摘要 |
A hub structure for use in an optical network, the optical network comprising a ring structure carrying a bidirectional optical data signal and a plurality of hub structures arranged in-line within the ring structure, the optical data signal comprising primary and secondary path transmission signals having opposing transmission directions on the ring structure, the hub structure comprising a drop unit arranged, in a normal state, to drop and through-connect a primary receive path signal for further processing at the hub structure, and, in a protection state, to drop and through-connect a secondary receive path signal for further processing at the hub structure.
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