Research On Dynamic Routing And Wavelength Assignment Algorithms In Ason

ASON (Automatically Switched Optical Network) stands for the developing direction of the transport network in NGN. The technology of control plane is crucial for ASON to make itself implemented.The control plane technology is the core technology of the ASON's realization. So it is significant to do deep research on this area. RWA (Routing and Wavelength Assignment) is another key problem to solve in control plane.In ASON, there is a high demand to be put forward for the flexibility of resource scheduling of network. At the same time, the low blocking probability of real-time business should be guaranteed.Because of the application of series new technologies, such as wavelength conversion, optical exchange, optical storage, etc. The calculation environment of ASON is more complicated than the traditional optical transport network. So a series of RWA strategies which are designed for traditional optical transport network can not work well in ASON. It has exposed a series of questions, such as considering reasonable resource assignment in part-purpose, optimizing goal singly, lacking sufficient flexibility of algorithms, etc.This thesis first introduced the research background of subject and the domestic and international development actuality related to ASON technology.It also studied the architecture in ASON and the composition of the Control Plane as well as the signaling technology. Then the problem of routing and wavelength assignment in ASON was analyzed in detail. Especially, the paper did further research on dynamic routing and wavelength assignment and analyzed RWA problem in WDM optical network in detail.Based on this, it summarized the main factors influencing the dynamic routing and wavelength assignment in ASON, and researched the current routing and wavelength assignment algorithms that have been used.Base on the genetic theory, the routing and wavelength assignment algorithm was improved by combining the genetic algorithm and Least Influence algorithm and a new genetic algorithm (N-RWA) was put forward. In designing the fitness function, it considered the hops of routing, the influence of the free wavelengths in the shared links and the wavelength conversion.Finally, the paper simulated N-RWA algorithm and the traditional RWA algorithm respectively by applying GMPLS Lightwave Switching Simulator (GLASS) simulation software. The simulation results indicate the N-RWA algorithm can reduce the blocking probability compared with the conventional dynamic RWA algorithms.