A group of major Japanese communications technology and service companies as well as academic and research institutes has reported their work on the use of an adaptive modulation OFDM transmission system for metro-access networks. The companies have created a testbed to demonstrate what they call an "Elastic Lambda Aggregation Network" (EλAN).
An EλAN supports flexible assignment of transmission speed and optical frequency bandwidth to support diversified services with different types of traffic, such as internet, enterprise line, and mobile services, over the same network according to the companies. The EλAN see the PON optical line terminal typically located in access central offices close to subscribers' homes relocated to a metro central office where traffic aggregation takes place. The network architecture features the use of wavelength-selective switches for traffic rerouting. The approach also leverages a digital coherent OFDM system with adaptive modulation to improve the efficiency of optical frequency utilization and large-scale service allocation flexibility by using the elastic control of transmission speed and optical frequency bandwidth.
In a recent reliability demonstration, the EλAN architecture enabled automatic rerouting of traffic from a "failed" hub to another approximately 10 km away within 10 seconds, the companies said.
The partners involved in the project include Nippon Telegraph and Telephone Corp., Hitachi, Ltd., Oki Electric Industry Co., Ltd., Keio University, KDDI Research, Inc., and Furukawa Electric Co., Ltd. The was contracted with the National Institute of Information and Communications Technology (NICT) of Japan. The group plans to present its work at The 13th International Conference on IP + Optical Network 2017 (iPOP2017) in Kawasaki-city, Kanagawa, Japan, June 1-2, 2017.
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