An Enhanced RFID Multiple Access Protocol for Fast Inventory

The relevant performance metric for successful deployment of radio frequency identification (RFID) systems for tag inventory applications is the latency for reading all tags with (high) reliability. Tag collisions in response to a reader query increase the read latency of the MAC protocol; the mean latency can be considerably improved by a combination of techniques including more efficient anti-collision approaches as well as via estimation of the number of backlogged tags. We propose a novel anti-collision algorithm: breadth-first-search with m-ary splitting (BMSA) within a TDMA frame structure. A simple backlogged tag estimation algorithm is used in conjunction with the above to dynamically set the splitting factor (SF) m. Simulation results demonstrate the superiority of the proposed scheme over existing methods in terms of throughput/latency.