Determining location via wireless access points

• US 10,448,210 B2
• Filed: 09/19/2018
• Issued: 10/15/2019
• Est. Priority Date: 09/14/2015
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Pandey, Santosh, Peng, Rong
• Primary Examiner(s): Mizrahi, Diane D
• Application Number:
  US16/136,185
• Publication Number:
  US 20190020977A1
• Time in Patent Office: 391 Days
• CPC Class Codes: G01C 21/26 specially adapted for navigation in a road network
• CPC Class Codes: G01S 5/0054 of actual mobile position, i.e. position calculation on base station
• CPC Class Codes: G01S 5/0268 by deriving positions from different combinations of signals or of estimated positions in a single positioning system
• CPC Class Codes: G01S 5/0278 involving statistical or probabilistic considerations G01S5/0252, G01S5/0294 take precedence
• CPC Class Codes: G01S 5/04 Position of source determined by a plurality of spaced direction-finders
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04W 4/023 using mutual or relative location information between multiple location based services [LBS] targets or of distance thresholds
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

Determining a location of a user device comprises a wireless computing system supported by an access point. The wireless computing system receives a signal from the user device. The system estimates a location of the user device based on RSSI and calculates a boundary around the estimated location. The wireless computing system selects a plurality of sections inside of the boundary and performs a coarse calculation of a location of the user device based on an angle of arrival of the received signal. The system determines sections of the plurality of sections that have results from the coarse calculation that are more likely to be a location of the user device. The system performs a fine calculation of the location based on the angle of arrival of the received signal within each of the sections. The system identifies a particular section as the location of the user device.

Claims

1. A method, comprising:

receiving, by each of a plurality of wireless computing system access points (APs) of a wireless computing system, a wireless signal from a user computing device;

calculating, by the wireless computing system, a boundary encompassing a first estimated location of the user computing device based on a signal strength of the received wireless signal at each AP;

computing, by the wireless computing system, a second estimated location of the user computing device within the boundary based on an angle of arrival of the signal of the received wireless signal at each AP;

generating, by the wireless computing system, a third estimated location of the user computing device based the second estimated location; and

transmitting, by the wireless computing system and to the user computing device, a location based on the third estimated location to indicate the location of the user computing device.

2. The method of claim 1, wherein a size of the boundary is based on an estimated accuracy of the calculation based on the received signal strength, wherein a higher estimated accuracy correlates to a smaller bound area and a lower estimated accuracy correlates to a larger bound area.

3. The method of claim 1, wherein:

computing the second estimated location of the user computing device based on an angle of arrival of the signal of the received wireless signal at each AP comprises;

dividing, by the wireless computing system, an area inside the boundary into a plurality of sections; and

determining, by the wireless computing system, a likelihood for each of the plurality of sections of being an actual location of the user computing device based on the angle of arrival of the signal of the received wireless signal at each AP; and

generating the final estimated location of the user computing device based the second estimated location comprises;

computing, by the wireless computing system, the third estimated location across a subset of the plurality of the sections, the subset comprising those sections characterized by a likelihood greater than or equal to the sections not in the subset.

4. The method of claim 3, wherein those sections characterized by a likelihood greater than or equal to sections not in the subset are determined by ranking the sections by likelihood and choosing the N highest ranked sections, where N is a number between 1 and the (total number of sections−

1).

5. The method of claim 3, wherein those sections characterized by a likelihood greater than or equal to sections not in the subset are those sections with a likelihood greater than a threshold.

6. The method of claim 3, wherein the computation of the third estimated location is finer than the computation of the second estimated location.

7. A computer program product, comprising:

a non-transitory computer-readable storage device having computer-executable program instructions embodied thereon that when executed by a computer cause the computer to locate a user computing device, the computer-executable program instructions comprising;

computer-executable program instructions to receive, by each of a plurality of wireless computing system access points (APs) of a wireless computing system, a wireless signal from a user computing device;

computer-executable program instructions to calculate, by the wireless computing system, a boundary encompassing a first estimated location of the user computing device based on a signal strength of the received wireless signal at each AP;

computer-executable program instructions to compute, by the wireless computing system, a second estimated location of the user computing device within the boundary based on an angle of arrival of the signal of the received wireless signal at each AP;

computer-executable program instructions to generate, by the wireless computing system, a third estimated location of the user computing device based the second estimated location; and

computer-executable program instructions to transmit, by the wireless computing system and to the user computing device, a location based on the third estimated location to indicate the location of the user computing device.

8. The computer program product of claim 7, wherein a size of the boundary is based on an estimated accuracy of the calculation based on the received signal strength, wherein a higher estimated accuracy correlates to a smaller bound area and a lower estimated accuracy correlates to a larger bound area.

9. The computer program product of claim 7, wherein:

computing a second estimated location of the user computing device based on an angle of arrival of the signal of the received wireless signal at each AP comprises;

dividing, by the wireless computing system, an area inside the boundary into a plurality of sections; and

determining, by the wireless computing system, a likelihood for each of the plurality of sections of being an actual location of the user computing device based on the angle of arrival of the signal of the received wireless signal at each AP; and

generating a final estimated location of the user computing device based the second estimated location comprises;

computing, by the wireless computing system, the third estimated location across a subset of the plurality of the sections, the subset comprising those sections characterized by a likelihood greater than or equal to the sections not in the subset.

10. The computer program product of claim 9, wherein those sections characterized by a likelihood greater than or equal to sections not in the subset are determined by ranking the sections by likelihood and choosing the N highest ranked sections, where N is a number between 1 and the (total number of sections−

1).

11. The computer program product of claim 9, wherein those sections characterized by a likelihood greater than or equal to sections not in the subset are those sections with a likelihood greater than a threshold.

12. The computer program product of claim 9, wherein the computation of the third estimated location is finer than the computation of the second estimated location.

13. A system, comprising:

a storage device; and

a processor communicatively coupled to the storage device, wherein the processor executes application code instructions that are stored in the storage device to cause the system to;

receive, by each of a plurality of wireless computing system access points (APs) of a wireless computing system, a wireless signal from a user computing device;

calculate, by the wireless computing system, a boundary encompassing a first estimated location of the user computing device based on a signal strength of the received wireless signal at each AP;

compute, by the wireless computing system, a second estimated location of the user computing device within the boundary based on an angle of arrival of the signal of the received wireless signal at each AP;

generate, by the wireless computing system, a third estimated location of the user computing device based the second estimated location; and

computer-executable program instructions to transmit, by the wireless computing system and to the user computing device, a location based on the third estimated location to indicate the location of the user computing device.

14. The system of claim 13, wherein a size of the boundary is based on an estimated accuracy of the calculation based on the received signal strength, wherein a higher estimated accuracy correlates to a smaller bound area and a lower estimated accuracy correlates to a larger bound area.

15. The system of claim 13, wherein:

computing a second estimated location of the user computing device based on an angle of arrival of the signal of the received wireless signal at each AP comprises;

dividing, by the wireless computing system, an area inside the boundary into a plurality of sections; and

determining, by the wireless computing system, a likelihood for each of the plurality of sections of being an actual location of the user computing device based on the angle of arrival of the signal of the received wireless signal at each AP; and

generating a final estimated location of the user computing device based the second estimated location comprises;

computing, by the wireless computing system, the third estimated location across a subset of the plurality of the sections, the subset comprising those sections characterized by a likelihood greater than or equal to the sections not in the subset.

16. The system of claim 15, wherein those sections characterized by a likelihood greater than or equal to sections not in the subset are determined by ranking the sections by likelihood and choosing the N highest ranked sections, where N is a number between 1 and the (total number of sections−

1).

17. The system duct of claim 15, wherein those sections characterized by a likelihood greater than or equal to sections not in the subset are those sections with a likelihood greater than a threshold.

18. The system of claim 15, wherein the computation of the third estimated location is finer than the computation of the second estimated location.