Towards global smart spaces: Merge Wireless Sensor Networks into context-aware systems

The integration of Wireless Sensor Networks at a global scale is a crucial step on the road to a tighter coupling between the virtual and real world. In a context-aware system with thousands or even millions of data items describing the current situation, it is obvious that this data needs to be filtered and aggregated in order to distribute the detection and processing efficiently. The need to aggregate data exists also from the perspective of the Wireless Sensor Network since energy is limited and there is a strong requirement to reduce communication traffic. Therefore, this paper illustrates the general concept of a context-aware system and explains in detail how to integrate Wireless Sensor Networks in such a system for global usage of information detected by numerous nodes. The concept is proven by implementation, measurements, and a theory of operation.