Implementing Anti Collision Algorithm for Multiple Tag Identification

RFID is core technology in the area of ubiquitous computing.To identify the objects begins with the reader query to the tag attached to the subject. When multiple tags exist in the reader’s interrogation zone, these tags simultaneously respond to the reader’s query, resulting in collision. This kind collision makes the reader to take long time to identify tags within the reader’s identification range and impossible to identify even one tag.In RFID system, the reader needa the anti-collision algorithm which can quickly identify all the tags in interrogation zone. This paper proposes a design methodology with two different RF modules, 433.92MHz and 315 MHz are interfaced into microcontroller, encoder, decoder IC’s are used.According to query technique, the reader sends the query signal to all tags with one frequency and the tag corresponding to the query will respond to reader with another frequency, likewise anti-collision algorithm is implemented to avoid collision and number of query reponses can be reduced.