共查询到18条相似文献,搜索用时 171 毫秒
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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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对光分组交换中波长共享(SPC)、链路共享(SPL)和节点共享(SPN)的结构进行了理论分析,推导出三种结构的丢包率公式,并对其系统丢包率与负载、输入光纤端口数和每纤波长数的关系进行了数值计算。结果表明:在相同的波长转换器数目(没有达到极限值)时,SPN结构的丢包率低于SPL的丢包率,并且在接近极限值时,SPN结构所需要的波长转换器数目也小于SPL结构所需要的波长转换器数目。 相似文献
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研究了FDL和有限长波长转换器(LRWC)相结合的方法来解决异步变长的分组交换网中的冲突问题,对这种冲突解决方案建立了数学模型并进行了理论分析,提出了一个用于修正最佳延迟单元的公式,即在负载较大的情况下,我们要求延迟单元较小,这样可显著的降低在此交换网中的分组丢失率;对系统丢包率与负载、FDL数目和最佳延迟单元的关系进行了研究和讨论,结果表明:在同样的输入负载情况下,有限长波长转换器(LRWC)的引入可以降低缓存的数量;对延迟单元的修正可以大大降低丢包率,同时系统的性能较之单独使用FDL时有较大的改善。 相似文献
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The wavelength conversion is regarded as an effective way to resolve the optical packet contention in the wavelength domain for optical packet switching. An optical packet switching node, based on shared-per-node equipped with limited range wavelength converters and parametric wavelength converters (SPN-LP), is designed to further reduce optical packet loss probability. A novel optical packet contention resolution with priority differentiation wavelength scheduling algorithm to support quality of service (QoS) for the SPN-LP architecture is put forward in the article. The simulation results show that proposed optical packet resolution enables a good QoS differentiation, namely the high priority contending optical packet has the sufficient low packet loss probability. 相似文献
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We propose an architecture for a bufferless packet optical switch employing the wavelength dimension for contention resolution. The optical packet switch is equipped with tunable wavelength converters shared among the input lines. An analytical model Is proposed in order to determine the number of converters needed to satisfy prefixed packet loss probability constraints. This analytical model very accurately fits with simulations results. A sensitivity analysis of the required number of converters as a function of the main system parameters (number of input and output lines, number of wavelengths, …) and traffic parameters has been carried out. Making use of the introduced dimensioning procedure we have observed that the proposed architecture allows a saving in terms of employed number of converters with respect to the other architectures proposed in literature. Such a saving can reach about 95% of the number of converters 相似文献
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Resources sharing in optical packet switches with limited-range wavelength converters 总被引:4,自引:0,他引:4
This paper compares selected optical packet switching architectures that use the wavelength conversion technique to solve the packet contention problem. The architectures are equipped with shared and limited-range wavelength converters (LRWCs). This paper focuses on two architectures: the shared per node (SPN) and the shared per output fiber (SPOF) architectures, in which the wavelength converters are SPN and output fiber, respectively. Packet loss probability is expressed as a function of the number of wavelength converters used, by means of analytical models validated by simulations. The analytical results show how the use of a reduced number of LRWCs with small range allows the switch to obtain the same performances of an architecture equipped with all of the wavelength converters and using a full wavelength conversion. 相似文献
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提出并分析了一种具有波分复用的光分组交换架构中置入波长转换器的模型,在该结构中每个输入线都共享波长转换器,讨论了在均衡和非均衡条件下,网络丢包率和波长转换器数目的关系,仿真结果表明该模型能在降低丢包率的同时又能减少波长转换器的数目. 相似文献
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A. Zalesky R.S. Tucker 《Photonics Technology Letters, IEEE》2006,18(2):352-354
An architecture is proposed for a wavelength-division-multiplexed (WDM) optical packet or circuit switch in which a bank of limited-range wavelength converters is shared among all input fibers, and in which any subset of converters can be dynamically concatenated (cascaded) to yield a wider conversion range for a packet that would otherwise be dropped because all unused wavelengths in its desired output fiber lie outside the range of a single converter. A probabilistic model of a switch is used to numerically determine the improvement in packet-drop probability achieved by dynamically concatenating converters. 相似文献
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This paper proposes new analytical models to study optical packet switching architectures with multi-fiber interfaces and shared wavelength converters. The multi-fiber extension of the recently proposed Shared-Per-Input-Wavelength (SPIW) scheme is compared against the multi-fiber Shared-Per-Node (SPN) scheme in terms of cost and performance for asynchronous traffic. In addition to using Markov chains and fixed-point iterations for modeling the mono-fiber case, a novel state aggregation technique is proposed to evaluate the packet loss in asynchronous multi-fiber scenario. The accuracy of the performance models is validated by comparison with simulations in a wide variety of scenarios with both balanced and imbalanced input traffic. The proposed analytical models are shown to remarkably capture the actual system behavior in all scenarios we tested. The adoption of multi-fiber interfaces is shown to achieve remarkable savings in the number of wavelength converters employed and their range. In addition, the SPIW solution allows to save, in particular conditions, a significant number of optical gates compared to the SPN solution. Indeed, SPIW allows, if properly dimensioned, potential complexity and cost reduction compared to SPN, while providing similar performance. 相似文献