Tag, You’re It: Ranging and finding via RFID technology

Over the last years, Radio Frequency identification (RFID) has gained enormous momentum. Lots of applications make use of RFID technologies, from passports to access control, from supply chain management to process improvements, from health equipment management to e-health. All these systems are primarily employed to answer the question: what objects and how many have just passed at the RFID reader? The current evolution of RFID-based systems is to make them aware of their position and their context. Such functionalities, which have been previously supported by different wireless standards, can now be carried out by RFID technology at microwave frequencies with lower cost and ease of deployment. Augmenting RFID systems with localization capabilities allow to pave the way for systems more and more distributed in the environment to be not only identifiable, but also localizable and selectable