The Research And Design Of Anti-Collision Algorithm In RFID

Radio Frequency Identification (RFID) is a contactless automatic identification technology. In a RFID system, wireless RF communication techniques are used to achieve the duplex communication between the reader and tags. RFID has advantages for example fast identifying speed, data encryption, longevity and is not affected by the surrounding environment. It is especially used to cooperate with other robotic equipments. In recent years RFID is one technology which developed at a rapid speed that has worldwide applications. RFID is now a third generation identification technology.Tag anti-collision is a significant issue in RFID system design, which determines the identification speed and efficiency. Tag anti-collision technology is a precondition of fasting identifying numerous tags. In this article, the basic concept of RFID is introduced firstly. Then, collision problem and some prevalent anti-collision algorithms are described. Finally, two new type deterministic algorithms are presented which are based on the analysing and concluding of Query Tree, Dynamic Query Tree and Binary Searching Tree algorithm.According to the principle of "fully using known information, not requesting or responding reduplicated information" , an anti-collision searching algorithm of delaminating deepness tree in RFID system is proposed, which bases on the dynamic query tree algorithm and adopts the method of "delaminating deepness searching" , "stack technology" and "back mechanism" . And moreover, Manchester coding is not used in delaminating deepness searching tree anti-collision algorithm. This new algorithm attains the goal of quick identification and especially fits the environment which contains large quantity of tags or tags with long ID. A novel anti-collision algorithm based on Binary Searching Tree algorithm and BIBD(6, 4, 3, 2, 1) is proposed in this paper too. A tag is divided into several sections, each of which only equals one of the subsets of BIBD(6,4,3,2,1). According to the performance of BIBD(6, 4, 3, 2, 1), Readers can efficiently get every ID by identifying each section one by one to achieve the aim of fasting identification.Mathematics analysis and simulation results show that the two algorithms presented improves the identification speed and outperforms the existing ones, and especially are the same with the environment which contains more tags or tags with long ID.In the end, reader collision problem is introduced in brief, and a simple time divided switching reader anti-collision method is proposed.