unit 11A selects the same number of packets as beams that have not been allocated an irradiation period, starting with those packets with the largest delay time.

[0304] In the case of UL communication, the allocation unit 11A determines the direction of the beam to be emitted to the second terminal 4A that will transmit the selected packet. The allocation unit 11A further allocates the beam irradiation period to the selected second terminal 4A. The allocation unit 11A further allocates communication resources other than the irradiation period to the selected second terminal 4A in the same manner as the method for allocating communication resources in the second exemplary embodiment.

[0305] In DL communication, the direction of the beam is determined to be the direction of the first terminal 3A, which is the destination (i.e., the transmission destination) of the selected packet. The allocation unit 11A further allocates the beam irradiation period to the selected first terminal 3A. The allocation unit 11A further allocates communication resources other than the irradiation period to the selected first terminal 3A in the same manner as the method for allocating communication resources in the second exemplary embodiment.

[0306] Figure 17 is a schematic diagram illustrating an example of beam irradiation from a satellite according to this disclosure. In Figure 17, d = N (where N is a numerical value) represents the delay time for each terminal. In the example in Figure 17, the number of beams that satellite 2A can irradiate in UL communication is 2. The number of beams that satellite 2A can irradiate in DL communication is also 2. In the example shown in Figure 17, the allocation unit 11A included in satellite 2A determines, in UL communication, to be the terminals to be irradiated with the beam, two terminals (second terminal 4_3A and second terminal 4_4A) with the largest delay time (in this case, total delay time) out of four terminals (second terminal 4_1A, second terminal 4_2A, second terminal 4_3A, and second terminal 4_4A). Satellite 2A irradiates the beam to the two determined terminals (second terminal 4_3A and second terminal 4_4A). The allocation unit 11A included in satellite 2A determines, in UL communication, that two terminals (first terminal 3_1A and first terminal 3_2A) with the largest delay time (in this case, total delay time) out of four terminals (first terminal 3_1A, first terminal 3_2A, first terminal 3_3A, and first terminal 3_4A) will be beamed to. Satellite 2A then beams to the two determined terminals (first terminal 3_1A and first terminal 3_2A).

[0307] The above describes an example where, when the number of terminals exceeds the number of beams that satellite 2A can illuminate, beam illumination is prioritized for terminals with high delay in transmittable traffic. Transmittable traffic refers to, for example, packets that have already been generated (more specifically, packets that have finished being stored in the transmission queue). The magnitude of traffic delay refers to, for example, the total delay time of packets that can be transmitted within the transmission period. Prioritizing beam illumination for terminals with high delay in transmittable traffic means, for example, selecting the same number of terminals as the number of unilluminated beams, starting with those with the highest total delay times, and then allocating illumination periods to the selected terminals and illuminating them with beams during those allocated periods. As mentioned above, the total delay time of the terminals is the total delay time of packets that can be transmitted within an illumination period set by beams that are not currently being illuminated. However, the method of selecting terminals to illuminate with beams is not limited to the above example.

[0308] If the number of terminals with packets stored in the transmission queue and not yet illuminated by a beam is greater than the number of beams that can be illuminated, the allocation unit 11A may determine which terminals satellite 2A will illuminate with a beam (in other words, which terminals will be illuminated by a beam) using FIFO (First In, First Out).

[0309] Specifically, in the case of UL communication, for example, when the beam irradiation that was being performed is completed, the allocation unit 11A takes the earliest time of generation of packets stored in the transmission queue of the second terminal 4A as the time of generation of packets from that second terminal 4A. Then, from among the second terminals 4A that are not being beam-irradiated, the allocation unit 11A selects a number of second terminals 4A equal to the number of beams that are not being irradiated, starting with those with the earliest packet generation times from the second terminals 4A, as the second terminals 4A that satellite 2A will irradiate. The allocation unit 11A excludes second terminals 4A that do not have packets stored in their transmission queue from the selection. The allocation unit 11A determines that the selected second terminals 4A are the second terminals 4A that satellite 2A will irradiate. The number of beams that are not being irradiated at a given time is the number of beams that satellite 2A can irradiate in addition to the beams that it is irradiating at that time. The number of beams that are not being irradiated at a given point in time is equal to the number of terminals that satellite 2A can irradiate with beams at that time, in addition to the terminals that are currently irradiating with beams.

[0310] In DL communication, for example, when the beam irradiation that was being performed ends, the allocation unit 11A identifies the earliest time among the timestamps of packets destined for the first terminal 3A stored in the transmission queue of satellite 2A as the timestamp of the packet destined for the first terminal 3A. Then, from among the first terminal 3A that have not been irradiated with a beam, the allocation unit 11A selects a number of first terminal 3A equal to the number of beams that have not been irradiated, starting with the earliest timestamp of the packet destined for that first terminal 3A, as the first terminal 3A that satellite 2A will irradiate with a beam. The allocation unit 11A excludes first terminal 3A that do not have packets stored in the transmission queue from the selection. The allocation unit 11A determines that the selected first terminal 3A will be the first terminal 3A that satellite 2A will irradiate with a beam.

[0311] The above method can be described as a method for selecting terminals to be newly illuminated by a beam, where the delay time includes processing time and waiting time, and the number of terminals with the longest delay times among the packets related to the terminal is equal to the number of unilluminated beams (i.e., the number of beams that can be newly illuminated). In this case, the terminal delay time may be the smallest packet delay time among the packets related to the terminal. In this case, the terminal delay time may be the sum of the packet delay times of packets that can be transmitted over a predetermined transmission period when packets related to the terminal are transmitted in the order they are generated.

[0312] If the number of terminals with packets stored in the transmission queue and not yet illuminated by beams is greater than the number of beams that can be illuminated, the allocation unit 11A may determine which terminals to illuminate by beams using a round-robin method, which allocates terminals to illuminate by beams in order. Specifically, in UL communication, for example, when the illumination of a beam that was being performed is completed, the allocation unit 11A selects, in order from the second terminal 4A that has not yet been illuminated by beams, a number equal to the number of beams that have not yet been illuminated. However, the allocation unit 11A skips the order of second terminals 4A that do not have packets stored in their transmission buffers. In DL communication, for example, when the illumination of a beam that was being performed is completed, the allocation unit 11A selects, in order from the first terminal 3A that has not yet been illuminated by beams, a number equal to the number of beams that have not yet been illuminated. However, if the allocation unit 11A does not have packets destined for a first terminal 3A stored in the transmission buffer of satellite 2A, it skips the order of that first terminal 3A.

[0313] If the number of terminals with packets stored in the transmission queue and not yet illuminated by beams is greater than the number of beams that can be illuminated, the allocation unit 11A may determine which terminals to illuminate by beams using SPT (Shortest Processing Time first). In this case, SPT means prioritizing the processing of traffic with the shortest processing time (in other words, prioritizing the processing of traffic with the shortest processing time). This processing time is, for example, the time for transmitting buffered traffic (i.e., packets stored in the transmission queue). This processing time is different from the processing time described above, which is the time for storing packets in the transmission queue. In this case, when satellite 2A has finished transmitting a predetermined unit of traffic, it stops illuminating terminals involved in the transmission of that traffic. In the case of UL communication, the terminal involved in the transmission of traffic is the terminal that transmits the traffic. In the case of DL communication, the terminal involved in the transmission of traffic is the destination terminal of the traffic. When the beam irradiation that was being performed is completed, the allocation unit 11A determines which terminal among the buffered traffic for each terminal has the shortest time for transmitting a predetermined unit of traffic to be the terminal to which satellite 2A will irradiate the beam.

[0314] This method can be described as selecting terminals to be newly illuminated by a beam, with the delay time including the transmission time (or the transmission time and propagation time), and the number of terminals to which the beam will be newly illuminated being the same as the number of beams that have not yet been illuminated (i.e., the number of beams that can be newly illuminated), starting with those terminals with the shortest delay times of the packets related to the terminal. In this case, the terminal delay time may be the smallest packet delay time among the packets related to the terminal. In this case, the terminal delay time may also be the sum of the packet delay times of packets that can be transmitted over a predetermined transmission period when packets related to the terminal are transmitted in the order of their occurrence.

[0315] Specifically, in UL communication, once the beam irradiation that was being performed is completed, the allocation unit 11A estimates the time required to transmit a predetermined number of packets (i.e., one or two or more predetermined numbers) from the second terminal 4A that is not being beam-irradiated to satellite 2A, by allocating available communication resources to the second terminal 4A that is not being beam-irradiated according to the method of allocating communication resources in the second exemplary embodiment. From among the second terminal 4A that is not being beam-irradiated and has packets stored in the transmission queue, the allocation unit 11A selects the same number of second terminals 4A that satellite 2A will beam-irradiate, starting with the one with the shortest estimated time, as the terminals to which the satellite 2A will beam-irradiate.

[0316] In DL communication, once the beam irradiation that was being performed is completed, the allocation unit 11A estimates the time required to transmit a predetermined number of packets (i.e., one or two or more predetermined numbers) from satellite 2A to the first terminal 3A that is not being beam-irradiated, by allocating the available communication resources according to the method for allocating communication resources in the second exemplary embodiment. From among the first terminals 3A that are destinations for packets stored in the transmission queue of satellite 2A and are not being beam-irradiated, the allocation unit 11A selects a number of first terminals 3A equal to the number of beams that are not being irradiated, starting with the one with the shortest estimated time, as terminals to which satellite 2A will irradiate.

[0317] In these cases, the processing time (i.e., the time required to transmit a packet) is, for example, the time from the start of the transmission time to the end of the propagation time, as described above. The allocation unit 11A may select the terminal to be beamed to by using the delay time as the processing time (i.e., the time required to transmit a packet). The allocation unit 11A may also use the time required to transmit all of the packets for each terminal stored in the transmission queue as the processing time. In this case, in UL communication, the packets for each terminal stored in the transmission queue are the packets stored in the transmission queue of each of the second terminals 4A. In DL communication, the packets for each terminal stored in the transmission queue are the packets for each destination first terminal 3A stored in the transmission queue of satellite 2A.

[0318] The processing time may be the time required to transmit all of the data that has been divided into one or more packets. In this case, once the transmission of one or more packets of divided data is completed, the allocation unit 11A identifies the packets generated from the same data among the packets for each terminal stored in the transmission queue. The allocation unit 11A then uses the time required for data transmission (transmission of all of the one or more packets of divided data) for each data set, when an available communication resource is allocated to a terminal, for example, by the method of allocating communication resources in the second exemplary embodiment, as the processing time. One or more packets of divided data (and one or more packets generated from the data) are, for example, packets generated from partial data generated by data division. The allocation unit 11A may have previously obtained information about packets generated from a set of data from the terminal that generated the packets. The allocation unit 11A may use information that identifies the data from which the packet was generated, contained in the packet, to identify packets generated from the same data.

[0319] If the number of terminals with packets stored in the transmission queue and not yet illuminated by a beam is greater than the number of beams that can be illuminated, the allocation unit 11A may determine which terminals to illuminate by a beam using SRPT (Shortest Remaining Processing Time first). In this case, SRPT targets the traffic with the shortest remaining processing time (in other words, prioritizes processing the traffic with the shortest remaining processing time). This remaining processing time is, for example, the time remaining until the completion of transmission of buffered traffic (i.e., packets stored in the transmission queue). In this case, the allocation unit 11A determines that the terminal with the smallest remaining time for transmission of a predetermined unit of traffic among the buffered traffic for each terminal is the terminal that satellite 2A will illuminate with a beam. The remaining time for transmission of traffic is, if transmission has started, the time to transmit the untransmitted portion of the traffic. The remaining time for transmission of traffic is, if transmission has not started, the time from the start to the end of transmission. In this case, when packet transmission is completed, the allocation unit 11A terminates beam irradiation and determines the terminal to which satellite 2A will irradiate the beam, which is the terminal with the smallest remaining time for transmitting a predetermined unit of traffic among the buffered traffic for each terminal. A predetermined unit of traffic may be, for example, a set of data. Specifically, a predetermined unit of traffic is, for example, one or more packets generated from a set of data. When packet transmission (in this case, propagation) is completed, satellite 2A terminates beam irradiation to the terminal involved in the transmission of that packet. In the case of UL communication, the terminal involved in the transmission of a packet is the terminal that sends the packet. In the case of DL communication, the terminal involved in the transmission of a packet is the destination terminal of the packet. When the beam irradiation that was being performed is completed, the allocation unit 11A determines the terminal to which satellite 2A will irradiate the beam, which is the terminal with the smallest remaining time for transmitting a predetermined unit of traffic among the buffered traffic for each terminal.

[0320] This method can be described as selecting terminals to be newly illuminated by a beam, where the delay time includes at least a portion of the waiting time and the transmission time (or at least a portion of the waiting time, the transmission time and the propagation time), and the number of terminals with the shortest delay times of the packets related to the terminal is equal to the number of unilluminated beams (i.e., the number of beams that can be newly illuminated). At least a portion of the waiting time is the waiting time from a reference time (for example, the current time or the starting time of the remaining time mentioned above). In this case, the terminal delay time may be the sum of the packet delay times of packets generated from a set of data related to the terminal that have not yet been transmitted (i.e., propagated).

[0321] Specifically, in the case of UL communication, once the beam irradiation that was being performed is finished, the allocation unit 11A classifies the packets stored in the transmission queue of the second terminal 4A into groups of packets generated from the same data. The allocation unit 11A identifies the group with the fewest packets. The allocation unit 11A calculates the remaining processing time for the second terminal 4A, which is the time required to transmit all packets included in the identified group from the second terminal 4A to the satellite 2A, if the available communication resources are allocated to the second terminal 4A according to the method of allocating communication resources in the second exemplary embodiment, for example. The allocation unit 11A determines the second terminal 4A with the shortest calculated remaining processing time to be the second terminal 4A to which the satellite 2A will irradiate the beam.

[0322] In DL communication, once the beam irradiation that was being performed is finished, the allocation unit 11A classifies the packets destined for the first terminal 3A stored in the transmission queue of satellite 2A into groups of packets generated from the same data. The allocation unit 11A identifies the group containing the fewest packets. The allocation unit 11A calculates the time required to transmit all packets included in the identified group from satellite 2A to the first terminal 3A, assuming that all available communication resources are allocated to the first terminal 3A according to, for example, the method of allocating communication resources in the second exemplary embodiment, as the remaining processing time for the first terminal 3A. The allocation unit 11A determines the first terminal 3A with the shortest calculated remaining processing time to be the first terminal 3A to which satellite 2A will irradiate the beam.

[0323] The allocation unit 11A may determine which terminal the satellite 2A will beam onto by a method that combines any of the above-described methods in a consistent manner: selecting the terminal with the greatest delay in transmittable traffic, selecting the terminal by FIFO, selecting the terminal by round robin, selecting the terminal by SPT, or selecting the terminal by SRPT.

[0324] The above example describes a case where the allocation unit 11A determines which terminal to irradiate next after the irradiation of a terminal with a beam has finished. However, the allocation unit 11A may determine which terminal to irradiate next after the irradiation of a terminal with a beam has finished, before the irradiation of a terminal with a beam has finished. For example, when determining which terminal to irradiate next, the allocation unit 11A may use information on the communication resources allocated to that terminal to determine the length of time for irradiating the terminal with a beam, i.e., the length of the irradiation period, to be, for example, a length that allows the terminal to transmit a predetermined number of packets. The allocation unit 11A may then determine which terminal to irradiate next by any of the methods described above, before a predetermined time has elapsed since the start of irradiating that terminal with a beam of the determined length. As described above, the length of time for irradiating the terminal with a beam, i.e., the length of the irradiation period, may be predetermined. In this case, the allocation unit 11A may determine which terminal to irradiate next by any of the methods described above, before a predetermined time has elapsed since the start of irradiating that terminal with a beam of the predetermined length.

[0325] The allocation unit 11A may predict the change in the positional relationship between satellite 2A and the terminal using information on the orbit of satellite 2A, information on the terminal's position, and information on the Earth's rotation. The allocation unit 11A may then use the predicted positional relationship information between the terminal and satellite 2A when a beam is newly shone on the terminal to estimate the communication resources that can be allocated to that terminal. In other words, the allocation unit 11A may estimate the communication resources that will be allocated to the terminal if the positional relationship between the terminal and satellite 2A is the predicted positional relationship and communication resources are allocated to the terminal according to a predetermined allocation method. The allocation unit 11A may use the estimated communication resource information to calculate the aforementioned delay time for the terminal.

[0326] Specifically, the allocation unit 11A may predict the change in the positional relationship between satellite 2A and the second terminal 4A in UL communication using information on the orbit of satellite 2A, information on the position of the second terminal 4A, and information on the rotation of the Earth. The allocation unit 11A may then use the predicted positional relationship information between the second terminal 4A and satellite 2A when a beam is newly shone on the second terminal 4A to estimate the communication resources that can be allocated to the second terminal 4A. The allocation unit 11A may use the estimated communication resource information to calculate the aforementioned delay time for the second terminal 4A.

[0327] The allocation unit 11A may predict the change in the positional relationship between satellite 2A and the first terminal 3A in DL communication using information on the orbit of satellite 2A, information on the position of the first terminal 3A, and information on the rotation of the Earth. The allocation unit 11A may then use the predicted positional relationship information between the first terminal 3A and satellite 2A when a beam is newly shone on the first terminal 3A to estimate the communication resources that can be allocated to the first terminal 3A. In other words, the allocation unit 11A may estimate the communication resources that will be allocated to the terminal if the positional relationship between the terminal and satellite 2A is the predicted positional relationship and communication resources are allocated to the terminal according to a predetermined allocation method. The allocation unit 11A may use the estimated communication resource information to calculate the aforementioned delay time for the first terminal 3A.

[0328] In at least one of UL communication and DL communication, if satellite 2A is irradiating multiple terminals with multiple beams, the allocation unit 11A may predict the positional relationship between satellite 2A and the terminals when the irradiation of each of the multiple beams ends. In this case, the allocation unit 11A further estimates the amount of communication resources that can be allocated to each terminal using the predicted positional relationship. Assuming that the estimated communication resources have been allocated to the terminals, the allocation unit 11A determines which terminals will be irradiated with beams using one of the above-described methods for determining which terminals will be irradiated with beams. In the following description, it will be explained that the allocation unit 11A determines which terminals will be irradiated with beams using the above-described delay time for each terminal.

[0329] In addition to determining which terminals will be beamed based on a prediction of the positional relationship between satellite 2A and the terminal when the ongoing beam irradiation ends, the allocation unit 11A may also predict the positional relationship between satellite 2A and the terminal when the beam irradiation to a determined but not yet started terminal ends, and determine which terminals will be beamed based on that prediction. The determination of which terminals will be beamed based on a prediction of the positional relationship between satellite 2A and the terminal refers to the estimation of the positional relationship between satellite 2A and the terminal, the estimation of the communication resources that can be allocated to the terminal when the positional relationship between satellite 2A and the terminal is the estimated positional relationship, the calculation of the delay time when the estimated communication resources are allocated to the terminal, and the determination of which terminals will be beamed using the calculated delay time.

[0330] The allocation unit 11A may determine which terminal will be beamed in UL communication at the timing of the end of each beam irradiation in UL communication. The allocation unit 11A may also determine which terminal will be beamed in DL communication at the timing of the end of each beam irradiation in DL communication. The timing of the end of beam irradiation may be, for example, the timing when the beam irradiation is completed. The timing of the end of beam irradiation may be, for example, a predetermined time before the time when the beam irradiation is completed. The timing of the end of beam irradiation may be, for example, a time before a predetermined time when the beam irradiation is completed, so that the determination of which terminal will be beamed in is made before the time when the beam irradiation is completed. The allocation unit 11A may continuously perform processing from predicting the positional relationship between the satellite 2A and the terminal when each of the multiple beam irradiations is completed to determining which terminal will be beamed in. The allocation unit 11A may perform processing from predicting the positional relationship between the satellite 2A and the terminal when the irradiation of each of the multiple beams ends at predetermined time intervals, to determining which terminal will be irradiated by the beam.

[0331] The allocation unit 11A may predict the status of transmittable traffic related to each terminal from the records of traffic occurrence related to each terminal. In the case of UL communication, the traffic related to each terminal is the traffic (e.g., packets) transmitted by the terminal. In the case of DL communication, the traffic related to each terminal is the traffic (e.g., packets) sent by satellite 2A to the terminal. In this case, the allocation unit 11A predicts the terminal's delay time using the predicted communication resources that can be allocated to the terminal and the predicted status of transmittable traffic related to the terminal.

[0332] Specifically, in the case of UL communication, the allocation unit 11A may predict the future packet transitions based on a record of the packet transitions that have occurred in the past at the second terminal 4A, under the assumption that the trend of packet transitions occurring at the second terminal 4A will continue. The allocation unit 11A uses the orbital information of satellite 2A and the position information of the second terminal 4A to predict the transition of the positional relationship between satellite 2A and the second terminal 4A. The allocation unit 11A uses the predicted transition of the positional relationship between satellite 2A and the second terminal 4A to predict the transition of communication resources to be allocated to the second terminal 4A when communication resources are allocated to the second terminal 4A. The allocation unit 11A uses the predicted transition of the packets to be generated and the predicted transition of the communication resources that can be allocated to the second terminal 4A to predict the transition of packets that the second terminal 4A can transmit. The allocation unit 11A determines the delay time of the second terminal 4A at the timing when the irradiation of any of the beams used for UL communication to the second terminal 4A ends, using the predicted packets that the second terminal 4A can transmit and the predicted communication resources that can be allocated to the second terminal 4A.

[0333] For example, as the distance between the terminal and the satellite increases, the attenuation of radio waves increases. As a result, the maximum communication capacity that can be provided in communication between the terminal and the satellite decreases. If the relative positions of the terminal and the satellite can be predicted, the allocation unit 11A can predict the maximum communication capacity that can be provided. This is because the allocation unit 11A can calculate the communication capacity using the available communication resources (for example, the communication capacity using the maximum available communication resources) based on the relative positions of the terminal and the satellite. If the maximum communication capacity that can be provided can be predicted, the allocation unit 11A can also predict the delay time of packets that are expected to be in a state where they can be transmitted in the future. As a result, the allocation unit 11A can calculate the total delay time for each terminal from the predicted packet delay time. Therefore, the allocation unit 11A can determine the direction of future beam irradiation (in other words, the terminals to which the beam will be irradiated). Furthermore, the allocation unit 11A can predict the state of packets remaining in the terminal and satellite after packet transmission in the future (i.e., the number and delay time, etc.). The allocation unit 11A can further use the results of the prediction of future packet transitions, as described above, to predict the delay time of even more transmittable packets. Then, the allocation unit 11A can calculate the total delay time for each terminal from the predicted delay times of even more transmittable packets. This allows the allocation unit 11A to determine the direction in which to shine the beam (i.e., the terminals to which the beam will be shone). In particular, in UL communication, satellite 2A cannot receive more packets than the capacity of satellite 2A's buffer. Packets exceeding the capacity of satellite 2A's buffer are packets that satellite 2A cannot receive because, even if it receives them, it cannot store them in the buffer due to insufficient free space. In such cases, since satellite 2A cannot receive the packets, the terminals do not transmit them. Therefore, the total delay time of transmittable packets for each terminal in future UL communication changes depending on the state of packets buffered by satellite 2A in the future. The allocation unit 11A predicts the state of packets buffered by satellite 2A in the future and predicts the total delay time of transmittable packets for each terminal according to the predicted buffer state.The allocation unit 11A uses the predicted total delay time per terminal, which is determined using the results of predicting the state of packets buffered on satellite 2A, to determine the communication resources (in this case, beam direction in time division) for future UL communications.

[0334] Furthermore, in the case of DL communication, the allocation unit 11A may predict the future trend of packets destined for the first terminal 3A based on a record of the past trend of packets destined for the first terminal 3A that occurred on satellite 2A, under the assumption that the trend of packet trends occurring on satellite 2A will continue. The allocation unit 11A can predict the packets sent to satellite 2A by UL communication by predicting the communication capacity that can be provided to the second terminal 4A in UL communication and the packets that occur on the second terminal 4A. Therefore, the allocation unit 11A can predict the packets that occur on satellite 2A in DL communication. The allocation unit 11A uses the orbital information of satellite 2A and the position information of the first terminal 3A to predict the trend of the positional relationship between satellite 2A and the first terminal 3A. The allocation unit 11A uses the predicted trend of the positional relationship between satellite 2A and the first terminal 3A to predict the trend of communication resources that can be allocated to the first terminal 3A when allocating communication resources to the first terminal 3A. The allocation unit 11A predicts the sequence of packets destined for the first terminal 3A that satellite 2A can transmit, using the predicted sequence of packets destined for the first terminal 3A that will be generated and the predicted sequence of communication resources allocated to the first terminal 3A. The allocation unit 11A determines the delay time of packets destined for the first terminal 3A at the timing when the irradiation of any of the beams used for DL ​​communication to the first terminal 3A ends, using the predicted number of packets destined for the first terminal 3A that satellite 2A can transmit and the predicted number of communication resources that can be allocated to the first terminal 3A.

[0335] The example described above illustrates the control of the beam direction by time-division multiplexing using delay time, that is, the process by which the allocation unit 11A determines which terminal to irradiate with the beam using delay time. The allocation unit 11A may allocate either power or bandwidth to a terminal according to its delay time.

[0336] Specifically, the allocation unit 11A may allocate power to each terminal such that the greater the terminal's delay time, the greater the power allocated to that terminal. If the number of terminals to which power is allocated is less than the number of existing terminals, the allocation unit 11A may determine the terminals to which power will be allocated, starting with those with the greatest delay time. The allocation unit 11A may determine the terminals to which power will be allocated, starting with those with the greatest delay time, and further determine the amount of power allocated to the determined terminals such that the amount of power allocated to the determined terminals increases as the terminal's delay time increases.

[0337] Furthermore, the allocation unit 11A may allocate bandwidth to each terminal such that the larger the terminal's latency, the larger the bandwidth allocated to it. If the number of terminals to which bandwidth is allocated is smaller than the number of existing terminals, the allocation unit 11A may determine the terminals to which bandwidth will be allocated, starting with the terminals with the largest latency. The allocation unit 11A may determine the terminals to which bandwidth will be allocated, starting with the terminals with the largest latency, and further determine the size of the bandwidth allocated to the determined terminals such that the size of the bandwidth allocated to the determined terminals increases as the terminal's latency increases.

[0338] The communication control system 100A according to this exemplary embodiment is otherwise identical to the communication control system 100A according to the second exemplary embodiment.

[0339] (Process flow executed in communication control system 100A) The process flow (communication control method) executed in communication control system 100A will be explained with reference to Figure 8. Figure 8 is a flowchart showing the process flow executed in communication control system 100A. The process executed in communication control system 100A of this exemplary embodiment is the same as the process executed in communication control system 100A of the second exemplary embodiment, except for the content of the process in step S11A.

[0340] In step S11A, the allocation unit 11A calculates the delay time for each terminal when communication resources are allocated to each terminal and beams are irradiated in both UL communication and DL communication. The allocation unit 11A allocates communication resources to terminals using the calculated delay time in both UL communication and DL communication. The allocation of communication resources to terminals using the calculated delay time involves, for example, determining terminals with larger delay times, the number of terminals that can be newly irradiated, and allocating the irradiation period during which the beams are irradiated and the communication resources other than the irradiation period to the determined terminals. Newly irradiable beams are beams other than the beams that continue to irradiate the terminals. When the allocation unit 11A allocates either power or bandwidth according to the delay time, in step S11A, the allocation unit 11A calculates the delay time for each terminal when predetermined communication resources are allocated to the terminal, and, as described above, allocates either power or bandwidth to the terminal using the magnitude of the calculated delay time.

[0341] (Effects) The communication control system 100A of this exemplary embodiment has the same effects as the second exemplary embodiment. The reason for this is the same as the reason for the effects of the second exemplary embodiment. The communication control system 100A of this exemplary embodiment has the further effect of further reducing communication delay. This is because the allocation unit 11A determines as terminals to be beamed the number of terminals that can be beamed from the terminal with the largest delay time. As a result, communication delay can be reduced overall. In the configuration of this exemplary embodiment, by referring to the delay time of the traffic that can actually be transmitted, it is possible to prevent a situation in which resources are wasted by not being able to transmit traffic even when the beam is irradiated, and delay time (i.e., the latency mentioned above) can be efficiently reduced.

[0342] [Example of implementation by software] Some or all of the functions of the communication control device 1, communication control device 2, satellite 2A, satellite 2_1B, satellite 2_2B, first terminal 3, first terminal 3A, first terminal 3B, second terminal 4, second terminal 4A, second terminal 4B (hereinafter also referred to as "each of the above devices") may be implemented by hardware such as integrated circuits (IC chips) or by software.

[0343] In the latter case, each of the above devices is implemented, for example, by a computer that executes instructions for a program, which is software that realizes each function. An example of such a computer (hereinafter referred to as computer C) is shown in Figure 15. Figure 15 is a block diagram showing the hardware configuration of computer C, which functions as each of the above devices.

[0344] Computer C comprises at least one processor C1 and at least one memory C2. Memory C2 stores a program P for operating Computer C as each of the above-mentioned devices. In Computer C, the processor C1 reads and executes the program P from memory C2, thereby realizing each of the above-mentioned devices.

[0345] For processor C1, for example, a CPU (Central Processing Unit), GPU (Graphic Processing Unit), DSP (Digital Signal Processor), MPU (Micro Processing Unit), FPU (Floating Point Number Processing Unit), PPU (Physics Processing Unit), TPU (Tensor Processing Unit), quantum processor, microcontroller, or a combination thereof can be used. For memory C2, for example, flash memory, HDD (Hard Disk Drive), SSD (Solid State Drive), or a combination thereof can be used.

[0346] Furthermore, computer C may also be equipped with RAM (Random Access Memory) for loading program P at runtime and for temporarily storing various data. Computer C may also be equipped with a communication interface for sending and receiving data with other devices. Furthermore, computer C may also be equipped with an input / output interface for connecting input / output devices such as a keyboard, mouse, display, and printer.

[0347] Furthermore, program P can be recorded on a non-temporary, tangible recording medium M that is readable by computer C. Such recording medium M can include, for example, tape, disk, card, semiconductor memory, or programmable logic circuitry. Computer C can acquire program P via such recording medium M. Program P can also be transmitted via a transmission medium. Such transmission mediums can include, for example, a communication network or broadcast waves. Computer C can also acquire program P via such transmission medium.

[0348] Furthermore, each of the above functions of each of the above devices may be implemented by a single processor in a single computer, by multiple processors in a single computer working together, or by multiple processors in each of multiple computers working together. In addition, the programs for implementing each of the above functions in each of the above devices may be stored in a single memory in a single computer, distributed and stored in multiple memories in a single computer, or distributed and stored in multiple memories in each of multiple computers.

[0349] Furthermore, each process described in the above embodiments may be executed by AI (Artificial Intelligence). In this case, the AI ​​may operate on the above-mentioned devices, or it may operate on other devices (for example, an edge computer or a cloud server). For example, the allocation unit 11 and the decision unit 21 may be machine learning models using CNN (Convolutional Neural Network), or they may be configured to be optimized by a search algorithm.

[0350] [Addendum A] This disclosure includes the technologies described in the following addendums. However, the present invention is not limited to the technologies described in the following addendums, and various modifications are possible within the scope of the claims.

[0351] (Appendix A1) A communication control device comprising: allocation means for allocating the communication resources of the relay device to be used by the relay device in communication with the first terminal and the second terminal, respectively, by referring to the maximum communication capacity that the relay device can provide in communication with the first terminal and the maximum communication capacity that the relay device can provide in communication with the second terminal; and setting means for setting the communication resources.

[0352] (Appendix A2) The communication control device according to Appendix A1, wherein the allocation means allocates the communication resources based on the smaller of the maximum communication capacity that the relay device can provide in communication with a first terminal and the maximum communication capacity that the relay device can provide in communication with a second terminal.

[0353] (Appendix A3) The communication control device according to Appendix A1 or A2, further comprising acquisition means for acquiring relay device location information indicating the location of the relay device, first terminal location information indicating the location of the first terminal, and second terminal location information indicating the location of the second terminal, wherein the allocation means further refers to the relay device location information, the first terminal location information, and the second terminal location information to allocate the communication resources.

[0354] (Appendix A4) A communication control device according to any one of Appendix A1 to A3, further comprising: a determination means for determining at least one of the communication settings for communication between the first terminal and the relay device and the communication settings for communication between the second terminal and the relay device, by referring to the communication resources; and an instruction means for instructing at least one of the first terminal and the second terminal to communicate based on the communication settings.

[0355] (Appendix A5) The communication control device described in Appendix A4, wherein the determination means determines the transmission power of the first terminal or the transmission power of the second terminal as a communication setting.

[0356] (Note A6) The communication control device according to any one of Notes A1 to A5, wherein the relay device includes a first relay device and a second relay device, the first relay device communicates with the first terminal, the second relay device communicates with the second terminal, and the allocation means allocates the respective communication resources of the first relay device and the second relay device by referring to the maximum communication capacity that the first relay device can provide in communication with the first terminal and the maximum communication capacity that the second relay device can provide in communication with the second terminal.

[0357] (Note A7) The communication control device according to any one of Notes A1 to A6, wherein the allocation means allocates the communication resources according to the amount of traffic between the relay device and the first terminal and the second terminal, respectively.

[0358] (Appendix A8) The communication control device according to any one of Appendix A1 to A7, wherein the allocation means allocates the communication resources according to the delay time of traffic between the relay device and the first terminal and the second terminal, respectively.

[0359] (Note A9) The communication control device according to any one of Notes A1 to A8, wherein the allocation means further refers to control information relating to the future status of the relay device, the first terminal, and the second terminal, and allocates the communication resources.

[0360] (Appendix A10) A communication control system comprising: a first terminal; a communication control device that controls communication between a second terminal and a relay device that relays communication between the first terminal, the second terminal, and the first terminal and the second terminal, wherein the communication control device comprises: allocation means for allocating communication resources of the relay device to be used by the relay device in communication with the first terminal and the second terminal, with reference to the maximum communication capacity that the relay device can provide in communication with the first terminal and the maximum communication capacity that the relay device can provide in communication with the second terminal; setting means for setting the communication resources; determination means for at least one processor to determine communication settings in communication between the first terminal and the relay device and communication settings in communication between the second terminal and the relay device, with reference to the communication resources; and instruction means for instructing the first terminal and the second terminal to communicate based on the communication settings, wherein the first terminal comprises: receiving means for receiving instructions from the communication control device; and communication means for performing communication based on the communication settings indicated by the instructions. The second terminal comprises a receiving means for receiving instructions from the communication control device and a communication means for performing communication based on the communication settings indicated by the instructions, forming a communication control system.

[0361] (Note A11) A first terminal that communicates with a second terminal via a relay device, comprising: a receiving means for receiving an instruction to communicate based on a communication setting for communication with the relay device, which is determined by referring to the maximum communication capacity that the relay device can provide in communication with the first terminal and the maximum communication capacity that the relay device can provide in communication with the second terminal, and which is allocated by referring to the communication resources of the relay device used by the relay device in communication with the first terminal and the second terminal, respectively; and a communication means for communicating based on the communication setting indicated by the instruction.

[0362] (Note A12) The communication control device according to Note A8, wherein the delay time includes any of processing time, waiting time, transmission time, and propagation time, the processing time is the time from the occurrence of the traffic until the traffic is stored in the transmission queue, the waiting time is the time from when the traffic is stored in the transmission queue until the transmission of the traffic is started, the transmission time is the time from when the transmission of the traffic is started until the transmission of the traffic is finished, and the propagation time is the time from when the transmission of the traffic is finished until the propagation of the traffic in the communication path is finished.

[0363] (Note A13) The communication control device according to Note A8, wherein the allocation means calculates the delay time of the traffic in the communication between the relay device and the first terminal as the delay time in the communication between the relay device and the first terminal when the communication resources are allocated to the first terminal according to a predetermined first allocation method, and calculates the delay time of the traffic in the communication between the relay device and the second terminal as the delay time in the communication between the relay device and the second terminal when the communication resources are allocated to the second terminal according to a predetermined second allocation method.

[0364] (Note A14) The communication control device according to Note A8, wherein the allocation means calculates the delay time of the traffic between the relay device and the first terminal when the communication resources are allocated to the first terminal according to a predetermined first allocation method, selects a number of first terminals that the relay device can newly communicate with from among the first terminals, starting with the one with the largest delay time, and allocates the communication resources to the selected first terminals; calculates the delay time of the traffic between the relay device and the second terminal when the communication resources are allocated to the second terminal according to a predetermined second allocation method, selects a number of second terminals that the relay device can newly communicate with from among the second terminals, starting with the one with the largest delay time, and allocates the communication resources to the selected second terminals.

[0365] (Appendix A15) The communication control device according to Appendix A8, wherein the allocation means predicts the traffic at the allocation timing for allocating the communication resources, calculates the delay time at the allocation timing using the predicted traffic information and the information of the communication resources allocated at the allocation timing according to a predetermined allocation method, and determines the allocation of the communication resources to be performed at the allocation timing according to the delay time.

[0366] [Addendum B] This disclosure includes the technologies described in the following addendums. However, the present invention is not limited to the technologies described in the following addendums, and various modifications are possible within the scope of the claims.

[0367] (Appendix B1) A communication control method comprising: an allocation process in which at least one processor refers to the maximum communication capacity that the relay device can provide in communication with a first terminal and the maximum communication capacity that the relay device can provide in communication with a second terminal, and allocates the communication resources of the relay device to be used by the relay device in communication with the first terminal and the second terminal, respectively; and a setting process in which the at least one processor sets the communication resources.

[0368] (Appendix B2) The communication control method according to Appendix B1, wherein in the allocation process, the at least one processor allocates the communication resources based on the smaller of the maximum communication capacity that the relay device can provide in communication with a first terminal and the maximum communication capacity that the relay device can provide in communication with a second terminal.

[0369] (Appendix B3) The communication control method according to Appendix B1 or B2, wherein the at least one processor further includes an acquisition process to acquire relay device location information indicating the location of the relay device, first terminal location information indicating the location of the first terminal, and second terminal location information indicating the location of the second terminal, and in the allocation process, the at least one processor further refers to the relay device location information, the first terminal location information, and the second terminal location information to allocate the communication resources.

[0370] (Appendix B4) A communication control method according to any one of Appendices B1 to B3, further comprising: a determination process in which at least one processor refers to the communication resources and determines at least one of the communication settings for communication between the first terminal and the relay device and the communication settings for communication between the second terminal and the relay device; and an instruction process in which at least one processor instructs at least one of the first terminal and the second terminal to communicate based on the communication settings.

[0371] (Appendix B5) The communication control method according to Appendix B4, wherein in the determination process, at least one processor determines the transmission power of the first terminal or the transmission power of the second terminal as a communication setting.

[0372] (Note B6) The communication control method according to any one of Notes B1 to B5, wherein the relay device includes a first relay device and a second relay device, the first relay device communicates with the first terminal, the second relay device communicates with the second terminal, and in the allocation process, the at least one processor refers to the maximum communication capacity that the first relay device can provide in communication with the first terminal and the maximum communication capacity that the second relay device can provide in communication with the second terminal, and allocates the respective communication resources of the first relay device and the second relay device.

[0373] (Appendix B7) The communication control method according to any one of Appendix B1 to B6, wherein in the allocation process, the at least one processor allocates the communication resources according to the amount of traffic between the relay device and the first terminal and the second terminal, respectively.

[0374] (Appendix B8) The communication control method according to any one of Appendices B1 to B7, wherein in the allocation process, the at least one processor allocates the communication resources according to the delay time of traffic between the relay device and the first terminal and the second terminal, respectively.

[0375] (Appendix B9) The communication control method according to any one of Appendices B1 to B8, wherein in the allocation process, the at least one processor further refers to control information relating to the future status of the relay device, the first terminal, and the second terminal, and allocates the communication resources.

[0376] (Appendix B10) A communication control method to be performed in a communication control system including a first terminal and a communication control device that controls communication between a second terminal and the first terminal, the second terminal and the first terminal and the second terminal by a relay device, wherein the communication control device includes: an allocation process in which at least one processor refers to the maximum communication capacity that the relay device can provide in communication with the first terminal and the maximum communication capacity that the relay device can provide in communication with the second terminal and allocates the communication resources of the relay device to be used by the relay device in communication with the first terminal and the second terminal, respectively; a setting process in which the at least one processor sets the communication resources; a communication setting determination process in which the at least one processor refers to the communication resources and determines the communication settings for communication between the first terminal and the relay device and for communication between the second terminal and the relay device; and an instruction process in which the at least one processor instructs the first terminal and the second terminal to communicate based on the communication settings, wherein in the first terminal, A communication control method comprising: an acceptance process in which at least one processor receives instructions from the communication control device; and a communication process in which the at least one processor performs communication based on the communication settings indicated by the instructions; and in the second terminal, an acceptance process in which at least one processor receives instructions from the communication control device; and a communication process in which the at least one processor performs communication based on the communication settings indicated by the instructions.

[0377] (Appendix B11) A communication control method performed by a first terminal communicating with a second terminal via a relay device, comprising: a reception process in which at least one processor receives an instruction to communicate based on a communication setting for communication with the relay device, which is determined by referring to the communication resources of the relay device used by the relay device in communication with the first terminal and the second terminal, and which are allocated by referring to the maximum communication capacity that the relay device can provide in communication with the first terminal and the maximum communication capacity that the relay device can provide in communication with the second terminal; and a communication process in which the at least one processor performs communication based on the communication setting indicated by the instruction.

[0378] (Note B12) The communication control method according to Note B8, wherein the delay time includes any of the processing time, waiting time, transmission time, and propagation time, the processing time is the time from the occurrence of the traffic until the traffic is stored in the transmission queue, the waiting time is the time from when the traffic is stored in the transmission queue until the transmission of the traffic is started, the transmission time is the time from when the transmission of the traffic is started until the transmission of the traffic is finished, and the propagation time is the time from when the transmission of the traffic is finished until the propagation of the traffic in the communication path is finished.

[0379] (Note B13) The communication control method according to Note B8, wherein the allocation process calculates the delay time of the traffic in the communication between the relay device and the first terminal as the delay time in the communication between the relay device and the first terminal when the communication resources are allocated to the first terminal according to a predetermined first allocation method, and calculates the delay time of the traffic in the communication between the relay device and the second terminal as the delay time in the communication between the relay device and the second terminal when the communication resources are allocated to the second terminal according to a predetermined second allocation method.

[0380] (Note B14) The communication control method according to Note B8, wherein the allocation process includes: calculating the delay time of the traffic between the relay device and the first terminal when the communication resources are allocated to the first terminal according to a predetermined first allocation method; selecting a number of first terminals that the relay device can newly communicate with from among the first terminals, starting with those with the largest delay times; and allocating the communication resources to the selected first terminals; calculating the delay time of the traffic between the relay device and the second terminal when the communication resources are allocated to the second terminal according to a predetermined second allocation method; selecting a number of second terminals that the relay device can newly communicate with from among the second terminals, starting with those with the largest delay times; and allocating the communication resources to the selected second terminals.

[0381] (Appendix B15) The communication control method described in Appendix B8, wherein the allocation process predicts the traffic at the allocation timing in which the communication resources are allocated, calculates the delay time at the allocation timing using the predicted traffic information and the information of the communication resources to be allocated at the allocation timing according to a predetermined allocation method, and determines the allocation of the communication resources to be performed at the allocation timing according to the delay time.

[0382] [Addendum C] This disclosure includes the technologies described in the following addendums. However, the present invention is not limited to the technologies described in the following addendums, and various modifications are possible within the scope of the claims.

[0383] (Appendix C1) A program for causing a computer to function as a communication control device, wherein the computer functions as an allocation means for allocating the communication resources of the relay device to be used by the relay device in communication with the first terminal and the second terminal, respectively, by referring to the maximum communication capacity that the relay device can provide in communication with a first terminal and the maximum communication capacity that the relay device can provide in communication with a second terminal, and a setting means for setting the communication resources.

[0384] (Appendix C2) The communication control program described in Appendix C1, wherein the allocation means allocates the communication resources based on the smaller of the maximum communication capacity that the relay device can provide in communication with the first terminal and the maximum communication capacity that the relay device can provide in communication with the second terminal.

[0385] (Appendix C3) The computer is further configured as an acquisition means for acquiring relay device location information indicating the location of the relay device, first terminal location information indicating the location of the first terminal, and second terminal location information indicating the location of the second terminal, and the allocation means further refers to the relay device location information, the first terminal location information, and the second terminal location information to allocate the communication resources, as described in Appendix C1 or C2.

[0386] (Appendix C4) A communication control program according to any one of Appendices C1 to C3, further comprising: a determination means for determining at least one of the communication settings for communication between the first terminal and the relay device and the communication settings for communication between the second terminal and the relay device, by referring to the communication resources; and an instruction means for instructing the computer to communicate based on the communication settings for at least one of the first terminal and the second terminal.

[0387] (Appendix C5) The determination means is the communication control program described in Appendix C4, which determines the transmission power of the first terminal or the transmission power of the second terminal as a communication setting.

[0388] (Note C6) The relay device includes a first relay device and a second relay device, the first relay device communicates with the first terminal, the second relay device communicates with the second terminal, and the allocation means allocates the respective communication resources of the first relay device and the second relay device by referring to the maximum communication capacity that the first relay device can provide in communication with the first terminal and the maximum communication capacity that the second relay device can provide in communication with the second terminal, the communication control program according to any one of Notes C1 to C5.

[0389] (Note C7) The allocation means is a communication control program according to any one of Notes C1 to C6, which allocates the communication resources according to the amount of traffic between the relay device and the first terminal and the second terminal, respectively.

[0390] (Note C8) The allocation means is a communication control program according to any one of Notes C1 to C7, which allocates the communication resources according to the delay time of traffic between the relay device and the first terminal and the second terminal, respectively.

[0391] (Note C9) The communication control program according to any one of Notes C1 to C8, wherein the allocation means further refers to control information relating to the future status of the relay device, the first terminal, and the second terminal, and allocates the communication resources.

[0392] (Appendix C10) A communication control program that causes a computer to function as a first terminal communicating with a second terminal via a relay device, the program comprising: a receiving means for receiving instructions to communicate based on communication settings for communication with the relay device, which are determined by referring to the communication resources of the relay device used by the relay device in communication with the first terminal and the second terminal, respectively, and communication means for performing communication based on the communication settings indicated by the instructions.

[0393] (Note C12) The communication control program described in Note C8, wherein the delay time includes any of the processing time, waiting time, transmission time, and propagation time, the processing time is the time from the occurrence of the traffic until the traffic is stored in the transmission queue, the waiting time is the time from when the traffic is stored in the transmission queue until the transmission of the traffic begins, the transmission time is the time from when the transmission of the traffic begins until the transmission of the traffic ends, and the propagation time is the time from when the transmission of the traffic ends until the propagation of the traffic in the communication path ends.

[0394] (Note C13) The allocation means calculates the delay time of the traffic in the communication between the relay device and the first terminal as the delay time in the communication between the relay device and the first terminal when the communication resources are allocated to the first terminal according to a predetermined first allocation method, and calculates the delay time of the traffic in the communication between the relay device and the second terminal as the delay time in the communication between the relay device and the second terminal when the communication resources are allocated to the second terminal according to a predetermined second allocation method. (Note C13) The communication control program according to Note C8.

[0395] (Note C14) The communication control program according to Note C8, wherein the allocation means calculates the delay time of the traffic between the relay device and the first terminal when the communication resources are allocated to the first terminal according to a predetermined first allocation method, selects a number of first terminals that the relay device can newly communicate with from among the first terminals, starting with the one with the largest delay time, and allocates the communication resources to the selected first terminals; calculates the delay time of the traffic between the relay device and the second terminal when the communication resources are allocated to the second terminal according to a predetermined second allocation method, selects a number of second terminals that the relay device can newly communicate with from among the second terminals, starting with the one with the largest delay time, and allocates the communication resources to the selected second terminals.

[0396] (Note C15) The allocation means predicts the traffic at the allocation timing for allocating the communication resources, calculates the delay time at the allocation timing using the predicted traffic information and the information of the communication resources allocated at the allocation timing according to a predetermined allocation method, and determines the allocation of the communication resources to be performed at the allocation timing according to the delay time, as described in Note C8.

[0397] [Addendum D] This disclosure includes the technologies described in the following addendums. However, the present invention is not limited to the technologies described in the following addendums, and various modifications are possible within the scope of the claims.

[0398] (Appendix D1) A communication control device comprising at least one processor, wherein the at least one processor performs an allocation process for allocating the communication resources of the relay device to be used by the relay device in communication with the first terminal and the second terminal, respectively, with reference to the maximum communication capacity that the relay device can provide in communication with a first terminal and the maximum communication capacity that the relay device can provide in communication with a second terminal, and a setting process for setting the communication resources.

[0399] The communication control device may also include a memory. Furthermore, the memory may store a program for causing at least one processor to execute each of the aforementioned processes.

[0400] (Appendix D2) The communication control device according to Appendix D1, wherein in the allocation process, the at least one processor allocates the communication resources based on the smaller of the maximum communication capacity that the relay device can provide in communication with a first terminal and the maximum communication capacity that the relay device can provide in communication with a second terminal.

[0401] (Note D3) The communication control device according to Note D1 or D2, wherein the at least one processor further performs an acquisition process to acquire relay device location information indicating the location of the relay device, first terminal location information indicating the location of the first terminal, and second terminal location information indicating the location of the second terminal, and in the allocation process, the at least one processor further refers to the relay device location information, the first terminal location information, and the second terminal location information and allocates the communication resources.

[0402] (Appendix D4) A communication control device according to any one of Appendix D1 to D3, further performing a determination process that refers to the communication resources and determines at least one of the communication settings for communication between the first terminal and the relay device and the communication settings for communication between the second terminal and the relay device, and an instruction process that instructs at least one of the first terminal and the second terminal to communicate based on the communication settings.

[0403] (Appendix D5) The communication control device according to Appendix D4, wherein in the determination process, at least one processor determines the transmission power of the first terminal or the transmission power of the second terminal as a communication setting.

[0404] (Note D6) The communication control device according to any one of Notes D1 to D5, wherein the relay device includes a first relay device and a second relay device, the first relay device communicates with the first terminal, the second relay device communicates with the second terminal, and in the allocation process, the at least one processor refers to the maximum communication capacity that the first relay device can provide in communication with the first terminal and the maximum communication capacity that the second relay device can provide in communication with the second terminal, and allocates the respective communication resources of the first relay device and the second relay device.

[0405] (Note D7) A communication control device according to any one of Notes D1 to D6, wherein in the allocation process, the at least one processor allocates the communication resources according to the amount of traffic between the relay device and the first terminal and the second terminal, respectively.

[0406] (Note D8) The communication control device according to any one of Notes D1 to D7, wherein in the allocation process, the at least one processor allocates the communication resources according to the delay time of traffic between the relay device and the first terminal and the second terminal, respectively.

[0407] (Note D9) A communication control device according to any one of Notes D1 to D8, wherein in the allocation process, the at least one processor further refers to control information relating to the future status of the relay device, the first terminal, and the second terminal, and allocates the communication resources.

[0408] (Note D10) A communication control system comprising: a first terminal; a second terminal and a communication control device that controls communication by a relay device that relays communication between the first terminal, the second terminal, and the first terminal and the second terminal, wherein the communication control device comprises at least one processor, and includes: an allocation process in which the at least one processor refers to the maximum communication capacity that the relay device can provide in communication with the first terminal and the maximum communication capacity that the relay device can provide in communication with the second terminal and allocates the communication resources of the relay device to be used by the relay device in communication with the first terminal and the second terminal, respectively; a setting process in which the at least one processor sets the communication resources; a determination process in which the at least one processor refers to the communication resources and determines the communication settings for communication between the first terminal and the relay device and the communication settings for communication between the second terminal and the relay device; and an instruction process in which the at least one processor instructs the first terminal and the second terminal, respectively, to communicate based on the communication settings, A communication control system comprising: the first terminal comprising at least one processor, wherein the at least one processor includes an acceptance process for receiving instructions from the communication control device and a communication process for performing communication based on the communication settings indicated by the instructions; and the second terminal comprising at least one processor, wherein the at least one processor includes an acceptance process for receiving instructions from the communication control device and a communication process for performing communication based on the communication settings indicated by the instructions.

[0409] (Note D11) A first terminal that communicates with a second terminal via a relay device, comprising at least one processor, wherein the at least one processor performs an acceptance process to receive an instruction to communicate based on a communication setting for communication with the relay device, which is determined by referring to the communication resources of the relay device used by the relay device in communication with the first terminal and the second terminal, and which are allocated by referring to the maximum communication capacity that the relay device can provide in communication with the first terminal and the maximum communication capacity that the relay device can provide in communication with the second terminal, and the at least one processor performs a communication process to communicate based on the communication setting indicated by the instruction.

[0410] (Note D12) The communication control device according to Note D8, wherein the delay time includes any of processing time, waiting time, transmission time, and propagation time, the processing time is the time from the occurrence of the traffic until the traffic is stored in the transmission queue, the waiting time is the time from when the traffic is stored in the transmission queue until the transmission of the traffic is started, the transmission time is the time from when the transmission of the traffic is started until the transmission of the traffic is finished, and the propagation time is the time from when the transmission of the traffic is finished until the propagation of the traffic in the communication path is finished.

[0411] (Note D13) The communication control device according to Note D8, wherein in the allocation process, the at least one processor calculates the delay time of the traffic in the communication between the relay device and the first terminal as the delay time in the communication between the relay device and the first terminal when the communication resources are allocated to the first terminal according to a predetermined first allocation method, and calculates the delay time of the traffic in the communication between the relay device and the second terminal as the delay time in the communication between the relay device and the second terminal when the communication resources are allocated to the second terminal according to a predetermined second allocation method.

[0412] (Note D14) The communication control device according to Note D8, wherein in the allocation process, the at least one processor calculates the delay time of the traffic between the relay device and the first terminal when the communication resources are allocated to the first terminal according to a predetermined first allocation method, selects a number of first terminals that the relay device can now communicate with from among the first terminals, starting with the one with the largest delay time, and allocates the communication resources to the selected first terminals; calculates the delay time of the traffic between the relay device and the second terminal when the communication resources are allocated to the second terminal according to a predetermined second allocation method, selects a number of second terminals that the relay device can now communicate with from among the second terminals, starting with the one with the largest delay time, and allocates the communication resources to the selected second terminals.

[0413] (Appendix D15) The communication control device according to Appendix D8, wherein in the allocation process, at least one processor predicts the traffic at the allocation timing for allocating the communication resources, calculates the delay time at the allocation timing using the predicted traffic information and the information of the communication resources allocated at the allocation timing according to a predetermined allocation method, and determines the allocation of the communication resources to be performed at the allocation timing according to the delay time.

[0414] [Addendum E] This disclosure includes the technologies described in the following addendums. However, the present invention is not limited to the technologies described in the following addendums, and various modifications are possible within the scope of the claims.

[0415] (Appendix E1) A non-temporary recording medium that records a communication control program for causing a computer to function as a communication control device, the program which causes the computer to perform an allocation process for allocating the communication resources of the relay device to be used by the relay device in communication with the first terminal and the second terminal, respectively, by referring to the maximum communication capacity that the relay device can provide in communication with a first terminal and the maximum communication capacity that the relay device can provide in communication with a second terminal, and a setting process for setting the communication resources.

[0416] (Appendix E2) A communication control program that causes a computer to function as a first terminal communicating with a second terminal via a relay device, the communication control program that causes the computer to perform: an acceptance process that receives an instruction to communicate based on communication settings for communication with the relay device, which are determined by referring to the communication resources of the relay device used by the relay device in communication with the first terminal and the second terminal, respectively, and a communication process that performs communication based on the communication settings indicated by the instruction; and a communication control program that records a communication control program.

[0417] The embodiments described above serve as exemplary examples for explaining this disclosure. However, the present invention is not limited to the embodiments described above. That is, various aspects of this disclosure that can be understood by those skilled in the art can be applied within the scope of this disclosure.

[0418] This application claims priority based on Japanese Patent Application No. 2024-211178, filed on 4 December 2024, and Japanese Patent Application No. 2025-116964, filed on 11 July 2025, and incorporates all of their disclosures herein.

[0419] 1, 2 Communication control device 2, 2A, 2_1B, 2_2B Satellite 3, 3A, 3B First terminal 3_1A, 3_2A, 3_3A, 3_4A First terminal 4, 4A, 4B Second terminal 4_1A, 4_2A, 4_3A, 4_4A Second terminal 11, 11A, 11_1B, 11_2B Cutting unit 12, 12A, 12_1B, 12_2B Setting unit 21, 21A, 21_1B, 21_2B Decision unit 22, 22A, 22_1B, 22_2B Instruction unit 23A, 23_1B, 23_2B Acquisition unit 24_1B, 24_2B, 33A, 33B, 43A, 43B Output Department 100, 100A, 100B Communication Control System

Claims

1. A communication control device comprising: allocation means for allocating communication resources of the relay device to be used by the relay device in communication with the first terminal and the second terminal, respectively, by referring to the maximum communication capacity that the relay device can provide in communication with a first terminal and the maximum communication capacity that the relay device can provide in communication with a second terminal; and setting means for setting the communication resources.

2. The communication control device according to claim 1, wherein the allocation means allocates the communication resources based on the smaller of the maximum communication capacity that the relay device can provide in communication with a first terminal and the maximum communication capacity that the relay device can provide in communication with a second terminal.

3. The communication control device according to claim 1 or 2, further comprising acquisition means for acquiring relay device location information indicating the location of the relay device, first terminal location information indicating the location of the first terminal, and second terminal location information indicating the location of the second terminal, wherein the allocation means further refers to the relay device location information, the first terminal location information, and the second terminal location information to allocate the communication resources.

4. A communication control device according to claim 1 or 2, further comprising: a determination means for determining at least one of the communication settings for communication between the first terminal and the relay device and the communication settings for communication between the second terminal and the relay device, by referring to the communication resources; and an instruction means for instructing at least one of the first terminal and the second terminal to communicate based on the communication settings.

5. The communication control device according to claim 4, wherein the determination means determines the transmission power of the first terminal or the transmission power of the second terminal as a communication setting.

6. The communication control device according to any one of claims 1 to 5, wherein the relay device includes a first relay device and a second relay device, the first relay device communicates with the first terminal, the second relay device communicates with the second terminal, and the allocation means allocates the respective communication resources of the first relay device and the second relay device by referring to the maximum communication capacity that the first relay device can provide in communication with the first terminal and the maximum communication capacity that the second relay device can provide in communication with the second terminal.

7. The communication control device according to claim 1 or 2, wherein the allocation means allocates the communication resources according to the amount of traffic between the relay device and the first terminal and the second terminal, respectively.

8. The communication control device according to claim 1 or 2, wherein the allocation means allocates the communication resources according to the delay time of traffic between the relay device and the first terminal and the second terminal, respectively.

9. The communication control device according to any one of claims 1 to 8, wherein the allocation means further refers to control information relating to the future status of the relay device, the first terminal, and the second terminal to allocate the communication resources.

10. The communication control device according to claim 8, wherein the delay time includes any of processing time, waiting time, transmission time, and propagation time, the processing time is the time from the occurrence of the traffic until the traffic is stored in the transmission queue, the waiting time is the time from when the traffic is stored in the transmission queue until the transmission of the traffic is started, the transmission time is the time from when the transmission of the traffic is started until the transmission of the traffic is finished, and the propagation time is the time from when the transmission of the traffic is finished until the propagation of the traffic in the communication path is finished.

11. The communication control device according to claim 8, wherein the allocation means performs either of the following: calculating the delay time of the traffic in the communication between the relay device and the first terminal as the delay time in the communication between the relay device and the first terminal when the communication resources are allocated to the first terminal in accordance with a predetermined first allocation method; or calculating the delay time of the traffic in the communication between the relay device and the second terminal as the delay time in the communication between the relay device and the second terminal when the communication resources are allocated to the second terminal in accordance with a predetermined second allocation method.

12. The communication control device according to claim 8, wherein the allocation means performs either of the following processes: 1) Calculate the delay time of the traffic between the relay device and the first terminal when the communication resources are allocated to the first terminal according to a predetermined first allocation method, select a number of the first terminals that the relay device can now communicate with from among the first terminals, starting with the one with the largest delay time, and allocate the communication resources to the selected first terminals; 2) Calculate the delay time of the traffic between the relay device and the second terminal when the communication resources are allocated to the second terminal according to a predetermined second allocation method, select a number of the second terminals that the relay device can now communicate with from among the second terminals, starting with the one with the largest delay time, and allocate the communication resources to the selected second terminals.

13. The communication control device according to claim 8, wherein the allocation means predicts the traffic at the allocation timing for allocating the communication resources, calculates the delay time at the allocation timing using the predicted traffic information and the information of the communication resources allocated at the allocation timing according to a predetermined allocation method, and determines the allocation of the communication resources to be performed at the allocation timing according to the delay time.

14. A communication control system comprising: a first terminal; a second terminal and a communication control device that controls communication between the first terminal, the second terminal, and the first terminal and the second terminal by a relay device, wherein the communication control device comprises: allocation means for allocating communication resources of the relay device to be used by the relay device in communication with the first terminal and the second terminal, with reference to the maximum communication capacity that the relay device can provide in communication with the first terminal and the maximum communication capacity that the relay device can provide in communication with the second terminal; setting means for setting the communication resources; determination means for determining communication settings in communication between the first terminal and the relay device and communication settings in communication between the second terminal and the relay device, with reference to the communication resources; and instruction means for instructing the first terminal and the second terminal to communicate based on the communication settings, wherein the first terminal comprises: receiving means for receiving instructions from the communication control device; and communication means for performing communication based on the communication settings indicated by the instructions; and the second terminal is A communication control system comprising: a receiving means for receiving instructions from the communication control device; and a communication means for performing communication based on the communication settings indicated by the instructions.

15. A first terminal that communicates with a second terminal via a relay device, comprising: a receiving means for receiving an instruction to communicate based on a communication setting for communication with the relay device, which is determined by referring to the maximum communication capacity that the relay device can provide in communication with the first terminal and the maximum communication capacity that the relay device can provide in communication with the second terminal, and which is allocated by referring to the communication resources of the relay device used by the relay device in communication with the first terminal and the second terminal, respectively; and a communication means for performing communication based on the communication setting indicated by the instruction.

16. A communication control method comprising: an allocation process in which at least one processor allocates the communication resources of the relay device to be used by the relay device in communication with the first terminal and the second terminal, with reference to the maximum communication capacity that the relay device can provide in communication with a first terminal and the maximum communication capacity that the relay device can provide in communication with a second terminal; and a setting process in which the at least one processor sets the communication resources.

17. The communication control method according to claim 16, wherein in the allocation process, the at least one processor allocates the communication resources based on the smaller of the maximum communication capacity that the relay device can provide in communication with a first terminal and the maximum communication capacity that the relay device can provide in communication with a second terminal.

18. The communication control method according to claim 16 or 17, wherein the at least one processor further includes an acquisition process for acquiring relay device location information indicating the location of the relay device, first terminal location information indicating the location of the first terminal, and second terminal location information indicating the location of the second terminal, and in the allocation process, the at least one processor further refers to the relay device location information, the first terminal location information, and the second terminal location information and allocates the communication resources.

19. A communication control method according to any one of claims 16 to 18, further comprising: a determination process in which the at least one processor refers to the communication resources and determines at least one of the communication settings for communication between the first terminal and the relay device and the communication settings for communication between the second terminal and the relay device; and an instruction process in which the at least one processor instructs at least one of the first terminal and the second terminal to communicate based on the communication settings.

20. A program for causing a computer to function as a communication control device, wherein the computer functions as an allocation means for allocating communication resources of the relay device to be used by the relay device in communication with the first terminal and the second terminal, respectively, by referring to the maximum communication capacity that the relay device can provide in communication with a first terminal and the maximum communication capacity that the relay device can provide in communication with a second terminal, and a setting means for setting the communication resources.

Images