Wireless sensor and actor networks context interpretation for the emergency preparedness class of applications

This paper presents a wireless sensor and actor network (WSAN) that can interpret from simple to complex contexts. In our solution, actors are used to aggregate sensor events, eliminate ambiguities and redundancy and realize context interpretations. Each actor of the WSAN is configured with rules that are determined by the application in the network configuration phase. An energy-aware event-ordering algorithm is also presented and evaluated against other existing solutions. After ordered, correlated events are interpreted resulting in contexts that go from simple questions, such as “what is the temperature of sector A” to more complex ones “why did the aircraft wing crack”. Context information is exchanged among actors and sink(s) of the WSAN through the publish/subscribe technique based on topics. Results from simulations have shown that by having actors for context interpretation and a fast energy-aware event-ordering algorithm, our solution can be a good alternative for emergency preparedness applications where lives and patrimony are at risk.