Implementation of dynamic slotted ALOHA protocol for RFID readers using Simple probability and Bayesian probability

RFID(Radio Frequency IDentification) is an emerging technique which uses radio waves for identification. One of the main application of RFID is equipment tracking in big logistics. But this is a major concern due to several disadvantages. Collision is one such issue which reduces the efficiency of RFID technique. Anti-collision protocols helps in reducing collision, but cannot eliminate it completely since readers are manufactured so as to read the most powerful tag that comes in its range. ALOHA (Abrahmson's Logic Of Hiring Access) based protocols are the commonly used anti-collision protocol in RFID network. This paper proposes two modifications of slotted ALOHA protocol that helps in efficient tracking. One is general probability based slot allocation method which can reduce the rate of tag missing and hence improve efficiency. Other method is a Bayesian probability based approach where the slot allocation is based on calculated posterior probability. Both approaches are used to increase the read operations of the mostly accessed reader thereby reducing the rate of tag missing.