A Survivable and Flexible WDM Access Network by Alternate FSO- and Fiber-Paths for Fault Protection

Inthe work, we study and express a new wavelength-division-multiplexing passive optical network (WDM-PON) architecture with fiber fault protection. The designed optical network unit (ONU) module and periodic spectrum of 2 × N array waveguide grating (AWG) are applied to produce the self-protected mechanism. Here, we employ the free space optical communication (FSO)- and fiber-based connection between two adjacent ONUs to achieve signal relink. Moreover, the corresponding signal performances of downstream and upstream are also analyzed and discussed.