铁路光传送网络是高速铁路地面基础设施的神经中枢,为避免网络故障给铁路运营带来巨大损失,重点研究光传送网P-Cycle(Pre-configured Cycle)保护技术,提出在圈扩展时以所有候选圈上未保护工作容量的方差、冗余度两个指标为比较标准的RVP...铁路光传送网络是高速铁路地面基础设施的神经中枢,为避免网络故障给铁路运营带来巨大损失,重点研究光传送网P-Cycle(Pre-configured Cycle)保护技术,提出在圈扩展时以所有候选圈上未保护工作容量的方差、冗余度两个指标为比较标准的RVPA(Redundancy and Variance Based P-Cycle Construction Algorithm)算法。圈扩展的过程中,算法将选择方差与冗余度能同时满足条件的候选圈作为本轮扩展圈,有效限制了完成保护的P-Cycle圈个数;圈扩展停止条件中,当UPL与参数M、冗余度的大小关系满足条件时,则停止圈扩展,从而限制圈上节点数,使圈个数与圈长度得到有效均衡;在仿真过程中,利用泛欧网络拓扑COST239对RVPA算法进行仿真,并对比分析不同M值下的性能。仿真结果表明,在相同空闲资源与待保护工作容量设定下,参数M取0.5时效果最优,并且RVPA算法的保护容量效率、所需圈的个数、算法整体耗时、总冗余度均优于已有的POCA(P-Cycle Optimization Configuration Heuristic Algorithm)算法。展开更多
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...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。展开更多
Pre-configured cycles (p-cycles) can attain high capacity efficiency and fast protection switching times in wavelength division multiplexing (WDM) networks. This article proposes the weighted straddling link algor...Pre-configured cycles (p-cycles) can attain high capacity efficiency and fast protection switching times in wavelength division multiplexing (WDM) networks. This article proposes the weighted straddling link algorithm(WSLA) for generating a subset of all cycles that can guarantee 100% restorability in case of dual link failure, and give an integer linear programming(1LP) formulation that solves the shared p-cycles design problem minimizing the total spare capacities. Numerical result shows that our method can achieve 100% dual link failure restorability with acceptable spare capacity. The larger standard deviation of demand set and the larger node degree network, the better the shared p-cycles scheme performs.展开更多
Aiming at minimizing spare capacity for optical WDM networks, we propose a new heuristic algorithm for preconfigured protection cycle (p-cycle) design. Numerical results show that the spare capacity obtained by our ne...Aiming at minimizing spare capacity for optical WDM networks, we propose a new heuristic algorithm for preconfigured protection cycle (p-cycle) design. Numerical results show that the spare capacity obtained by our new algorithm is very close to the optimal solution.展开更多
A novel prefigured-cycle(P-Cycle)algorithm was proposed to improve the protection success ratio for asymmetric traffic in mesh optical networks.The proposed algorithm was simulated in a Pan-European COST239 network en...A novel prefigured-cycle(P-Cycle)algorithm was proposed to improve the protection success ratio for asymmetric traffic in mesh optical networks.The proposed algorithm was simulated in a Pan-European COST239 network environment under an asymmetric dynamic traffic model.The experimental results show that the proposed algorithm has lower capacity redundancy and higher utilization rate of configured resources than traditional P-Cycle methods.Network performance can be improved when implementing this algorithm under single-link failure circumstances.The system behavior is analyzed under different traffic volumes and the configuration strategy is also investigated for the heavyload and light-load networks respectively.展开更多
In future high-capacity wavelength division multiplexed(WDM)optical networks,the failure of a network component such as a fiber link can lead to severe disruption in the networks’traffic.Hence,it is imperatively impo...In future high-capacity wavelength division multiplexed(WDM)optical networks,the failure of a network component such as a fiber link can lead to severe disruption in the networks’traffic.Hence,it is imperatively important to provide fast and full protection in WDM optical networks.In this paper,we propose a new approach,called shared preconfigured protection cycles(shared-p-cycles),for the design of survivable WDM networks.We develop an integer linear program(ILP)formulation to solve the problem of shared-p-cycles design for WDM networks with and without wavelength conversion.Numerical results show that the shared-p-cycles design is more efficient in the use of spare capacity and requires much less spare capacity than the conventional pcycles design.展开更多
分组传送网(Packet Transport Network,PTN)能够兼容多种网络,诸如ATM、SDH、以太网、PDH、PPP/HDLC等,被广泛地应用到各种组网通信,PTN能够有机地结合数据技术和传输技术,使运营商的基础网络优势得到很大程度的提高。目前,分组传送网(P...分组传送网(Packet Transport Network,PTN)能够兼容多种网络,诸如ATM、SDH、以太网、PDH、PPP/HDLC等,被广泛地应用到各种组网通信,PTN能够有机地结合数据技术和传输技术,使运营商的基础网络优势得到很大程度的提高。目前,分组传送网(PTN)在多网络通讯、传输带宽、流量、信息安全等方面无法满足用户需求,文中设计出新型的PTN网络安全架构,根据业务及流量选择架构类型,并引入融入OTN核心组网和p-Cycle保护算法,通过使用OTN核心组网方案,使汇聚机房带宽和数据传输能力大大提高,具有较强的扩容能力,通过使用p-Cycle保护算法并构建组网拓扑图,提高了PTN网络信息数据传递的安全性能。文中还设计出PTN组网软件架构,便于用户应用、查询。实验表明,设计的方案大大降低了组网难度,提高了网络速度、服务质量,具有较好的网络可扩展性和安全性。展开更多
文摘铁路光传送网络是高速铁路地面基础设施的神经中枢,为避免网络故障给铁路运营带来巨大损失,重点研究光传送网P-Cycle(Pre-configured Cycle)保护技术,提出在圈扩展时以所有候选圈上未保护工作容量的方差、冗余度两个指标为比较标准的RVPA(Redundancy and Variance Based P-Cycle Construction Algorithm)算法。圈扩展的过程中,算法将选择方差与冗余度能同时满足条件的候选圈作为本轮扩展圈,有效限制了完成保护的P-Cycle圈个数;圈扩展停止条件中,当UPL与参数M、冗余度的大小关系满足条件时,则停止圈扩展,从而限制圈上节点数,使圈个数与圈长度得到有效均衡;在仿真过程中,利用泛欧网络拓扑COST239对RVPA算法进行仿真,并对比分析不同M值下的性能。仿真结果表明,在相同空闲资源与待保护工作容量设定下,参数M取0.5时效果最优,并且RVPA算法的保护容量效率、所需圈的个数、算法整体耗时、总冗余度均优于已有的POCA(P-Cycle Optimization Configuration Heuristic Algorithm)算法。
文摘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。
基金This work is supported by the National Science Fund for Distinguished Young Scholars (60325104);the National Natural Science Foundation of China (60572021);the SRFDP of M0E (20040013001).
文摘Pre-configured cycles (p-cycles) can attain high capacity efficiency and fast protection switching times in wavelength division multiplexing (WDM) networks. This article proposes the weighted straddling link algorithm(WSLA) for generating a subset of all cycles that can guarantee 100% restorability in case of dual link failure, and give an integer linear programming(1LP) formulation that solves the shared p-cycles design problem minimizing the total spare capacities. Numerical result shows that our method can achieve 100% dual link failure restorability with acceptable spare capacity. The larger standard deviation of demand set and the larger node degree network, the better the shared p-cycles scheme performs.
文摘Aiming at minimizing spare capacity for optical WDM networks, we propose a new heuristic algorithm for preconfigured protection cycle (p-cycle) design. Numerical results show that the spare capacity obtained by our new algorithm is very close to the optimal solution.
基金supported by the Hi-Tech Research and Development Program of China (No.2006AA01Z246)the National Natural Science Foundation of China (Grant No.60602004).
文摘A novel prefigured-cycle(P-Cycle)algorithm was proposed to improve the protection success ratio for asymmetric traffic in mesh optical networks.The proposed algorithm was simulated in a Pan-European COST239 network environment under an asymmetric dynamic traffic model.The experimental results show that the proposed algorithm has lower capacity redundancy and higher utilization rate of configured resources than traditional P-Cycle methods.Network performance can be improved when implementing this algorithm under single-link failure circumstances.The system behavior is analyzed under different traffic volumes and the configuration strategy is also investigated for the heavyload and light-load networks respectively.
基金supported by China Postdoctoral Science Foundation (Nos.20070420013,200801030)Open Fund of National Laboratory on Local Fiber-Optic Communication Networks&Advanced Optical Communication Systems,Peking University,China,Guangxi Science Foundation (No.0731003)Science Foundation of Guangxi University (No.X071032).
文摘In future high-capacity wavelength division multiplexed(WDM)optical networks,the failure of a network component such as a fiber link can lead to severe disruption in the networks’traffic.Hence,it is imperatively important to provide fast and full protection in WDM optical networks.In this paper,we propose a new approach,called shared preconfigured protection cycles(shared-p-cycles),for the design of survivable WDM networks.We develop an integer linear program(ILP)formulation to solve the problem of shared-p-cycles design for WDM networks with and without wavelength conversion.Numerical results show that the shared-p-cycles design is more efficient in the use of spare capacity and requires much less spare capacity than the conventional pcycles design.
文摘分组传送网(Packet Transport Network,PTN)能够兼容多种网络,诸如ATM、SDH、以太网、PDH、PPP/HDLC等,被广泛地应用到各种组网通信,PTN能够有机地结合数据技术和传输技术,使运营商的基础网络优势得到很大程度的提高。目前,分组传送网(PTN)在多网络通讯、传输带宽、流量、信息安全等方面无法满足用户需求,文中设计出新型的PTN网络安全架构,根据业务及流量选择架构类型,并引入融入OTN核心组网和p-Cycle保护算法,通过使用OTN核心组网方案,使汇聚机房带宽和数据传输能力大大提高,具有较强的扩容能力,通过使用p-Cycle保护算法并构建组网拓扑图,提高了PTN网络信息数据传递的安全性能。文中还设计出PTN组网软件架构,便于用户应用、查询。实验表明,设计的方案大大降低了组网难度,提高了网络速度、服务质量,具有较好的网络可扩展性和安全性。