Grant: Idea to Innovation

Radio frequency identification (RFID) is a wireless communication technology for automatic identification of objects. In general, an RFID system consists of a reader and many low-cost tags. Each tag is typically attached to an object and programmed with a unique identification (ID) code. The reader interrogates and reads the tags in its vicinity by transmitting a wireless signal towards the tags and detecting the responses from the tags to obtain the tags' IDs and thereby identify the objects to which the tags are attached. A passive tag does not have a power supply but instead draws power from the RF signal received from the reader, and returns an encoded signal to the reader. An active (or semi-active) tag is equipped with a power supply (e.g., on-board battery) that energizes its circuitry. When a large number of tags are read simultaneously, their responses to the reader's query may collide. The identification time of conventional systems with collision recovery protocols, such as slotted-Aloha random access protocols or tree-based collision resolution protocols, generally increases dramatically with the number of colliding tags, which can lead to a very long identification delay when hundreds or thousands of tags are queried simultaneously. We have developed a class of novel tag grouping techniques and associated query-response protocols that allow a number of colliding tags to be identified without suffering from the usual consequence of tag collisions. This class of methods result in a deterministic identification delay regardless of the number of responding tags with the tag ID space. Thus the tag identification delay is scalable with respect to the increase in the number of responding tags. The proposed methods have been thoroughly analyzed, and the potential for superior performance in terms of identification delay and power consumption compared to existing methods have been demonstrated. In this Idea to Innovation project, we propose to put our innovative idea to practice, by implementing the proposed methods in passive and (semi-)active RFID systems for proof-of-concept demonstration. The prototypes developed in this project will enable our industry partners to readily evaluate the technology and possibly incorporate the technology in their commercial products.