Design And Simulated Implementation Of Multi-Domain Robust Routing Mechanism In WDM Optical Networks

Recently, Wavelength Division Multiplexing (WDM) technology has become one of the core technologies of next generation backbone networks since it can provide large bandwidth to meet the demand of explosive increase of network traffic. At present, although routing mechanisms and algorithms have been widely investigated in WDM optical networks, most of them are based on the condition that the traffic requirements are determined explicitly. However, it is very difficult to predict traffic pattern between each source and destination node-pair accurately in practice. Therefore, robust design in optical network is proposed to not only meet the requirements of variable traffic but also be able to optimize the network resource allocation. At the same time, with the continuous expanding of network scale, the backbone optical network presents the structure of multi-domain. However, the existing robust design is only considered in single-domain optical networks. So it is necessary to study the robust routing mechanism in multi-domain optical networks.For this reason, hose model is used to describe the traffic uncertain in this thesis. In this model, the exact network traffic matrix is not needed, while only the upper bound on the total amount of traffic entering the network and the upper bound on the total amount of traffic leaving the network at every node need to be specified. Since Valiant load-balancing method and robust routing based on tree are two efficient robust algorithms for backbone design, this thesis introduces the two ideas into the robust design in multi-domain optical networks and proposes two routing mechanisms, two step routing mechanism and tree routing mechanism. The former uses heuristic method, and the latter applies intelligent optimization algorithm. In the two mechanisms, the hose model is divided into multiple sub hose models according to the existing domains, and then the optimization problem of the whole network can be transformed to the sub-optimization problems. Based on this, some new routing mechanisms are designed for sub hose models in network domains. In addition, network survivability is also considered in this thesis and a routing protection mechanism based on tree is proposed that not only applies protection strategy to provide robust protection, but also is combined with the idea of intelligent optimization. Thus, with the objective of minimizing the total network resources, this routing protection mechanism can save more backup resources.To validate the viability and effectiveness of the proposed multi-domain robust routing mechanisms, simulation and performance analysis are implemented based on the platform of VC++. The results show that the designed mechanism can efficiently solve the routing under uncertain traffic matrix in WDM multi-domain networks and the algorithms also have good performances.