【作者】 鲍刚；

【导师】 吕锋；

【作者基本信息】 武汉理工大学 ， 通信与信息系统， 2008， 硕士

【摘要】 随着通信网络在生产、生活中发挥着越来越大的作用,现代信息社会对通信网络的接入系统、交换系统、传输系统等相关领域人才的需求量增大。传统高校通信学科教育由于缺乏通信网络的实训平台,无法全面开展整个教学过程中的实践环节。本文所依托的通信实训系统正是为解决此问题而设计,构建了可以模拟实际通信网络的小型通信网和配套的实训管理软件系统。该实训平台设备采用主流在网运行的通信设备,包含了SDH,软交换,无线通信等几个子系统,能够完全满足通信网络专业各方向的教学实验要求,帮助高校建立一流的通信网络实验室,结合理论概念培养学生实际动手的能力。本文主要讨论了通信实训系统的软件设计与实现,作者的主要研究工作如下:(1)介绍了通信网络实训系统的基本概念特点,给出了系统的整体硬件组成结构和几个子系统的拓扑结构设计与组网方法。(2)通信网络实训系统软件系统的设计与实现:设计时将系统定位为基于RMI技术的小型C/S分布式系统,参照RUP软件开发过程,借助UML建模工具建立系统模型;进行需求分析,根据主要用例进行类设计,然后将系统结构分为视图、模型、控制器三个主要模块分别进行设计与实现。(3)基于客户端缓存的设计与实现:针对过多重复远程调用会影响分布式系统性能和效率的问题,本文给出了一种基于客户端缓存的RMI方法,使用客户端本地缓存保存使用过的存根和结果,经过性能比较可以发现客户端缓存的加入能有效减少重复RMI调用的次数,从而提高程序响应速度并减少占用的网络带宽。(4)总结并分析了系统有待进一步改进和完善的问题,对今后工作进行展望。本文设计与实现的通信网络实训系统已通过青岛科技大学等高校的验收并投入实用,在实际的教学和实验中取得了良好效果。更多还原

【Abstract】 With the communication network playing an increasingly important role in our production and life,Modern information society has a increased demand for qualified personnel in access system,switching system,transmission system,and other related fields.But due to lacking of communication networks training platform,it is always unable to fully carry out the process of practice session in traditional college communication education.The communication network training system is designed to precisely solve the problem above.It is been constructed with mainstream communication facilities and necessary management software system as a small communication network to simulate the actual communication network.The system contains several sub-systems like SDH,soft exchange,wireless communication etc.It can completely satisfy the need of teaching and experiment of various communication subjects,and help the university to build the first-class communication network laboratory,raise student’s ability of applying theory to reality.This article mainly discussed the design and implementation of the communication network training system software based on RMI cache method, author’s main research work is as follows:(1)The basic concept of the communication network training system is introduced and then we present the system’s overall hardware composition structure and topologies design of its several sub-systems.(2)Refers to the RUP software development process,with the aid of the UML modeling tool,the system is design as a small C/S distributional architecture system on RMI technical,and the system’s model is established.We first carry on the demand analysis,according to mainly use cases we design the classes,and then divide the system structure into three main parts:the view,the model,the controller. These modules are designed and realized then.(3)In practice too many repeated remote method invocations may affect the performance of application.The paper gives a method for RMI based on client side cache.A client first query in local cache whether there is the stub or result the client tries to invocate,and if they exist the client will directly use them without further remote method call through the network.The performance comparison shows that the method improves the performance of RMI by decreasing repeated invocation times and reducing network bandwidth occupied.(4)Summarizes,proposes and analyzes some problems of the system that need to be improved further.Carry on the forecast to the future work.The system has already been in use in the Qingdao Scientific and technical university and other several universities.It has obtained good feedback on the actual teaching and experiment.更多还原