Performance Evaluation of Light-Tree Schemes in Flexgrid Optical Networks

New applications require conveying huge bitrate from a source node to multiple destinations. As a result, point-to-multipoint (P2MP) connections need to be established on the optical layer. In this paper, the P2MP routing and spectrum allocation (RSA) problem is formally stated and modelled as an Integer Linear Program (ILP). Exhaustive numerical results show that creating several transparent sub-trees noticeably improves the performance obtained by serving the demand using one single tree. Moreover, cost savings from exploiting traffic asymmetry can be obtained by installing directed optical transponders consisting of one single module.