iPOS: A Fault-Tolerant and Adaptive Multi-Sensor Positioning Architecture 
with QoS Guarantees 

Juergen Bohn Institute for Pervasive Computing ETH Zurich, Switzerland 

We describe the architecture of iPOS (short for iPAQ Positioning System), a 
fault-tolerant and adaptive self-positioning system with quality-of-service 
guarantees for resource-limited mobile devices. The architecture is based on a 
novel sensor modelling technique in combination with a probabilistic 
data-fusion engine, which is capable of efficiently combining the location 
information obtained from an arbitrary number of location sensors. As proof of 
concept, we present a prototypical implementation and discuss an experimental 
evaluation of the iPOS system. 

Keywords: Positioning, sensor modelling, sensor fusion, fault tolerance, 
quality of service, ubiquitous computing, mobile computing, location 
awareness. 

Contact: jjbohn@jjbohn.com