Automatic Switched Optical Network (ason) Routing And Wavelength Assignment Algorithm (rwa) Problem And Simulation

ASON (Automatically Switched Optical Network) represents the developing direction of the transport network in NGN. The technology of control plane is crucial for ASON to make itself implemented, Thus the deep research on this area is of significant importance. RWA (Routing and Wavelength Assignment) is another key problem to solve in control plane.This dissertation first introduces the basic concepts and hierarchies about ASON in brief, and illuminates the key technologies related to RWA. Then, it analyzes the RWA problem in WDM optical network in detail. Because of the lack of open uniform simulation platform for RWA algorithm, the dissertation implements a new simulation platform for RWA algorithm in WDM wavelength-routing optical network based on NS2 (Network Simulation version 2) and OWns (Optical WDM Network Simulation). It expends the original RWA algorithm by adding a new wavelength assignment algorithm. The performance simulation is done by using the common routing selection algorithm and wavelength assignment algorithm, and the simulation results are in accord with the theoretical analysis, thus proving that the simulation platform is quite available. At the same time, the methods to add other new RWA algorithms into this simulation platform are discussed. Lastly, in order to settle the problem that many RWAs in WDM network have to be revised to be adapted to the ASON due to introducing the new control plane technology to ASON, the dissertation analyzes this problem deeply. The dissertation focuses on the research of the route selection algorithm, revises the FAR algorithm and presents a new FAR algorithm, namely the disjoint part-link alternated path algorithm (DPLP). The new algorithm adds more alternated routes to FAR and enhances the availability of alternated paths; it improves the utilization of network resources and can be combined with the algorithms for network's survivability. The new algorithm's selecting-route performance is superior to FAR in the mesh network with more connectivity, and it is also helpful to jointly settle the RWA problem and network survivability problem.