共查询到17条相似文献,搜索用时 250 毫秒
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网状WDM网中支持区分可靠性的共享通路保护算法 总被引:2,自引:0,他引:2
光纤链路由于共享了某些物理资源(如光缆、管道、通路等),因此存在一定的故障相关性,术语“共享风险链路组(SRLG)”就是用于描述链路之间的这种风险共享关系的。SRLG分离成为保护设计的重要约束。该文研究了支持区分可靠性的SRLG分离共享通路保护设计问题。结合SRLG条件故障概率的概念,提出了部分SRLG分离的共享保护算法PSD-SPP(PartialSRLG-DisjointShared-PathProtection),有效地解决了SRLG分离约束下的区分可靠性设计问题。仿真结果表明该算法既满足了用户的区分可靠要求,又能有效利用资源。 相似文献
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抗毁WDM网中单SRLG故障的共享子通路保护 总被引:3,自引:0,他引:3
该文针对抗毁WDM网中单个共享风险链路组(Shared Risk Link Group,SRLG)故障,提出了一种动态共享子通路保护(Dynamic Shared Sub-Path Protection,DSSPP)算法.DSSPP为每条业务请求选择一条工作通路后,按照参数m把工作通路划分成若干条等长的子通路,其中m为子通路的长度,并为每条子通路各选择一条SRLG分离的保护通路.如果两条子通路SRLG分离,则它们对应的保护通路可以共享相同资源.在进行路由选择时,DSSPP考虑了负载均衡度和资源共享度,因此能有效地提高资源利用率和降低业务阻塞率.仿真表明,DSSPP不仅能保护单SRLG故障,而且能灵活地在资源利用率(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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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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本文研究了网状WDM网中的SRLG(Shared Risk Link Groups:共享风险链路组)分离约束下的静态共享通路保护设计问题-给定网络物理拓扑、业务量需求矩阵和工作路由,为每个波长需求确定保护路由,使得所需的备份资源最小.这个问题可以用整数线形规划公式来描述.由于这是一个NP-C问题,因此,本文提出一种启发式算法MSC(Maximally Share the Capacity)加以解决,该算法的核心思想是改变链路权重使得保护路由之间尽量共享资源.仿真结果表明,本文算法能有效地降低所需的备份资源,提高了网络的资源利用率. 相似文献
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基于共享风险链路组(SRLG,shared risk link group)和流量均衡的概念,研究了光网络抗毁设计中基于流量均衡的SRLO尽量分离路由问题,利用网络流量的实际分布来评价链路和SRLG重要性,提出基于流量均衡的SRIG分离算法TBDR.通过计算机仿真表明,TBDR算法性能优于保护路优先算法,该算法能有效降低网络阻塞率,提高网络资源利用率和网络抗毁能力,达到流量均衡的目标. 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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为了提高传统的共享风险链路组(SRLG)约束下的路由选择(TRSSC)算法的成功保护率提出了一种新的RSSC(NRSSC)算法.NRSSC算法的基本思想是,当计算工作路径时考虑SRLG束将SRLG作为链路代价公式的一部分,这样可以在选择工作路径时避免SRLG链路,提高成功保护率.为了提高资源利用率,本算法允许共享备份带宽.另外,NRSSC算法根据用户的不同靠性要求,提供不同等级的保护服务.仿真结果表明,与TRSSC算法相比较,NRSSC算法不仅能够增加成功保护率,而且可以提高资源利用率,有效地改善了网络性能. 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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《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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Path protection is a fast and capacity-efficient approach for increasing the availability of end-to-end connections. However, sometimes it is not possible to obtain a fully disjoint path pair. In this case, it may be admissible to consider a path pair which is as disjoint as possible, and thus provide the best (in a certain sense) level of the single-fault protection that can be ensured using this type of approach. A shared risk link group (SRLG) is a group of links which have a common risk of failure. Two new heuristics for solving the min-sum maximally node and SRLG-disjoint path pair are presented. The relative performance of the new heuristics and also of two other previously proposed heuristics is evaluated using four different networks. Results, regarding accuracy and execution time of the studied heuristics, show that one of the new proposed algorithms can be a good compromise for use in the Generalized Multi-protocol Label Switching control plane. 相似文献