Fiber optic communication systems in Japan

Thanks to broadband and low-loss characteristics of optical fiber, optical fiber systems have been widely installed as the main trunk line. In 1983, the 400 Mbps system (F-400M) was commercially introduced. The 3400 km main trunk line across Japan from the northernmost city to the southernmost city via 34 cities was completed. Trunk network including intra-office network has been completely opticalized in early 1990's. Currently, 170,000 km trunk transmission optical fiber cable is installed in Japan. To meet explosive data traffic demand such as high-speed Internet, the WDM systems of 8 to a few tens wavelengths are now being introduced. The possibility of new photonic networks, with large capacity TDM/WDM transmission systems operating at Tbps class, are now being studied.