# US 2019/0170869 A1 · Motion Detection and Localization Based on Bi-Directional Channel Sounding > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0170869 A1 - Document ID: US20190170869A1 - Status: Published application - Kind: A1 - Application number: 16/165,546 - Filed: 2018-10-19 - Published: 2019-06-06 - Earliest claimed: 2017-12-06 - Assignees: Cognitive Systems Corp. - Applicants: Cognitive Systems Corp. - Inventors: Oleksiy Kravets; Tajinder Manku - Web page: https://patentgrep.com/patent/US20190170869A1 ## CPC - G01S 13/56: for presence detection {(presence detection using near field arrangements G01V3/00, e.g. G01V3/08, G01V3/12; burglar, theft or intruder alarms with electrical actuation G08B13/22 - G08B13/26)} - G01S 7/41: using analysis of echo signal for target characterisation; Target signature; Target cross-section - G01S 13/003: {Bistatic radar systems; Multistatic radar systems} - G01S 13/765: {with exchange of information between interrogator and responder} - G01S 13/886: {for alarm systems (alarms with electrical actuation G08B13/22)} - G08B 13/2491: {Intrusion detection systems, i.e. where the body of an intruder causes the interference with the electromagnetic field} - G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES - G08B: SIGNALLING SYSTEMS, e.g. PERSONAL CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS ## Abstract In a general aspect of the examples described, motion is detected based on bi-directional channel sounding. In an example, a first set of channel information is obtained from a first device. The first set of channel information is based on a first set of wireless signals transmitted from a second device through a space at a first time in a timeframe. A second set of channel information is obtained from the second device. The second set of channel information is based on a second set of wireless signals transmitted from the first device through the space at a second time in the timeframe. The first and second sets of channel information are analyzed to detect a category of motion or a location of detected motion in the space during the timeframe. ## Claims ### Claim 1 A method comprising: obtaining a first set of channel information from a first device, the first set of channel information based on a first set of wireless signals transmitted from a second device through a space at a first time in a timeframe; obtaining a second set of channel information from the second device, the second set of channel information based on a second set of wireless signals transmitted from the first device through the space at a second time in the timeframe; and analyzing the first and second sets of channel information to detect a category of motion or a location of detected motion in the space during the timeframe, wherein analyzing the first and second sets of channel information comprises comparing a channel variation indicated by the first set of channel information with a channel variation indicated by the second set of channel information. ### Claim 2 (depends on 1) The method of claim 1, wherein the first and second sets of channel information are based on wireless signals transmitted bi-directionally through the space between the first and second devices. ### Claim 3 (depends on 1) The method of claim 1, wherein the wireless signals include reference signals or beacon signals. ### Claim 4 (depends on 1) The method of claim 1, wherein the first set of wireless signals is transmitted in a first direction from the first device to the second device, and the second set of wireless signals is transmitted in a second direction from the second device to the first device. ### Claim 5 (depends on 1) The method of claim 1, wherein analyzing the first and second sets of channel information comprises comparing the channel variation indicated by the first set of channel information to the channel variation indicated by the second set of channel information to determine whether an object is moving in a zone near the first device or the second device. ### Claim 6 (depends on 5) The method of claim 5, wherein determining whether an object is moving in a zone near the first device or the second device comprises: determining that an object is moving in a zone near the first device when the first set of channel information indicates more channel variation over time compared to the second set of channel information; or determining that an object is moving in a zone near the second device when the second set of channel information indicates more channel variation over time compared to the first set of channel information. ### Claim 7 (depends on 1) The method of claim 1, wherein analyzing the first and second sets of channel information comprises determining that an object is moving in a zone between the first device and the second device when the first set of channel information indicates similar channel variation over time compared to the second set of channel information. ### Claim 8 (depends on 1) The method of claim 1, wherein analyzing the first and second sets of channel information comprises determining the category of motion. ### Claim 9 (depends on 8) The method of claim 8, wherein determining the category of motion comprises identifying a type of moving object. ### Claim 10 (depends on 1) The method of claim 1, wherein analyzing the first and second sets of channel information comprises at least one of: determining that a small object is moving closer to the first device than to the second device when the first set of channel information indicates less channel variation over time compared to the second set of channel information; or determining that a large object is moving closer to the second device than to the first device when the first set of channel information indicates greater channel variation over time compared to the second set of channel information. ### Claim 11 A non-transitory computer-readable medium comprising instructions which, when executed by one or more processors, cause the one or more processors to: obtain a first set of channel information from a first device, the first set of channel information based on a first set of wireless signals transmitted from a second device through a space at a first time in a timeframe; obtain a second set of channel information from the second device, the second set of channel information based on a second set of wireless signals transmitted from the first device through the space at a second time in the timeframe; and analyze the first and second sets of channel information to detect a category of motion or a location of detected motion in the space during the timeframe, wherein analyzing the first and second sets of channel information comprises comparing a channel variation indicated by the first set of channel information with a channel variation indicated by the second set of channel information. ### Claim 12 (depends on 11) The computer-readable medium of claim 11, wherein the first and second sets of channel information are based on wireless signals transmitted bi-directionally through the space between the first and second devices. ### Claim 13 (depends on 11) The computer-readable medium of claim 11, wherein the wireless signals include reference signals or beacon signals. ### Claim 14 (depends on 11) The computer-readable medium of claim 11, wherein the first set of wireless signals is transmitted in a first direction from the first device to the second device, and the second set of wireless signals is transmitted in a second direction from the second device to the first device. ### Claim 15 (depends on 11) The computer-readable medium of claim 11, wherein analyzing the first and second sets of channel information comprises comparing the channel variation indicated by the first set of channel information to the channel variation indicated by the second set of channel information to determine whether an object is moving in a zone near the first device or the second device. ### Claim 16 (depends on 15) The computer-readable medium of claim 15, wherein determining whether an object is moving in a zone near the first device or the second device comprises: determining that an object is moving in a zone near the first device when the first set of channel information indicates more channel variation over time compared to the second set of channel information; or determining that an object is moving in a zone near the second device when the second set of channel information indicates more channel variation over time compared to the first set of channel information. ### Claim 17 (depends on 11) The computer-readable medium of claim 11, wherein analyzing the first and second sets of channel information comprises determining that an object is moving in a zone between the first device and the second device when the first set of channel information indicates similar channel variation over time compared to the second set of channel information. ### Claim 18 (depends on 11) The computer-readable medium of claim 11, wherein analyzing the first and second sets of channel information comprises determining the category of motion. ### Claim 19 (depends on 18) The computer-readable medium of claim 18. wherein determining the category of motion comprises identifying a type of moving object. ### Claim 20 (depends on 11) The device of claim 11, wherein analyzing the first and second sets of channel information comprises: determining that a small object is moving closer to the first device than to the second device when the first set of channel information indicates less channel variation over time compared to the second set of channel information; or determining that a large object is moving closer to the second device than to the first device when the first set of channel information indicates greater channel variation over time compared to the second set of channel information. ### Claim 21 A system comprising: a plurality of wireless communication devices comprising a first wireless communication device and a second wireless communication device; data processing apparatus; memory storing instructions that are operable when executed by the data processing apparatus to: obtain a first set of channel information from the first wireless communication device, the first set of channel information based on a first set of wireless signals transmitted from the second wireless communication device through a space at a first time in a timeframe; obtain a second set of channel information from the second wireless communications device, the second set of channel information based on a second set of wireless signals transmitted from the first wireless communication device through the space at a second time in the timeframe; and analyzing the first and second sets of channel information to detect a category of motion or a location of detected motion in the space during the timeframe, wherein analyzing the first and second sets of channel information comprises comparing a channel variation indicated by the first set of channel information with a channel variation indicated by the second set of channel information. ### Claim 22 (depends on 21) The system of claim 21, wherein the first and second sets of channel information are based on wireless signals transmitted bi-directionally through the space between the first and second wireless communication devices. ### Claim 23 (depends on 21) The system of claim 21, wherein the wireless signals include reference signals or beacon signals. ### Claim 24 (depends on 21) The system of claim 21, wherein the first set of wireless signals is transmitted in a first direction from the first wireless communication device to the second wireless communication device, and the second set of wireless signals is transmitted in a second direction from the second wireless communication device to the first wireless communication device. ### Claim 25 (depends on 21) The system of claim 21, wherein analyzing the first and second sets of channel information comprises comparing the channel variation indicated by the first set of channel information to the channel variation indicated by the second set of channel information to determine whether an object is moving in a zone near the first wireless communication device or the second wireless communication device. ### Claim 26 (depends on 25) The system of claim 25, wherein determining whether an object is moving in a zone near the first wireless communication device or the second wireless communication device comprises: determining that an object is moving in a zone near the first wireless communication device when the first set of channel information indicates more channel variation over time compared to the second set of channel information; or determining that an object is moving in a zone near the second wireless communication device when the second set of channel information indicates more channel variation over time compared to the first set of channel information. ### Claim 27 (depends on 21) The system of claim 21, wherein analyzing the first and second sets of channel information comprises determining that an object is moving in a zone between the first wireless communication device and the second wireless communication device when the first set of channel information indicates similar channel variation over time compared to the second set of channel information. ### Claim 28 (depends on 21) The system of claim 21, wherein analyzing the first and second sets of channel information comprises determining the category of motion. ### Claim 29 (depends on 28) The system of claim 28, wherein determining the category of motion comprises identifying a type of moving object. ### Claim 30 (depends on 21) The system of claim 21, wherein analyzing the first and second sets of channel information comprises at least one of: determining that a small object is moving closer to the first wireless communication device than to the second wireless communication device when the first set of channel information indicates less channel variation over time compared to the second set of channel information; or determining that a large object is moving closer to the second wireless communication device than to the first wireless communication device when the first set of channel information indicates greater channel variation over time compared to the second set of channel information.