Minimizing Installation Costs of Survivable DWDM-Mesh Networks: A Heuristic Approach

The cost function for the capacity of optical links follows a step function. That means, the support of one more lightpath might require a costly upgrade of an optical cross connect (OXC), but then additional lightpaths can be supported at almost no further cost. This should be considered when lightpaths are routed through an optical network. In this paper we optimize the routing of the lightpaths to minimize the costs for the required optical equipment. We consider this problem for the failure-free case only and for survivable networks using dedicated path protection. We formulate the problems by integer linear programs (ILPs). In addition, we propose heuristics to solve the problem since solving ILPs is computationally expensive and not feasible for large problem instances. We show that our heuristics lead to good results within a fraction of time compared to ILP solvers.