On regenerator site selection in translucent optical network design

In a dynamically reconfigurable wide-area translucent network, the pre-deployment of regenerators at few sites has its advantages due to the increased system optimization and incurred savings in capital/operational expenditure (CAPEX/OPEX). A node’s regeneration capability may be influenced by external factors like energy consumption, workforce, space availability, etc., which are harder to model but equally important for practical scenarios. The traffic-based regenerator placement algorithms proposed in the literature depend on the unrealistic assumption of the demands’ exact knowledge. In contrast, the topology-based approaches fall short in presenting high network performance. The translucent lightpaths are unique since it allows coexistence of non-simple routes substantially increasing alternate route availability. Moreover, heterogeneous optical connections with different spectrum lengths, data rates, and modulation formats affect the optical reachability. All these variabilities add to the complexity in network design and operations, adversely restricting existing solutions’ usability. This study revisits the regenerator site-selection/placement problem to address these primary concerns and strives to provide a unified solution. We believe that the solutions proposed would help decision-makers realize a practical solution to the problem. We, for the first time, consider node-specific constraints and hose traffic model in the placement problem. Regeneration demands are estimated with the use of an analytical topology-based method. Mathematical formulations are proposed for modeling the problem; exact and heuristic algorithms are proposed for solving the problem.