共查询到20条相似文献,搜索用时 125 毫秒
1.
2.
3.
全光网状网保护方式的研究 总被引:3,自引:2,他引:1
提出一种网状网的保护实施方案,即预选保护路由的方法,同时给出了保护路由选取的两个准则:相关性极小和跳数最小的原则并对此进行了详细分析认为保护路由的选取应该两个原则兼顾,折衷考虑,以最快和最小故障概率实施对网络的保护. 相似文献
4.
目前光网络的拓扑结构越来越复杂,逐渐向网状结构光网络发展。提出了一种新的网状光网络智能实时在线监测保护方案,该方案采用下层嵌入式监测设备+上层网管中心的模式。在嵌入式监测保护设备上加入保护光纤路由计算的功能,由嵌入式监测保护设备事先用路由算法计算出每条工作光纤的备用光纤路由,在工作光纤发生故障时及时进行切换。该方案实现了真正无人值守的光网络智能实时在线监测保护设备,适应网状光网络的发展要求,实现网状光网络的透明无阻断通信。 相似文献
5.
聚焦长距离无源光网络生存性机制研究,针对单共享风险链路组故障提出一种基于连接可用性的成本有效规划方法.首先,设计了一种基于故障概率的连接可用性模型,计算每个光网络单元的连接可用性.对于不满足连接可用性要求的每个工作光网络单元,为其分配备用光网络单元,其中每个备用光网络单元需要为工作光网络单元预留备用容量.然后,在不同光网络单元之间部署备用光纤,确保每对工作和备用光网络单元之间至少存在一条备用光路径.当一个工作光网络单元因为光纤链路故障而遭遇连接中断时,可将其业务通过备用光路径转移到备用光网络单元承载.通过仿真对所提方法在备用光纤部署成本方面的性能进行了分析.结果表明,该方法能实现比传统邻居保护方法更低的备用光纤部署成本,可解决备用容量分配和备用光纤部署的联合优化问题,在满足连接可用性要求的前提下,通过最小的备用光纤部署成本实现所有业务完全保护. 相似文献
6.
为了降低光纤光缆故障率和缩短光缆网络故障诊断时间,提出了一种基于光功率测试和光时域反射仪的光纤故障监测方法;利用光功率测试技术对光缆性能进行实时监控并预警光缆故障;分析光纤功率衰减的原因,计算得到光缆修理增加的长度,设计了修正故障地点的算法;当光缆网络发生故障时,利用光时域反射仪测试故障位置,并利用误差检测算法对电缆衰减进行分析排除,对故障地点进行故障位置修正以便快速抢修;结果表明,该方法可以降低光缆网络故障率,在故障定位中可以提高光缆故障定位的精度,计算的故障位置与实际故障位置的误差不超过10 m,可以进行实时快速的维修,对于运营时间较长的光缆网络的效果更明显,具有较好的应用价值。 相似文献
7.
一种新的WDM光网中的共享链路保护策略 总被引:2,自引:2,他引:0
研究了WDM光网中的链路保护问题.提出了一种新的共享链路保护策略--基于SRLG的共享链路保护策略(SRLG-SLP).SRLG(共享风险链路组)定义了对一条工作光通道分配保护资源时的资源可用性的约束.它规定任意两条有着同样故障风险或者说处于同一个SRLG的工作光通道不能利用同样的保护资源.另外,还提出了一种更加符合实际的单链路故障模型,其中链路故障间隔时间和链路故障保持时间被考虑作为两个独立的变量.基于该链路故障模型,通过大量的仿真试验,比较了专用链路保护(DLP)、共享链路保护(SLP)和提出的SRLG-SLP保护策略的资源利用率、保护效率以及业务中断率.结果显示,我们提出的SRLG-SLP在保护效率和业务中断率方面的保护性能远好于DLP和SLP,但会牺牲一些资源利用率. 相似文献
8.
9.
电力通信网可靠性在智能电网安全运行中起着至关重要的作用。采用层次化建模思想建立了典型电力通信系统的可靠性模型。首先,采用自顶向下分解法,将典型配电网通信系统解构成终端层子系统、接入层子系统、子站通信层子系统和主站控制层子系统;然后,采用平均故障间隔时间、平均无故障运行时间、平均修复时间等参数评估通信基础产品的可靠度,采用非冗余系统、完全冗余系统,部分冗余系统,以及旁联系统评估各个子系统的可靠度;最后,采用自底向上合成法,根据系统的拓扑结构评估整个网络的可靠性。提出的可靠性分析方法为电力通信网可靠性评估方法提供了理论依据。 相似文献
10.
11.
Optical burst switching is a switching technology that is able to provide viable switching for optical internet with the present day technology. This paper presents a new medium access protocol for wavelength division multiplexing based optical burst switched metro ring network namely distributed queue optical burst switched ring (DQOBSR). It is a slotted, distributed queue access protocol with fixed bus structure and simple wavelength assignment. The topology consists of two unidirectional, counter rotating rings and the medium access protocol is based on distributed queuing. The protocol provides zero blocking with acceptable access delays. A mathematical model is also presented to determine the mean access delay which is the important performance parameter for the protocol. The simulation and model based results are compared and found to be in good agreement. 相似文献
12.
束流位置监测器(BPM)和与其相邻的四极铁之间的电偏移对于电子储存环轨道校正十分重 要。改变四极铁的强度,并通过测量轨道变化就能够计算出该四极铁的磁中心相对于相邻的BPM的电中心 之间的偏差。基于NSRL储存环的BBA硬件系统和EPICS控制系统,采用Labview平台开发出了BBA测量 的软件控制程序。由计算机控制四极铁的强度,连续测量后拟合得到四极铁的磁中心与相邻BPM的相对偏 差,测量精度可以达到100μm。 相似文献
13.
Amit Kumar Garg 《Optik》2011,122(8):691-696
To avoid burst collision in OBS-WDM ring network, a novel scheme called Estimated Traffic based Longest Queue First (ETLQF) has been proposed. In it, the scheduler considers both the queue length and the incoming traffic. The scheduler can adjust the queue lengths in advance to cater to the incoming traffic, targeting to reduce cell loss ratio (CLR) and improve the buffer utilization. The simulation results show that the ETLQF in OBS ring networks not only reduces CLR by 10-60%, but also achieves high throughput while saving 65% of wavelengths, when compared to conventional schemes with only destination delay. 相似文献
14.
15.
This paper proposes the interesting nonlinear behavior of light known as bifurcation, where the use of such behavior in a micro ring resonator to form the secure digital codes for optical packet switching application is demonstrated. A new concept of the stop-start bits in an optical packet switching protocol is formed by using the bifurcation codes. Bifurcation is introduced when light is input into a nonlinear micro ring device, where the refractive index of an InGaAsP/InP is one of device parameters. The other parameters of the device are coupling coefficient (K) and the ring radius (R), where the ring radii used are ranged from 5 to 10 μm. Simulation results obtained have shown that the packet switching data can be secured by using the generated start-stop bits as the secured codes. 相似文献
16.
17.
18.
In this paper, we have investigated the wavelength division multiplexed (WDM) system using ring network topology. This network is used to increase the capacity with eight optical add/drop multiplexers (OADMs) by using dispersion compensating fiber and semiconductor optical amplifier (SOA) to achieve a distance up to 1600 km. It is observed that network shows the acceptable results at 15 Gbps data rate with 100 GHz channel spacing. The OADM nodes are also varied to investigate the network performance in the term of BER and Q-factor. 相似文献
19.
20.
In this paper, we have investigated wavelength division multiplexed (WDM) hybrid (ring-tree-star) topology. Eight optical add/drop multiplexers (OADMs) are used to make ring structure. The single mode fiber and dispersion compensating fiber and semiconductor optical amplifier (SOA) are employed between each OADM to achieve a maximum. To increase the number of users each OADM node of ring network is connected to star and tree network topology which can accommodate more than 2048 users. Various system parameters (for different channel spacing, different input power signal, different data rates and the fiber length) are varied to investigate the system performance in the term of BER and Q factor. 相似文献