A spectrum-sliced elastic optical path network (SLICE) architecture has been recently proposed as an efficient solution for a flexible bandwidth allocation in optical networks. In SLICE, the problem of Routing and Spectrum Assignment (RSA) emerges. In this letter, we both formulate RSA as an Integer Linear Programming (ILP) problem and propose an effective heuristic to be used if the solution of ILP is not attainable.

This article provides motivation for the elastic optical network (EON) approach, an efficient and cost-effective solution for provisioning of cloud computing traffic. As opposed to wavelength switched optical networks (WSONs), the capabilities of which are limited by the use of rigid frequency grids, EON architectures allow for both scalable bandwidth provisioning and flexible resource allocation. The deployment cost, energy consumption, and bandwidth usage for both EON and classical WSON transport networks are compared in pan-European and U.S. backbone networks for 2012-2020 using Cisco traffic predictions. Results show that the EON concept significantly outperforms WSON in all examined criteria, and the gap between the two architectures increases in subsequent years. Moreover, potential advantages of anycast routing in transport networks with data center traffic are demonstrated.

In this article, we analyze gains resulting from the use of EON architectures with special focus on transportation of cloud-ready and content-oriented traffic in the context of network resilience. EONs are a promising approach for future optical transport networks and, apart from improving the network spectral efficiency, bring such new capabilities as squeezed protection, which reduces resource requirements in failure scenarios. In the introductory part, we present a background on new network services based on cloud computing and content orientation paradigms, EON architectures, and their survivability mechanisms. Next, we show the impact of disasters on EON performance. To support the discussion, in the evaluation part we provide simulation results to compare survivable EONs and wavelength-switching optical networks, estimate the efficiency of different survivable EON schemes supporting cloud- and content-oriented traffic, and assess the robustness of EONs to disasters.

In this letter, we propose three new approaches to optimizing multicast traffic in elastic optical networks that implement distance-adaptive transmission. Two of the approaches are based on integer linear programming modeling, whereas the last one is an effective heuristic. We also compare our approaches with reference methods proposed in the literature. The comparison is based on numerical experiments supported by a discussion on the effectiveness and applicability of the considered methods. The algorithms based on candidate tree modeling of multicasting outperform other methods for larger problem instances in terms of spectrum usage and applicability.