| 摘要 |
PURPOSE:To switch a transmission line without causing any error and to transmit a multicarrier signal in a circuit constitution of a small scale by securing the coincidence of phases among plural incoming frame signals and changing all pointer values into a single equal value. CONSTITUTION:A transmitter end office 30 is provided with a transmitter end office phase matching circuit 3 which can secure the coincidence of phases among those frame signals of six systems incoming to the input terminals of these systems. Each transmitter end office pointer processing circuit 4 changes all pointer values into a single equal value based on the deciding result of a lead-lag deciding network 5. Thus it is possible to acquire a frame signal having coincidence the frame head position and the pointer value. Therefore no data is deteriorated at all even through a faulty working circuit is instantaneously switched to a stand-by circuit. Thus the switching is carried out with no error at all. Meanwhile just a single pointer value extracting circuit will do at a receiver end office 40 because all pointer values are set equal to each other at the office 30. |
