Optical communication system, method and related device

Abstract

The invention discloses an optical communication system and method and a related device, and belongs to the technical field of communication. Wherein the central optical module comprises a fixed wavelength laser for generating a plurality of optical signals with fixed wavelengths; the central optical module is used for sending a composite downlink optical signal to the plurality of access side optical modules, the composite downlink optical signal comprises a plurality of downlink optical signals of different downlink wavelengths generated by the fixed wavelength laser, and different downlink wavelengths correspond to different access side optical modules; each access side optical module comprises an adjustable wavelength laser, the adjustable wavelength laser is used for sending an optical signal of an uplink wavelength corresponding to the access side optical module to the central optical module, and different access side optical modules correspond to different uplink wavelengths; the central optical module is also used for receiving a composite uplink optical signal, and the composite uplink optical signal comprises a plurality of uplink optical signals with different uplink wavelengths. According to the application, the normalized access side optical module can be applied, the production and deployment difficulty of the access side optical module is reduced, and the networking difficulty is reduced.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to an optical communication system, method, and related devices. Background Art

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

[0003] Access devices are typically connected to a central switch through an intermediary device. A central switch can communicate optically with multiple access devices through the intermediary device. For example, eight access devices form a group. Each group of access devices is connected via optical fiber to a common intermediary device, which is then connected to the central switch via optical fiber, enabling optical communication between the group of access devices and the central switch. A central switch can connect one or more groups of access devices through one or more intermediary devices.

[0004] Each access device is equipped with (or integrated with) an optical module, and the central switch is also equipped with (or integrated with) an optical module. Optical modules generate and process optical signals and serve as a bridge for optical communication between the access device and the central switch. For ease of distinction, optical modules installed or integrated in access devices are referred to as access-side optical modules, while those installed or integrated in the central switch are referred to as central optical modules. Currently, wavelength division multiplexing (WDM) can be used to enable optical communication between multiple access-side optical modules and a single central optical module. Specifically, different access-side optical modules on a group of access devices correspond to different uplink and downlink wavelengths, and the uplink and downlink information is transmitted using optical signals corresponding to the wavelengths of the multiple access-side optical modules. In WDM schemes, the wavelength division spacing (WDM spacing) is one of the factors that influences the reliability of optical communication and the difficulty of networking. An appropriate WDM spacing helps ensure the reliability of optical communication and reduces the difficulty of networking. Summary of the Invention

[0005] This application provides an optical communication system, method, and related devices that can apply normalized access-side optical modules in campus scenarios, thereby simplifying the production and deployment of access-side optical modules. Furthermore, the implementation cost of normalizing access-side optical modules is reduced. The technical solution is as follows: 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 corresponding to multiple upstream wavelengths, and the multiple access-side optical modules corresponding to multiple downstream wavelengths, different access-side optical modules among the multiple access-side optical modules corresponding to different downstream wavelengths, and different access-side optical modules among the multiple access-side optical modules corresponding to different upstream wavelengths, the central optical module being connected to the multiple access-side optical modules, the central optical module comprising a fixed-wavelength laser, the fixed-wavelength laser being configured to generate multiple optical signals of fixed wavelengths, the multiple fixed wavelengths including the multiple downstream wavelengths, and each of the multiple access-side optical modules comprising a tunable-wavelength laser (also referred to as a wavelength-tunable laser); The central optical module is used to send a composite downlink optical signal to the multiple access-side optical modules, wherein the composite downlink optical signal includes multiple downlink optical signals generated by the fixed-wavelength laser, and the wavelengths of the multiple downlink optical signals are respectively the multiple downlink wavelengths; Each of the multiple access side optical modules is used to use the tunable wavelength laser to send an optical signal of an uplink wavelength corresponding to the access side optical module to the central optical module; The central optical module is further configured to receive a composite uplink optical signal, where the composite uplink optical signal includes a plurality of uplink optical signals, and the wavelengths of the plurality of uplink optical signals are respectively the plurality of uplink wavelengths.

[0006] In this application, the central optical module uses a fixed-wavelength laser, which is relatively low in cost. The access-side optical module uses a tunable-wavelength laser, which allows multiple access-side optical modules to be normalized. During optical communication, the tunable-wavelength laser of each access-side optical module transmits optical signals according to the corresponding uplink wavelength of the access-side optical module. The application of normalized access-side optical modules reduces the difficulty of production and deployment of access-side optical modules.

[0007] In one possible implementation, the wavelength division interval of the multiple downstream wavelengths is greater than the wavelength division interval of the multiple upstream wavelengths. That is, the present application can adopt a hybrid wavelength division solution, thereby taking into account both cost and production / deployment difficulty.

[0008] In one possible implementation, the multiple downstream optical signals included in the composite downstream optical signal are transmitted based on coarse wavelength division multiplexing (CWDM), and the multiple upstream optical signals included in the composite upstream optical signal are transmitted based on dense wavelength division multiplexing (DWDM). That is, the present application may adopt a wavelength division multiplexing scheme that combines coarse wavelength division multiplexing and dense wavelength division multiplexing.

[0009] In a possible implementation, the wavelength division interval of the multiple downstream wavelengths is greater than or equal to a first threshold, the wavelength division interval of the multiple upstream wavelengths is less than a second threshold, and the first threshold is greater than or equal to the second threshold.

[0010] In a 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 normalization of the access-side optical module.

[0011] As an example, the wavelength division interval of the multiple downstream wavelengths is 20 nm, and the wavelength division interval of the multiple upstream wavelengths is 2.4 nm.

[0012] In one possible implementation, the optical communication system further includes an intermediate device, the intermediate device including a first demultiplexer and an optical combiner, the intermediate device being connected to the central optical module via an optical fiber, and the intermediate device being further connected to the multiple access-side optical modules respectively via optical fibers; The first demultiplexer is configured to demultiplex the composite downlink optical signal received through the optical fiber to obtain a plurality of downlink optical signals, and send the corresponding downlink optical signals to the plurality of access-side optical modules through the optical fiber based on the respective downlink wavelengths of the plurality of downlink optical signals obtained by the demultiplexing; 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 send the composite uplink optical signal to the central optical module through an optical fiber.

[0013] In a 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 respectively connected to the multiple access side optical modules via the multiple downlink interfaces through optical fibers; The intermediate device is configured to receive the composite downlink optical signal and send 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 of the multiple downlink interfaces sends a downlink optical signal, and the downlink wavelengths of the optical signals sent by different downlink interfaces in the multiple 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 an uplink optical signal, and the uplink wavelengths of the optical signals received by different downlink interfaces among the multiple downlink interfaces are different.

[0014] In a possible implementation, each of the multiple downlink interfaces is connected to an optical fiber, that is, a single fiber connection is used between the intermediate device and the access-side optical module, thereby saving optical fiber resources and reducing the difficulty of optical fiber deployment.

[0015] 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 a plurality of first optical splitters, the first demultiplexer is respectively connected to the plurality of first optical splitters, the optical combiner is respectively connected to the plurality of first optical splitters, each of the plurality of first optical splitters is connected to one of the plurality of downstream interfaces, and different first optical splitters are connected to different downstream interfaces; each of the access-side optical modules includes a second optical splitter, the second optical splitter is connected to a downstream interface of the intermediate device via an optical fiber, the second optical splitters in different access-side optical modules among the plurality of access-side optical modules are connected to different downstream interfaces of the intermediate device, and the second optical splitter in the first optical module among the plurality of access-side optical modules is connected to the first downstream interface among the plurality of downstream interfaces via a first optical fiber; The first demultiplexer is specifically configured 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 different first optical splitters receive optical signals with different downlink wavelengths; 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 optical signal of the downlink wavelength 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 an optical signal of an uplink wavelength corresponding to the first optical module to the first downlink interface through the first optical fiber; Each downlink interface is further configured to transmit an uplink optical signal received by the downlink interface to the first optical splitter connected to the downlink interface; Each first optical splitter is further configured to transmit the uplink optical signal received by the first optical splitter to the optical combining device; The optical combining component is specifically configured 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.

[0016] In another possible implementation, each of the multiple downstream interfaces includes a first sub-interface and a second sub-interface, the first demultiplexer is respectively connected to the multiple first sub-interfaces of the multiple downstream interfaces, and the optical combiner is respectively connected to the multiple second sub-interfaces of the multiple downstream interfaces; different access side optical modules among the multiple access side optical modules are connected to different downstream interfaces of the intermediate device through optical fibers, and the first optical module among the multiple access side optical modules is respectively connected to the first sub-interface and the second sub-interface included in the first downstream interface of the multiple downstream interfaces through different optical fibers; The first demultiplexer is specifically configured to transmit the multiple downlink optical signals to the multiple first sub-interfaces, wherein one first sub-interface receives one downlink optical signal, and different first sub-interfaces receive optical signals with different downlink wavelengths; 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; The second sub-interface of the first downlink interface is used to receive an optical signal of an uplink wavelength corresponding to the first optical module and 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 optical signal of the uplink wavelength received by the second sub-interface to the optical combining device; 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.

[0017] 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.

[0018] In a possible implementation, the central optical module further includes a downlink interface, and the downlink interface of the central optical module is connected to an optical fiber, that is, a single-fiber connection is established between the central optical module and the intermediate device.

[0019] In the implementation mode where single-fiber connections are used between the central optical module and the intermediate device, and between the intermediate device and the access-side optical module, the connection method between devices is relatively simple, the optical networking difficulty is low, and the amount of optical fiber used is small, saving optical fiber resources.

[0020] To achieve a single-fiber connection between the central optical module and the intermediate device, in one possible implementation, the central optical module further includes a fourth optical splitter, a first multiplexer, a second demultiplexer, and a photoelectric conversion device, wherein the fourth optical splitter is connected to the downlink interface of the central optical module, and the fourth optical splitter is also connected to the first multiplexer and the second demultiplexer respectively; The fixed wavelength laser is used to generate the multiple downlink optical signals according to the multiple first electrical signals, and the multiple first electrical signals are electrical signals input by the routing switching device; 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, 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 second demultiplexer; The second demultiplexer is configured 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 switching device.

[0021] To achieve a single-fiber connection between the central optical module and the intermediate device, 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; The fixed wavelength laser is used to generate the multiple downlink optical signals according to the multiple first electrical signals, and the multiple first electrical signals are electrical signals input by the routing switching device; 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, and 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 configured to receive the composite uplink optical signal transmitted by the second demultiplexer, 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 third demultiplexer into multiple second electrical signals, and output the multiple second electrical signals to the routing switching device.

[0022] To achieve a single-fiber connection between the central optical module and the intermediate device, in another possible implementation, the central optical module further includes a multiplexer / demultiplexer and a photoelectric conversion device, and the multiplexer / demultiplexer is connected to the downlink interface of the central optical module; The fixed wavelength laser is used to generate the multiple downlink optical signals according to the multiple first electrical signals, and the multiple first electrical signals are electrical signals input by the routing switching device; The multiplexer / demultiplexer is configured 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 a 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 the multiple uplink optical signals demultiplexed by the multiplexer / demultiplexer into multiple second electrical signals, and output the multiple second electrical signals to the routing switching device.

[0023] 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 combiner, respectively; The third optical splitter is used to receive the composite downlink optical signal sent by the central optical module through the uplink interface, and transmit the composite downlink optical signal to the first demultiplexer; The third optical splitter is further configured to receive the composite uplink optical signal transmitted by the optical combining component, and send the composite uplink optical signal to the central optical module through the uplink interface.

[0024] In another possible implementation, the central optical module further includes a second downstream interface, a third downstream interface, a first multiplexer, a second demultiplexer, and a photoelectric conversion device, wherein the first multiplexer is connected to the second downstream interface, and the second demultiplexer is connected to the third downstream interface; The fixed wavelength laser is used to generate the multiple downlink optical signals according to the multiple first electrical signals, and the multiple first electrical signals are electrical signals input by the routing switching device; The first multiplexer is used to combine the multiple downlink optical signals into the composite downlink optical signal, and send the combined composite downlink optical signal through the second downlink interface; The second demultiplexer is configured to demultiplex the multiple uplink optical signals from the composite uplink optical signal received by the third downlink interface; The photoelectric conversion device is used to convert the multiple uplink optical signals into multiple second electrical signals and output the multiple second electrical signals to the routing switch device. In other words, the central optical module and the intermediate device are connected by dual fibers.

[0025] 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 and the second downlink interface of the central optical module, and the second uplink interface and the third downlink interface of the central optical module are respectively connected through 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.

[0026] In a possible implementation, each access-side optical module further includes a photoelectric converter capable of processing optical signals of different downstream wavelengths; The tunable wavelength laser is used to generate an optical signal of an uplink wavelength corresponding to the access side optical module according to 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 an optical signal of a downlink wavelength received by an access-side optical module to which the photoelectric converter belongs to obtain a fourth electrical signal, and output the fourth electrical signal to the access device.

[0027] In a possible implementation, the central optical module is integrated into or inserted into a routing switch device, and the optical signal of the downstream wavelength carries the downstream information sent by the routing switch device; and / or, Each of the multiple access side optical modules is integrated into or inserted into an access device, and the optical signal of the uplink wavelength carries uplink information sent by the access device.

[0028] The downlink information includes downlink instructions and / or downlink data; the uplink information includes uplink responses and / or uplink data.

[0029] In a second aspect, an optical communication method is provided, in which an optical communication system includes multiple access side optical modules, the multiple access side optical modules corresponding to multiple upstream wavelengths, and the multiple access side optical modules corresponding to multiple downstream wavelengths, different access side optical modules corresponding to different downstream wavelengths, different access side optical modules corresponding to different upstream wavelengths, and the wavelength division interval of the multiple downstream wavelengths is greater than the wavelength division interval of the multiple upstream wavelengths; the method is applied to a first optical module among the multiple access side optical modules, the first optical module being any one of the multiple access side optical modules, and the method includes: receiving a downlink optical signal, where the wavelength of the downlink optical signal is a first downlink wavelength corresponding to the first optical module; An uplink optical signal is generated and sent, where the wavelength of the uplink optical signal is the first uplink wavelength corresponding to the first optical module.

[0030] In a possible implementation, the wavelength division intervals of the multiple downstream wavelengths are determined based on a coarse wavelength division multiplexing (CWDM) scheme, and the wavelength division intervals of the multiple upstream wavelengths are determined based on a dense wavelength division multiplexing (DWDM) scheme.

[0031] In a possible implementation, the wavelength division interval of the multiple downstream wavelengths is greater than or equal to a first threshold, the wavelength division interval of the multiple upstream wavelengths is less than a second threshold, and the first threshold is greater than or equal to the second threshold.

[0032] In a possible implementation, the first threshold is 20 nanometers, and the second threshold is 2.5 nanometers.

[0033] In one possible implementation, the first optical module includes a photoelectric converter and a tunable wavelength laser, the photoelectric converter is capable of processing optical signals of different downstream wavelengths, and the tunable wavelength laser is capable of generating optical signals of different upstream wavelengths; the method further includes: The photoelectric converter performs photoelectric conversion on the downlink optical signal to obtain a first electrical signal; The generating and sending of an uplink optical signal includes: The tunable wavelength laser generates and sends the uplink optical signal.

[0034] In one possible implementation, the first optical module is integrated or inserted into a first access device, the downlink optical signal carries downlink information transmitted to the first access device, and the optoelectronic converter performs optoelectronic conversion on the downlink optical signal to obtain a 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 sends the uplink optical signal, the method further includes: A second electrical signal transmitted by the first access device is received, where the uplink optical signal carries uplink information sent by the first access device through the second electrical signal.

[0035] In a possible implementation, the first optical module includes an uplink interface and a beam splitter, the uplink interface is connected to the first optical fiber, and the beam splitter is connected to the uplink interface; The receiving of a downlink optical signal includes: The optical splitter receives the downlink optical signal transmitted by the first optical fiber through the uplink interface, and transmits the downlink optical signal to the photoelectric converter; The sending of the uplink optical signal includes: The beam splitter sends the uplink optical signal generated by the tunable wavelength laser to the first optical fiber through the uplink interface.

[0036] In a possible implementation, the first optical module includes a first uplink interface and a second uplink interface, and the first uplink interface and the second uplink interface are respectively connected to different optical fibers; The receiving of a downlink optical signal includes: 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; The sending of the uplink optical signal includes: The second uplink interface sends the uplink optical signal generated by the tunable wavelength laser through the connected optical fiber.

[0037] In one possible implementation, the tunable wavelength laser adopts a distributed Bragg reflector (DBR) laser, an electro-absorption (EA) modulated DBR laser, a Littman structure tunable external cavity semiconductor laser (TECDL), a Littman-Metcalf structure 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 an on-chip semiconductor optical amplifier (SOA), a Fabry-Pérot (FP) laser, a distributed feedback (DFB) laser array or a transmitter optical subassembly (TOSA) to adjust the emission wavelength by self-locking or injection locking.

[0038] In a possible implementation, the photoelectric converter uses a P-type semiconductor-impurity-N-type semiconductor (positive-intrinsic-negative, PIN), an avalanche photo diode (APD) or a SOA-PIN integrated photodetector to achieve photoelectric conversion.

[0039] In a third aspect, 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 comprising a plurality of access side optical modules, the plurality of access side optical modules corresponding to a plurality of upstream wavelengths, and the plurality of access side optical modules corresponding to a plurality of downstream wavelengths, different access side optical modules among the plurality of access side optical modules corresponding to different downstream wavelengths, different access side optical modules among the plurality of access side optical modules corresponding to different upstream wavelengths, the central optical module comprising a fixed wavelength laser, the fixed wavelength laser being used to generate a plurality of fixed wavelength optical signals, the plurality of fixed wavelengths including the plurality of downstream wavelengths, the method comprising: Sending a plurality of downlink optical signals, where the plurality of downlink optical signals are generated by the fixed-wavelength laser, and the wavelengths of the plurality of downlink optical signals are respectively the plurality of downlink wavelengths; receiving a plurality of uplink optical signals, where the wavelengths of the plurality of uplink optical signals are the plurality of uplink wavelengths respectively; The wavelength division interval of the multiple downstream wavelengths is greater than the wavelength division interval of the multiple upstream wavelengths.

[0040] In a possible implementation, the multiple downlink optical signals are transmitted based on a coarse wavelength division multiplexing (CWDM) manner, and the multiple uplink optical signals are transmitted based on a dense wavelength division multiplexing (DWDM) manner.

[0041] In a possible implementation, the wavelength division interval of the multiple downstream wavelengths is greater than or equal to a first threshold, the wavelength division interval of the multiple upstream wavelengths is less than a second threshold, and the first threshold is greater than or equal to the second threshold.

[0042] In a possible implementation, the first threshold is 20 nanometers, and the second threshold is 2.5 nanometers.

[0043] In a possible implementation, the central optical module further includes a multiplexer and at least one downlink interface, and the downlink interface is connected to the optical fiber; The sending of multiple downlink optical signals includes: The multiplexer combines the multiple downstream optical signals generated by the fixed wavelength laser into a composite downstream optical signal, and sends the composite downstream optical signal through the downstream interface.

[0044] In a possible implementation, the central optical module is integrated into or inserted into a routing switching device; The fixed wavelength laser generates the multiple downlink optical signals based on the multiple first electrical signals input by the routing and switching device. The multiple downlink optical signals carry the downlink information sent by the routing and switching device through the multiple first electrical signals. The multiple first electrical signals correspond one-to-one to the multiple access-side optical modules, and the downlink information includes information sent to the multiple access-side optical modules.

[0045] In a possible implementation, the central optical module further includes a photoelectric conversion device and a demultiplexer; The receiving of multiple uplink optical signals includes: receiving a composite uplink optical signal via the downlink interface; The demultiplexer demultiplexes the multiple uplink optical signals from the composite uplink optical signal, and the multiple uplink optical signals carry uplink information sent by the multiple access-side optical modules to the routing switching device; The method further comprises: 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 switching device.

[0046] In a possible implementation, the central optical module includes a downlink interface and a splitter, the splitter is connected to the multiplexer and the demultiplexer respectively, and the splitter is also connected to the downlink interface; The sending of the composite downlink optical signal through the downlink interface includes: The multiplexer transmits the composite downstream optical signal to the optical splitter, and the optical splitter sends the composite downstream optical signal to the downstream interface; The receiving of the composite uplink optical signal through the downlink interface includes: The optical splitter receives the composite upstream optical signal transmitted on the connected optical fiber through the downstream interface, and transmits the composite upstream optical signal to the demultiplexer.

[0047] In a possible implementation, the central optical module includes a downlink interface, the multiplexer is connected to the demultiplexer, and the multiplexer is further connected to the downlink interface; The sending of 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 the composite uplink optical signal through the downlink interface includes: The multiplexer receives the composite upstream optical signal transmitted on the connected optical fiber through the downstream interface, and transmits the composite upstream optical signal to the demultiplexer.

[0048] In a possible implementation, the central optical module includes a downlink interface and a photoelectric conversion device, and the multiplexer is connected to the downlink interface; The sending of 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 the composite uplink optical signal 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 multiple uplink optical signals from the composite uplink optical signal, and the multiple uplink optical signals carry uplink information sent by the multiple access-side optical modules to the routing switching device; 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 switching device.

[0049] In a possible implementation, the central optical module further includes a first downstream interface and a second downstream interface, the multiplexer is connected to the first downstream interface, the demultiplexer is connected to the second downstream interface, and the first downstream interface and the second downstream interface are respectively connected to different optical fibers; The sending of the composite downlink optical signal through the downlink interface includes: The multiplexer sends the composite downlink optical signal through the connected first downlink interface; The receiving of the composite uplink optical signal through the downlink interface includes: The demultiplexer receives the composite uplink optical signal through the connected second downlink interface.

[0050] In a fourth aspect, 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 comprising a plurality of access side optical modules, the plurality of access side optical modules corresponding to a plurality of upstream wavelengths, and the plurality of access side optical modules corresponding to a plurality of downstream wavelengths, different access side optical modules among the plurality of access side optical modules corresponding to different downstream wavelengths, and different access side optical modules among the plurality of access side optical modules corresponding to different upstream wavelengths, the intermediate device comprising a demultiplexer and an optical coupler, the method comprising: receiving a composite downlink optical signal, wherein the composite downlink optical signal includes a plurality of downlink optical signals; Demultiplexing the multiple downlink optical signals from the composite downlink optical signal through the demultiplexer; Sending corresponding downlink optical signals to the multiple access-side optical modules based on respective downlink wavelengths of the multiple downlink optical signals obtained by demultiplexing; Combining the multiple uplink optical signals from the multiple access-side optical modules through the optical coupler to obtain a composite uplink optical signal; The composite uplink optical signal is sent.

[0051] In a possible implementation, a wavelength division interval of the multiple downstream wavelengths is greater than a wavelength division interval of the multiple upstream wavelengths.

[0052] In a possible implementation, the multiple downstream optical signals included in the composite downstream optical signal are transmitted based on coarse wavelength division multiplexing (CWDM), and the multiple upstream optical signals included in the composite upstream optical signal are transmitted based on dense wavelength division multiplexing (DWDM).

[0053] In a possible implementation, the intermediate device further includes at least one uplink interface and multiple downlink interfaces, and the uplink interface and the downlink interface are respectively connected to optical fibers; receiving the composite downlink optical signal and sending the composite uplink optical signal through the at least one uplink interface; Sending corresponding downlink optical signals to the multiple access-side optical modules through the multiple downlink interfaces, wherein each of the multiple downlink interfaces sends an optical signal of a downlink wavelength, and the downlink wavelengths of the optical signals sent by different downlink interfaces in the multiple downlink interfaces are different; The corresponding uplink optical signals sent by the multiple access side optical modules are received through the multiple downlink interfaces, wherein 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.

[0054] In a possible implementation, each of the uplink interface and the downlink interface is connected to an optical fiber.

[0055] In a possible implementation, the intermediate device further includes a plurality of first optical splitters, the demultiplexer is connected to each of the plurality of first optical splitters, the optical coupler is connected to each of the plurality of first optical splitters, each of the plurality of first optical splitters is connected to one of the plurality of downstream interfaces, and different first optical splitters are connected to different downstream interfaces. The 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 a downlink optical signal, and different first optical splitters receive optical signals with different downlink wavelengths; The multiple first optical splitters respectively transmit the received downlink optical signals to the downlink interfaces to which they are connected; Each of the multiple downstream interfaces sends a downstream optical signal received by the respective downstream interface through the optical fiber to which the respective downstream interface is connected; Before combining the multiple uplink optical signals from the multiple access-side optical modules through the optical coupler to obtain a composite uplink optical signal, the method further includes: Each of the multiple downstream interfaces receives an upstream optical signal transmitted by the optical fiber to which it is connected, wherein one downstream interface receives one upstream optical signal, and different downstream interfaces receive optical signals with different downstream wavelengths; Each of the multiple downlink interfaces transmits a received uplink optical signal to the first optical splitter to which it is connected; The plurality of first optical splitters respectively transmit the received uplink optical signals to the optical coupler.

[0056] In a possible implementation, each of the multiple downstream interfaces includes a first sub-interface and a second sub-interface, the demultiplexer is respectively connected to the multiple first sub-interfaces of the multiple downstream interfaces, the optical coupler is respectively connected to the multiple second sub-interfaces of the multiple downstream interfaces, and the second sub-interface and the first sub-interface of each downstream interface are respectively connected to different optical fibers; The sending corresponding downlink optical signals to the multiple access-side optical modules through the multiple downlink interfaces includes: The demultiplexer transmits the multiple downlink optical signals to the multiple first sub-interfaces, wherein one first sub-interface receives one downlink optical signal, and different first sub-interfaces receive optical signals with different downlink wavelengths; The first sub-interface in each downstream interface sends the downstream optical signal received by the first sub-interface through the connected optical fiber; The receiving, through the multiple downlink interfaces, corresponding uplink optical signals sent by the multiple access-side optical modules includes: The second sub-interface among the multiple downstream interfaces receives an uplink optical signal transmitted by the optical fiber to which the second sub-interface is connected, and transmits the uplink optical signal received by the second sub-interface to the optical coupler.

[0057] In a possible implementation, 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 a composite downlink optical signal transmitted by the connected optical fiber, and transmits the received composite downlink optical signal to the second optical splitter; The second optical splitter sends the composite downlink optical signal to the demultiplexer; Sending 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 optical splitter; The second optical splitter transmits the composite uplink optical signal to the uplink interface; The uplink interface sends the composite uplink optical signal through the connected optical fiber.

[0058] 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 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 receiving the composite downlink optical signal through the at least one uplink interface includes: The first uplink interface receives a composite downlink optical signal transmitted on the connected optical fiber; The first uplink interface transmits the composite downlink optical signal to the demultiplexer; The sending of 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.

[0059] In a fifth aspect, a communication device is provided, wherein the communication device has the function of implementing the optical communication method described in the second aspect. Specifically, the communication device may be the first optical module described in the second aspect. The communication device includes one or more modules configured to implement the optical communication method described in the second aspect.

[0060] That is, a first optical module is provided, which is any one of a plurality of access-side optical modules included in an optical communication system, wherein the plurality of access-side optical modules correspond to a plurality of upstream wavelengths, and the plurality of access-side optical modules correspond to a plurality of downstream wavelengths, different access-side optical modules correspond to different downstream wavelengths, and different access-side optical modules correspond to different upstream wavelengths, and the wavelength division interval of the plurality of downstream wavelengths is greater than the wavelength division interval of the plurality of upstream wavelengths; the first optical module includes an optical fiber interface, an optical receiving component, and an optical transmitting component; The optical receiving component is used to receive a downlink optical signal transmitted by the optical fiber interface, wherein 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 send 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.

[0061] In a possible implementation, the wavelength division intervals of the multiple downstream wavelengths are determined based on a coarse wavelength division multiplexing (CWDM) scheme, and the wavelength division intervals of the multiple upstream wavelengths are determined based on a dense wavelength division multiplexing (DWDM) scheme.

[0062] In a possible implementation, the wavelength division interval of the multiple downstream wavelengths is greater than or equal to a first threshold, the wavelength division interval of the multiple upstream wavelengths is less than a second threshold, and the first threshold is greater than or equal to the second threshold.

[0063] In a possible implementation, the first threshold is 20 nanometers, and the second threshold is 2.5 nm.

[0064] In one possible implementation, the optical receiving component includes a photoelectric converter, and the optical transmitting component includes a tunable wavelength laser. The photoelectric converter has the ability to process optical signals of different downstream wavelengths, and the tunable wavelength laser has the ability to generate optical signals of different upstream 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 and send the uplink optical signal through the optical fiber interface.

[0065] In a possible implementation, the first optical module is integrated into or inserted into a first access device, and the downlink optical signal carries downlink information transmitted to the first access device; The photoelectric converter is further configured to transmit the first electrical signal to the first access device; The tunable wavelength laser is further configured 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.

[0066] In a possible implementation, the optical fiber 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; The optical splitter is configured to receive the downlink optical signal transmitted by the first optical fiber through the uplink interface and transmit the downlink optical signal to the optoelectronic converter; The beam splitter is further configured to send the uplink optical signal generated by the tunable wavelength laser to the first optical fiber through the uplink interface.

[0067] In a possible implementation, the optical fiber interface includes a first uplink interface and a second uplink interface, and the first uplink interface and the second uplink interface are respectively connected to different optical fibers; The first uplink interface is configured to receive the downlink optical signal transmitted on the connected optical fiber and transmit the downlink optical signal to the optoelectronic converter; The second uplink interface is used to send the uplink optical signal generated by the tunable wavelength laser through the connected optical fiber.

[0068] 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 an SOA, an FP laser, a DFB laser array or a TOSA to adjust the emission wavelength by self-locking or injection locking.

[0069] In a possible implementation, the photoelectric converter uses a PIN, APD, or SOA-PIN integrated photodetector to achieve photoelectric conversion.

[0070] In a sixth aspect, a communication device is provided, wherein the communication device has the function of implementing the optical communication method described in the third aspect. Specifically, the communication device may be the central optical module described in the third aspect. The communication device includes one or more modules configured to implement the optical communication method described in the third aspect.

[0071] That is, a central optical module is provided, the central optical module is included in an optical communication system, the optical communication system further includes a plurality of access side optical modules, the plurality of access side optical modules correspond to a plurality of upstream wavelengths, and the plurality of access side optical modules correspond to a plurality of downstream wavelengths, different access side optical modules among the plurality of access side optical modules correspond to different downstream wavelengths, and different access side optical modules among the plurality of access side optical modules correspond to different upstream wavelengths, the central optical module includes a fixed wavelength laser, the fixed wavelength laser is used to generate a plurality of fixed wavelength optical signals, the plurality of fixed wavelengths including the plurality of downstream wavelengths; the central optical module further includes an optical fiber interface, an optical transmitting component, and an optical receiving component; The optical sending component is used to send 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 respectively the multiple downlink wavelengths; The optical receiving component is configured to receive a plurality of uplink optical signals through the optical fiber interface, wherein the wavelengths of the plurality of uplink optical signals are respectively the plurality of uplink wavelengths; The wavelength division interval of the multiple downstream wavelengths is greater than the wavelength division interval of the multiple upstream wavelengths.

[0072] In a possible implementation, the multiple downlink optical signals are transmitted based on a coarse wavelength division multiplexing (CWDM) manner, and the multiple uplink optical signals are transmitted based on a dense wavelength division multiplexing (DWDM) manner.

[0073] In a possible implementation, the wavelength division interval of the multiple downstream wavelengths is greater than or equal to a first threshold, the wavelength division interval of the multiple upstream wavelengths is less than a second threshold, and the first threshold is greater than or equal to the second threshold.

[0074] In a possible implementation, the first threshold is 20 nanometers, and the second threshold is 2.5 nanometers.

[0075] In a possible implementation, the optical transmission component includes a multiplexer, the optical fiber interface includes at least one downstream interface, and the downstream interface is connected to an optical fiber; The multiplexer is configured to combine the multiple downlink optical signals generated by the fixed wavelength laser into a composite downlink optical signal, and send the composite downlink optical signal through the downlink interface.

[0076] In a possible implementation, the central optical module is integrated into or inserted into a routing switching device; The fixed wavelength laser is used to generate the multiple downlink optical signals based on the multiple first electrical signals input by the routing and switching device. The multiple downlink optical signals carry the downlink information sent by the routing and switching device through the multiple first electrical signals. The multiple first electrical signals correspond one-to-one to the multiple access-side optical modules, and the downlink information includes information sent to the multiple access-side optical modules.

[0077] In a possible implementation, the optical receiving component includes a demultiplexer, and the central optical module further includes a photoelectric conversion device; The demultiplexer is configured to receive the composite uplink optical signal via the downlink interface; The demultiplexer is further configured to demultiplex the multiple uplink optical signals from the composite uplink optical signal, wherein the multiple uplink optical signals carry uplink information sent by the multiple access-side optical modules to the routing switching device; The photoelectric conversion device is used to perform photoelectric conversion on the multiple uplink optical signals respectively, thereby obtaining multiple second electrical signals, and sending the multiple second electrical signals to the routing switching device.

[0078] In a possible implementation, the at least one downlink interface includes a downlink interface, the central optical module further includes a splitter, the splitter is connected to the multiplexer and the demultiplexer respectively, and the splitter is also connected to the downlink interface; The multiplexer is used to transmit the composite downlink optical signal to the optical splitter; The optical splitter is used to send the composite downlink optical signal to the downlink interface; The optical splitter is further configured to receive, via the downlink interface, a composite uplink optical signal transmitted on the connected optical fiber, and transmit the composite uplink optical signal to the demultiplexer.

[0079] In a possible implementation, the at least one downlink interface includes a downlink interface, the multiplexer is connected to the demultiplexer, and the multiplexer is further connected to the downlink interface; The multiplexer is used to send the composite downlink optical signal to the downlink interface; The multiplexer is further configured to receive a composite upstream optical signal transmitted on the connected optical fiber through the downstream interface, and transmit the composite upstream optical signal to the demultiplexer.

[0080] In a possible implementation, 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 further configured to receive, through the downlink interface, a composite uplink optical signal transmitted on the connected optical fiber; The multiplexer is further configured to demultiplex the multiple uplink optical signals from the composite uplink optical signal, wherein the multiple uplink optical signals carry uplink information sent by the multiple access-side optical modules to the routing switching device; The photoelectric conversion device is used to perform photoelectric conversion on the multiple uplink optical signals respectively, thereby obtaining multiple second electrical signals, and sending the multiple second electrical signals to the routing switching device.

[0081] In one possible implementation, the at least one downstream interface includes a first downstream interface and a second downstream interface, the multiplexer is connected to the first downstream interface, the demultiplexer is connected to the second downstream interface, and the first downstream interface and the second downstream interface are respectively connected to different optical fibers; The multiplexer is configured to send the composite downlink optical signal through the connected first downlink interface; The demultiplexer is configured to receive the composite uplink optical signal through the connected second downlink interface.

[0082] In a seventh aspect, a communication device is provided, wherein the communication device has the function of implementing the optical communication method described in the fourth aspect. That is, the communication device may be the intermediate device described in the fourth aspect. The communication device includes one or more modules configured to implement the optical communication method described in the fourth aspect.

[0083] That is, an intermediate device is provided, the intermediate device is included in an optical communication system, the optical communication system further includes a plurality of access side optical modules, the plurality of access side optical modules correspond to a plurality of upstream wavelengths, and the plurality of access side optical modules correspond to a plurality of downstream wavelengths, different access side optical modules among the plurality of access side optical modules correspond to different downstream wavelengths, and different access side optical modules among the plurality of access side optical modules correspond to different upstream wavelengths, the intermediate device includes an optical fiber interface, a demultiplexer, and an optical coupler; The optical fiber interface is configured to receive a composite downstream optical signal, wherein the composite downstream optical signal includes multiple downstream optical signals; The demultiplexer is configured to demultiplex the multiple downlink optical signals from the composite downlink optical signal, and send corresponding downlink optical signals to the multiple access-side optical modules based on respective downlink wavelengths of the multiple downlink optical signals obtained by demultiplexing; The optical coupler is configured to combine the multiple uplink optical signals from the multiple access-side optical modules to obtain a composite uplink optical signal; The optical fiber interface is also used to send the composite uplink optical signal.

[0084] In a possible implementation, a wavelength division interval of the multiple downstream wavelengths is greater than a wavelength division interval of the multiple upstream wavelengths.

[0085] In a possible implementation, the multiple downstream optical signals included in the composite downstream optical signal are transmitted based on coarse wavelength division multiplexing (CWDM), and the multiple upstream optical signals included in the composite upstream optical signal are transmitted based on dense wavelength division multiplexing (DWDM).

[0086] In a possible implementation, the optical fiber interface includes at least one uplink interface and multiple downlink interfaces, and the uplink interface and the downlink interface are respectively connected to optical fibers; The at least one uplink interface is configured to receive the composite downlink optical signal and send the composite uplink optical signal; The multiple downlink interfaces are used to send corresponding downlink optical signals to the multiple access-side optical modules, wherein each of the multiple downlink interfaces sends an optical signal of a downlink wavelength, and the downlink wavelengths of the optical signals sent by different downlink interfaces in the multiple downlink interfaces are different; The multiple downstream interfaces are also used to receive corresponding upstream optical signals sent by the multiple access side optical modules, wherein each of the multiple downstream interfaces receives an optical signal of a downstream wavelength, and the upstream wavelengths of the optical signals received by different downstream interfaces among the multiple downstream interfaces are different.

[0087] In a possible implementation, each of the uplink interface and the downlink interface is connected to an optical fiber.

[0088] In a possible implementation, the intermediate device further includes a plurality of first optical splitters, the demultiplexer is connected to each of the plurality of first optical splitters, the optical coupler is connected to each of the plurality of first optical splitters, each of the plurality of first optical splitters is connected to one of the plurality of downstream interfaces, and different first optical splitters are connected to different downstream interfaces. The demultiplexer is configured 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 different first optical splitters receive optical signals with different downlink wavelengths; The multiple first optical splitters are used to transmit the received downlink optical signals to the downlink interfaces to which they are connected respectively; Each of the multiple downstream interfaces is configured to send a received downstream optical signal through an optical fiber to which it is connected; Each of the multiple downstream interfaces is further configured to receive an upstream optical signal transmitted by the optical fiber to which it is connected, wherein one downstream interface receives one upstream optical signal, and different downstream interfaces receive optical signals having different downstream wavelengths; Each of the multiple downlink interfaces is further configured to transmit a received uplink optical signal to the first optical splitter to which it is connected; The plurality of first optical splitters are further configured to transmit respectively received uplink optical signals to the optical coupler.

[0089] In a possible implementation, each of the multiple downstream interfaces includes a first sub-interface and a second sub-interface, the demultiplexer is respectively connected to the multiple first sub-interfaces of the multiple downstream interfaces, the optical coupler is respectively connected to the multiple second sub-interfaces of the multiple downstream interfaces, and the second sub-interface and the first sub-interface of each downstream interface are respectively connected to different optical fibers; The demultiplexer is configured to transmit the multiple downlink optical signals to the multiple first sub-interfaces, wherein one first sub-interface receives one downlink optical signal, and different first sub-interfaces receive optical signals with different downlink wavelengths; The first sub-interface in each downstream interface is configured to send the downstream optical signal received by the first sub-interface through the connected optical fiber; The second sub-interface among the multiple downlink interfaces is configured to receive an uplink optical signal transmitted by the optical fiber to which the second sub-interface is connected, and transmit the uplink optical signal received by the second sub-interface to the optical coupler.

[0090] In one possible implementation, the optical fiber interface includes an uplink interface, 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; The uplink interface is configured to receive a composite downlink optical signal transmitted by the connected optical fiber and transmit the received composite downlink optical signal to the second optical splitter; The second optical 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 optical splitter; The second optical splitter is used to transmit the composite uplink optical signal to the uplink interface; The uplink interface is further configured to send the composite uplink optical signal via the connected optical fiber.

[0091] 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 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 configured to receive a composite downlink optical signal transmitted on the connected optical fiber and transmit the composite downlink optical signal to the demultiplexer; The optical coupler is configured 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.

[0092] In an eighth aspect, a network device is provided, comprising a processor and a memory, wherein the memory is configured to store a program for executing the optical communication method provided in the second, third, or fourth aspect, and to store data involved in 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.

[0093] In a possible implementation, the network device may further include a communication bus, which is used to establish a connection between the processor and the memory.

[0094] In a ninth aspect, a computer-readable storage medium is provided, wherein instructions are stored in the computer-readable storage medium. When the computer-readable storage medium is run on a computer, the computer executes the optical communication method provided in the second aspect, the third aspect, or the fourth aspect.

[0095] In a tenth aspect, a computer program product comprising instructions is provided, which, when executed on a computer, enables the computer to execute the optical communication method provided in the second aspect, the third aspect, or the fourth aspect.

[0096] The technical effects obtained in the above-mentioned second to tenth aspects are similar to the technical effects obtained by the corresponding technical means in the first aspect, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0097] Figure 1 This is an architecture diagram of an optical communication system provided by an embodiment of the present application; Figure 2 is an architecture diagram of another optical communication system provided in an embodiment of the present application; Figure 3 This is an architecture diagram of another optical communication system provided by an embodiment of the present application; Figure 4 This is an architecture diagram of another optical communication system provided by an embodiment of the present application; Figure 5 This is an architecture diagram of another optical communication system provided by an embodiment of the present application; Figure 6 This is an architecture diagram of another optical communication system provided by an embodiment of the present application; Figure 7 This is an architecture diagram of another optical communication system provided by an embodiment of the present application; Figure 8 This is an architecture diagram of another optical communication system provided by an embodiment of the present application; Figure 9 This is an architecture diagram of another optical communication system provided by an embodiment of the present application; Figure 10 This is a flow chart of an optical communication method provided by an embodiment of the present application; Figure 11 is a flow chart of another optical communication method provided by an embodiment of the present application; Figure 12 This is a flow chart of another optical communication method provided by an embodiment of the present application; Figure 13 This is a structural diagram of a network device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0098] In order to make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.

[0099] To facilitate understanding, some of the terms / nouns involved in the embodiments of this application are first introduced.

[0100] 1. Point to multi-point (P2MP): A transmission mode that transmits data from one source to one or more receivers.

[0101] 2. Passive Optical Network (PON): As an emerging broadband access fiber technology covering the last mile, it eliminates the need for node equipment at optical branching points, requiring only a simple optical splitter. This offers advantages such as conserving optical cable resources, sharing bandwidth resources, saving equipment room investment, enhancing equipment security, expediting network deployment, and reducing overall network construction costs. The intermediate device in the embodiments of this application is a passive device that can be used in a passive optical network.

[0102] 3. Multiplexing technology: As "optical fiber replacing copper" gradually becomes the mainstream technology of campus networks, on the one hand, due to limited resources and increasing manufacturing costs, the cost of laying optical fiber links is also increasing year by year. At the same time, for wireless transmission media, the limited available frequency is also a very valuable resource. Therefore, improving the utilization rate of communication lines has become a focus of everyone's attention, and multiplexing technology (referred to as multiplexing technology) has come into being. Multiplexing technology is a technology that improves the utilization rate of optical communication lines by transmitting multiple signals on a communication line. The most commonly used multiplexing technologies at present are wavelength division multiplexing, time division multiplexing, frequency division multiplexing, and code division multiplexing. The embodiments of this application focus on wavelength division multiplexing.

[0103] 4. Wavelength Division Multiplexing (WDM): Abbreviated as WDM, it typically utilizes multiple wavelengths to achieve multitasking. WDM is a data transmission technology. In optical communication systems, different optical signals are carried by different wavelengths (i.e., colors or frequencies). WDM refers to the technology of multiplexing multiple optical signals of different wavelengths for transmission over a single optical fiber. The optical communication system and method provided in the embodiments of the present application are applied to WDM systems and can address the high production cost and deployment difficulty of access-side optical modules in WDM systems of related technologies.

[0104] 5. Wavelength Division Interval (also called wavelength interval): In wavelength division multiplexing, the wavelength division interval of multiple upstream optical signals transmitted in a single optical fiber is the interval between each two adjacent upstream wavelengths after the upstream wavelengths are arranged in order of size (referred to as the upstream wavelength division interval). Similarly, the wavelength division interval of multiple downstream optical signals transmitted in a single optical fiber is the interval between each two adjacent downstream wavelengths after the downstream wavelengths are arranged in order of size (referred to as the downstream wavelength division interval).

[0105] In the embodiments of the present application, the downstream wavelength division interval can be larger than the upstream wavelength division interval, meaning that the embodiments of the present application provide a hybrid wavelength division solution. The embodiments of the present application do not limit the specific values of the downstream and upstream wavelength division intervals. For example, the downstream wavelength division interval can be the same as the wavelength division interval used in coarse wavelength division multiplexing (CWDM) in related art, namely 20 nm. Of course, the downstream wavelength division interval can also be other values, such as 15 nm, 25 nm, etc. As an example, with a wavelength interval of 20 nm, there can be 18 downstream wavelength channels (referred to as downstream channels) between 1270 nm and 1610 nm. The upstream wavelength division interval can be much smaller than the downstream wavelength division interval, such as 0.4 nm, 1 nm, 2.4 nm, or 2.5 nm. As an example, with a wavelength division interval of 1 nm, there can be 20 upstream wavelength channels (referred to as upstream channels) between 1050 nm and 1070 nm.

[0106] 6. Coarse Wavelength Division Multiplexing (CWDM) and Dense Wavelength Division Multiplexing (DWDM): Two implementations of WDM. CWDM is a technology that simultaneously transmits multiple optical signals of different wavelengths with widely spaced wavelengths on the same optical fiber, while DWDM is a technology that simultaneously transmits multiple optical signals of different wavelengths with closely spaced wavelengths on the same optical fiber. Simply put, the main difference between CWDM and DWDM is that CWDM uses a larger wavelength spacing, while DWDM uses a relatively smaller wavelength spacing.

[0107] In some embodiments of the technical solution of the present application, the downlink optical signal can use CWDM, and the uplink optical signal can use DWDM, that is, the technical solution provided by the embodiments of the present application can be a hybrid wavelength division solution that uses a mixture of coarse wavelength division and dense wavelength division.

[0108] In related technologies, besides CWDM and DWDM, WDM also includes medium wavelength division multiplexing (MWDM) and local area network wave division multiplexing (LAN-WDM, also known as LWDM, fine wavelength division multiplexing). CWDM uses a 20nm wavelength division interval, MWDM uses a 7nm / 13nm alternating wavelength division interval, LWDM uses a 4nm wavelength division interval, and DWDM uses 0.4nm, 0.8nm, or 1.6nm wavelength division intervals. The 7nm / 13nm alternating wavelength division interval of MWDM means that wavelength separation points are inserted at positions offset by 3.5nm to the left and right of multiple core wavelengths (i.e., 1271nm, 1291nm, 1311nm, etc.) of the 20nm CWDM wavelength division interval. These inserted wavelength separation points serve as new core wavelengths, thus forming an alternating 7nm and 13nm spacing pattern. In other words, the core concept of MWDM is to "interleave" multiple core wavelengths with relatively close wavelength spacing between multiple core wavelengths with relatively large wavelength spacing, thereby forming a spacing pattern with two different wavelength spacings alternating. In this way, the core wavelengths corresponding to the two wavelength division intervals are located in the same wavelength band. In contrast to the "interleave" concept, there is also the concept of "complete band separation", which means that the core wavelengths corresponding to the two wavelength division intervals are located in different wavelength bands.

[0109] Based on the idea that WDM can be "intermediately inserted" or "completely separated", the wavelength band where the multiple downstream wavelengths are located (referred to as the downstream band for short) and the wavelength band where the multiple upstream wavelengths are located (referred to as the upstream band for short) in the technical solution of this application can be completely separated, can be somewhat crossed, or can even overlap. As an example, taking the multiple downstream wavelengths corresponding to the downstream optical signal as multiple core wavelengths divided at intervals of 20nm between 1270nm and 1610nm as an example, when the downstream band and the upstream band are completely separated, the multiple upstream wavelengths corresponding to the upstream optical signal can be multiple core wavelengths divided at intervals of 1nm between 1525nm and 1545nm; when the downstream band and the upstream band overlap, the multiple upstream wavelengths corresponding to the upstream optical signal can be multiple core wavelengths divided at intervals of 1nm between 1260nm and 1280nm; when the downstream band and the upstream band overlap, the multiple upstream wavelengths corresponding to the upstream optical signal can be multiple core wavelengths divided at intervals of 1nm between 1270nm and 1610nm.

[0110] It should be noted that the wavelength interval of the uplink optical signal is the interval between each two adjacent uplink wavelengths after the multiple uplink wavelengths corresponding to the multiple access side optical modules are arranged in order of size when the system is designed; the wavelength interval of the downlink optical signal is the interval between each two adjacent downlink wavelengths after the multiple downlink wavelengths corresponding to the multiple access side optical modules are arranged in order of size when the system is designed. The two adjacent wavelengths are usually designed with equal intervals, but of course they can also be unequal intervals, which is not limited in the embodiments of the present application. Among them, in the case of unequal intervals, the minimum allowable wavelength interval for the uplink is smaller than the minimum allowable wavelength interval for the downlink. In addition, the multiple downlink wavelengths and multiple uplink wavelengths designed for the system may not all be used in actual applications. For example, some channels may be disabled / deactivated, and then the uplink and downlink wavelengths corresponding to the channel will not be used.

[0111] The various implementation methods of WDM each have their own advantages. Among them, due to the large wavelength spacing of CWDM, the cost of devices such as filters or lasers used in CWDM is relatively low, the power consumption is relatively low, and the device size is relatively small, which is conducive to energy saving and convenient deployment. In addition, it can effectively increase the transmission capacity of optical fibers, effectively utilize and save optical fiber resources. Due to the small wavelength spacing of DWDM, DWDM can enable a laser to have the ability to generate multiple optical signals with different wavelengths. Using a laser with this capability, multiple access-side optical modules can be normalized, thereby reducing the production difficulty and deployment cost of access-side optical modules. It should be understood that if the wavelength division interval is large, it is difficult to integrate multiple wavelengths with large wavelength division intervals into one laser at the hardware level. In other words, it is difficult to achieve normalization of access-side optical modules with CWDM. The introduction of DWDM technology makes normalization of access-side optical modules feasible, reducing the implementation cost of normalization of access-side optical modules.

[0112] In the embodiment of the present application, the "normalization" of the access side optical module means that the factory settings / configurations of all access side optical modules in the optical communication system are the same, for example, the wavelength range of the transmittable optical signal (referred to as the transmit wavelength range for short) is the same, and the wavelength range of the receivetable optical signal (referred to as the receive wavelength range for short) is also the same. All access side optical modules can be plug-and-play after leaving the factory, and there is no need for manufacturers to produce optical modules of different wavelengths according to wavelength groups. In addition, during on-site deployment, there is no need for network administrators to plug in access side optical modules of different wavelengths for each group of access devices. Each access side optical module can set the emission wavelength by itself according to a certain logic, without the need for manual configuration / adjustment by technical personnel. The set emission wavelength is the uplink wavelength of the corresponding uplink channel, and different access side optical modules have different emission wavelengths.

[0113] 7. Multiplexer (MUX) / Demultiplexer (DEMUX): Different multiplexing technologies utilize different multiplexers / demultiplexers. Wavelength division multiplexing (WDM) combines multiple modulated optical signals (optical signals, carrying useful information, such as uplink / downlink information) of different wavelengths (or frequencies) at the transmitting end through a multiplexer (such as a combiner) and transmits them through the same optical fiber of an optical line (i.e., a fiber optic transmission link) for transmission. At the receiving end, a demultiplexer (such as a wavelength splitter) is used to separate and receive the optical signals of different wavelengths.

[0114] 8. Wavelength splitter / combiner: This is a type of multiplexer / demultiplexer used in wavelength division multiplexing technology. A wavelength combiner includes multiple input ports and one output port. Each of the multiple input ports is used to input an optical signal of a certain wavelength. The wavelengths of the optical signals input from different input ports are generally different. The wavelength combiner is used to combine the multiple optical signals input from the multiple input ports, that is, to merge them into a single optical signal (called a composite optical signal). The composite optical signal includes multiple optical signals, each of which corresponds to a different wavelength. A wavelength splitter is the opposite of a wavelength combiner. A wavelength splitter includes one input port and multiple output ports. The input port is used to input a composite optical signal, which includes multiple optical signals, each of which corresponds to a different wavelength. The wavelength splitter is used to demultiplex the composite optical signal, that is, to decompose it into multiple optical signals, so that the device to which the wavelength splitter belongs receives multiple optical signals. Each output port of the wavelength splitter is used to output an optical signal of a certain wavelength. The wavelengths of the optical signals output from different output ports are generally different.

[0115] It should be noted that the input ports of a combiner are used to input optical signals of fixed wavelengths, and the output ports of a splitter are used to output optical signals of fixed wavelengths. If an optical signal of a different wavelength is input to a combiner input port, that optical signal will not be properly processed and will not be transmitted further. If the optical signal input to a splitter does not include the optical signal corresponding to a particular output port, that output port will not output any optical signal.

[0116] 9. Optical splitter (OS, also referred to as splitter) / optical coupler (OC, also referred to as coupler): Different from a wavelength splitter / combiner in design and function. An optical splitter includes an input port and multiple output ports. The input port of the optical splitter is used to input an optical signal, which can be an optical signal comprising a single wavelength (i.e., a single-wavelength optical signal) or a wavelength-division multiplexed optical signal (i.e., a composite optical signal). The optical splitter is used to split the input optical signal to obtain multiple optical signals. These multiple optical signals have the same wavelength. For example, if the optical signals are split according to energy, the energy of the multiple optical signals obtained can be substantially the same. The multiple output ports of the optical splitter each output an optical signal, and the multiple optical signals are output through the multiple output ports. The optical signals obtained by splitting have the same wavelength characteristics as the optical signal before splitting. For example, if the optical signal input to the optical splitter is a single-wavelength optical signal, the multiple optical signals obtained after splitting are also single-wavelength optical signals, and the wavelength of each of the multiple optical signals is the same as the wavelength of the optical signal input to the optical splitter. If the optical signal input to the optical splitter is a composite optical signal, each of the multiple optical signals obtained after the splitting is also a composite optical signal.

[0117] An optical coupler includes multiple input ports and one output port. Each of the multiple input ports can input an optical signal of any wavelength. The optical coupler is configured to couple the optical signals input from the multiple input ports to generate an optical signal whose wavelength includes all wavelengths of the optical signals input from the multiple input ports. In some embodiments, an optical splitter and an optical coupler are the same device, with different names depending on their functions in different scenarios.

[0118] 10. Beamsplitter: A filtering device that filters multiple optical signals with varying wavelengths by wavelength, separating them. For example, a beamsplitter can filter out an input optical signal of a certain wavelength and transmit it in one direction (reflection / refraction), while filtering out an input optical signal of a different wavelength and transmitting it in another direction (reflection / refraction).

[0119] In an embodiment of the present application, a spectrometer is used to separate an uplink optical signal from a downlink optical signal, wherein the uplink wavelength corresponding to the uplink optical signal and the downlink wavelength corresponding to the downlink optical signal have a certain gap. For example, the composite uplink optical signal received by the downlink interface of the central optical module can be input into the spectrometer 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 spectrometer of the central optical module. Since there is a certain gap between the uplink wavelength corresponding to the composite uplink optical signal and the downlink wavelength corresponding to the composite downlink optical signal, the spectrometer can separate the input composite uplink optical signal and the 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.

[0120] In the embodiments of the present application, in order to facilitate distinction, multiple devices belonging to the same category can be distinguished by words such as "first", "second", and "third". Similarly, the input / output ends of different devices can also be distinguished by words such as "first", "second", and "third".

[0121] Next, the background knowledge of the embodiments of this application is introduced.

[0122] The embodiments of this application are designed for the evolution of campus network architecture, but are not limited to campus networks. The demand for this solution is triggered by the evolution of campus networks to all-optical campuses, so the embodiments of this application will be explained according to the evolution of campus architecture and the route of this solution.

[0123] First, let’s introduce the architecture of traditional campus networks, the driving factors behind the evolution of campus network architecture, and the direction of evolution.

[0124] Traditional campus networks primarily utilize a tree-like architecture, with a three-layer network being the most typical. The three layers are the access layer, the aggregation layer, and the core layer. In this traditional architecture, the access layer directly extends network cables to user devices (also known as user devices, such as personal computers (PCs) and Wi-Fi devices). The aggregation layer aggregates north-south data and exchanges east-west data. The access layer primarily connects to user devices via network cables. Optical fiber is typically used to connect the access layer to the aggregation layer, and vice versa. Connections between each layer are point-to-point (P2P). Neither optical fiber nor network cables converge; data convergence and exchange occur only at switches.

[0125] The specific location of the three-tier structure varies slightly in different types of parks.

[0126] In large campuses, network construction is typically based on buildings. A core switching area (i.e., the core layer) is set up for the entire campus. Each building can be constructed using a two-layer tree structure, with each building acting as an independent aggregation point. This tree-like architecture allows data exchange within a building to occur locally, while data exchange between buildings is handled through the core layer.

[0127] Medium-sized campuses typically use a two-tier architecture, but a three-tier architecture can also be adopted 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 new office building, a weak current room on each floor can serve as an aggregation point, with the entire building adopting a three-tier architecture with a core layer. A three-tier architecture is suitable when different business operations require isolation, such as when departments require separate aggregation points for each business type or department.

[0128] Having briefly introduced the traditional three-tier campus network architecture, let's now move on to the next-generation campus architecture (the all-optical campus architecture). Current research in the field of all-optical campuses is primarily divided into two systems: the passive optical LAN (POL) solution based on PON technology, and the all-optical Ethernet solution based on traditional Ethernet.

[0129] POL is a local area network (LAN) based on PON 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 campus networks. Using a traditional three-layer campus network as an example, POL replaces the access and aggregation layers, colocating the optical line terminal (OLT) and core switches. Passive components and optical fiber are used in between to achieve P2MP connectivity. Compared to traditional solutions, POL simplifies the network architecture, transforming a three-layer network into a two-layer one. Furthermore, because the optical network units (ONUs) of the OLT and user equipment are located at opposite ends of the network, the intermediate links are fully passive, reducing equipment maintenance and power consumption. The P2MP design also significantly reduces fiber usage and equipment deployment space.

[0130] The application of PON technology in all-optical campuses has triggered the evolution of traditional Ethernet networks towards all-optical solutions. Key challenges faced by traditional campus network solutions include: a lack of direct fiber optic access to every room, multiple network layers, a high number of optical fibers and cables, and active devices in all interconnected links. To address these challenges, exploration of Ethernet-based all-optical campuses has begun.

[0131] In the fiber-to-the-home scenario, the user-side switch is miniaturized and its functions are weakened to obtain a box-type access switch. 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 realizing direct fiber pulling.

[0132] As can be seen from the foregoing, the embodiments of the present application are primarily used in wavelength division multiplexing systems. However, in current wavelength division multiplexing schemes, access-side optical modules have not yet been normalized. For example, the laser in each access-side optical module can only transmit optical signals of a fixed upstream wavelength. This upstream wavelength corresponds to the access-side optical module, and different access-side optical modules correspond to different upstream wavelengths, thereby achieving wavelength division multiplexing. For another example, each access-side optical module can only receive optical signals of a fixed downstream wavelength. This downstream wavelength corresponds to the access-side optical module, and different access-side optical modules correspond to different downstream wavelengths, thereby achieving wavelength division multiplexing. Therefore, it can be seen that the emission wavelengths and reception wavelengths of different access-side optical modules in a group of access-side optical modules connected to an intermediate module are different, and normalization has not been achieved. However, the embodiments of the present application can achieve normalization of color-scattered optical modules (i.e., access-side optical modules) in a wavelength division multiplexing system, thereby reducing the difficulty of optical communication networking and reducing the difficulty of equipment production, deployment, management, and maintenance.

[0133] Next, the implementation environment of the embodiments of the present application is introduced.

[0134] Figure 1 This is an architecture diagram of an optical communication system provided by an embodiment of the present application. Figure 1 The system includes a central optical module and multiple access-side optical modules, wherein the central optical module is connected to the multiple access-side optical modules. Optionally, the optical communication system further includes an intermediate device, through which the central optical module is connected to the multiple access-side optical modules. In other words, the central optical module is connected to the intermediate device via an optical fiber, and the intermediate device is further connected to the multiple access-side optical modules via optical fibers.

[0135] Multiple access side optical modules in the optical communication system correspond to multiple upstream wavelengths, and multiple access side optical modules correspond to multiple downstream wavelengths, wherein different access side optical modules among the multiple access side optical modules correspond to different downstream wavelengths, and different access side optical modules among the multiple access side optical modules correspond to different upstream wavelengths.

[0136] Continue to see Figure 1 In an embodiment of the present application, the central optical module includes a fixed wavelength laser, which is used to generate multiple fixed wavelength optical signals, and the multiple fixed wavelengths include multiple downlink wavelengths corresponding to multiple access side optical modules.

[0137] Optionally, in one implementation, the fixed wavelength laser in the central optical module includes multiple lasers for generating fixed wavelength optical signals, the wavelength of each laser in the multiple lasers is not adjustable, and different lasers in the multiple lasers correspond to different fixed wavelengths.

[0138] 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 tunable wavelength laser according to a certain logic. The set emission wavelength is the emission wavelength corresponding to the access-side optical module. The emission wavelength setting "logic" here can be implemented in various ways and is not limited in the present embodiment.

[0139] Continue to see Figure 1 The access-side optical module is inserted into or integrated into the access device, and the access device is used to access the optical communication system through the access-side optical module, thereby realizing communication with the routing and switching device. Similarly, the central optical module is inserted into or integrated into the routing and switching device, and the routing and switching device is used to realize communication with the access device through the central optical module. The figures in this article all take the insertion of the optical module into the corresponding device as an example. Accordingly, the optical signal of the downstream wavelength (referred to as the downstream optical signal for short) carries the downstream information sent by the routing and switching device, and the optical signal of the upstream wavelength (referred to as the upstream optical signal for short) carries the upstream information sent by the access device. Among them, the downstream information includes downstream instructions and / or downstream data; the upstream information includes upstream responses and / or upstream data.

[0140] There are multiple pairs of channels between the central optical module and the routing switch equipment, which are implemented using deserializers (serdes). Each serdes corresponds to an access-side optical module and is used to transmit 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.

[0141] In the embodiments of the present application, the access device may be an industry-standard "asteroid" switch, access point (AP), or other device. The access device may also be referred to as a remote access device, optical line terminal, or other name. The routing switching device may be a switch (such as a local area network switch (LSW)) or a router. The routing switching device may also be referred to as a central switch, core switch, or other name. The central optical module may also be referred to as a core-side optical module or a local-end optical module. The access-side optical module may also be referred to as a terminal optical module, a remote optical module, or the like.

[0142] The central optical module and the access side optical module 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 embodiment of the present application, and the uplink and downlink information is carried on the 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, and the composite downlink optical signal includes multiple downlink optical signals generated by the 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 use an adjustable wavelength laser to send an optical signal of the uplink wavelength corresponding to the access side optical module to the central optical module; the central optical module is also used to receive a composite uplink optical signal, and the composite uplink optical signal 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.

[0143] In one implementation, the wavelength division interval of the multiple downstream wavelengths is greater than the wavelength division interval of the multiple upstream wavelengths. For the relevant introduction of the wavelength division interval, please refer to the corresponding description above and will not be repeated here.

[0144] In one possible implementation, the multiple downstream optical signals included in the composite downstream optical signal are transmitted using coarse wavelength division multiplexing (CWDM), and the multiple upstream optical signals included in the composite upstream optical signal are transmitted using dense wavelength division multiplexing (DWDM). For more information on CWDM and DWDM, refer to the previous description and are not repeated here.

[0145] In one possible implementation, the wavelength division interval of the multiple downstream wavelengths is greater than or equal to a first threshold, and the wavelength division interval of the multiple upstream wavelengths is less than a second threshold. In other words, the multiple downstream wavelengths and the multiple upstream wavelengths can be designed based on the first threshold and the second threshold.

[0146] In one possible implementation, the first threshold is greater than the second threshold; in another possible implementation, the first threshold may be equal to the second threshold. In the implementation where the first threshold and the second threshold are equal, only one threshold may be set. Alternatively, two thresholds of equal value may be set as the first threshold and the second threshold, respectively.

[0147] As an example, the first threshold is 20nm and the second threshold is 2.5nm. The first threshold and the second threshold can be flexibly set according to actual conditions, and the embodiments of the present application are not limited to this. Among them, the setting factors of the second threshold may include the hardware implementation of the current laser. For example, according to the hardware implementation feasibility of the current tunable wavelength laser, the second threshold can be set to 2.5nm. Based on this, the wavelength division spacing of multiple upstream wavelengths can be less than 2.5nm, for example, it can be 2.4nm. If the wavelength division spacing of multiple upstream wavelengths exceeds 2.5nm, it will be difficult to implement the tunable wavelength laser.

[0148] It should be understood that 2.5nm may be the limit of current hardware feasibility, but it does not mean that 2.5nm will also be the limit in the future. In other words, with the development of laser-related technologies, the limit can be broken, and the wavelength division spacing of multiple uplink optical signals generated by tunable wavelength lasers can be greater than 2.5nm.

[0149] In some embodiments, if the wavelength division spacing of the multiple upstream wavelengths is less than 2.3 nm, the demultiplexer in the central optical module (described later) can use an arrayed waveguide grating (AWG) or silicon photonics Mach-Zehnder (MZ) wavelength division solution. If the wavelength division spacing of the multiple upstream wavelengths is greater than 2.3 nm, the demultiplexer in the central optical module can use a free-space thin film filter (TFF) wavelength division solution.

[0150] In order to realize the optical communication method provided in the embodiment of the present application, the embodiment of the present application provides a variety of specific implementation methods of the optical communication system. Figures 2 to 9 This paper introduces various specific implementation methods.

[0151] Figure 2 This is an architecture diagram of another optical communication system provided by an embodiment of the present application. Figure 2 In this embodiment of the present application, the fixed-wavelength laser in the central optical module includes multiple laser diodes (LDs), each of which is a laser. Each of the multiple LDs is configured to generate an optical signal with a fixed wavelength. The wavelength of each LD is not adjustable, and different LDs in the multiple LDs correspond to different fixed wavelengths. Each LD is configured to emit an optical signal with a fixed wavelength based on a received electrical signal, and different LDs emit optical signals with different wavelengths.

[0152] In an embodiment of the present application, 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 to the 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.

[0153] As an example, the fixed wavelength lasers in the central optical module include Figure 2 The multiple LDs in the central optical module correspond one-to-one to the multiple first electrical signals input by the routing and switching device, and each of the multiple LDs is used to generate a downlink optical signal according to a corresponding first electrical signal.

[0154] In an embodiment of the present application, the central optical module also 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 the multiple second electrical signals to the routing switching device. The multiple uplink optical signals correspond one-to-one to the multiple access side optical modules, and the multiple uplink optical signals carry uplink information sent by the multiple access side optical modules.

[0155] As an example, the optoelectronic conversion device in the central optical module includes Figure 2 The photodiodes (PDs) (n in the figure) in the central optical module are shown. Different PDs among the multiple PDs are used to receive optical signals of different upstream wavelengths. Each of the multiple PDs receives one of the multiple upstream optical signals. Each PD is used to perform photoelectric conversion on the received upstream optical signal to obtain a second electrical signal, and output the second electrical signal obtained by photoelectric conversion to the routing switching device.

[0156] It should be understood that the fact that multiple LDs, such as LD1, LD2, LD3, and LDn, are drawn in a box in the figure does not mean that the physical positions of LD1, LD2, LD3, and LDn must be together. Similarly, the fact that multiple PDs, such as PD1, PD2, PD3, and PDn, are drawn in a box in the figure does not mean that the physical positions of PD1, PD2, PD3, and PDn must be together. The physical positions of these devices can be set according to actual conditions, and the embodiments of the present application do not limit this. For example, LD1 and PD1 can be set together, LD2 and PD2 can be set together, and LD3 and PD3 can be set together. The same principle applies to similar places in the subsequent embodiment figures, which will not be repeated in the following text.

[0157] In an embodiment of the present application, the central optical module includes multiple LDs and multiple PDs in one-to-one correspondence. In some implementations, an LD and a PD with a corresponding relationship can be integrated together, such as integrated into a device, which can be called a photoelectric conversion sub-module. In this way, the central optical module includes multiple photoelectric conversion sub-modules, each photoelectric conversion sub-module includes an LD and a PD, and the multiple photoelectric conversion sub-modules correspond one-to-one to multiple serdes, and are used to transmit the uplink and downlink information corresponding to the multiple serdes respectively.

[0158] In some embodiments, the devices used for photoelectric conversion in the central optical module can be collectively referred to as photoelectric conversion devices. The photoelectric conversion devices include the multiple PDs described above. Optionally, the photoelectric conversion devices may also include other components, such as light tubes and lenses, without limitation. The devices used for transmitting optical signals in the central optical module can be collectively referred to as electro-optical conversion devices. The electro-optical conversion devices include the multiple LDs described above. Optionally, the electro-optical conversion devices may also include other components, without limitation.

[0159] Continue to see Figure 2 The central optical module may also include an optical multiplexer (OMUX, which can be referred to as a multiplexer for short), and transmit the data in the central optical module to the intermediate device.

[0160] 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, some of the multiple input terminals are connected to multiple LDs in a one-to-one correspondence, and some of the multiple output terminals are connected to multiple PDs in a one-to-one correspondence.

[0161] In an embodiment of the present application, the intermediate device includes a demultiplexer and an optical combiner. The demultiplexer in the intermediate device can be referred to as a 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, send the corresponding downlink optical signals to multiple access side optical modules through the optical fiber. The optical combiner is used to combine multiple uplink optical signals from multiple access side optical modules to obtain a composite uplink optical signal, and send the composite uplink optical signal to the central optical module through the optical fiber.

[0162] The first demultiplexer may include Figure 2 The DEMUX in the intermediate device shown. The optical combining device may include Figure 2 An optocoupler (splitter) is shown in the middle device.

[0163] It should be understood that the intermediate device serves as a transmission medium for optical signals between the central optical module and multiple access side optical modules, and is used to multiplex / couple and split / decouple the received optical signals, but does not perform information processing on these optical signals.

[0164] In an embodiment of the present application, 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 an optical fiber via the at least one uplink interface, and the intermediate device is connected to the multiple access-side optical modules via the multiple downlink interfaces. 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 interface.

[0165] The intermediate device is configured 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 configured 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 a downlink optical signal, and the downlink wavelengths of the optical signals transmitted by different downlink interfaces among the multiple downlink interfaces are different. The intermediate device is also configured 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 an uplink optical signal, and the uplink wavelengths of the optical signals received by different downlink interfaces among the multiple downlink interfaces are different.

[0166] In an embodiment of the present application, each access side optical module includes, in addition to a wavelength-tunable laser, a photoelectric converter, which has the ability to process optical signals of different downstream wavelengths. The wavelengths of the optical signals that can be processed by the photoelectric converter include multiple downstream wavelengths corresponding to multiple access side optical modules, that is, the photoelectric converter is a broadband receiving device. In actual applications, each photoelectric converter is used to perform photoelectric conversion on the optical signal of the downstream wavelength received by the access side optical module to which the photoelectric converter belongs, thereby obtaining an electrical signal (in some embodiments, referred to as the fourth electrical signal), and output the electrical signal (such as the fourth electrical signal) to the access device. The photoelectric converter in the access side optical module may include Figure 2 The PD shown is connected to the side light module.

[0167] The tunable wavelength laser in each access side optical module has the ability to emit optical signals of different uplink wavelengths. The wavelengths of optical signals that the tunable wavelength laser can emit 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 tunable, and therefore it is called a tunable wavelength laser. The tunable wavelength laser in the access side optical module is used to generate an optical signal of a corresponding uplink wavelength based on the electrical signal input by the corresponding access device, and the electrical signal input by the access device carries the uplink information sent by the access device. Taking the first optical module among the above-mentioned multiple access side optical modules as an example, the first optical module is used to receive the second electrical signal transmitted by the first access device, and the second electrical signal carries the uplink information sent by the first access device. The tunable wavelength laser in the first optical module is used to generate an optical signal of an uplink wavelength corresponding to the first optical module (referred to as an uplink optical signal for short) based on the second electrical signal, and send the uplink optical signal to the central optical module. Among them, the first access device is an access device into which the first optical module is integrated or inserted. The tunable wavelength laser in the access side optical module, for example, includes Figure 2 The tunable laser diode (TLD) connected to the side-light module is shown.

[0168] As an example, the tunable wavelength laser in each access-side optical module can use 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 an on-chip SOA, an FP laser, a DFB laser array, or a TOSA to adjust the emission wavelength using self-locking or injection locking. The photoelectric converter in each access-side optical module can use a PIN, an APD, or an SOA-PIN to achieve photoelectric conversion.

[0169] In the embodiments of this application, the connection between the intermediate device and the central optical module can be a single-fiber or dual-fiber connection; the connection between the intermediate device and the access-side optical module can be a single-fiber or dual-fiber connection. Based on this, the downstream and upstream interfaces of the intermediate device, as well as the upstream interface of the access-side optical module, can be implemented in a variety of ways. These will be described below.

[0170] First, the specific implementation methods of the uplink interface of the intermediate device and the downlink interface of the central optical module are introduced when a single-fiber connection is made between the central optical module and the intermediate device.

[0171] like Figure 2As shown, the intermediate device and the central optical module are connected via a single fiber. To this end, each includes a splitter. The splitter in the intermediate device used to connect to the central optical module can be referred to as the third splitter, while the splitter in the central optical module used to connect to the intermediate device can be referred to as the fourth splitter. The fourth splitter is connected to the downlink interface of the central optical module and is also connected to one input and one output of the OMUX. The fourth splitter is also connected to the third splitter via an optical fiber. For ease of distinction, this optical fiber is referred to as the fourth optical fiber.

[0172] In the case of a single-fiber connection between a central optical module and an intermediate device, the central optical module includes a single downlink interface, which is connected to a single optical fiber. In this case, the optical multiplexer (OMUX) in the central optical module can be implemented in several ways, each of which is described below.

[0173] In the first implementation, the OMUX includes a device that has both the functions of wavelength splitting and wavelength combining. That is, the OMUX of the central optical module includes a multiplexer / demultiplexer that has both the functions of wavelength combining and wavelength splitting. The multiplexer / demultiplexer is used to combine multiple downstream optical signals generated by a fixed wavelength laser into a composite downstream optical signal, and transmit the composite downstream optical signal to the fourth optical splitter. The fourth optical splitter is used to send the composite downstream optical signal through the downstream interface of the central optical module, and to receive the composite upstream optical signal transmitted on the connected optical fiber from the downstream interface of the central optical module, and transmit the composite upstream optical signal to the multiplexer / demultiplexer. The multiplexer / demultiplexer is also used to receive the composite upstream optical signal transmitted by the fourth optical splitter, demultiplex multiple upstream optical signals from the composite upstream optical signal, and transmit the demultiplexed multiple upstream optical signals to the optoelectronic conversion device.

[0174] As an example, you can Figure 2 The OMUX shown is configured as a MUX, which serves as a multiplexer / demultiplexer. In this implementation, the wavelength band of the MUX is relatively wide, that is, the wavelength band of the MUX includes both multiple downstream wavelengths and multiple upstream wavelengths.

[0175] In a second implementation, the OMUX of the central optical module may include two devices, namely a first multiplexer and a second demultiplexer. The first multiplexer has a wavelength combining function, and the second demultiplexer has a wavelength splitting function. The fixed wavelength laser is used to generate multiple downstream optical signals based on multiple first electrical signals and transmit the multiple downstream optical signals to the first multiplexer. The multiple first electrical signals are electrical signals input by the routing switching device. The first multiplexer is used to combine the multiple downstream optical signals into a composite downstream optical signal and transmit the composite downstream optical signal to the fourth optical splitter. The fourth optical splitter is used to send the composite downstream optical signal through the downstream interface of the central optical module, and receive the composite upstream optical signal transmitted on the connected optical fiber from the downstream interface of the central optical module, and transmit the composite upstream optical signal to the second demultiplexer. The second demultiplexer is used to receive the composite upstream optical signal transmitted by the fourth optical splitter, demultiplex multiple upstream optical signals from the composite upstream optical signal, and transmit the demultiplexed multiple upstream optical signals to the optoelectronic conversion device. 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 switching device.

[0176] As an example, see Figure 3 The OMUX in the central optical module can be implemented by a combiner (shown as a MUX, serving as the first multiplexer) and a demultiplexer (shown as a DEMUX, serving as the second demultiplexer). The multiple inputs of the combiner are connected one-to-one with the multiple LDs of the central optical module, and the multiple outputs of the demultiplexer are connected one-to-one with the multiple PDs of the central optical module. The fourth optical splitter is connected to the inputs of the demultiplexer and also to the outputs of the combiner.

[0177] That is, in Figure 3 In the implementation shown, the OMUX includes two devices: a MUX and a DEMUX. These two devices process upstream optical signals (implementing the wavelength splitting function) and downstream optical signals (implementing the wavelength combining function), respectively. In this way, the wavelength bands of these two devices are relatively narrow, making implementation easy. The wavelength band of the MUX only needs to include multiple downstream wavelengths, and the wavelength band of the DEMUX only needs to include multiple upstream wavelengths.

[0178] In addition to the two implementations described above, in some other implementations, the OMUX can have the functions of the fourth beam splitter in addition to the functions of wave splitting and combining. In other words, the functions of the fourth beam splitter are integrated into the OMUX.

[0179] In one possible implementation, the central optical module may include a multiplexer / demultiplexer, but not a fourth optical splitter. The multiplexer / demultiplexer is connected to the downstream interface of the central optical module. The fixed wavelength laser is used to generate multiple downstream optical signals based on multiple first electrical signals, and transmit the multiple downstream optical signals to the multiplexer / demultiplexer. The multiple first electrical signals are electrical signals input by the routing switching device. The multiplexer / demultiplexer is used to combine the multiple downstream optical signals into a composite downstream optical signal, send the composite downstream optical signal through the downstream interface of the central optical module, and receive the composite upstream optical signal transmitted on the optical fiber to which the downstream interface of the central optical module is connected, demultiplex multiple upstream optical signals from the composite upstream optical signal, and transmit the multiple upstream optical signals to the optoelectronic conversion device. The optoelectronic conversion device is used to convert the multiple upstream optical signals demultiplexed by the multiplexer / demultiplexer into multiple second electrical signals, and output the multiple second electrical signals to the routing switching device. That is, the multiplexer / demultiplexer has the functions of wave splitting, wave combining and optical splitting.

[0180] As an example, see Figure 4 , the OMUX in the central optical module can be realized by a MUX (as a multiplexer / demultiplexer), which has the functions of combining, splitting and splitting. Compared with the MUX in the first implementation method mentioned above, this MUX adds a splitting interface, which is directly connected to the third splitter of the intermediate device through an optical fiber. In other words, Figure 2 The beam splitter in the central optical module is integrated in Figure 2 In the OMUX shown in the figure, we can get Figure 4 The center optical module is shown.

[0181] In another possible implementation, the central optical module may include a second multiplexer and a third demultiplexer, but not a fourth optical splitter. The second multiplexer is connected to the downstream 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 multiple downstream optical signals based on multiple first electrical signals and transmit the multiple downstream optical signals to the second multiplexer. The multiple first electrical signals are electrical signals input by the routing and switching device. The second multiplexer is used to combine the multiple downstream optical signals into a composite downstream optical signal, send the composite downstream optical signal through the downstream interface of the central optical module, and receive the composite upstream optical signal transmitted on the optical fiber connected to the downstream interface of the central optical module, and transmit the composite upstream optical signal to the third demultiplexer. The third demultiplexer is used to receive the composite upstream optical signal transmitted by the second demultiplexer, demultiplex multiple upstream optical signals from the composite upstream optical signal, and transmit the multiple upstream optical signals to the optoelectronic conversion device. The optoelectronic conversion device is used to convert the multiple upstream optical signals demultiplexed by the third demultiplexer into multiple second electrical signals, and output the multiple second electrical signals to the routing and switching device. That is, the second multiplexer has the functions of combining and splitting, and the third demultiplexer has the function of splitting.

[0182] As an example, see Figure 5 , the OMUX in the central optical module can be implemented by a MUX (as the second multiplexer) and a DEMUX (as the third demultiplexer). Compared with the second implementation method mentioned above, the MUX has an additional optical splitting port, which is directly connected to the third optical splitter of the intermediate device through optical fiber and is also connected to the DEMUX. Figure 3 The beam splitter in the central optical module is integrated in Figure 3 In the MUX shown in the figure, we can get Figure 5 The center optical module is shown.

[0183] The implementations described above offer hardware design options for wavelength splitting, wavelength combining, and optical splitting. While these hardware designs differ, they ultimately achieve essentially the same technical results. The following examples use the OMUX in a central optical module, which consists of a MUX, a DEMUX, and an optical splitter.

[0184] In the case of a single-fiber connection between the central optical module and the intermediate device, the intermediate device also 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 via an optical fiber, and the third optical splitter is connected to the uplink interface of the intermediate device, the first demultiplexer, and the optical combiner, 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 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 send the composite uplink optical signal to the central optical module through the uplink interface of the intermediate device.

[0185] As an example, Figures 2 to 5 The optical splitter in the intermediate device shown is the third optical splitter, and the uplink interface connected to the third optical splitter is the uplink interface of the intermediate device.

[0186] Combination of the above Figures 2 to 5 The various ways to achieve single-fiber connection between the central optical module and the intermediate equipment are introduced. Figures 2 to 5 , which introduces the implementation method of dual-fiber connection between intermediate equipment and access-side optical modules.

[0187] That is, the following describes the specific implementation of the downlink interface of the intermediate device and the uplink interface of the access side optical module in the case of dual-fiber connection between the intermediate device and the access side optical module.

[0188] In the case of a dual-fiber connection between the intermediate device and the access-side optical module, each of the multiple downstream interfaces of the intermediate device includes a first sub-interface and a second sub-interface, the first demultiplexer of the intermediate device is respectively connected to the multiple first sub-interfaces of the multiple downstream interfaces, and the optical combiner of the intermediate device is respectively connected to the multiple second sub-interfaces of the multiple downstream interfaces; different access-side optical modules of the multiple access-side optical modules are connected to different downstream interfaces of the intermediate device via optical fibers. The first optical module of the multiple access-side optical modules is respectively connected to the first sub-interface and the second sub-interface of the first downstream interface of the multiple downstream interfaces via different optical fibers.

[0189] Based on this, the first demultiplexer is specifically used to transmit multiple downlink optical signals to the multiple first sub-interfaces, wherein a first sub-interface receives a downlink optical signal, and the downlink wavelengths of the optical signals received by different first sub-interfaces are different; the first sub-interface in 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 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; the second sub-interface in the multiple downlink interfaces is used to transmit the optical signal of the uplink wavelength received by this second sub-interface to the optical combining device, and an optical signal received by a second sub-interface is called an uplink optical signal; the optical combining device is specifically used to combine multiple uplink optical signals transmitted by multiple second sub-interfaces into a composite uplink optical signal.

[0190] Among them, the multiple output ends of the first demultiplexer in the intermediate device are connected to the multiple first sub-interfaces included in the multiple downstream interfaces in a one-to-one correspondence, and the multiple input ends of the optical combiner in the intermediate device are connected to the multiple second sub-interfaces included in the multiple downstream interfaces in a one-to-one correspondence. The multiple output ends of the first demultiplexer are used to output multiple downstream optical signals, and different output ends output downstream optical signals of different downstream wavelengths. The multiple input ends of the optical combiner are used to input multiple upstream optical signals, and different input ends are used to input upstream optical signals of different upstream wavelengths. Among them, in the case where the optical combiner is an optical coupler, each input end of the optical combiner allows the input of an optical signal of any upstream wavelength and continues to be transmitted, but there may be a problem of mismatch between the upstream and downstream optical signals; in the case where the optical combiner is a wave combiner, each input end of the optical combiner allows the input of an optical signal of a fixed upstream wavelength and continues to be transmitted. If an input end inputs an optical signal of another wavelength, the optical signal will not be able to continue to be transmitted.

[0191] As an example, Figures 2 to 5 Each of the multiple downlink interfaces of 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 Figure 2 One downstream interface of the intermediate device shown (interface 1 is used as an example) is labeled, while other downstream interfaces are not labeled. The same places in other figures are not labeled either. Figure 2 For ease of distinction, in the embodiments of the present application, the optical fiber connected to the first sub-interface may be referred to as the second optical fiber, and the optical fiber connected to the second sub-interface may be referred to as the third optical fiber. For example, the first optical module is connected to the first sub-interface of the first downstream interface via the second optical fiber, and is connected to the second sub-interface of the first downstream interface via the third optical fiber.

[0192] 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 single optical fiber (the second optical 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 optical fiber (the third optical fiber).

[0193] In the case where the first optical module includes two uplink interfaces, the optoelectronic converter in the first optical module can be connected to the first uplink interface of the first optical module, and the optoelectronic converter is used to receive the downlink optical signal transmitted by the first uplink interface, and perform optoelectronic conversion on the downlink optical signal transmitted by the first uplink interface to obtain a fourth electrical signal, and output the fourth electrical signal to the first access device. The downlink optical signal transmitted by the first uplink interface carries the downlink information transmitted by 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 of the first optical module, and the tunable wavelength laser is used to transmit the generated uplink optical signal to the intermediate device through the second uplink interface. Among them, the tunable wavelength laser can generate an optical signal of the uplink wavelength corresponding to the optical module on the access side according to the third electrical signal input by the first access device. The optical signal generated by the tunable wavelength laser in the first optical module carries the uplink information transmitted by the first access device to the routing switching device.

[0194] As an example, see Figures 2 to 5 The PD and LD in each access-side optical module are connected to different optical fibers through different uplink interfaces.

[0195] Figures 2 to 5 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 connected by a dual fiber. In other embodiments, the central optical module and the intermediate device can also be connected by a dual fiber, and the intermediate device and the access side optical module can also be connected by a single fiber. That is, the connection method between the two devices in the optical communication system can be flexibly set according to the actual situation. Based on this, Figures 2 to 5 There are many variations of the optical communication system shown. Figures 6 to 8 Three of its variants are introduced.

[0196] Among them, Figure 6 In the example, the central optical module and the intermediate device, as well as the intermediate device and the access side optical module are connected by single fiber. Figure 6 You can do this 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 example, the central optical module and the intermediate device are connected by dual fibers, and the intermediate device and the access side optical module are connected by single fibers. Figure 7 You can do this by Figure 6 The single-fiber connection between the central optical module and the intermediate device is replaced by a dual-fiber connection. Figure 8 In the process, the central optical module and the intermediate device, as well as the intermediate device and the access side optical module are connected by dual fibers. Figure 8 You can do this by Figure 3 The single-fiber connection between the central optical module and the intermediate device is replaced by a dual-fiber connection.

[0197] Next, combine Figure 6 and Figure 7 This section describes the specific implementation methods of the downstream interface of the intermediate device and the upstream interface of the access-side optical module when a single-fiber connection is established between the intermediate device and the access-side optical module.

[0198] In the case of a single-fiber connection between the intermediate device and the access-side optical module, see Figure 6 and Figure 7 Each of the multiple downstream interfaces of the intermediate device is connected to an optical fiber. It should be understood that each downstream interface of the intermediate device is a physical interface, and each downstream interface is connected to an access side optical module via an optical fiber.

[0199] To achieve a single-fiber connection between an intermediate device and an access-side optical module, in one implementation, the intermediate device further includes multiple first optical splitters, the first demultiplexer in the intermediate device is respectively connected to the multiple first optical splitters, the optical combiner in the intermediate device is respectively connected to the multiple first optical splitters, each of the multiple first optical splitters is connected to one of the multiple downstream interfaces of the intermediate device, and different first optical splitters are connected to different downstream interfaces; each access-side optical module further includes a second optical splitter, the second optical splitter is connected to a downstream interface of the intermediate device via an optical fiber, and the second optical splitters in different access-side optical modules in the multiple access-side optical modules are connected to different downstream interfaces of the intermediate device. Taking the first optical module (also referred to as 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 downstream interface among the multiple downstream interfaces via the first optical fiber.

[0200] The multiple output ends of the first demultiplexer in the intermediate device are connected to the multiple first beam splitters in a one-to-one correspondence, and the multiple input ends of the optical combiner are connected to the multiple first beam splitters in a one-to-one correspondence.

[0201] Based on this, the first demultiplexer is specifically used to transmit a downstream optical signal to each first optical splitter in a plurality of first optical splitters, wherein a first optical splitter receives a downstream optical signal, and the downstream wavelengths of the optical signals received by different first optical splitters are different; each first optical splitter is used to transmit the downstream optical signal received by the first optical splitter to the downstream interface connected to the first optical splitter; the first downstream interface is used to transmit the optical signal of the downstream wavelength received by the first downstream 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 optical signal of the upstream wavelength corresponding to the first optical module to the first downstream interface through the first optical fiber; each downstream interface is also used to transmit the upstream optical signal received by the downstream interface to the first optical splitter connected to the downstream interface; each first optical splitter is also used to transmit the upstream optical signal received by the first optical splitter to the optical combining device; the optical combining device is specifically used to receive multiple upstream optical signals transmitted by multiple first optical splitters, and merge the multiple upstream optical signals transmitted by multiple first optical splitters into a composite upstream optical signal.

[0202] As an example, in Figure 3 On the basis of Figure 6 n in the figure), as the multiple first splitters, and adding a splitter in each access side optical module as the second splitter, thereby obtaining Figure 6 The optical communication system shown. Figure 6 、 Figure 7 The optical splitter connected to the downlink interface of the intermediate device in the shown intermediate device is the first optical splitter described above. Figure 6 、 Figure 7 The beam splitter in the access-side optical module shown is the second beam splitter described above.

[0203] In the case of a single-fiber connection between the intermediate device and the access-side optical module, each access-side optical module can include an uplink interface. Taking the first optical module as an example, the first optical module can include an uplink interface. The uplink interface of the first optical module is connected to the first optical fiber, that is, connected to the first downlink interface of the intermediate device via the first optical fiber. The second optical splitter in the first optical module is connected to the uplink interface of the first optical module.

[0204] As an example, Figure 6 and Figure 7 The optical fiber between the intermediate device and the access-side optical module 1 (serving as the first optical module) is the first optical fiber.

[0205] Optionally, when the access-side optical module includes a second optical splitter, the second optical splitter is connected to the optoelectronic converter and the tunable wavelength laser in the access-side optical module, respectively. In the downlink direction, the second optical splitter receives the downlink optical signal transmitted by the first optical fiber through the uplink interface of the access-side optical module, and transmits the downlink optical signal to the optoelectronic converter. The optoelectronic converter in the access-side optical module is used to perform optoelectronic conversion on the downlink optical signal transmitted by the second optical splitter. In the uplink direction, accordingly, the tunable wavelength laser in the access-side optical module is used to transmit the generated uplink optical signal to the second optical splitter, and the second optical splitter is used to send the uplink optical signal generated by the tunable wavelength laser to the first optical fiber through the uplink interface.

[0206] As an example, Figure 6 and Figure 7 Taking the access side optical module 1 (as the first optical module) shown as an example, the processing flow of the optical signal is illustrated from the perspective of the access side optical module. In the downstream direction, the upstream interface of the access side optical module 1 is used to receive the downstream optical signal (with a wavelength of λ1) transmitted by the first optical fiber, and transmit the downstream optical signal to the second optical splitter. The second optical splitter is used to send the downstream optical signal to the PD in the access side optical module 1. The PD is used to perform photoelectric conversion on the received downstream optical signal to obtain a fourth electrical signal, and transmit the fourth electrical signal to the access device 1. In the upstream direction, the TLD in the access side optical module 1 is used to receive the third electrical signal input by the access device 1, and generate an optical signal of the upstream wavelength corresponding to the access side optical module 1 (referred to as the upstream optical signal, with a wavelength of λ1) according to the third electrical signal input by the access device 1. n+1 ), and transmits the uplink optical signal 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.

[0207] Finally, combine Figure 7 and Figure 8This section describes the specific implementation methods of the downstream interface of the central optical module and the upstream interface of the intermediate device when a dual-fiber connection is used between the central optical module and the intermediate device.

[0208] In the case of a dual-fiber connection between the central optical module and the intermediate device, the central optical module may include a second downstream interface, a third downstream interface, a first multiplexer, a second demultiplexer, and an optoelectronic conversion device. The first multiplexer is connected to the third downstream interface, and the second demultiplexer is connected to the third downstream interface. The fixed wavelength laser is used to generate multiple downstream optical signals based on multiple first electrical signals, and transmit the multiple downstream optical signals to the first multiplexer. The multiple first electrical signals are electrical signals input by the routing switching device. The first multiplexer is used to merge the multiple downstream optical signals into a composite downstream optical signal, and send the merged composite downstream optical signal through the second downstream interface. The second demultiplexer is used to demultiplex multiple upstream optical signals from the composite upstream optical signal received from the third downstream interface, and transmit the multiple upstream optical signals to the optoelectronic conversion device. The optoelectronic conversion device is used to convert the multiple upstream optical signals into multiple second electrical signals, and output the multiple second electrical signals to the routing switching device.

[0209] Accordingly, the intermediate device includes two uplink interfaces, referred to as a first uplink interface and a 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, respectively, via optical fibers. The first demultiplexer of the intermediate device is configured to receive the composite downlink optical signal transmitted by the central optical module via the first uplink interface. The optical combiner of the intermediate device is configured to transmit the composite uplink optical signal to the central optical module via the second uplink interface.

[0210] As an example, see Figures 7 and 8 The first multiplexer in the central optical module is a MUX, the second demultiplexer in the central optical module is a DEMUX, the first demultiplexer in the intermediate device is a DEMUX, and the optical combining device is an optical coupler. The MUX in the central optical module and the DEMUX in the intermediate device are connected via a single optical fiber, and the DEMUX in the central optical module and the optical coupler in the intermediate device are connected via another optical fiber.

[0211] Combined with the above Figures 2 to 8 This chapter introduces the connection between the intermediate equipment and the access side optical module, as well as the connection between the intermediate equipment and the central optical module. Figures 2 to 5 ,as well as Figure 9 The central optical module is connected to the intermediate device using a single fiber, while the intermediate device is connected to the access-side optical module using a dual fiber connection. 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 via dual fibers, while the intermediate device and the access-side optical module are connected via single fibers. Figure 8 The central optical module and the intermediate device are connected via dual fibers, and the intermediate device and the access-side optical module are also connected via dual fibers. This means that the connection between the two devices can be flexibly configured based on actual needs. The descriptions of the same parts in any two figures are applicable to both and are not detailed in this article.

[0212] It is worth noting that in the implementation mode where single fiber connection is used between the central optical module and the intermediate device, and between the intermediate device and the access side optical module (such as Figure 6 Embodiment), the connection method between devices is relatively simple, the difficulty of optical networking is low, and the amount of optical fiber used is small, saving optical fiber resources.

[0213] It should be understood that in Figures 2 to 8 In the optical communication system shown, the optical combining device in the intermediate device is an optical coupler, that is, the intermediate device uses an optical coupler to combine the optical signals from the access side optical module. In other embodiments, the optical combining device in the intermediate device can also be a wave combiner, that is, the intermediate device can also use a wave combiner to combine the optical signals from the access side optical module. Based on this, Figures 2 to 8 The optical couplers in the intermediate devices shown are replaced by a combiner, resulting in seven additional optical communication system architectures. Figure 3 Taking the "optical coupler" in the example, we can get the following Figure 9 The optical communication system shown.

[0214] In the case where the intermediate device uses an optical coupler as an uplink optical combining device, the cost of the intermediate device is relatively low.

[0215] Combine Figures 2 to 9It can be seen that after the various devices / apparatuses in the optical communication system are connected, the physical channels between the routing and switching devices and the various access devices have been established and can be used to transmit optical signals. There is a physical channel group between the routing and switching devices and each access device, which includes a downlink channel and an uplink channel. When each LD and PD in the central optical module on the routing and switching device are configured, the emission wavelength of each LD is fixed, and the receiving 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 an optical signal of the corresponding downlink wavelength to the corresponding access device. The access-side optical module receives an optical signal of a fixed downlink wavelength. Different downlink channels correspond to different downlink wavelengths, so different access-side optical modules receive different downlink wavelengths. The access-side optical module on the access device transmits an optical signal of the corresponding uplink wavelength to the routing and switching device via the corresponding uplink channel. The uplink wavelengths corresponding to the optical signals transmitted by different access devices should be different and should correspond to the corresponding uplink channel.

[0216] It should be understood that a downlink channel may include multiple devices and optical fibers that are connected. Figure 3 For example, a downlink channel consists of the downlink portion of a serdes, the electrical connection between the serdes and an LD in a central optical module, an LD in the central optical module, the optical path between an LD in the central optical module and the central optical module's multiplexer (MUX), the central optical module's multiplexer (MUX), the optical fiber link between the central optical module's multiplexer (MUX) and the intermediate device's demultiplexer (DEMUX), the intermediate device's demultiplexer (DEMUX), the optical path between an output port of the intermediate device's demultiplexer (DEMUX) and the downstream interface to which it is connected, the optical fiber link between the downstream interface of the intermediate device and a PD in an access-side optical module, and the electrical connection between the PD in the access-side optical module and the access device. Simply put, a downlink channel is all the components and links from a serdes in a routing switch device to the access device connected to it.

[0217] Similarly, an uplink channel may include multiple devices and optical fibers that are connected. Figure 3For example, an uplink channel consists of the electrical connection between an access device and the LD of an access-side optical module, the optical fiber link between the LD and the downlink interface of the 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 port 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. Simply put, an uplink channel is all the components and links from an access-side optical module to the serdes of the central optical module connected to it.

[0218] exist Figures 2 to 9 In the example, n access side optical modules and n physical channel groups are used to transmit optical signals of n downstream wavelengths and n upstream wavelengths. The n downstream wavelengths are denoted as λ1~λ n , these n uplink wavelengths are denoted as λ n+1 ~λ 2n The intermediate device includes n downstream interfaces, which are denoted as interface 1 to interface n. Figures 2 to 5 、 Figures 8 and 9 In the example, each interface from interface 1 to interface n includes a first sub-interface and a second sub-interface, that is, each interface includes two physical interfaces; Figures 6 and 7 In the example, each interface from interface 1 to interface n is a physical interface.

[0219] In summary, each access-side optical module in the embodiments of the present application can be connected to any downlink interface of an intermediate device via optical fiber, and different access-side optical modules are connected to different downlink interfaces on the intermediate device. In other words, these multiple access-side optical modules are "normalized" optical modules that can be mixed and matched to multiple downlink interfaces of the intermediate device, without having to worry about the correspondence between the downlink interfaces, access-side optical modules, and uplink and downlink wavelengths.

[0220] It should be understood that the system architecture and business scenarios described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided in the embodiments of the present application. Ordinary technicians in this field can know that with the evolution of the system architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0221] Next, the optical communication method provided by the embodiment of the present application is introduced. The optical communication method can be applied to Figures 2 to 9 In any optical communication system shown.

[0222] First, the optical communication method performed by the access side optical module is introduced.

[0223] Figure 10 This is a flow chart of an optical communication method provided in an embodiment of the present application, wherein the steps of the method are executed by a first optical module, and the first optical module is any one of a plurality of access side optical modules included in the optical communication system. Among them, the plurality of access side optical modules correspond to a plurality of upstream wavelengths and also correspond to a plurality of downstream wavelengths. Different access side optical modules correspond to different downstream wavelengths, and different access side optical modules correspond to different upstream wavelengths. The wavelength division interval of the plurality of downstream wavelengths is greater than the wavelength division interval of the plurality of upstream wavelengths. For the relevant introduction to the upstream and downstream wavelength division intervals, please refer to the above system embodiment, which will not be repeated here. Please refer to Figure 10 , the method includes the following steps.

[0224] Step 1001: Receive a downlink optical signal, where the wavelength of the downlink optical signal is a first downlink wavelength corresponding to a first optical module.

[0225] From the above introduction to the optical communication system, it can be seen that in one implementation, Figure 6 and Figure 7 As shown, the first optical module includes an uplink interface and a splitter. The uplink interface is connected to an optical fiber, which can be referred to as a first optical fiber, and the splitter is connected to the uplink interface. That is, the first optical module achieves a single-fiber connection with the intermediate device via a single optical fiber. In this case, the first optical module receives the downlink optical signal as follows: the splitter of the first optical module receives the downlink optical signal transmitted by the first optical fiber via the uplink interface of the first optical module. After receiving the downlink optical signal, the splitter of the first optical module also transmits the downlink optical signal to the optoelectronic converter in the first optical module.

[0226] In another implementation, 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 implements a dual-fiber connection with the intermediate device via two optical fibers. In this case, the first optical module receives the downlink optical signal as follows: the first uplink interface of the first optical module receives the downlink optical signal transmitted by 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 signal to the optoelectronic converter.

[0227] In the embodiment of the present application, the photoelectric converter in the first optical module has the ability to process optical signals of different downstream wavelengths. The photoelectric converter can perform photoelectric conversion on the received downstream optical signal to obtain the first electrical signal.

[0228] Among them, the first optical module is integrated or inserted into the first access device. The downlink optical signal received by the first optical module carries the downlink information transmitted by the routing switching device to the first access device. The optoelectronic converter of the first optical module performs optoelectronic conversion on the downlink optical signal to obtain a first electrical signal. The first electrical signal can also be transmitted to the first access device so that the first access device processes the downlink information carried by the first electrical signal.

[0229] Step 1002: Generate and send an uplink optical signal, where the wavelength of the uplink optical signal is the first uplink wavelength corresponding to the first optical module.

[0230] The first optical module includes a tunable wavelength laser. Compared to fixed-wavelength lasers, the wavelength of the optical signal generated by a tunable wavelength laser is not fixed and unique, but is 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 for the first optical module to generate and transmit the uplink optical signal is as follows: the tunable wavelength laser generates and transmits the uplink optical signal.

[0231] Before the tunable wavelength laser generates and transmits the uplink optical signal, the first optical module may 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 via the second electrical signal. Based on this, the tunable wavelength laser can generate the uplink optical signal based on the second electrical signal.

[0232] In the case where the first optical module includes an uplink interface and a splitter (such as Figure 6 and Figure 7 As shown), the tunable wavelength laser can be connected to the optical splitter, the tunable wavelength laser can send the uplink optical signal to the optical splitter, and the optical 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.

[0233] 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 to which it is connected.

[0234] It should be understood that there is no particular order for the above steps 1001 and 1002. These two steps may occur simultaneously or at different times, that is, the transmission processes of uplink and downlink information are independent of each other.

[0235] To sum up, in the embodiment of the present 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. In this way, a hybrid wavelength division scheme is adopted to 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.

[0236] Furthermore, when the access side optical module includes a tunable wavelength laser and the uplink dense wavelength division is used, the "normalization" solution of the access side optical module can be made feasible, thereby reducing the production cost and deployment difficulty of the access side optical module and reducing the difficulty of optical communication networking.

[0237] Next, the optical communication method performed by the central optical module is introduced. It should be understood that the steps performed by the central optical module can be coordinated with the steps performed by the access side optical module above, thereby completing the transmission of uplink and downlink information between the routing switch device and the access device.

[0238] Figure 11 This is a flow chart of another optical communication method provided by an embodiment of the present application. 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. The multiple access side optical modules correspond to multiple upstream wavelengths, and the multiple access side optical modules correspond to multiple downstream wavelengths. Different access side optical modules in the multiple access side optical modules correspond to different downstream wavelengths. Different access side optical modules in the multiple access side optical modules correspond to different upstream wavelengths. The central optical module includes a fixed wavelength laser. The fixed wavelength laser is used to generate multiple fixed wavelength optical signals. The multiple fixed wavelengths include the above-mentioned multiple downstream wavelengths. The wavelength division interval of the multiple downstream wavelengths is greater than the wavelength division interval of the multiple upstream wavelengths. For the relevant introduction of the fixed wavelength laser and the upstream and downstream wavelength division intervals, please refer to the above system embodiment and will not be repeated here. See Figure 11 , the method includes the following steps.

[0239] Step 1101: Send multiple downlink optical signals, where the multiple downlink optical signals are generated by a fixed wavelength laser of a central optical module, and the wavelengths of the multiple downlink optical signals are multiple downlink wavelengths corresponding to multiple access-side optical modules.

[0240] In an embodiment of the present application, a central optical module is integrated or inserted into a routing and switching device. 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 device. The multiple downlink optical signals carry downlink information sent by the routing and switching device via the multiple first electrical signals. The multiple first electrical signals correspond one-to-one to 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. For an introduction to the fixed-wavelength laser, please refer to the above system embodiment and will not be repeated here.

[0241] The central optical module further includes a multiplexer and at least one downstream interface, and the downstream interface of the central optical module is connected to the optical fiber. The implementation process of step 1101 may include: the multiplexer in the central optical module combines multiple downstream optical signals generated by the fixed wavelength laser into a composite downstream optical signal, and transmits the composite downstream optical signal through the downstream interface of the central optical module.

[0242] The multiplexer in the central optical module can be Figure 2 OMUX in , or Figures 3 to 9 The MUX in the center optical module is shown.

[0243] In a possible implementation, the central optical module includes a multiplexer (in some embodiments, it can be called a multiplexer / demultiplexer), a splitter and a downlink interface. Figure 2 The OMUX shown is a central optical module created by a MUX (which performs both wavelength combining and demultiplexing). The central optical module's optical splitter is connected to the multiplexer and also to the central optical module's downstream interface. Therefore, the multiplexer combines multiple downstream optical signals into a composite downstream optical signal and then transmits the composite downstream optical signal to the optical splitter. The optical splitter then sends the composite downstream optical signal to the downstream interface.

[0244] The central optical module includes a multiplexer, a demultiplexer, a downlink interface and a splitter (such as Figure 3 、 Figure 6 、 Figure 9 As shown, the optical splitter is connected to the multiplexer and demultiplexer of the central optical module, and is also connected to the downstream interface. Therefore, the multiplexer combines multiple downstream optical signals into a composite downstream optical signal and transmits the composite downstream optical signal to the optical splitter, which then sends the composite downstream optical signal to the downstream interface.

[0245] In another possible implementation, the central optical module includes a multiplexer, a demultiplexer, and a downlink interface (eg, Figure 5 As shown in FIG, the multiplexer is connected to the demultiplexer, which is also connected to the downlink interface. Based on this, the multiplexer combines multiple downlink optical signals into a composite downlink optical signal and sends the composite downlink optical signal to the downlink interface.

[0246] 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 sends the composite downlink optical signal to the downlink interface. In some embodiments, the multiplexer can also be called a multiplexer / demultiplexer.

[0247] 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 in FIG, these two downstream interfaces can be referred to as the first downstream interface and the second downstream interface of the central optical module. The multiplexer is connected to the first downstream interface, and the demultiplexer is connected to the second downstream interface. The first downstream interface and the second downstream interface are connected to different optical fibers. Based on this, the multiplexer combines multiple downstream optical signals into a composite downstream optical signal and then transmits the composite downstream optical signal through the connected first downstream interface.

[0248] Step 1102: Receive multiple uplink optical signals, where wavelengths of the multiple uplink optical signals are multiple uplink wavelengths corresponding to multiple access-side optical modules.

[0249] The multiple uplink optical signals carry uplink information sent by multiple access-side optical modules to the routing switching device.

[0250] In one possible implementation, the central optical module includes a demultiplexer and at least one downstream interface. The central optical module can receive a composite upstream optical signal through the downstream interface. The demultiplexer can demultiplex multiple upstream optical signals from the composite upstream optical signal, thereby receiving multiple upstream optical signals.

[0251] In the case where the central optical module includes a multiplexer, a demultiplexer, a downlink interface and a splitter (such as Figure 3 、 Figure 6 、 Figure 9 As shown), the optical splitter receives the composite upstream optical signal transmitted on the optical fiber to which the downstream interface is connected through the downstream interface, and transmits the composite upstream optical signal to the demultiplexer.

[0252] In the case where the central optical module includes a downlink interface, a multiplexer and a demultiplexer (such as Figure 5 As shown), the central optical module receives the composite upstream optical signal through the downstream interface, and the composite upstream optical signal received by the downstream interface is transmitted to the multiplexer, that is, the multiplexer receives the composite upstream optical signal transmitted on the connected optical fiber through the downstream interface, and then the multiplexer transmits the composite upstream optical signal to the demultiplexer.

[0253] In the case where the central optical module includes a multiplexer, a demultiplexer, a first downstream interface, and a second downstream interface (e.g. Figure 7 、 Figure 8 As shown), the central optical module receives the composite upstream optical signal through the second downstream interface, and the composite upstream optical signal received by the second downstream interface is transmitted to the demultiplexer, that is, the demultiplexer receives the composite upstream optical signal through the connected second downstream interface.

[0254] In another possible implementation, the central optical module includes a downlink interface and a multiplexer (also called a multiplexer / demultiplexer) (e.g. Figure 4 As shown), the central optical module receives the composite uplink optical signal through the downlink interface, and the composite uplink optical signal received by the downlink interface is transmitted to the multiplexer, that is, the multiplexer receives the composite uplink optical signal transmitted on the connected optical fiber through the downlink interface, and then the multiplexer demultiplexes multiple uplink optical signals from the composite uplink optical signal.

[0255] In another possible implementation, the central optical module includes a multiplexer / demultiplexer, a splitter and a downlink interface (e.g. Figure 2 The OMUX shown is configured as a MUX (with both multiplexing and demultiplexing functions). The central optical module receives the composite upstream optical signal through the downstream interface. The downstream interface transmits the composite upstream optical signal to the optical splitter. The optical splitter transmits the composite upstream optical signal to the multiplexer / demultiplexer. The multiplexer / demultiplexer then demultiplexes the composite upstream optical signal into multiple upstream optical signals.

[0256] In an embodiment of the present application, the central optical module also includes a photoelectric conversion device. After the central optical module demultiplexes multiple uplink optical signals through the multiplexer / demultiplexer, the multiple uplink optical signals are transmitted to the photoelectric conversion device of the central optical module. The photoelectric conversion device performs photoelectric conversion on the multiple uplink optical signals respectively, thereby obtaining multiple second electrical signals, and sends the multiple second electrical signals to the routing switching device.

[0257] It should be understood that there is no particular order for the above steps 1101 and 1102; these two steps may occur simultaneously or at different times, that is, the transmission processes of uplink and downlink information are independent of each other.

[0258] To sum up, in the embodiment of the present 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. In this way, a hybrid wavelength division scheme is adopted to 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.

[0259] Furthermore, when the access side optical module includes a tunable wavelength laser and the uplink dense wavelength division is used, the "normalization" solution of the access side optical module can be made feasible, thereby reducing the production cost and deployment difficulty of the access side optical module and reducing the difficulty of optical communication networking.

[0260] Next, the optical communication method performed by the intermediate device is introduced. It should be understood that the steps performed by the intermediate device can be coordinated with the steps performed by the access side optical module and the central optical module above, thereby completing the transmission of uplink and downlink information between the routing switch device and the access device.

[0261] Figure 12 This is a flowchart of another optical communication method provided in an embodiment of the present application. 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. The multiple access side optical modules correspond to multiple upstream wavelengths, and the multiple access side optical modules correspond to multiple downstream wavelengths. Different access side optical modules in the multiple access side optical modules correspond to different downstream wavelengths, and different access side optical modules in the multiple access side optical modules correspond to different upstream wavelengths. As can be seen from the above, the intermediate device may include a demultiplexer and an optical combiner. The optical combiner may include an optical coupler or a multiplexer (such as a combiner). Different types of optical combiners play similar roles in the embodiments of the present application. Figure 12 In the embodiment shown, the intermediate device includes a demultiplexer and an optical coupler (such as Figures 2 to 8 As shown in the figure), some steps performed by the intermediate device are introduced. When the optical combining device in the intermediate device is a combiner (such as Figure 9 As shown in Figure 2), the steps performed by the combiner are similar to those performed by the optical coupler and will not be repeated here. Figure 12 , the method includes the following steps.

[0262] Step 1201: Receive a composite downlink optical signal, where the composite downlink optical signal includes multiple downlink optical signals.

[0263] In an embodiment of the present application, the intermediate device further includes at least one uplink interface, the uplink interface of the intermediate device being connected to an optical fiber, and the uplink interface of the intermediate device being connected to the central optical module via the optical fiber. The intermediate device can receive the composite downlink optical signal via the at least one uplink interface. Each uplink interface of the intermediate device is connected to an optical fiber, and different uplink interfaces are connected to different optical fibers.

[0264] In one possible implementation, the intermediate device includes a demultiplexer, an optical coupler, and two uplink interfaces (e.g., Figure 7 and Figure 8 As shown in Figure 2, 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. Therefore, the intermediate device receives the composite downlink optical signal transmitted on the connected optical fiber via the first uplink interface, and transmits the composite downlink optical signal to the demultiplexer.

[0265] In another possible implementation, the intermediate device includes a demultiplexer, an optical coupler, and a splitter connected to the uplink interface (in different embodiments, the splitter has different names, for example, in the above system embodiment, it can be called the third splitter, in Figure 12In the embodiment, it can be called the second optical splitter) and an uplink interface (such as Figures 2 to 6 ), wherein the uplink interface is connected to an optical fiber, and the second optical splitter is respectively connected to the uplink interface, demultiplexer, and optical coupler of the intermediate device. Based on this, the process of implementing the intermediate device receiving the composite downlink optical signal via at least one uplink interface may include: the uplink interface of the intermediate device receives the composite downlink optical signal transmitted by the connected optical fiber, and transmits the received composite downlink optical signal to the second optical splitter. The second optical splitter then transmits the composite downlink optical signal to the demultiplexer of the intermediate device.

[0266] In an embodiment of the present application, the wavelength division interval of multiple downstream wavelengths is greater than the wavelength division interval of multiple upstream wavelengths, wherein the wavelength division interval of multiple downstream wavelengths is the wavelength division interval corresponding to the multiple downstream optical signals included in the composite downstream optical signal, and the wavelength division interval of multiple upstream wavelengths is the wavelength division interval corresponding to the multiple upstream optical signals included in the composite upstream optical signal mentioned later.

[0267] In a possible implementation, the wavelength division interval of the multiple downstream wavelengths is greater than or equal to a first threshold, the wavelength division interval of the multiple upstream wavelengths is less than a second threshold, and the first threshold is greater than or equal to the second threshold.

[0268] In a possible implementation, the multiple downlink optical signals included in the composite downlink optical signal are transmitted based on coarse wavelength division multiplexing (CWDM). Detailed description of CWDM can be found above and will not be repeated here.

[0269] Step 1202: Demultiplex a plurality of downstream optical signals from the composite downstream optical signal using a demultiplexer.

[0270] That is, after receiving the composite downstream optical signal, the demultiplexer of the intermediate device can demultiplex multiple downstream optical signals from the composite downstream optical signal.

[0271] Step 1203: Send corresponding downlink optical signals to multiple access-side optical modules based on respective downlink wavelengths of the multiple downlink optical signals obtained through demultiplexing.

[0272] In an embodiment of the present application, the intermediate device further includes multiple downlink interfaces, each of which is connected to an optical fiber. The multiple downlink interfaces are connected to multiple access-side optical modules via the optical fiber, with different access-side optical modules connected to different downlink interfaces on the intermediate device. Based on this, the intermediate device can send corresponding downlink optical signals to the multiple access-side optical modules via the multiple downlink interfaces, wherein each of the multiple downlink interfaces sends an optical signal at a downlink wavelength, and different downlink interfaces within the multiple downlink interfaces send optical signals at different downlink wavelengths.

[0273] In one possible implementation, each of the multiple downstream interfaces of the intermediate device is connected to an optical fiber, and different downstream interfaces are connected to different optical fibers. The intermediate device further includes multiple first optical splitters, a demultiplexer of the intermediate device is respectively connected to the multiple first optical splitters, an optical coupler of the intermediate device is respectively connected to the multiple first optical splitters, each of the multiple first optical splitters is connected to one of the multiple downstream interfaces of the intermediate device, and different first optical splitters are connected to different downstream interfaces (e.g., Figure 6 and 7 Based on this, after the demultiplexer demultiplexes multiple downstream optical signals from the composite downstream optical signal, it can transmit one downstream optical signal to each first optical splitter in the multiple first optical splitters. Each first optical splitter receives one downstream optical signal, and different first optical splitters receive optical signals with different downstream wavelengths. The multiple first optical splitters respectively transmit the received downstream optical signals to their respective connected downstream interfaces. Each of the multiple downstream interfaces sends the received downstream optical signal through the optical fiber to which it is connected.

[0274] In another possible implementation, each of the multiple downstream interfaces of the intermediate device includes a first sub-interface and a second sub-interface, the demultiplexer of the intermediate device is connected to the multiple first sub-interfaces of the multiple downstream interfaces respectively, the optical coupler of the intermediate device is connected to the multiple second sub-interfaces of the multiple downstream interfaces respectively, and the second sub-interface and the first sub-interface of each downstream interface are connected to different optical fibers (such as Figures 2 to 5 、 Figure 8 Based on this, after the demultiplexer demultiplexes multiple downstream optical signals from the composite downstream optical signal, it can transmit the multiple downstream optical signals to the multiple first sub-interfaces, wherein each first sub-interface receives one downstream optical signal, and different first sub-interfaces receive optical signals with different downstream wavelengths. The first sub-interface in each downstream interface transmits the downstream optical signal received by the first sub-interface via the connected optical fiber.

[0275] Through the above steps 1201 to 1203, the intermediate device can transmit the multiple downlink optical signals included in the received composite downlink optical signal to multiple access side optical modules, wherein 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 switching device to the access side optical module through the intermediate device.

[0276] Next, the process of transmitting the uplink optical signal by the intermediate device is introduced through steps 1204 and 1205.

[0277] Step 1204: Multiple uplink optical signals from multiple access-side optical modules are combined through an optical coupler to obtain a composite uplink optical signal.

[0278] In an embodiment of the present application, the intermediate device includes multiple downstream interfaces, and the intermediate device can receive corresponding upstream optical signals sent by multiple access side optical modules through the multiple downstream interfaces, wherein each of the multiple downstream interfaces receives an optical signal of a downstream wavelength, and different downstream interfaces among the multiple downstream interfaces receive optical signals with different upstream wavelengths.

[0279] Wherein, each of the multiple downstream interfaces of the intermediate device is connected to an optical fiber, different downstream interfaces are connected to different optical fibers, and the intermediate device further includes multiple first optical splitters (such as Figure 6 and Figure 7 As shown in FIG, each of the multiple downstream interfaces of the intermediate device receives an upstream optical signal transmitted by the optical fiber to which it is connected, wherein one downstream interface receives one upstream optical signal, and different downstream interfaces receive optical signals with different downstream wavelengths. Each of the multiple downstream interfaces transmits the upstream optical signal it receives to the first optical splitter to which it is connected, and the multiple first optical splitters transmit the upstream optical signal they receive to the optical coupler of the intermediate device.

[0280] In the case where each downstream 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), a second sub-interface among the multiple downstream interfaces of the intermediate device receives an upstream optical signal transmitted by the optical fiber to which the second sub-interface is connected, and transmits the upstream optical signal received by the second sub-interface to the optical coupler of the intermediate device.

[0281] After receiving multiple uplink optical signals from multiple access-side optical modules, the optical coupler can combine the multiple uplink optical signals to obtain a composite uplink optical signal.

[0282] In one possible implementation, the multiple uplink optical signals included in the composite uplink optical signal are transmitted based on dense wavelength division multiplexing (DWDM). Detailed description of DWDM can be found above and will not be repeated here.

[0283] Step 1205: Send the composite uplink optical signal.

[0284] In the embodiment of the present application, the intermediate device includes at least one uplink interface, and the intermediate device can send the composite uplink optical signal through the at least one uplink interface. In this way, the intermediate device can transmit the composite uplink optical signal to the central optical module.

[0285] Wherein, in the case where the intermediate device includes an uplink interface and also includes a second optical splitter (such as Figures 2 to 6 As shown), the optical coupler of the intermediate device transmits the composite upstream optical signal to the second optical splitter, the second optical splitter transmits the composite upstream optical signal to the upstream interface of the intermediate device, and the upstream interface of the intermediate device sends the composite upstream optical signal through the connected optical fiber.

[0286] 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 the composite upstream optical signal to the second upstream interface, and the second upstream interface sends the composite upstream optical signal to the connected optical fiber.

[0287] It should be understood that the above steps 1201 to 1203 can occur in sequence, and steps 1204 to 1205 can also occur in sequence, and the sub-process including steps 1201 to 1203 and the sub-process including steps 1204 to 1205 have no particular order, that is, the transmission processes of uplink and downlink information are independent of each other.

[0288] In summary, in the embodiments of the present application, the intermediate device uses a combination of a demultiplexer (such as DMUX) and an optical coupler (such as a splitter) to transmit optical signals, which reduces the cost of the intermediate device while ensuring the reliability of optical communication.

[0289] Furthermore, 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. 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.

[0290] Furthermore, when the access side optical module includes a tunable wavelength laser and the uplink dense wavelength division is used, the "normalization" solution of the access side optical module can be made feasible, thereby reducing the production cost and deployment difficulty of the access side optical module and reducing the difficulty of optical communication networking.

[0291] The above describes some implementations of the optical communication method provided in the embodiments of the present application. In combination with the above, it can be seen that in the embodiments of the present application, the downstream wavelength division interval (i.e., the wavelength division interval of multiple downstream wavelengths) is greater than the upstream wavelength division interval. For example, CWDM is used for the downstream and DWDM is used for the upstream. This 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.

[0292] The central optical module is a multi-wavelength transceiver. The laser at the transmitting end of the central optical module uses a fixed-wavelength laser (such as a DFB laser). This fixed-wavelength laser consists of multiple lasers, each emitting a different wavelength. For a group of N access-side optical modules (e.g., eight), these fixed-wavelength lasers share N fixed wavelengths. The receiving end of the central optical module uses a wavelength splitter to generate multiple uplink optical signals at different wavelengths. Using fixed-wavelength lasers reduces the cost of the central optical module.

[0293] The intermediate device can be a passive convergence module, serving as the transmission medium for optical signals between the central optical module and the access side optical module. The downstream of the intermediate device demultiplexes the composite optical signal transmitted by the central optical module into multiple downstream optical signals through a demultiplexer. The multiple downstream optical signals are respectively transmitted to multiple access side optical modules, and one access side optical module receives one downstream optical signal. The upstream of the intermediate device can use an optical coupler as an optical combining device, or a combiner as an optical combining device, and the upstream optical signals of multiple access side optical modules are converged / coupled into one optical fiber through the optical combining device. Among them, when a demultiplexer and an optical coupler are used to implement the intermediate device, the cost of the intermediate device can be reduced.

[0294] Multiple access-side optical modules can be standardized, with broadband reception at the receiving end and wavelength-tunable transmission at the transmitting end. This standardized optical module can reduce the production cost and deployment difficulty of access-side optical modules, and ease the difficulty of optical communication networking.

[0295] It should be understood that, considering the loss of optical signals during transmission in optical fibers over longer distances, the optical signal sent by the central optical module is not exactly the same as the optical signal received by the intermediate device, and the optical signal sent by the intermediate device is not exactly the same as the optical signal received by the access-side optical module. Based on this, in some embodiments, the sent optical signal and the received optical signal can be distinguished by words such as "first", "second", "third", and "fourth". For example, the composite downlink optical signal sent by the central optical module can be called the first composite downlink optical signal. After the first composite downlink optical signal is transmitted through the optical fiber between the central optical module and the intermediate device, it becomes the second composite downlink optical signal due to loss, that is, the composite downlink optical signal received by the intermediate device can be called the second composite downlink optical signal. In the embodiments of the present application, for ease of understanding and simplicity, the sent optical signal and the received optical signal may not be distinguished in naming in the above embodiments, but it does not mean that the sent optical signal and the received optical signal are exactly the same optical signals.

[0296] In addition, for ease of understanding and simplicity, since the loss of optical signals transmitted in the same device is very small and almost negligible, the naming of optical signals in the same device is simplified in the embodiments of the present application. In the absence of misunderstanding, the optical signals sent and received between different modules within the same device are named as the same optical signal. For example, the optical signal output from the output end of the demultiplexer in the intermediate device and the optical signal received by the downstream interface of the intermediate device are named as the same optical signal. In fact, due to the loss in optical fiber transmission, there may be certain differences between the optical signal sent by the module and the optical signal received by the opposite module. For example, there may be certain differences between the optical signal output from the output end of the demultiplexer in the intermediate device and the optical signal received by the downstream interface of the intermediate device.

[0297] The embodiment of the present application also provides an access side optical module, which can be implemented by software, hardware or a combination of both to become part or all of the access device, and the access device can be the above Figures 2 to 9 Any access device in the system shown can also be the above Figures 10 to 13 In the first access device of the method embodiment, the access side optical module can also be independent of the access device and inserted into the access device when used. 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 or inserted into the first access device, and the first optical module is connected to the first access device. Figures 2 to 9 Other devices / apparatuses in the system shown 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.

[0298] The first optical module is any one of a plurality of access side optical modules included in the optical communication system, the plurality of access side optical modules correspond to a plurality of upstream wavelengths, and the plurality of access side optical modules correspond to a plurality of downstream wavelengths, different access side optical modules correspond to different downstream wavelengths, and different access side optical modules correspond to different upstream wavelengths, and the wavelength division interval of the plurality of downstream wavelengths is greater than the wavelength division interval of the plurality of upstream wavelengths; the first optical module includes an optical fiber interface, an optical receiving component, and an optical transmitting component; An optical receiving component, configured to receive a downlink optical signal transmitted by the optical fiber interface, wherein the wavelength of the downlink optical signal is the first downlink wavelength corresponding to the first optical module; The optical transmitting assembly is used to generate an uplink optical signal and send 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.

[0299] In a possible implementation, the wavelength division intervals of the multiple downstream wavelengths are determined based on a coarse wavelength division multiplexing (CWDM) approach, and the wavelength division intervals of the multiple upstream wavelengths are determined based on a dense wavelength division multiplexing (DWDM) approach.

[0300] In one possible implementation, the wavelength division spacing of the multiple downstream wavelengths is greater than or equal to a first threshold, the wavelength division spacing of the multiple upstream wavelengths is less than a second threshold, and the first threshold is greater than or equal to the second threshold. The specific implementation of the wavelength division spacing can be found in the above description of the system and method embodiments and will not be further described here.

[0301] In a possible implementation, the first threshold is 20 nm, and the second threshold is 2.5 nm.

[0302] In one possible implementation, the optical receiving component includes a photoelectric converter, and the optical transmitting component includes a tunable wavelength laser. The photoelectric converter has the ability to process optical signals of different downstream wavelengths, and the tunable wavelength laser has the ability to generate optical signals of different upstream wavelengths. an optical-to-electrical converter, configured to perform optical-to-electrical conversion on the downlink optical signal to obtain a first electrical signal; The tunable wavelength laser is used to generate and transmit an uplink optical signal through an optical fiber interface. The specific implementation of the photoelectric converter and the tunable wavelength laser can be referred to the relevant introduction in the above system and method embodiments, which will not be repeated here.

[0303] 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; The photoelectric converter is further configured to transmit the first electrical signal to the first access device; The tunable wavelength laser is further 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.

[0304] In one possible implementation, the optical fiber 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; The optical splitter is used to receive the downlink optical signal transmitted by the first optical fiber through the uplink interface and transmit the downlink optical signal to the optical-to-electrical converter; The optical splitter is further used to send an uplink optical signal generated by the tunable wavelength laser to the first optical fiber through the uplink interface.

[0305] As above Figure 6 and Figure 7As 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 splitter. The uplink interface is used to connect to an optical fiber, which can be referred to as a first optical fiber. The splitter is connected to the uplink interface and is also connected to the tunable wavelength laser (such as a TLD) and the photoelectric converter (such as a PD) in the access-side optical module. For specific implementations, refer to the relevant descriptions of the system embodiments and method embodiments above and will not be repeated here.

[0306] In a possible implementation, the optical fiber interface includes a first uplink interface and a second uplink interface, and the first uplink interface and the second uplink interface are connected to different optical fibers respectively; A first uplink interface, configured to receive a downlink optical signal transmitted on the connected optical fiber and transmit the downlink optical signal to the optoelectronic converter; The second uplink interface is used to send an uplink optical signal generated by the tunable wavelength laser through the connected optical fiber.

[0307] As above Figures 2 to 5 、 Figure 8 、 Figure 9 As shown, in the case of dual-fiber connection between the intermediate device and the access side optical module, the access side optical module includes two uplink interfaces, namely the first uplink interface and the second uplink interface. These two uplink interfaces are connected 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 methods, please refer to the above Figures 2 to 5 、 Figure 8 、 Figure 9 The relevant introduction of the system embodiment and the method embodiment will not be repeated here.

[0308] 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 an SOA, an FP laser, a DFB laser array, or a TOSA to adjust the emission wavelength by self-locking or injection locking.

[0309] In a possible implementation, the photoelectric converter uses a PIN, APD, or SOA-PIN integrated photodetector to achieve photoelectric conversion.

[0310] In an embodiment of the present 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. In this way, a hybrid wavelength division scheme is adopted to 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.

[0311] Furthermore, when the access side optical module includes a tunable wavelength laser and the uplink dense wavelength division is used, the "normalization" solution of the access side optical module can be made feasible, thereby reducing the production cost and deployment difficulty of the access side optical module and reducing the difficulty of optical communication networking.

[0312] It should be noted that: the access side optical module provided in the above embodiment is only illustrated by the division of the above functional modules when it cooperates with the access device to perform optical communication. That is, the above device embodiment is only schematic. For example, the division of the modules is only a logical function 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 is 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 the present 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 the form of hardware, or in the form of software functional units, or in a combination of hardware and software. In addition, the access side optical module provided in the above embodiment and Figures 10 to 13 The optical communication method embodiments shown belong to the same concept, and their specific implementation processes are detailed in the method embodiments, which will not be repeated here.

[0313] It should also be noted that the access side optical module provided in the embodiment of the present application can be applied to Figures 2 to 9 The optical communication system shown can also be applied to other communication systems. That is, the embodiment of the present application does not limit the application scenarios and deployment locations of the access side optical modules provided above. For other equipment / systems with optical communication requirements, the access side optical modules provided in this embodiment can also be deployed in other systems as needed.

[0314] The embodiment of the present application also provides a central optical module, which can be implemented by software, hardware or a combination of both to become part or all of the routing switching device, and the routing switching device can be the above Figures 2 to 9 Any routing switching device in the system shown can also be the above Figures 10 to 13 In the routing switching device in the method embodiment, the central optical module can also be independent of the routing switching device and inserted into the routing switching device when applied. In the embodiment of the present application, the central optical module is integrated or inserted into the routing switching device. Figures 2 to 9 Other devices / apparatuses in the system shown cooperate with each other to ensure the reliability of optical communication.

[0315] Wherein, the central optical module is included in the optical communication system, and the optical communication system also includes multiple access side optical modules, the multiple access side optical modules correspond to multiple upstream wavelengths, and the multiple access side optical modules correspond to multiple downstream wavelengths, different access side optical modules in the multiple access side optical modules correspond to different downstream wavelengths, and different access side optical modules in the multiple access side optical modules correspond to different upstream wavelengths, the central optical module includes a fixed wavelength laser, the fixed wavelength laser is used to generate multiple fixed wavelength optical signals, and the multiple fixed wavelengths include multiple downstream wavelengths; the central optical module also includes an optical fiber interface, an optical transmitting component, and an optical receiving component; An optical transmitting component is used to transmit a plurality of downstream optical signals through an optical fiber interface, wherein the plurality of downstream optical signals are generated by a fixed wavelength laser, and the wavelengths of the plurality of downstream optical signals are a plurality of downstream wavelengths respectively; An optical receiving component, configured to receive a plurality of uplink optical signals through an optical fiber interface, wherein the wavelengths of the plurality of uplink optical signals are respectively a plurality of uplink wavelengths; The wavelength division interval of the multiple downstream wavelengths is greater than the wavelength division interval of the multiple upstream wavelengths. Specific implementations can refer to the relevant introductions of the above system embodiments and method embodiments, and will not be repeated here.

[0316] In a possible implementation, the multiple downlink optical signals are transmitted based on a coarse wavelength division multiplexing (CWDM) manner, and the multiple uplink optical signals are transmitted based on a dense wavelength division multiplexing (DWDM) manner.

[0317] In one possible implementation, the wavelength division interval of the multiple downstream wavelengths is greater than or equal to a first threshold, the wavelength division interval of the multiple upstream wavelengths is less than a second threshold, and the first threshold is greater than or equal to the second threshold. The specific implementation of the first threshold and the second threshold can be found in the above description of the system embodiment and method embodiment and will not be repeated here.

[0318] In a possible implementation, the first threshold is 20 nm, and the second threshold is 2.5 nm.

[0319] In one possible implementation, the optical transmission component includes a multiplexer, the optical fiber interface includes at least one downstream interface, and the downstream interface is connected to the optical fiber; The multiplexer is used to combine multiple downstream optical signals generated by fixed wavelength lasers into a composite downstream optical signal and transmit the composite downstream optical signal through the downstream interface. The specific implementation of the multiplexer can refer to the relevant introduction of the above system embodiment and method embodiment, which will not be repeated here.

[0320] In one possible implementation, the central optical module is integrated or inserted into the routing and switching equipment; A fixed-wavelength laser is configured to generate multiple downlink optical signals based on multiple first electrical signals input from a routing and switching device. The multiple downlink optical signals carry downlink information sent by the routing and switching device via the multiple first electrical signals. The multiple first electrical signals correspond one-to-one to 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 description of the system and method embodiments above and will not be further elaborated here.

[0321] In one possible implementation, the optical receiving component includes a demultiplexer, and the central optical module further includes a photoelectric conversion device; a demultiplexer, configured to receive a composite upstream optical signal via a downstream interface; The demultiplexer is further configured to demultiplex multiple uplink optical signals from the composite uplink optical signal, wherein the multiple uplink optical signals carry uplink information sent by multiple access side optical modules to the routing switching device; The photoelectric conversion device is used to perform photoelectric conversion on multiple uplink optical signals respectively, thereby obtaining multiple second electrical signals, and sending the multiple second electrical signals to the routing switching device. The specific implementation of the demultiplexer and the photoelectric conversion device can refer to the above Figures 2 to 9 System embodiments, and Figures 10 and 11 The relevant introduction of the method embodiment will not be repeated here.

[0322] In one possible implementation, the at least one downlink interface includes a downlink interface, the central optical module further includes a splitter, the splitter is connected to the multiplexer and the demultiplexer, respectively, and the splitter is also connected to the downlink interface; A multiplexer, used to transmit the composite downlink optical signal to the optical splitter; The optical splitter is used to send the composite downlink optical signal to the downlink interface; The optical splitter is also used to receive the composite upstream optical signal transmitted on the connected optical fiber through the downstream interface, and transmit the composite upstream optical signal to the demultiplexer.

[0323] like Figure 3 、 Figure 6 ,and Figure 9 As shown, in the case of a single-fiber connection between the central optical module and the intermediate device, in one implementation, the central optical module includes a DEMUX, a MUX, a splitter, and a downstream interface. The MUX acts as a multiplexer, the DEMUX acts as a demultiplexer, and the splitter is connected to the MUX, DEMUX, and downstream interface, respectively, and the downstream interface is connected to the optical fiber. In addition, the MUX is also connected to the fixed-wavelength lasers (such as multiple LDs) in the central optical module, and the DEMUX is also connected to the optoelectronic conversion devices (such as multiple PDs) in the central optical module. For specific implementation methods, please refer to the above. Figure 3 、 Figure 6 and Figure 9 The relevant introduction of the system embodiment will not be repeated here.

[0324] In one possible implementation, the at least one downstream interface includes a downstream interface, the multiplexer is connected to the demultiplexer, and the multiplexer is further connected to the downstream interface; A multiplexer, used for sending a composite downstream optical signal to a downstream interface; The multiplexer is further configured to receive a composite upstream optical signal transmitted on the connected optical fiber through a downstream interface, and transmit the composite upstream optical signal to the demultiplexer.

[0325] like Figure 5 As shown, in the case of a single-fiber connection between the central optical module and the intermediate device, in another implementation, the central optical module includes a DEMUX, a MUX, and a downstream interface. The MUX acts as a multiplexer, and the DEMUX acts as a demultiplexer. The MUX has the functions of combining and splitting. The MUX is connected to the DEMUX and the downstream interface respectively, and the downstream interface is connected to the optical fiber. In addition, the MUX is also connected to the fixed-wavelength lasers (such as multiple LDs) in the central optical module, and the DEMUX is also connected to the optoelectronic conversion devices (such as multiple PDs) in the central optical module. For specific implementation methods, please refer to the above. Figure 5 The relevant introduction of the system embodiment will not be repeated here.

[0326] 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; A multiplexer, used for sending a composite downstream optical signal to a downstream interface; The multiplexer is further configured to receive, through the downstream interface, a composite upstream optical signal transmitted on the connected optical fiber; The multiplexer is further used to demultiplex multiple uplink optical signals from the composite uplink optical signal, where the multiple uplink optical signals carry uplink information sent by multiple access side optical modules to the routing switching device; The optoelectronic conversion device is used to perform optoelectronic conversion on multiple uplink optical signals respectively, thereby obtaining multiple second electrical signals, and sending the multiple second electrical signals to the routing switch device. In some embodiments, the multiplexer can be called a multiplexer / demultiplexer.

[0327] like Figure 4As shown, in the case of a single-fiber connection between the central optical module and the intermediate device, in another implementation, the central optical module includes a MUX and a downstream interface. The MUX serves as a multiplexer / demultiplexer. The MUX has the functions of combining, splitting, and splitting. The MUX is connected to the downstream interface, and the downstream interface is connected to the optical fiber. In addition, the MUX is also connected to the fixed wavelength lasers (such as multiple LDs) in the central optical module and is also connected to the optoelectronic conversion devices (such as multiple PDs) in the central optical module. For specific implementation methods, please refer to the above. Figure 4 The relevant introduction of the system embodiment will not be repeated here.

[0328] In one possible implementation, the at least one downstream interface includes a first downstream interface and a second downstream interface, the multiplexer is connected to the first downstream interface, the demultiplexer is connected to the second downstream interface, and the first downstream interface and the second downstream interface are respectively connected to different optical fibers; a multiplexer, configured to send the composite downlink optical signal via the connected first downlink interface; The demultiplexer is configured to receive the composite upstream optical signal through the connected second downstream interface.

[0329] like Figure 7 and Figure 8 As shown, in the case of a dual-fiber connection between the central optical module and the intermediate device, the central optical module may include a DEMUX, a MUX, and two downstream interfaces, which are respectively referred to as a first downstream interface and a second downstream interface. The MUX acts as a multiplexer, and the DEMUX acts as a demultiplexer. The MUX is connected to the first downstream interface, and the DEMUX is connected to the second downstream interface. The two downstream interfaces are connected to different optical fibers. In addition, the MUX is also connected to the fixed wavelength lasers (such as multiple LDs) in the central optical module, and the DEMUX is also connected to the optoelectronic conversion devices (such as multiple PDs) in the central optical module. For specific implementation methods, please refer to the above. Figure 7 and Figure 8 The relevant introduction of the system embodiment will not be repeated here.

[0330] In an embodiment of the present 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. In this way, a hybrid wavelength division scheme is adopted to 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.

[0331] Furthermore, when the access side optical module includes a tunable wavelength laser and the uplink dense wavelength division is used, the "normalization" solution of the access side optical module can be made feasible, thereby reducing the production cost and deployment difficulty of the access side optical module and reducing the difficulty of optical communication networking.

[0332] It should be noted that: when the central optical module provided in the above embodiment cooperates with the routing switching equipment to perform optical communication, it only uses the division of the above functional modules as an example to illustrate, that is, the above device embodiment is only schematic. For example, the division of the modules is only a logical function 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 is 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 the present 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 central optical module can be implemented in the form of hardware, or in the form of software functional units, or in a combination of hardware and software. In addition, the central optical module provided in the above embodiment and Figures 10 to 13 The optical communication method embodiments shown belong to the same concept, and their specific implementation processes are detailed in the method embodiments, which will not be repeated here.

[0333] It should also be noted that the central optical module provided in the embodiment of the present application can be applied to Figures 2 to 9 The optical communication system shown can also be applied to other communication systems. That is, the embodiment of the present application does not limit the application scenarios and deployment locations of the central optical module provided above. For other equipment / systems with optical communication requirements, the central optical module provided in this embodiment can also be deployed in other systems as needed.

[0334] The embodiment of the present application also provides an intermediate device, which can be the above-mentioned Figures 2 to 9 The intermediate device in the system embodiment can be used as the above-mentioned Figures 10 to 13 The intermediate device in the optical communication method involved. That is, the intermediate device is included in the optical communication system, and the optical communication system also includes multiple access-side optical modules, the multiple access-side optical modules corresponding to multiple upstream wavelengths, and the multiple access-side optical modules corresponding to multiple downstream wavelengths, different access-side optical modules among the multiple access-side optical modules corresponding to different downstream wavelengths, and different access-side optical modules among the multiple access-side optical modules corresponding to different upstream wavelengths.

[0335] In one implementation, the intermediate device includes a fiber optic interface, a demultiplexer, and an optical coupler, wherein: An optical fiber interface, configured to receive a composite downstream optical signal, the composite downstream optical signal including multiple downstream optical signals; A demultiplexer, configured to demultiplex a plurality of downlink optical signals from the composite downlink optical signal, and transmit corresponding downlink optical signals to a plurality of access-side optical modules based on respective downlink wavelengths of the plurality of downlink optical signals obtained by demultiplexing; An optical coupler, configured to combine multiple uplink optical signals from multiple access-side optical modules to obtain a composite uplink optical signal; The optical fiber interface is also used to send composite uplink optical signals.

[0336] Among them, demultiplexing can be Figures 2 to 8 In the DEMUX shown, the optical coupler may be a splitter / coupler.

[0337] In one possible implementation, the wavelength division interval of the multiple downstream wavelengths is greater than the wavelength division interval of the multiple upstream wavelengths. The specific implementation of the wavelength division interval can refer to the relevant introduction in the above system and method embodiments and will not be repeated here.

[0338] In a possible implementation, the multiple downstream optical signals included in the composite downstream optical signal are transmitted based on coarse wavelength division multiplexing (CWDM), and the multiple upstream optical signals included in the composite upstream optical signal are transmitted based on dense wavelength division multiplexing (DWDM).

[0339] In one possible implementation, the optical fiber interface includes at least one uplink interface and multiple downlink interfaces, and the uplink interface and the downlink interface are respectively connected to optical fibers; At least one uplink interface, configured to receive a composite downlink optical signal and send a composite uplink optical signal; Multiple downlink interfaces, used to send corresponding downlink optical signals to multiple access-side optical modules, wherein each of the multiple downlink interfaces sends an optical signal of a downlink wavelength, and different downlink interfaces in the multiple downlink interfaces send optical signals of different downlink wavelengths; The multiple downstream interfaces are also used to receive corresponding upstream optical signals sent by multiple access side optical modules, wherein each of the multiple downstream interfaces receives an optical signal of a downstream wavelength, and the upstream wavelengths of the optical signals received by different downstream interfaces are different.

[0340] In a possible implementation, each of the uplink interface and the downlink interface is connected to an optical fiber. Figures 2 to 8 As shown in the figure, 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 a fiber. Figure 6 and Figure 7 As shown in FIG, in the case of a single-fiber connection between the intermediate device and the access-side optical module, each downstream interface is connected to one optical fiber.

[0341] In one possible implementation, the intermediate device further includes a plurality of first optical splitters, the demultiplexer is connected to each of the plurality of first optical splitters, the optical coupler is connected to each of the plurality of first optical splitters, each of the plurality of first optical splitters is connected to one of the plurality of downstream interfaces, and different first optical splitters are connected to different downstream interfaces. a demultiplexer, configured 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 different first optical splitters receive optical signals of different downlink wavelengths; A plurality of first optical splitters, configured to transmit respectively received downlink optical signals to respectively connected downlink interfaces; Each of the multiple downstream interfaces is configured to send a received downstream optical signal through an optical fiber to which it is connected; Each of the multiple downstream interfaces is further configured to receive an upstream optical signal transmitted by the optical fiber to which it is connected, wherein one downstream interface receives one upstream optical signal, and different downstream interfaces receive optical signals of different downstream wavelengths; Each of the multiple downlink interfaces is further configured to transmit a received uplink optical signal to the first optical splitter connected thereto; The multiple first optical splitters are further configured to transmit the received uplink optical signals to the optical couplers respectively.

[0342] 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 one by one, and the multiple optical splitters are called 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 the optical coupler respectively. For specific implementation methods, please refer to Figure 6 and Figure 7 , I will not go into details here.

[0343] In one possible implementation, each of the multiple downstream interfaces includes a first sub-interface and a second sub-interface, the demultiplexer is connected to the multiple first sub-interfaces of the multiple downstream interfaces respectively, the optical coupler is connected to the multiple second sub-interfaces of the multiple downstream interfaces respectively, and the second sub-interface and the first sub-interface of each downstream interface are connected to different optical fibers respectively; a demultiplexer, configured to transmit a plurality of downlink optical signals to a plurality of first sub-interfaces, wherein one first sub-interface receives one downlink optical signal, and different first sub-interfaces receive optical signals with different downlink wavelengths; The first sub-interface in each downstream interface is used to send the downstream optical signal received by the first sub-interface through the connected optical fiber; The second sub-interface among the multiple downstream interfaces is configured to receive an upstream optical signal transmitted by the optical fiber to which the second sub-interface is connected, and transmit the upstream optical signal received by the second sub-interface to the optical coupler.

[0344] 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 downstream interface of the intermediate device includes two sub-interfaces, respectively referred to as the first sub-interface and the second sub-interface. 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 the optical coupler. Multiple first sub-interfaces are used to transmit downstream optical signals, and multiple second sub-interfaces are used to receive upstream optical signals. For specific implementation methods, please refer to Figures 2 to 5 、 Figure 8 , I will not go into details here.

[0345] In one possible implementation, the optical fiber interface includes an uplink interface, 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; An uplink interface, configured to receive a composite downlink optical signal transmitted by the connected optical fiber and transmit the received composite downlink optical signal to the second optical splitter; A second optical splitter, used for sending the composite downlink optical signal to the demultiplexer; an optical coupler, configured to transmit the composite uplink optical signal to the second optical splitter; The second optical splitter is used to transmit the composite uplink optical signal to the uplink interface; The uplink interface is also used to send composite uplink optical signals through the connected optical fiber.

[0346] 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, which is called the second splitter. The uplink interface is connected to an optical fiber. The demultiplexer in the intermediate device is a DEMUX. The second splitter is connected to the uplink interface, the DEMUX, and the optical coupler. For specific implementation methods, please refer to Figures 2 to 6 , I will not go into details here.

[0347] 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 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; A first uplink interface is configured to receive a composite downlink optical signal transmitted on the connected optical fiber and transmit the composite downlink optical signal to the demultiplexer; an optical coupler, configured to transmit a composite uplink optical signal to the second uplink interface; The second uplink interface is used to send a composite uplink optical signal to the connected optical fiber.

[0348] like Figure 7 and Figure 8 As shown, in the case of dual-fiber connection between the intermediate device and the central optical module, the intermediate device includes two uplink interfaces, which are respectively called the first uplink interface and the second uplink interface. The two uplink interfaces are connected to different optical fibers. The demultiplexer in the intermediate device is DEMUX, which is connected to the first uplink interface and the optical coupler is connected to the second uplink interface. For specific implementation methods, please refer to Figure 7 and Figure 8 , I will not go into details here.

[0349] In an embodiment of the present application, the intermediate device uses a combination of a demultiplexer (such as DMUX) and an optical coupler (such as a splitter) to transmit optical signals, which reduces the cost of the intermediate device while ensuring the reliability of optical communication.

[0350] Furthermore, 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. 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.

[0351] Furthermore, when the access side optical module includes a tunable wavelength laser and the uplink dense wavelength division is used, the "normalization" solution of the access side optical module can be made feasible, thereby reducing the production cost and deployment difficulty of the access side optical module and reducing the difficulty of optical communication networking.

[0352] It should be noted that: when the intermediate device provided in the above embodiment cooperates with other devices / devices in the optical communication system to perform optical communication, only the division of the above functional modules is used as an example to illustrate, that is, the above device embodiment is only schematic. For example, the division of the modules is only a logical function 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 is 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 each embodiment of the present 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 the form of hardware, or in the form of software functional units, or in a combination of hardware and software. In addition, the intermediate device provided in the above embodiment and Figures 10 to 13 The optical communication method embodiments shown belong to the same concept, and their specific implementation processes are detailed in the method embodiments, which will not be repeated here.

[0353] It should also be noted that the intermediate device provided in the embodiment of the present application can be used in addition to Figures 2 to 9 The optical communication system shown can also be applied to other communication systems. That is, the embodiment of the present application does not limit the application scenarios and deployment locations of the intermediate equipment provided above. For other equipment / systems with optical communication requirements, the intermediate equipment provided in this embodiment can also be deployed in other systems as needed.

[0354] Figure 13 130 is a schematic diagram of the structure of a network device provided in an embodiment of the present application. The network device may be an access device, routing switching device, or intermediate device in any of the above embodiments. The network device may 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.

[0355] 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 solution of the present application, such as an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. Optionally, the above-mentioned PLD is a complex programmable logic device (CPLD), an FPGA, a generic array logic (GAL), or any combination thereof. When the network device is any access device, routing switch device, or intermediate device in the embodiments of the present application, the processor 1301 is used to cooperate with other devices / devices in the optical communication system to implement Figures 10 to 13 Any of the embodiments shown provides an optical communication method.

[0356] For example, when the network device is a routing and switching device, the network device is integrated with or inserted with a central optical module, and the processor of the network device can control the central optical module to generate an optical signal carrying downlink information; when the network device is an access device, the network device is integrated with or inserted with an access side optical module, and the processor of the network device can control the access side optical module to generate an optical signal carrying uplink information.

[0357] In one implementation, the network device also includes a communication bus 1302, which is used to transmit information between the aforementioned components. Communication bus 1302 is divided into an address bus, a data bus, a control bus, and the like. For ease of illustration, the figure uses only one thick line, but this does not indicate that there is only one bus or only one type of bus.

[0358] In some embodiments, the memory 1303 is a read-only memory (ROM), a random access memory (RAM), an electrically erasable programmable read-only memory (EEPROM), an optical disc (including a compact disc read-only memory (CD-ROM), a compact disc, a laser disc, a digital versatile disc, a Blu-ray disc, etc.), a magnetic disk storage medium, or other magnetic storage device, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. The memory 1303 exists independently and is connected to the processor 1301 via the communication bus 1302, or the memory 1303 is integrated with the processor 1301.

[0359] In one implementation, the network device also includes one or more communication interfaces 1304, which utilize any transceiver-like device for communicating with other devices or communication networks. Communication interfaces 1304 include wired communication interfaces and, optionally, wireless communication interfaces. Examples of wired communication interfaces include Ethernet interfaces. Ethernet interfaces can be optical, electrical, or a combination thereof. Wireless communication interfaces can include wireless local area network (WLAN) interfaces, cellular network communication interfaces, or a combination thereof.

[0360] For example, in the case where the network device is a routing switching device, the network device is integrated with or inserted into a central optical module, and the network device can send an electrical signal carrying downlink information to the central optical module through an electrical interface, so that the central optical module generates and sends an optical signal based on the electrical signal. For example, the network device sends multiple electrical signals to the central optical module through an electrical interface, and the central optical module generates multiple downlink optical signals based on the multiple electrical signals, and merges the multiple downlink optical signals into a composite downlink optical signal, and sends the composite downlink optical signal. The network device can also receive the electrical signal sent by the central optical module through the electrical interface, thereby obtaining the uplink information carried by the electrical signal. The specific implementation method can refer to the relevant introduction of the above system and method embodiments, and will not be repeated here.

[0361] If the network device is an access device, it may integrate or incorporate an access-side optical module. The network device may transmit an electrical signal to the access-side optical module via an electrical interface, causing the access-side optical module to generate and transmit an optical signal based on the electrical signal. The network device may also receive the electrical signal transmitted by the access-side optical module via the electrical interface, thereby obtaining the downlink information carried by the electrical signal. Specific implementation methods can be found in the description of the system and method embodiments above and will not be elaborated upon here.

[0362] In the case where the network device is an intermediate device, the network device includes an optical interface (also called a fiber optic interface), which may include multiple downstream interfaces and at least one upstream interface. The network device can receive optical signals (such as a composite downstream optical signal) transmitted by the central optical module through the upstream interface, and transmit optical signals (such as a composite upstream optical signal) to the central optical module. The network device can also receive optical signals (i.e., optical signals of the upstream wavelength corresponding to each access-side optical module) transmitted by the access-side optical module through the downstream interface, and transmit optical signals (i.e., optical signals of the downstream wavelength corresponding to each access-side optical module) to the access-side optical module. The specific implementation method can refer to the relevant introduction of the system and method embodiments above, and will not be repeated here.

[0363] In some embodiments, the network device includes multiple processors, such as Figure 13 1 and 1305. Each of these processors is a single-core processor or a multi-core processor. A processor herein refers to one or more devices, circuits, and / or processing cores for processing data (such as computer program instructions). As an example, each processor may include one or more CPUs, such as Figure 13 Each processor shown in includes CPU0 and CPU1.

[0364] In some embodiments, the network device also includes an output device and an input device. The output device communicates with the processor 1301 and can display information in various ways. For example, the output device can be a liquid crystal display (LCD), a light emitting diode (LED) display device, a cathode ray tube (CRT) display device, or a projector. The input device communicates with the processor 1301 and can receive user input in various ways. For example, the input device can be a mouse, keyboard, touch screen device, or sensor device.

[0365] In some embodiments, the memory 1303 is used to store the program code 1310 for executing the solution of the present application, and the processor 1301 can execute the program code 1310 stored in the memory 1303, prompting the network device to execute Figures 10 to 13 The processing steps of the access device or routing switching device or intermediate device in the embodiment shown can be referred to in detail. Figures 10 to 13 The detailed description of the illustrated embodiments will not be repeated here.

[0366] An embodiment of the present application further provides a computer-readable storage medium, which stores instructions. When the computer-readable storage medium is run on a computer, the computer executes the steps of the optical communication method shown in the above method embodiment.

[0367] An embodiment of the present application further provides a computer program product comprising instructions, which, when executed on a computer, enables the computer to execute the steps of the optical communication method shown in the above method embodiment.

[0368] An embodiment of the present application further provides a computer program, which, when executed on a computer, enables the computer to execute the steps of the optical communication method shown in the above method embodiment.

[0369] In the above embodiments, all or part of the embodiments can be implemented using software, hardware, firmware, or any combination thereof. When implemented using software, all or part of the embodiments can be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed on a computer, the computer instructions fully or partially perform the processes or functions described in the embodiments of this application. 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, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that can be accessed by a computer, or a data storage device such as a server or data center that integrates one or more available media. The available medium may be a magnetic medium (e.g., a floppy disk, a hard disk, or a magnetic tape), an optical medium (e.g., a digital versatile disc (DVD)), or a semiconductor medium (e.g., a solid state disk (SSD)). It is worth noting that the computer-readable storage medium mentioned in the embodiments of the present application may be a non-volatile storage medium, in other words, a non-transitory storage medium.

[0370] It should be understood that the "at least one" mentioned herein refers to one or more, and "a plurality of" refers to two or more. In the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B; "and / or" in this article is merely a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in order to facilitate a clear description of the technical solutions of the embodiments of the present application, in the embodiments of the present application, words such as "first" and "second" are used to distinguish between identical or similar items with substantially the same functions and effects. Those skilled in the art will understand that words such as "first" and "second" do not limit the quantity and execution order, and words such as "first" and "second" do not necessarily limit them to be different.

[0371] 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, stored data, displayed data, 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 relevant data must comply with the relevant laws, regulations and standards of relevant countries and regions.

[0372] The above description is an embodiment provided for this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc. made by those skilled in the art should be included in the scope of protection of this application.

Claims

1. An optical communication system, characterized in that: The optical module comprises a central optical module and a plurality of access side optical modules, wherein the plurality of access side optical modules correspond to a plurality of upstream wavelengths, and the plurality of access side optical modules correspond to a plurality of downstream wavelengths, different access side optical modules among the plurality of access side optical modules correspond to different downstream wavelengths, and different access side optical modules among the plurality of access side optical modules correspond to different upstream wavelengths, the central optical module is connected to the plurality of access side optical modules, the central optical module comprises a fixed wavelength laser, the fixed wavelength laser is used to generate a plurality of fixed wavelength optical signals, the plurality of fixed wavelengths include the plurality of downstream wavelengths, and each of the plurality of access side optical modules comprises a tunable wavelength laser; The central optical module is used to send a composite downlink optical signal to the multiple access-side optical modules, wherein the composite downlink optical signal includes multiple downlink optical signals generated by the fixed-wavelength laser, and the wavelengths of the multiple downlink optical signals are respectively the multiple downlink wavelengths; Each of the multiple access side optical modules is used to use the tunable wavelength laser to send an optical signal of an uplink wavelength corresponding to the access side optical module to the central optical module; The central optical module is further configured to receive a composite uplink optical signal, wherein the composite uplink optical signal includes a plurality of uplink optical signals, and the wavelengths of the plurality of uplink optical signals are respectively the plurality of uplink wavelengths.

2. The system according to claim 1, wherein The wavelength division interval of the multiple downstream wavelengths is greater than the wavelength division interval of the multiple upstream wavelengths.

3. The system according to claim 1, wherein: 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).

4. The system according to claim 1, wherein: The wavelength division interval of the multiple downstream wavelengths is greater than or equal to a first threshold, the wavelength division interval of the multiple upstream wavelengths is less than a second threshold, and the first threshold is greater than or equal to the second threshold.

5. The system according to claim 4, wherein: The first threshold is 20 nanometers, and the second threshold is 2.5 nanometers.

6. The system according to any one of claims 1 to 5, wherein: Also included is an intermediate device, the intermediate device including a first demultiplexer and an optical combining device, the intermediate device is connected to the central optical module through an optical fiber, and the intermediate device is also connected to the multiple access side optical modules respectively through optical fibers; The first demultiplexer is configured to demultiplex the composite downlink optical signal received through the optical fiber to obtain a plurality of downlink optical signals, and send the corresponding downlink optical signals to the plurality of access-side optical modules through the optical fiber based on the respective downlink wavelengths of the plurality of downlink optical signals obtained by the demultiplexing; 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 send the composite uplink optical signal to the central optical module through an optical fiber.

7. The system according to claim 6, wherein: 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 respectively connected to the multiple access side optical modules via the multiple downlink interfaces through optical fibers; The intermediate device is configured to receive the composite downlink optical signal and send 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 of the multiple downlink interfaces sends a downlink optical signal, and the downlink wavelengths of the optical signals sent by different downlink interfaces in the multiple 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 an uplink optical signal, and the uplink wavelengths of the optical signals received by different downlink interfaces among the multiple downlink interfaces are different.

8. The system according to claim 7, wherein: Each of the multiple downstream interfaces is connected to an optical fiber.

9. The system according to claim 8, wherein The intermediate device also includes a plurality of first optical splitters, the first demultiplexer is connected to the plurality of first optical splitters respectively, the optical combiner is connected to the plurality of first optical splitters respectively, each of the plurality of first optical splitters is connected to one of the plurality of downstream interfaces, and different first optical splitters are connected to different downstream interfaces; each of the access-side optical modules includes a second optical splitter, the second optical splitter is connected to a downstream interface of the intermediate device via an optical fiber, the second optical splitters in different access-side optical modules among the plurality of access-side optical modules are connected to different downstream interfaces of the intermediate device, and the second optical splitter in a first optical module among the plurality of access-side optical modules is connected to a first downstream interface among the plurality of downstream interfaces via a first optical fiber; The first demultiplexer is specifically configured 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 different first optical splitters receive optical signals with different downlink wavelengths; 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 optical signal of the downlink wavelength 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 an optical signal of an uplink wavelength corresponding to the first optical module to the first downlink interface through the first optical fiber; Each downlink interface is further configured to transmit an uplink optical signal received by the downlink interface to the first optical splitter connected to the downlink interface; Each first optical splitter is further configured to transmit the uplink optical signal received by the first optical splitter to the optical combining device; The optical combining component is specifically configured 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 claim 7, wherein: Each of the multiple downstream interfaces includes a first sub-interface and a second sub-interface, the first demultiplexer is respectively connected to the multiple first sub-interfaces of the multiple downstream interfaces, and the optical combiner is respectively connected to the multiple second sub-interfaces of the multiple downstream interfaces; different access side optical modules of the multiple access side optical modules are connected to different downstream interfaces of the intermediate device through optical fibers, and the first optical module of the multiple access side optical modules is respectively connected to the first sub-interface and the second sub-interface included in the first downstream interface of the multiple downstream interfaces through different optical fibers; The first demultiplexer is specifically configured to transmit the multiple downlink optical signals to the multiple first sub-interfaces, wherein one first sub-interface receives one downlink optical signal, and different first sub-interfaces receive optical signals with different downlink wavelengths; 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; The second sub-interface of the first downlink interface is used to receive an optical signal of an uplink wavelength corresponding to the first optical module and 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 optical signal of the uplink wavelength received by the second sub-interface to the optical combining device; The optical combining component is specifically configured to combine the multiple uplink optical signals transmitted by the multiple second sub-interfaces into the composite uplink optical signal.

11. The system according to any one of claims 7 to 10, wherein: The light combining device includes an optical coupler.

12. The system according to any one of claims 7 to 10, wherein: The central optical module further includes a downlink interface, and the downlink interface of the central optical module is connected to an optical fiber.

13. The system according to claim 12, wherein: The central optical module further includes a fourth optical splitter, a first multiplexer, a second demultiplexer, and a photoelectric conversion device, wherein the fourth optical splitter is connected to the downlink interface of the central optical module, and the fourth optical splitter is also connected to the first multiplexer and the second demultiplexer respectively; The fixed wavelength laser is used to generate the multiple downlink optical signals according to the multiple first electrical signals, and the multiple first electrical signals are electrical signals input by the routing switching device; 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, 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 second demultiplexer; The second demultiplexer is configured 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 switching device.

14. The system according to claim 12, wherein: The central optical module further includes a second multiplexer, a third demultiplexer and a photoelectric conversion device, wherein 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 multiple downlink optical signals according to the multiple first electrical signals, and the multiple first electrical signals are electrical signals input by the routing switching device; 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, and 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 configured to receive the composite uplink optical signal transmitted by the second multiplexer, 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 third demultiplexer into multiple second electrical signals, and output the multiple second electrical signals to the routing switching device.

15. The system of claim 12, wherein: The central optical module further comprises 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 multiple downlink optical signals according to the multiple first electrical signals, and the multiple first electrical signals are electrical signals input by the routing switching device; The multiplexer / demultiplexer is configured 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 a 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 the multiple uplink optical signals demultiplexed by the multiplexer / demultiplexer into multiple second electrical signals, and output the multiple second electrical signals to the routing switching device.

16. The system according to any one of claims 13 to 15, wherein: 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 combiner respectively; The third optical splitter is used to receive the composite downlink optical signal sent by the central optical module through the uplink interface, and transmit the composite downlink optical signal to the first demultiplexer; The third optical splitter is further configured to receive the composite uplink optical signal transmitted by the optical combining component, and send the composite uplink optical signal to the central optical module through the uplink interface.

17. The system according to any one of claims 7 to 10, characterized in that: The central optical module further includes a second downstream interface, a third downstream interface, a first multiplexer, a second demultiplexer, and a photoelectric conversion device, wherein the first multiplexer is connected to the second downstream interface, and the second demultiplexer is connected to the third downstream interface; The fixed wavelength laser is used to generate the multiple downlink optical signals according to the multiple first electrical signals, and the multiple first electrical signals are electrical signals input by the routing switching device; The first multiplexer is used to combine the multiple downlink optical signals into the composite downlink optical signal, and send the combined composite downlink optical signal through the second downlink interface; The second demultiplexer is configured to demultiplex the multiple uplink optical signals from the composite uplink optical signal received by the third downlink interface; The optoelectronic conversion device is used to convert the multiple uplink optical signals into multiple second electrical signals, and output the multiple second electrical signals to the routing switching device.

18. The system according to claim 17, wherein: The intermediate device includes a first uplink interface and a second uplink interface, wherein the first uplink interface and the second downlink interface of the central optical module, and the second uplink interface and the third downlink interface of the central optical module are respectively connected through 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.

19. The system according to any one of claims 1-5, 7-10, 13-15, and 18, wherein: Each access side optical module further includes a photoelectric converter capable of processing optical signals of different downstream wavelengths; The tunable wavelength laser is used to generate an optical signal of an uplink wavelength corresponding to the access side optical module according to 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 an optical signal of a downlink wavelength received by an access-side optical module to which the photoelectric converter belongs to obtain a fourth electrical signal, and output the fourth electrical signal to the access device.

20. The system according to any one of claims 1-5, 7-10, 13-15, and 18, wherein: The central optical module is integrated into or inserted into a routing switching device, and the optical signal of the downlink wavelength carries the downlink information sent by the routing switching device; and / or, Each of the multiple access side optical modules is integrated into or inserted into an access device, and the optical signal of the uplink wavelength carries uplink information sent by the access device.

21. An optical communication method, characterized in that: The optical communication system includes multiple access side optical modules, the multiple access side optical modules correspond to multiple upstream wavelengths, and the multiple access side optical modules correspond to multiple downstream wavelengths, different access side optical modules correspond to different downstream wavelengths, different access side optical modules correspond to different upstream wavelengths, and the wavelength division interval of the multiple downstream wavelengths is greater than the wavelength division interval of the multiple upstream wavelengths; the method is applied to the first optical module among the multiple access side optical modules, the first optical module is any one of the multiple access side optical modules, and the method includes: receiving a downlink optical signal, where the wavelength of the downlink optical signal is a first downlink wavelength corresponding to the first optical module; An uplink optical signal is generated and sent, where the wavelength of the uplink optical signal is the first uplink wavelength corresponding to the first optical module.

22. The method according to claim 21, wherein The wavelength division interval of the multiple downstream wavelengths is greater than or equal to a first threshold, the wavelength division interval of the multiple upstream wavelengths is less than a second threshold, and the first threshold is greater than or equal to the second threshold.

23. The method according to claim 22, wherein The first threshold is 20 nanometers, and the second threshold is 2.5 nanometers.

24. The method according to any one of claims 21 to 23, wherein: The first optical module includes a photoelectric converter and a tunable wavelength laser, wherein the photoelectric converter has the ability to process optical signals of different downstream wavelengths, and the tunable wavelength laser has the ability to generate optical signals of different upstream wavelengths; The method further comprises: The photoelectric converter performs photoelectric conversion on the downlink optical signal to obtain a first electrical signal; The generating and sending of an uplink optical signal includes: The tunable wavelength laser generates and sends the uplink optical signal.

25. The method of claim 24, wherein: The first optical module is integrated or inserted into a first access device, the downlink optical signal carries downlink information transmitted to the first access device, and the optoelectronic converter performs optoelectronic conversion on the downlink optical signal to obtain a 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 sends the uplink optical signal, the method further includes: A second electrical signal transmitted by the first access device is received, where the uplink optical signal carries uplink information sent by the first access device through the second electrical signal.

26. The method of claim 25, wherein: The first optical module includes an uplink interface and a beam splitter, the uplink interface is connected to the first optical fiber, and the beam splitter is connected to the uplink interface; The receiving of a downlink optical signal includes: The optical splitter receives the downlink optical signal transmitted by the first optical fiber through the uplink interface, and transmits the downlink optical signal to the photoelectric converter; The sending of the uplink optical signal includes: The beam splitter sends the uplink optical signal generated by the tunable wavelength laser to the first optical fiber through the uplink interface.

27. The method of claim 25, wherein: The first optical module 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; The receiving of a downlink optical signal includes: 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; The sending of the uplink optical signal includes: The second uplink interface sends the uplink optical signal generated by the tunable wavelength laser through the connected optical fiber.

28. An optical communication method, characterized in that: The method is applied to a central optical module in an optical communication system, wherein the optical communication system further comprises a plurality of access side optical modules, wherein the plurality of access side optical modules correspond to a plurality of upstream wavelengths, and the plurality of access side optical modules correspond to a plurality of downstream wavelengths, wherein different access side optical modules among the plurality of access side optical modules correspond to different downstream wavelengths, and different access side optical modules among the plurality of access side optical modules correspond to different upstream wavelengths, wherein the central optical module comprises a fixed wavelength laser, wherein the fixed wavelength laser is used to generate a plurality of fixed wavelength optical signals, wherein the plurality of fixed wavelengths include the plurality of downstream wavelengths, and wherein the method comprises: Sending a plurality of downlink optical signals, where the plurality of downlink optical signals are generated by the fixed-wavelength laser, and the wavelengths of the plurality of downlink optical signals are respectively the plurality of downlink wavelengths; receiving a plurality of uplink optical signals, where the wavelengths of the plurality of uplink optical signals are the plurality of uplink wavelengths respectively; The wavelength division interval of the multiple downstream wavelengths is greater than the wavelength division interval of the multiple upstream wavelengths.

29. The method of claim 28, wherein The wavelength division interval of the multiple downstream wavelengths is greater than or equal to a first threshold, the wavelength division interval of the multiple upstream wavelengths is less than a second threshold, and the first threshold is greater than or equal to the second threshold.

30. The method of claim 29, wherein: The first threshold is 20 nanometers, and the second threshold is 2.5 nanometers.

31. The method according to any one of claims 28 to 30, wherein: The central optical module further includes a multiplexer and at least one downlink interface, wherein the downlink interface is connected to the optical fiber; The sending of multiple downlink optical signals includes: The multiplexer combines the multiple downstream optical signals generated by the fixed wavelength laser into a composite downstream optical signal, and sends the composite downstream optical signal through the downstream interface.

32. The method of claim 31, wherein The central optical module is integrated or inserted into the routing switching device; The fixed wavelength laser generates the multiple downlink optical signals based on the multiple first electrical signals input by the routing and switching device. The multiple downlink optical signals carry the downlink information sent by the routing and switching device through the multiple first electrical signals. The multiple first electrical signals correspond one-to-one to the multiple access-side optical modules, and the downlink information includes information sent to the multiple access-side optical modules.

33. The method of claim 32, wherein: The central optical module also includes a photoelectric conversion device and a demultiplexer; The receiving of multiple uplink optical signals includes: receiving a composite uplink optical signal via the downlink interface; The demultiplexer demultiplexes the multiple uplink optical signals from the composite uplink optical signal, and the multiple uplink optical signals carry uplink information sent by the multiple access-side optical modules to the routing switching device; The method further comprises: 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 switching device.

34. The method of claim 33, wherein: The central optical module includes a downlink interface and a splitter, the splitter is connected to the multiplexer and the demultiplexer respectively, and the splitter is also connected to the downlink interface; The sending of the composite downlink optical signal through the downlink interface includes: The multiplexer transmits the composite downstream optical signal to the optical splitter, and the optical splitter sends the composite downstream optical signal to the downstream interface; The receiving of the composite uplink optical signal through the downlink interface includes: The optical splitter receives the composite upstream optical signal transmitted on the connected optical fiber through the downstream interface, and transmits the composite upstream optical signal to the demultiplexer.

35. The method of claim 33, wherein: 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 sending of 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 the composite uplink optical signal through the downlink interface includes: The multiplexer receives the composite upstream optical signal transmitted on the connected optical fiber through the downstream interface, and transmits the composite upstream optical signal to the demultiplexer.

36. The method of claim 32, wherein: The central optical module includes a downlink interface and a photoelectric conversion device, and the multiplexer is connected to the downlink interface; The sending of 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 the composite uplink optical signal 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 multiple uplink optical signals from the composite uplink optical signal, and the multiple uplink optical signals carry uplink information sent by the multiple access-side optical modules to the routing switching device; 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 switching device.

37. The method of claim 33, wherein: The central optical module further includes a first downstream interface and a second downstream interface, the multiplexer is connected to the first downstream interface, the demultiplexer is connected to the second downstream interface, and the first downstream interface and the second downstream interface are respectively connected to different optical fibers; The sending of the composite downlink optical signal through the downlink interface includes: The multiplexer sends the composite downlink optical signal through the connected first downlink interface; The receiving of the composite uplink optical signal through the downlink interface includes: The demultiplexer receives the composite uplink optical signal through the connected second downlink interface.

38. 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 comprising a plurality of access side optical modules, the plurality of access side optical modules corresponding to a plurality of upstream wavelengths, and the plurality of access side optical modules corresponding to a plurality of downstream wavelengths, different access side optical modules among the plurality of access side optical modules corresponding to different downstream wavelengths, and different access side optical modules among the plurality of access side optical modules corresponding to different upstream wavelengths, the intermediate device comprising a demultiplexer and an optical coupler, and the method comprising: receiving a composite downlink optical signal, wherein the composite downlink optical signal includes a plurality of downlink optical signals; Demultiplexing the multiple downlink optical signals from the composite downlink optical signal through the demultiplexer; Sending corresponding downlink optical signals to the multiple access-side optical modules based on respective downlink wavelengths of the multiple downlink optical signals obtained by demultiplexing; Combining the multiple uplink optical signals from the multiple access-side optical modules through the optical coupler to obtain a composite uplink optical signal; The composite uplink optical signal is sent.

39. The method of claim 38, wherein The wavelength division interval of the multiple downstream wavelengths is greater than the wavelength division interval of the multiple upstream wavelengths.

40. The method of claim 38, wherein 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).

41. The method according to any one of claims 38 to 40, wherein: The intermediate device further includes at least one uplink interface and multiple downlink interfaces, wherein the uplink interface and the downlink interfaces are respectively connected to optical fibers; receiving the composite downlink optical signal and sending the composite uplink optical signal through the at least one uplink interface; Sending corresponding downlink optical signals to the multiple access-side optical modules through the multiple downlink interfaces, wherein each of the multiple downlink interfaces sends an optical signal of a downlink wavelength, and the downlink wavelengths of the optical signals sent by different downlink interfaces in the multiple downlink interfaces are different; The corresponding uplink optical signals sent by the multiple access side optical modules are received through the multiple downlink interfaces, wherein 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.

42. The method of claim 41, wherein Each of the uplink interface and the downlink interface is connected to an optical fiber respectively.

43. The method of claim 42, wherein: The intermediate device further includes a plurality of first optical splitters, the demultiplexer is connected to each of the plurality of first optical splitters, the optical coupler is connected to each of the plurality of first optical splitters, each of the plurality of first optical splitters is connected to one of the plurality of downstream interfaces, and different first optical splitters are connected to different downstream interfaces; The 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 a downlink optical signal, and different first optical splitters receive optical signals with different downlink wavelengths; The multiple first optical splitters respectively transmit the received downlink optical signals to the downlink interfaces to which they are connected; Each of the multiple downlink interfaces sends a downlink optical signal received by the downlink interface through the optical fiber to which the downlink interface is connected; Before combining the multiple uplink optical signals from the multiple access-side optical modules through the optical coupler to obtain a composite uplink optical signal, the method further includes: Each of the multiple downstream interfaces receives an upstream optical signal transmitted by the optical fiber to which it is connected, wherein one downstream interface receives one upstream optical signal, and different downstream interfaces receive optical signals with different downstream wavelengths; Each of the multiple downlink interfaces transmits a received uplink optical signal to the first optical splitter to which it is connected; The plurality of first optical splitters respectively transmit the received uplink optical signals to the optical coupler.

44. The method of claim 41, wherein Each of the multiple downstream interfaces includes a first sub-interface and a second sub-interface, the demultiplexer is connected to the multiple first sub-interfaces of the multiple downstream interfaces respectively, the optical coupler is connected to the multiple second sub-interfaces of the multiple downstream interfaces respectively, and the second sub-interface and the first sub-interface of each downstream interface are connected to different optical fibers respectively; The sending corresponding downlink optical signals to the multiple access-side optical modules through the multiple downlink interfaces includes: The demultiplexer transmits the multiple downlink optical signals to the multiple first sub-interfaces, wherein one first sub-interface receives one downlink optical signal, and different first sub-interfaces receive optical signals with different downlink wavelengths; The first sub-interface in each downstream interface sends the downstream optical signal received by the first sub-interface through the connected optical fiber; The receiving, through the multiple downlink interfaces, corresponding uplink optical signals sent by the multiple access-side optical modules includes: The second sub-interface among the multiple downstream interfaces receives an uplink optical signal transmitted by the optical fiber to which the second sub-interface is connected, and transmits the uplink optical signal received by the second sub-interface to the optical coupler.

45. The method according to claim 42 or 43, wherein 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 a composite downlink optical signal transmitted by the connected optical fiber, and transmits the received composite downlink optical signal to the second optical splitter; The second optical splitter sends the composite downlink optical signal to the demultiplexer; Sending 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 optical splitter; The second optical splitter transmits the composite uplink optical signal to the uplink interface; The uplink interface sends the composite uplink optical signal through the connected optical fiber.

46. The method according to claim 42 or 43, wherein The intermediate device 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 receiving the composite downlink optical signal through the at least one uplink interface includes: The first uplink interface receives a composite downlink optical signal transmitted on the connected optical fiber; The first uplink interface transmits the composite downlink optical signal to the demultiplexer; The sending of 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.

47. A first optical module, characterized in that The optical communication system includes a plurality of access-side optical modules, the plurality of access-side optical modules corresponding to a plurality of upstream wavelengths, and the plurality of access-side optical modules corresponding to a plurality of downstream wavelengths, different access-side optical modules corresponding to different downstream wavelengths, different access-side optical modules corresponding to different upstream wavelengths, and the wavelength division interval of the plurality of downstream wavelengths being greater than the wavelength division interval of the plurality of upstream wavelengths; the first optical module is any one of the plurality of access-side optical modules, and the first optical module includes an optical fiber interface, an optical receiving component, and an optical transmitting component; The optical receiving component is used to receive a downlink optical signal transmitted by the optical fiber interface, wherein 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 send 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.

48. The first optical module according to claim 47, wherein: The wavelength division interval of the multiple downstream wavelengths is greater than or equal to a first threshold, the wavelength division interval of the multiple upstream wavelengths is less than a second threshold, and the first threshold is greater than or equal to the second threshold.

49. The first optical module according to claim 48, wherein The first threshold is 20 nanometers, and the second threshold is 2.5 nanometers.

50. The first optical module according to any one of claims 47 to 49, wherein: The optical receiving component includes a photoelectric converter, and the optical transmitting component includes a tunable wavelength laser. The photoelectric converter has the ability to process optical signals of different downstream wavelengths, and the tunable wavelength laser has the ability to generate optical signals of different upstream 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 and send the uplink optical signal through the optical fiber interface.

51. The first optical module according to claim 50, wherein: The optical fiber 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; The optical splitter is configured to receive the downlink optical signal transmitted by the first optical fiber through the uplink interface and transmit the downlink optical signal to the optoelectronic converter; The beam splitter is further configured to send the uplink optical signal generated by the tunable wavelength laser to the first optical fiber through the uplink interface.

52. The first optical module according to claim 50, wherein: The optical fiber interface includes a first uplink interface and a second uplink interface, wherein the first uplink interface and the second uplink interface are connected to different optical fibers respectively; The first uplink interface is configured to receive the downlink optical signal transmitted on the connected optical fiber and transmit the downlink optical signal to the optoelectronic converter; The second uplink interface is used to send the uplink optical signal generated by the tunable wavelength laser through the connected optical fiber.

53. A central optical module, characterized in that Included in an optical communication system, the optical communication system further includes a plurality of access side optical modules, the plurality of access side optical modules corresponding to a plurality of upstream wavelengths, and the plurality of access side optical modules corresponding to a plurality of downstream wavelengths, different access side optical modules among the plurality of access side optical modules corresponding to different downstream wavelengths, and different access side optical modules among the plurality of access side optical modules corresponding to different upstream wavelengths, the central optical module including a fixed wavelength laser, the fixed wavelength laser for generating a plurality of fixed wavelength optical signals, the plurality of fixed wavelengths including the plurality of downstream wavelengths, the central optical module further including an optical fiber interface, an optical transmitting component, and an optical receiving component; The optical sending component is used to send 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 respectively the multiple downlink wavelengths; The optical receiving component is configured to receive a plurality of uplink optical signals through the optical fiber interface, wherein the wavelengths of the plurality of uplink optical signals are respectively the plurality of uplink wavelengths; The wavelength division interval of the multiple downstream wavelengths is greater than the wavelength division interval of the multiple upstream wavelengths.

54. The central light module according to claim 53, wherein: The wavelength division interval of the multiple downstream wavelengths is greater than or equal to a first threshold, the wavelength division interval of the multiple upstream wavelengths is less than a second threshold, and the first threshold is greater than or equal to the second threshold.

55. The central light module according to claim 54, wherein: The first threshold is 20 nanometers, and the second threshold is 2.5 nanometers.

56. The central optical module according to any one of claims 53 to 55, wherein: The optical transmission component includes a multiplexer, and the optical fiber interface includes at least one downlink interface, and the downlink interface is connected to the optical fiber; The multiplexer is configured to combine the multiple downlink optical signals generated by the fixed wavelength laser into a composite downlink optical signal, and send the composite downlink optical signal through the downlink interface.

57. The central optical module according to claim 56, wherein: The central optical module is integrated or inserted into the routing switching device; The fixed wavelength laser is used to generate the multiple downlink optical signals based on the multiple first electrical signals input by the routing and switching device. The multiple downlink optical signals carry the downlink information sent by the routing and switching device through the multiple first electrical signals. The multiple first electrical signals correspond one-to-one to the multiple access-side optical modules, and the downlink information includes information sent to the multiple access-side optical modules.

58. The central light module according to claim 57, wherein: The optical receiving component includes a demultiplexer, and the central optical module also includes a photoelectric conversion device; The demultiplexer is configured to receive the composite uplink optical signal via the downlink interface; The demultiplexer is further configured to demultiplex the multiple uplink optical signals from the composite uplink optical signal, wherein the multiple uplink optical signals carry uplink information sent by the multiple access-side optical modules to the routing switching device; The photoelectric conversion device is used to perform photoelectric conversion on the multiple uplink optical signals respectively, thereby obtaining multiple second electrical signals, and sending the multiple second electrical signals to the routing switching device.

59. The central light module according to claim 58, wherein: The at least one downlink interface includes a downlink interface, and the central optical module further includes a splitter, the splitter is connected to the multiplexer and the demultiplexer respectively, and the splitter is also connected to the downlink interface; The multiplexer is used to transmit the composite downlink optical signal to the optical splitter; The optical splitter is used to send the composite downlink optical signal to the downlink interface; The optical splitter is further configured to receive, via the downlink interface, a composite uplink optical signal transmitted on the connected optical fiber, and transmit the composite uplink optical signal to the demultiplexer.

60. The central light module according to claim 58, wherein: The at least one downlink interface includes a downlink interface, the multiplexer is connected to the demultiplexer, and the multiplexer is further connected to the downlink interface; The multiplexer is used to send the composite downlink optical signal to the downlink interface; The multiplexer is further configured to receive a composite upstream optical signal transmitted on the connected optical fiber through the downstream interface, and transmit the composite upstream optical signal to the demultiplexer.

61. The central light module according to claim 57, wherein: 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 further configured to receive, through the downlink interface, a composite uplink optical signal transmitted on the connected optical fiber; The multiplexer is further configured to demultiplex the multiple uplink optical signals from the composite uplink optical signal, wherein the multiple uplink optical signals carry uplink information sent by the multiple access-side optical modules to the routing switching device; The photoelectric conversion device is used to perform photoelectric conversion on the multiple uplink optical signals respectively, thereby obtaining multiple second electrical signals, and sending the multiple second electrical signals to the routing switching device.

62. The central light module according to claim 58, wherein: The at least one downstream interface further includes a first downstream interface and a second downstream interface, the multiplexer is connected to the first downstream interface, the demultiplexer is connected to the second downstream interface, and the first downstream interface and the second downstream interface are respectively connected to different optical fibers; The multiplexer is configured to send the composite downlink optical signal through the connected first downlink interface; The demultiplexer is further configured to receive the composite uplink optical signal through the connected second downlink interface.

63. An intermediate device, characterized in that The intermediate device is included in an optical communication system, and the optical communication system further includes a plurality of access side optical modules, the plurality of access side optical modules corresponding to a plurality of upstream wavelengths, and the plurality of access side optical modules corresponding to a plurality of downstream wavelengths, different access side optical modules among the plurality of access side optical modules corresponding to different downstream wavelengths, and different access side optical modules among the plurality of access side optical modules corresponding to different upstream wavelengths, and the intermediate device includes an optical fiber interface, a demultiplexer, and an optical coupler; The optical fiber interface is configured to receive a composite downstream optical signal, wherein the composite downstream optical signal includes multiple downstream optical signals; The demultiplexer is configured to demultiplex the multiple downlink optical signals from the composite downlink optical signal, and send corresponding downlink optical signals to the multiple access-side optical modules based on respective downlink wavelengths of the multiple downlink optical signals obtained by demultiplexing; The optical coupler is configured to combine the multiple uplink optical signals from the multiple access-side optical modules to obtain a composite uplink optical signal; The optical fiber interface is also used to send the composite uplink optical signal.

64. The intermediate device according to claim 63, wherein The wavelength division interval of the multiple downstream wavelengths is greater than the wavelength division interval of the multiple upstream wavelengths.

65. The intermediate device of claim 63, wherein: 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).

66. The intermediate device according to any one of claims 63 to 65, characterized in that: The optical fiber interface includes at least one uplink interface and multiple downlink interfaces, and the uplink interface and the downlink interface are respectively connected to optical fibers; The at least one uplink interface is configured to receive the composite downlink optical signal and send the composite uplink optical signal; The multiple downlink interfaces are used to send corresponding downlink optical signals to the multiple access-side optical modules, wherein each of the multiple downlink interfaces sends an optical signal of a downlink wavelength, and the downlink wavelengths of the optical signals sent by different downlink interfaces in the multiple downlink interfaces are different; The multiple downstream interfaces are also used to receive corresponding upstream optical signals sent by the multiple access side optical modules, wherein each of the multiple downstream interfaces receives an optical signal of a downstream wavelength, and the upstream wavelengths of the optical signals received by different downstream interfaces among the multiple downstream interfaces are different.

67. The intermediate device according to claim 66, wherein Each of the uplink interface and the downlink interface is connected to an optical fiber respectively.

68. The intermediate device according to claim 67, wherein The intermediate device further includes a plurality of first optical splitters, the demultiplexer is connected to each of the plurality of first optical splitters, the optical coupler is connected to each of the plurality of first optical splitters, each of the plurality of first optical splitters is connected to one of the plurality of downstream interfaces, and different first optical splitters are connected to different downstream interfaces; The demultiplexer is configured 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 different first optical splitters receive optical signals with different downlink wavelengths; The multiple first optical splitters are used to transmit the received downlink optical signals to the downlink interfaces to which they are connected respectively; Each of the multiple downstream interfaces is configured to send a received downstream optical signal through an optical fiber to which it is connected; Each of the multiple downstream interfaces is further configured to receive an upstream optical signal transmitted by the optical fiber to which it is connected, wherein one downstream interface receives one upstream optical signal, and different downstream interfaces receive optical signals of different downstream wavelengths; Each of the multiple downlink interfaces is further configured to transmit a received uplink optical signal to the first optical splitter to which it is connected; The plurality of first optical splitters are further configured to transmit respectively received uplink optical signals to the optical coupler.

69. The intermediate device according to claim 66, wherein: Each of the multiple downstream interfaces includes a first sub-interface and a second sub-interface, the demultiplexer is connected to the multiple first sub-interfaces of the multiple downstream interfaces respectively, the optical coupler is connected to the multiple second sub-interfaces of the multiple downstream interfaces respectively, and the second sub-interface and the first sub-interface of each downstream interface are connected to different optical fibers respectively; The demultiplexer is configured to transmit the multiple downlink optical signals to the multiple first sub-interfaces, wherein one first sub-interface receives one downlink optical signal, and different first sub-interfaces receive optical signals with different downlink wavelengths; The first sub-interface in each downstream interface is configured to send the downstream optical signal received by the first sub-interface through the connected optical fiber; The second sub-interface among the multiple downlink interfaces is configured to receive an uplink optical signal transmitted by the optical fiber to which the second sub-interface is connected, and transmit the uplink optical signal received by the second sub-interface to the optical coupler.

70. The intermediate device according to claim 67 or 68, characterized in that The optical fiber 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; The uplink interface is configured to receive a composite downlink optical signal transmitted by the connected optical fiber and transmit the received composite downlink optical signal to the second optical splitter; The second optical 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 optical splitter; The second optical splitter is used to transmit the composite uplink optical signal to the uplink interface; The uplink interface is further configured to send the composite uplink optical signal via the connected optical fiber.

71. The intermediate device according to claim 67 or 68, 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 configured to receive a composite downlink optical signal transmitted on the connected optical fiber and transmit the composite downlink optical signal to the demultiplexer; The optical coupler is configured 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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