Video-Like Compression for High Efficiency Database Storage of Wireless Sensor Networks

Wireless Sensor Networks (WSNs) consist of group sensor nodes which are placed in an area to monitor the changes of environment. Usually, sensing data are gathered and stored in a data server which maintains a database to organize and manage numerous of WSNs data. It allows researchers to retrieve these data for further study or analysis. Since the size of WSNs data is huge and the storage resource is limited, this database needs compression to lower the data size. In this paper, we propose a video-like compression method for high efficiency database storage of WSNs. First, the raw data are arranged according to the spatial correlation as an image frame. Then, several image frames with temporal correlation are maintained as a sequence of frames and lossless video compression is adopt for lowering the data size. Based on this idea, we also propose a data retrieve/query algorithm for parallel processing. The trade-off between space saving and query time is discussed after experiencing with real-world data. At last, we compare our proposed method to MySQL, a well-known database which compression is supported. The experimental results reveal that our method achieves over 96% of the space savings. It is over 13% more than that achieved by MySQL.