  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 to parallelize interfaces referred to as Multi-lane Distribution (MLD).
OFDM-based optical network is a promising transmission option towards the goal
of Ethernet parallelization. It can allocate optical resource tailored for a
variety of bandwidth requirements and that in a fundamentally parallel fashion
with each sub-carrier utilizing a frequency slot at a lower rate than if serial
transmission was 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 ILP 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 parallel transmission in high-speed Ethernet. To
the best of our knowledge, this is the first attempt to investigate the
parallel transmission in elastic optical networks to support standardized
high-speed Ethernet.
