Multi Multi-Category RFID Estimation
Abstract: This paper concerns the practically important problem of multi multi-category category radio frequency identification (RFID) estimation: given a set of RFID tags, we want to quickly and accurately estimate the number of tags in each category. However, almost all the existing ting RFID estimation protocols are dedicated to the estimation problem on a single set, regardless of tag categories. A feasible solution is to separately execute the existing estimation protocols on each category. The execution time of such a serial solut solution ion is proportional to the number of categories, and cannot satisfy the delay delay-stringent stringent application scenarios. Simultaneous RIFD estimation over multiple categories is desirable, and hence, this paper proposes an approach called simultaneous estimation for multicategory RFID systems (SEM). SEM exploits the Manchester Manchester-coding coding mechanism, which is supported by the ISO 18000 18000-6 6 RFID standard, to decode the combined signals, thereby simultaneously obtaining the reply status of tags from each category. As a result,, multiple bit vectors are decoded from just one physical slotted frame. Built on our SEM, many existing excellent estimation protocols can be used to estimate the tag cardinality of each category in a simultaneous manner. To ensure the predefined accuracy accuracy,, we calculate the variance of the estimate in one round, as well as the variance of the average estimate in multiple rounds. To find the optimal frame size, we propose an efficient binary searchsearch based algorithm. To address significant variance in category sizes, we propose an