Optical communication apparatus, system and communication method

Abstract

An optical communication device, system, and communication method are disclosed. The optical communication device is used to communicate with multiple ONUs, including first-type ONUs and second-type ONUs. The first-type ONUs and second-type ONUs support different MAC protocols, and their uplink wavelengths overlap. The optical communication device includes: a first receiving component, a second receiving component, and a processing component. The first receiving component is used to receive a first optical signal transmitted by a first-type ONU in a first time slot group, and the second receiving component is used to receive a second optical signal transmitted by a second-type ONU in a second time slot group. The first time slot group includes at least one time slot, and the second time slot group includes at least one time slot. The processing component is used to ensure that the first and second time slot groups do not overlap in the time dimension through a first time slot scheduling mechanism. This enables the coexistence of ONUs supporting different MAC protocols and with overlapping uplink wavelengths in a PON system.

Description

[0001] This application claims priority to Chinese Patent Application No. 202310954175.5, filed on July 28, 2023, entitled "Optical Communication Apparatus, System and Communication Method", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of optical communication technology, and in particular to an optical communication device, system and communication method. Background Technology

[0003] A passive optical network (PON) is a point-to-multipoint, single-fiber, bidirectional optical access network. A PON system typically includes an optical line termination (OLT), an optical distributed network (ODN), and multiple optical network termination (ONU) devices. The OLT connects to multiple ONUs through the ODN.

[0004] With the development of optical communication technology, at a certain stage, a PON system may simultaneously contain at least two ONUs supporting different media access control (MAC) protocols. The uplink wavelengths used by ONUs supporting different MAC protocols may overlap, leading to uplink data conflicts and affecting the normal operation of the PON system. Summary of the Invention

[0005] This application provides an optical communication device, system, and communication method that enables the coexistence of ONUs supporting different MAC protocols and with overlapping uplink wavelengths in a PON system.

[0006] In a first aspect, this application provides an optical communication device for communicating with multiple ONUs. The multiple ONUs include a first type of ONU and a second type of ONU, wherein the first type of ONU and the second type of ONU support different MAC protocols, and their uplink wavelengths overlap. The optical communication device includes a first receiving component, a second receiving component, and a processing component. The first receiving component is used to receive a first optical signal transmitted by a first type of ONU in a first time slot group, and the second receiving component is used to receive a second optical signal transmitted by a second type of ONU in a second time slot group. The first time slot group includes at least one time slot, and the second time slot group includes at least one time slot. The processing component is used to ensure that the first time slot group and the second time slot group do not overlap in the time dimension through a first time slot scheduling mechanism.

[0007] In this application, the processing component uses a first time slot scheduling mechanism to ensure that the first time slot group and the second time slot group do not overlap in the time dimension. That is, the first time slot scheduling mechanism separates the first optical signals and the second optical signals transmitted by the first type of ONU and the second type of ONU with overlapping uplink wavelengths in the time dimension, so that they will not affect each other, thereby avoiding uplink data conflicts transmitted by the first type of ONU and the second type of ONU, and enabling the PON system to work normally.

[0008] In a first possible implementation, the plurality of ONUs further includes a third type of ONU, the third type of ONU supporting a MAC protocol different from that supported by the first type of ONU and the second type of ONU.

[0009] ONUs of the same type can use different uplink wavelengths. Here, different uplink wavelengths can refer to different center wavelengths and / or wavelength ranges. For ONUs of the same type, they can be further classified according to the uplink wavelengths used.

[0010] In some examples, the third type of ONU can be divided into a first subtype ONU, a second subtype ONU, and a third subtype ONU. The first type of ONU can be divided into a fourth subtype ONU and a fifth subtype ONU. The uplink wavelengths of the first subtype ONU, the second subtype ONU, and the second type of ONU do not overlap. The uplink wavelengths of the first subtype ONU, the second subtype ONU, and the third type of ONU all overlap. The uplink wavelength of the fourth subtype ONU is the same as that of the first subtype ONU, and the uplink wavelength of the fifth subtype ONU is the same as that of the third subtype ONU.

[0011] For example, the uplink wavelength of the first subclass ONU is 1290nm-1330nm, the second subclass ONU is 1260nm-1280nm, the third subclass ONU is 1260nm-1360nm, the fourth subclass ONU is 1290nm-1330nm, the fifth subclass ONU is 1260nm-1360nm, and the second class ONU has an uplink wavelength of 1284nm-1288nm.

[0012] In practical applications, the use of a third subclass ONU is rare, and it may not even exist. In this case, the third subclass ONU includes at least one of the first subclass ONU and the second subclass ONU.

[0013] When the third type of ONU includes a first subtype ONU and a second subtype ONU, that is, when the first subtype ONU, the second subtype ONU, the fourth subtype ONU, the fifth subtype ONU, and the second type ONU coexist in the PON system, the optical communication device further includes a third receiving component. This third receiving component is used to receive a third optical signal transmitted by the first subtype ONU and a fourth optical signal transmitted by the second subtype ONU in the second time slot group. The reception of the third and fourth optical signals by the third receiving component in the second time slot group is performed simultaneously with the reception of the second optical signal by the second receiving component, via wavelength division multiplexing. The processing component is further used to enable the third receiving component to receive the third optical signal transmitted by the first subtype ONU and the fourth optical signal transmitted by the second subtype ONU in the second time slot group using a second time slot scheduling mechanism.

[0014] When the third type of ONU includes the first subtype ONU but not the second subtype ONU, that is, when the first subtype ONU, the fourth subtype ONU, the fifth subtype ONU, and the second type ONU coexist in the PON system, the optical communication device further includes: a third receiving component. This third receiving component is used to receive the third optical signal transmitted by the first subtype ONU in the second time slot group. The reception of the third optical signal by the third receiving component in the second time slot group and the reception of the second optical signal by the second receiving component are performed simultaneously via wavelength division multiplexing.

[0015] When the third type of ONU includes a second subtype ONU but not a first subtype ONU, that is, when the second subtype ONU, the fourth subtype ONU, the fifth subtype ONU, and the second type ONU coexist in the PON system, the optical communication device further includes a third receiving component. This third receiving component is used to receive a fourth optical signal transmitted by the second subtype ONU in the second time slot group. The reception of the fourth optical signal by the third receiving component in the second time slot group and the reception of the second optical signal by the second receiving component are performed simultaneously via wavelength division multiplexing.

[0016] Since the uplink wavelengths of the first sub-type ONU and the second sub-type ONU do not overlap with the uplink wavelength of the second type ONU, the simultaneous existence of the third optical signal transmitted by the first sub-type ONU and the second optical signal transmitted by the second type ONU will not cause conflict. Similarly, the simultaneous existence of the fourth optical signal transmitted by the second sub-type ONU and the second optical signal transmitted by the second type ONU will not cause conflict. Therefore, the third receiving component's reception of the third optical signal and / or the fourth optical signal in the second time slot group, along with the second receiving component's reception of the second optical signal, can be performed simultaneously via wavelength division multiplexing. This improves the uplink bandwidth utilization of the system.

[0017] With the development of optical communication technology and the increase in transmission rate, ONUs typically use a narrower range of uplink wavelengths to transmit uplink data. ONUs using a wider range of uplink wavelengths will be prioritized for decommissioning from PON systems, enabling PON system upgrades. Therefore, the fifth subclass of ONUs will be prioritized for decommissioning from PON systems.

[0018] In this case, the first type of ONU includes a fourth subtype of ONU but does not include a fifth subtype of ONU. The second receiving component is also configured to receive a second optical signal transmitted by the second type of ONU in the first time slot group and the second time slot group. The third receiving component is also configured to receive a fifth optical signal transmitted by the fourth subtype of ONU in the first time slot group, and receive a third optical signal transmitted by the first subtype of ONU and / or a fourth optical signal transmitted by the second subtype of ONU in the second time slot group.

[0019] Optionally, the first type of ONU may also include a third subtype ONU, meaning that a third subtype ONU also exists in the PON system. Since the uplink wavelength of this third subtype ONU is the same as that of the fifth subtype ONU, its uplink wavelength also conflicts with the wavelengths of other ONUs, and it also needs to be decommissioned from the PON system. Before the third subtype ONU is decommissioned, the optical signal transmitted by the third subtype ONU is received by the first receiving component. That is, when the first type of ONU also includes the third subtype ONU, the first receiving component is also used to receive the first optical signal transmitted by the first type of ONU and the sixth optical signal transmitted by the third subtype ONU in a time-division multiplexing manner in the first time slot group.

[0020] In this application, the MAC protocols supported by the first type of ONU and the third type of ONU belong to the same standard system and have similar scheduling methods, so they can be scheduled through the same MAC module. The MAC protocols supported by the second type of ONU belong to different standard systems than those supported by the first type of ONU; therefore, the second type of ONU is scheduled through a different MAC module. Therefore, the processing component can include a first MAC module and a second MAC module. The first MAC module is used to schedule both the first type of ONU and the third type of ONU, and the second MAC module is used to schedule the second type of ONU.

[0021] In this first possible implementation, the optical communication device can adopt any of the following three structures:

[0022] The first type, the third receiving component, includes: a first optoelectronic conversion device and a first power divider. The first optoelectronic conversion device is used to convert the third optical signal, the fourth optical signal, and the fifth optical signal into a first electrical signal. The first power divider is connected to the first optoelectronic conversion device and is used to divide the first electrical signal into two sub-signals. The first MAC module includes a first single-speed burst clock and data recovery (BCDR) circuit and a second single-speed BCDR circuit. The first single-speed BCDR circuit and the second single-speed BCDR circuit support different rates. The first single-speed BCDR circuit and the second single-speed BCDR circuit are respectively connected to the first power divider and are respectively used to receive one of the two sub-signals output by the first power divider at the corresponding rate. The first MAC module selectively receives data recovered at different rates by the first single-speed BCDR circuit and the second single-speed BCDR circuit according to the scheduling information of the second time slot scheduling mechanism.

[0023] The second type, the third receiving component includes a second photoelectric conversion device. The second photoelectric conversion device is used to convert the third optical signal, the fourth optical signal, and the fifth optical signal into a second electrical signal. The first MAC module includes a dual-speed BCDR circuit, which is connected to the second photoelectric conversion device and is used to selectively receive the second electrical signal at a first rate and / or a second rate. The first MAC module selectively receives data at different rates recovered by the dual-speed BCDR circuit according to the scheduling information of the second time slot scheduling mechanism.

[0024] Thirdly, the third receiving component includes a third photoelectric conversion device and a fourth photoelectric conversion device. The third photoelectric conversion device is used to convert the fourth optical signal into a third electrical signal. The fourth photoelectric conversion device is used to convert the third optical signal and the fifth optical signal into a fourth electrical signal. The first MAC module includes a first single-speed BCDR circuit and a dual-speed BCDR circuit. The first single-speed BCDR circuit is connected to the fourth photoelectric converter and is used to receive the fourth electrical signal at a first rate. The dual-speed BCDR circuit is connected to the third photoelectric conversion device and is used to selectively receive the third electrical signal at the first rate or the second rate. The first MAC module is used to receive data at different rates recovered by the first single-speed BCDR circuit and the dual-speed BCDR circuit according to the scheduling information of the first time slot scheduling mechanism and the second time slot scheduling mechanism.

[0025] Optionally, in the third structure described above, the third photoelectric conversion device and the fourth photoelectric conversion device can be packaged in the same coaxial housing, or they can be packaged in separate coaxial housings.

[0026] For the first or second structure, before the fifth sub-type ONU is decommissioned, the first MAC module is used to obtain the uplink data transmitted by the first type of ONU based on the electrical signal output by the first receiving component in the first time slot group; and to obtain the uplink data transmitted by the first sub-type ONU and the second sub-type ONU based on the electrical signal output by the third receiving component in the second time slot group. Alternatively, after the fifth sub-type ONU is decommissioned, the first MAC module is used to obtain the uplink data transmitted by the fourth sub-type ONU based on the electrical signal output by the third receiving component in the first time slot group; and to obtain the uplink data transmitted by the first sub-type ONU and the second sub-type ONU based on the electrical signal output by the third receiving component in the second time slot group.

[0027] For this third structure, before the fifth sub-category ONU is decommissioned, the first MAC module is used to obtain uplink data transmitted by the first type of ONU based on the electrical signal output by the first receiving component in the first time slot group; to obtain uplink data transmitted by the first sub-category ONU and the asymmetric ONU in the second sub-category ONU based on the electrical signal output by the first receiving component in the second time slot group; and to obtain uplink data transmitted by the symmetric ONU in the second sub-category ONU based on the electrical signal output by the third optoelectronic conversion device in the second time slot group. Alternatively, after the fifth sub-category ONU is decommissioned, the first MAC module is used to obtain uplink data transmitted by the second sub-category ONU based on the electrical signal output by the third optoelectronic conversion device in the first and second time slot groups; and to obtain uplink data transmitted by the first sub-category ONU and the uplink data transmitted by the fourth sub-category ONU based on the electrical signal output by the fourth optoelectronic conversion device.

[0028] In a second possible implementation, the plurality of ONUs further includes a third type of ONU, wherein the MAC protocol supported by the third type of ONU is different from the MAC protocols supported by the first type of ONU and the second type of ONU, and the uplink wavelength of the third type of ONU overlaps with the uplink wavelength of the first type of ONU. The first receiving component is further configured to receive a third optical signal transmitted by the third type of ONU in the first time slot group. The processing component is further configured to use a third time slot scheduling mechanism to enable the first receiving component to receive the first optical signal and the third optical signal in a time-division multiplexing manner in the first time slot group.

[0029] In this embodiment, the processing component uses a third time slot scheduling mechanism to enable the first type ONU and the third type ONU to be time-division multiplexed within the first time slot group. This avoids uplink data conflicts between the first type ONU and the third type ONU whose uplink wavelengths overlap, thereby enabling the coexistence of the first type ONU, the second type ONU, and the third type ONU in the PON system.

[0030] In some examples, the first receiving component includes a fifth optoelectronic conversion device and a second power divider. The fifth optoelectronic conversion device converts the first optical signal and the third optical signal into a fifth electrical signal. The second power divider is connected to the fifth optoelectronic conversion device and is used to split the fifth electrical signal into two sub-signals. The processing component includes a first MAC module. The first MAC module includes a first single-speed BCDR circuit and a second single-speed BCDR circuit. The first single-speed BCDR circuit and the second single-speed BCDR circuit support different rates. The first single-speed BCDR circuit and the second single-speed BCDR circuit are respectively connected to the second power divider and are respectively used to receive one of the two sub-signals output by the second power divider at the corresponding rate. The first MAC module is used to selectively receive data at different rates recovered by the first single-speed BCDR circuit and the second single-speed BCDR circuit according to the scheduling information of the third time slot scheduling mechanism.

[0031] For the first MAC module, using two single-speed BCDR circuits to correspond to the uplink transmission rate of the first type of ONU and the uplink transmission rate of the third type of ONU respectively is beneficial to reducing the cost of optical communication devices.

[0032] In other examples, the first receiving component includes a sixth photoelectric conversion device. This sixth photoelectric conversion device is used to convert the first optical signal and the third optical signal into a fifth electrical signal. The processing component includes a first MAC module, which includes a dual-speed BCDR circuit connected to the sixth photoelectric conversion device and is used to selectively receive the fifth electrical signal at a first rate and / or a second rate. The first MAC module is used to selectively receive data at different rates recovered by the dual-speed BCDR circuit according to scheduling information of the third time slot scheduling mechanism.

[0033] By using a dual-speed BCDR to correspond to the uplink transmission rates of the first type ONU and the third type ONU respectively, the number of devices included in the first receiving component can be reduced, thereby simplifying the structure of the first receiving component.

[0034] In this first possible implementation, the MAC protocol supported by the first MAC module belongs to the same standard system as the MAC protocols supported by the first type of ONU and the third type of ONU. Therefore, the first type of ONU and the third type of ONU can be uniformly scheduled and the uplink data sent by the first type of ONU and the third type of ONU can be received.

[0035] Optionally, the processing component further includes a second MAC module, which is connected to the first MAC module. The second MAC module synchronizes bandwidth allocation information with the first MAC module to realize the function of the first time slot scheduling mechanism.

[0036] By connecting the second MAC module to the first MAC module, the bandwidth allocation information can be synchronized between the first MAC module and the second MAC module, thereby realizing the function of the first time slot scheduling mechanism.

[0037] Optionally, the processing component employs the following first time slot scheduling mechanism: Based on the bandwidth requirement information of the plurality of ONUs, a first time slot group and a second time slot group are determined in the target period. The target period includes M time slots, where M is greater than 1 and M is an integer. The first time slot group includes X time slots from the M time slots, and the second time slot group includes Y time slots from the M time slots. X and Y are both positive integers, and the sum of X and Y is less than or equal to M. The time slots of the first time slot group are used to allocate time slots to first-type ONUs according to the MAC protocol supported by the first-type ONUs, and the time slots of the second time slot group are used to allocate time slots to second-type ONUs according to the MAC protocol supported by the second-type ONUs.

[0038] The time slots in the first time slot group will be referred to as the first time slots, and the time slots in the second time slot group will be referred to as the second time slots.

[0039] In one possible implementation, the first time slot group includes at least two first subsets, each of the at least two first subsets including one first time slot or including at least two consecutive first time slots, and at least one second time slot exists between two adjacent first subsets; and / or, the second time slot group includes at least two second subsets, each of the at least two second subsets including one second time slot or including at least two consecutive time slots, and at least one first time slot exists between two adjacent second subsets.

[0040] In another possible implementation, the first time slot group includes a first time slot or includes at least two consecutive first time slots; and / or, the second time slot group includes a second time slot or includes at least two consecutive second time slots.

[0041] Optionally, at least one first time slot in the first time slot group is a windowed time slot; and / or, at least one second time slot in the second time slot group is a windowed time slot.

[0042] Optionally, the first time slot scheduling mechanism further includes: using a time slot outside the target period or at least two consecutive time slots as an open window time slot.

[0043] Optionally, the bandwidth requirement information of the ONU includes at least one of the following: the number of ONUs of each type, and the service information of the services activated by the ONU. Optionally, the service information includes service type or latency requirements, etc.

[0044] In this application, a first time slot group is used to schedule ONUs in a first set of terminals, and a second time slot group is used to schedule ONUs in a second set of terminals. The more ONUs in the first set of terminals, and the greater the bandwidth requirement for the services activated by each ONU, the larger the proportion of time slots included in the first time slot group in the target period. Similarly, the more ONUs in the second set of terminals, and the greater the bandwidth requirement for the services activated by each ONU, the larger the proportion of time slots included in the second time slot group in the target period.

[0045] In some examples, the first terminal set includes a first type of ONU, and the second terminal set includes a second type of ONU; or, the first terminal set includes both a first type of ONU and a third type of ONU, and the second terminal set includes a second type of ONU.

[0046] In some examples, the receiving wavelength range of the first receiving component is 1260nm-Xnm, wherein X is less than or equal to 1360 and greater than 1330.

[0047] In actual network deployments, this optical communication device is typically a component of an OLT, which connects to multiple ONUs via an ODN. If reflections occur on the ODN, and the receiving wavelength range of the first receiving component overlaps with the downlink wavelength of the second type of ONU, there is a possibility that the downlink optical signal of the second type of ONU may be reflected back to the OLT by the ODN and enter the first receiving component. This will affect the reception and data recovery of uplink signals from both the first and third type of ONUs. To mitigate this risk, the receiving wavelength range of the first receiving component can be set to not overlap with the downlink wavelength of the second type of ONU. For example, when the downlink wavelength of the second type of ONU is 1340nm-1344nm, X can be set to be less than or equal to 1340nm. Simultaneously, to avoid affecting the normal reception of the third optical signal transmitted by the first sub-type ONU and the fifth optical signal transmitted by the fourth sub-type ONU, X needs to be greater than 1330nm.

[0048] For example, the first type of ONU supports the EPON protocol as its MAC protocol, the second type of ONU supports the 50G PON protocol as its MAC protocol, and the third type of ONU supports the 10G EPON protocol as its MAC protocol.

[0049] When the second type of ONU is a 50G PON ONU, that is, when the MAC protocol supported by the second type of ONU is the 50G PON protocol, since the corresponding MAC protocol specifies a strict 125μs superframe structure and superframe synchronization, in this embodiment of the application, the length of a single time slot in the first time slot group and the second time slot group is an integer multiple of 125μs, so that the time slots in the second time slot group can meet the requirements of the MAC protocol, and the time slots in the first time slot group can also be aligned and synchronized.

[0050] In some examples, the length of a single time slot in the first time slot group is M times 125 μs, and the length of a single time slot in the second time slot group is N times 125 μs. Optionally, M equals N, which simplifies the scheduling mechanism for the first time slot. Alternatively, M may not equal N. The values ​​of M and N can be determined according to actual needs, such as 1, 2, or 3, etc.

[0051] Optionally, the optical communication device further includes a transmitting component. This transmitting component is used to transmit optical signals to the aforementioned first-type ONU, second-type ONU, and third-type ONU.

[0052] Secondly, this application also provides an optical communication system. The optical communication system includes an OLT and multiple ONUs, wherein the OLT includes any of the aforementioned optical communication devices.

[0053] Thirdly, this application also provides a communication method. This method is used to receive optical signals transmitted by multiple ONUs through multiple receiving components, including a first receiving component, a second receiving component, and a third receiving component. For details regarding the first type of ONU, the second type of ONU, and the third type of ONU, as well as the details regarding the first receiving component, the second receiving component, and the third receiving component, please refer to the first aspect.

[0054] In one possible implementation, the method includes: in a first stage, obtaining uplink data transmitted by a first type of ONU based on an electrical signal output by the first receiving component in a first time slot group, obtaining uplink data transmitted by a second type of ONU based on an electrical signal output by the second receiving component in a second time slot group, and obtaining uplink data transmitted by the first sub-type ONU and the second sub-type ONU based on an electrical signal output by the third receiving component in the second time slot group; or, in a second stage, obtaining uplink data transmitted by a second type of ONU based on an electrical signal output by the second receiving component in the first and second time slot groups, obtaining uplink data transmitted by a fourth sub-type ONU based on an electrical signal output by the third receiving component in the first time slot group, and obtaining uplink data transmitted by the first sub-type ONU and the second sub-type ONU based on an electrical signal output by the third receiving component in the second time slot group.

[0055] In another possible implementation, the method includes: in a first stage, obtaining uplink data transmitted by a first type of ONU and a first subtype of ONU based on an electrical signal output by a first receiving component in a first time slot group; obtaining uplink data transmitted by a second type of ONU based on an electrical signal output by a second receiving component in a second time slot group; and obtaining uplink data transmitted by a second subtype of ONU based on an electrical signal output by a third optoelectronic conversion device in a third receiving component in the second time slot group; or, in the second stage, obtaining uplink data transmitted by a second type of ONU based on an electrical signal output by a second receiving component, while simultaneously receiving uplink data transmitted by a second subtype of ONU, uplink data transmitted by a fourth subtype of ONU, and uplink data transmitted by a first subtype of ONU based on a third receiving component. Wherein, the uplink data transmitted by the second subtype of ONU is obtained through an electrical signal output by a third optoelectronic conversion device, and the uplink data transmitted by the fourth subtype of ONU and the uplink data transmitted by the first subtype of ONU are obtained through an electrical signal output by a fourth optoelectronic conversion device.

[0056] In the first phase, the PON system contained Type I, Type II, and Type III ONUs simultaneously, with Type I ONUs including Type IV and Type V ONUs. In the second phase, the Type V ONUs of Type I ONUs and the Type III ONUs of Type III ONUs have either been decommissioned or upgraded to Type II, Type I, or Type II ONUs. Therefore, Type V and Type III ONUs no longer exist in the PON system.

[0057] By selecting the appropriate receiving component to receive uplink data sent by the ONU at different stages, it is possible to communicate with existing ONUs in the PON system using an OLT with the same hardware structure before and after the PON system upgrade. The OLT's hardware structure remains unchanged before and after the PON system upgrade, which helps reduce costs.

[0058] Fourthly, this application provides a communication method for a passive optical network (PON) system, the PON system including an optical line terminal (OLT) and at least one optical network unit (ONU), the method comprising:

[0059] The ONU receives a first downlink physical frame sent by the OLT, the first downlink physical frame including an index of the downlink wavelength channel available in the PON system; then, the ONU determines whether the downlink wavelength channel corresponding to the index of the downlink wavelength channel is available. If the ONU determines that the downlink wavelength channel corresponding to the index of the downlink wavelength channel is available, it further receives a second downlink physical frame sent by the OLT on the downlink wavelength channel.

[0060] In the communication method provided in this application, since the OLT can notify the ONU of the available downlink wavelength channels in the current PON system through the downlink wavelength channel index in the first downlink physical frame, communication conflicts caused by downlink wavelength mismatch between the OLT and the ONU are avoided, thus improving communication efficiency.

[0061] In one possible implementation, the communication method provided in this application is used in a time-division and wavelength-division multiplexing (TWDM) PON system. In a TWDM PON system, the downlink direction of the OLT employs wavelength division multiplexing, and the downlink channel is wavelength-division multiplexed into multiple downlink wavelength channels. These multiple downlink wavelength channels do not interfere with each other.

[0062] In one possible implementation, the communication method provided in this application includes:

[0063] The ONU receives a first downlink physical frame sent by the OLT, the first downlink physical frame including an index of the downlink wavelength channel available in the PON system; the ONU determines whether the downlink wavelength channel corresponding to the index of the downlink wavelength channel is available; if the ONU determines that the downlink wavelength channel corresponding to the index of the downlink wavelength channel can be activated, the ONU enters the sequence number state of the activation process.

[0064] In one possible scenario, if the ONU determines that the downlink wavelength channel corresponding to the index of the downlink wavelength channel is unavailable, it searches for other available downlink wavelength channels and enters the asynchronous state in the activation process. In the asynchronous state, the ONU retains the system and channel mode information but discards the burst mode information.

[0065] The ONU can tune its receiver to search for other available downlink wavelength channels.

[0066] In the scheme provided in the fourth aspect, the ONU determines whether the downlink wavelength channel corresponding to the index of the downlink wavelength channel is available for activation. If it is available for activation, it further receives a second downlink physical frame transmitted by the OLT on the downlink wavelength channel. If it is not available for activation, it searches for other downlink wavelength channels that can be activated.

[0067] In one possible scenario, the ONU receives a first downlink physical frame from the OLT during the mode learning state in the activation process. The first downlink physical frame includes an index of the downlink wavelength channel available in the PON system.

[0068] In one possible implementation, the operation control body of the first downlink physical frame carries an index of the downlink wavelength channel. Furthermore, the operation control body of the downlink physical synchronization block of the downlink physical frame carries the aforementioned index of the downlink wavelength channel.

[0069] The ONU determining whether the downlink wavelength corresponding to the index of the downlink wavelength channel is available includes: the ONU determining whether the downlink wavelength channel corresponding to the index of the downlink wavelength channel included in the operation control main unit of the first downlink physical frame can be used for activation.

[0070] The index of the downlink wavelength channel occupies at least 2 bits in the operation control body field, for example, 3 bits.

[0071] In one possible approach, if the ONU determines that the downlink wavelength channel corresponding to the index of the downlink wavelength channel is available, then the step of receiving the second downlink physical frame sent by the OLT on the downlink wavelength channel can be replaced by: when the ONU determines that the downlink wavelength channel corresponding to the index of the downlink wavelength channel is available for activation, the ONU enters the sequence number state of the activation process.

[0072] In the sequence number state, the ONU can start its transmitter and tune it to the uplink wavelength channel. Subsequently, after receiving the sequence number grant message from the OLT, the ONU sends its own sequence number to the OLT on that uplink wavelength channel.

[0073] When the ONU sends its own sequence number to the OLT, if the ONU supports power balancing, the ONU can perform ONU-activated power balancing to save power consumption.

[0074] In one possible implementation, the ONU enters an asynchronous state when it finds an available downlink wavelength channel. If the ONU does not find an available downlink wavelength channel, it enters an initial state. In the initial state, the ONU performs a downlink channel scan.

[0075] In one possible scheme, the OLT can identify the ONU by sending an assigned ONU identifier (ID) to the ONT. The OLT can also send a ranging request message to the ONU. Upon receiving the ranging request message, the ONU returns a ranging response message to the OLT. The OLT calculates the equalization parameters corresponding to the ONU based on the ranging response message and then sends a ranging time message to the ONU, which carries the equalization delay of the ONU. After receiving the equalization delay, the ONU can enter the operational state (completing the activation process).

[0076] In operation, the ONU can process the second downlink physical frame received on the downlink wavelength channel and obtain the user data carried in the second downlink physical frame.

[0077] In one possible scenario, the ONU receives a wavelength adjustment message sent by the OLT, tunes its transmitter to the target uplink wavelength channel according to the wavelength adjustment message, and then sends an uplink message to the OLT through the target uplink wavelength channel to complete the activation process.

[0078] In the scheme provided in this application, other downlink physical frames may be spaced between the first downlink physical frame and the second downlink physical frame, and the downlink message sent by the OLT to the ONT can be carried through the downlink physical frame.

[0079] Fifthly, this application provides a communication method for a passive optical network (PON) system, the PON system including an optical line terminal (OLT) and at least one optical network unit (ONU), the method comprising:

[0080] The OLT sends a first downlink physical frame to the ONU, the first downlink physical frame including an index of the downlink wavelength channel available in the PON system; the OLT sends a second downlink physical frame to the ONU on the downlink wavelength channel corresponding to the index of the downlink wavelength channel.

[0081] The communication method provided in this application can be applied to time-division multiplexing (TWDM) PON systems, whose transmission rates can include 10G, 50G, 100G, 200G, or higher. In a TWDM PON system, the downlink direction (from OLT to ONU) employs wavelength division multiplexing (WDM), with the downlink channel WDM multiplexed into multiple downlink wavelength channels. These multiple downlink wavelength channels do not interfere with each other. By sending the downlink wavelength channel index to the ONU, the OLT can enable the ONU to determine the available downlink wavelength channel for activation based on this index. The ONU then performs the activation process on the determined downlink wavelength channel, avoiding downlink wavelength channel conflicts between the OLT and the ONU.

[0082] Similar to the fourth aspect, the OLT can include the index of the downlink wavelength channel in the operation control body field of the first downlink physical frame.

[0083] The index of the downlink wavelength channel occupies at least 2 bits in the operation control body field. For example, the index of the downlink wavelength channel occupies 3 bits.

[0084] In this context, other downlink physical frames may be spaced between the first downlink physical frame and the second downlink physical frame, and downlink messages sent by the OLT to the ONT can be carried through downlink physical frames.

[0085] In the communication method provided in the fifth aspect, when the ONU determines that the downlink wavelength channel corresponding to the index of the downlink wavelength channel is available for activation, the ONU enters the sequence number state of the activation process. In the sequence number state, the OLT can send a sequence number grant message to the ONU. After receiving the sequence number grant message sent by the OLT, the ONU sends its own sequence number to the OLT on the uplink wavelength channel.

[0086] When the OLT receives a sequence number from an ONU, it determines that the ONU is a newly connected ONU and sends an assigned ONU identifier (ID) to that ONU. Additionally, the OLT can send wavelength adjustment or wavelength calibration messages to the ONU so that the ONU can tune its transmitter to the target uplink wavelength channel to communicate with the OLT.

[0087] In one possible scenario, the OLT can also send a ranging request message to the ONU. Upon receiving the ranging request message, the ONU returns a ranging response message to the OLT. The OLT calculates the equalization parameters corresponding to the ONU based on the ranging response message, and then sends a ranging time message to the ONU, which carries the equalization delay of the ONU. After receiving the equalization delay, the ONU can enter the operational state (complete the activation process).

[0088] Sixthly, this application also provides an optical communication device including a processor and a memory, the memory being used to store software programs, the processor causing the optical communication device to perform a communication method as performed by the ONU in the fourth aspect, or causing the optical communication device to perform a communication method as performed by the OLT in the fifth aspect, by running or executing the software programs stored in the memory.

[0089] The optical communication device provided in this aspect can be used as an optical line terminal or an optical network unit device.

[0090] In a seventh aspect, this application provides a computer-readable storage medium for storing program code executed by a processor, the program code including instructions for implementing the communication method in any of the possible embodiments of the fourth or fifth aspect described above.

[0091] Eighthly, this application provides a chip including a processor, the processor being configured to retrieve and execute instructions stored in a memory, causing an optical communication device on which the chip is mounted to perform the communication method in any of the possible embodiments of the fourth or fifth aspect described above. Attached Figure Description

[0092] Figure 1 This is a schematic diagram of the structure of a PON system provided in an embodiment of this application;

[0093] Figure 2 This is a schematic diagram of the structure of an optical communication device provided in an embodiment of this application;

[0094] Figure 3 This is a schematic diagram of another optical communication device provided in an embodiment of this application;

[0095] Figure 4 This is a schematic diagram of a time slot allocation method provided in an embodiment of this application;

[0096] Figure 5 A schematic diagram of another optical communication device provided in this application embodiment;

[0097] Figure 6 This is a schematic diagram of another optical communication device provided in an embodiment of this application;

[0098] Figure 7 This is a schematic diagram of the structure of another optical communication device provided in the embodiments of this application;

[0099] Figure 8 This is a schematic diagram of another time slot allocation method provided in the embodiments of this application;

[0100] Figure 9This is a schematic diagram of another optical communication device provided in an embodiment of this application;

[0101] Figure 10 This is a schematic diagram of a time slot allocation method provided in an embodiment of this application;

[0102] Figure 11 This is a schematic diagram of another optical communication device provided in an embodiment of this application;

[0103] Figure 12 This is a flowchart of an optical communication method provided in an embodiment of this application. Detailed Implementation

[0104] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0105] Figure 1 This is a schematic diagram of a PON system provided in an embodiment of this application. Figure 1 As shown, the PON system includes an OLT 110, an ONU device 120, and an ODN 130. The OLT 110 is connected to one or more ONUs 120 via the ODN 130. The ONU 120 can also be referred to as an optical network terminal (ONT).

[0106] The OLT 110 is typically located on the network side, such as the central office (CO), and can centrally manage multiple ONUs 120. The OLT 110 can act as a medium between the ONUs 120 and the upper-layer network (not shown in the diagram), forwarding data received from the upper-layer network to the ONUs 120, and forwarding data received from the ONUs 120 to the upper-layer network. The upper-layer network includes, but is not limited to, the Internet, the Public Switched Telephone Network (PSTN), and community antenna television (CATV).

[0107] Multiple ONUs 120 can be distributed and installed on the user side. An ONU 120 can be a network device that communicates with the OLT 110 and user equipment. An ONU 120 can act as an intermediary between the OLT 110 and user equipment; for example, an ONU 120 can forward data received from the OLT 110 to the user equipment, and forward data received from the user equipment to the OLT 110.

[0108] The ODN 130 is a data distribution / multiplexing system that may include a backbone fiber, a passive optical splitter, and user fibers. The passive optical splitter may include a first port and multiple second ports. The first port of the passive optical splitter is connected to the OLT 110 via the backbone fiber, and each second port of the passive optical splitter is connected to an ONU 120 via a user fiber.

[0109] In a PON system, the data flow from OLT 110 to ONU 120 is downlink. OLT 110 broadcasts downlink data to all ONU 120s, and each ONU 120 only receives data with its own identifier. Conversely, the data flow from ONU 120 to OLT 110 is uplink. Since all ONU 120s share ODN 130 and OLT 110, to ensure that uplink data from each ONU 120 does not conflict, the PON system uses time division multiplexing (TDM) or time division and wavelength division multiplexing (TWDM) to transmit uplink data. That is, OLT 110 allocates uplink time slots to each ONU 120, and each ONU 120 sends uplink data according to the uplink time slots allocated by OLT 110.

[0110] In this embodiment, at least two types of ONUs 120 exist, and the different types of ONUs support different MAC protocols. Optionally, the MAC protocol includes, but is not limited to, GPON, EPON, 10G PON, 10G EPON, or higher transmission rate MAC protocols such as 40G PON, 50G PON, and 100G PON.

[0111] For example, Figure 1 In this embodiment, the multiple ONUs 120 include at least a first-type ONU 120a, a second-type ONU 120b, and a third-type ONU 120c. The first-type ONU 120a, second-type ONU 120b, and third-type ONU 120c support different MAC protocols. In other embodiments, the multiple ONUs 120 may also include only the first-type ONU 120a and second-type ONU 120b, or may include more types of ONUs.

[0112] Different types of ONUs support MAC protocols that may belong to the same standard system or different standard systems. Here, standard systems include, but are not limited to, the Institute of Electrical and Electronics Engineers (IEEE) standard system and the International Telecommunication Union-Telecommunication Standardization Sector (ITU-T) standard system.

[0113] In some examples, the MAC protocol supported by the third type of ONU and the MAC protocol supported by the first type of ONU belong to the same standard system; for example, both belong to the IEEE standard system. In other examples, the MAC protocol supported by the second type of ONU and the MAC protocol supported by the first type of ONU belong to different standard systems; for example, the MAC protocol supported by the first type of ONU belongs to the IEEE standard system, while the MAC protocol supported by the second type of ONU belongs to the ITU-T standard system.

[0114] The uplink wavelengths of different types of ONUs may or may not overlap. The following explanation will use EPON as an example, 10G EPON as the MAC protocol supported by the first type of ONU, and 50G PON as the MAC protocol supported by the second type of ONU. For example, the uplink wavelength of the first type ONU 120a includes 1260nm-1360nm or 1290nm-1330nm; the uplink wavelength of the second type ONU 120b is 1284nm-1288nm, which overlaps with the uplink wavelength of the first type ONU 120a (1260nm-1360nm); the uplink wavelength of the third type ONU 120c includes 1260nm-1360nm, 1290nm-1330nm or 1260nm-1280nm. Therefore, the uplink wavelength of the third type ONU 120c (1260nm-1360nm) overlaps with the uplink wavelength of the second type ONU 120b, while the uplink wavelengths of the third type ONU 120c (1290nm-1330nm and 1260nm-1280nm) do not overlap with the uplink wavelength of the second type ONU 120b.

[0115] For the same type of ONU, the uplink wavelength may differ depending on the type of laser used. Here, different uplink wavelengths refer to differences in the center wavelength and / or the coverage (or bandwidth) of the uplink wavelength. For example, when the ONU is an EPON ONU, if it uses a Distributed Feedback (DFB) laser, the corresponding uplink wavelength is 1290nm-1330nm; if it uses a Fabry-Perot (FP) laser, the corresponding uplink wavelength is 1260nm-1360nm. As another example, when the ONU is an asymmetric 10G EPON ONU, if it uses a DFB laser, the corresponding uplink wavelength is 1290nm-1330nm or 1260nm-1280nm; if it uses an FP laser, the corresponding uplink wavelength is 1260nm-1360nm. For example, when the ONU is a symmetrical 10G EPON ONU, the ONU usually uses a DFB laser, and the corresponding uplink wavelength is 1260nm-1280nm.

[0116] For the ONU with the widest uplink wavelength coverage, i.e., the ONU using an FP laser, its uplink wavelength overlaps with that of other ONUs. Furthermore, since the transmission rate of FP laser-using ONUs is relatively low, they will be prioritized for exiting the PON system to facilitate upgrades. However, due to the large number of FP laser-using ONUs, it is difficult to remove them all from the PON system in a short period. Therefore, the coexistence of FP laser-using ONUs with other ONUs needs to be considered. After the FP laser-using ONU exits the PON system, the coexistence of the remaining ONUs needs to be considered. In other words, it is necessary to ensure the coexistence of multiple ONUs supporting different MAC protocols and with overlapping uplink wavelengths within the PON system.

[0117] To ensure the normal operation of the PON system, this application provides an optical communication device. This optical communication device can use time-division multiplexing or a combination of time-division multiplexing and wavelength-division multiplexing to schedule these ONUs, avoiding uplink data conflicts between ONUs with overlapping uplink wavelengths. This optical communication device can be an OLT or a part of an OLT.

[0118] The optical communication device provided in the embodiments of this application will be described in detail below.

[0119] Figure 2 This is a schematic diagram of the structure of an optical communication device provided in an embodiment of this application. Figure 2As shown, the optical communication device 1 includes a first receiving component 11, a second receiving component 12, and a processing component 20. The first receiving component 11 receives a first optical signal transmitted by a first type of ONU in a first time slot group, and the second receiving component 12 receives a second optical signal transmitted by a second type of ONU in a second time slot group. The first and second types of ONUs support different MAC protocols, and their uplink wavelengths overlap. The first time slot group includes at least one time slot, and the second time slot group includes at least one time slot. The processing component 20 uses a first time slot scheduling mechanism to ensure that the first and second time slot groups do not overlap in the time dimension.

[0120] Optionally, the optical communication device may further include a transmitting component 30 for transmitting optical signals to a first type ONU and a second type ONU.

[0121] In practical applications, the first receiving component 11, the second receiving component 12, and the transmitting component 30 can be integrated into the optical module. Since this optical module has multiple receiving components corresponding to different wavelengths, it can be called a combo optical module. The processing component 20 can be located on a single board, which is connected to the combo optical module.

[0122] In this embodiment, the first time slot scheduling mechanism is used to group time slots into a first time slot group and a second time slot group. The time slots of the first time slot group are used to schedule first-type ONUs, enabling them to transmit a first optical signal within the time slots of the first time slot group. The time slots of the second time slot group are used to schedule second-type ONUs, enabling them to transmit a second optical signal within the time slots of the second time slot group.

[0123] The first time slot scheduling mechanism ensures that the first and second time slot groups do not overlap in the time dimension. For Type I and Type II ONUs with overlapping uplink wavelengths, the first time slot scheduling mechanism can stagger the time dimension of the first optical signal transmitted by the Type I ONU and the second optical signal transmitted by the Type II ONU, preventing them from interfering with each other. This avoids uplink data conflicts between the Type I and Type II ONUs, allowing the PON system to function normally.

[0124] When the protocols supported by the first type of ONU and the second type of ONU belong to different standard systems, the processing component 20 may include a first MAC module and a second MAC module, wherein the first MAC module and the MAC protocol supported by the first type of ONU belong to the same standard system, and the second MAC module and the MAC protocol supported by the second type of ONU belong to the same standard system.

[0125] The first MAC module is connected to the second MAC module, and the first MAC module and the second MAC module synchronize bandwidth allocation information to realize the function of the aforementioned first time slot scheduling mechanism. Here, the bandwidth allocation information is used at least to indicate the time slots included in the first time slot group and the time slots included in the second time slot group.

[0126] In some examples, the first MAC module can implement the function of the first time slot scheduling mechanism, and then synchronize the bandwidth allocation information determined based on the first time slot scheduling mechanism to the second MAC module; or, the second MAC module can implement the function of the first time slot scheduling mechanism, and then synchronize the bandwidth allocation information determined based on the first time slot scheduling mechanism to the first MAC module.

[0127] For example, the first type of ONU can be an EPON ONU, and the second type of ONU can be a 50G PON ONU. When the second type of ONU is a 50G PON ONU, since the corresponding MAC protocol specifies a strict 125μs superframe structure and superframe synchronization, in this embodiment of the application, the time slot lengths of the first time slot group and the second time slot group are both integer multiples of 125μs, so that the time slots in the second time slot group can meet the requirements of the MAC protocol, and the time slots in the first time slot group can also be aligned and synchronized.

[0128] In some examples, the time slot length of the first time slot group is M times 125 μs, and the time slot length of the second time slot group is N times 125 μs. Optionally, M equals N, which simplifies the scheduling mechanism of the first time slot. Alternatively, M may not equal N. The values ​​of M and N can be determined according to actual needs, such as 1, 2, or 3, etc.

[0129] In this embodiment, the number of time slots in the first time slot group and the number of time slots in the second time slot group can be set according to actual needs. Furthermore, the number of time slots in a single first time slot group and the number of time slots in a single second time slot group can be equal or unequal.

[0130] In some examples, in addition to Type I and Type II ONUs, a Type III ONU is also included in the PON system. The structure of the optical communication device with the coexistence of these three types of ONUs is described in detail below. The following explanation will use the example of Type I ONUs supporting the EPON protocol, Type II ONUs supporting the 50G PON protocol, and Type III ONUs supporting the 10G EPON protocol.

[0131] Figure 3 This is a schematic diagram of another optical communication device provided in an embodiment of this application. This optical communication device is applicable to PON systems including the aforementioned first type ONU, second type ONU, and third type ONU.

[0132] In some examples, the third type of ONU includes a first subtype ONU, a second subtype ONU, and a third subtype ONU. The uplink wavelengths of the first subtype ONU and the second subtype ONU do not overlap, but the uplink wavelengths of the first subtype ONU, the second subtype ONU, and the third subtype ONU all overlap. For example, the uplink wavelength of the first subtype ONU is 1290nm-1330nm, the uplink wavelength of the second subtype ONU is 1260nm-1280nm, and the uplink wavelength of the third subtype ONU is 1260nm-1360nm.

[0133] The first type of ONU includes a fourth subtype and a fifth subtype. The uplink wavelengths of the fourth and fifth subtypes overlap. The uplink wavelength of the fourth subtype is the same as that of the first subtype, while the uplink wavelength of the fifth subtype is the same as that of the third subtype. That is, the uplink wavelength of the fourth subtype is 1290nm-1330nm, and the uplink wavelength of the fifth subtype is 1260nm-1360nm.

[0134] As mentioned earlier, the uplink wavelength of the second type of ONU is 1284nm-1288nm. Therefore, the uplink wavelength of the first subtype of ONU does not overlap with the uplink wavelength of the second type of ONU, and the uplink wavelength of the second subtype of ONU does not overlap with the uplink wavelength of the second type of ONU.

[0135] In other examples, the third type of ONU may not include the third subtype of ONU, because the third subtype of ONU is rarely used in practice. The following example illustrates this, where the third type of ONU includes the first and second subtypes of ONU, but does not include the third subtype of ONU.

[0136] like Figure 3 As shown, the optical communication device includes a first receiving component 11, a second receiving component 12, a third receiving component 13, and a processing component 20. The first receiving component 11 receives a first optical signal transmitted by a first type of ONU in a first time slot group. The second receiving component 12 receives a second optical signal transmitted by a second type of ONU in a second time slot group. The third receiving component 13 receives a third optical signal transmitted by a first subtype of ONU and a fourth optical signal transmitted by a second subtype of ONU in the second time slot group. The reception of the third and fourth optical signals by the third receiving component 13 in the second time slot group is performed simultaneously with the reception of the second optical signal by the second receiving component 12 through wavelength division multiplexing. The relevant details of the first and second time slot groups are described in the foregoing embodiments and are omitted here.

[0137] For example, when the first type of ONU includes a fourth subtype ONU and a fifth subtype ONU, the first optical signal transmitted by the first type of ONU includes a fifth optical signal transmitted by the fourth subtype ONU and a sixth optical signal transmitted by the fifth subtype ONU.

[0138] In this embodiment, for the first type of ONU and the second type of ONU with overlapping uplink wavelengths, a first time slot scheduling mechanism can be used to stagger the time dimension of the first optical signal transmitted by the first type of ONU and the second optical signal transmitted by the second type of ONU, so that they do not affect each other, thereby avoiding uplink data conflicts transmitted by the first type of ONU and the second type of ONU. Furthermore, since the uplink wavelengths of the first sub-type ONU and the second sub-type ONU in the third type of ONU do not overlap with the uplink wavelengths of the second type of ONU, the third optical signal transmitted by the first sub-type ONU and the fourth optical signal transmitted by the second sub-type ONU can be wavelength divided and multiplexed with the second optical signal transmitted by the second type of ONU. The third, fourth, and second optical signals are all transmitted in the second time slot group without interfering with each other. Simultaneously, the time dimension staggering of the third and fourth optical signals transmitted by the first sub-type ONU and the first optical signal transmitted by the first type of ONU also prevents them from affecting each other. Therefore, the uplink data sent by the first subclass ONU and the second subclass ONU does not conflict with the uplink data sent by the first type ONU and the second type ONU. The first type ONU, the second type ONU, the first subclass ONU and the second subclass ONU can coexist in the PON system, and the PON system can work normally.

[0139] In addition, the third receiving component 13 receives the third and fourth optical signals in the second time slot group and the second receiving component 12 receives the second optical signal simultaneously through wavelength division multiplexing, which is beneficial to improving the uplink bandwidth utilization of the system.

[0140] In this embodiment, the second sub-type ONU may include an asymmetric 10G EPON ONU or a symmetric 10G EPON ONU, that is, the uplink transmission rate of the second sub-type ONU may be 1.25Gbps or 10Gbps; while the first sub-type ONUs are all asymmetric 10G EPON ONUs, with a corresponding uplink transmission rate of 1.25Gbps. Therefore, the processing component 20 is further configured to use a second time slot scheduling mechanism to enable the third receiving component 13 to receive the third optical signal transmitted by the first sub-type ONU and the fourth optical signal transmitted by the second sub-type ONU in a time-division multiplexing manner in the second time slot group.

[0141] Here, the second time slot scheduling mechanism is used to generate scheduling information that indicates the authorized bandwidth of the first subclass ONU and the authorized bandwidth of the second subclass ONU, and the authorized bandwidths of the first and second subclass ONUs do not overlap in the time dimension. The authorized bandwidth of the second subclass ONU includes both symmetrical and asymmetric authorized bandwidths, and the symmetrical and asymmetric authorized bandwidths of the second subclass ONUs also do not overlap in the time dimension.

[0142] In this embodiment, the first receiving component 11 includes at least a photoelectric conversion device 111 for converting a first optical signal into an electrical signal for output. The first receiving component 11 may also include an amplifier (LA) 112 for amplifying the electrical signal output by the photoelectric conversion device 111. The second receiving component 12 includes at least a photoelectric conversion device 121 for converting the second optical signal into an electrical signal for output. The second receiving component may also include devices such as an LA, not shown in the figure. The first receiving component 11 and the second receiving component 12 may also include electrical signal processing devices such as transimpedance amplifiers for amplifying and processing the electrical signal output by the photoelectric conversion device before outputting it to other devices.

[0143] Optionally, the third receiving component 13 includes a first photoelectric conversion device 131a and a first power divider 132. The first photoelectric conversion device 131a is used to convert the third optical signal, the fourth optical signal, and the fifth optical signal into a first electrical signal. The first power divider 132 is connected to the first photoelectric conversion device 131a and is used to divide the first electrical signal into two sub-signals. These two sub-signals carry the same information.

[0144] The processing component 20 includes a first MAC module 21 and a second MAC module 22. The first MAC module 21 is connected to the first receiving component 11 and the third receiving component 13, and is used to perform uplink scheduling on the first type ONUs, first sub-type ONUs, and second sub-type ONUs corresponding to the first receiving component 11 and the third receiving component 13, and to recover the uplink data transmitted by the first type ONUs, first sub-type ONUs, and second sub-type ONUs from the electrical signals output by the first receiving component 11 and / or the electrical signals output by the third receiving component 13. The second MAC module 22 is connected to the second receiving component 12, and is used to perform uplink scheduling on the second type ONUs corresponding to the second receiving component 12, and to recover the uplink data transmitted by the second type ONUs from the electrical signals output by the second receiving component 12.

[0145] In this embodiment, since the MAC protocols supported by the first type of ONU and the third type of ONU belong to the same standard system, they can be managed uniformly through the first MAC module 21. That is, the MAC protocol supported by the first MAC module 21 belongs to the same standard system as the MAC protocols supported by the first type of ONU and the third type of ONU. The second MAC module 22 belongs to the same standard system as the MAC protocol supported by the second type of ONU.

[0146] The first MAC module 21 includes a first single-speed BCDR circuit 21a and a second single-speed BCDR circuit 21b. The first single-speed BCDR circuit 21a and the second single-speed BCDR circuit 21b each support different data rates. The first single-speed BCDR circuit 21a and the second single-speed BCDR circuit 21b are respectively connected to the first power divider 132 and are used to receive one of the two sub-signals output by the first power divider 132 at their respective data rates. Here, the first single-speed BCDR circuit 21a supports a data rate of 10Gbps, and the second single-speed BCDR circuit 21b supports a data rate of 1.25Gbps. That is, the first MAC module 21 can support either 1.25Gbps or 10Gbps.

[0147] Optionally, the first MAC module 21 further includes a third single-speed BCDR circuit 21d, which is connected to the first receiving component 11. It is used to receive the electrical signal output by the first receiving component 11 at a corresponding rate. Here, the third single-speed BCDR circuit 21d supports a rate of 1.25 Gbps. In other embodiments, the electrical signal output by the first receiving component 11 can also be received via a second single-speed BCDR circuit 21b. In this case, a switching switch is needed to select whether to receive the electrical signal output by the first receiving component 11 or the electrical signal output by the third receiving component 13. This switching switch has two input terminals, one output terminal, and one control terminal. The two input terminals are respectively connected to one output terminal of the first receiving component 11 and one output terminal of the first power divider 132, the output terminal is connected to the second single-speed BCDR circuit 21b, and the control terminal is connected to the first MAC module 21.

[0148] The second MAC module 22 supports rates corresponding to the uplink rates of the second type of ONU, which can be 12.5Gbps, 25Gbps, or 50Gbps. It should be noted that the second MAC module 22 also has a BCDR circuit with a corresponding rate, which is not shown in the figure.

[0149] exist Figure 3 In the illustrated embodiment, two single-speed BCDR circuits are used to correspond to the uplink transmission rate of the first type of ONU and the uplink transmission rate of the third type of ONU, which helps to reduce the cost of optical communication devices.

[0150] The first MAC module 21 selectively receives data at different rates recovered by the first single-speed BCDR circuit and the second single-speed BCDR circuit according to the scheduling information of the first and second time slot scheduling mechanisms. As mentioned above, through the first time slot scheduling mechanism, the first sub-type ONU can transmit the third optical signal in the second time slot group, the second sub-type ONU can transmit the fourth optical signal in the second time slot group, the fourth sub-type ONU can transmit the fifth optical signal in the first time slot group, and the fifth sub-type ONU can transmit the sixth optical signal in the first time slot group; through the second time slot scheduling mechanism, the symmetrical second sub-type ONU, the asymmetrical second sub-type ONU, and the first sub-type ONU can transmit optical signals in a time-division multiplexed manner within the second time slot group. Therefore, the first MAC module can determine the time slots of the symmetrical ONUs, the asymmetrical ONUs, and the first ONUs in the third type of ONU according to the scheduling information of the first and second time slot mechanisms. In the time slot of the symmetrical ONU (i.e., the symmetrical second sub-type ONU) in the third type of ONU, the first MAC module 21 receives the data recovered by the first single-speed BCDR circuit 21a; in the time slot of the asymmetrical ONU (including the first sub-type ONU and the asymmetrical second sub-type ONU) in the third type of ONU and the time slot of the first type of ONU, the first MAC module 21 receives the data recovered by the second single-speed BCDR circuit 21b.

[0151] The second MAC module 22 is connected to the first MAC module 21. The first MAC module 21 and the second MAC module 22 synchronize bandwidth allocation information to realize the function of the aforementioned first time slot scheduling mechanism. Here, the bandwidth allocation information is used at least to indicate the time slots included in the first time slot group and the time slots included in the second time slot group.

[0152] Optionally, the third receiving component 13 further includes a first LA 13a and a second LA 13b, wherein the first LA 13a is connected between one output terminal of the first power divider 132 and the first single-speed BCDR circuit 21a, and the second LA 13b is connected between the other output terminal of the first power divider 132 and the second single-speed BCDR circuit 21b.

[0153] In the embodiments of this application, the photoelectric conversion device and electrical device in each receiving component can be packaged in a coaxial tube, which is called a transistor outline can (TO-CAN) or a receiver (Rx).

[0154] With the development of optical communication technology, PON systems are evolving towards higher transmission rates. However, the aforementioned Class 5 ONUs, due to their excessively large uplink wavelength coverage, limit the use of high-speed ONUs in PON systems. Therefore, it is necessary to prioritize the decommissioning of Class 5 ONUs. After the decommissioning of Class 5 ONUs, time slots can be reallocated. After the decommissioning of Class 5 ONUs, the PON system includes Class 4 ONUs but not Class 5 ONUs. The following describes the operation of the optical communication device after the decommissioning of Class 5 ONUs.

[0155] Optionally, the second receiving component 12 is further configured to receive the second optical signal transmitted by the second type of ONU in both the first and second time slot groups. That is, after the fifth sub-type ONU is decommissioned, the first and second time slot groups are no longer distinguished for the second type of ONU. The third receiving component 13 is further configured to receive the fifth optical signal transmitted by the fourth sub-type ONU in the first time slot group, and the third optical signal transmitted by the first sub-type ONU and the fourth optical signal transmitted by the second sub-type ONU in the second time slot group. The processing component 20 is further configured to use a second time slot scheduling mechanism to enable the third receiving component to receive the third optical signal transmitted by the first sub-type ONU and the fourth optical signal transmitted by the second sub-type ONU in the second time slot group in a time-division multiplexing manner. That is, after the fifth sub-type ONU is decommissioned, the time slots in the first time slot group are used to schedule the fourth sub-type ONU, and the time slots in the second time slot group are used to schedule the first and second sub-type ONUs.

[0156] Assume that the first phase begins before the fifth subclass ONU is decommissioned, and the second phase begins after the fifth subclass ONU is decommissioned. The following will combine... Figure 4 The document explains the time slot usage in the first and second phases and the operation of the optical communication device.

[0157] Figure 4 This is a schematic diagram of time slot allocation before and after network decommissioning provided in an embodiment of this application. Figure 4 In this diagram, both the first and second time slot groups consist of two time slots. The number of time slots in the first and second time slot groups is merely an example and is not a limitation. The allocation of time slots in the first and second time slot groups can be adjusted based on the number of ONUs, ONU types, and service information used by the ONUs in the PON system.

[0158] Figure 4 Part (a) illustrates the time slot allocation method for the first phase. For example... Figure 4 As shown in part (a), the time slots in the first time slot group are used to allocate to the first type ONU (EPON ONU), and the time slots in the second time slot group are used to allocate to the first subclass ONU and the second subclass ONU in the second type ONU (50G PON) and the third type ONU (10G EPON) in a wavelength division multiplexing manner.

[0159] In the first stage: the first receiving component 11 receives the first optical signal transmitted by the first type of ONU in the first time slot group, and receives the second optical signal transmitted by the second type of ONU, the third optical signal transmitted by the first subtype of ONU, and the fourth optical signal transmitted by the second subtype of ONU in the second time slot group; the second receiving component receives the second optical signal transmitted by the second type of ONU in the second time slot group; the third receiving component receives the third optical signal transmitted by the first subtype of ONU and the fourth optical signal transmitted by the second subtype of ONU in the second time slot group.

[0160] In the first time slot group, processing component 20 receives the electrical signal output by the first receiving component 11 through the first MAC module 21, and obtains the uplink data sent by the first type of ONU from the electrical signal output by the first receiving component 11. In the second time slot group, processing component 20 receives the electrical signal output by the third receiving component 13 through the first MAC module 21, and obtains the uplink data sent by the first sub-type ONU and the second sub-type ONU from the electrical signal output by the third receiving component 13; in the second time slot group, it receives the electrical signal output by the second receiving component 12 through the second MAC module 22, and obtains the uplink data sent by the second type of ONU from the electrical signal output by the second receiving component 12.

[0161] Figure 4 Part (b) illustrates the time slot allocation method for the second phase. For example... Figure 4 As shown in section (b), the fourth subclass ONU in the first type of ONU (EPON ONU) and the first and second subclass ONUs in the third type of ONU (10G EPON ONU) correspond to the first row of time slots, while the second type of ONU (50G PON) corresponds to the second row of time slots. The two rows of time slots are aligned in the time dimension. It can be seen that in the second stage, the second and third receiving components receive the optical signals transmitted by the corresponding ONUs in a wavelength division multiplexing manner, and the third receiving component receives the optical signals transmitted by the fourth subclass ONU, the first subclass ONU, and the second subclass ONU in a time division multiplexing manner.

[0162] In the second stage: the first receiving component 11 receives the second optical signal transmitted by the second type of ONU and the fifth optical signal transmitted by the fourth subtype of ONU in the first time slot group, and receives the second optical signal transmitted by the second type of ONU, the third optical signal transmitted by the first subtype of ONU, and the fourth optical signal transmitted by the second subtype of ONU in the second time slot group; the second receiving component 12 receives the second optical signal transmitted by the second type of ONU in the first time slot group and the second time slot group; the third receiving component 13 receives the fifth optical signal transmitted by the fourth subtype of ONU in the first time slot group, and receives the third optical signal transmitted by the first subtype of ONU and the fourth optical signal transmitted by the second subtype of ONU in the second time slot group.

[0163] Processing component 20 no longer receives or ignores the electrical signals output by the first receiving component 11. In both the first and second time slot groups, processing component 20 receives the electrical signals output by the second receiving component 12 through the second MAC module 22, and obtains the uplink data transmitted by the second type of ONU from the electrical signals output by the second receiving component 12. In the first time slot group, processing component 20 also receives the electrical signals output by the third receiving component 13 through the first MAC module 21, and obtains the uplink data transmitted by the fourth subtype of ONU from the electrical signals output by the third receiving component 13. In the second time slot group, processing component 20 also receives the electrical signals output by the third receiving component 13 through the first MAC module 21, and obtains the uplink data transmitted by the first and second subtypes of ONU from the electrical signals output by the third receiving component 13.

[0164] In this embodiment, the receiving wavelength range of the first receiving component 11 is 1260nm-Xnm, where X is less than or equal to 1360nm and greater than 1330nm. Here, the receiving wavelength range of the first receiving component is the filtering range of the filter device corresponding to the first receiving component. The filter device corresponding to the first receiving component is used to filter out the optical signal within the corresponding wavelength range from the uplink optical signal received by the optical communication device and send the filtered optical signal to the first receiving component.

[0165] In actual network deployments, this optical communication device is typically a component of an OLT, which connects to multiple ONUs via an ODN. If reflections occur on the ODN, and the receiving wavelength range of the first receiving component overlaps with the downlink wavelength of the second type of ONU, there is a possibility that the downlink optical signal of the second type of ONU may be reflected back to the OLT by the ODN and enter the first receiving component. This will affect the reception and data recovery of uplink signals from both the first and third type of ONUs. To mitigate this risk, the receiving wavelength range of the first receiving component can be set to not overlap with the downlink wavelength of the second type of ONU. For example, when the downlink wavelength of the second type of ONU is 1340nm-1344nm, X can be set to be less than or equal to 1340nm. However, to avoid affecting the normal reception of uplink signals from the first type of ONU, X needs to be greater than 1330nm.

[0166] For example, X is equal to 1335 or 1340, etc.

[0167] The second receiving component 12 is used to receive the second optical signal transmitted by the second type of ONU. Therefore, the receiving wavelength range of the second receiving component 12 can be consistent with the uplink wavelength of the second type of ONU, which is 1284nm-1288nm. The third receiving component 13 is used to receive the third optical signal transmitted by the first sub-type ONU and the fourth optical signal transmitted by the second sub-type ONU. Therefore, the receiving wavelength range of the third receiving component 13 is a combination of the uplink wavelength of the first sub-type ONU and the uplink wavelength of the second sub-type ONU, that is, including 1260nm-1280nm and 1290nm-1330nm.

[0168] Optionally, the optical communication device further includes an optical path control component, which is used to send the optical signals received by the optical communication device to corresponding receiving components. For example, the optical path control component includes a beam splitter 41, filters 42 and 43. The beam splitter 41 splits the optical signals received by the optical communication device into two paths: one path is sent to the first receiving component 11, and the other path, after being filtered by filter 42, is sent to the second receiving component 12; after being filtered by filter 43, it is sent to the third receiving component 13. The filtering range of filter 42 is the receiving wavelength range of the second receiving component 12. The filtering range of filter 43 is the receiving wavelength range of the third receiving component 13.

[0169] Optionally, the optical communication device further includes a transmitting component 30. This transmitting component 30 is used to transmit optical signals to a first-type ONU, a second-type ONU, and a third-type ONU. For example, in... Figure 3 In the illustrated embodiment, the transmitting component 30 includes a first transmitting unit 31 (also referred to as a first transmitter (Tx)) and a second transmitting unit 32. The first transmitting unit 31 transmits optical signals with wavelengths of 1480nm-1500nm (corresponding to the downlink wavelength of a first-type ONT). The second transmitting unit 32 transmits optical signals with wavelengths of 1575nm-1580nm (corresponding to the downlink wavelength of a third-type ONU) and 1340nm-1344nm (corresponding to the downlink wavelength of a second-type ONU). The first transmitting unit 31 and the second transmitting unit 32 are both encapsulated in a coaxial housing. The downlink channel between the OLT and the ONU can be a wavelength division multiplexed downlink wavelength channel.

[0170] Optionally, the transmitting component 30 further includes a multiplexer 33, which is used to combine the optical signals output by the first transmitting unit 31 and the second transmitting unit 32 into one channel before outputting it from the optical communication device.

[0171] In other embodiments, the first transmitting unit 21 and the second transmitting unit 22 may also be packaged in the same coaxial housing, or the second transmitting unit 22 may be replaced by two independently packaged transmitting units, one for transmitting optical signals of 1575nm-1580nm and the other for transmitting optical signals of 1340nm-1344nm.

[0172] It should be noted that the above description uses the example of a third type of ONU including a first subtype ONU and a second subtype ONU. In other embodiments, the third type of ONU may only include a first subtype ONU or a second subtype ONU. In this case, the third receiving component is used to receive a third optical signal transmitted by a first subtype ONU or a fourth optical signal transmitted by a second subtype ONU in a second time slot group. The reception of the third or fourth optical signal by the third receiving component in the second time slot group and the reception of the second optical signal by the second receiving component are performed simultaneously through wavelength division multiplexing.

[0173] Figure 5 This is a schematic diagram of another optical communication device provided in an embodiment of this application. Figure 5 The optical communication device shown is Figure 3 The difference between the optical communication devices shown lies in the different structures of the third receiving component 13 and the first MAC module 21.

[0174] like Figure 5 As shown, the third receiving component 13 includes a second photoelectric conversion device 131b. The second photoelectric conversion device 131b is used to convert the third optical signal, the fourth optical signal, and the fifth optical signal into a second electrical signal.

[0175] The first MAC module 21 includes a dual-speed BCDR circuit 21c, which is connected to the second photoelectric conversion device 131b and is used to selectively receive a second electrical signal at a first rate and / or a second rate. The first MAC module 21 selectively receives data at different rates recovered by the dual-speed BCDR circuit 21c according to scheduling information from a first time slot scheduling mechanism and a second time slot scheduling mechanism.

[0176] Figure 5 The first and second time slot scheduling mechanisms used in optical communication devices are similar to those used in optical communication devices. Figure 3 The embodiments shown are the same, therefore, Figure 5 The corresponding time slot allocation method is also as follows Figure 4 As shown, the working process of optical communication devices is also related to... Figure 4 The same applies, so I won't repeat it here.

[0177] Figure 6 This is a schematic diagram of another optical communication device provided in an embodiment of this application. Figure 6 The optical communication device shown is Figure 3The difference between the optical communication devices shown lies in the different structures of the third receiving component and the first MAC module.

[0178] like Figure 6 As shown, the third receiving component 13 includes a third photoelectric conversion device 131c and a fourth photoelectric conversion device 131d. The third photoelectric conversion device 131c is used to convert a fourth optical signal into a third electrical signal. The fourth photoelectric conversion device 131d is used to convert the third optical signal and the fifth optical signal into a fourth electrical signal. The third photoelectric conversion device 131c and the fourth photoelectric conversion device 131d are respectively encapsulated in a coaxial housing.

[0179] The first MAC module 21 includes a first single-speed BCDR circuit 21a and a dual-speed BCDR circuit 21c. The first single-speed BCDR circuit 21a is connected to the fourth photoelectric converter 131d and is used to receive a fourth electrical signal at a first rate. The dual-speed BCDR circuit 21c is connected to the third photoelectric converter 131c and is used to selectively receive a third electrical signal at either the first rate or the second rate. For details regarding the first and second rates, please refer to [link to relevant documentation]. Figure 3 The embodiments shown will not be described in detail here.

[0180] The first MAC module 21 receives data at different rates recovered by the first single-speed BCDR circuit 21a and the dual-speed BCDR circuit 21c according to the scheduling information of the first time slot scheduling mechanism and the second time slot scheduling mechanism.

[0181] exist Figure 6 In the illustrated embodiment, the optical path control component includes a beam splitter 41 and filters 42, 43, and 44. The beam splitter 41 splits the optical signal received by the optical communication device into two paths: one path is sent to the first receiving component 11, and the other path, after being filtered by filter 42, is sent to the second receiving component 12; after being filtered by filter 43, it is sent to the third photoelectric converter of the third receiving component 13; and after being filtered by filter 44, it is sent to the fourth photoelectric converter of the third receiving component 13. The filtering range of filter 42 is the receiving wavelength range of the second receiving component 12. The combination of the filtering ranges of filters 43 and 44 constitutes the receiving wavelength range of the third receiving component 13.

[0182] Figure 7 This is a schematic diagram of another optical communication device provided in an embodiment of this application. Figure 7 The optical communication device shown is Figure 6 The difference in the optical communication devices shown lies in the structure of the third receiving component 13. Figure 7In this design, the third photoelectric conversion device 131c and the fourth photoelectric conversion device 131d are packaged in the same coaxial housing, a structure that can be referred to as a dual-integrated TO. This dual-integrated TO has two output terminals: one for outputting the third electrical signal from the third photoelectric conversion device 131c, and the other for outputting the fourth electrical signal from the fourth photoelectric conversion device 131d.

[0183] The first MAC module 21 includes a first single-speed BCDR circuit 21a and a dual-speed BCDR circuit 21c. The first single-speed BCDR circuit 21a is connected to the output terminal corresponding to the fourth photoelectric converter 131d and is used to receive the third electrical signal at a first rate. The dual-speed BCDR circuit 21c is connected to the output terminal corresponding to the third photoelectric converter 131c and is used to selectively receive the fourth electrical signal at either the first rate or the second rate. The first MAC module 21 receives data at different rates recovered by the first single-speed BCDR circuit 21a and the dual-speed BCDR circuit 21c according to the scheduling information of the first time slot scheduling mechanism and the second time slot scheduling mechanism.

[0184] As mentioned earlier, since the second subclass ONU is divided into symmetrical and asymmetrical second subclass ONU, the uplink transmission rate of the symmetrical second subclass ONU is 10Gbps, and the uplink transmission rate of the asymmetrical second subclass ONU is 1.25Gbps. Therefore, Figure 6 and Figure 7 In the embodiment shown, the dual-speed BCDR circuit 21c is used to receive the fourth electrical signal at a second rate in the time slot of the symmetrical second subclass ONU, and at a first rate in the time slot of the asymmetrical second subclass ONU.

[0185] Assume that the first phase begins before the fifth subclass ONU is decommissioned, and the second phase begins after the fifth subclass ONU is decommissioned. The following will combine... Figure 8 The document explains the time slot usage in the first and second phases and the operation of the optical communication device.

[0186] Figure 8 This is a schematic diagram of time slot allocation before and after network decommissioning provided in an embodiment of this application. For example... Figure 8 As shown, both the first and second time slot groups consist of two time slots. Figure 8 Part (a) shows the time slot allocation method in the first phase. Figure 8 Part (b) shows the time slot allocation method in the second phase.

[0187] like Figure 8As shown in part (a), the time slots in the first time slot group are used to allocate to the first type ONU (EPON ONU), and the time slots in the second time slot group are used to allocate to the first subclass ONU and the second subclass ONU in the second type ONU (50G PON) and the third type ONU (10GEPON) in a wavelength division multiplexing manner.

[0188] In the first stage: the first receiving component 11 receives the first optical signal transmitted by the first type of ONU in the first time slot group, and receives the second optical signal transmitted by the second type of ONU, the third optical signal transmitted by the first sub-type ONU, and the fourth optical signal transmitted by the second sub-type ONU in the second time slot group; the second receiving component 12 receives the second optical signal transmitted by the second type of ONU in the second time slot group; the third photoelectric conversion device in the third receiving component 13 receives the fourth optical signal transmitted by the second sub-type ONU in the second time slot group, and the fourth photoelectric conversion device receives the third optical signal transmitted by the first sub-type ONU and the fifth optical signal transmitted by the fourth sub-type ONU in the second time slot group.

[0189] In the first time slot group, processing component 20 receives the electrical signal output by the first receiving component 11 through the first MAC module 21, and obtains the uplink data transmitted by the first type of ONU from the electrical signal output by the first receiving component 11. In the second time slot group, processing component 20 receives the electrical signal output by the first receiving component 11 through the first MAC module 21, and obtains the uplink data transmitted by the asymmetric ONUs in the first and second sub-types of ONUs from the electrical signal output by the first receiving component 11. In the second time slot group, processing component 20 receives the electrical signal output by the second receiving component 12 through the second MAC module 22, and obtains the uplink data transmitted by the second type of ONU from the electrical signal output by the second receiving component 12. In the second time slot group, processing component 20 receives the electrical signal output by the fourth optoelectronic conversion device of the third receiving component 13 through the first MAC module 21, and obtains the uplink data transmitted by the symmetric ONUs in the second sub-type of ONUs from the electrical signal output by the fourth optoelectronic conversion device. Processing component 20 does not receive or ignores the electrical signal output by the third optoelectronic conversion device.

[0190] like Figure 8As shown in section (b), the fourth subclass ONU in the first type of ONU (EPON ONU) and the asymmetric ONUs in the first and second subclass ONUs in the third type of ONU (10GEPON ONU) correspond to the first row of time slots. The symmetric ONUs in the second subclass ONU correspond to the second row of time slots, and the second type of ONU (50G PON) corresponds to the third row of time slots. The three rows of time slots are aligned in the time dimension. It can be seen that in the second stage, the second receiving component and the third receiving component receive the optical signals transmitted by the corresponding ONUs in a wavelength division multiplexing manner, and the third receiving component receives the optical signals transmitted by the fourth subclass ONU, the first subclass ONU, and the second subclass ONU in a time division multiplexing manner.

[0191] In the second stage: the first receiving component 11 receives the second optical signal transmitted by the second type of ONU, the third optical signal transmitted by the first sub-type ONU, the fourth optical signal transmitted by the second sub-type ONU, and the fifth optical signal transmitted by the fourth sub-type ONU in the first and second time slot groups; the second receiving component 12 receives the second optical signal transmitted by the second type of ONU in the first and second time slot groups; the third receiving component 13 receives the third optical signal transmitted by the first sub-type ONU, the fourth optical signal transmitted by the second sub-type ONU, and the fifth optical signal transmitted by the fourth sub-type ONU in the first and second time slot groups. The third optical signal transmitted by the first sub-type ONU, the fourth optical signal transmitted by the second sub-type ONU, and the fifth optical signal transmitted by the fourth sub-type ONU are received in a time-division multiplexing manner.

[0192] In some examples, in this second phase, it is not necessary to divide the first time slot group and the second time slot group, that is, the second type of ONU is scheduled throughout the entire time dimension; at the same time, the first sub-type ONU, the second sub-type ONU and the fourth sub-type ONU are scheduled throughout the entire time dimension.

[0193] In other examples, in this second phase, a first time slot group and a second time slot group are still divided. The first time slot group is used to schedule the first subclass ONU and the fourth subclass ONU, and the second time slot group is used to schedule the second subclass ONU; or, the second time slot group is used to schedule the first subclass ONU and the fourth subclass ONU, and the first time slot group is used to schedule the second subclass ONU; or, the first time slot group is used to schedule the first subclass ONU, the fourth subclass ONU, and the asymmetric second subclass ONU, and the second time slot group is used to schedule the symmetric second subclass ONU; or, the second time slot group is used to schedule the first subclass ONU, the fourth subclass ONU, and the asymmetric second subclass ONU, and the first time slot group is used to schedule the symmetric second subclass ONU.

[0194] Processing component 20 does not receive or ignores the electrical signal output by the first receiving component 11. Processing component 20 receives the second electrical signal output by the second receiving component 12 through the second MAC module 22 in the first and second time slot groups, and obtains the uplink data transmitted by the second type of ONU from the second electrical signal output by the second receiving component 12. Processing component 20 receives the electrical signal output by the fourth optoelectronic conversion device through the first MAC module 21 in the first and second time slot groups, and obtains the uplink data transmitted by the second subtype of ONU from the electrical signal output by the fourth optoelectronic conversion device; and receives the electrical signal output by the third optoelectronic conversion device through the first MAC module 21, and obtains the uplink data transmitted by the first subtype of ONU and the uplink data transmitted by the fourth subtype of ONU from the electrical signal output by the third optoelectronic conversion device.

[0195] The foregoing embodiments have all been described using the example of a third type of ONU excluding a third subtype. However, if the third type of ONU also includes a third subtype ONU, the first receiving component 11 is further configured to receive the seventh optical signal transmitted by the third subtype ONU in the first time slot group. Correspondingly, the scheduling information generated by the second time slot scheduling mechanism is also used to indicate the authorized bandwidth of the third subtype ONU and the authorized bandwidth of the first type of ONU, and the authorized bandwidths of the third subtype ONU and the first type of ONU do not overlap in the time dimension. In this way, the first receiving component 11 receives the seventh optical signal transmitted by the third subtype ONU and the first optical signal transmitted by the first type of ONU in the first time slot group in a time-division multiplexing manner.

[0196] Since the uplink wavelengths of the third-subclass ONU and the fifth-subclass ONU are the same, during the PON system upgrade process, the third-subclass ONU and the fifth-subclass ONU need to be decommissioned together. After the third-subclass ONU and the fifth-subclass ONU are decommissioned, the operation process of the optical communication device is the same as the second stage mentioned above.

[0197] exist Figures 3 to 8 In the illustrated embodiment, the optical communication device employs a combination of time-division multiplexing and wavelength-division multiplexing to enable the coexistence of Type I, Type II, and Type III ONUs in the PON system. In other embodiments, the optical communication device can also achieve the coexistence of Type I, Type II, and Type III ONUs through time-division multiplexing. The following provides an example illustrating the coexistence of Type I, Type II, and Type III ONUs using time-division multiplexing.

[0198] Figure 9 This is a schematic diagram of another optical communication device provided in an embodiment of this application. This optical communication device is applicable to PON systems including the aforementioned first type ONU, second type ONU, and third type ONU.

[0199] like Figure 9As shown, the optical communication device includes a first receiving component 11, a second receiving component 12, and a processing component 20. The first receiving component 11 is used to receive a first optical signal transmitted by a first type of ONU and a third optical signal transmitted by a third type of ONU in a first time slot group. The second receiving component 12 is used to receive a second optical signal transmitted by a second type of ONU in a second time slot group. The first time slot group includes at least one time slot, and the second time slot group includes at least one time slot.

[0200] The processing component 20 is used to ensure that the first time slot group and the second time slot group do not overlap in the time dimension through the first time slot scheduling mechanism. The processing component 20 is also used to ensure that the first receiving component 11 receives the first optical signal and the third optical signal in the first time slot group in a time-division multiplexing manner through the third time slot scheduling mechanism.

[0201] Here, since both Type I and Type III ONUs are scheduled within the time slots of the first time slot group, a third time slot scheduling mechanism is needed to ensure that uplink data between Type I and Type III ONUs does not conflict. This third time slot scheduling mechanism is used to generate bandwidth allocation information (also known as scheduling information), which indicates the authorized bandwidth of Type I ONUs and the authorized bandwidth of Type III ONUs, and the authorized bandwidths of Type I ONUs and Type III ONUs do not overlap in the time dimension.

[0202] exist Figure 9 In the illustrated embodiment, the first receiving component 11 is used to receive the first optical signal transmitted by the first type of ONU and the third optical signal transmitted by the third type of ONU, and the maximum uplink wavelength coverage range of the first type of ONU and the third type of ONU is 1260nm-1360nm. Therefore, the receiving wavelength range of the first receiving component 11 is relatively large. For example, the receiving wavelength range of the first receiving component 11 can be 1260nm-1360nm, or the upper limit of the receiving wavelength range of the first receiving component 11 can be slightly less than 1360nm, for example, 1340nm. The second receiving component 12 is used to receive the second optical signal transmitted by the second type of ONU. Therefore, the receiving wavelength range of the second receiving component 12 can be consistent with the uplink wavelength of the second type of ONU, which is 1284nm-1288nm.

[0203] Optionally, the first receiving component 11 includes a fifth photoelectric conversion device 111a and a second power divider 112. The fifth photoelectric conversion device 111a converts the first optical signal and the third optical signal into a first electrical signal. The second power divider 112 is connected to the fifth photoelectric conversion device 111a and is used to split the first electrical signal into two sub-signals. These two sub-signals carry the same information.

[0204] Optionally, the second receiving component 12 includes at least a photoelectric conversion device 121 for converting the second optical signal into an electrical signal.

[0205] The fifth photoelectric conversion device 111a and photoelectric conversion device 121 can also be called receivers (Rx), and can be packaged in corresponding coaxial packages. This structure is called transistor outline can (TO-CAN).

[0206] The processing component 20 includes a first MAC module 21 and a second MAC module 22. The first MAC module 21 is connected to the first receiving component 11 and is used for uplink scheduling of the first type ONUs and third type ONUs corresponding to the first receiving component 11, and for recovering the uplink data transmitted by the first type ONUs and third type ONUs from the optical signals received by the first receiving component 11. The second MAC module 22 is connected to the second receiving component 12 and is used for uplink scheduling of the second type ONUs corresponding to the second receiving component 12, and for recovering the uplink data transmitted by the second type ONUs from the optical signals received by the second receiving component 12.

[0207] In this embodiment, the first MAC module 21 and the MAC protocols supported by the first type of ONU and the third type of ONU belong to the same standard system, and the second MAC module 22 and the MAC protocols supported by the second type of ONU belong to the same standard system.

[0208] The first MAC module 21 is connected to the second MAC module 22, and the first MAC module 21 and the second MAC module 22 synchronize bandwidth allocation information to implement the aforementioned first time slot scheduling mechanism. Here, the bandwidth allocation information is used at least to indicate the time slots included in the first time slot group and the time slots included in the second time slot group.

[0209] The first MAC module 21 includes a first single-speed BCDR circuit 21a and a second single-speed BCDR circuit 21b, which support different data rates. The first single-speed BCDR circuit 21a and the second single-speed BCDR circuit 21b are respectively connected to the two output terminals of the second power divider 112, and are respectively used to receive one of the two sub-signals output by the second power divider 112 at the corresponding rate. The first MAC module 21 is used to selectively receive data at different rates recovered by the first single-speed BCDR circuit 21a and the second single-speed BCDR circuit 21b according to the scheduling information of the third time slot scheduling mechanism.

[0210] Specifically, the first single-speed BCDR circuit 21a supports the same data rate as the first type of ONU, and the second single-speed BCDR circuit 21b supports the same data rate as the third type of ONU. For example, when the first type of ONU is an EPON ONU, both the first single-speed BCDR circuit and the first type of ONU support a data rate of 1.25Gbps; when the third type of ONU is a 50G PON ONU, both the second single-speed BCDR circuit and the third type of ONU support a data rate of 10.3125Gbps.

[0211] The second MAC module 22 supports rates corresponding to the uplink rates of the second type of ONU, which can be 12.5Gbps, 25Gbps, or 50Gbps. It should be noted that the second MAC module 22 also has a single-speed BCDR circuit with the corresponding rate, which is not shown in the figure.

[0212] exist Figure 9 In the illustrated embodiment, two single-speed BCDR circuits are used to correspond to the uplink transmission rate of the first type of ONU and the uplink transmission rate of the third type of ONU, which helps to reduce the cost of optical communication devices.

[0213] Optionally, the first receiving component 11 further includes a first limiting amplifier (LA) 113a and a second LA 113b. The first LA 113a is connected between one output terminal of the first power divider 112 and the first single-speed BCDR circuit 21a, and the second LA 113b is connected between the other output terminal of the first power divider 112 and the second single-speed BCDR circuit 21b. The first receiving component uses LAs to amplify the electrical signal before outputting it to the corresponding single-speed BCDR circuit, which is beneficial for the single-speed BCDR circuit to recover data from the received electrical signal.

[0214] Optionally, the optical communication device may also include a transmitting component 30. For details regarding the transmitting component 30, please refer to [link to relevant information]. Figure 3 The embodiments shown are not described in detail here.

[0215] Figure 10 This is a schematic diagram of another optical communication device provided in an embodiment of this application. Figure 9 The difference in the optical communication device shown lies in the different structures of the first receiving component 11 and the first MAC module 21. For example... Figure 10As shown, the first receiving component 11 includes a sixth photoelectric conversion device 111b, used to convert the first optical signal and the third optical signal into a fifth electrical signal. The first MAC module 21 includes a dual-speed BCDR circuit 21c, which is connected to the sixth photoelectric conversion device 111b and is used to selectively receive the fifth electrical signal at a first rate and / or a second rate. The first MAC module 21 is used to selectively receive data at different rates output by the dual-speed BCDR circuit 21c according to the scheduling information of the third time slot scheduling mechanism.

[0216] Since the first MAC module 21 can selectively recover data from the first electrical signal at different rates via the dual-speed BCDR 21c, it can... Figure 9 Based on the structure shown, the first power divider in the first receiving component 11 is omitted, simplifying the structure of the first receiving component 11.

[0217] Optionally, the first receiving component 11 further includes an LA 113c, which is connected between the first photoelectric conversion device 111 and the dual-speed BCDR circuit 21c. The first receiving component 11 uses the LA 113c to amplify the electrical signal before outputting it to the dual-speed BCDR circuit, which helps the dual-speed BCDR circuit recover data from the received electrical signal.

[0218] exist Figure 10 In the embodiment shown, the first MAC module 21 is further configured to output a speed selection signal based on the bandwidth allocation information. The speed selection signal is used to control the filtering bandwidth of the filter device corresponding to the first receiving component 11.

[0219] Optionally, the first MAC module 21 is also used to output a control signal according to the bandwidth allocation information. The control signal is used to control the operating bandwidth of LA 13c, so that the operating bandwidth of LA 13c is dynamically adjusted with the bandwidth of the optical signal to reduce noise and achieve better receiving sensitivity.

[0220] Figure 11 This is a schematic diagram illustrating the relationship between a first time slot group and a second time slot group provided in an embodiment of this application. For example... Figure 11 As shown, the time slots in the first time slot group are used to schedule the first type ONU and the third type ONU in a time-division multiplexing manner, and the time slots in the second time slot group are used to schedule the second type ONU.

[0221] The processing component 20 receives the electrical signal output by the first receiving component 11 through the first MAC module 21, and obtains the uplink data sent by the first type of ONU and the third type of ONU from the electrical signal output by the first receiving component 11; the processing component 20 receives the electrical signal output by the second receiving component 12 through the second MAC module 22, and obtains the uplink data sent by the second type of ONU from the electrical signal output by the second receiving component 12.

[0222] Optionally, the aforementioned first MAC module 21 and second MAC module 22 can be integrated on the same physical chip, or the first MAC module 21 and second MAC module 22 can be respectively set on different physical chips.

[0223] In the embodiments of this application, the physical chip may be a field-programmable gate array (FPGA), an application-specific integrated circuit (ASIC), a system on chip (SoC), a central processor unit (CPU), a digital signal processor (DSP), a programmable logic device (PLD), or other integrated chips, and this application does not limit this.

[0224] The first time slot scheduling mechanism used by the processing component is described below.

[0225] In this embodiment, the first time slot scheduling mechanism includes determining a first time slot group and a second time slot group within a target period based on the bandwidth requirement information of the plurality of ONUs. The target period includes M time slots, where M is greater than 1 and M is an integer. The first time slot group includes X time slots from the M time slots, and the second time slot group includes Y time slots from the M time slots. X and Y are both positive integers, and the sum of X and Y is less than or equal to M. The time slots of the first time slot group are used to allocate time slots to first-type ONUs according to the MAC protocol supported by the first-type ONUs, and the time slots of the second time slot group are used to allocate time slots to second-type ONUs according to the MAC protocol supported by the second-type ONUs.

[0226] The time slots in the first time slot group will be referred to as the first time slots, and the time slots in the second time slot group will be referred to as the second time slots.

[0227] In one possible implementation, the first time slot group includes at least two first subsets, each of the at least two first subsets including one first time slot or including at least two consecutive first time slots, and at least one second time slot exists between two adjacent first subsets; and / or, the second time slot group includes at least two second subsets, each of the at least two second subsets including one second time slot or including at least two consecutive time slots, and at least one first time slot exists between two adjacent second subsets.

[0228] Alternating between the first and second subsets within a target period allows for a more even distribution of time slots within the target period to the ONUs corresponding to the first and second time slot groups, minimizing the waiting time for different types of ONUs to send uplink data.

[0229] In another possible implementation, the first time slot group includes a first time slot or includes at least two consecutive first time slots; and / or, the second time slot group includes a second time slot or includes at least two consecutive second time slots.

[0230] Optionally, at least one first time slot in the first time slot group is a windowed time slot; and / or, at least one second time slot in the second time slot group is a windowed time slot. Setting a windowing period within the first time slot group can prevent the windowing period from affecting the normal service communication of the ONU corresponding to the second time slot group. Similarly, setting a windowing period within the second time slot group can prevent the windowing period from affecting the normal service communication of the ONU corresponding to the first time slot group.

[0231] In the embodiments of this application, an open window time slot refers to a time slot in one or more time slots where bandwidth is not authorized, but is used to receive registration requests from ONTs waiting to be connected, or for network operation and maintenance, such as rogue terminal detection, reflection detection, etc.

[0232] Optionally, the first time slot scheduling mechanism further includes: designating one time slot outside the target period or at least two consecutive time slots as the windowing time slot. This allows for the configuration of the windowing period after one or more target periods as needed, making the configuration of the windowing period more flexible.

[0233] Optionally, the bandwidth requirement information of the ONU includes at least one of the following: the number of ONUs of each type, and the service information of the services activated by the ONU. Optionally, the service information includes service type or latency requirements, etc.

[0234] In this embodiment, it is assumed that the first time slot group is used to schedule ONUs in the first terminal set, and the second time slot group is used to schedule ONUs in the second terminal set. In this embodiment, the more ONUs in the first terminal set, and the greater the bandwidth requirement corresponding to the services activated by each ONU, the larger the proportion of time slots included in the first time slot group in the target period. Similarly, the more ONUs in the second terminal set, and the greater the bandwidth requirement corresponding to the services activated by each ONU, the larger the proportion of time slots included in the second time slot group in the target period.

[0235] Optionally, the first time slot scheduling mechanism may determine the proportion of time slots contained in the first and second time slot groups in the target period using any of the following methods.

[0236] The first type of bandwidth requirement information includes the number of ONUs in the first terminal set and the number of ONUs in the second terminal set. The proportion of the first time slot group in the target period is equal to a first ratio of the number of ONUs in the first terminal set to the sum of the number of ONUs in the first terminal set and the number of ONUs in the second terminal set; similarly, the proportion of the second time slot group in the target period is equal to a second ratio of the number of ONUs in the second terminal set to the sum of the number of ONUs in the first terminal set and the number of ONUs in the second terminal set.

[0237] The second type of bandwidth requirement information includes the service types enabled by each ONU in the first terminal set and the service types enabled by each ONU in the second terminal set.

[0238] First, the OLT determines the bandwidth corresponding to the service type of each ONU based on the mapping relationship between service type and bandwidth, which serves as the bandwidth requirement for each ONU. Then, the ONU calculates the sum of the bandwidth requirements of all ONUs in the first terminal set and the sum of the bandwidth requirements of all ONUs in the second terminal set. The third ratio of the sum of the bandwidth requirements of all ONUs in the first terminal set to the sum of the bandwidth requirements of all ONUs in the first and second terminal sets is determined as the proportion of the first time slot group in the target period. The fourth ratio of the sum of the bandwidth requirements of all ONUs in the second terminal set to the sum of the bandwidth requirements of all ONUs in the first and second terminal sets is determined as the proportion of the second time slot group in the target period.

[0239] The third type of bandwidth requirement information includes the number of ONUs in the first terminal set, the number of ONUs in the second terminal set, the types of services activated by the ONUs in the first terminal set, and the types of services activated by the ONUs in the second terminal set.

[0240] The proportion of the first time slot group in the target period is obtained by multiplying the first ratio of the number of ONUs in the first terminal set to the sum of the number of ONUs in the first terminal set and the sum of the bandwidth requirements of all ONUs in the first terminal set and the sum of the bandwidth requirements of all ONUs in the first terminal set and the sum of the bandwidth requirements of all ONUs in the second terminal set, respectively, with their corresponding weights. Similarly, the proportion of the second time slot group in the target period is obtained by multiplying the third ratio of the number of ONUs in the second terminal set to the sum of the number of ONUs in the first terminal set and the sum of the bandwidth requirements of all ONUs in the second terminal set and the sum of the bandwidth requirements of all ONUs in the first terminal set and the sum of the bandwidth requirements of all ONUs in the second terminal set, respectively, with their corresponding weights. The sum of the weights corresponding to the first and second ratios is equal to 1; the sum of the weights corresponding to the third and fourth ratios is also equal to 1.

[0241] The weights corresponding to the first ratio, the second ratio, the third ratio, and the fourth ratio can be set as needed, for example, all of which can be 0.5.

[0242] Optionally, in addition to determining the proportion of the first time slot group and the second time slot group, determining the first time slot group and the second time slot group in the target period may also include: determining the distribution pattern of the first time slot group and the second time slot group based on the delay sensitivity of the ONUs in the first terminal set and the delay sensitivity of the ONUs in the second terminal set, wherein the distribution pattern is used to indicate the number of consecutive first time slot groups and the number of consecutive second time slot groups.

[0243] The higher the latency sensitivity of the ONUs in the first terminal set, the fewer consecutive first time slot groups there are. The lower the latency sensitivity of the ONUs in the first terminal set, the more consecutive first time slot groups there are. The higher the latency sensitivity of the ONUs in the second terminal set, the fewer consecutive second time slot groups there are. The lower the latency sensitivity of the ONUs in the second terminal set, the more consecutive second time slot groups there are.

[0244] For example, latency sensitivity can be represented by the maximum latency that the ONU can tolerate. The larger the maximum latency that the ONU can tolerate, the higher the latency sensitivity.

[0245] The embodiments of this application do not limit the specific implementation of the first time slot scheduling mechanism, and can be set as needed.

[0246] Optionally, the first terminal set includes a first type of ONU, and the second terminal set includes a second type of ONU, for example... Figure 1 The illustrated embodiment Figure 3 , Figures 5 to 7The illustrated embodiment; or, the first terminal set includes a first type of ONU and a third type of ONU, and the second terminal set includes a second type of ONU, for example... Figure 9 and Figure 10 The illustrated embodiment.

[0247] It should be noted that, in Figure 3 , Figures 5 to 7 In the illustrated embodiment, although the second time slot group is used to schedule the first subclass ONU and the second subclass ONU in the second type of ONU and the third type of ONU, the latency requirement of the second type of ONU is higher, so only the second type of ONU is considered.

[0248] This application also provides a communication method that can be implemented based on the aforementioned PON system. This communication method is executed by an OLT, for example by a processing component of the OLT, which includes the aforementioned first MAC module and the aforementioned second MAC module.

[0249] This method is used to receive optical signals transmitted by multiple ONUs through multiple receiving components, including a first receiving component, a second receiving component, and a third receiving component. For details regarding the first receiving component, the second receiving component, and the third receiving component, please refer to the aforementioned device embodiment. The multiple ONUs include first-type ONUs, second-type ONUs, and third-type ONUs; for details regarding the first-type ONUs, the second-type ONUs, and the third-type ONUs, please refer to the aforementioned device embodiment.

[0250] In one possible implementation, the method includes: in a first stage, obtaining uplink data transmitted by a first type of ONU and a first subtype of ONU based on an electrical signal output by a first receiving component in a first time slot group; obtaining uplink data transmitted by a second type of ONU based on an electrical signal output by a second receiving component in a second time slot group; and obtaining uplink data transmitted by a second subtype of ONU based on an electrical signal output by a third optoelectronic conversion device in a third receiving component in the second time slot group; or, in a second stage, obtaining uplink data transmitted by a second type of ONU based on an electrical signal output by a second receiving component in a first time slot group and a second time slot group; obtaining uplink data transmitted by a second subtype of ONU based on an electrical signal output by a third optoelectronic conversion device in a third receiving component in a first time slot group and a second time slot group; and obtaining uplink data transmitted by a fourth subtype of ONU and uplink data transmitted by a first subtype of ONU based on an electrical signal output by a fourth optoelectronic conversion device in a third receiving component.

[0251] This method can be based on Figure 3 or Figure 5 The optical communication device shown is implemented; see the aforementioned details. Figure 3 and Figure 5 The relevant content of the illustrated embodiment.

[0252] In another possible implementation, the method includes: in a first stage, obtaining uplink data transmitted by a first type of ONU and a first subtype of ONU based on an electrical signal output by a first receiving component in a first time slot group; obtaining uplink data transmitted by a second type of ONU based on an electrical signal output by a second receiving component in a second time slot group; and obtaining uplink data transmitted by a second subtype of ONU based on an electrical signal output by a third optoelectronic conversion device in a third receiving component in the second time slot group; or, in the second stage, obtaining uplink data transmitted by a second type of ONU based on an electrical signal output by a second receiving component, while simultaneously receiving uplink data transmitted by a second subtype of ONU, uplink data transmitted by a fourth subtype of ONU, and uplink data transmitted by a first subtype of ONU based on a third receiving component. Wherein, the uplink data transmitted by the second subtype of ONU is obtained through an electrical signal output by a third optoelectronic conversion device, and the uplink data transmitted by the fourth subtype of ONU and the uplink data transmitted by the first subtype of ONU are obtained through an electrical signal output by a fourth optoelectronic conversion device.

[0253] This method can be based on Figure 6 or Figure 7 The optical communication device shown is implemented; see the aforementioned details. Figure 6 and Figure 7 The relevant content of the illustrated embodiment.

[0254] In the first phase, the PON system contained Type I, Type II, and Type III ONUs simultaneously, with Type I ONUs including Type IV and Type V ONUs. In the second phase, the Type V ONUs of Type I ONUs and the Type III ONUs of Type III ONUs have either been decommissioned or upgraded to Type II, Type I, or Type II ONUs. Therefore, Type V and Type III ONUs no longer exist in the PON system.

[0255] By selecting the appropriate receiving component to receive uplink data sent by the ONU at different stages, it is possible to communicate with existing ONUs in the PON system using an OLT with the same hardware structure before and after the PON system upgrade. The OLT's hardware structure remains unchanged before and after the PON system upgrade, which helps reduce costs.

[0256] See Figure 12 , Figure 12 This is a flowchart of the optical communication method provided in the embodiments of this application.

[0257] The communication method provided in this application can be applied to the aforementioned time-division and wavelength-division multiplexing PON systems. The PON system includes an OLT and at least one ONU. After the ONU connects to the PON network, it can undergo an activation process. The communication method provided in this application can be used as part of the activation process or independently of it. The communication method provided in this application includes the following steps:

[0258] S101, the OLT sends a downlink physical frame to the ONU connected to the PON network, the downlink physical frame including an index of the downlink wavelength channel available in the PON system.

[0259] In a PON system, the OLT can continuously send downlink data (transmit downlink physical frames) to the ONU in the downlink direction.

[0260] Specifically, a downlink physical frame includes a downlink physical synchronization block and a payload, which can be protected by forward error correction coding. The downlink physical synchronization block structure can include a physical synchronization sequence, a counter, and an operation control structure. The physical synchronization sequence contains a fixed delimiter pattern. After receiving the physical synchronization sequence, the ONU uses this sequence to align the boundaries of the downlink physical frames. The counter is used to count downlink physical frames; the counter value of the current downlink physical frame is incremented by 1 relative to the previous downlink physical frame. The operation control structure includes a main body and an error correction header field. The value in the error correction header field is used by the ONU to perform error correction on the main body.

[0261] The main body of the operation control structure is populated by the OLT, which may include a PON IDtype (PIT) field and / or a PON ID field. The PIT field is used to identify the ODN architecture, ODN level, and whether the transmission convergence (TC) layer protocol is used, etc. The PON ID field is used to identify the OLT within a certain scope.

[0262] Specifically, the PON identification field can include the management label provided by the network management system to the OLT and the downlink wavelength channel identifier (referred to as wavelength channel identifier). Since there are time division multiplexing (TDM) PON and time division and wavelength division multiplexing (TWDM) PON in PON systems, the meaning of the above-mentioned downlink wavelength channel identifier is different in different types of PON systems.

[0263] In a Time Division Multiplexing (TWDM) PON system, the aforementioned downlink wavelength channel identifier can identify the index of the available downlink wavelength channels in the current PON system. The current PON system may include multiple downlink wavelength channels (which can be referred to as a downlink wavelength channel set), and the downlink wavelength channel identifier can identify the index of a subset of the available downlink wavelength channels within that set.

[0264] S102, ONU determines whether the downlink wavelength channel corresponding to the index of the downlink wavelength channel is available.

[0265] In this process, the ONU can receive the index of the downlink wavelength channel sent by the OLT during the profile learning state. After the ONU receives the first downlink physical frame carrying the index of the downlink wavelength channel available in the PON system, it can determine whether the downlink wavelength channel corresponding to the index is available, for example, whether the downlink wavelength can be used for the activation process (whether the downlink wavelength is occupied).

[0266] S103. Once the ONU determines that the downlink wavelength channel corresponding to the index of the downlink wavelength channel is available, it enters the sequence number state of the activation process.

[0267] If the downlink wavelength channel is available for activation, the ONU continues the current activation process and enters the sequence number state (sending the ONU's sequence number to the OLT). Upon receiving the sequence number from the ONU, if the OLT determines that the ONU is a newly connected ONU, it sends an assigned ONU identifier (ID) to that ONU. Additionally, the OLT can also send wavelength adjustment or wavelength calibration messages to the ONU, enabling the ONU to tune its transmitter to the target uplink wavelength channel for communication with the OLT.

[0268] After completing the subsequent activation process, the ONU can begin processing downlink physical frames and sending uplink bursts to the OLT, for example, by executing step 506.

[0269] The activation process of the ONT involves multiple message interactions with the OLT. For example, the OLT sends a sequence number request message to the ONT, and the ONT returns a sequence number response message. The OLT sends a ranging request message to the ONT, and the ONT returns a ranging response message. The OLT calculates the equalization parameters corresponding to the ONT based on the ranging response message, and then sends a ranging time message to the ONT, which carries the equalization delay of the ONT. When the ONT obtains the equalization delay, it enters the operational state (completing the activation process). In the operational state, the ONT can process downlink physical frames and send uplink bursts.

[0270] The uplink messages sent by the ONT during the activation process can be carried by the uplink physical frame, and the downlink messages sent by the OLT during the activation process can be carried by the payload in the aforementioned downlink physical frame.

[0271] S104. If the ONU determines that the downlink wavelength channel corresponding to the index of the downlink wavelength channel is unavailable, then it searches for other available downlink wavelength channels.

[0272] If the current downlink wavelength channel cannot be used for the activation process, the ONU searches for other downlink wavelength channels that can be used for activation. If other downlink wavelength channels that can be used for activation are found, the ONU enters an asynchronous state in the activation process (e.g., discarding local burst mode information).

[0273] S105, the OLT transmits a downlink physical frame in the aforementioned downlink wavelength channel, the downlink physical frame carrying the user data of the ONU.

[0274] After activation, the ONU can communicate with the OLT using a downlink wavelength channel. For example, the OLT sends downlink physical frames through this channel, which can carry the ONU's user data. The ONU processes the downlink physical frame to obtain the user data.

[0275] In addition, after receiving the equalization delay, the ONU can also calculate the uplink data transmission window based on the equalization delay and the time slot allocated by the OLT, and send an uplink physical frame to the OLT within the transmission window. The uplink physical frame carries the user data of the ONU.

[0276] The communication method provided in this embodiment can be used in time-division and wavelength-division multiplexed PON systems. Since the OLT can notify the ONU of the downlink wavelength channels available in the current PON system through the wavelength channel identifier in the downlink physical frame, communication conflicts caused by wavelength mismatch between the OLT and the ONU are avoided, and communication efficiency is improved.

[0277] In the communication method provided in this embodiment, the ONU can migrate between different states of the activation process (e.g., initial state, mode learning state, sequence number state, asynchronous state).

[0278] For example, when the ONU determines that the downlink wavelength channel corresponding to the index of a downlink wavelength channel can be used for activation, it can switch from the mode learning state (collecting mode parameters) to the sequence number state (sending the ONU's sequence number to the OLT). When the ONU determines that the downlink wavelength channel corresponding to the index of a downlink wavelength channel cannot be used for activation, and searches for other downlink wavelength channels that can be used for activation, it can switch from the mode learning state to the asynchronous state (retaining channel mode information but discarding burst mode information).

[0279] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this application pertains. The terms “first,” “second,” “third,” and similar terms used in this patent application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an” or “a” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “comprising” or “including” and similar terms mean that the elements or objects preceding “comprising” or “including” encompass the elements or objects listed following “comprising” or “including” and their equivalents, and do not exclude other elements or objects.

[0280] The above is merely one embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the principles of this application should be included within the protection scope of this application.

Claims

1. A communication method characterized by comprising: The method, applied to a Time Division and Wavelength Division Multiplexing (TWDM) Passive Optical Network (PON) system, wherein the PON system includes an Optical Line Terminal (OLT) and at least one Optical Network Unit (ONU), comprises: The ONU receives a first downlink physical frame sent by the OLT, the first downlink physical frame including an index of the downlink wavelength channel available in the PON system; The ONU determines whether the downlink wavelength channel corresponding to the index of the downlink wavelength channel can be activated; If the ONU determines that the downlink wavelength channel corresponding to the index of the downlink wavelength channel is available, then the ONU enters the sequence number state of the activation process; If the ONU determines that the downlink wavelength channel corresponding to the index of the downlink wavelength channel is unavailable, it searches for other available downlink wavelength channels. The ONU then enters the asynchronous state of the activation process. In the asynchronous state, the ONU retains the system and channel mode information but discards the burst mode information.

2. The method of claim 1, wherein, The ONU determines whether the downlink wavelength corresponding to the index of the downlink wavelength channel is available for activation, including: The ONU determines whether the index of the downlink wavelength channel included in the operation control main unit of the first downlink physical frame can be used for activation.

3. The method of claim 2, wherein, The index of the downlink wavelength channel occupies at least 2 bits in the operation control body field.

4. The method of claim 1, wherein, When the ONU fails to find an available downlink wavelength channel, the ONU enters an initial state.

5. The method according to claim 1 or 2, characterized in that, The method further includes: After the ONU completes the activation process, the ONU begins to receive the second downlink physical frame sent by the OLT in the downlink wavelength channel. The second downlink physical frame carries the user data of the ONU.

6. The method of claim 1 or 2, wherein, Also includes: The ONU receives the wavelength adjustment message sent by the OLT and tunes its transmitter to the target uplink wavelength channel according to the wavelength adjustment message.

7. An optical communication device, comprising: It includes a processor and a memory, the memory being used to store software programs, and the processor causing the optical communication device to perform the communication method performed by the ONU as claimed in any one of claims 1 to 6 by running or executing the software programs stored in the memory.

8. An optical communication system, characterized by, It includes an optical line terminal (OLT) and multiple optical network units (ONUs), wherein the ONUs are configured to perform the communication method as described in any one of claims 1 to 6.

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