Patent ID: 8139947
Filing Date: 2012-03-20
Classification: H04J

Abstract:
1. An optical transmission apparatus, comprising: a first optical transceiver unit configured to exchange optical signals with an apparatus connected to a first input and output node and to perform signal conversion between optical signals and electrical signals; a second optical transceiver unit configured to exchange optical signals with an apparatus connected to a second input and output node and to perform signal conversion between optical signals and electrical signals; an electrical signal processing unit configured to connect between the first transceiver unit and the second transceiver unit and to perform electrical signal processing; a first transmission clock generating unit configured to generate, based on a first clock of a signal arriving through the first input and output node, a transmission-purpose clock used by the second transceiver unit that has frequency in a predetermined proportion to frequency of the first clock and is synchronized with the first clock; a second transmission clock generating unit configured to generate, based on a second clock of a signal arriving through the second input and output node, a transmission-purpose clock used by the first transceiver unit that has frequency in a predetermined proportion to frequency of the second clock and is synchronized with the second clock; a selector configured to select an output clock of the first transmission clock generating unit at a time of optical input interruption at the second input and output node; and a frequency dividing unit configured to produce a frequency-divided clock obtained by dividing frequency of the output clock selected by the selector and to supply the frequency-divided clock to the second transmission clock generating unit.