Embodiments relate to optical transport technologies, and more specifically, to a clock transmission method. Under this method, a first optical data unit (ODU) container can be obtained. Phase discrimination can be performed on an obtained first clock and a first ODU clock of a transmit end, to generate a first PD value. The first PD value can then be inserted into an overhead of the first ODU container. The first ODU container can be encapsulated into a second ODU container, and the second ODU container can be sent. A rate of the second ODU container is higher than a rate of the first ODU container. The first PD value is transmitted in the first ODU container which is not decapsulated in a subsequent transmission process. Therefore, final recovery of the first clock is not affected, so that a deviation between a finally recovered clock and the first clock is greatly reduced.

This application provides a data transmission method in an optical network and an optical network device. The method includes: obtaining, by a first device, first synchronization information from a first service data stream, and determining a to-be-transmitted service data stream; generating second synchronization information based on the first synchronization information; mapping the second synchronization information and the to-be-transmitted service data stream to an optical carrier container; and sending the optical carrier container. A second device receives the optical carrier container; obtains a second service data stream and third synchronization information from the optical carrier container through demapping; generates fourth synchronization information based on the third synchronization information; and inserts the fourth synchronization information into the second service data stream, to obtain a third service data stream. In this way, time synchronization precision is improved.

This application provides a data transmission method in an optical network and an optical network device. The method includes: obtaining, by a first device, first synchronization information from a first service data stream, and determining a to-be-transmitted service data stream; generating second synchronization information based on the first synchronization information; mapping the second synchronization information and the to-be-transmitted service data stream to an optical carrier container; and sending the optical carrier container. A second device receives the optical carrier container; obtains a second service data stream and third synchronization information from the optical carrier container through demapping; generates fourth synchronization information based on the third synchronization information; and inserts the fourth synchronization information into the second service data stream, to obtain a third service data stream. In this way, time synchronization precision is improved.

Embodiments relate to optical transport technologies, and more specifically, to a clock transmission method. Under this method, a first optical data unit (ODU) container can be obtained. Phase discrimination can be performed on an obtained first clock and a first ODU clock of a transmit end, to generate a first PD value. The first

PD value can then be inserted into an overhead of the first ODU container. The first ODU container can be encapsulated into a second ODU container, and the second ODU container can be sent. A rate of the second ODU container is higher than a rate of the first ODU container. The first PD value is transmitted in the first ODU container which is not decapsulated in a subsequent transmission process. Therefore, final recovery of the first clock is not affected, so that a deviation between a finally recovered clock and the first clock is greatly reduced.

A method for passing communications over an Optical Transport Network (OTN) from a first communication interface to a second communication interface. The first interface extracts characters from received data symbols, maps the characters into OTN communication frames and discards the synchronization symbols. The mapping is performed using a Bit-synchronous Mapping Procedure (BMP), while filling some locations in the OTN frames with stuffing characters, so that the rate of the characters matches a desired rate of the OTN communication frames. The characters are extracted from the communication frames in the second communication interface by synchronizing to the mapped input frames independently of the synchronization symbols. The input frames are reconstructed to produce reconstructed input frames including the data symbols and the synchronization symbols, by re-encoding the extracted characters. In some embodiments, data from Ethernet frames is passed along with the extracted characters in the OTN frames.

A method for communication includes receiving in a first communication interface input frames, which include data symbols that were derived by encoding respective characters, and further include one or more synchronization symbols having no corresponding characters. The characters from the data symbols are recovered, and the recovered characters are transmitted to a second communication interface by mapping the characters into communication frames and discarding the synchronization symbols. The characters are extracted from the communication frames in the second communication interface by synchronizing to the input frames independently of the synchronization symbols. The input frames are reconstructed in the second communication interface, including the data symbols and the synchronization symbols, by re-encoding the extracted characters.

A method for communication includes, receiving in a first communication interface input frames, which include data symbols derived by encoding respective characters, and one or more synchronization symbols distinguishable from the data symbols. The characters are recovered from the data symbols, and transmitted to a second communication interface by mapping the characters into communication frames and discarding the synchronization symbols, wherein a protocol for delivering the characters supports a mapping scheme for delivering the characters at a first data rate, and mapping the characters includes mapping the characters so as to deliver the characters at a second data rate lower than the first data rate. The characters are extracted from the communication frames in the second communication interface by synchronizing to the mapped input frames independently of the synchronization symbols. The input frames are reconstructed to including the data symbols and the synchronization symbols, by re-encoding the extracted characters.