“…The facilities layer contains various facilities, such as cables, closures and other outside plants. For (b) ans (c), we have developed new water-blocking optical fiber cables and water sensors which employ water absorbent materials [1] and a fiber line testing system [8] which can automatically perform various line tests, such as optical time domain reflectometer (OTDR) tests, cable and splicing loss tests, and fiber identification, through remote control from work stations. Such a concept can classify the functions and compositions of the OA&M systems in the physical networks, which means that the applications can easily be designed.…”