JP2011151584A - Optical transmitting device and method for controlling optical transmitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical transmitting device capable of reducing a burden placed on a high order controller. <P>SOLUTION: The optical transmitting device includes: a preamplifier 11 for amplifying an optical signal including light of a plurality of wavelengths; increasing and decreasing means 13 and 14 for increasing or decreasing the number of light wavelengths; a booster amplifier 17 for amplifying and outputting the optical signal; a first detecting means 12 and a second detecting means 16 for detecting the power of the optical signal; a first calculating means 18 for calculating power per wavelength by dividing the power detected by the first detecting means by the number of wavelengths and calculating estimated optical power by subtracting loss from the power per wavelength; a second calculating means 18 for calculating observed optical power of one wavelength by dividing the power detected by the second detecting means by the number of wavelengths obtained as a result of increasing or decreasing; and a determining means 18 for determining that abnormality occurs when the observed optical power deviates from the estimated optical power by a predetermined value or more. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an optical transmission apparatus and an optical transmission apparatus control method.

  A node in an optical communication system includes a plurality of optical subsystem modules (hereinafter simply referred to as “optical modules”) such as a preamplifier, a booster amplifier, an optical splitter, and an optical cross-connect. Is controlled (or monitored) by Each optical module has a function of issuing an alarm when an abnormality is detected from information that can be detected by each optical module.

  For example, each optical module monitors the power of the input light, compares it with the alarm threshold set for each optical module, and if the monitored power is less than the alarm threshold, an alarm indicating an input interruption is generated. It is configured to emit.

  By the way, each optical module is controlled independently by a command from a host control device (host system), and information other than its own module cannot be known. For this reason, for example, when an abnormality occurs in a certain optical module, all subsequent optical modules notify the host controller of the occurrence of the abnormality, so the processing in the host controller becomes very complicated.

  Therefore, a technique for changing the frequency of occurrence of an abnormality detected in each optical module by enabling the alarm threshold to be changed in each optical module is disclosed (Patent Document 1).

JP 2008-098873 A

  However, in the technique disclosed in Patent Document 1, all abnormalities occurring in each optical module are notified to the host control device, and by collecting information notified from each optical module, the abnormality occurs in which optical module. The host controller determines whether it has been done. For this reason, the host controller has a problem in that the processing for aggregating information from each optical module becomes a load.

  Accordingly, the problem to be solved by the present invention is to provide an optical transmission device and a control method for the optical transmission device that are less burdensome on the host control device.

In order to solve the above problems, an optical transmission apparatus according to the present invention includes a preamplifier that receives and amplifies an optical signal including light of a plurality of wavelengths, and an increase / decrease unit that increases or decreases the number of wavelengths of the light included in the optical signal. A booster amplifier that amplifies and outputs the optical signal output from the increase / decrease means, first detection means that detects the power of the optical signal output from the preamplifier, and the booster amplifier that inputs the booster amplifier. A second detector for detecting the power of the optical signal; and the power detected by the first detector is divided by the number of wavelengths included in the input optical signal to obtain a power per wavelength, and the preamplifier The first calculation for calculating the expected optical power of the booster amplifier by subtracting the loss between the output of the booster amplifier and the input of the booster amplifier from the power per wavelength. Means, second calculation means for calculating measured light power of one wavelength by dividing the power detected by the second detecting means by the number of wavelengths obtained as a result of increase / decrease by the increase / decrease means, and the measured light And determining means for determining that an abnormality has occurred when the power deviates from the predicted optical power by a predetermined value or more.
According to such a configuration, it is possible to reduce the burden on the host system.

In addition to the above invention, another invention is characterized in that the increase / decrease means is an optical cross-connect or a splitter.
According to such a configuration, even when the number of wavelengths is increased or decreased by the optical cross-connect or the splitter, it is possible to accurately determine the occurrence of abnormality.

According to another aspect of the invention, in addition to the above aspect, the optical cross connect adds an optical signal having a predetermined number of wavelengths supplied from another optical transmission device to the optical signal input from the preamplifier. Alternatively, an optical signal having a predetermined number of wavelengths is transferred to another optical transmission device from the optical signals input from the preamplifier.
According to such a configuration, it is possible to accurately determine the occurrence of an abnormality even when an optical signal is exchanged with another optical transmission device.

In addition to the above-described invention, in another aspect of the invention, information indicating the number of wavelengths included in the input optical signal and the number of wavelengths obtained as a result of increase / decrease by the increase / decrease means is It is acquired from an apparatus.
According to such a configuration, even when an optical signal is exchanged with another optical transmission device, the occurrence of an abnormality can be accurately determined based on information from the host control device. It becomes possible.

According to another invention, in addition to the above invention, information indicating the number of wavelengths included in the input optical signal and the number of wavelengths obtained as a result of increase / decrease by the increase / decrease means is obtained by an optical channel monitor. Features.
According to such a configuration, even when an optical signal is exchanged with another optical transmission device, the occurrence of an abnormality can be accurately determined based on information from the optical channel monitor. It becomes possible. Further, based on the information from the optical channel monitor, communication with the host controller becomes unnecessary, so that the load on the host controller can be further reduced.

In addition to the above-mentioned invention, in another invention, when the determination means determines that an abnormality has occurred, the recovery means for recovering the abnormality by adjusting the gain of the preamplifier or the booster amplifier It is characterized by having.
According to such a configuration, even if an abnormality occurs, it is possible to keep the communication interruption state in the entire system to a minimum by recovering in each optical transmission device.

In addition to the above invention, another invention is characterized in that the recovery means notifies the host controller of the occurrence of an abnormality when the recovery fails.
According to such a configuration, since the host controller is notified for the first time when it cannot be recovered, the burden on the host controller can be reduced.

According to another invention, in addition to the above invention, the preamplifier, the increase / decrease unit, and the booster amplifier each have a specific control unit, and the control unit is configured to block an input optical signal. In the case where an alarm is issued and the determination means is in a case where a control unit preceding the control unit that issued the alarm has issued an alarm, even if an alarm is issued by the control unit. Is characterized by ignoring alarms issued by the control unit at the subsequent stage.
According to such a configuration, it is possible to prevent an increase in load even when alarms are issued in duplicate.

According to another invention, in addition to the above-described invention, the determination means may identify a device corresponding to the control unit existing in the most upstream among the control units issuing an alarm as an abnormality source. Features.
According to such a configuration, since the source of the abnormality can be specified, the recovery process can be performed quickly, and the load increases even when the alarms are issued repeatedly. Can be prevented.

According to another aspect of the invention, in addition to the above-described invention, the increase / decrease unit is an optical cross-connect, the determination unit refers to setting information of the optical cross-connect, and an optical signal is output from the optical cross-connect If no optical signal is detected by the second detection means, it is determined that an abnormality has occurred in the optical cross-connect.
According to such a configuration, it is possible to quickly detect an optical cross-connect abnormality as compared with a case where a channel abnormality is detected by an optical channel monitor.

Further, the present invention provides a preamplifier that receives and amplifies an optical signal including light of a plurality of wavelengths, an increase / decrease unit that increases / decreases the number of wavelengths of light included in the optical signal, and the output from the increase / decrease unit. A booster amplifier for amplifying and outputting an optical signal; first detection means for detecting the power of the optical signal output from the preamplifier; and a second detection for detecting the power of the optical signal input to the booster amplifier. And calculating the power per wavelength by dividing the power detected by the first detection means by the number of wavelengths included in the input optical signal, and the preamplifier. The expected optical power of the booster amplifier is calculated by subtracting the loss from the output of the power to the input of the booster amplifier from the power per wavelength. A first calculating step, a second calculating step of calculating the measured optical power of one wavelength by dividing the power detected by the second detecting unit by the number of wavelengths obtained as a result of the increase / decrease by the increasing / decreasing unit, A determination step of determining that an abnormality has occurred when the measured optical power deviates from the predicted optical power by a predetermined value or more.
According to such a method, it is possible to reduce the burden on the host system.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the control method of an optical transmission apparatus and an optical transmission apparatus with few burdens to a high-order control apparatus.

It is a figure which shows the structural example of the optical transmission apparatus which concerns on 1st Embodiment of this invention. It is a figure which shows the structural example of the control apparatus shown in FIG. It is a figure which shows the number of wavelengths in each part of 1st Embodiment shown in FIG. It is a flowchart for demonstrating an example of the process performed in embodiment of this invention. It is a figure which shows the structural example of the optical transmission apparatus which concerns on 2nd Embodiment of this invention. It is a figure which shows the structural example of the optical transmission apparatus which concerns on 3rd Embodiment of this invention. It is a figure which shows the number of wavelengths in each part of 3rd Embodiment shown in FIG. It is a figure which shows the structural example of the optical transmission apparatus which concerns on 4th Embodiment of this invention. It is a figure which shows the structural example of the optical transmission apparatus which concerns on 4th Embodiment of this invention. It is a figure which shows the structural example of the optical transmission apparatus which concerns on 7th Embodiment of this invention.

  Next, an embodiment of the present invention will be described.

(A) 1st Embodiment FIG. 1: is a figure which shows the structural example of the transmission apparatus which concerns on 1st Embodiment of this invention. As shown in FIG. 1, the optical transmission apparatus 1 according to the first embodiment includes a preamplifier 11, a photodiode (Photo Diode) 12, a splitter 13, an optical cross connect 14, an optical channel monitor 15, a photodiode 16, and a booster amplifier. 17 and the control device 18 are main components. The optical transmission device 1 is connected to the host control device 19, and the control device 18 controls each part of the optical transmission device 1 based on an instruction from the host control device 19. In the example of FIG. 1, only one optical transmission device 1 is configured, but actually, a plurality of optical transmission devices 1 are connected to the host control device 19.

  Here, the preamplifier 11 is composed of, for example, an EDFA (Erbium Doped Fiber Amplifier), uses a light emission action of erbium, which is a rare earth element, as an amplifier, and includes a wavelength including light of a plurality of wavelengths input to the optical transmission device 1. Multiplexed optical signal is amplified and output. Note that the output optical power of the preamplifier 11 is controlled by the control device 18. Control methods include constant gain control and constant output control.

  The photodiode 12 converts the optical signal output from the preamplifier 11 into an electrical signal having a corresponding voltage or current and outputs the electrical signal to the control device 18. The control device 18 detects the power of the optical signal output from the preamplifier 11 with reference to the electrical signal output from the photodiode 12. The photodiode 12 converts signals of all wavelengths included in the optical signal into corresponding electrical signals.

  The splitter 13 branches and attenuates the input optical signal. The optical cross connect 14 has a function of adding an optical signal output from another transmission device (not shown) to the optical signal output from the splitter 13. Specifically, when the number of wavelengths of the optical signal input to the preamplifier 11 is m, when the number of wavelengths added from another device is n and the number of wavelengths to be blocked is o, m + n− An optical signal having the number of wavelengths o is output. The optical cross connect 14 includes a variable optical attenuator (VOA) 14a, and the control device 18 refers to an output signal from the optical channel monitor 15 to newly add light having a wavelength. Is adjusted by the variable attenuator 14a so as to be equal to the power of the light of the wavelength output from the splitter 13.

  The optical channel monitor 15 monitors the power of each of the light of a plurality of wavelengths (channels) included in the optical signal output from the optical cross connect 14 and outputs it to the control device 18. As described above, the control device 18 controls the variable attenuator 14a based on the output from the optical channel monitor 15 to control the optical power of each wavelength to be equal.

  The photodiode 16 converts the optical signal output from the optical cross connect 14 into an electrical signal having a corresponding voltage or current and outputs the electrical signal to the control device 18. The control device 18 refers to the electrical signal output from the photodiode 16 and detects the power of the optical signal output from the optical cross connect 14. Note that the photodiode 16 converts signals of all wavelengths included in the optical signal into corresponding electrical signals, as in the case described above.

  Similarly to the preamplifier 11, the booster amplifier 17 is composed of, for example, an EDFA and uses a light emitting action of erbium, which is a rare earth element, as an amplifier, and wavelength multiplexed light including light of a plurality of wavelengths output from the optical cross connect 14 Amplifies the signal and outputs it. The output light power of the booster amplifier 17 is controlled by the control device 18. Control methods include constant gain control and constant output control, as in the case described above.

  As shown in FIG. 2, the control device 18 includes a central processing unit (CPU) 181, a read only memory (ROM) 182, a random access memory (RAM) 183, an I / F 184, and a bus 185 as main components. 1 controls the optical cross-connect 14 based on the output from the host controller 19 shown in FIG. 1, and preamplifier 11, booster amplifier 17, and the like based on the outputs of the photodiodes 12, 16 and the optical channel monitor 15. The variable attenuator 14a is controlled. The ROM 182 of the control device 18 stores a program 182a and data 182b. The program 182a is a program for controlling each part of the optical transmission apparatus 1. The data 182b is data necessary for controlling each unit by the program 182a.

  Next, the operation of the first embodiment will be described. Hereinafter, the outline of the operation of the first embodiment will be described, and then the details of the operation of the first embodiment will be described with reference to the flowchart shown in FIG.

  First, the outline | summary of operation | movement of 1st Embodiment is demonstrated. In the following, as shown in FIG. 3, an optical signal having a wavelength number m is input to the preamplifier 11, and light having a wavelength number n is added (added) to the optical cross-connect 14 and the optical cross-connect 14. A case where light having the number of wavelengths o is dropped will be described as an example.

  As shown in FIG. 3, when an optical signal having the number of wavelengths m is input to the preamplifier 11, the preamplifier 11 amplifies the optical signal with a predetermined gain according to the control of the control device 18 and outputs it. Note that the control device 18 controls the preamplifier 11 based on the output of the photodiode 12 so that the gain becomes a desired value.

  The optical signal amplified by the preamplifier 11 is supplied to the splitter 13. At this time, the photodiode 12 detects the power of the optical signal output from the preamplifier 11 and supplies it to the control device 18. Note that the photodiode 12 detects the power of all wavelengths included in the optical signal output from the preamplifier 11 and supplies it to the control device 18. As a result, the control device 18 obtains Pout_total as a value corresponding to the power of all wavelengths.

  Subsequently, the control device 18 divides the above-described Pout_total value by the value of the number of wavelengths m included in the control information supplied from the host control device 19 to obtain Pout_mon as optical power per wavelength. (= Pout_total / m) is obtained.

  The optical signal output from the preamplifier 11 is input to the splitter 13 where it is attenuated by the branch. The attenuation in the splitter 13 is LOSS_splitter.

  The optical signal output from the splitter 13 is input to the optical cross connect 14. In the optical cross-connect 14, based on the control of the control device 18, an optical signal having a predetermined number of wavelengths is input from another optical transmission device, added to the optical signal from the splitter 13, and output. The optical signal is interrupted and output. At that time, the control device 18 refers to the output from the optical channel monitor 15 to control the variable attenuator 14a, so that the power of each wavelength included in the optical signal supplied from another optical transmission device can be obtained. Then, the power is adjusted to be equal to the power of each wavelength included in the optical signal output from the splitter 13. As a result, the power of each wavelength included in the optical signal output from the optical cross connect 14 becomes equal.

  The photodiode 16 outputs an electrical signal corresponding to the power of the optical signal output from the optical cross connect 14. The control device 18 sets the electric signal input from the photodiode 16 as the input power Pin_total of the optical signal to the booster amplifier 17. Then, the control device 18 calculates the measured optical power Pin_mon for each wavelength of the optical signal input to the booster amplifier 17 based on the following equation.

Pin_mon = Pin_total / (mo−n) (1)
Here, m is the number of wavelengths of the optical signal input to the preamplifier 11, o is the number of wavelengths added by the optical cross-connect 14, and n is the number of wavelengths blocked by the optical cross-connect 14. These pieces of information m, o, n are notified as control information from the host controller 19. Note that the number of channels (= number of wavelengths) detected by the optical channel monitor 15 may be used instead of (m−o + n).

  Next, the control device 18 calculates an expected optical power Pin_calc as an expected power of each wavelength of the optical signal input to the booster amplifier 17 based on the following expression.

Pin_calc = Pout_mon-Loss_mid (2)

Here, Loss_mid is defined by the following equation.
Loss_mid = LOSS_splitter + LOSS_add_oxc + LOSS_voa + LOSS_coupler (3)

  LOSS_splitter is a loss in the splitter 13, LOSS_add_oxc is a loss in the optical cross-connect 14, LOSS_voa is a loss in the variable attenuator 14 a, and LOSS_coupler exists between the preamplifier 11 and the booster amplifier 17. Loss of the fiber coupler.

Further, Pout_mon is expressed by the following equation as described above.
Pout_mon = Pout_total / m (4)

  Subsequently, the control device 18 compares the measured optical power Pin_mon with the expected optical power Pin_calc, and if the measured optical power Pin_mon is smaller than the expected optical power Pin_calc (or smaller than a predetermined amount), the optical transmission device. 1 It is determined that a problem has occurred inside. That is, the expected optical power Pin_calc is substantially equal to the measured optical power Pin_mon when there is no malfunction inside the optical transmission device 1. However, if they are not equal, it is determined that a loss that is not included in the equation (ie, a loss caused by a malfunction) has occurred.

  Next, the control device 18 executes a self-recovery process. Specifically, the expected optical power Pin_calc and the measured optical power Pin_mon are controlled to be equal by increasing the output of the preamplifier 11 or the booster amplifier 17 or decreasing the attenuation rate of the variable attenuator 14a. Try to do. As a result, when they are equal, the state is maintained as it is, and when the power cannot be increased to the desired power even by the self-recovery process, the control device 18 determines that the failure has occurred. To notify.

  Receiving such notification, the host controller 19 executes a recovery process. Specifically, the recovery process is executed by changing the wavelength so as to use a wavelength that is different from the wavelength at which the problem has occurred under the control of the host controller 19. Alternatively, when the optical transmission device 1 becomes unusable, the recovery processing is performed by stopping the use of the optical transmission device 1 and substituting the processing with another optical transmission device under the control of the host control device 19. Execute. If recovery is still not possible, the optical transmission device 1 in which a problem has occurred is replaced.

  According to the above processing, each optical module (the preamplifier 11, the splitter 13, the optical cross connect 14, and the booster amplifier 17) constituting the optical transmission device 1 independently detects an abnormality and individually transmits it to the host control device 19. There are the following merits compared with the case of notifying to:

(1) Since the expected optical power and the measured optical power are obtained for each wavelength and compared with each other, even if the number of wavelengths increases or decreases in the apparatus, it is possible to accurately determine whether or not a failure has occurred. it can.
(2) Since the loss in the apparatus is also taken into account when obtaining the predicted optical power, it is possible to accurately determine the occurrence of a problem by increasing the calculation accuracy of the predicted optical power.
(3) When a malfunction occurs, the self-recovery process is executed in each optical transmission device, and if the recovery is still not possible, the higher-order control device 19 is notified. Can be further reduced.

  Next, details of processing executed in the control device 18 shown in FIG. 2 will be described with reference to FIG. This process is realized by reading and executing the program 182a shown in FIG. 2 by the CPU 181.

  Step S <b> 10: The CPU 181 receives control information from the host controller 19. Specifically, the CPU 181 receives, for example, control information for each optical module from the host controller 19, the number of wavelengths m of the optical signal input to the preamplifier 11, the number of wavelengths o added by the optical cross-connect 14, the light Information such as the number of wavelengths n blocked by the cross connect 14 is received.

  Step S11: The CPU 181 determines whether or not the control information acquired in Step S10 has changed from the previous time. If it has changed (Step S11; YES), the process proceeds to S12, and otherwise (Step S11). ; NO), the process proceeds to step S14. For example, when the wavelength number m increases (or decreases), the process proceeds to step S12.

  Step S12: The CPU 181 recalculates the value of the predicted optical power Pin_calc based on the new control information. Specifically, the CPU 181 divides Pout_total as a value corresponding to the power of all wavelengths supplied from the photodiode 12 by the number of wavelengths m included in the control information received in step S10. The optical power Pout_mon for each wavelength is obtained. Next, the CPU 181 obtains Pin_calc by subtracting Loss_mid as a value obtained by adding LOSS_splitter, LOSS_add_oxc, LOSS_voa, and LOSS_coupler as default values included in the data 182b from Pout_mon, for example.

  Step S13: The CPU 181 controls each optical module based on the control information received in step S10. Specifically, the CPU 181 controls the optical cross connect 14 based on the control information, for example.

  Step S14: The CPU 181 acquires the detection value of the photodiode 16 as Pin_total. That is, the CPU 181 obtains the detected value of optical power for all wavelengths output from the photodiode 16 as Pin_total.

  Step S15: The CPU 181 calculates Pin_mon from the monitor value acquired in S14. Specifically, the CPU 181 receives the wavelength number m of the optical signal input to the preamplifier 11, the wavelength number o added by the optical cross connect 14, and the wavelength number n blocked by the optical cross connect 14 in step S10. Is obtained from the control information, and Pin_mon is calculated based on Expression (1). As described above, the number of channels (= number of wavelengths) detected by the optical channel monitor 15 may be used instead of (mo−n).

  Step S16: The CPU 181 determines whether or not Pin_mon <Pin_calc is satisfied. If satisfied (step S16; YES), the process proceeds to step S17. Otherwise (step S16; NO), the process proceeds to step S20.

  Step S17: The CPU 181 executes self-recovery processing. Specifically, the CPU 181 increases the output of the preamplifier 11 and / or the booster amplifier 17, and detects whether Pin_mon is within a normal range. Or CPU181 reduces the attenuation factor of the variable attenuator 14a, and detects whether Pin_mon is settled in a normal range.

  Step S18: The CPU 181 determines whether or not Pin_mon is within the normal range (recovered) by the self-recovery process of step S17. If it has recovered (step S18; YES), the process proceeds to step S20. In other cases (step S18; NO), the process proceeds to step S19.

  Step S19: The CPU 181 notifies the host controller 19 that an abnormality has occurred, and waits for the host controller 19 to execute a recovery process. At this time, the CPU 181 may also notify the host controller 19 of, for example, information related to the wavelength (channel) in which the problem has occurred. As a method of knowing the channel in which the defect has occurred, for example, the output of the optical channel monitor 15 can be referred to and it can be determined that the channel having a low detection value has a defect. Note that the host control device 19 executes the recovery process by changing the wavelength so as to use a wavelength different from the wavelength at which the problem has occurred. Alternatively, when the optical transmission device 1 becomes unusable, the recovery processing is performed by stopping the use of the optical transmission device 1 and substituting the processing with another optical transmission device under the control of the host control device 19. Execute. If recovery is still not possible, the administrator is instructed to replace the optical transmission device 1 in which a problem has occurred, and waits for the replacement.

  Step S20: The CPU 181 determines whether or not to end the process. If the process is not ended (step S20; NO), the process returns to step S10 to repeat the same process, otherwise (step S20; YES). Ends the process. Specifically, for example, when the optical transmission device 1 is removed from the system, YES is determined in step S20 and the process is terminated. Note that it is also possible to end the process for other reasons (for example, when an operation stop is instructed from the host control device 19).

  According to the above processing, as described above, even when the number of wavelengths increases or decreases in the apparatus, it is possible to accurately determine whether or not a failure has occurred. In addition, since the expected optical power is obtained in consideration of the loss inside the apparatus, it is possible to accurately determine the occurrence of a problem. Furthermore, when a failure occurs, each optical transmission device executes self-recovery processing, and when recovery is still not possible, the higher-order control device 19 is notified. Further reduction can be achieved.

(B) Second Embodiment FIG. 5 is a diagram for explaining a second embodiment of the present invention. In this figure, parts corresponding to those in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted. In the second embodiment shown in FIG. 5, an optical channel monitor 20 is newly added between the preamplifier 11 and the splitter 13 as compared with the case of FIG. Other configurations are the same as those in FIG.

  The second embodiment is different from the first embodiment in that the wavelength number m included in the optical signal input to the preamplifier 11 is not acquired from the host controller 19 but is acquired from the optical channel monitor 20. Yes. Other operations are the same as those in the first embodiment. The optical channel monitor 20 requires a certain amount of time to detect light of all wavelengths included in the optical signal. Therefore, for example, when the number of wavelengths included in the input optical signal changes, a certain amount of time is required until the change is detected. Therefore, in the process of FIG. 4, in step S11, whether or not the control information (m in this example) changes is determined based on the time required for detection by the optical channel monitor 20 (time required for detecting all channels). In this case, the monitoring is performed only for a long time, and if there is no change, the process proceeds to step S14.

  According to the second embodiment, since it is not necessary to receive control information from the host control device 19, the processing required for communication with the host control device 19 is omitted. Such a load can be reduced. In addition, since the optical transmission device 1 can independently detect the occurrence of a failure and perform self-recovery processing, the burden on the host control device 19 can be further reduced.

  In order to detect the wavelength of the optical signal input to the booster amplifier 17, the optical channel monitor 15 may be used. In this case, as in the case described above, the process of step S11 may be repeated for a time required for detection of all wavelengths by the optical channel monitor 15.

(C) Third Embodiment FIG. 6 is a diagram for explaining a third embodiment of the present invention. In this figure, parts corresponding to those in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted. In the third embodiment shown in FIG. 6, the splitter 13 is replaced with an optical cross connect 30 as compared with the case of FIG. 1. Other configurations are the same as those in FIG.

  In the third embodiment, as shown in FIG. 7, in the optical cross-connect 30, the optical signal with the wavelength number p is transferred from the optical signal with the wavelength number m output from the preamplifier 11 to another optical transmission device. The increase / decrease in the number of other wavelengths is the same as in FIG.

In the third embodiment, Pin_calc is calculated based on the following equation.
Pin_calc = Pout_mon-Loss_mid (5)
Here, Loss_mid and Pout_mon are expressed by the following equations.
Loss_mid = LOSS_drop_oxc + LOSS_add_oxc + LOSS_voa + LOSS_coupler (6)
Pout_mon = Pout_total / m (7)
Note that LOSS_drop_oxc is a loss in the optical cross connect 30.

Pin_mon is calculated by the following equation.
Pin_mon = Pin_total / (m−p−o + n) (8)

  In the third embodiment, as in the first embodiment, whether or not a failure has occurred is determined by comparing the measured optical power Pin_mon and the expected optical power Pin_calc.

  As described above, according to the third embodiment of the present invention, even if the optical cross-connect 30 is provided and a part of the wavelength included in the optical signal is transferred to another optical transmission device, Therefore, it is possible to accurately determine the occurrence of a malfunction.

(D) Fourth Embodiment FIG. 8 is a diagram for explaining a fourth embodiment of the present invention. In this figure, parts corresponding to those in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted. In the fourth embodiment shown in FIG. 8, a photodiode 40 is added on the input side of the preamplifier 11 as compared with the case of FIG. Further, in the example of FIG. 8, the input from the other optical transmission apparatus is blocked in the optical cross connect 14. Further, in the example of FIG. 8, each optical module has a control unit (not shown), and each control unit is configured to issue an alarm according to the presence or absence of input. For example, the control unit included in the booster amplifier 17 issues an alarm to the control device 18 when the input is cut off based on the output of the photodiode 16. Other configurations are the same as those in FIG.

  In the fourth embodiment of the present invention, even when it is detected by the photodiode 16 that the input of the booster amplifier 17 is cut off, if the predetermined condition is satisfied, the control device 18 It is not determined that the fault is in the optical transmission device 1. This will be described below.

Considering the case where the input to the booster amplifier 17 is cut off, one of the following cases is assumed.
(1) When there is no input to the preamplifier 11 (when the output of the photodiode 40 is “0” or close to it)
(2) When the output of the preamplifier 11 is blocked (3) When the optical cross connect 14 blocks light of all wavelengths included in the optical signal In addition to these, the following conditions must be satisfied: is there.
(4) When there is no signal added in the optical cross connect 14

  Furthermore, as shown in FIG. 9, when the optical cross-connect 30 is used instead of the splitter 13, (5) the case where the optical cross-connect 30 blocks light of all wavelengths is It is assumed in addition to 1) to (3). That is, when it corresponds to any one of (1) to (3) and (5) and corresponds to (4), the input to the booster amplifier 17 is blocked. The configuration of FIG. 9 is the same as that of FIG. 8 except that the splitter 13 is replaced with the optical cross connect 30 as compared with the case of FIG. That is, each optical module has a unique control unit, and notifies the control device 18 when a malfunction occurs.

  In the fourth embodiment, for example, when a problem occurs on the downstream side of the optical transmission apparatus 1 and it is necessary to bypass the optical transmission apparatus 1, it is detected that the input to the booster amplifier 17 is in a cutoff state. However, it is characterized by performing control to ignore it. Specifically, when a failure occurs on the downstream side of the optical transmission device 1, the control device 18 uses, for example, an optical transmission device to bypass the optical transmission device 1 based on an instruction from the host control device 19. The light of all wavelengths is blocked by the cross connect 14 or the signals of all wavelengths are blocked by the optical cross connect 30. In such a case, the input to the booster amplifier 17 is cut off. At this time, when the booster amplifier 17 has the unique control unit described above, the control device 18 is notified from the control unit of the booster amplifier 17 that an abnormality has occurred. However, in the fourth embodiment, the control device 18 ignores the notification of abnormality from the booster amplifier 17 when receiving an instruction to shut off from the host control device 19.

  Conventionally, all the abnormalities detected by each optical module have been notified to the host control device, so when the host control device 19 receives the notification of the abnormality, it executes a process for dealing with the occurrence of the abnormality, A load has arisen for the necessity of monitoring an optical module in which an abnormality has occurred for a certain period of time. However, in the fourth embodiment, as described above, even when an abnormality occurs in the optical module, if a predetermined condition is satisfied, the control device 18 determines and ignores it. Since it did in this way, the burden concerning the high-order control apparatus 19 can be reduced. In addition, when the notification of the abnormality from the booster amplifier 17 can be invalidated by masking on the control device 18 side, it may be invalidated by masking instead of ignoring it.

  As described above, in the fourth embodiment of the present invention, even when the input of the booster amplifier 17 is in a cut-off state, if the predetermined condition is satisfied, this can be ignored. The burden placed on the host control device 19 can be reduced.

(E) 5th Embodiment 5th Embodiment of this invention has the structure similar to FIG. That is, an optical cross connect 30 is provided instead of the splitter 13. In such a case, as in the case described above, if a problem occurs on the downstream side of the optical transmission device 1 and it is necessary to bypass the optical transmission device 1, the host controller 19 controls the control device 18. Is instructed to block the optical signal. As a result, the control device 18 is set so as to block signals of all wavelengths by the optical cross connect 30. As a result, as shown in FIG. 9, the signals of all wavelengths output from the preamplifier 11 are not output to the optical cross connect 14.

Incidentally, in FIG. 9, the optical signal input to the optical cross connect 14 is blocked in the following cases.
(1) When no optical signal is input to the preamplifier 11 (2) When the output of the preamplifier 11 is blocked (3) When all the optical signals of the wavelength are blocked by the optical cross-connect 30

  These occur upstream of the optical cross-connect 14 and the control device 18 knows that these conditions are met. In such a case, assuming that the optical cross-connect 14 has a unique control unit, the control device 18 is in a case where the control unit 18 of the optical cross-connect 14 is notified that the input is blocked. Ignore this, if any. As a result, the following effects can be obtained as in the case described above. That is, conventionally, the abnormality detected by each optical module was all notified to the host controller, so when the host controller is notified of the abnormality, it executes a process for dealing with the occurrence of the abnormality, A load has arisen for the necessity of monitoring an optical module in which an abnormality has occurred for a certain period of time. However, in the fifth embodiment, as described above, even when an input disconnection occurs in the optical cross-connect 14, if a predetermined condition is satisfied, the control device 18 determines and determines this. Therefore, the burden on the host control device 19 can be reduced. In addition, when the notification of the abnormality from the optical cross connect 14 can be invalidated by masking on the control device 18 side, it may be invalidated by masking instead of ignoring it.

  As described above, in the fifth embodiment of the present invention, even when the input of the optical cross-connect 14 is in the cut-off state, if the predetermined condition is satisfied, this can be ignored. The burden on the host control device 19 can be reduced.

(F) Sixth Embodiment A sixth embodiment of the present invention has a configuration similar to that of FIG. That is, an optical cross connect 30 is provided instead of the splitter 13. In such a case, assuming that the optical cross-connect 30 has a unique control unit, if there is no output from the preamplifier 11, there is an abnormality in the control device 18 from the control unit of the optical cross-connect 30. Although notified, the control device 18 ignores the notification of the abnormality. That is, in FIG. 9, the input of the optical signal to the optical cross connect 30 is blocked in any of the following cases.
(1) When no optical signal is input to the preamplifier 11 (2) When the output of the preamplifier 11 is cut off

  The control device 18 controls the preamplifier 11 and can know that these conditions are satisfied. For this reason, when any of these conditions is satisfied and the abnormality is notified from the control unit of the optical cross-connect 30, the control device 18 ignores the notification. Thereby, the burden concerning the high-order control apparatus 19 can be reduced. In addition, when the notification of the abnormality from the optical cross-connect 30 can be invalidated by masking on the control device 18 side, it may be invalidated by masking instead of ignoring it.

  As described above, in the sixth embodiment of the present invention, even when the input of the optical cross-connect 30 is in the cut-off state, if the predetermined condition is satisfied, this can be ignored. The burden on the host control device 19 can be reduced.

(G) Seventh Embodiment The seventh embodiment of the present invention is the booster amplifier 17 according to the fourth embodiment of the present invention when the input of the optical signal to the booster amplifier 17 is interrupted under a predetermined condition. Ignore the notification that the output of is degraded. That is, in the seventh embodiment, in the configuration shown in FIG. 10, it is known that there is no input to the booster amplifier 17, and it is detected by the photodiode 41 that the output is deteriorated from the booster amplifier 17 in the following cases. Ignore this even if it happens. Alternatively, mask this.
(1) When there is no input to the optical transmission device 1 (2) When the output of the preamplifier 11 is cut off (3) When an optical cross-connect 30 is added instead of the splitter 13 of FIG. When optical signals of all wavelengths are blocked by the optical cross connect 30

  In the configuration shown in FIG. 10, a photodiode 41 is newly added on the output side of the booster amplifier 17 as compared with the case of FIG. A control unit (not shown) of the booster amplifier 17 issues an alarm based on the output of the photodiode 41 when the output of the booster amplifier 17 is in a cut-off state. The other configuration is the same as in the case of FIG.

  As described above, in the seventh embodiment of the present invention, even if the output of the booster amplifier 17 is deteriorated, if the predetermined condition is satisfied, this is ignored, so that the upper control The burden on the device 19 can be reduced.

(H) Eighth Embodiment In the eighth embodiment of the present invention, in the configuration shown in FIG. 1, the control device 18 uses the wavelength selection setting information of the optical cross-connect 14 and the input information of the booster amplifier 17 so that the control device 18 An internal failure of the cross connect 14 is detected. That is, as the function of the optical cross connect 14, (1) a function of passing a signal of a predetermined wavelength among the input optical signals downstream, and (2) an optical signal of a predetermined wavelength among the input optical signals. (3) A function of adding and outputting an optical signal from another optical transmission device.

  Here, it is assumed that the number of wavelengths selected and passed by the optical cross-connect 14 is q, and the number of wavelengths added from other optical transmission devices by the optical cross-connect 14 is n. In this case, since the optical cross-connect 14 is controlled by the control device 18, the control device 18 has information regarding q and n. Here, the input of the optical signal to the booster amplifier 17 is cut off in spite of the setting in which the optical output from the optical cross connect 14 exists (at least one of q and n is 1 or more). Therefore, it can be determined that the optical output has been lost due to the malfunction of the optical cross-connect 14.

  Conventionally, the presence or absence of a signal is detected by the optical channel monitor 15 disposed immediately after the optical cross-connect 14 to detect a problem. However, since the optical channel monitor 15 has a lower detection speed than the photodiode 16, it takes time to detect that the signal has been cut off due to a malfunction. On the other hand, in the eighth embodiment, since the determination is made based on the setting information and the output of the photodiode 16, a failure of the optical cross connect 14 can be detected instantaneously. Then, by notifying the host controller 19 of the malfunction detected in this way, the host controller 19 can quickly take measures such as diverting the optical signal to another optical transmission device. Thereby, since the time during which the optical signal is blocked can be reduced, the reliability of the entire system can be improved.

  As described above, in the eighth embodiment of the present invention, the presence / absence of a defect in the optical cross-connect 14 is detected based on the setting information of the optical cross-connect 14 and the output of the photodiode 16. The presence or absence of a defect can be determined instantaneously, and an early recovery process by the host control device 19 can be executed.

(I) Ninth Embodiment In the ninth embodiment, for example, in the configuration shown in FIG. 1, when an abnormality occurs in the optical module included in the optical transmission apparatus 1 in the configuration shown in FIG. By determining the presence or absence of occurrence, the cause optical module is identified, and it is determined that the optical module downstream of the optical module is normal even if an abnormality is detected. That is, conventionally, an input cutoff alarm is output from an “alarm issuing signal pin” that detects an input cutoff state in each optical module and notifies an abnormality of each interface connector. Specifically, there are three optical modules that detect an input interruption alarm: a preamplifier 11, an optical cross connect 14, and a booster amplifier 17. The control device provided in each optical module constantly monitors the input power, detects an abnormality in comparison with the threshold value, and notifies the host control device 19 of the abnormality.

  Here, the input power of the optical cross connect 14 depends on the output power of the preamplifier 11. It is clear that there is no input to the optical cross connect 14 while the preamplifier 11 is shut down. In the conventional control for each optical module, the optical cross-connect 14 cannot know the shutdown state of the preamplifier 11, so that the optical cross-connect 14 uniformly issues an input interruption alarm regardless of the state of the preamplifier 11.

  Therefore, by integrating the control devices conventionally provided in the optical modules into one control device 18, the integrated control device 18 has the cause of the input disconnection of the optical cross-connect 14 being the output of the preamplifier 11. It can be judged that there is not. In this case, the input disconnection of the optical cross connect 14 is not an abnormality of the optical cross connect 14 itself. It is possible to reduce the input interruption alarm notification from the optical cross connect 14 to the host control device 19. As a result, the number of input interruption alarms, which has been necessary for the number of optical modules, can be reduced, and the number of alarm signals between the host controller 19 and the optical module can be reduced, thereby reducing the size of the interface. be able to.

  As described above, according to each embodiment of the present invention, it is possible for both the host control device 19 and the control device 18 to simplify the maintenance of an alarm when a failure occurs. That is, since the optical transmission device of each embodiment can separately notify all the individual alarms that are being issued at that time and the failure factor alarm to the host controller separately, the alarm analysis conventionally supported by the host controller Processing can be performed at high speed by the control device. For this reason, since fault isolation and post-processing (for example, route switching processing) can be performed quickly, a highly reliable and safe communication system can be constructed.

  Conventionally, the signal light input level alarm, which has been determined based on whether or not the threshold value is exceeded, is analyzed by aggregating information of all the optical modules in the optical transmission device by integrating the optical modules. Since it can be determined that the signal light is partially deteriorated, it is possible to detect an internal abnormality of the transmission apparatus. Also, by integrating a plurality of optical modules existing in the optical transmission apparatus, it is possible to determine by itself which optical module is causing the alarm. This eliminates the need for the host control device 19 to determine the location where the alarm occurs, thereby reducing the load. Also for the optical transmission apparatus, since it is not necessary to monitor the alarm downstream from the location where the input interruption alarm occurs, the load is reduced. Furthermore, an internal failure can be detected at high speed by combining the signal wavelength selection information of the optical cross-connect and the optical input power monitor information. As a result, the host control device 19 can quickly bypass the signal path and minimize communication interruption. In addition, since redundant input interruption alarms can be reduced, it is possible to reduce the signal line and size of the interface connector.

(J) Modified Embodiment Each of the above embodiments is an example, and there are various modified embodiments other than this. For example, in each of the embodiments described above, the control device 18 is provided. However, for example, a control unit is provided in each optical module, and each control unit recognizes the state by information exchange through communication, and a prescribed or arbitrary The control unit may report the occurrence of a problem to the host control device 19.

  In each of the above embodiments, the presence or absence of a defect is detected based on the magnitude of the measured optical power Pin_mon and the predicted optical power Pin_calc. For example, a predetermined threshold M is set, and the measured optical power Pin_mon is When it becomes smaller than the power Pin_calc-M, it may be determined as a malfunction.

1, 1A, 1B, 1C, 1D, 1E Optical transmission device 11 Preamplifier 12 Photodiode (first detection means)
16 Photodiode (second detection means)
13 Splitter (increase / decrease means)
14 Optical cross connect
14a Variable attenuator 15 Optical channel monitor 17 Booster amplifier 18 Control device (first calculation means, second calculation means, determination means, recovery means)
19 Host controller 40, 41 Photodiode 181 CPU
182 ROM
183 RAM
184 I / F
185 bus

Claims (11)

A preamplifier for receiving and amplifying an optical signal including light of a plurality of wavelengths;
Increase / decrease means for increasing / decreasing the number of wavelengths of light contained in the optical signal;
A booster amplifier that amplifies and outputs the optical signal output from the increase / decrease means;
First detection means for detecting the power of the optical signal output from the preamplifier;
Second detection means for detecting the power of the optical signal input to the booster amplifier;
The power detected by the first detection means is divided by the number of wavelengths included in the input optical signal to determine the power per wavelength, and the loss between the output of the preamplifier and the input of the booster amplifier First calculating means for calculating the expected optical power of the booster amplifier by subtracting from the power per wavelength,
Second calculation means for calculating the measured optical power of one wavelength by dividing the power detected by the second detection means by the number of wavelengths obtained as a result of increase / decrease by the increase / decrease means;
When the measured optical power deviates from the expected optical power by a predetermined value or more, determination means for determining that an abnormality has occurred;
An optical transmission device comprising: The optical transmission apparatus according to claim 1, wherein the increase / decrease means is an optical cross-connect or a splitter. The optical cross-connect adds an optical signal having a predetermined number of wavelengths supplied from another optical transmission device to the optical signal input from the preamplifier or the optical signal input from the preamplifier. 3. The optical transmission device according to claim 2, wherein an optical signal having a predetermined number of wavelengths is transferred to another optical transmission device. The information indicating the number of wavelengths included in the input optical signal and the number of wavelengths obtained as a result of increase / decrease by the increase / decrease means is acquired from a host control device as a host control device. 4. The optical transmission device according to claim 1. The information indicating the number of wavelengths contained in the input optical signal and the number of wavelengths obtained as a result of increase / decrease by the increase / decrease means is acquired by an optical channel monitor. An optical transmission device according to 1. 2. The apparatus according to claim 1, further comprising: a recovery unit configured to recover the abnormality by adjusting a gain of the preamplifier or the booster amplifier when the determination unit determines that an abnormality has occurred. 6. The optical transmission device according to any one of items 1 to 5. 7. The optical transmission apparatus according to claim 6, wherein the recovery unit notifies the host controller of the occurrence of an abnormality when recovery fails. The preamplifier, the increase / decrease unit, and the booster amplifier each have a unique control unit, and the control unit issues an alarm when an input optical signal is interrupted,
Even if an alarm is issued by the control unit, the determination unit may issue a control unit in the subsequent stage if the control unit in the previous stage issues an alarm from the control unit that issued the alarm. 8. The optical transmission apparatus according to claim 1, wherein alarms to be ignored are ignored. 9. The optical transmission apparatus according to claim 8, wherein the determination unit identifies a device corresponding to a control unit existing in the most upstream among control units issuing an alarm as an abnormality generation source. The increase / decrease means is an optical cross connect,
The determination means refers to the setting information of the optical cross-connect, and when the optical signal is output from the optical cross-connect, when the optical signal is not detected by the second detection means, the optical cross-connect The optical transmission device according to claim 1, wherein it is determined that an abnormality has occurred. A preamplifier for receiving and amplifying an optical signal including light of a plurality of wavelengths; an increase / decrease unit for increasing / decreasing the number of wavelengths of light included in the optical signal; and amplifying the optical signal output from the increase / decrease unit Light having: a booster amplifier that outputs; first detection means that detects power of the optical signal output from the preamplifier; and second detection means that detects power of the optical signal input to the booster amplifier. In the control method of the transmission device,
The power detected by the first detection means is divided by the number of wavelengths included in the input optical signal to determine the power per wavelength, and the loss between the output of the preamplifier and the input of the booster amplifier A first calculation step of calculating the expected optical power of the booster amplifier by subtracting from the power per wavelength,
A second calculation step of calculating the measured optical power of one wavelength by dividing the power detected by the second detection unit by the number of wavelengths obtained as a result of increase / decrease by the increase / decrease unit;
A determination step of determining that an abnormality has occurred when the measured optical power deviates from the predicted optical power by a predetermined value or more;
A method for controlling an optical transmission apparatus, comprising:

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