FLCS-PON – A 100 Gbit/s Flexible Passive Optical Network: Concepts and Field Trial

Digital Subcarrier Multiplexing: Enabling Software-Configurable Optical Networks

“…This scenario is expected to change with the introduction of 5G/6G and Virtual and Augmented Reality (VR/AR). Next-generation access PON will support up to IM-DD 50G with Time Division Multiplexing (TDM) [36], [39] and 100G with flexible-rate achieved using flexible modulation format, and FEC code rate [40]. In 100G coherent outlook PON [41], both TDM and Frequency Division Multiplexing (FDM) are being considered in [19], instead of FDM only for PON overlay, 5G front-haul and metro aggregation, etc., as proposed in [7], [34], [42], [43].…”

Overview of high-speed TDM-PON beyond 50 Gbps per wavelength using digital signal processing [Invited Tutorial]

“…For XG-PON and XGS-PON, relatively simple hard-decision Reed-Solomon (RS) FEC, for instance RS(255, 239), was widely used and led to a pre-FEC BER=10 -3 threshold. A higher performance FEC has been defined for 50G-PON in G.9804 using LDPC codes, leading to a pre-FEC BER=10 -2 threshold, as shown in the first line of Table I [24]. LDPC can be implemented as a hard decision FEC.…”

“…Moreover, taking advantage of DSP introduction in PON, they can be implemented as a more powerful soft-decision FEC. A list of different LDPC code variants is shown in Table I [24], showing that even more powerful FEC options can be selected for future PON physical layers above 50G-PON, allowing for a relaxed BER target of 1.9×10 -2 , thus enabling a power budget increase. The list of LDPC options presented in Table 1 is obtained assuming the same mother code (the one defined for 50G-PON) to which shortening and puncturing was subsequently applied [24].…”

“…A list of different LDPC code variants is shown in Table I [24], showing that even more powerful FEC options can be selected for future PON physical layers above 50G-PON, allowing for a relaxed BER target of 1.9×10 -2 , thus enabling a power budget increase. The list of LDPC options presented in Table 1 is obtained assuming the same mother code (the one defined for 50G-PON) to which shortening and puncturing was subsequently applied [24]. Other LDPC codes are available with even better coding-gain performance, even though typically at the expenses of longer coding blocks and thus higher complexity and latency.…”

“…Table I. List of some LDPC variants, taken from [24]. *Assuming NRZ over a binary symmetric channel, hard input FEC decoder providing a post-FEC bit error ratio <10 −12 .…”