Determining an estimated location of a base station

• US 9,357,521 B2
• Filed: 02/21/2014
• Issued: 05/31/2016
• Est. Priority Date: 02/27/2013
• Status: Active Grant

• Current Assignee: Marvell Asia Pte Limited (Marvell Technology Group Limited)
• Original Assignee: Marvell World Trade Limited (Marvell Technology Group Limited)
• Inventors: Liu, BoChih, Jia, Zhike, Yu, Jing, Chen, Jian
• Primary Examiner(s): Batista, Marcos
• Application Number:
  US14/186,909
• Publication Number:
  US 20140243013A1
• Time in Patent Office: 830 Days
• Field of Search: 4554561-4563, 370/338
• US Class Current: 1/1
• CPC Class Codes: G01S 5/0242 Determining the position of transmitters to be subsequently used in positioning G01S5/0289 takes precedence
• CPC Class Codes: G01S 5/0252 Radio frequency fingerprinting
• CPC Class Codes: G01S 5/0278 involving statistical or probabilistic considerations G01S5/0252, G01S5/0294 take precedence
• CPC Class Codes: H04W 64/003 locating network equipment

Abstract

In some implementations, a system for determining an estimated location of a base station includes a server that receives location information from mobile devices located within a communication range of base stations of a wireless communication network, processes the location information, and stores the location information in a data repository. The location information includes a location of a mobile device, the location associated with an identifier of a base station and a received signal strength indication between the mobile device and the base station. The server excludes at least one location of the mobile device from a set of locations of the mobile device using a previously determined coverage area length and a previously determined transmission signal range, and calculates a geographic location of each base station using non-excluded locations of the mobile device by accessing a base station information table using an identifier of each base station.

Claims

1. A method performed by a server system, the method comprising:

receiving a set of identifiers of base stations within a communication range of a mobile device, each identifier of the set of identifiers of the base stations associated with a set of locations of the mobile device, each location of the set of locations of the mobile device associated with a received signal strength indication from each of the base stations;

accessing a base station information table based on the set of identifiers, wherein the base station information table stores previously determined location data associated with each of the base stations, the previously determined location data associated with each of the base stations including an estimated geographic location of the base station, an uncertainty value of the estimated geographic location, a coverage area length of the base station, and a transmission signal range of the base station;

excluding at least one location of the mobile device from the set of locations using at least one of the previously determined coverage area length stored in the base station information table and at least one of the previously determined transmission signal range stored in the base station information table;

determining, by processing circuitry of the server system, updated location data of each of the base stations using non-excluded locations of the set of locations of the mobile device; and

updating the base station information table with the updated location data of each of the base stations.

2. The method of claim 1, wherein each of the base stations includes at least one of a cell tower, a WiFi access point, or a Bluetooth device.

3. The method of claim 1, wherein excluding the at least one location of the mobile device from the set of locations comprises excluding the at least one location of the mobile device based on the at least one location having a distance to a previously determined estimated geographic location that exceeds the at least one of the previously determined coverage area length.

4. The method of claim 1, wherein excluding the at least one location of the mobile device from the set of locations comprises excluding the at least one location of the mobile device based on the at least one location being associated with a received signal strength indication corresponding to a transmission signal range that exceeds the at least one of the previously determined transmission signal range.

5. The method of claim 1, wherein determining the updated location data of each of the base stations comprises:

calculating a first average geographic location using the non-excluded locations of the mobile device;

allocating the non-excluded locations of the mobile device to a subset of two or more subsets based on the first average geographic location;

for each of the two or more subsets, calculating a sum of closeness metrics associated with the non-excluded locations in the subset;

selecting a first subset from the two or more subsets based on the calculated sums for the two or more subsets;

calculating a second average geographic location using locations of the mobile device in the first subset;

allocating the locations of the mobile device in the first subset to a sub-subset of two or more sub-subsets based on the second average geographic location;

for each of the two or more sub-subsets, calculating a sum of closeness metrics associated with locations in the sub-subset;

selecting a second subset from the two or more sub-subsets based on the calculated sums for the two or more sub-subsets;

assigning a weight to each location of the mobile device in the second subset; and

calculating an updated estimated geographic location of the base station by averaging the weighted locations of the mobile device in the second subset.

6. The method of claim 5, wherein:

calculating the first average geographic location comprises;

calculating a first average latitude and a first average longitude based on latitudes and longitudes of the non-excluded locations, and

designating the first average latitude and the first average longitude as the first average geographic location; and

calculating the second average geographic location comprises;

calculating a second average latitude and a second average longitude based on latitudes and longitudes of the locations in the first subset, and

designating the second average latitude and the second average longitude as the second average geographic location.

7. The method of claim 6, wherein:

allocating the non-excluded locations of the mobile device is based on at least one of the first average latitude or the first average longitude; and

allocating the locations of the mobile device in the first subset is based on at least one of the second average latitude or the second average longitude.

8. The method of claim 5, wherein:

calculating the sum of closeness metrics associated with the non-excluded locations in the subset includes calculating a closeness metric for each of the non-excluded locations in the subset based on the received signal strength indication associated with the non-excluded location; and

calculating the sum of closeness metrics associated with the locations in the sub-subset includes calculating a closeness metric for each of the locations in the sub-subset based on the received signal strength indication associated with the location in the sub-subset.

9. The method of claim 8, wherein calculating a closeness metric for a location comprises assigning a larger closeness metric to the location for a high received signal strength indication relative to a low received signal strength indication.

10. The method of claim 5, wherein:

selecting the first subset includes selecting a subset from the two or more subsets having a largest of the calculated sums for the two or more subsets; and

selecting the second subset includes selecting a subset from the two or more sub-subsets having a largest of the calculated sums for the two or more sub-subsets.

11. The method of claim 5, wherein assigning the weight to each location of the mobile device in the second subset comprises assigning a larger weight to a location of the mobile device that is closer to the base station relative to a location of the mobile device that is farther from the base station.

12. The method of claim 5, wherein calculating the updated estimated geographic location of the base station comprises:

calculating an average of weighted latitudes and an average of weighted longitudes of the weighted locations; and

designating the calculated average of the weighted latitudes and the calculated average of the weighted longitudes as the updated estimated geographic location of the base station.

13. The method of claim 1, wherein determining the updated location data of each of the base stations comprises calculating an uncertainty value of an updated estimated geographic location of the base station including calculating 95% radius of the updated estimated geographic location of the base station using circular error probable (CEP) theory.

14. The method of claim 1, wherein determining the updated location data of each of the base stations comprises:

determining locations of the mobile device that are to be used to calculate an updated coverage area length based on a threshold percentage of locations of the set of locations of the mobile device;

designating four sets of coordinates as extreme points of an area that includes an updated estimated geographic location of the base station based on the locations of the mobile device that are to be used to calculate the updated coverage area length; and

calculating the updated coverage area length to be a length that corresponds to a longest distance between two of the extreme points.

15. The method of claim 1, wherein determining the updated location data of each of the base stations comprises:

determining received signal strength indications that are to be used to determine an updated transmission signal range based on a threshold percentage of received signal strength indications associated with the set of locations of the mobile device;

designating, as the updated transmission signal range, a value that corresponds to a minimum of the received signal strength indications.

16. A system, comprising:

a server system that includes processing circuitry configured to perform operations comprising;

receiving a set of identifiers of base stations within a communication range of a mobile device, each identifier of the set of identifiers of the base stations associated with a set of locations of the mobile device, each location of the set of locations of the mobile device associated with a received signal strength indication from each of the base stations;

accessing a base station information table based on the set of identifiers, wherein the base station information table stores previously determined location data associated with each of the base stations, the previously determined location data associated with each of the base stations including an estimated geographic location of the base station, an uncertainty value of the estimated geographic location, a coverage area length of the base station, and a transmission signal range of the base station;

excluding at least one location of the mobile device from the set of locations using at least one of the previously determined coverage area length stored in the base station information table and at least one of the previously determined transmission signal range stored in the base station information table;

determining updated location data of each of the base stations using non-excluded locations of the set of locations of the mobile device; and

updating the base station information table with the updated location data of each of the base stations.

17. The system of claim 16, wherein each of the base stations includes at least one of a cell tower, a WiFi access point, or a Bluetooth device.

18. The system of claim 16, wherein excluding the at least one location of the mobile device from the set of locations comprises excluding the at least one location of the mobile device based on the at least one location having a distance to a previously determined estimated geographic location that exceeds the at least one of the previously determined coverage area length.

19. The system of claim 16, wherein excluding the at least one location of the mobile device from the set of locations comprises excluding the at least one location of the mobile device based on the at least one location being associated with a received signal strength indication corresponding to a transmission signal range that exceeds the at least one of the previously determined transmission signal range.

20. The system of claim 16, wherein determining the updated location data of each of the base stations comprises:

calculating a first average geographic location using the non-excluded locations of the mobile device;

allocating the non-excluded locations of the mobile device to a subset of two or more subsets based on the first average geographic location;

for each of the two or more subsets, calculating a sum of closeness metrics associated with the non-excluded locations in the subset;

selecting a first subset from the two or more subsets based on the calculated sums for the two or more subsets;

calculating a second average geographic location using locations of the mobile device in the first subset;

allocating the locations of the mobile device in the first subset to a sub-subset of two or more sub-subsets based on the second average geographic location;

for each of the two or more sub-subsets, calculating a sum of closeness metrics associated with locations in the sub-subset;

selecting a second subset from the two or more sub-subsets based on the calculated sums for the two or more sub-subsets;

assigning a weight to each location of the mobile device in the second subset; and

calculating an updated estimated geographic location of the base station by averaging the weighted locations of the mobile device in the second subset.

21. The system of claim 20, wherein:

calculating the first average geographic location comprises;

calculating a first average latitude and a first average latitude based on latitudes and longitudes of the non-excluded locations, and

designating the first average latitude and the first average longitude as the first average geographic location; and

calculating the second average geographic location comprises;

calculating a second average latitude and a second average longitude based on latitudes and longitudes of the locations in the first subset; and

designating the second average latitude and the second average longitude as the second average geographic location.

22. The system of claim 21, wherein:

allocating the non-excluded locations of the mobile device is based on at least one of the first average latitude or the first average longitude; and

allocating the locations of the mobile device in the first subset is based on at least one of the second average latitude or the second average longitude.

23. The system of claim 20, wherein:

calculating the sum of closeness metrics associated with the non-excluded locations in the subset includes calculating a closeness metric for each of the non-excluded locations in the subset based on the received signal strength indication associated with the non-excluded location; and

calculating the sum of closeness metrics associated with the locations in the sub-subset includes calculating a closeness metric for each of the locations in the sub-subset based on the received signal strength indication associated with the location in the sub-subset.

24. The system of claim 23, wherein calculating a closeness metric for a location comprises assigning a larger closeness metric to the location a high received signal strength indication relative to a low received signal strength indication.

25. The system of claim 20, wherein:

selecting the first subset includes selecting a subset from the two or more subsets having a largest of the calculated sums for the two or more subsets; and

selecting the second subset includes selecting a subset from the two or more sub-subsets having a largest of the calculated sums for the two or more sub-subsets.

26. The system of claim 20, wherein assigning the weight to each location of the mobile device in the second subset comprises assigning a larger weight to a location of the mobile device that is closer to the base station relative to a location of the mobile device that is farther from the base station.

27. The system of claim 20, wherein calculating the updated estimated geographic location of the base station comprises:

calculating an average of weighted latitudes and an average of weighted longitudes of the weighted locations; and

designating the calculated average of the weighted latitudes and the calculated average of the weighted longitudes as the updated estimated geographic location of the base station.

28. The system of claim 16, wherein determining the updated location data of each of the base stations comprises calculating an uncertainty value of an updated estimated geographic location including calculating 95% radius of the updated estimated geographic location of the base station using circular error probable (CEP) theory.

29. The system of claim 16, wherein determining the updated location data of each of the base stations comprises:

determining locations of the mobile device that are to be used to calculate an updated coverage area length based on a threshold percentage of locations of the set of locations of the mobile device;

designating four sets of coordinates as extreme points of an area that includes an updated estimated geographic location of the base station based on the locations of the mobile device that are to be used to calculate the updated coverage area length; and

calculating the updated coverage area length be a length that corresponds to a longest distance between two of the extreme points.

30. The system of claim 16, wherein determining the updated location data of each of the base stations comprises:

determining received signal strength indications that are to be used to determine an updated transmission signal range based on a threshold percentage of received signal strength indications associated with the set of locations of the mobile device;

designating, as the updated transmission signal range, a value that corresponds to a minimum of the received signal strength indications.