Research Of Mobile Database Based On Wireless Sensor Network

There are lots of advantages in wireless sensor network such as cabling with low cost, high-precision monitoring, fault-tolerant, remote monitoring, facilitate the diagnosis and maintenance. There are broad prospects for application in areas such as military, ecological and environmental protection, monitoring of projects, health care. Its fundamental task is to accurately access to valuable information of the physical world. Now, people are out of the limitations of fixed wire line networks and share data gradually network by using the PDA, cell phones and other mobile devices. They are entering a mobile computing era no matter when, where they can acquire and process Information. In a variety of network conditions mobile database system can support users to access data effectively and query data, complete the transaction. By the mobile database copy/cache technology or data broadcasting technology, even in the case of disconnect users can continue to access the required information, which makes mobile database system with a high degree of availability.Based on wireless sensor network data features, this thesis design a mobile database system based on a wireless sensor network (WsnMDB), mobile users can access the information of sensor network at any time.First of all, this thesis introduce wireless sensor networks briefly, compare data management in the sensor network and distributed database, elaborate the structure of data management in sensor network. Then, this thesis research and discuss the data management techniques of wireless sensor network. In detail we study data storage, query technology and data fusion technology of wireless sensor networks .we focus on the query processing, query optimization and in-network data fusion technology. Then, the article presents a mobile database system WsnMDB based on wireless sensor network. WsnMDB system is designed based on the characteristics of data in wireless sensor network. It is a mobile database and users can query data in wireless sensor network at any time and anywhere. We give the architecture of WsnMDB and the function of each module and the software platform on which each floor run. Migrating the java virtual machine to embedded arm board was made a detailed presentation .A database query language was analyzed. Finally, we design the WsnMDB system including mobile clients, the database server at clustering node and nodes in WSN, Which we focused on the design of query manager, the memory modules and synchronization module of the database server at clustering node. In the design of memory modules, a storage method of historical data flow was applied, which combine sample storage and aggregation storage to support the various historical data gathering.