RFID tag systems, RFID tags and RFID processes using N-ary FSK

• US 20050237158A1
• Filed: 03/25/2005
• Published: 10/27/2005
• Est. Priority Date: 04/13/2004
• Status: Abandoned Application

• Current Assignee: Impinj, Inc.
• Original Assignee: Impinj, Inc.
• Inventors: Diorio, Christopher J., Moretti, Vincent C., Humes, Todd E., Cooper, Scott Anthony, Esterberg, Aanand, Sundstrom, Kurt Eugene
• Application Number:
  US11/090,961
• Publication Number:
  US 20050237158A1
• Time in Patent Office: Days
• US Class Current: 340/10.200
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: G06K 7/10049 binary tree

Abstract

A process is disclosed for communicating with individual tags in a population of tags having a binary tree organization, wherein each tag corresponds to a leaf node of the binary tree. The process includes singulating a predetermined leaf node and returning to a designated re-entry node associated with the predetermined leaf node after singulating.

Claims

1. A process for communicating with individual tags in a population of tags having a binary tree organization extending from a root node to a plurality of leaf nodes, each tag corresponding to a leaf node of the binary tree, the process comprising:

singulating a predetermined leaf node; and

returning to a designated re-entry node associated with the predetermined leaf node after singulating, where the designated re-entry node is other than the root node.

2. The process of claim 1, wherein singulating comprises:

transmitting a mute command configured to cause a subset of the population associated with a branch node of the binary tree to enter a mute state; and

iterating transmitting until the predetermined leaf node is singulated.

3. The process of claim 1, further comprising:

second singulating a second predetermined leaf node associated with the re-entry node;

iterating second singulating until all leaf nodes associated with the re-entry node have been singulated;

third singulating another leaf node not associated with the designated re-entry node; and

returning to another re-entry node associated with the another leaf node.

4. The process of claim 1, further comprising, after iterating and before returning, exchanging data with the predetermined tag.

5. The process of claim 1, further comprising transmitting re-entry node information to the population of tags prior to singulating.

6. The process of claim 1, further comprising transmitting a list of re-entry nodes to the population of tags.

7. The process of claim 1, further comprising, after iterating and before returning, determining that the predetermined tag corresponding to the predetermined leaf node is not in the population of tags.

8. The process of claim 1, further comprising, after iterating and before returning, determining that the predetermined tag corresponding to the predetermined leaf node is in the population of tags.

9. The process of claim 1, further comprising:

returning to a root node;

singulating another leaf node not associated with the designated re-entry node; and

returning to another re-entry node associated with the another leaf node.

10. The process of claim 1, wherein returning comprises returning to a re-entry node in response to a command to return to a re-entry node N many node levels higher in the binary tree.

11. The process of claim 1, wherein returning comprises returning to a re-entry node in response to a series of commands each corresponding to a single node level in the binary tree.

12. The process of claim 1, wherein returning comprises returning to a re-entry node in response to an N-bit command to return to a re-entry node N many node levels higher in the binary tree.

13. The process of claim 1, wherein returning comprises returning to a re-entry node in response to a command to return to a re-entry node N many node levels higher in the binary tree, where N is a number stored in a memory in the tag.

14. A process for designating a set of re-entry nodes in a population of tags having a binary tree organization comprising:

selecting a group of re-entry nodes; and

transmitting a list of the group of re-entry nodes to the population of tags.

15. The process of claim 14, further comprising transmitting a revised list of re-entry nodes to the population of tags.

16. The process of claim 14, further comprising transmitting a signal configured to cause the tags in the population to index back to a designated re-entry node from the list.

17. The process of claim 14, further comprising, after transmitting:

singulating a first leaf node; and

returning to a designated re-entry node associated with the first leaf node.

18. The process of claim 14, further comprising, after transmitting:

singulating a leaf node;

returning to a designated re-entry node associated with the leaf node; and

repeating singulating and returning until all leaf nodes associated with the designated re-entry node have been singulated.

19. The process of claim 14, further comprising, after transmitting:

singulating a leaf node;

returning to a designated re-entry node associated with the leaf node;

repeating singulating and returning until all leaf nodes associated with the designated re-entry node have been singulated;

singulating another leaf node not associated with the designated re-entry node; and

returning to another re-entry node associated with the another leaf node.

20. In a tag, a process for coordinating multiple tags organized into a binary tree structure, comprising:

receiving, by the tag, a list of one or more re-entry nodes; and

storing the list in a memory in the tag.

21. The process of claim 20, wherein receiving the list comprises receiving the list comprising information chosen from a group consisting of:

an ID code, a serial number, a unique ID, a pseudo ID code or a pseudo identification code.

22. The process of claim 20, further comprising returning to a re-entry node from the list that is associated with a leaf node following singulation of the leaf node.

23. The process of claim 20, further comprising:

returning to a re-entry node associated with a leaf node following singulation of the leaf node; and

entering a mute state when the tag is not associated with the re-entry node.

24. The process of claim 20, further comprising:

entering a traverse state;

returning to a re-entry node from the list associated with a leaf node following singulation of the leaf node; and

entering a mute state when the tag is not associated with the re-entry node.

25. The process of claim 20, further comprising:

entering a traverse state in response to a command from a reader;

returning to a re-entry node from the list associated with a leaf node following singulation of the leaf node; and

entering a mute state when the tag is not associated with the re-entry node.

26. The process of claim 20, wherein storing comprises storing the list in a volatile memory in the tag.

27. The process of claim 20, wherein storing comprises storing the list in a non-volatile memory in the tag.

28. An RF tag in a population of RF tags organized into a binary tree structure comprising a root node, branch nodes and leaf nodes, each of the leaf nodes being associated with one of the population of RF tags, the RF tag being configured to:

accept re-entry node information; and

store the re-entry node information.

29. The RF tag of claim 28, wherein the RF tag is configured to store re-entry node information comprising a list of re-entry nodes in a non-volatile memory.

30. The RF tag of claim 28, wherein the RF tag accepts the re-entry node information from an interrogation unit.

31. The RF tag of claim 28, wherein the RF tag is further configured to modify the stored information in response to a command from an interrogation unit.

32. The RF tag of claim 28, wherein the RF tag is further configured to:

return to a re-entry node associated with a leaf node following singulation of the leaf node; and

enter a mute state when the RF tag is not associated with the re-entry node.

33. A tag configured to be attached to an object, the tag including:

a transceiver;

a processor coupled to the transceiver and configured to respond to commands received by the transceiver and to transmit responses to the commands via the transceiver; and

a memory coupled to the processor, the memory and processor being configured to cooperatively track a set of re-entry nodes, and to place the tag in a mute state when the re-entry node is not a re-entry node associated with the tag and to place the tag in a traverse state when the re-entry node is a re-entry node associated with the tag.

34. The tag of claim 33, wherein the tag is an RFID tag.

35. The tag of claim 33, wherein the memory includes non-volatile read-write memory configured to store a list of re-entry nodes in response to commands received by the transceiver.

36. The tag of claim 33, wherein the memory includes non-volatile memory configured to store a list of re-entry nodes.

37. The tag of claim 33, wherein the memory includes a stack, and wherein the processor pushes data onto the stack to track branch nodes.

38. The tag of claim 33, wherein the tag is configured to automatically return to a nearest branch node in response to signals received by the transceiver.

39. An apparatus for designating a set of re-entry nodes in a population of tags having a binary tree organization comprising:

means for selecting a group of re-entry nodes; and

means transmitting a list of the group of re-entry nodes to the population of tags.

40. The apparatus of claim 39, further comprising means for transmitting a revised list of re-entry nodes to the population of tags.

41. The apparatus of claim 39, further comprising means for transmitting a signal configured to cause the tags in the population to index back to a designated re-entry node from the list.

42. The apparatus of claim 39, further comprising:

means for singulating a first leaf node after the transmitting means transmits the list; and

means returning to a designated re-entry node associated with the first leaf node.

43. The apparatus of claim 39, further comprising:

means for singulating a leaf node after the transmitting means transmits the list;

means for returning to a designated re-entry node associated with the leaf node; and

means for iterating singulating and returning until all leaf nodes associated with the designated re-entry node have been singulated.

44. The apparatus of claim 39, further comprising:

means for singulating a leaf node after the transmitting means transmits the list;

means for returning to a designated re-entry node associated with the leaf node;

means for repeating singulating and returning until all leaf nodes associated with the designated re-entry node have been singulated;

means for singulating another leaf node not associated with the designated re-entry node; and

means for returning to another re-entry node associated with the another leaf node.

45. In a tag, an apparatus for coordinating multiple tags organized into a binary tree structure, comprising:

means for receiving, by the tag, a list of one or more re-entry nodes; and

means for storing the list in a memory in the tag.

46. The apparatus of claim 45, wherein the receiving means comprises means for receiving the list comprising information chosen from a group consisting of:

an ID code, a serial number, a unique ID, a pseudo ID code or a pseudo identification code.

47. The apparatus of claim 45, further comprising means for returning to a re-entry node from the list that is associated with a leaf node following singulation of the leaf node.

48. The apparatus of claim 45, further comprising:

means for returning to a re-entry node associated with a leaf node following singulation of the leaf node; and

means for entering a mute state when the tag is not associated with the re-entry node.

49. The apparatus of claim 45, further comprising:

means for entering a traverse state;

means for returning to a re-entry node from the list associated with a leaf node following singulation of the leaf node; and

means for entering a mute state when the tag is not associated with the re-entry node.

50. The apparatus of claim 45, further comprising:

means for entering a traverse state in response to a command from a reader;

means for returning to a re-entry node from the list associated with a leaf node following singulation of the leaf node; and

means for entering a mute state when the tag is not associated with the re-entry node.

51. The apparatus of claim 45, wherein the storing means comprises means for storing the list in a volatile memory in the tag.

52. The apparatus of claim 45, wherein the storing means comprises means for storing the list in a non-volatile memory in the tag.