Single-fiber protection in telecommunications networks

Protected single fibre passive optical network detecting and recovering failure of a scheme. Detector is used for detecting of the light signal power level of the reducing. The invention claims an improved resolution the number of the example of the onu with variable number of symmetrical light splitting ratio method. Claims a single fibre passive optical network the optical fibre network uses the connected with the interface between the optical fiber in the multiple passive node the node passive optical splitter and 2x2 optical combiner is used for the predetermined of spectroscopical ratio the optical power is connected with the input and output optical fiber.