Optical communication systems, methods and related devices

Abstract

This application discloses an optical communication system, method, and related apparatus, belonging to the field of communication technology. The central optical module includes a fixed-wavelength laser for generating multiple fixed-wavelength optical signals. The central optical module transmits composite downlink optical signals to multiple access-side optical modules. These composite downlink optical signals include multiple downlink optical signals of different downlink wavelengths generated by the fixed-wavelength laser, with different downlink wavelengths corresponding to different access-side optical modules. Each access-side optical module includes a tunable-wavelength laser for transmitting an uplink optical signal of its corresponding wavelength to the central optical module. Different access-side optical modules correspond to different uplink wavelengths. The central optical module also receives composite uplink optical signals, which include multiple uplink optical signals of different uplink wavelengths. This application enables the use of normalized access-side optical modules, reducing the difficulty of manufacturing and deploying access-side optical modules and simplifying network construction.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to an optical communication system, method and related apparatus. Background Technology

[0002] Optical communication refers to the transmission of optical signals carrying information via optical fibers. To ensure the quality of optical communication, optical fibers can be directly laid into users' rooms, thus achieving fiber-to-the-home (FTTH). In one FTTH scenario, optical fibers are laid into rooms on various floors within a campus, transmitting uplink and downlink information between access devices in the rooms and the central switch within the campus.

[0003] Access devices typically connect to a central switch via intermediate devices. A central switch can communicate optically with multiple access devices through intermediate devices. As an example, eight access devices form a group, connected to the same intermediate device via fiber optic cable. This intermediate device then connects to the central switch via fiber optic cable, thus enabling optical communication between this group of access devices and the central switch. A central switch can connect one or more groups of access devices through one or more intermediate devices.

[0004] Each access device has an optical module inserted (or integrated), and the central switch also has an optical module inserted (or integrated). The optical module generates and processes optical signals, serving as one of the bridges between the access devices and the central switch to achieve optical communication. For ease of distinction, the optical module inserted or integrated on the access device can be called the access-side optical module, and the optical module inserted or integrated on the central switch can be called the central optical module. Currently, wavelength division multiplexing (WDM) schemes can be used to achieve optical communication between multiple access-side optical modules and one central optical module. That is, different access-side optical modules on a group of access devices correspond to different uplink and downlink wavelengths, using the optical signals of the respective uplink and downlink wavelengths of multiple access-side optical modules to transmit their respective uplink and downlink information. In WDM schemes, the WDM interval is one of the factors affecting the reliability of optical communication and the difficulty of network deployment. A suitable WDM interval helps ensure the reliability of optical communication and reduces the difficulty of network deployment. Summary of the Invention

[0005] This application provides an optical communication system, method, and related apparatus, enabling the application of normalized access-side optical modules in campus scenarios, thereby simplifying the production and deployment of access-side optical modules. Furthermore, it reduces the implementation cost of access-side optical module normalization. The technical solution is as follows:

[0006] In a first aspect, an optical communication system is provided, comprising a central optical module and multiple access-side optical modules. The multiple access-side optical modules correspond to multiple uplink wavelengths and multiple downlink wavelengths. Different access-side optical modules correspond to different downlink wavelengths, and different access-side optical modules correspond to different uplink wavelengths. The central optical module is connected to the multiple access-side optical modules. The central optical module includes a fixed-wavelength laser for generating multiple fixed-wavelength optical signals, including the multiple downlink wavelengths. Each access-side optical module includes a tunable-wavelength laser (also referred to as a wavelength-tunable laser).

[0007] The central optical module is used to send a composite downlink optical signal to the plurality of access side optical modules. The composite downlink optical signal includes a plurality of downlink optical signals generated by the fixed wavelength laser, and the wavelengths of the plurality of downlink optical signals are the plurality of downlink wavelengths.

[0008] Each of the plurality of access-side optical modules is used to send an uplink optical signal corresponding to its own wavelength to the central optical module using the tunable wavelength laser.

[0009] The central optical module is also used to receive composite uplink optical signals, which include multiple uplink optical signals, and the wavelengths of the multiple uplink optical signals are the multiple uplink wavelengths.

[0010] In this application, the central optical module uses a fixed-wavelength laser, which is less expensive; the access-side optical modules use tunable-wavelength lasers, allowing multiple access-side optical modules to be normalized. During optical communication, each access-side optical module's tunable-wavelength laser emits an optical signal according to its corresponding uplink wavelength. The application of normalized access-side optical modules reduces the difficulty of their production and deployment.

[0011] In one possible implementation, the wavelength division multiplexing (WDM) spacing of the plurality of downlink wavelengths is greater than the wavelength division multiplexing (WDM) spacing of the plurality of uplink wavelengths. That is, this application can adopt a hybrid WDM scheme to balance cost and production / deployment difficulty.

[0012] In one possible implementation, the multiple downlink optical signals included in the composite downlink optical signal are transmitted using coarse wavelength division multiplexing (CWDM), and the multiple uplink optical signals included in the composite uplink optical signal are transmitted using dense wavelength division multiplexing (DWDM). That is, this application can employ a wavelength division multiplexing scheme that combines coarse and dense wavelength division multiplexing.

[0013] In one possible implementation, the wavelength division multiplexing (WDM) interval of the plurality of downlink wavelengths is greater than or equal to a first threshold, and the wavelength division multiplexing (WDM) interval of the plurality of uplink wavelengths is less than a second threshold, wherein the first threshold is greater than or equal to the second threshold.

[0014] In one possible implementation, the first threshold is 20 nanometers (nm) and the second threshold is 2.5 nm. A smaller second threshold can reduce the implementation cost of access-side optical module normalization.

[0015] As an example, the wavelength division multiplexing (WDM) spacing for multiple downlink wavelengths is 20 nm, and the wavelength division multiplexing (WDM) spacing for multiple uplink wavelengths is 2.4 nm.

[0016] In one possible implementation, the optical communication system further includes an intermediate device, which includes a first demultiplexer and a optical combiner. The intermediate device is connected to the central optical module via an optical fiber, and the intermediate device is also connected to the plurality of access-side optical modules via optical fibers.

[0017] The first demultiplexer is used to demultiplex the composite downlink optical signal received through the optical fiber to obtain multiple downlink optical signals, and based on the downlink wavelength of each of the multiple downlink optical signals obtained by demultiplexing, to send the corresponding downlink optical signals to the multiple access-side optical modules through the optical fiber.

[0018] The optical combining device is used to combine multiple uplink optical signals from the multiple access side optical modules to obtain a composite uplink optical signal, and then transmit the composite uplink optical signal to the central optical module through an optical fiber.

[0019] In one possible implementation, the intermediate device further includes at least one uplink interface and multiple downlink interfaces. The intermediate device is connected to the central optical module via the at least one uplink interface through an optical fiber, and the intermediate device is connected to the multiple access-side optical modules via the multiple downlink interfaces through optical fibers, respectively.

[0020] The intermediate device is used to receive the composite downlink optical signal and transmit the composite uplink optical signal through the at least one uplink interface;

[0021] The intermediate device is used to send corresponding downlink optical signals to the multiple access-side optical modules through the multiple downlink interfaces, wherein each downlink interface sends one downlink optical signal, and the downlink wavelengths of the optical signals sent by different downlink interfaces are different.

[0022] The intermediate device is used to receive corresponding uplink optical signals sent by the multiple access-side optical modules through the multiple downlink interfaces, wherein each of the multiple downlink interfaces receives one uplink optical signal, and the uplink wavelengths of the optical signals received by different downlink interfaces are different.

[0023] In one possible implementation, each of the plurality of downlink interfaces is connected to a single optical fiber. That is, the intermediate device and the access-side optical module are connected via a single fiber, thereby saving optical fiber resources and reducing the difficulty of optical fiber deployment.

[0024] To achieve a single-fiber connection between the intermediate device and the access-side optical module, in one possible implementation, the intermediate device further includes multiple first optical splitters. A first demultiplexer is connected to each of the multiple first optical splitters, and a optical combiner is also connected to each of the multiple first optical splitters. Each of the multiple first optical splitters is connected to one of the multiple downlink interfaces, and different first optical splitters are connected to different downlink interfaces. Each access-side optical module includes a second optical splitter, which is connected to one downlink interface of the intermediate device via an optical fiber. The second optical splitters in different access-side optical modules are connected to different downlink interfaces of the intermediate device. The second optical splitter in a first optical module of the multiple access-side optical modules is connected to a first downlink interface of the multiple downlink interfaces via a first optical fiber.

[0025] The first demultiplexer is specifically used to transmit a downlink optical signal to each of the plurality of first optical splitters, wherein each first optical splitter receives a downlink optical signal, and the downlink wavelengths of the optical signals received by different first optical splitters are different.

[0026] Each first optical splitter is used to transmit the downlink optical signal received by the first optical splitter to the downlink interface connected to the first optical splitter;

[0027] The first downlink interface is used to transmit the downlink wavelength optical signal received by the first downlink interface to the second optical splitter in the first optical module through the first optical fiber;

[0028] The second beam splitter in the first optical module is used to transmit the optical signal of the uplink wavelength corresponding to the first optical module to the first downlink interface through the first optical fiber;

[0029] Each downlink interface is also used to transmit the uplink optical signal received by the downlink interface to the first optical splitter connected to the downlink interface;

[0030] Each first beam splitter is also used to transmit the uplink optical signal received by the first beam splitter to the optical combining device;

[0031] The optical combining device is specifically used to receive the multiple uplink optical signals transmitted by the multiple first optical splitters and combine the multiple uplink optical signals transmitted by the multiple first optical splitters into the composite uplink optical signal.

[0032] In another possible implementation, each of the plurality of downlink interfaces includes a first sub-interface and a second sub-interface. The first demultiplexer is connected to the plurality of first sub-interfaces of the plurality of downlink interfaces, and the optical combining device is connected to the plurality of second sub-interfaces of the plurality of downlink interfaces. Different access-side optical modules of the plurality of access-side optical modules are connected to different downlink interfaces of the intermediate device via optical fibers. The first optical module of the plurality of access-side optical modules is connected to the first sub-interface and the second sub-interface of the first downlink interface of the plurality of downlink interfaces via different optical fibers.

[0033] The first demultiplexer is specifically used to transmit the multiple downlink optical signals to the multiple first sub-interfaces, wherein one first sub-interface receives one downlink optical signal, and the downlink wavelengths of the optical signals received by different first sub-interfaces are different;

[0034] The first sub-interface in the first downlink interface is used to transmit the downlink optical signal received by the first sub-interface to the first optical module through the connected optical fiber;

[0035] The second sub-interface in the first downlink interface is used to receive the optical signal of the uplink wavelength corresponding to the first optical module sent by the first optical module through the connected optical fiber;

[0036] The second sub-interface among the plurality of downlink interfaces is used to transmit the uplink wavelength optical signal received by this second sub-interface to the optical combining device;

[0037] The optical combining device is specifically used to combine the multiple uplink optical signals transmitted by the multiple second sub-interfaces into the composite uplink optical signal. That is, a dual-fiber connection is established between the intermediate device and the access-side optical module.

[0038] In one possible implementation, the optical combining device includes an optical coupler. That is, the intermediate device uses a combination of a demultiplexer and an optical coupler to transmit optical signals, which reduces the cost of the intermediate device while ensuring the reliability of optical communication.

[0039] In one possible implementation, the central optical module further includes a downlink interface connected to an optical fiber. That is, the central optical module has a single-fiber connection with the intermediate devices.

[0040] In the implementation method where single-fiber connections are used between the central optical module and intermediate devices, as well as between intermediate devices and access-side optical modules, the connection method between devices is relatively simple, the optical networking difficulty is low, and the amount of optical fiber used is small, thus saving optical fiber resources.

[0041] To achieve a single-fiber connection between the central optical module and intermediate devices, in one possible implementation, the central optical module further includes a fourth beam splitter, a first multiplexer, a second demultiplexer, and a photoelectric conversion device. The fourth beam splitter is connected to the downlink interface of the central optical module, and the fourth beam splitter is also connected to the first multiplexer and the second demultiplexer, respectively.

[0042] The fixed-wavelength laser is used to generate the plurality of downlink optical signals based on a plurality of first electrical signals, wherein the plurality of first electrical signals are electrical signals input from the routing switching equipment;

[0043] The first multiplexer is used to combine the multiple downlink optical signals into the composite downlink optical signal and transmit the composite downlink optical signal to the fourth optical splitter;

[0044] The fourth optical splitter is used to send the composite downlink optical signal through the downlink interface of the central optical module, and to receive the composite uplink optical signal transmitted on the connected optical fiber from the downlink interface of the central optical module, and to transmit the composite uplink optical signal to the second demultiplexer.

[0045] The second demultiplexer is used to receive the composite uplink optical signal transmitted by the fourth optical splitter and demultiplex the multiple uplink optical signals from the composite uplink optical signal;

[0046] The optoelectronic conversion device is used to convert the multiple uplink optical signals demultiplexed by the second demultiplexer into multiple second electrical signals, and output the multiple second electrical signals to the routing and switching equipment.

[0047] To achieve a single-fiber connection between the central optical module and intermediate devices, in another possible implementation, the central optical module further includes a second multiplexer, a third demultiplexer, and an optoelectronic conversion device. The second multiplexer is connected to the downlink interface of the central optical module, and the second multiplexer is also connected to the third demultiplexer.

[0048] The fixed-wavelength laser is used to generate the plurality of downlink optical signals based on a plurality of first electrical signals, wherein the plurality of first electrical signals are electrical signals input from the routing switching equipment;

[0049] The second multiplexer is used to combine the multiple downlink optical signals into the composite downlink optical signal, send the composite downlink optical signal through the downlink interface of the central optical module, receive the composite uplink optical signal transmitted on the optical fiber connected to the downlink interface of the central optical module, and transmit the composite uplink optical signal to the third demultiplexer.

[0050] The third demultiplexer is used to receive the composite uplink optical signal transmitted by the second demultiplexer, and demultiplex the plurality of uplink optical signals from the composite uplink optical signal;

[0051] The photoelectric conversion device is used to convert the multiple uplink optical signals demultiplexed by the third demultiplexer into multiple second electrical signals, and output the multiple second electrical signals to the routing and switching equipment.

[0052] To achieve a single-fiber connection between the central optical module and intermediate devices, in another possible implementation, the central optical module further includes a multiplexer / demultiplexer and an optoelectronic conversion device, wherein the multiplexer / demultiplexer is connected to the downlink interface of the central optical module;

[0053] The fixed-wavelength laser is used to generate the plurality of downlink optical signals based on a plurality of first electrical signals, wherein the plurality of first electrical signals are electrical signals input from the routing switching equipment;

[0054] The multiplexer / demultiplexer is used to combine the multiple downlink optical signals into the composite downlink optical signal, send the composite downlink optical signal through the downlink interface of the central optical module, and receive the composite uplink optical signal transmitted on the optical fiber connected to the downlink interface of the central optical module, and demultiplex the multiple uplink optical signals from the composite uplink optical signal.

[0055] The optoelectronic conversion device is used to convert multiple uplink optical signals demultiplexed by the multiplexer into multiple second electrical signals, and output the multiple second electrical signals to the routing and switching equipment.

[0056] To achieve a single-fiber connection between the central optical module and the intermediate device, in one possible implementation, the intermediate device further includes an uplink interface and a third optical splitter. The uplink interface is connected to the downlink interface of the central optical module via an optical fiber, and the third optical splitter is connected to the uplink interface, the first demultiplexer, and the optical combining device, respectively.

[0057] The third optical splitter is used to receive the composite downlink optical signal sent by the central optical module through the uplink interface, and to transmit the composite downlink optical signal to the first demultiplexer;

[0058] The third beam splitter is also used to receive the composite uplink optical signal transmitted by the beam combining device, and to send the composite uplink optical signal to the central optical module through the uplink interface.

[0059] In another possible implementation, the central optical module further includes a second downlink interface, a third downlink interface, a first multiplexer, a second demultiplexer, and an optoelectronic conversion device, wherein the first multiplexer is connected to the second downlink interface, and the second demultiplexer is connected to the third downlink interface;

[0060] The fixed-wavelength laser is used to generate the plurality of downlink optical signals based on a plurality of first electrical signals, wherein the plurality of first electrical signals are electrical signals input from the routing switching equipment;

[0061] The first multiplexer is used to combine the multiple downlink optical signals into the composite downlink optical signal, and to send the combined composite downlink optical signal through the second downlink interface;

[0062] The second demultiplexer is used to demultiplex the multiple uplink optical signals from the composite uplink optical signal received from the third downlink interface;

[0063] The photoelectric conversion device is used to convert the plurality of uplink optical signals into a plurality of second electrical signals, and output the plurality of second electrical signals to the routing and switching equipment. That is, there is a two-fiber connection between the central optical module and the intermediate equipment.

[0064] To achieve a dual-fiber connection between the central optical module and the intermediate device, in one possible implementation, the intermediate device includes a first uplink interface and a second uplink interface, wherein the first uplink interface is connected to the second downlink interface of the central optical module, and the second uplink interface is connected to the third downlink interface of the central optical module via optical fibers.

[0065] The first demultiplexer is used to receive the composite downlink optical signal sent by the central optical module through the first uplink interface;

[0066] The optical combining device is used to send the composite uplink optical signal to the central optical module through the second uplink interface.

[0067] In one possible implementation, each access-side optical module further includes a photoelectric converter capable of processing optical signals of different downlink wavelengths;

[0068] The tunable wavelength laser is used to generate an uplink wavelength optical signal corresponding to the optical module on this access side based on a third electrical signal, wherein the third electrical signal is an electrical signal input by the access device.

[0069] The photoelectric converter is used to perform photoelectric conversion on the downlink wavelength optical signal received by the access side optical module to which the photoelectric converter belongs, thereby obtaining a fourth electrical signal, and outputting the fourth electrical signal to the access device.

[0070] In one possible implementation, the central optical module is integrated with or inserted into a routing and switching device, and the optical signal of the downlink wavelength carries downlink information transmitted by the routing and switching device; and / or,

[0071] Each of the plurality of access-side optical modules is integrated into or inserted into the access device, and the uplink wavelength optical signal carries the uplink information sent by the access device.

[0072] The downlink information includes downlink commands and / or downlink data; the uplink information includes uplink responses and / or uplink data.

[0073] Secondly, an optical communication method is provided. The optical communication system includes multiple access-side optical modules, each corresponding to a multiple uplink wavelength and a multiple downlink wavelength. Different access-side optical modules correspond to different downlink wavelengths, and different access-side optical modules correspond to different uplink wavelengths. The wavelength division multiplexing (WDM) interval of the multiple downlink wavelengths is greater than the WDM interval of the multiple uplink wavelengths. The method is applied to a first optical module among the multiple access-side optical modules, where the first optical module is any one of the multiple access-side optical modules. The method includes:

[0074] Receive downlink optical signals, wherein the wavelength of the downlink optical signals is the first downlink wavelength corresponding to the first optical module;

[0075] An uplink optical signal is generated and transmitted, wherein the wavelength of the uplink optical signal is the first uplink wavelength corresponding to the first optical module.

[0076] In one possible implementation, the wavelength division spacing of the plurality of downlink wavelengths is determined based on coarse wavelength division multiplexing (CWDM), and the wavelength division spacing of the plurality of uplink wavelengths is determined based on dense wavelength division multiplexing (DWDM).

[0077] In one possible implementation, the wavelength division multiplexing (WDM) interval of the plurality of downlink wavelengths is greater than or equal to a first threshold, and the wavelength division multiplexing (WDM) interval of the plurality of uplink wavelengths is less than a second threshold, wherein the first threshold is greater than or equal to the second threshold.

[0078] In one possible implementation, the first threshold is 20 nanometers and the second threshold is 2.5 nanometers.

[0079] In one possible implementation, the first optical module includes a photoelectric converter and a tunable wavelength laser, the photoelectric converter having the ability to process optical signals of different downlink wavelengths, and the tunable wavelength laser having the ability to generate optical signals of different uplink wavelengths; the method further includes:

[0080] The photoelectric converter performs photoelectric conversion on the downlink optical signal to obtain a first electrical signal;

[0081] The generation and transmission of the uplink optical signal includes:

[0082] The tunable wavelength laser generates and transmits the uplink optical signal.

[0083] In one possible implementation, the first optical module is integrated into or inserted into a first access device, the downlink optical signal carries downlink information transmitted to the first access device, and after the photoelectric converter performs photoelectric conversion on the downlink optical signal to obtain a first electrical signal, the method further includes:

[0084] The photoelectric converter transmits the first electrical signal to the first access device;

[0085] Before the tunable wavelength laser generates and transmits the uplink optical signal, the method further includes:

[0086] The system receives a second electrical signal transmitted by the first access device, wherein the uplink optical signal carries uplink information sent by the first access device through the second electrical signal.

[0087] In one possible implementation, the first optical module includes an uplink interface and a beam splitter, the uplink interface being connected to a first optical fiber and the beam splitter being connected to the uplink interface;

[0088] The receiving of downlink optical signals includes:

[0089] The beam splitter receives the downlink optical signal transmitted through the first optical fiber via the uplink interface and transmits the downlink optical signal to the photoelectric converter;

[0090] The transmission of the uplink optical signal includes:

[0091] The beam splitter transmits the uplink optical signal generated by the tunable wavelength laser to the first optical fiber through the uplink interface.

[0092] In one possible implementation, the first optical module includes a first uplink interface and a second uplink interface, the first uplink interface and the second uplink interface being connected to different optical fibers respectively;

[0093] The receiving of downlink optical signals includes:

[0094] The first uplink interface receives the downlink optical signal transmitted on the connected optical fiber and transmits the downlink optical signal to the photoelectric converter;

[0095] The transmission of the uplink optical signal includes:

[0096] The second uplink interface transmits the uplink optical signal generated by the tunable wavelength laser through the connected optical fiber.

[0097] In one possible implementation, the tunable wavelength laser employs a distributed Bragg reflector (DBR) laser, an electroabsorption (EA) modulated DBR laser, a Littman tunable external cavity semiconductor laser (TECDL), a Littman-Metcalf TECDL, a fiber Bragg grating tunable external cavity semiconductor laser (FBG-TECDL), a micro-ring (MRR) tunable laser, a fully integrated tunable laser based on a semiconductor optical amplifier (SOA), a Fabry-Pérot (FP) laser, a distributed feedback (DFB) laser array, or a transmitter optical subassembly (TOSA) with self-locking or injection-locking methods to achieve wavelength adjustment.

[0098] In one possible implementation, the photoelectric converter uses a P-type semiconductor-negative-N-type semiconductor (positive-intrinsic-negative, PIN), an avalanche photodiode (APD), or an SOA-PIN integrated photodetector to achieve photoelectric conversion.

[0099] Thirdly, an optical communication method is provided, the method being applied to a central optical module in an optical communication system. The optical communication system further includes multiple access-side optical modules, each corresponding to a multiple uplink wavelength and a multiple downlink wavelength. Different access-side optical modules among the multiple access-side optical modules correspond to different downlink wavelengths, and different access-side optical modules among the multiple access-side optical modules correspond to different uplink wavelengths. The central optical module includes a fixed-wavelength laser, which is used to generate optical signals of multiple fixed wavelengths, including the multiple downlink wavelengths. The method includes:

[0100] Multiple downlink optical signals are transmitted, wherein the multiple downlink optical signals are generated by the fixed-wavelength laser, and the wavelengths of the multiple downlink optical signals are the multiple downlink wavelengths;

[0101] Receive multiple uplink optical signals, wherein the wavelengths of the multiple uplink optical signals are the multiple uplink wavelengths;

[0102] The wavelength division multiplexing interval of the plurality of downlink wavelengths is greater than the wavelength division multiplexing interval of the plurality of uplink wavelengths.

[0103] In one possible implementation, the plurality of downlink optical signals are transmitted using coarse wavelength division multiplexing (CWDM), and the plurality of uplink optical signals are transmitted using dense wavelength division multiplexing (DWDM).

[0104] In one possible implementation, the wavelength division multiplexing (WDM) interval of the plurality of downlink wavelengths is greater than or equal to a first threshold, and the wavelength division multiplexing (WDM) interval of the plurality of uplink wavelengths is less than a second threshold, wherein the first threshold is greater than or equal to the second threshold.

[0105] In one possible implementation, the first threshold is 20 nanometers and the second threshold is 2.5 nanometers.

[0106] In one possible implementation, the central optical module further includes a multiplexer and at least one downlink interface connected to an optical fiber;

[0107] The transmission of multiple downlink optical signals includes:

[0108] The multiplexer combines the multiple downlink optical signals generated by the fixed-wavelength laser into a composite downlink optical signal, and sends the composite downlink optical signal through the downlink interface.

[0109] In one possible implementation, the central optical module is integrated into or inserted into the routing and switching equipment;

[0110] The fixed-wavelength laser generates the plurality of downlink optical signals based on the plurality of first electrical signals input by the routing switching device. The plurality of downlink optical signals carry downlink information sent by the routing switching device through the plurality of first electrical signals. The plurality of first electrical signals correspond one-to-one with the plurality of access-side optical modules. The downlink information includes information sent to the plurality of access-side optical modules.

[0111] In one possible implementation, the central optical module further includes an optoelectronic conversion device and a demultiplexer;

[0112] The receiving of multiple uplink optical signals includes:

[0113] The composite uplink optical signal is received through the downlink interface;

[0114] The demultiplexer demultiplexes the composite uplink optical signal to extract the plurality of uplink optical signals, and the plurality of uplink optical signals carry uplink information sent by the plurality of access-side optical modules to the routing and switching device;

[0115] The method further includes:

[0116] The photoelectric conversion device performs photoelectric conversion on the multiple uplink optical signals respectively, thereby obtaining multiple second electrical signals;

[0117] The plurality of second electrical signals are sent to the routing and switching device.

[0118] In one possible implementation, the central optical module includes a downlink interface and a beam splitter, the beam splitter being connected to the multiplexer and the demultiplexer respectively, and the beam splitter being connected to the downlink interface;

[0119] The step of transmitting the composite downlink optical signal through the downlink interface includes:

[0120] The multiplexer transmits the composite downlink optical signal to the beam splitter, and the beam splitter sends the composite downlink optical signal to the downlink interface;

[0121] The receiving of composite uplink optical signals through the downlink interface includes:

[0122] The optical splitter receives the composite uplink optical signal transmitted on the connected optical fiber through the downlink interface and transmits the composite uplink optical signal to the demultiplexer.

[0123] In one possible implementation, the central optical module includes a downlink interface, the multiplexer is connected to the demultiplexer, and the multiplexer is also connected to the downlink interface;

[0124] The step of transmitting the composite downlink optical signal through the downlink interface includes:

[0125] The multiplexer sends the composite downlink optical signal to the downlink interface;

[0126] The receiving of composite uplink optical signals through the downlink interface includes:

[0127] The multiplexer receives the composite uplink optical signal transmitted on the connected optical fiber through the downlink interface and transmits the composite uplink optical signal to the demultiplexer.

[0128] In one possible implementation, the central optical module includes a downlink interface and an optoelectronic conversion device, and the multiplexer is connected to the downlink interface;

[0129] The step of transmitting the composite downlink optical signal through the downlink interface includes:

[0130] The multiplexer sends the composite downlink optical signal to the downlink interface;

[0131] The receiving of composite uplink optical signals through the downlink interface includes:

[0132] The multiplexer receives the composite uplink optical signal transmitted on the connected optical fiber through the downlink interface;

[0133] After the multiplexer receives the composite uplink optical signal transmitted on the connected optical fiber through the downlink interface, the method further includes:

[0134] The multiplexer demultiplexes the composite uplink optical signal to obtain the plurality of uplink optical signals, and the plurality of uplink optical signals carry uplink information sent by the plurality of access-side optical modules to the routing and switching equipment;

[0135] The photoelectric conversion device performs photoelectric conversion on the multiple uplink optical signals respectively, thereby obtaining multiple second electrical signals;

[0136] The plurality of second electrical signals are sent to the routing and switching device.

[0137] In one possible implementation, the central optical module further includes a first downlink interface and a second downlink interface, the multiplexer is connected to the first downlink interface, the demultiplexer is connected to the second downlink interface, and the first downlink interface and the second downlink interface are respectively connected to different optical fibers;

[0138] The step of transmitting the composite downlink optical signal through the downlink interface includes:

[0139] The multiplexer transmits the composite downlink optical signal through the first downlink interface it is connected to;

[0140] The receiving of composite uplink optical signals through the downlink interface includes:

[0141] The demultiplexer receives the composite uplink optical signal through the connected second downlink interface.

[0142] Fourthly, an optical communication method is provided, the method being applied to an intermediate device included in an optical communication system. The optical communication system further includes multiple access-side optical modules, each corresponding to multiple uplink wavelengths and multiple downlink wavelengths. Different access-side optical modules among the multiple access-side optical modules correspond to different downlink wavelengths, and different access-side optical modules among the multiple access-side optical modules correspond to different uplink wavelengths. The intermediate device includes a demultiplexer and an optical coupler. The method includes:

[0143] Receive a composite downlink optical signal, wherein the composite downlink optical signal comprises multiple downlink optical signals;

[0144] The multiple downlink optical signals are demultiplexed from the composite downlink optical signal using the demultiplexer.

[0145] Based on the downlink wavelength of each of the multiple downlink optical signals obtained by demultiplexing, the corresponding downlink optical signals are sent to the multiple access-side optical modules.

[0146] The optical coupler combines multiple uplink optical signals from the multiple access-side optical modules to obtain a composite uplink optical signal.

[0147] The composite uplink optical signal is transmitted.

[0148] In one possible implementation, the wavelength division multiplexing (WDM) interval of the plurality of downlink wavelengths is greater than the wavelength division multiplexing (WDM) interval of the plurality of uplink wavelengths.

[0149] In one possible implementation, the multiple downlink optical signals included in the composite downlink optical signal are transmitted based on coarse wavelength division multiplexing (CWDM), and the multiple uplink optical signals included in the composite uplink optical signal are transmitted based on dense wavelength division multiplexing (DWDM).

[0150] In one possible implementation, the intermediate device further includes at least one uplink interface and multiple downlink interfaces, wherein the uplink interface and the downlink interface are respectively connected to optical fibers;

[0151] The composite downlink optical signal is received and the composite uplink optical signal is transmitted through the at least one uplink interface;

[0152] The downlink optical signals are sent to the multiple access-side optical modules through the multiple downlink interfaces, wherein each downlink interface sends an optical signal of a downlink wavelength, and the downlink wavelengths of the optical signals sent by different downlink interfaces are different.

[0153] The multiple downlink interfaces receive corresponding uplink optical signals sent by the multiple access-side optical modules. Each downlink interface receives an optical signal of a downlink wavelength, and the uplink wavelengths of the optical signals received by different downlink interfaces are different.

[0154] In one possible implementation, each of the uplink and downlink interfaces is connected to an optical fiber.

[0155] In one possible implementation, the intermediate device further includes a plurality of first beam splitters, the demultiplexer is connected to the plurality of first beam splitters respectively, the optical coupler is connected to the plurality of first beam splitters respectively, each of the plurality of first beam splitters is connected to one of the plurality of downlink interfaces, and different first beam splitters are connected to different downlink interfaces;

[0156] The step of sending corresponding downlink optical signals to the multiple access-side optical modules through the multiple downlink interfaces includes:

[0157] The demultiplexer transmits a downlink optical signal to each of the plurality of first optical splitters, wherein each first optical splitter receives one downlink optical signal, and the downlink wavelengths of the optical signals received by different first optical splitters are different.

[0158] The plurality of first optical splitters respectively transmit their respective received downlink optical signals to their respective connected downlink interfaces;

[0159] Each of the plurality of downlink interfaces transmits its received downlink optical signal through its respective connected optical fiber;

[0160] Before combining multiple uplink optical signals from the plurality of access-side optical modules through the optical coupler to obtain a composite uplink optical signal, the method further includes:

[0161] Each of the plurality of downlink interfaces receives the uplink optical signal transmitted by the optical fiber to which it is connected. Each downlink interface receives one uplink optical signal, and the downlink wavelengths of the optical signals received by different downlink interfaces are different.

[0162] Each of the plurality of downlink interfaces transmits its received uplink optical signal to the first optical splitter to which it is connected;

[0163] The plurality of first beam splitters respectively transmit their respective received uplink optical signals to the optical coupler.

[0164] In one possible implementation, each of the plurality of downlink interfaces includes a first sub-interface and a second sub-interface, the demultiplexer is connected to the plurality of first sub-interfaces of the plurality of downlink interfaces respectively, the optical coupler is connected to the plurality of second sub-interfaces of the plurality of downlink interfaces respectively, and the second sub-interface and the first sub-interface of each downlink interface are respectively connected to different optical fibers;

[0165] The step of sending corresponding downlink optical signals to the multiple access-side optical modules through the multiple downlink interfaces includes:

[0166] The demultiplexer transmits the multiple downlink optical signals to the multiple first sub-interfaces, wherein each first sub-interface receives one downlink optical signal, and the downlink wavelengths of the optical signals received by different first sub-interfaces are different.

[0167] The first sub-interface in each downlink interface transmits the downlink optical signal received by the first sub-interface through the connected optical fiber;

[0168] The step of receiving the corresponding uplink optical signals sent by the multiple access-side optical modules through the multiple downlink interfaces includes:

[0169] The second sub-interface of the plurality of downlink interfaces receives the uplink optical signal transmitted by the optical fiber connected to the second sub-interface, and transmits the uplink optical signal received by the second sub-interface to the optical coupler.

[0170] In one possible implementation, the intermediate device includes an uplink interface and a second optical splitter, the uplink interface being connected to an optical fiber, and the second optical splitter being connected to the uplink interface, the demultiplexer, and the optical coupler, respectively.

[0171] Receiving the composite downlink optical signal through the at least one uplink interface includes:

[0172] The uplink interface receives the composite downlink optical signal transmitted through the connected optical fiber and transmits the received composite downlink optical signal to the second optical splitter.

[0173] The second beam splitter sends the composite downlink optical signal to the demultiplexer;

[0174] Transmitting the composite uplink optical signal through the at least one uplink interface includes:

[0175] The optical coupler transmits the composite uplink optical signal to the second beam splitter;

[0176] The second beam splitter transmits the composite uplink optical signal to the uplink interface;

[0177] The uplink interface transmits the composite uplink optical signal through the connected optical fiber.

[0178] In one possible implementation, the intermediate device includes a first uplink interface and a second uplink interface, the first uplink interface and the second uplink interface being connected to different optical fibers respectively, the demultiplexer being connected to the first uplink interface, and the optical coupler being connected to the second uplink interface.

[0179] Receiving the composite downlink optical signal through the at least one uplink interface includes:

[0180] The first uplink interface receives the composite downlink optical signal transmitted on the connected optical fiber;

[0181] The first uplink interface transmits the composite downlink optical signal to the demultiplexer;

[0182] The step of transmitting the composite uplink optical signal through the at least one uplink interface includes:

[0183] The optical coupler transmits the composite uplink optical signal to the second uplink interface;

[0184] The second uplink interface sends the composite uplink optical signal to the connected optical fiber.

[0185] Fifthly, a communication device is provided, which has the function of implementing the optical communication method described in the second aspect above. That is, the communication device can be the first optical module described in the second aspect above. The communication device includes one or more modules for implementing the optical communication method provided in the second aspect above.

[0186] That is, a first optical module is provided, which is any one of multiple access-side optical modules included in the optical communication system. The multiple access-side optical modules correspond to multiple uplink wavelengths and multiple downlink wavelengths. Different access-side optical modules correspond to different downlink wavelengths, and different access-side optical modules correspond to different uplink wavelengths. The wavelength division multiplexing (WDM) interval of the multiple downlink wavelengths is greater than the wavelength division multiplexing (WDM) interval of the multiple uplink wavelengths. The first optical module includes an optical fiber interface, an optical receiving component, and an optical transmitting component.

[0187] The optical receiving component is used to receive the downlink optical signal transmitted by the optical fiber interface, and the wavelength of the downlink optical signal is the first downlink wavelength corresponding to the first optical module.

[0188] The optical transmitting component is used to generate an uplink optical signal and transmit the uplink optical signal through the optical fiber interface. The wavelength of the uplink optical signal is the first uplink wavelength corresponding to the first optical module.

[0189] In one possible implementation, the wavelength division spacing of the plurality of downlink wavelengths is determined based on coarse wavelength division multiplexing (CWDM), and the wavelength division spacing of the plurality of uplink wavelengths is determined based on dense wavelength division multiplexing (DWDM).

[0190] In one possible implementation, the wavelength division interval of the plurality of downlink wavelengths is greater than or equal to a first threshold, and the wavelength division interval of the plurality of uplink wavelengths is less than a second threshold, wherein the first threshold is greater than or equal to the second threshold.

[0191] In one possible implementation, the first threshold is 20 nanometers and the second threshold is 2.5 nanometers.

[0192] In one possible implementation, the optical receiving component includes a photoelectric converter, the optical emitting component includes a tunable wavelength laser, the photoelectric converter has the ability to process optical signals of different downlink wavelengths, and the tunable wavelength laser has the ability to generate optical signals of different uplink wavelengths;

[0193] The photoelectric converter is used to perform photoelectric conversion on the downlink optical signal to obtain a first electrical signal;

[0194] The tunable wavelength laser is used to generate and transmit the uplink optical signal through the optical fiber interface.

[0195] In one possible implementation, the first optical module is integrated into or inserted into the first access device, and the downlink optical signal carries downlink information transmitted to the first access device;

[0196] The photoelectric converter is also used to transmit the first electrical signal to the first access device;

[0197] The tunable wavelength laser is also used to receive a second electrical signal transmitted by the first access device, and the uplink optical signal carries uplink information sent by the first access device through the second electrical signal.

[0198] In one possible implementation, the fiber optic interface includes an uplink interface, the first optical module further includes a beam splitter, the uplink interface is connected to the first optical fiber, and the beam splitter is connected to the uplink interface;

[0199] The beam splitter is used to receive the downlink optical signal transmitted through the first optical fiber via the uplink interface and to transmit the downlink optical signal to the photoelectric converter.

[0200] The beam splitter is also used to transmit the uplink optical signal generated by the tunable wavelength laser to the first optical fiber through the uplink interface.

[0201] In one possible implementation, the fiber optic interface includes a first uplink interface and a second uplink interface, wherein the first uplink interface and the second uplink interface are respectively connected to different optical fibers;

[0202] The first uplink interface is used to receive the downlink optical signal transmitted on the connected optical fiber and transmit the downlink optical signal to the photoelectric converter;

[0203] The second uplink interface is used to transmit the uplink optical signal generated by the tunable wavelength laser through the connected optical fiber.

[0204] In one possible implementation, the tunable wavelength laser uses a DBR laser, an EA-modulated DBR laser, a Littman structure TECDL, a Littman-Metcalf structure TECDL, an FBG-TECDL, an MRR tunable laser, a fully integrated tunable laser based on SOA, an FP laser, a DFB laser array, or a TOSA self-locking or injection-locking method to achieve adjustment of the emission wavelength.

[0205] In one possible implementation, the photoelectric converter uses a PIN, APD, or SOA-PIN integrated photodetector to achieve photoelectric conversion.

[0206] Sixthly, a communication device is provided, which has the function of implementing the optical communication method described in the third aspect above. That is, the communication device can be the central optical module described in the third aspect above. The communication device includes one or more modules for implementing the optical communication method provided in the third aspect above.

[0207] That is, a central optical module is provided, which is included in an optical communication system. The optical communication system also includes multiple access-side optical modules, which correspond to multiple uplink wavelengths and multiple downlink wavelengths. Different access-side optical modules correspond to different downlink wavelengths, and different access-side optical modules correspond to different uplink wavelengths. The central optical module includes a fixed-wavelength laser for generating multiple fixed-wavelength optical signals, including the multiple downlink wavelengths. The central optical module also includes an optical fiber interface, an optical transmitting component, and an optical receiving component.

[0208] The optical transmitting component is used to transmit multiple downlink optical signals through the optical fiber interface. The multiple downlink optical signals are generated by the fixed wavelength laser, and the wavelengths of the multiple downlink optical signals are the multiple downlink wavelengths.

[0209] The optical receiving component is used to receive multiple uplink optical signals through the optical fiber interface, wherein the wavelengths of the multiple uplink optical signals are the multiple uplink wavelengths;

[0210] The wavelength division multiplexing interval of the plurality of downlink wavelengths is greater than the wavelength division multiplexing interval of the plurality of uplink wavelengths.

[0211] In one possible implementation, the plurality of downlink optical signals are transmitted using coarse wavelength division multiplexing (CWDM), and the plurality of uplink optical signals are transmitted using dense wavelength division multiplexing (DWDM).

[0212] In one possible implementation, the wavelength division multiplexing (WDM) interval of the plurality of downlink wavelengths is greater than or equal to a first threshold, and the wavelength division multiplexing (WDM) interval of the plurality of uplink wavelengths is less than a second threshold, wherein the first threshold is greater than or equal to the second threshold.

[0213] In one possible implementation, the first threshold is 20 nanometers and the second threshold is 2.5 nanometers.

[0214] In one possible implementation, the optical transmitting component includes a multiplexer, and the optical fiber interface includes at least one downlink interface connected to an optical fiber;

[0215] The multiplexer is used to combine the multiple downlink optical signals generated by the fixed-wavelength laser into a composite downlink optical signal, and transmit the composite downlink optical signal through the downlink interface.

[0216] In one possible implementation, the central optical module is integrated into or inserted into the routing and switching equipment;

[0217] The fixed-wavelength laser is used to generate the plurality of downlink optical signals based on the plurality of first electrical signals input by the routing switching device. The plurality of downlink optical signals carry downlink information sent by the routing switching device through the plurality of first electrical signals. The plurality of first electrical signals correspond one-to-one with the plurality of access-side optical modules. The downlink information includes information sent to the plurality of access-side optical modules.

[0218] In one possible implementation, the optical receiving component includes a demultiplexer, and the central optical module further includes a photoelectric conversion device;

[0219] The demultiplexer is used to receive composite uplink optical signals through the downlink interface;

[0220] The demultiplexer is further configured to demultiplex the plurality of uplink optical signals from the composite uplink optical signal, wherein the plurality of uplink optical signals carry uplink information sent by the plurality of access-side optical modules to the routing and switching device;

[0221] The photoelectric conversion device is used to perform photoelectric conversion on the plurality of uplink optical signals respectively to obtain a plurality of second electrical signals, and to send the plurality of second electrical signals to the routing switching device.

[0222] In one possible implementation, the at least one downlink interface includes a downlink interface, and the central optical module further includes a beam splitter, which is connected to the multiplexer and the demultiplexer respectively, and the beam splitter is also connected to the downlink interface;

[0223] The multiplexer is used to transmit the composite downlink optical signal to the beam splitter;

[0224] The beam splitter is used to send the composite downlink optical signal to the downlink interface;

[0225] The optical splitter is also used to receive the composite uplink optical signal transmitted on the connected optical fiber through the downlink interface, and to transmit the composite uplink optical signal to the demultiplexer.

[0226] In one possible implementation, the at least one downlink interface includes a downlink interface, the multiplexer is connected to the demultiplexer, and the multiplexer is also connected to the downlink interface;

[0227] The multiplexer is used to send the composite downlink optical signal to the downlink interface;

[0228] The multiplexer is also used to receive composite uplink optical signals transmitted on the connected optical fiber through the downlink interface, and to transmit the composite uplink optical signals to the demultiplexer.

[0229] In one possible implementation, the at least one downlink interface includes a downlink interface, the central optical module further includes an optoelectronic conversion device, and the multiplexer is connected to the downlink interface;

[0230] The multiplexer is used to send the composite downlink optical signal to the downlink interface;

[0231] The multiplexer is also used to receive composite uplink optical signals transmitted on the connected optical fiber through the downlink interface;

[0232] The multiplexer is further configured to demultiplex the multiple uplink optical signals from the composite uplink optical signal, the multiple uplink optical signals carrying uplink information sent by the multiple access-side optical modules to the routing and switching device;

[0233] The photoelectric conversion device is used to perform photoelectric conversion on the plurality of uplink optical signals respectively to obtain a plurality of second electrical signals, and to send the plurality of second electrical signals to the routing switching device.

[0234] In one possible implementation, the at least one downlink interface includes a first downlink interface and a second downlink interface, the multiplexer is connected to the first downlink interface, the demultiplexer is connected to the second downlink interface, and the first downlink interface and the second downlink interface are respectively connected to different optical fibers;

[0235] The multiplexer is used to transmit the composite downlink optical signal through the connected first downlink interface;

[0236] The demultiplexer is used to receive the composite uplink optical signal through the connected second downlink interface.

[0237] In a seventh aspect, a communication device is provided, which has the function of implementing the optical communication method described in the fourth aspect above. That is, the communication device can be an intermediate device as described in the fourth aspect above. The communication device includes one or more modules for implementing the optical communication method provided in the fourth aspect above.

[0238] That is, an intermediate device is provided, which is included in an optical communication system. The optical communication system further includes multiple access-side optical modules, which correspond to multiple uplink wavelengths and multiple downlink wavelengths. Different access-side optical modules in the multiple access-side optical modules correspond to different downlink wavelengths, and different access-side optical modules in the multiple access-side optical modules correspond to different uplink wavelengths. The intermediate device includes an optical fiber interface, a demultiplexer, and an optical coupler.

[0239] The fiber optic interface is used to receive composite downlink optical signals, which include multiple downlink optical signals;

[0240] The demultiplexer is used to demultiplex the multiple downlink optical signals from the composite downlink optical signal, and send the corresponding downlink optical signals to the multiple access side optical modules based on the downlink wavelengths of the multiple downlink optical signals obtained by demultiplexing.

[0241] The optical coupler is used to combine multiple uplink optical signals from the multiple access side optical modules to obtain a composite uplink optical signal;

[0242] The fiber optic interface is also used to transmit the composite uplink optical signal.

[0243] In one possible implementation, the wavelength division multiplexing (WDM) interval of the plurality of downlink wavelengths is greater than the wavelength division multiplexing (WDM) interval of the plurality of uplink wavelengths.

[0244] In one possible implementation, the multiple downlink optical signals included in the composite downlink optical signal are transmitted based on coarse wavelength division multiplexing (CWDM), and the multiple uplink optical signals included in the composite uplink optical signal are transmitted based on dense wavelength division multiplexing (DWDM).

[0245] In one possible implementation, the fiber optic interface includes at least one uplink interface and multiple downlink interfaces, wherein the uplink interface and the downlink interface are respectively connected to optical fibers;

[0246] The at least one uplink interface is used to receive the composite downlink optical signal and transmit the composite uplink optical signal;

[0247] The plurality of downlink interfaces are used to send corresponding downlink optical signals to the plurality of access-side optical modules, wherein each downlink interface sends an optical signal of a downlink wavelength, and the downlink wavelengths of the optical signals sent by different downlink interfaces are different;

[0248] The plurality of downlink interfaces are also used to receive corresponding uplink optical signals sent by the plurality of access-side optical modules, wherein each of the plurality of downlink interfaces receives an optical signal of a downlink wavelength, and the uplink wavelengths of the optical signals received by different downlink interfaces are different.

[0249] In one possible implementation, each of the uplink and downlink interfaces is connected to an optical fiber.

[0250] In one possible implementation, the intermediate device further includes a plurality of first beam splitters, the demultiplexer is connected to the plurality of first beam splitters respectively, the optical coupler is connected to the plurality of first beam splitters respectively, each of the plurality of first beam splitters is connected to one of the plurality of downlink interfaces, and different first beam splitters are connected to different downlink interfaces;

[0251] The demultiplexer is used to transmit a downlink optical signal to each of the plurality of first optical splitters, wherein each first optical splitter receives one downlink optical signal, and the downlink wavelengths of the optical signals received by different first optical splitters are different.

[0252] The plurality of first optical splitters are used to transmit their respective received downlink optical signals to their respective connected downlink interfaces.

[0253] Each of the plurality of downlink interfaces is used to transmit its received downlink optical signal through the optical fiber to which it is connected.

[0254] Each of the plurality of downlink interfaces is also used to receive uplink optical signals transmitted by the optical fiber to which it is connected. Each downlink interface receives one uplink optical signal, and the downlink wavelengths of the optical signals received by different downlink interfaces are different.

[0255] Each of the plurality of downlink interfaces is also used to transmit its received uplink optical signal to the first optical splitter to which it is connected;

[0256] The plurality of first beam splitters are also used to transmit their respective received uplink optical signals to the optical coupler.

[0257] In one possible implementation, each of the plurality of downlink interfaces includes a first sub-interface and a second sub-interface, the demultiplexer is connected to the plurality of first sub-interfaces of the plurality of downlink interfaces respectively, the optical coupler is connected to the plurality of second sub-interfaces of the plurality of downlink interfaces respectively, and the second sub-interface and the first sub-interface of each downlink interface are respectively connected to different optical fibers;

[0258] The demultiplexer is used to transmit the multiple downlink optical signals to the multiple first sub-interfaces, wherein each first sub-interface receives one downlink optical signal, and the downlink wavelengths of the optical signals received by different first sub-interfaces are different.

[0259] The first sub-interface in each downlink interface is used to transmit the downlink optical signal received by the first sub-interface through the connected optical fiber;

[0260] The second sub-interface among the plurality of downlink interfaces is used to receive the uplink optical signal transmitted by the optical fiber connected to the second sub-interface, and to transmit the uplink optical signal received by the second sub-interface to the optical coupler.

[0261] In one possible implementation, the fiber optic interface includes an uplink interface, the intermediate device further includes a second beam splitter, the uplink interface is connected to an optical fiber, and the second beam splitter is connected to the uplink interface, the demultiplexer and the optical coupler respectively;

[0262] The uplink interface is used to receive the composite downlink optical signal transmitted through the connected optical fiber and to transmit the received composite downlink optical signal to the second optical splitter.

[0263] The second beam splitter is used to send the composite downlink optical signal to the demultiplexer;

[0264] The optical coupler is used to transmit the composite uplink optical signal to the second beam splitter;

[0265] The second beam splitter is used to transmit the composite uplink optical signal to the uplink interface;

[0266] The uplink interface is also used to transmit the composite uplink optical signal through the connected optical fiber.

[0267] In one possible implementation, the optical fiber interface includes a first uplink interface and a second uplink interface, the first uplink interface and the second uplink interface being connected to different optical fibers respectively, the demultiplexer being connected to the first uplink interface, and the optical coupler being connected to the second uplink interface;

[0268] The first uplink interface is used to receive the composite downlink optical signal transmitted on the connected optical fiber and transmit the composite downlink optical signal to the demultiplexer;

[0269] The optical coupler is used to transmit the composite uplink optical signal to the second uplink interface;

[0270] The second uplink interface is used to send the composite uplink optical signal to the connected optical fiber.

[0271] Eighthly, a network device is provided, the network device including a processor and a memory, the memory being used to store a program for executing the optical communication method provided in the second, third, or fourth aspect, and to store data related to implementing the optical communication method provided in the second, third, or fourth aspect. The processor is configured to execute the program stored in the memory.

[0272] In one possible implementation, the network device may further include a communication bus for establishing a connection between the processor and the memory.

[0273] Ninthly, a computer-readable storage medium is provided, wherein instructions are stored therein, which, when executed on a computer, cause the computer to perform the optical communication method provided in the second, third, or fourth aspects described above.

[0274] In a tenth aspect, a computer program product containing instructions is provided, which, when run on a computer, causes the computer to perform the optical communication method provided in the second, third, or fourth aspect described above.

[0275] The technical effects achieved by the second to tenth aspects mentioned above are similar to those achieved by the corresponding technical means in the first aspect, and will not be repeated here. Attached Figure Description

[0276] Figure 1 This is an architecture diagram of an optical communication system provided in an embodiment of this application;

[0277] Figure 2 This is an architectural diagram of another optical communication system provided in an embodiment of this application;

[0278] Figure 3 This is an architectural diagram of another optical communication system provided in the embodiments of this application;

[0279] Figure 4 This is an architectural diagram of another optical communication system provided in the embodiments of this application;

[0280] Figure 5 This is an architectural diagram of another optical communication system provided in the embodiments of this application;

[0281] Figure 6 This is an architectural diagram of another optical communication system provided in the embodiments of this application;

[0282] Figure 7 This is an architectural diagram of another optical communication system provided in the embodiments of this application;

[0283] Figure 8 This is an architectural diagram of another optical communication system provided in the embodiments of this application;

[0284] Figure 9 This is an architectural diagram of another optical communication system provided in the embodiments of this application;

[0285] Figure 10 This is a flowchart of an optical communication method provided in an embodiment of this application;

[0286] Figure 11 This is a flowchart of another optical communication method provided in an embodiment of this application;

[0287] Figure 12 This is a flowchart of another optical communication method provided in the embodiments of this application;

[0288] Figure 13 This is a schematic diagram of the structure of a network device provided in an embodiment of this application. Detailed Implementation

[0289] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the implementation methods of this application will be further described in detail below with reference to the accompanying drawings.

[0290] To facilitate understanding, some terms / nouns involved in the embodiments of this application will be introduced first.

[0291] 1. Point to multi-point (P2MP): A transmission mode that transmits data from one source to one or more receivers.

[0292] 2. Passive Optical Network (PON): As an emerging broadband access fiber optic technology covering the last mile, it does not require node equipment at the optical branch point; only a simple optical splitter needs to be installed. Therefore, it has advantages such as saving optical cable resources, sharing bandwidth resources, saving data center investment, high equipment security, fast network construction speed, and low overall network construction cost. The intermediate device in the embodiments of this application is a passive device that can be applied in passive optical networks.

[0293] 3. Multiplexing Technology: As "fiber-to-the-home" (FTTH) gradually becomes the mainstream technology for campus networks, on the one hand, resource constraints and increasing manufacturing costs lead to a year-on-year increase in the cost of laying fiber optic links; on the other hand, the limited available frequencies for wireless transmission media are also a very valuable resource. Therefore, improving the utilization rate of communication lines has become a key focus, leading to the development of multiplexing technology. Multiplexing technology improves the utilization rate of optical communication lines by transmitting multiple signals on a single communication line. Currently, the most commonly used multiplexing technologies include wavelength division multiplexing (WDM), time division multiplexing (TDM), frequency division multiplexing (FDM), and code division multiplexing (CDM). This application focuses on wavelength division multiplexing in its embodiments.

[0294] 4. Wavelength Division Multiplexing (WDM): Often abbreviated as WDM, it typically utilizes multiple wavelengths to achieve multiple tasks. WDM is a data transmission technology where different optical signals are carried by different wavelengths (i.e., colors or frequencies) in optical communication systems. WDM refers to the technology of multiplexing multiple optical signals of different wavelengths onto a single optical fiber for transmission. The optical communication system and method provided in this application are applied to WDM systems, and can solve the problems of high production costs and deployment difficulties of access-side optical modules in related WDM systems.

[0295] 5. Wavelength Division Spacing (also known as wavelength spacing): In wavelength division multiplexing, the wavelength division spacing (WDM) of multiple uplink optical signals transmitted in a single optical fiber is the interval between any two adjacent uplink wavelengths arranged in order of magnitude. Similarly, the wavelength division spacing (WDM) of multiple downlink optical signals transmitted in a single optical fiber is the interval between any two adjacent downlink wavelengths arranged in order of magnitude.

[0296] In this application embodiment, the downlink wavelength division multiplexing (WDM) spacing can be greater than the uplink WDM spacing, meaning this application embodiment provides a hybrid WDM scheme. This application embodiment does not limit the specific values ​​of the downlink and uplink WDM spacings. For example, the downlink WDM spacing can be the same as the WDM spacing in coarse wavelength division multiplexing (CWDM) in related technologies, i.e., 20nm. Of course, the downlink WDM spacing can also be other values, such as 15nm, 25nm, etc. As an example, with a wavelength spacing of 20nm, there can be 18 downlink wavelength channels (referred to as downlink channels) between 1270nm and 1610nm. The uplink WDM spacing can be much smaller than the downlink WDM spacing, for example, it can be 0.4nm, 1nm, 2.4nm, or 2.5nm, etc. As an example, with a WDM spacing of 1nm, there can be 20 uplink wavelength channels (referred to as uplink channels) between 1050nm and 1070nm.

[0297] 6. Coarse Wavelength Division Multiplexing (CWDM) and Dense Wavelength Division Multiplexing (DWDM): These are two implementations of WDM. CWDM is a technology that simultaneously transmits multiple optical signals of different wavelengths with large wavelength intervals in the same optical fiber, while DWDM is a technology that simultaneously transmits multiple optical signals of different wavelengths with small wavelength intervals in the same optical fiber. In short, the main difference between CWDM and DWDM is that CWDM has a larger wavelength interval, while DWDM has a relatively smaller wavelength interval.

[0298] In some embodiments of the technical solution of this application, the downlink optical signal can adopt CWDM and the uplink optical signal can adopt DWDM. That is, the technical solution provided by the embodiments of this application can be a hybrid wavelength division scheme that uses coarse wavelength division and dense wavelength division.

[0299] In related technologies, besides CWDM and DWDM, WDM implementations also include medium wavelength division multiplexing (MWDM) and local area network wave division multiplexing (LAN-WDM, or LWDM for short, also known as fine wavelength division multiplexing). CWDM has a wavelength division spacing of 20nm, MWDM has an alternating spacing of 7nm / 13nm, LWDM has a spacing of 4nm, and DWDM has spacings of 0.4nm, 0.8nm, or 1.6nm. The alternating 7nm / 13nm spacing in MWDM refers to inserting wavelength separation points at positions offset 3.5nm to the left and right of multiple core wavelengths (i.e., 1271nm, 1291nm, 1311nm, ...) in a 20nm CWDM configuration. These inserted wavelength separation points serve as new core wavelengths, thus forming an alternating 7nm and 13nm spacing pattern. In other words, the core idea of ​​MWDM is to "insert" multiple core wavelengths with relatively small wavelength intervals between multiple core wavelengths with relatively large wavelength intervals, thereby forming two different alternating wavelength interval patterns. In this way, the core wavelengths corresponding to these two wavelength division intervals are located in the same band. In contrast to the idea of ​​"insertion," there is also the idea of ​​"complete band separation," which means that the core wavelengths corresponding to the two wavelength division intervals are located in different bands.

[0300] Based on the concept that WDM can be "interspersed" or "completely separated," the bands containing multiple downlink wavelengths (hereinafter referred to as downlink bands) and the bands containing multiple uplink wavelengths (hereinafter referred to as uplink bands) in this application's technical solution can be completely separated, overlap, or even coincide. As an example, if the multiple downlink wavelengths corresponding to the downlink optical signal are multiple core wavelengths divided at 20nm intervals between 1270nm and 1610nm, then when the downlink and uplink bands are completely separated, the multiple uplink wavelengths corresponding to the uplink optical signal can be multiple core wavelengths divided at 1nm intervals between 1525nm and 1545nm; when the downlink and uplink bands overlap, the multiple uplink wavelengths corresponding to the uplink optical signal can be multiple core wavelengths divided at 1nm intervals between 1260nm and 1280nm; and when the downlink and uplink bands coincide, the multiple uplink wavelengths corresponding to the uplink optical signal can be multiple core wavelengths divided at 1nm intervals between 1270nm and 1610nm.

[0301] It should be noted that the wavelength spacing of the uplink optical signal is the interval between any two adjacent uplink wavelengths after arranging the multiple uplink wavelengths corresponding to multiple access-side optical modules in ascending order during system design; the wavelength spacing of the downlink optical signal is the interval between any two adjacent downlink wavelengths after arranging the multiple downlink wavelengths corresponding to multiple access-side optical modules in ascending order during system design. Adjacent wavelengths are usually designed with equal spacing, but unequal spacing is also possible, and this application does not limit this. In the case of unequal spacing, the minimum permissible wavelength spacing for uplink is less than the minimum permissible wavelength spacing for downlink. Furthermore, the multiple downlink and uplink wavelengths designed for the system may not all be used in actual applications. For example, some channels may be disabled / deactivated, in which case the corresponding uplink and downlink wavelengths will not be used.

[0302] Each implementation of WDM has its own advantages. CWDM, with its larger wavelength spacing, allows for relatively lower cost, lower power consumption, and smaller size of filters and lasers, promoting energy conservation, easier deployment, and improved fiber optic transmission capacity, thus effectively utilizing and saving fiber resources. DWDM, with its smaller wavelength spacing, enables a single laser to generate multiple optical signals with different wavelengths. This capability allows for the normalization of multiple access-side optical modules, reducing production complexity and deployment costs. It should be understood that with large wavelength spacing, it is difficult to integrate multiple wavelengths into a single laser at the hardware level. In other words, CWDM struggles to achieve access-side optical module normalization, while DWDM technology makes it feasible, reducing the implementation cost of access-side optical module normalization.

[0303] In this embodiment, "normalization" of the access-side optical modules means that all access-side optical modules in the optical communication system have the same factory settings / configurations. For example, the wavelength range of the optical signals that can be emitted (referred to as the emission wavelength range) is the same, and the wavelength range of the optical signals that can be received (referred to as the reception wavelength range) is also the same. All access-side optical modules can be plugged and used immediately after leaving the factory, without the need for manufacturers to produce optical modules of different wavelengths in groups according to wavelength. Furthermore, during field deployment, network administrators do not need to plug access-side optical modules of different wavelengths into each group of access devices. Each access-side optical module can set its emission wavelength according to certain logic, without the need for manual configuration / adjustment by technicians. The set emission wavelength is the uplink wavelength of the corresponding uplink channel, and different access-side optical modules have different set emission wavelengths.

[0304] 7. Multiplexer (MUX) / Demultiplexer (DEMUX): Different multiplexing technologies employ different multiplexers / demultiplexers. Wavelength division multiplexing (WDM) technology combines multiple modulated optical signals (or signals carrying useful information, such as uplink / downlink information) with different wavelengths (or frequencies) at the transmitting end using a multiplexer (e.g., a multiplexer) and transmits them along the same optical fiber in the optical line (i.e., the fiber optic transmission link). At the receiving end, a demultiplexer (e.g., a wavelength divider) separates the optical signals of different wavelengths for reception.

[0305] 8. Wavelength Demultiplexer / Demultiplexer: A multiplexer / demultiplexer used in wavelength division multiplexing (WDM) technology. A multiplexer includes multiple input terminals and one output terminal. Each input terminal is used to input an optical signal of a specific wavelength. The wavelengths of the optical signals input to different input terminals are usually different. The multiplexer combines these multiple optical signals into a single optical signal (called a composite optical signal). This composite optical signal contains multiple optical signals, each corresponding to a different wavelength. A wavelength demultiplexer is the opposite of a multiplexer. A wavelength demultiplexer includes one input terminal and multiple output terminals. The input terminal is used to input a composite optical signal, which contains multiple optical signals, each corresponding to a different wavelength. The wavelength demultiplexer demultiplexes this composite optical signal, breaking it down into multiple optical signals, allowing the device associated with the demultiplexer to receive these signals. Each output terminal of the wavelength demultiplexer outputs an optical signal of a specific wavelength, and the wavelengths of the optical signals output from different output terminals are usually different.

[0306] It should be noted that the input terminals of a multiplexer are used to input optical signals of a fixed wavelength, and the output terminals of a demultiplexer are used to output optical signals of a fixed wavelength. If an optical signal of a different wavelength is input to one of the input terminals of the multiplexer, that optical signal will not be processed correctly and will not be transmitted further. If the optical signal input to a demultiplexer does not include the optical signal corresponding to a certain output terminal, that output terminal will not output any optical signal.

[0307] 9. Optical Splitter (OS, also known as a splitter) / Optical Coupler (OC, also known as a coupler): Its design and function differ from wavelength dividers / multiplexers. An optical splitter includes one input and multiple outputs. The input is used to input a single optical signal, which can be a single-wavelength signal or a wavelength-division multiplexed signal (i.e., a composite optical signal). The splitter separates the input optical signal into multiple optical signals, all of which contain the same wavelength. For example, if the splitting is based on energy, the resulting signals can have approximately the same energy. The multiple outputs of the splitter each output an optical signal, thus providing a series of output signals. The wavelength characteristics of the resulting optical signals are the same as those of the original optical signal. For instance, if the input signal is a single-wavelength signal, the resulting multiple optical signals will also be single-wavelength signals, with each signal having the same wavelength as the input signal. If the optical signal input to the beam splitter is a composite optical signal, then each of the multiple optical signals obtained after splitting is also a composite optical signal.

[0308] An optical coupler includes multiple input terminals and one output terminal. Each input terminal can receive an optical signal of any wavelength. The optical coupler couples the optical signals input from these multiple input terminals to obtain a single optical signal whose wavelength includes all wavelengths of the optical signals input from the multiple input terminals. In some embodiments, a beam splitter and an optical coupler are the same device, but they have different names due to their different functions in different scenarios.

[0309] 10. Beam splitter: A filtering device that filters multiple optical signals with a certain wavelength difference when input into it, separating the signals according to their wavelengths. For example, a beam splitter can filter out an input optical signal of a certain wavelength and transmit it in one direction (reflection / refraction), and filter out an input optical signal of another wavelength and transmit it in another direction (reflection / refraction).

[0310] In this embodiment, a beam splitter is used to separate uplink and downlink optical signals, wherein the uplink wavelength corresponding to the uplink optical signal and the downlink wavelength corresponding to the downlink optical signal have a certain difference. For example, the composite uplink optical signal received by the downlink interface of the central optical module can be input into the beam splitter in the central optical module, and the composite downlink optical signal output by the multiplexer in the central optical module can also be input into the beam splitter of the central optical module. Since there is a certain difference between the uplink wavelength corresponding to the composite uplink optical signal and the downlink wavelength corresponding to the composite downlink optical signal, the beam splitter can separate the input composite uplink optical signal and composite downlink optical signal, thereby outputting the composite downlink optical signal to the downlink interface of the central optical module and outputting the composite uplink optical signal to the demultiplexer of the central optical module.

[0311] In the embodiments of this application, for ease of distinction, multiple devices belonging to the same category can be distinguished by words such as "first", "second", and "third". Similarly, the input / output terminals of different devices can also be distinguished by words such as "first", "second", and "third".

[0312] The following section provides a background introduction to the embodiments of this application.

[0313] This application's embodiments are designed for the evolution of campus network architecture, but are not limited to campus networks. The requirement for this solution is triggered by the evolution of campus networks to all-optical campuses; therefore, this application's embodiments will be described according to the evolution of campus architecture and the line of thought behind this solution.

[0314] First, let's introduce the architecture of traditional campus networks, the driving factors for the evolution of campus network architecture, and the direction of evolution.

[0315] In traditional campus networks, the network structure is mainly tree-based, with the most typical tree architecture being a three-layer network. The three layers are the access layer, aggregation layer, and core layer. In traditional structures, the access layer directly connects to the network-using devices (also known as user equipment, such as personal computers (PCs) / Wi-Fi devices), while the aggregation layer handles north-south data aggregation and east-west data exchange. The access layer connects downwards (to network-using devices) primarily via network cables. The connections between the access layer and the aggregation layer, as well as between the aggregation layer and the core layer, are typically via fiber optic cables. The connections between layers are point-to-point (P2P), with no convergence between fiber optic cables and network cables; data convergence and exchange only occur at the switches.

[0316] The specific location of the three-story structure varies slightly depending on the type of park.

[0317] In large campuses, networks are typically built on a building-by-building basis. The entire campus is configured with a core switching area (i.e., the core layer). Each building can be built using a two-tiered tree structure, meaning each building acts as an independent aggregation point. When a large campus adopts this tree architecture, data exchange within the same building can be completed within that building, while data exchange between different buildings is handled through the core layer.

[0318] Medium-sized campuses typically use a two-tier architecture, but a three-tier architecture can also be used depending on network scale and business needs. A three-tier architecture is suitable when there are many network access points and multiple aggregation points are required. For example, in a newly built office building, each floor may have a low-voltage electrical room, which can serve as an aggregation point, with the entire building using a three-tier architecture and a core layer. A three-tier architecture can also be used when there are different business isolation requirements, such as isolation between departments, requiring a separate aggregation point for each type of business or department.

[0319] The traditional three-layer architecture of campus networks has been briefly introduced above. Next, we will introduce the next-generation campus architecture (i.e., all-optical campus architecture). Currently, the exploration of all-optical campuses in related fields is mainly divided into two systems: one is the passive optical LAN (POL) solution system based on PON technology, and the other is the all-optical Ethernet solution based on traditional Ethernet solutions.

[0320] POL (Portable LAN) is a local area network based on PON (Portable LAN) technology, providing users with converged data, voice, video, and other low-voltage services via optical fiber. POL is a solution that directly applies access network PON technology to a campus network. Taking a traditional three-layer campus network as an example, POL replaces the access and aggregation layers by placing the optical line termination (OLT) equipment and the core layer switch together, using passive devices and optical fiber to complete the P2MP (Portable LAN to Portable LAN) connection. Compared to traditional solutions, POL simplifies the network architecture, reducing the three-layer network to a two-layer network. Furthermore, since the OLT equipment and the user equipment's optical network unit (ONU) are placed at opposite ends of the network, the intermediate link can be completely passive, reducing the number of devices to maintain and power consumption. The P2MP design also significantly saves on optical fiber usage and reduces equipment deployment space.

[0321] The application of PON technology in all-optical campuses has triggered the evolution of traditional Ethernet towards all-optical solutions. The main problems encountered by traditional campus network solutions include: lack of direct fiber optic cabling to rooms, multiple network layers, a large number of fiber optic / network cables, and active devices in all interconnecting links. To address these issues, the exploration of all-optical Ethernet campuses has commenced.

[0322] In fiber-to-the-home (FTTH) scenarios, user-side switches are miniaturized and have reduced functionality to create box-type access switches. For example, a 24-port box-type access switch can be placed directly on the user's desktop to form a 4-port or 8-port desktop switch, thus achieving direct fiber optic cable connection.

[0323] As mentioned above, the embodiments of this application are mainly applied to wavelength division multiplexing (WDM) systems. However, in current WDM schemes, the access-side optical modules have not yet achieved normalization. For example, the laser in each access-side optical module can only emit optical signals with a fixed uplink wavelength, which corresponds to the access-side optical module. Different access-side optical modules correspond to different uplink wavelengths, thus achieving WDM multiplexing. Similarly, each access-side optical module can only receive optical signals with a fixed downlink wavelength, which corresponds to the access-side optical module. Different access-side optical modules correspond to different downlink wavelengths, thus achieving WDM multiplexing. Therefore, the emission and reception wavelengths of different access-side optical modules in a group connected in the middle are different, and normalization has not been achieved. The embodiments of this application can achieve normalization of the colored light scattering optical modules (i.e., access-side optical modules) in the WDM system, thereby reducing the networking difficulty of optical communication and reducing the difficulty of equipment production, deployment, management, and maintenance.

[0324] The implementation environment of the embodiments of this application will be described next.

[0325] Figure 1 This is an architecture diagram of an optical communication system provided in an embodiment of this application. See also... Figure 1 The system includes a central optical module and multiple access-side optical modules, with the central optical module connected to the multiple access-side optical modules. Optionally, the optical communication system also includes intermediate equipment, through which the central optical module is connected to the multiple access-side optical modules. That is, the central optical module is connected to the intermediate equipment via optical fiber, and the intermediate equipment is also connected to each of the multiple access-side optical modules via optical fiber.

[0326] In an optical communication system, multiple access-side optical modules correspond to multiple uplink wavelengths, and multiple access-side optical modules correspond to multiple downlink wavelengths. Among these multiple access-side optical modules, different access-side optical modules correspond to different downlink wavelengths, and different access-side optical modules correspond to different uplink wavelengths.

[0327] See also Figure 1 In this embodiment, the central optical module includes a fixed-wavelength laser, which is used to generate multiple fixed-wavelength optical signals, including multiple downlink wavelengths corresponding to multiple access-side optical modules.

[0328] Optionally, in one implementation, the fixed-wavelength laser in the central optical module includes multiple lasers for generating fixed-wavelength optical signals, wherein the wavelength of each laser is not adjustable, and different lasers among the multiple lasers correspond to different fixed wavelengths.

[0329] Each of the multiple access-side optical modules includes a tunable wavelength laser. Each access-side optical module can automatically set the emission wavelength of its included tunable wavelength laser according to certain logic. The set emission wavelength is the emission wavelength corresponding to this access-side optical module. The "logic" for setting the emission wavelength can be implemented in various ways, and this application embodiment does not limit it.

[0330] See also Figure 1 The access-side optical module is inserted into or integrated into the access device. The access device uses the access-side optical module to access the optical communication system, thereby enabling communication with the routing and switching equipment. Similarly, the central optical module is inserted into or integrated into the routing and switching equipment. The routing and switching equipment uses the central optical module to communicate with the access device. The figures in this article all use the insertion of the optical module into the corresponding device as an example. Accordingly, the downlink wavelength optical signal (referred to as downlink optical signal) carries the downlink information sent by the routing and switching equipment, and the uplink wavelength optical signal (referred to as uplink optical signal) carries the uplink information sent by the access device. The downlink information includes downlink commands and / or downlink data; the uplink information includes uplink responses and / or uplink data.

[0331] The central optical module has multiple pairs of channels with the routing and switching equipment. These channels are implemented using deserializers (SERDes). Each SERDe corresponds to one access-side optical module and is used to transmit the uplink and downlink information of the corresponding access-side optical module. For example, n SERDes correspond one-to-one with n access-side optical modules.

[0332] In this embodiment, the access device can be an industry-standard "Asteroid" switch, access point (AP), or other device. The access device can also be called a remote access device, optical line terminal, or other names. The routing and switching device can be a switch (such as a local area network switch (LSW)) or a router. The routing and switching device can also be called a central switch, core switch, or other names. The central optical module can also be called a core-side optical module or central office optical module. The access-side optical module can also be called a terminal optical module, remote optical module, etc.

[0333] The central optical module and access-side optical modules are used to transmit uplink and downlink information between the routing switching device and the access device according to the optical communication method provided in the embodiments of this application. The uplink and downlink information is carried on uplink and downlink optical signals. For example, the central optical module is used to send a composite downlink optical signal to multiple access-side optical modules. The composite downlink optical signal includes multiple downlink optical signals generated by a fixed-wavelength laser of the central optical module, and the wavelengths of the multiple downlink optical signals are multiple downlink wavelengths corresponding to the multiple access-side optical modules. Each of the multiple access-side optical modules is used to send an uplink optical signal corresponding to its own uplink wavelength to the central optical module using a tunable-wavelength laser. The central optical module is also used to receive a composite uplink optical signal, which includes multiple uplink optical signals, and the wavelengths of the multiple uplink optical signals are multiple uplink wavelengths corresponding to the multiple access-side optical modules.

[0334] In one implementation, the wavelength division multiplexing (WDM) spacing of the multiple downlink wavelengths is greater than the wavelength division multiplexing (WDM) spacing of the multiple uplink wavelengths. For a detailed explanation of WDM spacing, please refer to the corresponding description above; it will not be repeated here.

[0335] In one possible implementation, the multiple downlink optical signals included in the composite downlink optical signal are transmitted using coarse wavelength division multiplexing (CWDM), while the multiple uplink optical signals included in the composite uplink optical signal are transmitted using dense wavelength division multiplexing (DWDM). A brief introduction to CWDM and DWDM can be found in the descriptions above, and will not be repeated here.

[0336] In one possible implementation, the wavelength division multiplexing (WDM) interval of the multiple downlink wavelengths is greater than or equal to a first threshold, and the wavelength division multiplexing (WDM) interval of the multiple uplink wavelengths is less than a second threshold. That is, multiple downlink wavelengths and multiple uplink wavelengths can be designed based on the first threshold and the second threshold.

[0337] In one possible implementation, the first threshold is greater than the second threshold; in another possible implementation, the first threshold can be equal to the second threshold. In the implementation where the first and second thresholds are equal, only one threshold needs to be set. Of course, it is also possible to set two thresholds with equal values ​​as the first and second thresholds, respectively.

[0338] As an example, the first threshold is 20nm, and the second threshold is 2.5nm. The first and second thresholds can be flexibly set according to actual conditions, and this application embodiment does not limit this. The factors for setting the second threshold may include the current hardware implementation of the laser. For example, based on the current feasibility of implementing tunable wavelength lasers, the second threshold can be set to 2.5nm. Based on this, the wavelength division multiplexing (WDM) interval of multiple uplink wavelengths can be less than 2.5nm, for example, it can be 2.4nm. If the WDM interval of multiple uplink wavelengths exceeds 2.5nm, it will be very difficult to implement a tunable wavelength laser.

[0339] It should be understood that 2.5nm may be the current limit of hardware feasibility, but it does not mean that 2.5nm will also be the limit in the future. That is, with the development of laser-related technologies, the limit can be broken, and the wavelength division multiplexing interval of multiple uplink optical signals generated by tunable wavelength lasers can be greater than 2.5nm.

[0340] In some embodiments, if the wavelength division multiplexing (WDM) interval of the multiple uplink wavelengths is less than 2.3 nm, the demultiplexer in the central optical module (described below) can employ an arrayed waveguide grating (AWG) or a silicon photonics Mach-Zehnder (MZ) demultiplexing scheme. If the WDM interval of the multiple uplink wavelengths is greater than 2.3 nm, the demultiplexer in the central optical module can employ a free-space thin-film filter (TFF) demultiplexing scheme.

[0341] To implement the optical communication method provided in the embodiments of this application, the embodiments of this application provide various specific implementations of optical communication systems. The following will refer to... Figures 2 to 9 These various specific implementation methods will be introduced.

[0342] Figure 2 This is an architectural diagram of another optical communication system provided in an embodiment of this application. See also... Figure 2 In this embodiment, the fixed-wavelength laser in the central optical module includes multiple laser diodes (LDs), each LD being a laser. Each LD generates a fixed-wavelength optical signal, and the wavelength of each LD is not adjustable. Different LDs correspond to different fixed wavelengths. Each LD is used to emit a fixed-wavelength optical signal based on a received electrical signal, and different LDs emit optical signals with different wavelengths.

[0343] In this embodiment, the fixed-wavelength laser in the central optical module is used to generate multiple downlink optical signals based on multiple first electrical signals input by the routing switching device. The multiple downlink optical signals carry downlink information sent by the routing switching device through the multiple first electrical signals. The multiple first electrical signals correspond one-to-one with multiple access-side optical modules. The downlink information carried by the multiple first electrical signals includes information sent to the multiple access-side optical modules.

[0344] As an example, the fixed-wavelength laser in the central optical module includes Figure 2 The central optical module shown has multiple LDs, each corresponding to a first electrical signal input by the routing and switching equipment. Each LD is used to generate a downlink optical signal based on a corresponding first electrical signal.

[0345] In this embodiment of the application, the central optical module further includes a photoelectric conversion device, which is used to receive multiple uplink optical signals, perform photoelectric conversion on the multiple uplink optical signals to obtain multiple second electrical signals, and output multiple second electrical signals to the routing and switching equipment. The multiple uplink optical signals correspond one-to-one with multiple access-side optical modules, and the multiple uplink optical signals carry uplink information sent by multiple access-side optical modules.

[0346] As an example, the photoelectric conversion device in the central optical module includes Figure 2 The central optical module shown contains photodiodes (PDs) (n in total). Different PDs are used to receive optical signals of different uplink wavelengths. Each PD receives one of the multiple uplink optical signals. Each PD performs photoelectric conversion on the received uplink optical signal to obtain a second electrical signal, and outputs the photoelectric converted second electrical signal to the routing and switching equipment.

[0347] It should be understood that drawing multiple LDs (LD1, LD2, LD3, LDn) in a single box in the diagram does not mean that LD1, LD2, LD3, LDn must be physically together. Similarly, drawing multiple PDs (PD1, PD2, PD3, PDn) in a single box does not mean that PD1, PD2, PD3, PDn must be physically together. The physical positions of these devices can be set according to actual conditions, and this application embodiment does not limit this. For example, LD1 and PD1 can be placed together, LD2 and PD2 can be placed together, and LD3 and PD3 can be placed together. The same principle applies to similar places in subsequent embodiment diagrams, which will not be explained again below.

[0348] In this embodiment, the central optical module includes multiple LDs and multiple PDs in a one-to-one correspondence. In some implementations, an LD and a PD with a corresponding relationship can be integrated together, for example, integrated on a single device, which can be called a photoelectric conversion submodule. Thus, the central optical module includes multiple photoelectric conversion submodules, each of which includes an LD and a PD. These multiple photoelectric conversion submodules correspond one-to-one with multiple SERDEs and are used to transmit uplink and downlink information corresponding to the multiple SERDEs respectively.

[0349] In some embodiments, the devices used for photoelectric conversion in the central optical module can be collectively referred to as photoelectric conversion devices. These photoelectric conversion devices include the aforementioned plurality of photodiodes (PDs). Optionally, the photoelectric conversion devices may also include other components, such as optical tubes or lenses, without limitation. The devices used for emitting optical signals in the central optical module can be collectively referred to as electro-optical conversion devices. These electro-optical conversion devices include the aforementioned plurality of optical depletion units (LDs). Optionally, the electro-optical conversion devices may also include other components, without limitation.

[0350] See also Figure 2 The central optical module may also include an optical multiplexer (optical MUX, OMUX, which can be simply referred to as a multiplexer), which is located in the central optical module and transmits to intermediate devices.

[0351] like Figure 2 As shown, the central optical module also includes an OMUX, which is connected to multiple LDs and multiple PDs of the central optical module. The OMUX includes multiple input terminals and multiple output terminals. A portion of the input terminals are connected to a corresponding LD, and a portion of the output terminals are connected to a corresponding PD.

[0352] In this embodiment, the intermediate device includes a demultiplexer and a combining device. The demultiplexer in the intermediate device can be referred to as the first demultiplexer in the system embodiment. The first demultiplexer is used to demultiplex the composite downlink optical signal received through the optical fiber to obtain multiple downlink optical signals, and based on the respective downlink wavelengths of the multiple downlink optical signals obtained by demultiplexing, transmit the corresponding downlink optical signals to multiple access-side optical modules through the optical fiber. The combining device is used to combine the multiple uplink optical signals from the multiple access-side optical modules to obtain a composite uplink optical signal, and transmit the composite uplink optical signal to the central optical module through the optical fiber.

[0353] The first demultiplexer may include Figure 2 The DEMUX is shown in the intermediate device. The optical combining device may include... Figure 2 The optical coupler / splitter in the intermediate device shown.

[0354] It should be understood that the intermediate device, as the transmission medium for optical signals between the central optical module and multiple access-side optical modules, is used to perform multiplexing / coupling and decoupling of the received optical signals, but does not perform information processing on these optical signals.

[0355] In this embodiment, the intermediate device further includes at least one uplink interface and multiple downlink interfaces. The intermediate device is connected to the central optical module via the at least one uplink interface through an optical fiber, and the intermediate device is connected to multiple access-side optical modules via the multiple downlink interfaces through optical fibers. In short, the intermediate device is connected to the central optical module via the uplink interface and to the access-side optical modules via the downlink interfaces.

[0356] The intermediate device is used to receive and transmit the composite downlink optical signal through at least one uplink interface. The intermediate device is also used to transmit corresponding downlink optical signals to multiple access-side optical modules through the multiple downlink interfaces, wherein each of the multiple downlink interfaces transmits one downlink optical signal, and the downlink wavelengths of the optical signals transmitted by different downlink interfaces are different. The intermediate device is further used to receive corresponding uplink optical signals transmitted by multiple access-side optical modules through the multiple downlink interfaces, wherein each of the multiple downlink interfaces receives one uplink optical signal, and the uplink wavelengths of the optical signals received by different downlink interfaces are different.

[0357] In this embodiment, each access-side optical module includes, in addition to a tunable wavelength laser, a photoelectric converter. This photoelectric converter is capable of processing optical signals of different downlink wavelengths. The wavelengths of the optical signals that the photoelectric converter can process include multiple downlink wavelengths corresponding to multiple access-side optical modules; that is, the photoelectric converter is a broadband receiving device. In practical applications, each photoelectric converter is used to perform photoelectric conversion on the downlink wavelength optical signal received by the access-side optical module to which it belongs, thereby obtaining an electrical signal (in some embodiments, referred to as a fourth electrical signal), and outputting this electrical signal (e.g., the fourth electrical signal) to the access device. The photoelectric converter in the access-side optical module may include... Figure 2 The PD in the access side optical module is shown.

[0358] Each access-side optical module contains a tunable wavelength laser capable of emitting optical signals with different uplink wavelengths. The wavelengths of the optical signals emitted by the tunable wavelength laser include multiple uplink wavelengths corresponding to multiple access-side optical modules; that is, the emission wavelength of the laser in the access-side optical module is adjustable, hence the name tunable wavelength laser. The tunable wavelength laser in the access-side optical module is used to generate an optical signal with a corresponding uplink wavelength based on the electrical signal input by the corresponding access device. The electrical signal input by the access device carries the uplink information sent by the access device. Taking the first optical module among the aforementioned multiple access-side optical modules as an example, the first optical module receives a second electrical signal transmitted by the first access device. The second electrical signal carries the uplink information sent by the first access device. The tunable wavelength laser in the first optical module generates an optical signal with an uplink wavelength corresponding to the first optical module (referred to as the uplink optical signal) based on the second electrical signal and sends this uplink optical signal to the central optical module. The first access device is an access device integrated into or inserted into the first optical module. The tunable wavelength laser in the access-side optical module may include, for example,... Figure 2 The tunable laser diode (TLD) in the access side light module is shown.

[0359] As an example, the tunable wavelength laser in each access-side optical module can employ a DBR laser, an EA-modulated DBR laser, a Littman-structured TECDL, a Littman-Metcalf-structured TECDL, an FBG-TECDL, an MRR tunable laser, a fully integrated tunable laser based on on-chip SOA, an FP laser, a DFB laser array, or a TOSA self-locking or injection-locking method to achieve wavelength adjustment. The photoelectric converter in each access-side optical module can employ a PIN, APD, or SOA-PIN for photoelectric conversion.

[0360] In this embodiment, the intermediate device and the central optical module can be connected via a single fiber or a dual fiber; similarly, the intermediate device and the access-side optical module can also be connected via a single fiber or a dual fiber. Therefore, the downlink and uplink interfaces of the intermediate device, as well as the uplink interface of the access-side optical module, can be implemented in various ways. These will be described below.

[0361] First, we will introduce the specific implementation methods of the uplink interface of the intermediate device and the downlink interface of the central optical module in the case of a single-fiber connection between the central optical module and the intermediate device.

[0362] like Figure 2As shown, the intermediate device and the central optical module are connected via a single fiber. Therefore, both the intermediate device and the central optical module include a beam splitter. The beam splitter in the intermediate device used to connect to the central optical module can be called the third beam splitter, and the beam splitter in the central optical module used to connect to the intermediate device can be called the fourth beam splitter. The fourth beam splitter is connected to the downlink interface of the central optical module, and it is also connected to one input and one output of the OMUX. The fourth beam splitter is also connected to the third beam splitter via an optical fiber; for ease of distinction, this optical fiber is called the fourth optical fiber.

[0363] In the case of a single-fiber connection between the central optical module and intermediate equipment, the central optical module includes a downlink interface that connects to a single optical fiber. In this scenario, the optical multiplexer (OMUX) within the central optical module can be implemented in several ways, which will be described below.

[0364] In the first implementation, the OMUX includes a device that simultaneously performs wavelength division and multiplexing. That is, the OMUX of the central optical module includes a multiplexer / demultiplexer that performs both multiplexing and wavelength division. This multiplexer / demultiplexer combines multiple downlink optical signals generated by a fixed-wavelength laser into a composite downlink optical signal, which is then transmitted to the fourth optical splitter. The fourth optical splitter transmits the composite downlink optical signal through the downlink interface of the central optical module and receives composite uplink optical signals transmitted on the connected optical fiber from the downlink interface of the central optical module, transmitting the composite uplink optical signal to the multiplexer / demultiplexer. The multiplexer / demultiplexer also receives the composite uplink optical signal transmitted by the fourth optical splitter, demultiplexes it into multiple uplink optical signals, and transmits the demultiplexed uplink optical signals to the optoelectronic conversion device.

[0365] As an example, it can be Figure 2 The OMUX shown is configured as a MUX, which acts as a multiplexer / demultiplexer. In this implementation, the MUX has a wide band, meaning that its band includes multiple downlink wavelengths as well as multiple uplink wavelengths.

[0366] In the second implementation, the OMUX of the central optical module can include two devices: a first multiplexer and a second demultiplexer. The first multiplexer has a multiplexing function, and the second demultiplexer has a wavelength demultiplexing function. A fixed-wavelength laser is used to generate multiple downlink optical signals based on multiple first electrical signals and transmit these multiple downlink optical signals to the first multiplexer. These multiple first electrical signals are electrical signals input from the routing switching equipment. The first multiplexer is used to combine the multiple downlink optical signals into a composite downlink optical signal and transmit the composite downlink optical signal to the fourth optical splitter. The fourth optical splitter is used to send the composite downlink optical signal through the downlink interface of the central optical module and receive the composite uplink optical signal transmitted on the connected optical fiber from the downlink interface of the central optical module, and transmit the composite uplink optical signal to the second demultiplexer. The second demultiplexer is used to receive the composite uplink optical signal transmitted by the fourth optical splitter, demultiplex multiple uplink optical signals from the composite uplink optical signal, and transmit the demultiplexed multiple uplink optical signals to the optoelectronic conversion device. The optoelectronic conversion device is used to convert multiple uplink optical signals demultiplexed by the second demultiplexer into multiple second electrical signals, and output multiple second electrical signals to the routing and switching equipment.

[0367] As an example, see Figure 3 The OMUX in the central optical module can be implemented by a multiplexer (shown as MUX, serving as the first multiplexer) and a demultiplexer (shown as DEMUX, serving as the second demultiplexer). Multiple inputs of the multiplexer are connected one-to-one with multiple LDs of the central optical module, and multiple outputs of the demultiplexer are connected one-to-one with multiple PDs of the central optical module. The fourth beam splitter is connected to the input of the demultiplexer and also to the output of the multiplexer.

[0368] That is to say, in Figure 3 In the implementation shown, OMUX includes two devices: MUX and DEMUX. These two devices process uplink optical signals (to achieve wavelength division function) and downlink optical signals (to achieve wavelength multiplexing function) respectively. Thus, the bands of both devices are relatively narrow and easy to implement. The band of MUX only needs to include multiple downlink wavelengths, and the band of DEMUX only needs to include multiple uplink wavelengths.

[0369] Besides the two implementation methods mentioned above, in some other implementations, OMUX, in addition to having the functions of wavelength division multiplexing and wavelength splitting, can also simultaneously have the function of the aforementioned fourth beam splitter. That is, the function of the fourth beam splitter is integrated into OMUX.

[0370] In one possible implementation, the central optical module may include a multiplexer / demultiplexer but not a fourth beam splitter. The multiplexer / demultiplexer is connected to the downlink interface of the central optical module. A fixed-wavelength laser is used to generate multiple downlink optical signals based on multiple first electrical signals and transmit these multiple downlink optical signals to the multiplexer / demultiplexer. These multiple first electrical signals are electrical signals input from the routing switching equipment. The multiplexer / demultiplexer is used to combine the multiple downlink optical signals into a composite downlink optical signal, transmit the composite downlink optical signal through the downlink interface of the central optical module, and receive composite uplink optical signals transmitted on the optical fiber connected to the downlink interface of the central optical module. It then demultiplexes the composite uplink optical signal to extract multiple uplink optical signals and transmits these multiple uplink optical signals to an optoelectronic conversion device. The optoelectronic conversion device is used to convert the multiple uplink optical signals demultiplexed by the multiplexer / demultiplexer into multiple second electrical signals and output these multiple second electrical signals to the routing switching equipment. That is, the multiplexer / demultiplexer simultaneously performs wavelength division, multiplexing, and beam splitting functions.

[0371] As an example, see Figure 4 The OMUX in the central optical module can be implemented by a MUX (acting as a multiplexer / demultiplexer). This MUX simultaneously performs multiplexing, demultiplexing, and beam splitting functions. Compared to the MUX in the first implementation mentioned above, this MUX adds a beam splitting interface, which is directly connected to the third beam splitter of the intermediate device via optical fiber. That is, [the following text is incomplete and requires further context: "will..."] Figure 2 The beam splitter in the central optical module shown is integrated in Figure 2 In the OMUX shown, the following can be obtained: Figure 4 The central optical module shown.

[0372] In another possible implementation, the central optical module may include a second multiplexer and a third demultiplexer, but not a fourth beam splitter. The second multiplexer is connected to the downlink interface of the central optical module and is also connected to the third demultiplexer. A fixed-wavelength laser is used to generate multiple downlink optical signals based on multiple first electrical signals and transmit these downlink optical signals to the second multiplexer. These multiple first electrical signals are electrical signals input to the routing switching equipment. The second multiplexer is used to combine the multiple downlink optical signals into a composite downlink optical signal, transmit the composite downlink optical signal through the downlink interface of the central optical module, and receive composite uplink optical signals transmitted on the optical fiber connected to the downlink interface of the central optical module, transmitting the composite uplink optical signal to the third demultiplexer. The third demultiplexer is used to receive the composite uplink optical signal transmitted by the second demultiplexer, demultiplex multiple uplink optical signals from the composite uplink optical signal, and transmit these multiple uplink optical signals to an optoelectronic conversion device. The optoelectronic conversion device is used to convert the multiple uplink optical signals demultiplexed by the third demultiplexer into multiple second electrical signals and output multiple second electrical signals to the routing switching equipment. That is, the second multiplexer has the functions of multiplexing and splitting, and the third demultiplexer has the function of splitting.

[0373] As an example, see Figure 5 The OMUX in the central optical module can be implemented by a MUX (as a second multiplexer) and a DEMUX (as a third demultiplexer). Compared to the second implementation method mentioned above, this MUX adds a splitting port, which is directly connected to the third splitter of the intermediate device via optical fiber and also connected to the DEMUX. That is, it... Figure 3 The beam splitter in the central optical module shown is integrated in Figure 3 In the MUX shown, the following can be obtained: Figure 5 The central optical module shown.

[0374] The implementation methods described above actually provide several hardware design approaches for wavelength division, multiplexing, and beam splitting. Although the hardware design methods differ, they all ultimately achieve essentially the same technical effect. The following text will use the OMUX in the central optical module, which includes one MUX, one DEMUX, and one beam splitter, as an example for explanation.

[0375] In the case of a single-fiber connection between the central optical module and the intermediate equipment, the intermediate equipment also includes an uplink interface and a third optical splitter. The uplink interface of the intermediate equipment is connected to the downlink interface of the central optical module via a single optical fiber. The third optical splitter is connected to the uplink interface, the first demultiplexer, and the optical combiner of the intermediate equipment, respectively. The third optical splitter is used to receive the composite downlink optical signal sent by the central optical module through the uplink interface of the intermediate equipment and to transmit the composite downlink optical signal to the first demultiplexer. The third optical splitter is also used to receive the composite uplink optical signal transmitted by the optical combiner and to send the composite uplink optical signal to the central optical module through the uplink interface of the intermediate equipment.

[0376] As an example, Figures 2 to 5 The beam splitter in the intermediate device shown is the third beam splitter, and the uplink interface connected to the third beam splitter is the uplink interface of the intermediate device.

[0377] The above combination Figures 2 to 5 This paper introduces various implementation methods for single-fiber connections between the central optical module and intermediate devices. The following section will continue to combine... Figures 2 to 5 This paper introduces the implementation method of dual-fiber connection between intermediate equipment and access side optical module.

[0378] In other words, the following section will introduce the specific implementation methods of the downlink interface of the intermediate device and the uplink interface of the access side optical module in the case of a dual-fiber connection between the intermediate device and the access side optical module.

[0379] In the case of a dual-fiber connection between the intermediate device and the access-side optical module, each of the multiple downlink interfaces of the intermediate device includes a first sub-interface and a second sub-interface. The first demultiplexer of the intermediate device is connected to each of the multiple first sub-interfaces of the multiple downlink interfaces, and the optical combiner of the intermediate device is connected to each of the multiple second sub-interfaces of the multiple downlink interfaces. Different access-side optical modules are connected to different downlink interfaces of the intermediate device via optical fibers. The first optical module of the multiple access-side optical modules is connected to the first and second sub-interfaces of the first downlink interface of the multiple downlink interfaces via different optical fibers.

[0380] Based on this, the first demultiplexer is specifically used to transmit multiple downlink optical signals to the multiple first sub-interfaces, wherein each first sub-interface receives one downlink optical signal, and the downlink wavelengths of the optical signals received by different first sub-interfaces are different; the first sub-interface of the first downlink interface is used to transmit the downlink optical signal received by this first sub-interface to the first optical module through the connected optical fiber; the second sub-interface of the first downlink interface is used to receive the uplink wavelength optical signal corresponding to the first optical module sent by the first optical module through the connected optical fiber; the second sub-interface of the multiple downlink interfaces is used to transmit the uplink wavelength optical signal received by this second sub-interface to the optical combining device, and one optical signal received by one second sub-interface is called one uplink optical signal; the optical combining device is specifically used to combine the multiple uplink optical signals transmitted by the multiple second sub-interfaces into a composite uplink optical signal.

[0381] In this intermediate device, multiple outputs of the first demultiplexer are connected one-to-one with multiple first sub-interfaces of multiple downlink interfaces, and multiple inputs of the optical combiner are connected one-to-one with multiple second sub-interfaces of multiple downlink interfaces. The multiple outputs of the first demultiplexer are used to output multiple downlink optical signals, with different outputs outputting downlink optical signals of different wavelengths. The multiple inputs of the optical combiner are used to input multiple uplink optical signals, with different inputs inputting uplink optical signals of different wavelengths. Specifically, when the optical combiner is an optical coupler, each input of the optical combiner allows input of an optical signal of any uplink wavelength and continues transmission, although there may be a mismatch between uplink and downlink optical signals. When the optical combiner is a multiplexer, each input of the optical combiner allows input of an optical signal of a fixed uplink wavelength and continues transmission; if an input of a different wavelength is input, that optical signal will not be able to continue transmission.

[0382] As an example, Figures 2 to 5 Each of the multiple downlink interfaces in the intermediate device shown includes a pair of sub-interfaces, namely the first sub-interface and the second sub-interface mentioned above. The first sub-interface is used to transmit downlink optical signals, and the second sub-interface is used to transmit uplink optical signals. For simplicity, the first sub-interface and the second sub-interface are referred to as... Figure 2 The downstream interface of the intermediate device shown is labeled (taking interface 1 as an example), while other downstream interfaces are not labeled, nor are they labeled in the same places in other diagrams. (Refer to...) Figure 2 That's it. For ease of distinction, in this embodiment, the optical fiber connected to the first sub-interface can be referred to as the second optical fiber, and the optical fiber connected to the second sub-interface can be referred to as the third optical fiber. For example, the first optical module is connected to the first sub-interface of the first downlink interface via the second optical fiber, and to the second sub-interface of the first downlink interface via the third optical fiber.

[0383] In the case of a dual-fiber connection between the intermediate device and the access-side optical module, the first optical module may include two uplink interfaces. In some embodiments, for ease of distinction and description, the two uplink interfaces of the first optical module may be referred to as the first uplink interface and the second uplink interface. The first uplink interface of the first optical module is connected to the first sub-interface of the first downlink interface of the intermediate device via a fiber (the second fiber), and the second uplink interface of the first optical module is connected to the second sub-interface of the first downlink interface of the intermediate device via another fiber (the third fiber).

[0384] When the first optical module includes two uplink interfaces, the photoelectric converter in the first optical module can be connected to the first uplink interface. The photoelectric converter receives the downlink optical signal transmitted through the first uplink interface and performs photoelectric conversion on the downlink optical signal to obtain a fourth electrical signal, which is then output to the first access device. The downlink optical signal transmitted through the first uplink interface carries downlink information transmitted from the routing switching device to the first access device. The tunable wavelength laser in the first optical module can be connected to the second uplink interface. The tunable wavelength laser transmits the generated uplink optical signal to the intermediate device through the second uplink interface. The tunable wavelength laser can generate an optical signal with the corresponding uplink wavelength based on the third electrical signal input from the first access device. The optical signal generated by the tunable wavelength laser in the first optical module carries uplink information transmitted from the first access device to the routing switching device.

[0385] As an example, see Figures 2 to 5 In each access-side optical module, the PD and LD are connected to different optical fibers through different uplink interfaces.

[0386] Figures 2 to 5 The diagram shows a single-fiber connection between the central optical module and the intermediate device, and a dual-fiber connection between the intermediate device and the access-side optical module. In other embodiments, the connection between the central optical module and the intermediate device can also be dual-fiber, and the connection between the intermediate device and the access-side optical module can also be single-fiber. That is, the connection method between two devices in an optical communication system can be flexibly configured according to actual conditions. Based on this, Figures 2 to 5 The optical communication system shown has several variations. The following will combine... Figures 6 to 8 Three of the variants will be introduced.

[0387] Among them, Figure 6 In this process, the connections between the central optical module and intermediate devices, as well as between the intermediate devices and access-side optical modules, are all single-fiber connections. Figure 6 By Figure 3 The dual-fiber connection between the intermediate device and the access-side optical module is replaced with a single-fiber connection. Figure 7 In the process, the central optical module is connected to the intermediate equipment via a two-fiber connection, while the intermediate equipment is connected to the access-side optical module via a single-fiber connection. Figure 7 By Figure 6 The single-fiber connection between the central optical module and the intermediate device is replaced with a dual-fiber connection. Figure 8 In this system, the connections between the central optical module and intermediate devices, as well as between the intermediate devices and access-side optical modules, are all dual-fiber connections. Figure 8 By Figure 3 The single-fiber connection between the central optical module and the intermediate device is replaced with a dual-fiber connection.

[0388] Next, combine Figure 6 and Figure 7 This paper introduces the specific implementation methods of the downlink interface of the intermediate device and the uplink interface of the access side optical module in the case of a single-fiber connection between the intermediate device and the access side optical module.

[0389] In the case of a single-fiber connection between the intermediate device and the access-side optical module, see [link / reference]. Figure 6 and Figure 7 Each of the multiple downlink interfaces in the intermediate device is connected to an optical fiber. It should be understood that each downlink interface of the intermediate device is a physical interface, and each downlink interface is connected to an access-side optical module via an optical fiber.

[0390] To achieve a single-fiber connection between the intermediate device and the access-side optical module, in one implementation, the intermediate device further includes multiple first optical splitters. A first demultiplexer in the intermediate device is connected to each of the multiple first optical splitters, and a optical combiner in the intermediate device is also connected to each of the multiple first optical splitters. Each of the multiple first optical splitters is connected to one of the multiple downlink interfaces of the intermediate device, and different first optical splitters are connected to different downlink interfaces. Each access-side optical module further includes a second optical splitter, which is connected to one downlink interface of the intermediate device via an optical fiber. Different access-side optical modules in the multiple access-side optical modules have their second optical splitters connected to different downlink interfaces of the intermediate device. Taking the first optical module (also called the first access-side optical module) among the multiple access-side optical modules as an example, the second optical splitter in the first optical module is connected to the first downlink interface among the multiple downlink interfaces via a first optical fiber.

[0391] In this intermediate device, multiple output terminals of the first demultiplexer are connected to multiple first beam splitters in a one-to-one correspondence, and multiple input terminals of the beam combining device are connected to multiple first beam splitters in a one-to-one correspondence.

[0392] Based on this, the first demultiplexer is specifically used to transmit a downlink optical signal to each of the multiple first optical splitters, wherein each first optical splitter receives one downlink optical signal, and the downlink wavelengths of the optical signals received by different first optical splitters are different; each first optical splitter is used to transmit the downlink optical signal received by it to the downlink interface connected to it; the first downlink interface is used to transmit the downlink wavelength optical signal received by the first downlink interface to the second optical splitter in the first optical module through the first optical fiber; the second optical splitter in the first optical module is used to transmit the uplink wavelength optical signal corresponding to the first optical module to the first downlink interface through the first optical fiber; each downlink interface is also used to transmit the uplink optical signal received by it to the first optical splitter connected to it; each first optical splitter is also used to transmit the uplink optical signal received by it to the optical combining device; the optical combining device is specifically used to receive multiple uplink optical signals transmitted by the multiple first optical splitters and combine the multiple uplink optical signals transmitted by the multiple first optical splitters into a composite uplink optical signal.

[0393] As an example, in Figure 3 Based on this, multiple beam splitters are added to the intermediate equipment. Figure 6 (where n are the number of first beam splitters mentioned above), and an additional beam splitter is added to each access-side optical module as the second beam splitter mentioned above, thereby obtaining... Figure 6 The optical communication system shown. Figure 6 , Figure 7 The beam splitter connected to the downlink interface of the intermediate device shown is the first beam splitter described above. Figure 6 , Figure 7 The beam splitter in the access side optical module shown is the second beam splitter described above.

[0394] In the case of a single-fiber connection between the intermediate device and the access-side optical module, each access-side optical module may include an uplink interface. Taking the first optical module as an example, the first optical module may include an uplink interface, which is connected to the first optical fiber, that is, connected to the first downlink interface of the intermediate device through the first optical fiber. The second optical splitter in the first optical module is connected to the uplink interface of the first optical module.

[0395] As an example, Figure 6 and Figure 7 The optical fiber between the intermediate device shown and the access side optical module 1 (as the first optical module) is the first optical fiber.

[0396] Optionally, when the access-side optical module includes a second beam splitter, the second beam splitter is connected to both the photoelectric converter and the tunable wavelength laser in the access-side optical module. In the downlink direction, the second beam splitter receives the downlink optical signal transmitted through the first optical fiber via the uplink interface of the access-side optical module and transmits the downlink optical signal to the photoelectric converter. The photoelectric converter in the access-side optical module performs photoelectric conversion on the downlink optical signal transmitted by the second beam splitter. In the uplink direction, correspondingly, the tunable wavelength laser in the access-side optical module transmits the generated uplink optical signal to the second beam splitter, and the second beam splitter sends the uplink optical signal generated by the tunable wavelength laser to the first optical fiber via the uplink interface.

[0397] As an example, with Figure 6 and Figure 7 Taking the access-side optical module 1 (as the first optical module) as an example, the optical signal processing flow is illustrated from the perspective of the access-side optical module. In the downlink direction, the uplink interface of the access-side optical module 1 receives the downlink optical signal (wavelength λ1) transmitted from the first optical fiber and transmits it to the second beam splitter. The second beam splitter sends the downlink optical signal to the PD in the access-side optical module 1. The PD performs photoelectric conversion on the received downlink optical signal to obtain a fourth electrical signal, which is then transmitted to the access device 1. In the uplink direction, the TLD in the access-side optical module 1 receives the third electrical signal input from the access device 1 and generates an optical signal of the corresponding uplink wavelength (referred to as the uplink optical signal, wavelength λ1) based on the third electrical signal input from the access device 1. n+1 The uplink optical signal is transmitted to the second optical splitter, which is used to send the uplink optical signal to the first optical fiber through the uplink interface of the access side optical module 1.

[0398] Finally, combining Figure 7 and Figure 8This paper introduces the specific implementation methods of the downlink interface of the central optical module and the uplink interface of the intermediate device in the case of a dual-fiber connection between the central optical module and the intermediate device.

[0399] In the case of a two-fiber connection between the central optical module and intermediate equipment, the central optical module may include a second downlink interface, a third downlink interface, a first multiplexer, a second demultiplexer, and an optoelectronic conversion device. The first multiplexer is connected to the third downlink interface, and the second demultiplexer is also connected to the third downlink interface. A fixed-wavelength laser is used to generate multiple downlink optical signals based on multiple first electrical signals, and transmits these multiple downlink optical signals to the first multiplexer. These multiple first electrical signals are electrical signals input to the routing switching equipment. The first multiplexer is used to combine the multiple downlink optical signals into a composite downlink optical signal, and transmits the combined composite downlink optical signal through the second downlink interface. The second demultiplexer is used to demultiplex multiple uplink optical signals from the composite uplink optical signal received from the third downlink interface, and transmits these multiple uplink optical signals to the optoelectronic conversion device. The optoelectronic conversion device is used to convert the multiple uplink optical signals into multiple second electrical signals and output these multiple second electrical signals to the routing switching equipment.

[0400] Accordingly, the intermediate equipment includes two uplink interfaces, referred to as the first uplink interface and the second uplink interface. The first uplink interface is connected to the second downlink interface of the central optical module, and the second uplink interface is connected to the third downlink interface of the central optical module via optical fibers. The first demultiplexer of the intermediate equipment is used to receive the composite downlink optical signal sent by the central optical module through the first uplink interface. The optical combiner of the intermediate equipment is used to send the composite uplink optical signal to the central optical module through the second uplink interface.

[0401] As an example, see Figures 7 to 8 The central optical module has a first multiplexer (MUX) and a second demultiplexer (DEMUX). The intermediate equipment also has a first demultiplexer (DEMUX) and a combining device (optical coupler). The central optical module's MUX and the intermediate equipment's DEMUX are connected via one optical fiber, and the central optical module's DEMUX and the intermediate equipment's optical coupler are connected via another optical fiber.

[0402] The above text combined Figures 2 to 8 This paper describes the connection methods between the intermediate device and the access-side optical module, as well as the connection methods between the intermediate device and the central optical module. Specifically, Figures 2 to 5 ,as well as Figure 9 The central optical module and the intermediate device are connected by a single fiber, while the intermediate device and the access side optical module are connected by a dual fiber. Figure 6 The central optical module and the intermediate device are connected by a single fiber, and the intermediate device and the access side optical module are also connected by a single fiber. Figure 7The central optical module and the intermediate device are connected by a dual-fiber connection, while the intermediate device and the access-side optical module are connected by a single-fiber connection. Figure 8 The central optical module and intermediate equipment shown are connected via a two-fiber connection, as are the intermediate equipment and the access-side optical module. This means the connection method between the two devices can be flexibly configured according to actual needs. Descriptions of the same parts in any two diagrams are interchangeable and will not be repeated here.

[0403] It is worth noting that in implementations where single-fiber connections are used between the central optical module and intermediate devices, and between the intermediate devices and access-side optical modules (e.g.) Figure 6 (Example) The connection method between devices is relatively simple, the optical networking is less difficult, and the amount of optical fiber used is less, saving optical fiber resources.

[0404] It should be understood that, in Figures 2 to 8 In the illustrated optical communication system, the optical combining device in the intermediate equipment is an optical coupler; that is, all intermediate equipment uses optical couplers to combine optical signals from the access-side optical module. In other embodiments, the optical combining device in the intermediate equipment can also be a multiplexer; that is, the intermediate equipment can also use a multiplexer to combine optical signals from the access-side optical module. Based on this, it can be... Figures 2 to 8 The optical couplers in the intermediate devices shown are all replaced with a multiplexer, resulting in seven other optical communication system architectures. For example, replacing one with a "multiplexer" Figure 3 Taking the "optical coupler" in the example, we can obtain the following: Figure 9 The optical communication system shown.

[0405] Among them, when the intermediate equipment uses an optical coupler as the uplink combining device, the cost of the intermediate equipment is relatively low.

[0406] Combination Figures 2 to 9As can be seen, after all the devices / appliances in the optical communication system are connected, the physical channels between the routing and switching equipment and each access device are established and can be used to transmit optical signals. There is a physical channel group between the routing and switching equipment and each access device, which includes one downlink channel and one uplink channel. With each LD and PD in the central optical module of the routing and switching equipment configured, the transmit wavelength of each LD is fixed, and the receive wavelength of each PD is also fixed. Thus, the downlink wavelength corresponding to each downlink channel is fixed, and the uplink wavelength corresponding to each uplink channel is also fixed. Each downlink channel is used to transmit optical signals of the corresponding downlink wavelength to the corresponding access device. The access-side optical module receives optical signals of fixed downlink wavelengths. Different downlink channels correspond to different downlink wavelengths, therefore, different access-side optical modules receive different downlink wavelengths. The access-side optical modules on the access devices transmit optical signals of the corresponding uplink wavelengths to the routing and switching equipment through the corresponding uplink channels. The uplink wavelengths corresponding to the optical signals transmitted by different access devices should be different and should correspond to the corresponding uplink channels.

[0407] It should be understood that a downlink channel can include multiple devices and optical fibers that are interconnected. For example, with... Figure 3 For example, a downlink channel consists of the downlink portion of a SERDS, the electrical connection between the SERDS and an LD of the central optical module, an LD of the central optical module, the optical path between an LD of the central optical module and the MUX of the central optical module, the MUX of the central optical module, the fiber optic link between the MUX of the central optical module and the DEMUX of an intermediate device, the DEMUX of the intermediate device, the optical path between an output of the DEMUX of the intermediate device and its connected downlink interface, the fiber optic link between the downlink interface of the intermediate device and the PD of an access-side optical module, and the electrical connection between the PD of the access-side optical module and the access device. In simple terms, a downlink channel is all the devices and links from a SERDS of a routing switching device to the access device with which it is connected.

[0408] Similarly, an uplink channel can include multiple interconnected devices and optical fibers. For example, using... Figure 3For example, an uplink channel comprises the electrical connection between an access device and the LD of the access-side optical module, the optical fiber link between the LD and the downlink interface of an intermediate device, the optical path between the downlink interface of the intermediate device and the optical coupler of the intermediate device, the optical fiber link between the optical coupler of the intermediate device and the DEMUX of the central optical module, the optical path between an output of the DEMUX of the central optical module and a PD of the central optical module, and the electrical connection between the PD and the SERDEs. In simple terms, an uplink channel consists of all the devices and links from an access-side optical module to the SERDEs of the central optical module with which it is connected.

[0409] exist Figures 2 to 9 Taking n access-side optical modules and n physical channel groups as an example, the optical communication system is used to transmit optical signals of n downlink wavelengths and n uplink wavelengths, respectively. These n downlink wavelengths are denoted as λ1~λ2. n These n uplink wavelengths are denoted as λ. n+1 ~λ 2n The intermediate device includes n downlink interfaces, denoted as interface 1 to interface n. Among them, in Figures 2 to 5 , Figures 8 to 9 In the diagram, each interface from interface 1 to interface n includes a first sub-interface and a second sub-interface, meaning each interface comprises two physical interfaces; Figures 6 to 7 In this context, each of the interfaces from interface 1 to interface n is a physical interface.

[0410] In summary, each access-side optical module in this embodiment can be connected to any downlink interface of the intermediate device via optical fiber, and different access-side optical modules can be connected to different downlink interfaces on the intermediate device. That is, these multiple access-side optical modules are "normalized" optical modules that can be mixed and matched into multiple downlink interfaces of the intermediate device without needing to consider the correspondence between downlink interfaces, access-side optical modules, and uplink / downlink wavelengths.

[0411] It should be understood that the system architecture and business scenarios described in the embodiments of this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided in the embodiments of this application. As those skilled in the art will know, with the evolution of system architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0412] The optical communication method provided in the embodiments of this application will be described next. This optical communication method can be applied to... Figures 2 to 9 In any of the optical communication systems shown.

[0413] First, we will introduce the optical communication method executed by the access-side optical module.

[0414] Figure 10 This is a flowchart of an optical communication method provided in an embodiment of this application. The steps of the method are executed by a first optical module, which is any one of multiple access-side optical modules included in the optical communication system. These multiple access-side optical modules correspond to multiple uplink wavelengths and multiple downlink wavelengths. Different access-side optical modules correspond to different downlink wavelengths, and different access-side optical modules correspond to different uplink wavelengths. The wavelength division multiplexing (WDM) interval of the multiple downlink wavelengths is greater than the WDM interval of the multiple uplink wavelengths. For a detailed description of the uplink and downlink WDM intervals, please refer to the system embodiment above; it will not be repeated here. Please refer to... Figure 10 The method includes the following steps.

[0415] Step 1001: Receive downlink optical signal, the wavelength of which is the first downlink wavelength corresponding to the first optical module.

[0416] As can be seen from the above introduction to optical communication systems, in one implementation method, such as Figure 6 and Figure 7 As shown, the first optical module includes an uplink interface and a beam splitter. The uplink interface is connected to an optical fiber, which can be referred to as the first optical fiber. The beam splitter is connected to the uplink interface. That is, the first optical module achieves a single-fiber connection with the intermediate device through a single optical fiber. In this case, the specific implementation of the first optical module receiving downlink optical signals is as follows: the beam splitter of the first optical module receives the downlink optical signal transmitted through the first optical fiber via the uplink interface of the first optical module. After receiving the downlink optical signal, the beam splitter of the first optical module also transmits the downlink optical signal to the photoelectric converter in the first optical module.

[0417] In another implementation, such as Figures 2 to 5 , Figure 8 , Figure 9 As shown, the first optical module includes two uplink interfaces, referred to in this embodiment as the first uplink interface and the second uplink interface, respectively. The first uplink interface and the second uplink interface are connected to different optical fibers. That is, the first optical module achieves a two-fiber connection with the intermediate device through two optical fibers. In this case, the specific implementation of the first optical module receiving downlink optical signals is as follows: the first uplink interface of the first optical module receives the downlink optical signals transmitted on the optical fiber to which it is connected. The first uplink interface is also connected to the optoelectronic converter of the first optical module, and the first uplink interface transmits the received downlink optical signals to the optoelectronic converter.

[0418] In this embodiment of the application, the photoelectric converter in the first optical module has the ability to process optical signals of different downlink wavelengths. The photoelectric converter can perform photoelectric conversion on the received downlink optical signal to obtain the first electrical signal.

[0419] The first optical module is integrated into or inserted into the first access device. The downlink optical signal received by the first optical module carries downlink information transmitted from the routing switching device to the first access device. The photoelectric converter of the first optical module performs photoelectric conversion on the downlink optical signal to obtain the first electrical signal. After obtaining the first electrical signal, it can also transmit the first electrical signal to the first access device so that the first access device can process the downlink information carried by the first electrical signal.

[0420] Step 1002: Generate and send an uplink optical signal. The wavelength of the uplink optical signal is the first uplink wavelength corresponding to the first optical module.

[0421] The first optical module includes a tunable wavelength laser. Compared to a fixed wavelength laser, the wavelength of the optical signal generated by the tunable wavelength laser is not fixed and unique, but adjustable within a certain range. In other words, the tunable wavelength laser has the ability to generate optical signals of different wavelengths. Based on this, the specific implementation method of the first optical module generating and transmitting uplink optical signals is as follows: the tunable wavelength laser generates and transmits the uplink optical signal.

[0422] Before the tunable wavelength laser generates and transmits the uplink optical signal, the first optical module can also receive a second electrical signal transmitted by the first access device. The uplink optical signal generated by the tunable wavelength laser carries the uplink information transmitted by the first access device through the second electrical signal. Based on this, the tunable wavelength laser can generate the uplink optical signal based on the second electrical signal.

[0423] In the case where the first optical module includes an uplink interface and a beam splitter (e.g.) Figure 6 and Figure 7 As shown, a tunable wavelength laser can be connected to the beam splitter, and the tunable wavelength laser can send the uplink optical signal to the beam splitter. The beam splitter can send the uplink optical signal generated by the tunable wavelength laser to the first optical fiber through the uplink interface of the first optical module.

[0424] In the case where the first optical module includes a first uplink interface and a second uplink interface (e.g.) Figures 2 to 5 , Figure 8 , Figure 9 As shown, the tunable wavelength laser can be connected to the second uplink interface, and the tunable wavelength laser can transmit the uplink optical signal generated by the tunable wavelength laser to the second uplink interface. The second uplink interface sends the uplink optical signal generated by the tunable wavelength laser through the optical fiber it is connected to.

[0425] It should be understood that steps 1001 and 1002 are not in any particular order. These two steps can occur simultaneously or at different times, meaning that the transmission processes of uplink and downlink information are independent of each other.

[0426] In summary, in the embodiments of this application, the wavelength division interval of multiple downlink wavelengths is greater than the wavelength division interval of multiple uplink wavelengths, such as coarse wavelength division for downlink and dense wavelength division for uplink. Thus, the hybrid wavelength division scheme ensures the reliability of optical communication while taking into account the cost of equipment / devices in the optical communication system, as well as the difficulty of production and deployment.

[0427] Furthermore, when the access-side optical module includes a tunable wavelength laser and the uplink is dense wavelength division multiplexing, the "normalization" scheme of the access-side optical module becomes feasible, thereby reducing the production cost and deployment difficulty of the access-side optical module and reducing the networking difficulty of optical communication.

[0428] Next, we will introduce the optical communication method executed by the central optical module. It should be understood that the steps executed by the central optical module can be combined with the steps executed by the access-side optical module described above, thereby completing the transmission of uplink and downlink information between the routing switching equipment and the access equipment.

[0429] Figure 11 This is a flowchart of another optical communication method provided in this application embodiment. The method is applied to a central optical module in an optical communication system. The optical communication system also includes multiple access-side optical modules, each corresponding to a multiple uplink wavelength and a multiple downlink wavelength. Different access-side optical modules correspond to different downlink wavelengths, and different access-side optical modules correspond to different uplink wavelengths. The central optical module includes a fixed-wavelength laser, which generates multiple fixed-wavelength optical signals, including the aforementioned multiple downlink wavelengths. The wavelength division multiplexing (WDM) interval of the multiple downlink wavelengths is greater than the WDM interval of the multiple uplink wavelengths. For details regarding the fixed-wavelength laser and the uplink / downlink WDM intervals, please refer to the system embodiment above; further details are omitted here. See also... Figure 11 The method includes the following steps.

[0430] Step 1101: Send multiple downlink optical signals. These multiple downlink optical signals are generated by the fixed-wavelength laser of the central optical module. The wavelengths of these multiple downlink optical signals are multiple downlink wavelengths corresponding to multiple access-side optical modules.

[0431] In this embodiment, the central optical module is integrated into or inserted into the routing and switching equipment. The fixed-wavelength laser in the central optical module can generate multiple downlink optical signals based on multiple first electrical signals input from the routing and switching equipment. These multiple downlink optical signals carry downlink information sent by the routing and switching equipment through the multiple first electrical signals. Each of the multiple first electrical signals corresponds one-to-one with a multiple access-side optical module, and the downlink information carried by the multiple first electrical signals includes information sent to the multiple access-side optical modules. For a detailed description of the fixed-wavelength laser, please refer to the system embodiment described above; it will not be repeated here.

[0432] The central optical module further includes a multiplexer and at least one downlink interface, the downlink interface of which is connected to an optical fiber. Step 1101 can be implemented by the multiplexer in the central optical module merging multiple downlink optical signals generated by a fixed-wavelength laser into a composite downlink optical signal, and then transmitting the composite downlink optical signal through the downlink interface of the central optical module.

[0433] The multiplexer in the central optical module can be Figure 2 OMUX in the context can also be Figures 3 to 9 The MUX is shown in the central optical module.

[0434] In one possible implementation, the central optical module includes a multiplexer (in some embodiments, this may be referred to as a multiplexing-demultiplexer), a beam splitter, and a downlink interface. The central optical module can be a [missing information - likely a specific component or interface]. Figure 2 The OMUX shown is configured as the central optical module obtained by the MUX (which has both multiplexing and demultiplexing functions). The splitter of the central optical module is connected to the multiplexer and also to the downlink interface of the central optical module. Based on this, after the multiplexer combines multiple downlink optical signals into a composite downlink optical signal, it transmits the composite downlink optical signal to the splitter, and the splitter sends the composite downlink optical signal to the downlink interface.

[0435] The central optical module includes a multiplexer, a demultiplexer, a downlink interface, and a beam splitter (e.g., ...). Figure 3 , Figure 6 , Figure 9 As shown, the beam splitter is connected to the multiplexer and demultiplexer of the central optical module, and is also connected to the downlink interface. Based on this, after the multiplexer combines multiple downlink optical signals into a composite downlink optical signal, it transmits the composite downlink optical signal to the beam splitter, and the beam splitter sends the composite downlink optical signal to the downlink interface.

[0436] In another possible implementation, the central optical module includes a multiplexer, a demultiplexer, and a downlink interface (such as...). Figure 5 As shown, the multiplexer is connected to the demultiplexer and also to the downlink interface. Based on this, the multiplexer combines multiple downlink optical signals into a composite downlink optical signal and then sends the composite downlink optical signal to the downlink interface.

[0437] In another possible implementation, the central optical module includes a multiplexer and a downlink interface (such as...). Figure 4 As shown, the multiplexer is connected to the downlink interface. Based on this, the multiplexer combines multiple downlink optical signals into a composite downlink optical signal and then sends the composite downlink optical signal to the downlink interface. In some embodiments, the multiplexer may also be referred to as a multiplexing-demultiplexer.

[0438] In another possible implementation, the central optical module includes a multiplexer, a demultiplexer, and two downlink interfaces (such as...). Figure 7 , Figure 8 As shown, these two downlink interfaces can be referred to as the first downlink interface and the second downlink interface of the central optical module. The multiplexer is connected to the first downlink interface, and the demultiplexer is connected to the second downlink interface. The first downlink interface and the second downlink interface are connected to different optical fibers, respectively. Based on this, after the multiplexer combines multiple downlink optical signals into a composite downlink optical signal, it transmits the composite downlink optical signal through the connected first downlink interface.

[0439] Step 1102: Receive multiple uplink optical signals, the wavelengths of which are multiple uplink wavelengths corresponding to multiple access side optical modules.

[0440] Among them, the multiple uplink optical signals carry uplink information sent by multiple access-side optical modules to the routing and switching equipment.

[0441] In one possible implementation, the central optical module includes a demultiplexer and at least one downlink interface. The central optical module can receive composite uplink optical signals through the downlink interface. The demultiplexer can demultiplex multiple uplink optical signals from the composite uplink optical signals, thereby receiving multiple uplink optical signals.

[0442] In the case where the central optical module includes a multiplexer, a demultiplexer, a downlink interface, and a beam splitter (e.g.) Figure 3 , Figure 6 , Figure 9 As shown, the optical splitter receives the composite uplink optical signal transmitted on the optical fiber connected to the downlink interface through the downlink interface, and transmits the composite uplink optical signal to the demultiplexer.

[0443] In the case where the central optical module includes a downlink interface, a multiplexer, and a demultiplexer (e.g.) Figure 5 As shown), the central optical module receives composite uplink optical signals through the downlink interface. The composite uplink optical signals received by the downlink interface are transmitted to the multiplexer. That is, the multiplexer receives composite uplink optical signals transmitted on the connected optical fiber through the downlink interface. After that, the multiplexer transmits composite uplink optical signals to the demultiplexer.

[0444] In the case where the central optical module includes a multiplexer, a demultiplexer, a first downlink interface, and a second downlink interface (e.g.) Figure 7 , Figure 8 As shown), the central optical module receives composite uplink optical signals through the second downlink interface. The composite uplink optical signals received by the second downlink interface are transmitted to the demultiplexer, that is, the demultiplexer receives composite uplink optical signals through the connected second downlink interface.

[0445] In another possible implementation, the central optical module includes a downlink interface and a multiplexer (also known as a multiplexing / demultiplexer) (e.g. Figure 4 As shown), the central optical module receives composite uplink optical signals through the downlink interface. The composite uplink optical signals received by the downlink interface are transmitted to the multiplexer. That is, the multiplexer receives composite uplink optical signals transmitted on the connected optical fiber through the downlink interface. Then, the multiplexer demultiplexes multiple uplink optical signals from the composite uplink optical signals.

[0446] In another possible implementation, the central optical module includes a multiplexer / demultiplexer, a beam splitter, and a downlink interface (such as...). Figure 2 The OMUX shown is configured as a MUX (which has both multiplexing and demultiplexing functions). The central optical module receives composite uplink optical signals through the downlink interface. The downlink interface transmits composite uplink optical signals to the splitter. The splitter transmits composite uplink optical signals to the multiplexer / demultiplexer. Then, the multiplexer / demultiplexer demultiplexes multiple uplink optical signals from the composite uplink optical signals.

[0447] In this embodiment of the application, the central optical module further includes an optoelectronic conversion device. After the central optical module demultiplexes multiple uplink optical signals through a multiplexer / demultiplexer, the multiple uplink optical signals are transmitted to the optoelectronic conversion device of the central optical module. The optoelectronic conversion device performs optoelectronic conversion on the multiple uplink optical signals respectively to obtain multiple second electrical signals, and sends the multiple second electrical signals to the routing and switching equipment.

[0448] It should be understood that steps 1101 and 1102 above are not in any particular order. These two steps can occur simultaneously or at different times, meaning that the transmission processes of uplink and downlink information are independent of each other.

[0449] In summary, in the embodiments of this application, the wavelength division interval of multiple downlink wavelengths is greater than the wavelength division interval of multiple uplink wavelengths, such as coarse wavelength division for downlink and dense wavelength division for uplink. Thus, the hybrid wavelength division scheme ensures the reliability of optical communication while taking into account the cost of equipment / devices in the optical communication system, as well as the difficulty of production and deployment.

[0450] Furthermore, when the access-side optical module includes a tunable wavelength laser and the uplink is dense wavelength division multiplexing, the "normalization" scheme of the access-side optical module becomes feasible, thereby reducing the production cost and deployment difficulty of the access-side optical module and reducing the networking difficulty of optical communication.

[0451] Next, we will introduce the optical communication method executed by the intermediate device. It should be understood that the steps executed by the intermediate device can be combined with the steps executed by the access-side optical module and the central optical module described above, thereby completing the transmission of uplink and downlink information between the routing switching device and the access device.

[0452] Figure 12 This is a flowchart of another optical communication method provided in this application embodiment. The method is applied to an intermediate device included in an optical communication system. The optical communication system also includes multiple access-side optical modules, each corresponding to multiple uplink wavelengths and multiple downlink wavelengths. Different access-side optical modules correspond to different downlink wavelengths, and different access-side optical modules correspond to different uplink wavelengths. As can be seen from the above, the intermediate device may include a demultiplexer and a optical combiner. The optical combiner may include an optical coupler or a multiplexer (such as a wavelength multiplexer). Different types of optical combiners play similar roles in this application embodiment. Figure 12 In the illustrated embodiment, the intermediate device includes a demultiplexer and an optical coupler (such as...). Figures 2 to 8 Taking the example shown, we will introduce some steps performed by the intermediate equipment, especially when the optical combining device in the intermediate equipment is a wave multiplexer (such as...). Figure 9 As shown in the diagram, the steps performed by the multiplexer are similar to those performed by the optocoupler, and will not be repeated here. See also Figure 12 The method includes the following steps.

[0453] Step 1201: Receive a composite downlink optical signal, which includes multiple downlink optical signals.

[0454] In this embodiment, the intermediate device further includes at least one uplink interface, which is connected to an optical fiber and connected to the central optical module via the optical fiber. The intermediate device can receive composite downlink optical signals through this at least one uplink interface. Each uplink interface of the intermediate device is connected to one optical fiber, and different uplink interfaces are connected to different optical fibers.

[0455] In one possible implementation, the intermediate device includes a demultiplexer, an optical coupler, and two uplink interfaces (such as...). Figure 7 and Figure 8 As shown in the diagram, these two uplink interfaces are referred to as the first uplink interface and the second uplink interface of the intermediate device, respectively. The first and second uplink interfaces of the intermediate device are connected to different optical fibers. The demultiplexer of the intermediate device is connected to the first uplink interface, and the optical coupler of the intermediate device is connected to the second uplink interface. Based on this, the intermediate device receives the composite downlink optical signal transmitted on the connected optical fiber through the first uplink interface, and transmits the composite downlink optical signal to the demultiplexer through the first uplink interface.

[0456] In another possible implementation, the intermediate devices include a demultiplexer, an optical coupler, and a beam splitter connected to the uplink interface (this beam splitter has different names in different embodiments; for example, in the system embodiment described above, it could be called the third beam splitter). Figure 12In the embodiment, it can be referred to as the second beam splitter) and an uplink interface (such as... Figures 2 to 6 As shown in the diagram, the uplink interface connects to an optical fiber, and the second optical splitter is connected to the uplink interface, demultiplexer, and optical coupler of the intermediate device, respectively. Based on this, the process of the intermediate device receiving a composite downlink optical signal through at least one uplink interface can include: the uplink interface of the intermediate device receives the composite downlink optical signal transmitted through the connected optical fiber and transmits the received composite downlink optical signal to the second optical splitter. Then, the second optical splitter transmits the composite downlink optical signal to the demultiplexer of the intermediate device.

[0457] In the embodiments of this application, the wavelength division interval of the multiple downlink wavelengths is greater than the wavelength division interval of the multiple uplink wavelengths. The wavelength division interval of the multiple downlink wavelengths is the wavelength division interval corresponding to the multiple downlink optical signals included in the composite downlink optical signal, and the wavelength division interval of the multiple uplink wavelengths is the wavelength division interval corresponding to the multiple uplink optical signals included in the composite uplink optical signal as described below.

[0458] In one possible implementation, the wavelength division multiplexing (WDM) intervals of multiple downlink wavelengths are greater than or equal to a first threshold, and the wavelength division multiplexing (WDM) intervals of multiple uplink wavelengths are less than a second threshold, wherein the first threshold is greater than or equal to the second threshold.

[0459] In one possible implementation, the multiple downlink optical signals included in the aforementioned composite downlink optical signal are transmitted using coarse wavelength division multiplexing (CWDM). A detailed introduction to CWDM can be found above and will not be repeated here.

[0460] Step 1202: Demultiplex the composite downlink optical signal into multiple downlink optical signals using a demultiplexer.

[0461] In other words, after the demultiplexer of the intermediate device receives the composite downlink optical signal, it can demultiplex multiple downlink optical signals from the composite downlink optical signal.

[0462] Step 1203: Based on the downlink wavelengths of the multiple downlink optical signals obtained by demultiplexing, send the corresponding downlink optical signals to multiple access-side optical modules.

[0463] In this embodiment, the intermediate device further includes multiple downlink interfaces connected to optical fibers. These downlink interfaces are connected to multiple access-side optical modules via optical fibers, and different access-side optical modules are connected to different downlink interfaces on the intermediate device. Therefore, the intermediate device can send corresponding downlink optical signals to the multiple access-side optical modules through these multiple downlink interfaces. Each downlink interface sends an optical signal of a downlink wavelength, and the downlink wavelengths of the optical signals sent by different downlink interfaces are different.

[0464] In one possible implementation, each of the multiple downlink interfaces of the intermediate device is connected to an optical fiber, and different downlink interfaces are connected to different optical fibers. The intermediate device also includes multiple first optical splitters, and the demultiplexer of the intermediate device is connected to each of the multiple first optical splitters. The optical coupler of the intermediate device is also connected to each of the multiple first optical splitters. Each of the multiple first optical splitters is connected to one of the multiple downlink interfaces of the intermediate device, and different first optical splitters are connected to different downlink interfaces (e.g., ...). Figure 6 and 7 (As shown). Based on this, after the demultiplexer demultiplexes multiple downlink optical signals from the composite downlink optical signal, it can transmit a downlink optical signal to each of the multiple first optical splitters. Each first optical splitter receives one downlink optical signal, and the downlink wavelengths of the optical signals received by different first optical splitters are different. Each of the multiple first optical splitters transmits its received downlink optical signal to its respective connected downlink interface, and each of the multiple downlink interfaces transmits its received downlink optical signal through its respective connected optical fiber.

[0465] In another possible implementation, each of the multiple downlink interfaces of the intermediate device includes a first sub-interface and a second sub-interface. The demultiplexer of the intermediate device is connected to each of the multiple first sub-interfaces of the multiple downlink interfaces, and the optical coupler of the intermediate device is connected to each of the multiple second sub-interfaces of the multiple downlink interfaces. The second sub-interface and the first sub-interface of each downlink interface are connected to different optical fibers (e.g., Figures 2 to 5 , Figure 8 (As shown). Based on this, after the demultiplexer demultiplexes multiple downlink optical signals from the composite downlink optical signal, it can transmit multiple downlink optical signals to the multiple first sub-interfaces. Each first sub-interface receives one downlink optical signal, and the downlink wavelengths of the optical signals received by different first sub-interfaces are different. Each downlink interface transmits the downlink optical signal received by its first sub-interface through the connected optical fiber.

[0466] Through steps 1201 to 1203 above, the intermediate device can transmit the multiple downlink optical signals included in the received composite downlink optical signal to multiple access-side optical modules. Among them, one access-side optical module receives one downlink optical signal, and different access-side optical modules receive different downlink optical signals. In this way, the optical communication system completes the downlink information transmission from the routing and switching device to the access-side optical modules through the intermediate device.

[0467] The process of transmitting uplink optical signals by intermediate devices will be described in steps 1204 and 1205 below.

[0468] Step 1204: Combine multiple uplink optical signals from multiple access side optical modules using an optical coupler to obtain a composite uplink optical signal.

[0469] In this embodiment, the intermediate device includes multiple downlink interfaces. The intermediate device can receive corresponding uplink optical signals sent by multiple access-side optical modules through these multiple downlink interfaces. Each of the multiple downlink interfaces receives an optical signal of a downlink wavelength, and the uplink wavelengths of the optical signals received by different downlink interfaces are different.

[0470] In this configuration, each of the multiple downlink interfaces in the intermediate device is connected to an optical fiber, with different downlink interfaces connected to different optical fibers. The intermediate device may also include multiple first optical splitters (e.g., ...). Figure 6 and Figure 7 As shown), each of the multiple downlink interfaces in the intermediate device receives the uplink optical signal transmitted by its respective connected optical fiber. Each downlink interface receives one uplink optical signal, and the downlink wavelengths of the optical signals received by different downlink interfaces are different. Each of the multiple downlink interfaces transmits its received uplink optical signal to its respective connected first optical splitter, and the multiple first optical splitters transmit their received uplink optical signals to the optical coupler of the intermediate device.

[0471] In the case where each downlink interface of the intermediate device includes a first sub-interface and a second sub-interface (e.g.) Figures 2 to 5 , Figure 8 As shown), the second sub-interface among the multiple downlink interfaces of the intermediate device receives the uplink optical signal transmitted by the optical fiber connected to the second sub-interface, and transmits the uplink optical signal received by the second sub-interface to the optical coupler of the intermediate device.

[0472] After receiving multiple uplink optical signals from multiple access-side optical modules, the optical coupler can combine these multiple uplink optical signals to obtain a composite uplink optical signal.

[0473] In one possible implementation, the multiple uplink optical signals included in the aforementioned composite uplink optical signal are transmitted using dense wavelength division multiplexing (DWDM). A detailed introduction to DWDM can be found above and will not be repeated here.

[0474] Step 1205: Send composite uplink optical signal.

[0475] In this embodiment, the intermediate device includes at least one uplink interface, through which it can transmit composite uplink optical signals. Thus, the intermediate device can transmit composite uplink optical signals to the central optical module.

[0476] In the case where the intermediate device includes an uplink interface and a second beam splitter (e.g.) Figures 2 to 6 As shown, the optical coupler of the intermediate device transmits the composite uplink optical signal to the second optical splitter, the second optical splitter transmits the composite uplink optical signal to the uplink interface of the intermediate device, and the uplink interface of the intermediate device sends the composite uplink optical signal through the connected optical fiber.

[0477] In the case where the intermediate device includes a first uplink interface and a second uplink interface (e.g.) Figure 7 and Figure 8 As shown, the optical coupler of the intermediate device transmits a composite uplink optical signal to the second uplink interface, and the second uplink interface sends a composite uplink optical signal to the connected optical fiber.

[0478] It should be understood that steps 1201 to 1203 can occur in sequence, and steps 1204 to 1205 can also occur in sequence. However, the sub-processes including steps 1201 to 1203 and the sub-processes including steps 1204 to 1205 are not in any particular order. That is, the transmission processes of uplink and downlink information are independent of each other.

[0479] In summary, in the embodiments of this application, the intermediate device adopts a combination of demultiplexer (such as DMUX) and optical coupler (such as splitter) to transmit optical signals, which makes the cost of the intermediate device lower and can also ensure the reliability of optical communication.

[0480] Furthermore, the wavelength division spacing of multiple downlink wavelengths is greater than that of multiple uplink wavelengths, such as coarse wavelength division for downlink and dense wavelength division for uplink. In this way, the hybrid wavelength division scheme can ensure the reliability of optical communication while taking into account the cost of equipment / devices in the optical communication system, as well as the difficulty of production and deployment.

[0481] Furthermore, when the access-side optical module includes a tunable wavelength laser and the uplink is dense wavelength division multiplexing, the "normalization" scheme of the access-side optical module becomes feasible, thereby reducing the production cost and deployment difficulty of the access-side optical module and reducing the networking difficulty of optical communication.

[0482] The above describes some implementation methods of the optical communication method provided in the embodiments of this application. As can be seen from the above, in the embodiments of this application, the downlink wavelength division spacing (i.e., the wavelength division spacing of multiple downlink wavelengths) is greater than the uplink wavelength division spacing. For example, CWDM is used for downlink and DWDM is used for uplink, thereby ensuring the reliability of optical communication while taking into account the cost of equipment / devices in the optical communication system, as well as the difficulty of production and deployment.

[0483] The central optical module is a multi-wavelength transceiver optical module. The laser at the transmitting end of the central optical module is a fixed-wavelength laser (such as a DFB laser). This fixed-wavelength laser comprises multiple lasers, each with a different emission wavelength, corresponding to a group of N access-side optical modules (e.g., 8). These fixed-wavelength lasers share N fixed wavelengths. The receiving end of the central optical module can use a wavelength divider to obtain multiple uplink optical signals with different uplink wavelengths. Using a fixed-wavelength laser reduces the cost of the central optical module.

[0484] Intermediate equipment can be a passive aggregation module, serving as the transmission medium for optical signals between the central optical module and the access-side optical modules. In the downlink direction, the intermediate equipment uses a demultiplexer to demultiplex the composite optical signal transmitted from the central optical module into multiple downlink optical signals. These multiple downlink optical signals are then transmitted to multiple access-side optical modules, with each access-side optical module receiving one downlink optical signal. In the uplink direction, the intermediate equipment can use an optical coupler or a multiplexer as the optical combining device, which aggregates / couples the uplink optical signals from multiple access-side optical modules into a single optical fiber. Using a demultiplexer and an optical coupler to implement the intermediate equipment can reduce its cost.

[0485] Multiple access-side optical modules can be normalized optical modules, with broadband reception at the receiving end and wavelength tunable transmission at the transmitting end. "Normalized" optical modules can reduce the production cost and deployment difficulty of access-side optical modules, and reduce the networking difficulty of optical communication.

[0486] It should be understood that, considering the loss of optical signals during transmission over long distances in optical fibers, the optical signals transmitted by the central optical module and received by intermediate devices are not entirely the same, and the optical signals transmitted by intermediate devices are not entirely the same as those received by the access-side optical module. Therefore, in some embodiments, terms such as 'first,' 'second,' 'third,' and 'fourth' can be used to distinguish between the transmitted and received optical signals. For example, the composite downlink optical signal transmitted by the central optical module can be called the first composite downlink optical signal. After transmission through the optical fiber between the central optical module and the intermediate devices, the first composite downlink optical signal becomes the second composite downlink optical signal due to loss; that is, the composite downlink optical signal received by the intermediate devices can be called the second composite downlink optical signal. However, in the embodiments of this application, for ease of understanding and simplicity, the transmitted and received optical signals may not have been distinguished in their naming in the above embodiments, but this does not mean that the transmitted and received optical signals are completely identical.

[0487] Furthermore, for ease of understanding and simplicity, since the loss of optical signals transmitted within the same device is very small and almost negligible, the naming of optical signals within the same device has been simplified in this embodiment. Without causing misunderstanding, optical signals transmitted and received between different modules within the same device are named the same optical signal. For example, the optical signal output from the demultiplexer in the intermediate device and the optical signal received by the downlink interface of the intermediate device are named the same optical signal. In reality, however, due to losses in optical fiber transmission, the optical signal transmitted by a module may differ from the optical signal received by the peer module. For instance, the optical signal output from the demultiplexer in the intermediate device may differ from the optical signal received by the downlink interface of the intermediate device.

[0488] This application embodiment also provides an access-side optical module, which can be implemented by software, hardware, or a combination of both as part or all of an access device. The access device can be as described above. Figures 2 to 9 Any of the access devices in the system shown can also be the aforementioned Figures 10 to 13 In the method embodiment, the first access device may also have an access-side optical module that is independent of the access device and inserted into it during application. Taking the access device as the first access device and the access-side optical module as the first optical module as an example, the first optical module is integrated into or inserted into the first access device. The first optical module and... Figures 2 to 9 The other devices / devices in the system cooperate with each other to ensure the reliability of optical communication, and the first optical module is a normalized access-side optical module, which reduces the production cost and deployment difficulty of the access-side optical module.

[0489] The first optical module is any one of the multiple access-side optical modules included in the optical communication system. The multiple access-side optical modules correspond to multiple uplink wavelengths and multiple downlink wavelengths. Different access-side optical modules correspond to different downlink wavelengths, and different access-side optical modules correspond to different uplink wavelengths. The wavelength division multiplexing (WDM) interval of the multiple downlink wavelengths is greater than the wavelength division multiplexing (WDM) interval of the multiple uplink wavelengths. The first optical module includes an optical fiber interface, an optical receiving component, and an optical transmitting component.

[0490] An optical receiving component is used to receive downlink optical signals transmitted through an optical fiber interface, wherein the wavelength of the downlink optical signal is the first downlink wavelength corresponding to the first optical module.

[0491] An optical transmitting component is used to generate an uplink optical signal and transmit the uplink optical signal through an optical fiber interface. The wavelength of the uplink optical signal is the first uplink wavelength corresponding to the first optical module.

[0492] In one possible implementation, the wavelength division spacing of multiple downlink wavelengths is determined based on coarse wavelength division multiplexing (CWDM), and the wavelength division spacing of multiple uplink wavelengths is determined based on dense wavelength division multiplexing (DWDM).

[0493] In one possible implementation, the wavelength division multiplexing (WDM) intervals of multiple downlink wavelengths are greater than or equal to a first threshold, and the WDM intervals of multiple uplink wavelengths are less than a second threshold, wherein the first threshold is greater than or equal to the second threshold. Specific implementation methods for the WDM intervals can be found in the relevant descriptions of the system and method embodiments above, and will not be repeated here.

[0494] In one possible implementation, the first threshold is 20nm and the second threshold is 2.5nm.

[0495] In one possible implementation, the optical receiving component includes a photoelectric converter, and the optical emitting component includes a tunable wavelength laser. The photoelectric converter has the ability to process optical signals with different downlink wavelengths, and the tunable wavelength laser has the ability to generate optical signals with different uplink wavelengths.

[0496] A photoelectric converter is used to perform photoelectric conversion on the downlink optical signal to obtain a first electrical signal;

[0497] A tunable wavelength laser is used to generate and transmit uplink optical signals through an optical fiber interface. The specific implementation methods of the photoelectric converter and the tunable wavelength laser can be found in the relevant descriptions in the system and method embodiments above, and will not be repeated here.

[0498] In one possible implementation, the first optical module is integrated into or inserted into the first access device, and the downlink optical signal carries downlink information transmitted to the first access device;

[0499] The photoelectric converter is also used to transmit a first electrical signal to the first access device;

[0500] The tunable wavelength laser is also used to receive the second electrical signal transmitted by the first access device, and the uplink optical signal carries the uplink information sent by the first access device through the second electrical signal.

[0501] In one possible implementation, the fiber optic interface includes an uplink interface, and the first optical module further includes a splitter. The uplink interface is connected to the first optical fiber, and the splitter is connected to the uplink interface.

[0502] The beam splitter is used to receive the downlink optical signal transmitted through the first optical fiber via the uplink interface and transmit the downlink optical signal to the photoelectric converter.

[0503] The beam splitter is also used to send uplink optical signals generated by a tunable wavelength laser to the first optical fiber via the uplink interface.

[0504] As mentioned above Figure 6 and Figure 7 As shown, in the case of a single-fiber connection between the intermediate device and the access-side optical module, the access-side optical module includes an uplink interface and a beam splitter. The uplink interface is used to connect to an optical fiber, which can be referred to as the first optical fiber. The beam splitter is connected to the uplink interface and also to the tunable wavelength laser (such as a TLD) and photoelectric converter (such as a PD) in the access-side optical module. For specific implementation details, please refer to the relevant descriptions in the system and method embodiments above; they will not be repeated here.

[0505] In one possible implementation, the fiber optic interface includes a first uplink interface and a second uplink interface, which are respectively connected to different optical fibers.

[0506] The first uplink interface is used to receive downlink optical signals transmitted on the connected optical fiber and transmit downlink optical signals to the photoelectric converter.

[0507] The second uplink interface is used to transmit uplink optical signals generated by a tunable wavelength laser through the connected optical fiber.

[0508] As mentioned above Figures 2 to 5 , Figure 8 , Figure 9 As shown, in the case of a dual-fiber connection between the intermediate device and the access-side optical module, the access-side optical module includes two uplink interfaces, referred to as the first uplink interface and the second uplink interface, respectively. These two uplink interfaces connect to different optical fibers. The first uplink interface is also connected to a photoelectric converter (such as a PD), and the second uplink interface is also connected to a tunable wavelength laser (such as a TLD). For specific implementation details, please refer to the above text. Figures 2 to 5 , Figure 8 , Figure 9 The relevant descriptions of the system implementation and method implementation will not be repeated here.

[0509] In one possible implementation, the tunable wavelength laser employs a DBR laser, an EA-modulated DBR laser, a Littman structure TECDL, a Littman-Metcalf structure TECDL, an FBG-TECDL, an MRR tunable laser, a fully integrated tunable laser based on SOA, an FP laser, a DFB laser array, or a TOSA self-locking or injection-locking method to achieve adjustment of the emission wavelength.

[0510] In one possible implementation, the photoelectric converter uses a PIN, APD, or SOA-PIN integrated photodetector to achieve photoelectric conversion.

[0511] In the embodiments of this application, the wavelength division interval of multiple downlink wavelengths is greater than the wavelength division interval of multiple uplink wavelengths. For example, the downlink wavelength division is coarse and the uplink wavelength division is dense. In this way, the hybrid wavelength division scheme can ensure the reliability of optical communication while taking into account the cost of equipment / devices in the optical communication system, as well as the difficulty of production and deployment.

[0512] Furthermore, when the access-side optical module includes a tunable wavelength laser and the uplink is dense wavelength division multiplexing, the "normalization" scheme of the access-side optical module becomes feasible, thereby reducing the production cost and deployment difficulty of the access-side optical module and reducing the networking difficulty of optical communication.

[0513] It should be noted that the access-side optical module provided in the above embodiments, when used in conjunction with the access device for optical communication, is only illustrated by the division of the above functional modules. That is, the above device embodiments are merely illustrative. For example, the division of the modules is only a logical functional division. In actual implementation, there may be other division methods, that is, 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. For example, multiple modules or components can be combined or integrated into another device / device, or some features can be ignored or not executed. The functional modules in the various embodiments of this application can be integrated into one module, or each module can exist physically separately, or two or more modules can be integrated into one module. The above units in the first optical module can be implemented in hardware, in software functional units, or in a combination of hardware and software. In addition, the access-side optical module provided in the above embodiments and Figures 10 to 13 The optical communication method embodiments shown belong to the same concept, and the specific implementation process can be found in the method embodiments, which will not be repeated here.

[0514] It should also be noted that the access-side optical module provided in this application embodiment can be applied to... Figures 2 to 9 The optical communication system shown can also be applied to other communication systems. That is, the embodiments of this application do not limit the application scenarios and deployment locations of the access-side optical module provided above. For other devices / systems with optical communication needs, the access-side optical module provided in this embodiment can also be deployed in other systems as needed.

[0515] This application embodiment also provides a central optical module, which can be implemented by software, hardware, or a combination of both as part or all of a routing and switching device, which can be the aforementioned Figures 2 to 9 Any of the routing and switching devices in the system shown can also be the aforementioned Figures 10 to 13In the method embodiments, the central optical module of the routing and switching device can also be independent of the routing and switching device and inserted into it during application. In this application embodiment, the central optical module is integrated into or inserted into the routing and switching device, and the central optical module and... Figures 2 to 9 The other devices / appliances in the system cooperate with each other to ensure the reliability of optical communication.

[0516] The central optical module is included in the optical communication system, which also includes multiple access-side optical modules. These multiple access-side optical modules correspond to multiple uplink wavelengths and multiple downlink wavelengths. Different access-side optical modules correspond to different downlink wavelengths, and different access-side optical modules correspond to different uplink wavelengths. The central optical module includes a fixed-wavelength laser used to generate optical signals of multiple fixed wavelengths, including multiple downlink wavelengths. The central optical module also includes an optical fiber interface, an optical transmitting component, and an optical receiving component.

[0517] An optical transmission component is used to transmit multiple downlink optical signals through an optical fiber interface. The multiple downlink optical signals are generated by a fixed-wavelength laser, and the wavelengths of the multiple downlink optical signals are multiple downlink wavelengths.

[0518] An optical receiving component is used to receive multiple uplink optical signals through an optical fiber interface, wherein the wavelengths of the multiple uplink optical signals are multiple uplink wavelengths;

[0519] In this configuration, the wavelength division multiplexing (WDM) intervals of multiple downlink wavelengths are greater than the WDM intervals of multiple uplink wavelengths. For specific implementation details, please refer to the system and method embodiments described above; they will not be repeated here.

[0520] In one possible implementation, the plurality of downlink optical signals are transmitted using coarse wavelength division multiplexing (CWDM), and the plurality of uplink optical signals are transmitted using dense wavelength division multiplexing (DWDM).

[0521] In one possible implementation, the wavelength division multiplexing (WDM) intervals of multiple downlink wavelengths are greater than or equal to a first threshold, and the WDM intervals of multiple uplink wavelengths are less than a second threshold, wherein the first threshold is greater than or equal to the second threshold. Specific implementations of the first and second thresholds can be found in the system and method embodiments described above, and will not be repeated here.

[0522] In one possible implementation, the first threshold is 20nm and the second threshold is 2.5nm.

[0523] In one possible implementation, the optical transmission component includes a multiplexer, and the optical fiber interface includes at least one downlink interface connected to an optical fiber.

[0524] A multiplexer is used to combine multiple downlink optical signals generated by a fixed-wavelength laser into a composite downlink optical signal, and then transmit the composite downlink optical signal through a downlink interface. The specific implementation of the multiplexer can be found in the system and method embodiments described above, and will not be repeated here.

[0525] In one possible implementation, the central optical module is integrated into or inserted into the routing and switching equipment;

[0526] A fixed-wavelength laser is used to generate multiple downlink optical signals based on multiple first electrical signals input from the routing and switching equipment. These downlink optical signals carry downlink information transmitted by the routing and switching equipment via the multiple first electrical signals. Each of the multiple first electrical signals corresponds one-to-one with multiple access-side optical modules, and the downlink information includes information sent to the multiple access-side optical modules. The specific implementation of the fixed-wavelength laser can be found in the relevant descriptions of the system and method embodiments above, and will not be repeated here.

[0527] In one possible implementation, the optical receiving component includes a demultiplexer, and the central optical module also includes an optoelectronic conversion device;

[0528] Demultiplexer, used to receive composite uplink optical signals through the downlink interface;

[0529] The demultiplexer is also used to demultiplex multiple uplink optical signals from the composite uplink optical signal. These multiple uplink optical signals carry uplink information sent by multiple access-side optical modules to the routing and switching equipment.

[0530] The optoelectronic conversion device is used to perform optoelectronic conversion on multiple uplink optical signals to obtain multiple second electrical signals, which are then sent to the routing and switching equipment. The specific implementation methods of the demultiplexer and optoelectronic conversion device can be found above. Figures 2 to 9 System implementation examples, and Figures 10 to 11 The details of the method implementation examples will not be repeated here.

[0531] In one possible implementation, at least one downlink interface includes a downlink interface, and the central optical module further includes a beam splitter connected to a multiplexer and a demultiplexer respectively, and the beam splitter is also connected to the downlink interface;

[0532] Multiplexer, used to transmit composite downlink optical signals to the beam splitter;

[0533] A beam splitter is used to send composite downlink optical signals to the downlink interface.

[0534] The optical splitter is also used to receive composite uplink optical signals transmitted on the connected optical fiber through the downlink interface, and to transmit composite uplink optical signals to the demultiplexer.

[0535] like Figure 3 , Figure 6 ,and Figure 9 As shown, in one implementation where a single-fiber connection exists between the central optical module and intermediate equipment, the central optical module includes a DEMUX, a MUX, a beam splitter, and a downlink interface. The MUX acts as a multiplexer, the DEMUX as a demultiplexer, and the beam splitter is connected to the MUX, DEMUX, and downlink interface, respectively. The downlink interface is connected to an optical fiber. Furthermore, the MUX is connected to a fixed-wavelength laser (such as multiple LDs) within the central optical module, and the DEMUX is connected to a photoelectric conversion device (such as multiple PDs) within the central optical module. For specific implementation details, please refer to the above text. Figure 3 , Figure 6 and Figure 9 The details of the system implementation will not be repeated here.

[0536] In one possible implementation, at least one downlink interface includes a downlink interface, the multiplexer is connected to the demultiplexer, and the multiplexer is also connected to the downlink interface;

[0537] Multiplexer, used to send composite downlink optical signals to the downlink interface;

[0538] The multiplexer is also used to receive composite uplink optical signals transmitted on the connected optical fiber through the downlink interface and to transmit composite uplink optical signals to the demultiplexer.

[0539] like Figure 5 As shown, in another implementation where a single fiber connection exists between the central optical module and intermediate devices, the central optical module includes a DEMUX, a MUX, and a downlink interface. The MUX acts as a multiplexer, the DEMUX as a demultiplexer, and the MUX performs both multiplexing and splitting functions. The MUX is connected to both the DEMUX and the downlink interface, with the downlink interface connected to an optical fiber. Furthermore, the MUX is connected to a fixed-wavelength laser (such as multiple LDs) within the central optical module, and the DEMUX is connected to photoelectric conversion devices (such as multiple PDs) within the central optical module. For specific implementation details, please refer to the above text. Figure 5 The details of the system implementation will not be repeated here.

[0540] In one possible implementation, at least one downlink interface includes a downlink interface, the central optical module further includes an optoelectronic conversion device, and the multiplexer is connected to the downlink interface;

[0541] Multiplexer, used to send composite downlink optical signals to the downlink interface;

[0542] The multiplexer is also used to receive composite uplink optical signals transmitted on the connected optical fiber via the downlink interface;

[0543] The multiplexer is also used to demultiplex multiple uplink optical signals from the composite uplink optical signal, and the multiple uplink optical signals carry uplink information sent by multiple access side optical modules to the routing and switching equipment;

[0544] An optoelectronic conversion device is used to perform optoelectronic conversion on multiple uplink optical signals to obtain multiple second electrical signals, and then send the multiple second electrical signals to a routing and switching device. In some embodiments, this multiplexer may be referred to as a multiplexing-demultiplexer.

[0545] like Figure 4 As shown, in another implementation where a single fiber connection exists between the central optical module and intermediate devices, the central optical module includes a multiplexer (MUX) and a downlink interface. The MUX acts as a multiplexer / demultiplexer, performing multiplexing, demultiplexing, and beam splitting functions. The MUX is connected to the downlink interface, which in turn connects to an optical fiber. Furthermore, the MUX is also connected to a fixed-wavelength laser (such as multiple LDs) within the central optical module, and to photoelectric conversion devices (such as multiple PDs) within the central optical module. For specific implementation details, please refer to the above text. Figure 4 The details of the system implementation will not be repeated here.

[0546] In one possible implementation, at least one downlink interface includes a first downlink interface and a second downlink interface, a multiplexer is connected to the first downlink interface, a demultiplexer is connected to the second downlink interface, and the first downlink interface and the second downlink interface are respectively connected to different optical fibers.

[0547] Multiplexer for transmitting composite downlink optical signals through the connected first downlink interface;

[0548] A demultiplexer is used to receive composite uplink optical signals through the connected second downlink interface.

[0549] like Figure 7 and Figure 8 As shown, in the case of a two-fiber connection between the central optical module and intermediate equipment, the central optical module may include a DEMUX, a MUX, and two downlink interfaces, referred to as the first downlink interface and the second downlink interface, respectively. The MUX acts as a multiplexer, and the DEMUX acts as a demultiplexer. The MUX is connected to the first downlink interface, and the DEMUX is connected to the second downlink interface. These two downlink interfaces are connected to different optical fibers. Furthermore, the MUX is also connected to a fixed-wavelength laser (such as multiple LDs) in the central optical module, and the DEMUX is also connected to a photoelectric conversion device (such as multiple PDs) in the central optical module. For specific implementation details, please refer to the above text. Figure 7 and Figure 8 The details of the system implementation will not be repeated here.

[0550] In the embodiments of this application, the wavelength division interval of multiple downlink wavelengths is greater than the wavelength division interval of multiple uplink wavelengths. For example, the downlink wavelength division is coarse and the uplink wavelength division is dense. In this way, the hybrid wavelength division scheme can ensure the reliability of optical communication while taking into account the cost of equipment / devices in the optical communication system, as well as the difficulty of production and deployment.

[0551] Furthermore, when the access-side optical module includes a tunable wavelength laser and the uplink is dense wavelength division multiplexing, the "normalization" scheme of the access-side optical module becomes feasible, thereby reducing the production cost and deployment difficulty of the access-side optical module and reducing the networking difficulty of optical communication.

[0552] It should be noted that the central optical module provided in the above embodiments, when used in conjunction with routing and switching equipment for optical communication, is only illustrated by the division of the above functional modules. That is, the above device embodiments are merely illustrative. For example, the division of modules is only a logical functional division. In actual implementation, there may be other division methods, that is, 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. For example, multiple modules or components can be combined or integrated into another device / apparatus, or some features can be ignored or not executed. The functional modules in the various embodiments of this application can be integrated into one module, or each module can exist physically separately, or two or more modules can be integrated into one module. The above-mentioned units in the central optical module can be implemented in hardware, as software functional units, or in a combination of hardware and software. Furthermore, the central optical module provided in the above embodiments and... Figures 10 to 13 The optical communication method embodiments shown belong to the same concept, and the specific implementation process can be found in the method embodiments, which will not be repeated here.

[0553] It should also be noted that the central optical module provided in this application embodiment can be applied to... Figures 2 to 9 The optical communication system shown can also be applied to other communication systems. That is, the embodiments of this application do not limit the application scenario and deployment location of the central optical module provided above. For other devices / systems with optical communication needs, the central optical module provided in this embodiment can also be deployed in other systems as needed.

[0554] This application embodiment also provides an intermediate device, which may be the aforementioned intermediate device. Figures 2 to 9 The intermediate device in the system embodiment can be used as described above. Figures 10 to 13The intermediate device in the optical communication method involved. That is, the intermediate device is included in the optical communication system, which also includes multiple access-side optical modules. The multiple access-side optical modules correspond to multiple uplink wavelengths and multiple downlink wavelengths. Different access-side optical modules correspond to different downlink wavelengths, and different access-side optical modules correspond to different uplink wavelengths.

[0555] In one implementation, the intermediate devices include an optical fiber interface, a demultiplexer, and an optical coupler, wherein...

[0556] The fiber optic interface is used to receive composite downlink optical signals, which include multiple downlink optical signals.

[0557] The demultiplexer is used to demultiplex multiple downlink optical signals from the composite downlink optical signal and send the corresponding downlink optical signals to multiple access side optical modules based on the downlink wavelengths of the multiple downlink optical signals obtained by demultiplexing.

[0558] An optical coupler is used to combine multiple uplink optical signals from multiple access-side optical modules to obtain a composite uplink optical signal;

[0559] The fiber optic interface is also used to transmit composite uplink optical signals.

[0560] Demultiplexing can be... Figures 2 to 8 The DEMUX shown can use a splitter / coupler as the optical coupler.

[0561] In one possible implementation, the wavelength division multiplexing (WDM) spacing of the multiple downlink wavelengths is greater than the WDM spacing of the multiple uplink wavelengths. Specific implementation methods for the WDM spacing can be found in the relevant descriptions in the system and method embodiments above, and will not be repeated here.

[0562] In one possible implementation, the multiple downlink optical signals included in the composite downlink optical signal are transmitted using coarse wavelength division multiplexing (CWDM), and the multiple uplink optical signals included in the composite uplink optical signal are transmitted using dense wavelength division multiplexing (DWDM).

[0563] In one possible implementation, the fiber optic interface includes at least one uplink interface and multiple downlink interfaces, with the uplink and downlink interfaces respectively connected to optical fibers;

[0564] At least one uplink interface is provided for receiving composite downlink optical signals and transmitting composite uplink optical signals;

[0565] Multiple downlink interfaces are used to send corresponding downlink optical signals to multiple access-side optical modules. Each downlink interface sends an optical signal of a downlink wavelength, and the downlink wavelengths of the optical signals sent by different downlink interfaces are different.

[0566] Multiple downlink interfaces are also used to receive corresponding uplink optical signals sent by multiple access-side optical modules. Each downlink interface receives an optical signal of a downlink wavelength, and the uplink wavelengths of the optical signals received by different downlink interfaces are different.

[0567] In one possible implementation, each of the uplink and downlink interfaces is connected to a separate optical fiber. For example... Figures 2 to 8 As shown, in the case of a single-fiber or dual-fiber connection between the intermediate device and the central optical module, each uplink interface is connected to one optical fiber. For example... Figure 6 and Figure 7 As shown, in the case of a single-fiber connection between the intermediate device and the access-side optical module, each downlink interface is connected to a single optical fiber.

[0568] In one possible implementation, the intermediate device further includes a plurality of first optical splitters, a demultiplexer connected to the plurality of first optical splitters respectively, an optical coupler connected to the plurality of first optical splitters respectively, each of the plurality of first optical splitters being connected to one of the plurality of downlink interfaces, and different first optical splitters being connected to different downlink interfaces.

[0569] The demultiplexer is used to transmit a downlink optical signal to each of the multiple first optical splitters, wherein each first optical splitter receives a downlink optical signal and the downlink wavelengths of the optical signals received by different first optical splitters are different.

[0570] Multiple first optical splitters are used to transmit their respective received downlink optical signals to their respective connected downlink interfaces;

[0571] Each of the multiple downlink interfaces is used to transmit its received downlink optical signal through the optical fiber to which it is connected;

[0572] Each of the multiple downlink interfaces is also used to receive uplink optical signals transmitted through the optical fiber to which it is connected. Each downlink interface receives one uplink optical signal, and the downlink wavelengths of the optical signals received by different downlink interfaces are different.

[0573] Each of the multiple downlink interfaces is also used to transmit its received uplink optical signal to the first optical splitter to which it is connected;

[0574] Multiple first beam splitters are also used to transmit their respective received uplink optical signals to the optical coupler.

[0575] like Figure 6 and Figure 7 As shown, in the case of a single-fiber connection between the intermediate device and the access-side optical module, the intermediate device includes multiple optical splitters connected to multiple downlink interfaces. These multiple optical splitters are referred to as multiple first optical splitters. The demultiplexer in the intermediate device is a DEMUX, and the multiple first optical splitters are also connected to the DEMUX and an optical coupler, respectively. For specific implementation details, please refer to... Figure 6 and Figure 7 This will not be elaborated upon here.

[0576] In one possible implementation, each of the multiple downlink interfaces includes a first sub-interface and a second sub-interface. The demultiplexer is connected to the multiple first sub-interfaces of the multiple downlink interfaces respectively, and the optical coupler is connected to the multiple second sub-interfaces of the multiple downlink interfaces respectively. The second sub-interface and the first sub-interface of each downlink interface are connected to different optical fibers respectively.

[0577] The demultiplexer is used to transmit multiple downlink optical signals to multiple first sub-interfaces, wherein each first sub-interface receives one downlink optical signal, and the downlink wavelengths of the optical signals received by different first sub-interfaces are different.

[0578] The first sub-interface in each downlink interface is used to transmit the downlink optical signal received by this first sub-interface through the connected optical fiber;

[0579] The second sub-interface among multiple downlink interfaces is used to receive the uplink optical signal transmitted by the optical fiber connected to the second sub-interface, and to transmit the uplink optical signal received by the second sub-interface to the optical coupler.

[0580] like Figures 2 to 5 , Figure 8 As shown, in the case of a dual-fiber connection between the intermediate device and the access-side optical module, each downlink interface of the intermediate device includes two sub-interfaces, referred to as the first sub-interface and the second sub-interface, respectively. The demultiplexer in the intermediate device is a DEMUX. Multiple first sub-interfaces are connected to the DEMUX, and multiple second sub-interfaces are connected to an optical coupler. The multiple first sub-interfaces are used to transmit downlink optical signals, and the multiple second sub-interfaces are used to receive uplink optical signals. For specific implementation details, please refer to [reference needed]. Figures 2 to 5 , Figure 8 This will not be elaborated upon here.

[0581] In one possible implementation, the fiber optic interface includes an uplink interface, and the intermediate device further includes a second optical splitter. The uplink interface is connected to an optical fiber, and the second optical splitter is connected to the uplink interface, the demultiplexer, and the optical coupler, respectively.

[0582] The uplink interface is used to receive the composite downlink optical signal transmitted through the connected optical fiber and transmit the received composite downlink optical signal to the second optical splitter.

[0583] The second beam splitter is used to send the composite downlink optical signal to the demultiplexer;

[0584] An optical coupler is used to transmit composite uplink optical signals to the second beam splitter;

[0585] The second beam splitter is used to transmit composite uplink optical signals to the uplink interface;

[0586] The uplink interface is also used to transmit composite uplink optical signals through the connected optical fiber.

[0587] like Figures 2 to 6 As shown, in the case of a single-fiber connection between the intermediate device and the central optical module, the intermediate device includes an uplink interface and a splitter, referred to as the second splitter. The uplink interface is connected to a single optical fiber. The demultiplexer in the intermediate device is a DEMUX. The second splitter is connected to the uplink interface, the DEMUX, and an optical coupler. For specific implementation details, please refer to [reference needed]. Figures 2 to 6 This will not be elaborated upon here.

[0588] In one possible implementation, the fiber optic interface includes a first uplink interface and a second uplink interface, which are respectively connected to different optical fibers. The demultiplexer is connected to the first uplink interface, and the optical coupler is connected to the second uplink interface.

[0589] The first uplink interface is used to receive the composite downlink optical signal transmitted on the connected optical fiber and transmit the composite downlink optical signal to the demultiplexer.

[0590] An optical coupler is used to transmit composite uplink optical signals to the second uplink interface;

[0591] The second uplink interface is used to send composite uplink optical signals to the connected optical fiber.

[0592] like Figure 7 and Figure 8 As shown, in the case of a two-fiber connection between the intermediate device and the central optical module, the intermediate device includes two uplink interfaces, referred to as the first uplink interface and the second uplink interface, respectively. These two uplink interfaces are connected to different optical fibers. The demultiplexer in the intermediate device is a DEMUX, which is connected to the first uplink interface, and the optical coupler is connected to the second uplink interface. For specific implementation details, please refer to [reference needed]. Figure 7 and Figure 8 This will not be elaborated upon here.

[0593] In the embodiments of this application, the intermediate device adopts a combination of demultiplexer (such as DMUX) and optical coupler (such as splitter) to transmit optical signals, which makes the cost of the intermediate device low, while ensuring the reliability of optical communication.

[0594] Furthermore, the wavelength division spacing of multiple downlink wavelengths is greater than that of multiple uplink wavelengths, such as coarse wavelength division for downlink and dense wavelength division for uplink. In this way, the hybrid wavelength division scheme can ensure the reliability of optical communication while taking into account the cost of equipment / devices in the optical communication system, as well as the difficulty of production and deployment.

[0595] Furthermore, when the access-side optical module includes a tunable wavelength laser and the uplink is dense wavelength division multiplexing, the "normalization" scheme of the access-side optical module becomes feasible, thereby reducing the production cost and deployment difficulty of the access-side optical module and reducing the networking difficulty of optical communication.

[0596] It should be noted that the intermediate device provided in the above embodiments, when used in conjunction with other devices / appliances in an optical communication system for optical communication, is only illustrated by the division of the above functional modules. That is, the above device embodiments are merely illustrative. For example, the division of modules is only a logical functional division. In actual implementation, there may be other division methods, that is, 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. For example, multiple modules or components can be combined or integrated into another device / appliance, or some features can be ignored or not executed. The functional modules in the various embodiments of this application can be integrated into one module, or each module can exist physically separately, or two or more modules can be integrated into one module. The above units in the intermediate device can be implemented in hardware, as software functional units, or in a combination of hardware and software. Furthermore, the intermediate device provided in the above embodiments and... Figures 10 to 13 The optical communication method embodiments shown belong to the same concept, and the specific implementation process can be found in the method embodiments, which will not be repeated here.

[0597] It should also be noted that the intermediate device provided in this application embodiment can be applied to... Figures 2 to 9 The optical communication system shown can also be applied to other communication systems. That is, the embodiments of this application do not limit the application scenarios and deployment locations of the intermediate device provided above. For other devices / systems with optical communication needs, the intermediate device provided in this embodiment can also be deployed in other systems as needed.

[0598] Figure 13This is a schematic diagram of a network device provided in an embodiment of this application. The network device can be an access device, routing / switching device, or intermediate device as described in any of the above embodiments. The network device can be a switch, router, or other network device that forwards packets. In this embodiment, the network device includes: a memory 1303, and one or more processors 1301.

[0599] The processor 1301 is a general-purpose central processing unit (CPU), a network processor (NP), a microprocessor, or one or more integrated circuits for implementing the solutions of this application, such as application-specific integrated circuits (ASICs), programmable logic devices (PLDs), or combinations thereof. Optionally, the PLD is a complex programmable logic device (CPLD), an FPGA, generic array logic (GAL), or any combination thereof. When the network device is any access device, routing and switching device, or intermediate device in the embodiments of this application, the processor 1301 is used to cooperate with other devices / apparatus in the optical communication system to achieve... Figures 10 to 13 The optical communication method provided in any of the embodiments shown.

[0600] For example, if the network device is a routing and switching device, it integrates or inserts a central optical module, and the processor of the network device can control the central optical module to generate optical signals carrying downlink information; if the network device is an access device, it integrates or inserts an access-side optical module, and the processor of the network device can control the access-side optical module to generate optical signals carrying uplink information.

[0601] In one implementation, the network device further includes a communication bus 1302, which is used to transmit information between the aforementioned components. The communication bus 1302 includes an address bus, a data bus, and a control bus. For ease of illustration, only one thick line is used to represent this in the figure, but this does not imply that there is only one bus or one type of bus.

[0602] In some embodiments, the memory 1303 may be a read-only memory (ROM), random access memory (RAM), electrically erasable programmable read-only memory (EEPROM), optical disc (including compact disc read-only memory (CD-ROM), compressed optical disc, laser disc, digital versatile optical disc, Blu-ray disc, etc.), magnetic disk storage medium, or other magnetic storage device, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but not limited thereto. The memory 1303 exists independently and is connected to the processor 1301 via a communication bus 1302, or the memory 1303 is integrated with the processor 1301.

[0603] In one implementation, the network device further includes one or more communication interfaces 1304. The communication interfaces 1304 use any transceiver-like device for communicating with other devices or communication networks. The communication interfaces 1304 include wired communication interfaces, and optionally, also include wireless communication interfaces. The wired communication interfaces include, for example, Ethernet interfaces. The Ethernet interface can be an optical interface, an electrical interface, or a combination thereof. The wireless communication interfaces can be wireless local area networks (WLAN) interfaces, cellular network communication interfaces, or combinations thereof.

[0604] For example, if the network device is a routing and switching device, it may integrate or insert a central optical module. The network device can send electrical signals carrying downlink information to the central optical module via an electrical interface, enabling the central optical module to generate and transmit optical signals based on these signals. For instance, the network device can send multiple electrical signals to the central optical module via the electrical interface, and the central optical module can generate multiple downlink optical signals based on these signals, combine them into a composite downlink optical signal, and then transmit the composite downlink optical signal. The network device can also receive electrical signals sent by the central optical module via the electrical interface to obtain the uplink information carried by those signals. Specific implementation details can be found in the system and method embodiments described above, and will not be repeated here.

[0605] When the network device is an access device, it integrates or inserts an access-side optical module. The network device can send electrical signals to the access-side optical module via an electrical interface, causing the access-side optical module to generate and transmit optical signals based on these signals. The network device can also receive electrical signals sent by the access-side optical module via the electrical interface, thereby obtaining the downlink information carried by those signals. Specific implementation details can be found in the system and method embodiments described above, and will not be repeated here.

[0606] When the network device is an intermediate device, it includes an optical interface (also called a fiber optic interface), which may include multiple downlink interfaces and at least one uplink interface. The network device can receive optical signals (e.g., composite downlink optical signals) transmitted by the central optical module through the uplink interface, and transmit optical signals (e.g., composite uplink optical signals) to the central optical module. The network device can also receive optical signals (i.e., optical signals at uplink wavelengths corresponding to each access-side optical module) transmitted by the access-side optical modules through the downlink interface, and transmit optical signals (i.e., optical signals at downlink wavelengths corresponding to each access-side optical module) to the access-side optical modules. Specific implementation details can be found in the system and method embodiments described above, and will not be repeated here.

[0607] In some embodiments, the network device includes multiple processors, such as Figure 13 The processors 1301 and 1305 shown are illustrated. Each of these processors is either a single-core processor or a multi-core processor. Here, a processor refers to one or more devices, circuits, and / or processing cores used to process data (such as computer program instructions). As an example, each processor may include one or more CPUs, such as... Figure 13 Each processor shown includes CPU0 and CPU1.

[0608] In some embodiments, the network device further includes output devices and input devices. The output devices communicate with the processor 1301 and are capable of displaying information in various ways. For example, the output devices are liquid crystal displays (LCDs), light-emitting diode (LED) displays, cathode ray tube (CRT) displays, or projectors. The input devices communicate with the processor 1301 and are capable of receiving user input in various ways. For example, the input devices are mice, keyboards, touchscreen devices, or sensing devices.

[0609] In some embodiments, memory 1303 is used to store program code 1310 for executing the scheme of this application, and processor 1301 is capable of executing the program code 1310 stored in memory 1303, causing the network device to perform... Figures 10 to 13 The processing steps of the access device, routing / switching device, or intermediate device in the illustrated embodiment can be referred to for specific implementation. Figures 10 to 13 The detailed descriptions of the embodiments shown will not be repeated here.

[0610] This application also provides a computer-readable storage medium storing instructions that, when executed on a computer, cause the computer to perform the steps of the optical communication method shown in the above-described method embodiments.

[0611] This application also provides a computer program product containing instructions that, when run on a computer, causes the computer to perform the steps of the optical communication method shown in the above-described method embodiments.

[0612] This application also provides a computer program that, when run on a computer, causes the computer to perform the steps of the optical communication method shown in the above-described method embodiments.

[0613] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer instructions. When the computer instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible to a computer, or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., digital versatile disc (DVD)), or a semiconductor medium (e.g., solid state disk (SSD)). It is worth noting that the computer-readable storage medium mentioned in the embodiments of this application can be a non-volatile storage medium; in other words, it can be a non-transient storage medium.

[0614] It should be understood that "at least one" as mentioned herein refers to one or more, and "multiple" refers to two or more. In the description of the embodiments of this application, unless otherwise stated, " / " means "or," for example, A / B can mean A or B; "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. In addition, in order to clearly describe the technical solutions of the embodiments of this application, the terms "first," "second," etc., are used in the embodiments of this application to distinguish identical or similar items with substantially the same function and effect. Those skilled in the art will understand that the terms "first," "second," etc., do not limit the quantity or execution order, and the terms "first," "second," etc., are not necessarily different.

[0615] It should be noted that the information (including but not limited to user device information, user personal information, etc.), data (including but not limited to data used for analysis, data stored, data displayed, etc.) and signals involved in the embodiments of this application are all authorized by the user or fully authorized by all parties, and the collection, use and processing of related data must comply with the relevant laws, regulations and standards of the relevant countries and regions.

[0616] The above descriptions are embodiments provided in this application and are not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made by those skilled in the art should be included within the protection scope of this application.

Claims

1. An optical communication system, characterized in that, The system includes a central optical module and multiple access-side optical modules. These access-side optical modules correspond to multiple uplink wavelengths and multiple downlink wavelengths. Different access-side optical modules correspond to different downlink wavelengths, and different access-side optical modules correspond to different uplink wavelengths. The wavelength division multiplexing (WDM) interval of the multiple downlink wavelengths is greater than the WDM interval of the multiple uplink wavelengths. The wavelength bands of the multiple uplink wavelengths are completely separated from the wavelength bands of the multiple downlink wavelengths. The central optical module is connected to the multiple access-side optical modules. The central optical module includes a fixed-wavelength laser for generating multiple fixed-wavelength optical signals, including the multiple downlink wavelengths. Each access-side optical module includes an uplink interface, a second beam splitter, a photoelectric converter, and a tunable wavelength laser. The second beam splitter in each access-side optical module is connected to the uplink interface, the photoelectric converter, and the tunable wavelength laser in that access-side optical module, respectively. The central optical module is used to send a composite downlink optical signal to the plurality of access side optical modules. The composite downlink optical signal includes a plurality of downlink optical signals generated by the fixed wavelength laser, and the wavelengths of the plurality of downlink optical signals are the plurality of downlink wavelengths. Each of the plurality of access-side optical modules is used to send an uplink optical signal corresponding to its own wavelength to the central optical module using the tunable wavelength laser. The central optical module is also used to receive composite uplink optical signals, which include multiple uplink optical signals, and the wavelengths of the multiple uplink optical signals are the multiple uplink wavelengths.

2. The system as described in claim 1, characterized in that, The composite downlink optical signal includes multiple downlink optical signals transmitted based on coarse wavelength division multiplexing (CWDM), and the composite uplink optical signal includes multiple uplink optical signals transmitted based on dense wavelength division multiplexing (DWDM).

3. The system as described in claim 1, characterized in that, The wavelength division interval of the plurality of downlink wavelengths is greater than or equal to a first threshold, and the wavelength division interval of the plurality of uplink wavelengths is less than a second threshold, wherein the first threshold is greater than or equal to the second threshold.

4. The system as described in claim 3, characterized in that, The first threshold is 20 nanometers, and the second threshold is 2.5 nanometers.

5. The system as described in claim 1, characterized in that, The tunable wavelength laser in each access-side optical module is used to transmit the optical signal of the uplink wavelength corresponding to the access-side optical module to the second beam splitter in the access-side optical module. The second beam splitter in each access-side optical module is used to send an optical signal of the uplink wavelength corresponding to the access-side optical module to the central optical module through the uplink interface of the access-side optical module; The uplink interface in each access-side optical module is used to receive the optical signal of the downlink wavelength corresponding to the access-side optical module and transmit the optical signal of the downlink wavelength corresponding to the access-side optical module to the second beam splitter in the access-side optical module. The second beam splitter in each access-side optical module is used to transmit the optical signal of the downlink wavelength corresponding to the access-side optical module to the photoelectric converter in the access-side optical module.

6. The system according to any one of claims 1-5, characterized in that, It also includes intermediate equipment, which includes a first demultiplexer and a optical combining device. The intermediate equipment is connected to the central optical module via optical fiber, and the intermediate equipment is also connected to the plurality of access-side optical modules via optical fiber. The first demultiplexer is used to demultiplex the composite downlink optical signal received through the optical fiber to obtain multiple downlink optical signals, and based on the downlink wavelength of each of the multiple downlink optical signals obtained by demultiplexing, to send the corresponding downlink optical signals to the multiple access-side optical modules through the optical fiber. The optical combining device is used to combine multiple uplink optical signals from the multiple access side optical modules to obtain a composite uplink optical signal, and then transmit the composite uplink optical signal to the central optical module through an optical fiber.

7. The system as described in claim 6, characterized in that, The intermediate device further includes at least one uplink interface and multiple downlink interfaces. The intermediate device is connected to the central optical module via the at least one uplink interface through an optical fiber, and the intermediate device is connected to the multiple access-side optical modules via the multiple downlink interfaces through optical fibers respectively. The intermediate device is used to receive the composite downlink optical signal and transmit the composite uplink optical signal through the at least one uplink interface; The intermediate device is used to send corresponding downlink optical signals to the multiple access-side optical modules through the multiple downlink interfaces, wherein each downlink interface sends one downlink optical signal, and the downlink wavelengths of the optical signals sent by different downlink interfaces are different. The intermediate device is used to receive corresponding uplink optical signals sent by the multiple access-side optical modules through the multiple downlink interfaces, wherein each of the multiple downlink interfaces receives one uplink optical signal, and the uplink wavelengths of the optical signals received by different downlink interfaces are different.

8. The system as described in claim 7, characterized in that, Each of the plurality of downlink interfaces is connected to an optical fiber.

9. The system as described in claim 8, characterized in that, The intermediate device further includes a plurality of first optical splitters, the first demultiplexer being connected to each of the plurality of first optical splitters, the optical combining device being connected to each of the plurality of first optical splitters, each of the plurality of first optical splitters being connected to one of the plurality of downlink interfaces, and different first optical splitters being connected to different downlink interfaces; the second optical splitter in each access-side optical module is connected to one downlink interface of the intermediate device via an optical fiber, the second optical splitters in different access-side optical modules are connected to different downlink interfaces of the intermediate device, and the second optical splitter in the first optical module of the plurality of access-side optical modules is connected to the first downlink interface of the plurality of downlink interfaces via a first optical fiber; The first demultiplexer is specifically used to transmit a downlink optical signal to each of the plurality of first optical splitters, wherein each first optical splitter receives a downlink optical signal, and the downlink wavelengths of the optical signals received by different first optical splitters are different. Each first optical splitter is used to transmit the downlink optical signal received by the first optical splitter to the downlink interface connected to the first optical splitter; The first downlink interface is used to transmit the downlink wavelength optical signal received by the first downlink interface to the second optical splitter in the first optical module through the first optical fiber; The second beam splitter in the first optical module is used to transmit the optical signal of the uplink wavelength corresponding to the first optical module to the first downlink interface through the first optical fiber; Each downlink interface is also used to transmit the uplink optical signal received by the downlink interface to the first optical splitter connected to the downlink interface; Each first beam splitter is also used to transmit the uplink optical signal received by the first beam splitter to the optical combining device; The optical combining device is specifically used to receive the multiple uplink optical signals transmitted by the multiple first optical splitters and combine the multiple uplink optical signals transmitted by the multiple first optical splitters into the composite uplink optical signal.

10. The system according to any one of claims 7-9, characterized in that, The optical combining device includes an optical coupler.

11. The system according to any one of claims 7-9, characterized in that, The central optical module also includes a downlink interface, which is connected to an optical fiber.

12. The system as claimed in claim 11, characterized in that, The central optical module further includes a fourth beam splitter, a first multiplexer, a second demultiplexer, and a photoelectric conversion device. The fourth beam splitter is connected to the downlink interface of the central optical module, and the fourth beam splitter is also connected to the first multiplexer and the second demultiplexer respectively. The fixed-wavelength laser is used to generate the plurality of downlink optical signals based on a plurality of first electrical signals, wherein the plurality of first electrical signals are electrical signals input from the routing switching equipment; The first multiplexer is used to combine the multiple downlink optical signals into the composite downlink optical signal and transmit the composite downlink optical signal to the fourth optical splitter; The fourth optical splitter is used to send the composite downlink optical signal through the downlink interface of the central optical module, and to receive the composite uplink optical signal transmitted on the connected optical fiber from the downlink interface of the central optical module, and to transmit the composite uplink optical signal to the second demultiplexer. The second demultiplexer is used to receive the composite uplink optical signal transmitted by the fourth optical splitter and demultiplex the multiple uplink optical signals from the composite uplink optical signal; The optoelectronic conversion device is used to convert the multiple uplink optical signals demultiplexed by the second demultiplexer into multiple second electrical signals, and output the multiple second electrical signals to the routing and switching equipment.

13. The system as described in claim 11, characterized in that, The central optical module further includes a second multiplexer, a third demultiplexer, and an optoelectronic conversion device. The second multiplexer is connected to the downlink interface of the central optical module, and the second multiplexer is also connected to the third demultiplexer. The fixed-wavelength laser is used to generate the plurality of downlink optical signals based on a plurality of first electrical signals, wherein the plurality of first electrical signals are electrical signals input from the routing switching equipment; The second multiplexer is used to combine the multiple downlink optical signals into the composite downlink optical signal, send the composite downlink optical signal through the downlink interface of the central optical module, receive the composite uplink optical signal transmitted on the optical fiber connected to the downlink interface of the central optical module, and transmit the composite uplink optical signal to the third demultiplexer. The third demultiplexer is used to receive the composite uplink optical signal transmitted by the second multiplexer, and demultiplex the plurality of uplink optical signals from the composite uplink optical signal; The photoelectric conversion device is used to convert the multiple uplink optical signals demultiplexed by the third demultiplexer into multiple second electrical signals, and output the multiple second electrical signals to the routing and switching equipment.

14. The system as claimed in claim 11, characterized in that, The central optical module also includes a multiplexer / demultiplexer and a photoelectric conversion device, wherein the multiplexer / demultiplexer is connected to the downlink interface of the central optical module; The fixed-wavelength laser is used to generate the plurality of downlink optical signals based on a plurality of first electrical signals, wherein the plurality of first electrical signals are electrical signals input from the routing switching equipment; The multiplexer / demultiplexer is used to combine the multiple downlink optical signals into the composite downlink optical signal, send the composite downlink optical signal through the downlink interface of the central optical module, and receive the composite uplink optical signal transmitted on the optical fiber connected to the downlink interface of the central optical module, and demultiplex the multiple uplink optical signals from the composite uplink optical signal. The optoelectronic conversion device is used to convert multiple uplink optical signals demultiplexed by the multiplexer into multiple second electrical signals, and output the multiple second electrical signals to the routing and switching equipment.

15. The system according to any one of claims 12-14, characterized in that, The intermediate device includes an uplink interface and a third optical splitter. The uplink interface of the intermediate device is connected to the downlink interface of the central optical module through an optical fiber. The third optical splitter is connected to the uplink interface of the intermediate device, the first demultiplexer, and the optical combining device, respectively. The third optical splitter is used to receive the composite downlink optical signal sent by the central optical module through the uplink interface of the intermediate device, and to transmit the composite downlink optical signal to the first demultiplexer; The third beam splitter is also used to receive the composite uplink optical signal transmitted by the beam combining device, and send the composite uplink optical signal to the central optical module through the uplink interface of the intermediate device.

16. The system according to any one of claims 7-9, characterized in that, The central optical module further includes a second downlink interface, a third downlink interface, a first multiplexer, a second demultiplexer, and an optoelectronic conversion device. The first multiplexer is connected to the second downlink interface, and the second demultiplexer is connected to the third downlink interface. The fixed-wavelength laser is used to generate the plurality of downlink optical signals based on a plurality of first electrical signals, wherein the plurality of first electrical signals are electrical signals input from the routing switching equipment; The first multiplexer is used to combine the multiple downlink optical signals into the composite downlink optical signal, and to send the combined composite downlink optical signal through the second downlink interface; The second demultiplexer is used to demultiplex the plurality of uplink optical signals from the composite uplink optical signals received from the third downlink interface; The photoelectric conversion device is used to convert the plurality of uplink optical signals into a plurality of second electrical signals, and output the plurality of second electrical signals to the routing and switching equipment.

17. The system as claimed in claim 16, characterized in that, The intermediate device includes a first uplink interface and a second uplink interface, wherein the first uplink interface is connected to the second downlink interface of the central optical module, and the second uplink interface is connected to the third downlink interface of the central optical module via optical fibers. The first demultiplexer is used to receive the composite downlink optical signal sent by the central optical module through the first uplink interface; The optical combining device is used to send the composite uplink optical signal to the central optical module through the second uplink interface.

18. The system as described in any one of claims 1-5, 7-9, 12-14, and 17, characterized in that, The photoelectric converter in each access-side optical module has the ability to process optical signals of different downlink wavelengths; The tunable wavelength laser is used to generate an uplink wavelength optical signal corresponding to the optical module on this access side based on a third electrical signal, wherein the third electrical signal is an electrical signal input by the access device. The photoelectric converter is used to perform photoelectric conversion on the downlink wavelength optical signal received by the access side optical module to which the photoelectric converter belongs, thereby obtaining a fourth electrical signal, and outputting the fourth electrical signal to the access device.

19. The system as described in any one of claims 1-5, 7-9, 12-14, and 17, characterized in that, The central optical module is integrated into or inserted into the routing and switching equipment, and the downlink wavelength optical signal carries the downlink information sent by the routing and switching equipment; and / or, Each of the plurality of access-side optical modules is integrated into or inserted into the access device, and the uplink wavelength optical signal carries the uplink information sent by the access device.

20. An optical communication method, characterized in that, An optical communication system includes multiple access-side optical modules, each corresponding to multiple uplink wavelengths and multiple downlink wavelengths. Different access-side optical modules correspond to different downlink wavelengths, and different access-side optical modules also correspond to different uplink wavelengths. The wavelength division multiplexing (WDM) interval of the multiple downlink wavelengths is greater than the WDM interval of the multiple uplink wavelengths, and the bands of the multiple uplink wavelengths are completely separated from the bands of the multiple downlink wavelengths. The method is applied to a first optical module among the multiple access-side optical modules. The first optical module is any one of the multiple access-side optical modules. The first optical module includes an uplink interface, a beam splitter, a photoelectric converter, and a tunable wavelength laser. The beam splitter is connected to the uplink interface, the photoelectric converter, and the tunable wavelength laser, respectively. The method includes: Receive downlink optical signals, wherein the wavelength of the downlink optical signals is the first downlink wavelength corresponding to the first optical module; An uplink optical signal is generated and transmitted, wherein the wavelength of the uplink optical signal is the first uplink wavelength corresponding to the first optical module.

21. The method as described in claim 20, characterized in that, The wavelength division interval of the plurality of downlink wavelengths is greater than or equal to a first threshold, and the wavelength division interval of the plurality of uplink wavelengths is less than a second threshold, wherein the first threshold is greater than or equal to the second threshold.

22. The method as described in claim 21, characterized in that, The first threshold is 20 nanometers, and the second threshold is 2.5 nanometers.

23. The method according to any one of claims 20-22, characterized in that, The photoelectric converter has the ability to process optical signals with different downlink wavelengths, and the tunable wavelength laser has the ability to generate optical signals with different uplink wavelengths. The method further includes: The photoelectric converter performs photoelectric conversion on the downlink optical signal to obtain a first electrical signal; The generation and transmission of the uplink optical signal includes: The tunable wavelength laser generates and transmits the uplink optical signal.

24. The method as described in claim 23, characterized in that, After the first optical module is integrated into or inserted into the first access device, the downlink optical signal carries downlink information transmitted to the first access device, and the photoelectric converter performs photoelectric conversion on the downlink optical signal to obtain the first electrical signal, the method further includes: The photoelectric converter transmits the first electrical signal to the first access device; Before the tunable wavelength laser generates and transmits the uplink optical signal, the method further includes: The system receives a second electrical signal transmitted by the first access device, wherein the uplink optical signal carries uplink information sent by the first access device through the second electrical signal.

25. The method as described in claim 23, characterized in that, The uplink interface of the first optical module is connected to the first optical fiber, and the beam splitter is connected to the uplink interface; The receiving of downlink optical signals includes: The beam splitter receives the downlink optical signal transmitted through the first optical fiber via the uplink interface and transmits the downlink optical signal to the photoelectric converter; The transmission of the uplink optical signal includes: The tunable wavelength laser sends the generated uplink optical signal to the beam splitter; The beam splitter transmits the uplink optical signal generated by the tunable wavelength laser to the first optical fiber through the uplink interface.

26. The method as described in claim 24, characterized in that, The uplink interface of the first optical module is connected to the first optical fiber, and the beam splitter is connected to the uplink interface; The receiving of downlink optical signals includes: The beam splitter receives the downlink optical signal transmitted through the first optical fiber via the uplink interface and transmits the downlink optical signal to the photoelectric converter; The transmission of the uplink optical signal includes: The tunable wavelength laser sends the generated uplink optical signal to the beam splitter; The beam splitter transmits the uplink optical signal generated by the tunable wavelength laser to the first optical fiber through the uplink interface.

27. An optical communication method, characterized in that, The method is applied to a central optical module in an optical communication system. The optical communication system further includes multiple access-side optical modules, each corresponding to a multiple uplink wavelength and a multiple downlink wavelength. The bands of the uplink wavelengths and the bands of the downlink wavelengths are completely separate. Different access-side optical modules correspond to different downlink wavelengths, and different access-side optical modules correspond to different uplink wavelengths. The central optical module includes a fixed-wavelength laser for generating multiple fixed-wavelength optical signals, including the multiple downlink wavelengths. The method includes: Multiple downlink optical signals are transmitted, wherein the multiple downlink optical signals are generated by the fixed-wavelength laser, and the wavelengths of the multiple downlink optical signals are the multiple downlink wavelengths; Receive multiple uplink optical signals, wherein the wavelengths of the multiple uplink optical signals are the multiple uplink wavelengths; The wavelength division multiplexing interval of the plurality of downlink wavelengths is greater than the wavelength division multiplexing interval of the plurality of uplink wavelengths.

28. The method as described in claim 27, characterized in that, The wavelength division interval of the plurality of downlink wavelengths is greater than or equal to a first threshold, and the wavelength division interval of the plurality of uplink wavelengths is less than a second threshold, wherein the first threshold is greater than or equal to the second threshold.

29. The method as described in claim 28, characterized in that, The first threshold is 20 nanometers, and the second threshold is 2.5 nanometers.

30. The method according to any one of claims 27-29, characterized in that, The central optical module also includes a multiplexer and at least one downlink interface, which is connected to an optical fiber. The transmission of multiple downlink optical signals includes: The multiplexer combines the multiple downlink optical signals generated by the fixed-wavelength laser into a composite downlink optical signal, and sends the composite downlink optical signal through the downlink interface.

31. The method as described in claim 30, characterized in that, The central optical module is integrated into or inserted into the routing and switching equipment; The fixed-wavelength laser generates the plurality of downlink optical signals based on the plurality of first electrical signals input by the routing switching device. The plurality of downlink optical signals carry downlink information sent by the routing switching device through the plurality of first electrical signals. The plurality of first electrical signals correspond one-to-one with the plurality of access-side optical modules. The downlink information includes information sent to the plurality of access-side optical modules.

32. The method as described in claim 31, characterized in that, The central optical module also includes an optoelectronic conversion device and a demultiplexer; The receiving of multiple uplink optical signals includes: The composite uplink optical signal is received through the downlink interface; The demultiplexer demultiplexes the composite uplink optical signal to extract the plurality of uplink optical signals, and the plurality of uplink optical signals carry uplink information sent by the plurality of access-side optical modules to the routing and switching device; The method further includes: The photoelectric conversion device performs photoelectric conversion on the multiple uplink optical signals respectively, thereby obtaining multiple second electrical signals; The plurality of second electrical signals are sent to the routing and switching device.

33. The method as described in claim 32, characterized in that, The central optical module includes a downlink interface and a beam splitter. The beam splitter is connected to the multiplexer and the demultiplexer, respectively, and is also connected to the downlink interface. The step of transmitting the composite downlink optical signal through the downlink interface includes: The multiplexer transmits the composite downlink optical signal to the beam splitter, and the beam splitter sends the composite downlink optical signal to the downlink interface; The receiving of composite uplink optical signals through the downlink interface includes: The optical splitter receives the composite uplink optical signal transmitted on the connected optical fiber through the downlink interface and transmits the composite uplink optical signal to the demultiplexer.

34. The method as described in claim 32, characterized in that, The central optical module includes a downlink interface, the multiplexer is connected to the demultiplexer, and the multiplexer is also connected to the downlink interface; The step of transmitting the composite downlink optical signal through the downlink interface includes: The multiplexer sends the composite downlink optical signal to the downlink interface; The receiving of composite uplink optical signals through the downlink interface includes: The multiplexer receives the composite uplink optical signal transmitted on the connected optical fiber through the downlink interface and transmits the composite uplink optical signal to the demultiplexer.

35. The method as described in claim 31, characterized in that, The central optical module includes a downlink interface and a photoelectric conversion device, and the multiplexer is connected to the downlink interface; The step of transmitting the composite downlink optical signal through the downlink interface includes: The multiplexer sends the composite downlink optical signal to the downlink interface; The receiving of composite uplink optical signals through the downlink interface includes: The multiplexer receives the composite uplink optical signal transmitted on the connected optical fiber through the downlink interface; After the multiplexer receives the composite uplink optical signal transmitted on the connected optical fiber through the downlink interface, the method further includes: The multiplexer demultiplexes the composite uplink optical signal to obtain the plurality of uplink optical signals, and the plurality of uplink optical signals carry uplink information sent by the plurality of access-side optical modules to the routing and switching equipment; The photoelectric conversion device performs photoelectric conversion on the multiple uplink optical signals respectively, thereby obtaining multiple second electrical signals; The plurality of second electrical signals are sent to the routing and switching device.

36. The method as described in claim 32, characterized in that, The downlink interface of the central optical module includes a first downlink interface and a second downlink interface. The multiplexer is connected to the first downlink interface, and the demultiplexer is connected to the second downlink interface. The first downlink interface and the second downlink interface are respectively connected to different optical fibers. The step of transmitting the composite downlink optical signal through the downlink interface includes: The multiplexer transmits the composite downlink optical signal through the first downlink interface it is connected to; The receiving of composite uplink optical signals through the downlink interface includes: The demultiplexer receives the composite uplink optical signal through the connected second downlink interface.

37. An optical communication method, characterized in that, The method is applied to an intermediate device included in an optical communication system. The optical communication system further includes multiple access-side optical modules, each corresponding to multiple uplink wavelengths and multiple downlink wavelengths. The wavelength division multiplexing (WDM) interval of the multiple downlink wavelengths is greater than that of the multiple uplink wavelengths. The bands of the multiple uplink wavelengths are completely separated from the bands of the multiple downlink wavelengths. Different access-side optical modules within the multiple access-side optical modules correspond to different downlink wavelengths, and different access-side optical modules within the multiple access-side optical modules correspond to different uplink wavelengths. The intermediate device includes a demultiplexer and an optical coupler. The method includes: Receive a composite downlink optical signal, wherein the composite downlink optical signal comprises multiple downlink optical signals; The multiple downlink optical signals are demultiplexed from the composite downlink optical signal using the demultiplexer. Based on the downlink wavelength of each of the multiple downlink optical signals obtained by demultiplexing, the corresponding downlink optical signals are sent to the multiple access-side optical modules. The optical coupler combines multiple uplink optical signals from the multiple access-side optical modules to obtain a composite uplink optical signal. The composite uplink optical signal is transmitted.

38. The method as described in claim 37, characterized in that, The composite downlink optical signal includes multiple downlink optical signals transmitted based on coarse wavelength division multiplexing (CWDM), and the composite uplink optical signal includes multiple uplink optical signals transmitted based on dense wavelength division multiplexing (DWDM).

39. The method as described in claim 37 or 38, characterized in that, The intermediate device further includes at least one uplink interface and multiple downlink interfaces, wherein the uplink interface and the downlink interface are respectively connected to optical fibers; The composite downlink optical signal is received and the composite uplink optical signal is transmitted through the at least one uplink interface; The downlink optical signals are sent to the multiple access-side optical modules through the multiple downlink interfaces, wherein each downlink interface sends an optical signal of a downlink wavelength, and the downlink wavelengths of the optical signals sent by different downlink interfaces are different. The multiple downlink interfaces receive corresponding uplink optical signals sent by the multiple access-side optical modules. Each downlink interface receives an optical signal of a downlink wavelength, and the uplink wavelengths of the optical signals received by different downlink interfaces are different.

40. The method as described in claim 39, characterized in that, Each of the uplink and downlink interfaces is connected to an optical fiber.

41. The method as described in claim 40, characterized in that, The intermediate device further includes a plurality of first beam splitters, the demultiplexer is connected to the plurality of first beam splitters respectively, the optical coupler is connected to the plurality of first beam splitters respectively, each of the plurality of first beam splitters is connected to one of the plurality of downlink interfaces, and different first beam splitters are connected to different downlink interfaces; The step of sending corresponding downlink optical signals to the multiple access-side optical modules through the multiple downlink interfaces includes: The demultiplexer transmits a downlink optical signal to each of the plurality of first optical splitters, wherein each first optical splitter receives one downlink optical signal, and the downlink wavelengths of the optical signals received by different first optical splitters are different. The plurality of first optical splitters respectively transmit their respective received downlink optical signals to their respective connected downlink interfaces; Each of the plurality of downlink interfaces transmits its received downlink optical signal through its respective connected optical fiber; Before combining multiple uplink optical signals from the plurality of access-side optical modules through the optical coupler to obtain a composite uplink optical signal, the method further includes: Each of the plurality of downlink interfaces receives the uplink optical signal transmitted by the optical fiber to which it is connected. Each downlink interface receives one uplink optical signal, and the downlink wavelengths of the optical signals received by different downlink interfaces are different. Each of the plurality of downlink interfaces transmits its received uplink optical signal to the first optical splitter to which it is connected; The plurality of first beam splitters respectively transmit their respective received uplink optical signals to the optical coupler.

42. The method as described in claim 40 or 41, characterized in that, The intermediate device includes an uplink interface and a second optical splitter. The uplink interface is connected to an optical fiber, and the second optical splitter is connected to the uplink interface, the demultiplexer, and the optical coupler, respectively. Receiving the composite downlink optical signal through the at least one uplink interface includes: The uplink interface receives the composite downlink optical signal transmitted through the connected optical fiber and transmits the received composite downlink optical signal to the second optical splitter. The second beam splitter sends the composite downlink optical signal to the demultiplexer; Transmitting the composite uplink optical signal through the at least one uplink interface includes: The optical coupler transmits the composite uplink optical signal to the second beam splitter; The second beam splitter transmits the composite uplink optical signal to the uplink interface; The uplink interface transmits the composite uplink optical signal through the connected optical fiber.

43. The method as described in claim 40 or 41, characterized in that, The intermediate device includes a first uplink interface and a second uplink interface, which are respectively connected to different optical fibers. The demultiplexer is connected to the first uplink interface and the optical coupler is connected to the second uplink interface. Receiving the composite downlink optical signal through the at least one uplink interface includes: The first uplink interface receives the composite downlink optical signal transmitted on the connected optical fiber; The first uplink interface transmits the composite downlink optical signal to the demultiplexer; The step of transmitting the composite uplink optical signal through the at least one uplink interface includes: The optical coupler transmits the composite uplink optical signal to the second uplink interface; The second uplink interface sends the composite uplink optical signal to the connected optical fiber.

44. A first optical module, characterized in that, An optical communication system includes multiple access-side optical modules, each corresponding to a multiple uplink wavelength and a multiple downlink wavelength. Different access-side optical modules correspond to different downlink wavelengths, and different access-side optical modules correspond to different uplink wavelengths. The wavelength division multiplexing (WDM) interval of the multiple downlink wavelengths is greater than the WDM interval of the multiple uplink wavelengths, and the wavelength bands of the multiple uplink wavelengths are completely separated from the wavelength bands of the multiple downlink wavelengths. The first optical module is any one of the multiple access-side optical modules. The first optical module includes an optical fiber interface, an optical receiving component, and an optical transmitting component. The optical receiving component includes a photoelectric converter, and the optical transmitting component includes a tunable wavelength laser. The optical fiber interface includes an uplink interface. The first optical module also includes a beam splitter, which is connected to the uplink interface, the photoelectric converter, and the tunable wavelength laser, respectively. The optical receiving component is used to receive the downlink optical signal transmitted by the optical fiber interface, and the wavelength of the downlink optical signal is the first downlink wavelength corresponding to the first optical module. The optical transmitting component is used to generate an uplink optical signal and transmit the uplink optical signal through the optical fiber interface. The wavelength of the uplink optical signal is the first uplink wavelength corresponding to the first optical module.

45. The first optical module as described in claim 44, characterized in that, The wavelength division interval of the plurality of downlink wavelengths is greater than or equal to a first threshold, and the wavelength division interval of the plurality of uplink wavelengths is less than a second threshold, wherein the first threshold is greater than or equal to the second threshold.

46. ​​The first optical module as described in claim 45, characterized in that, The first threshold is 20 nanometers, and the second threshold is 2.5 nanometers.

47. The first optical module as described in any one of claims 44-46, characterized in that, The optical fiber interface is used to receive the downlink optical signal and transmit the downlink optical signal to the photoelectric converter through the beam splitter; The tunable wavelength laser is used to generate the uplink optical signal and send the uplink optical signal to the beam splitter; The beam splitter is used to transmit the uplink optical signal through the optical fiber interface.

48. The first optical module as described in any one of claims 44-46, characterized in that, The photoelectric converter has the ability to process optical signals with different downlink wavelengths, and the tunable wavelength laser has the ability to generate optical signals with different uplink wavelengths. The photoelectric converter is used to perform photoelectric conversion on the downlink optical signal to obtain a first electrical signal; The tunable wavelength laser is used to generate the uplink optical signal based on the second electrical signal.

49. The first optical module as described in claim 47, characterized in that, The uplink interface is connected to the first optical fiber; The beam splitter is used to receive the downlink optical signal transmitted through the first optical fiber via the uplink interface, and to transmit the downlink optical signal to the photoelectric converter; The beam splitter is also used to transmit the uplink optical signal generated by the tunable wavelength laser to the first optical fiber through the uplink interface.

50. A central optical module, characterized in that, Included in an optical communication system, the optical communication system further includes multiple access-side optical modules, the multiple access-side optical modules corresponding to multiple uplink wavelengths, and the multiple access-side optical modules corresponding to multiple downlink wavelengths. Different access-side optical modules among the multiple access-side optical modules correspond to different downlink wavelengths, and different access-side optical modules among the multiple access-side optical modules correspond to different uplink wavelengths. The central optical module includes a fixed-wavelength laser, the fixed-wavelength laser is used to generate optical signals of multiple fixed wavelengths, the multiple fixed wavelengths including the multiple downlink wavelengths. The central optical module also includes an optical fiber interface, an optical transmitting component, and an optical receiving component. The optical transmitting component is used to transmit multiple downlink optical signals through the optical fiber interface. The multiple downlink optical signals are generated by the fixed wavelength laser, and the wavelengths of the multiple downlink optical signals are the multiple downlink wavelengths. The optical receiving component is used to receive multiple uplink optical signals through the optical fiber interface, wherein the wavelengths of the multiple uplink optical signals are the multiple uplink wavelengths; Wherein, the wavelength division interval of the plurality of downlink wavelengths is greater than the wavelength division interval of the plurality of uplink wavelengths, and the bands in which the plurality of uplink wavelengths are located are completely separated from the bands in which the plurality of downlink wavelengths are located.

51. The central optical module as described in claim 50, characterized in that, The wavelength division interval of the plurality of downlink wavelengths is greater than or equal to a first threshold, and the wavelength division interval of the plurality of uplink wavelengths is less than a second threshold, wherein the first threshold is greater than or equal to the second threshold.

52. The central optical module as described in claim 51, characterized in that, The first threshold is 20 nanometers, and the second threshold is 2.5 nanometers.

53. The central optical module as described in any one of claims 50-52, characterized in that, The optical transmission component includes a multiplexer, and the optical fiber interface includes at least one downlink interface, which is connected to an optical fiber. The multiplexer is used to combine the multiple downlink optical signals generated by the fixed-wavelength laser into a composite downlink optical signal, and transmit the composite downlink optical signal through the downlink interface.

54. The central optical module as described in claim 53, characterized in that, The central optical module is integrated into or inserted into the routing and switching equipment; The fixed-wavelength laser is used to generate the plurality of downlink optical signals based on the plurality of first electrical signals input by the routing switching device. The plurality of downlink optical signals carry downlink information sent by the routing switching device through the plurality of first electrical signals. The plurality of first electrical signals correspond one-to-one with the plurality of access-side optical modules. The downlink information includes information sent to the plurality of access-side optical modules.

55. The central optical module as described in claim 54, characterized in that, The optical receiving component includes a demultiplexer, and the central optical module further includes a photoelectric conversion device; The demultiplexer is used to receive composite uplink optical signals through the downlink interface; The demultiplexer is further configured to demultiplex the plurality of uplink optical signals from the composite uplink optical signal, wherein the plurality of uplink optical signals carry uplink information sent by the plurality of access-side optical modules to the routing and switching device; The photoelectric conversion device is used to perform photoelectric conversion on the plurality of uplink optical signals respectively to obtain a plurality of second electrical signals, and to send the plurality of second electrical signals to the routing switching device.

56. The central optical module as described in claim 55, characterized in that, The at least one downlink interface includes a downlink interface, and the central optical module further includes a beam splitter, which is connected to the multiplexer and the demultiplexer respectively, and the beam splitter is also connected to the downlink interface; The multiplexer is used to transmit the composite downlink optical signal to the beam splitter; The beam splitter is used to send the composite downlink optical signal to the downlink interface; The optical splitter is also used to receive the composite uplink optical signal transmitted on the connected optical fiber through the downlink interface, and to transmit the composite uplink optical signal to the demultiplexer.

57. The central optical module as described in claim 55, characterized in that, The at least one downlink interface includes a downlink interface, the multiplexer is connected to the demultiplexer, and the multiplexer is also connected to the downlink interface; The multiplexer is used to send the composite downlink optical signal to the downlink interface; The multiplexer is also used to receive composite uplink optical signals transmitted on the connected optical fiber through the downlink interface, and to transmit the composite uplink optical signals to the demultiplexer.

58. The central optical module as described in claim 54, characterized in that, The at least one downlink interface includes a downlink interface, the central optical module further includes a photoelectric conversion device, and the multiplexer is connected to the downlink interface; The multiplexer is used to send the composite downlink optical signal to the downlink interface; The multiplexer is also used to receive composite uplink optical signals transmitted on the connected optical fiber through the downlink interface; The multiplexer is further configured to demultiplex the multiple uplink optical signals from the composite uplink optical signal, the multiple uplink optical signals carrying uplink information sent by the multiple access-side optical modules to the routing and switching device; The photoelectric conversion device is used to perform photoelectric conversion on the plurality of uplink optical signals respectively to obtain a plurality of second electrical signals, and to send the plurality of second electrical signals to the routing switching device.

59. The central optical module as described in claim 55, characterized in that, The at least one downlink interface further includes a first downlink interface and a second downlink interface, the multiplexer is connected to the first downlink interface, the demultiplexer is connected to the second downlink interface, and the first downlink interface and the second downlink interface are respectively connected to different optical fibers; The multiplexer is used to transmit the composite downlink optical signal through the connected first downlink interface; The demultiplexer is also used to receive the composite uplink optical signal through the connected second downlink interface.

60. An intermediate device, characterized in that, The intermediate device is included in an optical communication system, which further includes multiple access-side optical modules. The multiple access-side optical modules correspond to multiple uplink wavelengths and multiple downlink wavelengths. The wavelength division multiplexing (WDM) interval of the multiple downlink wavelengths is greater than that of the multiple uplink wavelengths. The bands in which the multiple uplink wavelengths are located are completely separated from the bands in which the multiple downlink wavelengths are located. Different access-side optical modules in the multiple access-side optical modules correspond to different downlink wavelengths, and different access-side optical modules in the multiple access-side optical modules correspond to different uplink wavelengths. The intermediate device includes an optical fiber interface, a demultiplexer, and an optical coupler. The fiber optic interface is used to receive composite downlink optical signals, which include multiple downlink optical signals; The demultiplexer is used to demultiplex the multiple downlink optical signals from the composite downlink optical signal, and send the corresponding downlink optical signals to the multiple access side optical modules based on the downlink wavelengths of the multiple downlink optical signals obtained by demultiplexing. The optical coupler is used to combine multiple uplink optical signals from the multiple access side optical modules to obtain a composite uplink optical signal; The fiber optic interface is also used to transmit the composite uplink optical signal.

61. The intermediate device as described in claim 60, characterized in that, The composite downlink optical signal includes multiple downlink optical signals transmitted based on coarse wavelength division multiplexing (CWDM), and the composite uplink optical signal includes multiple uplink optical signals transmitted based on dense wavelength division multiplexing (DWDM).

62. The intermediate device as described in claim 60 or 61, characterized in that, The fiber optic interface includes at least one uplink interface and multiple downlink interfaces, wherein the uplink interface and the downlink interface are respectively connected to optical fibers; The at least one uplink interface is used to receive the composite downlink optical signal and transmit the composite uplink optical signal; The plurality of downlink interfaces are used to send corresponding downlink optical signals to the plurality of access-side optical modules, wherein each downlink interface sends an optical signal of a downlink wavelength, and the downlink wavelengths of the optical signals sent by different downlink interfaces are different; The plurality of downlink interfaces are also used to receive corresponding uplink optical signals sent by the plurality of access-side optical modules, wherein each of the plurality of downlink interfaces receives an optical signal of a downlink wavelength, and the uplink wavelengths of the optical signals received by different downlink interfaces are different.

63. The intermediate device as described in claim 62, characterized in that, Each of the uplink and downlink interfaces is connected to an optical fiber.

64. The intermediate device as described in claim 63, characterized in that, The intermediate device further includes a plurality of first beam splitters, the demultiplexer is connected to the plurality of first beam splitters respectively, the optical coupler is connected to the plurality of first beam splitters respectively, each of the plurality of first beam splitters is connected to one of the plurality of downlink interfaces, and different first beam splitters are connected to different downlink interfaces; The demultiplexer is used to transmit a downlink optical signal to each of the plurality of first optical splitters, wherein each first optical splitter receives one downlink optical signal, and the downlink wavelengths of the optical signals received by different first optical splitters are different. The plurality of first optical splitters are used to transmit their respective received downlink optical signals to their respective connected downlink interfaces. Each of the plurality of downlink interfaces is used to transmit its received downlink optical signal through the optical fiber to which it is connected. Each of the plurality of downlink interfaces is also used to receive uplink optical signals transmitted by the optical fiber to which it is connected. Each downlink interface receives one uplink optical signal, and the downlink wavelengths of the optical signals received by different downlink interfaces are different. Each of the plurality of downlink interfaces is also used to transmit its received uplink optical signal to the first optical splitter to which it is connected; The plurality of first beam splitters are also used to transmit their respective received uplink optical signals to the optical coupler.

65. The intermediate device as described in claim 63 or 64, characterized in that, The fiber optic interface includes an uplink interface, and the intermediate device further includes a second beam splitter. The uplink interface is connected to an optical fiber, and the second beam splitter is connected to the uplink interface, the demultiplexer, and the optical coupler, respectively. The uplink interface is used to receive the composite downlink optical signal transmitted through the connected optical fiber and to transmit the received composite downlink optical signal to the second optical splitter. The second beam splitter is used to send the composite downlink optical signal to the demultiplexer; The optical coupler is used to transmit the composite uplink optical signal to the second beam splitter; The second beam splitter is used to transmit the composite uplink optical signal to the uplink interface; The uplink interface is also used to transmit the composite uplink optical signal through the connected optical fiber.

66. The intermediate device as described in claim 63 or 64, characterized in that, The optical fiber interface includes a first uplink interface and a second uplink interface, the first uplink interface and the second uplink interface are respectively connected to different optical fibers, the demultiplexer is connected to the first uplink interface, and the optical coupler is connected to the second uplink interface; The first uplink interface is used to receive the composite downlink optical signal transmitted on the connected optical fiber and transmit the composite downlink optical signal to the demultiplexer; The optical coupler is used to transmit the composite uplink optical signal to the second uplink interface; The second uplink interface is used to send the composite uplink optical signal to the connected optical fiber.

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