| 題目：Routing Issues in All-Optical WDM Networks 主講人：王聲葦 副教授(佛光大學資工系) 時間：103年5月14日(星期三13:30-15:30) 地點：三峽校區商學院商1F01教室 Abstract In all-optical WDM networks, routing algorithms play an important role in the performance of the networks. In this talk, some research topics related to routing algorithms in all-optical WDM networks are discussed.Among the three categories of routing algorithms for all-optical WDM networks, alternate routing algorithms are computationally efficient and able to yield low connection blocking probability. In the first part, we propose a new approach to designing alternate routing algorithms for all-optical WDM networks in order to reduce the connection blocking probability. The key idea is to try to route traffic in approximately the optimal way of splitting the traffic among the multiple routing paths between each source-destination pair. Two alternate routing algorithms are proposed based on this approach. Our simulation results show that the alternate routing algorithms designed according to the optimal way of splitting the traffic can effectively reduce the connection blocking probability.In the second part, we consider the routing paths for alternate routing algorithms. Depending on the traffic requirements of all source-destination pairs, hop-count based k-shortest link-disjoint paths used in previous works may not be the best choice for the predetermined routing paths. We propose 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. Our simulation results show that using the link-disjoint routing paths found by the proposed method yields significantly lower connection blocking probability than some other previous researches. In the third part, the placement of wavelength converters is discussed. Since the optimal traffic pattern can be easily calculated, the optimal traffic pattern which minimizes the blocked traffic intensity is utilized for finding the locations of wavelength converters. The key idea is to place the wavelength converters at the nodes where they are needed most. Simulations have been performed to study the performance of the proposed wavelength converter placement method. The simulation results have shown that the proposed placement method combined with the proposed probability based dynamic-alternate routing algorithm yields smaller connection blocking probability than the two converter placement methods with their corresponding alternate routing algorithms. |
