# US 2021/0243669 A1 · Controlling tree topology over mesh topology based on autonomous decentralized control > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0243669 A1 - Document ID: US20210243669A1 - Status: Published application - Kind: A1 - Application number: 17/238,349 - Filed: 2021-04-23 - Published: 2021-08-05 - Earliest claimed: 2018-05-02 - Assignees: PicoCELA Inc. - Applicants: PicoCELA Inc. - Inventors: Hiroshi Furukawa - Web page: https://patentgrep.com/patent/US20210243669A1 ## CPC - H04W 40/08: based on transmission power - H04W 40/246: {Connectivity information discovery} - H04W 40/02: Communication route or path selection, e.g. power-based or shortest path routing - H04W 40/12: based on transmission quality or channel quality - H04W 40/14: based on stability - H04W 40/24: Connectivity information management, e.g. connectivity discovery or connectivity update - H04W 84/22: with access to wired networks - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract A first wireless node transmits a control signal to be propagated to each of a plurality of wireless links linked up between a plurality of wireless nodes that forms a backhaul network. Each of second wireless nodes that is different from the first wireless node selects, for a transmission route of a data signal, a wireless link corresponding to one of different routes in an upstream direction toward the first wireless node among the linked up wireless links, based on an indicator indicative of a radio wave propagation quality of one or more wireless links through which a plurality of the control signals received from different routes are propagated. ## Claims ### Claim 1 A communication system comprising: a mesh topology that is formed by a plurality of nodes including a node which supports a connection by a wireless link and a node which supports connections by a wireless link and a wired link; and a tree topology that is formed over the mesh topology by a link selection of the wireless link or the wired link based on an autonomous decentralized control in the individual nodes. ### Claim 2 (depends on 1) The communication system according to claim 1, wherein the tree topology includes at least one wired link. ### Claim 3 (depends on 1) The communication system according to claim 1, wherein the autonomous decentralized control includes a process to update at least one link status among the wireless link and the wired link between any of the nodes that forms the mesh link. ### Claim 4 (depends on 3) The communication system according to claim 3, wherein each of the plurality of nodes comprises a memory to store information on the link status. ### Claim 5 (depends on 3) The communication system according to claim 3, wherein each of the plurality of nodes comprises a processor to calculate the link status. ### Claim 6 (depends on 1) The communication system according to claim 1, wherein the link selection includes a process to select the wired link in preference to the wireless link when the connection by the wired link is established. ### Claim 7 (depends on 6) The communication system according to claim 6, wherein the process to select the wired link in preference to the wireless link includes a setting to set a propagation loss of the wired link to a predetermined value smaller than a propagation loss of the wireless link, the propagation loss of the wired link being used to calculate a route metric for the link selection. ### Claim 8 A node which constitutes a mesh topology, the node comprising: a wireless interface that supports a connection by a wireless link; a wired interface that supports a connection by a wired link; a controller that controls a link selection of the wireless link or the wired link which forms a tree topology over the mesh topology, based on a status of communication by at least one of the wireless link and the wired link. ### Claim 9 (depends on 8) The node according to claim 8, wherein the controller calculates a route metric indicative of the status of communication by setting a propagation loss of the wired link to a predetermined value smaller than a propagation loss of the wireless link. ### Claim 10 A method comprising: forming a mesh topology by a plurality of nodes including a node which supports a connection by a wireless link and a node which supports connections by a wireless link and a wired link; and forming a tree topology over the mesh topology by a link selection of the wireless link or the wired link based on an autonomous decentralized control in the individual nodes. ### Claim 11 A communication system comprising: a mesh topology formed by a plurality of node, a part or all of the plurality of node being available to mutually establish a connection to other plurality of the nodes, wherein a destination node of the connection is not fixed and is changeable according to a state of communications, at least one of the plurality of nodes is selectable as a core node which is a final destination of the communication, at least a part of the plurality of nodes is available in communications by a wireless connection and a wired connection, each of the plurality of the nodes forms a tree topology over the mesh topology by determining a connection destination for an upstream direction towards the core node. ### Claim 12 (depends on 11) The communication system according to claim 11, wherein all of the plurality of the nodes are available in communications by both of the wireless connection and the wired connection. ### Claim 13 (depends on 11) The communication system according to claim 11, wherein the plurality of the node perform an autonomous decentralized control which updates at least one connection status of the wireless connection and the wired connection between the respective nodes that forms the mesh topology. ### Claim 14 (depends on 13) The communication system according to claim 13, wherein each of the plurality of the nodes comprises a memory to store information on the connection status. ### Claim 15 (depends on 13) The communication system according to claim 13, wherein each of the plurality of the nodes comprises a processor to calculate the connection status. ### Claim 16 (depends on 11) The communication system according to claim 11, wherein the determining of the connection destination for the upstream direction includes a process to select the connection destination for the wired connection in preference to the connection destination for the wireless connection when both of the wireless connection and the wired connection are available. ### Claim 17 (depends on 11) The communication system according to claim 11, wherein, when both of the wireless connection and the wired connection are available in the plurality of the nodes, the determining of the connection destination for the upstream direction includes a setting to set a propagation loss of the wired connection to a predetermined value smaller than a propagation loss of the wireless connection, the propagation loss of the wired connection being used to calculate a route metric for selecting the connection destination.