【作者】 孙慧丽；

【导师】 谭献海；

【作者基本信息】 西南交通大学 ， 计算机应用技术， 2007， 硕士

【摘要】 随着通信网络技术的迅速发展，特别是高速通信网络的发展，网络的规模越来越大，链路容量越来越高，链路越来越稀疏，网络可靠性研究越来越为人们所关注。目前，有关系统可靠性约束或目标的网络设计已经成为许多研究的课题，并且已经在通信网、计算机网和电气控制等相关领域得到广泛应用。可靠性是进行通信网络规划设计与性能评价的重要指标。本文从理论与方法两个方面对网络系统中有关可靠性问题进行了较为深入的研究，主要研究了网络系统一种随机性可靠性指标----全端可靠性的计算问题。研究内容主要包括三个部分：全端可靠性界的问题、全端可靠性计算和仿真方法。给出其实验结果，数值分析结果表明每种方法有各自的优缺点和适用范围。根据基于可靠性约束的网络优化的实际情况和满意优化的优点，提出了基于可靠性约束的网络多目标满意优化思想，设计出了主干网设计求解模型，改进了遗传算法，并应用于网络优化设计中。成功解决了网络设计中各性能指标之间的矛盾，即如何使可靠性尽可能高，而且全网费用和时延尽可能小。采用所提出的基于可靠性约束的网络多目标满意优化模型，研究了容量非受限型网络拓扑优化设计和企业网拓扑优化设计问题，并进行了仿真验证。仿真结果表明，该方法要优于传统的优化方法，能极大地缩短求解时间，一般能找到比较满意的解。网络可用性是网络性能评价的另一个重要指标，从网络可用性的概念着手，重点研究了网络可用性参考模型，三种生存机制下可用性的计算方法，将参考模型运用在实际网络中，通过比较三种生存机制下端端连通可用性，进行网络可用性分析，并给出实验结果。更多还原

【Abstract】 With the development of telecommunication network. Modern telecommunication networks tend to have large scale, sparse topology and high capacity. Now these concerns have increased in network design and motivated the research in this dissertation. Network design based on reliability constraint or object has widely applied to telecommunication network, computer network and electric control.Reliability is main index of network design and performance analysis. This thesis studies some network reliability issues existing in network systems from two aspects: analysis methods and theoretic models. The calculation problem of all-node reliability which is a kind of probabilistic measure is studied. The research is comprised mainly of three aspects: bounds of all-node reliability, calculation method and simulation approaches for all-node reliability. The results of experiment are given and numerical examples demonstrate that there are different advantages, disadvantages and applicating scopes.Based on actual instance of network optimization considering reliability and the advantage of satisfactory optimization method, this thesis presents a new approach of multi-criteria satisfactory optimization of network subject to reliability constraint. The mathematical model is established and applied to communication network based on reliability. In addition, an improving genetic algorithm is used to search the satisfactory solution. The joining of satisfactory optimization and genetic algorithm can solve the problem of contradiction among the performance indices such as high reliability, low cost and low mean delay of the network.The model for multi-criteria satisfactory optimization of network subject to reliability constraint has been adopted. Uncapacitated network design problem and Intranet topology optimization problem are studied and simulated. The emulational results indicate that the model is more excelled than traditional model. It can efficiently shorten the search time and find the more satisfying results.Network availability is another main index of performance analysis. Based on the concept of network availability, the network availability reference model and the availability calculation method for three resilience mechanisms are stressed. The reference model has been applied to real network scenarios. The end-to-end connection availability for three resilience mechanisms is compared. The network availability is analyzed, and the analysis results are given.更多还原