Survivable waveband grooming in multi-domain optical networks

Since the size of traffic demands ranges from sub-wavelength-level to wavelength-level, traffic demands need to be aggregated and carried over the network in a cost effective manner to make sure that the resources can be utilized effectively. Therefore, the technique called waveband grooming is proposed to save the cost and to reduce the number of switching ports in Optical-Cross Connects (OXCs). However, the existing waveband grooming algorithms are mostly limited to single-domain optical networks and also do not consider the survivability. The current optical backbones keeps enlarging, and the backbones are actually divided into multiple independent domains to provide the needed scalability and the confidentiality. It is necessary to study the survivable waveband grooming in multi-domain optical networks. In this paper, we propose two new heuristic algorithms called Intra-domain Sub-path Survivable Grooming (ISSG) algorithm and Inter-domain End-to-end Survivable Grooming (IESG) algorithm, respectively. In ISSG, we allocate an end-to-end inter-domain working path for each demand and then calculate a link-disjoint backup sub-path for each intra-domain working sub-path. In IESG, we allocate two link-disjoint end-to-end inter-domain paths for each demand, one is working path and the other one is backup path. Simulation results show that ISSG and IESG have similar trend with different parameters. In addition, IESG has lower blocking probability while ISSG has lower average port-cost.