Urban environments are increasingly pervaded by ICT devices. Soon, citizens and technologies could collaboratively constitute large-scale socio-technical organisms supporting both individual and collective awareness. This paper illustrates a modern awareness framework designed to deal with the complexity of this scenario. The framework is able to collect and classify data streams in a modular way by supporting service oriented, reconfigurable components. Furthermore, we evaluate an innovative meta-classifcation scheme based on state-automata for (i) improving energy efficiency, (ii) improving classification accuracy and (iii) improving software engineering of aware systems, without affecting the overall performance.