# US 11,445,454 B2 · Localized optimization of isolated sub-DAG based on edge node parenting and distributed density-based optimization > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,445,454 B2 - Document ID: US11445454B2 - Status: Granted - Kind: B2 - Application number: 17/324,284 - Filed: 2021-05-19 - Published: 2021-09-16 - Granted: 2022-09-13 - Earliest claimed: 2020-03-10 - Assignees: Cisco Technology, Inc. - Applicants: Cisco Technology, Inc. - Inventors: Pascal Thubert; Robert Edgar Barton; Jerome Henry; Eric Michel Levy-Abegnoli - Web page: https://patentgrep.com/patent/US11445454B2 ## CPC - H04W 52/322: {Power control of broadcast channels} - H04W 52/383: {power control in peer-to-peer links} - H04W 24/02: Arrangements for optimising operational condition - H04W 40/244: {using a network of reference devices, e.g. beaconing} - H04W 40/246: {Connectivity information discovery} - H04W 52/283: {Power depending on the position of the mobile} - H04W 52/346: {distributing total power among users or channels} - H04W 52/367: {Power values between minimum and maximum limits, e.g. dynamic range} - H04W 84/18: Self-organising networks, e.g. ad-hoc networks or sensor networks - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract In one embodiment, a method comprises: determining, by a constrained network device in a low power and lossy network (LLN), a self-estimated density value of neighboring LLN devices based on wirelessly receiving an identified number of beacon message transmissions within an identified time interval from neighboring transmitting LLN devices in the LLN; setting, by the constrained network device, a first wireless transmit power value based on the self-estimated density value; and transmitting a beacon message at the first wireless transmit power value, the beacon message specifying the self-estimated density value, a corresponding trust metric for the self-estimated density value, and the first wireless transmit power value used by the constrained network device for transmitting the beacon message. ## Claims ### Claim 1 A method comprising: determining, by a wireless network device in a wireless network, a self-estimated density value of neighboring wireless devices based on wirelessly receiving an identified number of beacon message transmissions within an identified time interval from neighboring transmitting wireless devices in the wireless network; setting, by the wireless network device, a first wireless transmit power value based on the self-estimated density value; and transmitting a beacon message at the first wireless transmit power value, the beacon message specifying the self-estimated density value, a corresponding trust metric for the self-estimated density value, and the first wireless transmit power value used by the wireless network device for transmitting the beacon message. ### Claim 2 (depends on 1) The method of claim 1, wherein the wireless network device is confined within an isolated area of the wireless network. ### Claim 3 (depends on 2) The method of claim 2, further comprising: the wireless network device wirelessly attaching to a parent network device that is positioned outside the isolated area; the wireless network device selectively changing its transmit power from the first wireless transmit power value to a second wireless transmit power value for each data packet transmitted to the parent network device; the wireless network device resuming the first wireless transmit power value for each data packet transmitted within the isolated area. ### Claim 4 (depends on 3) The method of claim 3, further comprising: the wireless network device receiving, from the parent network device, an instruction specifying the wireless network device is to operate as a subroot for wireless devices in the isolated area; outputting, by the wireless network device, an advertisement message at the first wireless transmit power value and specifying the wireless network device is the subroot in the isolated area, the advertisement message causing the wireless devices in the isolated area to establish a directed acyclic graph (DAG) rooted at the wireless network device. ### Claim 5 (depends on 1) The method of claim 1, wherein the determining includes: determining, from each beacon message transmission, a corresponding estimated density value calculated by the corresponding neighboring transmitting wireless device, a corresponding trust metric allocated to the estimated density value by the corresponding neighboring transmitting wireless device, and a transmit power value used by the corresponding neighboring transmitting wireless device for transmitting the beacon message transmission; determining the self-estimated density based on the number of beacon message transmissions within the identified time interval, relative to the estimated density values and respective trust metrics. ### Claim 6 (depends on 1) The method of claim 1, further comprising: determining, by the wireless network device, an updated self-estimated density based on wirelessly receiving a second number of beacon message transmissions within a second instance of the identified time interval; and setting, by the wireless network device, an updated wireless transmit power value based on the updated self-estimated density value. ### Claim 7 (depends on 1) The method of claim 1, further comprising: repeating, by the wireless network device, the determining, setting, and transmitting for each of a plurality of available wireless channels; selectively limiting use, by the wireless network device, of the available wireless channels based on the wireless network device detecting a determined higher value in the self-estimated density among one or more of the available wireless channels; and generating updated self-estimated density values using successively-increasing identified time intervals. ### Claim 8 One or more non-transitory tangible media encoded with logic for execution by a machine and when executed by the machine operable for: determining, by the machine implemented as a wireless network device in a wireless network, a self-estimated density value of neighboring wireless devices based on wirelessly receiving an identified number of beacon message transmissions within an identified time interval from neighboring transmitting wireless devices in the wireless network; setting, by the wireless network device, a first wireless transmit power value based on the self-estimated density value; and transmitting a beacon message at the first wireless transmit power value, the beacon message specifying the self-estimated density value, a corresponding trust metric for the self-estimated density value, and the first wireless transmit power value used by the wireless network device for transmitting the beacon message. ### Claim 9 (depends on 8) The one or more non-transitory tangible media of claim 8, wherein the wireless network device is confined within an isolated area of the wireless network. ### Claim 10 (depends on 9) The one or more non-transitory tangible media of claim 9, further operable for: the wireless network device wirelessly attaching to a parent network device that is positioned outside the isolated area; the wireless network device selectively changing its transmit power from the first wireless transmit power value to a second wireless transmit power value for each data packet transmitted to the parent network device; the wireless network device resuming the first wireless transmit power value for each data packet transmitted within the isolated area. ### Claim 11 (depends on 10) The one or more non-transitory tangible media of claim 10, further operable for: the wireless network device receiving, from the parent network device, an instruction specifying the wireless network device is to operate as a subroot for wireless devices in the isolated area; outputting, by the wireless network device, an advertisement message at the first wireless transmit power value and specifying the wireless network device is the subroot in the isolated area, the advertisement message causing the wireless devices in the isolated area to establish a directed acyclic graph (DAG) rooted at the wireless network device. ### Claim 12 (depends on 8) The one or more non-transitory tangible media of claim 8, wherein the determining includes: determining, from each beacon message transmission, a corresponding estimated density value calculated by the corresponding neighboring transmitting wireless device, a corresponding trust metric allocated to the estimated density value by the corresponding neighboring transmitting wireless device, and a transmit power value used by the corresponding neighboring transmitting wireless device for transmitting the beacon message transmission; determining the self-estimated density based on the number of beacon message transmissions within the identified time interval, relative to the estimated density values and respective trust metrics. ### Claim 13 (depends on 8) The one or more non-transitory tangible media of claim 8, further operable for: determining, by the wireless network device, an updated self-estimated density based on wirelessly receiving a second number of beacon message transmissions within a second instance of the identified time interval; and setting, by the wireless network device, an updated wireless transmit power value based on the updated self-estimated density value. ### Claim 14 (depends on 8) The one or more non-transitory tangible media of claim 8, further operable for: repeating, by the wireless network device, the determining, setting, and transmitting for each of a plurality of available wireless channels; selectively limiting use, by the wireless network device, of the available wireless channels based on the wireless network device detecting a determined higher value in the self-estimated density among one or more of the available wireless channels; and generating updated self-estimated density values using successively-increasing identified time intervals.