OPN01-1: 1:N Protection Scheme for AWG-based WDM PONs

This paper presents a 1:N protection scheme based on the cyclic property of an array waveguide grating (AWG) and a specific connection pattern among the optical network units (ONUs). A self-protecting architecture for WDM passive optical networks (PONs) has been proposed in previous studies, and a novel centrally controlled protection scheme has recently been proposed with reduced network resources. However, previous studies focused only on 1:1 protection and developed schemes in which the number of required wavelengths was twice the number of ONUs. Furthermore, these studies located the protection scheme either at the ONU end or at the optical line terminal (OUT) end. By contrast, this study distributes the controlled protection scheme to both the ONU end and the optical line terminal (OLT) end. The proposed scheme provides an automatic traffic restoration capability in the event of a single distribution fiber cut between the remote node and the ONU through its specific design of the OLT and ONU and the cyclic property of the AWG. The cost and performance of the current protection scheme are evaluated and compared with those of previous schemes. Although the current scheme expenses more fiber links among the ONUs than previous schemes, the network resource demands are greatly reduced (i.e. the number of wavelengths is reduced) and the protection performance is improved (i.e. a 1:N protection capability is achieved.).