A Reprocessing Model Based on Continuous Queries for Writing Data to RFID Tag Memory

摘要

This paper investigates the problem of writing data to passive RFID tag memory and proposes a reprocessing model for assuring the atomicity and durability of writing transactions in volatile RF communications. This study is motivated by the need to support persistent writing transactions of RFID tag data despite asynchronous and intermittent RF connections. The problem arises when the tag disappears from the interrogation area of the reader before all data is written completely. The disconnection during the process of a write operation causes the tag data to be inconsistent. To solve the problem, we propose an asynchronous wake-up reprocessing model for resuming unsuccessful write operations. The basic idea is to use a continuous query scheme for asynchronously detecting re-observations of unsuccessfully written tags. To achieve this, we employ a continuous query index, which monitors the tag stream continuously and finds unsure tags efficiently. We also discuss implementation issues for the proposed model. This shows that the reprocessing model processes unsuccessful operations completely and avoids inconsistent data, despite volatile characteristics in the RF communications.