Trends in optical access networks and related technology

Today, demand is increasing for networks and associated technology to offer lower price and more flexible communication services, such as Internet ser vices that are provided at a variety of speeds. While work has been progres sing on the development of a trunk network that uses WDM technology, it has remained difficult to reduce access network costs despite the recognized i mportance of fiber-optics. Since the 1995 launch of its R&D project designe d to achieve substantial construction cost reductions, NTT has made conside rable progress towards this goal, and is on the verge of success. This arti cle reviews recent conditions in the information transmission market, and d escribes system technologies that can provide access to various new service s (especially in the optical access network), as well as NPT's efforts, whi ch have helped to reduce the cost of optical systems to that of metallic sy stems.