NGN网络测试仪表实时统计方案的设计与应用

本文介绍了NGN网络测试仪表中一种支持用户自定义时段统计结果查看的统计方案设计与应用,实现用户自由输入任一时间段,查看该时段网络的通信状况,极大地方便了用户对通信网络的运管维护。本文对统计的粒度、文件、模块进行了分析、设计,并在此基础上提出了统计与统计结果获取的实现方式,以INAP协议监测为例阐述了该方案在NGN测试仪中的具体应用,从该实例中证明了设计的合理性和可行性。本文涉及的统计方案在其他网络测试仪表的研发中具有通用的指导和推广意义。     

NGN测试系统MAP监测模块的研究与实现

MAP监测模块是NGN网络测试仪表中针对移动网进行测试的部分。为了正确地将MAP协议运用于系统中,遵循基于ASN．1的MAP协议编码规范,采用面向对象的软件设计方法,开发出用于NGN网络测试仪的MAP监测模块。从用户需求出发,介绍了模块的设计和实现方法,并经过充分测试,效果良好,符合使用要求。     

NGN测试系统MAP监测模块的研究与实现

MAP监测模块是NGN网络测试仪表中针对移动网进行测试的部分。为了正确地将MAP协议运用于系统中,本文遵循基于ASN．1的MAP协议编码规范,采用面向对象的软件设计方法,开发出用于NGN网络测试仪的MAP监测模块。从用户需求出发,介绍了模块的设计和实现方法,并经过充分测试,效果良好,符合使用要求。     

NGN网络测试仪表中智能网应用协议软件模块的研究

将智能网应用协议(INAP)运用于应用系统中,采用面向对象的软件设计方法,开发研究出运用于通信测试仪表的INAP软件模块,并重点对INAP软件模块设计的方法及INAP软件模块的实现作了详尽的论述.并在实践中得到应用.     

NGN网络测试仪RTP模块CDR合成的研究与实现

文中在介绍RTP协议的基础上,进一步针对NGN网络测试仪中RTP模块的CDR合成处理流程进行分析,并对整个流程涉及到的重要环节,如RTP协议解码分析、CDR合成方案进行了详细的介绍.通过实际数据的测试,验证了所提方法的有效性,解决了NGN网络测试仪中RTP模块的测试功能的问题,具有一定的实用价值.     

NGN网络MGCP协议模块合成方案

介绍了NGN网络中MGCP协议模块的基本概念和实现方法,在对MGCP协议深入研究基础上,提出了CDR合成的方案,并在测试仪中得到了应用。通过测试仪对数据的采集也验证了CDR合成方案的正确性和高效性。     

GPRS网络GTP协议解析方法研究

GPRS是GSM向3G迈进的一个重要步骤。文章以NGN网络测试仪的信令分析功能作为研究背景，介绍了GPRS骨干网中GPRS隧道协议功能和消息结构，并且在此基础上着重探讨了GTP解析方法，目的是对网络测试仪中GTP模块的软件实现提出解决方案。GTP协议的分析思路和方法对研究传输层的其他协议具有指导和推广意义。     

NGN网络测试仪H.264合成模块的研究与实现

以下一代网络(NGN)网络测试仪的研制为背景,在基于对H.264协议的深入理解基础上,通过软件方法将H.264协议数据从IP包、实时传送协议,实时传送控制协议(RTP/RTCP)消息中分离出来,然后对H.264协议的数据按帧进行解码处理,通过软件实现其数据合成,最后在NGN网络测试仪中成功建立基于H.264的视频合成模块.     

NGN网络测试仪中No．7信令采集卡的研制

在NGN网络测试仪的开发中,No．7信令采集卡的研制非常关键,它是针对核心网测试最重要的采集卡之一。在本文中,介绍了No．7信令采集卡的设计方案,硬件设计与实现,及驱动程序的设计。经过现场测试表明,本文研制的No．7信令采集卡能够满足NGN网络测试仪现场采集数据的要求。     

移动智能网CAMEL的信令监测实现和分析

文中介绍了NGN测试仪中GSM移动智能网CAMEL协议在网络中的结构，功能．并在此基础上探讨了CAMEL协议在NGN测试仪中的解码功能，呼叫合成功能以及性能分析功能的设计方案和实现，最后对监测结果进行了分析．     

基于F2812的VPN管理服务器设计

为充分利用公共网络资源来提供优质信息安全服务,文中介绍了一种新型的高安全虚拟专用网安全通信解决方案,该方案将网络安全协议完全嵌入到网络设备之中,从而使网络设备具有身份认证、通信保密以及防止主动攻击的功能,给出了该方案的硬件平台组成及组网网络拓扑结构,详细介绍了方案中管理服务器的功能设计、硬件结构及软件结构,同时介绍了RSA算法的实现方式,经验证该方案达到了预期的目的。     

A spare bandwidth sharing scheme based on network reliability

Spare bandwidth is required for recovering the network service from network faults. However, it degrades the efficiency of network utilization. Spare bandwidth demand can be reduced significantly by letting spare bandwidth be shared among several network services. Spare bandwidth reserved on a network element can be shared by a set of network services for a network fault if they are not simultaneously affected by the network fault. A new, and more practical spare bandwidth sharing scheme, which is based on the network reliability, is proposed in this paper. In the proposed scheme, multiple link failures are allowed with a given link failure rate, and a reasonable restoration level of near 100%; while in the conventional scheme, only a single link failure, and 100% restoration level are considered. To develop the spare bandwidth sharing scheme, we first investigate the framework for evaluating the reliability of path-based network services, and then we explain the proposed spare bandwidth sharing scheme with decision parameters such as lifetime of the path, restoration level, and the maximum number of working paths which can be protected by a backup link. Simulation results show that the proposed spare bandwidth sharing scheme requires a smaller amount of spare bandwidth than the conventional scheme.     

C~4ISR网络对抗技术

攻击和防御是对抗的两个基本方面。文章首先阐述了C^4ISR的概念,然后对信息网络的对抗技术进行了归纳分类,讨论了各种信息网络防御机制,重点分析了不同防御机制中所存在的脆弱性,并提出了相应的攻击措施。最后,对C^4ISR网络对抗机制间的攻防关系进行了总结。     

基于协作中继的多元网络乘积码

相比基于XOR的网络编码协作方案,网络乘积编码协作方案是一种更有前景的抗衰落技术,既能明显地提高误码率性能,又能减少网络中所需要的中继个数。基于协作多址接入场景设计了一种多元网络乘积编码协作方案,通过深入的理论分析表明所构建的网络乘积码能实现近似高斯权重分布,从而能明显地提高误码纠错率。仿真结果也验证了该协作方案相比传统网络乘积码能获得更高的误码率性能。     

Security and Cooperation in clustered mobile ad hoc networks with centralized supervision

Although individual node cooperation is necessary for the correct execution of network protocols in mobile ad hoc networks (MANETs), it is not always guaranteed. In this paper, we present a node reputation scheme aiming at reinforcing node cooperation in MANETs with centralized control. This scheme was designed for centralized ad hoc network architecture (CANA), an ad hoc enhancement to the HIPERLAN/2 WLAN standard. Misbehavior detection techniques for protocol attacks in both the cluster formation and data transmission phases of the network operation are developed. Statistical methods for selecting the optimal parameters of the reputation scheme are investigated and their efficiency is illustrated through theoretical analysis and simulation results. Throughout this paper, the specific aspects of CANA that impose particular design decisions are outlined and the applicability of our scheme to other network architectures is discussed.     

应急现场通信组网方案探讨

应急通信是确保重大自然灾害救援行为有效开展的前提,而应急现场通信网络的建设水平直接影响着应急通信的保障效果。介绍了应急通信过程中应急报警、应急处理、应急通报、应急沟通4阶段的特征,通过对当前主要应急现场通信技术卫星通信、集群通信、微波通信、短波通信、无线传感器网络、移动Adhoc网络的分析,提出了基于卫星、无线传感器网的组网方案,基于卫星、Adhoc网的组网方案以及综合以上通信手段的综合组网方案,应急事故发生后,应根据不同阶段的特点灵活采取组网方案。     

A network selection scheme for multicast applications in wireless network convergence

In wireless network convergence, each mobile host is expected to have multiple kinds of wireless interfaces. Multicast‐based applications are expected to be widely deployed. In this paper, a new network selection scheme is proposed for a mobile host to select the most appropriate wireless access network to maximize user satisfaction and ISP's profit, simultaneously. We have devised a metric to measure a user's satisfaction and we also developed a ‘normalized network resource’ metric for system profit measure. We have compared our scheme with three other reference schemes, through simulations. Depending on the network deployment situations, our scheme exhibits one‐fifth service disruption time of other reference schemes, while the resource consumption of our scheme is comparable to that of the minimum resource scheme. Overall, the gain of our scheme becomes higher as users move faster and/or the population density increases. Copyright © 2010 John Wiley & Sons, Ltd.     

异构网络中多网络并行传输的网络选择算法

为了充分利用异构网络中的无线资源,提出了一种基于多网络并行传输的异构网络接入选择算法,该算法根据终端接收信号功率确定能够进行通信的无线网络,以这些无线网络的任意非空子集作为候选方案,计算各个方案对应的聚合属性,再根据吞吐量和功耗阈值条件限定候选网络方案,对这些方案建立多属性决策矩阵,采用基于用户偏好的逼近理想值排序法(TOPSIS)得到各个候选网络方案的效用函数值,从中选出与理想方案最接近的多网络接入方案。仿真结果表明该算法能有效改善用户服务质量,提高用户吞吐量,降低用户的单位吞吐量对应的功耗和费用,保证网络的负载均衡。      

A resilient star-ring optical broadcast-and-select network with a centralized multi-carrier light source

This article presents a resilient star-ring optical broadcast-and-select network with a centralized multi-carrier light source (C-MCLS). It consists of a star part network and a ring part network. Optical carriers generated by the C-MCLS are broadcast to all network nodes, which select and utilize them for data transmission. Optical carrier distribution as well as data transmission and receiving are performed in the star part network. The ring part network is for fiber failure recovery. The network resilience property enables the design of a fast distributed failure recovery scheme to deal with single and multiple fiber failures. We introduce a fiber connection automatic protection switching (FC-APS) architecture that only consists of optical couplers and 1 × 2 optical switches for each network node. Based on the FC-APS architecture, we design a distributed failure recovery scheme to recover the carriers and data affected by fiber failures. The fiber failure detection and failure recovery operations are performed by each network node independently only using its local information. We evaluate the recovery time of the distributed failure recovery scheme compared with that of the centralized one. Numerical results show that the distributed scheme greatly reduces the recovery time compared to the centralized configuration in the recoveries of both single and multiple fiber failures. Optical power loss analysis and compensation of the recovery routes in the distributed scheme are also presented. We show the required number of optical amplifiers for the longest recovery route in the distributed scheme under different numbers of network nodes and fiber span lengths.     

嵌入式以太网接口及精简网络协议的非常规实现

嵌入式系统资源有限,因此要求嵌入式以太网的应用在实现网络功能的前提下,尽可能对协议栈精简。分析了嵌入式网络协议栈的一般精简方法,并在此基础上提出更进一步的网络精简策略,即通过对应用层标准网络协议的改造,同时简略ARP协议、ICMP协议这些非常规实现方法下,仍能确保网络数据的正常通信和一定的网络测试功能。从而使嵌入式网络协议得到最大化的精简,为资源极端匮乏的应用提供一套切实可行的方案。