The use of Internet-of-Things (IoT) devices in many applications has been increasing exponentially. By connecting billions of sensors, actuators, and various smart objects to the Internet, IoT will produce an unprecedented amount of information for making more informed decisions in numerous public and private sectors. To support various applications, IoT devices are connected via different types of communication networks (e.g., LTE, WiFi, ZigBee, etc.). To support future IoT devices, backscatter technology provides a promising direction with i) high spectrum efficiency by reusing existing RF signal; ii) energy-efficient communication; and iii) low cost. In this project, we propose to create a frequency agnostic backscatter system that can operate across different protocols and frequency bands. The proposed research, if successful, can be a catalyst for developing and deploying new applications, thus having a potentially enormous impact on the U.S. economy by fostering job growth related to IoT-based applications. The proposed research will also enrich the scientific knowledge of wireless networking and mobile computing. The PIs have been strongly committed to broadening participation in computing and have plans to raise interest in technology among K-12 students and other underrepresented minority groups. In addition, the PIs aim to enhance undergraduate research experience through senior design projects.<br/><br/>The goal of this project is to design a frequency agnostic backscatter system that can operate across different wireless protocols (e.g., LTE, WiFi, ZigBee) and frequency bands and has the potential to be deployed at different locations to support various applications. To achieve this goal, we propose a holistic solution to address the challenges of spectrum utilization and coexistence among active, semi-passive, and passive IoT devices across different frequency bands. Specifically, we seek to investigate novel hardware designs that can improve the overall spectrum utilization in heterogeneous networks that work in different frequency bands. Our proposed research can effectively address the challenges of spectrum utilization in the IoT networks with coexisting active and passive radios.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.