Client proximity detection method and system

• US 20040236850A1
• Filed: 09/30/2003
• Published: 11/25/2004
• Est. Priority Date: 05/19/2003
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Marsh, David J., Krumm, John C., Woolf, Susan D., Fernandez, Roland, King, Wayne G., Jee, Albert D.
• Granted Patent: US 7,936,872 B2
• Time in Patent Office: Days
• US Class Current: 709/224
• CPC Class Codes: H04L 67/04 specially adapted for terminals or networks with limited capabilities; specially adapted for terminal portability
• CPC Class Codes: H04L 67/51 Discovery or management thereof, e.g. service location protocol [SLP] or web services
• CPC Class Codes: H04L 67/52 specially adapted for the location of the user terminal
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 64/006 with additional information processing, e.g. for direction or speed determination
• CPC Class Codes: H04W 8/005 Discovery of network devices, e.g. terminals
• CPC Class Codes: Y10S 370/913 Wireless or radio

Abstract

A system and method in a wireless network for discovering which resources (e.g., other wireless computing devices) are proximate a user'"'"'s wireless computing device. Wireless signal strengths with respect to various base stations are compared with the signal strengths of other network devices or resources, to determine which devices are experiencing similar signal strengths. Devices with similar signal strengths are deemed proximate. Each participating computing device may send its signal strength reports to a proximity server, which distributes proximity data to network clients. Each client may receive and process the signal strength data for determining which other clients/resources are proximate, or the server can perform proximity computations and return a list of proximate clients. Once computed, the identities of the proximate clients can be used to query for additional data about the clients, such as the names and other details of their owners, or information about the resource.

Claims

1. In a network environment, a method comprising:

obtaining signal strength data of a first network device with respect to signals received from at least one base station; and

determining whether the first network device is proximate a resource based on the signal strength data.

2. The method of claim 1 wherein obtaining signal strength data of the network device comprises scanning at the first network device for radio signals at radio frequencies.

3. The method of claim 2 wherein scanning for radio signals comprises scanning a subset of channels.

4. The method of claim 2 wherein scanning for radio signals comprises performing a passive scan.

5. The method of claim 2 wherein scanning for radio signals comprises performing an active scan.

6. The method of claim 2 further comprising mathematically smoothing a plurality of signal strength data into a smoothed value.

7. The method of claim 1 wherein obtaining signal strength data of the first network device comprises receiving a report from the first network device at a server.

8. The method of claim 7 wherein the report is received on a regular basis from the client.

9. The method of claim 7 wherein the report is received as determined by the client.

10. The method of claim 1 wherein the resource comprises a second network device, and wherein obtaining signal strength data of the first network device comprises receiving a report at the second network device from the first network device.

11. The method of claim 1 wherein determining whether the first network device is proximate the resource comprises evaluating signal strength data of the first network device against signal strength data of the resource.

12. The method of claim 11 wherein evaluating signal strength data comprises evaluating a number of base stations in common between the first network device and the resource.

13. The method of claim 11 wherein first signal strength data comprises a first set of signal strength values, each value associated with each base station of a plurality of base stations seen by the first device, wherein second signal strength data comprises a second set of signal strength values, each value paired with each base station of a plurality of base stations seen by a second device corresponding to the resource, and wherein evaluating signal strength data comprises evaluating signal strength values for base stations seen in common by the first device and the resource.

14. The method of claim 13 wherein evaluating signal strength values for base stations seen in common comprises, ordering base stations seen in common by signal strength values into a first ordering for the first device and a second ordering for the resource, and determining similarity between the first order and the second ordering.

15. The method of claim 1 wherein a server determines that the resource is proximate the first network device, and further comprising, returning proximity-related data to the first network device that corresponds to the resource.

16. The method of claim 15 further comprising, at the first network device, querying a database based on the proximity-related for additional information corresponding to the resource.

17. The method of claim 16 wherein the resource comprises a second network device, and further comprising, receiving additional information including biographical information corresponding to a user of the second network device.

18. The method of claim 15 wherein returning proximity-related data to the first network device comprises transmitting a list of at least one proximate client including proximity-related data corresponding to the resource to the first network device.

19. The method of claim 18 wherein returning the proximity-related data to the first network device further comprises transmitting additional information corresponding to the resource to the first network device.

20. The method of claim 15 wherein the resource comprises a second network device, wherein a server receives signal strength data from the second network device, and wherein returning proximity-related data to the first network device that corresponds to the second network device comprises transmitting the signal strength data of the second device to the first network device.

21. The method of claim 20 wherein determining whether the first network device is proximate the second network device comprises processing the signal strength data at the first device.

22. The method of claim 1 wherein the resource is fixed, and further comprising, providing a simulated signal strength for the resource.

23. A computer-readable medium having computer-executable instructions for performing the method of claim 1.

24. In a network environment, a system comprising:

a client device having an output mechanism and a client program that detects signal strengths based on signals received from a base stations, the program further configured to;

1) report the signal strengths to another network entity;

2) receive proximity-related data corresponding to another resource; and

3) present information that corresponds to the proximity-related data on the output mechanism of the client device.

25. The system of claim 24 wherein the other entity comprises a server.

26. The system of claim 24 wherein the other entity comprises a different client device in the network.

27. The system of claim 24 wherein the proximity-related data comprises a list of other resources that are proximate the client device.

28. The system of claim 24 wherein the proximity-related data comprises a set of at least one other client device and base station signal strengths detected by at least one other client device in the set.

29. The system of claim 28 wherein the client program processes the signal strengths to determine which other resources are proximate the client device.

30. The system of claim 28 wherein the client program receives the proximity-related data from a server.

31. The method of claim 24 wherein the output mechanism comprises a display.

32. The system of claim 24 further comprising a database, wherein the client program accesses the database to present the information that corresponds to the proximity-related data on the output mechanism of the client device.

33. The system of claim 32 wherein the resource comprises another client device, and wherein the database returns biographical data corresponding to a user of the other client device.

34. The system of claim 24 wherein the other client device comprises a printer.

35. The system of claim 24 wherein the network comprises a wireless 802.11 network.

36. A computer-readable medium having stored thereon a data structure, comprising:

a plurality of data sets, each data set comprising;

a first set of data representative of a network device;

a second set of data comprising a set of at least one association, each association comprising;

an identifier of a base station, and

a signal strength value representative of

a signal strength of the network device with respect to that base station; and

wherein a network entity compares the associations for one network device with the associations for another resource to determine whether the network device is proximate the resource.