Optical fiber loops and maintenance support systems for subscriber network

The authors describe the configuration of the fiber-optic subscriber network introduced in NTT and its operation support systems. NTT is currently constructing a fiber-optic subscriber network where optical fiber cables are laid in loops and optical fibers in star configurations. Such a configuration can ensure high reliability and security for each customer, as well as flexibility with respect to randomly arising demands. Thus, it is considered to be adequate for a subscriber network. NTT is also introducing various operation support systems for the large-scale single star network to be economically operated and maintained. These systems are also described