IXIA虚拟化测试技术介绍

主要介绍了采用IxVM IxChariot所实现的虚拟化测试方案,并列举了8个典型测试例进行具体分析 总结了IXIA在数据中心以太网虚拟化测试技术方面与相关厂商的合作情况。     

无线承载测试

无线承载测试的应用取决于UE上行、下行无线接入能力以及UE支持的电信业务和承载业务.不同的电信业务和承载业务需要不同无线承载.对无线承载配置统一规定,确保了UE和不同网络之间的互操作性,解决了UE和不同网络之间的网络兼容性问题.无线接入承载测试就是来验证UE在建立业务时是否对应规定的无线承载.     

服务质量（QoS）测试方法介绍

介绍了QoS的原理,描述了用IxNetwork5.40实现2层和3层QoS的测试方法与步骤,总结了IxNetwork5.40的5大优势特性。     

INAP协议一致性测试生成的形式化方法

文章应用形式化方法对INAP协议进行测试，基于INAP协议描述的I／O FSM模型，应用UIO方法生成一致性测试序列，然后应用中国乡村邮递员算法对测试序列进行优化，生成的测试序列可以覆盖状态机的每个变迁，且生成的测试序列较短。     

Defect Simulation Methodology for iDDT Testing

The International Technology Roadmap for Semiconductors (ITRS) identifies two main challenges associated with the testing of manufactured ICs. First, the increase in complexity of semiconductor manufacturing process, physical properties of new materials, and the constraints imposed by resolution of lithography techniques etc., give rise to more complex failure mechanisms and hard-to-model defects that can no longer be abstracted using traditional fault models. Majority of defects, in today's technology, include resistive bridging and open defects with diverse electrical characteristics. Consequently, conventional fault models, and tools based on these models are becoming inadequate in addressing defects resulting from new failure mechanisms. Second, the defect detection resolution of main-stream I_DDQ testing is challenged by significant elevation in off-state quiescent current and process variability in newer technologies. Overcoming these challenges demands innovative test solutions that are based on realistic fault models capable of targeting real defects and thus, providing high defect coverage. In prior works power supply transient current or i_DDT testing has been shown to detect resistive bridging and open defects. The ability of transient currents to detect resistive opens and their insensitivity (virtually) to increase in static leakage current make i_DDT testing all the more attractive. However, in order to integrate i_DDT based methods into production test flows, it is necessary to develop a fault simulation strategy to assess the defect detection capability of test patterns and facilitate the ATPG process. The analog nature of the test observable, i.e., i_DDT signals, entail compute intensive transient simulations that are prohibitive. In this work, we propose a practical fault simulation model that partitions the task of simulating the DUT (device under test) into linear and non-linear components, comprising of power/ground-grid and core-logic, respectively. Using divide-and-conquer strategy, this model replaces the transient simulations of power/ground-grid with simple convolution operations utilizing its impulse response characteristics. We propose a path isolation strategy for core-logic as a means of reducing the computational complexity involved in deriving i_DDT signals in the non-linear portion. The methodology based on impulse response functions and isolated path simulation, can enable i_DDT fault simulation without having to simulate the entire DUT. To our knowledge, no practical technique exists to perform fault simulation for i_DDT based methods. The proposed fault simulation model offers two main advantages, first, it allows fault induction at geometric or layout level, thus providing a realistic representation of physical defects, and second, the current/voltage profile of power/ground-grid, derived for i_DDT fault simulation, can be used to perform accurate timing verification of logic circuit, thus facilitating design verification. In summary, the proposed fault simulation framework not only enables the assessment of defect detection capabilities of i_DDT test methodologies, but also establishes a platform for performing defect-based testing on practical designs.     

A Queueing Model for Radio Nets--Part I: Methodology

In voice radio communication nets, digital-frequency assignment patterns and multiple-access discrete address transceivers are being studied to improve grade of service, mean access delay, and other aspects of system performance. An analytical methodology based on a calling system-outer system queueing model is presented. This model permits study of these radio communication problems and system design tradeoffs without computer simulation. In addition, the model utilizes several types of statistics (e.g., Poisson, Erlangian, or hyperexponential). In this paper, the model and the mathematical methodology are explained in detail. Formulas for equilibrium performance measures are derived from their definitions. The concept of station-busy probabilities is introduced and a matrix technique for obtaining numerical results is illustrated.     

Business Process Modelling and Design — A Formal Model and Methodology

This paper presents a formal framework for representing enterprise knowledge. The concepts of our framework (objectives and goals, roles and actors, actions and processes, responsibilities and constraints) allow business analysts to capture knowledge about an enterprise in a way that is both intuitive and mathematically formal. It also outlines the basic steps of a methodology that allows business analysts to go from high-level enterprise objectives, to detailed and formal specifications of business processes that can be enacted to realise these objectives. The formal language used means that the specifications can be verified as having certain correctness properties, e.g. that responsibilities assigned to roles are fulfilled, and constraints are maintained as a result of process execution.     

基于无线电层析成像的目标定位

无线电层析成像(RTI)是通过分析因环境改变引起无线链路接收信号强度(RSS)的变化情况来推测场景信息的过程。文章运用一种新的链路分析方法,通过分别分析场景目标对链路的两种影响,即因阻挡而阴影衰减的影响和因反射而使链路多径分量增加的功率增强影响,得到不同的场景信息,最后综合两种信息得到场景信息,大大减少无线信号噪声干扰,通过实验证实该方法能减少噪声对RTI的干扰,实验结果有较好的收敛度。     

IEEE1588协议测试方法

根据IXIA IEEE1588测试解决方案,详细介绍了IEEE1588协议主要测试项目,包括校正系数（Correction Factor）测试和BMC测试。     

CDMA无线容量分析与测试方法探讨

从CDMA软容量的特点出发，根据CDMA的噪声受限理论并与实测技术相结合，研究CDMA无线容量的算法，分析影响无线容量的各种因素，探讨无线容量的测试方法。     

广播电视网波分复用器件的测试

本文论述了DWDM系统中OMU和ODU的测试原理和方法。包括光反射系数、极化相关损耗，信号之间的隔离度、通带特性等项目的定义和测试原理及方法。     

无线对讲机发信部分的调试

介绍了当无线电话对讲机经长时间的使用,通信距离达不到原设计要求时,对其发信部分进行测试、调整的内容和方法。     

HD Radio传输系统实验室性能测试

HD Radio是美国AM与FM波段的数字广播标准,为了了解其信号的传输性能及其在我国实际播出环境及广播频道规划条件下,与邻频道广播电台之间相互干扰的情况,需要对其传输性能进行实验室测试和场地测试,为我国调频频段广播数字化提供技术参考依据。本文主要探讨实验室性能测试的相关技术和方法。     

Testing of Radio and Television Coverage in Tunnels

介绍了隧道中广播电视信号的测试与分析方法,通过移动路测采集数据、Excel表单统计数据、Matlab软件仿真场强分布,全面掌握隧道中调频广播(FM)、移动电视以及CMMB信号的覆盖情况,为地铁等其他封闭区域内的信号覆盖测试提供参考.     

Rural Subscriber Loops via Carrier and Radio

Ever since carrier was developed for trunk usage, carrier for subscriber use, either over wire or radio, has been considered as a means for providing telephone service in rural areas. Starting with the Bell System development of its"M"type power line carrier, there have been 34 years of progress and subscriber carrier is now a reality. It is now beginning to become widely accepted in the telephone industry. Every year improvements in the state of the art are made. There is little doubt today that more and more subscriber carrier on wire lines and radio will be used in future years. This concise paper includes the history of the development of subscriber carrier and radio in the Telephone Program of the Rural Electrification Administration (REA). Also, the authors attempt a prognosis of what will happen in the next ten years (or longer). Suggestions are made for improvements still deemed necessary in equipment of this type.     

基于UML和XML的测试规范形式化描述

针对分布式系统的测试,需要测试环境及测试规范的支持,文档性质的测试规范不适合计算机仿真的测试环境。为了使测试规范,可以直接应用于测试环境,创造性地用针对系统的建模方法剖析文档性质的规范。通过一种特殊的类划分及关联方法,对测试规范建立基于UML类图的概念层静态模型,并根据一种从UML类图到XML Schema的三层设计方法将其转换为逻辑层静态模型,最终通过映射关系得到了XML Schema,获得了可以直接用于计算机仿真测试环境的形式化测试规范,这种形式化的测试规范具有较好的完整性与一致性。     

隧道中的广播电视信号覆盖测试

介绍了隧道中广播电视信号的测试与分析方法,通过移动路测采集数据、Excel表单统计数据、Matlab软件仿真场强分布,全面掌握隧道中调频广播(FM)、移动电视以及CMMB信号的覆盖情况,为地铁等其他封闭区域内的信号覆盖测试提供参考。     

基于PCI总线的无线电高度表测试系统

通过对无线电高度表进行分析与研究,并对被测对象测试需求特征进行综合分析,优化测试项目,优化测试资源配置,设计出适用的无线电高度表测试设备。测试仪硬件采用基于PCI总线结构的工控机,软件采用LabWindows/CVI开发平台。     

广播电视链路测评技术及其实践

本文详细阐述了视频链路测试的原理、方法和手段,剖析了数字电视最新动态图像测试技术,提出了链路质量量化分级的工程实例,对全面改善广播电视全链路技术质量具有参考意义。