KR20100015508A - Protecting system and method for passive optical network - Google Patents

Abstract

A protecting system and method are provided, wherein said system includes: optical detecting unit (202), used to detect the optical power of the optical transmitter of the end device in the passive optical network; protection control unit (204), used to decide whether the end device has a fault according to the detecting result of the optical detecting unit (202) within a predetermined period before or after the transmission of the upstream data of the end device, and indicates the optical control unit (206) to shut down the optical transmitter of the end device if the end device has a fault; and optical control unit (206), used to shut downthe optical transmitter of the end device so as to isolate the end device from the passive optical network. By the present invention, the restoring time of the passive optical network can be greatly reduced when optical fault appears, and the robustness and reliability of the passive optical network are increased.

Description

Passive Optical Network Protection System and Method {Protecting System And Method For Passive Optical Network}

TECHNICAL FIELD The present invention relates to the field of communications, and more particularly, to a passive optical network protection system and method thereof.

Passive Optical Network (PON) is a new broadband optical access network technology. In physical topologies, PON is a point-to-multipoint structure but is logically point-to-point. It is a point-to-point structure, where the downlink data transmission is broadcast, whereby all PON terminal devices, or Optical Network Units (ONUs), can receive all downlink data frames on their physical PON ports. On the other hand, the uplink is a time division multiple access (TDMA) method, and each ONU is assigned an uplink allocated only from a PON CO (Central Office) device, that is, an optical line terminal (OLT). Uplink data can be transmitted only within an authorization time slot.

The adoption of upstream TDMA access technology has created a serious safety problem for PON networks. If one ONU constantly transmits an uplink optical signal due to a failure, the normal data sent by all other ONUs cannot be recovered from the OLT and thus cannot successfully register with the OLT, indicating a collapse in the PON network. Although this type of failure is unlikely to occur in practical applications, if a continuous flashing occurs, the aftermath is very severe and difficult to determine where the failure occurred. Currently, only by sequentially turning off the ONU or unplugging the ONU fiber, the only way to determine the location of the failed ONU is to replace the ONU. In practice, however, under normal circumstances, the physical location of each ONU connected to the OLT is relatively distributed, and the distance from the OLT is relatively far. If there are many ONUs (e.g. 32 or 64), the work is cumbersome and wastes time and labor.

If the ONU can automatically detect that it is in a state of a failure that continuously emits light and take measures to stop the light emission, it can significantly shorten the time to interfere with other ONUs after the failure occurs. Recovery time can also be shortened. However, there are currently no reports on methods and devices related to this.

In order to solve the above problems, the present invention prevents a terminal device that has a failure from interfering with other terminal devices in the PON network, thereby significantly reducing the PON recovery time when a failure occurs, thereby improving the soundness and reliability of the PON network. Provided is a continuous light emission failure protection system and method for a terminal device.

The passive optical network protection system according to the present invention includes a light emitting detection unit for detecting the emission optical power of an optical transmitter of a terminal device of a passive optical network, and a light emitting detection unit within a predetermined time after the terminal starts or binds uplink data. Based on the detection result of the control unit, it is judged whether or not the terminal device has failed, and in the event of a failure, the protection control unit instructs the light emitting control unit to stop the optical transmitter of the terminal device, and stops the optical transmitter of the terminal device. And a light emission control unit for separating the passive optical network.

Among them, the protection control unit includes a timer unit which starts a transmission start timer when the terminal starts transmitting the uplink data and starts a transmission binding timer when the terminal completes the transmission of the upstream data, and a transmission start timer or transmission binding timer sets the time. The apparatus further includes a failure determining unit that determines whether a failure of the terminal device occurs on the basis of the detection result of the light emitting detection unit under the exceeding situation, wherein the light emitting detection unit fails under the situation that the light emitting detection unit detects that the emitted light power is smaller than the predetermined threshold value. The judging unit judges that a failure has occurred in the terminal device, and the failure judging unit determines that a failure occurs in the terminal device under a situation where the light emitting detection unit detects that the emitted light power exceeds a threshold.

Among them, the light emitting detection unit further includes a receiving unit for receiving an optical signal emitted from the terminal device, and a comparing unit for comparing the emission light power of the optical transmitter of the terminal device with a predetermined threshold value.

Among them, the timing interval of the transmission start timer exceeds the maximum data transmission time of the terminal device. The timing interval of the transmission binding timer exceeds the stop-off time of the optical transmitter of the terminal device. The protection control unit is connected to the light emission detecting unit and the light emission control unit via signal lines. The light emission control unit is a switch, one end of which is connected to a power pin of an optical transmitter of a terminal device and the other end of which is connected to a DC power source.

In the passive optical network protection method according to the present invention, the light emitting detection unit detects the emission optical power of the optical transmitter of the terminal device, and the protection control unit is within a predetermined time after the terminal starts or binds the transmission of the upstream data. A step S404 of determining whether or not a failure of the terminal device occurs on the basis of the detection result of the light emitting detection unit; and when the protection control unit determines that a failure has occurred in the terminal device, the light emission control unit stops the optical transmitter of the terminal device to A step S406 of separating the passive optical network is included.

Among them, in step S402, the light emission detecting unit compares the emission light power of the optical transmitter of the terminal device with a predetermined threshold value.

Among them, in step S404, the protection control unit starts the transmission start timer at the time when the terminal starts transmitting the uplink data, and starts the transmission binding timer at the time when the terminal binds the uplink data transmission, and the transmission start timer or The protection control unit further comprises a step S4044 of determining whether or not a failure of the terminal device occurs based on the detection result of the light emitting detection unit when the transmission binding timer time is exceeded, wherein the light emitting detection unit has a threshold value at which the emission light power is scheduled. If it detects that the protection control unit detects that the terminal device has not failed, and when the emission detection unit detects that the emission light power exceeds the predetermined threshold, the protection control unit determines that the terminal device has failed. .

Among them, the timing interval of the transmission start timer exceeds the maximum data transmission possible time of the terminal device. The timing interval of the transmission binding timer exceeds the stop response time of the optical transmitter of the terminal device.

According to the present invention, it is possible to automatically detect a continuous light emission failure in a passive optical network terminal device and automatically stop the optical transmitter when a failure occurs to avoid interference with other terminal devices and to recover the failure state of the passive optical network. This greatly shortens the speed and improves the health and reliability of passive optical networks.

BRIEF DESCRIPTION OF THE DRAWINGS The drawings described herein are for further understanding of the present invention and are a part of the present invention, and the examples and descriptions thereof described are for interpreting the present invention and not for limiting the present invention.

1 is a topology diagram of a PON system according to the present invention,

2 is a block diagram of a passive optical network protection system according to the invention,

3 is a view showing a connection relationship between each module of the passive optical network protection system of the present invention and each module of the terminal device,

4 is a schematic flowchart of a passive optical network protection method and a step S404 of the present invention;

5 is a detailed flowchart when the passive optical network protection method of the present invention uses a passive optical network terminal device.

6 is a time sequence diagram in operation of the passive optical network protection system and method according to the present invention.

Specific embodiments of the present invention will be described in conjunction with the drawings below.

TECHNICAL FIELD The present invention relates to a passive optical network system, and more particularly, to a method and apparatus for automatically protecting a continuous light emission failure of a passive optical network terminal device (i.e., an optical network unit).

Fig. 1 shows a polo map of the PON network according to the present invention. As shown in the figure, multiple ONUs were connected to one OLT through a spectrometer. The downlink data transmission scheme from the OLT to the ONU is a time division multiple access and physical layer broadcast scheme, that is, each downlink frame is transmitted to the PON ports of all ONUs. The uplink data transmission from ONU to OLT is TDMA.

2 is a block diagram of a passive optical network protection system of the present invention. As shown in Fig. 2, the passive optical network protection system of the present invention includes a light emitting detection unit 202 for detecting the emission optical power of the optical transmitter of the passive optical network terminal device, and the terminal device starting or binding uplink data. A protection control unit for judging whether or not a failure of the terminal device occurs on the basis of the detection result of the light emitting detection unit within a predetermined time period and instructing the light emission control unit to stop the optical transmitter of the terminal device in a situation where the terminal device has failed; 204 and a light emission control unit 206 for stopping the optical transmitter of the terminal device to separate the terminal and the passive optical network.

Among them, the protection control unit 204 starts a transmission start timer when the terminal starts transmitting the uplink data, and a timer unit 2042 for starting the transmission binding timer when the terminal completes the transmission of the upstream data, and a transmission start timer or the like. And a failure determination unit 2044 that determines whether a failure of the terminal device occurs on the basis of the detection result of the light emission detection unit under the condition that the transmission binding timer has timed out, wherein the light emission detection unit is the threshold at which the emission light power is scheduled. The fault determination unit determines that a failure has occurred in the terminal device under the detected situation that the value is smaller than the value, and the failure determination unit determines that a failure occurs in the terminal device under the situation that the emission light power exceeds the threshold value.

Among them, the light emission detecting unit 202 includes a receiving unit 2022 for receiving light emitted from the optical transmitter of the terminal device, and a comparison unit 2024 for comparing the emission light power of the optical transmitter of the terminal device with a threshold value. do.

Among them, the timing interval of the transmission start timer exceeds the maximum data transmission time of the terminal device. The timing interval of the transmission binding timer exceeds the stop-off time of the optical transmitter of the terminal device. The protection control unit is connected to the light emission detecting unit and the light emission control unit via signal lines. The light emission control unit is a switch, one end of which is connected to the power pin of the optical transmitter of the terminal device, and the other end of which is connected to a DC power source.

3 shows a connection relationship between each module of the passive optical network protection system of the present invention and each module of the passive optical network terminal device.

As shown in Fig. 3, the passive optical network protection system of the present invention includes a protection control unit, a light emission detection unit and a light emission control unit. When the passive optical network protection system of the present invention is used for the ONU of the passive optical network, the connection relationship between the optical transmitter, the PON MAC chip, and the CPU of the ONU is as shown in FIG. Among them, the protection control unit was connected to the PON MAC chip, the light emission detection unit, the light emission control unit and the CPU, respectively. Connection with all three can be realized through one signal line, respectively, and the signal transmission direction is from the PON MAC to the protection control unit, from the light emission detection unit to the protection control unit, and from the protection control unit to the light emission control unit. Connection to the CPU can be realized through an address bus, a data bus and a control bus.

Among them, the protection control unit repairs two timers, one of which is a transmission start timer and the other of which is a transmission binding timer. The transmission start timer is started by the light emission start instruction signal output from the light emission detection unit, and is reset and stopped by the light emission binding instruction signal. The transmission binding timer is triggered by the light emission binding instruction signal output from the PON MAC. The light emission start timer starts and at the same time the work of the light emission start timer is stopped. Even if the timer expires, the protection control unit then checks the light emitting instruction of the optical transmitter transmitted from the light emitting detection unit and indicates that it is currently emitting light (for example, it can be physically indicated to be at a high level). Command to stop the optical transmitter by sending a command (for example, it can be physically indicated to a high level) to the light emission control unit. In addition, a parameter (for example, a timing interval of a timer) of the protection control unit can be assigned via the CPU.

The light emission detecting unit detects the emitted light power of the optical transmitter at a suitable time, compares it with the threshold value, and transmits the result to the protection control unit through one signal line. It can be connected to the optical transmitter via one spectrometer.

The light emission control unit stops the optical transmitter when a continuous light emission failure occurs. It receives a command sent from the protection control unit and determines whether the light emitting function is stopped. The connection with the optical transmitter can be realized in various ways. For example, it can be realized by connecting a 1 × 2 electrical switch in series to a transmission power line of an optical transmitter or by connecting a 1 × 2 optical switch in series to an optical path line.

In addition, in a concrete realization, as described above, the three units can be realized through independent physical parts, and the protection control unit can be physically merged into the CPU. If the optical transmitter supports optical power inspection at an appropriate time, it corresponds to the already included optical detector in the optical transmitter, and the comparator function in the optical detector unit can be realized through software in the CPU.

That is, the passive optical network protection system of the present invention is composed of a protection control unit, a light emission detection unit and a light emission control unit in three parts. Among them, the protection control unit is the core of the overall system to detect and deal with faults. Its interior must realize the timer function, logic judgment function and control signal transmission function. The light emission detecting unit is one light detector and one comparator. The transmission status of the optical signal of the optical transmitter is detected at an appropriate time, the detected optical power value is compared with a predetermined threshold value, and the comparison result is transmitted to the protection control unit. The light emission control unit is similar to a switch to control whether or not the light transmitter emits light and perform ON / OFF operation of the light transmitter under the control of the protection control unit.

Among them, the connection relationship of each unit is as follows: The protection control unit is connected to the other parts. First, it is connected to the PON MAC via one signal line to obtain a data transmission state. Next, it is also connected to the light emitting detection unit through one signal line to obtain the current light emitting condition. Finally, the object of controlling the light emission of the optical transmitter is realized by being connected to the light emission control unit via one signal line. The light emitting detection unit is connected to the protection control unit and to the optical transmitter. The connection method with the protection control unit is as described above. There may be various types of connection with the optical transmitter, for example, it may be connected with the transmission port of the optical transmitter through a spectrometer. The light emission control unit is similar to the light emission detection unit and is connected to the protection control unit while also being connected to the optical transmitter. The connection with the protection control unit is as described above. There may be various connection methods with the optical transmitter. For example, one switch may be connected to a power pin of the optical transmitter and the other may be connected to a DC power source.

4 is a schematic flowchart of a passive optical network protection method of the present invention. As shown in Fig. 4, the passive optical network protection method of the present invention includes a step S402 in which the light emitting detection unit detects the emission optical power of the optical transmitter of the terminal device of the passive optical network, and the protection control unit transmits uplink data. In step S404 of determining whether a terminal device has failed based on the detection result of the light emitting detection unit within a predetermined time after the start and / or binding, and when the protection control unit determines that the terminal device has failed, The control unit includes a step S406 of stopping the optical transmitter of the terminal device and separating the terminal device from the passive optical network.

Among them, in step S402, the light emission detecting unit compares the emission light power of the optical transmitter of the terminal device with a predetermined threshold value.

In step S404, the protection control unit starts the transmission start timer at the time when the terminal starts transmitting the uplink data, and starts the transmission binding timer at the time when the terminal binds the uplink data transmission. The protection control unit further includes the step S4044 of determining whether or not a failure of the terminal device occurs based on the detection result of the light emitting detection unit, when the transmission binding timer time is exceeded, wherein the light emitting detection unit has a threshold value at which emission light power is scheduled. If the control unit detects that the error is less than or equal to the terminal unit, the protection control unit judges that no failure occurs in the terminal device, and when the emission detection unit detects that the emission light power exceeds a predetermined threshold, the protection control unit determines that the terminal unit has failed. do.

Among them, the timing interval of the transmission start timer exceeds the maximum data transmission possible time of the terminal device. The timing interval of the transmission binding timer exceeds the stop response time of the optical transmitter of the terminal device.

Specifically, with reference to Figure 5 will be described the specific flow when the passive optical network protection method of the present invention is applied to a passive optical network. As shown in Fig. 5, after the passive optical network system of the present invention starts work, the PON MAC starts transmitting uplink data in an authorized time slot (S502). At this time, when the light detecting unit detects light emission and outputs a light emitting instruction signal to the protection control unit, the protection control unit starts the transmission start timer (S504). After the PON MAC has transmitted all the data (S506), it transmits a binding instruction to the protection control unit (S508), thereby triggering the protection control unit to start the transmission binding timer and simultaneously stops the previous transmission start timer. (S510). The protection control unit detects whether the timer has timed out (S512), and if the timer has timed out (any timer), examines the light emission instruction sent from the light emission detection unit (S514). Detects whether the optical transmitter still transmits the optical signal (S516). If the indication signal at this time indicates that the optical transmitter is still transmitting the optical signal, it transmits a stop command to the light emitting control unit to The transmission function is stopped (S518). This isolates the failed ONU from the PON network.

That is, the protection method of the passive optical network of the present invention is realized through the following steps: The light emitting detection unit continuously detects the emitted optical power of the optical transmitter and compares it with a predetermined threshold (for example, transmits a "0" bit). Optical power in the case), and a comparison result is sent to the protection control unit; The ONU's PON MAC chip starts transmitting uplink data and outputs an indication signal to the protection control unit after the transmission is finished; The protection control unit starts the timer (called the transmission start timer and the transmission binding timer) and receives the transmission binding instruction after receiving the emission start instruction sent from the light emitting detection unit and the transmission binding instruction sent from the PON MAC chip. After that, or after detecting the light emission stop, stop the transmission start timer. The timing interval of the transmit start timer can be arranged, the value of which exceeds the ONU's maximum data transmission time (e.g., the DBA's dispatch cycle). The timing interval of the transmission binding timer exceeds the stop response time of the optical transmitter and is less than twice the stop response time. After either timer has timed out, the protection control unit checks whether the light transmitter is still emitting light through the light emitting detection unit, and if it is still emitting light, recognizes that a continuous light emitting failure has occurred in the ONU and operates the light emitting control unit; The protection control unit stops light emission of the optical transmitter through the operation of the light emission control unit and realizes separation from the PON network.

6 shows a time sequence diagram of the method and system operation of the present invention. Among them, Optical Power indicates the emission optical power of the optical transmitter, Grant indicates that the OLT authorizes the ONU, and is used for transmission of upstream data, and ONU_TX_EN indicates that transmission of ONU Indicate that it is enabled, the Optical Power Indication indicates whether the optical transmitter is currently emitting, and the Transceiver Control controls whether the optical transmitter emits light. The ONU shows a situation where a fault has occurred, for convenience, all valid signals are marked high level.

Through the present invention, the terminal device side of the passive optical network automatically detects a continuous light emission failure, and when a failure occurs, the optical transmitter is automatically stopped to avoid interference with other terminal devices, and such failure occurs in the passive optical network. In this case, the recovery time can be greatly reduced, and the soundness and reliability of the passive optical network can be improved.

The foregoing is not intended to limit the invention to the optimized embodiments of the invention. Those skilled in the art can bring about various modifications and changes to the present invention. All the number, equivalent exchange, improvement, etc. which were performed within the range without deviating from the mind and principle of this invention belong to the protection scope of this invention.

Claims (12)

A light emitting detection unit for detecting the emission optical power of the optical transmitter of the terminal device of the passive optical network, and the terminal based on the detection result of the light emitting detection unit within a predetermined time after the terminal starts or binds the uplink data transmission. And a protection control unit for instructing the light emitting control unit to stop the optical transmitter of the terminal device in case of a failure of the terminal device and stopping the optical transmitter of the terminal device. Passive optical network protection system comprising the light emitting control unit for separating the passive optical network. The method of claim 1, The protection control unit includes a timer unit which starts a transmission start timer when the terminal starts to transmit the uplink data, and starts a transmission binding timer when the terminal completes the transmission of the uplink data, and the transmission start timer or the transmission binding unit. Further comprising a failure determination unit for determining whether a failure of the terminal device on the basis of the detection result of the light emitting detection unit under the condition that the timer has timed out, Among them, the failure determining unit determines that a failure has occurred in the terminal device under the situation that the emission detecting unit detects that the emitted light power is smaller than a predetermined threshold value. Passive optical network protection system, characterized in that the failure determination unit determines that a failure in the terminal under the situation that the light emitting detection unit detects that the emission optical power exceeds the predetermined threshold value. The method according to claim 1 or 2, The light emitting detection unit further includes a receiving unit for receiving an optical signal emitted from the optical transmitter of the terminal device, and a comparison unit for comparing the emission optical power of the optical transmitter of the terminal device with the predetermined threshold value. Passive optical network protection system. The method of claim 3, And a timing interval of the transmission start timer exceeds a maximum data transmission time of the terminal device. The method of claim 3, Passive optical network protection system, characterized in that the timing interval of the transmission binding timer exceeds the stop response time of the optical transmitter of the terminal device. The method of claim 3, And said protective control unit is connected to said light emitting detection unit and said light emitting control unit via signal lines. The method of claim 3, And said light emission control unit is a switch, one end of which is connected to a power pin of an optical transmitter of the terminal device and the other end of which is connected to a direct current power source. In step S402, the light emitting detection unit detects the emission optical power of the optical transmitter of the terminal device of the passive optical network, and the protection control unit of the light emitting detection unit within a predetermined time after the terminal device starts or binds the uplink data. Step S404 of determining whether or not a failure of the terminal device based on the detection result, and when the protection control unit determines that a failure has occurred in the terminal device, the light emission control unit stops the optical transmitter of the terminal device to the terminal Passive optical network protection method comprising the step of separating the passive optical network and the passive optical network. The method of claim 8, In the step S402, the light emitting detection unit passive optical network protection method, characterized in that for comparing the emission light power of the optical transmitter of the terminal device with a predetermined threshold value. The method according to claim 8 or 9, In step S404, the protection control unit starts a transmission start timer at a time when the terminal starts transmitting uplink data, and starts the transmission binding timer at a time when the terminal binds uplink data transmission. The protection control unit further comprises the step S4044 of determining whether a failure of the terminal device occurs based on a detection result of the light emitting detection unit when the start timer or the time of the transmission binding timer is exceeded. Among them, when the light emission detecting unit detects that the emitted light power is less than or equal to a predetermined threshold value, the protection control unit determines that a failure has not occurred in the terminal device. And when the emission detecting unit detects that the emitted optical power exceeds the predetermined threshold, the protection control unit determines that a failure occurs in the terminal. The method of claim 10, And a timing interval of the transmission start timer exceeds a maximum data transmission possible time of the terminal device. The method of claim 10, And a timing interval of the transmission binding timer exceeds a stop response time of the optical transmitter of the terminal device.

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