This application provides data transmission methods and apparatuses. One method includes: processing, by a network device, a first optical data unit (ODU) to obtain a second ODU, wherein a bit rate of the second ODU is lower than a bit rate of the first ODU; and sending, by the network device, the second ODU.

The disclosure relates to a distribution device and an information device. The distribution device comprises a communication part, a memory part and a controller. The communication part communicates with an external device. The memory part stores a video data. The controller transmits the video data to the external device through the communication part. The controller transmits the video data to the external device based on a request signal from the external device, and the video data includes a predetermined data that is different from the video data.

Methods and devices for transmitting a continuous bit stream in a digital network non-synchronous with the bit stream are disclosed. In one aspect, the method includes digitizing a continuous bit stream implemented by a transmitting apparatus and restoring the continuous bit stream implemented by a receiving apparatus. A processor of the transmitting apparatus digitizes the initial continuous bit stream into a binary data sequence to be transmitted at a nominal frequency corresponding to a set clock period, the binary data to be transmitted being encapsulated in at least one transport frame sent to the receiving apparatus. The digitization includes estimating a mean emission clock period value of the data sequence, and inserting, in a predetermined field of the transport frame, information making it possible to restore, in the receiving apparatus, the mean emission clock period value of the data sequence.

Methods and devices for transmitting a continuous bit stream in a digital network non-synchronous with the bit stream are disclosed. In one aspect, the method includes digitizing a continuous bit stream implemented by a transmitting apparatus and restoring the continuous bit stream implemented by a receiving apparatus. A processor of the transmitting apparatus digitizes the initial continuous bit stream into a binary data sequence to be transmitted at a nominal frequency corresponding to a set clock period, the binary data to be transmitted being encapsulated in at least one transport frame sent to the receiving apparatus. The digitization includes estimating a mean emission clock period value of the data sequence, and inserting, in a predetermined field of the transport frame, information making it possible to restore, in the receiving apparatus, the mean emission clock period value of the data sequence.

The present disclosure relates to a service sending method and apparatus, and a service receiving method and apparatus. One example service sending method includes obtaining, by a network device, a first data stream and a second data stream, and inserting the first data stream into the second data stream to generate a third data stream. The third data stream includes a first information block and a second information block, the first information block is used to carry the first data stream, the second information block is used to carry a first data stream distribution indication map, the first data stream distribution indication map is used to indicate a location of the first information block, and the second information block is identified by using a preset map block type.

A method for rate adapting a constant bit rate (CBR) client signal into a signal stream in a telecom signal communication link includes at a source node encoding into a control block a control block header, and an ordered set block-designator, encoding into a plurality of path overhead data blocks a data block header and a count of data blocks to be encoded in a signal block, encoding into each of a plurality of signal blocks a data block header, the data blocks from the CBR signal equal to the count and pad blocks, assembling the blocks into a path signal frame, appending a set of idle character blocks following the end of the path signal frame to match a link bit rate of a first link segment, and transmitting the path signal frame and idle character blocks into the first link segment at the link bit rate.

A data transmission method, a transmitter, and a receiver, where the method includes obtaining constant bit rate (CBR) service data, performing physical coding sublayer (PCS) encoding on the CBR service data, inserting a rate adaptation code block in a PCS bitstream obtained by PCS encoding to perform rate adaptation on the PCS bitstream, mapping the adapted PCS bitstream to N timeslots of a flexible Ethernet (FlexE) frame, where N is a positive integer greater than or equal to one, and sending the FlexE frame, where FlexE overhead of the FlexE frame includes information indicating the N timeslots corresponding to the PCS bitstream. Hence, according to the data transmission method, the transmitter, and the receiver, the CBR service data may be mapped to a FlexE, and a carrying capability of the FlexE is improved.

An optical transmission apparatus includes a detecting circuit configured to detect one or more empty slots in which a data signal is not accommodated in a plurality of slots included in a frame, a frame processing circuit configured to reduce size of the frame by deleting the one or more empty slots from the frame based on a detection result of the one or more empty slots and closing up gaps between remaining slots in the plurality of slots, and an optical modulation processing circuit configured to carry out multi-level modulation of the frame at a bit rate according to size of the frame after reduction.

A data transmission method, a transmitter, and a receiver, where the method includes obtaining constant bit rate (CBR) service data, performing physical coding sublayer (PCS) encoding on the CBR service data, inserting a rate adaptation code block in a PCS bitstream obtained by PCS encoding to perform rate adaptation on the PCS bitstream, mapping the adapted PCS bitstream to N timeslots of a flexible Ethernet (FlexE) frame, where N is a positive integer greater than or equal to one, and sending the FlexE frame, where FlexE overhead of the FlexE frame includes information indicating the N timeslots corresponding to the PCS bitstream. Hence, according to the data transmission method, the transmitter, and the receiver, the CBR service data may be mapped to a FlexE, and a carrying capability of the FlexE is improved.

This application provides a data transmission method and apparatus. The method includes: processing, by a network device, a to-be-sent optical data unit ODU to obtain another ODU, where a bit rate of the another ODU is lower than a bit rate of the ODU; and sending, by the network device, the another ODU. In embodiments of this application, the ODU is processed to obtain the another ODU with a lower bit rate, and this helps reduce a rate increase when service data is transmitted in an OTN, so as to reduce an OTN interface rate and OTN costs.