Transmission apparatus and plug-in unit

A plug-in unit of a plurality of plug-in units each executing a part of functions of a transmission apparatus, the plug-in unit comprising:

• a clock generator configured to generate a clock signal;
• a frame pulse generator configured to generate a first frame pulse signal based on the clock signal;
• a detector configured to compare a first phase of the first frame pulse signal with a second phase of a second frame pulse signal transmitted from other plug-in unit of the plurality of plug-in units, detect a phase difference between the first phase and the second phase, and generate phase difference information based on the phase difference detected;
• and
• a transmitter configured to transmit a control signal including the phase difference information to the other plug-in unit.

A plug-in unit of a plurality of plug-in units each executing a part of functions of a transmission apparatus, the plug-in unit comprising:

• a clock generator configured to generate a clock signal;
• a receiver configured to receive a control signal including a phase difference information based on a phase difference between a first phase of a first frame pulse signal generated by another plug-in unit of the plurality of plug-in units and a second phase of a second frame pulse signal to be transmitted to the another plug-in unit, the control signal being transmitted from the another plug-in unit;
• a controller configured to control a phase of the clock signal generated by the clock generator, based on the phase difference information included in the control signal;
• and
• a frame pulse generator configured to generate the second frame pulse signal having the second phase based on the clock signal generated by the clock generator.