Abstract
This paper proposes new switch architectures for hierarchical optical path cross-connect (HOXC) systems. The architectures allow incremental expansion of system scale in terms of the number of input/output fiber ports, wavebands, and optical paths per waveband. These features assure the cost-effective introduction of HOXCs even at the outset when traffic volume is not so large. Furthermore the effectiveness of the proposed switch architectures is demonstrated in a comparison with single-layer OXCs (conventional OXCs). The results provide useful criteria for the introduction of HOXCs in terms of hardware scale.