Dynamic Establishment of All-Optical Connections in Wavelength-Routed Optical Networks Using Genetic Algorithms

In this paper we propose the use of genetic algorithms (GA) for solving the problem of dynamic establishment of all-optical connections in wavelengthrouted optical networks. All-optical connections can be required to be either fault tolerant or not. We first consider the case where no failure restoration capability is demanded to the optical layer. In this case, an all-optical connection consists of a single lightpath between a source node and a destination node. A genetic algorithm called GRWA is developed to perform routing and wavelength assignment (RWA) of lightpaths. By means of extensive simulation experiments we evaluate its blocking performance and compare it to that of existing algorithms. Results show that GRWA is able to achieve good blocking performance while employing very short computation times. We then consider the case where the optical layer is expected to provide failure restoration capability. This can be achieved by means of protection, wherein each all-optical connection is provided with a pair of lightpaths, a primary lightpath and a backup lightpath, instead of one. Another GA, called FT-GRWA, is derived from GRWA to perform routing and wavelength assignment of primary-backup lightpath pairs, improving the results obtained with existing methods.