System and method for detecting proximity between mobile device users

• US 20040198398A1
• Filed: 04/01/2003
• Published: 10/07/2004
• Est. Priority Date: 04/01/2003
• Status: Active Grant

• Current Assignee: Toronto-Dominion Bank
• Original Assignee: International Business Machines Corporation
• Inventors: Amir, Arnon, Efrat, Alon
• Granted Patent: US 7,289,814 B2
• Time in Patent Office: Days
• US Class Current: 455/456.6
• CPC Class Codes: H04W 4/02 Services making use of location information
• CPC Class Codes: H04W 4/029 Location-based management or tracking services
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management
• CPC Class Codes: H04W 84/04 Large scale networks; Deep hierarchical networks

Abstract

A system and method are provided to alert two mobile communications users in the event they come in close proximity to one another. The present system uses a distributed algorithm denoted as the Strips algorithm, in which a pair of moving friends with mobile telecommunications devices makes an agreement about a static buffering region between them. After the agreement is made, the users do not need to follow each other'"'"'s location until one of them enters the buffering region for the first time. By doing so, they invalidate the agreement. Consequently, they replace a location update message between them, determine if they got within the vicinity of each other, and otherwise make a new agreement on a new buffering region. When one of them enters the buffering region for the first time, a message is sent to both friends alerting them of the proximity of the other.

Claims

1. A method for detecting proximity between at least a first mobile device and a second mobile device, comprising:

determining a position of the first and second mobile devices;

automatically notifying any of the first mobile device or the second mobile device in response to a relative position between the first and the second mobile devices;

defining the relative position by a space that is partitioned into a first region, a second region, and a third region;

defining the first region relative to the first mobile device;

defining the second region relative to the second mobile device;

wherein the third region forms a boundary region between the first region and the second region; and

wherein automatically notifying occurs if;

at least any of the first and second mobile devices enters the third region; and

the relative position is determined to be less than a predetermined value.

2. The method of claim 1, wherein the first and second mobile devices comprise handheld telecommunication devices.

3. The method of claim 1, wherein automatic notification is implemented by a central communications authority.

4. The method of claim 1, wherein automatic notification is implemented by any one of the first mobile device or the second mobile device.

5. The method of claim 1, further comprising determining whether any one of the first or the second mobile device is moving.

6. The method of claim 5, wherein the location of the first mobile device is fixed.

7. The method of claim 6, wherein the relative position is determined to be less than the predetermined value if the second mobile device has crossed the third region.

8. The method of claim 1, further comprising determining if the first mobile device has received a location notification from the second mobile device.

9. The method of claim 8, further comprising checking the relative position of the first mobile device with associated mobile devices.

10. The method of claim 9, further comprising transmitting the location of the first mobile device to the associated mobile devices.

11. The method of claim 1, further comprising sending an alert message from the first mobile device to the second mobile device;

wherein the second mobile device temporarily blocks the alert message; and

if desired, selectively delaying a retrieval of the alert message by the second mobile device, or deleting the alert message.

12. The method of claim 9, comprising comparing the distance between the first mobile device and the second mobile device to the predetermined value.

13. The method of claim 12, further comprising sending an alert message from the first mobile device to the second mobile device if the distance is less than the predetermined value.

14. The method of claim 1, further comprising setting data structure and boundary definitions relating to the second mobile device.

15. The method of claim 14, further comprising updating the data structure and boundary definitions for the second mobile device if a distance between the first mobile device and the second mobile device is greater than the predetermined value.

16. The method of claim 1, wherein each of the first and second regions is divided into a plurality of regions.

17. The method of claim 1, further comprising determining if any of the first region or the second region contains a user.

18. The method of claim 17, wherein any one of the first region or the second region is divided into a plurality of regions if it contains at least one user.

19. The method of claim 18, wherein none of the first and second regions is divided into regions if it does not contain a user.

20. The method of claim 1, further comprising registering any of the first mobile device or the second mobile device upon initialization.

21. A computer program product having instruction codes for detecting proximity between at least a first mobile device and a second mobile device, comprising:

a first set of instruction codes for determining a position of the first and second mobile devices;

a second set of instruction codes for automatically notifying any of the first mobile device or the second mobile device in response to a relative position between the first and the second mobile devices;

a third set of instruction codes for defining the relative position by a space that is partitioned into a first region, a second region, and a third region;

wherein the third set of instruction codes further defines the first region relative to the first mobile device;

wherein the third set of instruction codes further defines the second region relative to the second mobile device;

wherein the third region further forms a boundary region between the first region and the second region; and

wherein the second set of instruction codes automatically notifies any of the first mobile device or the second mobile device, if;

at least any of the first and second mobile devices enters the third region; and

the relative position is determined to be less than a predetermined value.

22. The computer program product of claim 21, wherein the first and second mobile devices comprise handheld telecommunication devices.

23. The computer program product of claim 21, wherein the second set of instruction codes is executed by a central communications authority.

24. The computer program product of claim 21, wherein the second set of instruction codes is executed by any one of the first mobile device or the second mobile device.

25. The computer program product of claim 21, further comprising a fourth set of instruction codes for determining whether any one of the first or the second mobile device is moving.

26. The computer program product of claim 25, wherein the location of the first mobile device is fixed.

27. The computer program product of claim 26, wherein the relative position is determined to be less than the predetermined value if the second mobile device has crossed the third region.

28. The computer program product of claim 21, further comprising a fifth set of instruction codes for determining if the first mobile device has received a notification from a second mobile device.

29. The computer program product of claim 28, further comprising a sixth set of instruction codes for checking the relative position for each second mobile device.

30. The computer program product of claim 29, further comprising a seventh set of instruction codes for transmitting the location of the first mobile device to the second mobile device.

31. A system for detecting proximity between at least a first mobile device and a second mobile device, comprising:

means for determining a position of the first and second mobile devices;

means for automatically notifying any of the first mobile device or the second mobile device in response to a relative position between the first and the second mobile devices;

means for defining the relative position by a space that is partitioned into a first region, a second region, and a third region;

wherein the means for defining the relative position defines the first region relative to the first mobile device, and further defines the second region relative to the second mobile device;

wherein the third region forms a boundary region between the first region and the second region; and

wherein the means for automatically notifying, provides notification to any of the first mobile device or the second mobile device, if;

at least any of the first and second mobile devices enters the third region; and

the relative position is determined to be less than a predetermined value.

32. The system of claim 31, wherein the first and second mobile devices comprise handheld telecommunication devices.

33. The system of claim 31, wherein the means for automatically notifying comprises a central communications authority.

34. The system of claim 31, wherein the notification is implemented by any one of the first mobile device or the second mobile device.

35. The system of claim 31, further comprising means for determining whether any one of the first or the second mobile device is moving.

36. The system of claim 35, wherein the location of the first mobile device is fixed.

37. The system of claim 36, wherein the relative position is determined to be less than the predetermined value if the second mobile device has crossed the third region.

38. The system of claim 31, further comprising means for determining if the first mobile device has received a notification from a friend.

39. The system of claim 38, further comprising means for checking the relative position for each friend of the first mobile devices until all known friends are checked.

40. The system of claim 39, further comprising means for transmitting the location of the first mobile device to the second mobile device.

41. A method for detecting proximity between at least a first mobile device and a second mobile device, comprising:

determining a position of the first and second mobile devices;

automatically notifying any of the first mobile device or the second mobile device in response to a relative position between the first and the second mobile devices;

defining the relative position by a space that is partitioned into two or more regions

defining the first region relative to the first mobile device;

defining the second region relative to the second mobile device;

wherein automatically notifying occurs if the first region is adjacent to the second region; and

determining the relative position to be less than a predetermined value, when the second mobile device enters the second region.

42. The method of claim 41, wherein automatically notifying comprises generating a notification if the first mobile device and the second mobile device are listed as associated devices.

43. The method of claim 41, wherein the first region and the second regions are represented by a quadtree.

44. The method of claim 41, wherein the first region and the second regions are represented by a spatial data structure represented by a tree.

45. The method of claim 43, further comprising maintaining a list of associated devices at a plurality of nodes of the quadtree along a path from the first region to a root of the quadtree.

46. A method for detecting proximity between at least a first mobile device and a second mobile device, comprising:

determining a position of the first and second mobile devices;

detecting an event related to a relative position between a first device and a second mobile device;

defining the relative position by a space that is partitioned into a first region, a second region, and a third region;

defining the first region relative to the first mobile device;

defining the second region relative to the second mobile device;

wherein the third region forms a boundary region between the first region and the second region; and

wherein automatically notifying occurs if;

at least any of the first and second mobile devices enters the third region; and

the relative position is determined to be less than a predetermined value.