Shared protected grouped optical path routing network design employing iterative path group relocation

The wide deployment of ROADM based photonic networks, particularly in metro areas, compels an increase in the number of WSSs traversed by the average optical path. The impairment caused by optical filtering of WSSs, called spectrum narrowing effect, can be a serious problem in transparent optical networks. To resolve this impairment and to enable higher fiber frequency utilization while achieving resiliency against a failure, we propose a coarse granular routing optical network architecture which adopts shared protection and its design algorithm that considers the impairment and applies an iterative relocation of bundles of paths. Proposed shared protection scheme successfully resolves the impairment caused by spectrum narrowing, and as a result, much dense optical path accommodation within fibers become possible. Numerical experiments shows that the spectral utilization efficiency can be substantially improved and hence needed number of fibers can be reduced over conventional path granular routing networks with path level shared protection.