Emerging Next-Generation TWDM-PON with Suitable Modulation Format

The exponential growth of high-speed broadband services, an increase in the number of end-users, high bandwidth, and massive data rate demand innovative and emerging points to a multipoint network that satisfies the need for next-generation passive optical access network (NG-PON). Next-generation passive optical access network stage 2 (NG-PON2)-based time and wavelength division multiplexing passive optical network (TWDM-PON) are mostly considered as the most promising optical access candidate due to its high-speed services, low power consumption, back-to-back compatibility, and cost-effectiveness. In this paper, the eight wavelengths-based bidirectional 80/20 Gbps TWDM-PON system using return to zero (RZ), non-return to zero (NRZ), and carrier suppressed return to zero (CSRZ) data modulation formats have been proposed and analyzed by varying input power, transmission distance, and bit rate. Further, the system is evaluated in terms of minimum bit error rate (BER), quality factor (Q factor), received optical power (dBm), eye diagrams, and eye height. It has been observed that the most appropriate modulation format for downstream transmission is NRZ while for upstream transmission, the most suitable modulation formats are RZ and NRZ.