A new high speed switch for computer communication networks

The existing telecommunication networks, whether circuit switched or packet switched, are oriented towards particular applications e.g. Voice has Telephone Networks, Video has CATV, and Data Applications has Arpanet, Bitnet, Sitanet etc. All of these networks operate in parallel and independently. Each of these networks are suitable for the application for which they are designed, they are not very efficient for supporting other applications. New applications are inevitable but the existing and planned networks are unlikely to be able to accommodate them. High speed switching that provide basic communication capabilities in an application-independent fashion is required and proposed. In this paper we present a new switch architecture whose speed is clock rate dependent. The switch has less stages and provides a pipeline activity which makes it nonblocking. These features makes it highly attractive for use in real-time traffic environment.     

机载大屏幕显示器高速通信系统设计

传统低速航空总线已无法满足机载座舱大屏幕显示器高速数据通信的应用需求。针对此现状,提出了一种基于MPC8548E的高速总线通信系统。该系统以MPC8548E为核心,采用PCIE总线,通过PES12T3G2交换机扩展出2个接口,连接高速航空总线模块,实现了显示器与其他机载设备的高速数据交互;采用RapidIO总线,通过TSI578交换机扩展出3个端口,将显示器内部模块组网,实现了背板总线快速通信。经验证,本通信系统具有传输数据带宽大、传输速率快等优点,完全能够满足机载座舱大屏幕显示器外部和内部数据实时通信的应用需求。     

航电系统高速串行通信中的抖动分析研究

基于机载航电系统高速串行通信的基本架构介绍了抖动的分类和抖动分析常用的方法。结合实际情况对某案例进行测试和分析,通过眼图、直方图和浴盆曲线分析找出抖动的根源并给出解决方案,达到了预期的效果。本文所介绍的方法可以广泛应用于航电系统以及其他领域的高速串行通信中的抖动分析。     

光纤通信传输技术的应用探讨

目前人类正处于信息化时代,各种信息之间不断传输,在数量上呈现爆炸式增加,光纤技术的发展与介入,使得现代通信更加快捷、方便。同时也使光纤通信的技术更加复杂化,本文主要探讨光纤技术发展的优势与不足,新技术以及光纤技术的发展展望。     

运动控制高速实时串行总线研究

现场总线技术引入数控系统成为PC与数字伺服驱动与IO设备数据交换的接口。提出一种运动控制高速实时串行现场总线RTSB。给出了总线型广播方式的拓扑结构,提出了RTSB的工业控制应用的参考模型,给出了RTSB的报文结构及通讯机制,提出了RTSB的主控卡设计原理、用户层接口及RTSB基于Windows平台的驱动程序结构。RTSB实现了由非实时操作系统实现硬实时功能,为实现控制系统的高速、高精度性能奠定了基础。     

高速高性能单片机在网络监控中的应用

当前,网络通信设备成本居高不下。为降低网络实时监控系统中传输设备成本,设计采用高速、高性能单片机作为网络服务器,完成大数据量视频图像传输以及控制信号传递。搭建实验环境,编程实现前端视频采集、图像数据在网络服务器中的传输以及后端接收、处理和显示等代码。为改进和提高网络图像传输性能,使用单片机嵌入μC/OSII操作系统。实验结果表明,接收端视频图像显示清晰,控制信号传输时延满足使用要求。     

简析光纤通信的传输特性及应用

光纤作为一种新型的通信材料,对于通信方式的变革起着非常积极的促进作用.要想发挥光纤的优势,就必须要了解其传输特性,然后根据信号传输的需要进行应用上的调整.     

用于液体粒子计数的PIN光检测传感器的设计

设计了用于液体粒子计数的PIN光检测传感器,介绍了光散射式粒子传感器的工作原理及其光学检测系统构成,并且对其放大电路的原理做了具体的分析。理论和实践证明:这种新型光检测传感器具有信噪比高、体积小、灵敏度高、测量准确,抗干扰能力强、能耗低等特点,可识别的粒径范围为0.1～10μm,尤其适用对液体中微粒光散射信号的有效检出与在线监测。     

Interprocessor communication for high performance, explicit time integration

Parallel, explicit finite element analysis is based almost exclusively on point-to-point interprocessor communication. However, point-to-point communication on multicore architectures results in large performance variability because of shared caches and sockets. The interprocessor communication required during the solution phase must be designed to achieve a high degree of scalability and performance for explicit time integration operators. An analysis of point-to-point communication on different hardware platforms, communication library implementations, and message sizes demonstrates the need for a flexible software design that allows for optimization. Autotuning modules and preliminary performance tests are necessary to identify the optimal combination of calls. Performance differences of point-to-point messaging on multicore machines are illustrated with a test that uses combinations of MPI communication calls. The differences are apparent when cache and sockets are shared among the cores and for message sizes up to 1.5 MB. Alternative communication schemes are shown to perform faster depending on the architecture and message size. Nearly linear scalability results for explicit time integration are demonstrated using the design techniques.     

地空信息传输系统中的高速接口设计

当前各种高速数据接口已大量应用在数字电视中,但在地空信息传输系统中还没有使用。随着信息时代的飞速发展,地空信息传输系统对高速数据传输的需求越来越强烈,传统的数字接口已不能满足要求,需要设计新型的高速数据接口来适应新的需求。通过分析数字电视中的各种高速数据接口,结合地空信息传输系统的特点,设计出高速接口方案,并分析了方案的性能,同时给出实际设备的测试指标。     

基于FPGA的超高速数据采集与处理系统

介绍了一种基于FPGA的超高速数据采集与处理系统,给出了系统实现的方案,并详细阐述了各硬件电路的具体构成.对系统软件功能做了简要介绍,并利用嵌入式逻辑分析仪对该超高速数据采集系统进行了测试,验证了采样结果的正确性.该超高速数据采集与处理系统通用性和可扩展性较强,适合工程应用.     

Wavelength division multiplexing: ultra high speed fiber optics

The global telecommunications and networking backbone contains millions of kilometers of fiber-optic cabling, but we use only one ten-thousandth of the potential bandwidth of those cables. One reason is that a single converter from electrical to optical signals can only make use of a small amount of the optical spectrum, limiting the achievable bandwidth to about 2.5 Gbit/s. Wavelength division multiplexing (WDM) helps to resolve this disparity. WDM takes advantage of the fact that multiple wavelengths (or frequencies) of IR light can be transmitted simultaneously down a single optical fiber, and each of those frequency channels can carry independent information. With the use of WDM, the capacity of a single strand of fiber, 250 microns in diameter, can carry between 10 and 80 Gbps; a typical cable of 18 mm in diameter contains up to 200 fibers     

影响光纤SPR传感器性能的几个因素

要设计最佳性能的光纤表面等离子体波共振(SPR)传感器,必须研究各种参数对传感器性能的影响,根据给出的评估标准进行优化.由于所有参数统一优化存在困难,同时也没有必要,因此参数的优化可以在特定条件下进行.在给出理论公式的基础上,利用设计的SPR传感器对影响性能的各参数进行了理论计算,并对结果进行了比较和分析,为光纤SPR传感系统的优化设计提供了参考,并给出了设计建议.     

新能源电厂的可重构高透明度光通信技术

随着新能源技术的迅猛发展,使得数据光通信呈现出一种爆炸式增长态势,因此其安全性、可靠性、管理方式等都成为在电力光通信网管理工作中急需考虑的问题,并需要优化相应的新能源电厂光通信并网的管理方式。本文提出了一种高透明度、可重构性的波长转换方案,并提出了最优驱动条件。通过理论推导、仿真模拟和实验分析,验证了该驱动条件可以使波长转换具有最高转换效率和误比特率性能,同时验证了该波长方案可以动态可控地调整转换波长的频率,对转换信号几乎没有波形损伤等优点。     

高速RS-422串行通信接口板设计

设计了一种高速RS-422串行通信接口板,采用通用的异步串行通信控制器,以嵌入式PC为控制核心,以双端口RAM作为数据缓存,并对双端口RAM的程序设计进行了详细说明。应用结果表明,该接口板通信速率高,数据缓存能力强,使用简单。     

飞思卡尔微处理器帮助实现汽车网络高速通信

<正>近年来,随着微控制器进入汽车控制领域,汽车工业产生了划时代的变化。汽车的动力性、操作稳定性、安全性、燃油经济性、对环境的改善得到了大幅提升。     

LVDS高速并口通信协议设计

提出高速数据传输系统中IEEE802.3千兆网卡与同步静态存储器间非对称点对点高速通信接口和通信协议设计方案,接口速率不低于1 Gb/s。基于高速接口中常用的低电压差分信号技术,电气连接单向使用5路低摆幅差分信号对,其中1路时钟,4路数据,双沿采样源同步传输;基于适用于短传播延时的停止等待自动重复请求协议,通信协议使用命令——应答机制;利用模256校验保证数据的可靠传输。理论分析表明,通信接口带宽可达1.2 Gb/s,协议效率在99%以上,协议工作稳定可靠,在满足千兆网卡全速接收转发数据的情况下,高速并口带宽仍有裕量。     

Overcoming performance pitfalls in rate-diverse high speed WLANs

Recent developments on the IEEE 802.11 family of standards promise significant increases in speed by incorporating multiple enhancements at the physical layer. These high modulation speeds apply to the data portion of the transmitted frames, while headers must remain at lower speeds; this has motivated the use of frame aggregation to increase data payloads in the newer standards. However, this simple method may still utterly fail to deliver the promised speeds, due to a series of cross-layer effects involving the transport and multiple access layers: the downward equalization of throughputs imposed by TCP under physical rate diversity, the excessive impact of the TCP ACK stream, or the unreasonable fraction of access opportunities taken by uplink flows when competing with the more numerous downlink connections. A first contribution of this paper is to demonstrate these impediments and isolate their causes through a series of experiments with the ns3 packet simulator, on the 802.11n and 802.11ac protocol versions.     

Accelerating IP routing algorithm using graphics processing unit for high speed multimedia communication

This paper presents a Graphics Processing Unit (GPU)-based implementation of a Bellman-Ford (BF) routing algorithm using NVIDIA’s Compute Unified Device Architecture (CUDA). In the proposed GPU-based approach, multiple threads run concurrently over numerous streaming processors in the GPU to dynamically update routing information. Instead of computing the individual vertex distances one-by-one, a number of threads concurrently update a larger number of vertex distances, and an individual vertex distance is represented in a single thread. This paper compares the performance of the GPU-based approach to an equivalent CPU implementation while varying the number of vertices. Experimental results show that the proposed GPU-based approach outperforms the equivalent sequential CPU implementation in terms of execution time by exploiting the massive parallelism inherent in the BF routing algorithm. In addition, the reduction in energy consumption (about 99 %) achieved by using the GPU is reflective of the overall merits of deploying GPUs across the entire landscape of IP routing for emerging multimedia communications.