Adaptive bandwidth mechanism using dual rate OLT for energy efficient WDM-TDM passive optical network

This paper reviews various energy efficient approaches in existence and proposes a Hybrid WDM-TDM PON architecture that allows the adaptive bandwidth allocation mechanism to reduce central office power consumption with acceptable performance. Our proposed architecture allows sending two signals, one broadband and other narrowband to each optical networking unit so an appropriate signal can be utilized according to the traffic demand. In case of very low traffic, only narrowband signal is used and a significant amount of energy consumption and OPEX is reduced. By using power splitter and interleaver, proposed architecture provides broadcasting at both broadband and narrowband signal depending on the required link rate. This further reduces energy consumption and OPEX by avoiding the transmission of same signal from multiple sources. Offered data rates to the optical distribution networks (ODNs) may also be varied by doubling the wavelength spacing of remote node AWG so that two contiguous wavelengths can be transmitted at each port or ODN. This provides the geographical dynamic bandwidth allocation. Proposed architecture also support simultaneous transmission of both broadband and narrowband signals to the ODN to provide bandwidth scalability and network extensibility for supporting future access network in terms of new users and data rates. As two signals are reaching to any ODN, resiliency against OLT TRx and line card failure is also achieved. The performance of the proposed design is verified by simulation results in terms of bit error rate and receiver sensitivity to demonstrate its feasibility for the next-generation optical access network.