Distributed Shared Memory as an Approach for Integrating WSNs and Cloud Computing

In this paper we discuss the idea of combining wireless sensor networks and cloud computing starting with a state of the art analysis of existing approaches in this field. As result of the analysis we propose to reflect a real wireless sensor network by virtual sensors in the cloud. The main idea is to replicate data stored on the real sensor nodes also in the virtual sensors, without explicit triggering such updates from the application. We provide a short overview of the resulting architecture before explaining mechanisms to realize it. The means to ensure a certain level of consistency between the real WSN and the virtual sensors in the cloud is distributed shared memory. In order to realize DSM in WSNs we have developed a middleware named tinyDSM which is shortly introduced here and which provides means for replicating sensor data and ensuring the consistency of the replicates. Even though tinyDSM is a pretty good vehicle to realize our idea there are some open issues that need to be addressed when realizing such an architecture. We discuss these challenges in an abstract way to ensure clear separation between the idea and its specific realization.