Sensing and analysis of ambient contextual signals for discriminating between indoor and outdoor locations

• US 7,327,245 B2
• Filed: 11/22/2004
• Issued: 02/05/2008
• Est. Priority Date: 11/22/2004
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Horvitz, Eric J., Krumm, John C., Hariharan, Ramaswamy
• Primary Examiner(s): TRIEU, VAN THANH
• Application Number:
  US10/994,550
• Publication Number:
  US 20060167647A1
• Time in Patent Office: 1,170 Days
• Field of Search: 340/500, 340/501, 340/506, 340/517, 340/524, 340/539.13, 340/539.22, 340/539.28, 340/541, 340/686.1, 340/905, 455/41.2, 455/550.1, 455/567, 701/29, 715/716, 399/44, 399/45
• US Class Current: 340/501
• CPC Class Codes: G01W 1/17 Catathermometers for measuring "cooling value" related either to weather conditions or to comfort of other human environment
• CPC Class Codes: H04M 1/72454 according to context-related or environment-related conditions
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Methods and systems that determine automatically the likelihood that a device is inside or outside of a structure or building. The system uses one or more sensors to detect ambient conditions, and make the determination. The inference can be used to save power or suppress services from certain devices, which are irrelevant, cannot be used effectively, or do not function under certain circumstances. In support thereof, the system includes one or more context sensors that measure parameters associated probabilistically with the context of a device. A context computing component considers one or more context sensors and facilitates determination of ideal actions, policies, and situations associated with the device. A service provided by the subject invention is the inference from one or more available observations the probability that the device is inside versus outside.

Claims

1. A system that facilitates determination of a device context, comprising:

a context sensor that measures a parameter of a first context associated with a first ambient condition of a device; and

a context computing component that interfaces to the context sensor and facilitates determination of a change from the first context to a second context associated with a second ambient condition, comprising computing an inference that the device is inside or outside and turning off at least one component of the system, to facilitate saving power, based on the inference.

2. The system of claim 1, wherein the context sensor senses at least one of temperature, humidity, and pressure.

3. The system of claim 1, wherein the context sensor senses at least one of electromagnetic wave frequency and images.

4. The system of claim 1, wherein the context sensor includes a GPS (Global Positioning System) receiver that facilitates determining the first context of the device based on receiving a GPS signal.

5. The system of claim 1, wherein the context sensor includes a GPS receiver that facilitates determining speed of the device based on receiving GPS location signals from at least two locations.

6. The system of claim 1, wherein the context sensor is part of a sensing system that includes a GPS subsystem which is activated periodically to sense GPS signals.

7. The system of claim 6, wherein the absence of the GPS signals facilitates powering the GPS subsystem off.

8. The system of claim 6, wherein detection of the GPS signals indicates that the device is outside.

9. The system of claim 1, wherein the parameter measured by the context sensor powers on at least one of a GPS subsystem of the device and the device.

10. The system of claim 1, wherein the parameter indicates that a user of the device is available for interactive communications.

11. The system of claim 1, wherein data the represents the change from the first context to the second context is used to add metadata to a digital photograph.

12. The system of claim 11, wherein the metadata is used to filter the digital photograph from a plurality of photographs during a search process.

13. The system of claim 11, wherein the metadata includes information related to whether the photograph was taken indoors or outdoors.

14. A portable computing device that includes the system of claim 1.

15. The system of claim 1, fun her comprising an artificial intelligence component that employs a probabilistic and/or statistical-based analysis to prognose or infer an action that a user desires to be automatically performed.

16. A computer readable medium having stored thereon computer executable instructions for carrying out the system of claim 1.

17. A system that facilitates determination of a device context, comprising:

a context sensor system that measures at least one environmental parameter of a first context associated with a first environmental condition of a portable device; and

a context computing component that interfaces to the context sensor to compute a probability inference that the portable device changed from the first context to a second context associated with a second environmental condition and turns off at least one component of the system based on the inference.

18. The system of claim 17, wherein location information is entered one of manually and automatically to facilitate determination of the device context.

19. The system of claim 18, wherein the location information is a postal code that is manually entered.

20. The system of claim 18, wherein the location information is longitude/latitude data that is automatically accessed via a network, and entered.

21. The system of claim 17, wherein the context sensor system measures parameters that indicate at least one a change in light, change in motion, and change in radio frequency strength, in response to which a device system is power up or down.

22. The system of claim 17, wherein the context sensor system measures parameters that indicate at least one a change in light, change in motion, and change in radio frequency strength, in response to which a device subsystem is power up or down.

23. A system that facilitates determination of a device context, comprising:

a temperature sensor employed in a portable computing device to measure temperature; and

a context computing component of the portable computing device that interfaces to the temperature sensor to compute a probability inference that a location of the portable device has changed and changing a power-saving policy of at least one component of the system based on the inference.

24. The system of claim 23, wherein the probability inference is determined from at least one of a measured ambient temperature, and expected temperature inside a structure, and a temperature outside the structure derived from interpolation.

25. The system of claim 24, wherein the expected inside temperature is derived from a Gaussian distribution.

26. The system of claim 24, wherein the temperature outside the structure is derived by accessing longitude/latitude data.

27. The system of claim 23, wherein the probability inference is derived based upon a measured ambient temperature and an interpolated outside temperature.

28. A computer readable medium having computer computer-executable instructions for performing a method of determining context of a portable computing device, comprising:

measuring a first parameter of a first context associated with a first ambient condition of the portable computing device;

determining a second parameter of a second context associated with a second ambient condition of the portable computing device;

computing a probability inference based on the first and second parameters that the portable computing device moved from the first context to the second context; and

changing a power-saving policy of at least one component of the system based on the probability inference.

29. The method of claim 28, wherein the first context is outside of a building or structure and the second context is inside of the building or structure.

30. The method of claim 28, wherein the first parameter is associated with latitude data and longitude data.

31. The method of claim 28, further comprising accessing GPS information to derive the probability inference.

32. The method of claim 28, further comprising accessing weather information to derive the probability inference.

33. A method of determining context of a portable computing device, comprising:

determining a probability distribution of a first temperature of a first context of the portable computing device;

measuring a second temperature of a second context of the portable computing device;

computing a probability inference based on the first and second temperatures that the portable computing device moved from the first context to the second context; and

changing a power-saving policy of at least one component of the system based on the inference.

34. The method of claim 33, wherein the first temperature is determined outside of a structure by accessing weather information associated with a geographic location of the first context.

35. The method of claim 33, wherein the first temperature is determined outside of a structure by interpolating weather information obtained by accessing weather stations.

36. The method of claim 33, further comprising deriving a probability distribution for an expected third temperature of the second context.