A pon system and signal transmission method

Abstract

The embodiment of the application discloses a PON system and a signal transmission method. The system comprises an OLT, an ODN and a plurality of ONUs. The OLT is provided with a plurality of optical modules with different rates. The ODN comprises a first conversion device, a multi-core optical fiber main cable, a multi-core optical fiber optical branching device and a multi-core optical fiber lead-in cable. The optical modules are connected to the input end of the first conversion device through corresponding single-core optical fibers, and transmit downlink optical signals carrying wavelength information to the first conversion device. The multi-core optical fiber main cable is connected to the output end of the first conversion device. The multi-core optical fiber optical branching device performs branching processing on the downlink optical signals transmitted by the multi-core optical fiber main cable, and transmits the downlink optical signals to corresponding multi-core optical fiber lead-in cables. Each multi-core optical fiber lead-in cable transmits the downlink optical signals to the ONUs. The multi-core optical fibers transmit the downlink optical signals of different optical modules through different fiber cores. After receiving the downlink optical signals, the ONUs select matched downlink optical signals based on the carried wavelength information.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a PON system and a signal transmission method. Background Technology

[0002] In Passive Optical Networks (PONs), a single optical module is typically used, such as a GPON (1G PON) single-mode optical module or an XG(S)-PON (10G PON) compatible dual-mode PON solution. With the development of PON technology and increasing demands, higher-speed PONs, such as 50G PON, have been proposed.

[0003] To adapt to 50G PON, a coexistence technology architecture and solution for three generations of PON systems based on GPON / XG(S)-PON / 50G-PON tri-mode (MPM) optical modules is proposed, that is, the optoelectronic components of existing 1G / 10G rate optical modules are integrated into one optical module.

[0004] However, trimode optical modules have significant limitations on wavelength; the wavelengths corresponding to different rates need to be completely different, and the performance of trimode optical modules will also be affected. Summary of the Invention

[0005] This application provides a PON system and signal transmission method to reduce the wavelength limitations corresponding to different rates and improve the performance of optical modules.

[0006] In a first aspect, embodiments of this application provide a PON system, the system comprising: an optical line terminal (OLT), an optical distribution network (ODN), and multiple optical network units (ONUs);

[0007] The OLT is equipped with multiple optical modules, some or all of which correspond to different rates; the ODN includes a first conversion device, a multi-core fiber optic trunk cable, a multi-core fiber optic splitter, and multiple multi-core fiber optic drop cables; the first conversion device is a single-core to multi-core device.

[0008] Each optical module is connected to the input end of the first conversion device through a corresponding single-core optical fiber, and transmits downlink optical signals carrying wavelength information to the first conversion device; the multi-core optical fiber trunk cable is connected to the output end of the first conversion device, and transmits downlink optical signals corresponding to different optical modules through different fiber cores.

[0009] The multi-core fiber optic splitter is connected to the multi-core fiber trunk optical cable and the multi-core fiber drop optical cable respectively, and is used to split the downlink optical signal transmitted by the multi-core fiber trunk optical cable and transmit each downlink optical signal obtained by the splitting process to the corresponding multi-core fiber drop optical cable.

[0010] Each multi-core fiber optic cable is connected to its corresponding ONU, and the downlink optical signal corresponding to the different optical modules is transmitted through different fiber cores;

[0011] Each ONU is used to select a downlink optical signal that matches the ONU based on the wavelength information carried by the downlink optical signal after receiving the downlink optical signal transmitted by the multi-core optical fiber drop cable.

[0012] In some optional implementations, the plurality of optical modules includes a first optical module and a second optical module; wherein the first optical module and the second optical module correspond to different rates.

[0013] In some optional implementations, the first optical module is a dual-mode optical module compatible with 1G PON and 10G PON, and the second optical module is a single-mode optical module with 50G PON.

[0014] In some alternative implementations, the number of the second optical modules is one or more.

[0015] In some optional implementations, the plurality of optical modules further includes a third optical module and / or a fourth optical module; wherein the third optical module is an alternative 50G PON single-mode optical module; and the fourth optical module is a detection optical module.

[0016] In some optional implementations, the multi-core fiber optic splitter includes a second conversion device, a plurality of 1:N optical splitters, and N third conversion devices; wherein the second conversion device is a multi-core to single-core device, the third conversion device is a single-core to multi-core device, and N is the number of ONUs;

[0017] The multi-core optical fiber trunk cable is connected to the input end of the second conversion device, and the 1:N optical splitter is connected to the output end of the second conversion device through the corresponding single-core optical fiber; different 1:N optical splitters correspond to different optical modules;

[0018] Each 1:N optical splitter is used to split the downlink optical signal transmitted by the second conversion device through the corresponding single-core optical fiber to obtain N downlink optical signals corresponding to the same optical module, and transmit the N downlink optical signals to the input end of each third conversion device through N single-core optical fibers respectively.

[0019] The output of each third conversion device is connected to the corresponding multi-core optical fiber drop cable.

[0020] In some optional implementations, each ONU includes a fourth conversion device, a wavelength division multiplexer, and a detector; wherein the fourth optical splitting device is a multi-core to single-core device;

[0021] The input end of the fourth conversion device is connected to the multi-core optical fiber drop cable, and the output end is connected to the wavelength division multiplexer through multiple single-core optical fibers.

[0022] The fourth conversion device is used to convert the multi-core downlink optical signal of the multi-core optical fiber introduced into the optical cable into downlink optical signals in multiple single-core optical fibers.

[0023] The wavelength division multiplexer is used to combine the downlink optical signals from the plurality of single-core optical fibers into a single downlink optical signal, and transmit the single downlink optical signal to the detector through a single optical fiber;

[0024] The detector is used to select a downlink optical signal that matches the ONU based on the wavelength information carried by each downlink optical signal in the downlink optical signal path.

[0025] In some alternative implementations, the detector is specifically used for:

[0026] The wavelength information carried by each downlink optical signal is compared with the preset wavelength information of the ONU;

[0027] The downlink optical signal whose wavelength information is the same as the preset wavelength information is selected as the matched downlink optical signal.

[0028] Secondly, embodiments of this application provide a signal transmission method applied to the aforementioned OLT, the method comprising:

[0029] Each optical module incorporates the corresponding wavelength information into the downlink optical signal.

[0030] Each optical module sends a downlink optical signal carrying the wavelength information to the ODN, so that the ODN sends the downlink optical signal to each ONU respectively, and the ONU selects a downlink optical signal that matches the wavelength information of the downlink optical signal.

[0031] Thirdly, embodiments of this application provide a signal transmission method applied to the aforementioned ONU, the method comprising:

[0032] Receive downlink optical signals transmitted by the ODN; wherein, the downlink optical signals are transmitted by the OLT to the ODN through each optical module;

[0033] Based on the wavelength information carried by the downlink optical signal, a downlink optical signal matching the ONU is selected.

[0034] The beneficial effects of this application are as follows:

[0035] This application discloses a PON system and signal transmission method. In this PON system, the OLT is equipped with multiple optical modules, some or all of which correspond to different rates. Multi-generation PON coexistence is achieved through different optical modules, improving the performance of the optical modules. This offers significant advantages over tri-mode optical modules in terms of technical difficulty, miniaturization, high integration, high reliability, industry chain, and module cost. Different optical modules use independent fiber cores in space-division multiplexed multi-core optical fibers for optical signal transmission, meaning multiple generations of PON coexist on different physical media optical fibers. The optical signals from each optical module do not interfere with each other; therefore, the wavelengths corresponding to different rates can partially overlap, reducing wavelength limitations. Since some or all ONUs in the system support different rates, and the ONUs support broadband reception, automatic matching of the PON rate supported by the terminal is achieved by analyzing the optical signal wavelength information. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of the structure of a first type of PON system provided in an embodiment of this application;

[0038] Figure 2 This is a schematic diagram of the structure of a first type of OLT provided in an embodiment of this application;

[0039] Figure 3 This is a schematic diagram of the structure of a second type of OLT provided in an embodiment of this application;

[0040] Figure 4 This is a schematic diagram of the structure of a third type of OLT provided in an embodiment of this application;

[0041] Figure 5 This is a schematic diagram of the structure of a multi-core fiber optic splitter provided in an embodiment of this application;

[0042] Figure 6 This is a schematic diagram of the structure of the ONU provided in the embodiments of this application;

[0043] Figure 7 This is a schematic diagram of the structure of a second PON system provided in an embodiment of this application;

[0044] Figure 8 A flowchart illustrating the first signal transmission method provided in this application embodiment;

[0045] Figure 9 This is a flowchart illustrating a second signal transmission method provided in an embodiment of this application. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0047] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0048] In the description of this application, unless otherwise expressly specified and limited, the term "connection" should be interpreted broadly. For example, it can refer to a direct connection, an indirect connection through an intermediate medium, or a connection within two devices. Those skilled in the art can understand the specific meaning of the above term in this application based on the specific circumstances.

[0049] In PON, a single optical module is typically used, such as the GPON single-mode optical module or the XG(S)-PON compatible dual-mode PON solution. With the development of PON technology and the increase in demand, higher-speed PON, such as 50G PON, has been proposed.

[0050] To adapt to 50G PON, a coexistence technology architecture and solution for three generations of PON systems based on GPON / XG(S)-PON / 50G-PON tri-mode optical modules is proposed, that is, the optoelectronic components of existing 1G / 10G rate optical modules are integrated into one optical module.

[0051] However, trimode optical modules have significant limitations on wavelength; the wavelengths corresponding to different rates need to be completely different, and the performance of trimode optical modules will also be affected.

[0052] For example, GPON uses a 1490nm downlink operating wavelength (operating range 1480nm~1500nm) and a 1310nm uplink operating wavelength (operating range 1290nm~1330nm); XG(S)-PON uses a 1577nm downlink operating wavelength (operating range 1575nm~1580nm) and a 1270nm uplink operating wavelength (operating range 1260nm~1280nm). When upgrading to 50G PON in the future, if the coexistence of three generations of PON is required, the uplink and downlink operating wavelengths of 50G PON must avoid the uplink and downlink operating wavelengths of the aforementioned GPON / XG(S)-PON. In the uplink direction, all ONUs use TDMA time-division multiplexing, which significantly limits bandwidth and increases latency.

[0053] Based on this, embodiments of this application provide a PON system and a signal transmission method to reduce the limitations of wavelengths corresponding to different rates and improve the performance of optical modules.

[0054] The components and connections in each unit of the above-mentioned PON system will be described below with reference to the accompanying drawings and specific embodiments.

[0055] See Figure 1 As shown, the PON system includes: OLT10, ODN, and multiple ONUs; Figure 1 Taking N ONUs—ONU310, ONU320, ..., ONU3N0—as an example, the specific value of N can be set according to the actual application scenario.

[0056] The OLT is equipped with multiple optical modules. Figure 1 Taking m optical modules as an example, the specific value of m can be set according to the actual application scenario;

[0057] Some or all of the optical modules in a system may have different rates, meaning that multiple generations of PON can coexist through different optical modules; correspondingly, some or all of the ONUs in the system may also support different rates.

[0058] The ODN includes a first conversion device 210, a multi-core fiber optic trunk cable 220, a multi-core fiber optic splitter 230, and multiple multi-core fiber optic drop cables.

[0059] Since the multi-core fiber optic drop cable is connected to the ONU, the number of multi-core fiber optic drop cables can be the same as the number of ONUs; see reference. Figure 1 As shown, it includes multi-core optical fiber drop cable 241, multi-core optical fiber drop cable 242, ..., multi-core optical fiber drop cable 24N.

[0060] The first conversion device 210 is a single-core to multi-core device. The forward input of the single-core to multi-core device is multiple single-core optical signals. The single-core to multi-core device converts the multiple single-core optical signals into signals in each core of the multi-core optical fiber. The functions of the single-core to multi-core device will not be described in detail later.

[0061] In this embodiment, each optical module is connected to the input end of the first conversion device 210 through a corresponding single-core optical fiber, and transmits downlink optical signals carrying wavelength information to the first conversion device 210; the multi-core optical fiber trunk cable 220 is connected to the output end of the first conversion device 210, and transmits downlink optical signals corresponding to different optical modules through different fiber cores.

[0062] See Figure 1 As shown, optical module 1 is connected to the input end of the first conversion device 210 through a corresponding single-core optical fiber, and transmits a downlink optical signal carrying wavelength information corresponding to the rate of optical module 1 to the first conversion device 210; optical module 2 is connected to the input end of the first conversion device 210 through a corresponding single-core optical fiber, and transmits a downlink optical signal carrying wavelength information corresponding to the rate of optical module 2 to the first conversion device 210; ..., optical module m is connected to the input end of the first conversion device 210 through a corresponding single-core optical fiber m, and transmits a downlink optical signal carrying wavelength information corresponding to the rate of optical module m to the first conversion device 210;

[0063] The first conversion device 210 converts the optical signal in the single-core optical fiber 1 into the optical signal in the fiber core 1 of the multi-core optical fiber trunk cable 220; converts the optical signal in the single-core optical fiber 2 into the optical signal in the fiber core 2 of the multi-core optical fiber trunk cable 220; ...; converts the optical signal in the single-core optical fiber m into the optical signal in the fiber core m of the multi-core optical fiber trunk cable 220. Fiber cores 1 to m are not shown in the figure; these m fiber cores are independent of each other.

[0064] In this embodiment, the multi-core fiber optic splitter 230 is connected to the multi-core fiber optic trunk cable 220 and each multi-core fiber optic drop cable, respectively, to split the downlink optical signal transmitted by the multi-core fiber optic trunk cable, and to transmit each downlink optical signal obtained by the splitting process to the corresponding multi-core fiber optic drop cable.

[0065] Since the system has N ONUs, it is necessary to split the circuit using a multi-core fiber optic splitter, and then transmit the data to the corresponding ONU via an optical cable through each multi-core fiber optic cable.

[0066] The multi-core fiber optic trunk cable 220 transmits the downlink optical signal (λ1-λm) to the multi-core fiber optic splitter 230 through m fiber cores in one optical cable. The multi-core fiber optic splitter 230 splits the downlink optical signal to obtain N downlink optical signals (λ1-λm).

[0067] As mentioned above, a multi-core fiber optic cable corresponds to an ONU. Therefore, any multi-core fiber optic cable can transmit downlink optical signals corresponding to different optical modules to the corresponding ONU through different fiber cores.

[0068] See Figure 1 As shown, multi-core fiber optic cable 241 transmits the first multi-core downlink optical signal (λ1-λm) to ONU310; multi-core fiber optic cable 242 transmits the second multi-core downlink optical signal (λ1-λm) to ONU320; ...; multi-core fiber optic cable 24N transmits the Nth multi-core downlink optical signal (λ1-λm) to ONU3N0.

[0069] In this embodiment, some or all ONUs in the system support different rates. Therefore, the ONU supports broadband reception, that is, it receives downlink optical signals transmitted by multi-core fiber optic cables (downlink optical signals corresponding to all optical modules). However, the ONU usually only supports the rate corresponding to one type of optical module. Based on this, the ONU selects the downlink optical signal that matches the wavelength information carried by the downlink optical signal.

[0070] This embodiment does not specifically limit the wavelength information carried by the downlink optical signal, such as wavelength identifiers (different identifiers represent wavelengths corresponding to different PON rates), or specific wavelength value ranges.

[0071] The above solution, because the OLT in the PON system has multiple optical modules, some or all of which correspond to different rates, enables the coexistence of multiple generations of PON through different optical modules, improving the performance of the optical modules. It offers significant advantages over tri-mode optical modules in terms of technical difficulty, miniaturization, high integration, high reliability, industry chain, and module cost. Different optical modules use independent fiber cores in space-division multiplexed multi-core optical fibers for optical signal transmission, meaning multiple generations of PON coexist on different physical fiber media. The optical signals of each optical module do not interfere with each other, therefore, the wavelengths corresponding to different rates can partially overlap, reducing wavelength limitations. Since some or all ONUs in the system support different rates, and ONUs support broadband reception, they can automatically match the PON rate supported by the terminal by analyzing the wavelength information of the optical signal. Furthermore, only ONUs corresponding to the same optical module need to use TDMA time-division multiplexing when transmitting uplink optical signals. Uplink optical signal transmissions between ONUs corresponding to different optical modules do not interfere with each other, reducing bandwidth limitations and latency.

[0072] In some optional implementations, the plurality of optical modules includes a first optical module and a second optical module; wherein the first optical module and the second optical module correspond to different rates.

[0073] In this embodiment, the rate corresponding to the first optical module and the rate corresponding to the second optical module are not specifically limited. They can be any PON rate that needs to coexist. In this way, different PON rates can coexist by using at least two optical modules with different rates.

[0074] See Figure 2 As shown, in some optional embodiments, the first optical module is a dual-mode optical module compatible with 1G PON and 10GPON, and the second optical module is a single-mode optical module with 50G PON.

[0075] In practice, since 1G PON and 10G PON are mainstream broadband technologies that are being used on a large scale (and may not be directly phased out for a long time in the future), and 1G PON and 10G PON compatible dual-mode optical modules are relatively mature optical modules that have achieved good compatibility between the two PON rates; therefore, the first optical module can be a 1G PON and 10G PON compatible dual-mode optical module to meet the ONU requirements of supporting 1G PON and 10G PON.

[0076] 50G PON is the next-generation general-purpose broadband technology currently being promoted, which significantly improves access bandwidth, better service support capabilities (high bandwidth, low latency, low jitter), and network protection / security; therefore, the second optical module can be a 50G PON single-mode optical module to meet the requirements of the ONU supporting 50G PON.

[0077] The above solution, by using dual-mode optical modules compatible with 1G PON and 10G PON, as well as single-mode optical modules for 50GPON, enables the coexistence of 50G PON technology with existing 1G PON and 10G PON technologies, thus meeting the needs of different ONUs.

[0078] See above Figure 2 As shown, in some optional implementations, the number of the second optical module (50G PON single-mode optical module) is one;

[0079] See Figure 3 As shown, in some optional embodiments, the number of the second optical module (50G PON single-mode optical module) is multiple. Figure 3 Taking three second optical modules as an example, more or fewer second optical modules can be set up in practice.

[0080] As mentioned above, when an ONU corresponding to the same optical module transmits uplink optical signals, it needs to use TDMA (Time Division Multiplexing). If the number of 50G PON ONUs is small, only one optical module supporting 50GPON can be set up without significant latency. As the number of 50G PON ONUs increases, one optical module supporting 50G PON may not be able to meet the needs of 50GPON ONUs. By setting up multiple optical modules supporting 50G PON, the transmission of uplink optical signals between ONUs corresponding to different optical modules will not affect each other. Even when the number of 50G PON ONUs is large, significant latency will not occur, thus meeting the needs of different scenarios.

[0081] This embodiment does not limit the specific number of the second optical modules; the number of the second optical modules can be set according to the number of ONUs in a 50G PON.

[0082] In some optional implementations, the plurality of optical modules further includes a third optical module and / or a fourth optical module; wherein the third optical module is an alternative 50G PON single-mode optical module; and the fourth optical module is a detection optical module.

[0083] See Figure 4 As shown, in Figure 2 Based on the OLT, an optional 50G PON single-mode optical module and a detection optical module have been added (one of which can also be added during implementation);

[0084] During implementation, if the optical module or the corresponding physical medium fiber of the 50G PON fails, the 50G PON service will be affected. In order to ensure the normal operation of the 50G PON service, a backup 50G PON single-mode optical module can be set up.

[0085] Since each optical module corresponds to a different physical medium fiber, whether the 50G PON optical module fails or the corresponding physical medium fiber fails, the 50G PON service can still be guaranteed to operate normally through the alternative 50GPON single-mode optical module and the corresponding physical medium fiber.

[0086] In practice, since multi-core fiber space division multiplexing typically provides four or more fiber cores, if there are still physical medium fibers without corresponding optical modules, a detection optical module can be set up to avoid wasting resources. This detection optical module can provide optical time domain reflectometer (OTDR) detection or fiber optic sensing detection, etc.

[0087] See Figure 5As shown, in some optional embodiments, the multi-core fiber optic splitter 230 includes a second conversion device 231, a 1:N optical splitter, and a third conversion device; the 1:N optical splitter has the same number of fiber cores as the multi-core fiber optic trunk cable, corresponding to m fiber cores, with m 1:N optical splitters - 1:N optical splitter 2321, 1:N optical splitter 2322, ..., 1:N optical splitter 232m; the third conversion device has the same number as the ONUs, corresponding to N ONUs, with N third conversion devices - third conversion device 2331, third conversion device 2332, ..., third conversion device 233N.

[0088] The second conversion device is a multi-core to single-core device. The forward input of the multi-core to single-core device is the signal from all the cores in the multi-core optical fiber. The single-core to multi-core device converts the signal from each core in the multi-core optical fiber into a single-core optical signal. The functions of the multi-core to single-core devices will not be described in detail hereafter. The third conversion device is a single-core to multi-core device. Please refer to the description of the single-core to multi-core device in the above embodiments. It will not be repeated here.

[0089] In this embodiment, the multi-core fiber optic trunk cable transmits multi-core signals, which cannot be directly split. Therefore, by connecting the multi-core fiber optic trunk cable to the input end of the second conversion device, and connecting each 1:N optical splitter to the output end of the second conversion device through the corresponding single-core fiber, the single-core optical signal is split.

[0090] See Figure 5 As shown, the multi-core optical fiber trunk cable 220 is connected to the input end of the second conversion device 231. The second conversion device 231 converts the multi-core signal transmitted by the multi-core optical fiber trunk cable into a single-core optical signal corresponding to the 1:N optical splitter 2321, the 1:N optical splitter 2322, ..., the 1:N optical splitter 232m.

[0091] In this embodiment, each 1:N optical splitter is used to split the downlink optical signal transmitted by the second conversion device through the corresponding single-core optical fiber to obtain N downlink optical signals corresponding to the same optical module, and transmit the N downlink optical signals to the input end of each third conversion device through N single-core optical fibers respectively; the output end of each third conversion device is connected to the corresponding multi-core optical fiber drop cable.

[0092] Since the system has N ONUs, each needs a 1:N optical splitter to split the received downlink optical signal into N downlink optical signals corresponding to the same optical module; thus, m 1:N optical splitters output N downlink optical signals corresponding to all optical modules; the N downlink optical signals are transmitted to the input end of each third conversion device through N single-core optical fibers, and the third conversion device converts the optical signal in the single-core optical fiber into the optical signal in the fiber core of the optical cable through the multi-core optical fiber;

[0093] See Figure 5 As shown, 1: N-optical splitter 2321 splits the downlink optical signal corresponding to optical module 1 to obtain N downlink optical signals corresponding to optical module 1; 1: N-optical splitter 2322 splits the downlink optical signal corresponding to optical module 2 to obtain N downlink optical signals corresponding to optical module 2; ...; 1: N-optical splitter 232m splits the downlink optical signal corresponding to optical module m to obtain N downlink optical signals corresponding to optical module m;

[0094] The third conversion device 2331 converts the first downlink optical signal corresponding to optical module 1, optical module 2, ..., optical module m into a first multi-core downlink optical signal (λ1-λm), and the multi-core optical fiber is introduced into optical cable 241 to transmit the first multi-core downlink optical signal to ONU310; the third conversion device 2332 converts the second downlink optical signal corresponding to optical module 1, optical module 2, ..., optical module m into a second multi-core downlink optical signal (λ1-λm), and the multi-core optical fiber is introduced into optical cable 242 to transmit the second multi-core downlink optical signal to ONU320; ...; the third conversion device 233N converts the Nth downlink optical signal corresponding to optical module 1, optical module 2, ..., optical module m into an Nth multi-core downlink optical signal (λ1-λm), and the multi-core optical fiber is introduced into optical cable 24N to transmit the Nth multi-core downlink optical signal to ONU3N0.

[0095] See Figure 6 As shown, in some optional implementations, each ONU includes a fourth conversion device, a wavelength division multiplexing (WDM) device, and a detector; wherein, the fourth beam splitting device is a multi-core to single-core device, which can be referred to the description of the multi-core to single-core device in the above embodiments, and will not be repeated here.

[0096] The input end of the fourth conversion device is connected to the multi-core optical fiber drop cable, and the output end is connected to the wavelength division multiplexer through multiple single-core optical fibers.

[0097] The fourth conversion device is used to convert the multi-core downlink optical signal of the multi-core optical fiber introduced into the optical cable into downlink optical signals in multiple single-core optical fibers.

[0098] The wavelength division multiplexer is used to combine the downlink optical signals from the plurality of single-core optical fibers into a single downlink optical signal, and transmit the single downlink optical signal to the detector through a single optical fiber;

[0099] The detector is used to select a downlink optical signal that matches the ONU based on the wavelength information carried by each downlink optical signal in the downlink optical signal path.

[0100] In this embodiment, the signal input to the ONU via the multi-core fiber optic cable is a multi-core signal, which the ONU cannot directly process. Therefore, a fourth conversion device (multi-core to single-core device) is set in the ONU to first convert the multi-core signal into a single-core optical signal.

[0101] Since the ONU's detector receives one signal, a wavelength division multiplexer is also set in the ONU to combine the downlink optical signals from multiple single-core optical fibers into one downlink optical signal. This allows the downlink optical signal to be transmitted to the detector through a single optical fiber. In addition, in some embodiments, the OLT is equipped with a non-working optical module (such as a detection optical module), and the wavelength division multiplexer can also filter the downlink optical signals of non-working wavelengths, so that this downlink optical signal is a downlink optical signal of all working wavelengths.

[0102] ONUs with different PON rates support broadband reception (downlink optical signals of all operating wavelengths). They need to use a detector to select the downlink optical signal that matches the ONU based on the wavelength information carried by each downlink optical signal in one downlink optical signal. That is, they automatically match according to the PON rate supported by this ONU.

[0103] In some alternative implementations, the detector described above is specifically used for:

[0104] The wavelength information carried by each downlink optical signal is compared with the preset wavelength information of the ONU;

[0105] The downlink optical signal whose wavelength information is the same as the preset wavelength information is selected as the matched downlink optical signal.

[0106] In this embodiment, there is preset wavelength information corresponding to the ONU, that is, wavelength information corresponding to the supported PON rate.

[0107] The form of the preset wavelength information corresponds to the form of the wavelength information carried by the downlink optical signal. For example, if the carried wavelength information is a wavelength identifier, the preset wavelength information is also a wavelength identifier; if the carried wavelength information is a specific wavelength value range, the preset wavelength information is also a specific wavelength value range.

[0108] Select the downlink optical signal whose wavelength information is the same as the preset wavelength information from the downlink optical signals, and use it as the matching downlink optical signal.

[0109] The following is a specific example to illustrate this:

[0110] See Figure 7 As shown, the PON system includes: OLT10, ODN, and 8 ONUs;

[0111] The OLT10 has four optical modules: a dual-mode optical module compatible with 1G PON and 10G PON (optical module 1), a single-mode optical module with 50G PON (optical module 2), an alternative single-mode optical module with 50G PON (optical module 3), and a detection optical module (optical module 4).

[0112] The ODN includes a first conversion device 210, a multi-core fiber optic trunk cable 220, a second conversion device 231, four 1:8 optical splitters, eight third conversion devices, and eight multi-core fiber optic drop cables.

[0113] Optical module 1 transmits downlink optical signals λ1+λ2 carrying wavelength information of 1G PON and 10G PON to the first conversion device 210; optical module 2 transmits downlink optical signals λ3 carrying wavelength information corresponding to the 50G PON rate to the first conversion device 210; optical module 3 transmits downlink optical signals λ3 carrying wavelength information corresponding to the 50GPON rate to the first conversion device 210; optical module 4 transmits downlink optical signals λ4 carrying wavelength information corresponding to the detection optical module rate to the first conversion device 210.

[0114] The first conversion device 210 converts λ1+λ2, λ3 and λ4 into optical signals λ1~λ4 in the fiber cores 1-4 of the multi-core optical fiber trunk cable 220.

[0115] The multi-core fiber optic trunk cable 220 is connected to the input end of the second conversion device 231. The second conversion device 231 converts the multi-core fiber optic signals transmitted by the multi-core fiber optic trunk cable into single-core optical signals λ1+λ2 corresponding to the 1:8 optical splitter 2321, λ3 corresponding to the 1:8 optical splitter 2322, λ3 corresponding to the 1:8 optical splitter 2323, and λ4 corresponding to the 1:8 optical splitter 2324.

[0116] 1:8 optical splitter 2321 splits the downlink optical signal corresponding to optical module 1 to obtain 8 downlink optical signals λ1+λ2 corresponding to optical module 1; 1:8 optical splitter 2322 splits the downlink optical signal corresponding to optical module 2 to obtain 8 downlink optical signals λ3 corresponding to optical module 2; 1:8 optical splitter 2323 splits the downlink optical signal corresponding to optical module 3 to obtain 8 downlink optical signals λ3 corresponding to optical module 3; 1:8 optical splitter 2324 splits the downlink optical signal corresponding to optical module 4 to obtain 8 downlink optical signals λ4 corresponding to optical module 4.

[0117] The third conversion device 2331 converts the first downlink optical signal corresponding to optical module 1, optical module 2, optical module 3, and optical module 4 into a first multi-core downlink optical signal (λ1~λ4), and the multi-core optical fiber is introduced into optical cable 241 to transmit the first multi-core downlink optical signal to ONU310; the third conversion device 2332 converts the second downlink optical signal into a second multi-core downlink optical signal (λ1-λ4), and the multi-core optical fiber is introduced into optical cable 242 to transmit the second multi-core downlink optical signal to ONU320; ...; the third conversion device 2338 converts the eighth downlink optical signal into an eighth multi-core downlink optical signal (λ1-λ4), and the multi-core optical fiber is introduced into optical cable 248 to transmit the eighth multi-core downlink optical signal to ONU380;

[0118] ONU310 includes a fourth conversion device 311, a wavelength division multiplexer 312, and a detector 313; ONU320 includes a fourth conversion device 321, a wavelength division multiplexer 322, and a detector 323; ...; ONU380 includes a fourth conversion device 381, a wavelength division multiplexer 382, ​​and a detector 383.

[0119] The fourth conversion device in each ONU converts the multi-fiber signal into a single-core optical signal from multiple single-core optical fibers. The wavelength division multiplexer combines the downlink optical signals from the multiple single-core optical fibers into a single downlink optical signal, which is then transmitted to the detector through a single optical fiber. Based on the wavelength information carried by each downlink optical signal in the single downlink optical signal, the detector selects the downlink optical signal that matches the ONU, i.e., it automatically matches the signal according to the PON rate supported by this ONU.

[0120] like Figure 8 The image shows a first signal transmission method provided in this application embodiment. This signal transmission method is applied to any of the OLTs described above, and the method includes the following steps:

[0121] S801: Each optical module places the corresponding wavelength information into the downlink optical signal;

[0122] S802: Each optical module sends a downlink optical signal carrying the wavelength information to the ODN, so that the ODN sends the downlink optical signal to each ONU respectively, and the ONU selects a downlink optical signal that matches the wavelength information of the downlink optical signal.

[0123] like Figure 9 As shown, this is a second signal transmission method provided in an embodiment of this application. This signal transmission method is applied to an OLT as described in any of the above descriptions, and the method includes the following steps:

[0124] S901: Receive downlink optical signals transmitted by the ODN; wherein, the downlink optical signals are transmitted by the OLT to the ODN through each optical module;

[0125] S902: Based on the wavelength information carried by the downlink optical signal, select a downlink optical signal that matches the ONU.

[0126] In some optional implementations, each ONU includes a fourth conversion device, a wavelength division multiplexer, and a detector; wherein the fourth optical splitter is a multi-core to single-core device; the input end of the fourth conversion device is connected to the multi-core optical fiber drop cable, and the output end is connected to the wavelength division multiplexer through multiple single-core optical fibers;

[0127] Receiving the downlink optical signal transmitted by the ODN includes:

[0128] The fourth conversion device receives the multi-core downlink optical signal of the multi-core fiber optic cable and converts the multi-core downlink optical signal of the multi-core fiber optic cable into downlink optical signals in multiple single-core fibers.

[0129] The wavelength division multiplexer combines downlink optical signals from multiple single-core optical fibers into a single downlink optical signal, and transmits the single downlink optical signal to the detector through a single optical fiber.

[0130] Based on the wavelength information carried by the downlink optical signal, a downlink optical signal matching the ONU is selected, including:

[0131] The detector selects a downlink optical signal that matches the ONU based on the wavelength information carried by each downlink optical signal in the downlink optical signal path.

[0132] In some optional implementations, based on the wavelength information carried by each downlink optical signal in the downlink optical signal path, a downlink optical signal matching the ONU is selected, including:

[0133] The wavelength information carried by each downlink optical signal is compared with the preset wavelength information of the ONU;

[0134] The downlink optical signal whose wavelength information is the same as the preset wavelength information is selected as the matched downlink optical signal.

[0135] Figures 8-9 The specific implementation of the provided signal transmission method can be found in the above embodiments, and will not be repeated here.

[0136] Based on the same technical concept, embodiments of this application also provide a computer-readable storage medium storing a computer program executable by a processor, which, when run on the processor, causes the processor to perform the steps of the above-described signal transmission method.

[0137] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0138] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to this application. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0139] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0140] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0141] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0142] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A passive optical network (PON) system, characterized in that, The system includes: an optical line terminal (OLT), an optical distribution network (ODN), and multiple optical network units (ONUs); The OLT is equipped with multiple optical modules, some or all of which correspond to different rates; the ODN includes a first conversion device, a multi-core fiber optic trunk cable, a multi-core fiber optic splitter, and multiple multi-core fiber optic drop cables; the first conversion device is a single-core to multi-core device; wherein, multiple generations of PON coexistence are achieved through different optical modules. Each optical module is connected to the input end of the first conversion device through a corresponding single-core optical fiber, and transmits downlink optical signals carrying wavelength information to the first conversion device; the multi-core optical fiber trunk cable is connected to the output end of the first conversion device, and transmits downlink optical signals corresponding to different optical modules independently through different fiber cores. The multi-core fiber optic splitter is connected to the multi-core fiber trunk optical cable and the multi-core fiber drop optical cable respectively, and is used to split the downlink optical signal transmitted by the multi-core fiber trunk optical cable and transmit each downlink optical signal obtained by the splitting process to the corresponding multi-core fiber drop optical cable. Each multi-core fiber optic cable is connected to its corresponding ONU, and the downlink optical signal corresponding to the different optical modules is transmitted through different fiber cores; Each ONU is used to select a downlink optical signal that matches the rate of the ONU based on the wavelength information carried by the downlink optical signal after receiving the downlink optical signal transmitted by the multi-core optical fiber drop cable. The plurality of optical modules includes a first optical module and a second optical module; wherein the first optical module and the second optical module correspond to different rates. The first optical module is a dual-mode optical module compatible with 1G PON and 10G PON, and the second optical module is a single-mode optical module with 50G PON. The number of the second optical modules is multiple, and the number of the second optical modules is determined based on the number of ONUs.

2. The system as described in claim 1, characterized in that, The plurality of optical modules further includes a third optical module and / or a fourth optical module; wherein the third optical module is an alternative 50G PON single-mode optical module; and the fourth optical module is a detection optical module.

3. The system as described in claim 1, characterized in that, The multi-core fiber optic splitter includes a second conversion device, multiple 1:N optical splitters, and N third conversion devices; wherein, the second conversion device is a multi-core to single-core device, the third conversion device is a single-core to multi-core device, and N is the number of ONUs; The multi-core optical fiber trunk cable is connected to the input end of the second conversion device, and the 1:N optical splitter is connected to the output end of the second conversion device through the corresponding single-core optical fiber; different 1:N optical splitters correspond to different optical modules; Each 1:N optical splitter is used to split the downlink optical signal transmitted by the second conversion device through the corresponding single-core optical fiber to obtain N downlink optical signals corresponding to the same optical module, and transmit the N downlink optical signals to the input end of each third conversion device through N single-core optical fibers respectively. The output of each third conversion device is connected to the corresponding multi-core optical fiber drop cable.

4. The system as described in claim 1, characterized in that, Each ONU includes a fourth conversion device, a wavelength division multiplexer, and a detector; wherein, the fourth conversion device is a multi-core to single-core device; The input end of the fourth conversion device is connected to the multi-core optical fiber drop cable, and the output end is connected to the wavelength division multiplexer through multiple single-core optical fibers. The fourth conversion device is used to convert the multi-core downlink optical signal of the multi-core optical fiber introduced into the optical cable into downlink optical signals in multiple single-core optical fibers. The wavelength division multiplexer is used to combine the downlink optical signals from the plurality of single-core optical fibers into a single downlink optical signal, and transmit the single downlink optical signal to the detector through a single optical fiber; The detector is used to select a downlink optical signal that matches the ONU based on the wavelength information carried by each downlink optical signal in the downlink optical signal path.

5. The system as described in claim 4, characterized in that, The detector is specifically used for: The wavelength information carried by each downlink optical signal is compared with the preset wavelength information of the ONU; Select the downlink optical signal whose wavelength information is the same as the preset wavelength information as the matched downlink optical signal.

6. A signal transmission method, characterized in that, The method, applied to an OLT in a passive optical network (PON) system as described in any one of claims 1 to 5, comprises: Each optical module incorporates the corresponding wavelength information into the downlink optical signal. Each optical module sends a downlink optical signal carrying the wavelength information to the ODN, so that the ODN sends the downlink optical signal to each ONU respectively, and the ONU selects a downlink optical signal that matches the wavelength information of the downlink optical signal.

7. A signal transmission method, characterized in that, Applied to an ONU in a passive optical network (PON) system as described in any one of claims 1 to 5, the method includes: Receive downlink optical signals transmitted by the ODN; wherein, the downlink optical signals are transmitted by the OLT to the ODN through each optical module; Based on the wavelength information carried by the downlink optical signal, a downlink optical signal matching the ONU is selected.

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