Multi-layer Multi-domain Grooming Wdm Optical Network Algorithm Design

As the scale of the internet becomes larger and larger, and the explosive increase of network service types and traffic stream requires more and more bandwidth resources. The WDM optical network system that based on high-speed OXCs and OADMs can supply large amount of bandwidth, and it has been the key solution of the next generation backbone network. In the WDM optical network, there is a big gap between the granularity of lightpaths(e.g., up to OC-192or OC-768) and typical LSP requests(e.g., OC-1, OC-3, or OC-12), and the network deploy one lightpath to carry every traffic stream in this situation, but this will cause the main part of bandwidth unused and bring a serious waste of bandwidth of lightpath. The traffic grooming technology tries to integrated multiple sub-wavelength traffic streams onto a high-speed lightpath to realize the sharing of bandwidth resource of a lightpath and the efficiently utilization of network resource. To date, there has been a lot of research on the algorithms and models of traffic grooming, while, as the evolution of network’s architecture, the appearance of new service and the new problem comes along with the development of network, more research is needed in the traffic grooming of WDM networks.In this work, the research is concentrate on the strategy of path selection of grooming route, the path computation of traffic grooming and the hierarchical traffic grooming model in multi-layer and multi-domain networks. During the process of research, it draws on the traditional theory and methods, and gives out some analyzation and summarization, and finally determines the direction and intention of the research.Firstly, the background, definition intention and significance of the research are introduced, and it summarize the existed research of traffic grooming, and finally finds out the problems and research that involves in this work.Secondly, it states the network model and the types of traffic grooming, furthermore, it analyze the network equipment and control plane that needed in traffic grooming and the feasibility of traffic grooming in WDM optical networks, which is configured with existing optical networks.Based on the introduced background and the environment of the modern optical networks, the author knows the grooming route computation that is based on two-level network model plays a key role in the solution of traffic grooming. It introduced two traditional grooming route selection strategy:IP/MPLS layer route first and optical layer route first. But these two strategies take the two-level network model as two independent resource levels, and cannot integrated them as a whole. Thus, this will impose a bad influence on the performance of grooming route and cannot compute an optimal path. Herein, it proposes a new solution named Hybrid Plane model that takes these two layers as a whole for route. The result of the simulation shows that the proposed scheme is better than traditional schemes. Furthermore, it analyzes the congestion-inflation problem that existed in grooming route, and proposes an adaptive path selection algorithm that can control congestion-inflation. The results shows that APS perform better than the network without APS algorithm.In the second part of this work, it studies dynamic traffic grooming problem in multi-layer multi-domain optical network, mainly the inter-domain grooming route computation. It analyzed the difference between the route computation in single-domain and that in multi-domain networks, and facing challenges. Although the appearance of PCE supplies a good solution for path computation in multi-layer multi-domain optical network, the domain-sequence that is needed for inter-domain path computation in PCE based optical networks is still need some more study. Hierarchical-PCE can fulfill inter-domain path computation perfectly without breaking the limitation of scalability and confidentiality. Then we apply hierarchical traffic grooming scheme to the hierarchical-PCE based optical multi-domain network. The simulation results shows that the domain sequence that is determined by hierarchical-PCE architecture performance better in the items of blocking probability and utilization ratio of network resource.The main contribution of this work consists of two parts. Firstly, it studies the path selection problem with two sub problem by trying to integrated two-level network resource together for grooming route and trying to control the congestion inflation that existed in grooming path computation. Secondly, it studies the traffic grooming in multi-domain network by combining the hierarchical-PCE architecture and hierarchical traffic grooming scheme together, and manage to fully use the virtue of these two solutions. At last, it prove the advantage of proposed scheme by computer simulation.This work was supported by the National Natural Science Foundation of China (61071101), the National High-Tech Research&Development Program of China (863Program,2009AA01Z254)...