Optical network design and restoration

The explosion of data traffic and the availability of enormous bandwidth vi a dense wavelength division multiplexing (DWDM) and optical amplifier (OA) technologies make it important to study optical layer networking and restor ation. This paper is concerned with fast distributed restoration and provis ioning for generic mesh-based optical networks. We consider two problems of practical importance: determining the best restoration route for each wave length demand, given the network topology and the capacities and primary ro utes of all demands, and determining primary and restoration routes for eac h wavelength demand to minimize network capacity and cost The approach we p ropose for both problems is based on precomputing. For each problem, we des cribe specific algorithms used for computing routes. We also describe endpo int-based failure defection, message flows, and cross;connect actions for e xecution of fast restorations. Finally we report test results for large car rier-scale networks that include both the computational performance of the optimization algorithms and the restoration speed obtained by simulation. O ur results indicate that subsecond restoration, high capacity efficiency, a nd scalability can be achieved without fault isolation and with moderate pr ocessing. We also discuss methods for scaling algorithms to problems with v ery large numbers of demands. The wavelength routing and restoration algori thms the failure detection, and the message exchange and activation archite ctures we propose are collectively known as WaveStar(TM) advanced routing p latform.