Design And Simulated Implementation Of Traffic Grooming Protection Algorithms In Multi-domain Optical Networks

In Wavelength Division Multiplexing (WDM) optical networks, each wavelength can be operated at very high tranmission rate. However, in operational networks, the required tranmission rate of each connection is much lower than that of each wavelength. Accommodating such kind of low-rate connections with one lightpath will lead to inefficient resource utilization and high blocking probability. In order to save this problem, the academia proposed traffic grooming technology that allowed several low-rate connections to be grouped into a wavelength lightpath. At the same time, since a lightpath may carry lots of data streams, any failure can lead to significant loss. So, the survivability problem should be considered in optical networks. Furthermore, with the growing size of the network, the actual backbone optical network is divided into multiple domains, so that the previous single-domain traffic grooming and protection algorithm may be not well suited for multi-domain network environment. Therefore, the study and resolution of multi-domain optical networks traffic grooming and survivability is necessary, which is the main content of this thesis.Based on two kinds of traffic-grooming-capable Optical Cross-Connect (OXC), this thesis designs two intra-domain auxiliary graphs for intra-domain traffic grooming; namely, Intra-domain Single-hop Auxiliary Graph and Intra-domain Integrated Auxiliary Graph. Combined with the characteristics of multi-domain optical networks, this thesis designs an auxiliary graph for inter-domain traffic grooming, which is made up of a multi-domain virtual topology and a multi-domain logical topology, and it is a good solution of inter-domain grooming and routing problem. Based on these auxiliary graphs, two algorithms named Multi-Domain Hierarchical Single-hop Grooming Algorithm (MD-HSGA) and Multi-Domain Hierarchical Integrated Grooming Algorithm (MD-HIGA) are designed to improve the resource utilization efficency and reduce the blocking probability. To achieve survivability, two protection algorithms named Multi-Domain Hierarchical Single-hop Grooming protection Algorithm (MD-HSGPA) and Multi-Domain Hierarchical Integrated Grooming protection Algorithm (MD-HIGPA) are designed based on the two proposed traffic grooming algorithms. The main idea of protection is assigning a dedicated and link-disjoint protection path for the working path to provide the effecticve protection for each intra-domain or inter-domain connection request.In order to assess the performances, this thesis develops the simulation and analysis by VC++software. Simulation results show that the designed algorithms have better performance in reducing the blocking probability and economizing resources.