A Geometric Distribution Reader Anti-Collision Protocol for RFID Dense Reader Environments

Dense passive radio frequency identification (RFID) systems are particularly susceptible to reader collision problems, categorized by reader-to-tag and reader-to-reader collisions. Both may degrade the system performance decreasing the number of identified tags per time unit. Although many proposals have been suggested to avoid or handle these collisions, most of them are not compatible with current standards and regulations, require extra hardware and do not make an efficient use of the network resources. This paper proposes the Geometric Distribution Reader Anti-collision (GDRA), a new centralized scheduler that exploits the Sift geometric probability distribution function to minimize reader collision problems. GDRA provides higher throughput than the state-of-the-art proposals for dense reader environments and, unlike the majority of previous works, GDRA is compliant with the EPCglobal standard and ETSI EN 302 208 regulation, and can be implemented in real RFID systems without extra hardware. Note to Practitioners -UHF RFID systems with multiple readers are commonly installed in many scenarios, where readers are placed in strategic places for checking specific areas. In these scenarios, the reader interferences occur and they can degrade the performance of our system. An efficient anticollision scheduler is necessary for avoiding and minimizing these interferences, and the current standards and regulations do not propose any efficient solution. In this work, a new scheduler is proposed to get the best performance of a typical UHF RFID system with multiple readers. Our proposal is compatible with the global standard and the current European regulations and is designed to be implemented in any commercial UHF reader in the market without extra hardware cost.