# US 10,371,788 B2 · Device positioning > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,371,788 B2 - Document ID: US10371788B2 - Status: Granted - Kind: B2 - Application number: 15/375,249 - Filed: 2016-12-12 - Published: 2017-03-30 - Granted: 2019-08-06 - Earliest claimed: 2014-06-12 - Assignees: Nidatech Sweden AB - Applicants: Nida Tech Sweden AB - Inventors: Håkan Dackefjord; Bogdan Shelest - Web page: https://patentgrep.com/patent/US10371788B2 ## CPC - G01S 5/06: Position of source determined by co-ordinating a plurality of position lines defined by path-difference measurements (G01S5/12 takes precedence) - G01S 5/0249: {Determining position using measurements made by a non-stationary device other than the device whose position is being determined} - G01S 5/10: Position of receiver fixed by co-ordinating a plurality of position lines defined by path-difference measurements {, e.g. omega or decca systems}(G01S5/12 takes precedence {; beacons and receivers cooperating therewith G01S1/306, G01S1/308}) - G01S 5/14: Determining absolute distances from a plurality of spaced points of known location - H04W 4/025: {using location based information parameters} - G01S 2205/01: specially adapted for specific applications - G01S 2205/05: Anti-theft or abduction - H04W 64/006: {with additional information processing, e.g. for direction or speed determination} - 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 - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract Described are, among other things, a method, a device and a computer program wherein a large search area for a device that is to be located is successively narrowed by moving and/or rotating a locator device. ## Claims ### Claim 1 A method of determining the location of a device comprising a radio transceiver, the method comprising: receiving in a mobile locator device a radio signal from said device, determining a distance to said device from the locator device at the position of the locator device, said determined distance having a determined distance accuracy, and/or determining a direction to the device with a determined direction accuracy, wherein said determined distance and/or direction is based on the radio signal received from the device, forming a geographical area with boundaries set as the determined distance+/−said determined accuracy, and/or as the determined direction+/−said determined direction accuracy, subdividing said geographical area into a number of sub-areas and removing any sub area that is not included in all geographical areas formed for each new position of the locator device, moving said locator device to a new position and repeating removal of subareas for new positions of the locator device until the total area of the remaining sub-areas is below a threshold value, and determining the location of the device as the area of the remaining sub-areas. ### Claim 2 (depends on 1) The method according to claim 1, wherein sub-areas are successively removed until the number of remaining sub-areas is reduced to only one remaining sub-area. ### Claim 3 (depends on 1) The method according to claim 1, wherein the received signal from the device is a signal received in response to a signal transmitted to the device from the locator device. ### Claim 4 (depends on 3) The method according to claim 3, wherein the distance to the device is determined based on the roundtrip time for transmitted radio signal and the received response signal. ### Claim 5 (depends on 4) The method according to claim 4, wherein the roundtrip time is received from the device by the locator device. ### Claim 6 (depends on 1) The method according to claim 1, wherein the direction to the device is determined based on the direction having the strongest received signal strength. ### Claim 7 (depends on 6) The method according to claim 6, wherein the direction is also determined based on the direction opposite to the direction having the weakest received signal strength. ### Claim 8 A mobile locator device for locating a device, the locator device comprising a radio transceiver, the locator device being adapted to: receive a radio signal from said device, determine a distance to said device from the locator device at the position of the locator device, said determined distance having a determined distance accuracy, and/or determine a direction to the device with a determined direction accuracy, wherein said determined distance and or direction is based on the radio signal received from the device, form a geographical area with boundaries set as the determined distance+/−said determined accuracy, and/or as the determined direction+/−said determined direction accuracy, subdivide said geographical area into a number of sub-areas, and remove any sub area that is not included in all geographical areas formed for each new position of the mobile device, determine the location of the device as the remaining area(s) when the total area of the remaining sub-areas is below a threshold value. ### Claim 9 (depends on 8) The locator device according to claim 8, wherein the locator device is adapted to determine the location of the device when only one sub-area remains. ### Claim 10 (depends on 8) The locator device according to claim 8, wherein the locator device is adapted to transmit a signal to the device requesting a response from the device. ### Claim 11 (depends on 10) The locator device according to claim 10, wherein the locator device is adapted to determine the distance to the device based on the roundtrip time for transmitted radio signal and the received response signal. ### Claim 12 (depends on 11) The locator device according to claim 11, wherein the locator device is adapted to receive the roundtrip time from the device. ### Claim 13 (depends on 8) The locator device according to claim 8, wherein the locator device is adapted to determine the direction to the device based on the direction having the strongest received signal strength. ### Claim 14 (depends on 13) The locator device according to claim 13, wherein the locator device is adapted to determine the direction also based on the direction opposite to the direction having the weakest received signal strength.