Enabling communication among smart tags in an UHF RFID Local Area Network

Adding computational and sensing capabilities to the new generation of passive UHF RFID tags has contributed to overcome the idea of considering them as mere identification transponders. These new functionalities give smart RFID tags the chance to be included in the global network of interconnected objects envisioned by the Internet of Things (IoT) paradigm. However, to fully enable RFID tags to participate in machine-to-machine (M2M) communications, RFID systems still lack an important feature, namely the capability of exchanging unicast messages between tags. In this paper, we propose an effective approach to enable real-time bidirectional communications among tags belonging to an RFID Local Area Network (i.e., under the coverage area of the same reader). The presented solution is based on the main idea of utilizing the User Memory of the tag as a virtual channel for transferring messages, and the tag reader as a message forwarder. As a proof-of-concept for our proposal, a novel smart RFID tag able to exploit the RFID radio interface for bidirectional real-time communications with other tags is designed, and experimental measures on the deployed testbed are discussed.