An optical transmission device for transmitting and receiving a multilevel-modulated optical signal includes a plurality of transmission frame processors for generating transmission frame signals accommodating a plurality of client signals that are each subjected to error correction processing and scrambling/descrambling processing, and a digital modulator/demodulator for mapping the transmission frame signals that are input to and output from the plurality of transmission frame processors to a multilevel signal. The digital modulator/demodulator performs digital modulation/demodulation, in which the plurality of transmission frame processors each have a function of shifting a phase of a pattern between a plurality of transmission frames to be mapped to a multilevel signal and to be digitally modulated/demodulated.

A Flexible Ethernet (FlexE) switch system configured to switch a FlexE client service includes interface circuitry configured to ingress and egress a plurality of FlexE clients; and switch circuitry configured to switch portions of the FlexE clients based on 64b/66b block boundaries between the interface circuitry. A node configured to switch a Flexible Ethernet (FlexE) client service in a network includes one or more line cards configured to ingress and egress a plurality of FlexE clients; and one or more switch fabrics configured to switch portions of the FlexE clients based on 64b/66b block boundaries between the one or more line cards.

A node for a communications network has a converter for digitizing at a receiver clock rate a received optical signal received over an optical link from an optical transmitter at a source node, a framer for detecting frames and a forward error correction part for correcting errors in the payload of the frame. An error rate in the received payload part is monitored and a processor sends, according to the monitored error rate, a request to the optical transmitter to adapt a length of the transmitted forward error correction part and to adapt a clock rate of the transmission of the frame if FEC length is reduced or FEC is disabled. This can enable power saving, when less FEC information is being sent.

A method and device for transmitting data are disclosed, the method comprising: mapping the data to an ODUS, and mapping the ODUS into an OTUS, wherein the rate of the ODUS and the OTUS are M*100 Gb/s, M is a positive integer greater than or equal to 2, and the tributary slot size of the ODUS and the OTUS are 100 Gb/s; distributing the OTUS into M groups of electric channel signals, wherein each group of electric channel signals corresponds to N electric layer channels, N is a positive integer; and mapping all the data distributed into the electric channel signals by the OTUS into the same OChS for transmission, wherein the rate of the OChS is M*100 Gb/s, the M groups of electric channel signals are carried by a single frequency sequence or multiple non-continuous frequency sequences, each frequency sequence carries m groups of electric channel signals, 1mM, m is an integer. The disclosure improves optical fibber utilization efficiency as well as system flexibility and compatibility.

A method, an apparatus, and a system for clock recovery may be used in an optical transport network (OTN). The method includes: receiving a first optical transport network OTN frame data stream, obtaining, from the first OTN frame data stream, a server layer clock and phase difference information carried in a second OTN frame, and adjusting a reference clock of the second OTN frame based on the server layer clock and the phase difference information, where the reference clock of the second OTN frame is used to recover a clock of the second OTN frame.

A method for multiplexing optical signals for transmission over a communication link includes receiving a set of input optical signals. Each input optical signal has an optical intensity at a given time in one of at least two amplitude states. The method further includes selectively adjusting the optical intensity of the input optical signals so that each input optical signal has a respective specific optical intensity for each of the at least two amplitude states. The respective specific optical intensity of each input optical signal in the at least two amplitude states differs such that the respective specific optical intensity of each input optical signal in the at least two amplitude states has a magnitude in which any combination of the input optical signals at any given time sums to a different combined magnitude. The input optical signals are combined to form a combined beam for transmission.

A service processing method and apparatus and a device is disclosed. Synchronization headers of four 66b code blocks are removed, and a 1-bit code block type indication is added as control information of service data, to be encoded as a 257b code block. This avoids a bandwidth waste caused by the synchronization headers, and improves bandwidth utilization. When a 257b code block stream is mapped to an OSUflex frame, the code block type indication is mapped to an overhead area of the OSUflex frame, the four 66b code blocks from which the synchronization headers are removed are mapped to a payload area of the OSUflex frame, and check information obtained by checking the control information is mapped to the overhead area of the OSUflex frame, so that bit error protection is performed on the control information.