A Novel Query Tree Protocol Based on Partial Responses for RFID Tag Anti-collision

In the RFID system, when two or more tags respond their IDs to the reader simultaneously, wireless signal collision occurs and no tag can be identified successfully by the reader. How to reduce such collisions in order to speed up the identification performance is thus important. There are many anti-collision protocols proposed to solve the tag collision problem. They can be categorized into two classes: ALOHA-based and tree-based protocols. The query tree (QT) protocol is a famous tree-based protocol having many advantages. It is stateless and uses no on-tag memory to keep protocol states, it is a plain protocol and uses no special techniques, such as bit-tracking, ID-revising, and re-identification. In this paper, we propose a stateless and plain tree based anti-collision protocol, called PRQT, by using tag ID partial responses to speed up tag identification. We also conduct simulation experiments for PRQT and compare it with QT in terms of the number of iterations to identify tags. As we will show, the PRQT protocol uses less numbers of iterations to identify tags than the QT protocol.