Client proximity detection method and system

• US 7,936,872 B2
• Filed: 09/30/2003
• Issued: 05/03/2011
• Est. Priority Date: 05/19/2003
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Krumm, John C., Woolf, Susan D., Fernandez, Roland, King, Wayne G., Jee, Albert D., Marsh, David J.
• Primary Examiner(s): Moazzami; Nasser
• Assistant Examiner(s): YALEW, FIKREMARIAM A
• Application Number:
  US10/677,125
• Publication Number:
  US 20040236850A1
• Time in Patent Office: 2,772 Days
• Field of Search: 380/34, 380/247
• US Class Current: 380/34
• 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 for detecting a proximity of multiple client stations and identifying proximate client stations to a one or more of the client station, the method comprising:

obtaining signal strength data of a first client station with respect to signals received by the first client station from at least one stationary base station wherein the first client station is mobile;

obtaining signal strength data of other client stations with respect to signals received by the other client stations from the at least one stationary base station, the other client stations and the first client station being remote to the at least one stationary base station and wherein at least one of the other client stations is mobile;

comparing the signal strength data of the first client station with the signal strength data of the other client stations;

comparing the signal strength data of the first client station with simulated signal strength data of a non-networked, non-electronic, fixed resource;

remote from the first client station and the other client stations, determining that the first client station is proximate one or more of the other client stations or the non-networked, non-electronic, fixed resource based on the signal strength data of the first client station, signal strength data of the other client stations to the at least one stationary base station, and simulated signal strength data of the non-networked, non-electronic, fixed resource; and

sending to the first client station an identification of the one or more other client stations or of the non-networked, non-electronic, fixed resource determined to be proximate the first client station.

2. The method of claim 1 wherein obtaining signal strength data of the first client station comprises scanning at the first client station 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 client station comprises receiving a report from the first client station at a server.

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

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

10. The method of claim 1 wherein the other client stations comprise a second client station, and wherein obtaining signal strength data of the first client station comprises receiving a report at the second client station from the first client station.

11. The method of claim 10 wherein comparing the signal strength data comprises evaluating a number of base stations in common between the first client station and the one or more other client stations.

12. The method of claim 10 wherein the signal strength data of the first client station 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 client station, and wherein the signal strength data of other client stations 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 client station corresponding to the other client stations, and wherein comparing the signal strength data comprises evaluating signal strength values for base stations seen in common by the first device and the second client station.

13. The method of claim 12 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 client station and a second ordering for the second client station, and determining similarity between the first ordering and the second ordering.

14. The method of claim 11 wherein a server determines that the one or more other client stations are proximate the first client station, and further comprising, the server returning proximity-related data to the first client station that corresponds to the one or more other client stations determined to be proximate the first client station.

15. The method of claim 14 further comprising, at the first client station, querying a database based on the proximity-related data for additional information corresponding to the one or more other client stations determined to be proximate the first client station.

16. The method of claim 15 wherein the one or more other client stations determined to be proximate the first client station comprises a second client station, and further comprising, receiving at the first client station additional information including biographical information corresponding to a user of the second client station.

17. The method of claim 10 wherein identifying to the first client station the one or more other client stations determined to be proximate the first client station comprises transmitting a list of at least one proximate client, including proximity-related data corresponding to the client, to the first client station.

18. The method of claim 14 wherein the one or more other client stations comprises a second client station, wherein a server receives signal strength data from the second client station, and wherein the server returning proximity-related data to the first client station that corresponds to the second client station comprises transmitting the signal strength data of the second client station to the first client station.

19. The method of claim 18 wherein determining that the first client station is proximate the second client station comprises processing the signal strength data of the second client station at the first client station.

20. The method of claim 1 wherein at least one of the one or more of the other client stations is fixed, and further comprising, providing a simulated signal strength for the fixed network resource.

21. One or more computer-readable media having stored thereon computer-executable instructions for performing the method of claim 1, wherein at least a portion of the computer-readable media is storage, non-communication-type media.

34. The method of claim 1 wherein the one or more non-networked, non-electronic fixed resources includes a fixed resource not having wireless capabilities, and wherein the signal strength data of the fixed resource not having wireless capabilities and determined to be proximate the first client station is a simulated wireless signal strength based on an actual wireless device and reported on behalf of the fixed resource.

22. In a network environment, a system for obtaining at a client device information corresponding to other client devices located near the client device, the system comprising:

a client device having an output mechanism for providing information to a user of the client device wherein the client device is mobile, the client device further having a client program that detects signal strengths based on signals received by the client device from one or more base stations, the client program further being configured to;

report the detected signal strengths to a second network entity;

receive proximity-related data corresponding to the one or more separate client stations and one or more non-networked, non-electronic fixed resources from the second network entity, wherein at least one of the one or more separate client stations is mobile, wherein the proximity-related data relates to which of the one or more separate client stations and one or more fixed resources are proximate the client device as determined by the second network entity, wherein proximity of the one or more separate client stations is based on signal strengths of the one or more separate client stations detected based on signals received by the one or more separate client stations from the one or more base stations and proximity of the one or more fixed resources is based on simulated signal strengths of the one or more fixed resources, and wherein the client device and the one or more separate client stations are remote to the second network entity and the one or more base stations; and

present to the user of the client device information that corresponds to the proximity-related data of the one or more separate client stations and the one or more fixed resources on the output mechanism of the client device, based on proximity of the client device to the one or more separate client stations to the one or more base stations and proximity of the one or more fixed resources to the one or more base stations.

23. The system of claim 22 wherein the second network entity comprises a server.

24. The system of claim 22 wherein the second network entity comprises a different client device in the network.

25. The system of claim 22 wherein the proximity-related data comprises a list of other client stations that are proximate the client device.

26. The system of claim 22 wherein the client device is a first mobile client device and wherein the one or more separate client stations comprises at least one other mobile client device.

27. The system of claim 26 wherein the client program of the first client device processes the signal strengths of the one or more separate client stations to determine which other client stations are proximate the client device.

28. The system of claim 26 wherein the client program receives the proximity-related data from a server.

29. The method of claim 22 wherein the output mechanism comprises a display.

30. The system of claim 22 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.

31. The system of claim 30 wherein the one or more separate client stations comprises another client device, and wherein the database returns biographical data corresponding to a user of the another client device for display on the client device.

32. The system of claim 22 wherein the one or more separate client stations comprises a plurality of stations and wherein one of the plurality of stations comprises a printer.

33. The system of claim 22 wherein the network comprises a wireless 802.11 network.

35. In a wireless network having one or more base stations providing a wireless signal to a plurality of mobile client devices, a method for notifying users of one or more mobile client devices of the proximity of other users of mobile client devices, the method comprising:

obtaining signal strength data of a first mobile client device with respect to signals received by the first mobile client device from at least one stationary base station;

obtaining signal strength data of a second mobile client device with respect to signals received by the second mobile client device from the at least one stationary base station;

obtaining simulated signal strength data of a non-networked, non-electronic fixed resource participating in proximity detection relative to the first mobile client, wherein the simulated signal strength is an equivalent signal strength were the fixed resource a mobile client device, and is reported by a mobile device positioned near the fixed resource and on behalf of the fixed resource;

at the one or more base stations and remote from the plurality of mobile client devices;

comparing the signal strength data of the first mobile client device with the signal strength data of the second mobile client device and the simulated signal strength of the fixed resource;

determining that the first mobile client device is located at a geographic location that is proximate a geographic location of at least one of the second mobile client device or the fixed resource; and

sending to the first mobile client device a notice that the first mobile client device is located near the at least one of the second mobile client device or the fixed resource, wherein when the notice is that the first mobile client device is located near the second mobile client device, the notice to the first mobile client device includes at least an identity of the user of the second mobile client device.

36. The method of claim 35, wherein when the notice is that the first mobile client device is located near the fixed resource, the notice to the first mobile device includes at least an identification of a type of resource that is the fixed resource.