Mechanism to reduce missing breach detection in geofencing solution

• US 9,219,983 B2
• Filed: 12/20/2012
• Issued: 12/22/2015
• Est. Priority Date: 05/01/2012
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Sheshadri, Suhas H., Srivastava, Aditya N.
• Primary Examiner(s): Appiah, Charles
• Assistant Examiner(s): Peaches, Randy
• Application Number:
  US13/722,705
• Publication Number:
  US 20130295969A1
• Time in Patent Office: 1,097 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G01S 19/25 involving aiding data received from a cooperating element, e.g. assisted GPS
• CPC Class Codes: G01S 19/34 Power consumption
• CPC Class Codes: G01S 19/52 Determining velocity
• CPC Class Codes: H04W 4/021 Services related to particular areas, e.g. point of interest [POI] services, venue services or geofences

Abstract

A system and method for a mobile device to efficiently use a geofence capability without draining its battery, and to allow flexibility in specifying various parameters related to geofencing, such as the latency and confidence in determining when or where a geofence breach occurs, and reducing the probability of not detecting a geofence breach.

Claims

1. A mobile device comprising a processor, the processor including a memory to store instructions that, when executed on the processor, cause the processor to perform a procedure comprising:

setting a location update time interval for the mobile device to an initial value;

updating the location of the mobile device according to the location update time interval;

generating a set of weights based upon a set of estimates of a velocity component of the mobile device toward a geofence, wherein the set of weights comprises higher weights for more recent estimates of the velocity component among the set of estimates and for larger magnitude estimates of the velocity component among the set of estimates;

generating a predicted velocity component based on applying the set of weights to the set of estimates of the velocity component;

generating a predicted time interval based on the predicted velocity component and a distance of the mobile device to the geofence; and

setting the location update time interval to the predicted time interval if the predicted time interval is less than the initial value.

2. The mobile device of claim 1, the procedure further comprising;

setting the location update time interval to the initial value if a set of exit criteria is met.

3. The mobile device of claim 2, wherein the set of exit criteria is met if the mobile device is detected to be moving away from the geofence.

4. The mobile device of claim 2, wherein the set of exit criteria is met if the mobile device has not entered the geofence for some specified time T since setting the location update time interval equal to the predicted time interval.

5. The mobile device of claim 1, wherein the set of weights, denoted by W_i where i=1, 2, . . . , N and N denotes a number of estimates of the velocity component towards the geofence, the procedure further comprising:

evaluating W_i=(V_i+W_C)/L_i, where V_i denotes a measurement of the velocity component toward the geofence at time instant t_i, W_C is a constant weight, and L_i=t−

t_i, where t is a present time for which the weight W_i is being calculated.

6. The mobile device of claim 5, the predicted velocity component towards the geofence at time t denoted as V_P (t), the procedure further comprising:

evaluating V_P(t)=(Σ

V_iW_i)/Σ

W_i, where the summation is over i=1, 2, . . . , N.

7. The mobile device of claim 6, wherein the geofence has a boundary and the predicted time interval at time t is denoted as T_P (t), the procedure further comprising:

evaluating T_P (t)=(D_B (t)−

X_C)/V_P (t), where D_B(t) denotes the distance of the mobile device to the geofence at time t, and where X_C denotes the distance before the geofence for which it is desired to attempt a location fix.

8. The mobile device of claim 1, wherein the processor is an application processor.

9. The mobile device of claim 1, wherein the processor is a modem.

10. A method to adjust a location update time interval of a mobile device, the method comprising:

providing a geofence client to a processor in the mobile device, wherein the geofence client specifies a geofence and a set of parameters;

determining a location calculation interval based on the geofence and the set of parameters;

setting the location update time interval to the location calculation interval;

generating a set of weights based upon a set of estimates of a velocity component of the mobile device toward the geofence, wherein the set of weights comprises higher weights for more recent estimates of the velocity component among the set of estimates and for larger magnitude estimates of the velocity component among the set of estimates;

generating a predicted velocity component based on applying the set of weights to the set of estimates of the velocity component;

generating a predicted time interval based on the predicted velocity component and a distance of the mobile device to the geofence; and

setting the location update time interval to the predicted time interval if the predicted time interval is less than the location calculation interval.

11. The method of claim 10, further comprising:

setting the location update time interval to the location calculation interval if a set of exit criteria is met.

12. The method of claim 11, wherein the set of exit criteria is met if the mobile device is detected to be moving away from the geofence.

13. The method of claim 11, wherein the set of exit criteria is met if the mobile device has not entered the geofence for some specified time T since setting the location update time interval equal to the predicted time interval.

14. The method of claim 10, the set of parameters comprising a geofence breach latency.

15. The method of claim 10, the set of parameters comprising a breach confidence.

16. The method of claim 10, wherein the set of weights, denoted by W_i where i=1, 2, . . . , N and N denotes a number of estimates of the velocity component towards the geofence, the method further comprising:

evaluating W_i=(V_i+W_C)/L_i, where V_i denotes a measurement of the velocity component toward the geofence at time instant t_i, W_C is a constant weight, and L_i=t−

t_i, where t is a present time for which the weight W_i is being calculated.

17. The method of claim 16, the predicted velocity component towards the geofence at time t denoted as V_P (t), the method further comprising:

evaluating V_P (t)=(Σ

V_iW_i)/Σ

W_i, where the summation is over i=1, 2, . . . , N.

18. The method of claim 17, wherein the geofence has a boundary and the predicted time interval at time t is denoted as T_P (t), the method further comprising:

evaluating T_P (t)=(D_B (t)−

X_C)/V_P (t), where D_B(t) denotes the distance of the mobile device to the geofence at time t, and where X_C denotes the distance before the geofence for which it is desired to attempt a location fix.

19. The method of claim 10, wherein the processor is an application processor.

20. The method of claim 10, wherein the processor is a modem.

21. A non-transitory computer readable storage medium having stored instructions, the stored instructions when executed by a processor of a mobile device to perform a procedure to adjust a location update time interval of the mobile device, the procedure comprising:

providing a geofence client to a processor in the mobile device, wherein the geofence client specifies a geofence and a set of parameters;

determining a location calculation interval based on the geofence and the set of parameters;

setting the location update time interval to the location calculation interval;

generating a set of weights based upon a set of estimates of a velocity component of the mobile device toward the geofence, wherein the set of weights comprises higher weights for more recent estimates of the velocity component among the set of estimates and for larger magnitude estimates of the velocity component among the set of estimates;

generating a predicted velocity component based on applying the set of weights to the set of estimates of the velocity component;

generating a predicted time interval based on the predicted velocity component and a distance of the mobile device to the geofence; and

setting the location update time interval to the predicted time interval if the predicted time interval is less than the location calculation interval.

22. The non-transitory computer readable storage medium of claim 21, the procedure further comprising:

setting the location update time interval to an initial value if a set of exit criteria is met.

23. The non-transitory computer readable storage medium of claim 22, wherein the set of exit criteria is met if the mobile device is detected to be moving away from the geofence.

24. The non-transitory computer readable storage medium of claim 22, wherein the set of exit criteria is met if the mobile device has not entered the geofence for some specified time T since setting the location update time interval equal to the predicted time interval.

25. The non-transitory computer readable storage medium of claim 21, the set of parameters comprising a geofence breach latency.

26. The non-transitory computer readable storage medium of claim 21, the set of parameters comprising a breach confidence.

27. The non-transitory computer readable storage medium of claim 21, wherein the set of weights, denoted by W_i where i=1, 2, . . . , N and N denotes a number of estimates of the velocity component towards the geofence, the procedure further comprising:

evaluating W_i=(V_i+W_C)/L_i, where V_i denotes a measurement of the velocity component toward the geofence at time instant t_i, W_C is a constant weight, and L_i=t−

t_i, where t is a present time for which the weight W_i is being calculated.

28. The non-transitory computer readable storage medium of claim 27, the predicted velocity component towards the geofence at time t denoted as V_P (t), the procedure further comprising:

evaluating V_P (t)=(Σ

V_iW_i)/Σ

W_i, where the summation is over i=1, 2, . . . , N.

29. The non-transitory computer readable storage medium of claim 28, wherein the geofence has a boundary and the predicted time interval at time t is denoted as T_P (t), the procedure further comprising:

evaluating T_P (t)=(D_B (t)−

X_C)/V_P (t), where D_B(t) denotes the distance of the mobile device to the geofence at time t, and where X_C denotes the distance before the geofence for which it is desired to attempt a location fix.

30. The non-transitory computer readable storage medium of claim 21, wherein the processor is an application processor.

31. The non-transitory computer readable storage medium of claim 21, wherein the processor is a modem.

32. A mobile device comprising a processor, and a memory to store instructions that, when executed on the processor, cause the processor to perform a procedure comprising:

means for setting a location update time interval for the mobile device to an initial value;

means for updating the location of the mobile device according to the location update time interval;

means for generating a set of weights based upon a set of estimates of a velocity component of the mobile device toward a geofence, wherein the set of weights comprises higher weights for more recent estimates of the velocity component among the set of estimates and for larger magnitude estimates of the velocity component among the set of estimates;

means for generating a predicted velocity component based on applying the set of weights to the set of estimates of the velocity component;

means for generating a predicted time interval based on the predicted velocity component and a distance of the mobile device to the geofence; and

means for setting the location update time interval to the predicted time interval if the predicted time interval is less than the location update time interval.

33. The mobile device of claim 32, the procedure further comprising:

means for setting the location update time interval to the initial value if a set of exit criteria is met.

34. The mobile device of claim 33, wherein the set of exit criteria is met if the mobile device is detected to be moving away from the geofence.

35. The mobile device of claim 33, wherein the set of exit criteria is met if the mobile device has not entered the geofence for some specified time T since setting the location update time interval equal to the predicted time interval.

36. The mobile device of claim 32, wherein the set of weights, denoted by W_i where i=1, 2, . . . , N and N denotes a number of estimates of the velocity component towards the geofence, the procedure further comprising:

means for evaluating W_i=(V_i+/L_i, where V_i denotes a measurement of the velocity component toward the geofence at time instant t_i, W_C is a constant weight, and L_i=t−

t_i, where t is a present time for which the weight W_i is being calculated.

37. The mobile device of claim 36, the predicted velocity component towards the geofence at time t denoted as V_P (t), the procedure further comprising:

means for evaluating V_P (t)=(Σ

V_iW_i)/Σ

W_i, where the summation is over i=1, 2, . . . , N.

38. The mobile device of claim 37, wherein the geofence has a boundary and the predicted time interval at time t is denoted as T_P (t), the procedure further comprising:

means for evaluating T_P (t)=(D_B (t)−

X_C)/V_P (t), where D_B(t) denotes the distance of the mobile device to the geofence at time t, and where X_C denotes the distance before the geofence for which it is desired to attempt a location fix.

39. The mobile device of claim 32, wherein the processor is an application processor.

40. The mobile device of claim 32, wherein the processor is a modem.