Investigating Optical Transport Network Performance:A Recurrence Plot Approach

In future optical transport networks,lightpath performance analysis is of great practical significance for fully automated management.In general,the quality of transmission(QoT)of lightpaths,measured by optical quality factor or optical signal-to-noise ratio,has a complex time-varying process,along with the interactions of the other lightpath state parameters(LSPs),such as transmit power,chromatic dispersion,polarization mode dispersion.Current studies are mostly focused on lightpath QoT estimation,but ignoring lightpath-level data analytics.In this case,our article proposes a novel lightpath performance analysis method considering recurrence plot(RP)and cross recurrence plot(CRP).Firstly,we give a detailed interpretation on the recurrence patterns of LSPs via a qualitative 2-D RP representation and its quantitative measure.It can potentially enable the accurate and fast lightpath failure detection with a low computational burden.On the other hand,CRP is devoted to modeling the relationships between lightpath QoT and LSPs,and the correlation degree is determined by a geometric mean of multiple indexes of cross recurrence quantification analysis.From the view of application,such CRP analysis can provide the effective knowledge sharing to guarantee more credible QoT prediction.Extensive experiments on a real-world optical network dataset have clearly demonstrated the effectiveness of our proposal.

5G Flexible Optical Transport Networks with Large-Capacity, Low-Latency and High-Efficiency

The fifth generation(5G) of mobile communications are facing big challenges, due to the proliferation of diversified terminals and unprecedented services such as internet of things(IoT), high-definition videos, virtual/augmented reality(VR/AR). To accommodate massive connections and astonish mobile traffic, an efficient 5G transport network is required. Optical transport network has been demonstrated to play an important role for carrying 5G radio signals. This paper focuses on the future challenges, recent studies and potential solutions for the 5G flexible optical transport networks with the performances on large-capacity, low-latency and high-efficiency. In addition, we discuss the technology development trends of the 5G transport networks in terms of the optical device, optical transport system, optical switching, and optical networking. Finally, we conclude the paper with the improvement of network intelligence enabled by these technologies to deterministic content delivery over 5G optical transport networks.

Application of Neural Network in Fault Location of Optical Transport Network

Due to the increasing variety of information and services carried by optical networks, the survivability of network becomes an important problem in current research. The fault location of OTN is of great significance for studying the survivability of optical networks. Firstly, a three-channel network model is established and analyzing common alarm data, the fault monitoring points and common fault points are carried out. The artificial neural network is introduced into the fault location field of OTN and it is used to judge whether the possible fault point exists or not. But one of the obvious limitations of general neural networks is that they receive a fixedsize vector as input and produce a fixed-size vector as the output. Not only that, these models is even fixed for mapping operations (for example, the number of layers in the model). The difference between the recurrent neural network and general neural networks is that it can operate on the sequence. In spite of the fact that the gradient disappears and the gradient explodes still exist in the neural network, the method of gradient shearing or weight regularization is adopted to solve this problem, and choose the LSTM (long-short term memory networks) to locate the fault. The output uses the concept of membership degree of fuzzy theory to express the possible fault point with the probability from 0 to 1. Priority is given to the treatment of fault points with high probability. The concept of F-Measure is also introduced, and the positioning effect is measured by using location time, MSE and F-Measure. The experiment shows that both LSTM and BP neural network can locate the fault of optical transport network well, but the overall effect of LSTM is better. The localization time of LSTM is shorter than that of BP neural network, and the F1-score of LSTM can reach 0.961566888396156 after 45 iterations, which meets the accuracy and real-time requirements of fault location. Therefore, it has good application prospect and practical value to introduce neural network into the fault location field of optical transport network.

STUDY ON STRATEGY OF DYNAMIC JOINT ROUTING AND RESOURCE ALLOCATION IN LAYERED OPTICAL TRANSPORT NETWORKS

A layered network model for optical transport networks is proposed in this paper,which involves Internet Protocol(IP) ,Synchronous Digital Hierarchy(SDH) and Wavelength Division Mul-tiplexing(WDM) layers. The strategy of Dynamic Joint Routing and Resource Allocation(DJRRA) and its algorithm description are also presented for the proposed layered network model. DJRRA op-timizes the bandwidth usage of interface links between different layers and the logic links inside all layers. The simulation results show that DJRRA can reduce the blocking probability and increase network throughput effectively,which is in contrast to the classical separate sequential routing and resource allocation solutions.

Evolution of Optical Transport Networks and Their Solution in 3G Networks

As new generation mobile networks, 3G networks focus on data services and integrate voice, data and multimedia services. However, traditional Optical Transport Networks (OTNs) cannot meet the requirements of 3G networks anymore, because of their complicated configuration, low bandwidth efficiency, high cost, and bad network and service scalability. The emerging of Multi-Service Transport Platform (MSTP), Wavelength Division Multiplexing (WDM), and Automatically Switched Optical Network (ASON) technologies for optical fiber communications makes up for these weaknesses. The leading solution to 3G access transport networks is the MSTP technology based on Synchronous Digital Hierarchy (SDH), while that to 3G core transport network is ASON+WDM.

Selective deletion of zinc transporter 3 in amacrine cells promotes retinal ganglion cell survival and optic nerve regeneration after injury

Vision depends on accurate signal conduction from the retina to the brain through the optic nerve,an important part of the central nervous system that consists of bundles of axons originating from retinal ganglion cells.The mammalian optic nerve,an important part of the central nervous system,cannot regenerate once it is injured,leading to permanent vision loss.To date,there is no clinical treatment that can regenerate the optic nerve and restore vision.Our previous study found that the mobile zinc(Zn^(2+))level increased rapidly after optic nerve injury in the retina,specifically in the vesicles of the inner plexiform layer.Furthermore,chelating Zn^(2+)significantly promoted axonal regeneration with a long-term effect.In this study,we conditionally knocked out zinc transporter 3(ZnT3)in amacrine cells or retinal ganglion cells to construct two transgenic mouse lines(VGAT^(Cre)ZnT3^(fl/fl)and VGLUT2^(Cre)ZnT3^(fl/fl),respectively).We obtained direct evidence that the rapidly increased mobile Zn^(2+)in response to injury was from amacrine cells.We also found that selective deletion of ZnT3 in amacrine cells promoted retinal ganglion cell survival and axonal regeneration after optic nerve crush injury,improved retinal ganglion cell function,and promoted vision recovery.Sequencing analysis of reginal ganglion cells revealed that inhibiting the release of presynaptic Zn^(2+)affected the transcription of key genes related to the survival of retinal ganglion cells in postsynaptic neurons,regulated the synaptic connection between amacrine cells and retinal ganglion cells,and affected the fate of retinal ganglion cells.These results suggest that amacrine cells release Zn^(2+)to trigger transcriptomic changes related to neuronal growth and survival in reginal ganglion cells,thereby influencing the synaptic plasticity of retinal networks.These results make the theory of zinc-dependent retinal ganglion cell death more accurate and complete and provide new insights into the complex interactions between retinal cell networks.

2 Tbit/s based coherent wavelength division multiplexing passive optical network for 5G transport

Future high-speed mobile communication systems require low latency and high capacity networks.Coherent wavelength division multiplexing(WDM)passive optical network(PON)scheme is expected to play a vital role in these systems.In this paper,coherent WDM-PON scheme based on dual-polarization 16-quadrature amplitude modulation(DP-16 QAM)transceiver has been investigated.The aim of this scheme is to build a 2 Tbit/s(125 Gbit/s/λ×16 wavelengths)network that will be used in the construction of the transport architecture of fifth generation(5 G)and beyond 5 G(B5 G)cellular networks either in mobile front haul(MFH)or mobile back haul(MBH).The results indicate that the proposed scheme is very adequate for both 5 G and B5 G cellular networks requirements.

基于SOTN技术和5G网络切片技术的传输组网技术

为提升网络的传输效率和传输质量,研究基于软件定义光传送网(Software Optical Transport Network,SoTN)技术和第五代移动通信技术(5th Generation Mobile Communication Technology,5G)的传输组网技术。首先分析了5G传输网端到端架构存在的优势及不足,其次采用SOTN技术和5G网络切片技术设计了一种传输组网方案,最后进行实验分析。测试结果表明,该传输组网技术具有较好的应用效果,数据包的传输成功率均在90.00%以上,并且端到端的最大时延为16.11ms,能够保证网络的传输效果。

知识图谱在光传送网络智能运维中的应用研究

为了解决光传送网络传统运维模式成本高、效率低、智能程度弱等问题,分析了知识图谱技术在电信行业的研究现状以及面临的挑战。首先,提出了基于知识图谱的光传送网络智能运维系统架构,重点研究了网络状态感知、知识图谱构建、搜索能力开放等关键技术以及典型应用场景;然后,以智能割接在中国电信某市分公司的应用为案例,对其应用成效进行了分析,测试表明智能割接上线后,整体割接效率提升了约3倍;最后,对基于知识图谱的光传送网络智能运维发展趋势进行了展望。

基于一张光缆网提升传输网络健壮性策略研究

基于一张光缆网的建设落地实施,分析了传输网络现状及存在的痛点,借助一张光缆网丰富的光缆路由,提出了使用同路由隐患改造,调整OTN、PTN/SPN及PON系统架构来提升整个传输网络的健壮性策略,以达到提高客户使用感知度。

基于ACTN和SDOTN标准的SDN跨域管控研究

【目的】为了实现云光智能一体化,解决现有光网络业务部署慢的问题,文章给出了一种跨域跨厂商的端到端业务快速部署方法。【方法】通过分析现网跨域跨厂商业务部署现状,并结合基于流量工程网络抽象与控制(ACTN)标准和软件定义光传送网(SDOTN)标准,发现并解决现有软件定义网络(SDN)管控系统光业务智能一体化部署存在的问题,提出设备厂商SDN管控系统需要改进的方法和方向。【结果】测试验证表明,通过优化改进设备厂商的同步数字体系(SDH)管控系统,能够提升域内端到端业务的开通效率并实现跨域端到端业务的智能一键部署。【结论】测试结果证明,优化和改进设备厂商的SDN管控系统有利于云光智能一体化的业务开通。

100 G OTN超长站距通信关键技术研究与应用

近年来,随着能源互联网的快速发展,国家电网有限公司各业务系统对通信系统传输带宽的要求越来越高,单波10 G大容量骨干光传送网络(optical transport network,OTN)已无法满足数据类业务和大颗粒业务的带宽需求。目前单波100 G OTN系统技术日趋成熟,但大跨距的100 G OTN应用研究与分析较少,文章介绍了新疆A站—B站385 km大跨距100 G OTN传输设计中遇到的超长站距难以开通满足业务的OTN波数问题,并通过实验测试和数据分析,得出了相关结论和解决方案,对后续国家电网有限公司大容量骨干光传输系统大档距的应用具有重要的参考价值。

基于OTN OSU协议的油气管道阀室通信网络方案

随着油气管道阀室通信网络逐渐扩张和承载业务的复杂化,现有的组网方案亟需进行升级更新。提出了基于光传送网光业务单元(OTN OSU)的油气管道阀室通信网络方案。首先,分析了油气管道阀室通信网络组网过程中面临的挑战,并概述了当前组网方案的现状;然后,引入OTN OSU协议对油气管道阀室通信光网络架构进行优化,并设计了工业级光传输客户前端设备(CPE)样机;最后,对方案进行现网环境测试验证。测试结果表明:所提方案有效改善网络时延,且支持多种业务承载,CPE样机功耗低于40 W,提升了网络效率。

OTN光传送网DVB-ASI信号接口板卡国产化应用与优化研究

本文主要介绍在OTN光传送网中直接接入传输DVB-ASI信号的工作原理,针对DVB-ASI信号接口板卡在实际应用中所遇到的问题进行分析与研究,以及如何对DVB-ASI信号接口板卡的性能进行优化。本次优化工作实现了DVB-ASI信号直接在OTN光传送网更高质量传输适配的目标,在提高广播电视传输系统集约化水平和有效降低系统成本的基础上,减少了对国外技术的依赖,增强了相关技术的自主可控能力。

PTN和OTN传输设备的优劣势及发展趋势

在信息技术飞速发展和通信网络日新月异的今天,传输设备在现代通信系统中有着举足轻重的地位。分组传送网(Packet Transport Network,PTN)和光传输网络(Optical Transport Network,OTN)是目前两大主流的传输技术,可满足人们对高速、大容量、低延迟的业务需求。因此,文章综合分析PTN和OTN传输设备,探讨其优劣势及未来发展趋势,旨在给相关领域决策者与研究人员提供参考,推动通信网络不断创新与发展。

浅谈光纤传输接入网络中OTN技术的应用

文章深入研究了光纤传输接入网络中光传送网(Optical Transport Network,OTN)技术的应用。详细介绍了OTN技术,包括其特点和组成等内容,并分析了OTN技术在光纤传输接入网络中的应用。本研究为理解和应用OTN技术性提供了坚实的理论和实践基础。

基于全光网络的光纤通信传送网性能监测技术

文章针对全光网络中光纤通信传送网的性能监测问题,提出一种基于光电检测、信号处理、大数据分析以及机器学习等技术的智能监测系统。该系统采用模块化设计,可实现光信号质量监测、网络性能分析、故障诊断与定位等功能。通过实验验证,该系统在实时性、准确性、可靠性等方面均达到预期目标,为全光网络的智能化管理和优化控制提供了有力支撑。

光纤传输接入网络中OTN技术的运用研究

为优化光纤传输质量,满足宽带接入的可控化管理需求,要严格遵循光纤传输应用控制的技术规范,有效建立基于光传送网(Optical Transport Network,OTN)技术的光纤传输接入网络,从而维系信息传输的及时性,搭建完整的技术运行框架。应从大颗粒信息传输处理、城域核心网和干线网络、宽带用户接入、长途网应用交叉设备等方面对OTN技术的具体应用内容进行系统化分析,更好地实现网络性能的平滑升级,从而满足城域网建设的具体需求。因此,系统研究光纤传输接入网络中OTN技术的应用要点具有现实意义。

基于OTN技术的电力通信传输网络优化研究

在现代社会,电力通信传输网络的重要性日益凸显,不仅关系到电力系统的正常运行,还直接影响着我国经济的可持续发展。为提升电力通信传输网络的质量,文章将通过理论与实践相结合的方法,深入探讨运用光传送网(Optical Transport Network,OTN)技术优化电力通信传输网络的方案。首先,简单介绍OTN技术的原理;其次,分析基于OTN技术的电力通信传输网络优化策略;最后,探讨基于OTN技术的电力通信传输网络优化案例。