Control device, control method, and control program

Abstract

To avoid the situation in a satellite backhaul communication system in which QoS parameters are adjusted and PDU sessions are released due to deterioration of communication quality caused by weather effects, temporary increases in traffic, etc.SOLUTION: A statistical processing unit 701 acquires a measurement result of communication quality in a communication in which a beam transmitted and received between an artificial satellite and an earth station is used as a backhaul line. An adjustment unit 703 adjusts at least one of the frequency bandwidth and the shape of the beam on the basis of the measurement result.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a communication system (hereinafter also referred to as a satellite backhaul communication system) in which a beam transmitted and received between a satellite (hereinafter simply also referred to as a satellite) and an earth station is used as a backhaul line. In the following, such a backhaul line is referred to as a satellite backhaul line.

Background Art

[0002] With the globalization and diversification of recent social and economic activities, discussions have been held on providing a broadband environment in a wide range of activity areas such as the air, sea, rural areas, etc. For example, discussions on non-terrestrial networks: NTN have been started at 3GPP (registered trademark), which formulates standard technical specifications for mobile communication (cellular communication) systems, various national organizations, academic societies, etc. Note that "NTN" means "Non-Terrestrial Network". Also, "3GPP" means "3rd Generation Partnership Project". Among them, standardization regarding NTN has been gradually advanced for 5G (fifth-generation mobile communication system). Also, discussions for Beyond 5G / 6G (sixth-generation mobile communication system) have been steadily advanced. Thus, recently, expectations for the utilization of satellite communication have been increasing.

[0003] Regarding the architecture for 5G network access using satellites, discussions have been held on a form in which a cellular terminal directly communicates via a satellite. Furthermore, discussions have also been held on a satellite backhaul type architecture that has also been partially realized before 4G.

[0004] In Non-Patent Document 1, QoS control in a satellite backhaul communication system is cited as one of the key issues. "QoS" means "Quality of Service". Non-patent document 1 describes a technology for an interface (N3 I / F) that utilizes a satellite communication link between a UPF and a RAN node (cellular base station) located on the core network side. "UPF" stands for "User Plane Function," and "RAN" stands for "Radio Access Network." More specifically, Non-Patent Document 1 describes an example in which QoS constraints are recognized by an SMF located on the core network side by monitoring QoS properties such as transmission delay. "SMF" stands for "Session Management Function."

[0005] Patent Document 1 describes a mobile communication system using a satellite backhaul link. More specifically, Patent Document 1 describes an example of how to convert service quality indicators for different communication sections while suppressing the influence of service quality indicators between base stations.

[0006] Meanwhile, development is underway on a technology that uses an onboard digital channelizer to control the frequency band for multi-beam communications satellites, known as HTS, which are capable of transmitting multiple beams (for example, more than 100). "HTS" stands for "High Throughput Satellite."

[0007] For example, Patent Document 2 provides a method for dynamically allocating satellite radio resources and a method for implementing this method in a VHTS system. "VHTS" stands for "Very High Throughput Satellite." The technology described in Patent Document 2 is implemented by a ground-based RRM. "RRM" stands for "Radio Resource Manager." Patent Document 2 also describes how time-frequency resources for the downlink (from satellite to user terminal direction) of each spot in multibeam coverage are dynamically allocated according to the propagation status of radio signals, current or future traffic profiles, and interference levels generated by adjacent beams. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Patent No. 7038928 [Patent Document 2] US 10,644,788 B2 [Non-patent literature]

[0009] [Non-Patent Document 1] 3GPP TR23.737 [Overview of the project] [Problems that the invention aims to solve]

[0010] In a satellite backhaul communication system that connects UPF and RAN nodes via satellite communication links, the communication quality of each PDU session may fluctuate significantly due to weather conditions, temporary increases in satellite communication link traffic, etc. "PDU" stands for "Packet Data Unit". In this case, when the core network detects a deterioration in communication quality between the UPF and RAN nodes (for example, an increase in transmission delay), it determines that it cannot maintain QoS for the PDU session in question. As a result, QoS parameters may be adjusted, or the PDU session may be released. The technologies described in Patent Documents 1 and 2 cannot avoid situations where such QoS parameters are adjusted or PDU sessions are released.

[0011] The primary purpose of this disclosure is to address these issues. More specifically, the primary purpose of this disclosure is to avoid situations in satellite backhaul communication systems where QoS parameters are adjusted due to deterioration of communication quality caused by weather conditions, temporary increases in traffic, etc., and where PDU sessions are released.

Means for Solving the Problem

[0012] The control device according to the present disclosure is an acquisition unit that acquires measurement results of communication quality in communication where a beam transmitted and received between a satellite and an earth station is used as a backhaul line, and an adjustment unit that adjusts at least one of the frequency bandwidth of the beam and the shape of the beam based on the measurement results.

Effect of the Invention

[0013] According to the present disclosure, in a satellite backhaul communication system, it is possible to avoid a situation where QoS parameters are adjusted due to deterioration of communication quality caused by weather effects, temporary increase in traffic, etc., and a situation where a PDU session is released.

Brief Description of the Drawings

[0014] [Figure 1] It is a diagram showing a configuration example of a satellite backhaul type cellular communication system according to Embodiment 1. [Figure 2] It is a diagram showing a functional configuration example of a core network according to Embodiment 1. [Figure 3] It is a diagram showing a functional configuration example of a NOC and a UPF according to Embodiment 1. [Figure 4] It is a flowchart showing an operation example of an adjustment unit according to Embodiment 1. [Figure 5] It is a diagram showing an adjustment example of the frequency bandwidth of a beam according to Embodiment 1. [Figure 6] It is a diagram showing a hardware configuration example of a NOC according to Embodiment 1. [Figure 7] It is a flowchart showing an operation example of an adjustment unit according to Embodiment 2. [Figure 8] It is a diagram showing an IP header according to Embodiment 3. [Figure 9] It is a diagram showing a functional configuration example of a NOC and a UPF according to Embodiment 4.

Mode for Carrying Out the Invention

[0015] Hereinafter, embodiments will be described with reference to the drawings. In the following description of the embodiments and the drawings, those denoted by the same reference numerals indicate the same or corresponding parts.

[0016] Embodiment 1. In the present embodiment, an example of adjusting the frequency bandwidth of a beam transmitted and received between a satellite and an earth station based on the communication quality in communication between a UPF and a RAN node included in a satellite backhaul communication system will be described.

[0017] ***Description of the Configuration*** FIG. 1 shows a configuration example of a satellite backhaul communication system according to the present embodiment. The satellite backhaul communication system shown in FIG. 1 is a cellular communication system. Hereinafter, the communication system shown in FIG. 1 will also be referred to as a satellite backhaul type cellular communication system. As shown in FIG. 1, the satellite backhaul type cellular communication system includes a satellite 10, a satellite communication terminal 20, a cellular base station 21, a cellular terminal 22, a satellite communication terminal 25, a satellite gateway 30, a core network 40, a data network 50, a SOC 60, a NOC 70, a user link cell 80, and a user link cell 85. In FIG. 1, the satellite gateway 30 is denoted as satellite GW30. The core network 40 is denoted as core NW40. The data network 50 is denoted as data NW50.

[0018] The satellite 10 is a communication satellite. In the satellite backhaul type cellular communication system shown in FIG. 1, a beam (satellite communication line) transmitted and received between the satellite 10 and the satellite communication terminal 20 is used as a backhaul line. Also, a beam (satellite communication line) transmitted and received between the satellite 10 and the satellite communication terminal 25 is used as a backhaul line. Further, a beam (satellite communication line) transmitted and received between the satellite 10 and the satellite gateway 30 is used as a backhaul line. Satellite 10 transmits multiple beams to satellite communication terminals 20 and 25. Satellite 10 also receives multiple beams from satellite communication terminals 20 and 25. Furthermore, satellite 10 transmits multiple beams to satellite gateway 30. Satellite 10 also receives multiple beams from satellite gateway 30. In short, satellite 10 is a multi-beam satellite. Satellite 10 is, for example, a geostationary satellite.

[0019] Satellite communication terminal 20 and satellite communication terminal 25 are earth stations that transmit and receive beams with the artificial satellite 10, respectively. Satellite communication terminals 20 and 25 are, for example, VSATs. "VSAT" stands for "Very Small Aperture terminal".

[0020] Cellular base station 21 is a base station that connects to satellite communication terminal 20.

[0021] The cellular terminal 22 is a communication terminal that connects to the cellular base station 21.

[0022] Satellite Gateway 30 is also an earth station that transmits and receives beams with artificial satellite 10. The satellite gateway 30 is a gateway device that provides communication services to the cellular terminal 22 via the artificial satellite 10.

[0023] The core network 40 is the core network for cellular communications that connects to the satellite gateway 30.

[0024] Data network 50 is a data network such as an internet service provider's network or a corporate network that connects to core network 40.

[0025] SOC60 receives telemetry signals from satellite 10 and transmits commands to control satellite 10. "SOC" stands for "Satellite Operation Center".

[0026] NOC70 manages and monitors the entire satellite communications network. "NOC" stands for "Network Operation Center". The control device described herein is implemented by NOC70. The operating procedure of NOC70 corresponds to the control method. Furthermore, the program that implements the operation of NOC70 corresponds to the control program.

[0027] As mentioned above, satellite 10 is a multi-beam satellite capable of transmitting and receiving multiple beams. User link cells are generated by each of the multiple beams transmitted from satellite 10. In Embodiment 1, two user link cells, user link cell 80 and user link cell 85, are generated by each of the two beams transmitted from the artificial satellite 10. Multiple satellite communication terminals 20 are located in user link cell 80, and multiple satellite communication terminals 25 are located in user link cell 85. In this embodiment, only two user link cells are described for the sake of simplicity, but this embodiment is equally applicable to multiple beams and multiple user link cells. Furthermore, Figure 1 only shows one cellular base station 21 and one cellular terminal 22, omitting other details. In reality, it should be assumed that each of the multiple satellite communication terminals 20 is connected to a cellular base station 21. Similarly, it should be assumed that each of the multiple satellite communication terminals 25 is connected to a cellular base station 21. Moreover, it should be assumed that each cellular base station 21 is connected to multiple cellular terminals 22.

[0028] The satellite communication terminal 20 and the cellular base station 21 transmit various signals (control signals, user data, etc.) to and from the core network 40 via the artificial satellite 10 and the satellite gateway 30. The satellite communication terminal 20 and the cellular base station 21 also transmit various signals from and to the cellular terminal 22 to and from the core network 40. Furthermore, the satellite communication terminal 20 may be integrated with the cellular base station 21.

[0029] Figure 2 shows an example of a 5G system architecture as described in "3GPP TS23.501".

[0030] In Figure 2, UE22 corresponds to the cellular terminal 22. "UE" stands for "User Equipment". Furthermore, RAN21 indicates a node in the RAN, corresponding to cellular base station 21. As mentioned earlier, "RAN" stands for "Radio Access Network".

[0031] Core network 40 contains some of the functional configurations described in "3GPP TS23.501". UPF41 is a function that handles the transfer of user data, etc. As mentioned earlier, "UPF" stands for "User Plane Function". SMF42 is a function that handles session management, etc. "SMF" stands for "Session Management Function". AMF43 is a function that performs mobility management and other related tasks. "AMF" stands for "Access and Mobility Management Function". PCF44 is a function that provides unified control over network behavior. "PCF" stands for "Policy Control Function".

[0032] The interface between RAN21 and UPF41 is called "N3" (hereinafter referred to as "N3 I / F"). In the case of a satellite backhaul type cellular communication system, a satellite link is used for the "N3 I / F".

[0033] In this embodiment, the method for managing and monitoring communication satellites in a satellite backhaul type cellular communication system is described in a form applied to SOC60 and NOC70. However, the method for managing and monitoring communication satellites may be implemented in other forms. For example, these functions may be arranged under different names, such as DPRM and SDRM, which dynamically control communication mission equipment mounted on the artificial satellite 10, either collectively as SOC60 and NOC70, or as some of their functions. "DPRM" stands for "Digital Payload Resource Management," and "SDRM" stands for "System Dynamic Resource Management."

[0034] Figure 1 shows a configuration in which the satellite gateway 30 and SOC 60 communicate with the satellite 10 using separate antennas. Figure 1 also shows a configuration in which the satellite gateway 30 and SOC 60 transmit and receive communication signals for satellite communication terminals 20 and 25 using separate antennas. Alternatively, the satellite gateway 30 and SOC 60 may use a common antenna.

[0035] Figure 3 shows an example of the internal configuration of UPF41 and NOC70 according to this embodiment. Figure 3 shows only the functions necessary to explain this embodiment. Functions other than those shown in Figure 3 may be included in UPF41 and NOC70. Furthermore, the division of functions between UPF41 and NOC70 is not limited to what is shown in Figure 3. In other words, one function may be transferred to the other. Furthermore, the functions of UPF41 and NOC70 shown in Figure 3 may be incorporated into other devices not shown. Additionally, the functions shown in Figure 3 may be distributed among UPF41, NOC70, and other devices. The apparatus comprising the statistical processing unit 701 and the beam placement management unit 702 shown in Figure 3 corresponds to the control device according to this disclosure.

[0036] UPF41 consists of a communication quality measurement unit 411 and a cellular base station location management unit 412.

[0037] The communication quality measurement unit 411 measures the communication quality in the communication between the cellular base station 21, which is a RAN node, and the UPF 41. In this embodiment, the communication quality measurement unit 411 measures the N3 I / F transmission time (hereinafter also simply referred to as transmission time) between the cellular base station 21 and the UPF 41 as a measure of communication quality. Specifically, the communication quality measurement unit 411 measures the transmission round trip time of the N3 I / F between each cellular base station 21 and the UPF 41. Then, the communication quality measurement unit 411 measures the N3 I / F transmission time by dividing the transmission round trip time by one-half. For example, the communication quality measurement unit 411 measures the N3 I / F transmission time using the ping command of the ICPM protocol. "ICPM" stands for "Internet Control Message Protocol". Furthermore, the communication quality measurement unit 411 adds the location information of the cellular base station 21, which is held by the cellular base station location management unit 412, to the measurement results. Then, the communication quality measurement unit 411 transmits the measurement results, which now include the location information of the cellular base station 21, to the NOC 70.

[0038] NOC70 consists of a statistical processing unit 701, a beam placement management unit 702, and an adjustment unit 703.

[0039] The statistical processing unit 701 acquires the communication quality measurement results from the communication quality measurement unit 411. Then, the statistical processing unit 701 performs statistical processing on the communication quality measurement results. Specifically, the statistical processing unit 701 performs statistical processing, such as calculating the average value and variance of the transmission time measured by the communication quality measurement unit 411, at predetermined intervals. The statistical processing unit 701 then generates statistical information that shows the results of the statistical processing.

[0040] The beam placement management unit 702 manages the coverage area of ​​the transmit and receive beams of the satellite 10, which is a multi-beam satellite. If satellite 10 has a function such as DBF and can flexibly change the beam shape, the coverage area of ​​each beam is dynamic. "DBF" stands for "Digital Beam Forming." On the other hand, if satellite 10 cannot change the beam shape, the coverage area of ​​each beam is static. In this embodiment, for the sake of simplicity, the coverage area of ​​the transmitting beam from the satellite 10 and the coverage area of ​​the receiving beam from the satellite 10 are assumed to be the same. However, the coverage areas of the transmitting beam and the receiving beam may be different, in which case the beam placement management unit 702 manages the coverage areas of the transmitting beam and the receiving beam separately.

[0041] The statistical processing unit 701 obtains information on the coverage area of ​​each beam from the beam placement management unit 702. The statistical processing unit 701 also compares the location information of each cellular base station 21 obtained from the communication quality measurement unit 411 with the information on the coverage area of ​​each beam. Then, the statistical processing unit 701 determines which beam each cellular base station 21 is using to communicate with the UPF 41. Furthermore, the statistical processing unit 701 generates information (beam base station correspondence information) for each beam, indicating which cellular base station 21 is using that beam. The beam placement management unit 702 then outputs statistical information on transmission time and beam base station correspondence information for each beam to the adjustment unit 703. Furthermore, the beam placement management unit 702 acquires the communication quality measurement results from the communication quality measurement unit 411, and is equivalent to an acquisition unit. Also, the processing performed by the beam placement management unit 702 is equivalent to an acquisition process.

[0042] The adjustment unit 703 and the beam placement management unit 702 acquire statistical information on transmission time and beam base correspondence information for each beam. The adjustment unit 703 then adjusts the beam frequency bandwidth using statistical information on transmission time and beam base station correspondence information. In other words, the adjustment unit 703 adjusts the beam frequency bandwidth based on the measurement results of communication quality so as to improve communication quality and so as to prevent interference between beams.

[0043] ***Explanation of operation*** The operation of the adjustment unit 703 will be explained in detail using the flowchart in Figure 4.

[0044] (Step S101) The adjustment unit 703 obtains statistical information on the transmission time for each beam and beam base station correspondence information from the statistical processing unit 701.

[0045] (Step S102) The adjustment unit 703 uses statistical information on transmission time to perform calculations, for example, as shown in Equation 1. (Mean) + (Coefficient) × √(Variance) Equation 1 Furthermore, the adjustment unit 703 compares the calculation result of Equation 1 with a preset threshold. Note that Equation 1 is merely an example. The adjustment unit 703 may perform calculations different from those in Equation 1. Furthermore, only one threshold may be set, or multiple thresholds may be set. If only one threshold is set, the adjustment unit 703 determines whether the calculation result of Equation 1 exceeds that threshold. On the other hand, if multiple thresholds are set, the adjustment unit 703 determines whether the calculation result of Equation 1 falls between any two of the thresholds. Furthermore, the adjustment unit 703 may set a threshold for each cellular base station 21.

[0046] The adjustment unit 703 performs the above determination for each cellular base station 21. If two or more cellular base stations 21 are using the same beam, two or more determination results can be obtained for that beam. In this case, the adjustment unit 703 may adopt the determination result for the representative value, such as the one with the largest calculated value in Equation 1. Alternatively, the mean and variance values ​​may be averaged among the statistical information for two or more cellular base stations 21, and the averaged mean and variance values ​​may be applied to Equation 1.

[0047] (Step S103) In step S102, the adjustment unit 703 determines that the transmission time in the beam has increased if the calculation result of Equation 1 exceeds the threshold. If multiple thresholds are set, the adjustment unit 703 determines that the transmission time in the beam has increased if the calculation result of Equation 1 exceeds a specific threshold. Furthermore, if multiple thresholds are set, the adjustment unit 703 may determine the degree of increase in transmission time in stages. Conversely, if the calculation result of Equation 1 is below the threshold, the adjustment unit 703 determines that the transmission time in the beam is in a steady state.

[0048] (Step S104) The adjustment unit 703 then determines whether it is possible to allocate additional frequency bandwidth to the beam whose transmission time is increasing, taking into account interference with the bandwidth required by other beams.

[0049] For example, as shown in Figure 5, we assume that 500 MHz is allocated as the beam frequency bandwidth for user link cell 80 and user link cell 85, respectively. In this case, the adjustment unit 703 determines that the beam transmission time for user link cell 80 has increased, and that the beam transmission time for user link cell 85 is in a steady state. In this case, the adjustment unit 703 determines whether it is possible to adjust the beam frequency bandwidth by adding 50 MHz for the user link cell 80 and reducing it by 50 MHz for the user link cell 85. In other words, it determines whether interference will occur between the beam for user link cell 80 and the beam for user link cell 85 even after such adjustments are made.

[0050] Furthermore, if multiple thresholds are set and the degree of increase in transmission time is determined in stages, the adjustment unit 703 may assign a frequency bandwidth in stages, for example, 50 MHz, 100 MHz, according to the determination result.

[0051] Furthermore, for the sake of simplicity, this embodiment assumes that the same frequency bandwidth adjustment is performed for both the transmitting and receiving beams. However, the values ​​of the frequency bandwidth adjusted for the transmitting and receiving beams may be different.

[0052] In the example shown in Figure 5, for the sake of simplicity, an example of adjusting the frequency bandwidth between two beams is illustrated. As mentioned above, adjustments are required between numerous beams while considering interference, so it may not always be possible to adjust the frequency bandwidth. Also, there may be cases where frequency bandwidth adjustment is unnecessary.

[0053] If it is decided in step S104 to adjust the frequency bandwidth, the process proceeds to step S105. On the other hand, if it is decided in step S104 not to adjust the frequency bandwidth, the process proceeds to step S106.

[0054] (Step S105) When adjusting the frequency bandwidth, the adjustment unit 703 instructs the SOC60 to change the allocated bandwidth for each beam. After a certain waiting period, the process returns to step S101, and the process from step S101 onward is repeated.

[0055] (Step S106) If no adjustment of the frequency bandwidth is performed, the process waits for a certain period of time, then returns to step S101, and the process from step S101 onward is repeated.

[0056] Upon receiving instructions from the adjustment unit 703 to change the beam allocation bandwidth, the SOC60 sends a command to the satellite 10 to change the allocation bandwidth, and the satellite 10's settings are modified. Furthermore, SOC60 confirms that the configuration change was successfully implemented using telemetry transmitted from satellite 10.

[0057] If the above process is repeated and, for example, the increase in the transmission time of the user link cell 80 is not resolved, the adjustment unit 703 may allocate additional frequency bandwidth. In this case, the adjustment unit 703 may determine an upper limit on the additional frequency bandwidth to be allocated.

[0058] In this embodiment, the transmission time measurement result was described as an example of the communication quality measurement result notified from UPF41 to NOC70. Alternatively, the BER and / or FER values ​​measured by UPF41 may be notified as the communication quality measurement result. Then, in NOC70, statistical processing of the BER and / or FER values ​​may be performed in the same manner as described above, and the beam frequency bandwidth may be adjusted by comparing them with a threshold. Note that "BER" means "Bit Error Rate" and "FER" means "Frame Error Rate".

[0059] The operation of the NOC70 described in this embodiment 1 is achieved, for example, by the processor 705 within the NOC70 shown in Figure 6 executing a program stored in the memory 706. In other words, the processor 705 reads from memory 706 a program that implements the functions of the statistical processing unit 701, beam placement management unit 702, and adjustment unit 703 shown in Figure 3. Then, the processor 705 executes this program, thereby realizing the processing of the statistical processing unit 701, beam placement management unit 702, and adjustment unit 703. Thus, the NOC70 is a computer equipped with a processor 705 and memory 706.

[0060] Furthermore, in this embodiment, an example in which the artificial satellite 10 is a geostationary satellite was described. The artificial satellite 10 may also be a non-geostationary satellite such as an MEO or LEO. "MEO" stands for "Medium Earth Orbit," and "LEO" stands for "Low Earth Orbit."

[0061] ***Explanation of the effects of the embodiment*** As described above, in this embodiment, the NOC 70 can dynamically adjust the beam frequency bandwidth based on the communication quality measurement results notified from the core network 40. Therefore, additional frequency bandwidth can be dynamically allocated to beams whose communication quality has deteriorated due to weather effects, a temporary increase in satellite communication link traffic, etc. This reduces the deterioration of communication quality. As a result, in a satellite backhaul type cellular communication system, it is possible to avoid situations where the QoS parameters of a PDU session are adjusted or where a PDU session is released.

[0062] Embodiment 2. This embodiment will primarily describe the differences from Embodiment 1. Matters not described below are the same as in Embodiment 1.

[0063] Figure 7 is a flowchart showing an example of the operation of the adjustment unit 703 according to this embodiment. Steps S101 to S105 are the same as those shown in Figure 4. Therefore, their explanation is omitted. In this embodiment, if no adjustment of the frequency bandwidth is performed in step S104, the process proceeds to step S111.

[0064] (Step S111) The adjustment unit 703 determines whether the beam shape can be adjusted for a beam whose transmission time is increasing, taking into account interference with the bandwidth required by other beams. In other words, the adjustment unit 703 determines, after considering interference with beam shapes required by other beams, whether it is possible to adjust the beam shape for a beam whose transmission time is increasing so that the antenna gain at the location of the cellular base station 21 where the transmission time is increasing is improved. If, for example, the satellite 10 has a DBF function, the adjustment unit 703 determines whether it is possible to adjust the beam shape by controlling the antenna excitation coefficient.

[0065] (Step S112) If the beam shape can be adjusted, the process proceeds to step S113. On the other hand, if the beam shape cannot be adjusted, the process proceeds to step S114.

[0066] (Step S113) If the beam shape can be adjusted, the adjustment unit 703 instructs the SOC 60 to change the shape of each beam, for example, by setting a change in the antenna excitation coefficient for each beam. After a certain waiting period, the process returns to step S101, and the process from step S101 onward is repeated.

[0067] (Step S114) If the beam shape cannot be adjusted, the process waits for a certain period of time, then returns to step S101, and the process from step S101 onward is repeated.

[0068] In this embodiment, the adjustment unit 703 determines whether or not the frequency bandwidth of the beam can be adjusted, and adjusts the frequency bandwidth of the beam if it can be adjusted. On the other hand, if the frequency bandwidth of the beam cannot be adjusted, the adjustment unit 703 determines whether or not the shape of the beam can be adjusted. If the shape of the beam can be adjusted, the adjustment unit 703 adjusts the shape of the beam. Therefore, according to this embodiment, the degradation of communication quality can be mitigated by changing the shape of the beam in the case of beams whose communication quality has deteriorated due to the effects of weather, a temporary increase in traffic on satellite communication lines, etc.

[0069] Furthermore, in this embodiment, an example was described in which the adjustment unit 703 adjusts the beam shape when the beam frequency bandwidth cannot be adjusted. Alternatively, the adjustment unit 703 may also adjust the beam shape when the beam frequency bandwidth can be adjusted. In other words, the adjustment unit 703 may perform both the adjustment of the beam frequency bandwidth and the adjustment of the beam shape. Although not explicitly shown in the following embodiments, the adjustment unit 703 may similarly perform both the adjustment of the beam frequency bandwidth and the adjustment of the beam shape.

[0070] Embodiment 3. This embodiment will primarily describe the differences from Embodiment 1. Matters not described below are the same as in Embodiment 1.

[0071] In this embodiment, the communication quality measurement unit 411 measures the transmission time between each cellular base station 21 and the UPF 41, performing measurements for each QoS class. Figure 8 shows the IP header. "IP" stands for "Internet Protocol". The communication quality measurement unit 411 uses the 6-bit DSCP value in the service type field of Figure 8 as the QoS class. The communication quality measurement unit 411 then measures the transmission time for the DSCP value used on the N3 I / F. The communication quality measurement unit 411 transmits the measurement results obtained in this way to the NOC70, as in Embodiment 1.

[0072] The statistical processing unit 701 obtains the measurement results of the transmission time for each QoS class from the UPF41. Then, the statistical processing unit 701 performs statistical processing of the transmission time for each QoS class, similar to the first embodiment.

[0073] The adjustment unit 703 may perform the determination in step S102 for all QoS classes for each cellular base station 21, or it may limit the determination to any one of the QoS classes. For example, the adjustment unit 703 may perform the determination in step S102 only for the highest priority QoS class. Alternatively, the adjustment unit 703 may average the mean and variance values ​​among the statistical information of two or more specific QoS classes, and apply the averaged mean and variance values ​​to Equation 1 to perform the determination in step S102. The processing when multiple cellular base stations 21 are using the same beam is the same as that shown in Embodiment 1.

[0074] As described above, this embodiment makes it possible to adjust the frequency bandwidth while taking the QoS class into consideration. That is, for example, it becomes possible to control the system so that the frequency bandwidth is not adjusted for QoS classes that tolerate a degradation of communication quality, such as the best-effort class, and only the frequency bandwidth is adjusted for QoS classes that do not tolerate a degradation of communication quality.

[0075] Embodiment 4. This embodiment will primarily describe the differences from Embodiment 1. Matters not described below are the same as in Embodiment 1.

[0076] Figure 9 shows an example of the configuration of NOC70 according to this embodiment. In Figure 9, the quality degradation prediction unit 704 has been added compared to Figure 3. The elements other than the quality degradation prediction unit 704 are the same as those shown in Figure 3.

[0077] The quality degradation prediction unit 704 predicts the possibility of communication quality degradation for each beam or for each cellular base station 21. More specifically, the quality degradation prediction unit 704 separately acquires weather information and / or traffic volume information for each beam of the satellite 10 and predicts the possibility of communication quality degradation occurring for that beam. The quality degradation prediction unit 704 then outputs the prediction result to the adjustment unit 703.

[0078] The adjustment unit 703 refers to the prediction results of the quality degradation prediction unit 704 and, if a degradation of communication quality is predicted, adjusts the beam frequency bandwidth or beam shape in accordance with the predicted degradation of communication quality. For example, the adjustment unit 703 selects a threshold from among several thresholds that corresponds to the prediction of deterioration in communication quality as the threshold used in step S102. Specifically, the adjustment unit 703 selects a threshold that is lower than the threshold used in situations where deterioration in communication quality is not predicted.

[0079] As described above, according to this embodiment, when a deterioration in communication quality is predicted, it becomes possible to adjust the frequency bandwidth more appropriately in response to the predicted deterioration in communication quality.

[0080] Although embodiments 1 to 4 have been described above, two or more of these embodiments may be combined and implemented. Alternatively, one of these embodiments may be partially implemented. Alternatively, two or more of these embodiments may be partially combined and implemented. Furthermore, the configurations and procedures described in these embodiments may be modified as needed.

[0081] ***Supplementary explanation of hardware configuration*** Here, we will provide supplementary information about the hardware configuration of the NOC70. The processor 705 shown in Figure 6 is an integrated circuit (IC) that performs processing. "IC" stands for "Integrated Circuit". The 705 processor is a CPU, DSP, etc. "CPU" stands for "Central Processing Unit," and "DSP" stands for "Digital Signal Processor." The memory 706 shown in Figure 6 is RAM (Random Access Memory). "RAM" stands for "Random Access Memory". Although not shown in Figure 6, the NOC70 may be equipped with auxiliary storage. Auxiliary storage can be ROM, flash memory, HDD, etc. "ROM" stands for "Read Only Memory," and "HDD" stands for "Hard Disk Drive." Although not shown in Figure 6, the NOC70 may also be equipped with a communication device. The communication device is an electronic circuit that performs data communication processing. Communication devices include, for example, communication chips or NICs. "NIC" stands for "Network Interface Card".

[0082] Furthermore, the operating system (OS) is also stored in the auxiliary storage device. "OS" stands for "Operating System." Furthermore, at least a portion of the OS is executed by the 705 processor. The 705 processor runs the OS, handling task management, memory management, file management, communication control, and other functions. Furthermore, at least one of the information, data, signal values, and variable values ​​indicating the processing results of the statistical processing unit 701, beam placement management unit 702, and adjustment unit 703 is stored in at least one of the memory 706, auxiliary storage device, registers in the processor 705, and cache memory. Furthermore, the programs that implement the functions of the statistical processing unit 701, the beam placement management unit 702, and the adjustment unit 703 may be stored on a portable recording medium such as a magnetic disk, flexible disk, optical disk, compact disk, Blu-ray® disk, or DVD. A portable recording medium containing the programs that implement the functions of the statistical processing unit 701, the beam placement management unit 702, and the adjustment unit 703 may also be distributed.

[0083] Furthermore, at least one of the "parts" in the statistical processing unit 701, beam placement management unit 702, and adjustment unit 703 may be read as "circuit," "process," "procedure," "process," or "circuitry." Furthermore, NOC70 may be implemented by a processing circuit. Examples of such processing circuits include logic ICs, GAs, ASICs, and FPGAs. "GA" stands for "Gate Array." "ASIC" stands for "Application Specific Integrated Circuit." "FPGA" stands for "Field-Programmable Gate Array." In this case, the statistical processing unit 701, the beam placement management unit 702, and the adjustment unit 703 are each implemented as part of a processing circuit. In this specification, the higher-level concept of a processor and processing circuit is referred to as a "processing circuitry." In other words, a processor and a processing circuit are specific examples of "processing circuits," respectively.

[0084] The various aspects of this disclosure are summarized below as an appendix. (Note 1) An acquisition unit that acquires measurement results of communication quality in communications where a beam transmitted and received between an artificial satellite and an earth station is used as a backhaul link, A control device having an adjustment unit that adjusts at least one of the frequency bandwidth of the beam and the shape of the beam based on the measurement results. (Note 2) The adjustment unit is, The control device according to Appendix 1, which adjusts at least one of the frequency bandwidth of the beam and the shape of the beam in order to improve communication quality. (Note 3) The adjustment unit is, Determine whether the frequency bandwidth of the beam can be adjusted, and if the frequency bandwidth of the beam can be adjusted, adjust the frequency bandwidth of the beam. A control device according to Appendix 1 or Appendix 2, which determines whether the shape of the beam can be adjusted when the frequency bandwidth of the beam cannot be adjusted, and adjusts the shape of the beam if it can be adjusted. (Note 4) Multiple beams are transmitted and received between the artificial satellite and the earth station. The adjustment unit is, A control device according to any one of the appendices 1 to 3, which adjusts at least one of the frequency bandwidth of the beams and the shape of the beams so that interference between beams does not occur. (Note 5) The acquisition unit is, A control device according to any one of the appendices 1 to 4, which obtains the measurement result of at least one of the following: transmission time, BER (Bit Error Rate), and FER (Frame Error Rate). (Note 6) The adjustment unit is, A control device according to any one of Appendix 1 to Appendix 5, which compares the measurement result with a threshold for communication quality and adjusts at least one of the beam frequency bandwidth and the beam shape based on the comparison result. (Note 7) The acquisition unit is, Measurement results are obtained for each QoS class of multiple QoS (Quality of Service) classes. The adjustment unit is, A control device according to any one of the appendices 1 to 6, which adjusts at least one of the beam frequency bandwidth and the beam shape based on the measurement results of any of the plurality of QoS classes. (Note 8) The adjustment unit is, A control device according to any one of the appendices 1 to 7, which, when a deterioration in communication quality is predicted, adjusts at least one of the frequency bandwidth of the beam and the shape of the beam in accordance with the predicted deterioration in communication quality. (Note 9) The adjustment unit is, A control device according to any one of the appendices 1 to 8, which selects a threshold corresponding to the prediction of deterioration in communication quality from among a plurality of thresholds for communication quality, compares the measurement result with the selected threshold, and adjusts at least one of the frequency bandwidth of the beam and the shape of the beam based on the comparison result. (Note 10) The acquisition unit is, A control device according to any one of the appendices 1 to 9, which acquires the results of a measurement of the communication quality in communication between a UPF (User Plane Function) and a RAN (Radio Access Network) node in a communication system in which a beam transmitted and received between the artificial satellite and the earth station is used as the backhaul link. (Note 11) The computer obtains the results of measuring the communication quality in communications where beams transmitted and received between a satellite and an earth station are used as a backhaul link. A control method in which the computer adjusts at least one of the frequency bandwidth of the beam and the shape of the beam based on the measurement results. (Note 12) An acquisition process to obtain measurement results of communication quality in communications where a beam transmitted and received between an artificial satellite and an earth station is used as a backhaul link, A control program that causes a computer to perform an adjustment process to adjust at least one of the frequency bandwidth of the beam and the shape of the beam, based on the measurement results. [Explanation of symbols]

[0085] 10 Artificial satellite, 20 Satellite communication terminal, 21 Cellular base station, 22 Cellular terminal, 25 Satellite communication terminal, 30 Satellite gateway, 40 Core network, 41 UPF, 42 SMF, 43 AMF, 44 PCF, 50 Data network, 60 SOC, 70 NOC, 80 User link cell, 85 User link cell, 411 Communication quality measurement unit, 412 Cellular base station position management unit, 701 Statistical processing unit, 702 Beam placement management unit, 703 Adjustment unit, 704 Quality degradation prediction unit, 705 Processor, 706 Memory.

Claims

1. An acquisition unit that acquires measurement results of communication quality in communications where a beam transmitted and received between an artificial satellite and an earth station is used as a backhaul link, A control device having an adjustment unit that determines whether the frequency bandwidth of the beam can be adjusted based on the measurement results, adjusts the frequency bandwidth of the beam if it can be adjusted, and, if the frequency bandwidth of the beam cannot be adjusted, determines whether the shape of the beam can be adjusted based on the measurement results, and adjusts the shape of the beam if it can be adjusted.

2. An acquisition unit that acquires measurement results of communication quality in communications where a beam transmitted and received between an artificial satellite and an earth station is used as a backhaul link, The system includes an adjustment unit that adjusts at least one of the beam's frequency bandwidth and beam shape based on the measurement results, The acquisition unit is, Measurement results are obtained for each QoS class of multiple QoS (Quality of Service) classes. The adjustment unit is, A control device that adjusts at least one of the beam frequency bandwidth and the beam shape based on the measurement results of one of the plurality of QoS classes.

3. An acquisition unit that acquires measurement results of communication quality in communications where a beam transmitted and received between an artificial satellite and an earth station is used as a backhaul link, A control device having an adjustment unit that, when a deterioration in communication quality is predicted, selects a threshold from among several thresholds for communication quality that corresponds to the predicted deterioration in communication quality, compares the measurement result with the selected threshold, and adjusts at least one of the frequency bandwidth of the beam and the shape of the beam based on the comparison result.

4. The adjustment unit is, The control device according to any one of claims 1 to 3, which adjusts at least one of the frequency bandwidth of the beam and the shape of the beam so as to improve communication quality.

5. Multiple beams are transmitted and received between the artificial satellite and the earth station. The adjustment unit is, A control device according to any one of claims 1 to 3, which adjusts at least one of the frequency bandwidth of the beam and the shape of the beam so that interference between beams does not occur.

6. The acquisition unit is, The control device according to any one of claims 1 to 3, wherein the measurement results include obtaining at least one of the following: transmission time, BER (Bit Error Rate), and FER (Frame Error Rate).

7. The acquisition unit is, A control device according to any one of claims 1 to 3, which acquires the results of a measurement of the communication quality in communication between a UPF (User Plane Function) and a RAN (Radio Access Network) node, which are included in a communication system in which a beam transmitted and received between the artificial satellite and the earth station is used as the backhaul line.

8. The computer obtains the results of measuring the communication quality in communications where beams transmitted and received between a satellite and an earth station are used as a backhaul link. A control method in which the computer determines, based on the measurement results, whether or not the frequency bandwidth of the beam can be adjusted, and adjusts the frequency bandwidth of the beam if it can be adjusted, and if the frequency bandwidth of the beam cannot be adjusted, determines, based on the measurement results, whether or not the shape of the beam can be adjusted, and adjusts the shape of the beam if it can be adjusted.

9. An acquisition process to obtain measurement results of communication quality in communications where a beam transmitted and received between an artificial satellite and an earth station is used as a backhaul link, A control program that causes a computer to perform an adjustment process, which involves determining whether the frequency bandwidth of the beam can be adjusted based on the measurement results, adjusting the frequency bandwidth of the beam if it can be adjusted, and, if the frequency bandwidth of the beam cannot be adjusted, determining whether the shape of the beam can be adjusted based on the measurement results, and adjusting the shape of the beam if it can be adjusted.

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