A Flexible and Reliable 40-Gb/s OFDM Downstream TWDM-PON Architecture

In this paper, a flexible and reliable 40-Gb/s time and wavelength division multiplexing passive optical network (TWDM-PON) architecture is proposed and demonstrated. Here, a 4 × 10 Gb/s orthogonal frequency-division multiplexing (OFDM) downstream signal is achieved by utilizing four 2.5-GHz directly modulated lasers in the optical line terminal. A reflective optical semiconductor amplifier is utilized in each optical network unit to serve as upstream transmitter (Tx) transmitting 2.5-Gb/s on-off keying (OOK) and 10-Gb/s OFDM upstream traffic, respectively. In addition, the dynamic bandwidth (capacity) allocation and fiber fault protection also can be achieved by applying the new proposed PON architecture with software-defined networking approach.