Elastic Optical Networks: The Global Evolution to Software Defined Optical Networks

High speed 100G coherent optical networks are currently under deployment by many operators worldwide. To ensure competitiveness and significant performance improvements to cope with the ever-increasing traffic demand, a novel network concept for improved resource utilization has risen based on "elasticity", i.e. the ability to make a number of transmission parameters (optical data-rate, channel spacing…) tunable while currently fixed. Benefits are numerous, including increased network capacity, lower cost/bit, better energy-efficiency and better scalability. In this paper, we review the latest advances carried out in the CELTIC EO-Net project. We identify the key building blocks allowing elastic optical networks to meet the desired performance improvements compared to existing networks. We examine the design of elastic transponders capable of data-rate adaptation, the interfaces between routers and transponders for flexible traffic aggregation and the algorithms for traffic grooming and routing. Network cost/energy analyses are performed. Eventually elastic functionalities are experimentally demonstrated.