RFID tag data acquisition system

• US 7,667,572 B2
• Filed: 07/29/2005
• Issued: 02/23/2010
• Est. Priority Date: 07/30/2004
• Status: Active Grant

• Current Assignee: Quake Global, Inc.
• Original Assignee: Reva Systems Corp. (Quake Global, Inc.)
• Inventors: Stephenson, Robert A., Grady, Michael, Cabot, Chilton L., Barvick, Scott, Fischer, Jeffrey H., Husak, David J., Krishna, Pattabhiraman
• Primary Examiner(s): Zimmerman; Brian A
• Assistant Examiner(s): Nguyen; Nam V
• Application Number:
  US11/194,128
• Publication Number:
  US 20060022801A1
• Time in Patent Office: 1,670 Days
• Field of Search: 340/10.1, 340/10.2, 340/10.31, 340/572.1, 370/314, 370/445, 708/250, 708/255
• US Class Current: 340/10.1
• CPC Class Codes: G01S 5/02525 Gathering the radio frequency fingerprints
• CPC Class Codes: G01S 5/06 Position of source determined by co-ordinating a plurality of position lines defined by path-difference measurements G01S5/12 takes precedence
• CPC Class Codes: G06K 17/0029 the arrangement being specially adapted for wireless interrogation of grouped or bundled articles tagged with wireless record carriers
• 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 7/10356 using a plurality of antennas, e.g. configurations including means to resolve interference between the plurality of antennas

Abstract

An architecture of an RFID system that facilitates the accessing of RFID tag data within an RFID environment. The architecture includes a plurality of RFID readers, each reader being operative to transmit a first RF signal for scanning at least one RFID tag disposed within an RF coverage region associated with the reader, and to receive at least one second RF signal including tag data in response to the scanning of the tag. The architecture further includes at least one host computer operative to execute at least one client application, and at least one controller/processor communicably coupled to the plurality of readers and the at least one host computer. The controller/processor is operative to control operation of the plurality of readers, to process the tag data received by the plurality of readers, and to provide the processed tag data to the at least one host computer for use by the at least one client application executing thereon.

Claims

1. Apparatus for use in a radio frequency identification (RFID) system, said RFID system including at least one RF interrogator and at least one RF receiver, said at least one RF interrogator being operative to transmit at least one RF interrogation signal to at least one RFID tag, said at least one RF receiver being operative to receive tag data from at least one RFID tag, each of said at least one RF interrogator and said at least one RF receiver having an RF coverage zone associated therewith, said RFID system being deployed in an environment, said apparatus comprising:

a controller including an interface for communicably coupling said controller to said at least one RF interrogator and said at least one RF receiver, said controller including a data storage containing a database, said database being operative to store information pertaining to a configuration of said RFID system and an RF characteristic within said environment, said configuration of said RFID system including representations of physical locations of said at least one RF interrogator and said at least one RF receiver with respect to a physical layout,

wherein said controller is operative;

to receive data indicative of a change in said configuration of said RFID system or said RF characteristic within said environment, or presence information indicating a presence of at least one RFID tag within the RF coverage zone of one of said at least one RF interrogator or said at least one RF receiver; and

in response to the receipt of said data indicating said change or said presence information for the RFID tag, to generate a first parameter defining an operational characteristic of one of said at least one RF interrogator or said at least one RF receiver, to generate a message including a command for forwarding said first parameter, and to forward said command containing said first parameter to the respective RF interrogator or RF receiver to modify a behavior of the respective RF interrogator or RF receiver.

2. The apparatus of claim 1 wherein said controller is further operative to generate said message including said command for forwarding said first parameter to said one of said at least one RF receiver or said at least one RF interrogator to control the operation of the respective RF receiver or RF interrogator within said environment.

3. The apparatus of claim 2 wherein said controller is further operative, in response to said change in said configuration of said RFID system, said change in said RF characteristic within said environment, or the receipt of said presence information for the RFID tag, to generate said message including said command for forwarding said first parameter to said one of said at least one RF receiver or said at least one RF interrogator, to dynamically control the operation of the respective RF receiver or RF interrogator.

4. The apparatus of claim 1:

wherein said RFID system further includes a computer;

wherein said controller is communicably coupleable to said computer; and

wherein said controller is further operative to provide at least some of said information pertaining to said configuration of said RFID system or said RF characteristic within said environment to said computer, thereby allowing said computer to compute, based at least in part upon the information provided by said controller, additional information for use in controlling the respective RF receiver or RF interrogator.

5. The apparatus of claim 1 wherein said configuration of said RFID system includes at least one operational characteristic of one or more of said at least one RF receiver and said at least one RF interrogator.

6. The apparatus of claim 1 wherein said controller is communicably coupleable to said at least one RF receiver or said at least one RF interrogator via at least one network.

7. The apparatus of claim 6 wherein at least a portion of said at least one network is a wired network.

8. The apparatus of claim 6 wherein at least a portion of said at least one network is a wireless network.

9. The apparatus of claim 1 wherein said at least one controller is further operative:

to update the information stored in said at least one database in accordance with said data indicating said change in said configuration of said RFID system or said RF characteristic within said environment.

10. The apparatus of claim 1 wherein said first parameter corresponds to one or more of a transmit power, an availability of independent transmit functions for said at least one RF interrogator, a center frequency for said at least one RF interrogator, a frequency hopping pattern, an identification of a modulation scheme, a bandwidth, and an interrogation interval specifying a period between interrogations by said at least one RF interrogator.

11. The apparatus of claim 1 wherein said first parameter corresponds to one or more of a receive sensitivity, an availability of independent receive functions for said at least one RF receiver, a center frequency for said at least one RF receiver, a frequency hopping pattern, an identification of a modulation scheme, and a bandwidth.

12. The apparatus of claim 1:

wherein said RFID system further includes at least one host computer operative to execute at least one client application; and

wherein said controller is further operative;

to receive said RFID tag data from said at least one RF receiver;

to process said RFID tag data to produce processed RFID tag data; and

to forward said processed RFID tag data to the host computer for use by the client application.

13. The apparatus of claim 1 wherein said one of said at least one RF receiver is operative to associate a time stamp with RFID tag data received from at least one RFID tag by the respective RF receiver.

14. The apparatus of claim 1 further including at least one additional controller, said controller and said at least one additional controller being communicably coupled to one another, and wherein each of the controllers is associated with and in communication with one or more of said at least one RF receiver or said at least one RF interrogator.

15. The apparatus of claim 1 wherein said at least one RF receiver includes at least two distinct RF receivers and said at least one RF interrogator includes at least two distinct RF interrogators, and wherein said apparatus further includes at least one additional controller, said controller and said at least one additional controller being communicably coupled to one another, each of the controllers being associated with, and in communication with, one or more of said at least two distinct RF receivers or said at least two distinct RF interrogators, said associations being re-assignable from one of the controllers to the other controller in response to at least one predetermined event.

16. The apparatus of claim 15 wherein said predetermined event comprises a failure of one of the controllers.

17. The apparatus of claim 1

wherein said controller is further operative to determine a physical extent of the RF coverage zone associated with one of said at least one RF interrogator based at least in part upon whether at least one RF interrogation signal is received by an RFID tag disposed at a fixed location within said environment.

18. The apparatus of claim 1 wherein said controller is further operative to forward said command to said one of said at least one RF interrogator to transmit at least one RF interrogation signal to retrieve sensor data from at least one sensor, said at least one sensor being incorporated in at least one RFID tag, said at least one sensor being operative to sense one or more of a temperature, a humidity, a vibration, and an orientation of said at least one RFID tag within said environment to produce said sensor data.

19. The apparatus of claim 1:

wherein said at least one RF receiver comprises at least one physical RF receiver;

wherein said RFID system further includes at least one logical RFID tag reader, said at least one logical RFID tag reader being associated with said at least one physical RF receiver and at least one operating profile; and

wherein said controller is further operative to send at least one first signaling message to one of said at least one logical RFID tag reader to establish the operating profile associated with the respective logical RFID tag reader.

20. The apparatus of claim 19:

wherein said at least one RF interrogator comprises a physical RF interrogator associated with one of said at least one logical RFID tag reader; and

wherein said controller is further operative to send to said physical RF interrogator a scheduling message that specifies a timing of at least one transmission of an RF interrogation signal by said physical RF interrogator.

21. The apparatus of claim 1 wherein said controller is further operative to determine an operational status of one of said at least one RF receiver or said at least one RF interrogator by monitoring a condition of the respective RF receiver or RF interrogator.

22. The apparatus of claim 1 wherein said controller is further operative to determine an operational status of one of said at least one RF receiver or said at least one RF interrogator at least in part by monitoring a level of RF interference at the respective RF receiver or RF interrogator.

23. The apparatus of claim 1 wherein said controller is further operative, in response to an addition of at least one additional RF receiver or RF interrogator to said RFID system, to employ a predetermined protocol to identify said at least one additional RF receiver or RF interrogator.

24. The apparatus of claim 1 wherein said controller is further operative to assign at least one IP address to said at least one RF receiver or said at least one RF interrogator.

25. The apparatus of claim 1:

wherein said at least one RF receiver comprises at least one physical RF receiver;

wherein said RFID system further includes at least one logical RFID tag reader, one of said at least one logical RFID tag reader being associated with one of said at least one physical RF receiver and an operating profile; and

wherein said controller is further operative to reconfigure said operating profile in response to said change in said configuration of said RFID system or said RF characteristic within said environment.

26. A controller for use in a radio frequency identification (RFID) system, said RFID system including at least one RF interrogator and at least one RF receiver, said at least one RF interrogator being operative to transmit at least one RF interrogation signal to at least one RFID tag, said at least one RF receiver being operative to receive tag data from at least one RFID tag in response to the transmission of said at least one RF interrogation signal, each of said at least one RF interrogator and said at least one RF receiver having an RF coverage zone associated therewith, said RFID system being deployed in an environment, said controller comprising:

at least one processor;

a first interface in communication with the processor, the processor being operative to receive, via the first interface, data indicating a change in a configuration of said RFID system or an RF characteristic within said environment, or presence information indicating a presence of at least one RFID tag within the RF coverage zone of one of said at least one RF interrogator or said at least one RF receiver;

wherein the processor is further operative, in response to the receipt of said data indicating said change or said presence information for the RFID tag, to generate, in real-time, a parameter defining a characteristic of one of said at least one RF interrogator or said at least one RF receiver; and

a second interface in communication with the processor, the processor being further operative to send, via the second interface, a command containing said parameter to the respective RF interrogator or RF receiver for modifying, in real-time, an aspect of behavior of the respective RF interrogator or RF receiver.

27. A controller for use in a radio frequency identification (RFID) system, said RFID system including at least one RF interrogator and at least one RF receiver, said at least one RF interrogator being operative to transmit at least one RF interrogation signal to at least one RFID tag, said at least one RF receiver being operative to receive tag data from at least one RFID tag, said RFID system being deployed in an environment, said controller comprising:

at least one memory containing at least one tag scan database;

a first interface operative to receive tag data from one of said at least one RF receiver for storage in the tag scan database; and

at least one processor operative to store the received tag data in the tag scan database, and to process the tag data to produce processed tag data,

wherein said at least one processor is further operative to forward the processed tag data to a host computer for use by a client application executing on the host computer,

wherein said tag data includes one or more of a tag identifier, a time stamp corresponding to a time of receipt of the respective tag data by said one of said at least one RF receiver, and at least one operational parameter in use by one or more of said at least one RF receiver and said at least one RF interrogator during at least one interrogation of the respective RFID tag by said at least one RF interrogator, and

wherein said at least one operational parameter corresponds to one or more of a transmit power used by said at least one RF interrogator, a sensitivity of said at least one RF receiver, an identification of an antenna selection, an antenna pointing parameter, and presence information indicating whether a particular RFID tag is present within a specified interrogation zone associated with said at least one RF interrogator.

28. The controller of claim 27 wherein said controller is operative to identify and discard duplicative tag data within said tag scan database.

29. The controller of claim 27 wherein said controller is operative to discard duplicative tag data received over a specified time interval.

30. The controller of claim 27 wherein said controller is operative to discard tag data stored within said tag scan database for a specified time interval.

31. A radio frequency identification (RFID) system, said RFID system being deployed in an environment, said RFID system comprising:

a plurality of RFID system components including at least one RF interrogator and at least one RF receiver, each of said at least one RF interrogator and at least one RF receiver having an RF coverage zone associated therewith; and

a plurality of controllers,

wherein each of said plurality of controllers is associated with a subset of said plurality of RFID system components,

wherein said plurality of controllers are communicably coupled to each other and to their associated subsets of said plurality of RFID system components, and

wherein each of said plurality of controllers is operative, in response to a receipt of data indicating a change in a configuration of said system or an RF characteristic within said environment, or presence information indicating a presence of at least one RFID tag within the RF coverage zone of one of said at least one RF interrogator or said at least one RF receiver, to generate a first parameter defining an operational characteristic of one of said plurality of RFID system components in its associated subset of RFID system components, to generate a message including a command for forwarding said first parameter, and to forward said command containing said first parameter to said one of said plurality of RFID system components in its associated subset of RFID system components to modify a behavior of the respective RFID system component.

32. The system of claim 31 wherein said plurality of controllers includes a first controller and a second controller, said first controller being associated with a first subset of said plurality of RFID system components, and said second controller being associated with a second subset of said plurality of RFID system components.

33. The system of claim 32 wherein said first controller is associated with said second subset of said plurality of RFID system components as a first standby controller, and said second controller is associated with said first subset of said plurality of RFID system components as a second standby controller.

34. The system of claim 33 wherein each of said first and second controllers includes at least one tag scan database containing identical tag data so as to permit continuous operation of said system in the event one of said first and second controllers becomes inoperative.

35. The system of claim 31 wherein said plurality of controllers includes first and second controllers, and wherein each of said first and second controllers includes a switch configuration database containing identities of said first and second controllers, and an identity of the subset of said plurality of RFID system components associated therewith.

36. The system of claim 31 wherein said plurality of controllers includes first and second controllers, wherein each of said first and second controllers includes a switch configuration database identifying data services that the respective controller is capable of providing, and an indication of whether the respective controller is operative to provide each data service on an active basis or a standby basis.

37. The system of claim 31 wherein associations between said plurality of controllers and the subsets of said plurality of RFID system components are modifiable in response to at least one predetermined event.

38. The system of claim 37 wherein said at least one predetermined event includes a failure of at least one of said plurality of controllers.

39. The system of claim 37 wherein said at least one predetermined event includes a disconnection of one or more of said at least one RF interrogator and said at least one RF receiver from at least one network.

40. The system of claim 31 wherein each of said plurality of controllers is capable of providing at least one predetermined data service, and wherein each of said plurality of controllers is operative to perform at least one selected one of said at least one data service based upon at least one specified data service assignment.

41. The system of claim 40 wherein each of said plurality of controllers is capable of identifying said at least one predetermined data service provided by each of the respective controllers.

42. The system of claim 40 further including a plurality of host computers coupled to said plurality of controllers, each of said plurality of host computers being operative to execute at least one client application.

43. The system of claim 42 wherein each of said plurality of controllers is capable of providing an indication of said at least one predetermined data service provided by the respective controller to the plurality of host computers for use by the respective client applications.

44. The system of claim 40 wherein each of said plurality of controllers is operative to modify said at least one specified data service assignment in response to at least one predetermined event.

45. The system of claim 40 wherein at least one of said plurality of controllers is operative to reassign said at least one specified data service assignment in response to a failure of at least one of said plurality of controllers.

46. The system of claim 40 wherein at least one of said plurality of controllers is operative to reassign said at least one specified data service assignment in response to a disconnection of at least one of said at least one interrogator and said at least one RF receiver from at least one network.

47. The system of claim 40 wherein at least one of said plurality of controllers is operative to reassign said at least one specified data service assignment in response to an addition of at least one of at least one interrogator and at least one RF receiver to said system.

48. The system of claim 31 wherein said environment comprises an RF operational environment of said at least one interrogator and said at least one RF receiver, and wherein at least one of said plurality of controllers is operative to maintain a representation of said RF operational environment.

49. The system of claim 48 wherein said representation of the RF operational environment is based upon at least one of an RF coverage zone associated with at least one of said at least one RF interrogator and said at least one RF receiver, and a level of RF interference associated with said at least one of said at least one RF interrogator and said at least one RF receiver.

50. The system of claim 49 wherein said at least one of said plurality of controllers is operative to monitor and to characterize said RF interference associated with said at least one of said at least one interrogator and said at least one RF receiver.

51. The system of claim 31 wherein at least one of said plurality of controllers is operative to modify at least one association between said plurality of controllers and the subsets of said plurality of RFID system components in response to an addition of at least one of at least one RF interrogator and at least one RF receiver to said system.

52. The system of claim 31 wherein at least one of said at least one interrogator and said at least one RF receiver is maintained at a fixed physical location within said environment.

53. The system of claim 31 wherein at least one of said plurality of controllers is operative to synchronize operations of said plurality of controllers, said at least one interrogator, and said at least one RF receiver.

54. The system of claim 53 wherein said at least one of said plurality of controllers is operative to synchronize said operations of said plurality of controllers, said at least one interrogator, and said at least one RF receiver to a precision level selected from one of a plurality of available precision levels.

55. The system of claim 53 wherein said at least one of said plurality of controllers is operative to synchronize said operations of said plurality of controllers, said at least one interrogator, and said at least one RF receiver by sending at least one signaling message containing at least one command to at least one of said at least one interrogator and said at least one RF receiver.

56. The system of claim 31 wherein at least one of said plurality of controllers is operative to synchronize operations of said plurality of controllers, said at least one RF interrogator, and said at least one RF receiver to a real-time clock based upon a network time protocol (NTP).

57. The system of claim 31 wherein said at least one interrogator comprises a plurality of interrogators, and wherein at least one of said plurality of interrogators is operative to synchronize operations performed by other ones of said plurality of interrogators.

58. The system of claim 57 wherein at least one of said plurality of RF interrogators is operative to synchronize the operations performed by other ones of said plurality of RF interrogators to a real-time clock based upon a network time protocol (NTP).

59. A method of operating a radio frequency identification (RFID) system, said RFID system including at least one RF interrogator and at least one RF receiver, said at least one RF interrogator being operative to transmit at least one RF interrogation signal to at least one RFID tag, said at least one RF receiver being operative to receive tag data from at least one RFID tag, each of said at least one RF interrogator and said at least one RF receiver having an RF coverage zone associated therewith, said RFID system being deployed in an environment, said method comprising the steps of:

storing, by a processor in a database, information pertaining to a configuration of said RFID system and an RF characteristic within said environment, said database being contained in a data storage,

wherein said configuration of said RFID system includes representations of physical locations of said at least one RF interrogator and said at least one RF receiver with respect to a physical layout;

receiving, by said processor, data indicating a change in said configuration of said RFID system or said RF characteristic within said environment, or presence information indicating a presence of at least one RFID tag within the RF coverage zone of one of said at least one RF interrogator or said at least one RF receiver; and

in response to the receipt of said data indicating said change or said presence information for the RFID tag, generating, by said processor, a first parameter defining an operational characteristic of one of said at least one RF interrogator or said at least one RF receiver, generating a message including a command for forwarding said first parameter, and forwarding said command containing said first parameter to the respective RF interrogator or RF receiver to modify a behavior of the respective RF interrogator or RF receiver within said environment.

60. The method of claim 59 further including forwarding said command containing said first parameter to said one of said at least one RF interrogator or said at least one RF receiver to control the operation of the respective RF interrogator or RF receiver within said environment.

61. The method of claim 59 further including forwarding said command containing said first parameter to said one of said at least one RF interrogator or said at least one RF receiver in response to a change in a physical location of the respective RF interrogator or RF receiver, or a change in an operational or connection status of the respective RF interrogator or RF receiver, to dynamically control the operation of the respective RF interrogator or RF receiver within said environment.

62. The method of claim 59 further including the step of computing, by a computer in communication with said processor, information for use in the control of the respective RF interrogator or RF receiver based, at least in part, upon at least a portion of the information pertaining to said at least one configuration of said system.

63. The method of claim 62 further including the step of storing, by said processor, said information for use in the control of the respective RF interrogator or RF receiver in said database.

64. The method of claim 59 further including updating the information stored in said at least one database in accordance with said data indicating said change in said configuration of said RFID system or said RF characteristic within said environment.

65. The method of claim 59 further including the steps of:

executing, by a host computer, a client application;

receiving, at said controller, tag data from said at least one RF receiver;

processing, by said processor, said tag data to produce processed RFID tag data; and

forwarding, by said processor, said processed RFID tag data to said host computer for use by said client application.

66. A method of operating a radio frequency identification (RFID) system, said RFID system including at least one RF interrogator and at least one RF receiver, said at least one RF interrogator being operative to transmit at least one RF interrogation signal to at least one RFID tag, said at least one RF receiver being operative to receive tag data from at least one RFID tag, each of said at least one RF interrogator and said at least one RF receiver having an RF coverage zone associated therewith, said RFID system being deployed in an environment, said method comprising the steps of:

receiving, by a processor, data indicating a change in a configuration of said RFID system or an RF characteristic within said environment, or presence information indicating a presence of at least one RFID tag within the RF coverage zone of one of said at least one RF interrogator or said at least one RF receiver;

in response to the receipt of said data indicating said change or said presence information for the RFID tag, generating, by said processor in real-time, a first parameter defining an operational characteristic of one of said at least one RF interrogator or said at least one RF receiver; and

sending a command containing said first parameter to the respective RF interrogator or RF receiver for modifying, in real-time, a behavior of the respective RF interrogator or RF receiver.

67. A method of operating a radio frequency identification (RFID) system, said RFID system including at least one RF interrogator and at least one RF receiver, said at least one RF interrogator being operative to transmit at least one RF interrogation signal to at least one RFID tag, said at least one RF receiver being operative to receive tag data from at least one RFID tag, said RFID system being deployed in an environment, said method comprising the steps of:

receiving, by a processor, tag data from one of said at least one RF receiver;

storing, by said processor, said tag data in a database;

processing, by said processor, said tag data to produce processed tag data; and

forwarding, by said processor, the processed tag data to a host computer for use by a client application executing on said host computer,

wherein said tag data includes one or more of a tag identifier, a time stamp corresponding to a time of receipt of the respective tag data by said one of said at least one RF receiver, and at least one operational parameter in use by one of said at least one RF receiver or said at least one RF interrogator during at least one interrogation of the respective RFID tag by the respective RF interrogator, and

wherein said at least one operational parameter corresponds to one or more of a transmit power used by said one of said at least one RF receiver or said at least one RF interrogator, a sensitivity of said one of said at least one RF receiver or said at least one RF interrogator, an identification of an antenna selection, an antenna pointing parameter, and presence information indicating whether a particular RFID tag is present within a specified interrogation zone.

68. The method of claim 67 further including the step of identifying and discarding duplicative tag data within said database.

69. The method of claim 67 further including the step of discarding duplicative tag data received over a specified time interval.

70. The method of claim 67 further including the step of discarding tag data stored within said tag scan database for a specified time interval.

71. A controller for use in a tag data acquisition system, the system including at least one interrogator and at least one receiver, the system having a configuration involving one or more transmission parameters associated with the interrogator, one or more reception parameters associated with the receiver, and physical locations of the interrogator and the receiver with respect to a physical layout, each of said at least one interrogator having a tag interrogation zone associated therewith, each of said at least one receiver having a tag detection zone associated therewith, said controller comprising:

program and data storage containing program code and a first parameter associated with one of said at least one interrogator or said at least one receiver, said first parameter for defining an operational behavior of the respective interrogator or receiver;

a processor in communication with said program and data storage; and

an interface in communication with said processor, said interface being operative to communicably couple said controller to said at least one interrogator and said at least one receiver,

wherein said processor is operative to execute said program code contained in the program storage;

to receive an indication of a change in said configuration of the system, or presence information indicating a presence of at least one tag within said tag interrogation zone associated with the respective interrogator or said tag detection zone associated with the respective receiver;

to modify said first parameter in response to receiving said indication of said change in said configuration of the system, or said presence information for the tag; and

to transmit, via said interface, a message to the respective interrogator or receiver based at least in part upon the modified first parameter to alter said operational behavior of the respective interrogator or receiver.

72. In a tag data acquisition system including at least one interrogator and at least one receiver, the system having a configuration involving transmission characteristics of said at least one interrogator and reception characteristics of said at least one receiver, a method of dynamically changing operating characteristics of the system, the method comprising the steps of:

storing, by a processor in a data storage, a first parameter associated with an operational characteristic of one of said at least one interrogator or one of said at least one receiver;

transmitting, by said processor, a first message based at least in part upon said first parameter to said one of said at least one interrogator or said one of said at least one receiver to cause the respective interrogator or receiver to operate in a first manner;

receiving, at said processor, an indication of a change affecting said configuration of the system, or presence information indicating a presence of at least one tag within a tag interrogation zone associated with the respective interrogator or a tag detection zone associated with the respective receiver;

in response to receiving said indication of said change affecting said configuration of the system or said presence information for the tag, modifying said first parameter; and

transmitting, by said processor, a second message based at least in part upon the modified first parameter to said one of said at least one interrogator or said one of said at least one receiver to cause the respective interrogator or receiver to operate in a second manner.