【作者】 谢荣岳；

【导师】 余理富；

【作者基本信息】 国防科学技术大学 ， 电子科学与技术， 2004， 硕士

【摘要】 随着PDA的功能不断增强,无线网络技术和移动数据库技术的快速发展,开发基于PDA的移动信息系统是当前研究的热点。本文对移动信息系统的体系结构和关键技术作了深入研究。 文章在提出一种移动信息系统模型的基础上,深入分析了系统的体系结构,讨论了各个部分的主要特点和技术。研究了无线移动终端的无线上网技术、便携式智能终端的移动应用开发技术和本地数据库技术;讨论了目前成熟的无线网络连接技术,介绍了无线网络技术发展的关键技术即移动IP技术,分析比较了GPRS、CDMA 1X、WLAN三种典型的无线数据服务基本特点;讨论了无线接入局域网时基于数据安全的VPN技术;分析比较了系统调度监控中心的三种网络连接方式及其优缺点。 论文对移动信息系统中的四个难点问题提出了解决方案: 一是采用基于消息通信机制、调度监控中心服务器转发模式解决了移动终端间数据双向传输困难的问题; 二是采用握手机制和网络检测并及时进行处理解决了移动终端网络连接的状态的不确定性问题; 三是采用本地数据库访问和远程同步方式实现了通过无线网络对调度监控中心数据库数据的访问; 四是采用甘特图的方式对移动终端状态进行动态的图形化显示。 运用本文研究的技术开发了基于PDA的移动信息系统,用户使用效果良好。更多还原

【Abstract】 With the rapid development of advanced PDA, wireless network and mobile database technology, a good chance has been offered to the information of mobile operation and management. Developing the industrial mobile informational system (MIS) has become the hot spot. Aiming to the industrial application attracts most of the large-scale PDA manufacturer. The paper does advanced research with system-structure of MIS.Based on given a model of MIS, advanced analysis has been done and the key characteristic & technology has been discussed in this paper. In the following, the means of line to the Internet wirelessly is talked, the technology of mobile database and mobile IP are introduced. The analysis and comparison are done to the characteristic of three typical kind of wireless data service, which are GPRS, CDMA 1X and WLAN. The technology of VPN for the data’s security in the wireless environment is also discussed. The paper also provide the analysis and comparison of three typical model in sever part.In allusion to the uncertain state of PDA after it lines to the Internet, and the difficulty of exchanging information between two PDA online, this paper provide a solution of which is based on message and server’s transfer. The meaning of hand-shake and self-detecting the state of line-to-internet is given to solve the problem, which the application program must be steady. The Gantt chart is used to show some information about remote mobile client. In the following, it is offered that how to create local database application program using SQL Server CE.The research technology of this paper has been successfully applied in a design of the information system of mobile operation in airport.更多还原