Optimized Parallel Transmission in Elastic Optical Networks to Support High-Speed Ethernet

The need for optical parallelization is driven by the imminent optical capacity crunch, where the spectral efficiency required in the coming decades will be beyond the Shannon limit. To this end, the emerging high-speed Ethernet services at 100 Gbps have already standardized options to utilize parallel optics for data transmission, referred to as multi-lane distribution. OFDM-based optical network is a promising transmission option towards the goal of Ethernet parallelization. It can allocate optical spectrum resource tailored for a variety of bandwidth requirements in a fundamentally parallel fashion, with each sub-carrier utilizing a frequency slot at a lower rate than if serial transmission is used. In this paper, we propose a novel parallel transmission framework designed for elastic (OFDM-based) optical networks to support high-speed Ethernet services, in-line with IEEE and ITU-T standards. We formulate an optimization model based on integer linear programming, with consideration of various constraints, including spectrum fragmentation, differential delay and guard-band constraints. We also propose a heuristic algorithm which can be applied when the optimization model becomes intractable. The numerical results show the effectiveness and high suitability of elastic optical networks to support high-speed Ethernet parallel transmission, especially for connections with high bandwidth requirements. To the best of our knowledge, this is the first attempt to model parallel transmission in elastic optical networks in support of a standardized high-speed Ethernet system.