Qiongzheng Lin received the from Tsinghua University BS degree China, in 2012. He is now a PhD student of School of Software at Tsinghua University, China. His research interests include Radio Frequency IDentification (RFID) and sensor network, mobile sensing, and pervasive computing. He is a studentmember of IEEE and ACM. E-mail: lin@tagsys.org. Yi Guo is the founder and technical director of Shenzhen Huachuang Intelligent Control and Robotics Co. Ltd. He received the BE degree from Shanghai Jiao Tong University, China in 2011 and PhD degree from Hong Kong University of Science and Technology in 2015. His research interests include RadioFrequency IDentification (RFID) and pervasive computing. E-mail: yi@tagsys.org.