Redundant radio tomographic imaging for privacy-aware indoor user localization

Device-free localization of people in indoor environments is a key technology to gain a high user-acceptance in ambient assisted living scenarios. No hardware need to be worn for the privacy-aware detection and monitoring of one or more mobile users. Looking at performance metrics like detection / false alarm rates, a radio-based solution relying on the received signal strength (RSS) evaluation of a single radio channel is not sufficient. With a multi-channel approach and up to eight redundant RSS readings, the position estimation error can be reduced significantly. The paper focuses on the communication schedule to realize a real-time operation and the fusion of the redundant RSS readings, coming from IEEE 802.15.4 compliant 868 MHz and 2.4 GHz radio transceivers. Empirical positioning results for an office environment will be used to evaluate the influence of the redundant sensing.