Placement of Passive UHF RFID Tags and Readers Using Graph Models

Placement of passive UHF RFID tags and readers is an important consideration for accurate tracking of returnable transport items (RTI). The placement problem refers to the task of determining the position and orientation of RFID tags on RTIs and RFID reader in an interrogation zone such that the highest possible read accuracy can be achieved. The challenge with RFID tag and reader placement problem lies in the exhaustive evaluation of many possible combinations of positions and orientations of tags and readers. The paper presents a graph model based readability test approach for finding the least number of tags and their placement on RTIs and the least number of readers and their placement in an interrogation zone that yield the highest read accuracy, count and strength.