Wireless integrated sensor nodes for indoor monitoring and localization

This paper presents an overview of wireless integrated sensor node realizations for indoor monitoring and localization applications. Depending on the targeted application scenario different wireless sensor node implementations based on either high-performance processors or semi-passive radio-frequency identification (RFID) cores are outlined. The presented high-performance node realization with monitoring and seamless indoor and outdoor localization capability can operate independently for a duration of one day and additionally features wireless charging. Furthermore, a UHF RFID Gen2 sensor tag for indoor localization and fall detection is presented that enables a battery lifetime of approximately one month. Finally, ultra-low-power UHF RFID sensor node concepts based on sub-threshold wake-up receivers are introduced that can achieve operational times of several years for specific low duty cycle scenarios.