RadLoco: A rapid and low cost indoor location-sensing system

Ubiquitous location-aware systems and services are becoming a reality as made evident by the widely known Global Position System. However, indoor location-aware sensing systems are not yet commercially viable since the indoor signal propagation is complex and difficult to model. In this paper, we present RadLoco, a location-sensing system using IEEE 802.11 wireless LAN radio received signal strength (RSS) maps. The system makes use of a rapid and cost-effective survey data collection tool using an radio/ultrasonic sensory network. To provide highly accurate location estimation, we make use of a kernel-window estimation algorithm. Our experimental results indicate that a 2000 m² office building is surveyed in eight hours by a single technician, and that the mobile terminal is located with a mean error of less than 2.5 m.