Improving the Cost-Effectiveness of WDM Optical Networks

该提案是乔治华盛顿大学和威廉玛丽学院的研究人员联合提交的提案。 尽管错误率较低且容量较高，但 WDM（波分复用）​​光纤网络尚未与市场上的电子同行竞争。 主要原因是硬件成本高昂，这使得除了少数用户之外的所有人都无法使用光网络。这里提出的研究针对其中一些过高的成本，旨在帮助网络设计人员回答一些与尺寸和组件尺寸相关的问题，从而有助于降低硬件成本。拟议的研究以全光电路交换多光纤平均路由环（一种经过测试的技术）为起点，并提出了“可以用更少的硬件获得高性能吗？”的问题。网络的成本（从可制造性到更高级别的软件设计）构成了总体成本，该项目的重点是通过限制光交换机的复杂性（交叉点）以及通过时隙更有效地使用可用带宽来降低成本。将研究因这些成本考虑而产生的三类资源分配问题，并设计和评估执行资源分配的算法。第一类问题涉及限制光纤到光纤交换机的灵活性，以努力降低交换机的制造成本。初步结果表明，即使交换机的连接性显着降低，也可以获得接近最佳的吞吐量。在这种情况下将解决的一些研究问题是：性能如何随着改用光纤的限制而发生定量变化？波长分配与这些限制有根本不同吗？第二类问题涉及从较小的环构建较大的网络。该问题的研究问题包括：全光多环应如何以经济有效的方式连接，特别是利用光纤交换的限制？对于环间和环内会话，应该如何划分波长（如果有的话）？第三类问题涉及在带有时隙的光网络中有效调度多速率会话（时分复用）。该技术的实际可行性已经得到证明。这里的重点是资源分配问题，通过更有效地利用光纤交换限制的带宽，降低总体网络成本。最后，当所有三种类型的设计特征都存在时，将采用综合方法来研究网络性能。研究结果旨在在不久的将来得到应用，因​​此最初的方法将结合模拟和建模，而后来的 PI 将致力于对问题进行更深入的理论理解。

This proposal is a joint proposal submitted by investigators at the George Washington University and the College of William and Mary. In spite of lower error rates and far higher capacities, WDM (Wavelength Division Multiplexing) optical networks have yet to compete with their electronic counterparts in the marketplace. The main reason is the prohibitive cost of the hardware, which puts optical networks out of reach for all but a few users.The research proposed here takes aim at some of these prohibitive costs and is intended to help network designers answer some questions related to dimensioning and component-sizing that can help reduce hardware costs.The proposed research takes as a starting point an all-optical circuit-switched multifiber avelength-routing ring, a tested technology, and asks the question ``Can high performance be obtained with less hardware?'' While many aspects of a network (ranging from manufacturability to higher-level software design) make up the overall cost, this project focuses on reducing costs by limiting the complexity (crosspoints) of optical switches and from more effectively using available bandwidth by time-slotting.Three types of resource allocation problems that arise from these cost considerations will be investigated and algorithms that perform resource allocation will be designed and evaluated.The first type of problem involves limiting the flexibility of fiber-to-fiber switches in an effort to reduce the cost of manufacturing switches. Preliminary results indicate that near-optimal throughput can be obtained even with significant reduction in the connectivity of the switch. Some research questions that will be addressed in this case are: how does performance vary quantitatively with limitations in switching to fibers? does wavelength allocation differ fundamentally with these restrictions?The second type of problem involves constructing larger networks from smaller rings. Research questions for this problem include: how should all-optical multiple rings be connected in a cost-effective manner, especially by using fiber-switching limitations? how should wavelengths be partitioned (if at all) for inter-ring and intra-ring sessions?The third type of problem involves efficiently scheduling multi-rate sessions in an optical network with slots (time-division multiplexing). The practical feasibility of this technology has already been demonstrated. The focus here is on resource allocation problems that, by more effectively using bandwidth with fiber-switching limitations, reduce overall network cost.Finally, an integrative approach will be taken to study network performance when all three types of design features are present. The research results are intended to be applicable in the near future, and therefore the initial approach will use a combination of simulation and modeling, whereas later the PIs will aim for a deeper theoretical understanding of the problem.