Tracking of RFID tags in a sensing covered anchor-free network of RFID readers

In recent technological advances, RFID system is efficient for finding the position or identifying an object in an environment where direct human access is difficult or impossible. In this paper, we introduce 2-sensing covered (each point of the application field falls within the sensing zone of at least two readers) wireless networks of anchor-free RFID readers. We show that in a 2-sensing covered network every target (RFID tag) can be located with at most two possible positions which are useful in real applications. We derive a characterization to identify a 2-sensing covered network. We also provide an efficient algorithm to recognize 2-sensing covered networks. We adapt the algorithm to track the tags under the distributed environment.