【作者】 张南；

【导师】 刘治国；

【作者基本信息】 沈阳理工大学 ， 计算机应用， 2009， 硕士

【摘要】 应急通信系统是指在出现自然的或人为的突发性紧急情况时,综合利用各种通信资源,保障救援、紧急救助和必要通信所需的通信手段和方法。它应具有抗毁能力强、抗干扰能力强、通信安全可靠等特点。但是随着科技的发展和国际局势日趋复杂,它已暴露出一些问题:通信时间和地点的不确定性、通信网络本身受紧急事件破坏的程度具有不确定性、应急通信的容量需求的不可预测性等问题,因此建立更全面、稳定、高效的应急通信系统已势在必行。监控系统是应急通信系统的保障系统,它能够实时快速发现网络状况的变化而做出对策并选择最佳链路进行通信。因此监控系统的完善是应急通信系统发展的关键。数据采集是监控系统的基础和前提条件,设计优秀的数据采集系统,实现对被监控指标的有效监视是保障监控系统快速诊断、可靠运行的前提。本文以应急通信系统为背景,研究其链路的数据采集技术,针对其特点和需要,提出了一种基于分层分布式多域的数据采集模型,该模型包括域内采集部分和域间采集部分。域内数据采集利用域首节点派发移动代理来采集链路信息,从而降低网络开销、减少域首的工作;域间数据采集利用(逻辑)上层域首轮询下层各域首中驻留的域代理的方式来获得链路信息,以便高效快速的获取信息、减少网络负担。同时本文通过对传统链路带宽测量方法分析基础上提出改进方法:双向非对称链路低误差带宽测量方法。该方法利用发送ICMP包来实现对双向非对称链路的测量;计算被测链路和前一段链路延迟来消除逐跳误差累积;发送背靠背的两个包来计算带宽从而消除背景流量的影响。最后,本文针对无线链路提出采集方案,通过不同的协议转换来完成对无线链路的数据采集。通过仿真实验证明本文提出的改进方法更高效,数据采集系统可靠性更强,采集信息更全面。更多还原

【Abstract】 Emergency communication system is used for the event of natural or man-made sudden emergencies, communication means and methods of necessary for synthetically utilize various communication resources, ensure succor, emergency salvation and the necessary communication, whose characters are strong anti-destroy ability, anti-interference ability, secure and reliable communications. However, with the development of science and technology and international situation gradual trend to complex, a number of issues are exposed such as uncertain communication time and place, degree of communications network itself by the extent of the damage emergencies with uncertainty, and the uncertain capacity of emergency communication needs. Therefore to establish a more comprehensive, steady and effective emergency communication system is imperative.Monitoring System is safeguards system of emergency communication system that can real-time and quickly find changes of network status simultaneity to make countermeasures and choose the best link for communicate. So consummation of monitoring system is the key for development of emergency communication system. data collection is the basis and prerequisite of monitoring system, design of good data collection system, and the implementation of effective scout guide line which is monitored are prerequisite of guarantee monitoring system to fast diagnosis and credible run.The link’s data collection technology of emergency communication system, regarded as the background in this paper. According to its characteristics and needs, a data collection model which is based of the layered distributed multi-field system is established. There are two parts of the model, that is, inner domain data collection and external domain data collection. the header node domain distributed mobile agents is adopted to collect link information, thus reducing network spending and first, the header’s work in inner; while logic topper header poll domain agent is adopted which is stationed in each lower header to collect link information so that get information fleetly and high effectively and reduce network burden. At the same time, ameliorate method which is RI-TAW-PATHCHAR is brought forward on the basis of the analysis methods by means of the traditional link bandwidth measurement methods in this paper, which makes use of sending ICMP packets to achieve a two-way asymmetric links measurement, calculates the measured link and its previous links paragraph-by-hop delay to eliminate the accumulated error, and sends the two back-to-back package to calculate the bandwidth in order to eliminate the background flow impact. Additionally, on the basis of wire link data collection, the collecting design program of wireless link also is put forward in the article, with different protocol conversed to complete the data collection of wireless link. Ultimately, the more comprehensive, efficient and stable data collection of the emergency communication system is achieved.Through the simulation testing, it is showed that the improved method is more efficient, the reliability of system is stronger and the collection of information is more comprehensive.更多还原