System and method of alerting users based on proximity

• US 8,441,367 B1
• Filed: 11/10/2010
• Issued: 05/14/2013
• Est. Priority Date: 11/10/2009
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Google Inc. (Alphabet Inc.)
• Inventors: Lambert, Chris, Seth, Rohan, Chu, Michael, Luo, Yuhua, Lee, Steven
• Primary Examiner(s): Tweel, Jr., John A
• Application Number:
  US12/943,340
• Time in Patent Office: 916 Days
• Field of Search: 340/686.6, 340/539.11, 340/539.13, 342/450, 342/457, 701/410, 701/491
• US Class Current: 340/686.6
• CPC Class Codes: G01S 19/42 Determining position
• CPC Class Codes: G08B 21/18 Status alarms G08B21/02 takes precedence

Abstract

An alert server is operative to notify users when they are in proximity within one another. The alert server may determine to alert a first user of the proximity of a second user when the second user is in an unusual location. The alert server may determine that the second user is in an unusual location when the second user is outside his or her routine geographic location. The alert server may determine whether the second user is outside his or her routine geographic location by assigning confidence values to geographic locations that the second user has previously visited. The alert sent to the first user may be in the form of a text message, e-mail, or other electronic communication. The first user may receive the alert on a mobile device, such as a cellphone, smartphone, netbook, or other mobile device.

Claims

1. An apparatus for alerting one or more users to the proximity of an unusually located user, the apparatus comprising:

a memory operative to store a geographic location history for a first user, the geographic location history comprising a plurality of geographic locations, wherein each geographic location is associated with at least one time segment; and

a processor in communication with the memory, the processor being operative to;

determine a confidence value for each of the geographic locations of the plurality of geographic locations stored in the memory, wherein each confidence value for each of the geographic locations represents the likelihood of the first user being at the corresponding geographic location;

receive a current geographic location of the first user;

retrieve a corresponding confidence value for the received current geographic location of the first user;

determine that the current geographic location of the user is unusual based on the comparison of the retrieved corresponding confidence value with a threshold confidence value; and

transmit an alert to a second user in proximity to the first user when the processor determines that the current geographic location of the first user is unusual.

2. The apparatus of claim 1, wherein each of the geographic locations of the plurality of geographic locations were geographic locations in which the first user was relatively stationary.

3. The apparatus of claim 1, wherein at least one of the geographic locations of the plurality of geographic locations is a geographic location where the first user spent a predetermined amount of time being relatively stationary.

4. The apparatus of claim 1, wherein:

the memory is further operative to organize the geographic location history according to at least one time-keyed table and at least one region-keyed table; and

the processor is further operative to retrieve the corresponding confidence value with reference to the at least one time-keyed table or the at least one region-keyed table.

5. The apparatus of claim 1, wherein:

the processor is further operative to distribute a selected one of the determined confidence values among a subset of the plurality of geographic locations when the processor determines that it is likely that the first user was at any one of the geographic locations of the subset of geographic locations.

6. The apparatus of claim 1, wherein the processor is further operative to determine that the current geographic location of the user is unusual when the retrieved corresponding confidence value is less than the threshold confidence value.

7. The apparatus of claim 1, wherein:

the processor is operative to determine a selected one of the confidence values based on whether the corresponding geographic location of the selected one of the confidence values was determined according to one of two transmission modes; and

the selected one of the confidence values is determined to be of a lesser value when the corresponding geographic location was determined based on the first transmission mode than where the corresponding geographic location was determined based on the second transmission mode.

8. The apparatus of claim 1, wherein the processor is further operative to determine that the first user is in proximity to the second user when the distance between the first user and the second user is less than a pre-defined threshold distance.

9. The apparatus of claim 8, wherein the processor is further operative to:

decrease the pre-defined threshold distance when the alert is transmitted to the second user; and

transmit another alert to the second user when proximity between the first user and the second user is less than the decreased pre-defined threshold distance.

10. The apparatus of claim 1, wherein the type of alert transmitted to the second user is based on how a geographic location of the second user is determined.

11. A method for alerting one or more users to the proximity of an unusually located user, the method comprising:

storing, in a memory, a geographic location history for a first user, the geographic location history comprising a plurality of geographic locations, wherein each geographic location is associated with at least one time segment;

determining, with a processor in communication with the memory, a confidence value for each of the geographic locations of the plurality of geographic locations stored in the memory, wherein each confidence value for each of the geographic locations represents the likelihood of the first user being at the corresponding geographic location;

receiving a current geographic location of the first user;

retrieving a corresponding confidence value for the received current geographic location of the first user;

determining that the current geographic location of the user is unusual based on the comparison of the retrieved corresponding confidence value with a threshold confidence value; and

transmitting an alert to a second user in proximity to the first user when the processor determines that the current geographic location of the first user is unusual.

12. The method of claim 11, wherein each of the geographic locations of the plurality of geographic locations were geographic locations in which the first user was relatively stationary.

13. The method of claim 11, wherein at least one of the geographic locations of the plurality of geographic locations is a geographic location where the first user spent a predetermined amount of time being relatively stationary.

14. The method of claim 11, further comprising:

organizing the geographic location history according to at least one time-keyed table and at least one region-keyed table; and

retrieving the corresponding confidence value with reference to the at least one time-keyed table or the at least one region-keyed table.

15. The method of claim 11, further comprising distributing a selected one of the determined confidence values among a subset of the plurality of geographic locations when the processor determines that it is likely that the first user was at any one of the geographic locations of the subset of geographic locations.

16. The method of claim 11, further comprising determining that the current geographic location of the user is unusual when the retrieved corresponding confidence value is less than the threshold confidence value.

17. The method of claim 11, further comprising determining a selected one of the confidence values based on whether the corresponding geographic location of the selected one of the confidence values was determined according to one of two transmission modes;

and

wherein the selected one of the confidence values is determined to be of a lesser value when the corresponding geographic location of the selected confidence value was determined based on the first transmission mode than where the corresponding geographic location of the selected confidence value was determined based on the second transmission mode.

18. The method of claim 11, further comprising determining that the first user is in proximity to the second user when the distance between the first user and the second user is less than a pre-defined threshold distance.

19. The method of claim 18, further comprising:

decreasing the pre-defined threshold distance when the alert is transmitted to the second user; and

transmitting another alert to the second user when proximity between the first user and the second user is less than the decreased pre-defined threshold distance.

20. The method of claim 11, wherein the type of alert transmitted to the second user is based on how a geographic location of the second user is determined.