An Enhanced Query Tree (EQT) Protocol for Memoryless Tag Anti-collision in RFID Systems

One of the challenges in designing modern RFID systems is that when more than one tag exists in an RFID environment, it may occurs collisions so that the whole system becomes inefficient and increases the time for identifying RFID Tags. In order to simultaneously recognize several tags within a reader interrogation zone, an anti-collision algorithm should be applied. In this paper, we present an Enhanced Query Tree (EQT) protocol for memoryless tag anti-collision in RFID networks. The EQT is an enhanced technique based on the query tree protocol. The main advantage of EQT is that it can dynamically adjust length of prefix code to avoid unnecessary inquiry and reduce collisions. To evaluate performance of the proposed techniques, we have implemented the EQT along with the query tree protocol. The experimental results show that the EQT outperforms other tree based protocols in terms of the identification efficiency and its overhead, including number of collisions and time cost. Particularly, the EQT performs very well in neutral RFID systems.