Design And Application Of The Military Device Mobile Information System

With the development of internet and mobile communication technologies, it is possible for people to access data anywhere and at anytime. As a more flexible and complex mobile computing environment, traditional distributed database technologies can not support the need of mobile data-access,so mobile database comes into existence. How to construct a mobile database based on traditional distributed database technologies, which can adapt the wireless environment, has been a key problem of distributed database researches.This thesis particularly studies the status of mobile database, discusses architectures, characteristics, some key technologies of mobile database. And the thesis presents a data consistency maintenance solution based on bi-asynchronism data replication technology,which can maintains data consistency in mobile database environment. Combining characteristics of mobile database technologies with traditional duplication methods of distributed databases, bi-asynchronism data replication solution realizes the bi-asynchronism data replication between mobile clients and servers with SQL Server transaction-logs-tables and data broadcasting technologies. There are two links in this solution. As for the up link, it replicates from mobile clients to servers by SQL Server transaction-logs-tables. On the other hand, the down link replicates from servers to mobile clients by the broadcast average visited-time.The thesis designs a distributed application system under mobile computing environment with SQL Server 2000 as basical database flat and Delphi6.0 software,and realizes bi-asynchronism data replication solution in the Design and Application Of Military Device Mobile Information System. Practise proves that system has been realized the aim .Finally the thesis summarizes the running status of the system and shows the direction of the further studies.