A software radio-based UHF RFID reader for PHY/MAC experimentation

We present the design and evaluation of a flexible UHF RFID reader that enables new PHY/MAC designs to be prototyped and evaluated. Our reader is built using the USRP software radio platform in conjunction with software we developed in the open-source GNU Radio framework. We believe it is the first inexpensive tool that readily enables changes to the physical and MAC layer of RFID systems. We evaluate our reader and show that it can inventory commercial tags out to 6 meters, which approximates the range of a commercial reader with comparable transmit power. We then show two applications of our reader. The first evaluates the real-world performance of the EPC frame selection algorithm and finds that it performs better than expected. Second, using the Intel WISP programmable RFID tag, we implement and evaluate an extension to the Gen 2 standard that results in up to a five-fold increase in sample rate for streamed sensor data.