ONT (Optical Network Terminal) identification method and OLT (Optical Line Terminal)

Abstract

The embodiment of the invention discloses an ONT (Optical Network Terminal) identification method and an OLT (Optical Line Terminal). Specifically, the OLT converts a first optical signal from the ONT into an electrical signal, and detects the electrical signal to determine a spectral distribution characteristic of the first optical signal. The spectral distribution characteristic shows the characteristic that the light intensity of the first light signal changes along with the wavelength. Wherein the wavelength range of which the light intensity is greater than the second threshold value in the first optical signal is called a target wavelength range. Further, the OLT determines the type of the ONT by determining whether the target wavelength range is greater than a first threshold. And if the target wavelength range of the first optical signal is greater than a first threshold value, the OLT determines that the ONT is a first type of ONT. And if the target wavelength range of the first optical signal is smaller than or equal to the first threshold value, the OLT determines that the ONT is a second type of ONT. Different types of ONTs may be adapted to a 50G PON, and may also be not adapted to the 50G PON. Therefore, the OLT can check out the ONTs which are not matched with the 50G PON by identifying the types of the ONTs, so that the deployment of the 50G PON is prevented from being influenced.

Description

Technical Field

[0001] The present application relates to the field of optical communications, and in particular to an ONT identification method and an OLT. Background Art

[0002] Passive Optical Network (PON) has the advantages of point-to-multipoint and pure passive optical distribution network, and is the mainstream development technology of access network. In 1G and 10G PON networks, there are two technical solutions: Ethernet passive optical network (EPON) and Gigabyte Passive Optical Network (GPON). With the release of 50G PON standard, 50G PON has become the only choice for the next generation of PON after 10G. The 50G PON standard has established the option of three-mode wavelength division coexistence. The optical line terminal (OLT) of three-mode wavelength division coexistence PON must be compatible with the previous two generations of optical network terminals (ONT).

[0003] The uplink wavelength of the three-mode coexistence 50G PON specified by the standard is 1286±2nm, which overlaps with the uplink wavelength of 1310±50nm of some ONTs in the existing EPON network, and cannot coexist in wavelength division, resulting in the inability to deploy 50G PON. Among them, the optical transmitters of the ONTs that conflict with the uplink wavelength of 50G PON all use Fabry–Pérot (FP) lasers, while ONTs that use distributed feedback (DFB) lasers as optical transmitters will not affect the deployment of 50G PON. Therefore, how to detect and troubleshoot all ONTs using FP lasers without affecting the existing ONT services is an urgent problem to be solved before the deployment of 50G PON. Summary of the invention

[0004] The embodiment of the present application provides an ONT identification method and an OLT. The OLT can identify the type of the ONT and identify the ONT that is not compatible with 50G PON, thereby avoiding affecting the deployment of 50G PON.

[0005] In a first aspect, an embodiment of the present application provides an ONT identification method. Specifically, the OLT converts a first optical signal from the ONT into an electrical signal, and detects the electrical signal to determine the spectral distribution characteristics of the first optical signal. The spectral distribution characteristics show the characteristics of the light intensity of the first optical signal changing with the wavelength. Among them, the wavelength range in which the light intensity in the first optical signal is greater than the second threshold is called the target wavelength range. Furthermore, the OLT determines the type of the ONT by judging whether the target wavelength range is greater than the first threshold. If the target wavelength range of the first optical signal is greater than the first threshold, the OLT determines that the ONT is a first-class ONT. If the target wavelength range of the first optical signal is less than or equal to the first threshold, the OLT determines that the ONT is a second-class ONT.

[0006] In this implementation, different types of ONTs may be compatible with 50G PON or not. Therefore, the OLT can identify the type of ONT and identify the ONT that is not compatible with 50G PON, thereby avoiding affecting the deployment of 50G PON.

[0007] In some possible implementations, the first type of ONT uses a Fabry–Pérot (FP) laser, and the second type of ONT uses a distributed feedback (DFB) laser. It should be understood that the ONT using the FP laser cannot coexist with the ONT adapted to 50G PON, which will affect the deployment of 50G PON. However, the ONT using the DFB laser can coexist with the ONT adapted to 50G PON, which will not affect the deployment of 50G PON. This implementation provides a specific way to distinguish different types of ONTs, which improves the practicality of this solution.

[0008] In some possible implementations, the method further includes: the OLT splits the input optical signal from the ONT to obtain a first optical signal and a second optical signal. The second optical signal is transmitted to an optical transceiver component in the OLT. It should be understood that the optical power of the second optical signal is greater than the optical power of the first optical signal, that is, most of the optical signal after splitting is transmitted to the optical transceiver component to avoid affecting the normal optical signal interaction between the OLT and the ONT.

[0009] In some possible implementations, the OLT converts the first optical signal from the ONT into an electrical signal, including: the OLT splits the first optical signal to obtain n optical signals, where n is an integer greater than 1. The OLT filters the n optical signals respectively, wherein the n optical signals after filtering are distributed in n bands respectively. The OLT performs photoelectric conversion on the n optical signals after filtering to obtain n electrical signals. This implementation provides a specific way to achieve photoelectric conversion, which improves the feasibility of this solution.

[0010] In some possible implementations, the OLT converts the first optical signal from the ONT into an electrical signal, including: the OLT performs wavelength division on the first optical signal to obtain n optical signals, the n optical signals are respectively distributed in n bands, and n is an integer greater than 1. The OLT performs photoelectric conversion on the n optical signals to obtain n electrical signals. This implementation provides another specific way to achieve photoelectric conversion, and the function of wavelength division is equivalent to the function of light splitting and optical filtering, which improves the flexibility of this solution.

[0011] In some possible implementations, the OLT detects the electrical signal to determine the spectral distribution characteristics of the first optical signal, including: the OLT performs power detection on n electrical signals respectively to determine the spectral characteristics of the first optical signal in n bands. The OLT determines whether the target wavelength range of the first optical signal is greater than the first threshold, including: the OLT determines whether the number of target bands in the n bands is greater than the third threshold, wherein the target band is a band in the n bands where the light intensity of the first optical signal is greater than the second threshold. If so, the OLT determines that the ONT is a first-type ONT. If not, the OLT determines that the ONT is a second-type ONT. In this implementation, the optical signal emitted by the second-type ONT has a sufficiently large light intensity only in fewer bands, and the optical signal emitted by the first-type ONT has a sufficiently large light intensity in more bands. In this way, the type of ONT can be distinguished more directly.

[0012] In some possible implementations, the wavelength coverage range of the n bands includes 1260 nm to 1360 nm, thereby covering the upstream wavelength ranges of various types of ONTs.

[0013] In some possible implementations, the OLT converts the first optical signal from the ONT into an electrical signal, including: the OLT splits the first optical signal to obtain a first sub-optical signal and a second sub-optical signal. The OLT performs delay processing on the first sub-optical signal. The OLT combines the first sub-optical signal and the second sub-optical signal after the delay processing to obtain a combined optical signal. The OLT converts the combined optical signal into an electrical signal. This implementation uses a Mach-Zehnder Interferometer (MZI) and a photodetector (PD) to achieve photoelectric conversion, thereby improving the scalability of the solution.

[0014] In some possible implementations, the OLT detects the electrical signal to determine the spectral distribution characteristics of the first optical signal, including: the OLT performs Fourier transform on the electrical signal sequence to determine the spectral distribution characteristics of the first optical signal. The electrical signal sequence includes m electrical signals, where m is an integer greater than 1. The m electrical signals are converted from m combined optical signals, the m combined optical signals are obtained by combining m delayed first optical sub-signals and second optical sub-signals, respectively, and the m delayed first optical sub-signals are obtained by the OLT performing delay processing on the first optical sub-signals according to the m delays.

[0015] In some possible implementations, the OLT performing delay processing on the first sub-optical signal includes: the OLT performing delay processing on the first sub-optical signal through a heater or a phase shifter.

[0016] In a second aspect, an embodiment of the present application provides an OLT. The OLT includes: an optical processing unit and an electrical processing unit. The optical processing unit is used to: convert a first optical signal from an optical network terminal ONT into an electrical signal. The electrical processing unit is used to: detect the electrical signal to determine the spectral distribution characteristics of the first optical signal; determine whether the target wavelength range of the first optical signal is greater than a first threshold, wherein the target wavelength range is a wavelength range in which the light intensity in the first optical signal is greater than a second threshold; if so, determine that the ONT is a first-type ONT; if not, determine that the ONT is a second-type ONT.

[0017] In some possible implementations, the laser used by the first type of ONT is a FP laser, and the laser used by the second type of ONT is a DFB laser.

[0018] In some possible implementations, the OLT further includes a first optical splitter and an optical transceiver assembly. The optical splitter is used to split the input optical signal from the ONT to obtain a first optical signal and a second optical signal. The first optical signal is transmitted to the optical processing unit, and the second optical signal is transmitted to the optical transceiver assembly.

[0019] In some possible implementations, the optical processing unit includes a second optical splitter, n optical filters, and n PDs, where n is an integer greater than 1. The second optical splitter is used to split the first optical signal to obtain n sub-optical signals, and the n sub-optical signals are transmitted to the n optical filters in a one-to-one correspondence. The n optical filters are used to filter the n sub-optical signals respectively, wherein the filtered n sub-optical signals are distributed in n bands respectively. The n PDs are used to perform photoelectric conversion on the filtered n optical signals to obtain n electrical signals.

[0020] In some possible implementations, the optical processing unit includes a wavelength division multiplexer WDM and n PDs, where n is an integer greater than 1. The WDM is used to divide the first optical signal into n sub-optical signals, where the n sub-optical signals are respectively distributed in n bands. The n PDs are used to perform photoelectric conversion on the n sub-optical signals to obtain n electrical signals.

[0021] In some possible implementations, the electrical processing unit is specifically used to: perform power detection on n electrical signals respectively to determine the spectral characteristics of the first optical signal in n bands. Determine whether the number of target bands in the n bands is greater than a third threshold, wherein the target band is a band in the n bands where the light intensity of the first optical signal is greater than the second threshold. If yes, determine that the ONT is a first-type ONT. If no, determine that the ONT is a second-type ONT.

[0022] In some possible implementations, the wavelength coverage range of the n bands includes 1260 nm to 1360 nm.

[0023] In some possible implementations, the optical processing unit includes a third optical splitter, a delay device, a combiner, and a PD. The third optical splitter is used to split the first optical signal to obtain a first sub-optical signal and a second sub-optical signal. The delay device is used to perform delay processing on the first sub-optical signal. The combiner is used to combine the first sub-optical signal and the second sub-optical signal after delay processing to obtain a combined optical signal. The PD is used to convert the combined optical signal into an electrical signal.

[0024] In some possible implementations, the electrical processing unit is specifically used to: perform Fourier transform on the electrical signal sequence to determine the spectral distribution characteristics of the first optical signal. The electrical signal sequence includes m electrical signals, where m is an integer greater than 1. The m electrical signals are converted from m combined optical signals, and the m combined optical signals are obtained by combining m delayed first optical sub-signals and second optical sub-signals respectively, and the m delayed first optical sub-signals are obtained by the OLT performing delay processing on the first optical sub-signals according to the m delays.

[0025] In some possible implementations, the delay device is a heater or a phase shifter.

[0026] In an embodiment of the present application, the OLT converts the first optical signal from the ONT into an electrical signal, and detects the electrical signal to determine the spectral distribution characteristics of the first optical signal. The spectral distribution characteristics show the characteristics of the light intensity of the first optical signal changing with the wavelength. Among them, the wavelength range in which the light intensity in the first optical signal is greater than the second threshold is called the target wavelength range. Furthermore, the OLT determines the type of the ONT by judging whether the target wavelength range is greater than the first threshold. It should be understood that different types of ONTs may be adapted to 50G PON or may not be adapted to 50G PON. Therefore, the OLT can identify the type of ONT that is not adapted to 50G PON, thereby avoiding affecting the deployment of 50G PON. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the system architecture of PON;

[0028] Figure 2 This is a schematic diagram of an embodiment of a method for identifying an ONT in an embodiment of the present application;

[0029] Figure 3 A schematic diagram of a spectrum of an optical signal emitted by a first type of ONT;

[0030] Figure 4 is a schematic diagram of the spectrum of the optical signal emitted by the second type of ONT;

[0031] Figure 5 This is a schematic diagram of a first implementation method of OLT performing photoelectric conversion in an embodiment of the present application;

[0032] Figure 6 This is a schematic diagram of n optical signals distributed in n bands in an embodiment of the present application;

[0033] Figure 7 Schematic diagram of the spectrum of the optical signal emitted by the first type of ONT distributed in n bands;

[0034] Figure 8 Schematic diagram of the spectrum of the optical signal emitted by the second type of ONT distributed in n bands;

[0035] Fig. 9 This is a schematic diagram of a second implementation method of OLT performing photoelectric conversion in an embodiment of the present application;

[0036] Fig.10 This is a schematic diagram of a third implementation method of the OLT performing photoelectric conversion in the embodiment of the present application;

[0037] Fig.11 This is a schematic diagram of the structure of an OLT in an embodiment of the present application. DETAILED DESCRIPTION

[0038] The embodiment of the present application provides an ONT identification method and OLT. The OLT can identify the ONT that is not compatible with 50GPON by identifying the type of ONT, thereby avoiding affecting the deployment of 50G PON. It should be noted that the terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar objects, rather than to limit a specific order or sequence. It should be understood that the above terms can be interchanged where appropriate, so that the embodiments described in this application can be implemented in an order other than the content described in this application. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0039] The present application is mainly applied to a passive optical network (PON) system. The system architecture of PON is introduced below.

[0040] Figure 1 The following is a schematic diagram of the PON system architecture. The OLT is connected to the upper layer network side equipment (such as switches, routers, etc.), and the lower layer is connected to one or more optical distribution networks (ODN).

[0041] ODN includes a passive optical splitter for optical power distribution, a trunk optical fiber connected between the passive optical splitter and the optical line terminal (Optical Line Termination, OLT), and a branch optical fiber connected between the passive optical splitter and the optical network unit (Optical Network Unit, ONU). When transmitting data downstream, ODN transmits the downstream data of OLT to each ONU through the splitter, and the ONU selectively receives the downstream data carrying its own identification. When transmitting data upstream, ODN combines the optical signals sent by N ONUs into one optical signal and transmits it to the OLT. If the ONU also provides user port functions, such as the ONU provides an Ethernet user port or a plain old telephone service (POTS) user port, it is called an optical network terminal (Optical Network Termination, ONT).

[0042] It should be noted that OLT uses a three-mode wavelength division coexistence optical module. The three-mode wavelength division coexistence OLT is compatible with three generations of ONTs, including EPON, 1G / 10GEPON and 50G PON. Among them, ONT mainly uses two types of lasers, Fabry–Pérot (FP) laser and distributed feedback (DFB) laser. The following divides ONT into 6 categories based on PON system and laser type, and introduces the upstream wavelength range of these 6 types of ONT. Category 1 ONT is adapted to EPON, uses FP laser, and the upstream wavelength range is 1310±50nm. Category 2 ONT is adapted to EPON, uses DFB laser, and the upstream wavelength range is 1310±20nm. Category 3 ONT is adapted to 1G / 10G EPON, uses FP laser, and the upstream wavelength range is 1310±50nm. Category 4 ONTs are compatible with 1G / 10G EPON, using DFB lasers, and the upstream wavelength range is 1310±20nm. Category 5 ONTs are compatible with 1G / 10G EPON, using DFB lasers, and the upstream wavelength range is 1270±10nm. Category 6 ONTs are compatible with 50GPON, using DFB lasers, and the upstream wavelength range is 1286±2nm. It can be seen that the upstream wavelength ranges of Category 1 ONTs and Category 3 ONTs overlap with Category 6 ONTs, and they cannot coexist in wavelength division, which will affect the deployment of 50G PONs adapted to Category 6 ONTs.

[0043] To this end, the present application provides an ONT identification method, which can identify ONTs that are not compatible with 50G PON. The ONT identification method is applied to OLT, which is described in detail below.

[0044] Figure 2 The following is a schematic diagram of an embodiment of a method for identifying an ONT in an embodiment of the present application. In this example, the method for identifying an ONT includes the following steps.

[0045] 101. The OLT converts a first optical signal from the ONT into an electrical signal.

[0046] The OLT allocates corresponding upstream time slots to different ONTs, so the OLT knows which ONT the optical signal received in each upstream time slot comes from. For ease of introduction, one of the ONTs is used as an example for description below, and the method is applicable to any ONT. The OLT converts the first optical signal from the ONT into an electrical signal. The first optical signal can be converted into one electrical signal or multiple electrical signals, which will be introduced in combination with different embodiments below.

[0047] 102. The OLT detects the electrical signal to determine a spectrum distribution characteristic of the first optical signal.

[0048] It should be understood that the spectral distribution characteristics refer to the characteristics of the distribution of light intensity with wavelength or frequency, which can also be called optical spectrum characteristics. The implementation method of the OLT determining the spectral distribution characteristics of the first optical signal includes but is not limited to power detection of the electrical signal and Fourier transformation of the electrical signal, which will be introduced in combination with different embodiments later.

[0049] 103. The OLT determines whether the target wavelength range of the first optical signal is greater than a first threshold. If yes, execute step 104. If no, execute step 105.

[0050] It should be understood that the target wavelength range is a wavelength range in which the light intensity in the first optical signal is greater than the second threshold value. That is, the OLT first determines the target wavelength range with greater light intensity in the wavelength range covered by the first optical signal by detecting the electrical signal. Then, the OLT determines the type of the ONT by analyzing the size of the target wavelength range. Among them, the type of ONT is mainly distinguished by the type of laser used by the ONT. For example, the first type of ONT uses an FP laser, and the second type of ONT uses a DFB laser.

[0051] 104. The OLT determines that the ONT is a first-type ONT.

[0052] If the target wavelength range of the first optical signal is greater than the first threshold, the OLT determines that the ONT is a first-type ONT, that is, the ONT uses an FP laser. Figure 3 FIG. 1 is a schematic diagram of the spectrum of the optical signal emitted by the first type of ONT. Figure 3 As shown, there are optical signals with sufficient light intensity in the longer wavelength range, that is, the target wavelength range is large. It should be understood that since the ONT using FP lasers and the ONT adapted to 50G PON cannot coexist in wavelength division, the OLT can prompt to replace the first type of ONT using FP lasers with the second type of ONT using DFB lasers.

[0053] 105. The OLT determines that the ONT is a second-type ONT.

[0054] If the target wavelength range of the first optical signal is less than or equal to the first threshold, the OLT determines that the ONT is a second-type ONT, that is, the ONT adopts a DFB laser. Figure 4 Figure 2 is a schematic diagram of the spectrum of the optical signal emitted by the second type of ONT. Figure 4 As shown, the optical signal with sufficient intensity only exists in a shorter wavelength range, that is, the target wavelength range is small. It should be understood that since the ONT using the DFB laser and the ONT adapted to the 50G PON can coexist in wavelength division, it will not affect the deployment of the 50G PON, and there is no need to replace the second type of ONT.

[0055] The specific manners of performing photoelectric conversion on the OLT and obtaining spectral characteristics are introduced below in combination with different embodiments.

[0056] Embodiment 1: The first optical signal is converted into n-channel electrical signals by means of an optical splitter + an optical filter + a photodetector (PD).

[0057] Figure 5 Schematic diagram of the first implementation of the OLT photoelectric conversion in the embodiment of the present application. Figure 5 As shown, the OLT includes a splitter 201, n optical filters 202 (including optical filter 1-optical filter n) and n PDs 203 (including PD1-PDn), where n is an integer greater than 1. As an example, the splitter 201, the n optical filters 202 and the n PDs 203 are integrated on a silicon photonic chip. Specifically, the splitter 201 is used to split the first optical signal to obtain n sub-optical signals, and the n sub-optical signals are transmitted to the n optical filters 202 one by one. The n optical filters 202 are used to filter the n sub-optical signals respectively, wherein the n optical filters 202 are optical filters of n different bands, and the filtered n sub-optical signals are distributed in n bands respectively. The n PDs 203 are used to perform photoelectric conversion on the filtered n sub-optical signals to obtain n electrical signals.

[0058] Figure 6 FIG. 1 is a schematic diagram of n optical signals distributed in n bands in an embodiment of the present application. Figure 6 As shown, as an example, the wavelength coverage of the n bands includes 1260nm to 1360nm. The n optical filters may not be made into ideal bandpass filters, and the filtering bands of the optical filters of adjacent bands are allowed to overlap slightly.

[0059] It should be noted that the OLT performs power detection on the n electrical signals after the photoelectric conversion to determine the spectral characteristics of the first optical signal in the n bands. Furthermore, the OLT determines whether the ONT is a first-type ONT or a second-type ONT by analyzing the number of target bands in the n bands, wherein the target band refers to a band in the n bands where the light intensity of the first optical signal is greater than the second threshold. Specifically, the OLT determines whether the number of target bands in the n bands is greater than the third threshold. If so, the ONT is determined to be a first-type ONT using an FP laser. If not, the ONT is determined to be a second-type ONT using a DFB laser.

[0060] Figure 7 FIG. 1 is a schematic diagram of a spectrum of an optical signal emitted by a first type of ONT distributed in n bands. Figure 8 FIG. 1 is a schematic diagram of the spectrum of the optical signal emitted by the second type of ONT distributed in n bands. Figure 7 and Figure 8 As shown, as an example, the value of the third threshold is 1, that is, the optical signal emitted by the second type of ONT has a sufficiently large light intensity only in one band, and the optical signal emitted by the first type of ONT has a sufficiently large light intensity in multiple bands. It should be understood that in actual applications, the third threshold may also have other values, which are not specifically limited here.

[0061] Embodiment 2: Convert the first optical signal into n-channel electrical signals by means of wavelength division multiplexer (WDM) + PD.

[0062] Fig. 9 Schematic diagram of the second implementation of the OLT for photoelectric conversion in the embodiment of the present application. Fig. 9 As shown, the OLT includes a wavelength division multiplexer 301 and n PDs 302 (including PD1-PDn), where n is an integer greater than 1. As an example, the wavelength division multiplexer 301 and the n PDs 302 are integrated on a silicon photonic chip. Specifically, the wavelength division multiplexer 301 is used to demultiplex the first optical signal to obtain n sub-optical signals, and the n sub-optical signals are respectively distributed in n bands. The distribution of the n bands can be as follows: Figure 6 As shown. The n PDs 302 are used to perform photoelectric conversion on the n optical signals to obtain n electrical signals. That is to say, the function implemented by the wavelength division multiplexer 301 in Example 2 is equivalent to the function implemented by the optical splitter 201 and the n optical filters 202 in Example 1. It should be noted that Example 2 can determine the spectral characteristics of the first optical signal in n bands and identify the first type ONT and the second type ONT in a manner similar to Example 1. Please refer to the relevant introduction of Example 1 for details, which will not be repeated here.

[0063] Embodiment 3: The first optical signal is converted into an electrical signal by means of Mach-Zehnder Interferometer (MZI)+PD.

[0064] Fig.10 FIG. 3 is a schematic diagram of a third implementation method of OLT performing photoelectric conversion in an embodiment of the present application. Fig.10 As shown, the OLT includes an optical splitter 401, a delay device 402, a combiner 403 and a PD 404. As an example, the optical splitter 401, the delay device 402, the combiner 403 and the PD 404 are integrated on a silicon photonic chip. Specifically, the optical splitter 401 splits the first optical signal to obtain a first sub-optical signal and a second sub-optical signal. The delay device 402 performs delay processing on the first sub-optical signal. The combiner 403 combines the first sub-optical signal and the second sub-optical signal after the delay processing to obtain a combined optical signal. The PD 404 converts the combined optical signal into an electrical signal.

[0065] In one possible implementation, the delay device 402 is specifically a heater, which changes the transmission delay between the first sub-light signal and the second sub-light signal by heating. In another possible implementation, the delay device is specifically a phase shifter, which changes the transmission delay between the first sub-light signal and the second sub-light signal by phase adjustment. It should be understood that in practical applications, delay devices can also be set on both paths after splitting.

[0066] It should be noted that by setting different delays by the delay device 402, electrical signals under different delays can be obtained. For example, the electrical signal sequence output by the PD 404 includes m electrical signals, and the m electrical signals are obtained by processing according to m different delays, respectively, where m is an integer greater than 1. Then, the OLT performs Fourier transform on the electrical signal sequence to determine the spectral distribution characteristics of the first optical signal, and identifies the type of the ONT by analyzing the spectral distribution characteristics of the first optical signal. The specific method of identifying the type of the ONT can be referred to Figure 2 The related introduction of step 103 to step 105 in the illustrated embodiment will not be repeated here.

[0067] From the above introduction, it can be seen that the OLT converts the first optical signal from the ONT into an electrical signal, and detects the electrical signal to determine the spectral distribution characteristics of the first optical signal. The spectral distribution characteristics show the characteristics of the light intensity of the first optical signal changing with the wavelength. Among them, the wavelength range in which the light intensity in the first optical signal is greater than the second threshold is called the target wavelength range. Furthermore, the OLT determines the type of the ONT by judging whether the target wavelength range is greater than the first threshold. It should be understood that different types of ONTs may be adapted to 50G PON or may not be adapted to 50GPON. Therefore, the OLT can identify the ONT type that is not adapted to 50G PON, thereby avoiding affecting the deployment of 50G PON.

[0068] The above describes the ONT identification method provided in the embodiment of the present application. The following describes the OLT provided in the embodiment of the present application.

[0069] Fig.11 FIG. 1 is a schematic diagram of the structure of an OLT in an embodiment of the present application. Fig.11As shown, the OLT includes: an optical splitter 501, an optical transceiver component 502, an optical processing unit 503 and an electrical processing unit 504. The optical splitter 501 is used to split the optical signal from the ONT to obtain a first optical signal and a second optical signal. The first optical signal is output to the optical processing unit 503, and the second optical signal is output to the optical transceiver component 502. It should be understood that the present application does not limit the specific splitting ratio of the optical splitter 501. Generally, most of the optical signals after splitting are output to the optical transceiver component 502, and a small part of the optical signals are output to the optical processing unit 503. The optical processing unit 503 is used to perform the above Figure 2 The operation of step 101 in the embodiment shown. The electrical processing unit 504 is used to perform the above Figure 2 The operations of step 102 to step 105 in the illustrated embodiment. It should be understood that the electrical processing unit 504 may specifically be a microcontroller unit (MCU).

[0070] As an example, the light processing unit 503 includes the above Figure 5 The optical splitter 201, n optical filters 202 and n PDs 203 in the illustrated embodiment. As another example, the optical processing unit 503 includes the above Fig. 9 The wavelength division multiplexer 301 and n PDs 302 in the illustrated embodiment. As another example, the optical processing unit 503 includes the above Fig.10 The illustrated embodiment includes an optical splitter 401 , a delay device 402 , a combiner 403 and a PD 404 .

[0071] Finally, it should be noted that the above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for identifying an optical network terminal ONT, characterized in that: include: The optical line terminal OLT converts the first optical signal from the ONT into an electrical signal; The OLT detects the electrical signal to determine a spectrum distribution characteristic of the first optical signal; The OLT determines whether a target wavelength range of the first optical signal is greater than a first threshold, wherein the target wavelength range is a wavelength range in which an optical intensity in the first optical signal is greater than a second threshold; If yes, the OLT determines that the ONT is a first type ONT; If not, the OLT determines that the ONT is a second type ONT.

2. The method according to claim 1, characterized in that The laser used by the first type of ONT is a Fabry-Perot FP laser, and the laser used by the second type of ONT is a distributed feedback DFB laser.

3. The method according to claim 1 or 2, characterized in that: The method further comprises: The OLT splits the input optical signal from the ONT to obtain the first optical signal and the second optical signal, wherein the second optical signal is transmitted to the optical transceiver component in the OLT.

4. The method according to any one of claims 1 to 3, characterized in that The OLT converting the first optical signal from the ONT into an electrical signal comprises: The OLT splits the first optical signal to obtain n optical sub-signals, where n is an integer greater than 1; The OLT filters the n optical signals respectively, wherein the n optical signals after filtering are distributed in n bands respectively; The OLT performs photoelectric conversion on the filtered n sub-optical signals to obtain n electrical signals.

5. The method according to any one of claims 1 to 3, characterized in that The OLT converting the first optical signal from the ONT into an electrical signal comprises: The OLT demultiplexes the first optical signal to obtain n optical signals, wherein the n optical signals are respectively distributed in n bands, where n is an integer greater than 1; The OLT performs photoelectric conversion on the n optical sub-signals to obtain n electrical signals.

6. The method according to claim 4 or 5, characterized in that: The OLT detecting the electrical signal to determine the spectral distribution characteristics of the first optical signal includes: The OLT performs power detection on the n electrical signals respectively to determine the spectrum characteristics of the first optical signal in the n bands; The OLT determines whether the target wavelength range of the first optical signal is greater than a first threshold value, including: The OLT determines whether the number of target bands in the n bands is greater than a third threshold, wherein the target band is a band in the n bands where the light intensity of the first optical signal is greater than the second threshold; If yes, the OLT determines that the ONT is a first type ONT; If not, the OLT determines that the ONT is a second type ONT.

7. The method according to any one of claims 4 to 6, characterized in that The wavelength coverage range of the n wavebands includes 1260nm to 1360nm.

8. The method according to any one of claims 1 to 3, characterized in that The OLT converting the first optical signal from the ONT into an electrical signal comprises: The OLT splits the first optical signal to obtain a first sub-optical signal and a second sub-optical signal; The OLT performs delay processing on the first sub-optical signal; The OLT combines the delayed first optical sub-signal and the second optical sub-signal to obtain a combined optical signal; The OLT converts the combined optical signal into an electrical signal.

9. The method according to claim 8, characterized in that The OLT detecting the electrical signal to determine the spectral distribution characteristics of the first optical signal includes: The OLT performs Fourier transform on the electrical signal sequence to determine the spectral distribution characteristics of the first optical signal, wherein the electrical signal sequence includes m electrical signals, m is an integer greater than 1, the m electrical signals are converted from m combined optical signals, the m combined optical signals are obtained by combining m delayed first sub-optical signals with the second sub-optical signal respectively, and the m delayed first sub-optical signals are obtained by the OLT performing delay processing on the first sub-optical signal according to m delays.

10. The method according to claim 8 or 9, characterized in that: The OLT performing delay processing on the first sub-optical signal includes: The OLT performs delay processing on the first sub-optical signal through a heater or a phase shifter.

11. An optical line terminal OLT, characterized in that: include: Optical processing unit and electrical processing unit; The optical processing unit is used to: convert the first optical signal from the optical network terminal ONT into an electrical signal; The electrical processing unit is used to: detect the electrical signal to determine the spectral distribution characteristics of the first optical signal; Determining whether a target wavelength range of the first optical signal is greater than a first threshold, wherein the target wavelength range is a wavelength range in which an optical intensity of the first optical signal is greater than a second threshold; If yes, it is determined that the ONT is a first type ONT; If not, it is determined that the ONT is a second type ONT.

12. The OLT according to claim 11, characterized in that: The laser used by the first type of ONT is a Fabry-Perot FP laser, and the laser used by the second type of ONT is a distributed feedback DFB laser.

13. The OLT according to claim 11 or 12, characterized in that: The OLT also includes a first optical splitter and an optical transceiver assembly; The optical splitter is used to split the input optical signal from the ONT to obtain the first optical signal and the second optical signal, wherein the first optical signal is transmitted to the optical processing unit, and the second optical signal is transmitted to the optical transceiver component.

14. The OLT according to any one of claims 11 to 13, characterized in that: The optical processing unit comprises a second optical splitter, n optical filters and n photodetectors PD, wherein n is an integer greater than 1; The second optical splitter is used to split the first optical signal to obtain n optical sub-signals, and the n optical sub-signals are transmitted to the n optical filters in a one-to-one correspondence; The n optical filters are used to filter the n optical sub-signals respectively, wherein the n optical sub-signals after filtering are distributed in n bands respectively; The n PDs are used to perform photoelectric conversion on the n filtered sub-optical signals to obtain n electrical signals.

15. The OLT according to any one of claims 11 to 13, characterized in that: The optical processing unit includes a wavelength division multiplexer WDM and n PDs, wherein n is an integer greater than 1; The WDM is used to demultiplex the first optical signal to obtain n optical signals, wherein the n optical signals are distributed in n bands respectively; The n PDs are used to perform photoelectric conversion on the n optical sub-signals to obtain n electrical signals.

16. The OLT according to claim 14 or 15, characterized in that: The electrical processing unit is specifically used for: Performing power detection on the n electrical signals respectively to determine the spectral characteristics of the first optical signal in the n wavebands; Determine whether the number of target bands in the n bands is greater than a third threshold, wherein the target band is a band in the n bands where the light intensity of the first optical signal is greater than the second threshold; If yes, it is determined that the ONT is a first type ONT; If not, it is determined that the ONT is a second type ONT.

17. The OLT according to any one of claims 14 to 16, characterized in that: The wavelength coverage range of the n wavebands includes 1260nm to 1360nm.

18. The OLT according to any one of claims 11 to 13, characterized in that: The optical processing unit includes a third optical splitter, a delay device, a combiner and a PD; The third optical splitter is used to split the first optical signal to obtain a first sub-optical signal and a second sub-optical signal; The delay device is used to perform delay processing on the first sub-optical signal; The combiner is used for combining the delayed first optical sub-signal and the second optical sub-signal to obtain a combined optical signal; The PD is used to convert the combined optical signal into an electrical signal.

19. The OLT according to claim 18, characterized in that: The electrical processing unit is specifically used for: Performing Fourier transform on the electrical signal sequence to determine the spectral distribution characteristics of the first optical signal, wherein the electrical signal sequence includes m electrical signals, where m is an integer greater than 1, and the m electrical signals are converted from m combined optical signals, and the m combined optical signals are obtained by combining m delayed first sub-optical signals with the second sub-optical signal respectively, and the m delayed first sub-optical signals are obtained by the OLT performing delay processing on the first sub-optical signal according to m delays.

20. The OLT according to claim 18 or 19, characterized in that: The time delay device is a heater or a phase shifter.

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