CE-TIP: A Code Expansion Based Tag Identification Protocol for RFID Systems

With the ability of recognizing tag content wirelessly within a limited distance and a short period of query time, RFID technology has been adopted and deployed on various applications. In consequence, how to effectively avoid responses collision from multiple tags and to further reduce the average query time per tag becomes an important performance issue for RFID systems. To get better performance in comparison with current RFID anti-collision mechanisms from ISO and EPCglobal standards, an efficient tag identification scheme for RFID systems is presented. Instead of avoiding signal collision, the proposed protocol, called CE-TIP, adequately utilizes a code expansion mechanism and takes the advantage of signal collision to fast identify numerous tags. Compared to existing protocols such as QueryTree, BinarySearch and RN16QT, CE-TIP can reduce at least 13% (up to 58%) of communication overhead on the number of query commands issued and average 10% to 12.5% of total transmission delay on the number of transmitted bits, respectively. In addition, CE-TIP protocol can be easily adopted and implemented within current RFID tags and readers. A RFID tag only needs to store one extra code at its memory space.