Towards More Efficient Cardinality Estimation for Large-Scale RFID Systems

Abstract—Radio frequency identification (RFID) cardinality es-timation with an accuracy guarantee is of practical importance in various large-scale RFID applications. This paper proposes a fast RFID cardinality estimation protocol, named Zero-One Estimator (ZOE). ZOE only requires 1-bit response from the RFID tags per estimation round.More importantly, ZOE rapidly converges to op-timal parameter configurations and achieves higher estimation ef-ficiency compared to existing protocols. ZOE guarantees arbitrary accuracy requirement without imposing heavy computation and memory overhead at RFID tags except the routine operations of C1G2 standard. ZOE also provides reliable cardinality estimation with unreliable channels due to the robust protocol design.We pro-totype ZOE using the USRP software defined radio and the Intel WISP tags. We extensively evaluate the performance of ZOE com-pared to existing protocols, which demonstrates encouraging re-sults in terms of estimation accuracy, time efficiency, as well as ro-bustness over a large range of tag population. Index Terms—Cardinality estimation, radio frequency identifi-cation (RFID) systems. I