Signal transmission system

Abstract

A signal transmission system is disclosed. The system comprises: a first multiplexer / demultiplexer, a second multiplexer / demultiplexer, a time-frequency synchronization main station unit, a time-frequency synchronization secondary station unit, a first optical conversion unit, and a second optical conversion unit. A first input port of the first multiplexer / demultiplexer is connected to the time-frequency synchronization main station unit, a second input port of the first multiplexer / demultiplexer is connected to the first optical conversion unit, a first output port of the first multiplexer / demultiplexer is connected to a first input port of the second multiplexer / demultiplexer, a first output port of the second multiplexer / demultiplexer is connected to the time-frequency synchronization secondary station unit, and a second output port of the second multiplexer / demultiplexer is connected to the second optical conversion unit.

Description

Signal transmission system

[0001] This disclosure claims priority to Chinese patent application No. 202411803845.4, filed on December 9, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This disclosure relates to the field of communication technology, and more particularly to a signal transmission system. Background Technology

[0003] Fiber optic time synchronization networks require dedicated fiber optic cables for time synchronization. Therefore, building a fiber optic time synchronization network necessitates laying a large amount of new fiber optic cable.

[0004] Wavelength division multiplexing / optical transport network (WDM / OTN) network and fiber optic time synchronization network are two independent networks. Summary of the Invention

[0005] In a first aspect, a signal transmission system is provided, comprising a first multiplexer / demultiplexer, a second multiplexer / demultiplexer, a time-frequency synchronization master station unit, a time-frequency synchronization slave station unit, a first optical conversion unit, and a second optical conversion unit; the first input port of the first multiplexer / demultiplexer is connected to the time-frequency synchronization master station unit; the second input port of the first multiplexer / demultiplexer is connected to the first optical conversion unit; the first output port of the first multiplexer / demultiplexer is connected to the first input port of the second multiplexer / demultiplexer; the first output port of the second multiplexer / demultiplexer is connected to the time-frequency synchronization slave station unit; and the second output port of the second multiplexer / demultiplexer is connected to the second optical conversion unit.

[0006] In some embodiments, the second multiplexer / demultiplexer further includes a second input port and a third output port; the second input port of the second multiplexer / demultiplexer is connected to the time-frequency synchronization slave unit; and the third output port of the second multiplexer / demultiplexer is connected to the first multiplexer / demultiplexer.

[0007] In some embodiments, the first multiplexer / demultiplexer further includes a second output port; the second output port is connected to the time-frequency synchronization master station unit.

[0008] In some embodiments, a third optical conversion unit is further included between the time-frequency synchronization master station unit and the first multiplexer / demultiplexer.

[0009] In some embodiments, the third optical conversion unit is used to convert the signal wavelength of the time-frequency synchronization master station unit into a first wavelength; the first wavelength is different from the wavelength of the service signal of the first optical conversion unit.

[0010] In some embodiments, the time-frequency synchronization master station unit and the time-frequency synchronization slave station unit are connected based on a first optical path; the first optical conversion unit and the second optical conversion unit are connected based on a second optical path; the second optical path includes the first optical path and a first symmetrical optical path.

[0011] In some embodiments, the first optical path further includes at least one bidirectional optical amplifier.

[0012] In some embodiments, the first symmetrical optical path includes at least one unidirectional optical amplifier.

[0013] In some embodiments, the system further includes a third multiplexer and a fourth multiplexer; the number of first optical conversion units and second optical conversion units is multiple; the third multiplexer is located between the first optical conversion unit and the second optical path; and the fourth multiplexer is located between the second optical conversion unit and the second optical path.

[0014] In some embodiments, the multiplexing unit of the third multiplexer is connected to the first optical path; the demultiplexing unit of the third multiplexer is connected to the first symmetrical optical path; the demultiplexing unit of the fourth multiplexer is connected to the first optical path; and the multiplexing unit of the fourth multiplexer is connected to the first symmetrical optical path.

[0015] Secondly, a signal transmission device is provided, which can realize the functions performed by the system in the above aspects or various embodiments. The functions can be implemented by hardware. For example, in one design, the signal transmission device may include a processor and a communication interface. The processor can be used to support the signal transmission device in realizing the functions involved in the system of the first aspect or any embodiment of the first aspect.

[0016] In some embodiments, the signal transmission device may further include a memory for storing computer execution instructions and data necessary for the signal transmission device. When the signal transmission device is in operation, the processor executes the computer execution instructions stored in the memory to cause the signal transmission device to perform the functions involved in the system of the first aspect or any embodiment of the first aspect.

[0017] Thirdly, a computer-readable storage medium is provided, which may be a readable non-volatile storage medium storing computer instructions or programs that, when run on a computer, enable the computer to perform the functions involved in the system of the first aspect or any embodiment of the first aspect.

[0018] Fourthly, a computer program product containing instructions is provided, which, when run on a computer, enables the computer to perform the functions involved in the system of the first aspect or any embodiment of the first aspect.

[0019] Fifthly, an electronic device is provided, comprising one or more processors and one or more memories. The one or more memories are coupled to the one or more processors, and the one or more memories are used to store computer program code, including computer instructions, which, when executed by the one or more processors, cause the electronic device to perform the functions involved in the system of the first aspect or any embodiment of the first aspect.

[0020] In a sixth aspect, a chip system is provided, comprising a processor and a communication interface, which can be used to implement the functions performed by the signal transmission system in the first aspect or any embodiment thereof. In some embodiments, the chip system further includes a memory for storing program instructions and / or data. The chip system may be composed of chips or may include chips and other discrete devices, without limitation. Attached Figure Description

[0021] Figure 1 is a schematic diagram of the structure of a WDM system according to some embodiments of the present disclosure.

[0022] Figure 2 is a schematic diagram of the structure of an optical fiber timing system according to some embodiments of the present disclosure.

[0023] Figure 3 is a schematic diagram of a signal transmission system according to some embodiments of the present disclosure.

[0024] Figure 4 is a schematic diagram of another signal transmission system according to some embodiments of the present disclosure.

[0025] Figure 5 is a schematic diagram of the structure of another signal transmission system according to some embodiments of the present disclosure.

[0026] Figure 6 is a schematic diagram of the structure of another signal transmission system according to some embodiments of the present disclosure.

[0027] Figure 7 is a schematic diagram of the structure of another signal transmission system according to some embodiments of the present disclosure.

[0028] Figure 8 is a schematic diagram of the structure of a signal transmission device according to some embodiments of the present disclosure. Detailed Implementation

[0029] To enable those skilled in the art to better understand the technical solutions of this disclosure, the technical solutions in the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings.

[0030] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this disclosure are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this disclosure described herein can be implemented in orders other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of the embodiments of this disclosure as detailed in the appended claims.

[0031] It should also be understood that the term "comprising" indicates the presence of the described feature, whole, step, operation, element and / or component, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements and / or components.

[0032] Time synchronization technology plays a fundamental supporting role in information fusion, collaborative operations, and time and distance measurement in 5G and vertical industries. Existing operator synchronization networks widely support satellite time synchronization and the Precision Time Protocol (PTP). However, satellite time synchronization accuracy is at the level of hundreds of nanoseconds; PTP also suffers from the following problems: unresolved link latency asymmetry; synchronization accuracy of around tens of nanoseconds; and in multi-level cascading scenarios, synchronization accuracy decreases progressively, failing to meet sub-nanosecond accuracy requirements. In contrast, fiber optic time-frequency synchronization technology can achieve time synchronization deviation accuracy at the sub-nanosecond or even picosecond level. Therefore, introducing fiber optic time synchronization solutions to meet higher-precision time synchronization needs is an important technical approach that operators can consider.

[0033] The essence of fiber optic time synchronization is to modulate the timing signal output from the time and frequency reference onto an optical carrier and transmit it over long distances using optical fiber as the transmission medium, so that the timing signals of the master and slave stations can achieve picosecond (ps) level synchronization.

[0034] The core of fiber optic time synchronization is accurately subtracting the transmission delay of the fiber optic link and eliminating the impact of fiber optic link noise on time transmission. Because fiber optic delay varies with factors such as temperature fluctuations and changes in fiber tension, even if two fibers are located in the same cable and their physical lengths are exactly equal, it is still impossible to guarantee that their fiber optic delays are completely equal. Since fiber optic delay variations are uncontrollable and bidirectional asymmetric errors in dual-fiber systems cannot be eliminated, the industry currently primarily chooses single-fiber bidirectional methods to transmit fiber optic time signals, considering both performance and cost. Time information needs to be exchanged between the time-frequency synchronization master and slave devices; that is, a bidirectional time comparison method is required.

[0035] When high-precision time-frequency signals are transmitted over long distances (e.g., ≥100 km) via optical fiber, signal regeneration becomes a critical issue due to fiber transmission loss. This requires multiple devices and appropriate transmission methods, with repeater amplification being a common approach. Therefore, optical amplifiers can be introduced to amplify the optical signal power during signal transmission via optical fiber. Since bidirectional transmission using a single fiber is employed, the optical amplifier must be bidirectional, while also ensuring symmetrical transmission delay and low noise.

[0036] Figure 1 shows a schematic diagram of a WDM system. As shown in Figure 1, the WDM system may include a first optical transform unit (OTU), a second OTU, multiple unidirectional optical amplifiers (OA, also known as relay stations), a first optical multiplexer / optical demultiplexer (OM / OD), and a second optical multiplexer / demultiplexer.

[0037] The number of first OTUs and second OTUs can be multiple. The number of first OTUs and second OTUs can be set as needed, and is not limited in this disclosure.

[0038] The number of unidirectional optical amplifiers can be set as needed. For example, in the optical communication path where the first OTU sends a service signal to the second OTU, the number of unidirectional optical amplifiers can be two. For example, they can be OA1 and OA2 as shown in Figure 1.

[0039] In the optical communication path where the second OTU sends service signals to the first OTU, the number of multiple unidirectional optical amplifiers can be two. For example, they can be OA3 and OA4 as shown in Figure 1.

[0040] The signal transmission process of the WDM system is described below based on S1-S5:

[0041] S1. The first OTU sends multiple service signals to the first multiplexer / demultiplexer. Correspondingly, the first multiplexer / demultiplexer receives multiple service signals.

[0042] Each service signal can be a service signal with a different wavelength. For example, it can be λ1, λ2, etc.

[0043] S2. The first multiplexer / demultiplexer performs multiple signal multiplexing processing on the received service signals to obtain a multiplexed signal.

[0044] S3. The first multiplexer sends a multiplexed signal to the second multiplexer. Correspondingly, the second multiplexer receives the multiplexed signal.

[0045] S4, the second multiplexer / demultiplexer performs demultiplexing processing on the multiplexed signal to obtain multiple service signals.

[0046] S5, the second multiplexer / demultiplexer sends multiple service signals to the second OTU.

[0047] Figure 2 shows a schematic diagram of a fiber optic time synchronization system. As shown in Figure 2, the fiber optic time synchronization system may include a time-frequency synchronization master station unit, a time-frequency synchronization slave station unit, and multiple bidirectional optical amplifiers.

[0048] The time-frequency synchronization master station unit and the time-frequency synchronization slave station unit are connected via optical fiber. Multiple bidirectional optical amplifiers are positioned between the time-frequency synchronization master station unit and the time-frequency synchronization slave station unit.

[0049] Fiber optic time synchronization networks require dedicated fiber optic cables for time synchronization. Therefore, building a fiber optic time synchronization network necessitates laying a large amount of new fiber optic cable, resulting in a waste of fiber optic resources.

[0050] WDM / OTN networks and fiber optic time synchronization networks are two independent networks. Furthermore, the optical amplifiers in existing WDM / OTN networks are all unidirectional, while fiber optic time synchronization requires bidirectional optical amplification, making the amplifiers incompatible. Additionally, services in existing WDM / OTN networks are bidirectional (different directions of the service follow different fiber paths), while fiber optic time synchronization is bidirectional (single-fiber), meaning the signal transmission methods are different. Therefore, how to utilize existing fiber optic cables in WDM / OTN networks for time synchronization is a pressing technical problem that needs to be solved.

[0051] In view of this, the present disclosure provides a signal transmission system, including: a first multiplexer / demultiplexer, a second multiplexer / demultiplexer, a time-frequency synchronization master station unit, a time-frequency synchronization slave station unit, a first optical conversion unit, and a second optical conversion unit; the first input port of the first multiplexer / demultiplexer is connected to the time-frequency synchronization master station unit; the second input port of the first multiplexer / demultiplexer is connected to the first optical conversion unit; the first output port of the first multiplexer / demultiplexer is connected to the first input port of the second multiplexer / demultiplexer; the first output port of the second multiplexer / demultiplexer is connected to the time-frequency synchronization slave station unit; and the second output port of the second multiplexer / demultiplexer is connected to the second optical conversion unit.

[0052] The system provided in the embodiments of this disclosure will now be described in detail with reference to the accompanying drawings.

[0053] It should be noted that the network systems described in the embodiments of this disclosure are for the purpose of more clearly illustrating the technical solutions of the embodiments of this disclosure, and do not constitute a limitation on the technical solutions provided in the embodiments of this disclosure. As those skilled in the art will know, with the evolution of network systems and the emergence of other network systems, the technical solutions provided in the embodiments of this disclosure are also applicable to similar technical problems.

[0054] Figure 3 shows a schematic diagram of a signal transmission system provided in an embodiment of this disclosure. As shown in Figure 3, the signal transmission system may include a first multiplexer / demultiplexer 11, a second multiplexer / demultiplexer 12, a time-frequency synchronization master station unit 13, a time-frequency synchronization slave station unit 14, a first optical conversion unit 15, and a second optical conversion unit 16.

[0055] The first input port of the first multiplexer / demultiplexer 11 is connected to the time-frequency synchronization master station unit 13; the second input port of the first multiplexer / demultiplexer 11 is connected to the first optical conversion unit 15; and the first output port of the first multiplexer / demultiplexer 11 is connected to the first input port of the second multiplexer / demultiplexer 12.

[0056] The first output port of the second multiplexer / demultiplexer 12 is connected to the time-frequency synchronization slave unit 14; the second output port of the second multiplexer / demultiplexer 12 is connected to the second optical conversion unit 16.

[0057] The first input port of the first multiplexer / demultiplexer 11 is used to receive the time-frequency synchronization signal from the time-frequency synchronization master station unit 13. The second input port of the first multiplexer / demultiplexer 11 is used to receive the service signal from the first optical conversion unit 15.

[0058] The first multiplexer / demultiplexer 11 is used to perform multiplexing processing on the time synchronization signal from the time-frequency synchronization master station unit 13 and the service signal from the first optical conversion unit 15 to obtain a multiplexed signal.

[0059] The first output port of the first multiplexer / demultiplexer 11 can be used to send a multiplexed signal to the second multiplexer / demultiplexer 12. Correspondingly, the second multiplexer / demultiplexer 12 can receive the multiplexed signal based on its own first input port.

[0060] The second multiplexer / demultiplexer 12 can be used to perform demultiplexing processing on the multiplexed signal to obtain a time synchronization signal and a service signal. It can send the time synchronization signal to the time-frequency synchronization slave unit 14 based on the first output port and send the service signal to the second optical conversion unit 16 based on the second output port.

[0061] Based on the technical solution provided in this disclosure, the first input port of the first multiplexer / demultiplexer 11 is connected to the time-frequency synchronization master station unit 13; the second input port of the first multiplexer / demultiplexer 11 is connected to the first optical conversion unit 15; the first output port of the first multiplexer / demultiplexer 11 is connected to the first input port of the second multiplexer / demultiplexer 12; the first output port of the second multiplexer / demultiplexer 12 is connected to the time-frequency synchronization slave station unit 14; and the second output port of the second multiplexer / demultiplexer 12 is connected to the second optical conversion unit 16. That is, the first multiplexer / demultiplexer 11 is connected to the time-frequency synchronization master station unit 13 and the first optical conversion unit 15, respectively, and the second multiplexer / demultiplexer 12 is connected to the time-frequency synchronization slave station unit 14 and the second optical conversion unit 16, respectively. In this way, when transmitting time-frequency signals, the existing optical path between the first optical conversion unit 15 and the second optical conversion unit 16 can be used for connection, without the need to lay new optical paths, thus improving the utilization rate of optical fiber resources.

[0062] In some embodiments, the second multiplexer / demultiplexer 12 further includes a second input port (not shown in the figure) and a third output port (not shown in the figure); the second input port of the second multiplexer / demultiplexer 12 is connected to the time-frequency synchronization slave unit 14; the third output port of the second multiplexer / demultiplexer 12 is connected to the first multiplexer / demultiplexer 11.

[0063] The second multiplexer / demultiplexer 12 also includes a second input port for receiving a time-frequency synchronization response signal from the time-frequency synchronization slave unit 14. The third output port of the second multiplexer / demultiplexer 12 is used to send a time-frequency synchronization response signal to the first multiplexer / demultiplexer 11, so that the first multiplexer / demultiplexer 11 sends a time-frequency synchronization response signal to the time-frequency synchronization master unit 13.

[0064] In some embodiments, the first multiplexer / demultiplexer 11 further includes a second output port; the second output port is connected to the time-frequency synchronization master station unit 13.

[0065] The second output port is used to send a time-frequency synchronization reply signal from the time-frequency synchronization slave unit 14 to the time-frequency synchronization master unit 13.

[0066] In some embodiments, FIG4 shows a schematic diagram of another signal transmission system provided by an embodiment of the present disclosure. As shown in FIG4, the signal transmission system further includes a third optical conversion unit 17 between the time-frequency synchronization master station unit 13 and the first multiplexer / demultiplexer 11. A fourth optical conversion unit 18 is also included between the time-frequency synchronization slave station unit 14 and the second multiplexer / demultiplexer 12.

[0067] The third optical conversion unit 17 is used to convert the signal wavelength of the time-frequency synchronization master station unit 13 into the first wavelength. The fourth optical conversion unit 18 is used to convert the signal wavelength of the time-frequency synchronization slave station unit 14 into the first wavelength.

[0068] It should be noted that the first wavelength is different from the wavelength of the service signal of the first optical conversion unit 15.

[0069] The value of the first wavelength can be set as needed. For example, it can be λclk. That is, this wavelength is only used to transmit the time-frequency synchronization signal and is no longer used to transmit service signals. The time-frequency synchronization signal needs to occupy a specific wavelength in the service channel. The transmission method of service signals in the WDM / OTN system remains unchanged (except that λclk cannot be used).

[0070] When the time-frequency synchronization master station unit 13 is connected to the WDM / OTN system, it needs to undergo OTU wavelength conversion to convert the wavelength to λclk.

[0071] This ensures that the time-frequency synchronization signal and the service signal occupy different wavelength channels for signal transmission, thus avoiding transmission conflicts between the time-frequency synchronization signal and the service signal.

[0072] In some embodiments, FIG5 shows a schematic diagram of another signal transmission system provided by the present disclosure. As shown in FIG5, the time-frequency synchronization master station unit 13 and the time-frequency synchronization slave station unit 14 are connected based on the first optical path 19; the first optical conversion unit 15 and the second optical conversion unit 16 are connected based on the second optical path; the second optical path includes the first optical path 19 and the first symmetrical optical path 20.

[0073] The first optical path 19 and the first symmetrical optical path 20 are optical fiber communication links.

[0074] It should be noted that the time-frequency synchronization master station unit 13 and the time-frequency synchronization slave station unit 14 can be connected via a single-fiber bidirectional communication based on the first optical path 19.

[0075] For example, the time-frequency synchronization master station unit 13 can send a time-frequency synchronization signal to the time-frequency synchronization slave station unit 14 via the first optical path 19. The time-frequency synchronization slave station unit 14 can send a time-frequency synchronization reply signal to the time-frequency synchronization master station unit 13 via the first optical path 19.

[0076] In one example, based on the first optical path 19, the time-frequency synchronization signal and the time-frequency synchronization slave unit 14 can send bidirectional interactive information through time-division multiplexing (TDM).

[0077] It should be noted that the first optical conversion unit 15 and the second optical conversion unit 16 can be connected via a dual-fiber bidirectional communication based on the second optical path.

[0078] For example, the first optical conversion unit 15 can send a service signal to the second optical conversion unit 16 based on the first optical path 19. The second optical conversion unit 16 can send a service response signal to the first optical conversion unit 15 based on the first symmetrical optical path 20.

[0079] In one example, based on the first optical path 19, the first optical conversion unit 15 can send service signals to the second optical conversion unit 16 through wavelength division multiplexing technology.

[0080] Accordingly, based on the first symmetrical optical path 20, the second optical conversion unit 16 can send a service response signal to the first optical conversion unit 15 through wavelength division multiplexing technology.

[0081] In some embodiments, FIG6 shows a schematic diagram of another signal transmission system provided by the present disclosure. As shown in FIG6, the first optical path 19 further includes at least one bidirectional optical amplifier 21, and the first symmetrical optical path 20 includes at least one unidirectional optical amplifier 22.

[0082] The number of bidirectional optical amplifiers 21 can be set as needed. For example, there can be two. The bidirectional optical amplifiers 21 are located between the first multiplexer / demultiplexer 11 and the second multiplexer / demultiplexer 12.

[0083] It should be noted that the bidirectional optical amplifier 21 can enhance the signal strength of the multiplexed signal when it receives the multiplexed signal from the first multiplexer / demultiplexer 11, and send the enhanced multiplexed signal to the second multiplexer / demultiplexer 12.

[0084] The bidirectional optical amplifier 21 can also enhance the signal strength of the time-frequency synchronization response signal when it receives the time-frequency synchronization response signal from the second multiplexer / demultiplexer 12, and send the enhanced time-frequency synchronization response signal to the first multiplexer / demultiplexer 11.

[0085] It should be noted that the unidirectional optical amplifier 22 can enhance the signal strength of the service reply signal upon receiving the service reply signal from the second multiplexer / demultiplexer 12, and send the enhanced service reply signal to the first optical conversion unit 15.

[0086] In some embodiments, FIG7 shows a schematic diagram of another signal transmission system provided by an embodiment of the present disclosure. As shown in FIG7, the system further includes a third multiplexer / demultiplexer 23 and a fourth multiplexer / demultiplexer 24; the number of first optical conversion units 15 and second optical conversion units 16 is multiple.

[0087] The third multiplexer / demultiplexer 23 is located between the first optical conversion unit 15 and the second optical path; the fourth multiplexer / demultiplexer 24 is located between the second optical conversion unit 16 and the second optical path.

[0088] The multiplexing unit of the third multiplexer 23 is connected to the first optical path 19; the demultiplexing unit of the third multiplexer 23 is connected to the first symmetrical optical path 20; the demultiplexing unit of the fourth multiplexer 24 is connected to the first optical path 19; the multiplexing unit of the fourth multiplexer 24 is connected to the first symmetrical optical path 20.

[0089] It should be noted that the third multiplexer / demultiplexer 23 is used to receive multiple service signals from the first optical conversion unit 15 and perform multiplexer processing on the multiple service signals to obtain a service multiplexer signal.

[0090] It should be noted that the time-frequency synchronization master station unit 13 and the time-frequency synchronization slave station unit 14 can be connected to the WDM system as independent devices, or they can be developed or upgraded as a module unit in the WDM system, that is, integrated into the WDM system as an extension of the existing WDM system. In this scenario, there is no need to add additional multiplexers / demultiplexers, which can enable the WDM network to be integrated with fiber optic time synchronization, so that the WDM network can transmit service signals while having the ability to transmit high-precision time-frequency synchronization signals.

[0091] It should be noted that the various components (e.g., optical amplifiers) in the above embodiments can be connected to the optical fiber link by physical means (e.g., welding or using connection devices, etc.), and this application does not limit this.

[0092] Figure 7 is merely an exemplary framework diagram. The names of the various devices included in Figure 7 are not limited, and other nodes may be included in addition to the functional nodes shown in Figure 7. This disclosure does not limit the scope of the embodiments.

[0093] In actual implementation, each device in Figure 7 can adopt the composition structure shown in Figure 8, or include the components shown in Figure 8. Figure 8 is a schematic diagram of the structure of a signal transmission device 200 provided in an embodiment of this disclosure. The signal transmission device 200 can be a network device, or it can be a chip or system-on-a-chip in a network device. As shown in Figure 8, the signal transmission device 200 includes a processor 201, a communication interface 202, and a communication line 203.

[0094] Furthermore, the signal transmission device 200 may also include a memory 204. The processor 201, the memory 204, and the communication interface 202 can be connected via a communication line 203.

[0095] Processor 201 is a CPU, a general-purpose processor, a network processor (NP), a digital signal processor (DSP), a microprocessor, a microcontroller, a programmable logic device (PLD), or any combination thereof. Processor 201 may also be other devices with processing capabilities, such as circuits, devices, or software modules, without limitation.

[0096] Communication interface 202 is used to communicate with other devices or other communication networks. Communication interface 202 can be a module, circuit, communication interface, or any device capable of enabling communication.

[0097] Communication line 203 is used to transmit information between the components included in signal transmission device 200.

[0098] Memory 204 is used to store instructions. Instructions can be computer programs.

[0099] The memory 204 can be a read-only memory (ROM) or other type of static storage device that can store static information and / or instructions; it can also be a random access memory (RAM) or other type of dynamic storage device that can store information and / or instructions; it can also be an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, etc., without limitation.

[0100] It should be noted that the memory 204 can exist independently of the processor 201 or can be integrated with the processor 201. The memory 204 can be used to store instructions, program code, or some data, etc. The memory 204 can be located inside or outside the signal transmission device 200, without limitation. The processor 201 is used to execute the instructions stored in the memory 204 to implement the system or method provided in the embodiments of this disclosure.

[0101] In one example, processor 201 may include one or more CPUs, such as CPU0 and CPU1 in Figure 8.

[0102] In some implementations, the signal transmission device 200 includes multiple processors, for example, in addition to the processor 201 in FIG8, it may also include a processor 205.

[0103] It should be noted that the composition shown in Figure 8 does not constitute a limitation on the various devices in Figure 7. In addition to the components shown in Figure 8, the various devices in Figure 7 may include more or fewer components than those shown in Figure 8, or combine certain components, or have different component arrangements.

[0104] In this embodiment of the disclosure, the chip system may be composed of chips or may include chips and other discrete devices.

[0105] Furthermore, the actions, terms, etc., involved in the various embodiments of this disclosure can be referenced interchangeably without limitation. The message names or parameter names in the messages exchanged between the various devices in the embodiments of this disclosure are merely examples, and other names may be used in actual implementation without limitation.

[0106] To facilitate a clear description of the technical solutions of the embodiments of this disclosure, the terms "first" and "second" are used in the embodiments of this disclosure to distinguish identical or similar items with substantially the same function and effect. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and the terms "first" and "second" are not necessarily different.

[0107] It should be noted that in this disclosure, the terms "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in this disclosure should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0108] In this disclosure, "at least one" means one or more, and "more than one" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: only A; only B; and A and B, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can mean: only a, only b, or only c; a and b, a and c, or b and c; or a, b, and c, where the number of objects corresponding to a, b, and c can be single or multiple.

[0109] The transmission process in the signal transmission system provided in this embodiment of the present disclosure will now be described with reference to the signal transmission system shown in Figure 7. For example, the process may include the following S11-S20:

[0110] S11, the first optical conversion unit 15 sends multiple service signals to the third multiplexer / demultiplexer. Correspondingly, the third multiplexer / demultiplexer receives multiple service signals.

[0111] There are multiple first optical conversion units 15.

[0112] S12, the third multiplexer / demultiplexer, performs multiple signal multiplexing to obtain the multiplexed service signal.

[0113] S13, the third multiplexer / demultiplexer sends the combined service signal to the first multiplexer / demultiplexer 11 via a bidirectional optical amplifier.

[0114] S14. The time-frequency synchronization master station unit 13 sends a time-frequency synchronization signal to the third optical conversion unit 17. Correspondingly, the third optical conversion unit 17 receives the time-frequency synchronization signal.

[0115] S15, the third optical conversion unit 17 converts the received time-frequency synchronization signal (also known as fiber optic time synchronization signal) into a first wavelength and sends the first wavelength time-frequency synchronization signal to the first multiplexer / demultiplexer 11. Correspondingly, the first multiplexer / demultiplexer 11 receives the first wavelength time-frequency synchronization signal.

[0116] The time-frequency synchronization signal can be a second pulse signal. It can also be a signal generated by the time-frequency synchronization master station unit 13, such as satellite signals, atomic clock signals, or ground input reference signals.

[0117] S16, the first multiplexer / demultiplexer 11 performs multiplexing processing on the multiplexed service signal and the time-frequency synchronization signal of the first wavelength to obtain the multiplexed signal.

[0118] It should be noted that the first multiplexer 11 can perform multiplexing processing on the multiplexed service signal and the time-frequency synchronization signal of the first wavelength at the optical multiplex section (OMS) level to obtain the multiplexed signal.

[0119] S17. The first multiplexer / demultiplexer 11 sends a multiplexed signal to the second multiplexer / demultiplexer 12. Correspondingly, the second multiplexer / demultiplexer 12 receives the multiplexed signal.

[0120] S18 and the second multiplexer / demultiplexer 12 perform demultiplexing processing on the multiplexed signal to obtain the time-frequency synchronization signal and the multiplexed service signal.

[0121] S19. The second multiplexer / demultiplexer 12 sends a time-frequency synchronization signal to the time-frequency synchronization slave unit 14 and sends the multiplexed service signal to the fourth multiplexer / demultiplexer. Correspondingly, the time-frequency synchronization slave unit 14 receives the time-frequency synchronization signal, and the fourth multiplexer / demultiplexer receives the multiplexed service signal.

[0122] The type of time-frequency synchronization slave unit 14 can be set as needed. For example, it can be a terminal device, a computer, etc.

[0123] It should be noted that the time-frequency synchronization slave unit 14 can decode the time-frequency synchronization signal to obtain time code information, delay information, and second pulse position. Then, the time-frequency synchronization slave unit 14 can generate a high-precision PTP message using the time code information, delay information, and second pulse position, and can output the PTP message so that it can be used for time synchronization in the existing network. In this way, the time-frequency synchronization slave unit 14 can improve the time synchronization accuracy of PTP technology through the time-frequency synchronization signal.

[0124] PTP messages include various types of messages, such as PTP synchronization messages, broadcast messages, and delayed response messages.

[0125] S20 and the fourth multiplexer / demultiplexer 24 perform demultiplexing processing on the multiplexed service signals to obtain multiple service signals, and send multiple service signals to the second optical conversion unit 16.

[0126] The return process of service signals in the signal transmission system provided in this embodiment of the present disclosure will be described below with reference to the signal transmission system shown in Figure 7. For example, the process may include the following S21-S24:

[0127] S21. The second optical conversion unit 16 sends multiple service response signals to the fourth multiplexer / demultiplexer 24. Correspondingly, the fourth multiplexer / demultiplexer 24 receives multiple service response signals.

[0128] There are multiple first optical conversion units 15.

[0129] S22 and the fourth multiplexer / demultiplexer 24 perform multiplexing processing on multiple service response signals to obtain the multiplexed service response signal.

[0130] S23, the fourth multiplexer / demultiplexer 24 sends the multiplexed service response signal to the third multiplexer / demultiplexer 23 via an optical amplifier. Correspondingly, the third multiplexer / demultiplexer 23 receives the multiplexed service response signal.

[0131] S24, the third multiplexer / demultiplexer 23 demultiplexes the multiplexed service response signal to obtain multiple service response signals, and sends multiple service response signals to the first optical conversion unit 15.

[0132] The return process of the time-frequency synchronization signal in the signal transmission system provided in this embodiment of the present disclosure will be described below with reference to the signal transmission system shown in Figure 7. For example, the process may include the following S31-S34:

[0133] S31, the time-frequency synchronization master station unit 13 sends a time-frequency synchronization reply signal to the third optical conversion unit 17. Correspondingly, the third optical conversion unit 17 receives the time-frequency synchronization reply signal.

[0134] S32, the third optical conversion unit 17 converts the received time-frequency synchronization response signal wavelength into a first wavelength and sends the first wavelength time-frequency synchronization response signal to the second multiplexer / demultiplexer 12. Correspondingly, the second multiplexer / demultiplexer 12 receives the first wavelength time-frequency synchronization response signal.

[0135] S33. The second multiplexer / demultiplexer 12 sends a time-frequency synchronization response signal to the first multiplexer / demultiplexer 11 via a bidirectional optical amplifier. Correspondingly, the first multiplexer / demultiplexer 11 receives the time-frequency synchronization response signal.

[0136] S34, the first multiplexer / demultiplexer 11 sends multiple service signals to the time-frequency synchronization unit.

[0137] This disclosure embodiment can divide the signal transmission device into functional modules or functional units according to the above method examples. For example, each function can be divided into a separate functional module or functional unit, or two or more functions can be integrated into one processing module. The integrated module can be implemented in hardware or in software as a functional module or functional unit. The division of modules or units in this disclosure embodiment is illustrative and only represents one logical functional division; other division methods may be used in actual implementation.

[0138] This disclosure also provides a computer-readable storage medium. All or part of the processes in the above method embodiments can be implemented by a computer program instructing related hardware. This program can be stored in the computer-readable storage medium, and when executed, it can include the processes of the above method embodiments. The computer-readable storage medium can be an internal storage unit of the signal transmission device (including a data transmitter and / or a data receiver) of any of the foregoing embodiments, such as the hard disk or memory of the signal transmission device. The computer-readable storage medium can also be an external storage device of the terminal device, such as a plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, etc., equipped on the terminal device. Further, the computer-readable storage medium can include both the internal storage unit of the signal transmission device and an external storage device. The computer-readable storage medium is used to store the computer program and other programs and data required by the signal transmission device. The computer-readable storage medium can also be used to temporarily store data that has been output or will be output.

[0139] It should be noted that the terms "first" and "second," etc., in this disclosure, claims, and drawings are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may also include steps or units not listed, or may include other steps or units inherent to these processes, methods, products, or apparatuses.

[0140] It should be understood that in this disclosure, "at least one (item)" refers to one or more, "more than one" refers to two or more, "at least two (items)" refers to two or three or more, and "and / or" is used to describe the relationship between related objects, indicating that there can be three relationships. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the related objects before and after are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can mean: only a, only b, or only c; "a and b", "a and c", or "b and c"; or "a and b and c", where the number of objects corresponding to a, b, and c can be single or multiple.

[0141] Through the above description of the embodiments, those skilled in the art can clearly understand that, for the sake of convenience and brevity, only the division of the above functional modules is used as an example. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0142] In the several embodiments provided in this disclosure, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another device, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection of devices or units may be electrical, mechanical, or other forms.

[0143] The units described as separate components may or may not be physically separate. A component shown as a unit can be one or more physical units; that is, it can be located in one place or distributed in multiple different locations. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0144] Furthermore, the functional units in the various embodiments of this disclosure can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0145] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solutions of the embodiments of this disclosure, in essence, or the parts that contribute to the prior art, or all or part of the technical solutions, can be embodied in the form of a software product. This software product is stored in a storage medium and includes several instructions to cause a device (which may be a microcontroller, chip, etc.) or processor to execute all or part of the steps of the methods of the various embodiments of this disclosure. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM, RAM, magnetic disks, or optical disks.

[0146] The above are merely specific embodiments of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any changes or substitutions within the technical scope disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A signal transmission system, comprising a first multiplexer / demultiplexer, a second multiplexer / demultiplexer, a time-frequency synchronization master station unit, a time-frequency synchronization slave station unit, a first optical conversion unit, and a second optical conversion unit; The first input port of the first multiplexer / demultiplexer is connected to the time-frequency synchronization master station unit; the second input port of the first multiplexer / demultiplexer is connected to the first optical conversion unit; and the first output port of the first multiplexer / demultiplexer is connected to the first input port of the second multiplexer / demultiplexer. The first output port of the second multiplexer / demultiplexer is connected to the time-frequency synchronization slave unit; the second output port of the second multiplexer / demultiplexer is connected to the second optical conversion unit.

2. The system according to claim 1, wherein, The second combiner / demultiplexer also includes a second input port and a third output port; The second input port of the second multiplexer / demultiplexer is connected to the time-frequency synchronization slave unit; the third output port of the second multiplexer / demultiplexer is connected to the first multiplexer / demultiplexer.

3. The system according to claim 1, wherein, The first combiner / demultiplexer also includes a second output port; The second output port is connected to the time-frequency synchronization master station unit.

4. The system according to any one of claims 1-3, wherein, The time-frequency synchronization master station unit and the first multiplexer / demultiplexer also include a third optical conversion unit.

5. The system according to claim 4, wherein, The third optical conversion unit is used to convert the signal wavelength of the time-frequency synchronization master station unit into a first wavelength; the first wavelength is different from the wavelength of the service signal of the first optical conversion unit.

6. The system according to claim 1, wherein, The time-frequency synchronization master station unit and the time-frequency synchronization slave station unit are connected based on the first optical path; The first optical conversion unit and the second optical conversion unit are connected based on a second optical path; the second optical path includes the first optical path and a first symmetrical optical path.

7. The system according to claim 6, wherein, The first optical path also includes at least one bidirectional optical amplifier.

8. The system according to claim 6, wherein, The first symmetrical optical path includes at least one unidirectional optical amplifier.

9. The system according to claim 6, wherein, The system also includes a third multiplexer and a fourth multiplexer; the number of the first optical conversion unit and the second optical conversion unit is multiple; The third multiplexer / demultiplexer is located between the first optical conversion unit and the second optical path; The fourth combiner / demultiplexer is located between the second optical conversion unit and the second optical path.

10. The system according to claim 9, wherein, The multiplexing unit of the third multiplexer / demultiplexer is connected to the first optical path; the demultiplexing unit of the third multiplexer / demultiplexer is connected to the first symmetrical optical path. The demultiplexing unit of the fourth multiplexer is connected to the first optical path; the multiplexing unit of the fourth multiplexer is connected to the first symmetrical optical path.

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