卫星地面站在轨测试系统开关网络设计

对通信卫星的有效载荷进行在轨测试是一项重要的工作;在实际工作中,在轨测试的项目多,测试周期长,测量精度要求高,人工很难达到测试要求,因此开发一套卫星地面站在轨测试系统是十分必要的;在轨测试系统中的开关网络是该系统的重要组成部分;介绍了开关网络在系统中的作用,说明了开关网络在自动测量中的重要性;分析了开关网络的工作原理和功能,给出了开关网络的设计方案和实现方法;最后对测试结果进行了分析;该系统投入使用以后,测试效率高,测量精度高,自动化程度高,达到了设计要求。     

基于DSP芯片的高速数字电路模块BIT设计

随着雷达数字化和智能化,含有多个DSP芯片的高速数字电路模块得到了越来越广泛的应用;针对基于DSP芯片的高速数字电路模块构成的信号处理系统诊断能力弱的问题,提出了通过优化模块BIT软件设计提高模块故障诊断能力的方法;分析了该类模块的BIT测试需求,着重介绍了模块主要BIT测试项目的测试原理和设计方法;通过模块自检软面板对模块BIT测试方法进行了验证;试验结果表明该方法具有实用性强、成本低等优点。     

用于SCA ASIC测试的数字读出模块设计

高速开关电容阵列(SCA)具有高速采样、低功耗的特点,基于SCA的高速波形数字化是目前高精度时间测量的一个重要研究方向。为此,我们开展SCA芯片的研究,目前已设计完成原型ASIC设计,并正在进行后续版本的改进设计。为便于未来多版本ASIC的测试和评估,需设计具有一定通用性的数字读出模块,本论文工作主要介绍此模块的设计工作以及相应的数据读出软件。数字读出模块基于FPGA实现对待测ASIC的控制、配置及数据读出,采用DDR3片外存储芯片,使用USB3.0等接口进行数据传输;上位机软件基于Python3.7设计,实现了数据采集与波形绘制等功能。目前已使用设计完成的数字读出模块对第2版SCA ASIC进行了初步的测试,测试结果表明,此读出模块工作正常,且SCA芯片输出结果符合预期。     

基于VME总线的高速信号处理模块测试技术研究及应用

为解决某型号炮位侦察校射雷达中高速信号处理模块的测试,文中设计了基于VME总线的高速数字电路自动测试系统,该系统能模拟雷达工作环境,利用VME测试模块提供测试所需的光口、RapidIO等信号,测试结果通过VME主控器网口上报给系统管理平台;该系统成功应用于某型雷达高速信号处理模块的测试,可完成VME总线接口的测试;3路RapidIO信号的测试,Rapid IO信号传输速率为3.125 Gbps;4路光纤通道的测试,光纤通道波特率为2 Gbps;研究及实测结果表明该系统可解决基于VME总线的高速信号处理模块的测试。     

基于VPX总线的高速数字电路测试系统研究及应用

为解决战略预警雷达、舰载一体化等重点型号雷达中高速数字电路模块的维护能力,设计了基于VPX总线的高速数字电路自动测试系统,通过自研基于VPX总线的多功能测试模块、光纤测试模块,以及通用VPX背板,再结合通用的仪器设备构建测试系统,可兼顾多个型号雷达高速数字电路模块的测试。该系统可提供10路光纤通道,波特率最高为3.2Gbps;16路GPIO信号,中断响应时间＜50us;14路Rocket IO信号,传输速率2.5Gbps;4路*4Rapid IO信号,传输速率3.125Gbps。研究及实测结果表明该系统可解决基于VPX总线的高速数字电路模块的测试。     

零延时RS485模块在列车车载防火检测系统中的应用研究

随着高速列车技术的飞跃发展,车载设备之间的通讯信息、列车的故障检测和诊断信息、车内视频监控信息等信息数据的剧增,对信息承载媒介和通讯接口设备在可靠性和实时性方面提出了更高的要求;通过对RS485模块的研究设计了一种零延时RS485模块,应用于以太网主从式结构的列车车载防火检测系统中,达到实时、高效、安全可靠的设计目的;使用Multisim软件对零延时电路进行仿真验证,结果表明该设计的零延时RS485模块具有可靠的实时性。     

单块晶体集成的N×N纵横开关网络及其控制算法

设计了一种单块晶体集成的n×n纵横开关(Crossbar)网络。通过综合考虑晶体的双折射和全内双反射现象,以及晶体的电光效应,将构成n×n纵横开关网络的所有单元器件都集成到一块具有电光效应的双折射晶体上。同时,给出了该网络的控制算法,通过对开关工作状态的控制,可以实现任意输入输出通道之间的无阻塞连接。这种单块晶体集成的纵横开关网络具有能量损耗低、无阻塞、易安装、抗干扰等优点,适合于全光网络发展的需要。     

基于AFDX总线的飞机状态监控模块设计

为了实现飞机状态监控模块对机载高速AFDX总线网络海量数据的监控需求,分析机载网络构型,并从数据帧处理、文件管理和用户接口等几个方面对状态监控模块进行设计,通过中断和分级任务的相互配合,提出了两级筛选、三级缓冲的机制;使用专用地面数据分析工具对监控数据进行分析,结果表明此状态监控模块能够确保监控数据的实时捕获、处理和存储;经过验证,使用两级筛选、三级缓冲的机制设计的状态监控模块,可针对不同的任务配置不同的监控需求,能够实现飞机状态监控功能,符合设计要求,运行稳定。     

基于CPLD的多路瞬态冲击信号存储测试系统设计

为了对水平碰撞、跌落等环境试验中的多路瞬态冲击信号进行测试,基于CPLD设计了多路瞬态冲击信号嵌入式存储测试系统。系统采用高速串行AD转换芯片作为数据采集的执行器件,实现了多路冲击信号的同步高速采集;利用铁电存储器对采集到的信号进行在线存储;设计了USB接口模块,实现了PC机与测试系统之间的通信,并在LABVIEW环境下设计了数据回读软件;经试验验证了测试系统的正确性和可靠性。     

基于ATCA架构的加固服务器主模块设计技术

为了解决传统加固服务器主模块可靠性差和稳定性差的问题,提出了一种基于ATCA架构的加固主模块设计方法;该方法包括了基于冗余-48V的高性能服务器处理器供电电路设计技术、基于ECC校验的DDR2高带宽数据存储电路设计技术、基于SATA的高速存储技术等关键技术;经过了大量的测试和试验验证,该种新型的加固服务器主模块能够在恶劣环境下稳定运行,可靠性和稳定性都有了很大的提升。     

Network Evolution Toward a Carrier-Grade Ethernet Transport Network

Abstract

In this article, an overview is presented about state-of-the-art Ethernet technology and its evolutions beyond local area networks into metropolitan and wide area networks as carrier-grade technologies. It will be shown that the Ethernet can be used to guarantee the performance of current transport technologies in terms of operations, administration and maintenance, quality of service, monitoring, and test capabilities in support of service level agreements; in particular, the Ethernet could replace current transport techniques, simplifying network design and reducing both capital and operational expenditures. The Ethernet data-plane evolution will also be presented, from the virtual bridged local area network up to provider backbone bridging traffic engineering, including the issues related to the control plane. Also indicated is a future scenarios dealing with close interworking with optical technologies. In conclusion, a summary is given of experimental activities carried out on the virtual private local area network service, a current Layer 2 technique that can be assumed as a first step toward a carrier-grade Ethernet, which show the implementation of reliable wide area networks based only on gigabit Ethernet transmission.     

网络平均短程与网络乘积

讨论网络的平均短程.网络乘积的平均短程等于网络平均短程之和.由此可用其计算一些结构网络的平均短程.     

All-Optical Network

Abstract

A unique high-speed, protocol-independent, single-mode fiber wavelength division multiplexing network is presented, which operates over a hybrid bus/ring topology that supports Ethernet and many other protocols simultaneously and bidirectionally.     

新一代遥测网络系统及其传输组网方式研究分析

新一代遥测网络系统(TmNS)包括试验对象端(TAS)和地面站端(GSS)两大部分,在对这两部分的功能结构,包括系统组成,各组成单元功能关系进行研究的基础上,依据飞行试验遥测传输需求,对新一代遥测网络系统的传输与组网方式进行研究分析。     

Secure Physical Layer Network Coding versus Secure Network Coding

When a network has relay nodes, there is a risk that a part of the information is leaked to an untrusted relay. Secure network coding (secure NC) is known as a method to resolve this problem, which enables the secrecy of the message when the message is transmitted over a noiseless network and a part of the edges or a part of the intermediate (untrusted) nodes are eavesdropped. If the channels on the network are noisy, the error correction is applied to noisy channels before the application of secure NC on an upper layer. In contrast, secure physical layer network coding (secure PLNC) is a method to securely transmit a message by a combination of coding operation on nodes when the network is composed of set of noisy channels. Since secure NC is a protocol on an upper layer, secure PLNC can be considered as a cross-layer protocol. In this paper, we compare secure PLNC with a simple combination of secure NC and error correction over several typical network models studied in secure NC.     

医院网环境数据中心机房网络设计

为了确保医院环境下数据中心机房网络的安全、稳定的运行,需要对数据中心机房网络进行优化设计;采用当前方法进行数据中心机房网络设计时,未考虑到数据中心机房网络路径传输能耗、路径传输距离等影响,会造成网络寿命减少,影响数据中心机房网络的生存时间;为此,提出一种基于数据传输速度优化的医院网环境数据中心机房网络设计方法;该方法对数据中心机房网络供配电系统、机房监控系统和VPN虚拟系统等三大子系统进行设计优化,在医疗数据传输过程中,考虑医院网络节点能量优化理论对数据节点进行分簇,以需要传输的医疗数据节点为初始节点,汇聚节点作为医疗数据接收目标节点,采用蚁群优化方法对数据中心机房网络进行多路径搜索,搜索过程中考虑了数据中心机房网络路径传输能耗、路径传输距离以及医院网带宽等因素,最终选择满足多种条件的数据中心机房网络数据传输最优路径,完成医院网环境数据中心机房网络设计;实验结果表明,所提方法设计的医院网环境下数据中心机房网络具有耗能低、扩展灵活、周期短等优点。     

Network survivability analysis

Advances in fiber optic and local area network (LAN) technologies are providing system designers with many new options for interconnecting computer equipment. A recurring problem for military system designers, who are end-users of a LAN standard, is implementing LANs so that the survivability, reliability, maintainability, and availability (SRMA) of a system is maximized. LAN standards working groups are currently making design decisions about topologies, components, and protocols that directly affect the SRMA of the end-user's system. This article focuses on a new analytic technique, called “network survivability analysis,” that provides the mathematical tools needed to compare the survivability of arbitrary network topologies. For background, several network metrics are described and their limitations for LAN standards development identified. Network survivability is defined, and several token-passing ring case examples are analyzed. The primary strength of network survivability analysis is that it can be used to provide a quantitative comparison among LAN topologies without knowledge of the end-user's equipment, systems, or environments.     

Network survivability analysis

Advances in fiber optic and local area network (LAN) technologies are providing system designers with many new options for interconnecting computer equipment. A recurring problem for military system designers, who are end-users of a LAN standard, is implementing LANs so that the survivability, reliability, maintainability, and availability (SRMA) of a system is maximized. LAN standards working groups are currently making design decisions about topologies, components, and protocols that directly affect the SRMA of the end-user's system. This article focuses on a new analytic technique, called “network survivability analysis,” that provides the mathematical tools needed to compare the survivability of arbitrary network topologies. For background, several network metrics are described and their limitations for LAN standards development identified. Network survivability is defined, and several token-passing ring case examples are analyzed. The primary strength of network survivability analysis is that it can be used to provide a quantitative comparison among LAN topologies without knowledge of the end-user's equipment, systems, or environments.     

Advanced Optical Network

The following article describes an advanced dense wavelength division multiplexing (DWDM) Optical Network developed by L-3 Photonics. The network, configured as an amplified optical bus, carries traffic simultaneously in both directions, using multiple wavelengths. As a result, data distribution is of the form peer-to-multi-peer, it is protocol independent, and it is scalable. The network leverages the rapid growth in commercial optical technologies, including wavelength division multiplexing (WDM), and when applied to military and commercial platforms such as aircraft, ships, unmanned and other vehicles, provides a cost-effective, low-weight, high-speed, and high noise-immune data distribution system.     

Advanced Optical Network

The following article describes an advanced dense wavelength division multiplexing (DWDM) Optical Network developed by L-3 Photonics. The network, configured as an amplified optical bus, carries traffic simultaneously in both directions, using multiple wavelengths. As a result, data distribution is of the form peer-to-multi-peer, it is protocol independent, and it is scalable. The network leverages the rapid growth in commercial optical technologies, including wavelength division multiplexing (WDM), and when applied to military and commercial platforms such as aircraft, ships, unmanned and other vehicles, provides a cost-effective, low-weight, high-speed, and high noise-immune data distribution system.