Reroute sequence planning in telecommunication networks and compact vector summation

The paper deals with the reroute sequence planning in telecommunication networks. Initially, we are given communication requests between terminal pairs and a path system which is able to satisfy these demands while respecting the physical link capacities. A reconfiguration problem arises when the path set is recalculated by a global optimization method for achieving a better resource utilization. After the recalculation the paths in the routing have to be changed to the optimized ones in the working network. In this case, a sequence of one by one reroutings have to be found with the constraint that the capacities should not be violated and no one of the demands can become unsatisfied during the reroute process. Provided that the (initial and final) free capacities are large enough, such a permutation can be computed. The paper deals with theoretical results giving bounds for these free capacities, with vector-sum and discrepancy methods.