Optimal Design On Optical Transport Network Space Resources Based On Genetic Algorithm

As the fast development of internet and the increase of operation categories and quantity, we expect better and better internet transmission quality. Thus the network survivability technology which can guarantee the transmission quality drives more and more attention. In order to improve the current quality of the network and to construct the future network in a more scientific way, it is necessary to present more investment. Therefore, for the communication operators, how to get a good tradeoff between the improvement of the communication network and the cost is undoubted a problem worth consideration. The main job of this thesis is to study how to achieve optimal collection of the space capacity.The optimal collection of the protection capacity is always a focus, and on which researchers have proposed several methods based on different optimal standard. B. Van Caenegem and his coworkers proposed the lowest cost model of the whole WDM network including the distribution of the optical nodes, the optical cables arrangement and the distribution of the wavelength channel ect.; and based on the model, they performed the calculation using linear programming and simulating anneal algorithm. While S.Ramamurthy and B. Mukherjee proposed the optimal model according to the source of the wavelength channel required by the working optical path and the protection optical path; also they performed some simulation about the special path protection, the shared path protection and the shared chain route protection on the CPLEX platform using linear programming. Besides, other method emphasized particularly on converting the irregular network topology to regular topology or linear topology, so that the mature and easy-performed APS and loop network protection techniques can be adopted to capacity optimization. All of the above methods can obtain feasible optimal results, but their intrinsic disadvantages limit their application range. The first method requires a lot of initial parameter, some of which can only be obtained fromcomplex calculation rather than the current network topology. The second method can only applied to small-scale network, and it only considers the chain route constructed by single optical cable, i.e. for any wavelengthλ(λ= 1,2, ,λmax), the channel can only be unique. The topology converting method requires complicate algorithm designing and solving, so it is not easy to perform. This thesis proposed a new calculation method for the protection capacity requirement optimization problem based on genetic algorithm, which can find out the optimal solution in a fast and efficient way.First of all, we generally introduce the existed survivability and anti-damage technologies, present the recover scheme, category the recover methods, and give a simple analysis on prestored sources and dynamic routing. Secondly, we construct the optimal models for annular and reticulate optical transmission network, taking the cost of the protection capacity requirement as the optimized object function. Especially in the reticulate network, some options which have greater influence on the protection capacity requirement get optimally considered, for example remains release and the use of protection capacity. Also, we introduce the principle of generic algorithm and the function of it in solving combined optimization problem. We study how to use generic algorithm to solve reticulate network protection capacity optimization problem, and the main content including: the mathematic model of the optimal problem, the gene coding configuration of chromosome, inheritance operation regulations (selection operator, amphimixis operator and aberrance oprator) and the algorithm's breaking condition. The simulation results imply that the generic algorithm can obtain the approximate solution of the optimization problem in a shorter time.