| 摘要 |
PURPOSE: An apparatus for supplying induction clocks in an optical transmission apparatus is provided to generate a DS1E signal extracted and induced from a received optical signal, as used in an optical transmission apparatus carrying out optical signal type communication according to the synchronous digital hierarchy. CONSTITUTION: A reference clock selection unit(210) selects one out of an STM-16, an STM-14 or the tributary signal of an STM-1 as an input reference clock. A reference clock monitoring control unit(220) monitors the failure condition of the reference clock selected in the reference clock selection unit(210). An induction clock generation unit(230) generates a clock synchronized with the reference clock outputted from the reference clock selection unit(210). The induction clock output unit(240) forms an E1 frame for the clock generated in the induction clock generation unit(230) and outputs it by a DS1E signal to the external line. |
