WO2010022647A1

WO2010022647A1 - Optical network system, optical network device and its switching method

Info

Publication number: WO2010022647A1
Application number: PCT/CN2009/073488
Authority: WO
Inventors: 隋猛
Original assignee: 华为技术有限公司
Priority date: 2008-09-01
Filing date: 2009-08-25
Publication date: 2010-03-04
Also published as: CN101667862A

Abstract

A switching method of an optical network device, includes: the first optical network device receives the optical signal carrying the backup information which is sent by the second optical network device via the second optical fibre (S501), the first optical network device detects the received optical signal, and if the switching condition is satisfied, switches from the standby state to the master-used state by using the above backup information. An optical network system and optical network device are also provided. It not only realizes the speed trouble-detection and the data synchronization between the master and backup OLTs, when the master-used OLT is in trouble or requests switching, it can realize the switching between the master and the backup OLTs fast, but also do not need adding the active devices in the current ODN, and the change of OLT is also relatively simple, the cost of realization, operation, maintenance is also relatively lower.

Description

The present invention claims to be submitted to the Chinese Patent Office on September 1, 2008, and the application number is 200810141748.8, and the invention name is "an optical network system, an optical network device, and a switching method thereof". The priority of the Chinese Patent Application, the entire contents of which is incorporated herein by reference. Technical field

The present invention relates to the field of communications, and in particular to an optical network system, an optical network device, and a switching method thereof. Background technique

Passive Optical Network (hereinafter referred to as PON) is an optical line terminal (hereinafter referred to as OLT), an optical distribution network (hereinafter referred to as ODN), and an optical network unit (Optical Network Unit). ; The following abbreviation: ONU) composition. 1 is a schematic structural diagram of a passive optical network in the prior art. As shown in FIG. 1 , an OLT is used as a central office device, and is connected to an optical splitter through a trunk optical fiber. The optical splitter is connected through a separate branch optical fiber. An ONU. The conventional optical splitter only realizes the splitting and convergence of the optical signal, and has no amplification function of the optical signal, so it is called a passive optical network.

In order to ensure that the passive optical network can continue to provide services in the event of equipment failure or fiber failure, backup protection between OLTs is required in the backbone fiber segment. 2 is a schematic structural diagram of active and standby OLT protection of a passive optical network in the prior art. As shown in FIG. 2, two OLT devices that are mutually backup are connected to an optical splitter through independent trunk fibers. Under normal circumstances, only the primary OLT communicates with the ONU through the primary trunk fiber. When the system detects that the primary OLT device is faulty or the primary trunk fiber is faulty, the switchover to the standby OLT device and the standby trunk fiber communicates with the ONU. To ensure rapid service recovery, you should implement fast detection of OLT faults and minimize the time for reconfiguring the ONUs after the active and standby OLTs are switched. The configuration of the ONU is required to be synchronized between the active and standby OLTs. After the active/standby switchover, the new active OLT can transmit services immediately without reconfiguring the ONU. The prior art integrates an optical amplifier and two virtual ONUs in an optical splitter. FIG. 3 is a schematic structural diagram of an active optical multiplexer and a virtual ONU in the prior art optical splitter to implement active and standby OLT protection, as shown in FIG. An ONU communicates with the primary OLT, and an ONU communicates with the standby OLT. There is also a communication channel between the two ONUs. Because there is a communication channel between the two virtual ONUs, data communication can be realized between the active and standby OLTs. If the virtual ONU that communicates with the primary OLT sends a signal loss LOS alarm and considers that the primary trunk fiber is faulty or the primary OLT is faulty, the LOS alarm can communicate with the standby virtual ONU and the standby OLT through communication between the two virtual ONUs. Sended to the standby OLT, the standby OLT decides whether to switch to the primary OLT according to the LOS alarm.

In the process of implementing the present invention, the inventors have found that at least the following problems exist in the prior art: The prior art adds an optical amplifier and two virtual ONUs in the optical splitter, that is, an optical amplifier and a virtual ONU are added to the existing ODN. These active equipments have higher construction costs and are more complicated to maintain in the later stages. Summary of the invention

The technical problem to be solved by the embodiments of the present invention is: providing an optical network system, an optical network device, and a switching method thereof, and overcoming the existing OLT switching technology, in order to implement fast fault detection and data synchronization between active and standby OLT, an ODN is added. Active devices, resulting in high cost and complex maintenance defects.

To solve the above technical problem, an embodiment of the present invention provides an optical network device, including: an optical line termination module and an optical network unit module, where the optical network unit module is coupled to the optical line termination module, and the optical line termination module passes the first optical fiber and the optical The network side port of the splitter is connected, and the optical network unit module is connected to the user side port of the optical splitter through the second optical fiber, where: the optical network unit module is configured to communicate with the optical line terminal module of the opposite end, and pass the second optical fiber. Receiving an optical signal carried by the opposite optical network device carrying the backup information, or sending a message requesting the optical line terminal module of the opposite end to send corresponding information; detecting the received optical signal, and detecting the backup information in the optical signal Sending to the optical line terminal module; if it detects that the switching condition is met, notifying the optical line terminal module to switch to The active state, wherein the foregoing switching conditions include: an abnormality of the optical signal, an abnormality of the data in the optical signal, and one or more combinations of the optical signal including the switching command.

Correspondingly, an embodiment of the present invention further provides an optical network system, including: a user-side optical network device, an optical splitter, and at least two network-side optical network devices, where the user-side optical network device passes the optical fiber and the optical splitter. User-side port connection; each network-side optical network device is connected to the optical splitter through at least two optical fibers, wherein the first optical fiber is connected to the network side port of the optical splitter, and the second optical fiber is connected to the optical splitter The user-side port of the device, wherein: the first network-side optical network device of the at least two network-side optical network devices is configured to receive, by using the second optical fiber, the optical signal that is sent by the second network-side optical network device and that carries the backup information. The received optical signal is detected, and if the switching condition is met, the backup information is switched from the standby state to the active state, where the switching conditions include: an abnormality of the optical signal, an abnormality of the data in the optical signal, and a switching command including the optical signal in the optical signal. One or more combinations.

Correspondingly, the embodiment of the present invention further provides a method for switching an optical network device, where the optical network device is connected to a network side port of the optical splitter through a first optical fiber, and passes through a second optical fiber and a user side of the optical splitter. The method includes: the first optical network device receives, by using the second optical fiber, the optical signal that is sent by the second optical network device and carries the backup information; the first optical network device detects the received optical signal, if the switching condition is met. And switching the information from the standby state to the active state by using the backup information, where the foregoing switching conditions include: an abnormality of the optical signal, a data abnormality in the optical signal, and one or more combinations of the optical signal including the switching command.

As can be seen from the technical solutions provided by the foregoing embodiments of the present invention, the present invention provides an optical network system, an optical network device, and a switching method thereof, which not only implement fast fault detection and data synchronization between active and standby OLTs, but also fail in the primary OLT. When the OLT requires switching, the switching between the active and standby OLTs can be quickly realized, and the active device is not required to be added in the current ODN. The OLT modification is relatively simple, and the implementation, construction, and maintenance costs are relatively low. DRAWINGS 1 is a schematic structural diagram of a passive optical network in the prior art;

2 is a schematic structural diagram of active and standby OLT protection of a passive optical network in the prior art;

FIG. 3 is a schematic structural diagram of an active optical multiplexer and a virtual ONU in an optical splitter for implementing active/standby OLT protection in the prior art; FIG.

FIG. 4 is a schematic structural diagram of an optical network system according to an embodiment of the present disclosure;

FIG. 5 is a flowchart of a method for switching an optical network device according to an embodiment of the present invention. detailed description

The present invention will be further described in detail below with reference to the drawings and embodiments.

Embodiments of the present invention provide a method for switching optical network devices, optical network systems, and optical network devices. The optical network device includes: an optical line terminal module and an optical network unit module, where the optical network unit module is coupled to the optical line terminal module, and the optical line terminal module is connected to the network side port of the optical splitter through the first optical fiber, and the optical network unit The module is connected to the user side port of the optical splitter through the second optical fiber, where: the optical network unit module is configured to communicate with the optical line termination module of the opposite end, and receive the backup information sent by the opposite optical network device by using the second optical fiber. Optical signal, or send a message requesting the optical line termination module of the opposite end to send corresponding information; detecting the received optical signal, and transmitting the backup information in the detected optical signal to the optical line termination module; if it is detected that the handover is satisfied The condition that the optical line termination module is notified to switch to the active state, where the foregoing switching conditions include: an abnormality of the optical signal, an abnormality of the data in the optical signal, and one or more combinations of the optical signal including the switching command.

In the following embodiments of the present invention, the first optical fibers connected to the network side ports of the optical network device and the optical splitter are collectively referred to as backbone optical fibers, and the second optical fibers connected to the optical network devices and the user side ports of the optical splitters are collectively referred to. For branch fiber.

FIG. 4 is a schematic structural diagram of an optical network system according to an embodiment of the present invention, including: a user-side optical network device (ONU), an optical splitter, and at least two network-side optical network devices. (OLT), the user-side optical network device is connected to the user-side port of the optical splitter through the optical fiber; each network-side optical network device is connected to the optical splitter through at least two optical fibers, wherein the first optical fiber (the trunk optical fiber) a network side port connected to the optical splitter, connected to the user side port of the optical splitter by a second optical fiber (branch optical fiber), wherein: the first network side optical network device of the at least two network side optical network devices And receiving, by the second optical fiber, the optical signal carried by the second network side optical network device and carrying the backup information, detecting the received optical signal, and if the switching condition is met, using the backup information to switch from the standby state to the active state. The foregoing switching conditions include: an abnormality of the optical signal, an abnormality of the data in the optical signal, and one or more combinations including the switching command in the optical signal.

The foregoing detecting the received optical signal includes, but is not limited to, the following: detecting physical parameters of the optical signal itself (such as optical power, etc.), determining whether the optical signal itself is abnormal; performing photoelectric conversion on the received optical signal The data is detected to determine whether the data is abnormal (through the forward error correction (FEC) error rate or whether the error can be resolved), whether the backup information is included, and whether the switching command is included.

Specifically, the first network side optical network device includes: an optical network unit module and an optical line terminal module, where the optical network unit module is coupled to the optical line termination module, and the optical network unit module passes the branch side optical fiber and the user side port of the optical splitter The optical line terminal module is connected to the network side port of the optical splitter through the trunk optical fiber, where: the optical network unit module is configured to receive, by using the branch optical fiber, an optical signal that is sent by the second network side optical network device and carries the backup information. Detecting the received optical signal, and transmitting the backup information in the detected optical signal to the optical line terminal module; if it detects that the switching condition is met, notifying the optical line terminal module to switch to the active state, where the foregoing switching condition includes : The optical signal is abnormal, the data abnormality in the optical signal, and one or more combinations of the optical signal including the switching command.

The optical network unit module may be an existing optical network unit ONU optical module. The above backup information includes one or more combinations of ranging information, service configuration information, and operational status information. After the active/standby switchover, the new active OLT can transmit services without reconfiguring the ONU. The second network-side optical network device works in the active state, and the internal ONU module does not need to work, and the first network-side optical network device works in the standby state, and the internal ONU module needs to work. During normal operation, the primary OLT sends the information to be backed up through the downstream optical signal to the ONU module of the standby OLT via the trunk optical fiber of the primary OLT, the optical splitter, and the branch OLT of the standby OLT. The ONU module of the standby OLT passes through. The internal communication interface forwards the information directly to the OLT module of the standby OLT, so that when the switchover is performed, the backup OLT can use this information to quickly complete the switchover and prevent service interruption. The ONU module in the standby OLT also monitors the downlink optical signal sent by the active OLT through its trunk fiber through the branch fiber of the standby OLT. If an optical signal is abnormal or 3 in the optical signal is found:

If the primary OLT sends a switching command in the downstream optical signal (that is, the primary OLT actively requests the standby OLT to be used as the primary), the secondary OLT is notified to switch to the active state, and the active/standby switchover is performed. Alarm, then the ONU module stops working.

When the primary OLT sends information to the ONU module in the standby OLT by connecting the optical splitter to the branch optical fiber of the ONU module in the standby OLT, it only needs to be treated as if it were a normal ONU.

The optical network unit module is further configured to register with the second network side optical network device, and if the registration is successful, notify the optical line terminal module to enter a standby state; if the registration fails, notify the optical line terminal module to enter the active state.

When the OLT is powered on, the ONU module is first registered with the active OLT. If the registration is successful, it indicates that there is an active OLT. The ONU module notifies the OLT that it is in the standby startup state, does not emit light to the ODN, and the ONU module starts monitoring the active OLT. If the registration is unsuccessful, the ONU module is located. The OLT is the OLT that is started first, and the ONU module notifies the location

The OLT enters the normal startup state (ie, the active state), illuminates the ODN, measures the range, and starts all ONUs. At the same time, the ONU module completes the task and stops working.

In the embodiment of the present invention, the standby OLT receives the optical signal carrying the backup information sent by the primary OLT through the branch fiber, and detects the received optical signal. If the switching condition is met, the backup information is used to switch from the standby state to the active state. . Not only fast fault detection but also the number of active and standby OLTs According to the synchronization, the fast switching between the active and standby OLTs is ensured, and the active devices are not required to be added in the current ODN. The OLT changes are relatively simple, and the implementation, construction, and maintenance costs are relatively low.

As shown in FIG. 5, a flowchart of a method for switching an optical network device according to an embodiment of the present invention, where the optical network device is connected to a network side port of an optical splitter through a first optical fiber (backbone optical fiber), and The second optical fiber (branch fiber) is connected to the user side port of the optical splitter. The method includes the following steps: Step S501: The first optical network device receives, by using the second optical fiber, the optical signal that is sent by the second optical network device and carries the backup information.

Specifically, the foregoing backup information includes one or more combinations of ranging information, service configuration information, and running status information. The second optical network device (ie, the primary OLT) transmits the optical signal carrying the backup information to the first optical network device (ie, the standby OLT) via the primary trunk optical fiber, the optical splitter, and the backup branch optical fiber.

Step S502: The first optical network device detects the received optical signal, and if the switching condition is met, the backup information is used to switch from the standby state to the active state, where the switching condition includes: the optical signal is abnormal, and the optical signal is The data anomaly in the above and one or more combinations of the above-mentioned optical signals including the switching command.

Specifically, the foregoing detecting the received optical signal includes, but is not limited to, the following: detecting physical parameters of the optical signal itself (such as optical power, etc.), determining whether the optical signal itself is abnormal; and performing photoelectric processing on the received optical signal. Conversion, detecting data, judging whether the data is abnormal (whether the bit error rate of the forward error correction coding FEC or the message can be parsed), whether the backup information is included, and whether the switching command is included.

Specifically, the optical signal is abnormal, and the data in the optical signal is abnormal, that is, the primary OLT is faulty (including the failure of the primary OLT device or the backbone optical fiber of the primary OLT); the optical signal includes a switching command, that is, the primary OLT actively requests the standby OLT. For the main use.

Before the step S501, the method further includes: the first optical network device registers with the second optical network device; if the registration is successful, the first optical network device enters a standby state; if the registration fails, notifying the optical line terminal module to enter the active state. That is, when the OLT is powered on, it is first registered with the active OLT. If the registration is successful, it indicates that there is an active OLT. The OLT enters the standby startup state and does not emit light to the ODN. At the same time, the OLT starts monitoring the active OLT. If the registration is unsuccessful, the OLT is the first enabled OLT, and the OLT enters. Normal startup state (ie, active state), illuminate the ODN, measure distance, and start all ONUs.

In the embodiment of the present invention, the standby OLT receives the optical signal carrying the backup information sent by the primary OLT through the branch fiber, and detects the received optical signal. If the switching condition is met, the backup information is used to switch from the standby state to the active state. . Not only the fast fault detection and the master-slave OLT data synchronization are realized, so that the fast switching between the active and standby OLTs is ensured, and the active components are not required to be added in the current ODN. The OLT modification is relatively simple, and the implementation, construction, and maintenance costs are relatively Lower.

The above is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of changes or within the technical scope disclosed by the present invention. Alternatives are intended to be covered by the scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

Rights request

An optical network device, comprising: an optical line termination module and an optical network unit module, wherein the optical network unit module is coupled to the optical line termination module, and the optical line termination module passes the first optical fiber The network side port of the optical splitter is connected, and the optical network unit module is connected to the user side port of the optical splitter through a second optical fiber, where:

The optical network unit module is configured to communicate with the optical line termination module of the opposite end, receive the optical signal that carries the backup information sent by the opposite optical network device by using the second optical fiber, or send the message requesting the optical line termination module of the opposite end Transmitting the corresponding information; detecting the received optical signal, and transmitting the backup information in the detected optical signal to the optical line terminal module; if it detects that the switching condition is met, notifying the optical line terminal module to switch to the main In a state, wherein the switching condition comprises: an optical signal anomaly, a data anomaly in the optical signal, and one or more combinations of the optical signal including a switching command.

The optical network device according to claim 1, wherein the optical network unit module is further configured to register with the peer optical network device, and if the registration is successful, notify the optical line terminal module to enter the standby. Status; if the registration fails, the optical line terminal module is notified to enter the active state.

3. The optical network device according to claim 1, wherein the backup information comprises one or more combinations of ranging information, service configuration information, and operational status information.

An optical network system, comprising: a user side optical network device, an optical splitter, and at least two network side optical network devices, wherein the user side optical network device passes the optical fiber and the optical splitter User-side port connection; each network-side optical network device is connected to the optical splitter through at least two optical fibers, wherein the first optical fiber is connected to the network side port of the optical splitter, and the second optical fiber is passed through Connected to the user side port of the optical splitter, where:

The first network-side optical network device of the at least two network-side optical network devices is configured to receive, by using the second optical fiber, an optical signal that is sent by the second network-side optical network device and that carries backup information, and receives the received optical signal. The optical signal is detected, and if the switching condition is met, the backup information is used from the backup The state is switched to the active state, wherein the switching conditions include: an abnormality of the optical signal, an abnormality of the data in the optical signal, and one or more combinations of the optical signal including the switching command.

The optical network system according to claim 4, wherein the first network-side optical network device comprises: an optical network unit module and an optical line termination module, the optical network unit module and the optical line termination module Coupling, the optical network unit module is connected to the user side port of the optical splitter by the second optical fiber, and the optical line terminal module passes the first optical fiber and the network side of the optical splitter Port connection, where:

The optical network unit module is configured to receive, by using the second optical fiber, an optical signal that is sent by the second network side optical network device and that carries backup information, and detects the received optical signal, and detects the detected optical signal. The backup information is sent to the optical line terminal module; if it is detected that the switching condition is met, the optical line terminal module is notified to switch to the active state, where the switching condition includes: optical signal abnormality, data in the optical signal One or more combinations of switching commands are included in the anomaly and optical signals.

The optical network system according to claim 5, wherein the optical network unit module is further configured to register with the second network side optical network device, and if the registration is successful, notify the optical line terminal module Entering the standby state; if the registration fails, the optical line terminal module is notified to enter the active state.

The optical network system according to any one of claims 4 to 6, wherein the backup information comprises one or more combinations of ranging information, service configuration information, and operational status information.

A method for switching an optical network device, wherein the optical network device is connected to a network side port of an optical splitter through a first optical fiber, and passes through a second optical fiber and a user side of the optical splitter Port connection, the method includes:

The first optical network device receives, by using the second optical fiber, an optical signal that is sent by the second optical network device and carries the backup information;

The first optical network device detects the received optical signal, and if the switching condition is met, the backup information is used to switch from the standby state to the active state, where the switching condition includes: One or more combinations of optical signal anomalies, data anomalies in the optical signal, and optical signals include switching commands.

The method for switching the optical network device according to claim 8, wherein before the first optical network device receives the optical signal carried by the second optical network device and carries the backup information by using the second optical fiber, , Also includes:

The first optical network device registers with the second optical network device;

If the registration is successful, the first optical network device enters a standby state; if the registration fails, the optical line terminal module is notified to enter the active state.

The method for switching optical network devices according to claim 8 or 9, wherein the backup information comprises one or more combinations of ranging information, service configuration information, and operational status information.