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1.
光轨:一种实现IP突发业务的新方案   总被引:1,自引:0,他引:1  
综述了一种可以实现IP突发业务在光层透明传输的现实可行的新方案--光轨,分析了光轨节点结构以及涉及的信令协议,论述了光轨网络的研究现状以及有待探讨的几个问题,总结了光轨结构的优点.  相似文献   

2.
波分复用(WDM)光网络具有波长和节点数目众多、传输路径动态重构、业务/资源动态调度等特点,亟须发展低成本、高可靠的在线监测技术,以保障光网络的安全稳定运行。本文提出了一种基于四进制脉冲幅度调制(PAM4)数字光标签的低成本、高可靠、高效率监测方案,并创新设计了PAM4光标签加载、探测和处理等整套机制与方法,配合所提出的基于PAM4光标签序列特征的光功率监测误差修正方法以及基于频谱峰值的功率计算方法,所提方案可以准确高效地监测波长通道光功率、估计光信噪比(OSNR)并恢复数字标签信息等。搭建了16 GBaud偏振复用QPSK/16QAM WDM光传输仿真系统和离线实验平台,验证结果表明所提方案在25跨段长距离传输后的通道光功率监测误差不超过0.65 dB,OSNR估计误差不超过0.6 dB,性能略优于传统的基于差分相移键控(DPSK)低阶调制格式的光标签监测方案。  相似文献   

3.
自适应混合光交换的研究   总被引:1,自引:1,他引:1  
李玲霞  黄胜 《光通信技术》2006,30(12):48-49
针对已有混合光交换的不足之处,提出了自适应混合光交换.这种光交换方式能根据网络业务的状态,自适应调整光交换方式,从而提高了链路利用率,降低了网络丢包率.同时讨论了自适应混合光交换的边缘节点、核心节点的结构及其各部分功能.  相似文献   

4.
光分插复用网元节点的设计和实验研究   总被引:1,自引:0,他引:1  
提出了一种用于光传送网(OTN)的光分插复用(OADM)网元(NE)节点的体系结构,采用模块化方法,划分并设计出各功能模块。研制出可以同时支持8个波长动态分插复用的可重构OADM NE节点,提供2个双向全光网接口和网络管理接口。  相似文献   

5.
为了实现低轨卫星通信系统高效率低时延的用户接入,提出了适用于低轨卫星系统的两步随机接入方案,对随机接入信道的数据发送、信道结构、前导码设计以及映射关系进行了设计,并进行了现场可编程门阵列(Field Programmable Gate Array,FPGA)实现。针对传统MAX-LOG-MPA算法FPGA处理时延长的问题,提出了一种节点并行迭代更新的FPGA接收机设计来降低处理时延。仿真结果验证了所设计的信道结构以及FPGA实现的可行性,相比传统接入方式可接入的用户数量更多,同时采用并行节点迭代更新的接收机将迭代处理时延降低为1/6。  相似文献   

6.
分析了光交叉连接(OXC)设备和光分插复用(OADM)设备在WDM全光网络中的作用。说明了它们是克服网络节点瓶颈问题的有效方法。设计了一种有一个OXC节点及六个OADM节点的网络结构。提出了它的四个关键技术问题的解决方案。  相似文献   

7.
根据国际电信联盟(ITU—T)建议G.873定义的光传送网(OTN)中光路的假设参考模型(HRM).提出了光路经过多个光节点和光纤传输段后噪声积累的数学模型,推导了解析计算公式,并且按照节点隔离原理推导了计算噪声积累的简化公式以及工程等效模型。分析了光节点中增益(损耗)分配对噪声功率的影响.得出了光节点的优化设计原则。提出的光路噪声模型可以为光网络中光节点和光纤传输段的设计提供参考。  相似文献   

8.
数字电视网络调试与维修   总被引:1,自引:0,他引:1  
1同轴网络安装调试 1.1光节点安装调试注意事项 (1)主要以SG2000为例,其他型号的光节点依次类推。我们采用的是高增益的光节点,根据使用要求,输入的光信号最好为0~-4dBm,此时光节点内光接收模块的功率指示灯为绿灯。  相似文献   

9.
施正一  杨俊杰  何浩 《半导体光电》2006,27(2):188-191,213
提出一种新型的光分组交换(OPS)节点结构,即OFBFWC(Optical packet switch with Feedback Buffer and Fixed Wavelength Converter)交换结构,它使用固定波长变换器和反馈式的光缓存来解决光分组的冲突。为了提高OFBFWC的性能,还提出一种有效的控制算法。最后,使用仿真实验的方法对OFBFWC的性能进行评估。  相似文献   

10.
在光分组交换(0PS)节点结构中,由光纤延迟线(FDL)所构成的光缓存是解决光分组冲突的一种非常有效的方法。对于共享式FDL光缓存,由于FDL竞争的出现会导致光缓存性能的恶化。为了有效利用光缓存,需要对光缓存资源的分配进行有效的控制。为此,针对共事式FDL光缓存,提出一种有效的光缓存控制策略,即有限贪婪模式(limited greedy mode,LGM)缓存控制策略。使用仿真实验的方法对LGM的性能进行了评估。  相似文献   

11.
DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.  相似文献   

12.
From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.  相似文献   

13.
The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.  相似文献   

14.
The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.  相似文献   

15.
Today, micro-system technology and the development of new MEMS (Micro-Electro-Mechanical Systems) are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.  相似文献   

16.
This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel's.  相似文献   

17.
It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output(MIMO) communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.  相似文献   

18.
A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.  相似文献   

19.
A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.  相似文献   

20.
Call for Papers     
正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks  相似文献   

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