Registration method and device of optical communication network

Abstract

The invention discloses a registration method and device of an optical communication network, and relates to the technical field of optical communication. The discovery window opened by the OLT is determined according to the distance between the optical relay equipment and the next-level optical network equipment of the optical relay equipment, and the OLT already configures the specified BWmap information for the optical relay equipment, so that the OLT does not need to open a larger discovery window in the registration process of the next-level optical network equipment of the optical relay equipment, and the registration efficiency of the optical relay equipment is improved. And only the discovery window matched with the next-level optical network equipment needs to be opened. Therefore, the OLT only needs to open a smaller discovery window in the discovery process of the SN, the time slot corresponding to the smaller discovery window is reduced, the service interruption time of other optical network equipment communicating with the OLT is shortened, the uplink delay jitter of an optical communication network is reduced, and the communication stability of the optical communication network is improved.

Description

Optical communication network registration method and device

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office on October 13, 2023, with application number 202311327280.2 and application name “A registration method and device for an optical communication network”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of optical communication technology, and in particular to a registration method and device for an optical communication network. Background Art

[0003] A Passive Optical Network (PON) is an access network based on fiber-optic link transmission. In a PON, there are no powered electronic devices between the Optical Line Terminal (OLT) and the Optical Network Unit (ONU). In a PON, downstream transmission from the OLT to the ONU is broadcast, while upstream transmission from the ONU to the OLT uses Time Division Multiple Access (TDMA). Therefore, during upstream transmission from the ONU to the OLT, the time slots occupied by different ONUs cannot overlap. Information transmitted in overlapping time slots cannot be correctly received by the OLT. Therefore, ranging is required during the ONU registration phase to determine the time slot allocated to the ONU during normal service authorization.

[0004] During the ONU registration process, the OLT issues an authorization command and periodically opens a discovery window (discovery window) for the ONU's serial number (SN). During the time slot corresponding to this discovery window, the ONU sends an SN signal to the OLT. The OLT then assigns a registration identifier to the ONU to be online based on the received SN signal and opens a ranging window (ranging window). The OLT then performs ranging and authorization on the ONU to be online during the time slot corresponding to the ranging window to complete the ONU registration process. Because services to other ONUs connected to the OLT must be interrupted during the time slots corresponding to the discovery and ranging windows, when the OLT connects to a large number of ONUs via multiple optical repeaters (such as in a PON remote network), the OLT must maintain the discovery window open for a long time, resulting in significant delay jitter. This poses a challenge to PON systems in applications with high delay jitter requirements. To reduce the uplink delay jitter caused by the registration process, a more effective registration method for optical communication networks is needed.

[0005] Summary of the Invention

[0006] The present application provides a registration method and device for an optical communication network, which solves the uplink delay jitter caused by the registration process and is conducive to improving the communication efficiency of the optical communication network.

[0007] In the first aspect, the present application provides a registration method for an optical communication network. The registration method is performed by a first network device in the optical communication network, the first network device establishes an optical communication connection with an optical relay device, the optical relay device can use specified bandwidth mapping (bandwidth map, BWmap) information and pre-allocated equalization delay in the optical communication network, and the specified BWmap information is different from the standard BWmap information of the optical communication network. The registration method includes: the first network device sends a first overhead message and a first discovery message to the optical relay device, and opens a discovery window for the optical relay device; the first overhead message indicates the optical parameters to be adopted by the next-level optical network device of the optical relay device to transmit the optical signal, the first discovery message carries the specified BWmap information, and the size of the discovery window is determined according to the distance between the next-level optical network device of the optical relay device and the optical relay device. In the time slot corresponding to the discovery window, the first network device receives the first serial number (Serial number, SN) sent by the optical relay device, and the first SN is the SN sent by the next-level optical network device of the optical relay device based on the optical parameters. Then, the first network device sends a ranging request message to the optical relay device based on the first SN, along with the registration identifier of the optical network device downstream of the optical relay device. Finally, the first network device receives the ranging message from the optical relay device and sends a response message to the optical relay device; the ranging message carries the registration identifier, and the response message indicates the equalization delay to be used by the optical network device downstream of the optical relay device in the optical communication network.

[0008] In the present application, the discovery window opened by the first network device is determined based on the distance between the optical relay device and the optical network device at the next level of the optical relay device, and the first network device has configured specified BWmap information for the optical relay device. This allows the first network device to register the optical network device at the next level of the optical relay device without opening a larger discovery window and only needs to open a discovery window that is compatible with the aforementioned next level optical network device. Consequently, the first network device only needs to open a smaller discovery window during the SN discovery process. The time slot corresponding to the smaller discovery window is reduced, and the service interruption time of other optical network devices communicating with the first network device is shortened, which is beneficial for reducing the uplink delay jitter of the optical communication network and improving the communication efficiency and stability of the optical communication network.

[0009] In an optional implementation, before the first network device sends the first overhead message to the optical relay device, the registration method provided in this application further includes: the first network device sending configuration information to the optical relay device that has been online in the optical communication network, where the configuration information is used to indicate: the specified BWmap information and pre-allocated equalization delay that the optical relay device can use in the optical communication network. Subsequently, the first network device receives a response message sent by the optical relay device, where the response message indicates that the optical relay device has set the configuration information to the optical relay device.

[0010] In the present application, the first network device can send down configuration information so that the optical network device to be registered and the configuration information adapted by the optical network device can communicate with the first network device using the specified BWmap information and pre-allocated equalization delay indicated by the configuration information, thereby avoiding the problem that different optical network devices use the same BWmap information and pre-allocated equalization delay, causing the first network device to be unable to correctly identify each device, which is conducive to improving the accuracy of the registration process of the optical communication network.

[0011] In an optional implementation, a first network device receives a ranging message sent by an optical relay device and sends a response message to the optical relay device, including: the first network device receives the ranging message sent by the optical relay device and parses the ranging message to obtain a registration identifier; the first network device sends a response message to the optical relay device based on the registration identifier. In this way, the first network device determines that the optical network device to be brought online is a legitimate device based on the assigned registration identifier, and then allocates a reasonable balanced delay to the optical network device to be brought online, allowing the optical network device to access the optical communication network based on the balanced delay carried in the response message. This avoids communication anomalies caused by illegal optical network devices accessing the optical communication network, such as occupying a large amount of bandwidth and resulting in low communication efficiency between multiple optical network devices, and also improves the security of the optical communication network.

[0012] In an optional implementation, before the first network device sends a first discovery message to the optical relay device, the method provided in the present application also includes: the first network device sends a standard discovery message to the optical relay device, the standard discovery message carries standard SN window opening authorization information, and the standard SN window opening authorization information is used to indicate: the first network device opens a discovery window for any optical network device based on the standard BWmap information.

[0013] In the case where the first network device is not only directly connected to the optical relay device but also directly connected to other optical network devices, if the other optical network devices do not need to communicate with the first network device through the optical relay device, then these other optical network devices can send the SN of the other optical network devices to the first network device through the standard discovery message sent by the first network device, so that the first network device assigns registration identifiers to the other optical network devices according to the SN and performs the registration process of the other optical network devices.

[0014] In a second aspect, the present application provides a registration method for an optical communication network. The registration method is performed by an optical relay device, the optical relay device establishes an optical communication connection with a first network device in the optical communication network, and the optical relay device can use specified BWmap information and a second pre-allocated equalization delay in the optical communication network, and the specified BWmap information is different from the standard BWmap information of the optical communication network. The registration method includes: the optical relay device receives a first discovery message sent by the first network device, and sends a second discovery message to the second network device based on the first discovery message; the first discovery message carries the specified BWmap information, and the second discovery message carries the first standard SN windowing authorization information obtained based on the specified BWmap information, the first standard SN windowing authorization information indicates: the first network device opens a discovery window for the second network device based on the specified BWmap information, the size of the discovery window is determined based on the distance between the optical network device at the next level of the optical relay device and the optical relay device, and the second network device is any one of the optical network devices at the next level of the optical relay device. Then, the optical relay device receives the first SN sent by the second network device and sends the first SN to the first network device; the optical relay device receives the ranging request message and registration identifier sent by the first network device, and sends the ranging request message and registration identifier to the second network device; the registration identifier is the registration identifier assigned by the first network device to the second network device based on the first SN. Furthermore, the optical relay device receives the ranging message sent by the second network device and sends a ranging message to the first network device, the ranging message carrying the aforementioned registration identifier. Finally, the optical relay device receives the response message sent by the first network device and sends a response message to the second network device, the response message being used to indicate the equalization delay that the second network device will use in the optical communication network.

[0015] In the present application, the discovery window opened by the first network device is determined based on the distance between the optical relay device and the optical network device at the next level of the optical relay device, and the first network device has configured the specified BWmap information for the optical relay device, so that when the first network device performs the registration process of the optical network device at the next level of the optical relay device, the first network device does not need to open a larger discovery window, but only needs to open a discovery window that is compatible with the aforementioned next level optical network device. Thus, the optical relay device can set the standard SN window authorization information for the next level optical network device (the second network device) based on the aforementioned specified BWmap information. The discovery window indicated by the standard SN window authorization information is determined based on the distance between the optical network device at the next level of the optical relay device and the optical relay device. Therefore, the time slot corresponding to the discovery window is reduced, and the service interruption time of other optical network devices communicating with the first network device is shortened, which is conducive to reducing the uplink delay jitter of the optical communication network and improving the communication stability of the optical communication network.

[0016] In an optional implementation, before the optical relay device receives the first discovery message sent by the first network device, the registration method provided by the present application also includes: the optical relay device receives the first overhead message sent by the first network device, and sends a second overhead message to the second network device based on the first overhead message. The first overhead message indicates the optical parameters to be adopted by the optical network device of the next level of the optical relay device to transmit the optical signal, the first overhead message carries the first pre-allocated equalization delay of the optical communication network, the second overhead message carries the aforementioned second pre-allocated equalization delay, and the second network device is any one of the optical network devices of the next level of the optical relay device. It should be understood that the optical relay device modifies the BWmap information in the overhead message to the specified BWmap information, so that the next level optical network device can make an SN response within the set time slot, thereby avoiding the problem of registration error or registration failure caused by the next level optical network device not responding for a long time.

[0017] In an optional implementation, the optical relay device sends a second overhead message to the second network device based on the first overhead message, including: the optical relay device modifies the first pre-allocated equalization delay in the first overhead information to a second pre-allocated equalization delay set in the optical relay device, thereby obtaining the second overhead message; and the optical relay device sends the second overhead message to the second network device.

[0018] In an optional implementation, the optical relay device sends a second discovery message to the second network device based on the first discovery message, including: the optical relay device converts the specified BWmap information in the first discovery message into first standard SN windowing authorization information to obtain the second discovery message; and the optical relay device sends the second discovery message to the second network device.

[0019] In an optional implementation, before the optical relay device receives the first discovery message sent by the first network device, the registration method provided by the present application also includes: the optical relay device receives the standard discovery message sent by the first network device, and the standard discovery message carries the aforementioned first standard SN windowing authorization information. Then, the optical relay device deletes the first standard SN windowing authorization information in the standard discovery message, obtains an invalidation message, and sends an invalidation message; or, the optical relay device terminates the transmission process of the standard discovery message in the optical communication network. In the present application, the optical relay device can terminate the transmission of other optical signals after the SN, avoiding the problem of decreased registration efficiency and increased uplink delay jitter caused by the first network device receiving more optical signals.

[0020] In an optional implementation, the optical relay device receives the first SN sent by the second network device and sends the first SN to the first network device, including: the optical relay device receives the first SN sent by the second network device, and after receiving the first SN, the optical relay device sets the optical signal of the second network device received in the discovery window to an invalid optical signal.

[0021] In a third aspect, the present application provides a registration device, which includes a software unit or module for executing any optional implementation of the first aspect or the second aspect.

[0022] In a fourth aspect, the present application provides an optical network device. The optical network device includes a processor, a memory, and a transceiver. The memory is used to cache designated BWmap information and pre-allocated equalization delays that can be used in the optical communication network by an optical relay device that has established an optical communication connection with the network device. The designated BWmap information is different from the standard BWmap information of the optical communication network. The transceiver and the processor collaborate to perform the method of any optional implementation of the first aspect.

[0023] In a fifth aspect, the present application provides an optical relay device. The optical relay device includes a processor and a transceiver. The processor and the transceiver are configured to execute the method of any optional implementation manner in the second aspect.

[0024] In a sixth aspect, the present application provides a communication system, which includes an optical fiber, a network device according to the fourth aspect, and one or more optical relay devices according to the fifth aspect, wherein the optical fiber is used to connect the devices.

[0025] Regarding the beneficial effects of any aspect from the third aspect to the sixth aspect, reference may be made to the description of any optional implementation method from the first aspect to the third aspect, and no further details will be given here. Based on the implementation methods provided in the above aspects, this application can also be further combined to provide more implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIG1 is a schematic diagram of the structure of an optical communication network provided by this application;

[0027] FIG2 is a schematic diagram of the structure of a PON remote network provided by the present application;

[0028] FIG3 is a schematic diagram of the structure of the OLT, optical relay equipment and ONU provided in this application;

[0029] FIG4 is a schematic diagram of a flow chart of a registration method for an optical communication network provided by this application;

[0030] FIG5 is a schematic diagram comparing different registration methods provided in this application;

[0031] FIG6 is a schematic diagram of the structure of a registration device provided by this application;

[0032] FIG7 is a schematic diagram of the structure of the optical network device provided in this application. DETAILED DESCRIPTION

[0033] In order to make the description of the following embodiments clear and concise, a brief introduction to the relevant technology is first given.

[0034] Discovery Window: During the process of an ONU registering with the optical communication network, the OLT opens a silent window to discover the SN of the ONU to be brought online. During the time slot corresponding to the discovery window, the services of other ONUs registered with the optical communication network are interrupted. The time slot corresponding to the discovery window refers to the period of time during which the discovery window persists after the OLT opens it. In some examples, the discovery window is also called the SN discovery window. In a PON remote network scenario, the discovery window refers to the silent window opened by the OLT to discover the SNs of multiple ONUs to be brought online that are connected via one or more optical relay devices.

[0035] Ranging Window: During the process of ONUs registering with the optical communication network, the OLT opens a silent window for ranging the ONUs about to come online. During the time slot corresponding to the ranging window, services of other ONUs registered with the optical communication network are interrupted. The time slot corresponding to the ranging window refers to the period of time during which the ranging window persists after the OLT opens it. In FTTR scenarios, the ranging window refers to the silent window opened by the master ONU for ranging the slave ONUs about to come online. In PON remote network scenarios, the ranging window refers to the silent window opened by the OLT for ranging the multiple ONUs about to come online, connected via one or more optical relay devices.

[0036] Figure 1 is a structural diagram of the optical communication network provided in this application. The optical communication network can also be called an optical transmission network. The optical communication network includes multiple optical network devices, one or more of which are used to connect to user terminals (such as terminals 111 to 115 shown in Figure 1).

[0037] A terminal may also be referred to as terminal equipment, user equipment (UE), mobile station (MS), mobile terminal (MT), etc.

[0038] In some embodiments, the terminal may be a mobile phone (such as the terminal 111 shown in FIG1 ), a tablet computer (such as the terminal 112 shown in FIG1 ), a computer with wireless transceiver function (such as the terminal 113 shown in FIG1 ), a personal communication service (PCS) phone (such as the terminal 114 shown in FIG1 ), a desktop computer (such as the terminal 115 shown in FIG1 ), a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in a smart home, and the like.

[0039] In this embodiment, the optical network device may be a routing and forwarding device with optical communication capabilities, a home gateway, or other network device. For example, the routing and forwarding device may be a router or switch that supports optical fiber connections. The network device may also be a broadband network gateway (BNG) or a broadband remote access server (BRAS) with optical communication capabilities. The home gateway may be, for example, an optical network terminal (ONT). For example, the optical network devices 121, 124, and 125 shown in FIG1 may be optical network terminals. Optical network terminals can connect user devices such as PCs and mobile phones to the Internet. The home gateway can transmit data for the following services: Internet access services (such as interactive network television services, which include home gateway support for video on demand, live broadcast services, and distance education), online gaming services (such as gaming terminals conducting gaming services through the home gateway), Internet Protocol (IP) telephony, videophone, and video surveillance services. For another example, the home gateway can also implement home control and security service management on a remote network. For example, a user with a home gateway can access the automated lighting, heating, and security systems in the area covered by the home gateway while at work or away from home. The embodiments of the present application do not limit the specific technology and specific device form adopted by the terminal.

[0040] Exemplarily, each optical network device is connected by a wired optical cable. For example, the optical cable between the optical relay device 122 and the optical relay device 123 can be referred to as an access backbone layer optical cable. The optical cable between the optical relay device 123 and the optical network device 127 can include a distribution layer optical cable and a drop layer optical cable. The distribution layer optical cable refers to the optical cable between the optical relay device 123 and the optical splitter (not shown in FIG. 1 ), and the drop layer optical cable refers to the optical cable between the optical splitter and the optical network device 127.

[0041] The terminal can use the network device to access the server. As shown in Figure 1, the user can use the terminal 111 to establish a wireless communication connection with the optical network device 127 using wireless broadband (wireless-fidelity, WIFI) technology, so that the terminal 111 sends a data packet to the server 130. Exemplarily, the optical network devices communicate with each other through optical fibers, and the optical network device 127 communicates with each terminal through WIFI. As an optional implementation method, the optical network device 127 and each terminal can communicate through a WIFI channel such as connect.

[0042] In some possible scenarios, the terminal may also use optical communication technology to establish a communication connection with a radio access network (RAN) (not shown in FIG. 1 ) to access the server 130 .

[0043] The server 130 may be an application server or an authentication and authorization server. The server 130 may provide video services, game services, message services, music services, authentication and authorization services, etc. The server 130 may also provide interactive network television (IPTV), voice transmission over IP (Voice over Internet Protocol, VoIP) or other services, etc. In one example, the functions of multiple services may be integrated on the server 130, for example, game services and music services may be deployed on the server 130. In another example, the functions of some services may be integrated on the server 130, for example, some services of the game service and some services of the video service may be deployed on the server 130. The server 130 may also utilize virtualization technology to provide multiple virtual machines, which provide various services. The embodiments of the present application do not limit the deployment form of the services.

[0044] The optical network device is connected to the server 130 via wireless or wired connections. Figure 1 is only a schematic diagram, and the optical communication network may also include other devices that are not shown in Figure 1. The embodiments of this application do not limit the number of terminals, optical network devices, and servers included in the optical communication network.

[0045] The present application can be applied to scenarios such as PON, passive optical LAN (POL), industrial optical network or PON remote network. For example, in the PON scenario, the optical transmitting device can be located in the user's home or the user's corridor, and the optical receiving device can be located in the operator's computer room. The optical transmitting device and the optical receiving device in the POL scenario can be located in a park (such as an enterprise, campus, etc.). The optical transmitting device and the optical receiving device in the industrial optical network scenario can be located in an industrial manufacturing workshop. The optical transmitting device and the optical receiving device in the vehicle-mounted optical network scenario can be set in a vehicle. As an example, in the PON scenario, each optical network device can be an optical network unit (ONU) or an ONT, and the network device 121 can be an OLT. As another example, in the PON scenario, the network device 121 can be a master ONU, and the optical network device 124 can be a slave ONU. In the vehicle optical network scenario, the optical transmitting device can be a vehicle interface unit (VIU), and the optical receiving device can be a mobile data center (MDC), a vehicle dynamic control (VDC) or a cockpit data center (CDC). The technical solution proposed in this application can also be applied to optical backbone transmission networks, data center optical transmission, short-distance optical interconnection and wireless service fronthaul / backhaul, etc. Specifically, the technical solution proposed in this application can be used for optical transmitting devices and / or optical receiving devices corresponding to the above-mentioned different networks. Taking PON as an example, the embodiments of the present application can be applied to time division multiplexing passive optical networks (TDM-PON), wavelength division multiplexing passive optical networks (WDM-PON), and time and wavelength division multiplexing-passive optical networks (TWDM-PON). For example, PON may refer to GPON (Gigabit-Capable PON), XG-PON, 10GEPON, etc., which are upgraded versions of GPON, or optical communication network scenarios such as EPON, XGSPON, and 50G PON. This application does not limit this.

[0046] This embodiment uses the PON remote network scenario as an example to illustrate the registration method for the optical communication network provided by this application. The PON remote network scenario can be implemented by setting optical relay devices (such as optical relay devices 122 and optical relay devices 123) between the OLT and the ONU. Figure 2 is a schematic diagram of the structure of the PON remote network provided by this application. As shown in Figure 2, multiple ONUs (such as ONU1 to ONU8) communicate with the OLT 210 through optical network devices such as optical splitters, primary or multi-stage optical relay devices, etc.

[0047] It should be understood that PON is a passive optical network. For example, line loss during transmission in a PON remote network determines the splitting ratio and transmission distance. A PON remote network deploys one or more active optical relay devices within the PON network. These relays amplify the optical signal, thereby addressing the limited splitting ratio and transmission distance in PON remote networks.

[0048] On the access side of the optical communication network (the network side close to the OLT 210), the optical relay device 221 can be deployed in the central office. The optical relay device in the central office receives and sends optical signals, such as transmitting the collected optical signals to the OLT 210 via an optical cable (such as an optical fiber) to transmit the data carried by the optical signal to the data communication layer of the optical communication network.

[0049] On the client side of the optical communication network (the network side close to each ONU), the optical relay device 222 can be deployed in a remote computer room. The optical relay device in the remote computer room sends and receives optical signals, such as transmitting the optical signals collected from each ONU to the upper-level optical relay device (such as the optical relay device 221 in the central office room) through an optical cable (such as an optical fiber).

[0050] For example, the signal frames sent by ONU1 to ONU8 to OLT 210 are: optical signal t1 to optical signal t8. After receiving the optical signal sent by each ONU, OLT 210 performs the service or operation indicated by the optical signal, such as online, ranging or data communication for the ONU.

[0051] As a possible implementation method, the hardware implementation of the OLT, optical relay device and ONU shown in Figure 2 can adopt the method provided in Figure 3. Figure 3 is a structural diagram of the OLT, optical relay device and ONU provided in this application, wherein the ONU 310 can be any one of ONU1 to ONU8 shown in Figure 2, and the OLT 320 can register the ONU 310 to the optical communication network. For example, the OLT 320 can be used to implement the function of the OLT 210 shown in Figure 2.

[0052] As shown in FIG3 , the ONU 310 includes an ONU media access control (MAC) 311 , an ONU physical layer (PHY) 312 , a laser 313 and a photodetector 314 .

[0053] In the transmit direction, the ONU MAC 311 can control the laser 313 on and off via the transmit enable port (Tx_En, also known as the switch pin). For example, if the ONU 310 is currently in its transmit time slot (or occupied time slot), the ONU MAC 311 uses the transmit enable port to turn the laser 313 on. If the ONU 310 is not in its transmit time slot, the ONU MAC 311 uses the transmit enable port to turn the laser 313 off. The ONU MAC 311 can also adjust the physical parameters of the laser 313, such as the laser bias current and modulation current, via the transmit control port (Tx_Ctr). The ONU MAC 311 can send service data to the ONU PHY 312 via the data port (Data), which transparently transmits the service data. The ONU PHY 312, also known as the laser 313 driver, is used to drive the laser 313 to generate optical signals based on instructions from the transmit enable port and / or transmit control port of the ONU MAC 311. Under the control of the ONU PHY 312 , the laser 313 modulates the service data into an optical signal, and sends the uplink optical signal carrying the service data to the OLT 320 through an optical fiber.

[0054] In the receiving direction, the photodetector 314 receives the downstream optical signal from the OLT 320 and converts it into an electrical signal. The ONU PHY 312 transparently transmits the electrical signal, and the ONU MAC 311 parses the electrical signal to obtain service data. The ONU 310 may also include a wavelength division multiplexer 315, which is used to transmit the upstream optical signal generated by the laser 313 into the optical fiber and transmit the downstream optical signal received from the optical fiber to the photodetector 314.

[0055] In this embodiment, the ONU 310 may further include a Wi-Fi IPHY and an antenna. The Wi-Fi IPHY is used to establish a Wi-Fi channel (or Wi-Fi link) with the OLT 320 through the antenna. For example, the Wi-Fi channel may include but is not limited to: Connections and interconnection channels based on distributed systems, such as Harmony OS Connect TM , the Harmony OS Connect TM It will With Harmony OS TMThis integration results in a method for interconnecting devices. It's worth noting that different manufacturers can record Wi-Fi channels with different names based on differences in hardware components and device naming, thereby enabling coordination between Wi-Fi and optical communications between devices to improve the efficiency and robustness of optical communications. For example, when ONU 310 includes a Wi-Fi Hybrid (Wi-Fi Plug-in Hybrid) and an antenna, ONU 310 can refer to optical network device 127 in Figure 1, i.e., a router or switch that supports optical communication.

[0056] The wireless communication functions of ONU 310 and OLT 320 can be implemented through antennas, mobile communication modules, modem processors, and baseband processors (not shown). For example, antennas are used to transmit and receive electromagnetic wave signals. Each antenna can be used to cover a single or multiple communication frequency bands. Different antennas can also be reused to improve antenna utilization. For example, antennas can be reused as diversity antennas for wireless local area networks. In some embodiments, antennas can be used in conjunction with tuning switches. With respect to the mobile communication module, taking ONU 310 as an example, at least some of the functional modules of the mobile communication module can be provided in the Wi-Fi IPHY included in ONU 310, or at least some of the functional modules of the mobile communication module can be provided in the same device as at least some of the modules of the Wi-Fi IPHY.

[0057] OLT 320 may include OLT MAC 321, OLT PHY 323 (including a signal processing module), photodetector 324, and laser 325. In the receiving direction, photodetector 324 receives upstream optical signals from ONU 310 and converts them into electrical signals. These electrical signals can be analog or digital. The signal processing module can be implemented using analog devices (such as amplifiers) or digital devices (such as digital signal processors). Therefore, the signal processing module can perform either analog or digital signal processing. OLT MAC 321 parses the electrical signals passing through the signal processing module to obtain service data. In the transmitting direction, OLT MAC 321 generates service data, and the signal processing module performs analog or digital processing on the service data. Under the control of OLT PHY 323, laser 325 modulates the service data into an optical signal and transmits the downstream optical signal carrying the service data via optical fiber to ONU 310. The OLT 320 may further include a wavelength division multiplexer 326 for transmitting the downstream optical signal generated by the laser 325 to the optical fiber, and transmitting the upstream optical signal received from the optical fiber to the photodetector 324 .

[0058] As shown in Figure 3, the optical relay device 330 may include a processor 332. Optionally, the optical relay device 330 may further include a memory 333 and / or a transceiver 331. The processor 332 is coupled to the memory 333 and the transceiver 331, for example, via a communication bus.

[0059] The following describes in detail the various components of the optical relay device 330 with reference to FIG. 3 .

[0060] The processor 332 is the control center of the optical relay device 330 and can be a single processor or a collective term for multiple processing elements. For example, the processor 332 can be one or more central processing units (CPUs), an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application, such as one or more digital signal processors (DSPs) or one or more field programmable gate arrays (FPGAs).

[0061] Optionally, the processor 332 can perform various functions of the optical relay device 330 by running or executing software programs stored in the memory 333 and calling data stored in the memory 333. In a specific implementation, as an embodiment, the processor 332 may include one or more CPUs. Optionally, the optical relay device 330 may also include multiple processors. Each of these processors may be a single-core processor (single-CPU) or a multi-core processor (multi-CPU). The processor here may refer to one or more devices, circuits, and / or processing cores for processing data (e.g., computer program instructions).

[0062] The memory 333 is used to store the software program for executing the solution of the present application, and is controlled by the processor 332 for execution. The specific implementation method can refer to the above method embodiment and will not be repeated here. Exemplarily, the memory 333 can be a read-only memory (ROM) or other type of static storage device that can store static information and instructions, a random access memory (RAM) or other type of dynamic storage device that can store information and instructions, or an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compact disc, laser disc, optical disc, digital versatile disc, Blu-ray disc, etc.), a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited to these. The memory 333 may be integrated with the processor 332 or exist independently and be coupled to the processor 332 via an interface circuit (not shown in FIG. 3 ) of the optical relay device 330 , which is not specifically limited in the embodiment of the present application.

[0063] Transceiver 331 is used for communication with other communication devices. For example, transceiver 331 can be used to communicate with ONU 310, OLT 320, or other optical relay equipment. Optionally, transceiver 331 may include a receiver and a transmitter (not shown separately in FIG3 ). The receiver is used to receive optical signals, and the transmitter is used to transmit optical signals.

[0064] Optionally, the transceiver 331 may be integrated with the processor 332 or may exist independently and be coupled to the processor 332 via an interface circuit (not shown in FIG. 3 ) of the optical relay device 330 , which is not specifically limited in this embodiment of the present application.

[0065] It is worth noting that the structure of the optical relay device 330 shown in FIG3 does not constitute a limitation on the communication device. The actual communication device may include more or fewer components than shown in the figure, or combine certain components, or arrange the components differently.

[0066] In addition, the technical effects of the optical relay device 330 can refer to the technical effects described in the following method embodiments, which will not be described in detail here.

[0067] The ONU's access to the optical communication network in the OLT includes the following stages: discovery stage, ranging stage, authentication stage and operation stage. The discovery stage refers to the OLT opening the SN discovery window for the ONU and assigning a registration identifier to the ONU based on the obtained SN, such as the ONU's identification (ID). The ranging stage refers to the OLT opening the ranging window for the ONU and assigning balanced delay to the ONU based on the ONU's ranging message. The authentication stage includes: ONU SN authentication and password authentication at the OLT. The operation stage includes: optical network unit management and control interface (OMCI) configuration recovery and OMCI management, service flow, etc. For example, ONCI management includes: establishing service flow between OLT and ONU, service flow encryption, forward error correction (FEC) of service flow, etc.

[0068] Typically, an ONU needs to be legally connected to the network and needs to be activated. This activation process is performed under the control of the OLT. This embodiment describes the activation process from the perspective of the ONU.

[0069] The activation process mainly includes three stages: downlink synchronization stage, sequence number acquisition (ONU discovery) stage and ranging stage.

[0070] During the downstream synchronization phase, after powering up, the ONU enters an initial state, initializes its local implementation of the downstream synchronization state machine, synchronizes with the downstream signal, and begins learning system, channel, and burst profile parameters. In a TWDM-PON system, the ONU can repeat this process for two or more available downstream wavelength channels and create and store calibration records for these channels. This phase ends when the ONU selects a downstream wavelength channel to continue the activation process.

[0071] Specifically, the initial state also includes the Off-Sync substate and the Profile Learning substate. In the Off-Sync substate, the ONU searches for and attempts to synchronize to the downstream signal. Once the ONU achieves downstream synchronization, the ONU transitions to the Profile Learning substate. It should be understood that if the ONU's downstream synchronization state machine enters the Synchronization state from the Pre-Sync state, it is considered that the ONU has achieved downstream synchronization, and the ONU will perform a state transition. Similarly, if the ONU loses downstream synchronization in the Profile Learning substate, that is, the ONU's downstream synchronization state machine returns from the Pre-Sync state to the Search state, the ONU will return to the Off-Sync substate and continue searching for and attempting to synchronize to the downstream signal. Ensure that the ONU has achieved downstream synchronization before performing subsequent operations to avoid a large number of decoding errors and ensure the normal progress of the ONU activation process and the normal operation of the activated ONU.

[0072] After entering the Profile Learning substate, the ONU parses the physical layer operation, administration, and management (PLOAM) information of the downstream framing sublayer (FS) frame and begins to collect system, channel, and burst profile information. Once sufficient information is collected, the ONU performs upstream wavelength option evaluation in a TDM-PON system with multiple upstream wavelength options. In a TDM-PON system with multiple upstream wavelength options (e.g., 50G TDM-PON), if the ONU supports at least one of the upstream wavelength options included in the operation control body (OC body) or the Burst_Profile message, it continues to be activated and transitions to the Serial Number state. Otherwise, the ONU stops being activated.

[0073] During the serial number acquisition phase, when the ONU enters the serial number state, the ONU activates its transmitter while continuing to collect system, channel, and burst profile parameters, and announces its presence in the PON network by responding to a serial number grant. Once the ONU receives the serial number grant, the ONU sends a serial number management and maintenance message, wherein the serial number grant indicates that the ONU to be activated is allowed to join the passive optical network or that a disconnected ONU is allowed to re-enter the passive optical network. The serial number management and maintenance message indicates the serial number and random delay of the ONU. It should be understood that the serial number management and maintenance message may be a Serial_Number_ONU PLOAM message.

[0074] Furthermore, the ONU will decide whether to remain in the current state or enter the ranging phase based on the instruction information from the OLT. This phase ends when the OLT assigns a unique ONU-ID to the ONU to be activated, that is, when the OLT discovers the new ONU.

[0075] During the ranging phase, the ONU waits for the equalization delay assigned by the OLT and responds to the directional ranging grant. This phase ends when the OLT completes the round-trip delay measurement, calculates the equalization delay, and transmits the equalization delay to the ONU. The ONU adjusts its upstream clock based on the assigned equalization delay. At this point, the ONU is activated and begins operation.

[0076] It should be noted that if there is a dedicated activation wavelength in the passive optical network system, the above three stages can be performed in the activation wavelength channel, and the activation wavelength is different from the uplink wavelength used in the working state.

[0077] It should be noted that the compatibility of 50G PON has long been a focus of global operators. To ensure the continued use of GPON or XGSPON equipment and protect operators' network construction investments, 50G PON defines three upstream wavelength options: 1260nm-1280nm, 1290nm-1310nm, and 1284nm-1288nm. Given that the upstream wavelength of GPON networks is 1290nm-1330nm and that of XGSPON networks is 1260nm-1280nm, operators can choose different wavelength options based on their own network and industry chain conditions.

[0078] In this embodiment, the initial state of the ONU includes the Off-Sync substate and the Profile Learning substate, and the state transition method is described, which is relatively simple to implement. In addition, the activation process of the ONU in the 50G PON network requires attention to whether the ONU supports at least one of multiple upstream wavelength options. Only when it supports at least one upstream wavelength option can it enter the next state and activate the ONU transmitter, ensuring that the ONU can communicate upstream with the OLT at the wavelength adapted to the 50G PON network without compromising the compatibility of the existing 50G PON network.

[0079] In conventional technologies, such as in PON remote networks, when the OLT connects to a large number of ONUs via multiple optical repeaters (e.g., in PON remote networks), the OLT needs to maintain a long discovery window, resulting in significant latency and jitter. This poses a challenge to PON systems in applications with high latency and jitter requirements.

[0080] To reduce the upstream delay jitter caused by the registration process, based on the optical communication network and OLT, optical relay device, and ONU shown in Figures 1 to 3 above, an embodiment of the present application provides a possible implementation method, as shown in Figure 4, which is a flow chart of the registration method for the optical communication network provided by this application. The hardware implementation and optional implementation methods of OLT 41, optical relay device 42, ONU 43, and ONU 44 can be referred to as the description of Figures 1 to 3 above and will not be repeated here. In some optional implementation methods, the ONU to be online in Figure 4 can also be referred to as the next-level optical network device connected to optical relay device 42.

[0081] Please refer to FIG. 4 . The registration method provided in this embodiment includes the following S401 to S416 .

[0082] S401 . The OLT 41 establishes an optical communication connection with the optical relay device 42 .

[0083] Regarding the implementation process of S401, a possible specific example is provided below. In this example, the data frame refers to a signal frame transmitted in the form of an optical signal.

[0084] Step 1: OLT 41 continuously broadcasts data frames to multiple optical relay devices 42. Each data frame carries control information. This control information is used to instruct optical relay devices 42 to go online, perform ranging, or register in the optical communication network. In this embodiment, as illustrated in conjunction with Figure 3 , the data frame can be an optical signal generated by OLT PHY 323 driving laser 325 after OLT MAC 321 generates the data to be transmitted.

[0085] Optionally, the data frame may also be used to instruct the optical relay device 42 to forward one or more specific optical signals, or to interrupt the transmission process of one or more specific optical signals in the optical relay device 42 , and so on.

[0086] The following describes a process of establishing an optical communication connection between the OLT 41 and the optical relay device 42 by taking the optical relay device 42 as an example.

[0087] Step 2: The optical relay device 42 performs frame synchronization on the received data frame and establishes an optical communication connection with the OLT 41 .

[0088] Frame synchronization refers to the optical relay device 42 performing frame synchronization on the received serial signal. Frame synchronization involves the optical relay device 42 identifying the start and end of a frame, thereby determining the starting and ending positions of a data frame in the serial signal. Frame synchronization methods may include, but are not limited to, at least one of: a character count method, a start and end delimiter method with character padding, a start and end flag method with bit padding, and a physical layer coding violation method.

[0089] Taking the head and tail flag method with bit stuffing as an example, the frame synchronization process is illustrated. Each data frame's header carries a specific string of bits (e.g., 0101). If the optical relay device 42 recognizes these specific bits, it determines that it has identified a data frame header and considers the data before the next frame header in the serial data as the data of this data frame, thereby achieving frame synchronization of the data frames. In some possible scenarios, frame synchronization is also called "frame delimitation."

[0090] In some optional embodiments, since the frame lengths of the data frames are the same, after finding the frame header of data frame 1 (such as the specific bits at the starting position of the frame header are 0101), the optical relay device 42 can delay the frame length of one data frame and then identify the frame header of the next data frame (such as data frame 2).

[0091] The above example merely provides a possible implementation of the head and tail delimiter method with bit padding for this embodiment and should not be construed as limiting the present application. The optical relay device 42 may also employ other frame synchronization methods to achieve frame synchronization of data frames. The specific implementations of the character counting method, the head and tail delimiter method with character padding, and the physical layer coding violation method can be referred to the description of conventional techniques and are not detailed here.

[0092] Step 3: The optical relay device 42 parses the data frame to obtain control information and starts a process corresponding to the control information.

[0093] In this embodiment, if the control information is used to instruct optical relay device 42 and its downstream optical network device to go online on the optical communication network at OLT 41, the corresponding process is: optical relay device 42 initiates ranging and registration processes, completes ranging and goes online in the optical communication network. Therefore, in some examples, the process of establishing an optical communication connection between the OLT and the optical relay device can also be referred to as the process of the optical relay device completing ranging and going online with the OLT. After the optical communication connection is established between OLT 41 and optical relay device 42, step S402 is executed.

[0094] S402 . The OLT 41 sends configuration information to the optical relay device 42 .

[0095] Corresponding to the process of S402 , the optical relay device 42 receives the configuration information sent by the OLT 41 .

[0096] This configuration information includes the specified bandwidth map (BWmap) information and preallocation equalization delay (preEqd) that the optical relay device 42 can use in the optical communication network. The specified BWmap information indicates the position range of a single data frame within multiple continuously transmitted data frames (or data blocks) in burst transmission mode, as well as the position of the bandwidth allocation time slot within the burst. Each allocated time slot is controlled by the bandwidth allocation structure specified in the BWmap in the downlink frame. The preallocation equalization delay (preEqd) is used to indicate the channel to be used by the next-level optical network device during service communication between the OLT and the optical relay device.

[0097] In this embodiment, the above-mentioned specified BWmap information is different from the standard BWmap information in the optical communication network.

[0098] It is worth noting that Figure 4 only shows one optical relay device connected to the OLT 41, but in some optional implementations, the configuration information allocated by the OLT 41 to multiple different optical relay devices is different, that is, the BWmap information and equalization delay that can be used by the next-level optical network devices of different optical relay devices are different, thereby avoiding the problem of data transmission disorder in the optical communication network caused by different optical network devices using the same equalization delay, which is conducive to improving the communication robustness of the optical communication network.

[0099] For example, the process in which the OLT 41 determines the configuration information to be allocated to different optical relay devices may be random or performed according to a set logic or algorithm, which is not limited in this application.

[0100] S403 . The optical relay device 42 sends a response message 0 to the OLT 41 .

[0101] Corresponding to the process of S403 , the OLT 41 receives the response message 0 sent by the optical relay device 42 .

[0102] The response message 0 is used to indicate that the optical relay device 42 has set the configuration information in the optical relay device 42. In some possible examples, the response message 0 is also called a configuration success response or a configuration response message, etc., which is not limited in this application.

[0103] S404 . The OLT 41 sends an overhead message 1 to the optical relay device 42 .

[0104] Corresponding to the process of S404 , the optical relay device 42 receives the overhead message 1 sent by the OLT 41 .

[0105] Overhead message 1, also referred to as a first overhead message, carries a first pre-allocated equalization delay (first preEqd). This first pre-allocated equalization delay (first preEqd) is set by OLT 41 during the discovery phase for each optical network device to be brought online. This first preEqd can be preset or user-set. In some cases, this first preEqd can also be referred to as OLT 41's standard preEqd, which is not limited in this application.

[0106] S405. The optical relay device 42 sends an overhead message 2 to the ONU to be online based on the overhead message 1.

[0107] It should be noted that, taking FIG4 as an example, the ONU to be online is ONU 43. Corresponding to the process of S405, ONU 43 receives the overhead message 2 sent by the optical relay device 42.

[0108] Overhead message 2 is also called a second overhead message and carries a second pre-allocated equalization delay (second preEqd). The second preEqd is the pre-allocated equalization delay included in the configuration information in S402. In some possible scenarios, the second preEqd may also be called a dedicated preEqd for the optical relay device 42.

[0109] For the optical relay device 42, the above S405 may include the following steps: the optical relay device 42 modifies the pre-allocated equalization delay (first preEqd) in the overhead message 1 to the pre-allocated equalization delay (second preEqd) carried in the configuration information, thereby obtaining overhead message 2. For example, the pre-allocated equalization delay in the overhead message 1 is preEqd1, and the pre-allocated equalization delay in the overhead message 2 is preEqd2.

[0110] The above overhead messages are used to indicate the optical parameters to be used by the optical network device at the next level of the optical relay device 42. These optical parameters may include, but are not limited to, the frequency to be used by the ONU to send optical signals to the optical relay device 42, or the signal transmission power to be used by the laser in the ONU (such as laser 313 in Figure 3).

[0111] In this embodiment, the OLT can configure different pre-allocated equalization delays for different optical relay devices. During the registration process of the ONU, for the ONU that accesses the optical communication network through the optical relay device, the OLT can set different pre-allocated equalization delays for the ONUs connected to different optical relay devices, so that during the registration process of the ONU, the OLT only opens a discovery window adapted to the specific optical relay device for the optical relay device. The adapted discovery window will be smaller than the discovery window opened by the OLT for all ONUs indiscriminately, thereby reducing the uplink delay jitter in the optical communication network.

[0112] S406 . The OLT 41 sends a discovery message 0 to the optical relay device 42 .

[0113] Corresponding to the process of S406 , the optical relay device 42 receives the discovery message 0 sent by the OLT 41 .

[0114] The discovery message 0 is also called a standard discovery message. The discovery message 0 carries standard SN Request windowing authorization information, which is used to instruct the OLT 41 to open a discovery window for any optical network device to be online.

[0115] In the case where the OLT is not only directly connected to the optical relay device but also directly connected to other optical network devices, if the other optical network devices do not need to communicate with the OLT through the optical relay device, these other optical network devices can send the SN of the other optical network devices to the OLT through the standard discovery message sent by the OLT, so that the OLT can assign registration identifiers to the other optical network devices according to the SN and perform the registration process of the other optical network devices.

[0116] In this embodiment, OLT 41 opens a discovery window for ONUs connected via optical relay devices. Therefore, the standard SN (Request) windowing authorization information carried in the discovery message 0 is not applicable to ONU 43. To enable ONU 43 to register smoothly, two optional implementations are provided below.

[0117] In a first optional implementation, after optical relay device 42 receives Discovery Message 0 sent by OLT 41, it deletes the standard SN (Request) windowing authorization information in Discovery Message 0, thereby obtaining a deactivation message. Optical relay device 42 then sends this deactivation message to the optical network device immediately below it. This prevents the optical network device immediately below it from learning the standard SN (Request) windowing authorization information in Discovery Message 0 and, therefore, from performing the registration process within the discovery window indicated by this standard SN (Request) windowing authorization information.

[0118] In a second optional implementation, after optical relay device 42 receives Discovery Message 0 sent by OLT 41, optical relay device 42 terminates the transmission of Discovery Message 0 within the optical communication network. Subsequently, the optical network device downstream of optical relay device 42 does not receive Discovery Message 0 and therefore does not perform the registration process within the discovery window indicated by the aforementioned standard SN (Request) windowing authorization information.

[0119] In both of the above implementations, the optical network device at the next level of the optical relay device will not receive the standard SN (Request) windowing authorization information and will not report the SN, resulting in the SN being unable to be effectively received by the OLT. This helps improve the accuracy of the registration process in the optical communication network. The above two optional implementations are merely examples provided in this embodiment and should not be construed as limitations of this application.

[0120] S407 . The OLT 41 sends a discovery message 1 to the optical relay device 42 and opens a discovery window for the optical relay device 42 .

[0121] Corresponding to the process of S407 , the optical relay device 42 receives the discovery message 1 sent by the OLT 41 .

[0122] The discovery message 1 carries the specified BWmap information in the aforementioned configuration information.

[0123] The size of the discovery window is determined based on the distance between the optical relay device 42 and the optical network device downstream of the optical relay device 42 (also referred to as the access distance of the downstream network of the optical relay device). In this embodiment, the size of the discovery window is determined based on the distance between the optical relay device 42 and the ONU 43.

[0124] For example, if the distance between the optical relay device 42 and the ONU 43 is within a range of 0 to 40 kilometers (km), the size of the discovery window may be the transmission time slots corresponding to three data frames. The transmission time slots of a single data frame may vary in different protocols, and this application does not limit this.

[0125] S408 . The optical relay device 42 sends a discovery message 2 to the ONU 43 based on the discovery message 1 .

[0126] In the optical relay device 42, the optical relay device 42 converts the specified BWmap information in the discovery message 1 into the first standard SN Request windowing authorization information to generate the discovery message 2. Then, the optical relay device 42 sends the discovery message 2 to the ONU 43. The first standard SN (Request) windowing authorization information is used to indicate the discovery window opened by the OLT 41 for the ONU 43. The first standard SN (Request) windowing authorization information and the standard SN (Request) windowing authorization information carried by the aforementioned discovery message 0 have the same similarity in that the formats of the two are the same; the difference is that the values ​​contained in the first standard SN (Request) windowing authorization information and the standard SN (Request) windowing authorization information carried by the discovery message 0 are different. Among them, the discovery window indicated by the first standard SN (Request) windowing authorization information is consistent with the discovery window opened by the OLT 41 in S407.

[0127] Discovery Message 1 and Discovery Message 2 share the same format and carry information instructing the next-level optical network device of optical relay device 42 to initiate a registration process. Exemplarily, Discovery Message 1 and Discovery Message 2 instruct ONU 43 to report its SN. For example, ONU 43 responds to a received overhead message by sending its SN information to OLT 41. Specifically, the transmission of this SN information requires forwarding via optical relay device 42.

[0128] The difference between discovery message 1 and discovery message 2 is that the windowing authorization information field carried in the two discovery messages contains different contents. Discovery message 1 carries the specified BWmap information, and discovery message 2 carries the standard SN Request windowing authorization information generated based on the specified BWmap information.

[0129] In this embodiment, the standard SN Request windowing authorization information carried in the discovery message 2 received by the ONU is not the windowing authorization information generated by the OLT based on the standard BWmap information, but the windowing authorization information generated by the optical relay device based on the specified BWmap information. Since the discovery window corresponding to the specified BWmap information is smaller than the discovery window corresponding to the standard BWmap information, the ONU can only implement the ONU registration process within a smaller discovery window, that is: in the SN discovery phase, the discovery window opened by the OLT for the next-level optical network device of the optical relay device will be smaller than the standard discovery window, and the service interruption time of other ONUs connected to the OLT is shortened, which is beneficial to reducing the uplink delay jitter of the optical communication network and improving the communication stability of each optical network device in the optical communication network.

[0130] S409 . The ONU 43 responds to the discovery message 2 and sends a response message 1 to the optical relay device 42 .

[0131] Corresponding to the process of S409 , the optical relay device 42 receives the response message 1 sent by the ONU 43 .

[0132] The response message 1 carries the SN of the ONU 43, which is used to uniquely identify the ONU 43 in the optical communication network. The response message 1 may also be referred to as an SN message, an SN response, an SN response message, or an SN response packet, etc., which is not limited in this application.

[0133] In this embodiment, the process of ONU 43 sending response message 1 can be implemented based on the optical parameters carried in the aforementioned overhead message 2. The following uses the structure of ONU 43 being ONU 310 in Figure 3 as an example to illustrate the process of ONU sending response message 1. The process of sending response message 1 includes the following steps 1 and 2.

[0134] Step 1: The ONU MAC 311 in the ONU 310 sends an adjustment command to the ONU PHY 312: adjust the bias current (Ibias) based on the optical parameters so that the adjusted Ibias is the threshold current (IT) in the optical parameters; and turn off the modulation current (Imod) and Tx_En. For example, the threshold current can be 5 milliamperes (mA), 10 mA, or other values.

[0135] Step 2: After the laser 313 is stable, the ONU MAC 311 sends information of a specific frequency via Tx_En; and the laser 313 continuously switches the optical port to generate an optical signal corresponding to the information of the specific frequency, and sends the generated optical signal to the ONU 320.

[0136] The information of the specific frequency is the optical parameter carried by the overhead message 2 , and the response message carries the registration identifier corresponding to the ONU 310 .

[0137] For example, the maximum power of the optical signal generated in step 2 is -23.4 decibels per milliwatt (dBm), and the minimum power is -45.8 dBm.

[0138] In this embodiment, the index describing the power of the optical signal can be obtained by the following formula 1.

[0139] dBm = 10*log(P / 1mW) Formula 1

[0140] Where P represents the power value in watts.

[0141] Accordingly, after the OLT receives the optical signal in the above step 2, the received optical signal is photoelectrically converted according to the photodetector in the OLT (such as the photodetector in Figure 3) to obtain an electrical signal; then, the signal processing module in the OLT (such as the signal processing module in Figure 3) processes the electrical signal obtained by the photoelectric conversion to obtain a bit stream corresponding to the response message.

[0142] S410 . The optical relay device 42 sends a response message 2 to the OLT 41 based on the response message 1 .

[0143] Corresponding to the process of S410 , the OLT 41 receives the response message 2 sent by the optical relay device 42 .

[0144] The response message 2 also carries the SN of the ONU 43 .

[0145] In this example, both response message 2 and response message 1 are optical signals. The difference between response message 2 and response message 1 is that the optical signal after the SN of ONU 43 in response message 1 continues to be transmitted, while the optical signal after the SN of ONU 43 in response message 2 is set to an invalid optical signal, or the optical relay device 42 terminates the transmission process of the optical signal after the SN of ONU 43 in response message 2. The optical relay device 42 setting the optical signal after the SN of ONU 43 in response message 2 to an invalid optical signal may include: the optical relay device 42 setting the optical signal to an optical signal of a preset frequency, etc.

[0146] In this way, in the process of the ONU reporting the SN to the OLT, the optical signal after the SN in the response message does not need to be transmitted or is transmitted as an invalid optical signal, so that the OLT does not need to process this part of the optical signal, reducing the consumption of processing resources in the OLT.

[0147] S411. The OLT 41 sends a registration identifier and a ranging request message to the optical relay device 42 according to the SN carried in the response message 2.

[0148] Corresponding to the process of S411 , the optical relay device 42 receives the registration identifier and the ranging request message sent by the OLT 41 .

[0149] Exemplarily, the registration identifier is assigned to ONU 43 by OLT 41 based on ONU 43's SN. For example, the registration identifier is the identification (ID) of ONU 43, which is recorded as ONU ID 1. This registration identifier is the registration information required by the ONU when going online. During communication between ONU 43 and OLT 41, OLT 41 uniquely identifies ONU 43 based on ONU ID 1, preventing data sent to ONU 43 from being forwarded to other ONUs, thereby improving communication accuracy between ONU 43 and OLT 4.

[0150] In some optional implementations, the registration identifier may also refer to the ID of other types of home optical network devices, such as the ID of a single family unit (SFU) (abbreviated as SFU ID), the ID of a home gateway unit (HGU) (abbreviated as HGU ID), or the ID of a single business unit (SBU) (abbreviated as SBU ID), etc. In the text of this application, various embodiments are described using the ONU ID as an example, but this should not be understood to mean that the registration identifier provided in this application refers only to the ONU ID.

[0151] As another example, the ranging request message includes the registration identifier of the ONU 43 (eg, ONU ID 1).

[0152] In this embodiment, the OLT 41 may also open a ranging window for the ONU 43. The size of the ranging window may also be determined according to the access distance between the ONU 43 and the optical relay device 42. The implementation of the ranging window is similar to that of the discovery window and is not described in detail here.

[0153] S412 . The optical relay device 42 sends the registration identifier of the ONU 43 and a ranging request message to the ONU 43 .

[0154] Corresponding to the process of S412 , the ONU 43 receives the registration identifier of the ONU 43 and the ranging request message sent by the optical relay device 42 .

[0155] The ranging request message is used to instruct the ONU 43 to perform a ranging process of the ONU 43 according to the received registration identifier.

[0156] S413. The ONU 43 responds to the ranging request message and sends a ranging message to the optical relay device 42 according to the registration identifier of the ONU 43.

[0157] Corresponding to the process of S413 , the optical relay device 42 receives the ranging message sent by the ONU 43 .

[0158] The ranging message carries the registration identifier of the ONU 43. In some possible examples, the ranging message 1 may also be referred to as a first ranging message or other names.

[0159] S414 . The optical relay device 42 sends the ranging message in S413 to the OLT 41 .

[0160] Corresponding to the process of S414 , the OLT 41 receives the ranging message sent by the optical relay device 42 .

[0161] S415 . The OLT 41 responds to the ranging message and sends a response message to the optical relay device 42 .

[0162] Corresponding to the process of S414 , the optical relay device 42 receives the response message sent by the OLT 41 .

[0163] The response message is used to indicate the balanced delay that the ONU 43 will use to communicate in the optical communication network. The balanced delay indicates the channel that the ONU 43 uses to implement service data communication after accessing the optical communication network through the OLT 41 .

[0164] It can be understood that among the multiple optical network devices that access the optical communication network through OLT 41, different optical network devices use different channels, that is, each ONU will use a different equalization delay, which is conducive to avoiding the situation where different ONUs occupy the same channel and cause errors in business data communication, and improve the communication accuracy between the optical network devices in the optical communication network.

[0165] S416 . The optical relay device 42 sends the response message in S415 to the ONU 43 .

[0166] Corresponding to the process of S416 , the ONU 43 receives the response message sent by the optical relay device 42 .

[0167] In this embodiment, the discovery window opened by the OLT is determined based on the distance between the optical relay device and the next-level optical network device of the optical relay device, and the OLT has configured specified BWmap information for the optical relay device, so that when the OLT performs the registration process of the next-level optical network device of the optical relay device, the OLT does not need to open a larger discovery window, but only needs to open a discovery window that is compatible with the aforementioned next-level optical network device.

[0168] Therefore, the OLT only needs to open a smaller discovery window during the SN discovery process. The time slot corresponding to the smaller discovery window is reduced, and the service interruption time of other optical network devices communicating with the OLT is shortened, which is beneficial to reducing the uplink delay jitter of the optical communication network and improving the communication stability of the optical communication network.

[0169] In some optional implementations, the ONU to be put online refers to other ONUs (such as ONU 44) or other optical relay devices, etc. The registration process of these ONUs and optical relay devices can refer to the registration process of ONU 43 provided in this embodiment, which will not be repeated here.

[0170] The beneficial effects of the registration method provided in the present application are exemplarily described below with reference to the accompanying drawings, as shown in FIG5 , which is a schematic diagram comparing different registration methods provided in the present application.

[0171] In Cases 1 and 2 of Figure 5 , each data frame consists of a downstream physical synchronization block (PSBd) and a physical frame (PHY frame). The PSBd is used to provide synchronization and frame delimitation, while the PHY frame carries the payload of the data frame.

[0172] As shown in Case 1 in Figure 5, the transmission distance between the OLT and the ONU is 20 km. The ONU registration process with the OLT includes the following: 1. The OLT sends overhead information containing standard BWmap information to the ONU; 2. The ONU responds to the received overhead information by sending a response message to the OLT. The ONU's response time is T11; 3. The OLT receives the response message from the ONU and sends a discovery message to the ONU to initiate the ONU registration process with the OLT. T12 is the response time after the ONU receives the discovery message, T13 is the start time of the ONU's SN discovery phase, and T14 is the random time between the ONU's response to the discovery message and the sending of the SN. It is worth noting that, taking the average delay Teqd = 236 μs between the OLT sending the overhead message and the ONU sending the SN, the OLT needs to enable a silent window (discovery window) of at least 250 μs to meet the OLT's requirements for the ONU's SN discovery phase. Therefore, since the OLT opens the discovery window, there is at least 250us of uplink delay jitter between the OLT and the ONU.

[0173] As shown in Case 2 in Figure 5, the transmission distance between the OLT and ONU is 120 km, and the ONU registration process with the OLT is the same as in Case 1 above. T21 is the response time after the ONU receives the overhead message, T22 is the response time after the ONU receives the discovery message, T13 is the start time of the ONU's SN discovery phase, and T14 is the random time between the ONU responding to the discovery message and sending the SN. The difference between Case 2 and Case 1 is that the distance is greater, and the OLT enables a discovery window of 1250 μs. Furthermore, the OLT's enabled discovery window results in an uplink latency jitter of at least 1250 μs between the OLT and ONU.

[0174] Combining Case 1 and Case 2 in Figure 5, when the distance between the ONU and the OLT increases, the OLT indiscriminately opens the discovery window for all ONUs to be online, resulting in a rapid increase in the uplink delay jitter of other ONUs connected to the OLT, an increase in the interruption time of various services in the optical communication network, and a decrease in the communication performance of the optical communication network.

[0175] Compared to conventional technologies, the registration method provided in this application can reduce uplink latency jitter. For example, in Case 3 of Figure 5 , each data frame includes a physical control block downstream (PCBd) and a payload. For example, the three data frames in Figure 5 include payload N, payload N+1, and payload N+2, respectively. PCBd can be used to provide functions such as synchronization lock, timing, and dynamic bandwidth allocation. For more information about PCBd, please refer to the general description and will not be elaborated here.

[0176] The transmission distance between the OLT and the ONU is 120 km. The ONU registration process with the OLT includes the following: 1. The OLT sends a discovery message to the ONU via an optical relay device. The content and implementation of this discovery message can be found in the description of Discovery Messages 1 and 2 above. The ONU responds to this discovery message and feeds back its SN to the OLT. 2. The OLT receives the SN sent by the ONU, assigns a registration identifier (ONU ID = 254) to the ONU, and opens a ranging window. Based on the received registration identifier and ranging request message, the ONU sends a ranging message to the OLT via the optical relay device. 3. The OLT responds to the ranging message and assigns a balancing delay to the ONU, which it then sends to the ONU in the format of a Ranging message. For more details on Case 3, please refer to the description of Figure 4 above and will not be repeated here. In conjunction with Figure 5 , T31 is the propagation delay, T11 = 0.1 μs; T32 is the ONU response time to the discovery message; Eqd1 is the ONU's pre-allocated equalization delay; T33 is the random time between the ONU responding to the discovery message and sending the SN; Tstart is the start time in the standard SN (Request) windowing authorization message, and Tstop is the end time in the standard SN (Request) windowing authorization message; and T34 is the propagation delay between the ONU sending the SN and the OLT receiving the SN. In conjunction with the embodiment of Figure 4 , the discovery window enabled by the OLT for the ONU is associated with the distance between the ONU and the optical relay device. Therefore, the discovery silent window that the OLT needs to enable is only 250 μs, which is much smaller than the silent window in Case 2. This reduces upstream delay jitter in the remote PON network.

[0177] It is understood that to implement the functions described in the above embodiments, the ONU, OLT, and optical relay equipment include hardware structures and / or software modules corresponding to the respective functions. Those skilled in the art will readily appreciate that, in conjunction with the various exemplary units and method steps described in the embodiments disclosed herein, the present application can be implemented in hardware or a combination of hardware and computer software. Whether a function is implemented in hardware or in a hardware-driven manner by computer software depends on the specific application scenario and design constraints of the technical solution.

[0178] The registration method provided according to the present embodiment is described in detail above with reference to FIG. 1 to FIG. 5 . The registration device provided according to the present embodiment will be described below with reference to FIG. 6 .

[0179] Figure 6 is a schematic diagram of the structure of the registration device provided in this application. The registration device 600 can be used to implement the functions of any ONU in the above-mentioned method embodiment, thereby also achieving the beneficial effects of the above-mentioned method embodiment. In this embodiment, the registration device 600 can be the optical network device 121, optical relay device 122, other optical network devices or optical relay devices as shown in Figure 1, or any optical relay device or OLT shown in subsequent figures. It can also be a module (such as a chip) applied to an optical relay device or OLT.

[0180] As shown in Figure 6 , the registration device 600 includes a transceiver module 610 and a processing module 620. Transceiver module 610 and processing module 620 can collaboratively implement the various steps in the aforementioned method embodiments. A more detailed description of transceiver module 610 and processing module 620 can be directly obtained by referring to the descriptions of the optical relay devices or OLTs in the method embodiments shown in the aforementioned figures, and is not further elaborated here.

[0181] When the registration device implements any of the registration methods shown in the aforementioned figures through software, the registration device and its various units may also be software modules. The aforementioned registration method is implemented by invoking the software module through a processor. The processor may be a central processing unit (CPU), an application-specific integrated circuit (ASIC), or a programmable logic device (PLD). The PLD may be a complex programmable logical device (CPLD), a field programmable gate array (FPGA), a generic array logic (GAL), or any combination thereof.

[0182] For a more detailed description of the above-mentioned registration device, please refer to the relevant description of the embodiment shown in the aforementioned figures, and will not be repeated here. It is understood that the registration device shown in the aforementioned figures is only an example provided in this embodiment. Depending on the ranging process or service, the registration device may include more or fewer units, and this application is not limited to this.

[0183] When the registration device is implemented via hardware, the hardware may be implemented via a processor or a chip system. A chip system includes one or more chips, each of which includes an interface circuit and a control circuit. The interface circuit is used to receive data from devices outside the chip and transmit it to the control circuit, or to send data from the control circuit to devices outside the chip.

[0184] The control circuit and the interface circuit are used to implement any possible implementation method of the above embodiments through logic circuits or execution code instructions. The beneficial effects can be found in the description of any aspect of the above embodiments, which will not be repeated here.

[0185] It is understood that the processor in the embodiments of the present application may be a CPU, or other general-purpose processor, digital signal processor (DSP), ASIC, FPGA or other programmable logic device, transistor logic device, hardware component or any combination thereof. The general-purpose processor may be a microprocessor or any conventional processor.

[0186] In addition, the registration device 600 shown in FIG6 can also be implemented by an optical network device, as shown in FIG7 , which is a schematic structural diagram of the optical network device provided in this application. The optical network device 700 includes a memory 710 and at least one processor 720. The processor 720 can implement the registration method provided in the above embodiment, and the memory 710 is used to store software instructions corresponding to the above registration method. As an optional implementation, in hardware implementation, the optical network device 700 can be a chip or chip system encapsulated with one or more processors 720. For example, when the optical network device 700 is used to implement the method steps in the above embodiment, the processor 720 included in the optical network device 700 executes the steps of the above method and its possible sub-steps. In an optional scenario, the optical network device 700 can also include a communication interface 730, which can be used to transmit and receive data. For example, the communication interface 730 is used to receive or transmit ranging messages; the communication interface 730 can be implemented by the interface circuit included in the optical network device 700.

[0187] In an embodiment of the present application, the communication interface 730, the processor 720, and the memory 710 may be connected via a bus 740, which may be divided into an address bus, a data bus, a control bus, etc. The bus 740 may be a Peripheral Component Interconnect Express (PCIe) bus, an extended industry standard architecture (EISA) bus, a unified bus (Ubus or UB), a compute express link (CXL), a cache coherent interconnect for accelerators (CCIX), etc.

[0188] It is worth noting that the optical network device 700 can also perform the functions of the registration device 600 shown in FIG6 , which will not be described in detail here.

[0189] The optical network device 700 provided in this embodiment can be any of the above OLTs, or other optical network devices with data processing functions, which is not limited in this application. For example, the optical network device 700 can be any of the above optical network devices, such as OLT 41 or optical network device 121.

[0190] In addition, the registration device 600 shown in FIG6 may also be implemented by an optical relay device. When the registration device 600 is implemented by an optical relay device, the hardware implementation of the optical relay device may refer to the relevant description of FIG3 and will not be described in detail here.

[0191] The method steps in the embodiments of the present application can also be implemented by a processor executing software instructions. The software instructions can be composed of corresponding software modules, which can be stored in random access memory (RAM), flash memory, read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), registers, hard disks, mobile hard disks, CD-ROMs, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium can also be an integral part of the processor. The processor and storage medium can be located in an ASIC. In addition, the ASIC can be located in a network device or a terminal device. Of course, the processor and storage medium can also exist as discrete components in a network device or a terminal device.

[0192] The present application also provides a communication system, which includes an optical fiber, a master network device, and at least one slave network device. The optical fiber is used to connect the network devices. The network device may be the above-mentioned ONU.

[0193] In the above embodiments, all or part of the embodiments can be implemented by software, hardware, firmware or any combination thereof. When implemented using software, all or part of the embodiments can be implemented in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on a computer, the process or function described in the embodiments of the present application is performed in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user device or other programmable device. The computer program or instruction can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer program or instruction can be transmitted from one website, computer, server or data center to another website, computer, server or data center via wired or wireless means. The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium, such as a floppy disk, a hard disk, or a tape; it can also be an optical medium, such as a digital video disc (DVD); it can also be a semiconductor medium, such as a solid state drive (SSD).

[0194] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present application, and such modifications or substitutions should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A method for activating an optical network unit (ONU), characterized in that: The method comprises: If the ONU achieves downlink synchronization, the ONU enters a configuration file learning state; The ONU obtains a plurality of upstream wavelength options from the received data stream; If the ONU supports at least one of the multiple upstream wavelength options, the ONU enters a sequence number state from the configuration file learning state.

2. The method according to claim 1, characterized in that After the ONU enters the serial number state, the method further includes: If the ONU receives a serial number authorization, the ONU sends a serial number management and maintenance message, wherein the serial number authorization is used to indicate that the ONU is allowed to join or resume entering the passive optical network, and the serial number management and maintenance message is used to indicate the serial number and random delay of the ONU.

3. The method according to claim 2, characterized in that After the ONU sends the sequence number management and maintenance information, the method further includes: After the ONU receives the ONU-ID, the ONU enters a ranging state, wherein the ONU-ID is used to uniquely identify the ONU in the passive optical network.

4. The method according to claim 3, characterized in that After the ONU enters the ranging state, the method further includes: The ONU receives the equalization delay information, and adjusts the uplink clock based on the equalization delay information to complete the activation.

5. The method according to any one of claims 1 to 4, characterized in that The ONU implements downlink synchronization, specifically including: The downstream synchronization state machine of the ONU enters the synchronization state from the pre-synchronization state.

6. The method according to any one of claims 1 to 5, characterized in that After the ONU enters the configuration file learning state, the method further includes: If the ONU loses downstream synchronization, the ONU returns from the configuration file learning state to the desynchronized state.

7. The method according to claim 6, characterized in that The ONU loses downlink synchronization, specifically including: The downstream synchronization state machine of the ONU enters the search state from the pre-synchronization state.

8. The method according to any one of claims 1 to 7, characterized in that The received data stream includes a downlink physical frame, the downlink physical frame includes an operation control body (OC body), and the OC body includes the multiple uplink wavelength options; or, The received data stream includes a burst profile message including the plurality of upstream wavelength options.

9. The method according to any one of claims 1 to 8, characterized in that The multiple wavelength options are 3 wavelength options, the first wavelength option is 1260nm~1280nm, the second wavelength option is 1290nm~1310nm, and the third wavelength option is 1284nm~1288nm.

10. The method according to claim 9, characterized in that The method is performed on an activated wavelength, and the activated wavelength is different from all of the multiple upstream wavelength options.

11. An optical network unit, characterized in that: include: An interface and a processor, wherein the processor is configured to: If downlink synchronization is achieved, the configuration file learning state is entered; obtaining a plurality of upstream wavelength options from a data stream received through the interface; If the optical network unit supports at least one of the multiple upstream wavelength options, the configuration file learning state is converted to the sequence number state.

12. The optical network unit according to claim 11, characterized in that: The processor is used to: After entering the serial number state, if a serial number authorization is received, serial number management and maintenance information is sent, wherein the serial number authorization is used to indicate that the optical network unit is allowed to join or resume entering the passive optical network, and the serial number management and maintenance information is used to indicate the serial number and random delay of the optical network unit.

13. The optical network unit according to claim 12, characterized in that: The processor is used to: After sending the serial number management and maintenance information, if an ONU-ID is received, the ranging state is entered, wherein the ONU-ID is used to uniquely identify the optical network unit in the passive optical network.

14. The optical network unit according to claim 13, characterized in that: The processor is used to: After entering the ranging state, the equalization delay information is received through the interface, and the uplink clock is adjusted based on the equalization delay information to complete the activation.

15. The optical network unit according to any one of claims 11 to 14, characterized in that: The processor is specifically used for: If the downlink synchronization state machine enters the synchronization state from the pre-synchronization state, it enters the configuration file learning state.

16. The optical network unit according to any one of claims 11 to 15, characterized in that: The processor is further configured to: After entering the configuration file learning state, if downlink synchronization is lost, the configuration file learning state returns to the closed synchronization state.

17. The optical network unit according to claim 16, characterized in that: The processor is specifically used for: After entering the configuration file learning state, if the downlink synchronization state machine enters the search state from the pre-synchronization state, it returns from the configuration file learning state to the closed synchronization state.

18. The optical network unit according to any one of claims 11 to 17, characterized in that: The received data stream includes a downlink physical frame, the downlink physical frame includes an operation control body (OC body), and the OC body includes the multiple uplink wavelength options; or, The received data stream includes a burst profile message including the plurality of upstream wavelength options.

19. The optical network unit according to any one of claims 11 to 18, characterized in that: The multiple wavelength options are 3 wavelength options, the first wavelength option is 1260nm~1280nm, the second wavelength option is 1290nm~1310nm, and the third wavelength option is 1284nm~1288nm.

20. A communication system, characterized in that: include: An optical line terminal and at least one optical network unit according to any one of claims 11 to 19, wherein the optical line terminal is connected to the at least one optical network unit.

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