Pervasive computing solutions are now being integrated into everyday life. Pervasive computing systems are deployed in homes, offices, hospitals, universities. In this work we present ECSTRA – Enhanced Context Spaces Theory-based Reasoning Architecture. ECSTRA is a context awareness and situation awareness framework that aims to provide a comprehensive solution to reason about the context from the level of sensor data to the high level situation awareness. Also ECSTRA aims to fully take into account the massively multiagent distributed nature of pervasive computing systems. In this work we discuss the architectural features of ECSTRA, situation awareness approach and collaborative context reasoning. We also address the questions of multi-agent coordination and efficient sharing of reasoning information. ECSTRA enhancements related to those problems are discussed. Evaluation of proposed features is also discussed.