Information transmission method, apparatus and system based on coherent optical module

Abstract

Disclosed in the embodiments of the present application are an information transmission method, apparatus and system based on a coherent optical module. Two ends of a communication system are a first device and a second device, respectively. The first device sends a first frame to the second device to notify the second device of, in a first coherent optical module of the first device, whether an LO optical signal and an optical signal to be sent are from the same source; and the second device sends a second frame to the first device to notify the first device of, in a location second coherent optical module of the second device, whether an LO optical signal and an optical signal to be sent are from the same source. By means of the method, by means of sending frames to each other, two ends of a communication system can notify the peer end of, in respective coherent optical modules, whether an LO optical signal and an optical signal to be sent are from the same source, such that the coherent optical modules on the two ends can configure light emission frequencies for respective light sources in a targeted manner, thereby making the coherent optical modules on the two ends reduce frequency offsets to an allowable range, and thus ensuring correct recovery of data.

Description

Information transmission method, device and system based on coherent optical module

[0001] The present application claims priority from the Chinese patent application No. 202410979016.5 filed on July 19, 2024, and entitled "Information transmission method, device and system based on coherent optical module", the whole content of which is incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the field of communication technology, in particular to an information transmission method, device and system based on a coherent optical module. BACKGROUND

[0003] A coherent optical module refers to an optical module that uses coherent communication technology to realize data communication. Unlike a direct modulation / direct detection optical signal that only uses amplitude variation information of an optical signal to transmit data, both phase and amplitude information of a coherent optical signal are used to transmit data. The reception and demodulation of the coherent optical signal require mixing a local oscillator (LO) optical signal with the coherent optical signal to obtain phase information. In order to improve signal processing efficiency, reduce energy consumption and chip complexity, the coherent optical module requires that the frequency of the LO optical signal and the carrier frequency of the received coherent optical signal cannot have a large frequency deviation (referred to as frequency deviation) in order to recover data from the received signal.

[0004] In actual applications, the wavelengths of lasers provided by different manufacturers may be different, and therefore the coherent optical modules at both ends of the link may have the above-mentioned frequency deviation problem, and the frequency deviation may even exceed the standard allowed range. In the coherent optical module, the optical carrier used by the integrated coherent transmitter (ICT) and the LO optical signal used by the integrated coherent receiver (ICR) can be provided by the same light source or different light sources. At present, the frequency of the local LO optical signal is adjusted according to the actually received coherent optical signal for each type of coherent optical module to minimize the frequency deviation. However, based on the difference in the types of light sources of the coherent optical modules at both ends, there can be multiple different scenarios, and in some scenarios, even if the current way of dealing with frequency deviation is used, it cannot be guaranteed that the coherent optical modules at both ends can converge the frequency deviation to the allowed range, thereby affecting data recovery. SUMMARY

[0005] The present application provides an information transmission method, device and system based on a coherent optical module.

[0006] In a first aspect, the present application provides a method for information transmission based on a coherent optical module. Specifically, a first device sends a first frame to a second device, the first frame being used to indicate whether a local oscillator (LO) optical signal in a first coherent optical module and an optical signal to be transmitted are homologous. The first device is the first coherent optical module, or the first device is connected to the first coherent optical module. The first device receives a second frame sent by the second device, the second frame being used to indicate whether the LO optical signal in a second coherent optical module and the optical signal to be transmitted are homologous. The second device is the second coherent optical module, or the second device is connected to the second coherent optical module. It should be understood that if the LO optical signal and the optical signal to be transmitted are obtained from light emitted by the same light source, then the LO optical signal and the optical signal to be transmitted are homologous; if the LO optical signal and the optical signal to be transmitted are obtained from light emitted by different light sources, then the LO optical signal and the optical signal to be transmitted are not homologous.

[0007] In example 1, the first device is a first host, the second device is a second host, and the information transmission is performed between the first host and the second host. In example 2, the first device is a first host, the second device is a second coherent optical module, and the information transmission is performed between the first host and the second coherent optical module. In example 3, the first device is a first coherent optical module, the second device is a second host, and the information transmission is performed between the first coherent optical module and the second host. In example 4, the first device is a first coherent optical module, the second device is a second coherent optical module, and the information transmission is performed between the first coherent optical module and the second coherent optical module.

[0008] In this embodiment, the two ends of the communication system can inform the opposite end whether the LO optical signal and the optical signal to be transmitted in their respective coherent optical modules are homologous by sending frames to each other, so that the two ends of the coherent optical module can configure the light-emitting frequency for their respective light sources, and promote the two ends of the coherent optical module to converge the frequency offset to the allowed range, which is conducive to ensuring the correct recovery of data.

[0009] In some possible embodiments, in the coherent optical module using the first light source type, the LO optical signal and the optical signal to be transmitted are not homologous. In the coherent optical module using the second light source type, the LO optical signal and the optical signal to be transmitted are homologous. That is, the present application is compatible with optical modules of multiple different light source types, which enriches the application scenarios of the present application.

[0010] In some possible implementation manners, the first frame is further used to indicate whether there is a wavelength locking device in the light source of the first coherent light module, and the second frame is further used to indicate whether there is a wavelength locking device in the light source of the second coherent light module. The light source with the wavelength locking device has a smaller fluctuation range of the light emission frequency. That is, the first device and the second device can inform the peer of more information about the capability of the light source of the device in the capability advertisement stage, so as to facilitate the first device and the second device to negotiate a reasonable frequency adjustment mechanism more quickly, and facilitate the improvement of the convergence efficiency of the frequency offset.

[0011] In some possible implementation manners, the first frame is further used to indicate the accuracy of the light emission frequency of the light source in the first coherent light module, and the second frame is further used to indicate the accuracy of the light emission frequency of the light source in the second coherent light module. The accuracy of the light emission frequency of the light source is used to represent the fluctuation range of the light emission frequency of the light source. By extending the information transmitted by the first device and the second device in the capability advertisement stage, the first device and the second device can negotiate a reasonable frequency adjustment mechanism more quickly, and facilitate the improvement of the convergence efficiency of the frequency offset.

[0012] In some possible implementation manners, the method further includes: the first device sends a third frame to the second device. The third frame is used to request the second coherent light module to fix the frequency of the second LO optical signal or adjust the frequency of the second LO optical signal, and the third frame is further used to request the second coherent light module to fix the frequency of the second optical signal or adjust the frequency of the second optical signal. The second LO optical signal and the second optical signal are generated by the second coherent light module, and the second optical signal is used to send to the first coherent light module. In this implementation manner, after the capability advertisement is completed, the first device initiates negotiation with the second device according to the capabilities of both parties, so that the two parties can negotiate in a targeted manner to determine the frequency adjustment mechanism, and facilitate the improvement of the efficiency of negotiation and the efficiency of frequency offset convergence.

[0013] In some possible implementation manners, after the first device sends the third frame to the second device, the method further includes: the first device receives a fourth frame sent by the second device according to the third frame. The fourth frame is used to indicate whether to agree to the request of the third frame. That is, after receiving the request sent by the first device, the second device informs the first device whether to agree to the request of the first device, and the negotiation process of both parties is improved.

[0014] In some possible implementation manners, the fourth frame is used to indicate whether the second coherent light module fixes the frequency of the second LO optical signal or adjusts the frequency of the second LO optical signal, and the fourth frame is further used to indicate whether the second coherent light module fixes the frequency of the second optical signal or adjusts the frequency of the second optical signal. That is, the second device can inform the first device of the working mode selected by the local second coherent light module according to the request of the first device, so as to indicate whether to agree to the request of the first device in this way, and the implementation manners of the present solution are enriched.

[0015] In some possible implementation, the third frame is further configured to instruct the first coherent light module to fix or adjust a frequency of the first LO light signal, and the third frame is further configured to instruct the first coherent light module to fix or adjust a frequency of the first light signal. The first LO light signal and the first light signal are generated by the first coherent light module, and the first light signal is used to transmit to the second coherent light module. That is, the first device informs the second device of the working mode selected by the local first coherent light module through the third frame when initiating the request through the third frame, so that the second device can learn the working mode of the first coherent light module earlier, and the negotiation efficiency is improved.

[0016] In some possible implementation, the third frame is further configured to request the second coherent light module to transmit signals in a first signal mode, and the first signal mode includes at least one of a first signal modulation format and a first signal baud rate. It should be understood that the acceptance capability of the coherent light module to the frequency offset is different for different signal modulation formats and different signal baud rates. Therefore, the first device and the second device are required to negotiate based on the same signal mode, so that the first device and the second device can communicate with each other, thereby ensuring the smooth negotiation.

[0017] In some possible implementation, after the first device transmits the third frame to the second device, the method further includes that the first device transmits a fifth frame to the second device. The fifth frame is configured to request the second coherent light module to fix or adjust a frequency of the second LO light signal, and the fifth frame is further configured to request the second coherent light module to fix or adjust a frequency of the second light signal, and the fifth frame is further configured to request the second coherent light module to transmit signals in a second signal mode. The second signal mode includes at least one of a second signal modulation format and a second signal baud rate. In this implementation, the negotiation stage can be divided into multiple rounds of negotiation, that is, the frames transmitted in the first round of negotiation are all in the first signal modulation format and the first signal baud rate, and the frames transmitted in the second round of negotiation are all in the second signal modulation format and the second signal baud rate, so that the first device and the second device can complete the negotiation based on multiple signal modes, and the frequency offset convergence can be well achieved regardless of the actual signal mode adopted by the coherent light module.

[0018] In some possible implementation, the second signal modulation format is higher than the first signal modulation format, and the second signal baud rate is greater than the first signal baud rate. It should be understood that the higher the order of the signal modulation format and the higher the signal baud rate, the more stringent the requirement for the frequency offset. Therefore, the lower signal baud rate and the lower order signal modulation format can tolerate the transmission of information under a larger frequency offset, and the negotiation based on the lower signal baud rate and the lower order signal modulation format is more conducive to ensuring the smooth negotiation.

[0019] In some possible implementation, if the third frame is used to request the second coherent light module to adjust the frequency of the second LO light signal, and the second device agrees to the request of the third frame, the absolute value of the difference between the frequency of the first light signal sent by the first coherent light module and the frequency of the adjusted second LO light signal is smaller than the absolute value of the difference between the frequency of the first light signal sent by the first coherent light module and the frequency of the unadjusted second LO light signal. That is, after the scheme of frequency adjustment is determined through negotiation, the coherent light module adjusts the frequency of the LO light signal generated by itself according to the actual received light signal frequency, so as to reduce the frequency offset between them.

[0020] In some possible implementation, in the first coherent light module, the first LO light signal and the first light signal are from different sources. In the second coherent light module, the second LO light signal and the second light signal are from the same source. The third frame is used to request the second coherent light module to adjust the frequency of the second LO light signal and the frequency of the second light signal. After the second coherent light module adjusts the frequency of the second LO light signal and the frequency of the second light signal according to the frequency of the first light signal, the method further includes that the first device receives a sixth frame sent by the second device, and the sixth frame is used to request the first coherent light module to adjust the frequency of the first LO light signal and fix the frequency of the first light signal.

[0021] In this implementation, the first coherent light module adopts an independent LO light source, and the second coherent light module adopts a shared LO light source. The first coherent light module has higher flexibility in adjusting the light emission frequency of the light source. Therefore, through negotiation, it is determined that the frequency of the second LO light signal and the frequency of the second light signal are first adjusted by the second coherent light module, and then the frequency of the first LO light signal is adjusted by the first coherent light module, so as to ensure that the coherent light modules at both ends can well realize frequency offset convergence.

[0022] In some possible implementation, the third frame is further used to request the second coherent light module to transmit signals in a first signal mode, and the first signal mode includes at least one of a first signal modulation format and a first signal baud rate. After the first coherent light module adjusts the frequency of the first LO light signal according to the frequency of the second light signal, the method further includes that the first device sends a fifth frame to the second device. The fifth frame is used to request the second coherent light module to adjust the frequency of the second LO light signal and the frequency of the second light signal, and the fifth frame is further used to request the second coherent light module to transmit signals in a second signal mode, and the second signal mode includes at least one of a second signal modulation format and a second signal baud rate. That is, after the first round of negotiation between the first device and the second device based on the first signal mode is completed, the second round of negotiation between the first device and the second device based on the second signal mode is performed. No matter which signal mode is actually adopted by the coherent light module, frequency offset convergence can be well realized.

[0023] In some possible implementation manners, in the first coherent light module, the first LO light signal and the first light signal are from different sources. In the second coherent light module, the second LO light signal and the second light signal are from different sources. The third frame is used to request the second coherent light module to adjust the frequency of the second LO light signal and fix the frequency of the second light signal, and the method further includes: the first device receives a seventh frame sent by the second device, and the seventh frame is used to request the first coherent light module to adjust the frequency of the first LO light signal and fix the frequency of the first light signal.

[0024] In this implementation manner, both the first coherent light module and the second coherent light module use independent LO light sources, and both the first coherent light module and the second coherent light module can adjust the frequency of the LO light signal according to the frequency of the received light signal, so that the coherent light modules at both ends can well realize frequency offset convergence.

[0025] In some possible implementation manners, the third frame is further used to request the second coherent light module to transmit signals in a first signal mode, and the first signal mode includes at least one of a first signal modulation format and a first signal baud rate. After the first coherent light module adjusts the frequency of the first LO light signal according to the frequency of the second light signal, the method further includes: the first device sends a fifth frame to the second device. The fifth frame is used to request the second coherent light module to adjust the frequency of the second LO light signal and fix the frequency of the second light signal, and the fifth frame is further used to request the second coherent light module to transmit signals in a second signal mode, and the second signal mode includes at least one of a second signal modulation format and a second signal baud rate. That is, after the first device and the second device complete the first round of negotiation based on the first signal mode, the first device and the second device perform a second round of negotiation based on the second signal mode, and no matter which signal mode is actually used by the coherent light modules, frequency offset convergence can be well realized.

[0026] In some possible implementation manners, in the first coherent light module, the first LO light signal and the first light signal are from different sources; in the second coherent light module, the second LO light signal and the second light signal are from different sources. The method further includes: the first device negotiates with the second device to determine that the first coherent light module adjusts the frequency of the first LO light signal and the frequency of the first light signal first, and then the second coherent light module adjusts the frequency of the second LO light signal and the frequency of the second light signal.

[0027] In this implementation manner, the first coherent light module and the second coherent light module use shared LO light sources, and therefore, it is determined through negotiation that the first coherent light module adjusts the light emission frequency of the light source first and the second coherent light module adjusts the light emission frequency of the light source later, so that the negotiation process can be smoothly performed.

[0028] In some possible implementation manners, in the first coherent light module, the first LO light signal and the first light signal are homologous; in the second coherent light module, the second LO light signal and the second light signal are homologous. The light source of the first coherent light module has a wavelength locking device, the light source of the second coherent light module does not have a wavelength locking device, and / or the accuracy of the light emitting frequency of the light source in the first coherent light module is higher than the accuracy of the light emitting frequency of the light source in the second coherent light module. The third frame is used to request the second coherent light module to fix the frequency of the second LO light signal and the frequency of the second light signal, and the method further comprises: the first device receiving the eighth frame sent by the second device, the eighth frame being used to request the first coherent light module to adjust the frequency of the first LO light signal and the frequency of the first light signal. After the first coherent light module adjusts the frequency of the first LO light signal and the frequency of the first light signal according to the frequency of the second light signal, the method further comprises: the first device sending the ninth frame to the second device, the ninth frame being used to request the second coherent light module to adjust the frequency of the second LO light signal and the frequency of the second light signal.

[0029] In this implementation manner, although the first coherent light module and the second coherent light module both use the light source sharing the LO, the first coherent light module has a wavelength locking device, the second coherent light module does not have a wavelength locking device, and / or the accuracy of the light emitting frequency of the light source in the first coherent light module is higher than the accuracy of the light emitting frequency of the light source in the second coherent light module. Therefore, by negotiation, it is determined that the frequency of the first LO light signal and the frequency of the first light signal are first adjusted by the first coherent light module, and then the frequency of the second LO light signal and the frequency of the second light signal are adjusted by the second coherent light module, so that the coherent light modules at both ends can well realize the frequency offset convergence.

[0030] In some possible implementation manners, the third frame is further used to request the second coherent light module to transmit signals in a first signal mode, the first signal mode comprising at least one of a first signal modulation format and a first signal baud rate. After the second coherent light module adjusts the frequency of the second LO light signal and the frequency of the second light signal according to the frequency of the first light signal, the method further comprises: the first device receiving the tenth frame sent by the second device. The tenth frame is used to request the first coherent light module to adjust the frequency of the first LO light signal and the frequency of the first light signal, and the tenth frame is further used to request the first coherent light module to transmit signals in a second signal mode, the second signal mode comprising at least one of a second signal modulation format and a second signal baud rate. That is, after the first round of negotiation between the first device and the second device based on the first signal mode is completed, the second round of negotiation between the first device and the second device based on the second signal mode is performed, and no matter which signal mode is actually used by the coherent light modules, the frequency offset convergence can be well realized.

[0031] In a second aspect, the present application provides a method for information transmission based on a coherent light module. A first device generates a first frame and sends the first frame to a second device. The first frame is used to request the second coherent light module to fix or adjust the frequency of a second LO light signal and the frequency of a second light signal. The second LO light signal and the second light signal are generated by the second coherent light module, and the second light signal is used to send to the first coherent light module. In this embodiment, the first device initiates a negotiation with the second device, so that the two parties can determine a reasonable frequency adjustment mechanism through the negotiation, which is conducive to ensuring that the coherent light modules at both ends can well realize frequency offset convergence.

[0032] In some possible implementations, after the first device sends the first frame to the second device, the method further includes: the first device receives a second frame sent by the second device according to the first frame, and the second frame is used to indicate whether to agree with the request of the first frame. That is, after receiving the request sent by the first device, the second device informs the first device whether to agree with the request of the first device, which perfects the negotiation process of the two parties.

[0033] In some possible implementations, the second frame is used to indicate that the second coherent light module fixes or adjusts the frequency of the second LO light signal and the frequency of the second light signal. That is, the second device can inform the first device of the working mode selected by the local second coherent light module according to the request of the first device, so as to indicate whether to agree with the request of the first device in this way, which enriches the implementation manner of the present application.

[0034] In some possible implementations, the first frame is further used to indicate that the first coherent light module fixes or adjusts the frequency of a first LO light signal and the frequency of a first light signal. The first LO light signal and the first light signal are generated by the first coherent light module, and the first light signal is used to send to the second coherent light module. That is, the first device informs the second device of the working mode selected by the local first coherent light module through the first frame when initiating the request to the second device through the first frame, so that the second device can know the working mode of the first coherent light module earlier, which is conducive to improving the negotiation efficiency.

[0035] In some possible implementation manners, the first frame is further used to request the second coherent light module to transmit signals in a first signal mode, and the first signal mode comprises at least one of a first signal modulation format and a first signal baud rate. It should be understood that the acceptance capability of the coherent light module to the frequency offset is different for different signal modulation formats and different signal baud rates. Therefore, the first device and the second device are required to negotiate based on the same signal mode, so that the first device and the second device can communicate with each other, thereby ensuring the smooth negotiation.

[0036] In some possible implementation manners, after the first device sends the first frame to the second device, the method further comprises: the first device sends a third frame to the second device. The third frame is used to request the second coherent light module to fix or adjust the frequency of the second LO light signal, and is further used to request the second coherent light module to fix or adjust the frequency of the second light signal, and is further used to request the second coherent light module to transmit signals in a second signal mode. The second signal mode comprises at least one of a second signal modulation format and a second signal baud rate. In this implementation manner, the negotiation stage can be divided into multiple rounds of negotiation, that is, the frames transmitted in the first round of negotiation are all in the first signal modulation format and the first signal baud rate, and the frames transmitted in the second round of negotiation are all in the second signal modulation format and the second signal baud rate, so that the first device and the second device can complete the negotiation based on multiple signal modes, and the frequency offset convergence can be well achieved regardless of the actual signal mode adopted by the coherent light module.

[0037] In some possible implementation manners, the second signal modulation format is higher than the first signal modulation format, and the second signal baud rate is greater than the first signal baud rate. It should be understood that the higher the order of the signal modulation format and the higher the signal baud rate, the more stringent the requirement for the frequency offset, and therefore, the lower signal baud rate and the lower order signal modulation format can tolerate the transmission of information under a larger frequency offset, and the negotiation based on the lower signal baud rate and the lower order signal modulation format is more conducive to ensuring the smooth negotiation.

[0038] In some possible implementation manners, if the first frame is used to request the second coherent light module to adjust the frequency of the second LO light signal, and the second device agrees with the request of the first frame, the absolute value of the difference between the frequency of the first light signal transmitted by the first coherent light module and the frequency of the adjusted second LO light signal is less than the absolute value of the difference between the frequency of the first light signal transmitted by the first coherent light module and the frequency of the unadjusted second LO light signal. That is, after the frequency adjustment scheme is determined through negotiation, the coherent light module adjusts the frequency of the LO light signal generated by itself according to the actual received light signal frequency, so as to reduce the frequency offset between them.

[0039] In some possible implementation manners, in the first coherent light module, the first LO light signal and the first light signal are from different sources. In the second coherent light module, the second LO light signal and the second light signal are from the same source. The first frame is used to request the second coherent light module to adjust the frequency of the second LO light signal and the frequency of the second light signal. After the second coherent light module adjusts the frequency of the second LO light signal and the frequency of the second light signal according to the frequency of the first light signal, the method further includes that the first device receives a fourth frame sent by the second device, and the fourth frame is used to request the first coherent light module to adjust the frequency of the first LO light signal and fix the frequency of the first light signal.

[0040] In this implementation manner, the first coherent light module adopts an independent-LO light source, the second coherent light module adopts a shared-LO light source, and the first coherent light module has higher flexibility in adjusting the light-emitting frequency of the light source. Therefore, by negotiation, it is determined that the frequency of the second LO light signal and the frequency of the second light signal are first adjusted by the second coherent light module, and then the frequency of the first LO light signal is adjusted by the first coherent light module, so that the coherent light modules at both ends can well achieve frequency offset convergence.

[0041] In some possible implementation manners, the first frame is further used to request the second coherent light module to transmit a signal in a first signal mode, and the first signal mode includes at least one of a first signal modulation format and a first signal baud rate. After the first coherent light module adjusts the frequency of the first LO light signal according to the frequency of the second light signal, the method further includes that the first device sends a third frame to the second device. The third frame is used to request the second coherent light module to adjust the frequency of the second LO light signal and the frequency of the second light signal, and the third frame is further used to request the second coherent light module to transmit a signal in a second signal mode, and the second signal mode includes at least one of a second signal modulation format and a second signal baud rate. That is, after the first device and the second device complete the first round of negotiation based on the first signal mode, the first device and the second device perform the second round of negotiation based on the second signal mode, and no matter which signal mode is actually adopted by the coherent light module, frequency offset convergence can be well achieved.

[0042] In some possible implementation manners, in the first coherent light module, the first LO light signal and the first light signal are from different sources. In the second coherent light module, the second LO light signal and the second light signal are from different sources. The first frame is used to request the second coherent light module to adjust the frequency of the second LO light signal and fix the frequency of the second light signal, and the method further includes that the first device receives a fifth frame sent by the second device, and the fifth frame is used to request the first coherent light module to adjust the frequency of the first LO light signal and fix the frequency of the first light signal.

[0043] In this embodiment, both the first coherent light module and the second coherent light module use independent LO light sources, and both the first coherent light module and the second coherent light module can adjust the frequency of the LO light signal according to the frequency of the received optical signal, so that the coherent light modules at both ends can well realize frequency offset convergence.

[0044] In some possible embodiments, the first frame is further used to request the second coherent light module to transmit signals in a first signal mode, and the first signal mode includes at least one of a first signal modulation format and a first signal baud rate. After the first coherent light module adjusts the frequency of the first LO light signal according to the frequency of the second optical signal, the method further includes that the first device sends a third frame to the second device. The third frame is used to request the second coherent light module to adjust the frequency of the second LO light signal and fix the frequency of the second optical signal, and the third frame is further used to request the second coherent light module to transmit signals in a second signal mode. That is, after the first device and the second device complete the first round of negotiation based on the first signal mode, the first device and the second device perform a second round of negotiation based on the second signal mode, and no matter which signal mode the coherent light modules actually use, frequency offset convergence can be well realized.

[0045] In some possible embodiments, in the first coherent light module, the first LO light signal and the first optical signal are homologous; and in the second coherent light module, the second LO light signal and the second optical signal are homologous. The method further includes that the first device negotiates with the second device to determine that the frequency of the first LO light signal and the frequency of the first optical signal are first adjusted by the first coherent light module, and then the frequency of the second LO light signal and the frequency of the second optical signal are adjusted by the second coherent light module.

[0046] In this embodiment, both the first coherent light module and the second coherent light module use a shared LO light source, and therefore, it is necessary to determine through negotiation which of the first coherent light module and the second coherent light module first adjusts the light emission frequency of the light source and which of the first coherent light module and the second coherent light module later adjusts the light emission frequency of the light source, so that the negotiation process can be smoothly performed.

[0047] In some possible implementation manners, in the first coherent light module, the first LO light signal and the first light signal are homologous; in the second coherent light module, the second LO light signal and the second light signal are homologous. The light source of the first coherent light module has a wavelength locking device, the light source of the second coherent light module does not have a wavelength locking device, and / or the accuracy of the light emitting frequency of the light source in the first coherent light module is higher than the accuracy of the light emitting frequency of the light source in the second coherent light module. The first frame is used to request the second coherent light module to fix the frequency of the second LO light signal and the frequency of the second light signal, and the method further comprises: the first device receiving the sixth frame sent by the second device, the sixth frame being used to request the first coherent light module to adjust the frequency of the first LO light signal and the frequency of the first light signal. After the first coherent light module adjusts the frequency of the first LO light signal and the frequency of the first light signal according to the frequency of the second light signal, the method further comprises: the first device sending the seventh frame to the second device, the seventh frame being used to request the second coherent light module to adjust the frequency of the second LO light signal and the frequency of the second light signal.

[0048] In this implementation manner, although the first coherent light module and the second coherent light module both use the light source sharing the LO, the first coherent light module has a wavelength locking device, the second coherent light module does not have a wavelength locking device, and / or the accuracy of the light emitting frequency of the light source in the first coherent light module is higher than the accuracy of the light emitting frequency of the light source in the second coherent light module. Therefore, by negotiation, it is determined that the frequency of the first LO light signal and the frequency of the first light signal are first adjusted by the first coherent light module, and then the frequency of the second LO light signal and the frequency of the second light signal are adjusted by the second coherent light module, so that the coherent light modules at both ends can well realize the frequency offset convergence.

[0049] In some possible implementation manners, the third frame is further used to request the second coherent light module to transmit signals in a first signal mode, the first signal mode comprising at least one of a first signal modulation format and a first signal baud rate. After the second coherent light module adjusts the frequency of the second LO light signal and the frequency of the second light signal according to the frequency of the first light signal, the method further comprises: the first device receiving the tenth frame sent by the second device. The tenth frame is used to request the first coherent light module to adjust the frequency of the first LO light signal and the frequency of the first light signal, and the tenth frame is further used to request the first coherent light module to transmit signals in a second signal mode, the second signal mode comprising at least one of a second signal modulation format and a second signal baud rate. That is, after the first round of negotiation between the first device and the second device based on the first signal mode is completed, the second round of negotiation between the first device and the second device based on the second signal mode is performed, and no matter which signal mode is actually used by the coherent light modules, the frequency offset convergence can be well realized.

[0050] In a third aspect, the present application provides a communication device, which is the first device in any of the embodiments of the first aspect. The communication device comprises a sending unit and a receiving unit. The sending unit sends a first frame to a second device, the first frame being used to indicate whether the LO light signal and the to-be-sent light signal in the first coherent light module are homologous. The first device is the first coherent light module, or the first device is connected to the first coherent light module. The receiving unit receives a second frame sent by the second device, the second frame being used to indicate whether the LO light signal and the to-be-sent light signal in the second coherent light module are homologous. The second device is the second coherent light module, or the second device is connected to the second coherent light module.

[0051] In some possible embodiments, in the coherent light module of the first light source type, the LO light signal and the to-be-sent light signal are not homologous. In the coherent light module of the second light source type, the LO light signal and the to-be-sent light signal are homologous. That is, the present application is compatible with light modules of multiple different light source types, enriching the application scenarios of the present application.

[0052] In some possible embodiments, the first frame is further used to indicate whether there is a wavelength locking device in the light source of the first coherent light module, and the second frame is further used to indicate whether there is a wavelength locking device in the light source of the second coherent light module. The light source with the wavelength locking device has a smaller fluctuation range of the light emitting frequency. That is, the first device and the second device can inform the opposite end of more information related to the capability of the light source thereof in the capability announcement stage, so as to facilitate the first device and the second device to negotiate a reasonable frequency adjustment mechanism more quickly, and to improve the convergence efficiency of the frequency offset.

[0053] In some possible embodiments, the first frame is further used to indicate the accuracy of the light emitting frequency of the light source in the first coherent light module, and the second frame is further used to indicate the accuracy of the light emitting frequency of the light source in the second coherent light module. The accuracy of the light emitting frequency of the light source is used to represent the fluctuation range of the light emitting frequency of the light source. By expanding the information transmitted by the first device and the second device in the capability announcement stage, the first device and the second device can negotiate a reasonable frequency adjustment mechanism more quickly, and the convergence efficiency of the frequency offset can be improved.

[0054] In some possible implementation manners, the sending unit is further configured to send a third frame to the second device. The third frame is used to request the second coherent light module to fix or adjust a frequency of the second LO light signal, and the third frame is further used to request the second coherent light module to fix or adjust a frequency of the second light signal. The second LO light signal and the second light signal are generated by the second coherent light module, and the second light signal is used to send to the first coherent light module. In this implementation manner, after the capability advertisement is completed, the first device initiates negotiation with the second device according to the capabilities of both sides, so that the two devices can perform negotiation in a targeted manner to determine the frequency adjustment mechanism, and the efficiency of negotiation and the efficiency of frequency offset convergence are improved.

[0055] In some possible implementation manners, after the sending unit sends the third frame to the second device, the receiving unit is further configured to receive a fourth frame sent by the second device according to the third frame. The fourth frame is used to indicate whether to agree with the request of the third frame. That is, after receiving the request sent by the first device, the second device informs the first device whether to agree with the request of the first device, and the negotiation process of both sides is improved.

[0056] In some possible implementation manners, the fourth frame is used to indicate that the second coherent light module fixes or adjusts the frequency of the second LO light signal, and the fourth frame is further used to indicate that the second coherent light module fixes or adjusts the frequency of the second light signal. That is, the second device can inform the first device of the working mode selected by the local second coherent light module according to the request of the first device, so as to indicate whether to agree with the request of the first device in this way, and the implementation manners of the present solution are enriched.

[0057] In some possible implementation manners, the third frame is further used to indicate that the first coherent light module fixes or adjusts the frequency of the first LO light signal, and the third frame is further used to indicate that the first coherent light module fixes or adjusts the frequency of the first light signal. The first LO light signal and the first light signal are generated by the first coherent light module, and the first light signal is used to send to the second coherent light module. That is, the first device informs the second device of the working mode selected by the local first coherent light module through the third frame when initiating the request to the second device through the third frame, so that the second device can know the working mode of the first coherent light module earlier, and the negotiation efficiency is improved.

[0058] In some possible implementation, the third frame is further configured to request the second coherent light module to transmit signals in a first signal mode, the first signal mode comprising at least one of a first signal modulation format and a first signal baud rate. It should be understood that the acceptance of frequency offset by the coherent light module is different for different signal modulation formats and different signal baud rates. Therefore, the first device and the second device are required to negotiate based on the same signal mode so that the first device and the second device can communicate with each other, thereby ensuring the smooth negotiation.

[0059] In some possible implementation, after the sending unit sends the third frame to the second device, the sending unit is further configured to send a fifth frame to the second device. The fifth frame is configured to request the second coherent light module to fix or adjust the frequency of the second LO light signal, fix or adjust the frequency of the second light signal, and transmit signals in a second signal mode. The second signal mode comprises at least one of a second signal modulation format and a second signal baud rate. In this implementation, the negotiation stage can be divided into multiple rounds of negotiation, that is, the frames transmitted in the first round of negotiation are all in the first signal modulation format and the first signal baud rate, and the frames transmitted in the second round of negotiation are all in the second signal modulation format and the second signal baud rate, so that the first device and the second device can complete the negotiation based on multiple signal modes, and the frequency offset convergence can be well achieved regardless of the actual signal mode adopted by the coherent light module.

[0060] In some possible implementation, the second signal modulation format is higher than the first signal modulation format, and the second signal baud rate is greater than the first signal baud rate. It should be understood that the higher the order of the signal modulation format and the higher the signal baud rate, the more stringent the requirement for the frequency offset, and therefore, a lower signal baud rate and a lower order signal modulation format can be allowed to transmit information under a larger frequency offset, and the negotiation based on the lower signal baud rate and the lower order signal modulation format is more conducive to ensuring the smooth negotiation.

[0061] In some possible implementation, if the third frame is configured to request the second coherent light module to adjust the frequency of the second LO light signal, and the second device agrees to the request of the third frame, the absolute value of the difference between the frequency of the first light signal transmitted by the first coherent light module and the frequency of the adjusted second LO light signal is less than the absolute value of the difference between the frequency of the first light signal transmitted by the first coherent light module and the frequency of the unadjusted second LO light signal. That is, after the scheme of frequency adjustment is determined through negotiation, the coherent light module is required to adjust the frequency of the LO light signal generated by itself according to the actual received light signal frequency, so as to reduce the frequency offset between the two.

[0062] In some possible implementation, in the first coherent light module, the first LO light signal and the first light signal are from different sources. In the second coherent light module, the second LO light signal and the second light signal are from the same source. The third frame is used to request the second coherent light module to adjust the frequency of the second LO light signal and the frequency of the second light signal. After the second coherent light module adjusts the frequency of the second LO light signal and the frequency of the second light signal according to the frequency of the first light signal, the receiving unit is further configured to receive a sixth frame sent by the second device, and the sixth frame is used to request the first coherent light module to adjust the frequency of the first LO light signal and fix the frequency of the first light signal.

[0063] In this implementation, the first coherent light module adopts an independent-LO light source, and the second coherent light module adopts a shared-LO light source. The first coherent light module has higher flexibility in adjusting the light-emitting frequency of the light source. Therefore, by negotiation, it is determined that the frequency of the second LO light signal and the frequency of the second light signal are first adjusted by the second coherent light module, and then the frequency of the first LO light signal is adjusted by the first coherent light module, so that the coherent light modules at both ends can well achieve frequency offset convergence.

[0064] In some possible implementation, the third frame is further used to request the second coherent light module to transmit signals in a first signal mode, and the first signal mode includes at least one of a first signal modulation format and a first signal baud rate. After the first coherent light module adjusts the frequency of the first LO light signal according to the frequency of the second light signal, the sending unit is further configured to send a fifth frame to the second device. The fifth frame is used to request the second coherent light module to adjust the frequency of the second LO light signal and the frequency of the second light signal, and the fifth frame is further used to request the second coherent light module to transmit signals in a second signal mode, and the second signal mode includes at least one of a second signal modulation format and a second signal baud rate. That is, after the first round of negotiation based on the first signal mode between the first device and the second device is completed, the second round of negotiation based on the second signal mode between the first device and the second device is performed. No matter which signal mode is actually adopted by the coherent light module, frequency offset convergence can be well achieved.

[0065] In some possible implementation, in the first coherent light module, the first LO light signal and the first light signal are from different sources. In the second coherent light module, the second LO light signal and the second light signal are from different sources. The third frame is used to request the second coherent light module to adjust the frequency of the second LO light signal and fix the frequency of the second light signal, and the receiving unit is further configured to receive a seventh frame sent by the second device, and the seventh frame is used to request the first coherent light module to adjust the frequency of the first LO light signal and fix the frequency of the first light signal.

[0066] In this embodiment, both the first coherent light module and the second coherent light module use independent LO light sources, and both the first coherent light module and the second coherent light module can adjust the frequency of the LO light signal according to the frequency of the received optical signal, so that the coherent light modules at both ends can well realize frequency offset convergence.

[0067] In some possible embodiments, the third frame is further used to request the second coherent light module to transmit signals in a first signal mode, the first signal mode including at least one of a first signal modulation format and a first signal baud rate. After the first coherent light module adjusts the frequency of the first LO light signal according to the frequency of the second optical signal, the sending unit is further used to send a fifth frame to the second device. The fifth frame is used to request the second coherent light module to adjust the frequency of the second LO light signal and fix the frequency of the second optical signal, and the fifth frame is further used to request the second coherent light module to transmit signals in a second signal mode, the second signal mode including at least one of a second signal modulation format and a second signal baud rate. That is, after the first device and the second device complete the first round of negotiation based on the first signal mode, the first device and the second device perform a second round of negotiation based on the second signal mode, and no matter which signal mode the coherent light modules actually use, frequency offset convergence can be well realized.

[0068] In some possible embodiments, in the first coherent light module, the first LO light signal and the first optical signal are homologous; and in the second coherent light module, the second LO light signal and the second optical signal are homologous. The communication device further includes a processing unit, which is used to negotiate with the second device to determine that the frequency of the first LO light signal and the frequency of the first optical signal are first adjusted by the first coherent light module, and then the frequency of the second LO light signal and the frequency of the second optical signal are adjusted by the second coherent light module.

[0069] In this embodiment, both the first coherent light module and the second coherent light module use a shared LO light source, so that it is determined through negotiation which of the first coherent light module and the second coherent light module first adjusts the light emission frequency of the light source and which of the first coherent light module and the second coherent light module later adjusts the light emission frequency of the light source, so that the negotiation process can be smoothly performed.

[0070] In some possible implementation manners, in the first coherent light module, the first LO light signal and the first light signal are homologous; in the second coherent light module, the second LO light signal and the second light signal are homologous. The light source of the first coherent light module has a wavelength locking device, the light source of the second coherent light module does not have a wavelength locking device, and / or the accuracy of the light emitting frequency of the light source in the first coherent light module is higher than the accuracy of the light emitting frequency of the light source in the second coherent light module. The third frame is used to request the second coherent light module to fix the frequency of the second LO light signal and the frequency of the second light signal, and the receiving unit is further configured to receive an eighth frame sent by the second device. The eighth frame is used to request the first coherent light module to adjust the frequency of the first LO light signal and the frequency of the first light signal. After the first coherent light module adjusts the frequency of the first LO light signal and the frequency of the first light signal according to the frequency of the second light signal, the method further comprises that the first device sends a ninth frame to the second device. The ninth frame is used to request the second coherent light module to adjust the frequency of the second LO light signal and the frequency of the second light signal.

[0071] In this implementation manner, although the first coherent light module and the second coherent light module both use the light source sharing the LO, the first coherent light module has a wavelength locking device, the second coherent light module does not have a wavelength locking device, and / or the accuracy of the light emitting frequency of the light source in the first coherent light module is higher than the accuracy of the light emitting frequency of the light source in the second coherent light module. Therefore, it is determined by negotiation that the frequency of the first LO light signal and the frequency of the first light signal are first adjusted by the first coherent light module, and then the frequency of the second LO light signal and the frequency of the second light signal are adjusted by the second coherent light module, so that the frequency offset convergence of both ends of the coherent light module can be well realized.

[0072] In some possible implementation manners, the third frame is further used to request the second coherent light module to transmit signals in a first signal mode. The first signal mode comprises at least one of a first signal modulation format and a first signal baud rate. After the second coherent light module adjusts the frequency of the second LO light signal and the frequency of the second light signal according to the frequency of the first light signal, the receiving unit is further configured to receive a tenth frame sent by the second device. The tenth frame is used to request the first coherent light module to adjust the frequency of the first LO light signal and the frequency of the first light signal, and the tenth frame is further used to request the first coherent light module to transmit signals in a second signal mode. The second signal mode comprises at least one of a second signal modulation format and a second signal baud rate. That is, after the first device and the second device complete the first round of negotiation based on the first signal mode, the first device and the second device perform the second round of negotiation based on the second signal mode. No matter which signal mode is actually used by the coherent light module, the frequency offset convergence can be well realized.

[0073] In a fourth aspect, the present application provides a communication device, which is the first device in any of the above-mentioned embodiments of the second aspect. The communication device comprises a processing unit and a sending unit. The processing unit generates a first frame, and the sending unit sends the first frame to a second device. The first frame is used to request the second coherent light module to fix or adjust the frequency of a second LO light signal, and the first frame is also used to request the second coherent light module to fix or adjust the frequency of a second light signal. The second LO light signal and the second light signal are generated by the second coherent light module, and the second light signal is used to send to the first coherent light module. In this embodiment, the first device initiates negotiation with the second device, so that the two parties can determine a reasonable frequency adjustment mechanism through negotiation, which is conducive to ensuring that the coherent light modules at both ends can well realize frequency offset convergence.

[0074] In some possible implementation manners, the communication device further comprises a receiving unit. After the sending unit sends the first frame to the second device, the receiving unit is configured to receive a second frame sent by the second device according to the first frame. The second frame is used to indicate whether to agree with the request of the first frame. That is, after receiving the request sent by the first device, the second device informs the first device whether to agree with the request of the first device, which perfects the negotiation process of the two parties.

[0075] In some possible implementation manners, the second frame is used to indicate that the second coherent light module fixes or adjusts the frequency of the second LO light signal, and the second frame is also used to indicate that the second coherent light module fixes or adjusts the frequency of the second light signal. That is, the second device can inform the first device of the working mode selected by the local second coherent light module according to the request of the first device, so as to indicate whether to agree with the request of the first device in this way, which enriches the implementation manners of the present application.

[0076] In some possible implementation manners, the first frame is also used to indicate that the first coherent light module fixes or adjusts the frequency of a first LO light signal, and the first frame is also used to indicate that the first coherent light module fixes or adjusts the frequency of a first light signal. The first LO light signal and the first light signal are generated by the first coherent light module, and the first light signal is used to send to the second coherent light module. That is, the first device informs the second device of the working mode selected by the local first coherent light module through the first frame at the same time when initiating the request to the second device through the first frame, so that the second device can know the working mode of the first coherent light module earlier, which is conducive to improving the negotiation efficiency.

[0077] In some possible implementation, the first frame is further configured to request the second coherent light module to transmit signals in a first signal mode, the first signal mode comprising at least one of a first signal modulation format and a first signal baud rate. It should be understood that the acceptance of frequency offset by the coherent light module is different for different signal modulation formats and different signal baud rates. Therefore, the first device and the second device are required to negotiate based on the same signal mode so that the first device and the second device can communicate with each other, thereby ensuring the smooth negotiation.

[0078] In some possible implementation, after the sending unit sends the first frame to the second device, the sending unit is further configured to send a third frame to the second device. The third frame is configured to request the second coherent light module to fix or adjust the frequency of the second LO light signal, and to request the second coherent light module to fix or adjust the frequency of the second light signal, and to request the second coherent light module to transmit signals in a second signal mode. The second signal mode comprises at least one of a second signal modulation format and a second signal baud rate. In this implementation, the negotiation stage can be divided into multiple rounds of negotiation, that is, the frames transmitted in the first round of negotiation are all in the first signal modulation format and the first signal baud rate, and the frames transmitted in the second round of negotiation are all in the second signal modulation format and the second signal baud rate, so that the first device and the second device can complete the negotiation based on multiple signal modes, and the frequency offset convergence can be well achieved regardless of the actual signal mode adopted by the coherent light module.

[0079] In some possible implementation, the second signal modulation format is higher than the first signal modulation format, and the second signal baud rate is greater than the first signal baud rate. It should be understood that the higher the order of the signal modulation format and the higher the signal baud rate, the more stringent the requirement for the frequency offset, and therefore, a lower signal baud rate and a lower order signal modulation format can be allowed to transmit information under a larger frequency offset, and the negotiation based on the lower signal baud rate and the lower order signal modulation format is more conducive to ensuring the smooth negotiation.

[0080] In some possible implementation, if the first frame is configured to request the second coherent light module to adjust the frequency of the second LO light signal, and the second device agrees to the request of the first frame, the absolute value of the difference between the frequency of the first light signal transmitted by the first coherent light module and the frequency of the adjusted second LO light signal is less than the absolute value of the difference between the frequency of the first light signal transmitted by the first coherent light module and the frequency of the unadjusted second LO light signal. That is, after the scheme of frequency adjustment is determined through negotiation, the coherent light module is required to adjust the frequency of the LO light signal generated by itself according to the actual received light signal frequency, so as to reduce the frequency offset between them.

[0081] In some possible implementation, in the first coherent light module, the first LO light signal and the first light signal are from different sources. In the second coherent light module, the second LO light signal and the second light signal are from the same source. The first frame is used to request the second coherent light module to adjust the frequency of the second LO light signal and the frequency of the second light signal. After the second coherent light module adjusts the frequency of the second LO light signal and the frequency of the second light signal according to the frequency of the first light signal, the receiving unit is further configured to receive a fourth frame sent by the second device, and the fourth frame is used to request the first coherent light module to adjust the frequency of the first LO light signal and fix the frequency of the first light signal.

[0082] In this implementation, the first coherent light module adopts an independent-LO light source, and the second coherent light module adopts a shared-LO light source, and the first coherent light module has higher flexibility in adjusting the light-emitting frequency of the light source. Therefore, by negotiation, it is determined that the frequency of the second LO light signal and the frequency of the second light signal are first adjusted by the second coherent light module, and then the frequency of the first LO light signal is adjusted by the first coherent light module, so that the coherent light modules at both ends can well realize frequency offset convergence.

[0083] In some possible implementation, the first frame is further used to request the second coherent light module to transmit signals in a first signal mode, and the first signal mode includes at least one of a first signal modulation format and a first signal baud rate. After the first coherent light module adjusts the frequency of the first LO light signal according to the frequency of the second light signal, the sending unit is further configured to send a third frame to the second device. The third frame is used to request the second coherent light module to adjust the frequency of the second LO light signal and the frequency of the second light signal, and the third frame is further used to request the second coherent light module to transmit signals in a second signal mode, and the second signal mode includes at least one of a second signal modulation format and a second signal baud rate. That is, after the first round of negotiation between the first device and the second device based on the first signal mode is completed, the second round of negotiation between the first device and the second device based on the second signal mode is performed, and no matter which signal mode is actually adopted by the coherent light module, frequency offset convergence can be well realized.

[0084] In some possible implementation, in the first coherent light module, the first LO light signal and the first light signal are from different sources. In the second coherent light module, the second LO light signal and the second light signal are from different sources. The first frame is used to request the second coherent light module to adjust the frequency of the second LO light signal and fix the frequency of the second light signal, and the receiving unit is further configured to receive a fifth frame sent by the second device, and the fifth frame is used to request the first coherent light module to adjust the frequency of the first LO light signal and fix the frequency of the first light signal.

[0085] In this embodiment, both the first coherent light module and the second coherent light module use independent LO light sources, and both the first coherent light module and the second coherent light module can adjust the frequency of the LO light signal according to the frequency of the received optical signal, so that the coherent light modules at both ends can well realize frequency offset convergence.

[0086] In some possible embodiments, the first frame is further used to request the second coherent light module to transmit signals in a first signal mode, and the first signal mode includes at least one of a first signal modulation format and a first signal baud rate. After the first coherent light module adjusts the frequency of the first LO light signal according to the frequency of the second optical signal, the sending unit is further used to send a third frame to the second device. The third frame is used to request the second coherent light module to adjust the frequency of the second LO light signal and fix the frequency of the second optical signal, and the third frame is further used to request the second coherent light module to transmit signals in a second signal mode. That is, after the first device and the second device complete the first round of negotiation based on the first signal mode, the first device and the second device perform a second round of negotiation based on the second signal mode, and no matter which signal mode the coherent light module actually uses, frequency offset convergence can be well realized.

[0087] In some possible embodiments, in the first coherent light module, the first LO light signal and the first optical signal are homologous; and in the second coherent light module, the second LO light signal and the second optical signal are homologous. The processing unit is further used to negotiate with the second device to determine that the frequency of the first LO light signal and the frequency of the first optical signal are first adjusted by the first coherent light module, and then the frequency of the second LO light signal and the frequency of the second optical signal are adjusted by the second coherent light module.

[0088] In this embodiment, both the first coherent light module and the second coherent light module use a shared LO light source, and therefore, it is necessary to determine through negotiation which of the first coherent light module and the second coherent light module first adjusts the light emission frequency of the light source and which of the first coherent light module and the second coherent light module later adjusts the light emission frequency of the light source, so that the negotiation process can be smoothly performed.

[0089] In some possible implementation manners, in the first coherent light module, the first LO light signal and the first light signal are homologous; in the second coherent light module, the second LO light signal and the second light signal are homologous. The light source of the first coherent light module has a wavelength locking device, the light source of the second coherent light module does not have a wavelength locking device, and / or the accuracy of the light emission frequency of the light source in the first coherent light module is higher than the accuracy of the light emission frequency of the light source in the second coherent light module. The first frame is used to request the second coherent light module to fix the frequency of the second LO light signal and the frequency of the second light signal, and the receiving unit is further configured to receive a sixth frame sent by the second device. The sixth frame is used to request the first coherent light module to adjust the frequency of the first LO light signal and the frequency of the first light signal. After the first coherent light module adjusts the frequency of the first LO light signal and the frequency of the first light signal according to the frequency of the second light signal, the method further includes that the first device sends a seventh frame to the second device. The seventh frame is used to request the second coherent light module to adjust the frequency of the second LO light signal and the frequency of the second light signal.

[0090] In this embodiment, although the first coherent light module and the second coherent light module both use the light source sharing the LO, the first coherent light module has a wavelength locking device, the second coherent light module does not have a wavelength locking device, and / or the accuracy of the light emission frequency of the light source in the first coherent light module is higher than the accuracy of the light emission frequency of the light source in the second coherent light module. Therefore, it is determined by negotiation that the frequency of the first LO light signal and the frequency of the first light signal are first adjusted by the first coherent light module, and then the frequency of the second LO light signal and the frequency of the second light signal are adjusted by the second coherent light module, so that the coherent light modules at both ends can well realize the frequency offset convergence.

[0091] In some possible implementation manners, the third frame is further used to request the second coherent light module to transmit signals in a first signal mode. The first signal mode includes at least one of a first signal modulation format and a first signal baud rate. After the second coherent light module adjusts the frequency of the second LO light signal and the frequency of the second light signal according to the frequency of the first light signal, the receiving unit is further configured to receive a tenth frame sent by the second device. The tenth frame is used to request the first coherent light module to adjust the frequency of the first LO light signal and the frequency of the first light signal, and the tenth frame is further used to request the first coherent light module to transmit signals in a second signal mode. The second signal mode includes at least one of a second signal modulation format and a second signal baud rate. That is, after the first device and the second device complete the first round of negotiation based on the first signal mode, the first device and the second device perform the second round of negotiation based on the second signal mode. No matter which signal mode is actually used by the coherent light module, the frequency offset convergence can be well realized.

[0092] In a fifth aspect, an embodiment of the present application provides a chip. The chip includes a processor. The processor is configured to execute the method described in any of the embodiments of the first aspect and the second aspect.

[0093] In a sixth aspect, an embodiment of the present application provides a communication device, the communication device comprising a control circuit and an interface circuit, the interface circuit being configured to transceive signals, and the control circuit being configured to perform the method according to any one of the embodiments of the first aspect and the second aspect.

[0094] In a seventh aspect, an embodiment of the present application provides a communication system, the communication system comprising a first device and a second device, the first device being configured to perform the method according to any one of the embodiments of the first aspect and the second aspect.

[0095] In an eighth aspect, the present application provides a computer-readable storage medium, the computer-readable storage medium storing instructions, the instructions being configured to cause a computer to perform the method according to any one of the embodiments of the first aspect and the second aspect.

[0096] In a ninth aspect, the present application provides a computer program product, the computer program product comprising program instructions, the program instructions being configured to cause a computer to perform the method according to any one of the embodiments of the first aspect and the second aspect. BRIEF DESCRIPTION OF DRAWINGS

[0097] FIG. 1 is a schematic diagram of a communication system to which an embodiment of the present application is applied;

[0098] FIG. 2 is a schematic diagram of a coherent light module with a frequency offset according to an embodiment of the present application;

[0099] FIG. 3 is a schematic diagram of a first structure of a coherent light module according to an embodiment of the present application;

[0100] FIG. 4 is a schematic diagram of a second structure of a coherent light module according to an embodiment of the present application;

[0101] FIG. 5 is a schematic diagram of a possible light source structure according to an embodiment of the present application;

[0102] FIG. 6 is a comparison diagram of a light emission frequency fluctuation range according to an embodiment of the present application;

[0103] FIG. 7 is a schematic diagram of a flow of a method of information transmission based on a coherent light module according to an embodiment of the present application;

[0104] FIG. 8 is a schematic diagram of a frequency offset acceptance degree based on different signal modulation formats and signal baud rates according to an embodiment of the present application;

[0105] FIG. 9(a) is a schematic diagram of a first scenario of information transmission between a device 1 and a device 2 according to an embodiment of the present application;

[0106] FIG. 9(b) is a schematic diagram of a second scenario of information transmission between a device 1 and a device 2 according to an embodiment of the present application;

[0107] Fig. 9 (c) is a schematic diagram of a third scenario of information transmission between device 1 and device 2 in the embodiment of the present application;

[0108] Fig. 9 (d) is a schematic diagram of a fourth scenario of information transmission between device 1 and device 2 in the embodiment of the present application;

[0109] Fig. 10 is a schematic diagram of a structure of a first sub-frame in a super-frame in the embodiment of the present application;

[0110] Fig. 11 is a schematic diagram of a protocol stack layer model architecture applicable in the embodiment of the present application;

[0111] Fig. 12 is a schematic diagram of application scenario 1 in the embodiment of the present application;

[0112] Fig. 13 is a schematic diagram of an implementation based on application scenario 1 in the embodiment of the present application;

[0113] Fig. 14 is a schematic diagram of application scenario 2 in the embodiment of the present application;

[0114] Fig. 15 is a schematic diagram of an implementation based on application scenario 2 in the embodiment of the present application;

[0115] Fig. 16 is a schematic diagram of application scenario 3 in the embodiment of the present application;

[0116] Fig. 17 is a schematic diagram of an implementation based on application scenario 3 in the embodiment of the present application;

[0117] Fig. 18 is a schematic diagram of a structure of a communication device in the embodiment of the present application;

[0118] Fig. 19 is a schematic diagram of another structure of a communication device in the embodiment of the present application. DETAILED DESCRIPTION

[0119] The embodiment of the present application provides an information transmission method, device and system based on a coherent light module. Two ends of a communication system can inform the other end whether LO light signals and to-be-transmitted light signals in respective coherent light modules are homologous by transmitting frames to each other, so that the two ends of the coherent light modules can configure light emitting frequencies for respective light sources in a targeted manner, and the two ends of the coherent light modules can converge frequency offsets into an allowed range, which is beneficial to guarantee correct recovery of data.

[0120] Fig. 1 is a schematic diagram of a communication system to which embodiments of the present application are applied. As shown in Fig. 1, the communication system includes a sending device 01, a sending processing module 02, a channel transmission medium 03, a receiving processing module 04 and a receiving device 05. Taking the communication system as a data center network for example, the sending device 01 and the receiving device 05 can be a switch, a router or a server, and the sending device 01 is also referred to as a host at the sending end, and the receiving device 05 is also referred to as a host at the receiving end. The host can also be referred to as a host chip or a host module, etc. In the implementation of the present application, the host can be a server, and when the host is a server, the optical module in the embodiments of the present application can be connected to the server in a pluggable manner. For the convenience of introduction, the sending device 01 and the receiving device 05 are taken as examples of the host in the following description. Exemplarily, the host includes but is not limited to a switch chip or a physical layer (PHY) chip, etc., and the PHY chip is, for example, an application specific integrated circuit (ASIC) chip. The channel transmission medium 03 can be an optical fiber. The sending device 01 and the sending processing module 02 can be connected through a channel, and the receiving device 05 and the receiving processing module 04 can be connected through a channel. The type of the channel can depend on the type of the sending processing module 02 and the receiving processing module 04, and the type of the channel includes an electrical interface, for example, an attachment unit interface (AUI) and a common electrical interface (CEI). Alternatively, the channel can also be referred to as an electrical link. Exemplarily, the channel can be a physical medium such as a printed circuit board (PCB) trace, a copper cable or a connector. The sending processing module 02 and the receiving processing module 04 can be an optical module, an electrical module or other modules that process data in the data transmission process. It should be understood that the sending device 01, the sending processing module 02, the channel transmission medium 03, the receiving processing module 04 and the receiving device 05 in the communication system can support bidirectional transmission or unidirectional transmission, and the specific implementation is not limited here.

[0121] In the embodiments of the present application, the sending processing module 02 and the receiving processing module 04 can both be coherent optical modules. The coherent optical module includes a light source, an integrated coherent transmitter (ICT), an integrated coherent receiver (ICR), a micro controller unit (MCU), and the like. The ICT includes a modulator and the like, and the ICR includes a mixer and the like. As an example, an optical digital signal processor (oDSP) chip is arranged inside the coherent optical module, which can be referred to as a digital coherent optical (DCO) module. As another example, the oDSP chip is arranged outside the coherent optical module, and the oDSP chip is also not arranged inside the host, that is, the oDSP chip is placed independently of the coherent optical module and the host, which can be referred to as an analog coherent optical (ACO) module. For ease of introduction, the coherent optical module integrated with the oDSP chip is taken as an example for description below.

[0122] It should be understood that the coherent optical module refers to an optical module that uses coherent communication technology to achieve data communication. Unlike the analog direct-detection optical signal that only uses the amplitude variation information of the optical signal to transmit data, the phase and amplitude information of the coherent optical signal are both used to transmit data. The reception and demodulation of the coherent optical signal need to use a local oscillator (LO) optical signal to mix with the coherent optical signal to obtain the phase information. In the coherent optical module, the LO optical signal is provided by a continuous wave light source, and the LO optical signal and the coherent optical signal are mixed by an optical mixer and then converted into an electrical signal by a balanced detector. The oDSP chip performs clock data recovery (CDR) on the electrical signal and then performs digital signal processing (DSP) to compensate for link impairments and the like. For example, the coherent optical module can be specifically an 800LR optical module.

[0123] Figure 2 is a diagram of a frequency offset of a coherent optical module in an embodiment of the present application. As shown in Figure 2, the frequency of the LO optical signal generated by the coherent optical module is denoted as f LO, and the frequency of the optical signal received by the coherent optical module is denoted as f Sig. There can be a frequency offset between f LO and f Sig, which is also referred to as frequency offset. If the frequency offset is large, the coherent optical module can not be able to recover data from the received signal. Therefore, the coherent optical module needs to adjust the frequency of the light source to reduce the frequency offset, so that the frequency offset is within an allowable range.

[0124] It should be noted that in the coherent optical module, the optical carrier used by the ICT and the LO optical signal used by the ICR can be provided by the same light source, or can be provided by different light sources respectively. That is, the coherent optical module can have two different types of light sources, which are described below.

[0125] Figure 3 is a diagram of a first structure of a coherent optical module in an embodiment of the present application. As shown in Figure 3, the coherent optical module includes a light source 1 and a light source 2. The light source 1 is used to provide an optical carrier for the integrated coherent transmitter, and the light source 2 is used to provide an optical carrier for the integrated coherent receiver. The optical carrier provided by the light source 2 can be referred to as an LO optical signal. As can be seen, the optical carrier used by the integrated coherent transmitter and the LO optical signal used by the integrated coherent receiver are provided by different light sources respectively, that is, the LO optical signal and the optical signal to be transmitted are different sources. The light source type of the coherent optical module shown in Figure 3 can be referred to as an independent LO light source.

[0126] Figure 4 is a diagram of a second structure of a coherent optical module in an embodiment of the present application. As shown in Figure 4, the coherent optical module includes one light source. The optical carrier output by the light source is split by a power splitter, and one part of the optical carrier is transmitted to the integrated coherent transmitter, and the other part of the optical carrier is transmitted to the integrated coherent receiver. The optical carrier transmitted to the integrated coherent receiver can be referred to as an LO optical signal. As can be seen, the optical carrier used by the integrated coherent transmitter and the LO optical signal used by the integrated coherent receiver are provided by the same light source, that is, the LO optical signal and the optical signal to be transmitted are the same source. The light source type of the coherent optical module shown in Figure 4 can be referred to as a shared LO light source.

[0127] It should be noted that, as shown in FIG. 3 and as shown in FIG. 4, the controller of the coherent light module is configured to control the light source to adjust the light emitting frequency of the light source, and the controller and the oDSP chip can exchange information. The device controller of the host and the PHY chip can exchange information, and the device controller of the host and the controller of the coherent light module can also exchange information. For example, the controller of the coherent light module can be a micro controller unit (MCU), and the device controller of the host can be a central processing unit (CPU). The MCU and the CPU are connected through a management interface, and the coherent light module can report its light source type to the host through the management interface. For example, the management interface can be an inter-integrated circuit (IIC, I2C) interface, and the management protocol based on the management interface can be a common management interface specification (CMIS).

[0128] In the transmission direction, the PHY chip sends an electrical signal to the oDSP chip, for example, the electrical signal can be a non-return to zero (NRZ) signal or a pulse amplitude modulation 4-level (PAM4) signal, etc. The oDSP chip can generate a quadrature phase shift keying (QPSK) signal or a 16-ary quadrature amplitude modulation (16QAM) signal, etc. from the electrical signal sent by the PHY chip. The integrated coherent transmitter modulates the electrical signal from the oDSP chip onto the optical carrier to obtain the optical signal 1, and transmits the optical signal 1 through the channel transmission medium. In the receiving direction, the integrated coherent receiver receives the optical signal 2 through the channel transmission medium, and processes the optical signal 2 by mixing with the LO optical signal to convert the optical signal 2 into an electrical signal. The oDSP chip further processes the electrical signal by CDR and DSP, etc. and sends it to the PHY chip.

[0129] FIG. 5 is a schematic diagram of a possible light source structure in the embodiments of the present application. As shown in FIG. 5, the light source includes a driver and a laser, and the driver is used to drive the laser to emit light. For example, the controller of the coherent light module can specifically control the driver of the light source to adjust the light emitting frequency of the laser. Alternatively, the light source can also include a wave locker device, in which the light source with the wave locker device has higher precision of light emitting frequency and higher cost. It should be noted that the present application does not limit the specific type of the laser, for example, the laser can be a distributed feedback (DFB) laser, a distributed bragg reflector (DBR) laser or an external cavity laser, etc.

[0130] FIG. 6 is a comparison diagram of the light emitting frequency fluctuation range in the embodiments of the present application. As shown in FIG. 6, the fluctuation range of the light emitting frequency of the light source with the wave locker device is ±Δf1, and the fluctuation range of the light emitting frequency of the light source with the wave locker device is ±Δf2. It can be seen that Δf1<Δf2, and the light source with the wave locker device has higher precision of light emitting frequency.

[0131] In the embodiments of the present application, the two ends of the communication system can inform the opposite end whether the LO light signal and the to-be-sent light signal in the respective coherent light modules are homologous by sending frames to each other, so that the two ends of the coherent light modules can configure the light emitting frequency for the respective light sources, and promote the two ends of the coherent light modules to converge the frequency offset to the allowed range. The information transmission method based on the coherent light module passed by the embodiments of the present application will be introduced below.

[0132] Figure 7 is a flow diagram of a method for information transmission based on a coherent light module according to an embodiment of the present application. As shown in Figure 7, the two ends of a communication system are referred to as device 1 and device 2, for example, device 1 and device 2 are located at the two ends of an optical fiber. The end where device 1 is located includes a coherent light module 1, for example, device 1 can be a coherent light module 1, or device 1 can be a host 1 electrically connected to the coherent light module 1. The end where device 2 is located includes a coherent light module 2, for example, device 2 can be a coherent light module 2, or device 2 can be a host 2 electrically connected to the coherent light module 2. For ease of description, in some embodiments below, the coherent light module 1 can also be referred to as the local coherent light module at the end where device 1 is located, and the coherent light module 2 can also be referred to as the local coherent light module at the end where device 2 is located. The LO light signal generated by the coherent light module 1 is referred to as LO light signal 1, and the light signal transmitted by the coherent light module 1 is referred to as TX light signal 1. The LO light signal generated by the coherent light module 2 is referred to as LO light signal 2, and the light signal transmitted by the coherent light module 2 is referred to as TX light signal 2. Specifically, the information transmission process between device 1 and device 2 can be divided into a capability announcement stage and a negotiation stage.

[0133] In the capability announcement stage, device 1 transmits frame 1 to device 2, and frame 1 is used to indicate whether the LO light signal 1 and the TX light signal 1 in the coherent light module 1 are homologous; device 2 transmits frame 2 to device 1, and frame 2 is used to indicate whether the LO light signal 2 and the TX light signal 2 in the coherent light module 2 are homologous. In this way, device 1 and device 2 can determine the specific process of the negotiation stage according to the information received by each other. It should be understood that the present application does not limit the specific information carried in frame 1 and frame 2, as long as it can play a role in informing the opposite end of its own capability. In the following, several possible implementation manners are introduced by taking frame 1 as an example. As an example, one bit of frame 1 is used to indicate the light source type in the coherent light module 1, for example, a bit value of 1 represents an independent LO light source as shown in Figure 3, that is, the LO light signal 1 and the TX light signal 1 are not homologous; a bit value of 0 represents a shared LO light source as shown in Figure 4, that is, the LO light signal 1 and the TX light signal 1 are homologous. As another example, frame 1 carries at least one parameter, and the value of the at least one parameter can indicate whether the LO light signal 1 and the TX light signal 1 are homologous.

[0134] In some possible scenarios, in the capability announcement stage, the frames transmitted between device 1 and device 2 can also carry more other information in order to further distinguish the different light sources in the coherent light module. For example, frame 1 is also used to indicate whether there is a wavelength locking device in the light source of the coherent light module 1, and frame 2 is also used to indicate whether there is a wavelength locking device in the light source of the coherent light module 2. For example, frame 1 is also used to indicate the accuracy of the light emitting frequency of the light source in the coherent light module 1, and frame 2 is also used to indicate the accuracy of the light emitting frequency of the light source in the coherent light module 2.

[0135] The following Table 1 gives the definition of the values of the fields in the frame in the capability announcement stage. For the field of the light source type, the bit value of 1 represents the independent LO light source as shown in the above Fig. 3, and the bit value of 0 represents the shared LO light source as shown in the above Fig. 4. For the field of whether there is a wavelength locking device in the transmitting light source, the transmitting light source refers to the light source providing the optical carrier for the to-be-transmitted optical signal, the bit value of 0 represents that there is a wavelength locking device in the transmitting light source, and the bit value of 1 represents that there is no wavelength locking device in the transmitting light source. For the field of whether there is a wavelength locking device in the LO light source, the LO light source refers to the light source generating the LO optical signal, the bit value of 0 represents that there is a wavelength locking device in the LO light source, and the bit value of 1 represents that there is no wavelength locking device in the LO light source. For the field of the emission frequency accuracy of the transmitting light source, the bit value of 0 represents that the emission frequency of the transmitting light source is high accuracy, and the bit value of 1 represents that the emission frequency of the transmitting light source is low accuracy; or the field can also include multiple bits for representing the specific value (unit: GHz) of the emission frequency of the transmitting light source. For the field of the emission frequency accuracy of the LO light source, the bit value of 0 represents that the emission frequency of the LO light source is high accuracy, and the bit value of 1 represents that the emission frequency of the LO light source is low accuracy; or the field can also include multiple bits for representing the specific value (unit: GHz) of the emission frequency of the LO light source.

[0136] Table 1

[0137] In the negotiation stage, the device 1 sends a frame 3 to the device 2, the frame 3 is used to initiate a request to the device 2, the content of the request includes requesting the coherent light module 2 to fix or adjust the frequency of the LO optical signal 2 and requesting the coherent light module 2 to fix or adjust the frequency of the TX optical signal 2; the device 2 sends a frame 4 to the device 1 according to the frame 3, the frame 4 is used to indicate whether the device 2 agrees to the request initiated by the device 1. Correspondingly, in the negotiation stage, the device 2 sends a frame 5 to the device 1, the frame 5 is used to initiate a request to the device 1, the content of the request includes requesting the coherent light module 1 to fix or adjust the frequency of the LO optical signal 1 and requesting the coherent light module 1 to fix or adjust the frequency of the TX optical signal 1; the device 1 sends a frame 6 to the device 1 according to the frame 5, the frame 6 is used to indicate whether the device 1 agrees to the request initiated by the device 2. It should be understood that the negotiation process initiated by the device 1 to the device 2 is synchronous with the negotiation process initiated by the device 2 to the device 1.

[0138] In some possible implementation manners, the device 1 can also inform the device 2 of its decision by sending the frame 3, for example, the frame 3 is used to indicate that the coherent light module 1 fixes or adjusts the frequency of the LO light signal 1 and the coherent light module 1 fixes or adjusts the frequency of the TX light signal 1. Similarly, the device 2 can also inform the device 1 of its decision by sending the frame 5, for example, the frame 5 is used to indicate that the coherent light module 2 fixes or adjusts the frequency of the LO light signal 2 and the coherent light module 2 fixes or adjusts the frequency of the TX light signal 2.

[0139] In one possible scenario, one bit in the frame 4 sent by the device 2 to the device 1 is used to indicate whether to agree with the request initiated by the device 1, for example, the bit is valued as 0 to indicate disagreement, and the bit is valued as 1 to indicate agreement. Similarly, one bit in the frame 6 sent by the device 1 to the device 2 is used to indicate whether to agree with the request initiated by the device 2, for example, the bit is valued as 0 to indicate disagreement, and the bit is valued as 1 to indicate agreement. If the device 2 agrees with the request of the device 1, and the device 1 also agrees with the request of the device 2, the negotiation is considered successful.

[0140] In another possible scenario, the frame 4 sent by the device 2 to the device 1 is used to indicate that the coherent light module 2 fixes or adjusts the frequency of the LO light signal 2 and the coherent light module 2 fixes or adjusts the frequency of the TX light signal 2. If the content indicated by the frame 4 is consistent with the content requested by the frame 3, it indicates that the device 2 agrees with the request initiated by the device 1; otherwise, it indicates that the device 2 disagrees with the request initiated by the device 1. Similarly, the frame 6 sent by the device 1 to the device 2 is used to indicate that the coherent light module 1 fixes or adjusts the frequency of the LO light signal 1 and the coherent light module 1 fixes or adjusts the frequency of the TX light signal 1. If the content indicated by the frame 6 is consistent with the content requested by the frame 5, it indicates that the device 1 agrees with the request initiated by the device 2; otherwise, it indicates that the device 1 disagrees with the request initiated by the device 2. It should be noted that, in actual applications, the transmission process of the frame 3, the frame 4, the frame 5 and the frame 6 can be repeated N times, and if the content transmitted by the frame 3, the frame 4, the frame 5 and the frame 6 does not change after being repeated N times, the negotiation is considered successful.

[0141] It should be noted that after the device 1 and the device 2 negotiate successfully, the corresponding coherent optical module starts to adjust the light emitting frequency of the light source. Taking the case that the device 2 agrees with the request of the device 1 as an example, the coherent optical module 2 adjusts the frequency of the LO optical signal 2 according to the frequency of the received TX optical signal 1, so as to reduce the frequency offset between the TX optical signal 1 and the LO optical signal 2, thereby enabling the frequency offset between the TX optical signal 1 and the LO optical signal 2 to be adjusted to the allowed frequency offset range, and realizing the convergence of the frequency offset. Specifically, the oDSP chip of the coherent optical module 2 estimates the frequency offset df according to the frequency of the TX optical signal 1 and the frequency of the LO optical signal 2, and sends the frequency offset df to the controller (for example, MCU) of the coherent optical module 2, and the controller adjusts the light emitting frequency of the light source according to the frequency offset df. The following introduces several possible ways to adjust the light emitting frequency of the light source.

[0142] As an example, |df| is within the frequency adjustment capability range of the light source, the controller controls the light source to adjust the light emitting frequency, and the frequency adjustment amount is df, so as to eliminate the frequency offset. As another example, |df| is beyond the frequency adjustment capability of the light source, the controller controls the light source to adjust the light emitting frequency, and the frequency adjustment amount can be the maximum value within the frequency adjustment capability range of the light source, so as to reduce the frequency offset as much as possible. As yet another example, the controller controls the light source to adjust the light emitting frequency, which can be adjusted to the position in one step, or can be adjusted to the position in a step-by-step multi-step manner, for example, the controller determines the direction of frequency adjustment, the step size of frequency adjustment and the number of steps of frequency adjustment according to df. As still another example, if the estimated frequency offset df is within the allowed frequency offset range, the light emitting frequency of the light source can not be adjusted.

[0143] FIG. 8 is a schematic diagram of the frequency offset acceptance degree based on different signal modulation formats and signal baud rates in the embodiments of the present application. As shown in FIG. 8, for the coherent optical signal, the higher the order of the signal modulation format and the higher the signal baud rate, the more stringent the requirement for the frequency offset. For example, in a 100 gigabits per second (Gbps) rate coherent scenario, a DP-QPSK signal with a signal baud rate of 27.9525 GBd is used, and in a 400 Gbps rate coherent scenario, a DP-16QAM signal with a signal baud rate of 59.84375 GBd is used. The 400 Gbps rate coherent scenario is more sensitive to the frequency offset than the 100 Gbps rate coherent scenario. Therefore, if a lower signal baud rate and a lower order signal modulation format are used when the coherent optical link is initialized, it can be allowed to transmit information at a larger frequency offset, which supports the adjustment and optimization of the configuration of the coherent optical module from a poor initial condition, and finally achieves better link performance.

[0144] In some possible scenarios, the negotiation phase can be specifically divided into multiple rounds of negotiation. For example, the transmission processes of frame 3, frame 4, frame 5, and frame 6 in the above embodiment can be regarded as the first round of negotiation based on the first signal mode, that is, the frames transmitted in the first round of negotiation are all in the first signal modulation format and the first signal baud rate. Correspondingly, the frames transmitted in the first round of negotiation all carry information of the first signal mode, which is used to request the other end to transmit signals in the first signal mode. After the first round of negotiation ends and the first round of adjustment of the light-emitting frequency of the light source is completed, it can be considered that the frequency offset convergence based on the first signal mode is completed, and the device 1 and the device 2 further start the second round of negotiation based on the second signal mode, that is, the frames transmitted in the second round of negotiation are all in the second signal modulation format and the second signal baud rate. Correspondingly, the frames transmitted in the second round of negotiation all carry information of the second signal mode, which is used to request the other end to transmit signals in the second signal mode. It should be understood that the second signal modulation format is higher than the first signal modulation format, and the second signal baud rate is greater than the first signal baud rate, which is equivalent to upgrading from the first signal mode to the second signal mode. In actual application, the specific division of the negotiation phase into several rounds of negotiation depends on the target signal mode actually used by the coherent optical module for service transmission. In the above manner, M rounds of negotiation are performed until the target signal mode is upgraded, and the Mth round of negotiation and the Mth round of adjustment of the light-emitting frequency of the light source are completed, and it can be considered that the frequency offset convergence based on the target signal mode is completed.

[0145] The process of the second round of negotiation is similar to that of the first round of negotiation. For example, the device 1 sends frame 7 to the device 2, and frame 7 is used to initiate a request to the device 2, the content of the request including requesting the coherent light module 2 to fix or adjust the frequency of the LO optical signal 2 and requesting the coherent light module 2 to fix or adjust the frequency of the TX optical signal 2. The device 2 sends frame 8 to the device 1 according to frame 7, and frame 8 is used to indicate whether the device 2 agrees with the request initiated by the device 1. Correspondingly, the device 2 sends frame 9 to the device 1, and frame 9 is used to initiate a request to the device 1, the content of the request including requesting the coherent light module 1 to fix or adjust the frequency of the LO optical signal 1 and requesting the coherent light module 1 to fix or adjust the frequency of the TX optical signal 1. The device 1 sends frame 10 to the device 1 according to frame 9, and frame 10 is used to indicate whether the device 1 agrees with the request initiated by the device 2.

[0146] It should be understood that if the information of the signal mode carried by the frames sent by the device 1 and the device 2 is different, the two parties should send signals based on the higher-level signal mode. For example, the frame sent by the device 1 to the device 2 carries information of the first signal mode, and the frame sent by the device 2 to the device 1 carries information of the second signal mode. Therefore, the device 1 and the device 2 both send signals based on the second signal mode.

[0147] The following Table 2 gives the definition of the value of each field in the frame in the negotiation phase. For the field of whether to adjust the local TX optical signal, the bit value of 0 indicates to adjust the frequency of the local TX optical signal, and the bit value of 1 indicates to fix (not to adjust) the frequency of the local TX optical signal. For the field of whether to adjust the local LO optical signal, the bit value of 0 indicates to adjust the frequency of the local LO optical signal, and the bit value of 1 indicates to fix (not to adjust) the frequency of the local LO optical signal. For the field of whether to request the peer TX optical signal to adjust, the bit value of 0 indicates to request to adjust the frequency of the peer TX optical signal, and the bit value of 1 indicates to request to fix (not to adjust) the frequency of the peer TX optical signal. For the field of whether to request the peer LO optical signal to adjust, the bit value of 0 indicates to request to adjust the frequency of the peer LO optical signal, and the bit value of 1 indicates to request to fix (not to adjust) the frequency of the peer LO optical signal. For the field of signal modulation format, the bit value of 00 indicates QPSK, the bit value of 01 indicates 16QAM, the bit value of 10 indicates 32QAM, and the bit value of 11 indicates 64QAM. For the field of signal baud rate, the bit value of 00 indicates 27GBd, the bit value of 01 indicates 59GBd, the bit value of 10 indicates 132GBd, and the bit value of 11 indicates 236GBd.

[0148] Table 2

[0149] It should be noted that the oDSP chip of the coherent optical module participates in the above process shown in FIG. 7, and the oDSP chip can synchronize the obtained information to the controller (for example, MCU) of the coherent optical module. The controller can update the value of the register itself according to the information synchronized by the oDSP chip, so that the controller can better cooperate with the oDSP chip to realize the adjustment of the light source emitting frequency. Moreover, after the controller completes the adjustment of the light source emitting frequency, the oDSP chip can also be synchronized with the information of the adjustment completion. The following Table 3 gives the definition of the value of each field in the register. For the field of whether the capability announcement is completed, the bit value of 0 indicates that the capability announcement has been completed, and the bit value of 1 indicates that the capability announcement has not been completed. For the field of whether to start the negotiation, the bit value of 0 indicates not to start the negotiation, and the bit value of 1 indicates to start the negotiation. For the field of whether to adjust the light source, the bit value of 0 indicates not to adjust the light source, and the bit value of 1 indicates to adjust the light source.

[0150] Table 3

[0151] Figure 9(a) is a schematic diagram of a first scenario of information transmission between device 1 and device 2 in embodiments of the present application. As shown in Figure 9(a), device 1 is host 1 and device 2 is host 2, and the information transmission is between host 1 and host 2. In a possible implementation, taking the example of host 1 sending frames to host 2, the frame structure used by host 1 to send information to coherent light module 1 is different from the frame structure used by coherent light module 1 to send information to coherent light module 2. For example, coherent light module 1 reads information from frame A from host 1, coherent light module 1 generates frame B according to the read information and sends frame B to coherent light module 2, coherent light module 2 generates frame C according to the information read from frame B, and coherent light module 2 sends frame C to host 2. Generally, frame A and frame B carry the same information, and if coherent light module 1 finds that the information in frame A is incorrect, it can rewrite the information and then generate frame B. In another possible implementation, taking the example of host 1 sending frames to host 2, the frame structure used by host 1 to send information to coherent light module 1 is the same as the frame structure used by coherent light module 1 to send information to coherent light module 2. For example, coherent light module 1 reads information from frame A from host 1, if the information in frame A is correct, it transmits frame A to coherent light module 2 and further to host 2; if the information in frame A is incorrect, it rewrites the information and then sends frame A to coherent light module 2 and further to host 2. It should be understood that the way host 2 sends frames to host 1 is similar to the way host 1 sends frames to host 2, which will not be described here.

[0152] Figure 9(b) is a schematic diagram of a second scenario of information transmission between device 1 and device 2 in embodiments of the present application. As shown in Figure 9(a), device 1 is host 1 and device 2 is coherent light module 2, and the information transmission is between host 1 and coherent light module 2. In a possible implementation, the frame structure used by host 1 to transmit information to coherent light module 1 is different from the frame structure used by coherent light module 1 to transmit information to coherent light module 2. In another possible implementation, the frame structure used by host 1 to transmit information to coherent light module 1 is the same as the frame structure used by coherent light module 1 to transmit information to coherent light module 2.

[0153] Fig. 9(c) is a schematic diagram of a third scenario of information transmission between device 1 and device 2 in an embodiment of the present application. As shown in Fig. 9(c), device 1 is a coherent light module 1, and device 2 is a host 2. Information transmission is performed between the coherent light module 1 and the host 2. In one possible implementation, the frame structure used for information transmission between the host 2 and the coherent light module 2 is different from the frame structure used for information transmission between the coherent light module 1 and the coherent light module 2. In another possible implementation, the frame structure used for information transmission between the host 2 and the coherent light module 2 is the same as the frame structure used for information transmission between the coherent light module 1 and the coherent light module 2.

[0154] Fig. 9(d) is a schematic diagram of a fourth scenario of information transmission between device 1 and device 2 in an embodiment of the present application. As shown in Fig. 9(d), device 1 is a coherent light module 1, and device 2 is a coherent light module 2. Information transmission is performed between the coherent light module 1 and the coherent light module 2. In this scenario, the above-mentioned flow shown in Fig. 7 can be implemented without the host, and the coherent light module itself can adjust the light emitting frequency of the light source. Therefore, the scenario shown in Fig. 9(d) is more conducive to improving the efficiency of capability announcement and negotiation, and has better application value.

[0155] It should be noted that the frame used for transmission between device 1 and device 2 in the flow shown in Fig. 7 can have many different implementation forms, which will be introduced below.

[0156] In one possible implementation, a frame different from the frame used for service transmission can be used to transmit information in the capability announcement stage and the negotiation stage shown in Fig. 7. For example, this frame can be a differential Manchester encoding (DME) frame, and the information introduced in the embodiment shown in Fig. 7 can be carried by one or more bits in the base page or the next page of the DME frame. It should be understood that the frame used in this embodiment can be generated by the host or by the coherent light module.

[0157] In another possible implementation, the information introduced in the embodiment shown in Fig. 7 can also be carried in a reserved position of the frame used for service transmission. Fig. 10 is a schematic diagram of a structure of a first subframe in a superframe in an embodiment of the present application. As shown in Fig. 10, the first subframe in the superframe can be used to carry the information introduced in the embodiment shown in Fig. 7. The first subframe in the superframe includes Q pilot symbols, T training symbols, N FAWa frame alignment word symbol (FAW symbol), N RES reserved symbols, and a plurality of payload symbols. Specifically, the N RES reserved symbols can be used to carry the information introduced in the embodiment shown in FIG. 7. It should be understood that the frame adopted in this embodiment is generated by a coherent optical module.

[0158] FIG. 11 is a schematic diagram of a protocol stack layer model architecture applicable to an embodiment of the present application. The protocol stack layer model is the protocol stack layer of Ethernet. Ethernet is a set of standards defined by the Institute of Electrical and Electronics Engineers (IEEE) 802 standard organization, which relates to network, interface, and physical layer technologies. The relevant Ethernet physical layer can be the protocol stack layer thereof, which can be referred to with reference to FIG. 11. As shown in FIG. 11, the model architecture is a network interconnection model, which defines a seven-layer framework of network interconnection. From bottom to top, the seven layers are physical layer, data link layer, network layer, transport layer, session layer, presentation layer, and application layer.

[0159] Ethernet is in the data link layer and the physical layer in the open system interconnection (OSI) reference model. As shown in FIG. 11, the data link layer includes two sub-layers: a logical link control (LLC) sub-layer and a medium access control (MAC) sub-layer responsible for parsing and assembling Ethernet frames.

[0160] As shown in FIG. 11, the physical layer can include a physical medium dependent (PMD) sublayer, a physical medium attachment (PMA) sublayer, and a physical coding sublayer (PCS). There is also a reconciliation sublayer (RS) between the PCS and the MAC sublayer. There is a certain gigabit media independent interface (GMII) between the RS and the PCS, such as an XGMII, a 25GMII, a 50GMII, and the like. The PMD sublayer is connected with a medium through a medium dependent interface (MDI), which can be a cable or an optical fiber, and the like. It should be understood that the embodiments of the present application can be implemented in the PCS sublayer. For example, if the first subframe in the superframe shown in FIG. 10 is used to implement the flow shown in FIG. 7, for the step of generating the superframe in the PCS sublayer, the embodiments of the present application add the information introduced in the embodiments shown in FIG. 7 to the first subframe of the superframe.

[0161] It should be noted that after the completion of the capability announcement stage shown in FIG. 7, the capabilities of device 1 and device 2 are determined, and the subsequent negotiation process is determined. Based on the type of light source used by coherent light module 1 and coherent light module 2, there are three application scenarios. Application scenario 1: both the coherent light module 1 locally in device 1 and the coherent light module 2 locally in device 2 use an independent LO light source. Application scenario 2: the coherent light module 1 locally in device 1 uses an independent LO light source, and the coherent light module 2 locally in device 2 uses a shared LO light source. Application scenario 3: both the coherent light module 1 locally in device 1 and the coherent light module 2 locally in device 2 use a shared LO light source.

[0162] It should be understood that for the above three application scenarios, the specific process of negotiation between device 1 and device 2 will also be different. Specifically, for application scenario 1, both coherent light modules on both sides adjust the light emitting frequency of their own LO light source according to the received optical signal to achieve frequency offset convergence. For application scenarios 2 and 3, one side of the coherent light module adjusts the light emitting frequency of the light source first, and the other side of the coherent light module adjusts the light emitting frequency of the light source to follow, to ensure that both sides of the coherent light module achieve frequency offset convergence, wherein the coherent light module that adjusts the light emitting frequency first can be regarded as a master, and the coherent light module that adjusts the light emitting frequency later can be regarded as a slave.

[0163] In application scenario 2, since the coherent light module 2 adopts the light source sharing the LO, the flexibility of the coherent light module 2 to adjust the light emitting frequency of the light source is relatively low, so the coherent light module 2 needs to adjust the light emitting frequency of the light source first, that is, the coherent light module 2 is the master and the coherent light module 1 is the slave.

[0164] In application scenario 3, since the coherent light module 1 and the coherent light module 2 both adopt the light source sharing the LO, it is further needed to determine which coherent light module is the master and which coherent light module is the slave through other information. For example, the coherent light module 1 has a wavelength locking device and the coherent light module 2 does not have a wavelength locking device, so the coherent light module 1 is the master and the coherent light module 2 is the slave. For another example, the light emitting frequency precision of the light source in the coherent light module 1 is higher than that of the light source in the coherent light module 2, so the coherent light module 1 is the master and the coherent light module 2 is the slave. For another example, if the wavelength locking device and the light emitting frequency precision of the light source cannot distinguish the coherent light module 1 and the coherent light module 2, the coherent light module 1 and the coherent light module 2 can each generate a set of random numbers and inform the opposite end of the random numbers generated by each, so as to determine the master and the slave through the size of the random numbers. For example, if the random number generated by the coherent light module 1 is greater than the random number generated by the coherent light module 2, the coherent light module 1 is the master and the coherent light module 2 is the slave. The random number can be a set of seed bits, for example, the random number is obtained by assigning values to 5 bits.

[0165] According to the above introduction, in order to ensure that the negotiation process in each application scenario is completed as soon as possible, the information carried in the frame sent in the negotiation stage in the embodiment shown in FIG. 7 can be expanded, and Table 4 gives a specific example. For example, one bit in the frame is used to indicate whether the master and the slave need to be determined, wherein the bit value of 0 indicates that the master and the slave do not need to be determined, and the bit value of 1 indicates that the master and the slave need to be determined. For another example, one bit in the frame is used to indicate whether the local coherent light module is the master or the slave, wherein the bit value of 0 indicates that the local coherent light module is the slave, and the bit value of 1 indicates that the local coherent light module is the master. For another example, a plurality of seed bits in the frame are used to indicate the random number generated by the local coherent light module.

[0166] Table 4

[0167] In combination with the content of Table 4, it should be understood that for application scenario 1, no master and slave need to be determined, the corresponding bit value in the frame transmitted between device 1 and device 2 is 0, which is equivalent to both sides of the coherent optical module acting as a master. For application scenario 2, the master and slave need to be determined, the corresponding bit value in the frame transmitted between device 1 and device 2 is 1; since the coherent optical module 2 is the master and the coherent optical module 1 is the slave, the corresponding bit value in the frame transmitted from device 1 to device 2 is 0, and the corresponding bit value in the frame transmitted from device 2 to device 1 is 1. For application scenario 3, the master and slave need to be determined, the corresponding bit value in the frame transmitted between device 1 and device 2 is 1; as an example, the coherent optical module 1 has a wavelength locking device and the coherent optical module 2 does not have a wavelength locking device, the coherent optical module 1 is the master and the coherent optical module 2 is the slave, the corresponding bit value in the frame transmitted from device 1 to device 2 is 1, and the corresponding bit value in the frame transmitted from device 2 to device 1 is 0; as another example, the light source in the coherent optical module 1 has a higher light frequency accuracy than the light source in the coherent optical module 2, the coherent optical module 1 is the master and the coherent optical module 2 is the slave, the corresponding bit value in the frame transmitted from device 1 to device 2 is 1, and the corresponding bit value in the frame transmitted from device 2 to device 1 is 0; as yet another example, the coherent optical module 1 and the coherent optical module 2 cannot be distinguished by the wavelength locking device and the light source light frequency accuracy, the frame transmitted from device 1 to device 2 carries the first set of random numbers, the frame transmitted from device 2 to device 1 carries the second set of random numbers, the first set of random numbers is greater than the second set of random numbers, and it is determined that the coherent optical module 1 is the master and the coherent optical module 2 is the slave.

[0168] The specific negotiation process of device 1 and device 2 in the above three application scenarios will be described in detail below. It should be understood that in order to facilitate the introduction, the following examples are all based on one round of negotiation process based on one signal mode, and the process of multiple rounds of negotiation based on multiple signal modes can be flexibly extended on this basis.

[0169] FIG. 12 is a schematic diagram of application scenario 1 in the embodiments of the present application. As shown in FIG. 12, the coherent optical module 1 and the coherent optical module 2 both use independent LO light sources, corresponding to the above-mentioned application scenario 1. FIG. 13 is an implementation diagram based on application scenario 1 in the embodiments of the present application. As shown in FIG. 13, the implementation based on application scenario 1 includes the following steps.

[0170] In the capability announcement stage, the frame transmitted between device 1 and device 2 includes at least one bit, for example, the bit is 0, which indicates that the local light source type is a shared LO light source, and the bit is 1, which indicates that the local light source type is an independent LO light source. Device 1 sends frame 1-1 (1) to device 2, which indicates that the coherent light module 1 locally adopts an independent LO light source. Device 2 sends frame 2-1 (1) to device 1, which indicates that the coherent light module 2 locally adopts an independent LO light source.

[0171] In the negotiation stage, the frame transmitted between device 1 and device 2 includes at least four bits, and the meanings of the four bits are respectively whether the local TX optical signal is adjusted, whether the local LO optical signal is adjusted, whether the peer TX optical signal is requested to be adjusted, and whether the peer LO optical signal is requested to be adjusted. The information corresponding to different values of the four bits can be referred to Table 2. Device 1 sends frame 1-2 (1, 0, 1, 0) to device 2, which is used to indicate that the frequency of the fixed TX optical signal 1 is fixed and the frequency of the LO optical signal 1 is adjusted, and is also used to request that the frequency of the fixed TX optical signal 2 is fixed and the frequency of the LO optical signal 2 is adjusted; device 2 sends frame 2-3 (1, 0, 1, 0) to device 1 according to frame 1-2 (1, 0, 1, 0), which is used to indicate that the frequency of the fixed TX optical signal 2 is fixed and the frequency of the LO optical signal 2 is adjusted, and is also used to request that the frequency of the fixed TX optical signal 1 is fixed and the frequency of the LO optical signal 1 is adjusted, that is, device 2 agrees with the request of device 1. Correspondingly, device 2 sends frame 2-2 (1, 0, 1, 0) to device 1, which is used to indicate that the frequency of the fixed TX optical signal 2 is fixed and the frequency of the LO optical signal 2 is adjusted, and is also used to request that the frequency of the fixed TX optical signal 1 is fixed and the frequency of the LO optical signal 1 is adjusted; device 1 sends frame 1-3 (1, 0, 1, 0) to device 2 according to frame 2-2 (1, 0, 1, 0), which is used to indicate that the frequency of the fixed TX optical signal 1 is fixed and the frequency of the LO optical signal 1 is adjusted, and is also used to request that the frequency of the fixed TX optical signal 2 is fixed and the frequency of the LO optical signal 2 is adjusted, that is, device 1 agrees with the request of device 2. Further, the coherent light module 1 can adjust the frequency of the LO optical signal 1 according to the frequency of the TX optical signal 2 to converge the frequency offset, and the coherent light module 2 can adjust the frequency of the LO optical signal 2 according to the frequency of the TX optical signal 1 to converge the frequency offset.

[0172] FIG. 14 is a schematic diagram of application scenario 2 in the embodiment of the present application. As shown in FIG. 14, the coherent light module 1 adopts an independent LO light source, and the coherent light module 2 adopts a shared LO light source, which corresponds to the above-mentioned application scenario 2. FIG. 15 is a schematic diagram of the implementation based on the application scenario 2 in the embodiment of the present application. As shown in FIG. 15, the implementation based on the application scenario 2 includes the following steps.

[0173] In the capability announcement stage, the frame transmitted between device 1 and device 2 includes at least one bit, for example, the bit value of 0 indicates that the local light source type is a shared LO light source, and the bit value of 1 indicates that the local light source type is an independent LO light source. Device 1 sends frame 1-1 (1) to device 2, indicating that the coherent light module 1 locally adopts an independent LO light source. Device 2 sends frame 2-1 (0) to device 1, indicating that the coherent light module 2 locally adopts a shared LO light source.

[0174] In the negotiation stage, the frame transmitted between device 1 and device 2 includes at least 4 bits, and the meaning of each of the 4 bits is as follows: whether the local TX optical signal is adjusted, whether the local LO optical signal is adjusted, whether the opposite end TX optical signal is requested to be adjusted, and whether the opposite end LO optical signal is requested to be adjusted. The information corresponding to different values of the 4 bits can be referred to Table 2. Device 1 sends frame 1-2 (1, 1, 0, 0) to device 2, which is used to fix the frequency of TX optical signal 1 and the frequency of LO optical signal 1, and is also used to request to adjust the frequency of TX optical signal 2 and the frequency of LO optical signal 2; device 2 sends frame 2-3 (0, 0, 1, 1) to device 1 according to frame 1-2 (1, 1, 0, 0), which is used to adjust the frequency of TX optical signal 2 and the frequency of LO optical signal 2, and is also used to request to fix the frequency of TX optical signal 1 and the frequency of LO optical signal 1, that is, device 2 agrees with the request of device 1. Correspondingly, device 2 sends frame 2-2 (0, 0, 1, 1) to device 1, which is used to adjust the frequency of TX optical signal 2 and the frequency of LO optical signal 2, and is also used to request to fix the frequency of TX optical signal 1 and the frequency of LO optical signal 1; device 1 sends frame 1-3 (1, 1, 0, 0) to device 2 according to frame 2-2 (0, 0, 1, 1), which is used to fix the frequency of TX optical signal 1 and the frequency of LO optical signal 1, and is also used to request to adjust the frequency of TX optical signal 2 and the frequency of LO optical signal 2, that is, device 1 agrees with the request of device 2. Further, the coherent light module 2 adjusts the frequency of LO optical signal 2 and the frequency of TX optical signal 2 according to the frequency of TX optical signal 1 to converge the frequency offset. Then, device 2 sends frame 2-4 (1, 1, 1, 0) to device 1, which is used to fix the frequency of TX optical signal 2 and the frequency of LO optical signal 2, and is also used to request to fix the frequency of TX optical signal 1 and adjust the frequency of LO optical signal 1. Device 1 sends frame 1-4 (1, 0, 1, 1) to device 2 according to frame 2-4 (1, 1, 1, 0), which is used to fix the frequency of TX optical signal 1 and adjust the frequency of LO optical signal 1, and is also used to request to fix the frequency of TX optical signal 2 and the frequency of LO optical signal 2, that is, device 1 agrees with the request of device 2. Further, the coherent light module 1 adjusts the frequency of LO optical signal 1 according to the frequency of TX optical signal 2 to converge the frequency offset.

[0175] FIG. 16 is a schematic diagram of application scenario 3 in the embodiments of the present application. As shown in FIG. 16, both the coherent light module 1 and the coherent light module 2 use the light source sharing LO, which corresponds to the above-mentioned application scenario 3. FIG. 17 is a schematic diagram of an implementation based on the application scenario 3 in the embodiments of the present application. In the implementation shown in FIG. 17, the light source of the coherent light module 1 includes a wavelength locking device, and the light source of the coherent light module 2 does not include a wavelength locking device, i.e., the coherent light module 1 is regarded as a master, and the coherent light module 2 is regarded as a slave. In addition, the master and the slave can also be determined in other possible ways, and the specific implementation can be referred to the above-mentioned related description, which will not be introduced one by one here. As shown in FIG. 17, the implementation based on the application scenario 3 includes the following steps.

[0176] In the capability announcement stage, the frame transmitted between the device 1 and the device 2 includes at least two bits, for example, two bits are used to indicate the local light source type and whether the local light source includes a wavelength locking device, respectively. The information corresponding to different values of the two bits can be referred to Table 1. The device 1 sends the frame 1-1(0, 0) to the device 2, indicating that the coherent light module 1 in the local device 1 uses the light source sharing LO, and the light source includes a wavelength locking device. The device 2 sends the frame 2-1(0, 1) to the device 1, indicating that the coherent light module 2 in the local device 2 uses the light source sharing LO, and the light source does not include a wavelength locking device.

[0177] In the negotiation phase, the frame transmitted between the device 1 and the device 2 includes at least 4 bits, and the meaning of each of the 4 bits is as follows: whether the local TX optical signal is adjusted, whether the local LO optical signal is adjusted, whether the TX optical signal of the peer is requested to be adjusted, and whether the LO optical signal of the peer is requested to be adjusted. The information corresponding to different values of each of the 4 bits can be referred to Table 2. The device 1 sends the frame 1-2 (0, 0, 1, 1) to the device 2, for indicating that the frequency of the TX optical signal 1 and the frequency of the LO optical signal 1 are adjusted, and for requesting that the frequency of the TX optical signal 2 and the frequency of the LO optical signal 2 are fixed; the device 2 sends the frame 2-3 (1, 1, 0, 0) to the device 1 according to the frame 1-2 (0, 0, 1, 1), for indicating that the frequency of the TX optical signal 2 and the frequency of the LO optical signal 2 are fixed, and for requesting that the frequency of the TX optical signal 1 and the frequency of the LO optical signal 1 are adjusted, that is, the device 2 agrees with the request of the device 1. Correspondingly, the device 2 sends the frame 2-2 (1, 1, 0, 0) to the device 1, for indicating that the frequency of the TX optical signal 2 and the frequency of the LO optical signal 2 are fixed, and for requesting that the frequency of the TX optical signal 1 and the frequency of the LO optical signal 1 are adjusted; the device 1 sends the frame 1-3 (0, 0, 1, 1) to the device 2 according to the frame 2-2 (1, 1, 0, 0), for indicating that the frequency of the TX optical signal 1 and the frequency of the LO optical signal 1 are adjusted, and for requesting that the frequency of the TX optical signal 2 and the frequency of the LO optical signal 2 are fixed, that is, the device 1 agrees with the request of the device 2. Further, the coherent optical module 1 adjusts the frequency of the LO optical signal 1 and the frequency of the TX optical signal 1 according to the frequency of the TX optical signal 2, so as to converge the frequency offset. Then, the device 1 sends the frame 1-4 (1, 1, 0, 0) to the device 2, for indicating that the frequency of the TX optical signal 1 and the frequency of the LO optical signal 1 are fixed, and for requesting that the frequency of the TX optical signal 2 and the frequency of the LO optical signal 2 are adjusted. The device 2 sends the frame 2-4 (0, 0, 1, 1) to the device 1 according to the frame 1-4 (1, 1, 0, 0), for indicating that the frequency of the TX optical signal 2 and the frequency of the LO optical signal 2 are adjusted, and for requesting that the frequency of the TX optical signal 1 and the frequency of the LO optical signal 1 are fixed, that is, the device 2 agrees with the request of the device 1. Further, the coherent optical module 2 adjusts the frequency of the LO optical signal 2 and the frequency of the TX optical signal 2 according to the frequency of the TX optical signal 1, so as to converge the frequency offset.

[0178] FIG. 18 is a schematic diagram of a structure of a communication device according to an embodiment of the present application. As shown in FIG. 18, the communication device includes a sending unit 101 and a receiving unit 102. The communication device can be the device 1 or the device 2 in the above embodiments. In a possible implementation, the communication device is configured to perform the operations of the device 1 in the above embodiments. Specifically, the sending unit 101 is configured to perform the operation of sending a frame to the device 2, and the receiving unit 102 is configured to perform the operation of receiving a frame from the device 2. In another possible implementation, the communication device is configured to perform the operations of the device 2 in the above embodiments. Specifically, the sending unit 101 is configured to perform the operation of sending a frame to the device 1, and the receiving unit 102 is configured to perform the operation of receiving a frame from the device 1.

[0179] FIG. 19 is a schematic diagram of another structure of a communication device according to an embodiment of the present application. As shown in FIG. 19, the communication device includes a control circuit 201 and an interface circuit 202. It should be understood that the interface circuit 202 can be a transceiver or an input / output interface. The interface circuit is configured to receive a signal from another device outside the communication device and transmit the signal to the control circuit 201, or transmit a signal from the control circuit 201 to another device outside the communication device. In a possible implementation, the communication device is configured to perform the operations of the device 1 in the above embodiments. Specifically, the interface circuit 202 is configured to perform the operation of the device 1 in transmitting and receiving a frame, and the control circuit 201 is configured to perform other operations of the device 1 in addition to transmitting and receiving a frame. In another possible implementation, the communication device is configured to perform the operations of the device 2 in the above embodiments. Specifically, the interface circuit 202 is configured to perform the operation of the device 2 in transmitting and receiving a frame, and the control circuit 201 is configured to perform other operations of the device 2 in addition to transmitting and receiving a frame. Optionally, the communication device can further include a memory 203. The memory 203 is configured to store program instructions and data.

[0180] An embodiment of the present application further provides a chip. The chip integrates a circuit for implementing the functions of the control circuit 201 and one or more interfaces. As an example, the chip integrates a memory. As another example, when the chip does not integrate a memory, the chip can be connected to an external memory through an interface. The chip can complete the method steps of any one or more of the above embodiments. Alternatively, the chip implements the actions performed by the data processing apparatus in the above embodiments according to program codes stored in the memory.

[0181] As an example, the chip in embodiments of the application can be a CPU, and also can be other general-purpose processors, DSPs, ASICs, FPGAs or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The general-purpose processor can be a microprocessor, and also can be any conventional processor, and also can be a processing circuit implementing specific functions.

[0182] The embodiment of the application further provides a computer readable storage medium, comprising a program or instructions, which, when running on a computer, causes the method performed by the above method embodiment to be implemented.

[0183] It should be understood that the control circuit mentioned in the embodiment of the application can be implemented by hardware or software. When implemented by hardware, the control circuit can be a logic circuit, an integrated circuit, etc. When implemented by software, the control circuit can be a general-purpose processor, which is implemented by reading software codes stored in a memory. The memory can exist independently and be connected to the control circuit, or the memory can be integrated with the control circuit.

[0184] As an example, the control circuit in embodiments of the application can be a CPU, and also can be other general-purpose processors, DSPs, ASICs, FPGAs or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The general-purpose processor can be a microprocessor, and also can be any conventional processor, and also can be a processing circuit implementing specific functions.

[0185] The memory in the embodiment of the application can be a random access memory (RAM), a flash memory, a read-only memory (ROM), a programmable ROM (PROM), an erasable PROM (EPROM), an electrically EPROM (EEPROM), a register, a hard disk, a mobile hard disk, a CD-ROM, or any other form of storage medium well known in the art. An exemplary storage medium is coupled to the processor, so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium can also be an integral part of the processor. The processor and the storage medium can be located in an ASIC. In addition, the ASIC can be located in a network device or a terminal device. Of course, the processor and the storage medium can also exist as discrete components in the network device or the terminal device.

[0186] In the above embodiments, the data processing method can be implemented by software, hardware, firmware or any combination thereof, in whole or in part.

[0187] When implemented by hardware, the data processing method provided by the embodiments of the present application can be implemented without reading software codes or instructions, for example, by a CPU, a DSP, an ASIC, an FPGA, other programmable logic devices, transistor logic devices, hardware components or any combination thereof.

[0188] When implemented by software, the data processing method can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer programs or instructions are loaded and executed on a computer, the processes or functions of the embodiments of the present application are executed in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, a network device, a terminal device or other programmable devices. The computer programs or instructions can be stored in a computer-readable storage medium or transmitted by a computer-readable storage medium. The computer-readable storage medium can be any available medium accessible by a computer or a data storage device such as a server integrating one or more available media. The available medium can be a magnetic medium, for example, a floppy disk, a hard disk, a magnetic tape; an optical medium, for example, a digital versatile disc (DVD); or a semiconductor medium, for example, a solid state disk (SSD).

[0189] Finally, it should be noted that: the above, only for the specific embodiments of the present application, but the protection scope of the present application is not limited to this, any skilled in the art of the technical person in the technical range disclosed in the present application, can easily think of changes or replacement, should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

A method for information transmission based on a coherent optical module, characterized in that, The method comprises: The first device sends a first frame to a second device, the first frame being used to indicate whether a local oscillator (LO) optical signal in a first coherent optical module and an optical signal to be transmitted are homologous, the first device being the first coherent optical module or the first device being connected to the first coherent optical module; The first device receives a second frame sent by the second device, the second frame being used to indicate whether an LO optical signal in a second coherent optical module and an optical signal to be transmitted are homologous, the second device being the second coherent optical module or the second device being connected to the second coherent optical module. The method of claim 1, wherein In the coherent optical module using the first light source type, the LO optical signal and the optical signal to be transmitted are not homologous; in the coherent optical module using the second light source type, the LO optical signal and the optical signal to be transmitted are homologous. The method according to claim 1 or 2, characterized in that The first frame is further used to indicate whether there is a wavelength locking device in the light source of the first coherent optical module, and the second frame is further used to indicate whether there is the wavelength locking device in the light source of the second coherent optical module. The method according to any one of claims 1 to 3, characterized in that The first frame is further used to indicate the accuracy of the light-emitting frequency of the light source in the first coherent optical module, and the second frame is further used to indicate the accuracy of the light-emitting frequency of the light source in the second coherent optical module. The method according to any one of claims 1 to 4, characterized in that The method further comprises: The first device sends a third frame to the second device, the third frame being used to request the second coherent optical module to fix the frequency of a second LO optical signal or adjust the frequency of the second LO optical signal, and the third frame being further used to request the second coherent optical module to fix the frequency of a second optical signal or adjust the frequency of the second optical signal, wherein the second LO optical signal and the second optical signal are generated by the second coherent optical module, and the second optical signal is used to transmit to the first coherent optical module. The method according to claim 5, characterized in that After the first device sends the third frame to the second device, the method further comprises: The first device receives a fourth frame sent by the second device according to the third frame, the fourth frame being used to indicate whether to agree with the request of the third frame. The method according to claim 6, characterized in that The fourth frame is used to indicate that the second coherent optical module fixes the frequency of the second LO optical signal or adjusts the frequency of the second LO optical signal, and the fourth frame is further used to indicate that the second coherent optical module fixes the frequency of the second optical signal or adjusts the frequency of the second optical signal. The method according to any one of claims 5 to 7, characterized in that The third frame is further used to indicate that the first coherent optical module fixes the frequency of a first LO optical signal or adjusts the frequency of the first LO optical signal, and the third frame is further used to indicate that the first coherent optical module fixes the frequency of a first optical signal or adjusts the frequency of the first optical signal, wherein the first LO optical signal and the first optical signal are generated by the first coherent optical module, and the first optical signal is used to transmit to the second coherent optical module. The method according to any one of claims 5 to 8, characterized in that The third frame is further used to request the second coherent optical module to use a first signal mode to transmit a signal, the first signal mode comprising at least one of a first signal modulation format and a first signal baud rate. The method of claim 9, wherein After the first device sends the third frame to the second device, the method further comprises: The first device sends a fifth frame to the second device, the fifth frame being used to request the second coherent light module to fix or adjust a frequency of the second LO light signal, and to fix or adjust a frequency of the second light signal, and to request the second coherent light module to transmit signals in a second signal mode, the second signal mode including at least one of a second signal modulation format and a second signal baud rate. The method of claim 10, wherein The second signal modulation format is higher than the first signal modulation format, and the second signal baud rate is greater than the first signal baud rate. The method according to any one of claims 5 to 11, characterized in that If the third frame is used to request the second coherent light module to adjust the frequency of the second LO light signal, and the second device agrees to the request of the third frame, an absolute value of a difference between the frequency of the first light signal transmitted by the first coherent light module and the frequency of the second LO light signal after adjustment is less than an absolute value of a difference between the frequency of the first light signal transmitted by the first coherent light module and the frequency of the second LO light signal before adjustment. The method according to any one of claims 5 to 12, characterized in that In the first coherent light module, the first LO light signal and the first light signal are of different sources; in the second coherent light module, the second LO light signal and the second light signal are of the same source; the third frame is used to request the second coherent light module to adjust the frequency of the second LO light signal and the frequency of the second light signal. After the second coherent light module adjusts the frequency of the second LO light signal and the frequency of the second light signal according to the frequency of the first light signal, the method further comprises: The first device receives a sixth frame sent by the second device, the sixth frame being used to request the first coherent light module to adjust the frequency of the first LO light signal and fix the frequency of the first light signal. The method of claim 13, wherein The third frame is further used to request the second coherent light module to transmit signals in a first signal mode, the first signal mode including at least one of a first signal modulation format and a first signal baud rate. After the first coherent light module adjusts the frequency of the first LO light signal according to the frequency of the second light signal, the method further comprises: The first device sends a fifth frame to the second device, the fifth frame being used to request the second coherent light module to adjust the frequency of the second LO light signal and the frequency of the second light signal, and to request the second coherent light module to transmit signals in a second signal mode, the second signal mode including at least one of a second signal modulation format and a second signal baud rate. The method according to any one of claims 5 to 12, characterized in that In the first coherent light module, the first LO light signal and the first light signal are of different sources; in the second coherent light module, the second LO light signal and the second light signal are of different sources; The third frame is used to request the second coherent light module to adjust the frequency of the second LO light signal and fix the frequency of the second light signal, and the method further comprises: The first device receives a seventh frame sent by the second device, and the seventh frame is used to request the first coherent optical module to adjust the frequency of the first LO optical signal and fix the frequency of the first optical signal. The method of claim 15, wherein The third frame is also used to request the second coherent optical module to transmit signals in a first signal mode, and the first signal mode includes at least one of a first signal modulation format and a first signal baud rate. After the first coherent optical module adjusts the frequency of the first LO optical signal according to the frequency of the second optical signal, the method further comprises: The first device sends a fifth frame to the second device, and the fifth frame is used to request the second coherent optical module to adjust the frequency of the second LO optical signal and fix the frequency of the second optical signal, and the fifth frame is also used to request the second coherent optical module to transmit signals in a second signal mode, and the second signal mode includes at least one of a second signal modulation format and a second signal baud rate. The method according to any one of claims 1 to 12, characterized in that In the first coherent optical module, the first LO optical signal and the first optical signal are homologous; in the second coherent optical module, the second LO optical signal and the second optical signal are homologous; the method further comprises: The first device determines, by negotiation with the second device, that the frequency of the first LO optical signal and the frequency of the first optical signal are first adjusted by the first coherent optical module, and then the frequency of the second LO optical signal and the frequency of the second optical signal are adjusted by the second coherent optical module. The method according to any one of claims 5 to 12, characterized in that In the first coherent optical module, the first LO optical signal and the first optical signal are homologous; in the second coherent optical module, the second LO optical signal and the second optical signal are homologous; The light source of the first coherent optical module has a wavelength locking device, the light source of the second coherent optical module does not have a wavelength locking device, and / or the accuracy of the light emitting frequency of the light source in the first coherent optical module is greater than the accuracy of the light emitting frequency of the light source in the second coherent optical module; The third frame is used to request the second coherent optical module to fix the frequency of the second LO optical signal and the frequency of the second optical signal, and the method further comprises: The first device receives an eighth frame sent by the second device, and the eighth frame is used to request the first coherent optical module to adjust the frequency of the first LO optical signal and the frequency of the first optical signal. After the first coherent optical module adjusts the frequency of the first LO optical signal and the frequency of the first optical signal according to the frequency of the second optical signal, the method further comprises: The first device sends a ninth frame to the second device, and the ninth frame is used to request the second coherent optical module to adjust the frequency of the second LO optical signal and the frequency of the second optical signal. The method of claim 18, wherein The third frame is also used to request the second coherent optical module to transmit signals in a first signal mode, and the first signal mode includes at least one of a first signal modulation format and a first signal baud rate. After the second coherent optical module adjusts the frequency of the second LO optical signal and the frequency of the second optical signal according to the frequency of the first optical signal, the method further comprises: The first device receives a tenth frame transmitted by the second device, the tenth frame being used to request the first coherent optical module to adjust the frequency of the first LO optical signal and the frequency of the first optical signal, and the tenth frame being further used to request the first coherent optical module to transmit signals in a second signal mode, the second signal mode including at least one of a second signal modulation format and a second signal baud rate. A chip characterized by The chip comprises a processor configured to perform the method of any one of claims 1-19. A communication device, characterized by The communication device comprises a control circuit and an interface circuit, the interface circuit being configured to transceive signals, and the control circuit being configured to perform the method of any one of claims 1-19. A communication system characterized by The communication system comprises a first device and a second device, the first device being configured to perform the method of any one of claims 1-19. A computer-readable storage medium, characterized by The computer readable storage medium has stored thereon instructions which, when executed by a computer, cause performance of the method of any one of claims 1-19.

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