A Simple and Cost-effective Design for Simultaneous Transmission of Point-to-point and Broadcast Services in WDM-PON

A simple and cost-effective design of centralized light source wavelength division multiplexing passive optical network (WDM-PON) is proposed, which supports simultaneous transmission of point-to-point data and broadcast services. 10 Gbit/s differential quadrature phase shift keying (DQPSK) downstream data and superimposed 2.5 Gbit/s inverse return-to-zero (IRZ) broadcast service are simultaneously transmitted from optical line terminal (OLT) in downstream channels without pulse carving, whereas a 2.5 Gbit/s on-off keying (OOK) data signal is used for upstream signal using re-modulation of downstream signal power, no additional laser is used at optical network unit (ONU). Simulation results show that downstream transmissions of 10 DQPSK point-to-point channels with IRZ broadcast service and upstream transmission of 10 OOK channels, using 100 GHz channel spacing and high extinction ratio (ER), can be successfully achieved over a distance of 20 km with low transmission power penalties and improved receiver sensitivity. It is also evident from results that proposed simple technique has good tolerance against transmission nonlinearities and can be implemented as a cost-effective solution in future WDM-PON networks.