Efficient and robust missing key tag identification for large-scale RFID systems

Radio Frequency Identification (RFID) technology has been widely used to identify missing items. In many applications, rapidly pinpointing key tags that are attached to favorable or valuable items is critical. To realize this goal, interference from ordinary tags should be avoided, while key tags should be efficiently verified. Despite many previous studies, how to rapidly and dynamically filter out ordinary tags when the ratio of ordinary tags changes has not been addressed. Moreover, how to efficiently verify missing key tags in groups rather than one by one has not been explored, especially with varying missing rates. In this paper, we propose an Efficient and Robust missing Key tag Identification (ERKI) protocol that consists of a filtering mechanism and a verification mechanism. Specifically, the filtering mechanism adopts the Bloom filter to quickly filter out ordinary tags and uses the labeling vector to optimize the Bloom filter's performance when the key tag ratio is high. Furthermore, the verification mechanism can dynamically verify key tags according to the missing rates, in which an appropriate number of key tags is mapped to a slot and verified at once. Moreover, we theoretically analyze the parameters of the ERKI protocol to minimize its execution time. Extensive numerical results show that ERKI can accelerate the execution time by more than 2.14× compared with state-of-the-art solutions.