A 
passive optical network (100) with immediate fault protection comprises an 
optical line termination (OLT) (11), an optical distribution network communicating with the OLT (11), the optical distribution network comprising a splitter (13) connected to the OLT (11) through a feed 
fiber (15) for separating and distributing optical signals from the OLT (11), a plurality of optical network units (ONUs) (17) each connected to the splitter (13) through a distribution 
fiber (19), and characterized in that each ONU (17) is equipped with a 
wireless router (21) communicating with its adjacent 
wireless routers (21) to form a mesh-like 
wireless network, whereby when failure has occurred in any distribution 
fiber (19) connected to the ONUs (17), the 
wireless router (21) of the disabled ONU (17) connected to the fiber (19) automatically searches and receives bandwidth from the nearest 
wireless router (21) of the ONU (17) connected to the functioning fiber (19) or 
wireless router (21) of disabled ONU (17) through the mesh-like network to avoid connection failure of the ONU (17) to the OLT (11).