The increasing demand for high capacity optical networks and the decreasing revenues per bit, combined with the given economy of scale for optical networks, forces the network operators to enhance the channel data rates as well as the channel numbers. Higher channel data rates result in a lower footprint, energy consumption and a lower complexity in network management and operation support systems, due to lower channel numbers.
The enhancement of channel data rate in principle leads to a system tolerance reduction for chromatic dispersion, PMD and nonlinear effects. Furthermore higher order effects like dispersion slope and higher order polarization mode dispersion have to be taken into account.
On the other hand the fast pulse broadening leads to a quasi linear behaviour of the systems, which relaxed some link design rules compared to 40 Gbit/s transmission.
The lower tolerances can partially be mitigated by the implementation of more complex amplification schemes and compensators. The complexity of system design, accounting for less tolerances and adaptive compensating modules, is increased.
We investigate theoretically and numerically the limiting physical effects and the impact on the signal performance, induced by chromatic dispersion, PMD and nonlinear impairments. We present derived engineering rules for all relevant effects and for various fiber types, based on channel data rates of 160 Gbit/s. These engineering rules enable design engineers to perform a fast system design and system degradation estimation, without time consuming full numerical simulations.