CDC ROADM design tradeoffs due to physical layer impairments in optical networks

In this work, we assess the impact of several physical layer impairments (PLIs) on performance optical networks based colorless, directionless and contentionless reconfigurable add/drop multiplexers (ROADMs), through Monte-Carlo simulation, considering polarization division multiplexing 4 16 quadrature amplitude modulation (QAM) signals, at 28 GBaud, for 37.5 GHz channels. The PLIs taken into account are amplified spontaneous emission noise, filtering, in-band crosstalk nonlinear interference noise caused by Kerr effect. A detailed model ROADM node is built two typical architectures, broadcast select (B&S) route (R&S), different structures, multicast switches (MCSs) wavelength selective (WSSs), resulting in four scenarios. Our results have shown that 16QAM B&S ROADMs with WSSs-based structures scenario has best relation cost/performance, foreseeing its use metro networks, while 4QAM R&S structure allows a larger cascade an expectable lower cost anticipating implementation long-haul networks.