Mode transformation and united control mechanism supporting wavelength division multiplexing Ethernet passive optical network and orthogonal frequency division multiplexing passive optical network in multi-subsystem-based virtual passive optical network

In this study, mode transformation and united control mechanism for multiple subsystems in metro-access optical network (MAON) are proposed to realise multi-subsystem-based virtual passive optical network. By combing the characteristics of multi-point control protocols (MPCPs) of wavelength division multiplexing Ethernet passive optical network (WDM-EPON) and orthogonal frequency division multiplexing passive optical network (OFDM-PON), a unified MPCP (U-MPCP) is proposed. Based on the U-MPCP, flexible control node and central node are constructed to achieve asynchronous unified control of multiple subsystems. By designing new control frames, the mode transformation between two subsystems (WDM-EPON and OFDM-PON) can be carried out. It can not only finish the flexible transformation of optical network unit's (ONU's) working modes but also make the MAON have the backward compatibility to the existing access technologies. By creating transformation algorithm of ONU's working modes, the transmission delay of over-load subsystem can be effectively reduced when ONU meets the condition of the mode transformation and finishes the transformation. Finally, by simulation, the effectiveness of the proposed scheme is demonstrated.