Dynamic routing and wavelength assignment algorithms in wavelength division multiplexed translucent optical networks

In dynamic wavelength division multiplexed (WDM) translucent optical networks, lightpaths are setup and torn down dynamically, and some of the transceivers in optical nodes could be free. These spare transceivers can also be used for regeneration or wavelength conversion. In order to setup lightpaths in the translucent network, first an adaptive routing algorithm has been proposed, in which K edge-disjoint paths are selected first and then one of these K paths is chosen by considering not only the number of free wavelengths in the fibers and the length of the path, but also the number of free transceivers in the nodes along the path. After a path has been selected for a connection request, an auxiliary graph is generated for this path to assign wavelengths and determine the nodes for regeneration or wavelength conversion. The auxiliary graph for this path is generated by considering the transparent length limitation. If a least-weighted route can be found in the auxiliary graph, it means that the connection request could be successfully set up along this path. Through extensive simulation in typical networks, it is proved that the proposed routing and wavelength assignment algorithm can achieve better blocking performance than other algorithms.