3.4 Functionality
The basic RFID functionality is identification. When queried by a reader, tags return some
identifier that may be used to retrieve other data records. However, tags may offer various
other functionalities useful in different applications. The underlying principles and
technologies of these various types of tags are so closely related to strict RFID tags, that
they often collectively referred to as “RFID”. Although not strictly RFID, we discuss several
major classes of RFID-related devices.
We split RFID-style tags into five broad classes: EAS, read-only EPC, EPC, sensor tags, and
motes. These will be referred to as classes A through E. EPCglobal offers five similar classes
of tag based on functionality dubbed Class 0 through Class 4 [6]. The EPCglobal classes
closely align with ours, but differ somewhat. These five classes are summarized in Table 3.