WO2022062308A1

WO2022062308A1 - Reference clock determination method and apparatus, and system, storage medium and electronic apparatus

Info

Publication number: WO2022062308A1
Application number: PCT/CN2021/077118
Authority: WO
Inventors: 吴涛; 沈杰; 陈高强; 张静静; 马超
Original assignee: 三维通信股份有限公司
Priority date: 2020-09-23
Filing date: 2021-02-20
Publication date: 2022-03-31
Also published as: CN111934841A; CN111934841B

Abstract

Provided are a reference clock determination method and apparatus, and a system, a storage medium and an electronic apparatus. The method comprises: executing the following operations on each remote unit in a target loop, and when the following operations are executed on each remote unit, determining each remote unit as the current remote unit, said operations comprising: acquiring a first signal which is received by a first port of the current remote unit and is from the target loop, and a second signal which is received by a second port of the current remote unit and is from the target loop; according to the first signal and the second signal, determining one of the first port and the second port of the current remote unit as a slave port, and the other one of the first port and the second port of the current remote unit as a master port; and according to a signal which is received by the slave port of the current remote unit and is from the target loop, determining a reference clock of the current remote unit. By means of the present invention, the technical problem of an increase in the phase noise of a reference clock of a remote device in a loop due to an increase in the number of cascade stages of the remote device in the loop is solved.

Description

Reference clock determination method and device, system, storage medium and electronic device

technical field

The present invention relates to the field of communications, and in particular, to a method and device, system, storage medium and electronic device for determining a reference clock.

Background technique

The distributed coverage system includes a base station, a near-end unit (also known as an access unit, Access Unit, abbreviated as AU), a remote unit (also known as a remote unit, Remote Unit, abbreviated as RU) and other equipment. Each device includes a transmitter, a receiver, and a digital pre-distortion (Digital Pre-Distortion, referred to as DPD) feedback path. Various transmitters and receivers can include data converters such as Analog to Digital/Digital to Analog Converters (ADC/DAC for short), due to the phase noise and jitter performance of the clock generator. The dynamic range and linearity performance of the converter have a serious impact, which in turn affects the transmit/receive error vector magnitude (Error Vector Magnitude, referred to as EVM) specification, which further affects the signal transmission rate, so various transmitters and receivers (such as the Components such as the included ADC/DAC) and the Local Oscillator (LO) require a reference clock with low jitter and low phase noise to improve performance.

The clock source used for synchronization between base stations usually comes from the Global Positioning System (GPS for short), while the clock source for synchronization between devices such as AU or RU comes from the Common Public Radio Interface (CPRI for short) link. GPS has excellent long-term frequency stability; while devices such as RU need to recover the clock from the CPRI link and use it as the reference clock of the local clock chip, and the recovered clock has been generated relative to the reference clock of the upper-level device. Deterioration of phase noise and jitter, and therefore a poor reference clock, will lead to increased phase noise of the LO, which in turn increases the transmit/receive EVM and Signal Noise Ratio (SNR). Also, high clock jitter and noise floor can reduce system SNR and cause spurious radiation of data converters, which further reduces the spurious-free dynamic range (SFDR) of data converters, resulting in low performance. The clock source ultimately results in a reduction in system capacity and throughput.

In the related art, the networking modes of the distributed overlay system include a star type, a chain type, and a hybrid type of the star type and the chain type. Usually the networking mode requires loop protection, that is, the near-end unit and multiple remote units are connected in series to form a loop. However, the more remote units are cascaded on the loop, the more remote units in the last level The greater the clock phase noise, the greater the degradation to the EVM. As shown in Figure 1, on the physical connection of the loop, the A port of the AU is connected to RU1, RU1 is connected to RU2... RU7 is connected to RU8, and RU8 is connected to the D port of the AU. For each RU, its slave port (also called S port) is used to receive the downlink signal from the upper-level device in the loop, and transmit the received downlink signal to the master (master) of the RU ) port (also called M port), the M port is used to transmit the downlink signal transmitted from the S port to the next-level device in the loop. In the networking mode of FIG. 1 , the paths traversed by downlink signals are port A, RU1, RU2... RU7, RU8. Each RU device recovers a clock signal from the signal (eg, a signal based on the CPRI protocol) received from the loop according to its S port, and uses the recovered clock signal as a reference clock and transmits it to the local clock chip. With the increase of the number of RU devices in the loop, the RU devices in the loop, such as RU8 in Figure 1, are in the last stage of signal transmission and also the last stage of clock recovery. The received clock phase noise is the largest, so that the EVM of the clock phase signal of the RU8 will be correspondingly worse, thus affecting the signal transmission rate.

In the related art, an effective technical solution has not been proposed for the technical problem that the increase in the number of cascaded stages of the remote devices in the loop leads to an increase in the phase noise of the reference clock of the remote devices in the loop.

SUMMARY OF THE INVENTION

Embodiments of the present invention provide a method, device, system, storage medium, and electronic device for determining a reference clock, so as to at least solve the problem that the increase in the number of cascaded stages of remote devices in the loop causes the reference clock of the remote devices in the loop The technical problem of increasing phase noise.

According to an embodiment of the present invention, a method for determining a reference clock is provided, comprising: performing the following operations on each remote unit in a target loop, wherein when performing the following operations on each remote unit , determine each remote unit as the current remote unit: obtain the first signal received by the first port of the current remote unit from the target loop, and the second signal of the current remote unit The second signal received by the port from the target loop, wherein the target loop includes: a loop composed of a near-end machine and a plurality of remote machines; according to the first signal and the second signal , determine that one of the first port and the second port of the current remote machine is the slave port, and the other port of the first port and the second port is the master port; according to The signal received from the target loop by the slave port of the current remote unit determines the reference clock of the current remote unit.

Optionally, before performing the following operations on each remote machine in the target loop, the method further includes: using the first port of the near-end machine and the second port of the near-end machine respectively A first signal and a second signal are sent to the target loop, wherein the first signal is transmitted in the target loop according to a first signal transmission path, and the second signal is transmitted in the target loop according to The second signal transmission path is transmitted, and the first signal sent by the near-end unit carries first identification information and second identification information, and the first identification information is used to indicate the first identification information of the near-end unit. A port, the second identification information is used to indicate that the number of remote units that the first signal passes through in the target loop is an initial value, and the second signal sent by the near-end unit carries third identification information and fourth identification information, where the third identification information is used to indicate the second port of the near-end machine, and the fourth identification information is used to indicate that the second signal is in the target ring The number of remote units passing on the road is the initial value.

Optionally, obtaining the first signal received from the target loop by the first port of the current remote machine, and the second port of the current remote machine received from the target loop After the second signal of the current remote unit, the method further includes: receiving the first signal from a first device connected to the current remote unit through the first port of the current remote unit, and receiving the first signal through the current remote unit The second port of the terminal receives the second signal from a second device connected to the current remote, wherein the first device is the first device in the target loop that is connected to the current remote. A device connected to one port, the second device is a device in the target loop connected to the second port of the current remote machine; carrying the first signal received by the current remote machine After the value represented by the second identification information is increased by a preset value, the updated second identification information is obtained, and the fourth identification information carried in the second signal received by the second port of the current remote machine is obtained. After the indicated value is increased by the preset value, the updated fourth identification information is obtained; the second identification information in the first signal received by the current remote unit is updated using the updated second identification information. information is updated to obtain the updated first signal, and the updated first signal is sent to the second device through the second port of the current remote device; the updated fourth identification information is used The fourth identification information in the second signal received by the current remote unit is updated to obtain an updated second signal, and the updated second signal is passed through the first signal of the current remote unit. A port is sent to the first device.

Optionally, according to the first signal and the second signal, it is determined that one of the first port and the second port of the current remote machine is a slave port, and the first port is a slave port. One of the ports and the other port of the second port is the master port, including: acquiring the first identification information and the second identification information carried in the first signal, and the third identification carried in the second signal information and fourth identification information, wherein the second identification information is used to indicate the number of remote units that the first signal passes through in the target loop, and the fourth identification information is used to indicate the first The number of remote units that the second signal passes through in the target loop; the first identification information indicates one port of the near-end unit, and the third identification information indicates another port of the near-end unit In the case of a port, when the value represented by the second identification information is less than or equal to the value represented by the fourth identification information, the first port of the current remote unit is determined as the current remote unit. the slave port of the end machine, and the second port of the current remote machine is determined as the master port of the current remote machine; the first identification information indicates the one port of the near end machine , and when the third identification information indicates the other port of the near-end device, in the case that the value indicated by the second identification information is greater than the value indicated by the fourth identification information, the The second port of the current remote machine is determined as the slave port of the current remote machine, and the first port of the current remote machine is determined as the master port of the current remote machine.

Optionally, the determining the reference clock of the current remote machine according to the signal received from the target loop by the slave port of the current remote machine includes: acquiring the slave port of the current remote machine from the target loop. The signal received from the device connected to the slave port of the current remote machine in the target loop; according to the signal received from the device connected to the slave port of the current remote machine in the target loop and recover the clock signal; determine the recovered clock signal as the reference clock of the current remote unit.

Optionally, according to the first signal and the second signal, it is determined that one of the first port and the second port of the current remote machine is a slave port, and the first port is a slave port. The other one of one port and the second port is the main port, including: receiving the signal sent by the second remote machine connected to the main port of the current remote machine through the current remote machine, and passing the signal sent by the second remote machine connected to the main port of the current remote machine. In the case that the current remote unit does not receive a signal sent by the first remote unit connected to the slave port of the current remote unit within a preset time period, it is determined that the first remote unit is faulty; Switching the slave port of the current remote machine and the master port of the current remote machine, wherein the plurality of remote machines further includes the first remote machine and the second remote machine remote machine.

According to another embodiment of the present invention, an apparatus for determining a reference clock is provided, comprising: an acquisition module, a first determination module and a second determination module, the apparatus is configured to use the acquisition module, the first determination module The module and the second determining module determine the reference clock of each remote unit in the target loop, wherein when determining the reference clock of each remote unit, each remote unit is determined as the current Remote unit: wherein the acquisition module is configured to acquire the first signal received by the first port of the current remote unit from the target loop, and the second port of the current remote unit from the target loop. The second signal received on the target loop, wherein the target loop includes: a loop composed of a near-end machine and a plurality of remote machines; the first determining module is set to be based on the first signal and the second signal, determining that one of the first port and the second port of the current remote unit is a slave port, and the other one of the first port and the second port The port is the master port; the second determining module is configured to determine the reference clock of the current remote machine according to the signal received from the target loop by the slave port of the current remote machine.

According to another embodiment of the present invention, a system for determining a reference clock is provided, comprising: a near-end unit and a plurality of remote units, wherein each remote unit in the plurality of remote units is used to execute The following operation, wherein, when each remote terminal performs the following operation, it determines itself as the current remote terminal: acquiring the first signal received by the first port of the current remote terminal from the target loop , and the second signal received by the second port of the current remote machine from the target loop, wherein the target loop includes: a signal composed of the near-end machine and the plurality of remote machines loop; according to the first signal and the second signal, determine that one of the first port and the second port of the current remote machine is a slave port, and the first port and The other port in the second port is the master port; the reference clock of the current remote machine is determined according to the signal received from the target loop by the slave port of the current remote machine.

Through the present invention, the following operations are performed for each remote unit in the target loop, wherein when the following operations are performed on each remote unit, each remote unit is determined as the current remote unit: Obtain the first signal received by the first port of the current remote machine from the target loop, and the second signal received by the second port of the current remote machine from the target loop, wherein, The target loop includes: a loop composed of a near-end machine and a plurality of far-end machines; according to the first signal and the second signal, determine the first port and all the current far-end machines. One port in the second port is a slave port, and the other port in the first port and the second port is a master port; according to the slave port of the current remote machine, from the target loop The received signal determines the reference clock of the current remote unit. Therefore, it is possible to solve the technical problem that the increase in the number of cascaded stages of the remote device in the loop leads to an increase in the phase noise of the reference clock of the remote device in the loop, and reduce the problem caused by the increase of the number of cascaded stages of the remote device. The phase noise of the remote device's reference clock reduces the system's transmit/receive error vector magnitude degradation.

Description of drawings

The accompanying drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the attached image:

1 is a schematic diagram of a method for determining a reference clock in the related art;

2 is a flowchart of a method for determining a reference clock according to an embodiment of the present invention;

3 is a network topology diagram of a method for determining a reference clock according to an embodiment of the present invention;

4 is a schematic diagram (1) of loop protection according to another embodiment of the present invention;

5 is a schematic diagram (2) of loop protection according to another embodiment of the present invention;

6 is a structural block diagram of an apparatus for determining a reference clock according to another embodiment of the present invention;

FIG. 7 is a schematic structural diagram of an optional electronic device according to an embodiment of the present invention.

detailed description

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings and in conjunction with embodiments. It should be noted that the embodiments in the present application and the features of the embodiments may be combined with each other in the case of no conflict.

It should be noted that the terms "first", "second" and the like in the description and claims of the present invention and the above drawings are used to distinguish similar objects, and are not necessarily used to describe a specific sequence or sequence.

An embodiment of the present invention provides a method for determining a reference clock. FIG. 2 is a flowchart of a method for determining a reference clock according to an embodiment of the present invention. In the method, the following is performed for each remote unit in the target loop. The operations from step S102 to step S106, wherein, when the following operations are performed on each remote unit, each remote unit is determined as the current remote unit:

Step S102, acquiring the first signal received by the first port of the current remote machine from the target loop, and the second signal received by the second port of the current remote machine from the target loop , wherein the target loop includes: a loop composed of a near-end machine and a plurality of remote machines;

Step S104, according to the first signal and the second signal, determine that one of the first port and the second port of the current remote machine is a slave port, and the first port and the second port are The other port in the second port is the main port;

Step S106: Determine the reference clock of the current remote machine according to the signal received from the target loop by the slave port of the current remote machine.

In the above embodiment, the first port of each remote terminal receives the first signal from the target loop and the second port receives the second signal from the target loop, that is, there is a bidirectional signal transmission path in the target loop.

The method in the above embodiment can be applied to the network topology shown in FIG. 3 . As shown in FIG. 3 , the near-end machine AU sends the first signal to the target loop through its first port (that is, the A port in FIG. 3 ). , and send the second signal to the target loop through its second port (ie, the D port in FIG. 3 ), where the target loop is a loop composed of the AU and the remote units RU1 to RU8. Through the above embodiment, the slave port and the master port of each remote machine in the plurality of remote machines shown in FIG. 3 can be determined.

In the above embodiment, for the current remote machine (ie, any remote machine in the target ring), taking the remote machine RU1 in FIG. 3 as an example, the first port of RU1 (ie, port 1) from the target ring After receiving the first signal in the channel (that is, the AU in the target loop), update the value of the second identification information carried in the first signal, that is, increase the value of the second information identification by a preset value (for example, 1), and transmit the updated first signal of the second identification information to the second port (ie, port 2) of RU1, and the second port continues to send the updated first signal to the target loop connected to the second port. The next device (that is, RU2); after the first port of RU2 receives the first signal, it performs the same process as RU1, that is, adds 1 to the value of the second identification information in the received signal, and continues to send it to RU1. Connect the next device until the second port of the AU receives the signal sent by RU8; and, the second port of the AU sends the second signal to the target loop, and each remote unit in the target loop passes its first signal. When the port receives the second signal, the remote terminal also adds 1 to the value represented by the fourth identification information in the second signal to obtain the updated second signal, and continues to send the updated second signal through its second port For the next device connected to its second port, for example, after the first port of RU8 receives the second signal sent by the D port of the AU, it adds 1 to the value represented by the fourth identification information in the second signal to obtain the updated the second signal, and send the updated second signal to the next device in the target loop connected to the second port of RU8 through the second port of RU8, until the first port of the AU receives the updated second signal sent by RU1 second signal. The first identification information carried in the first signal sent by the A port of the AU is A (the content of the first identification information may be "A" expressed in hexadecimal form), and the value represented by the second identification information is 0, The third identification information carried in the first signal sent by the D port of the AU is D, and the value represented by the fourth identification information is 0. For example: the first signal received by the first port of RU1 carries "A1", and RU2 The first signal received from RU1 carries "A2", ... the first signal received by the D port of AU from RU8 carries "A9"; the second signal received by the second port of RU8 carries "A9"; "D1", the second signal received by RU7 from RU8 carries "D2", ... the second signal received by port A of the AU from RU1 carries "D9".

In the above embodiment, the first identification information carried in the first signal represents a port of the near-end machine (for example, the first port A), and the third identification carried in the second signal If the information indicates another port of the near-end unit (for example, the second port D), it can be determined that there is no faulty device in the target loop where the current far-end unit is located, and in the first If the value indicated by the second identification information is less than or equal to the value indicated by the fourth identification information, determine the first port of the current remote machine and the one port of the near end machine in the target loop The number of remote units in between is less than or equal to the number of remote units between the second port of the current remote unit and another port of the near-end unit; and the first received by the current remote unit. The value represented by the second identification information in the signal is also used to indicate the position sequence number of the current remote unit on the signal transmission path of the first signal in the target loop (that is, it indicates that the current remote unit is in the first signal). The number of remote units on the signal transmission path of the signal), and the value represented by the fourth identification information in the second signal received by the current remote unit is also used to indicate that the current remote unit is in the target loop The sequence number of the position on the signal transmission path of the second signal (that is, indicating the number of remote units that the current remote unit is on the signal transmission path of the second signal).

The above embodiment can be used in a distributed coverage system, that is, the near-end machine and a plurality of remote machines in the above-mentioned embodiment are all devices in the distributed coverage system. The method in the above embodiment is applied to any one of the multiple remote units, that is, the above operations are performed on each of the multiple remote units, so that each remote unit is According to the first signal and the second signal respectively received by the first port and the second port from the target loop, determine the position number of itself in the signal transmission path of the first signal, and the signal of the second signal. The position number in the transmission path, and then determine its own slave port and master port; because each remote machine determines the reference clock according to the signal received by the slave port from the target loop (that is, from the received signal The clock is recovered and provided to the local clock chip as a reference clock), through the above embodiment, the number of signal transmission stages in the clock recovery process in the target loop can be reduced, and the number of cascade stages of clock recovery in the target loop can be reduced , preventing the deterioration of the clock phase noise, thereby avoiding the deterioration of the system EVM.

It should be noted that since the current remote unit is connected to the first remote unit through its slave port, it means that the current remote unit determines the reference clock according to the signal received from the first remote unit. After the terminal unit fails, the current remote unit can no longer receive signals from the first remote unit. At this time, the slave port of the current remote unit and the master port of the current remote unit need to be Switchover (that is, the slave port and the master port are swapped, for example, the first port of the current remote machine is the slave port, and the second port is the master port. After the switchover, the first port of the current remote machine is determined as the master port, and identify the second port as the slave port).

Optionally, after the switching of the slave port of the current remote machine and the master port of the current remote machine, the method further includes: according to the current The reference clock of the current remote unit is determined from the signal received by the port from the second remote unit.

Optionally, after the switching of the slave port of the current remote machine and the master port of the current remote machine, the method further includes: A third signal is sent from the port to the target loop, wherein the third signal carries fifth identification information and sixth identification information, and the fifth identification information is used to indicate that the target loop is faulty, The value represented by the sixth identification information is used to represent the initial value; each remote machine in the first remote machine set in the plurality of remote machines receives the all sent by the current remote machine. In the case of the third signal, determine that the target loop is faulty according to the fifth identification information carried in the third signal, keep its own master port and slave port unchanged, and send a message to the target loop through its own slave port. A third device connected to its own slave port sends the third signal, wherein the first remote machine set includes the second remote machine, and the third device is a downlink connected to its own slave port. A far-end unit or a near-end unit.

Optionally, the fifth identification information is further used to indicate that the faulty device in the target loop is the first remote machine.

Optionally, when each remote machine in the first set of remote machines receives the third signal through its own main port, it also updates the value represented by the sixth identification information in the third signal to obtain. The updated third signal is sent to the next remote or near-end connected to itself.

As shown in FIG. 4 , after RU6 (that is, the first remote unit in the foregoing embodiment) fails, RU5 (that is, the current remote unit in the foregoing embodiment) performs the switching of the master port and the slave port, and The current slave port (ie, port 1 of RU5) sends the third data to the target loop (at this time, the path composed of RU4, RU3, RU2, RU1 and the A port of AU), after receiving the third signal, RU4 sends the third data to the target loop. After the sixth indication information is updated, it continues to be sent to RU3 connected to it. After receiving the third data from RU4, RU3 performs the same processing operation as that of RU4 until port A of the AU receives the third data sent by RU1.

Optionally, the method further includes: keeping the master port and slave port of the third remote unit unchanged, wherein the master port of the third remote unit is connected to the first remote unit, and the multiple The remote units include the third remote unit; send a fourth signal to the target loop through the slave port of the third remote unit, wherein the fourth signal carries seventh identification information and Eighth identification information, the seventh identification information is used to indicate that the target loop is faulty, and the eighth identification information is used to indicate the initial value; the second remote machine set in the plurality of remote machines In the case of receiving the fourth signal, each remote machine in the device determines that the target loop is faulty according to the seventh identification information carried in the fourth signal, and keeps its own master port and slave port different. Change; send the fourth signal to a fourth device connected to its own slave port through its own slave port, wherein the fourth device is the next remote machine or near-end machine connected to its own slave port.

It should be noted that, in the above embodiment, the initial value may be 1.

As shown in FIG. 5 , the operation performed by RU5 connected to the master port of RU6 is similar, and the operation performed by RU7 connected to the slave port of RU6 is the same as that of RU5, that is, RU7 loops to the target (in this case, D of RU8 and AU) The path formed by the port) sends the fourth signal. Among them, the master port and slave port of RU5 are switched, but the master and slave ports of RU1 to RU4, and the master and slave ports of RU7 and RU8 remain unchanged.

The method for determining the reference clock in the above embodiment is explained below with reference to an example, but is not used to limit the technical solution of the embodiment of the present invention.

As shown in FIG. 3 , the target loop is a loop formed by the first port of the AU (ie, port A), RU1 , RU2 . . . RU8 , and the second port of the AU (ie, port D).

In this embodiment of the present invention, the downlink signal flow includes two paths, and each RU detects its own position in the loop through the signals received from the two paths, specifically: the A port of the AU transmits a carrying There is fixed identification information (that is, the first identification information and the second identification information in the above-mentioned embodiment) id (for example, A1, where "A" is the first identification information, which is used to indicate the A port of the AU, and "1" is the first identification information. The first signal of the value represented by the two identification information) is sent to port 1 of RU1 (that is, the first port in the above embodiment). After port 1 receives the first signal, RU1 automatically sends the second identification information carried by the first signal. The value of the logo is incremented by 1 (that is, A1 becomes A2), and is transmitted to RU2 through port 2; port 1 of RU2 receives the first signal carrying A2 transmitted from port 2 of RU1, and automatically adds 1 to the signal carrying A3. The first signal is transmitted to RU3 through port 2, and so on, the first signal received by RU1 carries A1, the second signal received by RU2 carries A2, ... the first signal received by RU8 carries A8, The first signal received by the D port of the AU carries A9.

The D port of the AU transmits the second signal carrying D1 in the same way, and RU8...RU1 processes the received second signal in a similar manner to the received first signal, so the second signal received by RU8 The signal carries D1, the second signal received by RU7 carries D2, ... the second signal received by RU1 carries D8, and the second signal received by port A of the AU carries D9.

It should be noted that the signal received by the remote unit in the embodiment of the present invention refers to a device (that is, the remote unit or the near-end unit) that is directly connected to the port from the target loop through one of its ports. ) received signal.

Therefore, for RU1: port 1 receives a signal carrying A1, port 2 receives a signal carrying D8, and according to the values represented by the second identification information and the fourth identification information in the two signals, it is determined that RU1 is in the AU In the loop where the A port and the D port are connected; and according to the serial number values in the two signals, it is determined that RU1 is the first device connected to the A port of the AU, and the eighth device connected to the D port of the AU. Therefore, RU1 sets port 1 as port S and port 2 as port M. The downlink signal flows from port 1 to port 2 and continues to be transmitted to RU2. The process of clock recovery is that RU1 obtains a recovered clock from the data stream through the serializer/deserializer (SERializer/DESerializer, referred to as serdes) of the S port, and provides it to the clock chip on RU1 as a local reference clock.

As a result, RU1, RU2, RU3 and RU4 know that they are closer to port A in the ring topology, and set their own slave ports, so that the number of signal transmission stages under the link of port A is only four. Similarly, RU5, RU6, RU7, and RU8 know that they are the closest to port D in the ring topology, and set their own slave ports, so that the number of signal transmission stages under the link of port D is only 4. That is, in the above embodiment, two paths including the downlink signal flow as shown in FIG. 3 are formed, namely: the path composed of port A, RU1, RU2, RU3, and RU4 of the near-end AU, and the port D, RU, and RU4 of the AU. For the path composed of RU8, RU7, RU6, and RU5, the number of cascaded stages for clock recovery in the loop is reduced by half, thus preventing the EVM deterioration caused by the deterioration of clock phase noise caused by the excessive number of cascaded devices. signal coverage.

Through the above-mentioned embodiment, the signal transmission stages of the previous clock recovery in the loop topology are 8 stages, that is, the number of cascaded stages of 8 stages, but now it has only 4 stages of cascaded stages, so that the recovery of the clock The phase noise is much better than the noise situation before the loop topology, so that the performance of the EVM is improved to a certain extent, and the transmission rate and coverage of the signal are optimized. As shown in Figure 3, the number of signal transmission stages of the clock recovery in the loop topology has become a cascaded number of 4 stages, that is, the number of cascaded stages composed of RU1 to RU4 in Figure 3 is 4, and the number of cascaded stages composed of RU8 to RU5 in Figure 3 The number of cascades is also 4.

As shown in FIG. 4 , loop protection can also be implemented in the above method according to the embodiment of the present invention. When a certain RU in the middle (for example, RU6 in FIG. 4 ) fails, port 1 of RU5 cannot obtain optical fiber from RU6 because of failure. synchronization, so the identification information (id) on port 1 is set to f1 (wherein, the fifth identification information f is used to indicate that there is a faulty device in the loop, and 1 is the value identified by the sixth identification information; The identification information f is also used to indicate that RU6 (that is, the first remote unit in the above-mentioned embodiment has failed) and transmits back to RU4 a third signal carrying f1, the third signal received by RU4 carries f1... RU1 receives The third signal that arrives carries f4, and f5 is received on port A.

RU7 also returns the fourth signal in the same way. The fourth signal received by RU8 carries f1, and the fourth signal received by port D carries f2.

At this point, for RU1: port 1 receives A1, port 2 receives f4, and RU1 knows that there is a faulty device in the loop. At this time, RU1 is in the unidirectional link under port A and is port A. The first device under RU1, and there are 4 devices after RU1 in the unidirectional link. RU1 keeps its own S port and M port unchanged, and the downlink signal flows from port 1 to port 2 and continues to transmit to RU2. The process of clock recovery is that RU1 obtains a recovered clock from the data stream through the serializer/deserializer (SERializer/DESerializer, referred to as serdes) of the S port, and provides it to the clock chip on RU1 as a local reference clock.

Therefore, RU1, RU2, RU3, RU4, and RU5 know that they are closer to port A in the ring topology, so that the number of signal transmission stages for clock recovery under the link of port A is only five. In the same way, RU 7 and RU 8 know that they are the closest to the D port in the ring topology, so the number of signal transmission stages for clock recovery under the D port link is only two. Through the above embodiment, both the AU and each RU can obtain the topology information of the target loop, thereby locating the failure of the RU6 and realizing the loop protection function.

It should be noted that the first signal, the second signal, the third signal and the fourth signal in the above embodiment may be signals based on the CPRI protocol, that is, the CPRI protocol is used between the AU and RU1, RU8, and between each RU. communication, thus forming a CPRI link.

It should be noted that, in the above embodiment, the first identification information, the third identification information, the fifth identification information, and the seventh identification information may be the first fields in the signal based on the CPRI protocol, that is, the first identification information, the fifth identification information, and the seventh identification information. The third identification information and the fifth identification information can be the same field. When the near-end device sends a signal, the value of this field can be set to indicate the port that sends the signal, or, there is a fault in the target loop. When the remote unit is connected to the faulty remote unit, other remote units directly connected to the faulty remote unit can generate a signal, and set the value of the above-mentioned field of the signal to be used to indicate that the fault occurs; the second identification information, the fourth The identification information, the sixth identification information and the eighth identification information may be the second fields in the signal based on the CPRI protocol, that is, the second identification information, the fourth identification information, the sixth identification information and the eighth identification information may be the same one field, when the near-end station sends a signal, the value of this field can be set to the initial value (for example, 1), and when each remote station receives a signal from the device connected to it, the field of the signal indicates The value is updated, and the updated information is sent to the next device connected to it.

From the description of the above embodiments, those skilled in the art can clearly understand that the method according to the above embodiment can be implemented by means of software plus a necessary general hardware platform, and of course can also be implemented by hardware, but in many cases the former is better implementation. Based on this understanding, the technical solutions of the present invention can be embodied in the form of software products in essence or the parts that make contributions to the prior art, and the computer software products are stored in a storage medium (such as ROM/RAM, magnetic disk, CD-ROM), including several instructions to make a terminal device (which may be a mobile phone, a computer, a server, or a network device, etc.) to execute the methods described in the various embodiments of the present invention.

According to another embodiment of the present invention, an apparatus for determining a reference clock is provided, and the apparatus is used to implement the above-mentioned embodiments and preferred implementations, which have been described and will not be repeated. As used below, the term "module" may be a combination of software and/or hardware that implements a predetermined function. Although the apparatus described in the following embodiments is preferably implemented in software, implementations in hardware, or a combination of software and hardware, are also possible and contemplated.

FIG. 6 is a structural block diagram of an apparatus for determining a reference clock according to another embodiment of the present invention. The apparatus includes an acquisition module 72 , a first determination module 74 and a second determination module 76 , and the apparatus is configured to pass the acquisition module 72 . , the first determining module 74 and the second determining module 76 determine the reference clock of each remote unit in the target loop, wherein, when determining the reference clock of each remote unit, the Each remote unit is determined as the current remote unit:

The obtaining module 72 is configured to obtain the first signal received by the first port of the current remote machine from the target loop, and the second port of the current remote machine from the target loop The second signal received on the road, wherein the target loop includes: a loop composed of a near-end machine and a plurality of remote machines;

The first determining module 74 is configured to determine, according to the first signal and the second signal, that one of the first port and the second port of the current remote machine is a slave port, and the other of the first port and the second port is the primary port;

The second determining module 76 is configured to determine the reference clock of the current remote machine according to the signal received from the target loop by the slave port of the current remote machine.

Optionally, the device further includes a sending module, configured to transmit the data through the first port of the near-end machine and the second port of the near-end machine before determining the reference clock of each far-end machine in the target loop. The port sends a first signal and a second signal to the target loop respectively, wherein the first signal is transmitted in the target loop according to a first signal transmission path, and the second signal is transmitted in the target loop According to the second signal transmission path, the first signal sent by the near-end unit carries first identification information and second identification information, and the first identification information is used to indicate all the information of the near-end unit. The first port, the second identification information is used to indicate that the number of remote units that the first signal passes through in the target loop is an initial value, and the second signal sent by the near-end unit Carrying third identification information and fourth identification information, the third identification information is used to indicate the second port of the near-end machine, and the fourth identification information is used to indicate that the second signal is in the The number of remote units passing through the target loop is the initial value.

Optionally, the obtaining module 72 is further configured to: receive the first signal from the first device connected to the current remote machine through the first port of the current remote machine, and receive the first signal through the first port of the current remote machine The second port of the current remote unit receives the second signal from a second device connected to the current remote unit, wherein the first device is the target loop and the current remote unit The device connected to the first port of the target loop, the second device is the device connected to the second port of the current remote machine in the target loop; the first signal received by the current remote machine After the value represented by the second identification information carried in the device is increased by a preset value, the updated second identification information is obtained, and the fourth identification information carried in the second signal received by the second port of the current remote unit is After the value indicated by the identification information is increased by the preset value, the updated fourth identification information is obtained; The second identification information is updated to obtain the updated first signal, and the updated first signal is sent to the second device through the second port of the current remote device; using the updated fourth The identification information updates the fourth identification information in the second signal received by the current remote unit to obtain an updated second signal, and passes the updated second signal through the current remote unit of the first port to the first device.

Optionally, the obtaining module 72 is configured to: obtain the first identification information and the second identification information carried in the first signal, and the third identification information and the fourth identification information carried in the second signal , wherein the second identification information is used to indicate the number of remote units that the first signal passes through in the target loop, and the fourth identification information is used to indicate that the second signal is in the target loop The number of far-end machines passing through the loop; the second determining module 76 is further configured to: the first identification information indicates a port of the near-end machine, and the third identification information indicates the In the case of another port of the near-end machine, when the value indicated by the second identification information is less than or equal to the value indicated by the fourth identification information, the first port of the current far-end machine is Determining as the slave port of the current remote computer, and determining the second port of the current remote computer as the master port of the current remote computer; the first identification information indicates that the near end In the case where the one port of the remote device is represented by the third identification information and the other port of the near-end device is represented by the third identification information, the value represented by the second identification information is greater than the value represented by the fourth identification information In case of main port of the machine.

Optionally, the obtaining module 72 is further configured to: obtain the signal received by the current remote machine from the device connected to the slave port of the current remote machine in the target loop; The clock signal is recovered from the signal received from the device connected to the slave port of the current remote machine in the target loop; the recovered clock signal is determined as the reference clock of the current remote machine .

Optionally, the second determining module 76 is further configured to: after receiving the signal sent by the second remote machine connected to the main port of the current remote machine through the current remote machine, and passing the current remote machine In the case that the remote unit does not receive a signal sent by the first remote unit connected to the slave port of the current remote unit within a preset time period, it is determined that the first remote unit is faulty; The slave port of the current remote machine and the master port of the current remote machine are switched, wherein the plurality of remote machines further include the first remote machine and the second remote machine .

According to another embodiment of the present invention, there is provided an apparatus for determining a reference clock, comprising: a processing module configured to perform the following operations for each remote unit in the target loop, wherein, when performing the following operations on each remote unit When the terminal performs the following operations, determine each remote terminal as the current remote terminal: obtain the first signal received from the target loop by the first port of the current remote terminal, and the current remote terminal The second signal received by the second port of the remote machine from the target loop, wherein the target loop includes: a loop composed of a near-end machine and a plurality of remote machines; according to the first signal and the second signal, determining that one of the first port and the second port of the current remote unit is a slave port, and the other one of the first port and the second port The port is the master port; the reference clock of the current remote machine is determined according to the signal received from the target loop by the slave port of the current remote machine.

Another embodiment of the present invention also provides a system for determining a reference clock, including: a near-end unit and a plurality of remote units, wherein each remote unit in the plurality of remote units is configured to perform the following: operation, wherein, when each remote machine performs the following operations, it determines itself as the current remote machine:

Obtain the first signal received by the first port of the current remote machine from the target loop, and the second signal received by the second port of the current remote machine from the target loop, wherein, The target loop includes: a loop composed of the near-end machine and the plurality of remote machines;

According to the first signal and the second signal, it is determined that one of the first port and the second port of the current remote unit is a slave port, and the first port and the second port are The other port of the two ports is the primary port;

The reference clock of the current remote terminal is determined according to the signal received from the target loop by the slave port of the current remote terminal.

Optionally, the near-end machine is configured to send a first signal and a second signal to the target loop through a first port of the near-end machine and a second port of the near-end machine, respectively, wherein , the first signal is transmitted in the target loop according to the first signal transmission path, the second signal is transmitted in the target loop according to the second signal transmission path, and the The first signal carries first identification information and second identification information, the first identification information is used to indicate the first port of the near-end machine, and the second identification information is used to indicate the first port. The number of remote units that the signal passes through in the target loop is an initial value, and the second signal sent by the near-end unit carries third identification information and fourth identification information, and the third identification information The fourth identification information is used to indicate the second port of the near-end machine, and the fourth identification information is used to indicate that the number of the far-end machines that the second signal passes through in the target loop is the initial value.

Optionally, the current remote unit is further configured to: receive the first signal from the first device connected to the current remote unit through the first port of the current remote unit, and receive the first signal through the first port of the current remote unit. The second port of the current remote unit receives the second signal from a second device connected to the current remote unit, wherein the first device is the target loop and the current remote unit. A device connected to the first port of the current remote machine, the second device is a device in the target loop connected to the second port of the current remote machine; After the value represented by the second identification information carried in the signal is increased by a preset value, the updated second identification information is obtained, and the second identification information carried in the second signal received by the second port of the current remote unit is obtained. After the value represented by the four identification information is increased by the preset value, the updated fourth identification information is obtained; The second identification information is updated to obtain the updated first signal, and the updated first signal is sent to the second device through the second port of the current remote device; using the updated first signal Four identification information Update the fourth identification information in the second signal received by the current remote machine to obtain an updated second signal, and pass the updated second signal through the current remote The first port of the machine is sent to the first device.

Optionally, the current remote unit is further configured to obtain the first identification information and the second identification information carried in the first signal, and the third identification information and the fourth identification information carried in the second signal. identification information, wherein the second identification information is used to indicate the number of remote units that the first signal passes through in the target loop, and the fourth identification information is used to indicate that the second signal is in the target loop. The number of far-end machines passing through the target loop; in the case that the first identification information indicates one port of the near-end machine, and the third identification information indicates another port of the near-end machine , in the case that the value indicated by the second identification information is less than or equal to the value indicated by the fourth identification information, determine the first port of the current remote machine as the slave port of the current remote machine port, and the second port of the current remote computer is determined as the main port of the current remote computer; the first identification information indicates the one port of the near-end computer, and the In the case that the third identification information indicates the other port of the near-end device, in the case that the value indicated by the second identification information is greater than the value indicated by the fourth identification information, the current remote The second port of the current remote computer is determined as the slave port of the current remote computer, and the first port of the current remote computer is determined as the master port of the current remote computer.

Optionally, the current remote machine is further configured to: acquire the signal received by the current remote machine from the device connected to the slave port of the current remote machine in the target loop; Describe the signal received from the device connected to the slave port of the current remote machine in the target loop, recover the clock signal; determine the recovered clock signal as the reference of the current remote machine clock.

Optionally, the current remote unit is further configured to: receive a signal sent by a second remote unit connected to the main port of the current remote unit through the current remote unit, and send the signal through the current remote unit. In the case that the terminal unit does not receive a signal sent by the first remote unit connected to the slave port of the current remote unit within a preset time period, it is determined that the first remote unit is faulty; The slave port of the remote machine and the master port of the current remote machine are switched, wherein the plurality of remote machines further include the first remote machine and the second remote machine.

An embodiment of the present invention further provides a storage medium, where the storage medium includes a stored program, wherein the above-mentioned program executes any one of the above-mentioned methods when running.

Optionally, in this embodiment, the above-mentioned storage medium may be configured to store program codes for executing the following steps:

S1, perform the following operations on each remote unit in the target loop, wherein when performing the following operations on each remote unit, determine each remote unit as the current remote unit:

Obtain the first signal received by the first port of the current remote machine from the target loop, and the second signal received by the second port of the current remote machine from the target loop, wherein, The target loop includes: a loop composed of a near-end machine and a plurality of remote machines;

Optionally, in this embodiment, the above-mentioned storage medium may include but is not limited to: a USB flash drive, a read-only memory (Read-Only Memory, referred to as ROM), a random access memory (Random Access Memory, referred to as RAM), Various media that can store program codes, such as removable hard disks, magnetic disks, or optical disks.

Optionally, for specific examples in this embodiment, reference may be made to the examples described in the foregoing embodiments and optional implementation manners, and details are not described herein again in this embodiment.

An embodiment of the present invention also provides an electronic device, comprising a memory and a processor, where a computer program is stored in the memory, and the processor is configured to run the computer program to execute the steps in any of the above method embodiments.

Optionally, the above-mentioned electronic device may further include a transmission device and an input-output device, wherein the transmission device is connected to the above-mentioned processor, and the input-output device is connected to the above-mentioned processor.

Optionally, in this embodiment, the above-mentioned processor may be configured to execute the following steps through a computer program:

FIG. 7 is a schematic structural diagram of an optional electronic device according to an embodiment of the present invention. Optionally, those of ordinary skill in the art can understand that the structure shown in FIG. 7 is only for illustration, and the electronic device may also be a smart phone (such as an Android phone, an iOS phone, etc.), a tablet computer, a handheld computer, and a mobile Internet device (Mobile Internet device). Internet Devices, MID), PAD and other terminal equipment. FIG. 7 does not limit the structure of the above electronic device. For example, the electronic device may also include more or less components than those shown in FIG. 7 (eg, network interfaces, etc.), or have a different configuration than that shown in FIG. 7 .

The memory 1002 can be used to store software programs and modules, such as program instructions/modules corresponding to the method for determining the reference clock and the device for determining the reference clock in the embodiment of the present invention, and the processor 1004 executes the software program stored in the memory 1002 by running and modules, so as to perform various functional applications and data processing, that is, to implement the above-mentioned method for determining the reference clock. Memory 1002 may include high-speed random access memory, and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, memory 1002 may further include memory located remotely from processor 1004, and these remote memories may be connected to the terminal through a network. Examples of such networks include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof. As an example, the above-mentioned memory 1002 may include, but is not limited to, the obtaining module 72 , the first determining module 74 and the second determining module 76 of the above-mentioned device for determining the reference clock. In addition, it may also include, but is not limited to, other module units in the above-mentioned apparatus for determining the reference clock, which will not be repeated in this example.

Optionally, the above-mentioned transmission device 1006 is configured to receive or transmit data via a network. Specific examples of the above-mentioned networks may include wired networks and wireless networks. In one example, the transmission device 1006 includes a network adapter (Network Interface Controller, NIC), which can be connected to other network devices and routers through a network cable to communicate with the Internet or a local area network. In one example, the transmission device 1006 is a radio frequency (Radio Frequency, RF) module, which is used for wirelessly communicating with the Internet.

In addition, the above-mentioned electronic device further includes: a display 1008 for displaying a picture; and a connection bus 1010 for connecting various module components in the above-mentioned electronic device.

In other embodiments, the above-mentioned terminal or server may be a node in a distributed system, wherein the distributed system may be a blockchain system, and the blockchain system may be communicated by the multiple nodes through a network A distributed system formed by formal connections. Among them, a peer-to-peer (P2P, Peer To Peer) network can be formed between nodes, and any form of computing equipment, such as servers, terminals and other electronic devices can become a node in the blockchain system by joining the peer-to-peer network.

Obviously, those skilled in the art should understand that the above-mentioned modules or steps of the present invention can be implemented by a general-purpose computing device, which can be centralized on a single computing device, or distributed in a network composed of multiple computing devices Alternatively, they may be implemented in program code executable by a computing device, such that they may be stored in a storage device and executed by the computing device, and in some cases, in a different order than here The steps shown or described are performed either by fabricating them separately into individual integrated circuit modules, or by fabricating multiple modules or steps of them into a single integrated circuit module. As such, the present invention is not limited to any particular combination of hardware and software.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the principle of the present invention shall be included within the protection scope of the present invention.

Claims

A method for determining a reference clock, comprising:

Perform the following operations on each remote unit in the target loop, wherein each remote unit is determined to be the current remote unit when the following operations are performed on each remote unit:

Obtain the first signal received by the first port of the current remote machine from the target loop, and the second signal received by the second port of the current remote machine from the target loop, wherein, The target loop includes: a loop composed of a near-end machine and a plurality of remote machines;

According to the first signal and the second signal, it is determined that one of the first port and the second port of the current remote unit is a slave port, and the first port and the second port are The other port of the two ports is the primary port;

The reference clock of the current remote terminal is determined according to the signal received from the target loop by the slave port of the current remote terminal.
The method of claim 1, wherein, before performing the following operations on each remote unit in the target loop, the method further comprises:

A first signal and a second signal are sent to the target loop through a first port of the near-end unit and a second port of the near-end unit, respectively, wherein the first signal is in the target loop The second signal is transmitted according to the first signal transmission path, the second signal is transmitted according to the second signal transmission path in the target loop, and the first signal sent by the near-end unit carries the first identification information and the second signal. identification information, the first identification information is used to indicate the first port of the near-end unit, and the second identification information is used to indicate the far-end unit that the first signal passes through in the target loop The number is the initial value, the second signal sent by the near-end unit carries third identification information and fourth identification information, and the third identification information is used to indicate the second signal of the near-end unit. port, and the fourth identification information is used to indicate that the number of remote units that the second signal passes through in the target loop is the initial value.
The method according to claim 2, wherein the obtaining of the first signal received by the first port of the current remote unit from the target loop, and the second port of the current remote unit from the target loop After the second signal received on the target loop, the method further includes:

The first signal is received from a first device connected to the current remote unit through a first port of the current remote unit, and received from a first device connected to the current remote unit through a second port of the current remote unit The second signal is received in the second device connected to the terminal, wherein the first device is the device connected to the first port of the current remote terminal in the target loop, and the second device is A device connected to the second port of the current remote machine in the target loop;

After the value represented by the second identification information carried in the first signal received by the current remote unit is increased by a preset value, the updated second identification information is obtained, and the second identification information of the current remote unit is added. After the value represented by the fourth identification information carried in the second signal received by the second port is increased by the preset value, the updated fourth identification information is obtained;

Use the updated second identification information to update the second identification information in the first signal received by the current remote machine, obtain the updated first signal, and use the updated first signal to update the updated first signal. The signal is sent to the second device through the second port of the current remote machine;

Use the updated fourth identification information to update the fourth identification information in the second signal received by the current remote machine, obtain the updated second signal, and use the updated second signal. The signal is sent to the first device through the first port of the current remote machine.
The method according to claim 1, wherein, according to the first signal and the second signal, determining that one of the first port and the second port of the current remote terminal is A slave port, and the other one of the first port and the second port is a master port, including:

Obtain the first identification information and the second identification information carried in the first signal, and the third identification information and the fourth identification information carried in the second signal, wherein the second identification information is used to indicate the the number of remote units that the first signal passes through in the target loop, and the fourth identification information is used to indicate the number of remote units that the second signal passes through in the target loop;

In the case where the first identification information indicates one port of the near-end machine, and the third identification information indicates another port of the near-end machine, the value indicated by the second identification information is less than or In the case of being equal to the value represented by the fourth identification information, the first port of the current remote computer is determined as the slave port of the current remote computer, and the The second port is determined as the main port of the current remote computer;

When the first identification information indicates the one port of the near-end machine, and the third identification information indicates the other port of the near-end machine, the second identification information indicates In the case where the value is greater than the value represented by the fourth identification information, the second port of the current remote machine is determined as the slave port of the current remote machine, and the second port of the current remote machine is determined. The first port is determined as the main port of the current remote computer.
The method according to claim 1, wherein the determining the reference clock of the current remote terminal according to the signal received from the target loop by the slave port of the current remote terminal comprises:

Obtain the signal received by the current remote machine from the device connected to the slave port of the current remote machine in the target loop;

recovering a clock signal according to the signal received from the device connected to the slave port of the current remote machine in the target loop;

The recovered clock signal is determined as the reference clock of the current remote unit.
The method according to claim 1, wherein, according to the first signal and the second signal, determining that one of the first port and the second port of the current remote terminal is A slave port, and the other one of the first port and the second port is a master port, including:

When the signal sent by the second remote unit connected to the main port of the current remote unit is received through the current remote unit, and the signal sent by the second remote unit connected to the main port of the current remote unit is not received by the current remote unit within a preset time period In the case of a signal sent from the first remote unit connected to the port of the remote unit, it is determined that the first remote unit is faulty;

Switching the slave port of the current remote machine and the master port of the current remote machine, wherein the plurality of remote machines further includes the first remote machine and the second remote machine remote machine.
A device for determining a reference clock, comprising: an acquisition module, a first determination module and a second determination module, the device is configured to determine a target ring through the acquisition module, the first determination module and the second determination module The reference clock of each remote unit in the road, wherein when determining the reference clock of each remote unit, each remote unit is determined as the current remote unit:

Wherein, the acquisition module is configured to acquire the first signal received by the first port of the current remote machine from the target loop, and the second port of the current remote machine from the target loop The received second signal, wherein the target loop includes: a loop composed of a near-end unit and a plurality of remote units;

The first determining module is configured to determine, according to the first signal and the second signal, that one of the first port and the second port of the current remote machine is a slave port, and The other one of the first port and the second port is the primary port;

The second determining module is configured to determine the reference clock of the current remote machine according to the signal received from the target loop by the slave port of the current remote machine.
A system for determining a reference clock, comprising: a near-end unit and a plurality of remote units, wherein each remote unit in the plurality of remote units is configured to perform the following operations, wherein at each remote unit When the terminal performs the following operations, it determines itself as the current remote:

Obtain the first signal received from the target loop by the first port of the current remote terminal, and the second signal received from the target loop by the second port of the current remote terminal, wherein the The target loop includes: a loop composed of the near-end machine and the plurality of remote machines;

According to the first signal and the second signal, it is determined that one of the first port and the second port of the current remote unit is a slave port, and the first port and the second port are The other port of the two ports is the primary port;

The reference clock of the current remote terminal is determined according to the signal received from the target loop by the slave port of the current remote terminal.
A storage medium in which a computer program is stored, wherein the computer program is configured to execute the method of any one of claims 1 to 6 when run.
An electronic device comprising a memory and a processor, the memory having a computer program stored therein, the processor being arranged to perform the method of any one of claims 1 to 6 by the computer program.