A Presumed Write Protocol for Ensuring Complete Access to RFID Tag Memory

This paper addresses the tag data inconsistency problem to be caused by volatile RF communications during the writing of data to passive RFID tag memory. In the RF environment, a write command sent from the reader cannot guarantee the complete writing to the tag. When the tag disappears from the interrogation area of the reader while the operation is being processed, the tag data may be partially written or the tag state becomes indeterminate. It will bring into the inconsistency of tag data. To solve this problem, we propose a Presumed Write Protocol which ensures complete execution of the write operation in the middleware level. The basic idea is to suspend the execution of incomplete write operation and resume when the tag is re-observed at any readers. The experiment shows that proposed protocol eliminates inconsistent data access as well as complete execution of write operations. The main contribution of this paper is to define a complete set of message protocol for volatile RF write operations.