Radio Frequency Identification (RFID) technology holds the promise to 
automatically and inexpensively track items as they move through the supply 
chain. The proliferation of RFID tags and readers will require dedicated 
middleware solutions that manage readers and process the vast amount of 
captured data. In this paper we analyse the requirements and propose a design 
for such an RFID middleware. We argue that an RFID middleware should not only 
focus on the application needs, but must also consider the constraints imposed 
by passive RFID technology.