大容量光标记交换新技术

本文阐述了光标记交换的原理,介绍了当前研究较多的几种光标记交换技术,对基于正交调制格式与载波抑制调制格式的光标记交换技术进行了详述,展望了光标记交换技术的未来发展趋势。     

基于正交调制FSK/ASK光标记交换技术

光标记交换技术是近几年国外光交换技术研究的热点，光标记交换的关键技术主要集中在光标记的产生、提取和识别等方面。着眼于以广义多标记交换（GMPLS）为基础的光标记交换，对一种新的基于正交调制FSK／ASK光标记交换技术进行了研究，分析了基本原理并在此基础上建立了一套系统理论模型，最后对系统模型进行了仿真。     

一种新的光交换技术——光标记交换技术

介绍了光标记交换这种光子交换新技术，叙述了光标记交换技术的优点，总结了目前提出的几种光标记交换方法，指出了各种方法的优缺点。     

16QAM/PPM光标记交换系统的仿真研究

提出一种脉冲位置调制光标记(PPM)与正交幅度调制(QAM)净荷相结合的光标记交换系统。利用仿真对携带40Gbit/s 16QAM净荷和2.5Gbit/s 2PPM标记的系统传输特性进行验证。通过优化系统频率间隔,得到BER=10-9时,标记和净荷的接收灵敏度与光信噪比(OSNR)分别为-28.51dBm/13.65dB和-22.03dBm/15.02dB。经96km光纤传输后,传输代价均未超过1.5dB。结果证明:16QAM/2PPM光标记交换系统具备良好的传输特性。     

ASK／FSK光标记交换系统中的OBPF谱均衡法

基于幅移键控／频移键控（ASK／FSK）正交调制光标记交换（0LS）系统工作原理,提出了一种利用光带通滤波器（OBPF）对FSK标记进行谱均衡的方法,从而有效改善ASK净荷接收灵敏度。利用仿真,对40Gb／sASK／FSK正交调制OLS系统,在使用3种不同类型OBPF进行谱均衡时的传输性能进行了验证与比较分析。结果表明...     

光分组交换技术的研究

光分组交换技术的引入，改善了带宽的利用率和网络的灵活性，延伸了光的透明性。在光分组交换层中光分组的产生、同步、缓存、再生，分组头重写及分光组之间挑功率的均衡成为实现光分组产换的基本技术，而多波长方案并不是光分组交换的唯一模式，光时分分组交换、光标签交换、波分及混合分组交换、多协议标签交换、光突发分组交换等交换方式的出现必将对未来的通信网产生重要的影响。     

Tb/s单信道正交ASK/DQPSK光标记交换系统设计

随着光信道传输速率要求的不断增长,光标记交换(OLS)技术已成为目前光传输网中最具研究潜力的光交换技术,现阶段光标记交换系统中的单信道传输速率都在Gb/s量级上.为此,提出将正交调制光标记交换系统与光时分复用(OTDM)系统相结合,实现了一种Tb/s单信道的正交ASK/DQPSK光标记交换系统,并对系统进行了仿真实验,...     

基于多波长光标记交换技术的城域光以太网

在多波长光标记交换技术的基础上,结合当前应用广泛的光以太网技术,提出了构建城域光标记交换以太网的构想。在国际上首次搭建了多波长光标记交换试验床,成功完成了高速多媒体视频信号和摄像头捕捉信号的演示,实现了微秒量级的光标记包头和光包的可编程组装拆分。先进的多波长光标记交换加上商用化的光以太网技术,成为未来城域网建设的一种理想的组网方案。     

一种基于D8PSK／ASK正交调制的新型光标记方案研究

深入研究了差分八相移键控（I）8PSK）j幅移键控（AsK）正交调制格式的机理,提出了一种基于D8PsKjASK正交调制的新型光标记方案,利用D8PSK作为载荷的调制方式,ASK作为标记的调制方式,仿真实现了载荷120Gb／s、标记10Gb／s的传输速率。分析了信号的消光比（ER）对误码率（BER）的影响,仿真结果表明...     

Improve the performance of orthogonal ASK/DPSK optical label switching by DC-balanced line encoding

Orthogonal amplitude shift keying/differential phase-shift keying (ASK/DPSK) labeling is a promising approach to ultrahigh packet-rate routing and forwarding in the optical layer. However, the limitation on the payload extinction ratio (ER) is a detrimental effect for network scalability and transparency. This paper presents theoretical and experimental studies of ASK/DPSK labeling. It proposes that dc-balanced 8B10B coding can greatly improve ER tolerance, which in turn leads to better system performance. By using the 8B10B coding method, the paper demonstrates transmission and optical label swapping for a 40 Gb/s ASK payload and a 2.5 Gb/s DPSK label with an overall power penalty of 3.3 dB for the payload and 0.3 dB for the label. The experimental results also show that the ER is allowed to be as high as 12 dB.     

光分组交换系统中载波抑制光标签的研究

为了研究高带宽利用率和大容量的光分组交换系统,对载波抑制调制原理进行理论分析,提出了一种载波抑制调制光标签的方案,并对基于载波抑制调制的光标签系统进行了仿真分析和实验研究。结果表明,载波抑制光标签的中心载波抑制比达到21.3dB;在622Mbit/s和1.25Gbit/s的标签调制速率下,系统传输距离超过40km时,依然能保持低于10-10的误比特率;以误比特率10-10为标准,在传输距离为40km时,两种标签调制速率的功率代价分别为1.7dB和1.9dB。此结果说明载波抑制光标签在光分组交换系统中具有串扰小、功率代价低等特点,信号质量好,适合远距离传输。     

A novel orthogonal modulation format of D8PSK/ASK with differential bi-phase encoding and its application in a label switching optical network

The principle of a novel orthogonal modulation format of differential 8-level phase-shift keying amplitude-shift keying (D8PSK/ASK) with differential bi-phase encoding (DBC) is introduced. Based on it, an optical labeling scheme, in which the payload is 100 Gbit/s D8PSK signal and the label is 10 Gbit/s DBC-ASK signal, is proposed and simulated. The results are compared with other current schemes, and the effects of transmission range, modulation extinction ratio (ER) and received power on system performance are analyzed, respectively. The results show that the spectrum efficiency and bit error rate (BER) are improved greatly, and when the modulation ER is increased to 11 dB, the balanced performance between the payload and label is achieved.     

基于8PSK的新型高速正交光标记交换技术

提出了一种以八相移键控(8PSK)为净荷、ASK为标记的新型高谱效率高速正交光标记交换技术,首次实现了100 Gbit/s的高速正交光标记信号的80 km传输.分析了光信噪比(OSNR)、窄带滤波效应、信道中的非线性效应对标记与净荷性能的影响,并采用平衡相关探测和多符号相位估计(MSPE)技术实现了净荷8PSK信号的接收.与传统接收方式相比,8PSK净荷在相同误码率条件下,OSNR容限提升了约3 dB.经过80 km传输,ASK标记在BER=10~(-9),时OSNR为22.8 dB,8PSK相应的OSNR为20.3 dB.     

Improved optical coding method for orthogonal ASK/DPSK modulation format

Orthogonal ASK/DPSK labeling, which encodes label information on optical carriers in a modulation format, is regarded as a competing scheme to subcarrier multiplexed optical labeling. However, the inherent cross-talk limits the extinction ratio (ER) of the payload and label sensitivity. In this paper, two optical coding methods-Manchester coding and 8B10B coding-which can remarkably improve the system quality to obtain acceptable ER are discussed. A novel optical packet encoding methodmark-insertion coding-is demonstrated to significantly reduce cross-talk between the amplitude shift keying ASK) payload and the differential phase shift keying (DPSK) label through spectrum shaping. The performance of mark-insertion coding depends on the number of inserted 'marks'. Finally, the transmission over a 40 km single mode fiber (SMF) is compared with optical label swapping for a. 40 Gbit/s ASK payload and 2.5 Gbit/s DPSK label under these coding schemes. The experimental result is consistent with the theoretical analysis.     

Single modulator payload/label encoding and node operations for optical label switching

We present and analyze payload/label encoding based on a single Mach-Zehnder modulator, in which the payload is differential phase-shift keyed and the label is amplitude-shift keyed through modulation of either the modulator bias or the amplifier gain. The encoding is analyzed numerically and experimentally. Simultaneous encoding of a 10-Gb/s payload and a 155-Mb/s label is demonstrated with high receiver sensitivities. Penalty-free transmission over 80 km of standard single-mode fiber is achieved for both the payload (with dispersion compensation) and the label (without dispersion compensation). Furthermore, polarization-independent label processing and payload wavelength conversion at intermediate nodes are proposed for potentially cost-effective node operations.     

Using Superimposed ASK label in a 10-Gb/s multihop all-optical label swapping system

A novel optical-label-swapping technique is proposed, experimentally verified, and theoretically analyzed in this paper. The technique superimposes a low-speed amplitude-shift-keying (ASK) label on top of a high-speed dc-balanced-line-coded ASK payload. A multihop long-distance transmission experiment using a recirculating loop has been successfully demonstrated, and an experimental record is set when compared with other optical-label-swapping techniques.