Design and Implementation of an Index Structure Using Fixed Intervals for Tracing of RFID Tags

摘要

Recently, there has been a demand for RFID systems that can trace tag locations. For tracing tag locations, trajectories should be modeled and indexed in an RFID system. The trajectory of a tag is represented as a line that connects two spatiotemporal locations that are captured when the tag enters and leaves the vicinity of a reader. If a tag enters but does not leave a reader, its trajectory is represented only as the point captured at entry. When we process a query that finds the tag staying in a reader, it takes a long time to find this tag because it leads to searching the whole index. To solve this problem, we propose a data model in which trajectories of these tags are defined as intentional fixed intervals and a new index scheme called the Fixed Interval R-tree. We also propose a new insert and split policy to process queries efficiently. We evaluated the performance of the proposed index scheme and compared it with other schemes on various datasets and queries.