标题: | 阶层式交换器光纤网路中的通道设置及保护 Tunnel Allocation and Protection in Hierarchical Cross-connect WDM Networks |
作者: | 罗泽羽 Tse-Yu Lo 陈健 Chien Chen 资讯科学与工程研究所 |
关键字: | 多单位光学交换器;通道;容量平衡通道配置法;等长权重通道配置法;通道式分段保护机制;Multi-granularity Optical Cross-Connect;tunnel;Capacity-Balanced Static Tunnel Allocation;Constant Length Weighted Tunnel Allocation;Tunnel-based Segment Protection |
公开日期: | 2003 |
摘要: | 多单位光学交换器(Multi-granularity Optical Cross-Connect)架构是为了提供一个有效节省成本的方式来供应越来越大的网路资料流量的需求。在多单位交换器光纤网路中,数个绑成一束的连续波长形成一个通道(tunnel)并且像一个单独波长一样一起做交换。通道路径上的交换器尺寸可因此而变小并降低成本。这本论文主要在探讨多单位光学交换器上的通道配置及保护这两个问题。 最近提出的容量平衡通道配置法(Capacity-Balanced Static Tunnel Allocation)是用来解决通道配置问题。容量平衡通道配置法选择流量进出最大的两个节点并在这两点之间配置一条通道。然而当为每一个通道选择一对节点时,容量平衡通道配置法并没有考虑通道长度的限制。因此,我们提出等长权重通道配置法(Constant Length Weighted Tunnel Allocation,)来改善容量平衡通道配置法的问题。在等长权重通道配置法中,只有符合长度限制的两节点,才会试着在之间建立通道。我们藉由模拟来验证等长权重通道配置法的效能并与容量平衡通道配置法做出较。结果显示等长权重通道配置法的效能比容量平衡通道配置法更好。 在多单位交换器光纤网路的保护方面,我们探讨单一线路故障时的保护机制。多单位交换器光纤网路在保护机制方面还未被广泛研究,因此这篇论文提供一个有效解决单一线路故障发生时的保护机制。我们提出通道式分段保护机制(Tunnel-based Segment Protection)来回复因线路故障所中断的通讯,在通道式分段保护机制中,配置通道时同时也会考虑保护需求,当我们在网路上配置一个主要通道时,同时也配置一个相对应的备用通道。模拟结果显示通道式保护机制对多单位交换器光纤网路中的单一线路故障提供一个有效的解决方法。 Multi-granularity Optical Cross-Connect (MG-OXC) has been proposed to provide a cost efficient way to support the increasing number of traffic requests. In the MG-OXC networks, consecutive wavelengths are bundled to form a tunnel and switched as a single unit. Networks resources, including switching fabrics and multiplexers, at the mediate nodes on the route of a tunnel thus can be reduced. This thesis considers the static tunnel allocation problem and the protection problem in MG-OXC networks. For the tunnel allocation problem, a heuristic Capacity-Balanced Static Tunnel Allocation (CB-STA) [1] has been proposed. CB-STA always tries to allocate a tunnel from the node with maximal predicted traffic going out to the node with maximal predicted traffic coming in. However, the length constraint is not considered when selecting node pairs. We propose a heuristic, Constant Length Weighted Tunnel Allocation (CLWTA), to overcome this problem of CB-STA. Only node pairs whose hop distance complies with the length constraint are tried to be allocated tunnels in CLWTA. We examine the performance of the proposed schemes, CLWTA, and make a comparison with CB-STA. The results show that CLWTA outperforms CB-STA in all switching type combinations. For the protection problem, we investigate the protection schemes for the single-link failure in the MG-OXC networks. Since the protection problem has not been studied intensively in MG-OXC networks, this work aims to provide an efficient protection solution. A segment-based protection scheme, called Tunnel-based Segment Protection (TSP) that considers the tunnel allocation with protection requirement in mind is proposed to recover the communications interrupted by a fiber cut. In TSP, a corresponding link-disjoint protection tunnel is always allocated simultaneously with a working tunnel. Simulation results show that TSP provides an efficient protection solution for MG-OXC networks. |
URI: | http://140.113.39.130/cdrfb3/record/nctu/#GT009123589 http://hdl.handle.net/11536/53458 |
显示于类别: | Thesis |
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