Applying Prediction Concepts to Routing on Semi-Transparent Optical Transport Networks

This contribution deals with the RWA (routing and wavelength assignment) in semi-transparent optical networks. In semi-transparent networks, a parameter called maximum transmission distance (MTD) is used to indicate the distance reachable in wavelength continuity. When for a given lightpath, the signal cannot be detected at the destination node a regenerator has to be installed in an intermediate node. The regenerator breaks up the optical continuity and the optical network becomes a semi-transparent optical network. The new RWA mechanism proposed in this paper will take into account the physical impairment such as the Maximum Transmission Distance (MTD). Moreover this new RWA algorithm will be based on the Prediction-Based Routing (PBR) mechanism and will take into account the routing inaccuracy problem. The goal of the proposed algorithm will be both, to reduce the number of blocked connections due to the routing inaccuracy problem and to select routes that fulfil the MTD physical impairment.