In our previous studies, an optical-code-division multiplexing (OCDM)-based network architecture has been proposed to improve the wavelength utilization and to provide finer bandwidth granularities to users. However, since up-to-date all-optical regeneration technologies are still immature, signal quality degradation at intermediate nodes is considered as a crucial problem in transparent optical networks. Because the remaining noises may propagate, and be accumulated along the light-path, which eventually result in unacceptable signal quality. In this paper, we first define a cycle attack problem due to multi-access interference (MAI) propagation in transparent OCDM-based networks, which may cause severe service disruption. A depth-first-search (DFS)-based algorithm is proposed to diagnose such cycle attacks and a heuristic wavelength assignment called advanced first-fit (AFF) scheme taking cycle attacks into account is found to be a simple but effective approach mitigating the cycle attack impacts by computer simulations.
['Shaowei Huang', 'Ken-ichi Kitayama', 'Ken-ichi Baba', 'Masayuki Murata']
Impact of MAI Noise Cycle Attack on OCDM-Based Optical Networks and its Diagnostic/Mitigation Algorithm