This Small Business Innovation Research Phase I research project aims at developing a new class of Media Access Controller (MAC) algorithms to be particularly used with ultrawide band communication systems. The new algorithm is motivated by application of ultrawide band to the RFID (Radio Frequency Identification) market. Passive RFID tags are powered by the incident RF signals emitted by a reader. Tags accumulate the electrical energy and respond back with their IDs, usually 64 to 128 bits long. Passive tags are required to behave robustly while constrained by very stringent power budgets. The MAC layer algorithm proposed here satisfies both requirements. The low power requirement is achieved by changing the data format from a number representation in a burst to a temporalrepresentation by infrequent individual impulses. Robustness is achieved in part by enabling a stand-alone transmitter at extremely low power, in part by guaranteeing high probability of convergence and collision avoidance, and in part by repetition of the sequence with different codes in consecutive inventory rounds. The impulses from each tag are sufficiently sparse to allow low power operation of the tag. Upon completion of each inventory round, the scrambling/coding of the ID is changed to achieve, better spreading, lower probability of ambiguity and achieving superb security.
RFID is an exponentially growing market. However, the technology that supports its expansion is not able to provide robust communication and signaling between a tag and a reader. Furthermore, today's technology only supports a low tag density (10s of tags/sec/m2), while the applications that will fuel the exponential expansion of the RFID market, like point-of-sale, inventory management, shelf management, etc., requires 100s and 1000s of tags/sec/m2. The proposed MAC layer algorithms together with TagArray's (patent pending) Asymmetric Dual Mode Communication system (a combination of ultrawide band and narrowband RF technologies) provide unmatched robustness at high density. TagArray will work to make its technology the defacto standard for the 3rd generation of RFID technology. TagArray's technology and products (passive tags and readers) are applicable to existing applications such as pallet-level tagging for supply chain as well as future applications such as point of sale, security and access, and inventory management.
