UTILIZING MOTION DETECTION IN ESTIMATING VARIABILITY OF POSITIONING RELATED METRICS

• US 20160219550A1
• Filed: 04/07/2016
• Published: 07/28/2016
• Est. Priority Date: 06/26/2013
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Palanki, Ravi
• Granted Patent: US 9,686,768 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01S 5/0278 involving statistical or probabilistic considerations G01S5/0252, G01S5/0294 take precedence
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location
• CPC Class Codes: H04W 4/027 using movement velocity, acceleration information
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

Systems, apparatus and methods disclosed herein utilize motion detection to estimate variability of positioning related metrics. In some embodiments, a method may comprise obtaining the speeds of a plurality of mobile stations in a set of mobile stations connected to an AP in a wireless network. The frequency of Round Trip Time (RTT) measurements between a mobile station in the plurality of mobile stations and the AP is increased during periods when the speed of the mobile station does not exceed a threshold. An estimate of variability may be obtained for RTT measurements for the AP.

Claims

1. A processor-implemented method comprising:

determining a motion associated with a Mobile Station (MS) in communication with an Access Point (AP) in a wireless network; and

in response to a determination that the motion associated with the MS does not exceed a threshold, initiating an increase in a frequency of Round Trip Time (RTT) measurements between the MS and the AP.

2. The processor-implemented method of claim 1, further comprising:

in response to the determination that the motion associated with the MS does not exceed the threshold, obtaining a plurality of RTT measurements between the MS and the AP.

3. The processor-implemented method of claim 2, further comprising:

determining an RTT variability associated with the plurality of RTT measurements.

4. The processor-implemented method of claim 3, wherein the RTT variability is computed as at least one of:

a standard deviation of the plurality of RTT measurements, or

an average absolute deviation of the plurality of RTT measurements, or

a median absolute deviation of the plurality of RTT measurements.

5. The processor-implemented method of claim 2, further comprising:

normalizing the plurality of RTT measurements to derive a corresponding plurality of normalized RTT measurements.

6. The processor-implemented method of claim 5, further comprising:

determining an RTT variability associated with the plurality of normalized RTT measurements;

aggregating the plurality of normalized RTT measurements with previously stored normalized RTT measurements associated with the AP; and

determining an RTT variability for RTT measurements associated with the AP based on the aggregated normalized RTT measurements.

7. The processor-implemented method of claim 1, wherein the increase in the frequency of RTT measurements between the MS and the AP is relative to a period during which the motion of the MS exceeds the threshold.

8. The processor-implemented method of claim 1, wherein the threshold is zero.

9. The processor-implemented method of claim 1, wherein the motion of the MS is obtained based on measurements by an Inertial Management Unit (IMU) on the MS.

10. The processor-implemented method of claim 1, wherein initiating the increase in the frequency of RTT measurements between the MS and the AP comprises:

determining that a Received Signal Strength Indicator (RSSI) value associated with the AP and measured at the at least one MS is not less than a desired RSSI level; and

in response to the determination that the RSSI value is not less than the desired RSSI level, initiating the increase in the frequency of RTT measurements between the MS and the AP.

11. The processor-implemented method of claim 1, wherein the method is performed by one of:

the MS;

or

the AP;

or

a server communicatively coupled to the AP;

or a combination thereof.

12. An apparatus comprising:

a memory, and

a processor coupled to the memory, wherein the processor is configured to;

determine a motion associated with a Mobile Station (MS) in communication with an Access Point (AP) in a wireless network; and

in response to a determination that the motion associated with the MS does not exceed a threshold, initiate an increase in a frequency of Round Trip Time (RTT) measurements between the MS and the AP.

13. The apparatus of claim 12, wherein, in response to the determination that the motion associated with the MS does not exceed the threshold, the processor is further configured to:

obtain a plurality of RTT measurements between the MS and the AP.

14. The apparatus of claim 13, wherein the processor is further configured to determine an RTT variability associated with the plurality of RTT measurements.

15. The apparatus of claim 14, wherein the processor is configured to determine the RTT variability based on at least one of:

a standard deviation of the plurality of RTT measurements, or

an average absolute deviation of the plurality of RTT measurements, or

a median absolute deviation of the plurality of RTT measurements.

16. The apparatus of claim 13, wherein the processor is further configured to:

normalize the plurality of RTT measurements to derive a corresponding plurality of normalized RTT measurements.

17. The apparatus of claim 16, wherein:

the memory is configured to store a plurality of prior normalized RTT measurements associated with the AP; and

the processor is further configured to;

determine an RTT variability associated with the plurality of normalized RTT measurements;

aggregate the plurality of normalized RTT measurements with the stored prior normalized RTT measurements associated with the AP; and

determine an RTT variability for RTT measurements associated with the AP based on the aggregated normalized RTT measurements.

18. The apparatus of claim 12, wherein the increase in the frequency of RTT measurements between the MS and the AP is relative to a period when the motion of the MS exceeds the threshold.

19. The apparatus of claim 12, wherein the threshold is zero.

20. The apparatus of claim 12, wherein to initiate the increase in frequency of RTT measurements between the MS and the AP, the processor is configured to:

determine that a Received Signal Strength Indicator (RSSI) value associated with the AP and measured at the at least one MS is not less than a desired RSSI level; and

in response to the determination that the RSSI value is not less than the desired RSSI level, initiate the increase in the frequency of RTT measurements between the MS and the AP.

21. An apparatus comprising:

means for determining a motion associated with a Mobile Station (MS) in communication with an Access Point (AP) in a wireless network; and

in response to a determination that the motion associated with the MS does not exceed a threshold, means for initiating an increase in a frequency of Round Trip Time (RTT) measurements between the MS and the AP.

22. The apparatus of claim 21, further comprising:

in response to the determination that the motion associated with the MS does not exceed the threshold, means for obtaining a plurality of RTT measurements between the MS and the AP.

23. The apparatus of claim 22, further comprising:

means for determining an RTT variability associated with the plurality of RTT measurements.

24. The apparatus of claim 23, wherein the RTT variability is determined as at least one of:

a standard deviation of the plurality of RTT measurements, or

an average absolute deviation of the plurality of RTT measurements, or

a median absolute deviation of the plurality of RTT measurements.

25. The apparatus of claim 21, wherein the increase in the frequency of RTT measurements between the MS and the AP is relative to a period when the motion of the MS exceeds the threshold.

26. A non-transitory computer-readable medium comprising instructions executable by a processor to:

determine a motion associated with a Mobile Station (MS) in communication with an Access Point (AP) in a wireless network; and

in response to a determination that the motion associated with the MS does not exceed a threshold, initiate an increase in a frequency of Round Trip Time (RTT) measurements between the MS and the AP.

27. The computer-readable medium of claim 26, further comprising instructions executable by the processor to:

in response to the determination that the motion associated with the MS does not exceed the threshold, obtain a plurality of RTT measurements between the MS and the AP.

28. The computer-readable medium of claim 27, further comprising instructions executable by the processor to:

determine an RTT variability associated with the plurality of RTT measurements.

29. The computer-readable medium of claim 28, wherein the RTT variability is computed as at least one of:

a standard deviation of the plurality of RTT measurements, or

an average absolute deviation of the plurality of RTT measurements, or

a median absolute deviation of the plurality of RTT measurements.

30. The computer-readable medium of claim 26, wherein the threshold is zero.