The Research Of Dynamic Wavelength Assignment Algorithm In WDM Optical Networks

Due to its enormous bandwidth, high-speed, flexible performance and other superiority, WDM optical network is considered the future of backbone network. Wavelength resource is the major factor on impacting WDM optical network's performance, and wavelength assignment algorithm is an important approach to allocate resource reasonably and improve the network efficiency, therefore it is crucial to study the wavelength assignment algorithm. In this thesis, wavelength assignment algorithm is analyzed in two mathematical models: single-fiber (SF) model and multi-fiber (MF) model. SF model's objective is to balance number of wavelengths. MF model's objective is to balance path capacity of every wavelength. In the research, model building and software simulation is used to compare the performance of different algorithms. This thesis is divided into 4 parts:1. The SF and MF wavelength assignment are analyzed, including the mathematical model and theoretical algorithm. The author summarizes the wavelength assignment algorithms which can be often seen in the literatures, and interprets their ideas and performance. Besides, the author also introduces two traffic load model and explains how to generate them.2. Two improved heuristic wavelength assignment algorithm based on single-fiber model are proposed. The first one is based on pre-selecting wavelength idea, it restricts route problem by resource and improves wavelength utilizations rate. The other one use the idea named wavelength-set, it allocates different strategy for the different QoS traffic so that fairness can be improved.3. Two improved heuristic wavelength assignment algorithm based on multi-fiber model are proposed. The first one pays attention on the balancing strategy. The other one sets two optimized objectives in the algorithm, that are controlling priority and balancing traffic.4. Software WRON-RWA is developed to evaluate the improved algorithm. The author's main contributions are the wavelength assignment part, Topology Design components and Blocking Probability components.