40 Gbit/s(STM-256)SDH光纤传输设备的研究

随着信息传输需求的迅速增长,40 Gbit/s光传输成为下一代通信网的必然选择.文章阐述了40 Gbit/s(STM-256) SDH光纤传输设备的基本原理和组成结构,分析了实现40 Gbit/s(STM-256) SDH设备需要采用的关键技术,介绍了烽火通信科技股份有限公司40 Gbit/s SDH设备的最新研究成果.     

10 Gbit/s的判定反馈环路补偿

数字通信比特速率向上的压力形成对改进偏振模色散（PMD）诊断和控制的需求。对于400ps脉冲2.5Gbit/s的速率，偏振模色散一般不成问题。但是对于100ps脉冲10Gbit/s速率和超过20ps或30ps偏振模色散发生的脉冲加宽，问题就变得很大。在40Gbit/s速率下，由于相继比特的交叠引起的码位间干涉，问题变得更严重。贝尔实验室研究人员在判定反馈环路（DFL）的基础上，研发了对这个问题的电子学解决办法，判定反馈环路能处理的数据速率高达10Gbit/s。另一组研究人员已研发测量偏振模色散的时域方法，能提供完全的矢量信息，而不只是量值。由于与…     

高速光纤通信系统中高阶PMD补偿技术研究

随着光放大器和色度色散补偿技术的不断提高，光纤的偏振模色散（PMD）已经成为超高速、超长距离光纤通信系统发展的主要障碍，在40Gbit/s或更高速率的光纤通信系统中，PMD的影响已不可忽略，必须考虑PMD的补偿问题，从高阶PMD对40Gbit/s NRZ系统影响的数值模拟发现，当光纤中PMD高阶效应比较明显时，将严重劣化一阶PMD补偿的效果，另外，通过对两种高阶PMD补偿器的比较介绍，认为两段级联的高队PMD补偿系统是一种比较现实的补偿方法。     

大唐电信MSTP设备的高速连接解决方案

大唐电信针对新的网络特点专门设计的TranSmartTM SCTIOODO MSTP光传输设备，是集155Mbit/s、622Mbit/s、2.5Gbit/s、10Gbit/s的全兼容。一体化光传输系统。可以实现从STM-1至STM-64的平滑升级，单子架容量，10G系统拉入容量80G、2.5G系统接入容量40G。     

城域网与城域波分的应用

（续上期）西门子公司的城域波分设备Waveline系列，较好地满足了以上要求。其中包括：1.WavelineMetroNet OADM设备，32波全保护，或64波无保护，最大容量达640Gbit/s。独特的子带放大设计，使平滑扩容成为现实。自带TDM模块可将不同的业务如：ESCON、FICON、OC-3/STM-1、FE、OC12/STM-4、GE等，集成到一个波长，每个系统最多可提供256种业务。可靠性达99.999％，保护倒换时间小于50毫秒，可线路保护，通道保护。2.WavelineFeederLink TDM设备，可提供信号8:1的聚合。可选择机盘类型，支持从34Mbit/s至1.25Gbit/s以…     

高速光纤通信系统中一阶偏振模色散自动补偿技术的研究

偏振模色散(PMD)对10Gbit/s及更高速率的光纤通信系统的影响已不可忽略，因此PMD的补偿技术成为研究的热点问题。本文分析并通过实验验证了PMD引起的脉冲展宽对接收信号频谱的影响，在此基础上提出了一种PMD的补偿技术。在用保偏光纤模拟PMD效应的10Gbit/s的传输线路中实现了一阶PMD的自动补偿。     

偏振模色散对40Gbit／s脉冲传输的影响

本文利用垂直偏振分量所满足的非线性耦合方程,分析了偏振模色散（PMD）对40Gbit/s脉冲传输的影响,数值计算了PMD与脉冲传输最大距离的关系及在一定的PMD作用下,即速度色散以及占空比与脉冲传输最大距离的关系。     

高速光传输中PMD障碍的分析及解决

1 引言 在流媒体和其他多媒体应用的推动下,用户对带宽的需求越来越高,促使电信运营商不断提高网络容量.对于10 Gbit/s、40 Gbit/s或更高的传输速率,现有的网络设备已可以支持,但是现有的光网络不一定能够支持,高速传输时的色散(CD)和偏振模色散(PMD)等都会导致网络异常.     

Tektronix最新的SDN/SONET测试装置是行业中第一台优化用于DWDM用户系统测试的仪表——ST2400A对网元进行仿真,极大地减少了测试时间

Tektronix公司于1998年9月14日,宣布推出其最新型的ST2400A SDH/SONET测试装置,它采用了先进的光通信技术,是第一台优化用于测试密集波分复用(DWDM)用户系统的仪表。 ST2400A可以对SDH或SONET网元特性进行仿真。ST2400A最适合用来测试通过WDM系统传输的2.488Gbit/s STM-16(SDH)或OC-48(SONET)网络的传输质量。     

大唐电信MSTP设备的高速连接解决方案成都大唐光通信公司

一.大唐电信TranSmartTMSCT10000 MSTP系统简介 大唐电信针对新的网络特点专门设计的TranSmartTM SCT10000 MSTP光传 输设备,是集155Mbit/s、622Mbit/s、2.5Gbit/s、10Gbit/s的全兼容、一体化光传输系统,可以实现从STM-1至STM-64的平滑升级.单子架容量:10G系统接入容量80G.2.5G系统接入容量40G.     

光通信用10Gbit/s Transponder的设计

本文分析了在高速光模块设计中介质损耗和微带结构对信号的影响,并对PCB中信号串扰模型的参数进行了计算.解决了高速光模块设计的一些关键问题,设计出满足MSA的300-pin transponder,并对模块进行了一系列性能和指标测试.测试结果表明,该模块完全满足SDH/SONET(STM-64/OC-192)以及10G Ethernet应用要求.     

An STS-N byte-interleaving multiplexer/scrambler anddemultiplexer/descrambler architecture and its experimental OC-48implementation

The authors present a byte-interleaving architecture for generating higher-order signals in the synchronous optical network (SONET) digital hierarchy and report on the implementation and system performance results of an experimental 2.488 Gbit/s SONET STS-3c to STS-48 (OC-48) byte multiplexer/scrambler and STS-48 (OC-48) to STS-3c byte demultiplexer/descrambler. The proper operation of the byte multiplexer and demultiplexer has been verified in an OC-48 experiment with a bit error rate (BER) of less than 10^-14. It is shown that the byte-interleaving architecture leads to a simple and modular implementation of higher-rate interfaces (such as OC-192 at 9.95 Gbit/s) using state-of-the-art technologies     

10Gbit/s甚短距离并行光传输模块与实验系统

介绍符合OIF-VSR4-03.0规范的10Gbit/s甚短距离(VSR)实验系统研究.该系统由16×622Mbit/s到4×2.488Gbit/s转换集成电路、自制12通道850nm垂直腔面发射激光器(VCSEL)并行光发射模块和商用12通道并行接收光模块构成.用一片FPGA实现转换芯片的全部功能,采用基于二分查找法的SDH STM-64/OC192 并行帧对齐及同步算法,大大提高了转换芯片的工作速度和节省了逻辑资源,自制12通道VCSEL并行发射模块工作速率达到12×2.488Gbit/s的设计指标.在SDH STM-64/OC192 10Gbit/s测试仪点到点的传输系统测试中,采用5米的12芯400MHz·km 62.5μm多模带状光纤互联,系统误码率低于1×10^-14.     

Resilience for IP-over-DWDM backbone networks

Given the extensive growth in Internet traffic and increasing emphasis on service quality, one of the most crucial elements of IP backbone network design is to provide resilience to serious failures such as fibre-optic cable breaks. In previous years, the unit of bandwidth granularity for many IP backbone networks has grown from STM-1 (155 Mbit/s) through to STM-16 (2.4 Gbit/s), with STM-64 (10 Gbit/s) backbone circuits becoming prevalent. The increased concentration of traffic makes the IP backbone extremely vulnerable to failure, meaning a key challenge is to engineer embedded resilience into the network. This paper considers such issues and discusses various trade-offs associated with different levels of protection in an IP backbone network     

STM-64 linearly repeatered optical transmission experiment usingforward error correcting codes

STM-64 (10 Gbit/s) nonregenerative transmission experiments using forward error correcting codes have been conducted for the first time. Bit errors caused by dispersion in the transmission line and optical noise of Er-doped fibre amplifiers were successfully corrected by using (18880, 18865) and (2370, 2358) shortened Hamming codes     

High performance 10-12.5 Gbit/s modulator driver in InP SHBT technology

A high performance modulator driver circuit is presented using 4" InP SHBT technology. The IC was developed for driving EAM modulators in OC-192 (10 Gbit/s) and with forward error correction (FEC: 10.7 Gbit/s or 12.5 Gbit/s) optical fibre systems. The monolithic integrated circuit features output amplitude control, output crossing point control and output DC offset control. Measured results show the circuit operates at 10 to 12.5 Gbit/s with a swing of 3.1 V/sub p-p/ at each output and 20/18 ps rise/fall times. The power dissipation is 1.4 W with a standard power supply of -5.2 V.     

An optical modulation format generation scheme based on spectral filtering and frequency-to-time mapping

An optical modulation format generation scheme based on spectral filtering and frequency-to-time mapping is experimentally demonstrated. Many modulation formats with continuously adjustable duty radio and bit rate can be formed by changing the dispersion of dispersion element and the bandwidth of shaped spectrum in this scheme. In the experiment, non-return-to-zero (NRZ) signal with bit rate of 29.41 Gbit/s and 1/2 duty ratio return-to-zero (RZ) signal with bit rate of 13.51 Gbit/s are obtained. The maximum bit rate of modulation format signal is also analyzed.     

2 cm long monolithic multisection laser for active modelocking at 2.2 GHz

A 2 cm long three-contact multisection laser has been fabricated for modelocking at very low repetition rates. Active modelocking yields 8.0-12.3 ps pulses at 2.2, 4.3 and 6.5 GHz corresponding to the fundamental, first, and second harmonics of the cavity resonance frequency. This device demonstrates the feasibility of fabricating monolithic pulse sources operating at rates as low as the OC-48 Sonet transmission rate (2.488 Gbit/s).<>     

Coherent Equalization and POLMUX-RZ-DQPSK for Robust 100-GE Transmission

We discuss the use of a coherent digital receiver for the compensation of linear transmission impairments and polarization demultiplexing in a transmission system compatible with a future 100-Gb/s Ethernet standard. We present experimental results on the transmission performance of 111 Gbit/s POLMUX-RZ-DQPSK. For a dense WDM setup with channels carrying 111 Gbit/s with a 50 GHz channel spacing (2.0 bits/s/Hz), we show the feasibility of 2375 km transmission. This is enabled through coherent detection which results in excellent noise performance, and subsequent electronic equalization which provides the high tolerance to polarization mode dispersion and chromatic dispersion (CD). Furthermore, we discuss the impact of sampling and digital signal processing with either 1 or 2 samples/bit. We show that when combined with low-pass electrical filtering, 1 sample/bit signal processing is sufficient to obtain a large tolerance towards CD. The proposed modulation and detection techniques enable 111 Gbit/s transmission that is directly compatible with the existing 10 Gbit/s infrastructure.     

Noise caused by semiconductor lasers in high-speed fiber-opticlinks

Theoretical and experimental results are presented for the signal-to-noise (S/N) ratio caused by mode partition noise, intensity noise, and reflection-induced noise in optical data links. Under given conditions an additional noise source with a S /N ratio of 20 dB will cause a power penalty of 1 dB in order to maintain a 10^-9 bit error rate. From numerical simulations the authors predict the maximum allowable dispersion in the presence of mode partition noise to be approximately 40% of a clock period. This figure is almost independent of bit rate and laser structure and agrees well with the measurements and with results of other workers. Numerical simulations of a buried-heterostructure and a TJS laser were carried out at four bit rates from 565 Mbit/s to 4.5 Gbit/s and the measurements were done at 2.2 Gbit/s using a TJS laser