Communication path determination device and communication path determination method

Abstract

A communication path determination device (10) determines a communication path on a communication network having a plurality of nodes (N) and a plurality of links (R) connecting the plurality of nodes by free-space optical communications, and is provided with an information processing unit (11). The information processing unit executes: acquisition processing (S11) for acquiring weather information and the communication quality of at least one link among the plurality of links; prediction processing (S12) for, on the basis of the weather information and the communication quality of the at least one link, predicting communication qualities of the plurality of links after a predetermined time; and determination processing (S13) for, on the basis of the predicted communication qualities, determining a communication path after the predetermined time.

Description

Technical Field

[0001] The present invention relates to a communication path determination device, a communication path determination method, a communication device, a communication control device, and a communication system.

Background Art

[0002] Development of free-space optical communications (FSOC) that uses optical beams for communication has been underway (see Patent Document 1). FSOC is expected as a technology that can improve the communication speed of wireless communication networks.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in FSOC, for example, communication may be interrupted due to meteorological events such as heavy rain and strong winds. On the other hand, heavy rain and strong winds are meteorological events that occur locally and for a short time, and their prediction is not easy.

[0005] One aspect of the present invention has been made in view of the above problems, and an example of its object is to provide a communication path determination device, a communication path determination method, a communication device, a communication control device, and a communication system that can determine a future communication path in consideration of the influence of local meteorological events.

Means for Solving the Problems

[0006] A communication path determination device according to one aspect of the present invention is a communication path determination device that determines a communication path on a communication network having a plurality of nodes and a plurality of links connecting the plurality of nodes by optical space communication, and comprises an information processing unit, the information processing unit performs an acquisition process to acquire weather information and the communication quality of at least one link among the plurality of links; a prediction process to predict the communication quality on the plurality of links after a predetermined time based on the weather information and the communication quality of at least one link; and a determination process to determine the communication path after the predetermined time based on the predicted communication quality.

[0007] A communication path determination method according to one aspect of the present invention is a method for determining a communication path on a communication network having a plurality of nodes and a plurality of links connecting the plurality of nodes by optical space communication, and includes an acquisition process for acquiring weather information and the communication quality of at least one link among the plurality of links; a prediction process for predicting the communication quality on the plurality of links after a predetermined time based on the weather information and the communication quality of at least one link; and a determination process for determining the communication path after the predetermined time based on the predicted communication quality.

[0008] A communication device according to one aspect of the present invention is a communication device for placement at one node on a communication network having a plurality of nodes and a plurality of links connecting the plurality of nodes by optical spatial communication, comprising: a communication device placed at another node on the communication network; an optical transceiver unit for performing optical spatial communication; and an information processing unit, wherein the information processing unit performs an acquisition process for acquiring weather information and the communication quality of at least one link among the plurality of links; a prediction process for predicting the communication quality of the plurality of links after a predetermined time based on the weather information and the communication quality of at least one link; and a notification process for notifying the predicted communication quality.

[0009] A communication control device according to one aspect of the present invention includes a second information processing unit that performs a decision process to determine the communication path after a predetermined time based on the predicted communication quality notified by the communication device.

[0010] A communication system according to one aspect of the present invention comprises a communication device and a communication control device. [Effects of the Invention]

[0011] According to one aspect of the present invention, a communication path determination device, a communication path determination method, a communication device, a communication control device, and a communication system can be provided that can determine a future communication path while taking into account the influence of local weather events. [Brief explanation of the drawing]

[0012] [Figure 1] This is a block diagram showing an example configuration of a communication path determination device according to the first embodiment. [Figure 2] This is a flowchart showing an example of the processing flow in the communication path determination method according to the first embodiment. [Figure 3] This is a schematic diagram showing an example of the configuration of a communication network according to the second embodiment. [Figure 4] This is a block diagram showing an example configuration of a communication path determination device according to the second embodiment. [Figure 5] This is a flowchart showing an example of the processing flow in the communication path determination method according to the second embodiment. [Figure 6] This is a schematic diagram illustrating an example of a moving weather phenomenon. [Figure 7] This is a schematic diagram showing an example configuration of a communication system according to the third embodiment. [Figure 8] This is a block diagram showing a computer hardware configuration, which is one example of a communication path determination device according to each exemplary embodiment of the present invention. [Modes for carrying out the invention]

[0013] [First Embodiment] The first embodiment of the present invention will be described in detail with reference to the drawings. This embodiment is a basic form for the embodiments described later.

[0014] (Configuration of Communication Route Determination Device) The configuration of the communication route determination device according to this embodiment will be described with reference to FIG. 1. FIG. 1 is a block diagram showing a configuration example of a communication route determination device 10 according to the first embodiment. The communication route determination device 10 has an information processing unit 11 and determines a communication route on a communication network having a plurality of nodes and a plurality of links connecting the plurality of nodes by optical space communication. The information processing unit 11 executes a communication route determination method S10.

[0015] FIG. 2 is a flowchart showing an example of the processing flow in the communication route determination method S10 according to the first embodiment. It is a block diagram showing a configuration example of a processing system controlled by a communication route determination device. The communication route determination method S10 includes an acquisition process (step S11) and a prediction process (step S12).

[0016] (1) Acquisition Process (Step S11) The information processing unit 11 acquires weather information and the communication quality of at least one of the plurality of links.

[0017] (2) Prediction Process (Step S12) The information processing unit 11 predicts the communication quality of the plurality of links after a predetermined time based on the weather information and the communication quality of at least one link. For example, the information processing unit 11 estimates that a weather event has occurred at a specific location (as an example, the location of a link with deteriorated communication quality) based on the weather information and the communication quality of at least one link. Further, the information processing unit 11 estimates the location of the weather event after a predetermined time based on the weather information and the communication quality of at least one link, and predicts the communication quality of the plurality of links after a predetermined time based on these.

[0018] (3) Determination Process (Step S13) The information processing unit 11 determines the communication path after a predetermined time based on the predicted communication quality.

[0019] As described above, the communication path determination device 10 according to this embodiment is a communication path determination device that determines a communication path on a communication network having a plurality of nodes and a plurality of links connecting the plurality of nodes by optical space communication, and comprises an information processing unit 11, the information processing unit 11 performs an acquisition process (step S11) to acquire weather information and the communication quality of at least one link Ri among the plurality of links, a prediction process (step S12) to predict the communication quality on the plurality of links after a predetermined time based on the weather information and the communication quality of at least one link, and a determination process (step S13) to determine the communication path after a predetermined time based on the predicted communication quality.

[0020] In other words, the communication path determination device 10 estimates the location of a weather event after a predetermined time based on weather information and the communication quality of at least one link, predicts the communication quality on multiple links after a predetermined time, and determines the communication path after the predetermined time based on the predicted communication quality. Therefore, according to the communication path determination device 10 of this embodiment, it is possible to determine the future communication path while taking into account the influence of local weather events.

[0021] The communication path determination method S10 according to this embodiment is a communication path determination method for determining a communication path on a communication network having a plurality of nodes and a plurality of links connecting the plurality of nodes by optical space communication, and includes an acquisition process (step S11) for acquiring weather information and the communication quality of at least one link among the plurality of links; a prediction process (step S12) for predicting the communication quality on the plurality of links after a predetermined time based on the weather information and the communication quality of at least one link; and a determination process (step S13) for determining the communication path after the predetermined time based on the predicted communication quality.

[0022] In other words, the communication path determination method S10 predicts the communication quality on multiple links after a predetermined time by estimating the location of a weather event after a predetermined time based on weather information and the communication quality of at least one link, and then determines the communication path after the predetermined time based on the predicted communication quality. Therefore, according to the communication path determination method S10 of this embodiment, it is possible to determine the future communication path while taking into account the influence of local weather events.

[0023] [Second Embodiment] A second 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 first embodiment will be denoted by the same reference numerals, and their descriptions will be omitted as appropriate.

[0024] Figure 3 is a schematic diagram showing an example configuration of the communication network 100 according to the second embodiment. Figure 4 is a block diagram showing an example configuration of the communication path determination device 110 according to the second embodiment.

[0025] The communication network 100 includes a plurality of nodes N and a plurality of links R that connect the plurality of nodes N by optical spatial communication. The communication network 100 further includes a communication path determination device 110 and a weather information server 120.

[0026] In optical spatial communication, communication is performed by sending and receiving optical beams between N nodes. For example, visible light and infrared light can be used as optical beams. Optical spatial communication has features such as ease of installation, high security (difficulty of eavesdropping due to the narrow optical beam), and high communication speed.

[0027] In this context, optical space communication through the atmosphere is susceptible to atmospheric conditions. Localized weather events, such as heavy rain or strong winds, can degrade the communication quality of link R. For example, localized and short-term communication disruptions (interruptions) may occur.

[0028] The communication path determination device 110 predicts the communication quality on each link R at a predetermined time (in the future) and determines the communication path at that time. For example, when transmitting information from node Ns to node Ne, the path from node Ns to node Ne can be appropriately selected by selecting link R. Furthermore, if a local communication interruption occurs in the communication network 100, the communication path is determined to avoid the link R where communication was interrupted. As a result, it becomes possible to maintain a good communication state on the communication network 100.

[0029] The communication path determination device 110 can be placed at each node N as a communication device. That is, the communication path determination device 110 functions as a communication device to be placed at one node on a communication network 100 having multiple nodes N and multiple links R connecting the multiple nodes by optical space communication. The following explanation will continue assuming that the communication path determination device 110 is placed at each node N.

[0030] The communication path determination device 110 includes an information processing unit 111, a communication control unit 112, an optical transceiver unit 113, and a storage unit 114.

[0031] The information processing unit 111 executes the communication path determination method S100 described later. The communication control unit 112 controls the communication by the optical transceiver unit 113.

[0032] The optical transceiver 113 performs optical spatial communication between node N where the communication path determination device 110 is located and adjacent nodes N. The optical transceiver 113 functions as an optical transceiver for performing optical spatial communication with communication devices located at other nodes on the communication network 100.

[0033] At this time, the optical transceiver 113 can switch the node N with which it communicates. For the sake of clarity, as shown in Figure 3, it is possible to select two or more nodes as communication partners in two directions (x direction and y direction). For example, node Ni can switch the communication path by selecting four nodes as communication partners in the x and y directions.

[0034] The memory unit 114 stores the location information of node N.

[0035] The weather information server 120 is a server device that stores weather information and provides it to the communication route determination device 110 via the communication network 100 or other communication means. The weather information includes, for example, wind speed and rainfall information in the area where the communication network 100 is located. Here, it is preferable that the wind speed information is provided as a wind speed vector, including wind direction. This wind speed and rainfall information can be average wind speed and rainfall (average wind speed, average rainfall), but it may also include wind speed and rainfall information related to strong winds and heavy rainfall over a short period of time (for example, localized strong winds and localized heavy rainfall).

[0036] (Communication path determination method S100) Figure 5 is a flowchart showing an example of the processing flow in the communication path determination method S100 according to the second embodiment. The details of the communication path determination method S100 will be described below based on Figure 5.

[0037] (1) Acquisition process (Step S11) The information processing unit 111 acquires weather information and the communication quality of at least one link among the multiple links R.

[0038] The information processing unit 111 can obtain weather information (for example, weather forecast information) from the weather information server 120. The weather information includes, for example, average wind speed (for example, average wind speed vector) and average rainfall information. The weather information may also include information on instantaneous maximum wind speed or instantaneous maximum rainfall.

[0039] The information processing unit 111 can acquire the communication quality on link R connected to the optical transceiver unit 113 (node ​​Ni) of its own device. The information processing unit 11 can provide the communication quality on link R acquired from the optical transceiver unit 113 of its own device to other communication path determination devices 110 via the communication network 100 or other communication means. On the other hand, the information processing unit 111 can acquire the communication quality on link R connected to other node Nj from other communication path determination devices 110.

[0040] Communication quality is determined by factors such as the intensity of the optical beam received from link R, the bit error rate (BER), and the signal-to-noise ratio (SNR). Of these, the intensity of the optical beam can be easily used as an indicator of communication quality. In optical space communication, the intensity of the optical beam fluctuates depending on atmospheric conditions (e.g., strong winds, heavy rain), and when the intensity of the optical beam drops below a certain level, the bit error rate also deteriorates rapidly.

[0041] (2) Prediction processing (Step S12) The information processing unit 111 predicts the communication quality of the plurality of links after a predetermined time based on weather information and the communication quality of at least one link (step S12).

[0042] For example, in this prediction process, the information processing unit 11 estimates the location of a weather event that degrades the communication quality of Link R, based on the acquired communication quality (of Link R). Examples of such weather events include localized heavy rainfall or localized strong winds. Localized heavy rainfall or localized strong winds are difficult to forecast, and estimating their location based on the communication quality of Link R is effective.

[0043] More specifically, in the prediction process, the information processing unit 111 estimates the location of weather events based on the location of links whose acquired communication quality is below a predetermined standard. In other words, it can be assumed that a localized weather event occurs near link R whose communication quality is below a predetermined standard, and that this is degrading the communication quality of link R.

[0044] The information processing unit 111 estimates the direction and speed of movement of the weather event during the prediction process, and predicts the communication quality of multiple links R after a predetermined time based on the estimated location, direction, and speed of movement of the weather event. That is, it estimates the direction and speed at which the weather event will move from its estimated location, and estimates the communication quality of links R of the communication network 100 in conjunction with the movement of this weather event. As the weather event moves, the communication quality of links R that had deteriorated due to the weather event improves, and the communication quality of links R that had good communication quality deteriorates.

[0045] The direction and speed of movement of meteorological events can be estimated based on the average wind speed vector. That is, meteorological information contains information on the average wind speed vector, and the information processing unit 111 can estimate the direction and speed of movement of meteorological events based on this average wind speed vector.

[0046] A decrease in communication quality due to weather events can be predicted, for example, by instantaneous maximum wind speed or instantaneous maximum rainfall. That is, weather information includes information on instantaneous maximum wind speed or instantaneous maximum rainfall, and the information processing unit 111 may predict the communication quality on multiple links R after a predetermined time based on the estimated location, direction of movement, and speed of movement of the weather event, and the instantaneous maximum wind speed or instantaneous maximum rainfall.

[0047] Figure 6 is a schematic diagram illustrating an example of a moving weather event. Below, we will explain the prediction of communication quality for strong winds and heavy rain, based on Figure 6.

[0048] (a) Degradation of communication quality due to strong winds The following explains how to calculate the degradation of communication quality on link R due to strong winds. When a degradation in communication quality due to strong winds is detected on link R connected to node Ni, the risk of strong winds on other nodes N changes. As a result, the communication quality on links connected to nodes with increased risk of strong winds deteriorates.

[0049] Assume that node Ni has a link with communication quality below a predetermined standard. For example, suppose there is a communication interruption (e.g., a momentary disconnection) on link Rij of node Ni. In this case, the estimated instantaneous wind speed Wi' (vector) at node Ni is expressed as follows. Wi'=s(Δt)×(x,y) Δt: Communication interruption time s(Δt): A function that indicates the wind pressure stiffness at node Ni. (x,y): Wind speed vector

[0050] The function s(Δt) can be expressed, for example, as follows: s(Δt) = ki × Δt 1 / 2 ki: Coefficient of wind pressure stiffness at node Ni

[0051] The strong wind risk area r(t) is expressed as follows: r(t) = vi + Wi' × t + mi vi: Position vector of node Ni t: elapsed time from the start time t0 of the communication interruption mi: Expected margin of strong wind wave surface at node Ni

[0052] The expected margin mi can be expressed as follows: mi = ((α × γ) / β) × (1, -x / y) -u<γ α: A parameter representing the average wind speed. β: A parameter representing the ratio of instantaneous maximum wind speed to average wind speed. γ, u: Adjustment parameters for strong wind wave fronts

[0053] The strong wind risk qj(t) at any node Nj is expressed as follows: qj(t) = δ / (vj-r(t)) 2 δ: Adjustment parameter for risk intensity vj: Position vector of node Nj

[0054] ​Based on the strong wind risk qj(t) calculated as described above, the communication quality on link R can be estimated.

[0055] (b) Deterioration of communication quality due to heavy rain The following explains how to calculate the degradation of communication quality on link R due to heavy rain. When a degradation in communication quality due to heavy rain is detected on link R connected to node Ni, the risk of heavy rain on other nodes N changes. As a result, the communication quality on links connected to nodes with increased risk of heavy rain deteriorates.

[0056] Assume that node Ni has a link with communication quality below a predetermined standard. For example, suppose there is a communication interruption (e.g., a momentary disconnection) on link Rij of node Ni. In this case, the estimated instantaneous rainfall si' at node Ni is expressed as follows. si' = max(rth + φ × Δt, s) rth: Rainfall threshold (the amount of rainfall at which communication is expected to be disrupted due to the effects of rainfall) φ: Adjustment parameter Δt: Communication interruption time s: Rainfall (weather information, e.g., rainfall shown in weather forecasts)

[0057] The rainfall threshold rth can be calculated, for example, by the following formula: rth = rb × u rb: Rainfall threshold, i.e., the amount of rainfall (e.g., 100 mm / h) at which communication is interrupted over a standard communication distance (e.g., 1 km). u: Communication distance (distance between nodes, i.e., link length) The rainfall threshold value rb can be determined by prior measurements.

[0058] The heavy rain risk area r(t) is expressed as follows: r(t) = vi + Wav × t + mi vj: Position vector of node Ni Wav: Average wind speed vector t: elapsed time from the start time t0 of the communication interruption mi: Assumed margin for heavy rain area

[0059] The expected margin mi can be expressed as follows: mi = ((γ × s) / s') × (1, -x / y) -u<γ s': Estimated rainfall (rainfall estimated from the communication interruption time Δt) γ, u: Adjustment parameters for heavy rainfall areas Furthermore, the estimated rainfall s' is set so that it is not less than the actual rainfall s (s'≧s).

[0060] The heavy rainfall risk qj(t) at any node Nj is expressed as follows: qj(t) = δ / (vj-r(t)) 2 δ: Adjustment parameter for risk intensity vj: Position vector of node Ni

[0061] Based on the heavy rain risk qj(t) calculated in the manner described above, the communication quality on link R can be estimated.

[0062] (3) Decision process (Step S13) The information processing unit 11 determines the communication path after a predetermined time based on the predicted communication quality.

[0063] For example, in the decision-making process, the information processing unit 111 can determine a communication path by excluding links from multiple links R whose predicted communication quality is lower than a predetermined standard. As shown in Figure 6, as time t progresses from t1 to t3, the weather event F(t) moves from F(t1) to F(t3). In order to avoid link R where a deterioration in communication quality is predicted as the weather event F(t) approaches, the information processing unit 111 can select communication path K1 instead of communication path K0.

[0064] ​For the sake of clarity, it is assumed here that the communication path determination device 110(i) is located at node Ni, receives information from node Ns, and transfers the information to node Ne. However, the communication path determination device 110(i) may be located at any node of the communication network 100.

[0065] On the other hand, the information processing unit 111 may, in the decision-making process, set multiple communication costs C corresponding to each of the multiple links R based on the predicted communication quality, and determine the communication path based on the multiple communication costs C.

[0066] The following describes an example of a method for determining a communication path based on the communication cost C of link R. The communication cost C(k,t) on link Rk can be defined, for example, as follows: C(k,t)=C(h,g,t) =Co(h,g)+qh(t)+qg(t) Co(h,g): Communication cost between nodes Nh and Ng at the start and end of link Rk. k: Identifier of link Rk t: time qh: Risk at node Nh (high wind risk, heavy rain risk, or sum of high wind risk and heavy rain risk) qg: Risk at node Ng (strong wind risk, heavy rain risk, or sum of strong wind risk and heavy rain risk)

[0067] The communication cost Co(h,g) is determined based on the communication distance L(h,g) and congestion level D, and can be expressed, for example, by the following formula: Co(h,g)=μ×L(h,g)×D=μ×|vh-vg|×D μ: Adjustment parameter L(h,g): Communication distance between nodes Nh and Ng D: Link congestion status, e.g., measured or estimated link utilization rate. vh: Position vector of node Nh vg: Position vector of node Ng

[0068] The communication cost C(K,t) of communication path K is expressed as the sum of the communication costs C(k,t) of the links R included in communication path K. C(K,t)=ΣC(k,t)

[0069] The information processing unit 111 selects the communication path K that minimizes the communication cost C(K,t). For this selection, a known algorithm such as Dijkstra's algorithm can be used.

[0070] As described above, the communication path determination device 110 predicts the communication quality of multiple links after a predetermined time based on weather information and the communication quality of at least one link, and determines the communication path after the predetermined time based on the predicted communication quality. Therefore, according to the communication path determination device 110 of this embodiment, it is possible to determine the future communication path while taking into account the influence of local weather events.

[0071] [Third Embodiment] A third 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 first embodiment will be denoted by the same reference numerals, and their descriptions will be omitted as appropriate.

[0072] Figure 7 is a schematic diagram showing an example configuration of a communication system 200 according to the third embodiment. The communication system 200 includes a communication device 210a(i) and a communication control device 210b. The communication device 210a(i) is a communication device to be placed on one node Ni on a communication network having a plurality of nodes Ni and a plurality of links R that connect the plurality of nodes Ni by optical spatial communication.

[0073] The communication device 210a(i) comprises an information processing unit 211a and an optical transceiver unit 213. The optical transceiver unit 213 is an optical transceiver unit for performing optical spatial communication with a communication device located at another node Ni on the communication network.

[0074] The information processing unit 211a performs an acquisition process to acquire weather information and the communication quality of at least one link among multiple links; a prediction process to predict the communication quality of the multiple links after a predetermined time based on the weather information and the communication quality of at least one link; and a notification process to notify the predicted communication quality.

[0075] The information processing unit 211a acquires the communication quality of link R to which its own device (communication device 210a(i)) is connected, and notifies other devices (other communication devices 210a(j)).

[0076] The communication control device 210b includes an information processing unit 211a, a communication control unit 212, and a storage unit 214. The information processing unit 211a performs a decision process to determine the communication path after a predetermined time based on the predicted communication quality notified from the communication device 210a(i). The communication control unit 212 controls the communication by the communication device 210a(i) based on the determined communication path. The storage unit 214 stores the location information of node N.

[0077] The communication control device 210b may be placed in each node N, or it may be placed in the communication network independently of node N. For example, one communication control device 210b may be placed in the communication network to control communication at the communication devices 210a(i) placed in each node N.

[0078] Here, the communication device 210a(i) predicts the communication quality on multiple links after a predetermined time and notifies the communication control device 210b of the predicted communication quality. Alternatively, the communication device 210a(i) may notify the communication control device 210b of the communication quality of link R to which it is connected, and the communication control device 210b may predict the communication quality on multiple links after a predetermined time based on weather information and the communication quality of the link notified by the communication device 210a(i).

[0079] [Examples of implementation using software] Some or all of the functions of the information processing unit 111 may be implemented by hardware such as an integrated circuit (IC chip), or by software.

[0080] In the latter case, the information processing unit 111 is implemented by a computer that executes instructions for a program, which is software that implements each function. An example of such a computer (hereinafter referred to as computer C) is shown in Figure 8. Computer C includes, for example, at least one processor C1 and at least one memory C2. The memory C2 stores a program P that causes computer C to operate as the information processing unit 111. In computer C, the processor C1 reads the program P from the memory C2 and executes it, thereby implementing each function of the information processing unit 111.

[0081] 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.

[0082] Computer C may also be equipped with RAM (Random Access Memory) for loading program P at runtime and for temporarily storing various data. Furthermore, computer C may be equipped with communication interfaces for sending and receiving data with other devices. Additionally, computer C may be equipped with input / output interfaces for connecting input / output devices such as keyboards, mice, displays, and printers.

[0083] Furthermore, program P can be recorded on a non-temporary, tangible recording medium M that is readable by computer C. Such a recording medium M could be, for example, tape, disk, card, semiconductor memory, or programmable logic circuitry. Computer C can acquire program P via such a recording medium M. Program P can also be transmitted via a transmission medium. Such a transmission medium could be, for example, a communication network or broadcast waves. Computer C can also acquire program P via such a transmission medium.

[0084] [Additional Note 1] The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. For example, embodiments obtained by appropriately combining the technical means disclosed in the embodiments described above are also included in the technical scope of the present invention.

[0085] [Additional Note 2] Some or all of the embodiments described above may also be described as follows. However, the present invention is not limited to the embodiments described below.

[0086] (Note 1) The communication path determination device is a communication path determination device that determines a communication path on a communication network having a plurality of nodes and a plurality of links connecting the plurality of nodes by optical space communication, and includes an information processing unit, the information processing unit performs an acquisition process to acquire weather information and the communication quality of at least one link among the plurality of links; a prediction process to predict the communication quality on the plurality of links after a predetermined time based on the weather information and the communication quality of at least one link; and a determination process to determine the communication path after the predetermined time based on the predicted communication quality.

[0087] (Note 2) In the communication path determination device described in Appendix 1, the information processing unit determines the communication path by excluding links from the plurality of links whose predicted communication quality is lower than a predetermined standard during the determination process.

[0088] (Note 3) In the communication path determination device described in Appendix 1, the information processing unit, in the determination process, sets a plurality of communication costs corresponding to each of the plurality of links based on the predicted communication quality, and determines the communication path based on the plurality of communication costs.

[0089] (Note 4) In any of the communication path determination devices described in Appendix 1 to 3, the information processing unit estimates the location of weather events that degrade the communication quality of the link based on the acquired communication quality during the prediction process.

[0090] (Note 5) In the communication path determination device described in Appendix 4, the weather event is localized heavy rain or localized strong winds.

[0091] (Note 6) In the communication path determination device described in Appendix 4, the information processing unit, in the prediction process, Based on the location of the link whose acquired communication quality is below a predetermined standard, the location of the weather event is estimated.

[0092] (Note 7) In the communication path determination device described in Appendix 4, the information processing unit estimates the direction and speed of movement of the weather event in the prediction process, and predicts the communication quality of the multiple links after a predetermined time based on the estimated location, direction, and speed of movement of the weather event.

[0093] (Note 8) In the communication path determination device of Appendix 7, the weather information includes information on the average wind speed vector, The information processing unit estimates the direction and speed of movement of the meteorological event based on the average wind speed vector.

[0094] (Note 9) In the communication path determination device described in Appendix 7, the weather information includes information on the instantaneous maximum wind speed or instantaneous maximum rainfall, and the information processing unit predicts the communication quality of the multiple links after a predetermined time based on the location, direction of movement, and speed of movement of the estimated weather event, and the instantaneous maximum wind speed or instantaneous maximum rainfall.

[0095] (Note 10) A communication path determination method is a method for determining a communication path on a communication network having a plurality of nodes and a plurality of links connecting the plurality of nodes by optical space communication, comprising: an acquisition process for acquiring weather information and the communication quality of at least one of the plurality of links; a prediction process for predicting the communication quality on the plurality of links after a predetermined time based on the weather information and the communication quality of at least one link; and a determination process for determining the communication path after the predetermined time based on the predicted communication quality. Includes.

[0096] (Note 11) The communication device is a communication device for placement at one node on a communication network having a plurality of nodes and a plurality of links connecting the plurality of nodes by optical spatial communication, and comprises a communication device placed at another node on the communication network, an optical transceiver unit for performing optical spatial communication, and an information processing unit, the information processing unit performing an acquisition process to acquire weather information and the communication quality of at least one link among the plurality of links, a prediction process to predict the communication quality of the plurality of links after a predetermined time based on the weather information and the communication quality of at least one link, and a determination process to determine the communication path after the predetermined time based on the predicted communication quality.

[0097] (Note 12) The communication device is a communication device for placement at one node on a communication network having a plurality of nodes and a plurality of links connecting the plurality of nodes by optical spatial communication, and comprises a communication device placed at another node on the communication network, an optical transceiver unit for performing optical spatial communication, and an information processing unit, wherein the information processing unit performs an acquisition process to acquire weather information and the communication quality of at least one link among the plurality of links, a prediction process to predict the communication quality of the plurality of links after a predetermined time based on the weather information and the communication quality of at least one link, and a notification process to notify the predicted communication quality.

[0098] (Note 13) In the communication device described in Appendix 12, the information processing unit acquires the communication quality of the link to which its own device is connected and notifies other devices.

[0099] (Note 14) The communication control device includes a second information processing unit that performs a decision process to determine the communication path after a predetermined time, based on the predicted communication quality notified by the communication device specified in Appendix 12.

[0100] (Note 15) The communication system comprises the communication device specified in Appendix 12 and the communication control device specified in Appendix 14.

[0101] (Note 16) The communication path determination device is a communication path determination device that determines a communication path on a communication network having a plurality of nodes and a plurality of links connecting the plurality of nodes by optical space communication, and comprises at least one processor, the processor performing an acquisition process to acquire weather information and the communication quality of at least one link among the plurality of links; a prediction process to predict the communication quality on the plurality of links after a predetermined time based on the weather information and the communication quality of at least one link; and a determination process to determine the communication path after the predetermined time based on the predicted communication quality.

[0102] Furthermore, this communication path determination device may also be equipped with memory, and this memory may store a program that causes the processor to execute the acquisition process, the prediction process, and the determination process. This program may also be recorded on a computer-readable, non-temporary, tangible recording medium. [Explanation of Symbols]

[0103] 100 Communication Networks 110 Communication path determination device 111 Information Processing Department 112 Communication Control Unit 113 Optical Transceiver Unit 114 Storage section 120 Weather Information Server

Claims

1. A communication path determination device for determining a communication path on a communication network having multiple nodes and multiple links connecting the multiple nodes by optical spatial communication, Equipped with an information processing unit, The aforementioned information processing unit, An acquisition process that acquires weather information and the communication quality of at least one link among the plurality of links, A predictive process that predicts the communication quality of the plurality of links after a predetermined time, based on the weather information and the communication quality of the at least one link. Based on the predicted communication quality, a decision process is performed to determine the communication path after the predetermined time, A communication path determination device that performs the above, and in the prediction process, estimates the location of a weather event that degrades the communication quality of a link based on the acquired communication quality, estimates the direction and speed of movement of the weather event, and predicts the communication quality of the plurality of links after a predetermined time based on the estimated location, direction and speed of movement of the weather event.

2. The information processing unit, in the decision process, A communication path determination device according to claim 1, which determines the communication path by excluding links from the plurality of links whose predicted communication quality is lower than a predetermined standard.

3. The information processing unit, in the decision process, A communication path determination device according to claim 1, which sets a plurality of communication costs corresponding to each of the plurality of links based on the predicted communication quality, and determines the communication path based on the plurality of communication costs.

4. The communication path determination device according to claim 1, wherein the weather event is localized heavy rain or localized strong winds.

5. The information processing unit, in the prediction process, A communication path determination device according to claim 1, which estimates the location of the weather event based on the location of a link whose acquired communication quality is below a predetermined standard.

6. The aforementioned weather information includes information on the average wind speed vector, The communication path determination device according to claim 1, wherein the information processing unit estimates the direction and speed of movement of the weather event based on the average wind speed vector.

7. The aforementioned weather information includes information on the instantaneous maximum wind speed or instantaneous maximum rainfall. The communication path determination device according to claim 1, wherein the information processing unit predicts the communication quality of the plurality of links after a predetermined time based on the location, direction of movement and speed of movement of the estimated weather event, and the instantaneous maximum wind speed or instantaneous maximum rainfall.

8. A method for determining a communication path on a communication network having multiple nodes and multiple links connecting the multiple nodes by optical spatial communication, An acquisition process that acquires weather information and the communication quality of at least one link among the plurality of links, A predictive process that predicts the communication quality of the plurality of links after a predetermined time, based on the weather information and the communication quality of the at least one link. Based on the predicted communication quality, a decision process is performed to determine the communication path after the predetermined time, Includes, A communication path determination method comprising the following steps in the prediction process: estimating the location of a weather event that degrades the communication quality of a link based on the acquired communication quality; estimating the direction and speed of movement of the weather event; and predicting the communication quality of the multiple links after a predetermined time based on the estimated location, direction and speed of movement of the weather event.

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