Fair Routing in WDM All-Optical Networks

• Main Authors: Cheng-Huang Lien, 連政煌
• Other Authors: Jung-Tsung Tsai
• Format: Others
• Language: en_US
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/00054874937526812315

碩士 === 國立臺灣師範大學 === 資訊教育研究所 === 88 === The vast bandwidth in fibers can be efficiently tapped by advanced WDM technology, by which several different wavelengths are simultaneously transmitted in an optical fiber and each carries traffic at several Gbps. The use of wavelength router in WDM networks provides topological dynamics to support high aggregate capacity by wavelength reuse at disjoint paths. Without wavelength conversion, a connection is set up by allocating the same wavelength of every link along the path. Consequently, longer connections require to win more times contending to use the same wavelength on each link, which results in a higher blocking probability for distant connection requests. This thesis aims to solve the fairness issue, which arises from the imbalance of blocking probabilities with regard to connection-path length. We propose a strategy, which continues to allocate one more light-path for a source-destination(S-D) pair found to have a higher blocking probability than others. This strategy incorporates an analysis model which is proposed to compute the blocking probabilities for S-D pairs and to identify the S-D pairs with maximum blocking probability in the network. The proposed strategy for fairness and the analysis model are verified through simulations. Results show that the analysis model is accurate if offered load is high, and underestimated if offered load is low; and that the strategy, compared with others, achieves better fairness even for different network parameters and topologies.