共查询到17条相似文献,搜索用时 812 毫秒
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在光交换网络中,当同一波长两个或多个光分组同时离开光交换机的同一个输出端口时将会发生对输出端资源的竞争,竞争失败的光分组将受阻,如何有效地调度将使光交换系统性能受到很大影响,文章综述了目前解决光交换网分组冲突的几种方案,阐述了各种解决方法的原理、实现方式及特点,展望了今后可能采用的最佳竞争调度方案. 相似文献
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基于共享有限波长和参量波长转换器的冲突解决方案 总被引:1,自引:0,他引:1
研究了一种共享有限波长转换器(LRWC)和参量波长转换器(PWC)相结合的解决全光分组波长资源竞争的方案,并提出了PWC优先算法作为光分组交换中的波长竞争解决方案。仿真结果表明:本文结构与共享LRWC节点结构相比,减少了波长转换器的数目,并且能够明显降低光分组交换节点的分组丢包率(PLP),提高波长转换器的利用率。研究还发现,不同波长转换器配置方案对系统性能有影响。 相似文献
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OBS网络中冲突解决方法研究 总被引:4,自引:1,他引:3
在OBS网络中,当两个或多个突发包要求在同一时刻,同一输出端口的同一波长上预留资源时.就会产生突发数据包的资源竞争。如何解决资源竞争问题是OBS技术能否最终走向实际应用的关键技术之一。文章首先介绍OBS的基本原理、网络结构、OBS网络的资源预约机制、边缘路由器的封装机制和资源调度机制,接着研究解决OBS网络中突发数据包之间争夺链路资源问题的竞争解决机制,随后详细的给出四种竞争解决方案:光缓存、波长转换、偏射路由和突发分段丢弃,并分析了它们的性能。在此基础上,文章最后提出了各种资源竞争解决方案相结合的联合解决机制的思想。 相似文献
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共享有限范围多波长和全单波长转换器的光组播冲突解决方案 总被引:4,自引:4,他引:0
研究了一种有限范围多波长转换器(LMWC)反馈共享连接和全单波长转换器(FRWC)输出共享连接相结合的解决全光组播波长资源竞争的解决方案,并提出有限范围多波长转换器优先的波长变换调度算法,以最大双向匹配最小边长权重方法选择多波长转换器解决冲突光组播波长变换。仿真结果表明:所提的结构与输出共享全多波长转换器(FMWC)节点结构或输出共享FRWC节点结构相比,都能够明显降低光组播节点的分组丢包率(PLP),减少系统需求LM-WC多波长转换器的数目,提高多波长转换器的利用率;LMWC具有不同波长转换范围对光分组冲突解决性能也有影响。 相似文献
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随着电传送网技术向光传送网技术的演进.光层的联网能力越来越强,出现了几种光域上的交换技术:光线路交换/波长路由、光分组交换、光突发交换及为解决光分组在传送时出现丢失而重组时出现次序混乱等问题提出来的一种新颖的光分组流交换技术。下文将对这几种交换技术及其特点进行逐一介绍。 相似文献
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Performance of fiber delay‐line buffers in asynchronous packet‐based optical switching networks with wavelength conversion 下载免费PDF全文
A major challenge in asynchronous packet‐based optical networks is packet contention, which occurs when two or more packets head to the same output at the same time. To resolve contention in the optical domain, two primary approaches are wavelength conversion and fiber delay line (FDL) buffering. In wavelength conversion, a contending packet can be converted from one wavelength to another in order to avoid conflict. In FDL buffering, contending packets can be delayed for a fixed amount of time. While the performance of wavelength conversion and FDL buffering has been evaluated extensively in synchronous networks with fixed‐sized packets, in this paper, we study the performance of FDL buffers in asynchronous packet‐based optical networks with wavelength conversion. An analytical model is proposed to evaluate the performance in terms of packet loss probability and average delay. Extensive simulation and analytical results show that, with appropriate settings, FDL buffers can perform much better in switches with wavelength conversion than in switches with no conversion. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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主要研究解决光突发交换(OBS)网中突发数据包之间争夺链路资源问题的竞争解决机制.从时间域、波长域和空间域上探讨了解决冲突的方法,并给出了一种采用偏转路由机制和基于共享功能波长转换器的冲突部分转换方法(COCP)相结合的竞争解决方法. 相似文献
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Optical burst switching (OBS) has attracted interest as a transport network architecture for the future optical Internet. As OBS relies on statistical multiplexing efficient contention resolution is a key issue in order to achieve a low burst loss probability. First, this paper discusses options and key design parameters for contention resolution in OBS. Then, it evaluates the performance of OBS nodes which employ shared wavelength converter pools and simple fiber delay line (FDL) buffers. Finally, optimized strategies for the order of probing a wavelength converter pool and an FDL buffer for contention resolution are presented and compared. It is shown that these strategies can be used to optimize performance for a given, for example, minimal cost, dimensioning of the wavelength converter pool and the FDL buffer. 相似文献
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Develder Chris Houdt Benny Van Blondia Chris Pickavet Mario Demeester Piet 《Photonic Network Communications》2004,8(2):149-161
The major goal of optical packet switching (OPS) is to match switching technology to the huge capacities provided by (D)WDM. A crucial issue in packet switched networks is the avoidance of packet losses stemming from contention. In OPS, contention can be solved using a combination of exploitation of the wavelength domain (through wavelength conversion) and buffering. To provide optical buffering, fiber delay lines (FDLs) are used. In this paper, we focus on an optical packet switch with recirculating FDL buffers and wavelength converters. We introduce the Markovian arrival process with marked transitions (MMAP), which has very desirable properties as a traffic model for OPS performance assessment. Using this model, we determine lower and upper bounds for the packet loss rate (PLR) achieved by the aforementioned switch. The calculation of the PLR bounds through matrix analytical methods is repeated for a wide range of traffic conditions, including highly non-uniform traffic, both in space (i.e., packet destinations) and time (bursty traffic). The quality of these bounds is verified through comparison with simulation results. 相似文献