Method and apparatus for handling wireless transmissions from a tag

• US 7,982,607 B2
• Filed: 06/28/2006
• Issued: 07/19/2011
• Est. Priority Date: 06/28/2006
• Status: Active Grant

• Current Assignee: Savi Technology Incorporated
• Original Assignee: Savi Technology Incorporated
• Inventors: Cargonja, Nikola, Nardelli, Albert
• Primary Examiner(s): Bugg, George A
• Assistant Examiner(s): Labbees, Edny
• Application Number:
  US11/477,133
• Publication Number:
  US 20080012708A1
• Time in Patent Office: 1,847 Days
• Field of Search: 3405721-5729, 340/905, 340/10.1, 235375-385, 342/350
• US Class Current: 340/572.1
• CPC Class Codes: G08G 1/017 identifying vehicles G08G1/015, G08G1/054 take precedence

Abstract

A tag has a receiver section, a transmitter section, and a further section, the further section being responsive to receipt by the receiver section of a wireless signpost signal from one signpost in a group of signposts for thereafter inhibiting transmission of tag signals by the transmitter section pending receipt by the receiver section of a respective signpost signal from each signpost in the group. A different configuration includes a tag having a receiver section, a transmitter section, and a further section, the further section inhibiting transmission of tag signals by the transmitter section during a time period that ends as a function of the absence of receipt by the receiver section of signpost signals, the further section responding to receipt of signpost signals by the receiver section during the time period by saving information relating to signposts that generated the signpost signals.

Claims

1. An apparatus comprising a tag having circuitry that includes:

a receiver section configured to receive wireless signpost signals that each include a signpost identification;

a transmitter section configured to transmit wireless tag signals that each include a tag identification associated with said tag; and

a further section responsive to receipt by said receiver section of signpost signals for saving information relating to signposts that generated the received signpost signals, said further section being responsive to receipt of a signpost signal from one signpost in a group of signposts for thereafter inhibiting transmission of tag signals by said transmitter section pending receipt by said receiver section of a respective signpost signal from each signpost in the group.

2. An apparatus according to claim 1, wherein during said inhibiting of transmission of tag signals, said further section of said tag is responsive to an absence of signpost signals for causing said transmitter section to use at least one said tag signal to transmit all signpost identifications received from signposts in the group.

3. An apparatus according to claim 1,

wherein said further section of said tag maintains a timer, and responds to receipt in said receiver section of each signpost signal by restarting said timer;

and

wherein during said inhibiting of transmission of tag signals, said further section of said

tag is responsive to expiration of said timer for causing said transmitter section to use at least one said tag signal to transmit all signpost identifications received from signposts in the group.

4. An apparatus according to claim 1, wherein the wireless signpost signal received by said receiver section from the one signpost contains information representative of the number of signposts in the group.

5. An apparatus according to claim 1, wherein when said receiver section has received a respective signpost signal from each signpost in the group, said further section causes said transmitter section to use at least one said tag signal to transmit the signpost identifications of all signposts in the group.

6. An apparatus according to claim 5, wherein said further section causes the transmitter section to transmit the signpost identifications in a manner that conveys the sequence in which the signpost identifications were first received by said receiver section.

7. An apparatus according to claim 1,

wherein said tag has first and second operational modes, said circuitry consuming less power in said second operational mode than in said first operational mode;

and

wherein during said inhibiting of transmission of tag signals said tag switches from said first operational mode to said second operational mode in response to an occurrence of a first event, and thereafter switch from said second operational mode back to said first operational mode in response to an occurrence of a second event.

8. An apparatus according to claim 1, wherein said further section of said tag is responsive to the occurrence of an event for discarding said saved information relating to signposts.

9. An apparatus according to claim 8, wherein said event includes said transmitter section using at least one said tag signal to transmit all signpost identifications received from signposts in the group.

10. An apparatus according to claim 1, wherein said tag has a further receiver section configured to receive wireless signals different from said signpost signals;

and wherein said further section effects one of inhibiting reception of wireless signals by and turning off power to at least part of said further receiver section during at least part of the time that said further section is effecting said inhibiting of transmission of tag signals.

11. A method of operating a tag that configured to transmit wireless tag signals, comprising:

receiving wireless signpost signals that each include a signpost identification;

responding to receipt of signpost signals by saving information relating to signposts that generated the received signpost signals, including responding to receipt of a signpost signal from one signpost in a group of signposts by thereafter inhibiting transmission of tag signals by said tag pending receipt by said tag of a respective signpost signal from each signpost in the group.

12. A method according to claim 11, including during said inhibiting of transmission of tag signals, responding to an absence of signpost signals by causing said tag to use at least one tag signal to transmit all signpost identifications received from signposts in the group.

13. A method according to claim 11,

wherein said responding to receipt of signpost signals includes responding to receipt of each signpost signal by restarting a timer;

and

including responding to expiration of said timer during said inhibiting of transmission of tag signals by causing said tag to use at least one tag signal to transmit all signpost identifications received from signposts in the group.

14. A method according to claim 11, including configuring the wireless signpost signal received by said tag from the one signpost to contain information representative of the number of signposts in the group.

15. A method according to claim 11, including responding to receipt of a respective signpost signal from each signpost in the group by causing said tag to use at least one tag signal to transmit the signpost identifications of all signposts in the group.

16. A method according to claim 15, wherein said transmitting of signpost identifications is carried out in a manner that conveys the sequence in which the signpost identifications were first received by said tag.

17. A method according to claim 11,

wherein said tag has first and second operational modes, said tag consuming less power in said second operational mode than in said first operational mode;

including responding to an occurrence of a first event during said inhibiting of transmission of tag signals by switching said tag from said first operational mode to said second operational mode; and

thereafter responding to an occurrence of a second event by switching said tag from said second operational mode back to said first operational mode.

18. A method according to claim 11, including responding to an occurrence of an event by discarding said saved information relating to signposts.

19. A method according to claim 18 including selecting said event to include transmission by said tag in at least one said tag signal of all signpost identifications received from signposts in the group.

20. A method according to claim 11, including receiving in a receiver section of said tag wireless signals that are different from said signpost signals;

and including one of inhibiting reception of wireless signals by and turning off power to at least part of said receiver section during at least part of the time that said inhibiting of transmission of tag signals is taking place.

21. An apparatus comprising a tag having circuitry that includes:

a receiver section configured to receive wireless signpost signals that each include a signpost identification;

a transmitter section configured to transmit wireless tag signals that each include a tag identification associated with said tag; and

a further section that inhibits transmission of tag signals by said transmitter section during a time period that ends as a function of the absence of receipt by said receiver section of signpost signals, said further section being responsive to receipt of signpost signals by said receiver section during said time period for saving information relating to signposts that generated the signpost signals.

22. An apparatus according to claim 21, wherein said time period ends upon detection by said receiver section of the absence of any signpost signals.

23. An apparatus according to claim 21, wherein said time period ends upon the elapse of a predetermined time interval without receipt by said receiver section of any signpost signal, said time period being longer than said time interval.

24. An apparatus according to claim 23, wherein said further section of said tag maintains a timer having a duration equal to said time interval, and responds to receipt of each signpost signal by restarting said timer, said expiration of said time interval occurring upon expiration of said timer.

25. An apparatus according to claim 21, wherein said further section is responsive to the end of said time period for causing said transmitter section to use at least one said tag signal to transmit all signpost identifications saved by said further section during said time period.

26. An apparatus according to claim 25, wherein said further section causes said transmitter section to transmit the signpost identifications in a manner that conveys the sequence in which the signpost identifications were first received by said receiver section during said time period.

27. An apparatus according to claim 21, wherein said time period begins when said receiver section first receives a signpost signal following the end of a prior said time period.

28. An apparatus according to claim 21,

wherein said tag has first and second operational modes, said circuitry consuming less power in said second operational mode than in said first operational mode;

and

wherein during said inhibiting of transmission of tag signals said tag switches from said first operational mode to said second operational mode in response to an occurrence of a first event, and thereafter switch from said second operational mode back to said first operational mode in response to an occurrence of a second event.

29. An apparatus according to claim 21 wherein said tag has a further receiver section configured to receive wireless signals different from said signpost signals;

and wherein said further section effects one of inhibiting reception of wireless signals by and turning off power to at least part of said further receiver section during at least part of the time that said further section is effecting said inhibiting of transmission of tag signals.

30. A method of operating a tag, comprising:

receiving wireless signpost signals that each include a signpost identification; and

inhibiting transmission of tag signals by said tag during a time period that ends as a function of the absence of receipt by said tag of signpost signals; and

responding to receipt of signpost signals during said time period by saving information relating to signposts that generated the signpost signals.

31. A method according to claim 30, including ending said time period upon detection of the absence of any signpost signals.

32. A method according to claim 30, including ending said time period upon the elapse of a predetermined time interval without receipt of any signpost signal, said time period being longer than said time interval.

33. A method according to claim 32, including:

maintaining a timer having a duration equal to said time interval; and

responding to receipt of each signpost signal by restarting said timer, said expiration of said time interval occurring upon expiration of said timer.

34. A method according to claim 30, including responding to the end of said time period by using at least one said tag signal to transmit all signpost identifications saved during said time period.

35. A method according to claim 34, wherein said transmitting of signpost identifications is carried out in a manner that conveys the sequence in which the signpost identifications were first received by said tag during said time period.

36. A method according to claim 30, including starting said time period when said tag first receives a signpost signal following the end of a prior said time period.

37. A method according to claim 30,

wherein said tag has first and second operational modes, said tag consuming less power in said second operational mode than in said first operational mode;

including responding to an occurrence of a first event during said inhibiting of transmission of tag signals by switching said tag from said first operational mode to said second operational mode; and

including thereafter responding to an occurrence of a second event by switching said tag from said second operational mode back to said first operational mode.

38. A method according to claim 30, including receiving in a receiver section of said tag wireless signals that are different from said signpost signals;

and including one of inhibiting reception of wireless signals by and turning off power to at least part of said receiver section during at least part of the time that said inhibiting of transmission of tag signals is taking place.