WO2022206174A1

WO2022206174A1 - Data transmission method, optical line terminal, optical network unit, and communication system

Info

Publication number: WO2022206174A1
Application number: PCT/CN2022/075641
Authority: WO
Inventors: 景磊
Original assignee: 华为技术有限公司
Priority date: 2021-04-02
Filing date: 2022-02-09
Publication date: 2022-10-06

Abstract

The present application relates to the technical field of optical networks, and discloses a data transmission method, an optical line terminal (OLT), an optical network unit (ONU), and a communication system. The OLT may determine a downlink time window and an uplink time window according to a data transmission bandwidth requirement and a distance between the OLT and the ONU; send a superframe structure to the ONU, the superframe structure comprising information of the downlink time window and information of the uplink time window; send a first data packet to the ONU in the downlink time window; and receive a second data packet from the ONU in the uplink time window. According to the data transmission method provided in the present application, the OLT discontinuously transmits data during downlink transmission, which may be applicable to an optical transceiver assembly in which a transmitter and a receiver are separated, and may also be applicable to an optical device in which a transmitter and a receiver are integrated.

Description

A data transmission method, optical line terminal, optical network unit and communication system

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the priority of the Chinese patent application filed on April 2, 2021 with the State Intellectual Property Office of China, application number 202110362179.5, and the application name is "A data transmission method, optical line terminal, optical network unit and communication system", and the priority of a Chinese patent application filed on January 14, 2022 with the State Intellectual Property Office of China, application number 202210043535.1, and the application title is "A data transmission method, optical line terminal, optical network unit and communication system", The entire contents of which are incorporated herein by reference.

technical field

The present application relates to the technical field of optical networks, and in particular, to a data transmission method, an optical line terminal, an optical network unit and a communication system.

Background technique

When using the camera monitoring video of the passive optical network (PON) for video backhaul, multiple cameras pass through the passive optical distribution network (ODN) and the optical line terminal (OLT) Connection, each camera is equivalent to an optical network unit (optical network unit, ONU). The OLT provides a network-side interface for the PON system and can be connected to one or more ODNs. The ONU provides the user-side interface for the PON system and is connected to the ODN. ODN is a network composed of optical fibers and passive optical splitting devices, used to connect OLT equipment and ONU equipment, and used to distribute or multiplex data signals between OLT and ONU. In a PON system, the transmission of data signals from the OLT to the ONU is called downstream; on the contrary, the transmission of data signals from the ONU to the OLT is called upstream.

The downlink OLT transmitter uses light with a wavelength of 1550nm to transmit data continuously. After receiving all the downlink data, the ONU identifies the useful data and discards the useless data. The upstream ONU transmits data in different time slots with a wavelength of 1310 nm according to the OLT's instructions. The optical transceiver component couples two different wavelengths of light to the same optical fiber using a splitter to realize point-to-multipoint optical communication.

The optical transceiver component suitable for this data transmission method can be shown in Figure 1. The optical transceiver component uses a splitter to couple the signals of different upstream and downstream optical paths into the optical fiber, and the circuit connection is complicated. In addition, the optical transceiver component shown in Figure 1 Transmitter And the receiver is realized by two different optical devices, the cost is high, which is not conducive to saving costs.

With the development of optical transceiver components, some schemes propose to implement the transmitter and receiver through the same optical device, thereby saving costs. However, the improved optical transceiver components cannot transmit and receive at the same time in both uplink and downlink, so the above data transmission method is Improved optical transceiver components cannot be applied.

SUMMARY OF THE INVENTION

The embodiments of the present application provide a data transmission method, an optical line terminal, an optical network unit, and a communication system, so that the optical line terminal transmits data discontinuously when transmitting data, which can be applied to optical transceivers where the transmitter and the receiver are separated. components, and can also be applied to optical devices that integrate transmitter and receiver.

In the first aspect, an embodiment of the present application provides a data transmission method, which is applied to the OLT. When the method is executed, the OLT can first determine the downlink time window and the uplink time window according to the data transmission bandwidth requirement and the distance between the OLT and the ONU. Send superframe structure to ONU afterwards; Described superframe structure comprises: the information of described downlink time window and the information of described uplink time window; In described downlink time window, send the first data packet to described ONU; During the upstream time window, a second data packet is received from the ONU.

It should be noted that, in this application, the data transmission between the OLT and the ONU may be performed through point-to-point communication, or data transmission may be performed through point-to-multipoint communication. The OLT determines the uplink time window and the downlink time window according to the distance between the OLT and the ONU and the bandwidth required for uplink and downlink data transmission. After that, the OLT notifies the ONU of the information of the upstream time window and the information of the downstream time window through the superframe structure, and sends the downstream data packet, that is, the first data packet, in the downstream time window, and receives the upstream data packet from the ONU, that is, the first data packet in the upstream time window. Two packets. The method can be applied not only to the optical transceiver assembly in which the transmitter and the receiver are separated, but also to the optical device in which the transmitter and the receiver are integrated. In addition, this method can be applied to scenarios where uplink and downlink data transmissions do not match, such as video backhaul scenarios (there is a large amount of uplink data and a small amount of downlink data in the video backhaul scenario), avoiding the waste of continuous transmission of downlink data. The situation of transmission resources appears, and in addition, in the case of continuous transmission of downlink data, the power consumption of the device can be reduced. When the power consumption of the device is small, the usage time that the device can support will also be appropriately increased.

In an optional manner, the superframe structure includes multiple ones; the multiple superframe structures are sent in a first period.

It should be noted that, the superframe structure can be sent according to a fixed period, for example, 125 microseconds uS. The superframe structure is sent according to a fixed period, which can ensure that the superframe structure is notified to different ONUs in time, so as to avoid the situation that the information of the OLT and the ONU is not synchronized.

In an optional manner, the superframe structure further includes: a superframe header; the superframe header is sent by broadcasting.

In this embodiment of the present application, the super frame header can be notified to more ONUs through broadcast transmission, and multiple ONUs can all receive the super frame header from the OLT.

In an optional manner, the superframe header includes: synchronization information, frame number information, and dynamic bandwidth assignment (DBA) of the next N superframe structures; the N is greater than or equal to 1 ; The DBA includes: identification information of one or more ONUs, indication information of uplink and downlink data transmission, and location information of data transmission.

It should be noted that the next N superframe structures can be understood as a certain superframe structure after the current superframe structure. For example, the current superframe structure is the third superframe structure, assuming that N is 3, then the superframe header is The DBA of the 6th (3+3) superframe structure can be carried. Wherein, the DBA includes: identification information of one or more optical network units, uplink and downlink data transmission indication information and data transmission location information, so that the ONU can learn which ONU needs to receive downlink data packets according to the DBA, or which ONU needs to send uplink data. . The frame number information in the superframe structure can record the number of superframe structures sent by the optical line terminal, so that the ONU can better know the operations performed in different superframe structures. The synchronization information in the superframe structure can synchronize part of the information of the previous superframe structure so that the ONU can know the timing relationship between the received superframe structure and other superframe structures.

In an optional manner, the uplink and downlink data transmission indication information is identified by the value of the type; if the value of the type is 1, one or more ONUs in the DBA perform uplink data transmission; if The value of the type is 0, and one or more ONUs in the DBA perform downlink data transmission.

In an optional manner, there is a time interval between the first data packet and the second data packet; the time interval is greater than the switching time of uplink and downlink data transmission.

It should be noted that since the uplink and downlink data in this application may be transmitted through the same data transmission channel, in order to avoid transmission conflicts during data transmission, the uplink data packet (that is, the first data packet) and the downlink data packet (also That is, the second data packet) has a time interval.

In the second aspect, an embodiment of the present application provides a data transmission method, which is applied to an ONU. When the method is executed, the ONU can first receive a superframe structure from the OLT; the superframe structure includes: the downlink time window. information and the information of the uplink time window; then, in the downlink time window, receive the first data packet from the OLT; and send the second data packet to the OLT in the uplink time window.

In an optional manner, the superframe structure includes multiple; the multiple superframe structures are sent in a first cycle; and the receiving of the superframe structure from the optical line terminal includes: the ONU according to the The first cycle receives the superframe structure.

In an optional manner, the superframe structure further includes: a superframe header; the superframe header is sent by broadcasting. In an optional manner, the superframe header includes: synchronization information, frame number information, and the next N DBAs of the superframe structure; the N is greater than or equal to 1; the DBA includes: one or more Identification information of each ONU, indication information of uplink and downlink data transmission, and location information of data transmission.

In an optional manner, the optical network unit may determine that the identifier of the ONU is the same as the identifier of the ONU in the DBA, and receive the first data packet according to the downlink data transmission indication information.

In a third aspect, an embodiment of the present application provides an optical line terminal, including: a processing unit and a transceiver unit;

The processing unit is used to determine the downlink time window and the uplink time window according to the data transmission bandwidth requirement and the distance between the optical line terminal OLT and the optical network unit ONU; the transceiver unit is used to send the superframe structure to the optical network. unit; the superframe structure includes: the information of the downlink time window and the information of the uplink time window; and, in the downlink time window, send a first data packet to the ONU; in the uplink time In the window, a second data packet is received from the ONU.

In an optional manner, the superframe header includes: synchronization information, frame number information, and the next N DBAs of the superframe structure; the N is greater than or equal to 1; the DBA includes: one or more Identification information of each ONU, indication information of uplink and downlink data transmission, and location information of data transmission.

In a fourth aspect, an embodiment of the present application provides an optical network unit, including: a transceiver unit and a processing unit;

Wherein, the transceiver unit is used to receive the superframe structure from the optical line terminal OLT; the superframe structure includes: the information of the downlink time window and the information of the uplink time window; In the downlink time window, the first data packet from the OLT is received; in the uplink time window, the second data packet is sent to the OLT.

In an optional manner, the superframe structure includes multiple; the multiple superframe structures are sent according to a first cycle; the transceiver unit is configured to receive the superframe structure according to the first cycle .

In an optional manner, the processing unit is used for:

It is determined that the identifier of the ONU is the same as the identifier of the ONU in the DBA, and the first data packet is received according to the downlink data transmission indication information.

In a fifth aspect, an embodiment of the present application provides an optical line terminal, including: a processor and a memory;

the memory for storing computer programs;

The processor is configured to execute the computer program stored in the memory, so that the optical line terminal executes the method according to the first aspect.

In a sixth aspect, an embodiment of the present application provides an optical network unit, including: a processor and a memory;

the memory for storing computer programs;

The processor is configured to execute the computer program stored in the memory, so that the optical network unit executes the method according to the second aspect.

In a seventh aspect, an embodiment of the present application provides a communication system, where the communication system includes the optical line terminal of the third aspect and the optical network unit of the fourth aspect.

In an eighth aspect, an embodiment of the present application provides a computer-readable storage medium, where the computer-readable storage medium stores instructions, when the instructions are executed, so that the computer executes as described in the first aspect or the second aspect Methods.

These and other aspects of the present application will be more clearly understood in the description of the following embodiments.

Description of drawings

FIG. 1 shows a schematic structural diagram of an optical transceiver assembly;

FIG. 2 shows a schematic diagram of a topology structure of an optical communication system provided by an embodiment of the present application;

FIG. 3 shows a schematic flowchart of a data transmission method provided by an embodiment of the present application;

FIG. 4 shows a schematic diagram of a superframe structure provided by an embodiment of the present application;

FIG. 5 shows a schematic diagram of a superframe structure provided by an embodiment of the present application;

FIG. 6 shows a schematic structural diagram of a data packet provided by an embodiment of the present application;

7A shows a schematic diagram of a system architecture of a point-to-point communication system provided by an embodiment of the present application;

7B shows a schematic diagram of a system architecture of a point-to-multipoint communication system provided by an embodiment of the present application;

FIG. 8 shows a system architecture of another communication system provided by an embodiment of the present application;

FIG. 9 shows a schematic diagram of a communication scenario provided by an embodiment of the present application;

FIG. 10 shows a schematic diagram of another communication scenario provided by an embodiment of the present application;

FIG. 11 shows a schematic flowchart of a registration method provided by an embodiment of the present application;

FIG. 12 shows a schematic structural diagram of a communication apparatus provided by an embodiment of the present application;

FIG. 13 shows a schematic structural diagram of a communication apparatus provided by an embodiment of the present application.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings. The specific operation methods in the method embodiments may also be applied to the apparatus embodiments or the system embodiments. Wherein, in the description of the present application, unless otherwise specified, the meaning of "plurality" is two or more.

The embodiments of the present application may be applied to an optical communication system, and the optical communication system may be a PON system. The PON system may be a COMBO networking system. For example, users of the evolution of 10 gigabit-capable passive optical network (10G PON) need to consider the smooth transition from GPON to 10GPON. Therefore, the actual application environment of the 10GPON system is the COMBO networking of GPON and 10GPON.

In the embodiment of the present application, the COMBO networking may be the networking of GPON and 10GPON (denoted as GPON&10GPON COMBO), or may be the networking of EPON and 10GEPON (denoted as EPON&10GEPON COMBO). The COMBO networking can also be a combination of any variety of PON systems. For example, the PON system in the COMBO network can also be a time and wavelength division multiplexing passive optical network (time and wavelength division multiplexing passive optical network, TWDM-PON), a 10 gigabit passive optical network (10 gigabit-capable passive optical network) optical network, XG-PON) system or 10-gigabit-capable symmetric passive optical network (XGS-PON) system, and various systems that will evolve in the future.

The following describes the architecture of the optical communication system to which the embodiments of the present application can be applied. An optical communication system includes an OLT and a plurality of ONUs, and the ONUs may also be called optical network terminals (optical network terminals, ONTs). For example, if an ONU directly provides a user port function, such as an Ethernet user port for a personal computer (personal computer, PC) to access the Internet, such an ONU can be called an ONT.

In this embodiment of the present application, an ONU is used as an example for description. The OLT communicates with multiple ONUs respectively, and the optical communication system may also include an ODN, and multiple ONUs can be connected to the PON port of the same OLT through the ODN. The optical communication system may also include other network devices, such as user terminals, servers, mobile base stations, and the like. As shown in FIG. 2 , an optical communication system topology is exemplarily described. In the topology shown in FIG. 2 , the communication devices can be divided into "user side" and "network side" according to the connection relationship of the communication devices. For a user terminal that terminates services, such as a PC, the network topology shown in Figure 2 includes: OLT and multiple ONUs. In an optical communication system, the communication direction from OLT to ONU is called downlink, and the communication direction from ONU to OLT The direction is called up.

It should be noted that ONU and OLT usually transmit data through optical transceiver components. Conventional optical transceiver components include transceivers and receivers as shown in Figure 1. When the optical transceiver components work, the downlink OLT transmitter uses a wavelength The 1550nm light transmits data continuously. After receiving all the downlink data, the ONU identifies the useful data and discards the useless data. The upstream ONU transmits data in different time slots with a wavelength of 1310 nm according to the OLT's instructions. However, in the application scenario of video backhaul, the OLT usually sends less downlink data to the ONU. On the contrary, the ONU sends back a large amount of video data to the OLT. Based on this, some people propose an optical transceiver that integrates the transmitter and the receiver. components in order to save costs. Since the transmitter and the receiver are integrated, the uplink and downlink cannot transmit and receive at the same time. Based on this, the present application provides a new data transmission method which can be applied to the optical transceiver component with the transmitter and the receiver separated. It can also be applied to the integrated optical device of the transmitter and receiver.

Fig. 3 shows a data transmission method. The data transmission method requires the interaction between the OLT and the ONU. In actual application, the number of ONUs is not limited, but this application only uses 2 ONUs, that is, ONU1 and ONU2 for illustration. . Follow the steps below to execute:

Step 301: The OLT determines the downlink time window and the uplink time window according to the data transmission bandwidth requirement and the distance between the OLT and the ONU.

It should be noted that the bandwidths required for data uplink transmission and downlink transmission may be different, and the distances between the OLT and different ONUs may also be different. For example, the uplink transmission bandwidth is 20Mbps, the downlink transmission bandwidth is 1Mbps, the distance between ONU1 and OLT is 100 meters, the distance between ONU2 and OLT is 120 meters, and ONU1 and ONU2 are deployed in the same cell, so OLT can refer to this cell The conventional bandwidth requirements for mid-up and downlink data transmission and the distance between the OLT and each ONU perform data processing (data analysis, weighted calculation, etc. are not specifically limited in this application), and determine the time window for uplink transmission and downlink data transmission. time window.

Step 302: The OLT sends the superframe structure to ONU1; the superframe structure includes: information of the downlink time window and information of the uplink time window. Accordingly, ONU1 receives the superframe structure from the optical line terminal OLT. The OLT also sends the superframe structure to ONU2. Accordingly, ONU2 receives the superframe structure from the optical line terminal OLT.

In an optional embodiment, the superframe structure further includes: a superframe header; the superframe header is sent by broadcasting. The superframe header can be notified to more ONUs through broadcast transmission, and multiple ONUs can receive the superframe header from the OLT, that is, as shown in step 302, the OLT can send the superframe structure to multiple ONUs.

It should be noted that the OLT sends the information of the uplink time window and the downlink time window to the ONU, so that the ONU can know which time window to receive the downlink data in and which time window to send the uplink data. In this way, the uplink data and the downlink data can be guaranteed. Orderly delivery.

In an optional embodiment, the OLT may send multiple superframe structures, and the multiple superframe structures are sent according to the first cycle. Correspondingly, the ONU needs to receive the superframe structure according to the first cycle. As shown in FIG. 4 , after the Nth superframe structure is sent, the interval is a first period, for example, the first period is 125uS, and the N+1th superframe structure is sent after 125uS. It should be noted that, sending the superframe structure according to a fixed period can ensure that the superframe structure is notified to different ONUs in time, so as to avoid the situation that the information of the OLT and the ONU is not synchronized.

Step 303A: In the downlink time window, the OLT sends the first data packet, that is, the downlink data packet, to ONU1. Accordingly, ONU1 receives the first data packet from the OLT.

Step 303B: The OLT sends the first data packet to ONU2 in the downlink time window. Accordingly, ONU2 receives the first data packet from the OLT.

Since ONU1 and ONU2 work independently, there is no relationship between the two ONUs whether to send the second data packet. Both ONUs can send the second data packet in the uplink time window, or other ONUs can send the second data packet in the uplink time window. , which is not specifically limited in this application. Next, only the ONU1 sends the second data packet to the OLT, that is, the upstream data packet for description.

Step 304: ONU1 sends the second data packet to the OLT in the uplink time window. Accordingly, the OLLT receives the second data packet from ONU1.

In this application, the OLT determines the uplink time window and the downlink time window according to the distance between the OLT and the ONU and the bandwidth required for uplink and downlink data transmission. After that, the OLT notifies the ONU of the information of the upstream time window and the information of the downstream time window through the superframe structure, and sends the downstream data packet, that is, the first data packet, in the downstream time window, and receives the upstream data packet from the ONU, that is, the first data packet in the upstream time window. Two packets. The method can be applied not only to the optical transceiver assembly in which the transmitter and the receiver are separated, but also to the optical device in which the transmitter and the receiver are integrated. In addition, this method can be applied to scenarios where uplink and downlink data transmissions do not match, such as video backhaul scenarios (there is a large amount of uplink data and a small amount of downlink data in the video backhaul scenario), avoiding the waste of continuous transmission of downlink data. The situation of transmission resources appears, and in addition, in the case of continuous transmission of downlink data, the power consumption of the device can be reduced. When the power consumption of the device is small, the usage time that the device can support will also be appropriately increased. In an optional embodiment, the superframe header includes: synchronization information, frame number information, and DBAs of the next N superframe structures; wherein, N is greater than or equal to 1. The next N superframe structures can be understood as a certain superframe structure after the current superframe structure, such as the current superframe structure is the third superframe structure, assuming that N is 3, then the superframe header can carry the sixth ( 3+3) DBA of the superframe structure; if N is 1, the superframe header can carry the DBA of the 4th (3+1) superframe structure. Wherein, the DBA includes: identification information of one or more optical network units, uplink and downlink data transmission indication information and data transmission location information, so that the ONU can learn which ONU needs to receive downlink data packets according to the DBA, or which ONU needs to send uplink data. . The frame number information in the superframe structure can record the number of superframe structures sent by the optical line terminal, so that the ONU can better know the operations performed in different superframe structures. The synchronization information in the superframe structure can synchronize part of the information of the previous superframe structure so that the ONU can know the timing relationship between the received superframe structure and other superframe structures.

The DBA includes: identification information of one or more ONUs, indication information of uplink and downlink data transmission, and location information of data transmission. Correspondingly, the ONU will determine whether the identifier of the ONU is the same as the identifier of the ONU in the DBA, and if they are the same, the first data packet is received according to the downlink data transmission indication information. In an optional embodiment, the uplink and downlink data transmission indication information can be identified by the value of type (type); if the value of type is 1, one or more ONUs in the DBA perform uplink data transmission; If the value is 0, one or more ONUs in the DBA perform downlink data transmission. As shown in FIG. 5 , the Nth superframe header includes: synchronization information, frame number information, and the DBA of the next superframe structure (that is, the DBA of the second superframe structure), and the DBA of the N+1th superframe structure The identification information of the ONU included in it is indicated by AlloclID, the uplink and downlink transmission indication information is indicated by type (type), and the location information of data transmission is indicated by Star and End, as shown in the superframe structure in Figure 5, AlloclID is ONU1, and Start is 100 and End are 200, and the value of type (type) is 1, indicating that ONU1 needs to send uplink data packets to the OLT in rows 100 to 200 after receiving the second superframe structure. AlloclID is ONU2, Start is 300, End is 400, and the value of type (type) is 0, indicating that ONU2 needs to receive downlink data packets in rows 300 to 400 after receiving the second superframe structure.

In an optional embodiment, since the uplink and downlink data are not transmitted at the same time, there is a time interval between the first data packet and the second data packet, and the interval time is usually greater than the uplink and downlink data transmission switching time. And the first data packet and the second data packet are burst data packets, the specific number of the first data packet and the second data packet can be flexibly allocated according to the DBA, this application does not specifically limit it, it may be in a super frame. In the structure, the number of the first data packet and the second data packet is the same, but it is also possible that the number of the first data packet is less than the data of the second data packet, or the number of the first data packet is greater than the data of the second data packet. The number of the first data packet and the second data packet is determined according to actual data transmission requirements.

Figure 6 shows that the data information that may be included in the first data packet or the second data packet mainly includes a preamble, a delimiter, a payload and an end, wherein the preamble It is used to quickly recover data, the delimiter is used to define the range of the data packet, the information body is used to carry useful data information, and the end indicates the end of the data packet by a fixed 1 or 2 bytes.

Next, the data transmission method provided by the present application is introduced in combination with different communication scenarios and different optical transceiver components. FIG. 7A shows the system architecture of point-to-point communication, which includes: aggregation switch, access switch, OLT, optical distribution frame (ODF), multiple ONUs and multiple cameras (IPC), wherein, Both OLT and ONU components include optical transceiver components. Under the system architecture shown in FIG. 7A , it is assumed that the demand index during data transmission is as shown in Table 1, that is, during data transmission, it is necessary to ensure that the mainstream split ratio is 1:32 or 1:64. The maximum transmission distance, that is, the distance between the OLT and the ONU, needs to be less than 20km. The transmission delay needs to be less than 10mS, the bandwidth required by each camera to transmit uplink data is 20Mbps, and the bandwidth required by each camera to receive downlink data is less than 1Mbps. The OLT can determine the uplink time window information and the downlink time window information according to the demand index, so as to meet the demand of the demand index as much as possible during data transmission.

Table 1

Under the system architecture of FIG. 7A , using the data transmission method provided by the present application, both uplink and downlink use discontinuous data packets to transmit data, and the effects that can be achieved are shown in Table 2. Table 2 is only for schematic description, not for Specific restrictions. Two different situations are shown in Table 2. When the uplink and downlink switching times are 10uS and 50uS respectively, the delay is 10mS. When the delay is 10mS and the uplink and downlink are 20:1, each time slot can occupy 476uS. When calculating the actual bandwidth, it needs to be multiplied by the forward error correction (FEC) rate, which is 0.87. When the transmission and reception switching time is 10uS, the actual working bandwidth is 4G bps, which can support 200 cameras to return uplink data. When the transmission and reception switching time is 50uS, the actual working bandwidth is 3.7G bps, which can support 180 cameras to return uplink data. It can be seen from this that the data transmission scheme of the present application can support more cameras to return uplink data under the same bandwidth.

Table 2

FIG. 7B shows the system architecture of point-to-multipoint communication, which includes: aggregation switch, OLT, optical distribution frame (ODF), optical fiber access terminal (FAT) or optical cable handover A box (fiber distribution terminal, FDT) multiple ONUs and multiple cameras (IPC), wherein the components of the OLT and the ONU both include optical transceiver components. Under the system architecture shown in FIG. 7B , it is assumed that the demand indicators during data transmission are also shown in Table 1.

Under the system architecture of FIG. 7B , using the data transmission method provided by the present application, both uplink and downlink use discontinuous data packets to transmit data, and the achievable effects are shown in Table 3. Table 3 is only for schematic description, not for Specific restrictions. Two different situations are shown in Table 3. When the uplink and downlink switching times are 10uS and 50uS respectively, the delay is 10mS. When the delay is 10mS and the uplink and downlink are 20:1, each time slot can occupy 147uS. When calculating the actual bandwidth, the FEC rate needs to be multiplied by 0.87. When the transceiver switching time is 10uS, the actual working bandwidth is 0.12G bps, which can support 6 cameras to return uplink data. When the transceiver switching time is 50uS, the actual working bandwidth is The bandwidth is 0.08G bps, which can support 4 cameras to send back uplink data. It can be seen that the data transmission scheme of this application can support more cameras to send back uplink data under the same bandwidth.

table 3

FIG. 8 shows the architecture of another communication system, which includes: a broadband remote access server (BRAS), an OLT, a gateway of an ONU, and a plurality of ONUs, wherein the gateway of the ONU can be a home network different ONUs can be installed in different rooms, and both OLT and ONU components include optical transceiver components. Under the system architecture shown in Figure 8, it is assumed that the demand indicators during data transmission are shown in Table 4. That is, during data transmission, it is necessary to ensure that the main stream splitting ratio is less than 1:8. The maximum transmission distance, that is, the distance between the OLT and the ONU, is less than 1km. The transmission delay needs to be less than 1mS. Since the user may upload a lot of data or download a lot of data when surfing the Internet, the bandwidth is uncertain, so it is indicated by TBD here. The OLT can determine the uplink time window information and the downlink time window information according to the demand index, so as to meet the demand of the demand index as much as possible during data transmission.

Table 4

	主流分光比Mainstream splitting ratio	最大传输距离Maximum transmission distance	时延delay	带宽bandwidth
指标index	<1:8<1:8	<1km<1km	<1mS<1mS	TBDTBD

Under the system architecture of FIG. 8 , using the data transmission method provided by the present application, both uplink and downlink use discontinuous data packets to transmit data, and the effects that can be achieved are shown in Table 5. Table 5 is only for schematic description, not for Specific restrictions. Five different situations are shown in Table 5. When the uplink and downlink switching times are 1uS and 10uS respectively, the delay is 125uS; when the uplink and downlink switching times are 10uS, 50uS, and 1uS, the delay is 1000uS. When the delay is 125uS and the uplink and downlink are 8:1, each time slot can occupy 7.8125uS; when the delay is 1000uS and the uplink and downlink are 8:1, each time slot can occupy 62.5uS. When calculating the actual bandwidth, it is necessary to multiply the FEC rate, which is 0.87. When the transceiver switching time is 1uS and the delay is 125uS, the actual working bandwidth is 0.47Gbps; when the transceiver switching time is 10uS and the delay is 125uS, the actual working bandwidth is is -1.5Gbps; when the transceiver switching time is 10uS and the delay is 1000uS, the actual working bandwidth is 0.46G bps; when the transceiver switching time is 50uS and the delay is 1000uS, the actual working bandwidth is 0.1Gbps; When the delay is 1uS and the delay is 1000uS, the actual working bandwidth is 0.53Gbps.

table 5

In practical application, the data transmission method of the present application is not limited to the communication architecture shown in FIG. 7A and FIG. 7B or the communication architecture shown in FIG. 8 for data transmission, and the above communication systems are all applicable to this application. Next, the solution of the present application is introduced with reference to the different situations of the optical transceiver components in the OLT and the ONU, as follows:

Case 1: The optical transceiver components of the OLT and ONU are both integrated transceiver components

In order to illustrate the situation 1 more clearly, Fig. 9 is used to illustrate the situation, in which the optical transceiver components of the OLT and ONU are both integrated optical transceiver components, and Fig. 9 is identified by the half-transceive half-duplex component. If the OLT is based on the uplink and downlink bandwidth requirements and ranging information The calculated downlink time windows are 2, 4, 6, 8, and 10, and the uplink time windows are 1, 3, 5, 7, and 9. Then, the OLT can send downlink data in

downlink time windows

2, 4, 6, 8, and 10. When the OLT sends downlink data, the working mode of the half-transceive half-duplex component can be adjusted to transmitter, and the optical signal is sent to the ONU side at a wavelength of 1270nm. The ONU can change the working mode of the half-transceive half-duplex component to receive The machine receives optical signals in

time windows

2, 4, 6, 8, and 10. Since there may be a time difference when the ONU receives the optical signal from the OLT, clock synchronization is also required. The same ONU can send uplink data to the OLT in

time windows

1, 3, 5, 7, and 9. In actual work, the uplink data and downlink data can be carried in the superframe structure. By periodically sending the superframe header to the ONU, the ONU can learn which time slot to receive the downlink data packet and which superframe structure it is in. Send upstream data packets in time slots.

Case 2: The optical transceiver components of the OLT and ONU have only one component that integrates transceivers

In order to illustrate the situation 2 more clearly, Fig. 10 is used for illustration, in which only the optical transceiver components at the ONU end are integrated transceiver components. If the downlink time window calculated by the OLT according to the uplink and downlink bandwidth requirements and ranging information is 2, 4, 6, 8, 10. The uplink time windows are 1, 3, 5, 7, and 9, then the OLT can send downlink data in the

downlink time windows

2, 4, 6, 8, and 10. When the OLT sends downlink data, the transmitter sends an optical signal to the ONU side at a wavelength of 1270nm, and the ONU can switch the working mode of the half-transceiver half-duplex component to the receiver at the time window of 2, 4, 6, 8 , 10 receive the optical signal. Since there may be a time difference when the ONU receives the optical signal from the OLT, clock synchronization is also required. The same ONU can send uplink data to the OLT in

time windows

1, 3, 5, 7, and 9. In actual work, the uplink data and downlink data can be carried in the superframe structure. By periodically sending the superframe header to the ONU, the ONU can learn which time slot to receive the downlink data packet and in which superframe structure. Send upstream data packets in time slots.

It should be noted that, in this application, the data transmission between the OLT and the ONU may be performed through point-to-point communication, or data transmission may be performed through point-to-multipoint communication. The OLT determines the uplink time window and the downlink time window according to the distance between the OLT and the ONU and the bandwidth required for uplink and downlink data transmission. After that, the OLT notifies the ONU of the information of the upstream time window and the information of the downstream time window through the superframe structure, and sends the downstream data packet, that is, the first data packet, in the downstream time window, and receives the upstream data packet from the ONU, that is, the first data packet in the upstream time window. Two packets. The method can be applied not only to the optical transceiver assembly in which the transmitter and the receiver are separated, but also to the optical device in which the transmitter and the receiver are integrated.

In addition, it should also be noted that since the downlink data packets sent by the OLT are bursty, when the ONU registers with the OLT, the registration process will also change accordingly. Execute as follows:

Step 1101: The OLT periodically broadcasts the windowing information, that is, the start time and length of the uplink and downlink windows.

Step 1102: The unregistered ONU receives the windowing information and sends an online registration request to the OLT.

Step 1103 : the OLT and the ONU perform a ranging process, and transmit the superframe structure according to the first cycle during the ranging period; wherein, the ranging process is to measure the distance information between the OLT and the ONU.

It should be noted that the superframe structure sent by the OLT during the ranging period does not carry downlink data, and the downlink data may be empty.

Step 1104: The OLT allocates bandwidth to the ONU according to the ranging information.

Step 1105: The ONU requests the OLT for uplink and downlink bandwidth information.

Step 1106: The OLT allocates the DBA, and sends the DBA to the ONU through the superframe structure.

Step 1107: The ONU determines the uplink data transmission indication information and the downlink data transmission indication information in the DBA, and transmits data according to the uplink data transmission indication information and the downlink data transmission indication information.

As shown in FIG. 12 , a communication device provided by the present application includes a processing unit 1201 and a transceiver unit 1202 . In practical application, the communication device may be the above-mentioned optical line terminal or an optical network unit.

When the communication device is an optical line terminal, the processing unit 1201 is configured to determine the downlink time window and the uplink time window according to the data transmission bandwidth requirement and the distance between the optical line terminal OLT and the ONU of the optical network unit; the transceiver unit 1202 uses In sending a superframe structure to the optical network unit; the superframe structure includes: the information of the downlink time window and the information of the uplink time window; and, in the downlink time window, send to the ONU a first data packet; in the uplink time window, receive a second data packet from the ONU.

It should be noted that the superframe structure can be sent according to a fixed period, such as 125uS. The superframe structure is sent according to a fixed period, which can ensure that the superframe structure is notified to different ONUs in time, so as to avoid the situation that the information of the OLT and the ONU is not synchronized.

In an optional manner, the superframe header includes: frame number information, synchronization information, and N DBAs of the superframe structure; the N is greater than or equal to 1; the DBA includes: one or more Identification information of the ONU, indication information of uplink and downlink data transmission, and location information of data transmission.

When the communication device is an optical network unit, the transceiver unit 1202 is configured to receive a superframe structure from the optical line terminal OLT; the superframe structure includes: the information of the downlink time window and the information of the uplink time window ; a processing unit 1201, configured to receive a first data packet from the OLT in the downlink time window; and send a second data packet to the OLT in the uplink time window.

In an optional manner, the superframe header includes: synchronization information, frame number information, and the next N DBAs of the superframe structure; the N is greater than or equal to 1; the DBA includes: one or Identification of multiple ONUs, indication information of uplink and downlink data transmission, and location information of data transmission.

In an optional manner, the processing unit 1202 is configured to: determine that the identifier of the ONU is the same as the identifier of the ONU in the DBA, and receive the first data packet according to the downlink data transmission indication information .

In the embodiment of the present application, the ONU may determine whether data transmission is required according to the identification information of the optical network unit in the DBA, and in this manner, the ONU may perform data transmission in sequence.

Based on the same concept, an embodiment of the present application provides a communication apparatus 1300 . Illustratively, the communication device 1300 may be a chip or a system of chips. Optionally, in this embodiment of the present application, the chip system may be composed of chips, or may include chips and other discrete devices.

The communication apparatus 1300 may include at least one processor 1310, and the communication apparatus 1300 may further include at least one memory 1320 for storing computer programs, program instructions and/or data. Memory 1320 and processor 1310 are coupled. The coupling in the embodiments of the present application is an indirect coupling or communication connection between devices, units or modules, which may be in electrical, mechanical or other forms, and is used for information exchange between devices, units or modules. The processor 1310 may cooperate with the memory 1320. The processor 1310 may execute computer programs stored in the memory 1320 . Optionally, the at least one memory 1320 may be integrated into the processor 1310 .

The communication apparatus 1300 may further include a transceiver 1330, and the communication apparatus 1300 may exchange information with other devices through the transceiver 1330. The transceiver 1330 can be a circuit, a bus, a transceiver, or any other device that can be used for information exchange.

In a possible implementation manner, the communication apparatus 1300 may be applied to the aforementioned OLT, or may be the aforementioned ONU. The memory 1320 holds the necessary computer programs, program instructions and/or data to implement the functions of the network device in any of the above-described embodiments. The processor 1310 can execute the computer program stored in the memory 1320 to complete the method in any of the foregoing embodiments.

The specific connection medium between the transceiver 1330, the processor 1310, and the memory 1320 is not limited in the embodiments of the present application. In the embodiment of the present application, the memory 1320, the processor 1310, and the transceiver 1330 are connected by a bus in FIG. 13. The bus is represented by a thick line in FIG. 13. The connection mode between other components is only for schematic illustration. It is not limited. The bus can be divided into an address bus, a data bus, a control bus, and the like. For ease of presentation, only one thick line is used in FIG. 13, but it does not mean that there is only one bus or one type of bus.

In this embodiment of the present application, the processor may be a general-purpose processor, a digital signal processor, an application-specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component, which may implement or The methods, steps and logic block diagrams disclosed in the embodiments of this application are executed. A general purpose processor may be a microprocessor or any conventional processor or the like. The steps of the methods disclosed in conjunction with the embodiments of the present application may be directly embodied as executed by a hardware processor, or executed by a combination of hardware and software modules in the processor.

In this embodiment of the present application, the memory may be a non-volatile memory, such as a hard disk drive (HDD) or a solid-state drive (SSD), etc., or may also be a volatile memory (volatile memory), for example Random-access memory (random-acc ess memory, RAM). The memory may also be, but is not limited to, any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and that can be accessed by a computer. The memory in this embodiment of the present application may also be a circuit or any other device capable of implementing a storage function, for storing computer programs, program instructions and/or data.

Based on the above embodiments, the embodiments of the present application further provide a readable storage medium, where the readable storage medium stores instructions, and when the instructions are executed, the method for executing the security detection device in any of the above embodiments is implemented . The readable storage medium may include: a USB flash drive, a removable hard disk, a read-only memory, a random access memory, a magnetic disk or an optical disk and other media that can store program codes.

As will be appreciated by those skilled in the art, the embodiments of the present application may be provided as a method, a system, or a computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to the present application. It will be understood that each flow and/or block in the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to the processor of a general purpose computer, special purpose computer, embedded processor or other programmable data processing device to produce a machine such that the instructions executed by the processor of the computer or other programmable data processing device produce Means for implementing the functions specified in a flow or flow of a flowchart and/or a block or blocks of a block diagram.

These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory result in an article of manufacture comprising instruction means, the instructions The apparatus implements the functions specified in the flow or flow of the flowcharts and/or the block or blocks of the block diagrams.

These computer program instructions can also be loaded on a computer or other programmable data processing device to cause a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process such that The instructions provide steps for implementing the functions specified in the flow or blocks of the flowcharts and/or the block or blocks of the block diagrams.

Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the protection scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

A data transmission method, applied to an optical line terminal OLT, is characterized in that, comprising:

Determine the downlink time window and the uplink time window according to the data transmission bandwidth requirement and the distance between the OLT and the ONU of the optical network unit;

Send a superframe structure to the ONU; the superframe structure includes: the information of the downlink time window and the information of the uplink time window;

In the downlink time window, send the first data packet to the ONU;

During the upstream time window, a second data packet is received from the ONU.
The method according to claim 1, wherein the superframe structure comprises a plurality of superframe structures; and the plurality of superframe structures are sent in a first cycle.
The method according to claim 1 or 2, wherein the superframe structure further comprises: a superframe header; the superframe header is sent by broadcasting.
The method according to claim 3, wherein the superframe header includes: synchronization information, frame number information, and the dynamic bandwidth allocation DBA of the next N superframe structures; the N is greater than or equal to 1;

The DBA includes: identification information of one or more ONUs, indication information of uplink and downlink data transmission, and location information of data transmission.
The method according to claim 4, wherein the uplink and downlink data transmission indication information is identified by the value of the type; if the value of the type is 1, one or more ONUs in the DBA perform uplink Data transmission; if the value of the type is 0, one or more ONUs in the DBA perform downlink data transmission.
The method according to any one of claims 1-5, wherein a time interval exists between the first data packet and the second data packet; and the time interval is greater than a switching time of uplink and downlink data transmission.
A data transmission method, applied to an optical network unit ONU, is characterized in that, comprising:

Receive the superframe structure from the optical line terminal OLT; the superframe structure includes: the information of the downlink time window and the information of the uplink time window;

in the downlink time window, receiving the first data packet from the OLT;

In the uplink time window, a second data packet is sent to the OLT.
The method according to claim 7, wherein the superframe structure comprises a plurality of superframe structures; the plurality of superframe structures are sent according to a first cycle; and the superframe structure received from the optical line terminal comprises:

The ONU receives the superframe structure according to the first period.
The method according to claim 7 or 8, wherein the superframe structure further comprises: a superframe header; the superframe header is sent by broadcasting.
The method according to claim 9, wherein the superframe header includes: synchronization information, frame number information, and dynamic bandwidth allocation DBA of the next N superframe structures; the N is greater than or equal to 1;

The DBA includes: identifiers of one or more ONUs, indication information of uplink and downlink data transmission, and location information of data transmission.
The method according to claim 10, wherein the uplink and downlink data transmission indication information is identified by the value of the type; if the value of the type is 1, one or more ONUs in the DBA perform uplink Data transmission; if the value of the type is 0, one or more ONUs in the DBA perform downlink data transmission.
The method according to claim 10, wherein, in the downlink time window, receiving the first data packet from the OLT comprises:

It is determined that the identifier of the ONU is the same as the identifier of the ONU in the DBA, and the first data packet is received according to the downlink data transmission indication information.
The method according to any one of claims 7-12, wherein a time interval exists between the first data packet and the second data packet; and the time interval is greater than a switching time of uplink and downlink data transmission.
An optical line terminal, characterized in that it includes:

a processing unit, configured to determine a downlink time window and an uplink time window according to the data transmission bandwidth requirement and the distance between the optical line terminal OLT and the optical network unit ONU;

a transceiver unit, configured to send a superframe structure to the ONU; the superframe structure includes: the information of the downlink time window and the information of the uplink time window; and, in the downlink time window, to the The ONU sends the first data packet; and in the uplink time window, receives the second data packet from the ONU.
The optical line terminal according to claim 14, wherein the superframe structure comprises a plurality of superframe structures; and the plurality of superframe structures are sent in a first cycle.
The optical line terminal according to claim 14 or 15, wherein the superframe structure further comprises: a superframe header; the superframe header is sent by broadcasting.
The optical line terminal according to claim 16, wherein the superframe header includes: synchronization information, frame number information, and dynamic bandwidth allocation DBA of the next N superframe structures; the N is greater than or equal to 1 ;

The DBA includes: identification information of one or more ONUs, indication information of uplink and downlink data transmission, and location information of data transmission.
The optical line terminal according to claim 17, wherein the uplink and downlink data transmission indication information is identified by the value of the type; if the value of the type is 1, one or more ONUs in the DBA Perform uplink data transmission; if the value of the type is 0, one or more ONUs in the DBA perform downlink data transmission.
The optical line terminal according to any one of claims 14-18, wherein a time interval exists between the first data packet and the second data packet, and the time interval is greater than a switching time for uplink and downlink data transmission.
An optical network unit, comprising:

a transceiver unit, configured to receive a superframe structure from the optical line terminal OLT; the superframe structure includes: the information of the downlink time window and the information of the uplink time window;

A processing unit, configured to receive a first data packet from the OLT in the downlink time window; and send a second data packet to the OLT in the uplink time window.
The optical network unit according to claim 20, wherein the superframe structure comprises a plurality of superframe structures; the plurality of superframe structures are sent according to a first cycle; the transceiver unit is configured to be used according to the first cycle The superframe structure is received.
The optical network unit according to claim 20 or 21, wherein the superframe structure further comprises: a superframe header; the superframe header is sent by broadcasting.
The optical network unit according to claim 22, wherein the superframe header includes: synchronization information, frame number information, and dynamic bandwidth allocation DBA of the next N superframe structures; the N is greater than or equal to 1 ;

The DBA includes: identifiers of one or more ONUs, indication information of uplink and downlink data transmission, and location information of data transmission.
The optical network unit according to claim 23, wherein the uplink and downlink data transmission indication information is identified by the value of the type; if the value of the type is 1, one or more ONUs in the DBA Perform uplink data transmission; if the value of the type is 0, one or more ONUs in the DBA perform downlink data transmission.
The optical network unit according to claim 23, wherein the processing unit is configured to:

It is determined that the identifier of the ONU is the same as the identifier of the ONU in the DBA, and the first data packet is received according to the downlink data transmission indication information.
The optical network unit according to any one of claims 20-25, wherein a time interval exists between the first data packet and the second data packet; and the time interval is greater than a switching time of uplink and downlink data transmission.
An optical line terminal, comprising: a processor and a memory;

the memory for storing computer programs;

The processor is configured to execute the computer program stored in the memory, so that the optical line terminal executes the method according to any one of claims 1-6.
An optical network unit, comprising: a processor and a memory;

the memory for storing computer programs;

The processor is configured to execute the computer program stored in the memory, so that the optical network unit executes the method according to any one of claims 7-13.
A communication system, characterized by comprising the optical line terminal according to any one of claims 14-19 and the optical network unit according to any one of claims 20-26.
A computer-readable storage medium, characterized in that, the computer-readable storage medium stores instructions, when the instructions are executed, so that the computer executes any one of claims 1-6 or 7-13. method described.