Real-Time Experiment and Numerical Analysis of Highly-Survivable Adaptive Restoration for High-Capacity Optical Signal Transmission

Hiroki KAWAHARA  Kohei SAITO  Masahiro NAKAGAWA  Takashi KUBO  Takeshi SEKI  Takeshi KAWASAKI  Hideki MAEDA  

IEICE TRANSACTIONS on Communications   Vol.E104-B   No.4   pp.360-369
Publication Date: 2021/04/01
Publicized: 2020/09/28
Online ISSN: 1745-1345
DOI: 10.1587/transcom.2020EBP3036
Type of Manuscript: PAPER
Category: Transmission Systems and Transmission Equipment for Communications
high-order QAM modulation,  rate-adaptive transponder,  CD-/CDC-ROADM,  adaptive restoration,  

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An optical-layer adaptive restoration scheme is validated by a real-time experiment and numerical analyses. In this paper, it is assumed that this scheme can adaptively optimize the bitrate (up to 600Gb/s) and an optical reach with 100Gb/s granularity to maintain high-capacity optical signal transmission. The practicality of 600-Gb/s/carrier optical signal transmission over 101.6-km field-installed fiber is confirmed prior to the adaptive restoration experiment. After modifying the field setup, a real-time experiment on network recovery is demonstrated with bitrate adaptation for 600-Gb/s to 400-Gb/s signals. The results indicate that this scheme can restore failed connections with recovery times comparable to those of conventional restoration scheme; thus 99.9999% system availability can be easily attained even under double-link failures. Numerical analysis clarifies that adaptive restoration can recover >80% of double-link failures on several realistic topologies and improvement amount against conventional scheme is semi-statistically characterized by restoration path length.