# US 10,484,876 B2 · Assisted dynamic frequency scan for Wi-Fi access points > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,484,876 B2 - Document ID: US10484876B2 - Status: Granted - Kind: B2 - Application number: 15/594,419 - Filed: 2017-05-12 - Published: 2018-11-15 - Granted: 2019-11-19 - Earliest claimed: 2017-05-12 - Assignees: Verizon Patent and Licensing Inc. - Applicants: Verizon Patent and Licensing Inc. - Inventors: Jeemil Shah; Arun Kalmanje - Web page: https://patentgrep.com/patent/US10484876B2 ## CPC - H04W 16/14: Spectrum sharing arrangements {between different networks} - H04W 16/10: Dynamic resource partitioning - H04W 24/02: Arrangements for optimising operational condition - H04W 24/10: Scheduling measurement reports {; Arrangements for measurement reports} - H04W 36/008375: {based on historical data} - H04W 48/16: Discovering, processing access restriction or access information - H04W 72/0453: Resources in frequency domain, e.g. a carrier in FDMA - H04W 84/12: WLAN [Wireless Local Area Networks] - H04W 88/08: Access point devices - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract An access point (AP) may use historical Dynamic Frequency Selection (DFS) monitoring information to make a decision of whether to perform a DFS procedure on a particular channel. The historical information can be obtained from other APs, such as from other nearby APs. In this manner, historical DFS monitoring information, which was previously measured by the AP or by a nearby AP, can be used to improve the likelihood that a decision to perform the DFS procedure will result in a determination that a particular channel is useable. ## Claims ### Claim 1 An access point (AP) comprising: a radio transceiver to implement Wi-Fi radio connections in a 5 gigahertz (GHz) unlicensed band using a plurality of potential frequency channels; a network interface to connect to a network that provides network connectivity to the AP; and circuitry to: receive historical channel scan information relating to results of scans of the plurality of potential frequency channels by other APs; determine, based on the historical channel scan information, one or more of the plurality of potential frequency channels to exclude as a potential active Wi-Fi channel for the AP; select from the plurality of potential frequency channels to obtain one or more of the plurality of potential channels to scan, the selecting including refraining from selecting any of the plurality of potential frequency channels that were determined to be excluded; determine, for each of the selected potential frequency channels, one or more selection metrics; determine, for each of the selected potential frequency channels and based on the one or more selection metrics, an amount of time to scan each of the selected potential frequency channels, wherein a first amount of time is determined for a first potential frequency channel, of the selected potential frequency channels based on the one or more selection metrics associated with the first potential frequency channel, and wherein a second amount of time is determined for a second potential frequency channel, of the selected potential frequency channels based on the one or more selection metrics associated with the second potential frequency channel, the first and second amounts of time being different; and scan the selected potential frequency channels over a particular period of time, without scanning any of the plurality of potential frequency channels that were determined to be excluded, wherein scanning the selected potential frequency channels includes: scanning, during the particular period of time, the first potential frequency channel for the first amount of time, and scanning, during the particular period of time, the second potential frequency channel for the different second amount of time. ### Claim 2 (depends on 1) The AP of claim 1, wherein the circuitry is further to: transmit results of the scanning of the selected potential frequency channels to the other APs. ### Claim 3 (depends on 2) The AP of claim 2, wherein when transmitting the results to the other APs, the circuitry is further to: directly transmit the results of the scanning, to the other APs, using Wi-Fi beacons or broadcast frames. ### Claim 4 (depends on 2) The AP of claim 2, wherein when transmitting the results to the other APs, the circuitry is further to: transmit the results of the scanning, to the other APs, by transmitting the results of the scanning to a coordination server that coordinates the exchange of the historical channel scan information among APs based on relative locations of the APs. ### Claim 5 (depends on 1) The AP of claim 1, wherein the other APs, from which the historical channel scan information is received, include APs that are within a threshold geographic distance from the AP. ### Claim 6 (depends on 1) The AP of claim 1, wherein the scanning of the selected potential frequency channels includes performing a Dynamic Frequency Selection (DFS) procedure on the selected potential frequency channels to determine whether a radar pulse is detected. ### Claim 7 (depends on 1) The AP of claim 1, wherein the circuitry is further to: receive the historical channel scan information, from a coordination server, as an indication of the one or more of the plurality of potential frequency channels to exclude. ### Claim 8 (depends on 1) The AP of claim 1, wherein the circuitry is further to: switch an active frequency channel, of the AP, based on the scanning of the selected potential frequency channels. ### Claim 9 A method, performed by a Wi-Fi Access Point (AP), the method comprising: receiving historical channel scan information relating to results of scans of a plurality of potential frequency channels, in a 5 gigahertz (GHz) Wi-Fi frequency band, the historical channel scan information having been obtained by other APs; determining, based on the historical channel scan information, one or more of the plurality of potential frequency channels to exclude as a potential active Wi-Fi channel for the AP; selecting from the plurality of potential frequency channels to obtain one or more of the plurality of potential channels to scan, the selecting including refraining from selecting any of the plurality of potential frequency channels that were determined to be excluded; determining, for each of the selected potential frequency channels, one or more selection metrics; determining, for each of the selected potential frequency channels and based on the one or more selection metrics, an amount of time to scan each of the selected potential frequency channels, wherein a first amount of time is determined for a first potential frequency channel, of the selected potential frequency channels based on the one or more selection metrics associated with the first potential frequency channel, and wherein a second amount of time is determined for a second potential frequency channel, of the selected potential frequency channels based on the one or more selection metrics associated with the second potential frequency channel, the first and second amounts of time being different; and scanning the selected potential frequency channels, without scanning any of the plurality of potential frequency channels that were determined to be excluded, wherein scanning the selected potential frequency channels includes: scanning, during the particular period of time, the first potential frequency channel for the first amount of time, and scanning, during the particular period of time, the second potential frequency channel for the different second amount of time. ### Claim 10 (depends on 9) The method of claim 9, further comprising: transmitting results of the scanning of the selected potential frequency channels to the other APs. ### Claim 11 (depends on 10) The method of claim 10, wherein when transmitting the results to the other APs, the method further includes: directly transmitting the results of the scanning, to the other APs, using Wi-Fi beacon or broadcast frames. ### Claim 12 (depends on 10) The method of claim 10, wherein when transmitting the results to the other APs, the method further includes: transmitting the results of the scanning, to the other APs, by transmitting the results of the scanning to a coordination server that coordinates the exchange of the historical channel scan information among APs based on relative locations of the APs. ### Claim 13 (depends on 9) The method of claim 9, wherein the other APs, from which the historical channel scan information is received, include APs that are within a threshold geographic distance from the AP. ### Claim 14 (depends on 9) The method of claim 9, wherein the scanning of the selected potential frequency channels includes performing a Dynamic Frequency Selection (DFS) procedure on the selected potential frequency channels to determine whether a radar pulse is detected. ### Claim 15 (depends on 9) The method of claim 9, further comprising: receiving the historical channel scan information, from a coordination server, as an indication of the one or more of the plurality of potential frequency channels to exclude. ### Claim 16 (depends on 9) The method of claim 9, further comprising: switching an active frequency channel, of the AP, based on the scanning of the selected potential frequency channels. ### Claim 17 A non-transitory, computer-readable medium storing a plurality of processor-executable instructions, wherein executing the processor-executable instructions causes one or more processors, associated with an Access Point (AP), to: receive historical channel scan information relating to results of scans of a plurality of potential frequency channels, in a 5 gigahertz (GHz) Wi-Fi frequency band, the historical channel scan information having been obtained by other APs; determine, based on the historical channel scan information, one or more of the plurality of potential frequency channels to exclude as a potential active Wi-Fi channel for the AP; select from the plurality of potential frequency channels to obtain one or more of the plurality of potential channels to scan, the selecting including refraining from selecting any of the plurality of potential frequency channels that were determined to be excluded; determine, for each of the selected potential frequency channels, one or more selection metrics; determine, for each of the selected potential frequency channels and based on the one or more selection metrics, an amount of time to scan each of the selected potential frequency channels, wherein a first amount of time is determined for a first potential frequency channel, of the selected potential frequency channels based on the one or more selection metrics associated with the first potential frequency channel, and wherein a second amount of time is determined for a second potential frequency channel, of the selected potential frequency channels based on the one or more selection metrics associated with the second potential frequency channel, the first and second amounts of time being different; and scan the selected potential frequency channels, wherein scanning the selected Potential frequency channels includes: scanning, during the particular period of time, the first potential frequency channel for the first amount of time, and scanning, during the particular period of time, the second potential frequency channel for the different second amount of time. ### Claim 18 (depends on 17) The computer-readable medium of claim 17, further comprising: transmitting results of the scanning of the selected potential frequency channels to the other APs. ### Claim 19 (depends on 18) The computer-readable medium of claim 18, wherein when transmitting the results to the other APs, the method further includes: directly transmitting the results of the scanning, to the other APs, using Wi-Fi beacon or broadcast frames. ### Claim 20 (depends on 18) The computer-readable medium of claim 18, wherein when transmitting the results to the other APs, the method further includes: transmitting the results of the scanning, to the other APs, by transmitting the results of the scanning to a coordination server.