Demands on better interacting with physical world require an effective and comprehensive collaboration mechanism among multiple heterogeneous sensor networks. Previous works mainly focus on improving each single and specific sensor network, thus fail to address this newly emerged issue. In this paper, we study the issue of collaborative query processing among multiple heterogeneous sensor networks and formulate it into an optimization problem with respect to energy efficiency, called EE-QPS. To the best of our knowledge, we are the first one considering the collaborative query processing among heterogeneous sensor networks. By utilizing the implications among sensor networks, we design a heuristic approach named IAP to resolve EE-QPS. The experimental results validate our scheme and show that IAP achieves optimized energy efficiency under various environments. Categories and Subject Descriptors C.2.1 [Computer Communication Networks]: Network Architecture and Design ? Distributed netw...