Synchronization techniques in multi-technology/multi-frequency RFID reader arrays

• US 8,967,476 B2
• Filed: 09/07/2006
• Issued: 03/03/2015
• Est. Priority Date: 09/09/2005
• Status: Active Grant

• Current Assignee: Assa Abloy AB
• Original Assignee: Assa Abloy AB
• Inventors: Cummings, Nathan, Malone, Michael William, Andresky, David E., Clark, Philip Earl Jr., Fossen, Gregory Kenneth, Smith, Thad III
• Primary Examiner(s): JOHNSON, SONJI N
• Application Number:
  US11/470,660
• Publication Number:
  US 20070057057A1
• Time in Patent Office: 3,099 Days
• Field of Search: 340/10.3, 340/10.51, 340/10.33, 340/10.5, 340/572.1, 235/492, 235/451, 235/453, 455/435.1
• US Class Current: 235/451
• 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 7/10297 arrangements for handling protocols designed for non-contact record carriers such as RFIDs NFCs, e.g. ISO/IEC 14443 and 18092 cryptographic protocols H04L9/00; network security protocols H04L63/00; real-time communication protocols in data switching networks H04L65/00; network protocols for data switching network services H04L67/00
• CPC Class Codes: G06K 7/10356 using a plurality of antennas, e.g. configurations including means to resolve interference between the plurality of antennas

Abstract

Methods and apparatus for provisioning the use of multiple readers and/or wireless communication protocols within a defined area are provided. More specifically, a coordinator or the like can be used to manage the activation and deactivation of the multiple readers and/or communication protocols within a single reader such that interference between disparate technologies is avoided.

Claims

1. A method of controlling multiple radio frequency identification (RFID) communication protocols in a common area, comprising:

transmitting a control token from a coordinator to a first RFID reader;

in response to receiving the control token, the first RFID reader activating a first communication protocol that comprises;

determining, by the first RFID reader, that an RFID device is configured to communicating via the first communication protocol is not within the common area;

receiving, at the coordinator the control token from the first RFID reader;

after receiving the control token from the first RFID reader, monitoring, by the coordinator, Radio Frequency (RF) activity within the common area;

determining, by the coordinator and based on the RF activity within the common area, that a second communication protocol is activated within the common area without interfering with the first communication protocol, the second communication protocol varying from the first communication protocol by at least one of modulation method, data encoding method, error detection and correction method, data framing method, data communications speed, and carrier frequency; and

transmitting the control token from the coordinator to a second RFID reader; and

while the first and second RFID readers are activating their respective communication protocols, performing a coordination optimization process with the coordinator that comprises;

identifying, by the coordinator, that the RFID devices using the second communication protocol are being presented within the common area more frequently than RFID devices using the first communication protocol;

storing, by the coordinator, the information related to the relevant frequency of use of the first and second communication protocols in the common area; and

using, by the coordinator, the stored information related to the relevant frequency of use of the first and second communication protocols in the common area to increase, for subsequent cycles, an amount of time that the second RFID reader has the control token as compared to an amount of time that the first RFID reader has the control token.

2. The method of claim 1, wherein the second communication protocol is not activated while RF activity from the first communication protocol is detected in the common area.

3. The method of claim 1, further comprising adjusting, by the coordinator and for subsequent cycles, an amount of time that the first communication protocol is active relative to the second communication protocol based on time of day.

4. The method of claim 1, wherein a monitoring agent is used by the coordinator to determine information about current RF activity within the common area.

5. The method of claim 1, wherein the first RFID reader is a master reader and comprises the coordinator and wherein the second RFID reader is separate from the first RFID reader.

6. The method of claim 1, wherein the second RFID reader is only capable of activating the second communication protocol when the second RFID reader is in possession of the control token.

7. The method of claim 6, wherein the coordinator initially cycles between the first communication protocol and the second communication protocol at uniform time intervals and in subsequent cycles allows the second RFID reader to have the control token longer than the first RFID reader thereby implementing a non-uniform activation/deactivation of the second communication protocol as compared to the first communication protocol.

8. The method of claim 1, further comprising:

determining, by the coordinator, a period of time that should pass before switching from the first communication protocol to the second communication protocol, wherein the period of time depends upon data received at the coordinator during the monitoring step;

identifying that the period of time has passed since the first communication protocol was activated; and

switching between the first and second communication protocols.

9. The method of claim 8, wherein the amount of time during which the first communication protocol is active also depends on time of day.

10. The method of claim 1, further comprising:

determining that an RFID device capable of communicating via the second communication protocol is not within the common area; and

switching, by the coordinator, the active communication protocol from the second communication protocol to a third communication protocol by obtaining the control token from the second RFID reader and providing the control token to a third RFID reader.

11. The method of claim 10, wherein the third communication protocol is different from the first and second communication protocol.

12. The method of claim 10, wherein the third communication protocol is the first communication protocol.

13. The method of claim 1, further comprising:

detecting, by the second RFID reader, an RFID device capable of communicating via the second communication protocol within the common area; and

initiating communications with the detected RFID device via the second communication protocol.

14. The method of claim 1, further comprising:

identifying, by the coordinator, at least one non-interfering communication protocol that will not substantially disrupt communications via the second communication protocol with the RFID device;

activating the at least one non-interfering communication protocol.

15. The method of claim 14, wherein the at least one non-interfering communication protocol and second communication protocol are active at substantially the same time within the common area.

16. A system for controlling multiple radio frequency identification (RFID) communication protocols in a common area, comprising:

a first means for communicating operable to communicate with an RFID device via a first communication protocol;

a second means for communicating operable to communicate with an RFID device via a second communication protocol that differs from the first communication protocol by at least one of modulation method, data encoding method, error detection and correction method, data framing method, data communications speed, and carrier frequency; and

a means for coordinating the first and second means for communicating such that both the first and second means for communicating are operable to communicate with one or more RFID devices within the common area without substantially interfering with one another, wherein the means for coordinating is configured to dynamically adjust an amount of time during which the first means for communicating is active based, at least in part, upon current RF activity within the common area as well as historical RF activity within the common area, and wherein the means for coordinating adjusts an amount of time during which the first means for communicating is active as compared to an amount of time that the second means for communicating is active by providing the first means for communicating with a control token and controlling the amount of time that the first means for communicating is allowed to maintain the control token;

and while the first and second RFID readers are activating their respective communication protocols, performing a coordination optimization process with the coordinator that comprises;

identifying, by the coordinator, that the RFID devices using the second communication protocol are being presented within the common area more frequently than RFID devices using the first communication protocol;

storing, by the coordinator, the information related to the relevant frequency of use of the first and second communication protocols in the common area; and

using, by the coordinator, the stored information related to the relevant frequency of use of the first and second communication protocols in the common area to increase, for subsequent cycles, an amount of time that the second RFID reader has the control token as compared to an amount of time that the first RFID reader has the control token.

17. The system of claim 16, wherein the means for coordinating is operable to deactivate the first means for communicating prior to activating the second means for communicating.

18. The system of claim 16, wherein the first means for communicating and the means for coordinating are associated with a single master RFID reader.

19. The system of claim 16, wherein the first means for communicating is associated with a first RFID reader and the second means for communicating is associated with a second RFID reader.

20. The system of claim 19, wherein the means for coordinating is associated with the first RFID reader, wherein the means for coordinating is operable to determine that no RFID device capable of communicating via the first communication protocol is within the common area, send a message containing the control token to the second RFID reader indicating to the second RFID reader that no RFID device capable of communicating via the first communication protocol was within the common area, and deactivate the first means for communicating.

21. The system of claim 20, wherein the second RFID reader is operable to receive the message sent from the first RFID reader and activate the second means for communicating.

22. The system of claim 16, wherein the means for coordinating is operable to determine a period of time that should pass before switching an active means for communicating from the first means to the second means for communicating, identify that the period of time has passed since the first communication protocol was activated, and switch the active means for communicating from the first means to the second means for communicating.

23. The system of claim 22, further comprising a means for monitoring RF activity in the common area that is operable to communicate with the means for coordinating such that the means for coordinating can dynamically adjust the determined period of time based on time of day.

24. The system of claim 16, wherein the second means for communicating is operable to detect an RFID device capable of communicating via the second communication protocol within the common area and initiate communications with the detected RFID device via the second communication protocol.

25. The system of claim 24, wherein the means for controlling is operable to identify at least one non-interfering communication protocol that will not disrupt communications via the second communication protocol with the RFID device and activate the at least one non-interfering communication protocol.

26. An array of RFID readers, comprising:

a first RFID reader operable to communicate with RFID devices via a first communication protocol in an common area;

a second RFID reader operable to communicate with RFID devices via a second communication protocol in the common area, the second communication protocol varying from the first communication protocol by at least one of modulation method, data encoding method, error detection and correction method, data framing method, data communications speed, and carrier frequency; and

a coordinator operable to manage the activity of the first and second RFID readers by coordinating an exchange of a control token between the first and second RFID readers such that the first communication protocol does not substantially interfere with the second communication protocol, wherein the coordinator is configured to dynamically adjusting an amount of time during which the first RFID reader is active based, at least in part, upon current RF conditions within the common area and also based on historical information related to frequency of presentation of certain types of RFID devices within the common area by providing the first RFID reader with the control token and controlling the amount of time that the first RFID reader is allowed to maintain the control token; and

while the first and second RFID readers are activating their respective communication protocols, performing a coordination optimization process with the coordinator that comprises;

identifying, by the coordinator, that the RFID devices using the second communication protocol are being presented within the common area more frequently than RFID devices using the first communication protocol;

storing, by the coordinator, the information related to the relevant frequency of use of the first and second communication protocols in the common area; and

using, by the coordinator, the stored information related to the relevant frequency of use of the first and second communication protocols in the common area to increase, for subsequent cycles, an amount of time that the second RFID reader has the control token as compared to an amount of time that the first RFID reader has the control token.

27. The array of claim 26, wherein the coordinator is embodied in at least one of the first and second readers.

28. The array of claim 26, wherein the coordinator is connected to the first RFID reader by a first communication line and is connected to the second RFID reader by a second different communication line.

29. The array of claim 26, wherein the coordinator is connected to at least one of the first and second RFID readers by a communications bus.

30. The array of claim 26, wherein the coordinator communicates with at least one of the first and second RFID readers by at least one of serial asynchronous communications, I²C, SPI, and Wiegand communication methods.

31. The array of claim 26, wherein the coordinator is operable to determine that no RFID device capable of communicating via the first communication protocol is within the common area, send a message containing the control token to the second RFID reader indicating to the second RFID reader that no RFID device capable of communicating via the first communication protocol was within the common area, and deactivate the first RFID reader by virtue of the fact that the control token was taken from the first RFID reader and provided to the second RFID reader.

32. The array of claim 31, wherein the second RFID reader is operable to receive the message sent from the first RFID reader and become active upon receipt of the control token.

33. The array of claim 26, wherein the second RFID reader is operable to detect an RFID device capable of communicating via the second communication protocol within the common area and initiate communications with the detected RFID device via the second communication protocol.

34. The array of claim 26, wherein the coordinator is operable to identify at least one non-interfering communication protocol that will not disrupt communications of the second RFID reader and activate the at least one non-interfering communication protocol while the second RFID reader is also active.

35. The array of claim 26, wherein the first and second readers are in a common enclosure.

36. The array of claim 26, wherein the first reader is made by a first manufacturer and the second reader is made by a second different manufacturer.

37. A device for communicating with RFID devices via multiple communication protocols, comprising:

a first technology module operable to communicate with RFID devices via a first communication protocol;

a second technology module operable to communicate with RFID devices via a second communication protocol, the second communication protocol varying from the first communication protocol by at least one of modulation method, data encoding method, error detection and correction method, data framing method, data communications speed, and carrier frequency; and

a processor operable to coordinate the activity of the first and second technology modules such that the first technology module does not substantially interfere with the second technology module, wherein the processor is further configured to dynamically adjusting an amount of time during which the first technology module is active based, at least in part, upon current RF activity within the common area as well as an amount of power required to keep a particular communication protocol active by providing the first technology module with a control token and controlling an amount of time that the first technology module is allowed to maintain the control token; and

while the first and second RFID readers are activating their respective communication protocols, performing a coordination optimization process with the coordinator that comprises;

identifying, by the coordinator, that the RFID devices using the second communication protocol are being presented within the common area more frequently than RFID devices using the first communication protocol;

storing, by the coordinator, the information related to the relevant frequency of use of the first and second communication protocols in the common area; and

using, by the coordinator, the stored information related to the relevant frequency of use of the first and second communication protocols in the common area to increase, for subsequent cycles, an amount of time that the second RFID reader has the control token as compared to an amount of time that the first RFID reader has the control token.

38. The device of claim 37, wherein the processor comprises at least one of a field programmable gate array (FPGA), programmable logic device (PLD), and application specific integrated circuit (ASIC).

39. The device of claim 37, wherein the processor is operable to determine a period of time that should pass before switching from an active first technology module to a second technology module based on historical information related to a frequency of presentation of RFID devices in the common area, identify that the period of time has passed since the first technology module was activated, and activate the second technology module by transferring the control token to the second technology module.

40. The device of claim 37, wherein the second technology module is communicating with an RFID device, and wherein the processor is operable to identify at least one non-interfering technology module that will not disrupt communications via the second communication protocol with the RFID device and activate the at least one non-interfering technology module while the second communication protocol is also active.

41. The device of claim 37, wherein the first communication protocol uses a 125 kHz RF field and the second communication protocol uses a 13.56 MHz RF field.