Grid architecture of a metro-access optical network to support discretionary peer-to-peer intracommunication and intercommunication between ONUs

Direct communication between optical network units (ONUs) is an important function in metro-access optical networks. In this paper, a grid architecture supporting the intracommunication and intercommunication between ONUs is proposed. By employing an arrayed waveguide grating (AWG) and coarse wavelength division multiplexer in a remote node, not only can the intracommunication between ONUs within one WDM passive optical network (PON) be realized, but the intercommunication between ONUs belonging to different WDM-PONs can also be supported. By allocating one specific wavelength to the ONU to transmit direct communication signals and utilizing the periodic assignment property of the AWG, discretionary peer-to-peer direct communication between ONUs can be achieved. By adopting a grid topology and expanding module, the network can not only realize multiple-fault protection but also carry out online expansion. Both the scalability and the reliability of the network can be improved. Finally, the performance analyses and the simulations verify the feasibility of the proposed architecture.