90 Km Transmission with 12X64 Hybrid Architecture for Access Networks

Abstract

This paper proposes a 12X64 long haul optical passive access system that communicates at a cumulative line rate of 180 Gbps. Hybrid Time Division Multiplexing-Wavelength Division Multiplexing (TDM-WDM) technique is utilized for transmission of the information signal on twelve wavelengths for 768 subscribers. The system model utilizes Differential Phase Shift Keying (DPSK) modulation in downstream and re-modulation in upstream with downlink optical carrier signal. It helps in avoiding the use of a separate laser for transmission of the information bits in the uplink direction. Thus, suggesting economical solution for access networks where large number of subscribers shares the network infrastructure. The demonstrated architecture is tested for the impact of input signal power level on communicated information signals. Also, the system architecture is examined for finding the optimum light detector of the Optical Network Unit (ONU). It is therefore observed that the proposed system is a practical answer to meet the higher line rate requirements of multimedia streams in the access networks with longer network span.