This study a hybrid Optical Code Division Multiple Access (OCDMA) over Wavelength Division Multiplexing (WDM) network is proposed to supporting large numbers of subscribers for Gigabit Passive Optical Network (GPON). Gigabit Passive Optical Network (GPON) is a developing innovation for satisfying high transfer speed interest of clients with long separation scope. In this study, the Modified Double Weight (MDW) code is used as signature address to designing the system regarding this code can accommodate huge number of simultaneously active users. The simulation model of GPON systems is derived by Spectral Direct Detection (SDD) technique which has been developed for the analysis of feasibility and implementation issues of the application. The aim was to analyse the impact of the most important parameters of the components that are needed for new network elements. On the basis of the results achieved (e.g., =10-10) the optimal of the GPON system for 20 km fibre length. Hence, this system can be considered as a promising solution for gigabit passive optical network application.
