Localization and Tracking Challenges >RSS cannot provide accurate localization especially for UHF tags Need dense reference tags Need specified hardware,like USRP Require the predefined tag or reader movement >Environment noises,like multi-path propagation 1.4 Multipath Full Bandwidth ISM Band --- 1.2 Line-of-Sight 1 0.8 0 Rfind 0.4 (MobiCom 2017) 0.2 20 40 60 80 100 120 Time-of-flight(ns)Localization and Tracking Challenges à RSS cannot provide accurate localization especially for UHF tags à Need dense reference tags à Need specified hardware, like USRP à Require the predefined tag or reader movement à Environment noises, like multi-path propagation Rfind (MobiCom 2017)