Author: | Chan, Kam-wing |
Title: | Performance optimization of WDM lightwave networks |
Degree: | M.Sc. |
Year: | 1999 |
Subject: | Optical communications Laser communication systems Hong Kong Polytechnic University -- Dissertations |
Department: | Multi-disciplinary Studies Department of Computing |
Pages: | iii, 82 leaves : ill. ; 30 cm |
Language: | English |
Abstract: | In this dissertation, we consider percentages of improvement of WDM multihop lightwave network for non-uniform traffic. Our goal is to maximize the throughput of a store-and-forward network with infinite buffer in the nodes. The objective is the same as minimizing the largest link flow of the network. To achieve the goal, our work includes two parts. In the first part, we consider optimal node assignment problem (ONAP) for regular topologies. By optimal assigning the network nodes to network locations, we expect to obtain the minimum value of the largest link flow of the network. We solve the problem by formulating it as a quadratic assignment problem (QAP). By applying simulated annealing algorithm, we obtain a significant reduction in the largest link flow of the network. We study the percentage of improvement of four different regular topologies for four non-uniform traffic patterns. The results show that percentage of improvement is largely dependent on the number of routing paths between nodes and also the matching between topological structure and traffic pattern. In the second part, we study the link assignment problem (OLAP) for arbitrary topology. Through the optimal node assignment problem in the first part, we have conjectured that network throughput can be increased if there is a matching between traffic pattern and topology. We study the conjecture by formulating an optimal link assignment problem (OLAP) which studies the percentage of improvement of the largest link flow of the network between a randomly chosen topology and an optimal topology. By optimal assigning the logical links between nodes, an optimal topology with a minimal largest link flow is found. We solve the problem by formulating it as a Quadratic Assignment Problem. By applying simulated annealing algorithm, we show that the problem is NP-Hard. The largest link flow of the network decreases as the network size increases. Results also show that the optimal link assignment approach can have a large reduction to the largest link flow for four non-uniform store-and-forward traffic patterns. |
Rights: | All rights reserved |
Access: | restricted access |
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b14792849.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 2.55 MB | Adobe PDF | View/Open |
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