Frame generating apparatus and frame generating method

A frame generating method for accommodating a client signal in an optical data transfer unit frame with a higher bit rate than the client signal, the method comprising:

• deserializing, by an apparatus, the client signal into parallel signals, the number of parallel signals corresponding to the number of tributary slots used in the optical data transfer unit frame;
• inserting, by an apparatus, data and stuff into a frame accommodating portion of the optical data transfer unit frame based on a difference in bit rate between the client signal and the optical data transfer unit frame;
• and
• serializing, by an apparatus, the parallel signals after inserting data and stuff into the frame accommodating portion of the optical data transfer unit frame, wherein data is inserted into the frame accommodating portion of the optical data transfer unit frame in accordance with an address when a first expression (N×Cn) mod Tb<Cn is satisfied, and stuff is inserted into the frame accommodating portion in accordance with an address when a second expression (N×Cn) mod Tb>Cn is satisfied, “N” representing the address assigned to the frame accommodating portion of the optical data transfer unit frame, “Cn” representing (a bit rate of the client signal)÷(a bit rate of the optical data transfer unit frame)×(the total number of bytes in the frame accommodating portion of the optical data transfer unit frame), “Tb” representing the total number of bytes in a signal accommodating portion, and “mod” representing a remainder operator.

A frame generating apparatus that accommodates a client signal in an optical data transfer unit frame with a higher bit rate than the client signal, the frame generating apparatus comprising:

• a generic mapping procedure circuit circuitry that inserts data or stuff into a frame accommodating portion of the optical data transfer unit frame based on a difference in the bit rate between the client signal and the optical data transfer unit frame and maps a group of M successive bytes of the client signal into a group of M successive bytes of the optical data transfer unit frame, where M is the number of tributary slots of the optical data transfer unit frame;
• and
• wherein the generic mapping procedure circuit that circuitry in accordance with an address inserts data into the frame accommodating portion of the optical data transfer unit frame when a first expression (N×Cn) mod Tb<Cn is satisfied, and inserts stuff into the frame accommodating portion of the optical data transfer unit frame when a second expression (N×Cn) mod Tb≥Cn is satisfied, “N” representing the address assigned to the frame accommodating portion of the optical data transfer unit frame, “Cn” representing (a bit rate of the client signal)÷(a bit rate of the optical data transfer unit frame)×(the total number of bytes in the frame accommodating portion of the optical data transfer unit frame)(a total number of bytes in the frame accommodating portion of the optical data transfer unit frame), “Tb” representing the total number of bytes in a signal accommodating portion, and “mod” representing a remainder operator.