Systems and methods for locating mobile computer users in a wireless network

• US 20020095486A1
• Filed: 01/12/2001
• Published: 07/18/2002
• Est. Priority Date: 01/12/2001
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Bahl, Paramvir
• Granted Patent: US 7,133,909 B2
• Time in Patent Office: Days
• US Class Current: 709/223
• CPC Class Codes: H04L 67/52 specially adapted for the location of the user terminal
• CPC Class Codes: H04L 67/535 Tracking the activity of the user network monitoring arrangements H04L43/00; recording of computer activity G06F11/34
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

System and methods for locating a computer user are described wherein the computer either periodically updates a network server with its location, or updates the network server when asked by the server to do so. The network server can be a mobile computer. The user'"'"'s computer determines its physical location using a location tracker service and then transmits this location information to the server, which stores it in its memory. The information stored includes the physical location of the computer, the time when the location was identified, a name identifying the user of the computer, and an indicator, which indicates whether or not the user was active on the computer during a specified time interval prior to the transmission. The location of the user is deemed to be the last known location of the computer used by the user. If the user is logged onto more than one computer, the location of the user is deemed to be the last known location of the computer that indicates the user as being active.

Claims

1. A method, comprising:

periodically identifying a location of a first computer that is used by a first computer user;

receiving a request from a computing unit for the location of the first computer user;

determining the last known location of the first computer;

transmitting the location of the first computer to the computing unit; and

recognizing the location of the first computer as the location of the first computer user.

2. The method as recited in claim 1, wherein the first computer is a mobile computer operating within a wireless network.

3. The method as recited in claim 1, wherein the periodically identifying a location of the first computer comprises:

associating the first computer user with the location of the first computer;

transmitting the location of the first computer and the associated first computer user to a network server during each of several recurring time periods; and

storing the transmitted information on the network server.

4. The method as recited in claim 3, wherein the location of the first computer is represented in absolute geographical coordinates.

5. The method as recited in claim 3, wherein the location of the first computer is represented in coordinates relative to a known absolute location.

6. The method as recited in claim 3, wherein the location of the first computer is represented as a geographical unit.

7. The method as recited in claim 1, wherein the periodically identifying a location of the first computer further comprises:

associating the first computer user name with the location of the first computer;

transmitting the location of a network node to which the first computer is connected, the transmitting occurring once during each of several recurring time periods; and

storing the location of the network node on a network server together with the first computer user name.

8. The method as recited in claim 1, further comprising time-stamping the location of the first computer with the time that the first computer was identified.

9. The method as recited in claim 8, wherein the determining the last known location of the first computer further comprises determining the location of the first computer that has a most recent time stamp.

10. The method as recited in claim 8, wherein the determining the last known location of the first computing unit further comprises:

calculating a time differential between a current time and the time stamp of a most recent location identified for the first computer;

comparing the time differential with a pre-defined time threshold;

defining the last known location of the first computer as the most recent location if the time differential is less than the time threshold; and

invoking a location tracking service to identify a current location of the first computer as the last known location if the time differential is greater than the time threshold.

11. The method as recited in claim 1, wherein:

the periodically identifying a location of a first computer that is used by a first computer user further comprises periodically identifying a location of at least a second computer that is used by the first computer user and detecting an active signal from the computer that was most recently used by the first computer user; and

the determining the last known location of the first computer comprises determining the last known location of the computer indicating the active signal.

12. The method as recited in claim 1, wherein the determining the last known location of the first computing unit further comprises:

searching a server database having a plurality of computer users and locations contained therein; and

identifying a location associated with the first computer user.

13. The method as recited in claim 1, further comprising registering the first computer, and wherein the identifying a location of the first computer only occurs upon the receiving a request from the computing unit for the location of the first computer.

14. The method as recited in claim 1, wherein the last known location of the first computer is transmitted to the computing unit upon a request by the computing unit only if the computing unit is authorized to determine the location of the first computer.

15. The method as recited in claim 1, further comprising encrypting the location of the first computer prior to transmitting the location of the first computer.

17. The method as recited in claim 16, wherein:

the computing unit is a mobile computing unit; and

the network server is a wireless network server.

18. The method as recited in claim 16, further comprising time-stamping the transmission to the network server and transmitting the time stamp with the transmitted information.

19. The method as recited in claim 16, wherein the determining a location of a computing unit comprises receiving RF signals from a plurality of RF beacons having known locations and using environmental profiling to establish the location of the computing unit.

20. The method as recited in claim 16, wherein the location is rendered in latitude and longitude coordinates.

21. The method as recited in claim 16, wherein the location is rendered in latitude, longitude and altitude coordinates.

22. The method as recited in claim 16, wherein the location is rendered in coordinates relative to a known location.

23. The method as recited in claim 16, wherein the location is rendered as a geographical unit.

24. The method as recited in claim 16, wherein the location of the computing unit is the known location of a network node to which the computing unit is connected.

25. The method as recited in claim 16, wherein the user actively using the computing unit further comprises the user having used the computing unit within a pre-defined time period.

26. The method as recited in claim 16, wherein the periodically transmitting the location of the computer unit to a network server only occurs upon a request from the network server for the computer unit to update the location of the computer unit.

27. The method as recited in claim 16, further comprising encrypting the location of the computing unit prior to transmitting the location of the computing unit to the network server.

29. The system as recited in claim 28, wherein the computing unit is a stationary computing unit.

30. The system as recited in claim 28, wherein the computing unit is a mobile computing unit.

31. The system as recited in claim 28, wherein:

the mobile computer further comprises a clock;

the location manager is further configured to transmit a time of transmission to the server together with the location and user name information; and

the user database further comprises a time field for storing the time that a transmission identifying the location of the mobile user and the user name of the mobile computer user is received from the mobile computer.

32. The system as recited in claim 28, wherein the user database further comprises an active field indicating if the mobile computer user has used the mobile computer within a specified time period.

33. The system as recited in claim 28, wherein the location manager transmits the location of the mobile computer in absolute coordinates.

34. The system as recited in claim 28, wherein the location manager transmits the location of the mobile computer in coordinates relative to a known absolute location.

35. The system as recited in claim 28, wherein the location manager transmits the location of the mobile computer as a geographic unit.

36. The system as recited in claim 28, wherein the location manager transmits the location of a network node with which the mobile computer is communicating as the location of the mobile computer.

37. The system as recited in claim 28, wherein:

the mobile computer is a first computer;

the system further comprises a second computer having a location manager;

the user database further comprises an active field;

the mobile computer user is logged onto both the first mobile computer and the second computer;

the location manager of the first computer and the location manager of the second computer are further configured to transmit an active signal for a specified period of time after the respective computers are used;

the active field corresponding to the first computer indicating the mobile computer user last used the first computer when the active signal is transmitted from the first computer;

the active field corresponding to the second computer indicating the mobile computer user last used the second computer when the active signal is transmitted from the second computer; and

only one active field indicating activity by the mobile computer user at any given time.

38. The system as recited in claim 28, wherein:

the user database further comprises an OK field that contains data that identifies one or more system users that are authorized to receive data regarding the location of the mobile computer user identified in the corresponding user field.

39. The system as recited in claim 28, wherein the location manager of the computing unit is further configured to:

search the user database to locate an entry for a specific user;

calculate a time differential between a current time and a time stored in the time field corresponding to the specific user if the specific user is found;

compare the time differential to a time threshold;

recognize the location contained in the last known location field corresponding to the specific user as the location of the specific user if the time differential is within the time threshold;

transmit a signal to cause the location manager of the mobile computer to invoke the location tracking system of the mobile computer if the time differential is not within the time threshold, to determine the location of the mobile computer and transmit location and user information to the server where it is stored in the user database; and

recognize the newly stored location contained in the last known location field corresponding to the specific user as the location of the specific user.

16. A method, comprising:

determining a location of a computing unit;

periodically transmitting, from the computing unit, the location of the computing unit to a network server together with a user name of a user using the computing unit; and

including an active signal with the periodically transmitted information when the user is actively using the computing unit.

28. A system, comprising:

a server having memory;

a user database stored in the memory of the server, the user database containing a user field for storing a user name of a mobile computer user, and a last known location field for storing a most recent location of a computer user identified in a corresponding user field;

a wireless access point configured to receive network transmissions from one or more mobile computers;

a mobile computer having memory and a wireless network interface for communication with the wireless access point;

a location tracking system in the mobile computer memory configured to determine a location of the mobile computer;

a location manager in the mobile computer memory configured to periodically transmit the location of the mobile computer and the user name of a mobile computer user to the server via the wireless network interface; and

a computing unit having a computing unit location manager configured to search the user database of the server to determine information regarding the location of a mobile user.

40. A network server, comprising:

memory;

a user database stored in the memory containing one or more records, each record including;

a user field in the user database to store a user identifier; and

a last known location field in the user database to store a most recent location identified for the corresponding user field.

41. The network server as recited in claim 40, wherein each record further comprises a time field to store a time that the corresponding last known location was stored.

42. The network server as recited in claim 40, wherein each record further comprises an active field to store an indication of whether the user identified in the corresponding user field has been active on a client connected to the server within a specified period of time.

43. The network server as recited in claim 40, further comprising a wireless access point to which a mobile computing unit may connect to access the network.

44. The network server as recited in claim 43, further comprising a connection to wired network components.

46. The mobile computing unit as recited in claim 45, wherein the location manager is further configured to transmit a user name of a user logged onto the mobile computing unit to the remote server together with the location of the mobile computing unit.

47. The mobile computing unit as recited in claim 45, wherein the location manager is further configured to transmit an active signal to the remote server together with the location of the mobile computing unit when a user logged onto the mobile computing unit has actively used the unit within a specified period of time.

48. The mobile computing unit as recited in claim 45, further comprising a clock, and wherein the location manager is further configured to time-stamp the transmission of the location information with a time that the transmission is sent.

49. The mobile computing unit as recited in claim 45, wherein the location manager identifies and transmits the location of a network node with which the mobile computing unit is communicating as the location of the mobile computing unit.

50. The mobile computing unit as recited in claim 45, wherein the location manager is configured to invoke the location tracking service when commanded to do so by a second computing unit or the server.

51. The mobile computing unit as recited in claim 45, wherein the location manager transmits an absolute location of the mobile computing unit to the remote server.

52. The mobile computing unit as recited in claim 45, wherein the location manager transmits the a location of the mobile computing unit relative to a known absolute location.

53. The mobile computing unit as recited in claim 45, wherein the location manager transmits a geographic region to the remote server as the location of the mobile computing unit.

54. The mobile computing unit as recited in claim 45, wherein the location manager is further configured to encrypt the location of the mobile computing unit before transmitting the location of the mobile computing unit to the remote server.

45. A mobile computing unit, comprising:

memory;

a wireless network interface configured to connect the mobile computing unit to a wireless access point of a remote server;

a location tracking service configured to determine a location of the mobile computer unit; and

a location manager configured to periodically transmit the location of the mobile computing unit to the remote server via the wireless network interface.

55. A method for locating a mobile computer user in a wireless network, comprising:

periodically identifying a location of a mobile computer that is used by a mobile user and associating a time stamp with the location indicating a time at which the location was identified;

transmitting the location of the mobile computer to a network server together with the time stamp and a name of the mobile user;

storing the transmitted information on the network server;

receiving a request from a computing unit for the location of the mobile user;

determining the last known location of the mobile computer by accessing the network server and finding the location having a most recent time stamp; and

recognizing the last known location of the mobile computer as the location of the mobile user.

56. The method as recited in claim 55, wherein the periodically identifying a location of a mobile computer further comprises identifying the location of the mobile user by measuring relative strengths of radio frequency transmissions emitted from a plurality of base stations.

57. The method as recited in claim 55, further comprising:

transmitting an active signal together with the location information if the mobile user has actively used the mobile computer within a specified period of time.

58. A system, comprising:

a server having memory;

a user database stored in the memory of the server, the user database containing a user field for storing a user name of a mobile computer user, and a last known location field for storing a most recent location of a computer user identified in a corresponding user field;

a wireless access point configured to receive network transmissions from one or more mobile computers;

a mobile computer having memory and a wireless network interface for communication with the wireless access point;

a location tracking system in the mobile computer memory configured to determine a location of the mobile computer;

a location manager in the mobile computer memory configured to transmit the location of the mobile computer and the user name of a mobile computer user to the server via the wireless network interface when a request to do so is received from the server; and

a computing unit having a computing unit location manager configured to search the user database of the server to determine information regarding the location of a mobile user.