MULTI-PROTOCOL RFID SYSTEM

摘要

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; EGOTM RFID backscatter transponders, SEGOTM 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.

主权项

1. 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 at a single monitoring location; said two transceivers configured to establish a first tag communication signal sequence associated with said first transceiver and a second tag communication signal sequence associated with said second transceiver, said first tag communication signal sequence having a first tag communication sequence first portion and a first tag communication sequence second portion; said second tag communication signal sequence having a second tag communication sequence first portion and a second tag communication sequence second portion; such that said at least two transceivers operate the first protocol overlapping in time with each other during said first tag communication sequence first portion and said second tag communication sequence first portion and operate the second protocol overlapping in time with each other during said first tag communication sequence second portion and said second tag communication sequence second portion; wherein at least one of said first and second protocols reads backscatter transponders and wherein more than one command is transmitted to said backscatter transponders from at least one of said transceivers.