基于FTTH的光网络保护系统的研究

针对FTTH光纤线路的保护问题,提出了一种无源光网络光纤线路切换保护系统.光纤线路切换设备通过不同的光纤链路连接远端设备的两个光通信端口,当某一个与远端设备连接的分支光纤链路出现故障时,光纤线路切换设备通过连接备用的分支光纤链路,保障通信的及时恢复.实验结果表明,ONU能够在50ms内自动完成在光口1和光口2间的识别与光路保护切换,极大地提高了PON光纤线路保护的可靠性和生存性,有利于FTTH/B的应用.     

自动切换光路保护方案的应用与实现

针对光纤传输系统中光缆故障的解决方案,通过自动监测线路故障实现主备光纤问的实时切换,满足50ms电信级切换时间要求,以达到光传输设备间透明、无阻断通信的目的.通过对自动切换光路保护系统的系统结构的讨论,从实际应用角度出发,对基本原理、设计方案、软硬件结构及器件选择等方面进行了分析和研究,实现了完全满足电信标准要求的通信光路自动切换保护.     

一种基于以太网交换与SDH传输相结合的光网络组网保护技术研究

文章提出了一种基于以太网交换和SDH传输技术相结合的光传输网,每个通信节点放置主备两台设备,设备通过光纤互联组网,当网络中的光纤线路、终端以太网电链路、设备内部模块单元或整台设备出现故障时,网络都能快速检测到故障点,并在短时间内自动切换到保护通道,恢复网络通信。最后对该方案进行了测试验证,试验结果表明该方案是可行的。     

光线路保护技术的应用研究

1 OLP原理及技术要求 利用光线路保护(OLP)技术,当光传输线路上光纤意外折断或损耗变大导致通信质量下降或通信中断时,光线路自动倒换保护没备或系统实时检测发出告警信息,并能够自动地将光传输线路由主用线路切换至备用线路,使通信立即恢复,从而使传输系统的故障历时降至最小,保证光传输系统的可靠性.     

一种基于ARM的多路光纤自动保护系统

介绍了一种基于ARM+Linux的多路光纤自动保护倒换系统,采用ARM+Linux的高速数据采集平台,实时监测多路光纤光功率并智能判别光纤状态,当监测到光纤线路发生故障时,利用光开关及时有效地在工作光纤和保护光纤之间进行自动切换,并把故障信息通过网络告知监测站.     

双PON口冗余设计实现网络可靠传输——ONU双PON口冗余设计技术实现与应用

通信技术的发展,要求光纤通信网络能为用户提供可靠的不间断的服务,传统的人工维护方式已经很难满足光纤传输网络上的传输容量日益增加和数据传输等增殖业务的发展需求,网络生存能力成为影响网络设计和建设的重要因素,特别是在工业领域,网络的稳定性和可靠性要求非常高。因此,光纤线路网络的自动切换保护和恢复对整个网络的生存能力有着重大的影响,所以在EPON组网中终     

光纤自动切换保护系统在波分系统中的应用

文章论述光纤自动切换保护系统的原理和功能,根据波分系统光缆线路具体情况,提出各种相应的光纤自动切换保护方案以及光纤自动保护方案实现的具体要求。通过具体案例,从波分系统的色散、光功率、差分群时延(DGD)等方面进行分析,介绍如何在现有的波分系统中引入光纤自动切换保护系统,提高波分系统的安全性、可靠性及网络生存能力。     

光纤自动切换保护系统运用于DWDM的探讨

一、引入光纤自动切换保护系统的目的意义 随着铁路光纤建设不断增加和骨干网通信量的不断增长,对光纤维护质量要求越来越高,每一次光缆故障都会对骨干网所承载的业务造成一定的影响。因此,为了有效预防和减少光缆故障,在内渝线引入了光切换保护系统。光切换保护系统对提升DWDM安令性、可靠性的意义主要表现在以下两个方面：     

光电自适应通信技术在频谱监测中的应用

介绍了一种机载环境中光电自适应以太网通信技术在频谱检测中的应用,通信介质采用光纤和电缆双冗余热备份自适应的连接方式。光纤和电缆同时接入网络,通常情况下光纤作为主要的通信介质,当光纤链路发生故障时自动切换到电缆上,不影响系统的连接和中断系统的传输,提高了机载设备数据通信的灵活性和可靠性。对频谱监测的工作流程和光电自适应通信的原理进行了详细的描述,并对硬件和软件设计、调试方法及试验应用结果进行描述。     

SonicWALL发布新品TELE3 SP

互联网集成安全解决方案提供商SonicWALL公司发布了其最新产品TELE3SP（SmartPath：智能通道）。TELE3SP集成了自动执行故障切换和恢复技术的防火墙/VPN安全工具，可支持宽带和拨号连接，能够确保不间断的远程连接，是方便轻巧的硬件工具。TELE3SP中自动执行故障切换和恢复技术能够保持最佳路径返回网络总部，克服宽带网络中断的现象。通过自动切换到一个集成的模拟调制解调器，TELE3SP可确保VPN通道连续实时。一旦宽带连接重新建立，TELE3SP就能够自动恢复宽带连接并保持最佳连接状态。另外，TELE3SP外观独特、轻便灵…     

Access network survivability: an architecture approach for monitoring, protection and restoration in FTTH application

This paper presented a simple monitoring, protection switching, and fast restoration approach for fiber to the home passive optical network (FTTH-PON) using Access Control System (ACS). ACS is developed for centralized monitoring and failure detection from central office (CO) in downstream direction (from CO towards customer sides). The proposed system architecture incorporating low cost and enable the network service providers and field engineers to remotely control the testing module from anywhere in the world and automatically identify any fiber fault and address the failure location in the fiber field. Another unique function of ACS is to provide the activation for optical switching in a restoration scheme which implemented at the drop region of FTTH-PON. A protection device named Customer Protection Device that comprises of programmable optical switches will be employed at the customer sides, just before the optical network unit, for rerouting the disrupted signals to the protection line when failure occurs in the working line to ensure continuous service delivery to customers.     

Protection cycles in mesh WDM networks

A fault recovery system that is fast and reliable is essential to today's networks, as it can be used to minimize the impact of the fault on the operation of the network and the services it provides. This paper proposes a methodology for performing automatic protection switching (APS) in optical networks with arbitrary mesh topologies in order to protect the network from fiber link failures. All fiber links interconnecting the optical switches are assumed to be bidirectional. In the scenario considered, the layout of the protection fibers and the setup of the protection switches is implemented in nonreal time, during the setup of the network. When a fiber link fails, the connections that use that link are automatically restored and their signals are routed to their original destination using the protection fibers and protection switches. The protection process proposed is fast, distributed, and autonomous. It restores the network in real time, without relying on a central manager or a centralized database. It is also independent of the topology and the connection state of the network at the time of the failure.     

Strategies and technologies for planning a cost-effectivesurvivable fiber network architecture using optical switches

A 1:1 diverse routing protection switching architecture using optical protection switches to reduce costs for providing 1:1 (i.e. 100%) protection against fiber cable cuts is proposed. A cost analysis model is used to evaluate cost/survivability merits for 1:1 optical diverse protection architectures. Results show that the best place to deploy the 1:1 photonic diverse protection architecture in future networks is in spans carrying large DS3 demands, which are usually interhub spans. The proposed architecture can be implemented using electronically controlled low-speed single-mode fiber mechanical optical switches as protection switches to meet current performance and availability requirements     

Optical cross-connect system in broad-band networks: system conceptand demonstrators description

A network robust to future evolution in network topologies or transmission formats and bit rates, which would be achieved by introducing an all-optical transparent layer in the transport network hierarchy is considered. The transparency would permit use of physically common fiber lines and nodes for different transmission hierarchies and/or formats. A transparent network could be achieved by combining photonic switching with electronic switching technology in the network nodes. A combination of wavelength routing and space-division switching in the optical layer would increase the capacity, as well as the flexibility in a network, allowing routing with higher granularity within the optical layer. Two optical cross-connect demonstrators have been set up. One demonstrates protection switching and restoration of traffic in a future transport network, and the other demonstrates routing of subscriber signals to different service switches in a local exchange. Space switches, tunable lasers and filters are the key technologies used to obtain enhanced flexibility     

光线路自动倒换保护（OLP）系统建设方案

为有效地预防和压缩光缆传输系统故障,提高光通信网抗阻断、高可靠、安全、抗灾害能力,提高长途光缆维护质量,光纤自动监测倒换系统是实现这一责任目标的重要的现代化维护手段。实现光缆网的自动监测倒换系统,从而在通信光缆线路设备大幅度增加,原有的线路维护技术人员又不能同幅增员的情况下,确保巨额投资建成的光缆传输网高质、高效、安全地运行。     

对城域光缆传输物理双路由保护问题的讨论

城域光缆线路常会受到外力的作用而阻断,文章讨论了几种光缆传输物理双路由保护方式,其中由1/2分路器、1×2光开关和WDM组成的互保传输方式是依据城域光缆线路传输特点提出的一种设想,可供运行维护部门和有关商家做进一步的研究、探讨、实验。     

市县传输网光线路保护系统的设计和应用

本文首先介绍了某地级市有线市县传输网的拓扑结构和业务类型,然后阐述了光线路保护系统的组成和原理,最后提出了市县传输网光线路保护的设计方案。该方案从光缆长度估算、光功率调整、色散补偿计算等方面入手,详细论述了三个方面的设计方法。     

基于EPON的分布式光纤光栅传感网络研究

提出了一种基于以太无源光网络(EPON)的光纤布拉格光栅(FBG)传感网络多传感通道切换控制方案。控制传感通道切换的多个光开关分别与EPON系统中的多个光网络单元(ONU)相连,利用各ONU间严格的时间同步特性在各ONU控制下实施对多个光开关的同步切换控制,实现各FBG传感通道与传感解调模块间的有序连通。实验结果表明,此方案的稳定性较好,并且具有较灵活的扩展特性。     

有线数字电视市县联网光纤环网系统的设计与实践

通过对基于DVB—C1550nm长距离模拟单向光纤传输系统改造为自愈性环网的实践。解决了1550nm光纤环网工程中遇到的接收点主路与备路信号源QAM频点不一致，接收点光功率变化的控制及接收点主路、备路信号切换控制3个主要问题，说明了1550nm光纤环网在有线数字电视市县联网中的广泛应用前景。     

Solid state optical space switches for network cross-connect andprotection applications

Network protection and reconfiguration is becoming increasingly important in fiber optic communications systems. This is driven by the intense traffic and high cost of lost high-data-rate optical connections. Optical cross-connects at the nodes in transmission systems are developing rapidly in response. A key optical component required for these applications is an optical space switch. Since the required timescale of network reconfiguration at the optical level is on the order of 50 ms to prevent electrical intervention. The optical space switching speed must be approximately 5 ms or faster. The demand created by these applications has motivated the development of a solid state optical space switch based on a novel planar-waveguide technology. This planar integrated optics technology relies on the thermo-optic effect in specialized optical polymer materials and results in reliable optical space switches without moving parts to wear out. This article reviews the state of the art in solid state optical space switches based on thermo-optic polymers and applications of these switches in network communication systems. The same polymer-based planar waveguide technology used to make the solid state optical space switches of today provides the basis for WDM devices. Electro-optic modulators, and devices integrating several functions (space switching, wavelength multiplexing, light generation and detection) in one component in the years to come