Time-synchronized photoelectric decoupling wavelength division multiplexing system and method

Abstract

The invention discloses a time synchronization photoelectric decoupling wavelength division multiplexing system and method. The system comprises a plurality of network nodes, a plurality of sub-frames are configured in the plurality of network nodes, a time processing board card is configured in each sub-frame, the time processing board card comprises a clock source selection module, a synchronization module and a clock signal module, and the clock source selection module is used for selecting a target input clock signal from a plurality of candidate input clock signals; the synchronization module is used for adjusting the local time of the local network node where the time processing board card is located according to the target input clock signal; the clock signal module is used for generating an output clock signal according to the target input clock signal and the local time, and the output clock signal is used for issuing time information to a downstream network node of the local network node. According to the invention, the technical problems of low accuracy and poor stability of time synchronization of a wavelength division multiplexing system in the prior art are solved.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a time-synchronized optoelectronically decoupled wavelength division multiplexing system and method. Background Art

[0002] Fiber optic communication is a communication method that uses light waves as information carriers, converts electronic signals into optical signals, and transmits data through optical fiber media. The wavelength division multiplexing system is a technology that multiplexes light signals of different wavelengths on the same transmission line. In the wavelength division multiplexing system, each optical signal has its own unique wavelength, and these signals can be transmitted simultaneously in the same optical fiber or cable to achieve efficient signal transmission.

[0003] In the related technology, the wavelength division multiplexing (WDM) system is usually composed of an optical transmitter, an optical receiver, an optical fiber and a wavelength division multiplexer. Although it can achieve efficient signal transmission, the existence of electrical layer interference leads to low accuracy and poor stability of time synchronization in the wavelength division multiplexing system. In addition, some current WDM systems have introduced optoelectronic decoupling technology. Although it can make the network architecture more flexible and adapt to more business needs, it usually requires devices to be provided by multiple different manufacturers, resulting in the existence of multiple different external clock sources, making it more difficult to ensure accurate and stable time synchronization of the wavelength division multiplexing system.

[0004] To address the above-mentioned problems, no effective solution has been proposed yet. Summary of the invention

[0005] The embodiments of the present application provide a time-synchronized optoelectronically decoupled wavelength division multiplexing system and method to at least solve the technical problems of low accuracy and poor stability of time synchronization in wavelength division multiplexing systems in related technologies.

[0006] According to one aspect of an embodiment of the present application, a time-synchronized optoelectronically decoupled wavelength division multiplexing system is provided, comprising: multiple network nodes, multiple sub-racks are configured in the multiple network nodes, each sub-rack is configured with a time processing board, the time processing board comprises a clock source selection module, a synchronization module and a clock signal module, wherein the clock source selection module is used to select a target input clock signal from multiple candidate input clock signals; the synchronization module is used to adjust the local time of the local network node where the time processing board is located according to the target input clock signal; the clock signal module is used to generate an output clock signal according to the target input clock signal and the local time, wherein the output clock signal is used to publish time information to the downstream network nodes of the local network node.

[0007] Optionally, the multiple signal sources corresponding to the multiple candidate input clock signals include: the local network node where the time processing board is located, the upstream network node of the local network node, and an external clock source device associated with the local network node; the clock source selection module is also used to select the target input clock signal from the multiple candidate input clock signals according to the priority information of the multiple signal sources.

[0008] Optionally, the synchronization module includes a clock synchronization unit and a time synchronization unit, the clock synchronization unit is used to adjust the clock frequency of the local network node according to the target input clock signal; the time synchronization unit is used to adjust the local time based on the target input clock signal and the clock frequency so that the local time maintains timestamp synchronization with the target input clock signal.

[0009] Optionally, multiple candidate input clock signals and output clock signals are transmitted using a time synchronization message, and the time synchronization message is generated based on a target time protocol.

[0010] Optionally, multiple network nodes in the wavelength division multiplexing system adopt a chain networking structure; the multiple network nodes include optical forwarding nodes, optical amplification nodes and optical add / drop nodes; the multiple sub-racks include: optical layer sub-racks and electrical layer sub-racks in the optical forwarding nodes, optical layer sub-racks in the optical amplification nodes, and optical layer sub-racks and electrical layer sub-racks in the optical add / drop nodes.

[0011] Optionally, when the external clock source device supports the target time protocol, the electrical layer sub-rack in the local network node is configured as a boundary clock, wherein the local network node is any one of the optical forwarding nodes and the optical uplink and downlink nodes; the electrical layer sub-rack in the local network node is configured with an upstream port and a downstream port, wherein the upstream port is used to synchronize time information with a target input clock signal sent from the upstream network node, and the downstream port is used to publish time information to the optical layer sub-rack in the downstream network node through an output clock signal, the upstream network node is a network node that supports the target time protocol, and the downstream network node is an optical amplification node.

[0012] Optionally, when the external clock source device does not support the target time protocol, the electrical layer sub-rack in the local network node is configured as an ordinary clock, wherein the local network node is any one of the optical forwarding node and the optical uplink and downlink node; the electrical layer sub-rack in the local network node is configured with a downstream port, wherein the downstream port is used to publish time information to the optical layer sub-rack in the downstream network node by outputting a clock signal to the downstream network node.

[0013] Optionally, the optical layer subrack in the optical amplifier node is configured with an upstream port and a downstream port, wherein the upstream port is used to synchronize time information from the upstream network node of the optical amplifier node, and the downstream port is used to publish time information to the downstream network node of the optical amplifier node; when there is a port synchronization requirement in the optical layer subrack, the optical layer subrack is configured as a boundary clock, wherein the port synchronization requirement is used to characterize the requirement for the subrack time of the optical layer subrack to be synchronized with the network time corresponding to the upstream port; when there is no port synchronization requirement in the optical layer subrack, the optical layer subrack is configured as a transparent clock.

[0014] Optionally, the time processing board also includes a second pulse time module and a time protocol message module, wherein the second pulse time module is used to generate a second pulse signal and a time and date signal based on an external time signal, wherein the external time signal is provided by a satellite navigation system, the second pulse time signal is used to characterize a reference time point per second, and the time and date signal is used to record complete date and time information; the time protocol message module is used to parse the target input clock signal to obtain a parsing result, update the local time of the local network node according to the parsing result, and generate an output time message corresponding to the output clock signal according to the parsing result and the target time protocol.

[0015] According to another aspect of an embodiment of the present application, a time-synchronized optoelectronically decoupled wavelength division multiplexing method is also provided, wherein a plurality of network nodes of a wavelength division multiplexing system are provided, a plurality of sub-racks are configured in the plurality of network nodes, a time processing board is configured in each sub-rack, and the time synchronization method is applied to a time processing board of any local network node among the plurality of network nodes, and the time synchronization method comprises: receiving a plurality of candidate input clock signals; selecting a target input clock signal from the plurality of candidate input clock signals; adjusting the local time of the local network node where the time processing board is located according to the target input clock signal; and generating an output clock signal according to the target input clock signal and the local time, wherein the output clock signal is used to publish time information to a downstream network node of the local network node.

[0016] In an embodiment of the present application, multiple network nodes are configured with multiple sub-racks, each sub-rack is configured with a time processing board, and the time processing board includes a clock source selection module, a synchronization module and a clock signal module, wherein the clock source selection module is used to select a target input clock signal from multiple candidate input clock signals; the synchronization module is used to adjust the local time of the local network node where the time processing board is located according to the target input clock signal; the clock signal module is used to generate an output clock signal according to the target input clock signal and the local time, wherein the output clock signal is used to publish time information to the downstream network node of the local network node. Thus, the present application achieves the purpose of configuring a time processing board in each sub-rack so that the wavelength division multiplexing system can adapt to different external clock source devices and network structures, and perform time synchronization more accurately and stably, thereby achieving the technical effect of improving the accuracy and stability of the time synchronization of the wavelength division multiplexing system, and thus solving the technical problems of low accuracy and poor stability of the time synchronization of the wavelength division multiplexing system in the related art. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0018] Figure 1 is a structural block diagram of a time-synchronized optoelectronically decoupled wavelength division multiplexing system according to an embodiment of the present application;

[0019] Figure 2 is a structural block diagram of an optional time processing board according to an embodiment of the present application;

[0020] Figure 3 is a schematic diagram of selecting a source by an optional clock source selection module according to an embodiment of the present application;

[0021] Figure 4 is a schematic diagram of an optional optical forwarding node according to an embodiment of the present application;

[0022] Figure 5 is a schematic diagram of an optional optical amplification node according to an embodiment of the present application;

[0023] Figure 6 is a schematic diagram of an optional optical up / down node according to an embodiment of the present application;

[0024] Figure 7 is a schematic diagram of message data in an optional optical monitoring channel unit according to an embodiment of the present application;

[0025] Figure 8It is a hardware structure block diagram of a terminal device of an optional wavelength division multiplexing method for optoelectronic decoupling for time synchronization according to an embodiment of the present application. DETAILED DESCRIPTION

[0026] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0027] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0028] According to an embodiment of the present application, an embodiment of a time-synchronized optoelectronic decoupled wavelength division multiplexing method is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0029] Under the above operating environment, the embodiment of the present application provides the following Figure 1 The time-synchronized optoelectronic decoupled wavelength division multiplexing system shown in Figure 1 is a structural block diagram of a time-synchronized optoelectronic decoupled wavelength division multiplexing system according to an embodiment of the present application, such as Figure 1As shown, the system includes multiple network nodes, multiple sub-racks are configured in the multiple network nodes, each sub-rack is configured with a time processing board, and the time processing board includes a clock source selection module, a synchronization module and a clock signal module, wherein the clock source selection module is used to select a target input clock signal from multiple candidate input clock signals; the synchronization module is used to adjust the local time of the local network node where the time processing board is located according to the target input clock signal; the clock signal module is used to generate an output clock signal according to the target input clock signal and the local time, wherein the output clock signal is used to publish time information to the downstream network node of the local network node.

[0030] The above-mentioned time processing card (Time Unit, TU for short) can be used to achieve time synchronization, and the time processing card can be used to receive, process and regenerate time signals. The above-mentioned multiple network nodes can include optical forwarding nodes, optical amplification nodes and optical add / drop nodes.

[0031] The above-mentioned multiple candidate input clock signals can be obtained through multiple signal sources, and the multiple candidate input clock signals may include but are not limited to the clock signal of an external time server, the network protocol message of precise time synchronization of the network node (such as, 1588V2 protocol message), the recovered clock signal in the network node, and the real clock signal in the network node.

[0032] The above synchronization module can also be used to calibrate the local time of the local network node. The local time of the local network node can be adjusted through the synchronization module to keep the local time of the local network node consistent with the target input clock signal.

[0033] The above-mentioned output clock signal can use clock information in a variety of formats, such as 1588V2 protocol time message, Network Configuration Protocol (NETCONF) message, etc. The output clock signal can be transmitted within the time-synchronized optoelectronically decoupled wavelength division multiplexing system. The output clock signal can also be used to realize the time synchronization function of the wavelength division multiplexing system.

[0034] The aforementioned downstream node may be a node located after the local network node on the signal transmission path.

[0035] The above-mentioned time processing board may also include a first input interface, a second input interface, a first output interface, a second output interface, and a third output interface.

[0036] The above-mentioned first input interface can be used to receive a clock signal corresponding to a 1588V2 protocol message. The above-mentioned second input interface can be used to receive clock signals other than the clock signal corresponding to the 1588V2 protocol message. The above-mentioned first output interface can be used to provide a clock signal to other time processing boards in the sub-rack. The above-mentioned second output interface can be used to provide a clock signal to the time processing board where the second output interface is located. The above-mentioned third output interface can be used to provide a clock signal to an optical supervisory channel unit (Optical Supervisory Channel, referred to as OSC). The above-mentioned optical supervisory channel unit can be used to convert the clock signal into an optical layer signal and publish it to a downstream network node of the local network node.

[0037] Specifically, a clock source selection module in a wavelength division multiplexing system is used to monitor multiple candidate input clock signals, and based on a clock selection rule, multiple candidate input clock signals are evaluated, and according to the evaluation result, a target input clock signal is selected from the multiple candidate input clock signals, and the target input clock signal is transmitted to a synchronization module in the wavelength division multiplexing system; further, a synchronization module in the wavelength division multiplexing system is used to receive the target input clock signal selected by the clock source selection module, and a local time of a local network node is compared and analyzed with a time corresponding to the target input clock signal, and according to the analysis result, the local time of the local network node is adjusted so that the local time of the local network node is synchronized with the time corresponding to the target input clock signal; further, a clock signal module in the wavelength division multiplexing system is used to generate an output clock signal for publishing time information to a downstream network node of the local network node according to the target input clock signal and the local time, and the output clock signal is published to the downstream network node of the local network node through a corresponding interface to realize the transmission of time information.

[0038] In an exemplary application scenario, Figure 1 As shown, the wavelength division multiplexing system includes multiple network nodes, multiple network nodes are configured with multiple sub-racks, each sub-rack is configured with a time processing board (ie, TU), and the time synchronization function of the wavelength division multiplexing system is realized by configuring TU in each sub-rack.

[0039] Still in the above application scenario, Figure 2 is a structural block diagram of an optional time processing board according to an embodiment of the present application, such as Figure 2As shown, the time processing board includes a clock source selection module, a synchronization module and a clock signal module, wherein the synchronization module includes a clock synchronization unit and a time synchronization unit. The time processing board also includes a first input interface (i.e., a 1588 clock input interface), a second input interface (i.e., a non-1588 clock input interface), a first output interface (i.e., a clock output interface), a second output interface (i.e., a non-1588 time output interface), and a third output interface (i.e., a 1588 time output interface).

[0040] It is easy to understand that, through the above-mentioned time-synchronized optoelectronically decoupled wavelength division multiplexing system, in the embodiment of the present application, by configuring a time processing board in each sub-rack, the wavelength division multiplexing system can adapt to different external clock source devices and network structures, so that the wavelength division multiplexing system can be time synchronized more accurately and stably, thereby improving the accuracy and stability of the time synchronization of the wavelength division multiplexing system.

[0041] Optionally, in the above-mentioned time-synchronized optoelectronically decoupled wavelength division multiplexing system, the multiple signal sources corresponding to the multiple candidate input clock signals include: the local network node where the time processing board is located, the upstream network node of the local network node, and an external clock source device associated with the local network node; the clock source selection module is also used to select the target input clock signal from the multiple candidate input clock signals according to the priority information of the multiple signal sources.

[0042] The signal source corresponding to the local network node where the time processing board is located may include a service recovery clock corresponding to the local network node service and a real time clock (RTC) clock in the local network node.

[0043] The upstream node mentioned above may be a node located before the local network node on the signal transmission path.

[0044] The above-mentioned external clock source device may include a time server corresponding to a high-precision clock source of the Global Positioning System (GPS) and a time server corresponding to a high-precision clock source of a Beidou satellite.

[0045] The priority information can be determined according to the priority rule. The priority rule can be set according to the actual situation, for example, the priority rule can be set according to the signal source, the priority rule can also be set according to the signal strength of multiple candidate input clock signals, and the priority rule can also be set according to the signal source priority level and signal source strength.

[0046] Specifically, the clock source selection module in the time processing board obtains multiple candidate input clock signals corresponding to multiple signal sources (such as the service clock in the local network node, the RTC clock in the local network node, the upstream network node of the local network node, and the external clock source device associated with the local network node), monitors the signal strength of the multiple signal sources, and selects the target input clock signal from the multiple candidate input clock signals according to the priority information of the multiple signal sources.

[0047] In an exemplary application scenario, Figure 3 FIG. 1 is a schematic diagram of an optional clock source selection module for selecting a source according to an embodiment of the present application, such as Figure 3 As shown, the above-mentioned time processing board can receive candidate input clock signals corresponding to four signal sources, and the multiple signal sources can be the local network node where the time processing board is located, the upstream network node of the local network node (such as the 1588V2 synchronization clock of the upstream network node), and the external clock source device associated with the local network node (such as Beidou satellite time server, GPS time server). The signal source corresponding to the above-mentioned local network node may include the service recovery clock corresponding to the local network node service and the RTC clock in the local network node. The above-mentioned priority rules can be set according to the signal source, for example, the external clock source device associated with the local network node is the first level priority, the upstream network node of the local network node is the second level priority, the service recovery clock is the third level priority, and the RTC clock is the fourth level priority. The priority order is: first level priority, second level priority, third level priority, and fourth level priority. According to the priority information of multiple signal sources, the target input clock signal (that is, the clock signal of the working clock of this node) is selected from multiple candidate input clock signals.

[0048] Specifically, when the signal source corresponding to the target input clock signal is an external clock source device associated with the local network node (i.e., when the target input clock signal is external time), the time processing board is used to process the external time provided by the external clock source device to extract clock information and time information. When the signal source corresponding to the target input clock signal is the upstream network node of the local network node (i.e., when the target input clock signal does not monitor the channel time), the target input clock signal can be a 1588V2 message, and the time processing board is used to extract the clock information and time information from the 1588V2 message according to the method specified in the 1588V2 protocol. When the signal source corresponding to the target input clock signal is a service recovery clock (i.e., when the target input clock signal is the clock signal of the physical layer recovery clock), a service class board is configured in the electrical layer sub-rack, and the configured service class board is used to extract the service recovery clock information from the service signal by means of clock data recovery technology (Clock Data Recovery, referred to as CDR). When the signal source corresponding to the target input clock signal is the RTC clock (that is, when the target input clock signal is the clock signal of the local real-time clock), an OSC monitoring clock and an RTC clock are configured in the optical layer subrack. When the OSC monitoring clock is abnormal, the time processing board uses the RTC clock to determine the time information.

[0049] It is easy to understand that through the above-mentioned time-synchronized optoelectronically decoupled wavelength division multiplexing system, in the embodiment of the present application, multiple candidate input clock signals from multiple signal sources are obtained, which not only increases the dimension of obtaining clock signals and improves the accuracy of time synchronization of the wavelength division multiplexing system, but also can avoid time synchronization errors caused by failure of a single-dimensional signal source, thereby improving the reliability and stability of time synchronization of the wavelength division multiplexing system. In addition, in the embodiment of the present application, priority information is used to automatically select the target input clock signal, so that the wavelength division multiplexing system can automatically select the clock signal of the signal source according to different application scenarios, thereby enhancing the flexibility of the wavelength division multiplexing system and improving the intelligence of the wavelength division multiplexing system.

[0050] Optionally, in the above-mentioned time-synchronized optoelectronically decoupled wavelength division multiplexing system, the synchronization module includes a clock synchronization unit and a time synchronization unit, the clock synchronization unit is used to adjust the clock frequency of the local network node according to the target input clock signal; the time synchronization unit is used to adjust the local time based on the target input clock signal and the clock frequency, so that the local time maintains timestamp synchronization with the target input clock signal.

[0051] The clock frequency of the local network node can be used to determine the rate of time synchronization operation. Since the stability of the clock frequency will directly affect the accuracy of time synchronization, the clock frequency of the local network node needs to be kept within an acceptable deviation range to ensure the synchronization of data transmission.

[0052] The above-mentioned timestamp may be an identifier embedded in a data packet or a signal indicating the time when an event occurs, and the timestamp may include precise time information in seconds, milliseconds, or microseconds.

[0053] Specifically, the clock synchronization unit in the synchronization module compares the frequency difference between the local clock and the target clock according to the received target input clock signal, and uses the time fine-tuning technology to adjust the clock frequency of the local network node; further, the time synchronization unit in the synchronization module adjusts the clock phase of the local time based on the time information in the target input clock signal and the clock frequency adjusted by the clock synchronization unit, to ensure that the local time and the target input clock signal maintain timestamp synchronization. The above-mentioned time fine-tuning technology may include but is not limited to phase-locked loop technology and digital signal processing technology.

[0054] It is easy to understand that through the above-mentioned time-synchronized optoelectronically decoupled wavelength division multiplexing system, in the embodiment of the present application, by using the clock synchronization unit and the time synchronization unit to adjust the clock frequency of the local network node and the timestamp of the local time, the accuracy and precision of the time synchronization of the wavelength division multiplexing system can be improved.

[0055] Optionally, in the above-mentioned time-synchronized optoelectronically decoupled wavelength division multiplexing system, multiple candidate input clock signals and output clock signals are transmitted using time synchronization messages, and the time synchronization messages are generated based on a target time protocol.

[0056] The above-mentioned time synchronization message can be a data packet used to achieve time synchronization between nodes in the network, and the time synchronization message can include timestamp information, time correction factor data, etc. The time synchronization message can be used to achieve time synchronization, for example, a 1588V2 protocol message corresponding to the Institute of Electrical and Electronics Engineers (IEEE) 1588V2 protocol.

[0057] The target time protocol may include the IEEE 1588V2 protocol.

[0058] It is easy to understand that, through the above-mentioned time-synchronized optoelectronically decoupled wavelength division multiplexing system, in the embodiment of the present application, the time synchronization message is used to improve the accuracy of time synchronization and the accuracy of time synchronization of the wavelength division multiplexing system.

[0059] Optionally, in the above-mentioned time-synchronized optoelectronically decoupled wavelength division multiplexing system, multiple network nodes in the wavelength division multiplexing system adopt a chain networking structure; the multiple network nodes include optical forwarding nodes, optical amplification nodes, and optical add / drop nodes; the multiple sub-racks include: optical layer sub-racks and electrical layer sub-racks in the optical forwarding nodes, optical layer sub-racks in the optical amplification nodes, and optical layer sub-racks and electrical layer sub-racks in the optical add / drop nodes.

[0060] The above-mentioned chain-shaped networking structure may be a network architecture that sequentially connects network nodes through point-to-point links.

[0061] The above-mentioned optical transport unit (OTU) node can be used to convert the gray light signal (i.e., low-speed non-transparent signal) on the client side into a color light signal (i.e., high-speed transparent signal) on the line side, and transmit it over long distances in the optical fiber. The optical forwarding node can also include an optical forwarding board, an optical amplifier board, a multiplexer (MUX) board, an erbium doped fiber amplifier (EDFA), and an optical monitoring channel.

[0062] The optical amplifier (OA) node may be used to amplify optical signals and compensate for the loss of optical signals during transmission in optical fibers. The optical amplifier node may also include an optical amplifier board, an EDFA, and an optical monitoring channel.

[0063] The above-mentioned optical add-drop multiplexer (OADM) node can be used to access and distribute different services. The optical add-drop node can also include an optical forwarding board, an optical amplifier board, a wavelength selective switch (WSS), an EDFA, and an optical monitoring channel.

[0064] The optical layer sub-rack can be used to process and transmit optical signals. The electrical layer sub-rack can be used to convert electrical signals at the client side into optical signals, or to convert optical signals received from the optical layer sub-rack into electrical signals.

[0065] It should be noted that the above-mentioned multiple sub-racks can be supplied by different equipment manufacturers.

[0066] In an exemplary application scenario, Figure 1 As shown, multiple network nodes in the wavelength division multiplexing system adopt a chain networking structure, and the multiple network nodes may include two OTU nodes, multiple OA nodes, and multiple OADM nodes, wherein both the OTU nodes and the OADM nodes are configured with optical layer sub-racks and electrical layer sub-racks, and only the OA nodes are configured with optical layer sub-racks.

[0067] Still in the above application scenario, Figure 4 is a schematic diagram of an optional optical forwarding node according to an embodiment of the present application, such as Figure 4 As shown, the optical forwarding node (i.e., OTU node) includes two sub-racks (i.e., electrical layer sub-rack and optical layer sub-rack), each sub-rack is configured with a time processing board (i.e., time processing unit), the electrical layer sub-rack is configured with two optical forwarding boards (i.e., OTU boards), and the optical layer sub-rack is configured with an optical amplifier board (i.e., OA board), an erbium-doped fiber amplifier (i.e., EDFA), an optical monitoring channel unit (i.e., OSC unit), and a multiplexer board (i.e., MUX board).

[0068] Specifically, the time server is connected to the time processing unit of the electrical layer sub-rack of the OTU node, the time processing unit of the electrical layer sub-rack of the OTU node receives the clock signal of the time server, and synchronizes the time processing unit of the electrical layer sub-rack according to the clock signal of the time server, and transmits the synchronized time to the OTU board card of the electrical layer sub-rack and the time processing unit of the optical layer sub-rack; further, after the time processing unit of the optical layer sub-rack receives the time information sent by the upstream electrical layer sub-rack, it generates an output clock signal using the clock source selection module, the synchronization module, and the clock signal module, and the output clock signal can use the format of the synchronous clock message; further, the time processing unit of the optical layer sub-rack transmits the synchronous clock message to the OSC unit, and the OSC unit transmits the message data to the downstream network node. The above message data may include the synchronous clock message and the NETCONF message corresponding to the network configuration protocol.

[0069] Still in the above application scenario, Figure 5 is a schematic diagram of an optional optical amplification node according to an embodiment of the present application, such as Figure 5 As shown, the optical amplifier node (ie, OA node) includes an optical layer sub-rack, a time processing card (ie, time processing unit) is configured in the optical layer sub-rack, and an optical amplifier board (ie, OA board), an erbium-doped fiber amplifier (ie, EDFA), and an optical monitoring channel unit (ie, OSC unit) are configured in the optical layer sub-rack. Specifically, the OSC unit in the OA node receives the message data sent by the OSC unit in the OTU node, transmits the message data to the network element management unit, and uses the network element management unit to divide the message data into synchronization clock messages and NETCONF messages based on the message type; further, the synchronization clock message is transmitted to the time processing unit of the optical layer sub-rack of the OA node, and the synchronization clock message is parsed by the time processing unit, and the time of the OA node is adjusted according to the parsing result.

[0070] Still in the above application scenario, Figure 6 is a schematic diagram of an optional optical up / down node according to an embodiment of the present application, such as Figure 6As shown, the optical up / down node (i.e., OADM node) includes an optical layer sub-rack and two electrical layer sub-racks (recorded as electrical layer sub-rack-1 and electrical layer sub-rack-2). A time processing board (i.e., time processing unit) is configured in each sub-rack, an optical forwarding board (i.e., OTU board) is configured in each electrical layer sub-rack, and an optical amplifier board (i.e., OA board), erbium-doped fiber amplifier (i.e., EDFA), optical monitoring channel unit (i.e., OSC unit), and wavelength selective switch (i.e., WSS) are configured in the optical layer sub-rack. The time synchronization process of the OADM node is similar to that of the OTU node. For details, please refer to the time synchronization process of the OTU node mentioned above, which will not be repeated here.

[0071] Still in the above application scenario, Figure 7 is a schematic diagram of message data in an optional optical monitoring channel unit according to an embodiment of the present application, such as Figure 7 As shown, the message data in the OSC unit includes a synchronization clock message (denoted as PTP) and a NETCONF message corresponding to the network configuration protocol. The OSC unit performs photoelectric conversion on the message and transmits the processed message to the network element management unit.

[0072] It is easy to understand that through the above-mentioned time-synchronized optoelectronic decoupled wavelength division multiplexing system, in the embodiment of the present application, by adopting a chain networking structure and configuring optical layer sub-racks and electrical layer sub-racks in optical forwarding nodes, optical amplification nodes and optical uplink and downlink nodes, not only the network architecture is simplified, but also the efficiency and quality of signal transmission are improved, and the accuracy of time synchronization of the wavelength division multiplexing system is improved.

[0073] Optionally, in the above-mentioned time-synchronized optoelectronically decoupled wavelength division multiplexing system, when the external clock source device supports the target time protocol, the electrical layer sub-rack in the local network node is configured as a boundary clock, wherein the local network node is any one of the optical forwarding node and the optical uplink and downlink node; the electrical layer sub-rack in the local network node is configured with an upstream port and a downstream port, wherein the upstream port is used to synchronize time information with a target input clock signal sent from the upstream network node, and the downstream port is used to publish time information to the optical layer sub-rack in the downstream network node through the output clock signal, the upstream network node is a network node that supports the target time protocol, and the downstream network node is an optical amplification node.

[0074] The boundary clock (BC) may be a clock device in a time synchronization network. The boundary clock may be used to determine time synchronization information from a Precision Time Protocol (PTP) message.

[0075] In an exemplary application scenario, Figure 1As shown, the target time protocol may be the 1588V2 protocol, and the target input clock signal may be the 1588 clock signal corresponding to the 1588V2 protocol. When the external clock source device supports the 1588V2 protocol, the electrical layer sub-rack of the OTU node and the OADM node is configured as a boundary clock (i.e., BC); further, two clock ports (i.e., the upstream port of the electrical layer sub-rack and the downstream port of the electrical layer sub-rack) are configured in the electrical layer sub-rack of the OTU node and the OADM node, wherein the upstream port of the electrical layer sub-rack receives the 1588 node synchronization time information from the upstream network node, and the downstream port of the electrical layer sub-rack publishes the time information to the downstream network node (i.e., OA node).

[0076] Optionally, in the above-mentioned time-synchronized optoelectronically decoupled wavelength division multiplexing system, when the external clock source device does not support the target time protocol, the electrical layer sub-rack in the local network node is configured as an ordinary clock, wherein the local network node is any one of the optical forwarding nodes and the optical uplink and downlink nodes; the electrical layer sub-rack in the local network node is configured with a downstream port, wherein the downstream port is used to publish time information to the optical layer sub-rack in the downstream network node by outputting a clock signal to the downstream network node.

[0077] The above-mentioned ordinary clock (OC for short) may be a clock device for receiving and forwarding time synchronization messages in a time synchronization network. The ordinary clock may be used to transmit time synchronization information.

[0078] In an exemplary application scenario, Figure 1 As shown, when the external clock source device does not support the 1588V2 protocol, the electrical layer sub-rack of the OTU node and the OADM node is configured as a common clock (i.e., OC); further, a clock port (i.e., the downstream port of the electrical layer sub-rack) is configured in the electrical layer sub-rack of the OTU node and the OADM node, and the downstream port of the electrical layer sub-rack publishes time information to the optical layer sub-rack in the downstream network node by outputting a clock signal.

[0079] It is easy to understand that through the above-mentioned time-synchronized optoelectronically decoupled wavelength division multiplexing system, in the embodiment of the present application, by judging whether the external clock source device supports the target time protocol and selecting the boundary clock and the ordinary clock, not only can high-precision time synchronization be achieved, but also the compatibility of the wavelength division multiplexing system with different external clock source devices can be improved, thereby improving the stability and compatibility of the system.

[0080] Optionally, in the above-mentioned time-synchronized optoelectronic decoupled wavelength division multiplexing system, the optical layer subframe in the optical amplifier node is configured with an upstream port and a downstream port, wherein the upstream port is used to synchronize time information from an upstream network node of the optical amplifier node, and the downstream port is used to publish time information to a downstream network node of the optical amplifier node;

[0081] When there is a port synchronization requirement in the optical layer sub-rack, the optical layer sub-rack is configured as a boundary clock, wherein the port synchronization requirement is used to represent the requirement that the sub-rack time of the optical layer sub-rack is synchronized with the network time corresponding to the upstream port; when there is no port synchronization requirement in the optical layer sub-rack, the optical layer sub-rack is configured as a transparent clock.

[0082] The above transparent clock (TC) can be used to forward time synchronization messages without changing the timestamp information carried in the messages.

[0083] In an exemplary application scenario, Figure 1 As shown, when the subrack time of the optical layer subrack needs to be synchronized with the network time corresponding to the upstream port, that is, when the optical layer subrack has a port synchronization requirement, the optical layer subrack of the OA node is configured as a boundary clock (i.e., BC); when the optical layer subrack does not have a port synchronization requirement, the optical layer subrack of the OA node is configured as a transparent clock (i.e., TC).

[0084] Optionally, in the above-mentioned time-synchronized optoelectronically decoupled wavelength division multiplexing system, the time processing board also includes a second pulse time module and a time protocol message module, wherein the second pulse time module is used to generate a second pulse signal and a time and date signal according to an external time signal, wherein the external time signal is provided by a satellite navigation system, the second pulse time signal is used to characterize a reference time point per second, and the time and date signal is used to record complete date and time information; the time protocol message module is used to parse the target input clock signal to obtain a parsing result, update the local time of the local network node according to the parsing result, and generate an output clock signal corresponding to an output time message according to the parsing result and the target time protocol.

[0085] The satellite navigation system may include but is not limited to GPS and BeiDou satellite system. The time protocol message may include 1588V2 message.

[0086] In an exemplary application scenario, Figure 2 As shown, the time processing board also includes a pulse-second time module and a time protocol message module. The time protocol message can be a 1588V2 message. The pulse-second time module is recorded as a 1PPS+TOD module, and the time protocol message is recorded as a 1588V2 message module. Further, the pulse-second time module is used to generate a pulse-second signal and a time date signal based on an external time signal. The time protocol message module is used to parse the target input clock signal, and the local time of the local network node is updated according to the parsing result. The output time message corresponding to the output clock signal is generated according to the parsing result and the target time protocol.

[0087] It is easy to understand that through the above-mentioned time-synchronized optoelectronically decoupled wavelength division multiplexing system, in the embodiment of the present application, by utilizing the second pulse time module and the time protocol message module, high-precision time synchronization can be achieved, thereby improving the accuracy of time synchronization of the wavelength division multiplexing system.

[0088] In an embodiment of the present application, multiple network nodes are configured with multiple sub-racks, each sub-rack is configured with a time processing board, and the time processing board includes a clock source selection module, a synchronization module and a clock signal module, wherein the clock source selection module is used to select a target input clock signal from multiple candidate input clock signals; the synchronization module is used to adjust the local time of the local network node where the time processing board is located according to the target input clock signal; the clock signal module is used to generate an output clock signal according to the target input clock signal and the local time, wherein the output clock signal is used to publish time information to the downstream network node of the local network node. Thus, the present application achieves the purpose of enabling the wavelength division multiplexing system to adapt to different external clock source devices and network structures and perform time synchronization more accurately and stably by flexibly configuring the time processing board in each sub-rack, thereby achieving the technical effect of improving the accuracy and stability of the time synchronization of the wavelength division multiplexing system, and thus solving the technical problems of low accuracy and poor stability of the time synchronization of the wavelength division multiplexing system in the related art.

[0089] Figure 8 is a hardware structure block diagram of a terminal device of an optional wavelength division multiplexing method for photoelectric decoupling for time synchronization according to an embodiment of the present application, such as Figure 8 As shown, the terminal device may include one or more processors 102 (the processor 102 may include but is not limited to a processing device such as a microprocessor (Microcontroller Unit, referred to as MCU) or a programmable logic device (Field Programmable Gate Array, referred to as FPGA)), a memory 104 for storing data, and a transmission device 106 for communication functions. In addition, it may also include: a display device 110, an input / output device 108 (i.e., an I / O device), a Universal Serial Bus (USB) port (which may be included as one of the ports of a computer bus, not shown in the figure), a network interface (not shown in the figure), a power supply (not shown in the figure) and / or a camera (not shown in the figure). It can be understood by those skilled in the art that Figure 8 The structure shown is for illustration only and does not limit the structure of the above terminal device. Figure 8 More or fewer components as shown, or with Figure 8 Different configurations are shown.

[0090] It should be noted that the one or more processors 102 and / or other data processing circuits may be embodied in whole or in part as software, hardware, firmware or any other combination thereof. In addition, the data processing circuit may be a single independent processing module, or may be fully or partially integrated into any of the other components in the terminal device (or mobile device).

[0091] The memory 104 can be used to store software programs and modules of application software, such as the program instructions / data storage device corresponding to the time-synchronized photoelectric decoupling wavelength division multiplexing method in the embodiment of the present application. The processor 102 executes various functional applications and data processing by running the software programs and modules stored in the memory 104, that is, the above-mentioned time-synchronized photoelectric decoupling wavelength division multiplexing method is realized. The memory 104 may include a high-speed random access memory, and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include a memory remotely arranged relative to the processor 102, and these remote memories may be connected to the terminal device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and a combination thereof.

[0092] The transmission device 106 is used to receive or send data via a network. The specific example of the above network may include a wireless network provided by a communication provider of the terminal device. In one example, the transmission device 106 includes a network adapter (Network Interface Controller, referred to as NIC), which can be connected to other network devices through a base station so as to communicate with the Internet. In one example, the transmission device 106 can be a radio frequency (Radio Frequency, referred to as RF) module, which is used to communicate with the Internet wirelessly.

[0093] In the above operating environment, according to another aspect of the embodiment of the present application, a time synchronization method for a wavelength division multiplexing system based on optoelectronic decoupling is also provided, wherein the wavelength division multiplexing system has multiple network nodes, and multiple sub-racks are configured in the multiple network nodes, and each sub-rack is configured with a time processing board. The time synchronization method is applied to the time processing board of any local network node among the multiple network nodes, and the time synchronization method includes the following implementation steps: receiving multiple candidate input clock signals; selecting a target input clock signal from the multiple candidate input clock signals; adjusting the local time of the local network node where the time processing board is located according to the target input clock signal; generating an output clock signal according to the target input clock signal and the local time, wherein the output clock signal is used to publish time information to the downstream network node of the local network node.

[0094] Optionally, the specific examples in this embodiment may refer to the examples described in the above embodiment and its optional implementation manners, which will not be described in detail here.

[0095] The serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0096] In the above embodiments of the present application, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0097] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of the units can be a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0098] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0099] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0100] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can essentially or in other words contribute to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, read-only memory (Read-Only Memory, referred to as ROM), random access memory (Random Access Memory, referred to as RAM), mobile hard disk, disk or optical disk and other media that can store program codes.

[0101] The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A time-synchronized optoelectronically decoupled wavelength division multiplexing system, characterized in that: The wavelength division multiplexing system includes a plurality of network nodes, wherein the plurality of network nodes are configured with a plurality of sub-racks, each sub-rack is configured with a time processing board, and the time processing board includes a clock source selection module, a synchronization module and a clock signal module, wherein the clock source selection module is used to select a target input clock signal from a plurality of candidate input clock signals; The synchronization module is used to adjust the local time of the local network node where the time processing board is located according to the target input clock signal; The clock signal module is used to generate an output clock signal according to the target input clock signal and the local time, wherein the output clock signal is used to publish time information to a downstream network node of the local network node.

2. The time-synchronized optoelectronically decoupled wavelength division multiplexing system according to claim 1, characterized in that: The multiple signal sources corresponding to the multiple candidate input clock signals include: the local network node where the time processing board is located, the upstream network node of the local network node, and the external clock source device associated with the local network node; The clock source selection module is further used to select the target input clock signal from the multiple candidate input clock signals according to the priority information of the multiple signal sources.

3. The time-synchronized optoelectronically decoupled wavelength division multiplexing system according to claim 1, characterized in that: The synchronization module includes a clock synchronization unit and a time synchronization unit, wherein: The clock synchronization unit is used to adjust the clock frequency of the local network node according to the target input clock signal; The time synchronization unit is used to adjust the local time based on the target input clock signal and the clock frequency, so that the local time maintains time stamp synchronization with the target input clock signal.

4. The time-synchronized optoelectronically decoupled wavelength division multiplexing system according to claim 2, characterized in that: The multiple candidate input clock signals and the output clock signal are transmitted using a time synchronization message, and the time synchronization message is generated based on a target time protocol.

5. The time-synchronized optoelectronically decoupled wavelength division multiplexing system according to claim 4, characterized in that: The multiple network nodes in the wavelength division multiplexing system adopt a chain-shaped networking structure; The multiple network nodes include optical forwarding nodes, optical amplification nodes and optical add / drop nodes; The multiple sub-racks include: an optical layer sub-rack and an electrical layer sub-rack in the optical forwarding node, an optical layer sub-rack in the optical amplification node, and an optical layer sub-rack and an electrical layer sub-rack in the optical add / drop node.

6. The time-synchronized optoelectronically decoupled wavelength division multiplexing system according to claim 5, characterized in that: When the external clock source device supports the target time protocol, the electrical layer subrack in the local network node is configured as a boundary clock, wherein the local network node is any one of the optical forwarding node and the optical add / drop node; The electrical layer sub-rack in the local network node is configured with an upstream port and a downstream port, wherein the upstream port is used to synchronize time information from the target input clock signal emitted by the upstream network node, and the downstream port is used to publish time information to the optical layer sub-rack in the downstream network node through the output clock signal, the upstream network node is a network node that supports the target time protocol, and the downstream network node is the optical amplifier node.

7. The time-synchronized optoelectronically decoupled wavelength division multiplexing system according to claim 5, characterized in that: When the external clock source device does not support the target time protocol, the electrical layer subrack in the local network node is configured as a common clock, wherein the local network node is any one of the optical forwarding node and the optical add / drop node; The electrical layer subrack in the local network node is configured with a downstream port, wherein the downstream port is used to publish time information to the optical layer subrack in the downstream network node through the output clock signal.

8. The time-synchronized optoelectronically decoupled wavelength division multiplexing system according to claim 5, characterized in that: The optical layer subrack in the optical amplifier node is configured with an upstream port and a downstream port, wherein the upstream port is used to synchronize time information from an upstream network node of the optical amplifier node, and the downstream port is used to publish time information to a downstream network node of the optical amplifier node; When the optical layer sub-rack has a port synchronization requirement, the optical layer sub-rack is configured as a boundary clock, wherein the port synchronization requirement is used to represent the requirement that the sub-rack time of the optical layer sub-rack is synchronized with the network time corresponding to the upstream port; When the optical layer sub-rack does not have the port synchronization requirement, the optical layer sub-rack is configured as a transparent clock.

9. The time-synchronized optoelectronically decoupled wavelength division multiplexing system according to claim 1, characterized in that: The time processing board also includes a pulse-per-second time module and a time protocol message module, wherein: The second pulse time module is used to generate a second pulse signal and a time and date signal according to an external time signal, wherein the external time signal is provided by a satellite navigation system, the second pulse time signal is used to represent a reference time point per second, and the time and date signal is used to record complete date and time information; The time protocol message module is used to parse the target input clock signal to obtain a parsing result, update the local time of the local network node according to the parsing result, and generate an output time message corresponding to the output clock signal according to the parsing result and the target time protocol.

10. A time synchronization method for a wavelength division multiplexing system based on photoelectric decoupling, characterized in that: The wavelength division multiplexing system has multiple network nodes, the multiple network nodes are configured with multiple sub-racks, each sub-rack is configured with a time processing board, the time synchronization method is applied to the time processing board of any local network node in the multiple network nodes, and the time synchronization method includes: receiving a plurality of candidate input clock signals; Selecting a target input clock signal from the plurality of candidate input clock signals; Adjusting the local time of the local network node where the time processing board is located according to the target input clock signal; An output clock signal is generated according to the target input clock signal and the local time, wherein the output clock signal is used to publish time information to a downstream network node of the local network node.

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