Optical fiber communication network and terminal equipment

Abstract

The invention relates to a communication network, optical line terminal equipment, and a method for processing optical signals. The communication network comprises a first optical line terminal, a second optical line terminal, and equipment located at the customer's premises. The second optical line terminal can be connected to the first optical line terminal at the upper layer via a passive optical network (PON) interface, and can also be connected to the equipment located at the customer's premises at the lower layer via a PON interface. The communication network under the invention allows users in remote areas to access broadband services. In addition, the PON interface is characterized by point-to-multipoint transmission, and thus transmission media can be saved and networking costs can be reduced.

Description

Communication networks and related equipment Technical Field

[0001] This application relates to the field of optical communication technology, and in particular to communication networks and related equipment. Background Technology

[0002] Current broadband access technologies are mainly divided into copper wire access technologies (such as various DSL technologies) and optical access technologies. Access networks implemented using optical access technology are called optical access networks (OANs).

[0003] Passive optical network (PON) is an implementation technology of optical access network. PON is a point-to-multipoint optical access technology. The system architecture of PON is shown in Figure 1.

[0004] In Figure 1, the optical line terminal (OLT) is used to provide a network-side interface for the OAN. The OLT connects to upper-layer network-side devices (such as switches, routers, etc.) and lower-layer devices (such as optical distribution networks, ODNs).

[0005] The ODN includes passive optical splitters for optical power distribution, a backbone fiber connecting the passive optical splitters and the OLT, and branch fibers connecting the passive optical splitters and optical network units (ONUs). During downlink data transmission, the ODN transmits the downlink data from the OLT to each ONU via the splitters. Similarly, during uplink data transmission, the ODN aggregates the uplink data from the ONUs and transmits it to the OLT.

[0006] The ONU provides a user-side interface for the OAN and connects to the ODN. If the ONU also provides user port functionality, such as an Ethernet user port or a plain old telephone service (POTS) user port, it is called an optical network termination (ONT).

[0007] As shown in Figure 1, traditional OLTs are usually located in a central office (CO). The CO usually also includes network-side equipment. The PON network shown in Figure 1 is suitable for deploying ONUs and ONTs in cities and other areas that are close to the central office.

[0008] With the popularization of broadband services, the number of ONUs, ONTs, and other devices in remote areas is gradually increasing. The deployment location of OLT equipment needs to be gradually moved from the central equipment room to remote areas such as towns and villages. The traditional PON networking method shown in Figure 1 cannot meet this situation. Therefore, how to build a PON network so that ONUs, ONTs, and other devices can be deployed in remote areas to support broadband services is an urgent problem to be solved.

[0009] Summary of the Invention

[0010] This application provides a communication network and related apparatus that enables broadband services to be accessed in remote areas, and can save transmission media and reduce network construction costs.

[0011] In a first aspect, this application provides an optical line terminal, including: a processor, a memory, and a communication device, wherein the communication device is configured with a first PON interface and a second PON interface.

[0012] During downlink data transmission, the communication device is used to receive a first optical signal sent by a first optical line terminal through the first PON interface, the processor is used to process the first optical signal, and the communication device is also used to send the processed first optical signal to the user terminal equipment through the second PON interface.

[0013] During uplink data transmission, the communication device is used to receive a second optical signal sent by the user terminal equipment through the second PON interface, the processor is used to process the second optical signal, and the communication device is also used to send the processed second optical signal to the first optical line terminal through the first PON interface.

[0014] Specifically, the first PON interface can be connected to the upper-layer device of the optical line terminal, the first optical line terminal, and the second PON interface can be connected to the lower-layer device of the optical line terminal, the user terminal device.

[0015] Both the first PON interface and the second PON interface are ports used for data connection in a communication network employing PON technology. The first PON interface and the second PON interface can use different PON technologies, meaning they can correspond to different or the same PON protocol.

[0016] The following describes the processor's processing of the optical signal received by the optical line terminal in two scenarios:

[0017] (1) The first PON interface and the second PON interface correspond to different protocols.

[0018] When the first PON interface and the second PON interface are of different types, the optical line terminal (OLT) needs to perform protocol conversion on the received signal before transmitting it. This application proposes the following two conversion methods:

[0019] The first method involves directly performing protocol conversion on the optical signal. In an optional embodiment, during downlink data transmission, the processor parses the first optical signal received by the first PON interface using the protocol corresponding to the first PON interface, and encapsulates the parsed first optical signal using the protocol corresponding to the second PON interface, thus completing the protocol conversion of the first optical signal. During uplink data transmission, the processor parses the second optical signal received by the second PON interface using the protocol corresponding to the second PON interface, and encapsulates the parsed second optical signal using the protocol corresponding to the first PON interface, thus completing the protocol conversion of the second optical signal.

[0020] The second method involves converting the optical signal into an electrical signal and then performing a protocol conversion on the electrical signal. In an optional embodiment, the optical line terminal may further include an optical module, a first PON MAC chip, and a second PON MAC chip, wherein the first PON MAC chip uses the protocol corresponding to the first PON interface, and the second PON MAC chip uses the protocol corresponding to the second PON interface.

[0021] During downlink data transmission, the processor is specifically used to instruct the optical module to convert the first optical signal received by the first PON interface into a first electrical signal; instruct the first PON MAC chip to perform protocol deframing on the first electrical signal; instruct the second PON MAC chip to perform protocol framing on the first electrical signal after protocol deframing; and instruct the optical module to perform electro-optical conversion on the first electrical signal after protocol framing to obtain the processed first optical signal, thereby completing the protocol conversion of the first optical signal.

[0022] During uplink data transmission, the processor is specifically used to instruct the optical module to convert the second optical signal received by the second PON interface into a second electrical signal; instruct the second PON MAC chip to perform protocol deframing on the second electrical signal; instruct the first PON MAC chip to perform protocol framing on the second electrical signal after protocol deframing; and instruct the optical module to perform electro-optical conversion on the second electrical signal after protocol framing to obtain the processed second optical signal, thereby completing the protocol conversion of the second optical signal.

[0023] (2) The first PON interface and the second PON interface correspond to different protocols.

[0024] When the first PON interface and the second PON interface are of the same type, the optical line terminal can use a processor to perform noise reduction, signal enhancement, and other processing on the received signal to improve the reliability of signal transmission.

[0025] In an optional embodiment, the communication device is further configured with an Ethernet interface. During downlink data transmission, the communication device is also used to receive a first electrical signal sent by a network-side device via the Ethernet interface, the processor is further used to convert the first electrical signal into a third optical signal, and the communication device is further used to send the third optical signal to a user-side device via a second PON interface. During uplink data transmission, the communication device is also used to receive a fourth optical signal sent by a user-side device via the second PON interface, the processor is further used to convert the fourth optical signal into a second electrical signal, and the communication device is further used to send the second electrical signal to a network-side device via the Ethernet interface.

[0026] When connecting to upper-layer devices, the optical line terminal of this application can connect to devices supporting downlink PON (such as traditional optical line terminals) via the first PON interface, and can also connect to network-side devices such as switches and routers via traditional Ethernet interfaces. Compared with traditional optical line terminals, the optical line terminal of this application has a wider range of application scenarios.

[0027] Secondly, this application provides a communication network, including: a first optical line terminal, a second optical line terminal, and a user terminal device; wherein, the first optical line terminal is connected to at least one second optical line terminal via a PON interface, and the second optical line terminal is connected to at least one user terminal device via a PON interface.

[0028] During downlink data transmission, the first optical line terminal is used to send a first optical signal to at least one second optical line terminal, and the second optical line terminal is used to process the first optical signal and send the processed first optical signal to at least one user terminal device.

[0029] During uplink data transmission, the user terminal equipment sends a second optical signal to the second optical line terminal connected to the user terminal equipment. The second optical line terminal processes the second optical signal and sends at least one processed second optical signal to the first optical line terminal.

[0030] The second optical line terminal may be the optical line terminal provided by the first party, and the signal processing process of the second optical line terminal may refer to the relevant description of the optical line terminal of the first party.

[0031] Optionally, the communication network further includes: a first optical distribution network and a second optical distribution network. The first optical distribution network can provide an optical signal transmission channel between the first optical line terminal and the second optical line terminal, and the second optical distribution network can provide an optical signal transmission channel between the second optical line terminal and the user terminal equipment.

[0032] Furthermore, optionally, the first optical distribution network may include at least one optical splitter, and the second optical distribution network may also include at least one optical splitter. The at least one optical splitter in the first optical distribution network can be used to perform multi-stage splitting processing on the optical signal transmitted by the first optical line terminal before sending it to the second optical line terminal; the number of stages is related to the number of splitters. Similarly, the at least one optical splitter in the second optical distribution network can be used to perform multi-stage splitting processing on the optical signal transmitted by the second optical line terminal before sending it to the user terminal equipment; the number of stages is related to the number of splitters. By using optical splitters, the optical distribution network only needs to connect to upper-layer equipment through one optical fiber, and then use multiple optical fibers from the splitter to connect to lower-layer equipment respectively. This point-to-multipoint transmission method reduces transmission medium overhead and lowers networking costs.

[0033] In an optional embodiment, the distance between the optical splitter and the second optical line terminal in the first distribution network is less than the distance between the optical splitter and the first optical line terminal. Since the optical splitter connects to the first optical line terminal via one optical fiber uplink and to multiple second optical line terminals via multiple optical fibers downlink, when the optical splitter in the first distribution network is located closer to the second optical line terminals, the length of these multiple optical fibers can be reduced, thereby lowering the networking cost.

[0034] In an optional embodiment, the distance between the optical splitter and the user terminal equipment in the second optical distribution network is less than the distance between the optical splitter and the second optical line terminal. Since the optical splitter connects to the second optical line terminal via one optical fiber uplink and to multiple user terminal equipment via multiple optical fibers downlink, the length of these multiple optical fibers can be reduced and networking costs can be lowered when the optical splitter in the second optical distribution network is located closer to the user terminal equipment.

[0035] The communication network of this application includes a first optical line terminal (OLT), a second OLT, and user terminal equipment. The second OLT can be connected to the upper-layer first OLT via a PON interface, and can also be connected to the lower-layer user terminal equipment via a PON interface. This communication network enables users in remote areas to access broadband services. Furthermore, due to the point-to-multipoint transmission characteristics of the PON interface, it can save transmission media and reduce networking costs. Attached Figure Description

[0036] Figure 1 shows a PON network structure diagram provided by the prior art;

[0037] Figure 2 shows another PON network structure provided by existing technology;

[0038] Figure 3 is a schematic diagram of the hardware structure of an optical line terminal provided in this application;

[0039] Figure 4 is a schematic diagram of the device configuration of an optical line terminal provided in this application;

[0040] Figure 5 is a schematic diagram of another optical line terminal provided in this application;

[0041] Figure 6 is a schematic diagram of the communication network provided in this application;

[0042] Figure 7 is a schematic diagram of another communication network provided in this application;

[0043] Figure 8 is a schematic diagram of another communication network provided in this application;

[0044] Figure 9 is a schematic diagram of the downlink data transmission process of the communication network provided in this application;

[0045] Figure 10 is a schematic diagram of the downlink data transmission process of the communication network provided in this application;

[0046] Figure 11 is a functional block diagram of the optical line terminal provided in this application. Detailed Implementation

[0047] The terminology used in the implementation section of this application is for the purpose of explaining specific embodiments of this application only, and is not intended to limit this application.

[0048] Referring to Figure 2, which illustrates a possible PON network architecture in the prior art, the OLT equipment is no longer deployed in a central equipment room but rather closer to the ONT, ONU, and other devices. The PON network shown in Figure 2 can include more OLTs, enabling more users in remote areas to access broadband services.

[0049] While the PON network shown in Figure 2 enables broadband access in remote areas, the connection between the network-side devices and the OLT is via Ethernet interfaces, with the primary transmission media being network cables and fiber optic cables. Due to the one-to-one transmission nature of Ethernet interfaces, each OLT device and network-side device requires a separate transmission medium. Because there are many OLT devices, deploying a PON network like the one shown in Figure 2 requires a large number of transmission media, resulting in high networking costs.

[0050] In order to enable broadband services to be available in remote areas and reduce networking costs, this application provides a PON network and optical line terminal, which can provide broadband services to remote areas with low networking costs and easy implementation.

[0051] To facilitate understanding of this application, we will first introduce several technical terms involved in this application.

[0052] (I) PON Interface

[0053] PON is a point-to-multipoint optical access technology. The PON interface is a port used for data connection in a communication network that uses PON. The transmission medium connected by the PON interface is optical fiber, which can be used to receive or send optical signals.

[0054] Since PON includes various types, such as Asynchronous Transfer Mode PON (ATM passive optical network, APON), Broadband PON (broadband passive optical network, BPON), Ethernet PON (ethernet passive optical network, EPON), Gigabit PON (gigabit passive optical network, GPON), 10 Gigabit Ethernet PON (10G ethernet passive optical network, 10G-EPON), etc., PON interfaces can also be further divided into various types, such as GPON interfaces, EPON interfaces, symmetrical 10G GPON interfaces, asymmetrical 10G GPON interfaces, 10G EPON interfaces, TWDM PON interfaces, and other PON interfaces with higher operating speeds that have emerged later.

[0055] Understandably, different PONs may use different protocols, and the signal format may differ when using different PON technologies to transmit signals.

[0056] In this application, different types of PON interfaces correspond to different protocols, and the signals that a PON interface can recognize and transmit are signals encapsulated using the corresponding protocol. Therefore, if a device includes two different types of PON interfaces, a signal received from one PON interface needs to undergo protocol conversion processing so that the signal is encapsulated using the protocol corresponding to the other PON interface before it can be sent out from the other PON interface.

[0057] In this application, the type of PON interface identifies the type of optical access technology it employs and its corresponding protocol.

[0058] Understandably, PON interfaces use a point-to-multipoint communication method. For example, as shown in Figure 2, the OLT and user terminal equipment are connected via a PON interface, and the OLT can connect to multiple ONTs through one PON interface. That is, among the multiple PON interfaces connecting the OLT to user terminal equipment downstream, each PON interface can correspond to multiple user terminal equipment.

[0059] (ii) Branching ratio

[0060] Splitting ratio is a concept specific to PON interfaces, referring to the number of user-end devices that a single PON interface can support; in other words, how many user-end devices can be connected to one PON interface. For example, the EPON standard defines a splitting ratio of 1:32, while the GPON standard defines splitting ratios including 1:32, 1:64, and 1:128. To illustrate, an EPON interface can support a maximum splitting ratio of 1:32, meaning the optical signal output from this EPON interface can be divided into a maximum of 32 paths, each transmitted to a different user terminal.

[0061] Obviously, when communicating through a PON interface in a communication network, the use of a point-to-multipoint method reduces the amount of transmission medium used and lowers the cost.

[0062] (III) Ethernet Interface

[0063] Ethernet is currently the most widely used local area network (LAN) communication method, and it is also a protocol. An Ethernet interface is a port in a network structure that uses the Ethernet protocol for data connection. An Ethernet interface can be used to receive or send signals using the Ethernet protocol, such as Ethernet frames.

[0064] The Ethernet interface mentioned in this application may include various types, such as at least one of SC fiber optic interface, RJ-45 interface, FDDI interface, AUI interface, BNC interface, and Console interface. The transmission medium for Ethernet interface connection may include coaxial cable, twisted pair, fiber optic cable, etc.

[0065] Ethernet interfaces communicate in a point-to-point manner. For example, as shown in Figure 2, the switch and the OLT are connected via Ethernet interfaces. When there are multiple OLTs, the switch needs to connect to each OLT through a different Ethernet interface. In other words, among the multiple Ethernet interfaces on the switch connecting to the OLTs, each Ethernet interface corresponds to only one OLT.

[0066] Obviously, when communicating through an Ethernet interface in a communication network, the point-to-point transmission method requires more transmission media, resulting in higher costs.

[0067] Referring to Figure 3, Figure 3 is a schematic diagram of the hardware structure of an optical line terminal 300 provided in this application. As shown in Figure 3, the optical line terminal 300 mainly includes the following parts: processor 101, memory 102, communication device 103, and power management module 104.

[0068] The power management module 104 is used to provide a stable current to the optical line terminal 300.

[0069] The communication device 103 can be used for communication between the optical line terminal 300 and other communication devices, such as network-side devices, other optical line terminals, user terminal devices, etc. In this application, the communication device is configured with a first PON interface and a second PON interface. The first PON interface is used for optical communication between the optical line terminal 300 and upper-layer devices (other upper-layer optical line terminals), and the second PON interface is used for optical communication between the optical line terminal 300 and user terminal devices. Both the first PON interface and the second PON interface are ports connected using PON (Passive Optical Network) technology. The first PON interface may include at least one of the following: GPON interface, EPON interface, symmetrical 10G GPON interface, asymmetrical 10G GPON interface, 10G EPON interface, TWDM PON interface, or a PON interface with a higher operating speed that will appear in the future. The second PON interface may include at least one of the following: GPON interface, EPON interface, symmetrical 10G GPON interface, asymmetrical 10G GPON interface, 10G EPON interface, TWDM PON interface, or a PON interface with a higher operating speed that will appear in the future. Please refer to the relevant descriptions in the above technical terms (I), which will not be repeated here.

[0070] In this application, the first PON interface and the second PON interface can be different types of PON interfaces, or they can be the same type of PON interfaces. The functions of each module of the optical line terminal 300 are described below according to different cases.

[0071] (1) The first PON interface and the second PON interface are different types of PON interfaces.

[0072] Optionally, the first PON interface and the second PON interface can be different types of PON interfaces. The processor 101 is used to perform protocol conversion processing on the optical signals received by the first PON interface or the second PON interface so that the processed optical signals are suitable for the second PON interface or the first PON interface. Two conversion methods are described below.

[0073] The first method involves directly performing protocol conversion on the optical signal. In an optional embodiment, during downlink data transmission, the processor 101 parses the first optical signal received by the first PON interface using the protocol corresponding to the first PON interface, and encapsulates the parsed first optical signal using the protocol corresponding to the second PON interface, thus completing the protocol conversion of the first optical signal. During uplink data transmission, the processor 101 parses the second optical signal received by the second PON interface using the protocol corresponding to the second PON interface, and encapsulates the parsed second optical signal using the protocol corresponding to the first PON interface, thus completing the protocol conversion of the second optical signal.

[0074] The second method involves converting the optical signal into an electrical signal and then performing a protocol conversion on the electrical signal. In an optional embodiment, the optical line terminal 300 may further include an optical module 105, a first PON MAC chip 106, and a second PON MAC chip 107, wherein the first PON MAC chip 106 uses the protocol corresponding to the first PON interface, and the second PON MAC chip 107 uses the protocol corresponding to the second PON interface.

[0075] During downlink data transmission, the processor 101 is specifically used to instruct the optical module 105 to convert the first optical signal received by the first PON interface into a first electrical signal; instruct the first PON MAC chip 106 to perform protocol deframing on the first electrical signal; instruct the second PON MAC chip 107 to perform protocol framing on the first electrical signal after protocol deframing; and instruct the optical module 105 to perform electro-optical conversion on the first electrical signal after protocol framing to obtain the processed first optical signal, thereby completing the protocol conversion of the first optical signal.

[0076] During uplink data transmission, the processor 101 is specifically used to instruct the optical module 105 to convert the second optical signal received by the second PON interface into a second electrical signal; instruct the second PON MAC chip 107 to perform protocol deframing on the second electrical signal; instruct the first PON MAC chip 106 to perform protocol framing on the second electrical signal after protocol deframing; and instruct the optical module 105 to perform electro-optical conversion on the second electrical signal after protocol framing to obtain the processed second optical signal, thereby completing the protocol conversion of the second optical signal.

[0077] (2) The first PON interface and the second PON interface are the same type of PON interface.

[0078] When the first PON interface and the second PON interface are of the same type, the optical line terminal can use a processor to perform noise reduction, signal enhancement, and other processing on the received signal to improve the reliability of signal transmission.

[0079] Optionally, the communication device 103 may also be configured with an Ethernet interface, which is an interface that uses the Ethernet protocol for communication and can be used for communication between the optical line terminal 300 and upper-layer network-side devices (switches, routers, etc.).

[0080] Memory 102 is coupled to terminal processor 101 and is used to store various software programs and / or multiple sets of instructions. Specifically, memory 102 may include high-speed random access memory and may also include non-volatile memory, such as one or more disk storage devices, flash memory devices, or other non-volatile solid-state storage devices. Memory 102 may store an operating system (hereinafter referred to as the system), such as embedded operating systems like Android, iOS, Windows, or Linux. Memory 102 may also store network communication programs that can be used to communicate with one or more optical line terminals, one or more user terminal devices, and one or more network-side devices.

[0081] The processor 101 can be used to read and execute computer-readable instructions to perform management functions of the optical line terminal 300, interpret, control, or process messages received by the optical line terminal 300, etc. Specifically, the processor 101 can be used to call a program stored in the memory 212 and execute the instructions contained in the program, which can be used to implement the signal transmission function of the optical line terminal 300 in the PON communication network.

[0082] Understandably, the optical line terminal 300 may also include an uplink board, a backplane that provides physical connections for each unit, as well as a clock, fan, fan control module, etc., which will not be described in detail here.

[0083] It should be noted that the optical line terminal 300 shown in Figure 3 is only one implementation of this application. In actual applications, the optical line terminal 300 may include more or fewer components, which is not limited here.

[0084] As shown in Figure 3, when connecting to upper-layer devices, the optical line terminal 300 can connect to devices supporting downlink PON (such as traditional optical line terminals) through the first PON interface, and can also connect to network-side devices such as switches and routers through traditional Ethernet interfaces. Compared with traditional optical line terminals, the optical line terminal 300 in this application has a wider range of application scenarios.

[0085] In practice, optical line terminals can take many forms. Below, we will briefly introduce two possible implementation forms of optical line terminals.

[0086] In optional embodiments, the optical line terminal 300 can be implemented as a box-type device or an integrated device. Referring to Figure 4, from a protocol perspective, the optical line terminal includes one or more PON MAC chips for processing communication services between the terminal and upper-layer devices, used to complete PON media access control (MAC) layer protocol processing functions. The optical line terminal also includes components or chips for implementing forwarding functions, which can be used to implement LAN switch (LSW) forwarding, network process (NP), or traffic management (TM), etc. The optical line terminal also includes one or more PON MAC chips for processing communication services between the terminal and lower-layer devices, used to complete PON media access control (MAC) layer protocol processing functions.

[0087] Optionally, the optical line terminal may also include one or more ETH MAC / PHYs for handling communication services with upper-layer devices, and Ethernet MAC layer protocol processing functions / Ethernet physical layer protocol processing functions for completing communication with upper-layer devices.

[0088] In another alternative embodiment, the optical line terminal 300 can also be implemented as a chassis-type device. Referring to FIG5, the optical line terminal may include one or more uplink access modules, one or more control modules, and one or more downlink access modules.

[0089] The uplink access module provides the first PON interface, the downlink access module provides the second PON interface, and the control module is used to control the optical line terminal and complete functions such as protocol processing, message exchange or forwarding.

[0090] Furthermore, in order to enable optical line terminals to be applied to more optical communication scenarios, the uplink interface may also include a traditional Ethernet interface.

[0091] Based on the aforementioned optical line terminal 300, in order to enable remote areas to access broadband services and reduce network construction costs when building a communication network, this application provides a communication network.

[0092] The main inventive principle of this application may include: the optical line terminal includes a first PON interface for communicating with upper-layer equipment, and the first PON interface can be used to realize point-to-multipoint communication from the upper-layer equipment to multiple optical line terminals, which can save transmission media and reduce networking costs.

[0093] Referring to Figure 6, which is a schematic diagram of a communication network provided in this application, the following describes the various devices in the communication network of this application, the connection relationships between the devices, their deployment locations, and the data transmission process, etc., in conjunction with Figure 6.

[0094] (a) Connection relationships between devices

[0095] As shown in Figure 6, the communication network includes a first optical line terminal (OLT), a second optical line terminal (BRT), and user terminal equipment. The first OLT is connected to at least one second OLT via a PON interface, and the second OLT is connected to at least one user terminal equipment via a PON interface.

[0096] In this application, the first optical line terminal and the second optical line terminal are connected through a PON interface, and the second optical line terminal and the user terminal equipment are also connected through a PON interface. The transmission medium for all of them is optical fiber.

[0097] In an optional embodiment, the first optical line terminal and the second optical line terminal can be connected through a first optical distribution network, and the second optical line terminal and the user terminal equipment can be connected through a second optical distribution network. Referring to Figure 7, the first optical distribution network can provide an optical signal transmission channel between the first and second optical line terminals, and the second optical distribution network can provide an optical signal transmission channel between the second optical line terminal and the user terminal equipment. Specifically, both the first and second optical distribution networks can be implemented as intelligent ODN (iODN), easy ODN, smart ODN, or other types of ODN; this application does not impose any limitations.

[0098] Furthermore, in an optional embodiment, the first optical distribution network may include at least one optical splitter, and an optical fiber between a first optical line terminal and a second optical line terminal. The second optical distribution network may also include at least one optical splitter, an optical fiber between a second optical line terminal and a user terminal device. Here, the optical splitter is a passive device whose function is to distribute downlink data and concentrate uplink data. The optical splitter has one uplink optical interface and several downlink optical interfaces. Optical signals from the uplink optical interface are distributed to all the downlink optical interfaces for transmission, and optical signals from the downlink optical interfaces are distributed to the single uplink optical interface for transmission.

[0099] Understandably, at least one optical splitter in the first optical distribution network can be used to perform multi-stage splitting processing on the optical signal transmitted by the first optical line terminal before sending it to the second optical line terminal; the number of stages is related to the number of splitters. Similarly, at least one optical splitter in the second optical distribution network can be used to perform multi-stage splitting processing on the optical signal transmitted by the second optical line terminal before sending it to the user-end equipment; the number of stages is also related to the number of splitters. Clearly, optical splitters allow the optical distribution network to connect to upper-layer equipment via only one optical fiber, and then use multiple optical fibers from the splitter to connect to lower-layer equipment. This point-to-multipoint transmission method reduces transmission medium overhead and lowers networking costs.

[0100] In one specific embodiment, as shown in Figure 7, the first optical distribution network includes a first optical splitter, and the second optical distribution network includes a second optical splitter.

[0101] In the communication network shown in Figures 6 and 7, since the first optical line terminal can connect to multiple second optical line terminals, and the second optical line terminals can further connect to multiple user terminal devices, the communication network shown in Figures 6 and 7 can access more user terminal devices and expand the service range compared to Figure 1.

[0102] Furthermore, in the communication network shown in Figure 6 or Figure 7, multiple levels of second optical line terminals can be configured. Referring to Figure 8, the first optical line terminal connects to multiple second optical line terminals, and the second optical line terminals can also connect to other second optical line terminals, connecting to the user terminal equipment after multiple levels of connection. Through the communication network shown in Figure 8, more user terminal equipment can be accessed, expanding the service range.

[0103] (II) Implementation of each device

[0104] Specifically, in this application, the first optical line terminal provides a PON interface for communication with the lower-layer device (i.e., the second optical line terminal), which can be a traditional optical line terminal (i.e., a traditional OLT) or the optical line terminal shown in Figure 3.

[0105] Specifically, the second optical line terminal not only needs to provide a PON interface for communication with the lower-level equipment (user terminal equipment), but also needs to provide a PON interface for communication with the upper-level equipment (first optical line terminal), which can be the optical line terminal 300 shown in Figure 3 above.

[0106] Specifically, user-end equipment is a device that sends Ethernet data to or receives Ethernet data sent by users, and can provide users with various broadband services, such as Internet surfing, VoIP, HDTV, and VideoConference. In practice, user-end equipment can be ONU or ONT, etc.

[0107] Specifically, the communication network shown in Figure 6 is an optical access network, which connects to the core network. The network-side devices are those in the core network that are directly connected to the optical access network. In practice, network-side devices can be switches, routers, etc.

[0108] (III) Deployment location of each device

[0109] Specifically, network-side equipment is a crucial component of optical communication networks and is typically located in a central equipment room. In an optional embodiment, as shown in Figure 6, the first optical line terminal (OLT) can be installed together with the network-side equipment within the central equipment room. In another optional embodiment, the second OLT can be located in a remote area far from the central equipment room. Since the second OLT connects to the underlying user terminal equipment, the user terminal equipment in this application can be deployed in remote areas such as rural areas far from cities, enabling broadband service access in these remote areas.

[0110] In this application, the positions of each beam splitter can be set according to existing standards, and this application does not impose any restrictions. The following are examples of several possible beam splitter deployments, which are not intended to limit this application.

[0111] In an optional embodiment, the first optical line terminal and the second optical line terminal are connected via a first optical distribution network. When a first optical splitter is provided in the first optical distribution network, the distance between the first optical splitter and the second optical line terminal is less than the distance between the first optical splitter and the first optical line terminal. That is, the first optical splitter is located closer to the second optical line terminal. Since the first optical splitter connects to the first optical line terminal uplink via one optical fiber and to multiple second optical line terminals downlink via multiple optical fibers, when the first optical splitter is located closer to the second optical line terminal, the length of these multiple optical fibers can be reduced, thus lowering the networking cost.

[0112] Furthermore, when multiple optical splitters are set up in the first optical distribution network for multi-level optical splitting, the deployment locations of these multiple optical splitters can be set according to the actual situation and existing standards, and this application does not impose any restrictions.

[0113] Similarly, in an optional embodiment, the second optical line terminal and the user terminal equipment are connected via a second optical distribution network. When a second optical splitter is provided in the second optical distribution network, the distance between the second optical splitter and the user terminal equipment is less than the distance between the second optical splitter and the second optical line terminal. That is, the second optical splitter is located closer to the user terminal equipment. Since the second optical splitter connects to the second optical line terminal uplink via one optical fiber and to multiple user terminal equipment downlink via multiple optical fibers, placing the second optical splitter closer to the user terminal equipment reduces the length of these multiple optical fibers and lowers the networking cost.

[0114] Furthermore, when multiple optical splitters are set up in the second optical distribution network for multi-level optical splitting, the deployment locations of these multiple optical splitters can be set according to the actual situation and existing standards, and this application does not impose any restrictions.

[0115] (iv) Data transmission process

[0116] In this application, the data transmission process is divided into downlink transmission and uplink transmission. During downlink transmission, the signal is sent from the network-side device to the user-side device, and during uplink transmission, the signal is sent from the user-side device to the network-side device. These will be described separately below.

[0117] (1) Downlink transmission process

[0118] Referring to Figure 9, the downlink transmission process can be divided into the following steps:

[0119] 1. The first optical line terminal sends a first optical signal to at least one second optical line terminal.

[0120] In this application, the first optical signal can be converted from an electrical signal received by the first optical line terminal (OLT), which is then sent to the OLT by the network-side device via an Ethernet interface. Specifically, the OLT and the network-side device are connected via an Ethernet interface. Typically, the network-side device sends an electrical signal to the OLT. The OLT performs protocol conversion on the received electrical signal and then performs electro-optical conversion on the converted signal to obtain the first optical signal. This first optical signal is then sent to at least one second optical line terminal connected to the OLT via a PON interface.

[0121] In an optional embodiment, the communication network further includes a first optical distribution network. The first optical signal transmitted by the first optical line terminal can be transmitted by the first optical distribution network to at least one second optical line terminal.

[0122] Furthermore, in an optional embodiment, the first optical distribution network includes a first optical splitter, and the first optical signal emitted by the first optical line terminal can be transmitted by the first optical distribution network to at least one second optical line terminal through the first optical splitter.

[0123] 2. The second optical line terminal processes the first optical signal.

[0124] Specifically, after receiving the first optical signal through the PON interface of the upper-layer device (such as the first PON interface in Figure 3), the second optical line terminal performs protocol conversion processing on the first optical signal so that the processed first optical signal is suitable for the PON interface of the lower-layer device.

[0125] Here, the operation of the second optical line terminal in performing protocol conversion processing on the first optical signal can be referred to the relevant description in Figure 3, and will not be repeated here.

[0126] 3. The second optical line terminal sends the processed first optical signal to at least one user terminal device.

[0127] In this application, the second optical line terminal transmits the processed first optical signal to at least one user terminal device through the PON interface (e.g., the second PON interface in Figure 3) connected to the lower-level device.

[0128] In an optional embodiment, the communication network further includes a second optical distribution network. The processed first optical signal transmitted by the second optical line terminal can be transmitted to at least one user terminal device via the second optical distribution network.

[0129] Furthermore, in an optional embodiment, the second optical distribution network includes a second optical splitter, and the processed first optical signal emitted by the second optical line terminal can be transmitted by the second optical distribution network to at least one user terminal device through the second optical splitter.

[0130] Understandably, during downlink data transmission, the data is transmitted in a broadcast manner, and each user terminal device receives the same processed first optical signal. After receiving the first optical signal, the user terminal device can receive its own data based on the identification information carried in the first optical signal, and can further convert the data into photoelectric data before transmitting it to the terminal device (such as a computer) directly used by the user.

[0131] The downlink data transmission process is completed through the two steps described above. The functions and roles of each device during downlink transmission are also detailed in the above steps and will not be repeated here.

[0132] (2) Uplink transmission process

[0133] Referring to Figure 10, the uplink transmission process can be divided into the following steps:

[0134] 1. The user terminal equipment sends a second optical signal to the second optical line terminal connected to the user terminal equipment.

[0135] In this application, the second optical signal can be converted from an electrical signal received by the user terminal equipment. This electrical signal can be sent to the user terminal equipment by a terminal device (such as a computer) directly used by the user via an Ethernet interface. Specifically, the user terminal equipment and the terminal equipment are connected via an Ethernet interface. When the terminal equipment needs to send data to the network side, it sends an electrical signal to the user terminal equipment. The user terminal equipment performs protocol conversion on the received electrical signal and then performs electro-optical conversion on the protocol-converted electrical signal to obtain the second optical signal. The second optical signal is then sent to the second optical line terminal connected to the user terminal equipment via a PON interface.

[0136] In an optional embodiment, the communication network further includes a second optical distribution network. The second optical signal emitted by the user terminal equipment can be transmitted by the second optical distribution network to a second optical line terminal connected to the user terminal equipment.

[0137] Furthermore, in an optional embodiment, the second optical distribution network includes a second optical splitter, and the second optical signal emitted by the user terminal equipment can be transmitted by the second optical distribution network through the second optical splitter to the second optical line terminal connected to the user terminal equipment.

[0138] 2. The second optical line terminal processes the second optical signal.

[0139] In this application, the second optical line terminal connects to multiple user terminal devices. The second optical line terminal can receive multiple second optical signals, and the multiple second optical signals received by the second optical line terminal can be different. Specifically, after receiving the second optical signal through the PON interface connected to the lower-layer device (such as the second PON interface in Figure 3), the second optical line terminal performs protocol conversion processing on the second optical signal so that the processed second optical signal is suitable for the PON interface connected to the upper-layer device.

[0140] Here, the operation of the second optical line terminal in performing protocol conversion processing on the second optical signal can be referred to the relevant description in Figure 3, and will not be repeated here.

[0141] 3. The second optical line terminal sends the processed second optical signal to the first optical line terminal.

[0142] In this application, the second optical line terminal transmits the processed second optical signal to at least one user terminal device through the PON interface (e.g., the first PON interface in Figure 3) connected to the upper-layer device.

[0143] In an optional embodiment, the communication network further includes a first optical distribution network. The processed second optical signal transmitted by the second optical line terminal can be transmitted from the first optical line terminal to the first optical line terminal via the first optical distribution network.

[0144] Furthermore, in an optional embodiment, the first optical distribution network includes a first optical splitter, and the processed second optical signal emitted by the second optical line terminal can be transmitted from the first optical distribution network to the first optical line terminal through the first optical splitter.

[0145] Understandably, uplink data transmission can be performed in the form of time-division multiplexing (TDMA).

[0146] Understandably, after receiving the second optical signal, the first optical line terminal can further perform photoelectric conversion on the second optical signal and then transmit it to the network-side equipment.

[0147] The uplink data transmission process is completed through the two steps described above. The functions or roles of each device during the uplink transmission process can be found in the detailed description of the steps above, and will not be repeated here.

[0148] The communication network of this application has been described in detail above. Referring to Figure 11, Figure 11 is a functional block diagram of an optical line terminal provided by this application. As shown in the figure, the optical line terminal may include: a processing unit 111, a storage unit 112, and a communication unit 113, wherein the communication unit 113 is configured with a first PON unit and a second PON unit.

[0149] In the downlink data transmission, the communication unit 113 is used to receive the first optical signal sent by the first optical line terminal through the first PON unit, the processing unit 111 is used to process the first optical signal, and the communication unit 113 is also used to send the processed first optical signal to the user terminal equipment through the second PON unit.

[0150] During uplink data transmission, the communication unit 113 is used to receive the second optical signal sent by the user terminal equipment through the second PON unit, the processor 111 is used to process the second optical signal, and the communication unit 113 is also used to send the processed second optical signal to the first optical line terminal through the first PON unit.

[0151] Understandably, the optical line terminal shown in Figure 11 can be implemented as the second optical line terminal in Figures 6-8 above. The functions of each module can be referred to Figures 6-8 and related descriptions, and will not be repeated here.

[0152] In summary, the communication network of this application includes a first optical line terminal (OLT), a second OLT, and user terminal equipment. The second OLT can connect to the upper-layer first OLT via a PON interface, and can also connect to the lower-layer user terminal equipment via a PON interface. The communication network of this application enables users in remote areas to access broadband services. Furthermore, due to the point-to-multipoint transmission characteristics of the PON interface, it can save transmission media and reduce networking costs.

[0153] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible to a computer or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid-state disk).

Claims

1. A communication network, characterized in that, include: A first optical line terminal, a second optical line terminal, and a user terminal device; wherein the first optical line terminal is connected to at least one second optical line terminal via a PON interface, and the second optical line terminal is connected to at least one user terminal device via a PON interface; During downlink data transmission, the first optical line terminal is used to send a first optical signal to the at least one second optical line terminal, and the second optical line terminal is used to process the first optical signal and send the processed first optical signal to the at least one user terminal device. During uplink data transmission, the user terminal device is used to send a second optical signal to a second optical line terminal connected to the user terminal device. The second optical line terminal is used to process the second optical signal and send the processed second optical signal to the first optical line terminal.

2. The communication network as described in claim 1, characterized in that, The communication network further includes: a first optical distribution network and a second optical distribution network; During downlink data transmission, the first optical distribution network is used to transmit the first optical signal emitted by the first optical line terminal to the at least one second optical line terminal, and the second optical distribution network is used to transmit the processed first optical signal emitted by the second optical line terminal to the at least one user terminal device. During uplink data transmission, the second optical distribution network is used to transmit the second optical signal emitted by the user terminal equipment to the second optical line terminal connected to the user terminal equipment, and the first optical distribution network is used to transmit the processed second optical signal emitted by the second optical line terminal to the first optical line terminal.

3. The communication network as described in claim 2, characterized in that, The first optical distribution network includes a first optical splitter, and the second optical distribution network includes a second optical splitter; During downlink data transmission, the first optical distribution network is specifically used to transmit the first optical signal emitted by the first optical line terminal to the at least one second optical line terminal through the first optical splitter, and the second optical distribution network is specifically used to transmit the processed first optical signal emitted by the second optical line terminal to the at least one user terminal device through the second optical splitter. During uplink data transmission, the second optical distribution network is specifically used to transmit the second optical signal emitted by the user terminal device to the second optical line terminal connected to the user terminal device through the first optical splitter. The first optical distribution network is used to transmit the processed second optical signal emitted by the second optical line terminal to the first optical line terminal through the second optical splitter.

4. The communication network as described in claim 3, characterized in that, The distance between the first optical splitter and the second optical line terminal is less than the distance between the first optical splitter and the first optical line terminal.

5. The communication network as described in any one of claims 3 or 4, characterized in that, The distance between the second optical splitter and the user terminal equipment is less than the distance between the second optical splitter and the second optical line terminal.

6. The communication network according to any one of claims 1-5, characterized in that, The PON interface includes at least one of the following: GPON interface, EPON interface, 10G GPON interface, symmetrical 10G EPON interface, asymmetrical 10G GPON interface, and TWDM PON interface.

7. An optical line terminal, characterized in that, include: The processor, memory, and communication device, wherein the communication device is equipped with a first PON interface and a second PON interface, wherein... During downlink data transmission, the communication device is used to receive a first optical signal sent by a first optical line terminal through the first PON interface, the processor is used to process the first optical signal, and the communication device is also used to send the processed first optical signal to the user terminal equipment through the second PON interface. During uplink data transmission, the communication device is used to receive a second optical signal sent by the user terminal equipment through the second PON interface, the processor is used to process the second optical signal, and the communication device is also used to send the processed second optical signal to the first optical line terminal through the first PON interface.

8. The method as described in claim 7, characterized in that, The optical line terminal further includes: an optical module, a first PON MAC chip, and a second PON MAC chip; wherein the first PON MAC chip uses the protocol corresponding to the first PON interface, and the second PON MAC chip uses the protocol corresponding to the second PON interface. During downlink data transmission, the processor processes the first optical signal, specifically including: The processor is used to instruct the optical module to convert the first optical signal into a first electrical signal; instruct the first PON MAC chip to perform protocol deframing on the first electrical signal; instruct the second PON MAC chip to perform protocol reframing on the first electrical signal after protocol deframing; and instruct the optical module to perform electro-optical conversion on the first electrical signal after protocol reframing to obtain the processed first optical signal. During uplink data transmission, the processor processes the second optical signal, specifically including: The processor is used to instruct the optical module to convert the second optical signal into a second electrical signal; instruct the second PON MAC chip to perform protocol deframing on the second electrical signal; instruct the first PON MAC chip to perform protocol reframing on the second electrical signal after protocol deframing; and instruct the optical module to perform electro-optical conversion on the second electrical signal after protocol reframing to obtain the processed second optical signal.

9. The optical line terminal as described in any one of claims 7-8, characterized in that, The communication device is also equipped with an Ethernet interface. During downlink data transmission, the communication device is also used to receive a first electrical signal sent by a network-side device through the Ethernet interface, the processor is also used to convert the first electrical signal into a third optical signal, and the communication device is also used to send the third optical signal to the user terminal device through the second PON interface. During uplink data transmission, the communication device is further configured to receive a fourth optical signal sent by the user terminal device through the second PON interface, the processor is further configured to convert the fourth optical signal into a second electrical signal, and the communication device is further configured to send the second electrical signal to the network-side device through the Ethernet interface.

10. The optical line terminal as described in any one of claims 7-9, characterized in that, The first PON interface includes at least one of the following: GPON interface, EPON interface, symmetrical 10G GPON interface, asymmetrical 10G GPON interface, 10G EPON interface, and TWDM PON interface; The second PON interface includes at least one of the following: GPON interface, EPON interface, symmetrical 10G GPON interface, asymmetrical 10G GPON interface, 10G EPON interface, and TWDM PON interface.

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