Routing Information Generation Device, Program, and Routing Information Generation Method

Abstract

A routing information generating device (100) comprises: a period dividing unit (112) that divides a generation period, which is a period in which routing information of a network (200) including nodes (230) is generated, into one or more time slots; a model generating unit (113) that, on the basis of the position information and specifications of the nodes (230) and communication environment information in the positions thereof, determines, for each time slot, whether communication between two nodes (230) is possible or not, and generates a network model including a communicatable link and the nodes (230); a routing unit (114) that generates routing information in the network model; a model evaluating unit (115) that calculates an evaluation value; and a selection unit (116) that calculates evaluation values for divided generation periods and that selects a divided generation period having the best evaluation value.

Description

Technical Field

[0001] The present invention relates to a routing information generation device, a program, and a routing information generation method for generating routing information of a network including a mobile body.

Background Art

[0002] By enabling communication between a mobile terminal and a communication satellite in a low orbit or a base station (flying base station) flying in the stratosphere, etc., mobile communication services can be provided even in areas where it is difficult to install terrestrial base stations. Communication satellites and flying base stations are constantly moving, and dynamic routing according to the positional relationship between communication satellites and between flying base stations is required. In the technologies described in Non-Patent Documents 1 and 2, routing information is updated at regular intervals / periods based on the orbits of mobile nodes.

Prior Art Documents

Non-Patent Documents

[0003]

Non-Patent Document 1

Non-Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In communication within a network including mobile nodes, in addition to the positional relationship between nodes, dynamic routing according to changes in the communication environment such as weather and electromagnetic interference with other communications is required. When mobile nodes move at high speed, it is difficult to perform routing based on existing protocols between nodes, so a method of providing pre-computed routing to nodes can be considered. The techniques described in Non-Patent Documents 1 and 2 are limited to application to a group of mobile nodes having a specific configuration or trajectory, and communication environment changes are not considered in the pre-computation of routing.

[0005] The present invention has been made in view of such a background, and an object thereof is to enable pre-computation of routing in a network including mobile nodes considering the communication environment.

Means for Solving the Problems

[0006] In order to solve the above-described problems, a routing information generation apparatus according to the present invention divides a generation period, which is a period for generating routing information of a network including nodes that are mobile nodes or fixed nodes, into one or more time slots, and the divided generation period is plural a period division unit that generates; for each time slot included in one or more of the divided generation periods, based on at least one of the position information of the node, the specifications of the node, and the communication environment information at the position of the node in the period indicated by the time slot, determines whether communication is possible between two of the nodes, and generates a network model including a link between two nodes where communication is possible and the nodes; a routing unit that generates routing information in the network model; and in the network model calculated based on the position information of the nodes, the specifications of the nodes, and the communication environment information at the positions of the nodes among themA model evaluation unit that calculates an evaluation value based on communication quality, a selection unit that calculates an evaluation value for the divided generation period based on the evaluation value of the network model corresponding to the time slot included in the divided generation period, and selects the divided generation period in which the evaluation value is the best, and a node management unit that transmits the time slot of the selected divided generation period and the routing information associated with the time slot to the node.

Effect of the Invention

[0007] According to the present invention, it is possible to enable pre-calculation of routing in a network including mobile nodes considering the communication environment.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

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Figure 4

Figure 5

Mode for Carrying Out the Invention

[0009] ≪Outline of Routing Information Generation Device≫ The routing information generation device in the embodiment for implementing the present invention will be described below. The routing information generation device performs routing (generates routing information) in a network configured to include mobile nodes moving along an orbit, such as communication satellites and flying base stations (aerial base stations), and fixed nodes installed on the ground. An aerial base station is an unmanned aerial vehicle such as a balloon or a drone having a base station function.

[0010] The routing information generation device pre-generates routing information for a generation period, which is a predetermined future period. "Pre" means before performing path control (transfer of communication packets) based on the routing information. The routing information generation device divides the generation period into one or more time slots and generates one or more divided generation periods (split generation periods). Next, for each time slot, the routing information generation device calculates the communication quality (communication performance) between mobile nodes and the communication quality between a mobile node and a fixed node based on the positions of the mobile nodes and communication environment information, determines whether communication between nodes is possible, and generates a network model. Furthermore, the routing information generation device generates routing information for each network model and calculates the communication quality between nodes. Subsequently, for each split generation period, the routing information generation device calculates the communication quality over the entire generation period from the communication quality of the network models of the time slots included in the split generation period. Finally, the routing information generation device identifies the split generation period with the best communication quality among the one or more split generation periods and transmits the routing information for each time slot included in the split generation period to the nodes.

[0011] The routing information generation device calculates the communication quality in consideration of the communication environment information in addition to the positions of the mobile nodes and performs routing in advance (before the generation period). Therefore, compared with the case of performing routing without considering the communication environment information, communication can be performed via a communication path with better communication quality. Note that the communication quality includes, in addition to the bandwidth (communication speed), which is also called communication performance, delay, (packet) loss rate, jitter, and the like.

[0012] <<Overall Configuration of Network>> FIG. 1 is a diagram showing the overall configuration of a network 200 according to the present embodiment. The network 200 includes mobile nodes 211 to 215 and fixed nodes 221 and 222. The routing information generation device 100 is connected to the network 200 and can communicate with the mobile nodes 211 to 215 via the fixed nodes 221 and 222. Note that the mobile nodes 211 to 215 are collectively referred to as the mobile node 210, the fixed nodes 221 and 222 are collectively referred to as the fixed node 220, and the mobile nodes 211 to 215 and the fixed nodes 221 and 222 are collectively referred to as the node 230.

[0013] The mobile node 210 is a mobile node with a fixed orbit, such as a flight base station using an unmanned aircraft or a communication satellite, and its future position can be acquired (calculated). The mobile node 210 can also communicate with a ground mobile terminal (e.g., a mobile phone). For example, assume that a mobile terminal can communicate with the mobile node 211 and another mobile terminal can communicate with the mobile node 214. Also assume that communication is possible between the mobile nodes 211 and 212 and between the mobile nodes 212 and 214 (see FIG. 1). Then, the two mobile terminals can communicate via the mobile nodes 211, 212, and 214. The communication availability and quality between two mobile nodes 210 are determined according to the communication environment such as distance and weather. The same applies to the communication between the mobile node 210 and the fixed node 220.

[0014] <<Configuration of Routing Information Generation Device>> FIG. 2 is a functional block diagram of a routing information generation device 100 according to the present embodiment. The routing information generation device 100 is a computer and includes a control unit 110, a storage unit 120, and an input / output unit 180. User interface devices such as a display, a keyboard, and a mouse are connected to the input / output unit 180. The input / output unit 180 includes a communication device and can transmit and receive data to and from the node 230. A media drive may also be connected to the input / output unit 180 to enable data exchange using a recording medium.

[0015] <<Routing Information Generation Device: Memory Unit>> The memory unit 120 is configured to include memory devices such as a ROM (Read Only Memory), a RAM (Random Access Memory), and an SSD (Solid State Drive). The memory unit 120 stores a node information database 130, an environment information database 140, a model evaluation database 150, and a program 128.

[0016] The node information database 130 stores specification information and position information related to individual mobile nodes 210 and fixed nodes 220. The position information of the mobile node 210 is information related to the trajectory and is the information referred to when calculating the position of the mobile node 210. Examples of the specification information include the performance and number of communication antennas of the node 230, as well as the frequency band used for communication.

[0017] The environment information database 140 stores weather information that affects wireless communication between mobile nodes 210 and between mobile nodes 210 and fixed nodes 220. Examples of the weather information include information such as the moisture content in the air, rainfall, and precipitation probability. When the mobile node 210 is a communication satellite, it may include weather information in space that affects wireless communication (propagation loss in wireless communication) such as solar wind and magnetic storms. The communication environment information stored in the environment information database 140 may include electromagnetic interference with communication other than communication within the network 200.

[0018] The model evaluation database 150 stores information such as time slots, routing information, and communication quality related to the network model described later. The program 128 includes a description of the procedure in the routing information generation process (see FIG. 4 described later).

[0019] <<Routing Information Generation Device: Control Unit>> The control unit 110 includes a CPU (Central Processing Unit) and is provided with a node management unit 111, a period division unit 112, a model generation unit 113, a routing unit 114, a model evaluation unit 115, and a selection unit 116.

[0020] ≪Routing Information Generation Device: Control Unit: Node Management Unit≫ The node management unit 111 acquires information related to the mobile node 210 and the fixed node 220 and stores it in the node information database 130. For example, the node management unit 111 acquires the trajectory information of the mobile node 210 from a device that manages the trajectory of the mobile node 210 and stores it in the node information database 130. The node management unit 111 also acquires weather information and stores it in the environmental information database 140. Furthermore, the node management unit 111 transmits the generated routing information described later to the fixed node 220 and the mobile node 210 via the fixed node 220.

[0021] ≪Routing Information Generation Device: Control Unit: Period Division Unit≫ The period division unit 112 divides one generation period to be routed into time slots to generate one or more divided generation periods (divided generation periods). FIG. 3 is a diagram for explaining the divided generation period according to the present embodiment. The divided generation period 510 is a generation period divided into time slots of a fixed length, and is an example divided into 25 time slots. The divided generation period 520 is an example divided into time slots whose length ratio repeats 1:2:3. The divided generation period 530 is an example divided into time slots of random lengths.

[0022] ≪Routing Information Generation Device: Control Unit: Model Generation Unit≫ Returning to FIG. 2, the description of the control unit 110 will be continued. The model generation unit 113 generates a model of the network 200 (network model) based on the position of the moving node 210 and the communication environment information for the period corresponding to each time slot for each time slot. The presence or absence of a link between two nodes included in the network model depends on the communicability between the two nodes 230 corresponding to the two nodes. For example, for two moving nodes 210, if the distance during the period corresponding to the time slot is within the communicable distance, the line of sight is possible, and the surrounding communication environment satisfies a predetermined condition, a link exists between the nodes of the network model corresponding to the two moving nodes 210. The line of sight being possible means that there are no obstacles such as buildings, mountains, or the earth between the two nodes 230, and the nodes 230 can see each other, which means that wireless communication is possible. The same applies to the link between the moving node 210 and the fixed node 220. Also, even if the communication environment is poor due to the short distance between the two nodes 230, communication is possible as long as the distance is short enough.

[0023] In other words, the model generation unit 113 calculates the communication quality between two nodes 230 based on the position information of the nodes 230, the specifications of the nodes 230, and the communication environment at the positions of the nodes 230, and determines that communication is possible if this communication quality satisfies a predetermined condition. When there is no need to distinguish between the nodes 230 of the network 200 and the nodes of the network model, they are simply referred to as nodes or nodes 230.

[0024] The model generation unit 113 operates as follows. The model generation unit 113 calculates the position of the node based on the information in the node information database 130, and further obtains the communication environment information in the vicinity of the position from the environment information database 140. Next, the model generation unit 113 calculates a predicted value of the communication quality (such as bandwidth and delay) between the nodes, determines that communication is possible if the calculation result satisfies a predetermined condition, and generates a network model assuming that a link exists between the two nodes. The generated network model is stored in the model evaluation database 150 in association with the divided generation period and the time slot.

[0025] <<Routing Information Generation Device: Control Unit: Routing Unit>> The routing unit 114 obtains the shortest path between two nodes in the network model and generates routing information (the routing table of each node). When obtaining the shortest path, the routing unit 114 takes into account the cost of the link. The cost of the link is calculated from the position of the node, the distance between nodes, the specifications of the nodes, and communication environment information, and is, for example, the reciprocal of the calculated (predicted) bandwidth. The generated routing information is associated with the network model and stored in the model evaluation database 150.

[0026] <<Routing Information Generation Device: Control Unit: Model Evaluation Unit>> The model evaluation unit 115 evaluates the division generation period based on the evaluation of the network model corresponding to the time slots included in the division generation period. The model evaluation unit 115 calculates an evaluation value for the network model based on the communication quality. For example, the model evaluation unit 115 calculates the evaluation value of the network model based on the bandwidth, delay, loss rate, jitter, etc. between all nodes. Also, the evaluation value of the network model may be calculated based on the communication quality between specific nodes or between a mobile node 210 above a specific area and a specific fixed node 220. The evaluation value is associated with the network model and stored in the model evaluation database 150.

[0027] <<Routing Information Generation Device: Control Unit: Selection Unit>> The selection unit 116 calculates an evaluation value for the division generation period based on the network models of the time slots included in the division generation period. For example, the selection unit 116 uses the weighted average of the evaluation values of the network models according to the time slot lengths as the evaluation value for the division generation period. Next, the selection unit 116 selects the division generation period with the best evaluation among the division generation periods corresponding to the generation period. After that, the node management unit 111 transmits the time slots included in the selected division generation period and the routing information (routing table) in the time slot to the node 230 corresponding to the routing information. During the generation period, the node 230 transfers communication packets while switching the routing information for each time slot.

[0028] <<Routing Information Generation Process>> FIG. 4 is a flowchart of the routing information generation process according to the present embodiment. Assuming that the length of the generation period is 1 hour, the routing information generation process is executed prior to the generation period every 1 hour.

[0029] In step S11, the period division unit 112 divides one generation period to be routed into time slots to generate one or more division generation periods. In step S12, the period division unit 112 starts a process of repeating steps S13 to S18 for each of the division generation periods generated in step S11.

[0030] In step S13, the period division unit 112 starts a process of repeating steps S14 to S17 for each time slot included in the division generation period. In step S14, the model generation unit 113 calculates a predicted value of the communication quality between the nodes 230. In step S15, the model generation unit 113 generates a network model having links between nodes where the predicted value calculated in step S14 satisfies a predetermined condition.

[0031] In step S16, the routing unit 114 generates routing information in the network model generated in step S15. In step S17, the model evaluation unit 115 calculates an evaluation value of the network model. In step S18, the selection unit 116 calculates an evaluation value of the division generation period based on the evaluation values of the network models of the time slots included in the division generation period.

[0032] In step S19, the selection unit 116 selects a division generation period with the best evaluation value. In step S20, the node management unit 111 transmits the time slots included in the division generation period selected in step S19 and the routing information in the time slots to the node 230.

[0033] ≪Features of the Routing Information Generation Device≫ The routing information generation device 100 divides a generation period, which is a period for generating routing information in advance, into time slots, predicts the communication quality based on the positions of nodes and the communication environment in each time slot, and generates a network model. The routing information generation device 100 generates routing information in the network model and calculates an evaluation value of the communication quality. There is one or more division generation periods, and the routing information generation device 100 transmits the routing information corresponding to the division generation period with the best evaluation value to the node.

[0034] Existing routing information generation technologies perform routing based on the positions of mobile nodes. The routing information generation device 100 calculates the communication quality considering environmental information in addition to the positions of mobile nodes, and performs routing in advance (before the generation period). Therefore, compared with the case of routing without considering environmental information, communication can be performed on a communication path with better communication quality.

[0035] In addition, the routing information generation device 100 calculates routing information in advance and transmits it to the node 230. Compared with the case where the node 230 calculates routing information using an existing routing protocol, the load on the node 230 can be reduced, and the bandwidth of the link between the nodes 230 used for the routing protocol can be reduced. As a result, the bandwidth of the network 200 used for the original communication (communication as the service to be provided) can be widened, and the available time can be lengthened.

[0036] <<Modification Example: Division into Time Slots of Generation Period>> In the above-described embodiment, the period division unit 112 divides the period into time slots of a certain length or time slots of a length with a random change pattern (see FIG. 3). The period division unit 112 may divide the period according to the communication quality. For example, as a first process, the period division unit 112 generates a network model in a period (first time slot) of a predetermined period length at the beginning of the generation period and generates routing information. Next, as a second process, as long as the communication quality of the network model satisfies a predetermined condition, the period division unit 112 extends the first time slot by a certain period length. When the predetermined condition is not satisfied, the remaining generation period is set as a new generation period, and the first process and the second process are repeated. In other words, the period division unit 112 divides the generation period so that the time slot continues as long as the communication quality of the network model satisfies a predetermined condition in one time slot.

[0037] By doing so, the routing information generation device 100 can reduce the number of time slots and the load of generating routing information. Note that the routing information generation device 100 may generate one or more divided generation periods by changing the length of the first predetermined period, the length of a fixed period, a predetermined condition, etc. For example, when the time change of the communication environment is large (unstable), the routing information generation device 100 may generate a divided generation period by shortening the length of the predetermined period and the length of the fixed period. Conversely, when the communication environment is stable, the routing information generation device 100 may generate a divided generation period by increasing the length of the predetermined period and the length of the fixed period. Or the routing information generation device 100 may generate a divided generation period while adjusting the lengths of the predetermined period and the fixed period according to the time change of the communication environment. By doing so, the routing information generation device 100 can divide the generation period so that the number of time slots decreases according to the degree of change in the communication environment.

[0038] Even when dividing into time slots of a fixed length (see the divided generation period 510 in FIG. 3), the period division unit 112 may determine the time slot length according to the degree of time change of the communication environment. That is, the period division unit 112 may divide the generation period so that the time slot length becomes shorter as the time change of the communication environment is larger (more unstable). Also, even when dividing into time slots of random lengths (see the divided generation period 530), the period division unit 112 may determine the average time slot length according to the degree of time change of the communication environment. By doing so, the routing information generation device 100 can divide the generation period so that the number of time slots decreases according to the degree of change in the communication environment.

[0039] ≪Modification Example: Network for Generating Routing Information≫ In the above-described embodiment, the routing information generation device 100 generates routing information for the network 200 composed of nodes 230. On the other hand, the routing information may be generated limited to the mobile node 210. In this case, the fixed node 220 may communicate only with the nearest mobile node 210. The configuration of the network is simplified, and the load of generating routing information can be reduced.

[0040] <<Other Modification Examples>> As described above, some embodiments of the present invention have been described. However, these embodiments are merely examples and do not limit the technical scope of the present invention. The present invention can take various other embodiments, and various changes such as omission and substitution can be made without departing from the gist of the present invention. These embodiments and their modifications are included in the scope and gist of the invention described in this specification and the like, and are also included in the invention described in the claims and its equivalent scope.

[0041] <<Hardware Configuration>> The routing information generation device 100 according to the present embodiment is realized by a computer 900 having a configuration as shown in FIG. 5, for example. FIG. 5 is a hardware configuration diagram showing an example of a computer 900 that realizes the functions of the routing information generation device 100 according to the present embodiment. The computer 900 includes a CPU 901, a ROM 902, a RAM 903, an SSD 904, an input / output interface 905 (described as input / output I / F (Interface) in FIG. 5), a communication interface 906 (described as communication I / F in FIG. 5), and a media interface 907 (described as media I / F in FIG. 5). The computer 900 may include an HDD (Hard Disc Drive) instead of the SSD 904, or may further include an HDD in addition to the SSD 904.

[0042] The CPU 901 operates based on programs stored in the ROM 902 or the SSD 904 and performs control by the control unit 110 (see FIG. 2). The ROM 902 stores a boot program executed by the CPU 901 when the computer 900 is started up, programs related to the hardware of the computer 900, and the like. The CPU 901 controls an input device 910 such as a mouse or a keyboard and an output device 911 such as a display or a printer via the input / output interface 905. The CPU 901 acquires data from the input device 910 via the input / output interface 905 and outputs the generated data to the output device 911.

[0043] The SSD 904 stores programs executed by the CPU 901 and data used by the programs. The communication interface 906 receives data from another device (for example, node 230) not shown via a communication network and outputs it to the CPU 901, and also transmits data generated by the CPU 901 to other devices via the communication network. The media interface 907 reads a program or data stored in the recording medium 912 and outputs it to the CPU 901 via the RAM 903. The CPU 901 loads a program from the recording medium 912 onto the RAM 903 via the media interface 907 and executes the loaded program. The recording medium 912 is an optical recording medium such as a DVD (Digital Versatile Disk), a magneto-optical recording medium such as an MO (Magneto Optical disk), a magnetic recording medium, a conductor memory tape medium, or a semiconductor memory.

[0044] For example, when the computer 900 functions as the routing information generation device 100 according to the present embodiment, the CPU 901 of the computer 900 realizes the functions of the routing information generation device 100 by executing the program 128 (see FIG. 2) loaded on the RAM 903. The CPU 901 reads and executes the program from the recording medium 912. In addition, the CPU 901 may read the program from another device via a communication network, or may install the program 128 from the recording medium 912 to the SSD 904 and execute it.

[0045] ≪Effect≫ The effect of the routing information generation device 100 will be described below.

[0046] The routing information generation device 100 according to the present embodiment divides a generation period, which is a period for generating routing information of the network 200 including the node 230 that is the mobile node 210 or the fixed node 220, into one or more time slots, and includes a period division unit 112 that generates the divided generation period. For each time slot included in the one or more divided generation periods, based on at least one of the position information of the node 230, the specifications of the node 230, and the communication environment information at the position of the node 230 in the period indicated by the time slot, it determines whether communication is possible between two nodes 230, and generates a network model including a link between two nodes 230 where communication is possible and the node 230. It includes a model generation unit 113, a routing unit 114 that generates routing information in the network model, a model evaluation unit 115 that calculates an evaluation value based on the communication quality in the network model, and calculates an evaluation value of the divided generation period based on the evaluation value of the network model corresponding to the time slot included in the divided generation period, and selects the divided generation period with the best evaluation value. It is characterized by including a selection unit 116, and a node management unit 111 that transmits the time slot of the selected divided generation period and the routing information associated with the time slot to the node 230.

[0047] According to such a routing information generation device 100, it is possible to perform pre-calculation of routing in the network 200 including the mobile node 210 in consideration of the communication environment. This routing is a routing calculated in consideration of the communication environment in addition to the position of the mobile node 210. Also, since the routing information is calculated in advance, the available time of the network 200 can be extended.

[0048] The period division unit 112 according to the present embodiment is characterized in that it divides the generation period so that the time slot continues as long as the communication quality of the network model satisfies a predetermined condition in one time slot.

[0049] According to such a routing information generation device 100, the number of time slots can be reduced, and the load for generating the routing information can be reduced.

[0050] The period division unit 112 according to the present embodiment is characterized in that it divides the generation period so that the length of the time slot becomes shorter when the temporal change of the communication environment indicated by the communication environment information is large.

[0051] According to such a routing information generation device 100, the number of time slots can be reduced according to the communication environment, and the load for generating the routing information can be reduced.

[0052] The routing unit 114 according to the present embodiment is characterized in that it calculates the cost of the link based on at least one of the position information of the node 230, the specifications of the node 230, and the communication environment information at the position of the node 230 in the period indicated by the time slot, and generates routing information.

[0053] According to such a routing information generation device 100, routing information is generated based on the cost of a link considering communication environment information in addition to the position of a mobile node. Therefore, compared with the case of generating routing information without considering the communication environment, communication can be performed via a communication path with better communication quality.

[0054] The communication environment information according to the present embodiment is characterized by including weather information related to propagation loss in the wireless communication of the node 230.

[0055] According to such a routing information generation device 100, in addition to the meteorological information on the earth, routing can be performed in consideration of changes in the communication environment due to natural phenomena in outer space accompanying solar activity.

Explanation of Signs

[0056] 100 Routing information generation device 111 Node management unit 112 Period division unit 113 Model generation unit 114 Routing unit 115 Model evaluation unit 116 Selection unit 128 Program 130 Node information database 140 Environment information database 150 Model evaluation database 200 Network 210~215 Mobile nodes 220~222 Fixed nodes 230 Node 510, 520, 530 Division generation periods (divided generation periods)

Claims

1. A period division unit that divides a generation period, which is a period for generating routing information of a network including nodes that are mobile nodes or fixed nodes, into one or more time slots, and generates a plurality of divided generation periods; For each time slot included in one or more of the divided generation periods, based on at least one of the position information of the node, the specifications of the node, and the communication environment information at the position of the node during the period indicated by the time slot, a model generation unit that determines whether communication is possible between two of the nodes and generates a network model including a link between two nodes that can communicate and the nodes; A routing unit that generates routing information in the network model; A model evaluation unit that calculates an evaluation value based on the communication quality calculated based on the position information of the node, the specifications of the node, and the communication environment information at the position of the node in the network model; A selection unit that calculates an evaluation value of the divided generation period based on the evaluation value of the network model corresponding to the time slot included in the divided generation period, and selects the divided generation period in which the evaluation value is the best; And a node management unit that transmits the time slots of the selected divided generation period and the routing information associated with the time slots to the nodes. A routing information generation device characterized by the above.

2. The period division unit: Divides the generation period so that the time slot continues as long as the communication quality of the network model satisfies a predetermined condition in one time slot. The routing information generation device according to claim 1, characterized by the above.

3. The period division unit: Divides the generation period so that the length of the time slot becomes shorter when the time change of the communication environment indicated by the communication environment information is large. The routing information generation device according to claim 1, characterized by the above.

4. The routing unit: Based on at least one of the position information of the node, the specifications of the node, and the communication environment information at the position of the node during the period indicated by the time slot, calculates the cost of the link and generates the routing information. The routing information generation device according to claim 1, characterized by the above.

5. The communication environment information includes weather information related to propagation loss in the wireless communication of the node The routing information generation device according to claim 1, characterized in that

6. A program for causing a computer to function as the routing information generation device according to any one of claims 1 to 5

7. A routing information generation method executed by a routing information generation device, comprising dividing a generation period, which is a period for generating routing information of a network including nodes that are mobile nodes or fixed nodes, into one or more time slots to generate a plurality of divided generation periods for each time slot included in one or more of the divided generation periods, determining the availability of communication between two of the nodes based on at least one of the position information of the node, the specifications of the node, and the communication environment information at the position of the node during the period indicated by the time slot, and generating a network model including a link between two nodes for which communication is available and the nodes generating routing information in the network model calculating an evaluation value based on the communication quality calculated based on the position information of the node, the specifications of the node, and the communication environment information at the position of the node in the network model calculating an evaluation value of the divided generation period based on the evaluation value of the network model corresponding to the time slot included in the divided generation period, and selecting the divided generation period in which the evaluation value is the best transmitting the time slots of the selected divided generation period and the routing information associated with the time slots to the node The routing information generation method is characterized by the above

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