# US 12,772,140 B2 · Communication system and communication method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,772,140 B2 - Document ID: US12772140B2 - Status: Granted - Kind: B2 - Application number: 18/841,445 - Filed: 2022-02-28 - Published: 2025-05-22 - Granted: 2026-10-20 - Earliest claimed: 2022-02-28 - Assignees: NTT, Inc. - Applicants: NTT, Inc. - Inventors: Munehiro Matsui; Fumihiro Yamashita; Junichi Abe; Hisayoshi Kano - Web page: https://patentgrep.com/patent/US12772140B2 ## CPC - H04W 40/12: based on transmission quality or channel quality - H04L 43/0882: Utilisation of link capacity - H04W 84/06: Airborne or Satellite Networks (space-based or airborne stations H04B7/185) - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract Provided is a communication system that adaptively performs optimal routing in a network formed by linking communication stations to each other. A routing control device monitors a traffic amount of links between communication stations including a satellite and a flight vehicle, calculates a cost used for routing in the communication stations including the satellite and the flight vehicle, and performs routing based on the cost. The calculation of the cost includes at least two of a process of calculating the congestion level of each of the links, a process of calculating a delay time of each of the links, and a process of calculating reliability of each of the links. The cost is calculated by combining results obtained by applying a weight to each of at least two elements obtained in the foregoing process. ## Claims ### Claim 1 A communication system in which communication stations are linked to each other to form a network and transmit packets through links, the communication system comprises one or more processor circuitry configured to perform: monitoring a traffic amount of the link between the communication stations; calculating a cost used for routing in the communication stations; and executing routing based on the cost, wherein the cost calculation includes: at least two calculations among calculation of a congestion level of each link based on a traffic amount of a link between the communication stations, calculation of a delay time of each link based on at least one of a distance of the link between the communication stations and a transmit processing delay, and calculation of reliability of the link, applying a weight to each of elements obtained in the at least two calculations; and calculating the cost by combining results obtained by multiplying the elements by the weights. ### Claim 2 (depends on 1) The communication system according to claim 1, wherein said one or more processor is configured to perform: monitoring a connection status of the network; and setting the weight based on the connection status of the network. ### Claim 3 (depends on 2) The communication system according to claim 2, wherein the connection status of the network includes a disconnection ratio of the link, and the weight is set based on the disconnection ratio. ### Claim 4 (depends on 3) The communication system according to claim 3, wherein said one or more processor is configured to perform: detecting an operation policy applied to the network; and setting the weight based on the operation policy. ### Claim 5 (depends on 4) The communication system according to claim 4, comprising: a memory configured to store events that may occur in the network for each of a plurality of operation policies to be applied to the network, wherein the detection of the operation policy includes detecting, when one event stored in the memory occurs, an operation policy corresponding to the event as an operation policy applied to the network. ### Claim 6 (depends on 5) The communication system according to claim 5, wherein said one or more processor is configured to perform: monitoring at least one of a total traffic amount distributed in the network and a total packet stagnation amount of packets stagnating in the communication station; and calculating the weight based on at least one of the total traffic amount and the total packet stagnation amount. ### Claim 7 (depends on 6) The communication system according to claim 6, wherein said one or more processor is configured to perform: identifying at least one of QoS and an application type of traffic flowing in the network; and calculating the weight based on at least one of the QoS and the application type, and wherein the routing is executed for each traffic. ### Claim 8 (depends on 4) The communication system according to claim 4, wherein said one or more processor is configured to perform: monitoring at least one of a total traffic amount distributed in the network and a total packet stagnation amount of packets stagnating in the communication station; and calculating the weight based on at least one of the total traffic amount and the total packet stagnation amount. ### Claim 9 (depends on 3) The communication system according to claim 3, wherein said one or more processor is configured to perform: monitoring at least one of a total traffic amount distributed in the network and a total packet stagnation amount of packets stagnating in the communication station; and calculating the weight based on at least one of the total traffic amount and the total packet stagnation amount. ### Claim 10 (depends on 2) The communication system according to claim 2, wherein said one or more processor is configured to perform: detecting an operation policy applied to the network; and setting the weight based on the operation policy. ### Claim 11 (depends on 10) The communication system according to claim 10, comprising: a memory configured to store events that may occur in the network for each of a plurality of operation policies to be applied to the network, wherein the detection of the operation policy includes detecting, when one event stored in the memory occurs, an operation policy corresponding to the event as an operation policy applied to the network. ### Claim 12 (depends on 10) The communication system according to claim 10, wherein said one or more processor is configured to perform: monitoring at least one of a total traffic amount distributed in the network and a total packet stagnation amount of packets stagnating in the communication station; and calculating the weight based on at least one of the total traffic amount and the total packet stagnation amount. ### Claim 13 (depends on 2) The communication system according to claim 2, wherein said one or more processor is configured to perform: monitoring at least one of a total traffic amount distributed in the network and a total packet stagnation amount of packets stagnating in the communication station; and calculating the weight based on at least one of the total traffic amount and the total packet stagnation amount. ### Claim 14 (depends on 1) The communication system according to claim 1, wherein said one or more processor is configured to perform: detecting an operation policy applied to the network; and setting the weight based on the operation policy. ### Claim 15 (depends on 14) The communication system according to claim 14, comprising: a memory configured to store events that may occur in the network for each of a plurality of operation policies to be applied to the network, wherein the detection of the operation policy includes detecting, when one event stored in the memory occurs, an operation policy corresponding to the event as an operation policy applied to the network. ### Claim 16 (depends on 15) The communication system according to claim 15, wherein said one or more processor is configured to perform: monitoring at least one of a total traffic amount distributed in the network and a total packet stagnation amount of packets stagnating in the communication station; and calculating the weight based on at least one of the total traffic amount and the total packet stagnation amount. ### Claim 17 (depends on 14) The communication system according to claim 14, wherein said one or more processor is configured to perform: monitoring at least one of a total traffic amount distributed in the network and a total packet stagnation amount of packets stagnating in the communication station; and calculating the weight based on at least one of the total traffic amount and the total packet stagnation amount. ### Claim 18 (depends on 1) The communication system according to claim 1, wherein said one or more processor is configured to perform: monitoring at least one of a total traffic amount distributed in the network and a total packet stagnation amount of packets stagnating in the communication station; and calculating the weight based on at least one of the total traffic amount and the total packet stagnation amount. ### Claim 19 (depends on 1) The communication system according to claim 1, wherein said one or more processor is configured to perform: identifying at least one of QoS and an application type of traffic flowing in the network; and calculating the weight based on at least one of the QoS and the application type, wherein the routing is executed for each traffic. ### Claim 20 A communication method in which communication stations are linked to each other to form a network and transmit packets through links, the communication method comprising: monitoring a traffic amount of the link between the communication stations; calculating a cost used for routing in the communication stations; and executing routing based on the cost, wherein the cost calculation includes: at least two calculations among calculation of a congestion level of each link based on a traffic amount of a link between the communication stations, calculation of a delay time of each link based on at least one of a distance of the link between the communication stations and a transmit processing delay, and calculation of reliability of the link; applying a weight to each of elements obtained in the at least two processes; and calculating the cost by combining results obtained by multiplying the elements by the weights.