Design and implementation of bi-directional 4 × 10 Gb/s WDM-TDM PON with upstream remodulation

Paper presents a simulation of hybrid wavelength-division multiplexed/time-division multiplexed (WDM-TDM) passive optical network with upstream re-modulation and data rate of 10 Gb/s. With data re-modulation technique at the upstream optical network unit (ONU) we can avoid the use of laser and thus reduce overall system cost. The simulation result shows that the proposed architecture can support a link distance of 32 km in each direction with each wavelength supporting up to 16 users, i.e. giving an aggregate number of 64 users. Also the same architecture can be extended for more number of users, i.e. 256 for each wavelength by adding a pre-amplifier in the downstream link, thus giving an aggregate number of 1024 users over 37 km distribution link. Also, this paper investigates the trade-off between the link distance and the number of users, as the link distance increases the number of users supported by the architecture decreases and vice versa. Additionally, this paper investigates the performance of architecture under different modulation formats in terms of BER and Q factor. The simulation is carried out using optsim simulation software.