Indoor location signalling via light fittings

1. A method of determining a location of a mobile device comprising:

accessing location information, the location information identifying a plurality of indoor coordinates and, for each indoor coordinate, an intensity of light expected to be detected by the mobile device at the indoor coordinate from a first light source and an intensity of light expected to be detected by the mobile device at the indoor coordinate from a second light source, each light source being (a) configured to provide illumination of an indoor space, (b) identifiable by emitting a unique light attribute in conjunction with the illumination, and (c) disposed at a distance from the plurality of indoor coordinates such that the intensity of light expected to be detected at each indoor coordinate is less than the intensity of light at the light source and progressively decreases as the distance from the light source increases;

identifying, by one or more processors and based on light information detected by the mobile device, the first light source based on a first light attribute emitted by the first light source and a second light attribute emitted by the second light source, the first light attribute being different from the second light attribute;

detecting, with the mobile device and by the one or more processors, the intensity of light received at the mobile device from the first light source and the intensity of light received at the mobile device from the second light source; and

determining the location of the mobile device based on a comparison, by the one or more processors, of the intensity of light from the first and second light sources detected by the mobile device with the intensity of light from the first and second light sources that is expected to be detected at one or more of the plurality of indoor coordinates.

2. The method of claim 1 , wherein the unique light attribute comprises light emission frequency.

3. The method of claim 2 , wherein the unique light attribute comprises ultraviolet light and the first light source emits ultraviolet light at a different frequency than the second light source.

4. The method of claim 1 , wherein determining the location of the mobile device further comprises determining a location associated with the first light source and a location associated with the second light source, and triangulating the location associated with the first light source and the location associated with the second light source the second light source.

5. The method of claim 1 , wherein the unique light attribute is not perceivable by a user's naked eye.

6. The method of claim 1 , wherein the unique light attribute comprises flicker frequency.

7. The method of claim 1 , wherein determining the location of the mobile device further comprises selecting one of the indoor coordinates identified by the location information as the location of the mobile device.

8. The method of claim 7 , wherein the selected indoor coordinate is the indoor coordinate whose associated intensity of light expected to be detected from the first and second light sources closely matches the intensity of light detected by the mobile device from the first and second light sources, respectively.

9. A system for determining a location of a mobile device comprising:

a storage device storing location information, the location information identifying a plurality of indoor coordinates and, for each indoor coordinate, an intensity of light expected to be detected by the mobile device at the indoor coordinate from a first light source and an intensity of light expected to be detected by the mobile device at the indoor coordinate from a second light source, each light source being (a) configured to provide illumination of an indoor space, (b) identifiable by emitting a unique light attribute in conjunction with the illumination, and (c) disposed at a distance from the plurality of indoor coordinates such that the intensity of light expected to be detected at each indoor coordinate is less than the intensity of light at the light source and progressively decreases as the distance from the light source increases; and

one or more processors in communication with the storage device configured to:

identify based on light information detected by the mobile device, the first light source based on a first light attribute emitted by the first light source and a second light attribute emitted by the second light source, the first light attribute being different from the second light attribute;

detect, with the mobile device, the intensity of light received at the mobile device from the first light source and the intensity of light received at the mobile device from the second light source; and

determine the location of the mobile device based on a comparison of the intensity of light from the first and light sources detected by the mobile device with the intensity of light from the first and second light sources that is expected to be detected at one or more of the plurality of indoor coordinates.

10. The system of claim 9 , wherein the unique light attribute comprises light emission frequency.

11. The system of claim 10 , wherein the unique light attribute comprises ultraviolet light and the first light source emits ultraviolet light at a different frequency than the second light source.

12. The system of claim 11 , wherein determining the location of the mobile device further comprises selecting one of the locations identified by the location information as the location of the mobile device.

13. The system of claim 12 , wherein the selected indoor coordinate is the indoor coordinate whose associated intensity of light expected to be detected from the first and second light sources closely matches the intensity of light detected by the mobile device from the first and second light sources, respectively.

14. The system of claim 9 , wherein the location of the mobile device is further determined by determining a location associated with the first light source and a location associated with the second light source and triangulating the determined location associated with the first light source and the location associated with the second light source.

15. The system of claim 9 , wherein the unique light attribute is not perceivable by a user's naked eye.

16. The system of claim 9 , wherein the unique light attribute comprises flicker frequency.

17. A non-transitory computing-device readable storage medium on which processor-readable instructions of a program are stored, the instructions, when executed by one or more processor, causing the one or more processor to perform a method, the method comprising:

accessing location information, the location information identifying a plurality of indoor coordinates and, for each indoor coordinate, an intensity of light expected to be detected by a mobile device at the indoor coordinate from a first light source and an intensity of light expected to be detected by the mobile device at the indoor coordinate from a second light source, each light source being (a) configured to provide illumination of an indoor space, (b) identifiable by emitting a unique light attribute in conjunction with the illumination, and (c) disposed at a distance from the plurality of indoor coordinates such that the intensity of light expected to be detected at each indoor coordinate is less than the intensity of light at the light source and progressively decreases as the distance from the light source increases;

identifying, by one or more processors and based on light information detected by the mobile device, the first light source based on a first light attribute emitted by the first light source and a second light attribute emitted by the second light source, the first light attribute being different from the second light attribute;

detecting, with the mobile device and by the one or more processors, the intensity of light received at the mobile device from the first light source and the intensity of light received at the mobile device from the second light source; and

determining the location of the mobile device based on a comparison, by the one or more processors, of the intensity of light from the first and light sources detected by the mobile device with the intensity of light from the first and second light sources that is expected to be detected at one or more of the plurality of indoor coordinates.

18. The medium of claim 17 , wherein the unique light attribute is not perceivable by a user's naked eye.

19. The medium of claim 17 , wherein determining the location of the mobile device further comprises selecting one of the indoor coordinates identified by the location information as the location of the mobile device.