CN116915355B

CN116915355B - Optical network unit ONU and ONU configuration method

Info

Publication number: CN116915355B
Application number: CN202311136350.6A
Authority: CN
Inventors: 胡兆祥; 王瑾; 徐启斌; 董建峰
Original assignee: Wuhan Yangtze Optical Technology Co ltd
Current assignee: Wuhan Yangtze Optical Technology Co ltd
Priority date: 2023-09-05
Filing date: 2023-09-05
Publication date: 2023-12-05
Anticipated expiration: 2043-09-05
Also published as: CN116915355A

Abstract

The invention provides an Optical Network Unit (ONU) and an ONU configuration method, which relate to the technical field of optical communication, wherein the ONU comprises: the device comprises a filter module, a PON module, an adjustable laser module and an MAC module; the filter module is respectively connected with the PON module and the adjustable laser module and is used for filtering the optical signals input into the ONU and inputting the optical signals with corresponding wavelengths into the PON module or the adjustable laser module; the MAC module is respectively connected with the PON module and the adjustable laser module and is used for carrying out transmission processing on digital signals and controlling the adjustable laser module to switch working wavelength according to configuration information sent by the PON module; the PON module is used for negotiating the WDM working mode and the capability with the OLT and receiving the configuration information sent by the OLT; the tunable laser module is used for completing the sending and receiving functions of the uplink and downlink optical signals in the DWDM working mode.

Description

Optical network unit ONU and ONU configuration method

Technical Field

The present invention relates to the field of optical communications technologies, and in particular, to an optical network unit ONU and an ONU configuration method.

Background

Wavelength division multiplexing passive optical networks (Wavelength Division Multiplexing-Passive Optical Network, WDM-PON) enable point-to-point connections that provide each user with a proprietary wavelength, and are widely recognized as a representative technology for future broadband access. The key points of WDM-PON are: low cost, "colorless" optical network units (Optical Network Unit, ONUs) are required to avoid increased installation, operation, and maintenance costs associated with wavelength selective devices.

The colorless technology of the traditional WDM ONU is complex in technical processing when being compatible with a Gigabit passive optical network (Gigabit Passive Optical Network, GPON)/10 Gigabit passive optical network (10-Gigabit-capable Passive Optical Network, XGPON) and a multi-wavelength scheme of WDM, and generally needs to set up an array waveguide grating (Arrayed Waveguide Grating, AWG) for wavelength division multiplexing between the ONU and an optical distribution network (Optical Distribution Network, ODN), and has certain transformation cost for the traditional GPON/XGPON and other networks.

Disclosure of Invention

Aiming at the problems existing in the prior art, the invention provides an Optical Network Unit (ONU) and an ONU configuration method.

In a first aspect, the present invention provides an optical network unit ONU, comprising:

the system comprises a filter module, a Passive Optical Network (PON) module, an adjustable laser module and a Medium Access Control (MAC) module;

the filter module is respectively connected with the PON module and the adjustable laser module and is used for filtering the optical signals input into the ONU and inputting the optical signals with corresponding wavelengths into the PON module or the adjustable laser module;

the MAC module is respectively connected with the PON module and the adjustable laser module and is used for carrying out transmission processing on digital signals and controlling the adjustable laser module to switch working wavelength according to configuration information sent by the PON module;

the PON module is used for negotiating the working mode and the capacity of the wavelength division multiplexing WDM with the optical line terminal OLT, receiving the configuration information sent by the OLT and sending the configuration information to the MAC module;

the adjustable laser module comprises a wavelength-adjustable laser and is used for completing the functions of sending and receiving uplink and downlink optical signals in a dense wavelength division multiplexing DWDM working mode.

In some embodiments, the operating wavelength range of the filter module includes 1310nm wavelength and 1490nm wavelength;

after filtering the optical signal input to the ONU, inputting an optical signal with a corresponding wavelength to the PON module, including:

and inputting the optical signals with 1310nm or 1490nm wavelengths obtained after filtering into the PON module.

In some embodiments, the operating wavelength range of the filter module includes a 1525nm to 1565nm band;

after filtering the optical signal input to the ONU, inputting an optical signal with a corresponding wavelength to the tunable laser module, including:

and inputting the optical signals with wave bands of 1525nm to 1565nm obtained after filtering into the tunable laser module.

In some embodiments, the performing the transmission processing of the digital signal includes:

and carrying out transmission processing on the digital signals based on the parallel-serial conversion or serial-parallel conversion SERDES channel with fixed rate and the SERDES channel with configurable rate.

In some embodiments, the MAC module is further configured to configure a transmission rate of the rate-configurable SERDES channel according to the configuration information sent by the PON module.

In some embodiments, the MAC module is further configured to periodically send wavelength calibration feedback information to the tunable laser module when the ONU is in a WDM operation phase, where the wavelength calibration feedback information is used for wavelength locking by the tunable laser module.

In some embodiments, the fixed rate SERDES channel has a transmission rate of 2.5Gbps.

In some embodiments, the transmission rate of the rate-configurable SERDES channel comprises one or more of 1Gbps, 10Gbps, 25Gbps, 40 Gbps.

In a second aspect, the present invention further provides an optical network unit ONU configuration method, applied to the ONU in the first aspect, including:

after accessing a wavelength division multiplexing passive optical network WDM-PON, the filter module filters an optical signal input to the ONU, and the optical signal with 1310nm or 1490nm wavelength obtained after the filtering is input to the PON module for network registration by the PON module;

after network registration is completed, the PON module negotiates WDM working mode and capability with the OLT, receives the configuration information sent by the OLT, and sends the configuration information to the MAC module;

and the MAC module sends an instruction for switching the working wavelength to the adjustable laser module according to the configuration information, and configures the transmission rate of the SERDES channel with the configurable rate.

In some embodiments, the method further comprises:

the MAC module periodically transmits wavelength calibration feedback information to the adjustable laser module when the ONU is in a WDM working phase;

and the adjustable laser module performs wavelength locking according to the calibration feedback information of the wavelength.

The optical network unit ONU and the ONU configuration method provided by the invention have the advantages that the filter module, the adjustable laser module and the MAC module are arranged, the functions of filtering a plurality of downlink wavelengths of the OLT and the like are completed in the ONU, so that the multi-wavelength scheme of GPON/XGPON and WDM can be compatible without erecting AWG wave decomposition multiplexing between the ONU and the ODN, the cost of the WDM-PON is reduced, the adjustable laser module is controlled by a module related to digital control to dynamically and adaptively switch the wavelengths, and the requirements on the performance and the process of the adjustable laser are reduced, thereby the manufacturing cost of the ONU can be reduced.

Drawings

In order to more clearly illustrate the invention or the technical solutions in the related art, the following description will briefly explain the drawings used in the embodiments or the related art description, and it is obvious that the drawings in the following description are some embodiments of the invention, and other drawings can be obtained according to the drawings without inventive effort for those skilled in the art.

Fig. 1 is a schematic structural diagram of an optical network unit ONU according to the present invention;

fig. 2 is a flow chart of an optical network unit ONU configuration method provided in the present invention;

fig. 3 is an exemplary diagram of an ONU provided in the present invention applied to a WDM-PON.

Detailed Description

The term "and/or" in the present invention describes an association relationship of association objects, which means that three relationships may exist, for example, a and/or B may mean: a exists alone, A and B exist together, and B exists alone. The character "/" generally indicates that the context-dependent object is an "or" relationship.

The term "plurality" in the present invention means two or more, and other adjectives are similar thereto.

The terms "first," "second," and the like, herein, are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the invention are capable of operation in sequences other than those illustrated or otherwise described herein, and that the "first" and "second" distinguishing between objects generally are not limited in number to the extent that the first object may, for example, be one or more.

For the purpose of making the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is apparent that the described embodiments are some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Fig. 1 is a schematic structural diagram of an optical network unit ONU provided in the present invention, as shown in fig. 1, where the ONU includes: a filter module 110, a PON module 120, a tunable laser module 130, and a medium access control (Media Access Control, MAC) module 140.

The filter module 110 is connected to the PON module 120 and the tunable laser module 130, and is configured to filter an optical signal (WDM longitudinal wave) input to the ONU, and then input the optical signal with a corresponding wavelength to the PON module 120 or the tunable laser module 130.

The MAC module 140 is respectively connected to the PON module 120 and the tunable laser module 130, and is configured to perform transmission processing of digital signals, and control the tunable laser module 130 to perform switching of an operating wavelength according to configuration information sent by the PON module 120.

The PON module 120 is configured to negotiate WDM operation mode and capability with an optical line terminal (optical line terminal, OLT), receive configuration information sent by the OLT, and send the configuration information to the MAC module 140.

The tunable laser module 130 includes a wavelength tunable laser, which is used to perform the functions of sending and receiving uplink and downlink optical signals in the dense wavelength division multiplexing (Dense Wavelength Division Multiplexing, DWDM) operation mode.

Specifically, PON module 120, i.e., a PON optical module, may be, for example, a standard GPON or XGPON module. In some embodiments, it may be compatible with standard ITU-t.983 functions (ITU-t.983 is a fiber optic access network standard established by the International Telecommunications Union (ITU)) to enable compatibility with legacy carrier GPON or ethernet passive optical network (Ethernet Passive Optical Network, EPON).

The tunable laser module 130 includes a wavelength tunable laser, which can perform the function of sending and receiving the uplink and downlink optical signals in the DWDM mode of operation.

The filter module 110 includes a filter, which may be used to perform filtering processing on an optical signal, and the specific type of the filter is not limited in the present invention, so long as the function of the filter module 110 in the present invention can be implemented. In some embodiments, the filters in the filter module 110 may be thin film filters.

In some embodiments, PON module 120 and tunable laser module 130 correspond to different operating wavelengths, respectively. For example, the operating wavelength of PON module 120 is fixed and the operating wavelength of tunable laser module 130 is tunable.

In some embodiments, the operating wavelengths of PON module 120 are 1310nm and 1490nm.

In some embodiments, the tunable laser module 130 operates in the 1525nm-1565nm band (c-band).

The filter module 110 may select an appropriate filter according to the operating wavelengths of the PON module 120 and the tunable laser module 130, so as to filter the WDM longitudinal wave input to the ONU, and then input the optical signal with the corresponding wavelength to the PON module 120 or the tunable laser module 130.

In some embodiments, the operating wavelength range of the filter module 110 includes 1310nm wavelengths and 1490nm wavelengths;

after filtering the optical signal input to the ONU, the optical signal with the corresponding wavelength is input to the PON module 120, including:

the optical signal of 1310nm or 1490nm wavelength obtained by the filtering is inputted into the PON module 120.

For example, the filter module 110 may filter 1310/1490nm of the WDM longitudinal wave, and the optical signal with 1310/1490nm wavelength obtained after filtering may be sent to the GPON module 120 as a GPON compatible mode.

In some embodiments, the operating wavelength range of the filter module 110 includes a 1525nm to 1565nm band;

after filtering the optical signal input to the ONU, the optical signal with the corresponding wavelength is input to the tunable laser module 130, which includes:

the filtered 1525nm to 1565nm band optical signal is input to the tunable laser module 130.

For example, the filter module 110 may filter 1525nm to 1565nm bands within the WDM longitudinal wave, and the filtered 1525nm to 1565nm band optical signal may be sent to the tunable laser module 130.

In some embodiments, the filter module 110 is primarily responsible for filtering 1310/1490nm and DWDM wave complexes 1525nm to 1565nm (c-band) within a WDM longitudinal wave. Wherein 1310/1490nm wavelength WDM longitudinal waves will be directed to the GPON module as GPON compatible modes and 1525-1565nm wavelength WDM longitudinal waves will be directed to the tunable laser module 130.

The ONU provided by the invention can be assisted by a module (MAC module 140) related to digital control, the MAC module 140 can be used for carrying out transmission processing of a rear-end digital part, and can receive configuration information of the PON module 120, and the adjustable laser module 130 is dynamically controlled to switch working wavelength according to the configuration information, so that the dynamic self-adaptive wavelength switching can be realized, the requirements on the performance and the process of an adjustable laser are reduced, the technical difficulty of the ONU is reduced, and the manufacturing cost of the ONU is reduced. Wherein, the configuration information of the PON module 120 is sent to the ONUs by the OLT.

In some embodiments, the configuration information includes identification information of wavelength channels, such as channel codes (IDs), each of which is used to uniquely identify one wavelength channel and corresponds to one operating wavelength. The MAC module 140 may determine the operating parameters (such as wavelength, frequency, etc.) of the tunable laser module 130 according to the identification information of the wavelength channel, and then send a corresponding instruction for switching the operating wavelength to the tunable laser module 130, where the instruction may include parameters such as the operating frequency, etc., so as to control the tunable laser module 130 to switch the operating wavelength.

the transmission processing of the digital signal is performed based on a fixed rate parallel-to-serial or serial-to-parallel (SERializer/DESerializer, SERDES) channel and a configurable rate SERDES channel.

For example, MAC module 140 may provide serial data transfer function SERDES for the back-end digital portions of PON module 120 and tunable laser module 130, providing separate fixed rate SERDES channels and configurable rate SERDES channels.

In some embodiments, the MAC module 140 is further configured to configure a transmission rate of the SERDES channel with a configurable rate according to the configuration information sent by the PON module 120. The configuration information may include rate information for the SERDES channel.

Alternatively, in the event that no configuration information is received, the MAC module 140 will operate on a fixed rate SERDES channel.

In some embodiments, the fixed rate SERDES channel may have a transmission rate of 2.5Gbps.

In some embodiments, the transmission rate of the configurable rate SERDES channel may include one or more of 1Gbps, 10Gbps, 25Gbps, 40 Gbps.

In some embodiments, the MAC module 140 is further configured to periodically send wavelength calibration feedback information to the tunable laser module 130 when the ONU is in the WDM operation phase, where the wavelength calibration feedback information is used for wavelength locking by the tunable laser module 130.

Specifically, the MAC module 140 may also assist the tunable laser module 130 in performing periodic wavelength locking functions. The periodic calibration feedback (or wavelength locking) process starts at the ONU WDM operation phase and ends at the ONU exiting WDM operation phase, and is not performed if the ONU is always in standard GPON mode.

In one embodiment, the MAC module 140 may periodically compare the wavelength indicated by the configuration information sent by the PON module 120 with the wavelength indicated by the wavelength parameter information sent by the tunable laser module 130, and send wavelength calibration feedback information to the tunable laser module 130 according to the comparison result, so that the tunable laser module 130 performs wavelength locking.

For example, if the wavelength indicated by the configuration information sent by the PON module 120 differs from the wavelength indicated by the wavelength parameter information sent by the tunable laser module 130 by more than a preset threshold, it may be considered that the wavelength is inconsistent, the MAC module 140 may send calibration feedback information of the wavelength (such as information of a wavelength inconsistency, a wavelength or a frequency difference value that needs to be adjusted) to the tunable laser module 130, and after the tunable laser module 130 receives the calibration feedback information of the wavelength, the working wavelength may be adjusted to keep synchronization with the downlink designated wavelength of the OLT, so as to implement wavelength locking.

The ONU provided by the invention has the advantages that the filter module, the adjustable laser module and the MAC module are arranged, the functions of filtering a plurality of downlink wavelengths of the OLT and the like are completed in the ONU, so that the multi-wavelength scheme of GPON/XGPON and WDM can be compatible without erecting AWG wave decomposition multiplexing between the ONU and the ODN, the cost of the WDM-PON is reduced, the adjustable laser module is controlled by a module related to digital control to dynamically and adaptively switch the wavelengths, the requirements on the performance and the process of the adjustable laser are reduced, and the manufacturing cost of the ONU can be reduced.

Fig. 2 is a flow chart of an optical network unit ONU configuration method provided by the present invention, where the method is applied to the ONU described in each embodiment, and as shown in fig. 2, the method includes the following steps:

step 200, after accessing to the WDM-PON, the filter module filters the optical signal input to the ONU, and the optical signal with the wavelength of 1310nm or 1490nm obtained after the filtering is input to the PON module, so as to be used for network registration by the PON module.

Step 201, after network registration is completed, the PON module negotiates WDM operation mode and capability with the OLT, receives configuration information sent by the OLT, and sends the configuration information to the MAC module.

Step 202, the MAC module sends an instruction for switching the working wavelength to the tunable laser module according to the configuration information, and configures the transmission rate of the SERDES channel with a configurable rate.

Specifically, after the ONU accesses the WDM-PON, the filter module first filters the optical signal input to the ONU, and sends the separated optical signal with the wavelength of 1310/1490nm to the PON module, so that the PON module completes the flow of network registration of the ONU.

After registration is completed, the OLT may attempt to negotiate with the ONU about the WDM operation mode and capabilities, characterize the ONU to also start the WDM operation mode registration stage, and then the OLT may send configuration information to the ONU, and after the PON module receives the configuration information, send the configuration information to the MAC module, so that the MAC module may control wavelength switching of the tunable laser module, and perform configuration of the SERDES channel rate.

The MAC module can determine the working wavelength of the adjustable laser module according to the configuration information, send a corresponding command for switching the working wavelength to the adjustable laser module, and set the transmission rate of the SERDES channel.

In some embodiments, the method further comprises:

under the condition that the ONU is in the WDM working phase, the MAC module periodically transmits the wavelength calibration feedback information to the adjustable laser module;

and the adjustable laser module performs wavelength locking according to the wavelength calibration feedback information.

Specifically, the MAC module may also assist the tunable laser module in performing a periodic wavelength locking function. The periodic calibration feedback (or wavelength locking) process starts at the ONU WDM operation phase and ends at the ONU exiting WDM operation phase, and is not performed if the ONU is always in standard GPON mode.

In one embodiment, the MAC module may periodically compare the wavelength indicated by the configuration information sent by the PON module with the wavelength indicated by the wavelength parameter information sent by the tunable laser module, and send, according to the comparison result, calibration feedback information of the wavelength to the tunable laser module, so that the tunable laser module performs wavelength locking.

For example, if the wavelength indicated by the configuration information sent by the PON module differs from the wavelength indicated by the wavelength parameter information sent by the tunable laser module by more than a preset threshold, the wavelength may be considered inconsistent, the MAC module may send wavelength calibration feedback information (such as information about wavelength inconsistency, wavelength or frequency difference to be adjusted, etc.) to the tunable laser module, and after receiving the wavelength calibration feedback information, the tunable laser module may adjust the working wavelength to keep synchronization with the OLT downlink designated wavelength, so as to implement wavelength locking.

The ONU configuration method provided by the invention can realize the configuration of the ONU described in each embodiment, thereby effectively supporting the ONU implementation scheme provided by the invention.

The following illustrates the process of the ONU configuration method by an example of a specific application scenario. The technical real-time scenario and principle of the ONU are described below.

1. When accessing an OLT network with GPON and WDM-PON supporting capability, a thin film filter (filter module) separates the wavelengths of standard GPON 1310/1490nm and sends them to a GPON processing module, and if a SMALL FORM Plug (SFP) optical module supporting a CLASS-b+ or more is supported because the central wavelength of the band deviates from the DWDM beam greatly, the optical module will not be affected by the DWDM wave, i.e. the GPON module will complete the procedures of standard GPON registration of an ONU.

2. The ONU will complete negotiation of DWDM operating wavelength related parameters with the OLT, which will be sent by the GPON module to the MAC module, via an optical network management and control interface (Optical Network Management and Control Interface, OMCI) protocol that is scalable to the negotiation with the OLT. Under default boot-up, the MAC module will operate on a separate SERDES2.5G channel (i.e., a fixed rate SERDES channel with a transmission rate of 2.5 Gbps) and communicate with the GPON module in a docked mode.

3. The MAC module periodically detects the parameter command sent by the GPON module, when detecting that the ONU needs to be switched to the DWDM mode, the MAC module sends the command to the tunable laser module, and switches the SERDES channel to a 1G/10G/25G/40G channel (namely a channel with the transmission rate of 1Gbps/10Gbps/25Gbps/40 Gbps) according to the parameter command, wherein the specific rate is determined by the parameter. In addition, the MAC module is responsible for assisting the tunable laser module to complete the function of wavelength locking.

4. The adjustable laser module is mainly responsible for processing the wave beam of the DWDM wave band from the film filter, and completing the functions of sending and receiving uplink and downlink optical signals in the DWDM working mode, wherein the functions of selecting the speed, locking the wavelength and the like are mainly determined according to the parameters of the MAC module, and the adjustable laser module periodically receives the calibration feedback information of the MAC module, thereby keeping the synchronization with the downlink appointed wavelength of the OLT.

Fig. 3 is an exemplary diagram of an ONU provided by the present invention applied to a WDM-PON, as shown in fig. 3, where conventional AWG wavelength demultiplexing transformation is not required between ONDs and ONUs, so that the ONU can be well adapted to a large-scale application scenario of a current operator GPON/EPON, and the cost is lower for the entire WDM-PON.

The embodiments of the present invention are based on the same inventive concept, so that the embodiments can be mutually referred to, and the repetition is not repeated.

The apparatus embodiments described above are merely illustrative, wherein the modules illustrated as separate components may or may not be physically separate, and the components shown as modules may or may not be physical units, may be located in one place, or may be distributed over a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art will understand and implement the present invention without undue burden.

From the above description of the embodiments, it will be apparent to those skilled in the art that the embodiments may be implemented by means of software plus necessary general hardware platforms, or of course may be implemented by means of hardware. Based on this understanding, the foregoing technical solution may be embodied essentially or in a part contributing to the prior art in the form of a software product, which may be stored in a computer readable storage medium, such as ROM/RAM, a magnetic disk, an optical disk, etc., including several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the method described in the respective embodiments or some parts of the embodiments.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and are not limiting; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An optical network unit, ONU, comprising:

2. The ONU of claim 1, wherein the operating wavelength range of the filter module comprises a 1310nm wavelength and a 1490nm wavelength;

3. An ONU according to claim 1 or 2, characterized in that the operating wavelength range of the filter module comprises the 1525nm to 1565nm band;

4. The ONU of claim 1, wherein the performing transmission processing of the digital signal comprises:

5. The ONU of claim 4, wherein the MAC module is further configured to configure a transmission rate of the rate-configurable SERDES channel according to configuration information sent by the PON module.

6. The ONU of claim 1, wherein the MAC module is further configured to periodically send wavelength calibration feedback information to the tunable laser module, where the wavelength calibration feedback information is used for wavelength locking by the tunable laser module, if the ONU is in a WDM operating phase.

7. The ONU of claim 4, wherein the fixed-rate SERDES channel has a transmission rate of 2.5Gbps.

8. The ONU of claim 4 or 5, wherein the transmission rate of the rate-configurable SERDES channel comprises one or more of 1Gbps, 10Gbps, 25Gbps, 40 Gbps.

9. An optical network unit ONU configuration method applied to the ONU of any one of claims 1 to 8, comprising:

10. The ONU configuration method according to claim 9, characterized in that the method further comprises: