移动核心网电路域CE结构性隐患优化简

分析了移动核心网电路域CE组网的现状,指出原先CE接入网设计中存在结构性网络安全隐患,例如当单个路由器或接口故障时,会导致业务的中断。针对上述隐患提出网络安全隐患优化解决方案。该方案在实践中得到了验证,能有效消除了网络结构性安全隐患,增强网络的安全性和可靠性。     

A Method for Calculation of Network Reliability

The calculation of the probability that communication between two nodes in a given network is disrupted is difficult when the number of channels is large or when the network configuration is complex. This paper presents an efficient method, formalized as an algorithm, for calculating this probability using subnetworks that are smaller than the original one. This algorithm should prove useful in practice since it permits the possibility of choosing the subnetwork decomposition that one considers best suited for a specific problem.     

野战地域通信网可靠性的评价方法

本文针对野战地域通信网网络拓扑复杂并随战场环境发生变化的特点,提出了一种快速评价野战地域通信网可靠性的方法,给出了可靠性定量计算的数学解析式,该方法简单、直观,能反映网络拓扑的可靠性和抗毁性。     

关于通信网可靠性的研究方法

随着通信网规模和技术水平的不断发展，通信网故障的影响面和影响深度也在扩大，因此，通信网的可靠性已成为网路运行的必然要求。本文在了解了国内外研究进展的基础上，对通信网的研究内涵进行了分析，从而提出开展通信网可靠性工程的研究，利用系统工程的方法对通信网的可靠性问题进行分级分层划分，以便确定细化的子问题进行具体的可操作性研究     

关于概率网络可靠性的一种评估方法

论文主要针对概率网络,提出了一种评估其可靠性的指标,给出了其数学解析式。在文章最后假定了概率网络的一个实例模型并且对其进行了可靠性分析。该指标考虑到了通信节点间数据交换的不对称性;网络拓扑结构和它的时变性;网络链路和节点的不可靠性以及网络的迂回路由问题,能够简单、直观地反应整个概率网的可靠性和抗毁性。     

基于可靠性约束的网络多目标满意优化

利用满意优化方法综合考虑网络可靠性和网络费用,以此来建立网络拓扑结构设计的数学模型,并描述了用遗传算法求解该问题的方法。满意优化与遗传算法相结合成功解决了网络高可靠性和低费用之间的矛盾。最后,通过与一般优化方法结果相比较来说明算法的有效性,给出其仿真的结果。     

基于蒙特卡罗法对多目标配电网最优无功优化的可靠性分析

多目标(Multi-Objective,MO)无功优化调度(Optimal Reactive Power Dispatch,ORPD)是一个复杂的非线性多变量规划问题。文章采用蒙特卡罗法(MCM)对ORPD问题中的负荷不确定性进行建模,以实际功率损耗和电压偏差最小化为目标函数,使用混合整数非线性规划来解决提出MO-ORPD概率问题。并以发电机母线电压、变压器的分接比和无功功率补偿为控制变量,在IEEE30节点测试系统上进行测试,其结果验证了蒙特卡罗模型对MO-ORPD概率问题的适用性与可靠性。     

A New Method for Solving Reliability Optimization Problem

A simple and computationally attractive method for solving constrained (which may not be linear) reliability optimization problem, when both improved modules and redundancy are used, is presented. Usually only one initial point is sufficient to be considered. The method applies to both series as well as complex systems and some times gives better solution than Tillman et al. (1977).     

一种有共因失效的网络系统可靠性分析方法

在分析网络系统可靠性时,由于其诸多部分是冗余系统,共因(CCF)失效是必须考虑的因素.传统的共因方法分为显式方法和隐式方法,显武方法由于要引入大量共因失效基本事件,造成模型的复杂和难以求解;而隐式方法有较大的主观性,结果往往不够精确.本文基于决策二叉树(BBD)的共因分析法,能方便的进行计算同时得到了较理想的精确结果.     

User Selection Method Adopting Cross-Entropy Method for a Downlink Multiuser MIMO System

This letter presents a novel method of user selection in a downlink multi-user multiple input multiple output (MU-MIMO) system employing the precoding procedures of zero forcing or block diagonalization (BD). The proposed technique utilizes the cross-entropy method (CEM) in order to maintain a performance level comparable to that of the full search (FS) method with reasonable complexity. With the CEM, the proposed system can select multiple users at once instead of selecting a single user at each step. From various computer simulations, it has been verified that the proposed method exhibits nearly 98 % of the sum-rate compared to the FS method, which implies that the proposed method far outperforms conventional methods such as semi-orthogonal user selection (SUS) or the capacity-based suboptimal user selection (CBSUS) algorithm. Compared to CBSUS, the proposed technique enhances the sum-rate by approximately 1.1 bps/Hz with about half the complexity when each user is equipped with two receiving antennas. In the case where each user is equipped with a single antenna, the proposed method outperforms the method of SUS by about 0.3 bps/Hz, at the expense of a complexity increase of $O(2M)$ times.     

浅谈提升计算机网络可靠性的方法

随着信息技术时代的到来,计算机在人们的生活、工作中发挥着越来越重要的作用。那么因此也产生了以盗取网络信息为目的的黑客,令人们对计算机网络的安全性有所怀疑。进入21世纪以来,计算机网络因其功能强大,越来越受到人们的欢迎,但其中也存在着诸多风险。为了减少网络对生活、生产的损失,人们的要确保网络的可靠性,便要明确影响网络信息安全的因素都有什么,以便针对这些存在的问题来采用相应的方法来改善计算机网络的可靠性。     

网络抗攻击优化方法研究

研究了网络抗攻击问题.针对网络节点在传输过程中,当在节点密钥没有及时、快速更新的情况下,网络节点会失去密钥保护,容易受到来自外部的攻击,造成网络安全隐患.文中提出了一种基于改进Feistel算法的数据加密技术.通过把传统的抗攻击密钥分成四个层次,层次之间相互关联,分层更新计算,使得网络节点密钥能够快速更新,加强网络安全性.实验结果表明,新算法在节点密钥更新速度上,大大加快,增加了网络节点的安全性,取得了很好的效果.     

EDGE网络的优化方法

目前中国移动已经在全国大部分地市开通了EDGE。本文详述了EDGE网络的指标评估体系以及优化方法,指出了干扰、移动性和容量是影响EDGE网络性能的三要素。最后通过在重庆移动的优化实践细化了优化方法,为运营商及三方优化公司进行EDGE网络优化提供了参考。     

GSM网络优化准备工作及常用方法

本文论述了GSM无线系统优化的准备工作和优化常用的方法，讨论了GSM数字移动通信无线系统网络优化的问题。总结了常见的优化思路及方法。     

Optimization of System Reliability via Redundancy and/or Design Considerations

The two traditional methods used in improving the reliability of a multi-stage system are examined. The first method is the creation of redundancy in system components, whereas the second method consists of overdesigning the system components. An Integrated Reliability Optimization Model that includes both of these two methods for improving the reliability of a system is presented. It is shown that under certain assumptions the integrated model reduces to a Redundancy Optimization Model and under certain other assumptions reduces to a Design Optimization Model. Several methods that have been previously suggested for obtaining solutions to the Integrated Optimization Model are reviewed and a generalized solution procedure for such a model is presented. This solution procedure involves the successive solution of two subproblems a number of times. The first subproblem is a design optimization problem that is solved by the Davidon-Fletcher-Powell optimization algorithm. The second subproblem is a reliability redundancy optimization problem that is solved with the heuristic approach of Aggarwal, et al.     

Bayesian Decomposition Method for Computing the Reliability of an Oriented Network

For a nonoriented network, Bayesian decomposition is straightforward and well known. A keystone element is assumed perfect (shorted), then failed (open) and the reliabilities of the two subnetworks are calculated. But for an oriented network, when the keystone element is assumed perfect, it cannot always be shorted (the 2 nodes brought together), because even a perfect element still retains its orientation. A technique for choosing keystone elements is proposed.     

NB-IoT网络结构优化方法研究

窄带蜂窝物联网(NB-IoT)具有覆盖广泛、并发接入终端多、传输速率小、低功耗、建设成本低等优点,具有广阔的应用前景。但是现阶段的NB-IoT存在诸多网络结构问题,本文系统性的提出一种NB-IoT网络结构优化方法,能够有效提升网络结构性能,改善用户感知,为NB-IoT后期的大规模应用打好基础。     

电信级高可用率BGP/MPLS VPN网络部署与优化

BGP/MPLS VPN作为基于一种城域的VPN部署技术,发展成运营商VPN服务的跨域实现.本文从建设电信级BGP/MPLS VPN网络的实际出发,分析了跨AS实现方式,计算了网络可用率、并应用HSRP协议进行网络优化,确定优化后的目标网络达到了电信级高可用率的要求.     

面向时延与可靠性优化的服务功能链部署方法

针对5G网络高可靠性、低时延的服务需求,该文提出一种面向时延与可靠性优化的服务功能链(SFC)部署(DROSD)方法。在不预留冗余资源的情况下,首先通过功能互斥约束来确定SFC中相邻虚拟网络功能(VNF)是否可聚合;其次通过功能性约束、资源约束选择可聚合物理节点集合,实现负载均衡,提高SFC可靠性;然后通过跳数约束进行优化,进一步筛选可聚合物理节点集合以降低SFC的端到端时延;最后通过节点可用资源、节点度以及与原节点跳数指标进行降序排列,取最大值物理节点部署VNF。SFC的路由选择,采用K-最短路径算法。仿真实验表明,该文所提算法提高了请求接受率、长期平均收益开销比,增强了SFC可靠性,降低了端到端时延,减小了平均带宽开销。     

利用CRC校验提高HFC网络通信可靠性

有线电视网络分布广、环境复杂 ,通信过程中难免受到干扰 ,目前在一些厂家内部协议中的数据校验纠错方法还比较传统 ,不能有效起到抗干扰的作用。为了提高通信的可靠性 ,值得关注和广泛应用的是一种简单而重要的通信差错控制技术———CRC。介绍了循环冗余校验CRC(CyclicRedundancyCheck)的差错控制原理和程序实现 ,并提出更具有实际应用价值的快速CRC算法的程序实现。