Seng-Yong Lau Tsung-Han Lin Te-Yuan Huang I-Hei Ng Polly Huang A measurement study of zigbee-based indoor localization systems under RF interference. 35-42 2009 WiNTECH https://doi.org/10.1145/1614293.1614300 conf/mobicom/2009wintech db/conf/mobicom/wintech2009.html#LauLHNH09