Enhancing WSN-Based Indoor Positioning and Tracking through RFID Technology

Joint utilization of Wireless Sensor Networks (WSNs) and Radio Frequency Identification (RFID) technologies is gathering increasing attention within the Internet of Things (IoT) community due to the potential of providing pervasive context-aware applications with advantages from both worlds. While WSN system can in fact provide more sophisticated sensing, communication and processing capabilities, the possibility to passively perform detection of tags and the use of unique RFID identifiers provides IoT systems with several advantages, especially concerning maintenance, such advantages are considered especially beneficial in large-scale scenarios where thousands of nodes must be simultaneously deployed over wide areas. WSN-RFID convergence is considered especially promising in context-aware systems with indoor positioning capabilities, where data from already deployed WSN and RFID systems can be opportunistically exploited to refine and enhance collected data with position information. This paper discusses and evaluates a hybrid system where WSN and RFID technology have been integrated to support an indoor positioning service, feeding position information into a general-purpose IoT environment. Performance of the proposed system is evaluated by means of simulations and a small-scale experimental set-up. The performed analysis suggest that joint use of RFID and WSN can increase the robustness and accuracy of indoor positioning systems also in harsh propagation conditions.