Design of Optical Network Unit (ONU) for hybrid TDM/WDM NG-PON

Hybrid Wavelength/Time Division Multiplexing (WDM/TDM) NG-PONs have been proposed for the next generation of Passive Optical Networks (NG-PON2). They are advantageous because they dynamically allocate bandwidth among all the users and can coexist with the currently available NG-PONs but at an increased implementation cost of the network elements and components. Aiming at a relatively low cost solution for the WDM/TDM NG-PON Optical Network Unit/Terminal (ONU/ONT), this work introduces an ONU architecture, which supports the required functions of WDM/TDM NG-PON and keeps the implementation cost close to that of an XG-PON (also known as NG-PON1) ONU/ONT. The paper introduces the protocol extensions to the XG-PON, which are necessary for realizing the WDM/TDM NG-PON. It presents the architecture and organization of the proposed ONU and the specifics of the modules supporting the protocol extensions. An example implementation on a Xilinx VC709 board and the comparison with an XG-PON ONU on the same board validate the results.