A method of registering signal transmission and reception, an optical transmission device, an optical reception device, and a system

Abstract

The application discloses a registration signal sending and receiving method, an optical transmitting device, an optical receiving device and a system. The registration signal sending method comprises the following steps: generating registration information, loading the registration information into a spontaneous emission light signal generated by a laser through a transmitting enabling port, and generating a registration signal. The registration signal is an optical signal carrying the registration information. By loading the registration information into the laser through the transmitting enabling port to generate the registration signal, the registration process can be started without a mute window, the uplink delay jitter is reduced, and the registration signal is sent at low cost.

Description

Technical Field

[0001] This application relates to the field of optical communication, and in particular to methods for transmitting and receiving registered signals, optical transmitting devices, optical receiving devices and systems. Background Technology

[0002] A typical application of point-to-multipoint optical transmission systems based on time division multiple access (TDMA) technology is the passive optical network (PON). Figure 1 This is a schematic diagram of the architecture of a PON system in the prior art. Figure 1 As shown, a PON system may include an OLT 101, an optical splitter 102, and multiple ONUs 103-105. Downlink transmission from OLT 101 to ONUs 103-105 uses a broadcast method, while uplink transmission from ONUs 103-105 to OLT 101 uses TDMA optical transmission technology. In the uplink direction, different ONUs occupy different time slots to transmit services to the OLT; for example, ONU 101 occupies time slot t1, ONU 102 occupies time slot t2, and ONU 103 occupies time slot t3. The time slots occupied by different ONUs must not overlap; otherwise, it will cause severe interference, preventing the OLT from correctly receiving the overlapping information. In the uplink transmission of a PON system, when a new ONU comes online, the OLT needs to open a silent window (e.g., a 250µs silent window when the maximum distance from the OLT to the ONU is 20km). During the silent window period, the services of other ONUs are interrupted, allowing the newly online ONU to complete registration, ranging, and other processes. This ONU registration scheme requires periodically opening the silent window, resulting in latency jitter. This poses a challenge to PON systems in applications with high latency jitter requirements. Therefore, in point-to-point optical transmission systems (such as PON), it is necessary to reduce the uplink latency jitter caused by the registration process. Summary of the Invention

[0003] This invention proposes a method, optical transmitter, optical receiver, and system for transmitting and receiving registration signals, which can avoid opening a silent window during the registration process and reduce uplink latency jitter caused by the registration process.

[0004] In a first aspect, embodiments of this application provide a method for transmitting a registration signal. This method can be executed by an optical transmitting device (such as an ONU) and includes the following steps: the optical transmitting device generates registration information, loads the registration information into a spontaneously emitted light signal generated by a laser through a transmit enable port, and generates a registration signal. Then, the optical transmitting device transmits the registration signal, wherein the registration signal is an optical signal carrying the registration information.

[0005] In the technical solution provided in this application embodiment, registration information is loaded into the spontaneous emission light signal generated by the laser through the transmit enable port. The power of the registration signal is lower than that of the service signal, thus avoiding the impact of the registration signal on the service signal without opening a silent window. In addition, the registration process does not require opening a silent window, avoiding uplink latency jitter caused by the registration process.

[0006] In one possible implementation, the method further includes setting the bias current of the laser to be less than a threshold current, so that the laser generates a spontaneously emitting optical signal, wherein the threshold current is a preset current value.

[0007] By setting the bias current of the laser to be less than the threshold current, the laser generates a spontaneously radiating optical signal, thereby making the power of the registration signal lower than that of the service signal, which facilitates the separation of the registration signal and the service signal at the receiving end.

[0008] In one possible implementation, the method further includes setting the modulation current of the laser to zero.

[0009] Setting the modulation current of the laser to zero can prevent the modulation current from superimposed on the laser, thus avoiding fluctuations in the output power of the laser.

[0010] In one possible implementation, loading the registration information into the spontaneous emission light signal generated by the laser via the transmit enable port includes: controlling the laser to turn on and off via the transmit enable port based on the registration information, thereby loading the registration information into the spontaneous emission light signal generated by the laser.

[0011] Registration information is sent to the laser driver via the transmit enable port. The laser driver can then generate a switching signal based on the amplitude (e.g., power) of the transmission power of the registration information to control the laser's on and off states.

[0012] In one possible implementation, the registration information includes a first bit and a second bit of binary data. When the registration information includes the first bit, the laser is turned on via the transmit enable port. When the registration information includes the second bit, the laser is turned off via the transmit enable port.

[0013] When the registration information is represented by binary bits, the laser can be turned on and off according to bits 1 and 0 respectively, thereby loading the registration information into the optical signal generated by the laser.

[0014] In one possible implementation, the power of the registration signal is lower than the power of the service signal.

[0015] Secondly, embodiments of this application provide a method for receiving a registration signal. This method can be executed by an optical receiving device (such as an OLT) and includes the following steps: the optical receiving device receives an optical signal carrying registration information, the registration information being loaded into a spontaneously emitted optical signal generated by a first laser through a transmit enable port. Then, the optical receiving device performs photoelectric conversion on the optical signal to obtain the registration information.

[0016] In the technical solution provided in this application embodiment, the registration information is loaded into the spontaneous emission light signal generated by the laser through the transmit enable port, which can realize the reception of the registration signal at low cost and avoid the delay jitter problem caused by opening the silent window.

[0017] In one possible implementation, the optical signal also carries service data, which is loaded into the stimulated emission optical signal generated by the second laser via a data port.

[0018] The optical signals received by the optical receiving device may include registration signals (optical signals carrying registration information) from ONUs (such as ONU1 or the first laser) that are in the registration and online stage, and service signals (optical signals carrying service data) from ONUs (such as ONU2 or the second laser) that are online. The registration signals and service signals are optical signals of different powers, which facilitates the separation of these two types of signals by the optical receiving device.

[0019] In one possible implementation, after performing photoelectric conversion on the optical signal, the method further includes: obtaining an electrical signal, the electrical signal including the registration information and the service data; and extracting the registration information from the electrical signal.

[0020] The optical receiving device can extract the registration information based on its characteristics (e.g., the power of the registration signal is lower than the power of the service signal).

[0021] In one possible implementation, the power of the optical signal carrying the registration information is lower than the power of the optical signal carrying the service data.

[0022] Thirdly, embodiments of this application provide an optical emitting device, comprising: a processor for generating registration information, and loading the registration information into a spontaneously emitted light signal generated by a laser via a transmit enable port to generate a registration signal; and a laser for transmitting the registration signal, wherein the registration signal is an optical signal carrying the registration information.

[0023] The processor can be an ONU media access control (MAC) chip, used to generate registration information and send it to the driver via the transmit enable port. The driver can be an ONU physical layer (PHY) chip, used to control the laser according to the registration information and load the registration information into the spontaneous emission light signal generated by the laser. The ONU optical PHY and the laser can be implemented using different chips or on the same chip. The processor can load the registration information into the spontaneous emission light signal generated by the laser by sending the registration information to the laser driver. The beneficial effects of the third aspect or any possible implementation of the third aspect can be referred to the description of the first aspect or any possible implementation of the first aspect.

[0024] In one possible implementation, the processor is further configured to: set the bias current of the laser to be less than a threshold current, so that the laser generates a spontaneously emitting optical signal, wherein the threshold current is a preset current value. The processor can set the bias current of the laser via the laser driver.

[0025] In one possible implementation, the processor is further configured to: set the modulation current of the laser to zero. The processor can set the modulation current of the laser via the laser's driver. The processor can also set the bias current of the laser via the laser's driver.

[0026] In one possible implementation, the device further includes a driver configured to: control the laser to turn on and off based on the registration information, thereby loading the registration information into the spontaneous emission light signal generated by the laser. The driver obtains the registration information from the processor's transmit enable port and generates a switching signal based on the registration information to control the laser to turn on and off.

[0027] In one possible implementation, the registration information includes a first bit and a second bit of binary data. The driver is used to control the laser to turn on when the registration information includes the first bit, and to control the laser to turn off when the registration information includes the second bit.

[0028] In one possible implementation, the power of the registration signal is lower than the power of the service signal.

[0029] Fourthly, embodiments of this application provide an optical receiving device, comprising: an interface for receiving an optical signal, the optical signal carrying registration information, the registration information being loaded into a spontaneously emitted optical signal generated by a first laser via a transmit enable port; and a photoelectric converter for performing photoelectric conversion on the optical signal to obtain the registration information. The beneficial effects of the fourth aspect or any possible implementation of the fourth aspect can be referred to the description of the second aspect or any possible implementation of the second aspect.

[0030] In one possible implementation, the optical signal also carries service data, which is loaded into the stimulated emission optical signal generated by the second laser via a data port.

[0031] In one possible implementation, after the optical signal is photoelectrically converted, the device further includes a signal processor, which is configured to obtain an electrical signal, the electrical signal including the registration information and the service data, and extract the registration information from the electrical signal.

[0032] In one possible implementation, the power of the optical signal carrying the registration information is lower than the power of the optical signal carrying the service data.

[0033] Fifthly, embodiments of this application provide an apparatus for transmitting a registration signal, characterized in that the apparatus includes: a generation unit, configured to generate registration information by loading spontaneous emission light signals generated by a laser through a transmit enable port to generate a registration signal; and a transmission unit, configured to transmit the registration signal, wherein the registration signal is an optical signal carrying the registration information.

[0034] The beneficial effects of the fifth aspect or any possible implementation of the fifth aspect can be referred to the description of the first aspect or any possible implementation of the first aspect.

[0035] In one possible implementation, the device further includes: a first setting unit, configured to set the bias current of the laser to be less than a threshold current, so that the laser generates a spontaneously emitting light signal, wherein the threshold current is a preset current value.

[0036] In one possible implementation, the device further includes a second setting unit for setting the modulation current of the laser to zero.

[0037] In one possible implementation, the generation unit is configured to: control the laser to turn on and off via the emission enable port based on the registration information, thereby loading the registration information into the spontaneous emission light signal generated by the laser.

[0038] In one possible implementation, the registration information includes a first bit and a second bit of binary data. The generation unit is used to control the laser to turn on via the transmit enable port when the registration information includes the first bit, and to control the laser to turn off via the transmit enable port when the registration information includes the second bit.

[0039] In one possible implementation, the power of the registration signal is lower than the power of the service signal.

[0040] In a sixth aspect, embodiments of this application provide an optical communication system, which includes a plurality of optical transmitting devices as in the first aspect or any possible implementation of the first aspect, and an optical receiving device as in the second aspect or any possible implementation of the second aspect.

[0041] In a seventh aspect, embodiments of this application provide an optical chip for generating registration information. The optical chip loads the registration information into a spontaneous emission light signal generated by a laser through a transmit enable port to generate a registration signal; the registration signal is an optical signal carrying the registration information.

[0042] The optical chip is also used to execute any of the possible implementations of the first aspect. Attached Figure Description

[0043] The embodiments of this application will now be described in more detail with reference to the accompanying drawings:

[0044] Figure 1 This is a schematic diagram of the architecture of a PON system in the prior art;

[0045] Figure 2 This application provides a schematic diagram of the architecture of a PON system.

[0046] Figure 3 An exemplary flowchart of a PON system registration method provided for embodiments of this application;

[0047] Figure 4 An exemplary flowchart of an ONU registration method provided for embodiments of this application;

[0048] Figure 5 This is a schematic diagram showing the relationship between the bias current and optical power of a laser provided in an embodiment of this application.

[0049] Figure 6 This application provides a waveform diagram of ONU registration information as an embodiment of the present application.

[0050] Figure 7 An exemplary flowchart of an OLT registration method provided for embodiments of this application;

[0051] Figure 8 This is a schematic diagram illustrating the signal overlay of registration information and business data provided in the embodiments of this application.

[0052] Figure 9 A schematic diagram of the logic structure of an oDSP provided in this application;

[0053] Figure 10 This is a schematic diagram of the structure of an OLT provided in an embodiment of this application;

[0054] Figure 11 This is a schematic diagram of another OLT structure provided in an embodiment of this application. Detailed Implementation

[0055] The device configurations and business scenarios described in this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of the present invention, and do not constitute a limitation on the technical solutions provided by the embodiments of the present invention. Those skilled in the art will understand that, with the evolution of device configurations and the emergence of new business scenarios, the technical solutions provided in this application are also applicable to similar technical problems.

[0056] It should be noted that the terms "first," "second," etc., used in this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in an order not described in this application. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. The specific operational methods in the method embodiments can also be applied to the device embodiments. Conversely, the component function descriptions in the device embodiments also apply to the relevant descriptions in the method embodiments.

[0057] This application can be applied to scenarios such as PON, passive optical LAN (POL), industrial optical networks, vehicular optical networks, and the Internet of Things (IoT). For example, in a PON scenario, the optical transmitter can be located in a user's home or building corridor, and the optical receiver can be located in the operator's equipment room. In a POL scenario, the optical transmitter and receiver can be located in a campus (such as an enterprise or school). In an industrial optical network scenario, the optical transmitter and receiver can be located in an industrial manufacturing workshop. In a vehicular optical network scenario, the optical transmitter and receiver can be installed in a vehicle. As an example, in a PON scenario, the optical transmitter can be an optical network unit (ONU) or an optical network terminal (ONT), and the optical receiver can be an optical line terminal (OLT). In a vehicular optical network scenario, the optical transmitter can be a vehicle interface unit (VIU), and the optical receiver can be a mobile data center (MDC), vehicle dynamic control (VDC), or cockpit data center (CDC). The technical solutions proposed in this application can also be applied to optical backbone transmission networks, data center optical transmission, short-range optical interconnects, and wireless service fronthaul / backhaul. Specifically, the technical solutions proposed in this application can be used in optical transmitting devices and / or optical receiving devices corresponding to the above-mentioned different networks.

[0058] Taking PON as an example, this application embodiment can be applied to both time-division multiple-passive optical networks (TDM-PON) and wavelength-division multiplexed passive optical networks (WDM-PON). In this embodiment, the ONU's optical module lowers the laser's bias current, reducing the laser's emission power, and transmits the ONU's uplink registration signal through the laser's transmit enable port. The OLT does not need to open a silent window; the ONU's registration signal during the registration and online phase, along with the service signals of other online ONUs, are simultaneously received by the OLT. Due to the physical characteristics of the laser, the laser's turn-on time requires a certain amount of time (e.g., 25.6 ns). Therefore, the frequency of controlling the laser's turn-on and turn-off through the transmit enable port is relatively low (usually at most MHz). Consequently, the registration signal loaded through the transmit enable port is a low-rate signal. Furthermore, by lowering the laser's bias current, the ONU loads the registration signal into a low-power optical signal (such as the spontaneous emission optical signal mentioned in the following embodiment). Therefore, the registration signal is a low-power signal. Typically, the power of the registration signal is lower than the optical power of the service signals received by the OLT from all ONUs; for example, it is 15 dB lower than the minimum power service signal received by the OLT. Therefore, the registration signal has the characteristics of low data rate and low power compared to the service signal. The OLT can separate the registration signal and the service signal and recover both signals.

[0059] Figure 2 This is a schematic diagram of the architecture of a PON system provided in an embodiment of this application. Figure 2 As shown, multiple ONUs 210 (only one is shown in the figure) communicate through optical splitter 220 and OLT 230.

[0060] ONU 210 may include an ONU media access control (MAC) 211, an ONU physical layer (PHY) 212, a laser 213, and a photodetector 214. In the transmission direction, the ONU MAC 211 can control the laser 213 to turn on and off via the transmit enable port (Tx_En, also known as the switch pin). For example, if the ONU 210 is currently in a transmission time slot (or occupied time slot), the ONU MAC 211 controls the laser 213 to turn on via the transmit enable port; if it is not in a transmission time slot, the ONU MAC 211 controls the laser 213 to turn off via the transmit enable port. The ONU MAC 211 can also adjust the physical parameters of the laser 213, such as the laser bias current and modulation current, via the transmit control port (Tx_Ctr). The ONU MAC 211 can send service data to the ONU optical PHY 212 via its data port (Data), and the ONU optical PHY 212 transparently transmits the service data. The ONU optical PHY 212, also known as the driver for the laser 213, is used to drive the laser to generate optical signals according to commands from the ONU MAC 211's transmit enable port and / or transmit control port. Under the control of the ONU optical PHY 212, the laser 213 modulates the service data into the optical signal and transmits the uplink optical signal carrying the service data to the OLT 230 via optical fiber. In the receiving direction, the photodetector 214 receives the downlink optical signal from the OLT 230 and converts it into an electrical signal. The ONU optical PHY 212 transparently transmits the electrical signal, and the ONU MAC 211 parses the electrical signal to obtain the service data. ONU 210 may also include wavelength division multiplexer 215 for transmitting uplink optical signals generated by laser 213 into optical fiber, and transmitting downlink optical signals received from optical fiber into photodetector 214.

[0061] The OLT 230 may include an OLT MAC 231, a signal processing module 232, an OLT optical PHY 233, a photodetector 234, and a laser 235. In the receiving direction, the photodetector 234 receives the uplink optical signal from the ONU 210 and converts it into an electrical signal. This electrical signal can be an analog electrical signal or a digital electrical signal. The signal processing module 232 can be implemented using analog devices (such as amplifiers) or digital devices (such as digital signal processors), thus it can perform analog correlation processing or digital signal processing. The OLT MAC 231 parses the electrical signal processed by the signal processing module 232 to obtain service data. In the transmitting direction, the OLT MAC 231 generates service data, and the signal processing module 232 performs analog or digital correlation processing on the service data. Under the control of the OLT optical PHY 233, the laser 235 modulates the service data into an optical signal and transmits the downlink optical signal carrying the service data to the ONU 210 via optical fiber. The OLT 230 may also include a wavelength division multiplexer 236 for transmitting downlink optical signals generated by the laser 235 into the optical fiber, and for transmitting uplink optical signals received from the optical fiber into the photodetector 234.

[0062] The OLT periodically issues online enable commands to instruct offline ONUs to register. Figure 3 An exemplary flowchart of a PON system registration method provided for embodiments of this application.

[0063] like Figure 3 As shown, the method includes the steps performed by the ONU:

[0064] S301, the ONU receives the online enable command from the OLT and responds to the command according to its own status. S302, the ONU determines its own status. If the ONU is online, it executes S303, whereby the ONU can transmit optical signals carrying service data (or service signals) according to the time slots allocated by the OLT. If the ONU is in the pending registration and online stage, it needs to initiate the registration process. The ONU registration process includes: S304, the laser's modulation current is turned off, and the bias current is reduced to below the threshold current. S305, the ONU MAC generates registration information and controls the laser driver through the transmit enable port, thereby loading the registration information into the optical signal generated by the laser. S306, the ONU transmits the optical signal carrying the registration information.

[0065] The method also includes steps performed by the OLT:

[0066] S307, the OLT receives optical signals, including registration signals and / or service signals. The registration signal carries registration information, and the service signal carries service data. If there are ONUs in the pending registration / online stage and also ONUs in an online state, the OLT will simultaneously receive the registration signal from the ONU in the pending registration / online stage and the service signal from the online ONU. If only ONUs in the pending registration / online stage exist, the OLT receives the registration signal. If only ONUs in an online state exist, the OLT receives the service signal. If the OLT receives both the service signal and the registration signal simultaneously, the OLT executes S308 and S309 respectively for the service data and registration information carried by these two signals. S308, the OLT processes the service data. S309, the OLT processes the registration information. S310, the OLT MAC processes the service data and registration information.

[0067] In this embodiment, the service data can be a raw data stream or an electrical signal, and the service signal can be an optical signal modulated with the service data. The registration information can be an electrical signal, and the registration signal can be an optical signal modulated with the registration information.

[0068] Figure 4 This is an exemplary flowchart of an ONU registration method provided for an embodiment of this application. Figure 3 As shown, the method may include the following steps:

[0069] S401: The ONU generates registration information and loads the registration information into the spontaneous emission light signal generated by the laser through the transmit enable port to generate a registration signal.

[0070] The ONU can be an ONU in the pending registration and online stage (i.e., in an unactivated state or offline). First, configure the physical parameters of the laser in the ONU. Typically, the laser is current-driven, so the configurable physical parameters include bias current and modulation current. If a voltage-driven laser is used, the configurable physical parameters also include bias voltage and modulation voltage. For example, in... Figure 2In this embodiment, the ONU MAC 211 sends a physical parameter adjustment command to the ONU optical PHY 212 via the transmit control port to instruct the adjustment of the physical parameters of the laser 213. For example, this physical parameter adjustment command instructs the laser 213 to lower its bias current so that the bias current of the laser 213 is less than the threshold current. This physical parameter adjustment command also instructs the laser 213 to turn off the modulation current, i.e., set the modulation current to zero. Furthermore, during the adjustment of the laser bias current, to avoid abnormal laser emission, the ONU MAC 211 disables the transmit enable port. The threshold current is a fixed parameter of the laser and can be set at the factory. The bias current provides the DC power of the laser. When the bias current is greater than or equal to the threshold current, the optical signal generated by the laser is a stimulated emission optical signal, typically suitable for transmitting service signals. When the bias current is lower than the threshold current, the optical signal generated by the laser is a spontaneous emission optical signal, suitable for transmitting registration signals in this embodiment. The optical power of spontaneously emitted optical signals is typically lower than that of stimulated emission optical signals; therefore, the power of the registration signal is lower than that of the service signal. The modulation current provides gain for the AC signal. Normally, when service data is modulated into a service signal through the data port, the modulation current is not zero. However, in this embodiment, the registration information is loaded into the optical signal generated by the laser 213 through the transmit enable port, rather than through the data port. Therefore, the modulation current can be turned off (i.e., the modulation current can be set to zero). Turning off the modulation current also prevents the modulation current from superimposed on the laser, thus avoiding optical power fluctuations in the laser.

[0071] Figure 5 This is a schematic diagram illustrating the relationship between the bias current and optical power of a laser provided in an embodiment of this application. Figure 5 As shown, when the bias current is zero, the optical power generated by the laser is zero (point A in the figure). When the bias current is greater than zero and less than the threshold current, the laser generates a low-power spontaneous emission optical signal (between points A and B in the figure, excluding point A). In this embodiment, the OLT does not need to open a silent window (i.e., zero window) during the ONU registration process. To minimize the impact of the registration signal on the service signal, the bias current is adjusted to be less than the threshold current to achieve the transmission of a low-power optical signal (spontaneous emission optical signal).

[0072] The ONU MAC 211 generates uplink registration information, which can be an electrical signal. Figure 6 This is a waveform diagram of ONU registration information provided in an embodiment of this application. Figure 6As shown, the waveform of the registration information can be described by the maximum and minimum transmission power, and the frequency (or period T, where the frequency is the reciprocal of the period T). The registration information can include binary bits and is represented by the maximum and minimum transmission power, and the frequency. For example, Figure 6 The waveform diagram shown represents the binary sequence "101010101001000101101110". When the registration information is bit 0, it corresponds to the minimum transmission power; when the registration information is bit 1, it corresponds to the maximum transmission power. The number of bits transmitted per unit time corresponds to the frequency. The registration information may include one or more of the following: ONU identifier, ONU serial number, registration number, etc. Additionally, the registration information may also include a single-frequency sequence (such as the first 10 bits of the aforementioned binary sequence "1010101010"), used to indicate the frame header of the registration information. After the physical parameters of laser 213 are set stably, ONU MAC 211 sends the registration information to ONU optical PHY 212 through the transmit enable port. ONU optical PHY 212 controls the laser to turn on and off according to the registration information, thereby generating a registration signal. This registration signal can be an optical signal carrying registration information. For example, ONU MAC 211 according to... Figure 6 The registration information waveform diagram shown controls the ONU optical PHY 212 to generate a switching signal via the transmit enable port, thereby controlling the laser 213 to periodically turn on and off. The maximum transmit power in the waveform diagram (e.g., registration information bit 1) corresponds to the laser being on, and the minimum transmit power (e.g., registration information bit 0) corresponds to the laser being off. Alternatively, registration information bit 1 could correspond to the laser being off, and registration information bit 0 to the laser being on. Therefore, the turning on and off of the laser 213 is as follows: Figure 6 The registration information waveform diagram shown is implemented under control, thereby loading the registration information into the optical signal generated by the laser. The ONU loads the registration information into the optical signal generated by the laser through the transmit enable port, generating a registration signal. The transmit enable port can be a designated port in the ONU MAC 211 (such as Tx_En), or it can be implemented through an idle port or a reserved port on the ONU MAC 211. Since the bias current of the laser is set to be less than the threshold current, the optical signal generated by the laser is a spontaneous emission optical signal. Therefore, the registration signal can be implemented through the spontaneous emission optical signal of the laser.

[0073] S402: The ONU sends the registration signal, which is an optical signal carrying the registration information.

[0074] The registration signal of an ONU in the registration and online phase and the service signal of an ONU in the online state can be transmitted by optical signals of the same wavelength or by optical signals of different wavelengths.

[0075] The ONU registration method provided in this application embodiment can avoid the delay jitter problem caused by opening the silent window and realize the transmission of registration signal at low cost.

[0076] Figure 7 This is an exemplary flowchart of an OLT registration method provided for an embodiment of this application. Figure 6 As shown, the method may include the following steps:

[0077] S701: The OLT receives an optical signal carrying registration information, which is loaded into the optical signal generated by the laser through the transmit enable port.

[0078] The optical signal received by the OLT includes registration signals from one or more ONUs (first ONUs), and may also include service signals from other ONUs (second ONUs). The registration signal can be an optical signal carrying registration information, and the service signal can be an optical signal carrying service data. The power of the registration signal is lower than that of the service signal. Therefore, the optical signal received by the OLT can carry one or both of registration information and service data. The registration information can be as follows: Figure 4 As shown in S401, the spontaneous emission light signal generated by the ONU's laser (first laser) is loaded through the transmit enable port. Service information can be loaded through the stimulated emission light signal generated by the ONU's laser (second laser) via the data port.

[0079] S702: The OLT performs photoelectric conversion on the optical signal to obtain the registration information.

[0080] When the optical signal received by the OLT includes a registration signal, the OLT receiver (e.g., Figure 2 The photodetector 234 shown converts the received optical signal into an electrical signal and analyzes the electrical signal to obtain registration information. Compared with the service signal, the registration signal has the characteristics of low power and low data rate (or low frequency). Therefore, when the registration signal and the service signal are received by the OLT at the same time, the OLT can process the registration signal and the service signal separately according to the different characteristics of the two signals. Figure 8 This is a schematic diagram illustrating the signal overlay of registration information and business data provided in an embodiment of this application. (See diagram below.) Figure 8 As shown, the OLT simultaneously receives service data from ONU1, ONU2, and ONU3, as well as registration information from ONU4. From the power spectrum of the signals received by the OLT, the power of the registration information is lower than that of the service data, and the frequency of the registration information is lower than that of the service data. When the optical signal received by the OLT simultaneously includes both registration and service signals, the OLT's receiver (e.g., Figure 2The photodetector 234 shown converts the received optical signal into an electrical signal, analyzes the electrical signal, and obtains registration information and service data based on the different characteristics of the two signals. For example, in Figure 2 In this configuration, registration information and business data can be processed separately by signal processing module 232 and then by OLT MAC 231. Alternatively, business data can be processed by signal processing module 232 first and then by OLT MAC 231, while registration information can be processed directly by OLT MAC 231 without going through signal processing module 232.

[0081] The signal processing module 232 can be implemented using an optical digital signal processor (oDSP), which can process service signals and registration signals independently. Figure 9 This is a schematic diagram of the logic structure of an oDSP provided in this application. Figure 9 As shown, since the oDSP is a digital chip, an analog-to-digital converter is added in front of it to convert analog electrical signals into digital electrical signals. The digital electrical signals can include service data and registration information. The service data can be processed by one or more functions or modules such as clock recovery, equalization, sequence detection, and signal decision. The registration information is processed by one or more functions or modules such as downsampling, low-pass filtering, IIR filtering, feature detection, buffering, and signal enhancement. The functions of feature detection and signal enhancement are to extract the registration information. Feature detection is used to identify single-frequency sequences in the registration information, i.e., to identify the frame header of the registration information. When feature detection identifies the frame header of the registration information, it indicates that signal enhancement processing should be enabled. The registration information is periodically superimposed, thus enhancing the signal. Therefore, the service data can be removed as noise, resulting in registration information with higher signal strength. After the registration information processing is complete, the signal enhancement processing can be turned off, saving oDSP power consumption. By using the oDSP to receive and process service and registration information, the loss of sensitivity of service and registration signals caused by optical splitting is avoided.

[0082] The OLT registration method provided in this application embodiment can achieve low-cost reception of registration signals and avoid the delay and jitter problems caused by opening the silent window.

[0083] Figure 10 This is a schematic diagram of an OLT structure provided in an embodiment of this application. Figure 10As shown, the photodetector can be implemented using an avalanche photodiode (APD) 1001. A current mirror 1002 provides a high bias voltage to the APD, for example, a bias voltage of 20V-40V. The APD 1001 performs photoelectric conversion on the received optical signal to obtain an electrical signal. In this embodiment, the electrical signal includes registration information and service data as an example. The electrical signal containing registration information and service data is copied by the current mirror 1002 to obtain two electrical signals. One of the electrical signals is output by the APD 1001 and used to extract the service data. The electrical signal used to extract the service data passes through the burst TIA 1003, the service signal processing module 1004, and then enters the OLT MAC 1005 for data parsing. The function of the service signal processing module 1004 is the same as that of the APD MAC 1005. Figure 2 The signal processing module 232 has a similar function to the OLT MAC 1005. Figure 2 The function of the OLT MAC 231 is similar and will not be described in detail here. The other electrical signal copied by the current mirror 1002 is used to extract registration information. This electrical signal passes through the current mirror 1002 and amplifier 1006, and is then received by the OLT MAC 1005. The OLT MAC 1005 can perform registration information extraction, and its function is similar to... Figure 9 The functions of feature detection and signal enhancement processing are similar and will not be elaborated here. Amplifier 1006 may include one or more amplifiers such as a trans-impedance amplifier (TIA) and a clipping amplifier (LA). The current mirror replicates the photocurrent generated by the APD, generating a mirror photocurrent. For example, replicating 1 / 4 of the photocurrent generated by the APD at a 4:1 replication ratio results in the mirror photocurrent. The mirror photocurrent is converted into a voltage signal by a low-speed, high-gain trans-impedance amplifier (TIA), which is further amplified by a clipping amplifier (LA). The purpose of the TIA is to convert the weak mirror photocurrent into a voltage signal; to suppress noise, the gain is not too high. The purpose of the LA is to achieve two-stage amplification, so that the output level of the voltage signal meets the decision criteria of the OLT MAC 1005, while providing the optimal sampling point for clock and data recovery (CDR) function recovery decision. In some cases, if the recovery performance requirements of registration information are not high, only one-stage amplification can be used, i.e., only TIA or LA can be used. Figure 9 The laser, driver (or OLT optical PHY), and wavelength division multiplexer are also shown and can be referenced. Figure 2 The relevant descriptions will not be repeated here. In this embodiment, the registration information, after passing through the current mirror and amplifier, does not need to be processed by signal processing modules such as oDSP and directly enters the OLT MAC for processing, which simplifies the implementation and reduces costs.

[0084] Figure 11 This is a schematic diagram of another OLT structure provided in an embodiment of this application. Figure 10 The difference lies in the use of oDSP1104 to replace the service signal processing module 1004. Both registration information and service data are processed by oDSP 1104 and then enter the OLT MAC 1105 for processing. APD 1101 performs photoelectric conversion on the received optical signal to obtain an electrical signal. Again, the explanation uses an electrical signal including registration information and service data as an example. Service data passes through burst TIA 1103 and then enters oDSP1104 for processing. Registration information passes through current mirror 1102 and amplifier 1106 before entering oDSP 1004 for processing. The service data and registration information processed by oDSP1004 are then processed by the OLT MAC 1105. In this embodiment, the registration information is processed by signal processing modules such as oDSP, which can improve the reception performance of the registration signal.

[0085] Finally, it should be noted that the above descriptions are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for transmitting a registration signal, characterized in that, The method includes: Registration information is generated. Based on the registration information, the laser is turned on and off through the transmit enable port, thereby loading the registration information into the spontaneous emission light signal generated by the laser to generate a registration signal. The registration signal is sent, which is an optical signal carrying the registration information.

2. The method as described in claim 1, characterized in that, The method further includes: The bias current of the laser is set to be less than a threshold current so that the laser generates spontaneous emission light signals, wherein the threshold current is a preset current value.

3. The method as described in claim 1 or 2, characterized in that, The method further includes: Set the modulation current of the laser to zero.

4. The method as described in claim 1 or 2, characterized in that, The registration information includes a first bit and a second bit of binary data. When the registration information includes the first bit, the laser is turned on via the transmit enable port. When the registration information includes the second bit, the laser is turned off via the transmit enable port.

5. The method as described in claim 1 or 2, characterized in that, The power of the registration signal is lower than that of the service signal.

6. A method for registering signal reception, characterized in that, The method includes: The system receives an optical signal carrying registration information, which is loaded into the spontaneous emission optical signal generated by the first laser by controlling the opening and closing of the first laser through the transmit enable port. The optical signal is converted into photoelectric value to obtain the registration information.

7. The method as described in claim 6, characterized in that, The optical signal also carries service data, which is loaded into the stimulated emission optical signal generated by the second laser through the data port.

8. The method as described in claim 7, characterized in that, After performing photoelectric conversion on the optical signal, the method further includes: Obtain an electrical signal, the electrical signal including the registration information and the service data; The registration information is extracted from the electrical signal.

9. The method as described in claim 7 or 8, characterized in that, The power of the optical signal carrying the registration information is lower than the power of the optical signal carrying the service data.

10. A light emitting device, characterized in that, The device includes: The processor is used to generate registration information. A driver is used to control the laser to turn on and off via a transmit enable port based on the registration information, thereby loading the registration information into the spontaneous emission light signal generated by the laser to generate a registration signal. A laser is used to transmit the registration signal, which is an optical signal carrying the registration information.

11. The apparatus as claimed in claim 10, characterized in that, The processor is also used for: The bias current of the laser is set to be less than a threshold current so that the laser generates spontaneous emission light signals, wherein the threshold current is a preset current value.

12. The apparatus as claimed in claim 10 or 11, characterized in that, The processor is also used for: Set the modulation current of the laser to zero.

13. The apparatus as claimed in claim 10 or 11, characterized in that, The registration information includes the first and second bits of a binary string. The driver is used to control the laser to turn on when the registration information includes the first bit, and to control the laser to turn off when the registration information includes the second bit.

14. The apparatus as claimed in claim 10 or 11, characterized in that, The power of the registration signal is lower than that of the service signal.

15. An optical receiving device, characterized in that, The device includes: An interface for receiving optical signals, the optical signals carrying registration information, the registration information being loaded into the spontaneous emission optical signals generated by the first laser by controlling the opening and closing of the first laser through the transmit enable port; A photoelectric converter is used to perform photoelectric conversion on the optical signal to obtain the registration information.

16. The apparatus as claimed in claim 15, characterized in that, The optical signal also carries service data, which is loaded into the stimulated emission optical signal generated by the second laser through the data port.

17. The apparatus as claimed in claim 16, characterized in that, After the optical signal is converted into an optical signal by photoelectric conversion, the device further includes: a signal processor. The signal processor is used to obtain an electrical signal, the electrical signal including the registration information and the business data; and to extract the registration information from the electrical signal.

18. The apparatus as claimed in claim 16 or 17, characterized in that, The power of the optical signal carrying the registration information is lower than the power of the optical signal carrying the service data.

19. An optical chip, characterized in that, The optical chip is used to generate registration information. Based on the registration information, the laser is turned on and off through the transmit enable port, thereby loading the registration information into the spontaneous emission light signal generated by the laser to generate a registration signal; the registration signal is an optical signal carrying the registration information.

20. The optical chip as described in claim 19, characterized in that, The optical chip is used to perform the method as described in any one of claims 2-5.

21. A communication system, characterized in that, The system includes a plurality of optical emitting devices as described in any one of claims 10-14, and an optical receiving device as described in any one of claims 15-18.

Images