Novel Automatic Service Restoration Technique by Using Self-Reconfiguration of Network Resources for a Disaster-Stricken Metro-Access Network

This paper shows the concept of the elastic lambda aggregation network (E<formula> <tex>$\lamda$</tex> </formula>AN) that will achieve an elastic common access infrastructure for the metro-access network. It proposes a service restoration technique that uses optical path switching and inter-central office handover for E<formula> <tex>$\lamda$</tex> </formula>AN to recover from disasters. The feasibility of the proposed service restoration technique is successfully demonstrated for the first time by using a prototype testbed of a metro-access network. By applying both orthogonal frequency division multiplexing (OFDM) and adaptive modulation, the system automatically changes the transmission parameters (modulation level, the number of subcarriers and symbol rate) according to the service requirements and conditions of the optical distribution network (ODN), such as the link&#x0027;s end-to-end optical loss, in order to achieve accommodate multiple services. In the experiment, an optical network unit (ONU) in a faulted system automatically re-connected within 10 sec to another office 20-km away with the same throughput.