Abstract
In this paper, we consider the nodes migration scheduling problem that aims to migrate nodes from an outdated access network to a new one. In order to avoid services' interruption, a bridge is installed temporarily between the two networks and, as for the nodes, they are migrated, one at each time period, from the old to the new network. The objective is to find a migration's sequence that minimizes the cost of the capacity to install on the bridge. We provide a compact formulation of polynomial size in order to solve the problem optimally. We reformulate it in such a way that the new model reduces drastically the branch-and-bound search tree. In addition, we give a lower bound based on a bi-partitioning problem that turns out to be close to the optimal solutions. We conduct experiments on a case study consisting of migrating eNodeBs of a 4G network from an access network to another. The computational experiments show the performance of our approach as the proposed model provided optimal solutions for up to 40 nodes.