Integration of FSO Traffic in Ring-Topology Bidirectional Fiber Access Network With Fault Protection

In this work, we first propose and demonstrate a bidirectional time-division-multiplexing (TDM) free space optical communication (FSO) traffic integrated in ring-based fiber access network together with fiber fault protection. Here, while we add the new designed optical devices in the central office (CO) and each optical wireless unit (OWU) respectively, the TDM-FSO fiber system can achieve the self-protected operation against fault. In addition, according to the proposed ring-based fiber network, the maximum numbers of eight OWUs can be provided for the symmetric 10 Gbps on-off keying (OOK) FSO downstream and upstream connections. As a result, the proposed FSO access network can allow 25 km fiber transmission and proper FSO transmission length depending on the atmospheric attenuation of different weather condition.