Optical transmission system and method

An optical transmitter for accommodating client signals and transmission thereof as an optical signal, the optical transmitter comprising:

• new overhead applying means for adding new overheads and payloads corresponding to the new overheads to the client signals to generate new format signals wherein the new overheads define data storing bits for negative stuffing and stuffing information notification bits, and the payloads contain the client signals and define data storing bits for positive stuffing;
• signal transmitting means for transmitting the new format signals;
• clock frequency difference detecting means for detecting a clock frequency differences between a client side with at least two input client signals and a transmission path side in the optical transmitter by comparing counted numbers of divided clocks between the at least two input client signals and the transmission path side, the clock frequency difference detecting means comprising multiple clock frequency differences detection means for detecting multiple clock frequency differences with different clock division ratios to be used for comparing the counted numbers, wherein the clock frequency difference detection means utilizes the multiple clock frequency differences detection means to detect the clock frequency differences with multiple frequencies;
• and
• stuff processing means for adjusting the clock frequency difference by utilizing one of the data storing bits for negative stuffing and data storing bits for positive stuffing.