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该文研究了WDM网状网中双链路失效问题,在假定所有链路共享风险链路组(Share Risk Link Group, SRLG)分离的条件下,提出了一种动态共享路径保护(Dynamic Shared-Path Protection,DSPP)算法。DSPP能根据网络状态动态调整链路代价,为每条业务请求选择一条最小代价的工作路由和两条最小代价且SRLG分离的保护路由。仿真表明,DSPP不仅能完全保护双链路失效,并且能在资源利用率、阻塞率和保护切换时间之间进行性能折衷。 相似文献
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为了降低光组播路由 的光域网络编码代价和提高达到理论最大光组播容量的 概率,提出一种基于共享链路和网络编 码的优化光组播容量方法。首先设计一种从多条源- 宿最短路径中选择能达到最大光组播容量的最短路径簇,然后在 最短路径簇中计算路径的共享度,选择共享度高的组播路径传输网络编码信息,构造网络编 码次数最少的光组播编码子图, 解决传统的网络编码组 播路由和最大共享度链路组播路由中存在的网络编码次数过多和达到最大光组播容量概率过 低的问 题。仿真结果表明:本文提出的方法具有最低的网络编码代价,能以最大的概率达到光组播 理论最大容量。 相似文献
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针对数据传输型的大规模无线传感网络中路径能量损耗问题,建立在多跳模式下的网络路径能耗优化模型,得出可以使网络通信能耗最小的节点度取值规律。依据节点度的最优取值,通过控制网络平均节点度的适应度模型来构建网络拓扑,提出一种具有路径能耗优化特性的无标度容错拓扑控制算法EETA(energy efficiency topology algorithm)。动态性能分析表明,由该算法生成的网络拓扑,其节点的度分布服从幂律,具有无标度拓扑的强容错能力。仿真实验结果显示,该算法同时也降低了网络路径能量消耗,具有路径节能性。 相似文献
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求解开销最小组播树在数学上归结为Steiner树问题,但由于寻找最优的Steiner树问题是NP-Complete问题,因此在组播应用中,采用启发式算法获得次优的组播树是常见的方法。该文提出了一种新的的启发式组播路由算法(Shared Path First Heuristic,SPFH)该算法在选择目的节点加入组播树时,既考虑到目的节点到树上的距离,又考虑到先加入的节点对后续加入节点的影响。算法从距离当前组播树近的目的节点中挑选节点加入组播树,选择的规则是,把能够减小其它目的节点加入组播树开销的节点先加入树。仿真结果表明,SPFH算法能找到开销接近于最优解的组播树。 相似文献
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Ning-Hai Bao Le-Min Li Hong-Fang Yu Zhi-Zhong Zhang Hong-Bin Luo 《Optical Fiber Technology》2012,18(2):81-87
As the Internet continues to grow, the power consumption of telecommunication networks is rising at a considerable speed, which seriously increases the operational expenditure and greenhouse gas emission. Since optical Wavelength Division Multiplexing (WDM) networks are currently the most promising network infrastructures, power saving issue on these networks has received more attention in recent years. In traditional optical WDM networks, a large amount of power is drained by the redundant idle resources and reserved backup resources although these powered on resources do not carry traffic in most of the time. In order to reduce the network power consumption, turning off the corresponding network components or switching them to a low-power, standby state (or called sleep mode) is a promising greening approach. In this paper, we study the power-aware provisioning strategies and propose a sleep mode based Power-Aware Shared Path Protection (PASPP) heuristic algorithm to achieve the power efficiency of optical WDM networks. By jointly utilizing link-cost and fiber-cost in path routing, resource assignment, and resource release, PASPP makes working paths and backup paths converge on different fibers as much as possible, and switch idle and backup components to sleep mode to realize power saving. Simulation results show that our PASPP can obtain notable power saving and achieve satisfactory tradeoff between power efficiency and blocking probability with respect to Power-Unaware Shared Path Protection (PUSPP). 相似文献
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《AEUE-International Journal of Electronics and Communications》2007,61(6):353-362
This paper addresses the problem of shared path protection algorithm in survivable wavelength-division-multiplexing (WDM) optical networks, taking into consideration of differentiated reliability (DiR) under Shared-Risk-Link-Group (SRLG) constraint. A subset of network links that share the risk of failure at the same time are said to be in a common SRLG. Rather than the conventional complete SRLG-disjoint shared path protection, we introduce a heuristic Partial SRLG-disjoint Shared Path Protection algorithm (Pd-SPP) based on the concept of SRLG conditional failure probability, to provide differentiated reliability protection. The main target of our work is to improve the network resource utilization ratio under the DiR constraint. We adopt the ideas of partial SRLG-disjoint and the K-shortest paths algorithm such we can efficiently solve the “trap” problem. The experimental results show that our algorithm outperforms the complete SRLG-disjoint shared path protection in both blocking probability ratio and network resource utilization, i.e. the results are found to be promising. 相似文献
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Xu Shao Luying Zhou Xiaofei Cheng Chava Vijaya Saradhi Yixin Wang Jianqing Li 《Photonic Network Communications》2008,16(3):221-231
For 100% shared risk link group (SRLG) failure protection, conventional full path protection has to satisfy SRLG-disjoint
constraints, i.e., its working path and backup path cannot go though the same SRLG. With the increase of size and number of
SRLGs, capacity efficiency of conventional shared full path protection becomes poorer due to SRLG-disjoint constraints and
the blocking probability becomes much higher due to severe traps. To solve these problems, we present a partial path protection
scheme where SRLG-disjoint backup paths may only cover part of the working path. Full path protection becomes a special case
of partial path protection, in which the backup path covers the full working path. By choosing the most survivable partial
backup path as backup path, we can make the impact of SRLG failures as low as possible and accept as many as possible connection
requests. Assuming every SRLG has the same probability to fail, we present a heuristic algorithm to find the most survivable
partial backup path by choosing full path protection first, iteratively computing partial backup paths and choosing the most
survivable one. The benefit of this heuristic algorithm is that it can find the optimal results within less iteration. Analytical
and simulation results show that, compared to conventional full path protection, our proposed scheme can significantly reduce
blocking probability with little sacrifice on survivability. The proposed scheme is very useful particularly when the network
contains a lot of SRLGs and the blocking probability of conventional full path protection becomes too high.
相似文献
Jianqing LiEmail: |
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分两部分叙述了电传送网向光传送网进化的过程。第一部分叙述近年来以时分多路为基的电传送网的改进与发展,它采用同步数字体系,并在光纤传输线路上装用波分多路系统和光纤放大器。第二部分简单说明在不久的将来可能实用的、以波分多路为基础光传送网,其结构中的所有网络单元全是由光的代替电的。 相似文献
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电传送网向光传送网进化的过程 总被引:1,自引:0,他引:1
分两部分叙述了电传送网向光传送网进化的过程.第一部分叙述近年来以时分多路为基的电传送网的改进与发展,它采用同步数字体系.并在光纤传输线路上装用波分多路系统和光纤放大器,第二部分简单说明在不久的将来可能实用的、以波分多路为基的光传送网,其结构中的所有网络单元全是由光的代替电的. 相似文献
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This letter proposes a disjoint path selection scheme for generalized multi-protocol label switching (GMPLS) networks with shared risk link group (SRLG) constraints. It is called the weighted-SRLG (WSRLG) scheme. It treats the number of SRLG members related to a link as part of the link cost when the k-shortest path algorithm is executed. In WSRLG, a link that has many SRLG members is rarely selected as the shortest path. Simulation results show that WSRLG finds more disjoint paths than the conventional k-shortest path algorithm. 相似文献
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SDH传输网中的光电路路由算法 总被引:4,自引:0,他引:4
根据目前在SDH传输网管中存在的快速开通光路和电路的具体需求,针对由若干环构成的网络拓扑较为复杂的SDH传输网提出了光电路路由算法和电路路由算法,算法以光电路分层模型为基础进行,能迅速进行光路和电路的路由调度。最后对算法进行了简单的分析。 相似文献
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This paper proposes a new layered transport network architecture on which the WDM optical path network can be effectively created. The optical path network will play a key role in the development of the transport network that will realize the bandwidth-abundant B-ISDN. This paper extends the layered transport network architecture described in ITU-T Recommendation G.803 which is applied in existing SDH networks. First, we elucidate an application example of WDM optical path networks. Next, we propose a new layered architecture for WDM-based transport networks that retains maximum commonality with the layered architectures developed for existing B-ISDN networks. The proposed architecture is composed of circuit layer networks, electrical path layer networks, optical layer networks, and physical media (fiber) networks. The optical layer is divided into an optical path layer and an optical section layer. The optical path layer accommodates electrical paths. Optical section layer networks are divided into optical multiplex section (OMS) layer networks and optical repeater section (ORS) layer networks. The OMS layer network is concerned with the end-to-end transfer of information between locations transferring or terminating optical paths, whereas the ORS layer is concerned with the transfer of information between individual optical repeaters. Finally, a detailed functional block model of WDM optical path networks, the function allocation of each layer, and an optical transport module (OTM) are developed 相似文献