CN113346955B

CN113346955B - ONU module used in passive optical network above 50G

Info

Publication number: CN113346955B
Application number: CN202110896882.4A
Authority: CN
Inventors: 刘能; 蒋昌明; 魏志坚; 郑波; 过开甲; 孙鼎; 张伟
Original assignee: Jiangxi Sont Communication Technology Co ltd; Shenzhen Xunte Communication Technology Co ltd
Current assignee: Jiangxi Sont Communication Technology Co ltd; Shenzhen Xunte Communication Technology Co ltd
Priority date: 2021-08-05
Filing date: 2021-08-05
Publication date: 2021-12-17
Anticipated expiration: 2041-08-05
Also published as: CN113346955A

Abstract

The invention relates to an ONU module used in a passive optical network above 50G, which comprises: the system comprises a golden finger inserted on a system board, a burst uplink transmitting channel above 25G, a continuous downlink receiving channel above 50G and a BOSA optical assembly; the transmission channel comprises: the DFB driver chip and the core package coaxial TO assembly are arranged on the substrate; the DFB driving chip controls the light emission of the DFB according to a BEN signal provided by the system board, so that the ONU module emits NRZ signals of more than 25G in a burst mode in a time slice designated by the OLT module, and the receiving channel comprises: coaxially packaging TO and DSP; the coaxial package TO receives optical signals received by the BOSA optical assembly and converts the optical signals into PAM4 electrical signals with the power of more than 50G, and the DSP is used for decomposing the PAM4 electrical signals into two paths of NRZ RX signals with the power of more than 25G and inputting the NRZ RX signals into the system board. The ONU module can effectively increase the downlink speed of the access network from 10G to 50G and increase the uplink speed from 10G to 25G at the client.

Description

ONU module used in passive optical network above 50G

Technical Field

The present invention relates to the field of Optical communication technology, and in particular, to an ONU (Optical Network Unit) module for use in a passive Optical Network of 50G or more.

Background

At present, operators and manufacturers in China have an important position in the global optical access network industry. The current networks are in the transition phase to 10G PONs (Passive Optical networks) and are reaching a critical opportunity for the development and selection of next-generation PON technologies.

In the aspect of rate, there are choices in 25G, 50G, 100G and the like in the technical selection of the next-generation PON, the difference between 25G and 10G is too small, the difficulty of 100G is too large, 50G is relatively moderate, and the rule is basically consistent with the first 4-fold improvement (2.5G to 10G), and the 50G PON is suitable as the evolution technology of the 10G PON.

At present, manufacturers of PON industry chains in the industry increasingly support the development of 50G PON, and after 10G PON is deployed in a large scale, 50G PON is selected as a next-generation PON technology, and researches such as 50G PON wavelength planning are also promoted.

Under the co-efforts of Chinese operators and equipment vendors, the subject group of ITU-T officially started the standards of 50G single-wavelength PON in 2 months in 2018. The selection of 50G TDM PON (single channel 50G PON) as the next-generation PON technology is already known in the industry for deployment around 2025.

What is not negligible, the technical challenge of the PMD (Polarization Mode Dispersion) layer of the 50G PON is great, and the problems of high Dispersion cost, 50G optical devices and high power budget caused by high-speed signals need to be solved in an important way.

Therefore, how to provide an ONU module for implementing a passive optical network of 50G or more by using the existing optical communication chip system is a technical problem which needs to be solved at present.

Disclosure of Invention

Technical problem to be solved

In view of the above disadvantages and shortcomings of the prior art, the present invention provides an ONU module for use in a passive optical network of 50G or more.

(II) technical scheme

In order to achieve the purpose, the invention adopts the main technical scheme that:

in a first aspect, an embodiment of the present invention provides an ONU module for use in a passive optical network of 50G or above, where the ONU module includes: the system comprises a golden finger inserted on a system board, a burst uplink transmitting channel above 25G, a continuous downlink receiving channel above 50G and a single-fiber bidirectional BOSA optical assembly;

the transmitting channel and the receiving channel are respectively communicated with the golden finger and the BOSA optical assembly;

the burst uplink transmission channel comprises: a DFB driver chip, a core package coaxial TO package,

the DFB driving chip controls the light emission of the DFB according TO a BEN signal provided by a system board, so that the ONU module emits NRZ signals above 25G in a burst mode in a time slice appointed by the OLT module, and the NRZ signals above 25G pass through the core package coaxial TO assembly TO emit light signals through the BOSA optical assembly;

the continuous downlink receiving channel comprises: coaxially packaging TO and DSP;

the coaxial package TO receives optical signals received by the BOSA optical assembly and converts the optical signals into PAM4 electrical signals above 50G, and the DSP is used for decomposing the PAM4 electrical signals above 50G into two paths of NRZ RX signals above 25G TO be input TO the system board through a golden finger.

Optionally, the ONU module further includes: a TX burst control module for controlling the transmission of a signal,

and the TX burst control module is used for bypassing the DFB bias current and the modulation current output by the DFB driving chip through the high-speed radio frequency triode so as to realize a BEN high-level enabling device, a DFB normal emission optical signal, a BEN low-level device and a DFB no emission optical signal.

Optionally, the gold finger is used to support two 25G signal links for receiving signals, and one 25G signal link for transmitting signals.

Optionally, the core package coaxial TO assembly comprises: a 1270nm DFB coaxial packaging device with a TEC temperature control function;

the coaxial package TO includes: an APD-TIA coaxial packaging device integrally packaging PAM4 of more than 50G, wherein TIA is continuous 50G PAM4 TIA;

the DSP is 50G PAM4 DSP.

Optionally, the ONU module further includes:

and the MCU control units are all connected with the golden finger, the burst uplink transmitting channel, the continuous downlink receiving channel and the BOSA optical assembly and are used for acquiring working state monitoring and indicating signals of all assemblies in the ONU module, interacting with the system board and realizing management of all assemblies in the ONU module.

Optionally, the ONU module further includes: the power supply component is used for supplying power to each component in the ONU module according to respective time sequence;

the power supply assembly includes: the circuit comprises a slow starting circuit, a boosting circuit and a voltage reduction circuit.

Optionally, the DFB driving chip includes: a CDR and DFB drive unit;

the CDR is used for eliminating the signal jitter of the NRZ signal above 25G through a frequency locking and phase locking function, and the DFB driving unit is used for outputting continuous DFB bias current and modulation current.

In a second aspect, an embodiment of the present invention further provides a method for operating an ONU module based on the first aspect, where the method includes:

the MAC chip on the system board transmits continuous NRZ signals of more than 25G to the DFB driving chip through a golden finger, the CDR in the DFB driving chip eliminates the jitter of the NRZ signals of more than 25G through the frequency locking and phase locking functions, and then the DFB driving unit outputs continuous DFB bias current and modulation current,

and the TX burst control module receives a BEN signal sent by a system board, and bypasses continuous DFB bias current and modulation current output by the DFB driving chip during the low level period of the BEN to realize burst emission of forward light of the DFB during the high level period of the BEN signal.

Optionally, the method further comprises:

an SC optical port of the BOSA optical component refracts input 1342nm received light TO coaxial packaging TO of more than 50G;

the coaxial package TO converges the 1342nm received light TO a 50G APD-TIA in the coaxial package TO through an internal converging lens so as TO convert the 1342nm optical signal into a 50G PAM4 electric signal and transmit the electric signal TO a DSP,

the DSP decodes, locks frequency and phase, decomposes the single-path 50G PAM4 electric signal into two paths of 25-26G NRZ electric signals, and transmits the two paths of 25-26G NRZ electric signals to the MAC chip on the system board through a golden finger.

Optionally, the method further comprises:

the automatic sampling and holding circuit in the ONU module is used for measuring and calculating the backlight current of the DFB in the burst light emitting period, so that the MCU control unit can measure the backlight current by converting the voltage, the burst emitted light power is obtained, and the burst emitted light power is monitored and reported to a system board;

carrying out continuous mirror image on an APD optical circuit in the coaxial packaging TO through the APD RSSI, converting the APD optical circuit into voltage for the MCU control unit TO measure, obtaining received optical power, and monitoring and reporting the received optical power TO a system board;

and reading the bias current IBIAS of the DFB by an internal monitoring register of the DFB driving chip, and reading and reporting the DFB IBIAS value by the MCU through IIC communication.

(III) advantageous effects

The ONU module above 50G can effectively increase the downlink speed of the access network from 10G to 50G and increase the uplink speed from 10G to 25G at the client;

the ONU module reuses the existing mature optical communication chip system and the key electric chip scheme, and adopts 1342nm RX 50G PAM4 coding and 1270nm TX 25G NRZ;

the ONU module of the invention can complete the production and the manufacture of the module and an optical device without upgrading the precision of the processing and manufacturing equipment of the existing industrial chain, thereby realizing the speed upgrade of the access network.

Drawings

Fig. 1 is a schematic structural diagram of an ONU module used in a passive optical network of over 50G according to an embodiment of the present invention;

fig. 2 is a schematic diagram of an ONU module according to another embodiment of the present invention.

Detailed Description

For the purpose of better explaining the present invention and to facilitate understanding, the present invention will be described in detail by way of specific embodiments with reference to the accompanying drawings.

Typically, an optical node is provided that includes an interconnection between downstream optical receivers, upstream optical transmitters, and a plurality of bridged amplifier network monitoring devices.

The ONU module is used for: 1) selecting to receive broadcast data sent by an OLT; 2) responding to a ranging and power control command sent by the OLT, and performing corresponding adjustment; 3) and buffering the Ethernet data of the user and transmitting the Ethernet data in an uplink direction in a transmission window allocated by the OLT.

As shown in fig. 1, the ONU module used in the passive optical network over 50G of the present embodiment may include: the system comprises a golden finger inserted on a system board, a burst uplink transmitting channel above 25G, a continuous downlink receiving channel above 50G and a single-fiber bidirectional BOSA optical assembly;

the transmitting channel and the receiving channel in this embodiment are respectively communicated with the gold finger and the BOSA optical assembly. The gold fingers are used to transmit electrical signals from the system board and the BOSA optical subassembly is used to receive and transmit optical signals from the long-distance optical fiber. The electric signal received by the golden finger and used for transmission is processed by the transmitting channel and transmitted to the BOSA optical assembly for sending, and the optical signal received by the BOSA optical assembly is processed by the receiving channel and transmitted to the system board by the golden finger.

The gold finger in this embodiment may be a gold finger packaged by adopting the standard of QSFP28, and in this embodiment, the meaning of different PIN PINs is redefined to implement TX (transmission), RX (reception) high-speed signal link and PON system management function PIN PINs.

For example, the conventional gold finger includes four 25G transmission paths and four 25G reception paths, and in this embodiment, one 25G transmission path, two 25G reception paths and other control signal pins are defined, so as to support electrical signal transmission of 25-26G NRZ (non return to zero code).

The BOSA optical assembly in this embodiment includes: 1270nm25G continuous DFB (Distributed Feedback Laser) with TEC (Thermo Electric Cooler), receiving APD-TIA (APD-avalanche photodiode, Trans-Impedance Amplifier) using 50G PAM4 (4 Pulse Amplitude Modulation).

The burst uplink transmission channel includes: DFB driver chip, core package coaxial TO package (i.e.tx TO),

a signal of 25G NRZ TX CH1 passing through a gold finger as shown in fig. 1 is input TO the DFB driver chip, and the DFB driver chip controls the light emission of the DFB according TO the BEN signal provided by the system board, so that the ONU module bursts above 25G NRZ (Non Return Zero Code) signal within a time slice designated by the OLT module, and the burst above 25G NRZ signal passes through the core package coaxial TO package TO emit a light signal through the BOSA optical package.

The DFB driving chip adopts continuous 25G CDR and DFB driving units, works in a continuous 26.5625G NRZ mode, and the system board MAC chip provides BEN signals to control the light emission of the DFB, so that the function of burst transmission of data transmission by the ONU module in a corresponding time slice is realized. The CDR is used for eliminating the signal jitter of the NRZ signal above 25 through a frequency locking and phase locking function, and the DFB driving unit is used for outputting continuous DFB bias current and modulation current.

In a specific application, the burst uplink transmission channel further includes: a TX burst control module for controlling the transmission of a signal,

The continuous downlink receiving channel comprises: coaxially subpackaging TO (namely RX TO) and 50G PAM4 DSP;

the coaxial split TO receives optical signals received by the BOSA optical component and converts the optical signals into PAM4 electric signals with the power of more than 50G, and the DSP is used for decomposing the PAM4 electric signals with the power of more than 50G into two paths of NRZ RX signals with the power of more than 25G (such as 25G NRZ RX CH1 signals and 25G NRZ RX CH2 signals shown in figure 1) TO be input TO the system board through golden fingers.

The DSP can adopt an existing DSP PAM4 (4 Pulse Amplitude Modulation: four-Amplitude Modulation) receiving unit, a 50G PAM4 receiving channel is decomposed into two 25-26G NRZ channels in the DSP, and finally the two channels are transmitted to a system board MAC chip through a golden finger.

In this embodiment, the core package coaxial TO package includes: 1270nm DFB (Distributed Feedback Laser) coaxial package device with TEC (Thermo Electric Cooler) temperature control function.

The coaxial split TO includes: and the APD-TIA coaxial packaging device integrally packages PAM4 above 50G, and the TIA is a continuous 50G PAM4 TIA.

The coaxial package TO and the core package assembly described above reuse the existing mature optical communication chip system, and this implementation is only TO illustrate the internal structure thereof, and is not limited thereto, and is configured according TO the actual needs.

The ONU module above 50G can effectively increase the downlink speed of the access network from 10G to 50G and the uplink speed from 10G to 25G at the client.

As shown in fig. 2, fig. 2 shows a specific structure of an ONU module, which includes the structures shown in fig. 1, and further includes: the device comprises an MCU control unit, a power supply component, a peripheral circuit (such as APD RSSI) and a TEC control unit;

the MCU control units are connected with the golden finger, the burst uplink transmitting channel, the continuous downlink receiving channel and the BOSA optical assembly and are used for acquiring working state monitoring and indicating signals of all assemblies in the ONU module, interacting with a system board and realizing management of all assemblies in the ONU module.

The power supply component is used for supplying power to each component in the ONU module according to respective time sequence; the power supply assembly includes: the circuit comprises a slow starting circuit, a boosting circuit and a voltage reduction circuit.

The power supply assembly of the present embodiment may include: a 3.3V slow start circuit, an APD BOOST circuit (such as APD BOOST), and a voltage reduction circuit. The APD boosting circuit is used for boosting 3.3V to the voltage required by the APD, and the voltage reducing circuit can be used for reducing 3.3V to 1.8V or 0.8V to supply power for the DSP and the like.

In practical applications, the power supply component may further include other existing components that can provide power, and this embodiment is not limited to this and may be configured according to actual needs. Each circuit in the power supply module can supply power to the corresponding unit circuit according to the specified time sequence.

Typically, the APD boost circuit can boost 3.3V to around 22V to provide the appropriate operating voltage for the APD detector. The APD detector can be an APD detector in an APD-TIA in a TO (coaxial packaging) device.

And the APD RSSI is used for mirroring APD photocurrent, measuring and calculating the working current of an APD detector, and monitoring the received optical power by combining the MCU.

TX SD (burst emitted light signal indication) & TX POWER MON (emitted light POWER monitoring): by means of monitoring the backlight current, the burst emission light power of the DFB is monitored, and meanwhile, the burst working state indication of the DFB is reported to a system board.

The TEC control unit can control the working temperature under the 1270nm DFB laser, so that the DFB output wavelength is stabilized at 1270 nm.

According to another aspect of the embodiments of the present invention, an embodiment of the present invention further provides a method for operating the ONU module, where the method includes:

the transmission flow of the transmission signal channel:

a MAC chip on a system board transmits continuous 25-26G NRZ signals to a DFB driving chip through a golden finger, a CDR in the DFB driving chip eliminates signal jitter caused by a high-speed link through a frequency locking and phase locking function, and then an integrated DFB driving unit in the DFB outputs continuous DFB bias current and modulation current.

The TX burst control module receives a BEN signal sent by a system board, and bypasses continuous DFB bias current and modulation current output by the DFB driving chip during the BEN low level period, so that burst emission of forward light of the DFB during the BEN signal high level period is realized, and meanwhile, the TEC driving unit controls the temperature of 1270nm DFB in the TO (TX TO) of the coaxial package, so that the emission parameter constancy of the optical module in the whole commercial temperature grade range is realized.

Signal receiving process of the received signal channel:

the 45 degree slide in the BOSA optical package refracts 1342nm received light input from the SC optical port TO a 50G core package coaxial TO package (RX TO),

the 50G RX TO receives light at 1342nm and converges the light TO 25G APD-TIA through a converging lens on the TO, wherein the TIA is continuous 50G PAM4 TIA, thereby realizing that the 1342nm light signal is converted into an electric signal, and the electric signal is transmitted TO 50G PAM4DSP on the PCB inside the module through a soft belt PCB (namely welding a soft board of the RX TO between the PCBs), on one hand, the DSP improves the transmission sensitivity through resolving a check code, on the other hand, the DSP on the other hand, through decoding, locking frequency and phase, the 50G PAM4 electric signal of a single path is decomposed into two paths of 25-26G NRZ electric signals, and finally, the MAC chip on the system board is transmitted through a golden finger.

Digital monitoring and reporting of modules:

temperature monitoring: accurate temperature monitoring is realized through a special temperature monitoring chip (temperature control component) for the MCU control unit plug-in IIC communication.

Power supply voltage: internal supply voltage monitoring integrated within the MCU control unit is used.

Burst emitted optical power: and measuring and calculating the backlight current of the DFB in the burst light emitting period through an automatic sampling and holding circuit of TX SD & TX POWER MON, converting the voltage and holding the voltage for the MCU to measure, and finally realizing the monitoring and reporting of the burst emitted light POWER through calibration data in the ONU module.

And receiving optical power reporting: carrying out continuous mirror image on an optical circuit of the APD through the APD RSSI, converting the optical circuit into voltage for MCU to measure, and finally realizing monitoring and reporting of received optical power through internal calibration parameter measurement and calculation. And the report of the DFB IBIAS is realized directly by reading the internal monitoring register of the DFB driving chip.

Power supply: the 3.3V main power supply enters from the golden finger, and the current jitter when the module is inserted is eliminated through the slow starting circuit.

After the MCU finishes the initial start, the control chips in each DC-DC voltage reduction circuit are enabled to start in sequence, 3.3V is reduced to 1.8V,0.8V and the like required by other chips, the APD high voltage is boosted through the APD BOOST unit circuit, and after the normal APD voltage is monitored, the APD high voltage is connected to the APD detector, so that the voltage protection of 25G APDs is realized.

The ONU module in this embodiment can effectively increase the downlink rate of the access network from 10G to 50G and increase the uplink rate from 10G to 25G at the client;

the ONU module can complete the production and the manufacture of the module and an optical device without upgrading the precision of processing and manufacturing equipment of the existing industrial chain, and realizes the speed upgrade of an access network.

It should be noted that in the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps not listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In the claims enumerating several means, several of these means may be embodied by one and the same item of hardware. The use of the terms first, second, third and the like are for convenience only and do not denote any order. These words are to be understood as part of the name of the component.

Furthermore, it should be noted that in the description of the present specification, the description of the term "one embodiment", "some embodiments", "examples", "specific examples" or "some examples", etc., means that a specific feature, structure, material or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, the claims should be construed to include preferred embodiments and all changes and modifications that fall within the scope of the invention.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention should also include such modifications and variations.

Claims

1. An ONU module for use in a passive optical network of 50G or more, the ONU module comprising: the system comprises a golden finger inserted on a system board, a burst uplink transmitting channel above 25G, a continuous downlink receiving channel above 50G and a single-fiber bidirectional BOSA optical assembly; the ONU module is used for selectively receiving the broadcast data sent by the OLT and responding to the ranging and power control command sent by the OLT for adjustment,

the DFB driving chip adopts continuous 25G CDR and DFB driving units, works in a continuous 26.5625G NRZ mode, and controls the light emission of the DFB by providing a BEN signal through an MAC chip on a system board, so that the function of burst emission and data transmission of the ONU module in a corresponding time slice is realized; the CDR is used for eliminating signal jitter of NRZ signals above 25G through a frequency locking and phase locking function, and the DFB driving unit is used for outputting continuous DFB bias current and modulation current;

the coaxial package TO receives optical signals received by the BOSA optical assembly and converts the optical signals into PAM4 electrical signals above 50G, and the DSP is used for decomposing the PAM4 electrical signals above 50G into two paths of NRZ RX signals above 25G so as TO be input TO the system board through a golden finger;

the ONU module further comprises: a TX burst control module for controlling the transmission of a signal,

the TX burst control module is used for bypassing the DFB bias current and the modulation current output by the DFB driving chip through the high-speed radio frequency triode so as to realize a BEN high-level enabling device, a DFB normal emission optical signal, a BEN low-level device and a DFB no emission optical signal;

the ONU module further comprises:

2. The ONU module of claim 1, wherein the gold finger is used to support two 25G receive signal links and one 25G transmit signal link.

3. The ONU module of claim 1, wherein the core-on-package coaxial TO component comprises: a 1270nm DFB coaxial packaging device with a TEC temperature control function;

the coaxial package TO includes: the APT-TIA coaxial packaging device integrally packages PAM4 more than 50G, and the TIA is a continuous 50G PAM4 TIA;

the DSP is 50G PAM4 DSP.

4. The ONU module of claim 1, wherein the ONU module further comprises: the power supply component is used for supplying power to each component in the ONU module according to respective time sequence;

5. A method for operating an ONU module according to claim 1, comprising:

6. The method of operation of claim 5, further comprising:

7. The method of operation of claim 5 or 6, further comprising: