Patent ID: 8571037

Claim:
An optical digital transmission system that accommodates a plurality of client signals with multiplexing, and transmits the client signals as an optical channel transport unit (OTU) frame, wherein the optical digital transmission system newly defines one second negative stuff byte in an overhead area for accommodation of the client signals with multiplexing into the OTU frame, newly defines one third positive stuff byte in a corresponding tributary slot in a payload area for accommodation of client signals with multiplexing, newly defines stuff control bits that is used for decision of the use of the second negative stuff byte and the third positive stuff byte in three different places in the overhead area for client signal accommodation with multiplexing, performs control by using the newly defined stuff control bits when accommodation of the client signal with the third positive stuff byte or the second negative stuff byte is required, and performs stuff control without using the newly defined stuff control bits when accommodation of the client signal by the third positive stuff byte and the second negative stuff byte is not required, wherein the second negative stuff byte is disposed in a third row and a sixteenth column of the OTU frame, the stuff control bits in the three places are dispersedly disposed in a first row and a second row of the sixteenth column of the OTU frame, and the third positive stuff byte is disposed in a row directly above a first positive stuff byte in a corresponding tributary slot.