Abstract: A data transmission method, an apparatus, and a system are provided. An optical device of a transmitter may select one inner-code processing mode from a plurality of inner-code processing modes based on a requirement, and indicate the inner-code processing mode to an optical module of a receiver. The selected inner-code processing mode may be indicated to the receiver by using a PAD sequence, without requiring an additional resource and without changing a baud rate of a data stream. The optical device of the receiver may also detect quality of a current link, to select an inner-code processing mode that matches the quality, and feed back the inner-code processing mode to the transmitter, so that the transmitter can switch the inner-code processing mode based on an indication.

Abstract: This application discloses a data processing method. First data processing is performed on a plurality of first data streams obtained through first FEC encoding, to obtain m second data streams. Second FEC encoding has been performed for each of the second data streams, and each codeword obtained through the second FEC encoding includes N bits, where N=K+S. Second data processing is separately performed on the m second data streams to obtain m third data streams. Each of the third data streams includes at least one bit sequence, each bit sequence includes P+W bits, the P bits in each bit sequence are from the second data stream, and the W bits in each bit sequence are an added alignment marker, where P=N×b. Third data processing is performed on the m third data streams to obtain Y modulated symbol streams, where modulation has been performed for each of the modulated symbol streams.

Abstract: This disclosure relates to a receiver device for pulse amplitude modulation (PAM) signals. The receiver device calculates a transmitter dispersion eye closure quaternary (TDECQ). The receiver device first obtains a signal, wherein the signal is based on a PAM signal sent by a transmitter device over a channel to the receiver device, and filters the obtained signal. Further, the transmitter device equalizes the filtered signal using a FFE with multiple taps, and filters the equalized signal output by the FFE using a 2-tap post filter, wherein high frequency noise caused by the FFE is compressed. The receiver device applies a Max-Log-Map (MLM) algorithm on the filtered signal output by the 2-tap post filter, reconstructs a signal constellation of the PAM signal based on the result of the MLM algorithm, and calculates a TDECQ based on the reconstructed signal constellation.

Abstract: The disclosure relates to an optical device for wavelength division multiplexing of two or more input beams. The disclosure proposes the optical device, and a corresponding method for operating the optical device. The optical device comprises a multiplexer and two or more channels for the two or more input beams, wherein each channel is configured to receive one input beam of the two or more input beams and to provide a rotated beam, which has a polarization rotated compared to a polarization of the corresponding input beam, to the multiplexer, and wherein at least one channel of the two or more channels is configured to rotate the polarization of the corresponding input beam in a different direction than at least one other channel of the two or more channels.

Abstract: A dummy optical signal generation apparatus includes a multi-longitudinal mode laser configured to provide a light source signal. The dummy optical signal generation also includes a comb optical bandpass filter. The light source signal provided by the multi-longitudinal mode laser outputs a dummy optical signal through the comb optical bandpass filter. The dummy optical signal is an optical signal that does not comprise service information.

Abstract: A dummy optical signal generation apparatus includes a multi-longitudinal mode laser configured to provide a light source signal. The dummy optical signal generation also includes a comb optical bandpass filter. The light source signal provided by the multi-longitudinal mode laser outputs a dummy optical signal through the comb optical bandpass filter. The dummy optical signal is an optical signal that does not comprise service information.

Abstract: Techniques for providing curved facet semiconductor lasers. are disclosed. In one particular embodiment, the techniques may be realized as a semiconductor laser, comprising a waveguide, wherein the waveguide includes a facet formed at an edge of the semiconductor laser, and the facet has a curvature.

Abstract: The present invention discloses a rendezvous point convergence method and apparatus and relates to the field of communications, to solve a problem that an entire network cannot work normally for a long time because a network device cannot send a candidate RP advertisement message to a bootstrap router BSR when the network device served as a rendezvous point RP is entirely faulty. In the present invention, when a route of an original working RP is unreachable, a first node receives a bootstrap message sent by a BSR, where Holdtime of the original working RP carried in the bootstrap message is 0; and the first node disables the original working RP and enables a candidate RP as a new working RP according to the bootstrap message. The present invention is applicable to the field of communications to implement rendezvous point convergence.

Abstract: The present invention discloses a rendezvous point convergence method and apparatus and relates to the field of communications, to solve a problem that an entire network cannot work normally for a long time because a network device cannot send a candidate RP advertisement message to a bootstrap router BSR when the network device served as a rendezvous point RP is entirely faulty. In the present invention, when a route of an original working RP is unreachable, a first node receives a bootstrap message sent by a BSR, where Holdtime of the original working RP carried in the bootstrap message is 0; and the first node disables the original working RP and enables a candidate RP as a new working RP according to the bootstrap message. The present invention is applicable to the field of communications to implement rendezvous point convergence.