A transmission apparatus includes: a first mapping unit configured to allocate a first frame that stores a client signal to an intermediate frame; a second mapping unit configured to allocate the intermediate frame to a second frame that has a higher bit rate than a bit rate of the first frame; and a rate controller configured to control a bit rate of the intermediate frame based on the bit rate of the first frame and the bit rate of the second frame.

An optical receiver includes a reception module, a first detector, a second detector, a shift module, a first extraction module, and a second extraction module. The reception module receives a frame. The first detector detects a head position of a first layer, the head position being included in the frame. The second detector detects a head position of a second layer, the head position being included in the frame. The shift module shifts the frame so that the head position of the first layer and the head position of the second layer are located at respective predetermined positions. The first extraction module extracts a header of the first layer from the frame after the frame is shifted. The second extraction module extracts a header of the second layer from the frame after the frame is shifted.

A transmitter may receive client data, associated with a client rate, to be mapped to frames associated with a server rate. The transmitter may generate justifications associated with the mapping of the client data to the frames. The transmitter may create, based on the justifications, artificial justifications that include information associated with justifications created to shape phase variations present in a recovered client clock associated with the client rate. The phase variations may be shaped based on the artificial justifications to cause shaped phase variations to be present in the recovered client clock. The shaped phase variations may include phase variations that can be filtered from the recovered client clock. The transmitter may map the client data to the frames based on the artificial justifications to cause the shaped phase variations to be present in the recovered client clock.

The present invention and its embodiments are made to provide for dynamic hitless resizing in optical transport network without any identification of matching time slots by the Network Management System (NMS) or any control plane signaling including Generalised Multi Protocol Label Switching (GMPLS). An aspect of the invention provides for a method of hitless ODUflex connection resizing in an optical transport network by incrementing or decrementing the ODUflex connection between the nodes, based on an indication command given to a source node for bandwidth increase or decrease, by identifying and matching at least one time slot through Link Connection Resizing (LCR) protocol message exchanges. Another aspect of the invention provides for a method of hitless ODUflex connection resizing in an optical transport network by decrementing the matching time slot used for the incrementing operation, in case of unsuccessful incrementing operation between nodes.

A frame generating apparatus accommodating a client signal in an optical data transfer unit frame with a higher bit rate than the client signal includes a deserializer, a plurality of generic mapping procedure circuits, and a serializer. The deserializer deserializes 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. The plurality of generic mapping procedure circuits inserts data and 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. The serializer serializes the parallel signals output from the plurality of generic mapping procedure circuits.

Method and apparatus for transporting client signals in an MN are illustrated. In one embodiment, the method includes: mapping a client signal into a first Optical Channel Data Tributary Unit (ODTU) frame including an ODTU payload area and an ODTU overhead area, such that a plurality of n-bit data units of the client signal are inserted into the ODTU payload area and number information is inserted into the ODTU overhead area; mapping the first ODTU frame into the OPUk frame, such that the plurality of n-bit data units are mapped into an OPUk payload part occupying at least one Tributary Slot (TS) of the OPUk payload area and the number information of the ODTU overhead area is mapped into a first OPUk overhead part of the OPUk frame; forming an Optical Channel Transport Unit-k (OTUk) frame including the OPUk frame for transmission.

An embodiment method includes: mapping a to-be-transmitted optical channel unit signal of n times a benchmark rate to X first optical channel physical link signals; adding a link sequence indicator overhead to each of the X first optical channel physical link signals, to generate X second optical channel physical link signals; and modulating and sending the X second optical channel physical link signals by using X preset optical modules in a one-to-one manner. A rate of the first optical channel physical link signal is m.sub.i times the benchmark rate, n≥2, X≥2, m.sub.i≥1, and $\underset{t-1}{\overset{X}{.Math.}}{m}_i=n.$

A transmission apparatus includes: a generator configured to generate position information indicating a position of header information of each of a plurality of first signals from a second signal nesting the plurality of first signals; a storage configured to store the position information generated by the generator and the plurality of first signals; a monitor configured to read the position information and the plurality of first signals stored in the storage, and to monitor the header information of each of the plurality of first signals based on the position information; and an output unit configured to output the plurality of first signals after monitoring the contents of the header information.

In the optical transport system a transport frame generator divides a transport frame accommodating plural client signals into plural transmission signals. Subcarrier transmission units convert the signals into optical signals using different optical carriers and transmit the converted optical signals. Subcarrier reception units receive the transmitted optical signals and convert the optical signals into reception signals. A transport frame termination unit combines the reception signals to restore the transport frame. A time-demultiplexing processor time-demultiplexes the restored transport frame to be separated into the client signals. A time slot control unit determines a new time slot allocation when time-multiplexing the client signals in the transport frame and stops supply of electric power to a subcarrier transmission unit and a subcarrier reception unit that transmit and receive an optical signal to which the client signals are not allocated.

A framer in a transmission device allocates plural optical channel time slots to a plurality of logical prioritized paths. It allocates received client signals to the allocated time slots, and transmits the client signals by a plurality of optical subcarriers that use a plurality of optical wavelengths corresponding to the plurality of time slots. The framer includes: a time slot allocation unit that, in a case where an optical wavelength corresponding to a time slot allocated to a logical path having a high transmission priority is not used, allocates at least one of the plurality of time slots to the logical path having the high transmission priority while the time slot corresponding to the unused optical wavelength is avoided, to change the time slot allocated to the logical path having the high transmission priority.