A Bit Collision Detection Based Hybrid Query Tree Protocol for Anti-collision in RFID System

In radio frequency identification (RFID) systems, the anti-collision protocol is a key topic that has attracted a great deal of research interest. The protocols can be divided into two categories: ALOHA-based and binary query tree (QT) algorithms. The ALOHA-based protocols avoid collisions by distributing tags into different stochastic timeslots. In contrast, the QT-based protocols achieve a reliable throughput of identification and avoid collisions by using prefix matching. This paper proposes an improved QT protocol called BHQT (Bit collision detection based Hybrid Query Tree) which combining the basic principle of QT and a new bit collision detection mechanism for tag identification by a mobile reader. Analysis shows that the BHQT protocol reduces tag collisions, which accelerates the tag identification process in mobile identification. Simulation results substantiate the significant performance improvement by the BHQT protocol for tag identification.