Key points are not available for this paper at this time.
With the proliferation of RFID-enabled applications, multiple RFID readers (or reader antennas) must be used to provide full coverage to any deployment area beyond the communication range of a single reader. However, reader collision together with tag-to-tag collision seriously degrades the system performance or even blocks out some tags from being read. To address this problem, this paper proposes a time-efficient protocol stack that is tailored to the tag identification in a multi-reader RFID system, which consists of two protocols: one is for eliminating reader collision (RCE) and the other is for avoiding tag-to-tag collision (TCE). In RCE, we enable multiple readers to work in parallel for maximizing the number of tags to be read per unit of time. Where RCE shines is that it well addresses the problem of unbalanced load by each reader due to uneven tag distributions. Namely, in existing work, the readers with fewer tags covered will finish the tag identification earlier than other readers (with more tags). After that, these readers have to wait for all readers until they are done. This is a waste of time. The solution of RCE is to take the reader with the minimum number of tags as the reference and iteratively to update the set of concurrent readers. Besides, in TCE, we use bit-level tag response to resolve tag-to-tag collision and increase the number of useful slots, so does the read throughput. Theoretical analysis and simulation results show that the above two protocols can jointly improve the inventory efficiency and reduce the identification time by more than 50%, in comparison to the state-of-the-art. We validate TIMR's performance by comparing its results on a real-world library data set with simulated data, demonstrating consistency across both settings.
Wang et al. (Thu,) studied this question.