@article{oai:nagoya.repo.nii.ac.jp:00013086,
 author = {SATO, Ken-ichi and HASEGAWA, Hiroshi},
 issue = {8},
 journal = {IEICE transactions on communications},
 month = {Aug},
 note = {This paper investigates the prospects and challenges of hierarchical optical path networks. The merits and issues of introducing higher order optical paths are elucidated. State of the art of the key enabling technologies are demonstrated including hierarchical optical cross-connect switch architectures, hierarchical optical path network design algorithms, a newly developed waveband filter, and waveband conversion technologies.},
 pages = {1890--1902},
 title = {Prospects and Challenges of Multi-Layer Optical Networks},
 volume = {E90-B},
 year = {2007}
}