基于同波长光纤延迟线集光突发交换结构及其性能分析

由于光突发交换机制本身就避免了光缓存的使用，但是现实中，光突发包之间竞争以及提供优先级服务又依靠光纤延迟线来解决。为此，我们设计了应用光纤延迟线的光突发交换网络核心节点结构。为了避免光纤延迟线色散引起的突发包输入排队缓存偏移，在该结构中设计了同波长光纤延迟线集。采用了空分交换矩阵，避免了波长转换的需要。为了有效运行该交换结构，我们提出了输入排队与自适应光缓存调度算法，而该算法不仅仅适用于光突发交换，也适合于光纤延迟线得到普遍应用的光分组交换。该调度算法能够提供优先级服务，避免队头阻塞，对该调度算法建立了严格的理论分析模型，并进行了仿真。仿真结果表明，与传统的延迟线竞争解决方案相比，这一调度算法能够改善交换性能1到2个数量级，是利用光纤延迟线解决光突发交换中竞争问题的一个较佳方案。

Architecture and performance evaluation of optical burst switching based on the same wavelength fiber delay line set

A new architecture of optical burst switching based on the same wavelength fiber delay line set (OBS-SWDLS) is proposed in this paper, which breaks through the traditional restricting of fiber delay line (FDL) application. Another important feature of the OBS-SWDLS is that wavelength converters can be avoided by employing the same wavelength space division switching units Algorithm of input queuing and adaptively incremental buffer allocation scheduling applied to the SWFDLS is proposed. Accordingly, exact theoretical model has been established. It is applied to not only OBS but also optical packet switching (OPS). Prioritized service can be provided and blocking of the head of line (HOL) can be avoided by using it. The simulated results show that burst loss probability can be reduced by 1 to 2 orders of magnitude compared with the conventional schemes of fiber delay line in optical switching networks.