Radio Frequency IDentification (RFID) technology has been widely used in missing tag identification to reduce the economic loss caused by theft. Although many advanced works have been proposed, they cannot work properly in an open RFID system with unexpected tags. That is because the unexpected tags may reply to the reader when it is the missing tags’ turn, such that the replies are mistakenly treated as the missing tags’, leading to failure to detect the missing tags. To solve the problem, this article proposes an order-based missing tag identification protocol (OMTI) that efficiently identifies all missing tags even with the presence of unexpected tags. The key of OMTI is that we dynamically assign each tag an exclusive slot rather than use random hashes in traditional design. Namely, OMTI off-line serializes all known tags in advance by assigning each of them a unique and continuous slot, on-line identifies missing tags by checking tags’ responses in each slot, and dynamically updates the slot assignment to ensure the high efficiency of the next execution. Besides, we enhance OMTI to make it embrace newly added tags and spread to the multi-reader case from the single one. The simulation results demonstrate that OMTI can significantly reduce the identification time compared to the state-of-the-art.

中文翻译：

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开放式 RFID 系统中的省时缺失标签识别

射频识别（RFID）技术已被广泛应用于遗失标签识别，以减少因盗窃造成的经济损失。尽管已经提出了许多先进的工作，但它们无法在带有意外标签的开放式 RFID 系统中正常工作。这是因为在轮到丢失标签时，意外的标签可能会回复阅读器，从而将回复误认为是丢失的标签，导致无法检测到丢失的标签。为了解决这个问题，本文提出了一种基于顺序的缺失标签识别协议（OMTI），即使存在意外标签，也能有效识别所有缺失标签。OMTI 的关键是我们动态地为每个标签分配一个独占的插槽，而不是在传统设计中使用随机散列。即，OMTI离线将所有已知标签提前序列化，为每个已知标签分配一个唯一且连续的slot，在线通过检查每个slot中标签的响应来识别丢失的标签，并动态更新slot分配以确保下一个高效执行。此外，我们对 OMTI 进行了增强，使其包含新添加的标签，并从单一标签扩展到多阅读器案例。仿真结果表明，与最先进的技术相比，OMTI 可以显着减少识别时间。