Research On Optical Network RWA Problem Based On Ant Colony Algorithm

The ASON network is endowed with the unexpected flexibility and scalability, which stands for the intelligent which has became the development direction of next-generation optical networks. In recent years, as the control extension of wavelength network from ASON network, WSON inherits the features, such as high bandwidth utilization, network reliability and low operating costs, and now plans to resolve the wavelength of intelligent scheduling problems. However, due to the new requirements of wavelength intelligent scheduling in WSON, the flexibility of wavelength resource scheduling in the network is required, the low blocking probability satisfied to in time service request is guaranteed. Therefore, study and solve the RWA with wavelength of intelligent scheduling algorithm is very necessary. The major work is divided into the following sections, where (3) and (4) is the focus of the content of this article.(1) With the research on wavelength-routed optical network routing and wavelength assignment (RWA) problem, the paper introduces common methods and link weight definition about routing sub-problem and wavelength assignment sub-problems, sums up three types of RWA optimization solution, finally analyzes the current RWA algorithm design problems and explains the importance of resolving such problems.(2) Compile the algorithm simulation software, mainly to simulate RWA algorithm in a certain case of network environment, and then simulate and compare the performance of RWA algorithms. The software can not only simulate operating performance of RWA algorithm in this paper, but also can simulate the other RWA algorithms, thus have a certain value for the simulation of various operating performance of RWA algorithms.(3) According to the intelligent scheduling requirements of wavelength switched optical network (WSON) wavelength and the inspiration from wavelength layered graph model, construct a new type of wavelength rotation diagram model through distributing network virtual topology link and associated wavelength on the surface of rotation sphere, and propose a solution for RWA problem possessing wavelength conversion capability based on the wavelength rotation graph model. The simulation results show that if the wavelength number of each link is set separately to 4 and 8, the average blocking probability of the WRG-RWA algorithm reduces by 5.03% and 9.71%, and the average resource utilization increases by 3.3% and 1.54% respectively, as compared with the existing model. This method would be useful for solving the problem of optical network RWA which has wavelength conversion capabilities.(4) On the base of wavelength rotation graph model, design ACA-RWA algorithm with the principle of ant colony algorithm, and descript detailed the key steps and processes of ACA-RWA algorithm. The simulation results show that if the wavelength number of each link is set separately to 4 and 8, compared with ACA-RWA algorithm, the average blocking probability reduced by 13.99% and 42.83%, and the average resource utilization increased by 10.48% and 25.45% respectively. Therefore, ACA-RWA algorithm can effectively solve the limitations of the RWA with wavelength conversion problems. Compared with WLG-RWA algorithm and WRG-RWA algorithm, ACA-RWA algorithm is more suited to solve the limitations of the RWA with wavelength conversion problems. The simulation data also show that the algorithm not only decreases the service connection request blocking rate, but also can be rational and effective use of wavelength resources.