Dynamic routing and wavelength assignment in the presence of wavelength conversion for all-optical networks
Dynamic routing and wavelength assignment in the presence of wavelength conversion for all-optical networks
复制标题
DOI：
10.1109/tnet.2005.850226
复制
发表时间：
2005-06
期刊：
影响因子：
--
通讯作者：
Xiaowen Chu;Bo Li
中科院分区：
文献类型：
--
作者：
Xiaowen Chu;Bo Li
阻塞率是波长路由WDM全光网设计的关键性能指标之一。现有的研究表明，有效的路由和波长分配（RWA）算法和波长转换是提高阻塞性能的两个主要工具。然而，这两个问题在很大程度上被分开研究，特别是现有的RWA算法很少考虑波长转换的存在。在本文中，我们首先证明了现有的动态RWA算法不工作，以及在波长转换的存在，因为他们通常只考虑当前的流量，并没有明确考虑的路由长度。然后，我们提出了一个加权最小拥塞路由和第一适合波长分配（WLCR-FF）算法，同时考虑当前的流量负载和路由长度联合。我们进一步介绍了一个分析模型，可以评估阻塞性能的WLCR算法。我们进行了广泛的数值研究，典型的拓扑结构，包括环，网状环，和14节点的NSFNET的WLCR-FF与现有的各种路由算法，包括静态路由，固定备用路由和最小负载路由的性能进行比较。实验结果表明，在稀疏或/和全波长转换的情况下，WLCR-FF算法可以获得更好的阻塞性能。
Blocking probability has been one of the key performance indexes in the design of wavelength-routed all-optical WDM networks. Existing research has demonstrated that an effective Routing and Wavelength Assignment (RWA) algorithm and wavelength conversion are two primary vehicles for improving the blocking performance. However, these two issues have largely been investigated separately; in particular the existing RWA algorithms have seldom considered the presence of wavelength conversion. In this paper, we firstly demonstrate that the existing dynamic RWA algorithms do not work well in the presence of wavelength conversion as they usually only take into account the current traffic, and do not explicitly consider the route lengths. We then propose a weighted least-congestion routing and first-fit wavelength assignment (WLCR-FF) algorithm that considers both the current traffic load and the route lengths jointly. We further introduce an analytical model that can evaluate the blocking performance for WLCR algorithm. We carry out extensive numerical studies over typical topologies including ring, mesh-torus, and the 14-node NSFNET; and compare the performance of WLCR-FF with a wide variety of existing routing algorithms including static routing, fixed-alternate routing and least-loaded routing. The results conclusively demonstrate that the proposed WLCR-FF algorithm can achieve much better blocking performance in the presence of sparse or/and full wavelength conversion.