Optical fiber time synchronization method, device and electronic equipment

Abstract

The present invention provides an optical fiber time synchronization method, device and electronic equipment, the method comprising: a slave clock signal source of a slave clock site sends a first clock signal to a master clock signal source of a master clock site through an optical fiber; wherein, when the master clock signal source receives the first clock signal, according to the first clock signal, a second clock signal sent by the master clock signal source itself is time-reversed to obtain a second clock signal processed with time reversal, and the second clock signal processed with time reversal is sent to the slave clock signal source through the optical fiber; the first clock signal is processed by using the received second clock signal processed with time reversal, so that the first clock signal is synchronized with the second clock signal, and a time reversal processing method is used in the time synchronization process, so as to eliminate the time delay generated by the first clock signal and the second clock signal during the optical fiber transmission process, thereby realizing high-precision synchronization of the time signal of the slave clock site with the time signal of the master clock site.

Description

Technical Field

[0001] The present invention relates to the field of electronic information technology, and in particular to an optical fiber time synchronization method, device and electronic equipment. Background Art

[0002] At present, the most widely used time synchronization technology is to use the Precision Time Protocol (PTP) to encode the time difference data measured by the master clock site and the slave clock site for bidirectional transmission, thereby adjusting the time scale system at both ends so that the slave clock site can achieve synchronization with the master clock. However, this clock synchronization solution involves application data and requires the encoding and decoding transmission of data packets, which makes the time synchronization process very complicated. Summary of the invention

[0003] To solve the above problems, an object of the embodiments of the present invention is to provide a method, device and electronic device for optical fiber time synchronization.

[0004] In a first aspect, an embodiment of the present invention provides a method for optical fiber time synchronization, comprising:

[0005] The slave clock signal source of the slave clock site sends a first clock signal to the master clock signal source of the master clock site through an optical fiber; wherein, upon receiving the first clock signal, the master clock signal source performs time reversal processing on a second clock signal sent by the master clock signal source itself according to the first clock signal to obtain a time-reversed second clock signal, and sends the time-reversed second clock signal to the slave clock signal source through the optical fiber;

[0006] The first clock signal is processed using the received second clock signal subjected to the time inversion process, so that the first clock signal is synchronized with the second clock signal.

[0007] In a second aspect, an embodiment of the present invention further provides an optical fiber time synchronization device, comprising:

[0008] A sending module, used for sending a first clock signal to a master clock signal source of a master clock site through an optical fiber; wherein, when the master clock signal source receives the first clock signal, the master clock signal source performs time reversal processing on a second clock signal sent by the master clock signal source itself according to the first clock signal to obtain a time-reversed second clock signal, and sends the time-reversed second clock signal to the slave clock signal source through the optical fiber;

[0009] The synchronization module is used to process the first clock signal by using the received second clock signal subjected to the time reversal process, so that the first clock signal is synchronized with the second clock signal.

[0010] In a third aspect, an embodiment of the present invention further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the method described in the first aspect are executed.

[0011] In a fourth aspect, an embodiment of the present invention further provides an electronic device, comprising a memory, a processor and one or more programs, wherein the one or more programs are stored in the memory and configured so that the processor executes the steps of the method described in the first aspect above.

[0012] In the scheme provided by the first to fourth aspects of the embodiments of the present invention, a slave clock signal source of a slave clock site sends a first clock signal to a master clock signal source of a master clock site via an optical fiber; wherein, upon receiving the first clock signal, the master clock signal source performs time-reversal processing on a second clock signal emitted by the master clock signal source itself according to the first clock signal to obtain a time-reversed second clock signal, and sends the time-reversed second clock signal to the slave clock signal source via the optical fiber; the first clock signal is processed using the received time-reversed second clock signal so that the first clock signal is synchronized with the second clock signal; compared with the clock synchronization scheme in the related art which involves application data and requires data packet interaction and data packet encoding and decoding between the master clock site and the slave clock site, there is only interaction and processing of the physical clock signal at the bottom layer of the network between the slave clock signal source and the master clock signal source, without Without the need to perform data packet transmission and encoding and decoding operations, the second clock signal of the master clock signal source can be synchronized with the first clock signal in the slave clock signal source, which reduces the complexity of the clock synchronization scheme and improves the stability of the optical fiber transmission system; moreover, there is no need for data packet interaction between the master clock site and the slave clock site, which effectively avoids the use of encoders and decoders and greatly reduces the complexity of the systems of the master clock site and the slave clock site; furthermore, the clock synchronization process is initiated by the slave clock site, so that the influence of the first clock signal sent by the slave clock site on the clock synchronization needs to be considered during the clock synchronization process, so that the slave clock site can obtain a more stable and reliable synchronization time result; finally, a time reversal processing method is used in the time synchronization process to eliminate the time delay generated by the first clock signal and the second clock signal during the optical fiber transmission process, thereby achieving high-precision synchronization of the slave clock site time signal with the master clock site time signal.

[0013] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0015] Figure 1 An application scenario architecture diagram is shown that can implement the optical fiber time synchronization method, device and electronic device proposed in this application;

[0016] Figure 2 A flowchart of an optical fiber time synchronization method provided by Embodiment 1 of the present invention is shown;

[0017] Figure 3 A schematic diagram showing the structure of an optical fiber time synchronization device provided by Embodiment 2 of the present invention is shown;

[0018] Figure 4 A schematic structural diagram of an electronic device provided by Embodiment 3 of the present invention is shown. DETAILED DESCRIPTION

[0019] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0020] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0021] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0022] At present, the most widely used time synchronization technology is to use the Precision Time Protocol (PTP) to encode the time difference data measured by the master clock site and the slave clock site for bidirectional transmission, thereby adjusting the time scale system at both ends so that the slave clock site can achieve synchronization with the master clock. However, this clock synchronization solution involves application data and requires the encoding and decoding transmission of data packets, which makes the time synchronization process very complicated. Figure 1 The application scenario architecture diagram shown can implement the optical fiber time synchronization method, device and electronic device proposed in the present application; in this application scenario, it includes: a slave clock site 100 and a master clock site 110.

[0023] The slave clock station includes: a slave clock signal source 102 and a first time difference measuring device 104 ; the master clock station includes: a master clock signal source 112 and a second time difference measuring device 114 .

[0024] The slave clock signal source is connected to the master clock signal source via an optical fiber, the slave clock signal source sends a first clock signal to the master clock signal source via the optical fiber, and the master clock signal source sends a second clock signal to the slave clock signal source via the optical fiber.

[0025] The first time difference measuring device is connected to the slave clock signal source; the first time difference measuring device is used to compare the first clock signal and the second clock signal obtained from the slave clock signal source to obtain a first clock difference value.

[0026] The second time difference measuring device is connected to the main clock signal source; the second time difference measuring device is used to compare the second clock signal and the first clock signal obtained from the clock signal source to obtain a second clock difference value.

[0027] An intermediate download point 130 may also be provided on the optical fiber for downloading, comparing and time synchronizing the first clock signal and the second clock signal passing through the intermediate download point itself.

[0028] In order to synchronize the first clock signal with the second clock signal, the following embodiments of the present application propose an optical fiber time synchronization method, device and electronic device, wherein a slave clock signal source of a slave clock site sends a first clock signal to a master clock signal source of a master clock site through an optical fiber; wherein, when the master clock signal source receives the first clock signal, it performs time reversal processing on the second clock signal emitted by the master clock signal source itself according to the first clock signal to obtain a time-reversed second clock signal, and sends the time-reversed second clock signal to the slave clock signal source through an optical fiber; the first clock signal is processed using the received time-reversed second clock signal so that the first clock signal is synchronized with the second clock signal; during the clock synchronization process, only the interaction and processing of the physical clock signal at the bottom layer of the network between the slave clock signal source and the master clock signal source, without the need for data packet transmission and encoding and decoding operations, the second clock signal of the master clock signal source can be synchronized with the first clock signal in the slave clock signal source, thereby reducing the complexity of the clock synchronization scheme and improving the stability of the optical fiber transmission system; moreover, data packet interaction between the master clock site and the slave clock site is no longer required, effectively avoiding the use of encoders and decoders, and greatly reducing the complexity of the system of the master clock site and the slave clock site.

[0029] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0030] Example 1

[0031] This embodiment provides an optical fiber time synchronization method, so that the slave clock signal source sending a first clock signal to the master clock signal source through the optical fiber can be synchronized with the master clock signal source sending a second clock signal to the slave clock signal source through the optical fiber.

[0032] See also Figure 2 The flowchart of a fiber optic time synchronization method is shown in FIG. 1 . This embodiment proposes a fiber optic time synchronization method, including the following specific steps:

[0033] Step 200, the slave clock signal source of the slave clock site sends a first clock signal to the master clock signal source of the master clock site via optical fiber; wherein, when the master clock signal source receives the first clock signal, it performs time-reversal processing on the second clock signal emitted by the master clock signal source itself according to the first clock signal to obtain the time-reversed second clock signal, and sends the time-reversed second clock signal to the slave clock signal source via optical fiber.

[0034] In the above step 200, the master clock signal source performs time-reversal processing on the second clock signal emitted by the master clock signal source itself according to the first clock signal to obtain the time-reversed second clock signal, including the following steps (1) to (2):

[0035] (1) The master clock signal source inputs the first clock signal into a second time difference measuring device, and the second time difference measuring device compares the first clock signal and the second clock signal to obtain a first clock difference between the first clock signal and the second clock signal;

[0036] (2) The negative value of the first clock difference is added to the second clock signal to complete the time reversal processing of the second clock signal emitted by the main clock signal source itself, thereby obtaining the time-reversed second clock signal.

[0037] In the above step (1), the specific process of the second time difference measurement device comparing the first clock signal and the second clock signal is prior art and will not be described in detail here.

[0038] Specifically, the second clock signal generated by the main clock signal source is represented by T M , the first clock signal generated from the clock signal source is represented by T S First, the slave clock station generates the second clock signal T generated from the clock signal source S The master clock signal source transmitted to the master clock site. The time signal received by the master clock site is represented by T S1 . S With T S1 By comparing the two, the first clock difference t can be obtained. TD1 :

[0039] t TD1 =T S1 -T M =T S +t p -T M =Δt+t p (1)

[0040] In the above formula 1, Δt represents T S and T M The clock difference, t p It is the time delay of the optical fiber link during the transmission of the first clock signal from the slave clock signal source to the master clock signal source.

[0041] In formula 1, t TD1 is the measured value of the second time difference measuring device, which is a known quantity; Δt and t p All are unknown quantities.

[0042] In the above step (2), the time difference t TD1 The local clock signal T is inverted and added to the master clock M The second clock signal T′ is adjusted to obtain the time-reversed processing M As shown in formula 2:

[0043] T′ M =T M -t TD1 =T M -(Δt+t p ) (2)

[0044] However, in actual operation, it is difficult to adjust a time signal in the reverse time axis given by the above formula 2. Therefore, when performing the time reversal operation on the second clock signal, a time delay constant C is added, so that the time-reversed second clock signal T′ M Satisfies the following formula 3:

[0045] T′ M =T M -t TD1 =T M +C-(Δt+t p ) (3)

[0046] The delay constant C may be cached in the first time difference measurement device and the second time difference measurement device.

[0047] Then, the time-reversed second clock signal T′ M The signal sent to the slave clock station by the slave clock signal source is represented by T S2 , as shown in the following formula 4:

[0048] T S2 =T′ M +t′ p =T M -Δt+t′ p -t p =T M +C-Δt+Δt p (4)

[0049] Among them, t′ p represents the time delay of the optical fiber link during the transmission of the second clock signal processed by time reversal from the master clock signal source to the slave clock signal source; T S2 Indicates that t′ p The time-delayed time-reversed second clock signal; Δt p Indicates the difference in fiber round-trip delay time.

[0050] Step 202: Use the received second clock signal subjected to the time-reversal process to process the first clock signal so that the first clock signal is synchronized with the second clock signal.

[0051] In the above step 202, in order to synchronize the first clock signal with the second clock signal, the following steps (1) to (2) may be performed:

[0052] (1) inputting the received second clock signal processed by time reversal into a first time difference measuring device, wherein the first time difference measuring device compares the first clock signal with the second clock signal processed by time reversal to obtain a second clock difference between the first clock signal and the second clock signal processed by time reversal;

[0053] (2) The obtained second clock difference is added to the first clock signal to complete the processing of the first clock signal, so that the processed first clock signal is synchronized with the second clock signal processed by the time reversal.

[0054] In the above step (1), specifically, after the slave clock signal source obtains the time-reversed second clock signal transmitted from the master clock signal source, it is necessary to first perform time compensation processing on the received time-reversed second clock signal, and then the following steps (11) to (14) need to be performed:

[0055] (11) after receiving the time-reversed second clock signal, determining that the optical fiber between the slave clock signal source and the master clock signal source is not faulty;

[0056] (12) acquiring a first optical carrier wavelength of the first clock signal, a second optical carrier wavelength of the second clock signal subjected to the time reversal process, first longitude and latitude information of the slave clock site, and second longitude and latitude information of the master clock site;

[0057] (13) when the wavelength difference between the first optical carrier wavelength and the second optical carrier wavelength is less than an optical carrier wavelength difference threshold and a Sagnac effect difference is calculated based on the first longitude and latitude information and the second longitude and latitude information and the Sagnac effect difference is compensated, it is determined that the difference in the optical fiber round-trip delay time is 0, and there is no need to perform delay compensation on the received second clock signal subjected to the time reversal processing;

[0058] (14) The received second clock signal processed by time reversal is input into a first time difference measuring device, and the first time difference measuring device compares the first clock signal and the second clock signal processed by time reversal to obtain a second clock difference between the first clock signal and the second clock signal processed by time reversal.

[0059] In the above step (12), the slave clock signal source can parse the first clock signal to obtain the first optical carrier wavelength of the first clock signal; and p The time-delayed time-reversed second clock signal is analyzed to obtain a second optical carrier wavelength of the time-reversed second clock signal.

[0060] When the wavelength difference between the first optical carrier wavelength and the second optical carrier wavelength is greater than a wavelength threshold, the delay difference caused by the wavelength difference can be calibrated and compensated through calibration.

[0061] The process of analyzing the first clock signal and the second clock signal from the clock signal source is prior art and will not be described in detail here.

[0062] In the above step (13), the optical carrier wavelength difference threshold is cached in the slave clock signal source; the calibration and compensation of the delay difference according to the optical carrier wavelength difference is a prior art in the field and will not be described in detail here.

[0063] The specific process of calculating the delay time compensation value based on the first longitude and latitude information and the second longitude and latitude information is prior art and will not be described in detail here.

[0064] Compensating the Sagnac effect difference means compensating the Sagnac effect difference so that the compensated Sagnac effect difference is 0.

[0065] In the above step (14), the first time difference measuring device compares the first clock signal and the second clock signal processed by time reversal to obtain the second clock difference between the first clock signal and the second clock signal processed by time reversal. The specific process is prior art and will not be repeated here.

[0066] The method proposed in this solution is further described using the above example: Δt in the above formula (4) p , can be expressed by the following formula 5:

[0067] Δt p =t Δλ +t Sagnac +t BR (5)

[0068] Among them, t Δλ is caused by the carrier wavelength difference between the first optical carrier wavelength and the second optical carrier wavelength, and can be 0 when the wavelength difference between the first optical carrier wavelength and the second optical carrier wavelength is less than the optical carrier wavelength difference threshold; the Sagnac effect difference t Sagnacis the time delay caused by the Sagnac effect, t BR is the time delay caused by the birefringence of the optical fiber; t Sagnac It can be calculated based on the first longitude and latitude information and the second longitude and latitude information. After compensation, t Sagnac Can be regarded as 0; when there is no major defect in the optical fiber, t BR = 0. Then, t Δλ ,t Sagnac and t BR When both are 0, Δt p =0; that is, the fiber link delay is automatically eliminated through the time reversal method, the fiber round-trip delay time is the same, and the difference is 0.

[0069] Then, the second clock signal after the time compensation and the time reversal processing is sent to the first time difference measuring device, and the time-compensated T S2 With the first clock signal T S By comparing the measurements, the second clock difference t can be obtained. TD2 , expressed by the following formula 6:

[0070] t TD2 =T S2 -T S =C-2Δt (6)

[0071] Among them, t TD2 is the measured value and is a known quantity.

[0072] Finally, add half of the second clock difference to the first clock signal T S A first clock signal T is obtained which is sent from a clock signal source and is synchronized with the second clock signal. M1 , expressed by the following formula 7:

[0073]

[0074] Because C is a known quantity, after compensating and eliminating the constant C, the local clock signal T of the master clock site is obtained. M Synchronous time signal.

[0075] From the above description, it can be seen that the first clock signal T synchronized with the second clock signal M1 The time delay between them is only related to a time delay constant and has nothing to do with the master clock site, the slave clock site, and the optical fiber between the master clock site and the slave clock site. The time delay t′ generated during the optical fiber transmission p and t p , are automatically offset by the time reversal operation. Therefore, Δt can be directly obtained later to achieve high-precision synchronization of the time signal of the slave clock site with the time signal of the master clock site.

[0076] Further, based on formula 6, the clock difference Δt between the first clock signal and the second clock signal can be calculated by the following process:

[0077] Obtain a delay constant, and calculate a clock difference between the first clock signal and the second clock signal using the following formula 8:

[0078] Δt=1 / 2(Ct TD2 ) (8)

[0079] Wherein, Δt represents the clock difference between the first clock signal and the second clock signal; t TD2 represents the second clock difference; C represents the delay constant.

[0080] Through the above formula 8, the solution to Δt is completed.

[0081] In addition to being able to synchronize the time signal at the slave clock site with the master clock site, the optical fiber time synchronization method proposed in this embodiment can also achieve synchronized downloading of the time signal at any point in the optical fiber link.

[0082] In order to achieve synchronous downloading of the time signal at any point in the optical fiber link, the optical fiber time synchronization method proposed in this embodiment may further perform the following steps (1) to (3):

[0083] (1) An intermediate download point set on the optical fiber downloads a first clock signal at the intermediate download point to obtain a third clock signal, and simultaneously downloads a second clock signal at the intermediate download point to obtain a fourth clock signal; wherein the third clock signal is obtained by adding a first time delay from the clock signal source to the intermediate download point to the first clock signal; and the fourth clock signal is obtained by adding a second time delay from the master clock signal source to the intermediate download point to the second clock signal subjected to time inversion;

[0084] (2) the intermediate download point compares the third clock signal and the fourth clock signal to obtain a third clock difference between the third clock signal and the fourth clock signal;

[0085] (3) The intermediate download point obtains the first clock signal synchronized with the second clock signal downloaded by the intermediate download point through the following equation group 9:

[0086]

[0087] Among them, T S3 represents the third clock signal; T S represents the first clock signal; t p1 represents the first delay from the clock signal source to the intermediate download point; T M represents the second clock signal; TM2 Represents a first clock signal synchronized with a second clock signal downloaded by an intermediate download point.

[0088] In the above step (1), the third clock signal and the fourth clock signal can be expressed by the following equation group 10:

[0089]

[0090] Among them, T S4 represents the fourth clock signal; t′ p2 Indicates the second delay between the main clock signal source and the intermediate download point.

[0091] However, from the above content, we can know that: in the case of intermediate download points, t p and t′ p It can be expressed by the following formula 11:

[0092]

[0093] Among them, t p2 represents the third delay generated when the first clock signal is downloaded from the intermediate point to the main clock signal source; t' p1 The fourth delay generated when the second clock signal subjected to the time reversal processing is downloaded from the intermediate point to the slave clock signal source.

[0094] After calibration, the following relationship equation can be obtained, as shown in Formula 12:

[0095]

[0096] After determining the above formula 12, the above step (2) may be continued to be performed, and the third clock signal and the fourth clock signal are compared through the intermediate download point to obtain a third clock difference between the third clock signal and the fourth clock signal.

[0097] In the above step (3), since C is a known quantity, after compensating and eliminating the constant C, the local clock signal T of the master clock site is obtained. M Synchronous time signal.

[0098] From the description of steps (1) to (3) above, it can be seen that the delay time of the first clock signal downloaded by setting an intermediate download point at any position in the optical fiber is only related to the delay constant and has nothing to do with the master clock site, the slave clock site, and the optical fiber between the master clock site and the slave clock site. Therefore, two synchronized time signals can be downloaded at any position of the optical fiber, which greatly expands the application scope of time synchronization.

[0099] The optical fiber time synchronization method proposed in this embodiment has the following advantages:

[0100] 1. No need for data interaction, avoiding the generation of data layers, improving stability and enhancing reliability

[0101] Traditional fiber optic time synchronization schemes need to measure or calculate the round-trip or one-way delay of the fiber optic link, and the two-way transmission scheme also needs to record and transmit the time points of sending and receiving on both sides with timestamps. Since data packets are transmitted, in addition to clock signals, the data packets mainly include application data, which makes it impossible for the master clock site and the slave clock site to avoid the use of encoders and decoders, reducing the synchronization stability. However, in the time reversal scheme used in the fiber optic time synchronization method proposed in this embodiment, only the clock signal is processed, and the processing of the clock signal is flattened to the physical layer. There is no need to measure or calculate the round-trip or one-way delay of the fiber optic link, and the encoding and transmission of the timestamp is eliminated. The transmitted information also only contains the clock signal required for synchronization. This greatly reduces the signal complexity of the synchronization scheme and improves the stability of the system. Therefore, there is no need for data packet interaction between the master clock site and the slave clock site, which effectively avoids the use of encoders and decoders and greatly reduces the complexity of the system.

[0102] 2. Time synchronization is initiated by the slave clock site, and the time signal can be downloaded at any point in the optical fiber link

[0103] The traditional loopback method relies on the master clock site to synchronize the clocks of the slave clock sites, and the slave clock sites have low degrees of freedom and low reliability. The fiber optic time synchronization method based on time reversal in the fiber optic time synchronization method proposed in this embodiment is a time synchronization method initiated by the slave clock site, which has high degrees of freedom and high reliability. However, the traditional opposite transmission scheme requires synchronous transmission processing at both ends of the fiber optic link because it relies on the calculation of timestamps. This makes the actual scope of the fiber optic link limited to the head and tail ends of the fiber optic link. During long-distance transmission, the utilization rate of the fiber optic link along the way becomes very low. In the fiber optic time synchronization method based on time reversal proposed in this embodiment, the fiber optic link transmits the lowest-level physical clock signal rather than the encoded digital signal. Therefore, the special properties of time reversal can be used to process the clock signal, and any intermediate download point in the fiber optic link can offset the delay changes introduced by the fiber optic link, thereby realizing the synchronous download of the time signal at any position of the fiber optic link.

[0104] The fiber optic time synchronization method proposed in this embodiment is an innovation at the principle level of the time synchronization scheme, and is not an advantageous combination of existing schemes. The loopback method and the counter-transmission method are completely non-overlapping schemes. Although both are compensation for the delay of the optical fiber link, there is a conflict in their synchronization principles and they cannot be combined together. The loopback method adjusts the time signal of the master clock site by the difference of the physical time signal obtained by loopback to perform link compensation, and the slave clock site is completely controlled by the master clock site. The counter-transmission method relies on the master clock site and the slave clock site to record timestamps, transmit timestamp data in opposite directions, and adjust and compensate according to the timestamp data signal. The counter-transmission method needs to rely on the cooperation of the master and slave clock sites to implement. It can be seen that the above two methods have conflicting differences in the underlying logic, implementation objects, and technical means and cannot be used in combination.

[0105] The optical fiber time synchronization method proposed in this embodiment is innovative in principle, so that time synchronization can be transmitted using only basic physical clock signals (physical clock signals are square wave signals) without encoding, and no data that needs to be encoded needs to be transmitted in opposite directions. At the same time, it can also avoid the system instability caused by the time synchronization being controlled by the master clock site alone, and can realize the function of downloading the synchronization signal at the intermediate point. This innovation in principle makes up for the problems existing in the above two methods.

[0106] In summary, this embodiment proposes an optical fiber time synchronization method, in which a slave clock signal source of a slave clock site sends a first clock signal to a master clock signal source of a master clock site through an optical fiber; wherein, when the master clock signal source receives the first clock signal, it performs time-reversal processing on a second clock signal emitted by the master clock signal source itself according to the first clock signal to obtain a time-reversed second clock signal, and sends the time-reversed second clock signal to the slave clock signal source through an optical fiber; the first clock signal is processed using the received time-reversed second clock signal so that the first clock signal is synchronized with the second clock signal; compared with the clock synchronization scheme in the related art, which involves application data and requires data packet interaction and data packet encoding and decoding between the master clock site and the slave clock site, there is only interaction and processing of the lowest-level physical clock signal in the network between the slave clock signal source and the master clock signal source, and no need By performing data packet transmission and encoding and decoding operations, the second clock signal of the master clock signal source can be synchronized with the first clock signal of the slave clock signal source, reducing the complexity of the clock synchronization scheme and improving the stability of the optical fiber transmission system; moreover, there is no need for data packet interaction between the master clock site and the slave clock site, effectively avoiding the use of encoders and decoders, greatly reducing the system complexity of the master clock site and the slave clock site; furthermore, the clock synchronization process is initiated by the slave clock site, so that the influence of the first clock signal sent by the slave clock site on the clock synchronization needs to be considered during the clock synchronization process, so that the slave clock site can obtain a more stable and reliable synchronization time result; finally, a time reversal processing method is used in the time synchronization process to eliminate the time delay generated by the first clock signal and the second clock signal during the optical fiber transmission process, thereby achieving high-precision synchronization of the slave clock site time signal with the master clock site time signal.

[0107] Example 2

[0108] This embodiment provides an optical fiber time synchronization device, which is used to execute an optical fiber time synchronization method provided in the above embodiment 1.

[0109] See also Figure 3 The structure diagram of a fiber optic time synchronization device is shown in FIG. 1 . This embodiment provides a fiber optic time synchronization device, including:

[0110] A sending module 300 is used to send a first clock signal to a master clock signal source of a master clock site through an optical fiber; wherein, when the master clock signal source receives the first clock signal, the master clock signal source performs time reversal processing on a second clock signal sent by the master clock signal source itself according to the first clock signal to obtain a time-reversed second clock signal, and sends the time-reversed second clock signal to the slave clock signal source through the optical fiber;

[0111] The synchronization module 302 is used to process the first clock signal by using the received second clock signal subjected to the time reversal process, so that the first clock signal is synchronized with the second clock signal.

[0112] Specifically, the synchronization module 302 is specifically used for:

[0113] Inputting the received second clock signal processed by time reversal into a first time difference measuring device, wherein the first time difference measuring device compares the first clock signal with the second clock signal processed by time reversal to obtain a second clock difference between the first clock signal and the second clock signal processed by time reversal;

[0114] The obtained second clock difference is added to the first clock signal to complete the processing of the first clock signal, so that the processed first clock signal is synchronized with the second clock signal subjected to the time-reversal processing.

[0115] In summary, the present embodiment proposes an optical fiber time synchronization device, in which a slave clock signal source of a slave clock site sends a first clock signal to a master clock signal source of a master clock site through an optical fiber; wherein, when the master clock signal source receives the first clock signal, it performs time-reversal processing on a second clock signal emitted by the master clock signal source itself according to the first clock signal to obtain a time-reversed second clock signal, and sends the time-reversed second clock signal to the slave clock signal source through an optical fiber; the first clock signal is processed using the received time-reversed second clock signal so that the first clock signal is synchronized with the second clock signal; compared with the clock synchronization scheme in the related art, which involves application data and requires data packet interaction and data packet encoding and decoding between the master clock site and the slave clock site, there is only interaction and processing of the lowest-level physical clock signal in the network between the slave clock signal source and the master clock signal source, and no need By performing data packet transmission and encoding and decoding operations, the second clock signal of the master clock signal source can be synchronized with the first clock signal of the slave clock signal source, reducing the complexity of the clock synchronization scheme and improving the stability of the optical fiber transmission system; moreover, there is no need for data packet interaction between the master clock site and the slave clock site, effectively avoiding the use of encoders and decoders, greatly reducing the system complexity of the master clock site and the slave clock site; furthermore, the clock synchronization process is initiated by the slave clock site, so that the influence of the first clock signal sent by the slave clock site on the clock synchronization needs to be considered during the clock synchronization process, so that the slave clock site can obtain a more stable and reliable synchronization time result; finally, a time reversal processing method is used in the time synchronization process to eliminate the time delay generated by the first clock signal and the second clock signal during the optical fiber transmission process, thereby achieving high-precision synchronization of the slave clock site time signal with the master clock site time signal.

[0116] Example 3

[0117] This embodiment provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the steps of the optical fiber time synchronization method described in the above embodiment 1 are executed. The specific implementation can be found in the method embodiment 1, which will not be described in detail here.

[0118] In addition, see Figure 4 The structural diagram of an electronic device shown in FIG. 1 is a schematic diagram of a structure of an electronic device. This embodiment further provides an electronic device, which includes a bus 51 , a processor 52 , a transceiver 53 , a bus interface 54 , a memory 55 and a user interface 56 . The electronic device includes a memory 55 .

[0119] In this embodiment, the electronic device further includes: one or more programs stored in the memory 55 and executable on the processor 52, and configured so that the processor executes the one or more programs to perform the following steps (1) to (2):

[0120] (1) A slave clock signal source of a slave clock station sends a first clock signal to a master clock signal source of a master clock station via an optical fiber; wherein, upon receiving the first clock signal, the master clock signal source performs time reversal processing on a second clock signal sent by the master clock signal source itself according to the first clock signal to obtain a time-reversed second clock signal, and sends the time-reversed second clock signal to the slave clock signal source via an optical fiber;

[0121] (2) Using the received second clock signal subjected to the time-reversal processing, the first clock signal is processed so that the first clock signal is synchronized with the second clock signal.

[0122] The transceiver 53 is used to receive and send data under the control of the processor 52.

[0123] Among them, the bus architecture (represented by bus 51), bus 51 can include any number of interconnected buses and bridges, and bus 51 links various circuits including one or more processors represented by processor 52 and memory represented by memory 55. Bus 51 can also link various other circuits such as peripherals, voltage regulators, and power management circuits together, which are all well known in the art, so this embodiment will not be further described. Bus interface 54 provides an interface between bus 51 and transceiver 53. Transceiver 53 can be one element or multiple elements, such as multiple receivers and transmitters, providing a unit for communicating with various other devices on a transmission medium. For example: transceiver 53 receives external data from other devices. Transceiver 53 is used to send data processed by processor 52 to other devices. Depending on the nature of the computing system, a user interface 56, such as a keypad, display, speaker, microphone, joystick, can also be provided.

[0124] The processor 52 is responsible for managing the bus 51 and general processing, such as running a general operating system as mentioned above, while the memory 55 can be used to store data used by the processor 52 when performing operations.

[0125] Optionally, the processor 52 may be, but is not limited to: a central processing unit, a single-chip microcomputer, a microprocessor or a programmable logic device.

[0126] It can be understood that the memory 55 in the embodiment of the present invention can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory can be a random access memory (RAM), which is used as an external cache. By way of example but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDRSDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM) and direct RAM bus random access memory (DRRAM). The memory 55 of the system and method described in the present embodiment is intended to include, but is not limited to, these and any other suitable types of memory.

[0127] In some implementations, the memory 55 stores the following elements, executable modules or data structures, or a subset thereof, or an extended set thereof: an operating system 551 and application programs 552 .

[0128] The operating system 551 includes various system programs, such as a framework layer, a core library layer, a driver layer, etc., which are used to implement various basic services and process hardware-based tasks. The application 552 includes various application programs, such as a media player (Media Player), a browser (Browser), etc., which are used to implement various application services. The program for implementing the method of the embodiment of the present invention can be included in the application 552.

[0129] In summary, the present embodiment proposes a computer-readable storage medium and an electronic device, wherein a slave clock signal source of a slave clock site sends a first clock signal to a master clock signal source of a master clock site through an optical fiber; wherein, upon receiving the first clock signal, the master clock signal source performs time-reversal processing on a second clock signal emitted by the master clock signal source itself according to the first clock signal to obtain a time-reversed second clock signal, and sends the time-reversed second clock signal to the slave clock signal source through the optical fiber; the first clock signal is processed using the received time-reversed second clock signal so that the first clock signal is synchronized with the second clock signal; compared with the clock synchronization scheme in the related art, which involves application data and requires data packet interaction and data packet encoding and decoding between the master clock site and the slave clock site, there is only interaction and processing of the lowest-level physical clock signal in the network between the slave clock signal source and the master clock signal source. , the second clock signal of the master clock signal source can be synchronized with the first clock signal of the slave clock signal source without the need for data packet transmission and encoding and decoding operations, which reduces the complexity of the clock synchronization scheme and improves the stability of the optical fiber transmission system; moreover, there is no need for data packet interaction between the master clock site and the slave clock site, which effectively avoids the use of encoders and decoders, greatly reducing the system complexity of the master clock site and the slave clock site; furthermore, the clock synchronization process is initiated by the slave clock site, so that the influence of the first clock signal sent by the slave clock site on the clock synchronization needs to be considered during the clock synchronization process, so that the slave clock site can obtain a more stable and reliable synchronization time result; finally, the time reversal processing method is used in the time synchronization process, which eliminates the time delay generated by the first clock signal and the second clock signal during the optical fiber transmission process, and realizes high-precision synchronization of the slave clock site time signal with the master clock site time signal.

[0130] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for optical fiber time synchronization, characterized in that: include: The slave clock signal source of the slave clock site sends a first clock signal to the master clock signal source of the master clock site through an optical fiber; wherein, upon receiving the first clock signal, the master clock signal source performs time reversal processing on a second clock signal sent by the master clock signal source itself according to the first clock signal to obtain a time-reversed second clock signal, and sends the time-reversed second clock signal to the slave clock signal source through the optical fiber; Processing the first clock signal using the received second clock signal subjected to the time inversion process so that the first clock signal is synchronized with the second clock signal; The master clock signal source performs time-reversal processing on a second clock signal emitted by the master clock signal source itself according to the first clock signal to obtain a time-reversed second clock signal, including: The master clock signal source inputs the first clock signal into a second time difference measuring device, and the second time difference measuring device compares the first clock signal and the second clock signal to obtain a first clock difference between the first clock signal and the second clock signal; The negative value of the first clock difference is added to the second clock signal to complete the time reversal processing of the second clock signal emitted by the main clock signal source itself, thereby obtaining the time-reversed second clock signal.

2. The method according to claim 1, characterized in that The method of processing the first clock signal by using the received second clock signal subjected to the time reversal process so that the processed first clock signal is synchronized with the second clock signal subjected to the time reversal process comprises: Inputting the received second clock signal processed by time reversal into a first time difference measuring device, wherein the first time difference measuring device compares the first clock signal with the second clock signal processed by time reversal to obtain a second clock difference between the first clock signal and the second clock signal processed by time reversal; The obtained second clock difference is added to the first clock signal to complete the processing of the first clock signal, so that the processed first clock signal is synchronized with the second clock signal subjected to the time-reversal processing.

3. The method according to claim 2, characterized in that The step of inputting the received second clock signal processed by time reversal into a first time difference measuring device, wherein the first time difference measuring device compares the first clock signal with the second clock signal processed by time reversal to obtain a second clock difference between the first clock signal and the second clock signal processed by time reversal, comprises: After receiving the time-reversed second clock signal, determining that the optical fiber between the slave clock signal source and the master clock signal source has no faults; Acquire a first optical carrier wavelength of the first clock signal, a second optical carrier wavelength of the second clock signal subjected to the time reversal process, first longitude and latitude information of a slave clock site, and second longitude and latitude information of a master clock site; When the wavelength difference between the first optical carrier wavelength and the second optical carrier wavelength is less than the optical carrier wavelength difference threshold and the Sagnac effect difference is calculated according to the first longitude and latitude information and the second longitude and latitude information and the Sagnac effect difference is compensated, it is determined that the difference in the optical fiber round-trip delay time is 0, and there is no need to perform delay compensation on the received second clock signal subjected to the time reversal processing; The received second clock signal processed by time reversal is input into a first time difference measuring device, and the first time difference measuring device compares the first clock signal and the second clock signal processed by time reversal to obtain a second clock difference between the first clock signal and the second clock signal processed by time reversal.

4. The method according to claim 3, characterized in that Also includes: Obtain a delay constant, and calculate a clock difference between the first clock signal and the second clock signal using the following formula: Δt=1 / 2(C-t TD2 ) Wherein, Δt represents the clock difference between the first clock signal and the second clock signal; t TD2 represents the second clock difference; C represents the delay constant.

5. The method according to claim 4, characterized in that Also includes: The intermediate download point set on the optical fiber downloads the first clock signal at the intermediate download point to obtain the third clock signal, and at the same time downloads the second clock signal at the intermediate download point to obtain the fourth clock signal; wherein the third clock signal is obtained by adding the first time delay between the slave clock signal source and the intermediate download point to the first clock signal; and the fourth clock signal is obtained by adding the second time delay between the master clock signal source and the intermediate download point to the second clock signal subjected to time inversion processing; The intermediate download point compares the third clock signal and the fourth clock signal to obtain a third clock difference between the third clock signal and the fourth clock signal; The intermediate download point obtains the first clock signal synchronized with the second clock signal downloaded by the intermediate download point through the following equation group: Among them, T S3 represents the third clock signal; T S represents the first clock signal; t p1 represents the first delay from the clock signal source to the intermediate download point; T M represents the second clock signal; T M2 Represents a first clock signal synchronized with a second clock signal downloaded by an intermediate download point.

6. An optical fiber time synchronization device, characterized in that: include: A sending module, used for sending a first clock signal from a slave clock signal source of a slave clock site to a master clock signal source of a master clock site through an optical fiber; wherein, when the master clock signal source receives the first clock signal, it performs time reversal processing on a second clock signal sent by the master clock signal source itself according to the first clock signal to obtain a time-reversed second clock signal, and sends the time-reversed second clock signal to the slave clock signal source through the optical fiber; a synchronization module, configured to process the first clock signal by using the received second clock signal subjected to the time reversal process, so that the first clock signal is synchronized with the second clock signal; The synchronization module is specifically used for: Inputting the received second clock signal processed by time reversal into a first time difference measuring device, wherein the first time difference measuring device compares the first clock signal with the second clock signal processed by time reversal to obtain a second clock difference between the first clock signal and the second clock signal processed by time reversal; The obtained second clock difference is added to the first clock signal to complete the processing of the first clock signal, so that the processed first clock signal is synchronized with the second clock signal subjected to the time-reversal processing.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 5 are executed.

8. An electronic device, characterized in that: The electronic device includes a memory, a processor and one or more programs, wherein the one or more programs are stored in the memory and are configured so that the processor executes the steps of the method according to any one of claims 1 to 5.

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