Multiple Object Identification with Passive RFID Tags 

Harald Vogt Department of Computer Science ETH Zürich 8092 Zürich, 
Switzerland 

Abstract 

We investigate the applicability of passive RFID systems to the task of 
identifying multiple tagged objects simultaneously, assuming that the number 
of tags is not known in advance. We present a combinatorial model of the 
communication mechanism between the reader device and the tags, and use this 
model to derive the optimal parameter setting for the reading process, based 
on estimates for the number of tags. Some results on the performance of an 
implementation are presented.