Date Added: Nov 2009
RFID (Radio Frequency IDentification) is a technology where the reader accesses automatically the data stored on the tag, label, or card, which has built in a micro-chip. EPCglobal Class-1 Generation-2 standard is a passive RFID system where the reader transmits Continuous Wave (CW) to power on tags. This means that a tag does not have any energy source. Reader starts to communicate while tag responds to the reader with specified answers including random numbers and some identifying numbers. EPCglobal Class-0 and Class-1 Standards have different protocols. For instance, in the downlink, Class-0 has three data symbols ('0', '1' and 'Null') with varying duty cycles. But Class-1 uses just two data symbols, Data '0' and '1'.