Incremental planning of multi-layer elastic optical networks

Traditionally, network upgrade cycles are long and performed independently for the IP edges and the optical transport layers. The traffic in metro and core networks is forecasted to grow in volume but also in dynamicity and the network operators face the challenge of shorter upgrades, influencing the cost efficiency and suppressing the return of investment. Thus, it is imminent to adopt a multi-period network planning approach and account jointly for the upgrade of the optical but also the IP edges of the network. In this work we formulate the problem of the incremental joint multi-layer planning of an IP over elastic optical network (EON) and propose an ILP formulation to solve it. Our objective is to deploy in a period the minimum additional network resources to cope with the changed traffic (CapEx) from the previous period, but also to minimize the changes for the transition between the two periods (OpEx). Simulation results based on realistic network scenarios validate the proposed planning approach.