抗毁WDM网中单SRLG故障的共享子通路保护

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.     

网状WDM网中双链路失效的共享路径保护设计

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。     

IP/MPLSoverWDM网中基于共享风险链路组限制的共享通路保护算法

本文研究了IP/MPLS over WDM网中,如何建立两条共享风险链路组(SRLG)分离的标记交换路径(LSP)问题,提出一种新的基于SRLG分离的共享通路保护算法.该算法既可以保证用户业务的可靠性要求,同时又能够有效提高全网的资源利用率,从而大大降低全网LSP建立请求的阻塞率.本文还对所提算法进行了仿真研究,并给出了仿真结果.     

光网络中基于流量均衡的SRLG分离路由算法

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.     

抗毁WDM光网络中SRLG约束下p-Cycles配置算法

基于共享风险链路组(SRLG,shared risk link group)和P圈(P-Cycles,pre-configured cycles)的概念,研究了SRLG约束下p-Cycles的构造问题,引入SRLG完全分离p-Cycles的概念,基于SRLG的简单p-Cycles构造算法和获得更多p-Cycles的SRLG约束下的圈扩展算法提出的SRLG约束下的p-Cycles配置算法(SCAA),实现在光网络中优化配置SRLG完全分离的p-Cycles。通过计算机仿真表明,SCAA最小容量配置方案可以预留更少的网络资源,而SCAA优化容量配置方案可以实现p-Cycles快速配置容量,SCAA算法可以保障配置SRLG分离p-Cycles的高保护效能,使网络具备单SRLG故障恢复能力。     

WDM光网络中一种新型的动态共享保护算法

波分复用(WDM)光网络中引入了共享风险链路组(SRLG)的概念 ,要求工作通路与保护通路不能处于同一个SRLG之中.文章提出了一种基于SRLG限制的动态共享通道保护算法,即满足K对业务的动态链路权重配置(K-Dynamic Link Weight Configuration, K-DLWC)算法 ,该算法的     

一种基于SRLG限制的动态共享通道保护算法

光网络中引入了共享风险链路组(SRLG)的概念,要求工作通道与保护通道不能处于同一个SRLG之中.文章提出了一种基于SRLG限制的动态共享通道保护算法--动态链路权重配置(Dynamic Link Weight Configuration,DLWC)算法,该算法的关键在于为链路定义了两个动态权重.在计算工作通道和保护通道时,它能综合解决SRLG限制、动态负载均衡和自陷等3个关键问题.     

WDM网状网中基于共享风险链路组限制的业务量疏导算法

该文研究了业务量疏导WDM网状网中如何建立可靠的业务连接问题,提出一种新的基于共享风险链路组(SRLG)限制的共享通路保护算法。该算法既可以保证用户业务不同的可靠性要求,同时又能够有效提高全网的资源利用率,从而大大降低全网的业务阻塞率。该文还对所提算法进行了仿真研究,并给出了仿真结果。     

网状WDM网中支持区分可靠性的共享通路保护算法

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。     

WDM光网络中一种基SRLG限制的动态共享保护算法研究

WDM光网络中引入了共享风险链路组(SRLG)的概念,要求工作通道与保护通道不能处于同一个SRLG之中.文章提出了一种基于SRLG限制的动态共享通道保护算法,即满足K对业务的动态链路权重配置(K-Dynamic Link weight Configuration,K-DLWC)算法,该算法的关键在于为链路定义了两个动态权重.在计算工作通道和保护通道时,它能综合解决SRLG限制、局部最优等关键问题.     

Shared partial path protection in WDM networks with shared risk link groups

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.

WDM网基于混合共享和SRLG约束的通路保护

研究了网状波分复用（WDM）网中动态生存性路由配备问题，提出了一种新颖的基于共享风险链路组（SRLG）束的混合共享通路保护（MSPP）方案。MSPP为每个业务请求分配丁作通路和SRLG分离的保护通路，因此能完全保护单SRLG故障。与传统的共享通路保护（SPP）方案不同，在满足某些约束条件下，MSPP允许部分工作通路和保护通路共享资源。仿真结果表明，MSPP性能优于SPP。     

WDM光网络中一种优先共享通路保护算法

为了提高波分复用光网络的可靠性,常采用分段共享通路保护算法,该方法通常要求保护通路要均匀分段并且应满足共享风险链路组约束,网络业务的阻塞率也就比较高,因此提出了用优先共享通路保护算法来降低业务阻塞率。通过计算机仿真进行了理论分析和实验验证,取得了两种保护算法下的业务阻塞率和资源预留比的数据。结果表明,优先共享保护通路算法能够有效地融合分段共享通路保护算法的优点,同时在业务的阻塞率和资源预留比方面优于分段共享保护通路算法。     

Partial SRLG-disjoint shared path protection with differentiated reliability in survivable WDM network

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.     

On Finding the Multicast Protection Tree Considering SRLG in WDM Optical Networks

In this letter, a new sharing mechanism, SRLG sharing, is proposed, which allows the links of the same shared risk link group (SRLG) in a primary light tree to share protections in WDM optical networks. In previous studies, how to share spare resources with SRLG constraints has not been studied in multicast optical networks. In this letter, considering SRLG sharing, we propose a novel algorithm –multicast with SRLG sharing (MSS)– to establish a protection light tree. Finally, the algorithm MSS and the algorithm multicast with no SRLG sharing (MNSS) are compared through a simulation to show that our new sharing scheme of SRLG sharing is more efficient than that of no SRLG sharing in terms of spare resource utilization and blocking probability.