【作者】 张继军；

【导师】 赵梓森； 毛谦；

【作者基本信息】 华中科技大学 ， 信息与通信工程， 2006， 博士

【摘要】 本文是作者在参与了武汉邮电科学研究院承担的国家“863”项目“自动交换光网络节点设备研制与系统实验”(2003AA122120)和武汉邮电科学研究院2005年度科研项目“ASON网络规划与优化软件(OTNPlanner)的设计与开发”等科研工作的背景下写作而成的。项目的目标是实现基于SDH的ASON节点设备和ASON网络规划与优化软件。为此,本文主要对基于SDH的ASON相关关键技术进行了较为深入的研究。归纳起来,本文的贡献主要包括以下五个方面:(1) ASON生存性技术。本文提出了一种新的、与传统单纯由传送平面实现不同的基于SDH的ASON保护方案,即ASON保护过程中控制平面和SDH传送平面的协同方案(双向1+1专用保护、带额外业务的1 : 1专用保护),并在理论分析的基础上得出了选择协同方案的具体结论。提出了4种改进的,能够优化ASON恢复时间性能,并适用于不同应用情况的路径恢复机制:执行反向确认等待操作的前向并行(FPC)路径恢复机制、无反向确认等待操作的前向并行(FPNC)路径恢复机制、执行反向确认等待操作的双向并行(BPC)路径恢复机制和无反向确认等待操作的双向并行(BPNC)路径恢复机制。实验证明,改进的ASON恢复机制可以有效地实现相应的保护功能,恢复性能也得到了较大优化。(2)基于共享链路路径恢复机制中共享资源需求的计算和分析方法,本文提出了一种新的共享链路路径恢复机制中备用容量设计的启发式算法,进行了仿真实验与分析。(3) ASON的组播与组播恢复技术。本文针对ASON网络中部分节点不具有组播能力或组播能力受限的实际情况,提出了一种新的有节点组播能力约束的受限组播路由算法,即受限组播最近树节点优先(LMNTF)算法。为保证ASON承载组播业务的可用性,提出了一种新的组播树区段恢复方法,即断开树节点区段恢复(BTSR)机制。在BTSR机制中,源节点s负责计算恢复路径,利用组播树失效断开后的残余子树和新子树上的已有连接,将断开树连接起来,尽量减少因新建组播树所需的大量交叉配置操作而带来的时间损耗。我们以实际开发的ASON设备平台为基础,对上述算法和机制进行了实验验证。实验证明,新的算法高效地实现了不同应用模式下的ASON组播功能,并可以在网络发生单点失效时在较短时间内恢复组播业务。(4) ASON多径传输以太网业务。本文深入研究了实现ASON多径传输以太网业务和多径传输保护的两项关键技术“SDH传送平面的VC虚级联”和“LCAS”的原理,并在此基础上设计了一种实现多径传输保护的方案。该方案已经在实际的产品开发和系统测试中得到了验证。进而,本文提出了新的,基于SDH的ASON多径传输以太网业务路由设计的ILP算法和启发式算法,进行了仿真实验与分析。(5) ASON网络规划与优化软件。采用Rational统一过程方法,设计实现了ASON网络规划与优化软件:从网络规划与优化对象的分析,到需求分析、用例分析、结构设计,再到关键算法和策略,比较完整地分析了软件开发各阶段的设计思想;基于分层优化的算法思想,综合运用了已有的各类网络规划与优化算法,包括本文针对两类特定的应用模式所提出的共享链路路径恢复机制中备用容量设计的启发式算法和ASON多径传输以太网业务路由设计的启发式算法。最后,我们对本文所做工作进行了总结,并讨论了将来可能继续的研究方向。更多还原

【Abstract】 This dissertation is based on the research of National 863 Hi-tech Project -“Equipment Development and System Trial of Automatic Switched Optical Network (ASON)”(2003AA122120) and the WRI R&D project in 2005 -“Designing and Development of ASON Network Programming and Optimization Software (OTNPlanner)”. These two projects aim to design and implement“SDH-based ASON equipment”and“ASON network programming and optimization software”. So it is focused on the research of SDH-based ASON related key issues. The main contribution of this paper can be summarized as follows:(1) The survivability technologies of ASON. A new cooperation scheme between control plane and transport plane during the recovery procedure of ASON (bidirectional 1+1 dedicated protection, 1:1 dedicated protection with extra services) is proposed, and some conclusions based on the theories analysis are drawn. Some improved path restoration schemes—Forward Parallel Processing with Reverse Confirmation (FPC), Forward Parallel Processing with no Reverse Confirmation (FPNC), Bidirectional Parallel Processing with Reverse Confirmation (BPC), and Bidirectional Parallel Processing with no Reverse Confirmation (BPNC) are also proposed.(2) Based on the calculating and analyzing method of the resource requirements for shared-link path recovery, A heuristic algorithm of backup capability design for shared-link path restoration scheme is proposed.(3) ASON multicast and multicast recovery technologies. A Limited Multicasting the Nearest Tree-node First (LMNTF) algorithm is proposed, aiming at the networks constructed with the ASON nodes having limited multicasting capability. For improving the availability of multicast services, Break Tree-node Segment Restoration (BTSR) scheme is proposed. In this scheme, source node calculates the restoration path; using the connections existed in the“remained sub-tree”and“new sub-tree”created after the failure of multicast tree, it connects those disconnected sub-trees, so as to decrease the time consumed over the amount of cross-connect operations for new multicast tree constructing. It has been proved that BTSR can recovery those networks services with single-failures.(4) Carrying Ethernet services with multi-paths in ASON. Two key technologies for carrying Ethernet services with multi-paths in ASON—“VC virtual concatenation in SDH transport plane”and“Link Capacity Adjustment Scheme (LCAS)”are analyzed, and R&D schemes in actual ASON equipment are designed. And then an ILP formulation and a heuristic algorithm of routing design for carrying Ethernet services with multi-paths in ASON are proposed. The simulation work has been done.(5) ASON network programming and optimization software. Adopting Rational unified process, the ASON network programming and optimization software is designed. In this part, various ASON programming and optimization algorithms are deployed, including the heuristic algorithms proposed in this paper. The simulation work has been done.At last, the research work is summarized, and those potential research topics in future are discussed.更多还原