Next-Generation Optical WDM Mesh Networks

该项目旨在为构建下一代光波分复用（WDM）骨干网创造设计、分析和优化新系统架构、网络协议和软件算法的新知识。特别的研究重点将包括分层光交换、光组播和最优拓扑重构。对于分层光交换，将发展具有多层级的通用光交换架构，发挥光学和电子学的优势。例如，混合开关架构将包括全光切换的波段（波长带），而波长和亚波长连接可能使用光-电-光（OEO）开关进行切换。这项调查的结果将为在何处战略性地放置资源（如分层光开关）提供指导。该项目还将设计光多播交换机架构，并开发数学模型和有效算法，以支持具有分层光交换的网络中的光树。研究小组将为网络运营商开发新的高效模型，并将设计新的算法，使用各种方案（如链路保护和共享保护）来保护光树。特别是，基于光树的连接的建立、维护和终止的信令协议将通过仿真设计和研究。最后，在与虚拟拓扑设计相关的研究部分，将研究WDM网络的重新配置，以便考虑带宽升级，例如，当需要一小部分空闲容量时，可以升级现有光路，而不是完全取消轻负载光路或增加最大容量光路。特别是，流量波动，例如跨时区的全球光网络内的流量波动，可以产生另一种动态，即流量强度峰值率。在此背景下，研究团队将研究不同的虚拟拓扑设计方法，以更好地理解这一问题以及与动态流量波动相关的类似问题。

This project aims at creating new knowledge on the design, analysis, and optimization of novel system architectures, network protocols, and software algorithms for building next generation optical Wavelength Division Multiplexing (WDM) backbone networks. Particular research focus will include hierarchical optical switching, optical multicasting, and optimal topology reconfiguration. For hierarchical optical switching, the generalized optical switch architecture with multiple levels will be developed where the advantages of both optics and electronics will be exploited. For example, a hybrid switch architecture will include wavebands (bands of wavelengths) being switched all-optically, while wavelength and sub-wavelength connections may be switched with optical-electrical-optical (OEO) switches. Results from this investigation will provide guidelines on where to strategically place resources such as hierarchical optical switches. This project will also design optical multicasting switch architectures and develop mathematical models and efficient algorithms for supporting light-trees in a network with hierarchical optical switching. The research team will develop new efficient models for network operators as well as will design new algorithms for protecting light-trees using various schemes such as link protection and shared protection. In particular, the signaling protocols for set up, maintenance, and termination of light-tree based connections will be designed and studied by simulation. Finally, in the part of the research related to the virtual topology design, the reconfigurations of WDM networks will be studied so that the bandwidth upgrades are taken into account, e.g. instead of fully taking down a lightly-loaded lightpath or adding a maximum-capacity lightpath, an existing lightpath can be upgraded when a fraction of its free capacity is needed. In particular, traffic fluctuations, such as within the global optical network over the time zones, can create another dynamism, i.e., traffic intensity peak rates. In this context, the research team will study different virtual topology-design methods to obtain a better understanding of this and similar problems related to dynamic traffic fluctuations.