Method and system for a plurality of mobile units to locate one another

• US 6,867,733 B2
• Filed: 04/09/2001
• Issued: 03/15/2005
• Est. Priority Date: 04/09/2001
• Status: Expired due to Term

• Current Assignee: Trimble Navigation Limited (Trimble Inc.)
• Original Assignee: At Road Incorporated
• Inventors: Nguyen, Kenny, Fan, Carey, Sandhu, Kulbir S., Fan, Roderic C., Mleczko, David
• Primary Examiner(s): Issing, Gregory C.
• Application Number:
  US09/829,645
• Publication Number:
  US 20020145561A1
• Time in Patent Office: 1,436 Days
• Field of Search: 342/357.07, 342/357.08, 342/357.09, 342/357.1, 342/457, 701/208, 701/213, 455/456.3, 455/456.5, 455/456.6
• US Class Current: 342/357.34
• CPC Class Codes: G01S 19/40 Correcting position, velocity or attitude
• CPC Class Codes: G01S 19/51 Relative positioning
• CPC Class Codes: G01S 5/0027 of actual mobile position, i.e. position determined on mobile
• CPC Class Codes: G01S 5/0072 Transmission between mobile stations, e.g. anti-collision systems
• CPC Class Codes: G08G 1/20 Monitoring the location of vehicles belonging to a group, e.g. fleet of vehicles, countable or determined number of vehicles

Abstract

A method and system whereby two mobile units can locate each other is presented. A user connects an interface device, such as a personal digital assistance (PDA), a wireless phone, a laptop, or a pager, to a mobile unit. The mobile unit regularly obtains its location through a location-determining technology (e.g., GPS) and sends the location to a service provider computer. The service provider computer maintains a database of the current location of all the mobile units, and provides the location of mobile units to each of the mobile units. The mobile unit communicates with the service provider wirelessly through a communication network and a data network, for example the Internet.

A user of the mobile unit can send messages to other users with a location stamp, which indicates the location of the message sender'"'"'s mobile unit. In addition, a user can send a request to be notified when a target mobile unit reaches a reference point. The reference point may be defined relative to the location of the requester. Alternatively, the reference point may be an address or a landmark. Upon receiving the request, the service provider computer tracks the distance between the target mobile unit and the reference point, and sends a notification to the requester when the target mobile unit reaches the reference point.

Claims

1. A method of providing the location of a second mobile unit to a first mobile unit, said method comprising:

maintaining personal profiles each associated with a user of one of said first and second mobile units, each personal profile specifying an access condition under which another user may access that personal profile;

receiving from said first mobile unit a first packet including a current location of said first mobile unit;

receiving from said second mobile unit a second packet including a current location of said second mobile unit;

storing said current locations in a database;

receiving a request from a user of said first mobile unit specifying a condition based on said current location of said first mobile unit or a future location of said first mobile unit; and

upon ascertaining that said user of said first mobile unit satisfies said access condition in the user profile of a user associated with said second mobile unit, transmitting a data package to said first mobile unit in response to a said request from said first mobile unit upon satisfaction of said condition, wherein said data package comprises said current location of said second mobile unit retrieved from said database.

2. The method of claim 1, wherein said receiving and said storing of current locations are repeated at a regular time interval.

3. The method of claim 1, wherein said first packet includes said request, and wherein, prior to said transmitting, said method further comprises:

obtaining the current location of said second mobile unit from said database; and

including in said data package said current location of said second mobile unit.

4. The method of claim 1, wherein said request comprises a request for a notification when said second mobile unit arrives at a reference point, and wherein, prior to said transmitting, said method further comprises:

calculating a distance between said second mobile unit and said reference point; and

including a notification to said data package when said distance is approximately zero.

5. The method of claim 4, wherein said notification comprises at least one of:

sound;

flashing light;

text; and

graphics.

6. The method of claim 1, wherein said receiving and said transmitting are done through a data network.

7. The method of claim 6, wherein said data network comprises the Internet.

8. The method of claim 6, wherein said data network comprises a wireless communication network, said wireless communication network being selected from a group consisting of CDPD, CDMA, GSM, iDEN, and AMPS.

9. The method of claim 1, wherein said transmitting a data package is carried out based on the satisfaction of the condition that said second mobile unit has not requested that said first mobile unit be excluded from a group of potential recipients of said data package.

10. A method comprising:

maintaining personal profiles each associated with a user of a mobile unit, each personal profile specifying an access condition under which a user of another mobile unit may access that personal profile;

receiving from a first mobile unit units a first packet including a request for access to personal profiles of users of said mobile units that satisfy a specified selection criterion and a current location of said first mobile unit, said first packet further providing at least one of;

personal information about a first user, said first user being a user of said first mobile unit; and

an announcement;

storing said current locations in a database; and

upon ascertaining that said user of said first mobile unit satisfies the access conditions associated with the personal profiles of one or more users of said mobile units that satisfy the specified selection criterion, transmitting a data package in response to said request from said first mobile unit.

11. The method of claim 10, wherein said data package comprises a list of mobile units used by users having similar personal information in their personal profile as said personal information of said first user.

12. The method of claim 10, wherein said first packet provides an announcement and a list of recipients, and wherein said data package comprises:

said announcement; and

a location stamp showing the location of said first mobile unit.

13. The method of claim 10, wherein said personal information comprises at least one of:

name of said first user;

telephone number of said first user;

address of said first user;

e-mail address of said first user; and

hobbies of said first user.

14. An apparatus for tracking the location of a second mobile unit from a first mobile unit, said apparatus comprising:

a processing station that receives location data from said first and second mobile units;

a database of said location data connected to said processing station; and

a data network through which packets are sent between said processing station and said first and said second mobile units, wherein said packets comprise a current location of said second mobile unit being sent from said processing station to said first mobile unit in response to a request from said first mobile unit, upon satisfaction of a search criterion specified in said request and after ascertaining that said first mobile unit has a right to receive said current location of said second mobile unit.

15. The apparatus of method 14, further comprising a map storage connected to said processing station.

16. The apparatus of method 14, wherein said packets comprise a current location of said first mobile unit and a current location of said second mobile units being sent from said first and second mobile units, respectively, to said processing station at regular time interval.

17. The apparatus of method 14, wherein said data network comprises the Internet.

18. A method of providing the current location of a second mobile unit to a first mobile unit, said method comprising:

maintaining access control data indicating an access condition under which information regarding said second mobile unit may be accessed by another mobile unit;

said first mobile unit transmitting a first packet to a service provider computer, said first packet indicating the current location of said first mobile unit;

said second mobile unit transmitting a second packet to said service provider computer, said second signal indicating the current location of said second mobile unit;

said service provider computer receiving said first and second signals and storing said current locations of said first and said second mobile units in a database;

said service provider computer receiving from said first mobile unit a request including a condition based upon said current location of said first mobile unit or a future location of said first mobile unit, and retrieving said current location of said second mobile unit from said database in response to a request from said first mobile unit; and

said service provider computer, upon satisfaction of said condition and upon ascertaining from said access control data that said first mobile unit satisfies said access condition, transmitting said current location of said second mobile unit to said first mobile unit.

19. The method of claim 18, wherein said transmitting is done through the Internet and a data network, said data network selected from a group consisting of CDPD, CDMA, GSM, iDEN, and AMPS.

20. The method of claim 18, wherein said request comprises a request to be notified when said second mobile unit arrives at a reference point, said method further comprising:

said service provider computer calculating the distance between said current location of said second mobile unit and said reference point, and

said service provider computer sending a notification to said first mobile unit when said distance is approximately zero.

21. A system, comprising:

a first mobile unit and a second mobile unit connected to a data network; and

a processing station connected to said data network and receiving current locations over said data network from said first and second mobile units, the processing station (a) maintaining an access control list including an access condition under which information regarding said second mobile unit may be accessed by another mobile unit;

(b) being connected to a database storing said current locations of said first and second mobile units, and;

(c) upon request from the first mobile unit and upon satisfaction of a condition based on said current location or a future location of said first mobile unit and said access condition, providing the first mobile unit the stored current location of the second mobile unit.

22. The system of claim 21 wherein each of said first and second mobile units comprises:

a GPS receiver for receiving GPS code sequences;

a processor that converts said GPS code sequences to location data;

a memory containing conversion data for converting said GPS code sequences to location data; and

a wireless modem connecting said first and said second mobile unit to said data network.

23. The system of claim 22 wherein said conversion data comprises:

preliminary location data; and

correction factors.

24. The system of claim 22, wherein each of said first and second mobile units comprises a plurality of mobile units.

25. The system of claim 21, each of said first and second mobile units further comprising a user interface device connected to each of said first and second mobile units, said user interface device selected from a group consisting of personal digital assistant, laptop, wireless phone, and pager.

26. The system of claim 25, said user interface conveying at least one of:

sound;

flashing light;

text; and

graphics.

27. The system of claim 21, wherein said data network comprises the Internet.

28. The system of claim 21, wherein said data network comprises a wireless communication network selected from a group consisting of CDPD, CDMA, GSM, 15 AMPS, and iDEN.

29. The system of claim 21, wherein said database comprises:

a storage for personal information of users;

a map storage; and

a storage for the current locations of said first and second mobile units.