# US 12,010,641 B2 · Wireless mesh network and method of relaying signal in wireless mesh network > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,010,641 B2 - Document ID: US12010641B2 - Status: Granted - Kind: B2 - Application number: 17/906,846 - Filed: 2021-03-19 - Published: 2023-04-27 - Granted: 2024-06-11 - Earliest claimed: 2020-03-20 - Assignees: Katholieke Universiteit Leuven - Applicants: Katholieke Universiteit Leuven - Inventors: Danny Hughes; Sam Michiels; Jonathan Oostvogels; Fan Yang - Web page: https://patentgrep.com/patent/US12010641B2 ## CPC - H04W 56/0025: {synchronizing potentially movable access points} - H04W 56/0045: {compensating for timing error by altering transmission time} - H04B 10/11: Arrangements specific to free-space transmission, i.e. transmission through air or vacuum - H04W 56/0015: {one node acting as a reference for the others} - H04W 56/002: {Mutual synchronization} - H04W 84/18: Self-organising networks, e.g. ad-hoc networks or sensor networks - Y02D 30/70: in wireless communication networks - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04B: TRANSMISSION - Y02D: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE ## Abstract A wireless mesh network of nodes includes at least one relay node, the at least one relay node being configured to receive a first signal, the first signal corresponding to a first symbol comprised in a data frame, the first symbol having a first symbol duration s; and to generate and transmit a second signal, the second signal corresponding to the first signal. The first signal and the second signal are modulated such that a sum of the first signal and the second signal is capable of being received and demodulated by at least one relay node so as to obtain a sum of symbols including the first symbol and the second symbol. ## Claims ### Claim 1 A wireless mesh network of nodes comprising at least one relay node, wherein the at least one relay node is configured to: receive a first signal, the first signal corresponding to a first symbol comprised in a data frame, the first symbol having a first symbol duration s; and generate and transmit a second signal, the second signal corresponding to the first signal; wherein the first signal and the second signal are modulated such that a sum of the first signal and the second signal is capable of being received and demodulated by at least one relay node so as to obtain a sum of symbols including the first syMbol and the second symbol; wherein a time offset r between the start time of the transmission of the second signal by the relay node and the time at which the first signal was received by the relay node is smaller than the first symbol duration s; and wherein the time offset r is chosen such at any pair of corresponding signals has a time offset q which is less than s from the perspective of any relay node in the network. ### Claim 2 (depends on 1) A network according to claim 1, wherein the at least one relay node is configured, upon receiving a subsequent third signal, to relay the third signal only if the third signal is received at a time offset relative to the time of receiving the first signal which is greater than or equal to the first symbol duration s. ### Claim 3 (depends on 1) A network according to claim 1, wherein the nodes are configured to communicate by optical wireless communication. ### Claim 4 (depends on 1) A network according to claim 1, wherein a relay node or a send node is configured to transmit signals using on-off keying. ### Claim 5 (depends on 1) A network according to claim 1, wherein a relay node or a send node is configured to transmit signals using a self-clocking code. ### Claim 6 (depends on 5) A network according to claim 5, wherein a relay node or a send node is configured to transmit signals using a run-length limited code. ### Claim 7 (depends on 5) A network according to claim 5, wherein a relay node and optionally a send node is configured to delineate a data frame by suppressing a clocking event in a signal encoded with a self-clocking code. ### Claim 8 (depends on 5) A network according to any of claim 5, wherein a relay node and optionally a send node is configured to detect a state change in a received signal by determining whether the received signal is convex or concave. ### Claim 9 (depends on 8) A network according to claim 8, wherein determining whether the received signal is convex or concave comprises comparing a difference between at least two approximations of the signal's first derivative with a noise threshold value. ### Claim 10 (depends on 9) A network according to claim 9, wherein a node comprised in the network is configured to modify the noise threshold value in dependence upon a background noise level. ### Claim 11 (depends on 9) A network according to claim 9, wherein a node comprised in the network is configured to modify the noise threshold value in dependence upon intensity values of valid received signals. ### Claim 12 (depends on 1) A network according to claim 1, wherein a send node is configured to pause, halt, or modify a transmission of data in dependence upon a signal received from another node in the network. ### Claim 13 (depends on 1) A network according to claim 1, wherein a relay node and optionally a send node comprises a detector, an emitter, a processor and a transceiver, wherein the transceiver is configured to receive samples of a signal received by the detector from the detector, wherein the transceiver is configured to demodulate the received samples and to output demodulated data, wherein the transceiver is configured to receive data to be transmitted, and wherein the transceiver is configured to modulate the received data to be transmitted and provide the resulting signal to the emitter. ### Claim 14 (depends on 13) A network according to claim 13, wherein a relay and optionally a send node is configured to: i) at the transceiver, retrieve from the detector a sample of a signal at a particular time step and perform an edge or pulse detection based on the received data and stored data points corresponding to earlier measurements received from the detector in order to determine a received symbol; ii) at the transceiver, determine the required state of the emitter of the relay node in dependence upon the determined received symbol and upon whether the node is acting as a send node; iii) provide from the transceiver to the emitter a signal for setting the stateof the emitter; iv) at the transceiver, determining whether the end of a frame has been reached and, if it is determined that the end of a frame has been reached, setting the transceiver to not initiate transmissions for a predetermined period. ### Claim 15 A method of relaying a signal in a wireless mesh network of nodes, the method comprising: receiving, at a first node comprised in the network, a first signal, the first signal corresponding to a first symbol comprised in a data frame, the first symbol having a first symbol duration s; generating and transmitting, at the first node, a second signal, the second signal corresponding to the first signal; wherein the first signal and the second signal are modulated such that a sum of the first signal and the second signal is capable of being received and demodulated by at least one relay node so as to obtain a sum of symbols including the first symbol and the second symbol; wherein a time offset r between the start titne of the transmission of the second signal by the relay node and the time at which the first signal was received by the relay node is smaller than the first symbol duration s; and wherein the time offset r is chosen such that any pair of corresponding signals has a time offset q which is less than s from the perspective of any relay node in the network.