| 摘要 |
<p>A discontinuous ring is formed by separate bidirectional optical communication links (10-13), with possibly different transmission speeds, synchronous or asynchronous transmission, and ratios of working (W) to protection (P) channels, each linking a pair of terminals (22, 23) in different nodes (1-4) of a communication system. To protect protection-switched traffic on a communication link from a link failure, it is routed around the ring via the protection channel of the oter communcication links. To this end, an optical switch (20) is provided between the protection channel of each link and the associated terminals in each node, and is controlled differently in nodes (1, 4) adjacent the link failure and in nodes (2, 3) not adjacent the link failure to route the protection-switched traffic accordingly. Rapid protection switching is facilitated by controlling the optical switches using wavelength (μ1, μ2) detectors directionally coupled to the protection channel at each node.</p> |
