Forward Error Correction in Optical Core and Access Networks

Forward error correction techniques are essential for optical core and access networks. In optical access networks, low-complexity coding schemes with low power consumption are required. In core networks, the emphasis is on high coding gains and extremely low output bit error rates, while allowing decoder realizations operating at a throughput of 100 Gb/s and above. In current and future core networks, coherent optical transmission with higher order modulation formats becomes mandatory to achieve the high spectral efficiencies required in next generation core networks. In this paper, we provide an overview of the requirements and techniques, and highlight how coding and modulation can be best combined in core networks. We also present guidelines for system design if a receiver with limitations on complexity shall be employed for access networks.