Hierarchical Optical Path Network Design Algorithm Considering Waveband Protection

This paper proposes a hierarchical optical path network design algorithm employing dedicated protection in the waveband layer. The proposed algorithm reduces network costs by joint optimization of grooming wavelength paths and placing waveband paths as well as ensures network survivability. It realizes node and link disjoint protection based on the observation that a pair of primary and backup waveband paths forms a loop. The algorithm attains high waveband utilization rates by employing the newly developed concept of a concatenated loop chain, which consists of a series of waveband paths. Analyses demonstrate that the proposed algorithm is superior to not only the simple End-to-End method but also the single layer optical path networks that employ wavelength path protection. The results also show that reliable hierarchical optical path networks offering waveband protection can be realized with marginal cost increase from unprotected single layer optical path networks.