Method and apparatus for assigning location estimates from a first transceiver to a second transceiver

• US 6,275,707 B1
• Filed: 10/08/1999
• Issued: 08/14/2001
• Est. Priority Date: 10/08/1999
• Status: Expired due to Term

• Current Assignee: Motorola Solutions, Inc.
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Smith, Jack Anthony, Reed, John Douglas
• Primary Examiner(s): Trost, William G.
• Assistant Examiner(s): Milord, Marceau
• Application Number:
  US09/415,591
• Time in Patent Office: 676 Days
• Field of Search: 455/456, 455/457, 455/517, 455/525, 342/457, 342/357.1, 342/357.16, 342/357.08
• US Class Current: 455/456.3
• CPC Class Codes: G01S 19/05 providing aiding data
• CPC Class Codes: G01S 5/0072 Transmission between mobile stations, e.g. anti-collision systems
• CPC Class Codes: G01S 5/0244 Accuracy or reliability of position solution or of measurements contributing thereto

Abstract

A method and apparatus for assigning location estimates from a first transceiver of a plurality of wireless transceivers to a second transceiver is disclosed. The present invention makes use of a low power short-range auxiliary communication link incorporated within networked devices to interact with nearby devices for obtaining location estimates of the current location of a device. Confidence levels are then assigned to the information obtained from the interactions with the nearby devices, and a determination of whether to update the location estimate is made.

Claims

1. A method for transferring a location estimate from a first transceiver of a plurality of wireless transceivers to a second transceiver, the method comprising the steps of:

transmitting, from a first transceiver, a location estimate of the first transceiver and predetermined attributes of the location estimate of the first transceiver;

calculating a first confidence level of the location estimate of the first transceiver based upon the predetermined attributes;

receiving, at a second transceiver, the location estimate of the first transceiver and the first confidence level, the second transceiver having a location estimate of the second transceiver and corresponding second confidence level; and

determining whether to update the location estimate of the second transceiver and corresponding second confidence level based upon the location estimate and first confidence level of the first transceiver.

2. A method as recited in claim 1, including a step of adjusting a confidence level of a location estimate of a transceiver based upon one of

the lapsed time since receiving an updated location estimate;

an estimate of motion of another transceiver; and

the proximity of the first transceiver to the second transceiver.

3. A method as recited in claim 1, including the step of attenuating a confidence level with each generation of exchanging location estimates, thereby reducing the impact of second and third hand information.

4. A method as recited in claim 1, including the step of storing and averaging location estimates from those transceivers of the plurality of transceivers with the highest confidence levels to improve a base line location estimate for those transceivers.

5. A method as recited in claim 1, including the step of utilizing a third transceiver to communicate the location estimate of the first transceiver and first confidence level to the second transceiver.

6. A method as recited in claim 1, further comprising the step of preprogramming fixed ones of the plurality of wireless transceivers with location information corresponding to a location at which each is placed.

7. A method for transferring a location estimate from a first transceiver of a plurality of wireless transceivers to a second transceiver, the method comprising the steps of:

at a second transceiver having location estimate of the second transceiver and a corresponding second confidence level;

receiving a first transceiver'"'"'s location estimate and predetermined attributes of the first transceiver'"'"'s location estimate;

receiving a calculated confidence level of the first transceiver'"'"'s location estimate based upon the predetermined attributes; and

determining whether to update the location estimate of the second transceiver and the corresponding second confidence level based upon the first transceiver'"'"'s location estimate and calculated confidence level of the first transceiver.

8. A method as recited in claim 7, including a step of adjusting a confidence level of a location estimate of a transceiver based upon one of:

the lapsed time since receiving an updated location estimate;

an estimate of motion of another transceiver; and

the proximity of the first transceiver to the second transceiver.

9. A method as recited in claim 8, including the step of utilizing a third transceiver to communicate the first transceiver'"'"'s location estimate and confidence level to the second transceiver.

10. A method as recited in claim 8, including the step of adjusting a confidence level of a location estimate based upon one of

the lapsed time since receiving an updated location estimate;

an estimate of motion of a transceiver; and

the proximity of the first transceiver to the second transceiver.

11. A method as recited in claim 7, including the step of storing and averaging location estimates from those transceivers of the plurality of transceivers with the highest confidence levels to improve a base line location estimate for those transceivers.

12. A method as recited in claim 7, including the step of utilizing a third transceiver to communicate the first transceiver'"'"'s location estimate and the first confidence level to the second transceiver.

13. An apparatus for transferring a location estimate from a first transceiver of a plurality of transceivers to a second transceiver, the second transceiver having a location estimate of the second transciever and a corresponding second confidence level, the apparatus comprising:

a receiver adapted to receive a location estimate;

a transmitter adapted to transmit the location estimate; and

a processing system coupled to the receiver and coupled to the transmitter, the processing system programmed to;

receive a first transceiver'"'"'s location estimate and predetermined attributes of the first transceiver'"'"'s location estimate;

calculate a calculated confidence level of the first transceiver'"'"'s location estimate based upon the predetermined attributes; and

determine whether to update the location estimate of the second transceiver and the corresponding second confidence level based upon the first transceiver'"'"'s location estimate and calculated confidence level of the first transceiver.

14. An apparatus as recited in claim 13, wherein the processing system is further programmed to adjust a confidence level of a location estimate of a transceiver based upon one of:

the lapsed time since receiving an updated location estimate;

an estimate of motion of another transceiver; and

the proximity of the first transceiver to the second transceiver.

16. An apparatus as recited in claim 13, wherein the processing system is further programmed to store and average location estimates from those transceivers of the plurality of transceivers with the highest confidence levels to improve a base line location estimate for those transceivers.

17. An apparatus as recited in claim 13, wherein the processing system is further programmed to utilize a third transceiver to communicate the first transceiver'"'"'s location estimate and predetermined attributes to the processing system.

15. An apparatus for assigning a location estimate from a first transceiver of a plurality of transceivers to a second transceiver, the second transceiver having its own location estimate and confidence level, the apparatus comprising:

a receiver adapted to receive the location estimate;

a transmitter adapted to transmit the location estimate; and

a processing system coupled to the receiver and coupled to the transmitter, the processing system programmed to;

receive the first transceiver'"'"'s location estimate and predetermined attributes describing the first transceiver'"'"'s location estimate;

calculate a confidence level of the first transceiver'"'"'s location estimate based upon the predetermined attributes; and

determine whether to update the second transceiver'"'"'s location estimate and confidence level based upon the received location estimate and calculated confidence level of the first transceiver.

18. An apparatus as recited in claim 15, wherein the processing system is further programmed to store and averaging the location estimates from those transceivers with the highest confidence levels to improve the base line location estimate for the transceiver receiving the location estimate.

19. An apparatus as recited in claim 15, wherein the processing system is further programmed to utilize a third transceiver to communicate the first transceiver'"'"'s location estimate and confidence level to the second transceiver.

20. An apparatus as recited in claim 15, wherein the processing system is further programmed to detect a need for a location estimate.

21. An apparatus as recited in claim 15, wherein the processing system is further preprogrammed with location information corresponding to a location at which each one of fixed ones of the plurality of wireless transceivers is placed.