Fast and flexible optical path accommodation design based on Pre-planning and Reconfiguration in transparent optical mesh networks

This paper proposes the Pre-planning and Reconfiguration of Wavelength (PRW) scheme which achieves a fast and flexible optical path accommodation design that deals with sequential traffic demand and addresses the Routing and Wavelength Assignment (RWA) problem. The proposed scheme comprises four key steps. First, in the pre-planning stage, Integer Linear Programming (ILP) is used to design routes and wavelengths according to the prediction for all traffic demand before requesting to establish an optical path. Second, the designed routes and wavelengths for each source and destination node pair are defined as the Wavelength-grouped Transmission Guaranteed Link (λTGLs), and the resources necessary to establish an optical path in all the λTGLs are secured in the network operation stage. Third, in the network operation stage, the optical path is accommodated using the above secured route and wavelength. Fourth, when the traffic demand prediction is different from the actual traffic demand, routes and wavelengths are reconfigured according to the updated traffic demand prediction. This is done without interrupting the existing optical paths while minimizing any increase in the number of fibers when the λTGLs are modified. The PRW scheme achieves fast provisioning and flexibility in dealing with changes in the traffic demand prediction. This paper assesses the cost-effectiveness of the PRW scheme compared to the conventional post-planning scheme, which dynamically assigns a route and wavelength set to each optical path setup request.