Load Adaptive Dynamic Wavelength and Bandwidth Assignment for TWDM PON

Time and Wavelength Division Multiplexing PON (TWDM-PON) is next generation PON technology that increases the PON capacity due to having multiple wavelengths for both upstream and downstream links with tunable transceivers in the optical network units (ONUs). It is also proposed for connecting radio units to the cloud, termed as mobile front-haul, in 5G. The most important feature of TWDM PON is a dynamic wavelength assignment scheme that can efficiently handle ONU migration from one wavelength to another to balance the traffic load. In this study, the working of DWA mechanism for ITU compliant TWDM PON is presented and an adaptive DWBA scheme is presented that can dynamically handle ONU migration in case of asymmetric traffic load conditions. The performance of the proposed scheme is evaluated through a TWDM PON test bed implemented in OMNET++ environment. For the traffic load analysis a simple regression model is used. Overall, the ADWBA scheme reduces the average upstream delays of T2 and T3 up to 28% and of T4 up to 50% with valuable reduction in bandwidth wastage.