MULTI-PROTOCOL RFID SYSTEM USING BIT-LOCK OR STEP-LOCK SYNCHRONIZATION
First Claim
1. ) An interrogator system to read active RFID transponders and to read backscatter RFID transponders comprising at least two transceivers, each transceiver covering a respective capture zone, the two capture zones being in proximity to each other, wherein said transceivers are adapted to use time division multiplexing to read the active RFID transponders in a first capture zone during a first time period, to then read the active RFID transponders in a second capture zone during a second time period and to simultaneously read the backscatter RFID transponders in both capture zones during a third time period.
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Accused Products
Abstract
A multi-protocol RFID interrogating system employs a synchronization technique (step-lock) for a backscatter RFID system that allows simultaneous operation of closely spaced interrogators. The multi-protocol RFID interrogating system can communicate with backscatter transponders having different output protocols and with active transponders including: Title 21 compliant RFID backscatter transponders; IT2000 RFID backscatter transponders that provide an extended mode capability beyond Title 21; EGO™ RFID backscatter transponders, SEGO™ RFID backscatter transponders; ATA, ISO, ANSI AAR compliant RFID backscatter transponders; and IAG compliant active technology transponders. The system implements a step-lock operation, whereby adjacent interrogators are synchronized to ensure that all downlinks operate within the same time frame and all uplinks operate within the same time frame, to eliminate downlink on uplink interference.
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Citations
25 Claims
- 1. ) An interrogator system to read active RFID transponders and to read backscatter RFID transponders comprising at least two transceivers, each transceiver covering a respective capture zone, the two capture zones being in proximity to each other, wherein said transceivers are adapted to use time division multiplexing to read the active RFID transponders in a first capture zone during a first time period, to then read the active RFID transponders in a second capture zone during a second time period and to simultaneously read the backscatter RFID transponders in both capture zones during a third time period.
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10. ) An interrogator system using at least a first and second protocol to read RFID transponders comprising:
- at least two transceivers, each transceiver covering a respective capture zone, the respective capture zones being in proximity to each other; and
a synchronization circuit adapted to synchronize the two transceivers such that said at least two transceivers operate the first protocol simultaneously with each other during a first time period and operate the second protocol simultaneously with each other during a second and subsequent time period. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
- at least two transceivers, each transceiver covering a respective capture zone, the respective capture zones being in proximity to each other; and
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21. ) An interrogator system for reading RFID transponders comprising:
- at least two transceivers and a synchronization circuit, each of the at least two transceivers covering a respective capture zone and being arranged for transmitting a downlink signal in its respective capture zone, and each of the downlink signals comprising plural bits, wherein the respective capture zones overlap at least partially, creating an overlap capture zone in which an RFID transponder may be located, and wherein the synchronization circuit synchronizes the downlink signals from each of the two transceivers such that each bit in the downlink signals starts at substantially the same time.
- View Dependent Claims (22, 23, 24, 25)
Specification