| 摘要 |
<p>An SDH telecommunications system includes a plurality of tributary cards through which signals are switched, a protection card is included for the tributary cards and a multiplex controller controls the output of a plurality of line termination (LTU's) units there being one unit provided respectively for each tributary card including the protection card, the multiplex controller being arranged to switch signals from a faulty tributary card to the protection card through the LTU associated with the faulty tributary card but without involving any switching taking place within the faulty tributary card so as to effectively replace the faulty tributary card.</p> |
