Finding Routing Paths for Alternate Routing in All-Optical WDM Networks
Finding Routing Paths for Alternate Routing in All-Optical WDM Networks
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DOI：
10.1109/jlt.2008.923642
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发表时间：
2008-06
影响因子：
4.7
通讯作者：
Hwa-Chun Lin;Sheng-Wei Wang;Meng-Lin Hung
中科院分区：
文献类型：
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作者：
Hwa-Chun Lin;Sheng-Wei Wang;Meng-Lin Hung
备用路由算法需要在每个源-目的对之间设置一组预先确定的路由路径。为了降低连接阻塞的概率，希望每个源-目的对之间的预定路由路径是链路不相交的。在以前的交替路由研究中，预先确定的路由路径是指跳数最短的链路不相交路径。不同源-目的对之间的最短链路不相交路径之间的共享链路可能导致高的连接阻塞概率。因此，根据所有源-目的对的流量需求，基于跳数的最短链路不相交路径可能不是预定路由路径的最佳选择。为了降低连接阻塞概率，本文提出了一种在每个源-目的对之间寻找一组链路不相交路由路径的方法，供备选路由算法使用。其核心思想是基于网络中最优流量模式所使用的路由路径，找到一组链路不相交的路由路径。然后，对于每个源-目的对，我们从最优流量模式所利用的路由路径中选择一组链路不相交路由路径，使所选的链路不相交路由路径集承载源-目的对之间的大部分流量。通过仿真比较了采用该方法得到的链路不相交路径作为预定路径与采用基于跳数的最短链路不相交路径和采用Ho和Mouftah（2002年）提出的容量均衡替代路由方法得到的路由路径作为预定路径的性能。我们的仿真结果表明，与使用基于跳数的最短链路不相交路径和使用由容量均衡替代路由方法找到的路由路径相比，使用由所提出的方法找到的链路不相交路径产生的连接阻塞概率要低得多（Ho和Mouftah， 2002）。
An alternate routing algorithm requires a set of predetermined routing paths between each source-destination pair. To reduce the connection blocking probability, it is desirable that the predetermined routing paths between each source-destination pair be link-disjoint. The predetermined routing paths used in previous works on alternate routing are the -shortest link-disjoint paths in terms of hop count. The shared links among the -shortest link-disjoint paths between different source-destination pairs may cause high connection blocking probability. Thus, depending on the traffic requirements of all source-destination pairs, hop-count based -shortest link-disjoint paths may not be the best choice for the predetermined routing paths. This paper proposes a method to find a set of link-disjoint routing paths between each source-destination pair to be used by an alternate routing algorithm in order to reduce the connection blocking probability. The key idea is to find a set of link-disjoint routing paths based on the routing paths that are utilized by the optimal traffic pattern in the network. Then, for each source-destination pair, we select a set of link-disjoint routing paths from the routing paths that are utilized by the optimal traffic pattern such that the selected set of link-disjoint routing paths carries the most of the traffic between the source-destination pair. Simulations are performed to compare the performance of using the link-disjoint routing paths found by the proposed method as the predetermined routing paths and those of using the hop-count based -shortest link-disjoint paths and employing the routing paths found by the capacity-balanced alternate routing method proposed method by Ho and Mouftah (in 2002) as the predetermined routing paths. Our simulation results show that using the link-disjoint routing paths found by the proposed method yields significantly lower connection blocking probability than employing the hop-count based -shortest link-disjoint paths and using the routing paths found by the capacity-balanced alternate routing method (Ho and Mouftah, 2002).