DATA FRAME GENERATION CIRCUIT AND DATA FRAME GENERATION METHOD

PROBLEM TO BE SOLVED: To store signals so that low frequency beat noise is not generated in each data frame of data transmitted by an optical transmission network.SOLUTION: In a data frame generation circuit, a frame generation unit 1 outputs a data frame storing client signals on the basis of a system clock, and outputs the number of client signals stored in the data frame for each data frame. A storage unit 2 is storing the range of the number of signals possibly generating beat noise. A comparison unit 3 compares the number of storage outputted from the frame generation unit 1 with the range of the number of signals. A control unit 4 controls the frequency of system clock on the basis of the comparison results from the comparison unit 3, and if the number of storage is included in the range of the number of signals, changes the frequency of system clock so that the number of storage deviates from the range of the number of signals.