Research On Multi-objective Ant Colony Algorithm For Static Traffic Resource Optimization In Elastic Optical Networks

The increase in communication traffic and the diversity of communication services result in that the networks must provide users with a more flexible bandwidth allocation and that the traditional wavelength division multiplexing(WDM) networks with fixed-size wavelength bandwidth allocation become increasingly difficult to meet the demands of variable bandwidth traffics. Therefore, the Elastic Optical Networks(EONs) with better flexibility and higher efficiency in bandwidth allocation has been proposed in recent years. The Routing and Spectrum Assignment(RSA) algorithm can extremely affects the Quality of Service(Qo S) in the EONs, which makes RSA algorithm an important research issue in EONs. Sponsored by the sub-project, the research and industrialization of the key technologies of Terabit Packet Transport Network, from the Ministry of Industry and Information Technology, this dissertation studies the multi-objective RSA problem for static traffic in EONs, and tries to optimize two goals of the power cost and blocking probability simultaneously.This dissertation gives a brief review of the development status of optical networks and Elastic Optical Networks, and summarizes the research status of EONs. It introduces the structure and the key components of Elastic Optical Networks and reviews the main technologies of Elastic Optical Networks, and a brief introduction to the Orthogonal Frequency Division Multiplexing(OFDM) modulation technology is given. This dissertation analyzes the RSA problem in Elastic Optical Networks and discusses the main RSA methods and the RSA research status. It also addresses the key theory basis of Multi-Objective Problem(MOP) and Ant Colony Optimization algorithm.The main contributions in this dissertation include two following parts:To solve the multi-objective RSA problem for static traffic in Elastic Optical Networks, a mathematical model which includes objective functions and constrained conditions is built. Learned from the classical multi-objective algorithm NSGAII, a RSA algorithm named Ant Colony Multi-Objective Optimization Algorithm(ACMOOA) is proposed to solve this problem. Taking advantage of a special encoding, we turn the routing problem into a combination optimization problem, then uses Ant Colony Optimization(ACO) algorithm to solve this combination optimization problem. The ACMOOA usesfast-non-dominated-sort and updates the pheromone according to the dominated rank while spectrum assignment uses First-Fit policy.The performance evaluation program of the proposed algorithm in this dissertation is implemented via C programming language. Then the program is simulated in NSF network topology. A comparison of the simulation results to those from other existing algorithms is given to verify the feasibility and the effectiveness of the proposed ACMOOA. It also analyzes the effect of some key parameters in the proposed algorithm on the simulation results.The result shows that the proposed algorithm in this dissertation has a good performance, and can be used to solve the RSA problem for various kinds of static traffic in EONs.