Telecommunication Node Clustering with Node Compatibility and Network Survivability Requirements

We consider the node clustering problem that arises in designing a survivable two-level telecommunication network. The problem simultaneously determines an optimal partitioning of the whole network into clusters (local networks) and hub locations in each cluster. Intercluster traffic minimization is chosen as the clustering criterion to improve the service quality. Various constraints on the clustering are considered which reflect both the physical structures of local networks, such as the connectivity requirement, and the node compatibility relations such as community of interest or policy. Additional constraints may be imposed on the hub selection to ensure network survivability. We propose an integer programming formulation of the problem by decomposing the entire problem into a master problem and a number of column generation problems. The master problem is solved by column generation and the column generation problems by branch-and-cut. We develop and use strong cutting-planes for the cluster generation subproblems. Computational results using real data are reported.