WO2011132417A1 - ノード装置 - Google Patents
ノード装置 Download PDFInfo
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- WO2011132417A1 WO2011132417A1 PCT/JP2011/002318 JP2011002318W WO2011132417A1 WO 2011132417 A1 WO2011132417 A1 WO 2011132417A1 JP 2011002318 W JP2011002318 W JP 2011002318W WO 2011132417 A1 WO2011132417 A1 WO 2011132417A1
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- level detection
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J14/00—Optical multiplex systems
- H04J14/02—Wavelength-division multiplex systems
- H04J14/0221—Power control, e.g. to keep the total optical power constant
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/07—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems
- H04B10/075—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal
- H04B10/079—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal using measurements of the data signal
- H04B10/0795—Performance monitoring; Measurement of transmission parameters
- H04B10/07955—Monitoring or measuring power
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/29—Repeaters
- H04B10/291—Repeaters in which processing or amplification is carried out without conversion of the main signal from optical form
- H04B10/293—Signal power control
- H04B10/294—Signal power control in a multiwavelength system, e.g. gain equalisation
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/29—Repeaters
- H04B10/291—Repeaters in which processing or amplification is carried out without conversion of the main signal from optical form
- H04B10/293—Signal power control
- H04B10/294—Signal power control in a multiwavelength system, e.g. gain equalisation
- H04B10/2941—Signal power control in a multiwavelength system, e.g. gain equalisation using an equalising unit, e.g. a filter
Definitions
- the present invention relates to a node device that transmits wavelength division multiplexed light and has a function of multiplexing and demultiplexing, and does not affect a service wavelength even when a fitting failure occurs in a connector in the node device. .
- a wavelength division multiplexing transmission system in which a plurality of node devices are connected uses a wavelength division division method (Wavelength Division Multiplexing) to multiplex signal light assigned to a plurality of wavelengths and transmit the signal in one fiber.
- An optical transmission communication system for increasing transmission capacity.
- This wavelength division division method is a communication method that applies the fact that signal lights of different wavelengths can exist independently, and it is possible to easily increase the transmission capacity by increasing the number of wavelengths to be wavelength multiplexed. Further, it is possible to multiplex / demultiplex a specific wavelength without affecting other wavelengths.
- This wavelength division multiplexing transmission system includes an optical amplification function unit that compensates for optical level loss caused by transmission paths and various optical devices, a wavelength multiplexing / demultiplexing function unit that performs wavelength multiplexing and demultiplexing, and a signal received from a downstream device.
- Wavelength multiplexing / demultiplexing function unit performs wavelength multiplexing (Add) / demultiplexing (Drop) / transmission (Through) switch function unit, and DGE (Dynamic-Gain-Equalizer) function for equalizing the light level of each wavelength Corresponding by including the part.
- the signal light assigned to each wavelength is independent, and the signal quality of the signal light not related to the failure is affected by the failure of the signal light of other wavelengths. It is structured on the assumption that there is no.
- optical devices such as optical amplifiers and variable optical attenuators in the optical amplifying function unit are used so that the optical level of one wavelength unit is appropriate in order to ensure long-distance transmission and high transmission quality. It is managed correctly by performing feedforward control or feedback control.
- each functional block is often divided into node devices or packages, and feedback control may be performed to manage the light level across the packages.
- the optical level loss increases due to fiber microbending (extreme decrease in the radius of curvature of the fiber), adhesion of foreign matter to the connector end face, or half-fitting of the connector to the connecting optical cord connecting between packages.
- the gain of the optical amplifier and the loss value of the variable optical attenuator can be automatically changed so that the target optical level that is the management value is obtained by feedback control.
- the package may be exchanged.
- the connector In the upstream device or package of the DGE function unit, the connector is in a half-fitted state or a half-removed state with a connecting optical cord that connects between the packages. In some cases, the maintenance person notices the half-extraction state and then completely inserts the connector again for correction.
- wavelength multiplexing transmission systems include a point-to-point system and a ring system based on OADM (Optical Add Drop Drop Multiplexer) that adds / drops / through only an arbitrary wavelength with light.
- OADM Optical Add Drop Drop Multiplexer
- a node device an OADM device which is a component thereof, the respective settings are mixedly operated.
- a ring configuration if a failure occurs in the transmission path or upstream node equipment, even if a failure occurs in the signal light having a wavelength that passes through the corresponding location, a signal with a wavelength that does not pass through that location. The light must not be disturbed.
- the level of only the signal light of the Thru set wavelength (Through wavelength) is instantaneously increased at the output of the DGE function unit.
- the signal light having the wavelength set for Add (Add wavelength) is not affected by the re-insertion of the connector, so that the normal light level is maintained.
- the transmission optical amplifier arranged downstream of the DGE function unit an optical level difference is generated between the input signal light having the Add wavelength and the signal light having the Through wavelength, and the Through wavelength is in an excessive input state.
- a transmission optical amplifier can amplify signal light as light by using a pump laser diode, but its output level has a saturation level (Psat_th) as a total power, and can output more than that. Can not. For this reason, when the total power is in an over-input state with respect to the transmission optical amplifier, gain saturation occurs in the transmission optical amplifier and the gain of each wavelength cannot be kept constant, and the short-wave side optical output level (Add wavelength signal) A phenomenon occurs in which the gain of the light level is significantly reduced.
- the signal receiving unit on the opposite side cannot maintain the signal quality and loses information.
- the signal quality of the signal light having a wavelength other than the faulty part is affected.
- an optical level adjusting unit is provided in each receiving unit after demultiplexing wavelength multiplexed light, and the number of wavelengths fluctuates due to the optical level adjusting unit. In this case, the level is changed.
- the present invention has been made to solve the above-described problems. Even when an abnormality occurs in a connection optical cord in a node device during system maintenance, a service wavelength signal that is not subject to failure is provided.
- An object of the present invention is to provide a node device capable of constructing an inexpensive and highly reliable system without affecting quality.
- a node device includes a light attenuating unit for optically attenuating received wavelength multiplexed light, and an optical multiplexing / demultiplexing unit for optically multiplexing / demultiplexing wavelength multiplexed light received from the optical attenuating unit via an optical code.
- an output level detection unit that detects the optical level of the wavelength multiplexed light in the previous stage of the optical code
- an input level detection unit that detects the optical level of the wavelength multiplexed light in the subsequent stage of the optical code
- an output level detection unit is included in the apparatus.
- a determination unit that performs abnormality determination on the amount of loss of the light level by the optical code based on the light level detected by the input level detection unit, and a light attenuation unit based on the abnormality determination result by the determination unit And a controller for controlling the amount of light attenuation.
- the output level detector configured as described above and detecting the optical level of the wavelength multiplexed light in the previous stage of the optical code, and the input level detection detecting the optical level of the wavelength multiplexed light in the subsequent stage of the optical code.
- a determination unit that performs an abnormality determination on the amount of loss of the light level due to the optical code based on the light level detected by the output unit, the light level detected by the output level detection unit, and the light level detected by the input level detection unit; Since the transmission light amplifying unit does not receive a rapid level increase by including the control unit that controls the light attenuation amount of the light attenuating unit based on the abnormality determination result, the signal quality of the Add wavelength can be ensured. . Further, the gain saturation level of the transmission light amplifying unit can be reduced, and the output power of the pumping LD used in the transmission light amplifying unit can be reduced, so that the cost can be reduced.
- FIG. 1 is a diagram showing a configuration of a node device 1 according to Embodiment 1 of the present invention.
- the node device 1 includes a received light amplification unit 2, a plurality of signal transmission units (TX) 3, a plurality of signal reception units (RX) 4, an optical multiplexing / demultiplexing unit 5, and a transmission light amplification unit 6. Composed.
- the received light amplifying unit 2 compensates for transmission path loss with respect to the optical level of wavelength multiplexed light received from an upstream node device (not shown) via the transmission path 101.
- the received light amplifying unit 2 includes a variable optical attenuating unit (VOA, optical attenuating unit) 21, a received light amplifying function unit (RXAMP, optical amplifying unit) 22, an optical branching coupler 23, an output level detecting circuit (output level detecting unit). 24, a determination circuit (determination unit) 25, an attenuation unit control circuit (control unit) 26, and an amplification unit control circuit (control unit) 27.
- the variable optical attenuating unit 21 optically attenuates the wavelength multiplexed light received from the upstream node device via the transmission path 101 under the control of the attenuating unit control circuit 26.
- the wavelength multiplexed light attenuated by the variable light attenuating unit 21 is transmitted to the received light amplifying function unit 22.
- the received light amplification function unit 22 optically amplifies the wavelength multiplexed light attenuated by the variable light attenuation unit 21 in accordance with the control by the amplification unit control circuit 27.
- the wavelength multiplexed light optically amplified by the received light amplification function unit 22 is transmitted to the optical branching coupler 23.
- the optical branching coupler 23 optically branches the wavelength multiplexed light that has been optically amplified by the received light amplification function unit 22.
- One of the wavelength multiplexed lights branched by the optical branching coupler 23 is sent to the optical multiplexing / demultiplexing unit 5 as light through the connection optical code (optical code) 11, and the other wavelength multiplexed light is output to the output level detection circuit. 24.
- the output level detection circuit 24 periodically detects and observes the total light level (absolute value) of the wavelength division multiplexed light branched by the light branching coupler 23.
- the light level detection result (Prx_out) by the output level detection circuit 24 is transmitted to the determination circuit 25.
- the determination circuit 25 performs a relative comparison between the detection result (Prx_out) of the optical level by the output level detection circuit 24 and the detection result (Padm_in) of the optical level by the input level detection circuit 52 (to be described later) of the optical multiplexing / demultiplexing unit 5.
- the optical level loss amount (L Prx_out ⁇ Padm_in) by the connection optical cord 11 is calculated, and it is determined whether this loss amount (L) is in an abnormal state.
- the determination circuit 25 determines that the loss amount (L) is in an abnormal state, the determination circuit 25 notifies the attenuation unit control circuit 26 to that effect (abnormality determination notification) and the optical attenuation of the variable optical attenuation unit 21. Increase the amount.
- the determination circuit 25 determines that the loss amount (L) is in an abnormal state, the light level detection result (Prx_out) by the output level detection circuit 24 and the light level detection result (Padm_in) by the input level detection circuit 52. ) With respect to each other, the loss amount (L) of the optical level due to the connection optical cord 11 is calculated, and it is determined whether the loss amount (L) has returned to the normal state.
- the determination circuit 25 determines that the loss amount (L) has returned to the normal state, the determination circuit 25 notifies the attenuation unit control circuit 26 of the fact (normal determination notification), and the light of the variable optical attenuation unit 21 Return the attenuation to the normal value.
- the attenuating unit control circuit 26 is variable according to the transmission line loss of the wavelength multiplexed light received by the variable optical attenuating unit 21 so that the optical level of the wavelength multiplexed light input to the received light amplifying function unit 22 is constant.
- the light attenuation amount of the light attenuation unit 21 is controlled. Further, when receiving the abnormality determination notification from the determination circuit 25, the attenuation unit control circuit 26 sets itself to the fixed loss mode and increases the light attenuation amount of the variable optical attenuation unit 21. In addition, when receiving the normality determination notification from the determination circuit 25, the attenuation unit control circuit 26 sets itself to the normal mode and returns the optical attenuation amount of the variable optical attenuation unit 21 to the normal value.
- the amplification unit control circuit 27 controls the amount of light amplification of the received light amplification function unit 22.
- the amplification unit control circuit 27 performs AGC control so that the ratio (gain) of the total input level and the total output level of the reception light amplification function unit 22 is constant in order to make the light level per wavelength constant. It is also possible to perform APC (Automatic Power Control) control that keeps the output level constant regardless of the input level, and it is also possible to switch the control method.
- AGC Automatic Gain Control
- the signal transmission unit 3 transmits the signal light assigned to each wavelength to the optical multiplexing / demultiplexing unit 5 as light through the connection optical cord 13.
- the signal receiving unit 4 receives the corresponding signal light demultiplexed by the optical multiplexing / demultiplexing unit 5 as light through the connection optical cord 14.
- the optical multiplexing / demultiplexing unit 5 multiplexes (Adds) the signal light received from the signal transmitting unit 3 with respect to the wavelength multiplexed light received from the received light amplifying unit 2 or demultiplexes the signal light having a specific wavelength. (Drop) and transmitted to the signal receiving unit 4 or transmitted as it is.
- the optical multiplexing / demultiplexing unit 5 includes an optical branching coupler 51, an input level detection circuit (input level detection unit) 52, a demultiplexing function unit (DEMUX) 53, a plurality of individual channel optical switch function units (SW) 54, and a plurality of individual units.
- a channel light level equalization unit (DGE) 55 and a multiplexing function unit (MUX) 56 are included.
- the optical branching coupler 51 optically branches the wavelength multiplexed light received from the received light amplifying unit 2 via the connection light cord 11.
- One of the wavelength multiplexed lights branched by the optical branching coupler 51 is transmitted to the demultiplexing function unit 53, and the other wavelength multiplexed light is transmitted to the input level detection circuit 52.
- the input level detection circuit 52 periodically detects and observes the total optical level (absolute value) of the wavelength multiplexed light that has been optically branched by the optical branching coupler 51.
- the light level detection result (Padm_in) by the input level detection circuit 52 is transmitted to the determination circuit 25 by inter-package communication such as electrical communication via the backboard or front electrical connection. Note that the inter-package communication has a parity check and CRC error check function for confirming the correctness of the communication.
- the demultiplexing function unit 53 demultiplexes the wavelength division multiplexed light branched by the light branching coupler 51 into each wavelength unit.
- the signal light demultiplexed for each wavelength by the demultiplexing function unit 53 is transmitted to the individual channel optical switch function unit 54 corresponding to each wavelength.
- the individual channel optical switch function unit 54 selects Through / Drop / Add of signal light.
- the individual channel optical switch function unit 54 is set to Through, the signal light demultiplexed by the demultiplexing function unit 53 is transmitted to the individual channel light level equalizing unit 55 as it is.
- the individual channel optical switch function unit 54 is set to Drop, the signal light demultiplexed by the demultiplexing function unit 53 is transmitted to the signal receiving unit 4 as light through the connection light cord 14.
- the individual channel optical switch function unit 54 is set to Add, the signal light received from the signal transmission unit 3 via the connection optical cord 13 is transmitted to the individual channel light level equalization unit 55.
- the individual channel optical level equalization unit 55 automatically adjusts the optical level of the signal light received from the individual channel optical switch function unit 54 so as to match the target optical level determined by the wavelength division multiplexing transmission system. Is. Details of the individual channel light level equalizer 55 will be described later.
- the signal light whose light level is adjusted by the individual channel light level equalizing unit 55 is transmitted to the multiplexing function unit 56.
- the multiplexing function unit 56 wavelength-multiplexes the signal light received from the plurality of individual channel light level equalization units 55 again.
- the wavelength multiplexed light wavelength-multiplexed by the multiplexing function unit 56 is transmitted to the transmission light amplifying unit 6 as light through the connection optical cord 12.
- the transmission light amplifying unit 6 compensates for the loss in the node device 1 with respect to the wavelength multiplexed light received from the optical multiplexing / demultiplexing unit 5 via the signal light code 12 and transmitted to the transmission path 102.
- the transmission light amplification unit 6 includes a transmission light amplification function unit (TXAMP) 61 and an amplification unit control circuit 62.
- TXAMP transmission light amplification function unit
- the transmission light amplification function unit 61 optically amplifies the wavelength multiplexed light received from the optical multiplexing / demultiplexing unit 5 in accordance with control by the amplification unit control circuit 62.
- the wavelength multiplexed light optically amplified by the transmission light amplification function unit 61 is sent to a downstream node device (not shown) via the transmission path 102.
- the amplification unit control circuit 62 controls the amount of optical amplification of the transmission light amplification function unit 61.
- the amplifier control circuit 62 controls the amount of optical amplification of the transmission light amplification function unit 61 by performing AGC control or APC control. It is also possible to switch the control method.
- FIG. 2 is a diagram showing the configuration of the individual channel light level equalization unit 55 in the first embodiment of the present invention
- FIG. 3 explains the control state transition of the VOA control circuit unit 554 in the first embodiment of the present invention.
- the individual channel optical level equalizing unit 55 includes a variable optical attenuating unit (VOA) 551, an optical branching coupler 552, an optical level detecting unit 553, and a VOA control circuit unit (control unit) 554. .
- VOA variable optical attenuating unit
- control unit control unit
- the variable optical attenuating unit 551 has a preset CH output target value (Pt) according to the control by the VOA control circuit unit 554 with respect to the optical level of the signal light received from the individual channel optical switch function unit 54. To be adjusted.
- Pt CH output target value
- the optical branching coupler 552 optically branches the signal light whose optical level is adjusted by the variable optical attenuating unit 551.
- One signal light that is optically branched by the optical branching coupler 552 is transmitted to the multiplexing function unit 56, and the other signal light is transmitted to the optical level detection unit 553.
- the light level detection unit 553 periodically detects and observes the light level (absolute value) of the signal light branched by the light branching coupler 552.
- the detection result (Pch) of the optical level by the optical level detection unit 553 is transmitted to the VOA control circuit unit 554.
- the VOA control circuit unit 554 compares with a preset CH output target value (Pt), shutdown detection threshold value (Pd), and shutdown return threshold value (Pr) based on the detection result (Pch) by the optical level detection unit 553. Thus, the amount of light attenuation of the variable light attenuation unit 551 is controlled.
- the shutdown return threshold (Pr) is set to the light level that is optically attenuated by the fixed loss of the variable optical attenuator 551 when the minimum optical level during normal operation is input from the individual channel optical switch function unit 54. Is set. Further, the shutdown detection threshold (Pd) is set so as to be a light level at which the normal operation cannot be performed by detecting a decrease in the light level in the ALC control mode.
- the VOA control circuit unit 554 operates in the control state transition shown in FIG. 3, and the optical level (Pch) from the optical level detection unit 553 is compared with the shutdown return threshold (Pr), and Pch ⁇ In the case of Pr, it operates in the fixed loss mode. In this fixed loss mode, the VOA control circuit unit 554 increases the optical attenuation amount of the variable optical attenuation unit 551 according to the system in order not to transmit unnecessary signal light to the downstream multiplexing function unit 56.
- the VOA control circuit unit 554 performs ALC control on the optical attenuation amount of the variable optical attenuation unit 551 so that the optical level (Pch) becomes the CH output target value (Pt).
- the optical level (Pch) is compared with the shutdown detection threshold (Pd) and Pch ⁇ Pd, it is determined that the optical input interruption of the corresponding channel (CH) has occurred, and the fixed loss Operate in mode.
- the shutdown detection threshold (Pd) and the shutdown return threshold (Pr) may be lower than the shutdown return threshold (Pr).
- the shutdown detection threshold (Pd) is fixed from the ALC control mode. Have time protection on transition to loss mode.
- FIG. 4 is a flowchart showing the main operation of the node device 1 according to Embodiment 1 of the present invention.
- the main operation of the node device 1 is as follows. First, the variable optical attenuating unit 21 of the received light amplifying unit 2 is controlled from the upstream node device via the transmission line 101 according to the control by the attenuating unit control circuit 26. The received wavelength multiplexed light is optically attenuated (step ST41). The wavelength multiplexed light attenuated by the variable light attenuating unit 21 is transmitted to the received light amplifying function unit 22.
- the received light amplifying function unit 22 optically amplifies the wavelength multiplexed light that has been optically attenuated by the variable optical attenuating unit 21 under the control of the amplifying unit control circuit 27 (step ST42).
- the wavelength multiplexed light optically amplified by the received light amplification function unit 22 is transmitted to the demultiplexing function unit 55 of the optical multiplexing / demultiplexing unit 5 through the optical branching coupler 23, the connection optical cord 11 and the optical branching coupler 51.
- the demultiplexing function unit 53 demultiplexes the wavelength multiplexed light received from the received light amplification function unit 22 via the optical branching coupler 23, the connection light cord 11, and the optical branching coupler 51 in units of wavelengths (step ST43). .
- the signal light demultiplexed for each wavelength by the demultiplexing function unit 53 is transmitted to the individual channel optical switch function unit 54 corresponding to each wavelength.
- the individual channel optical switch function unit 54 selects Through / Drop / Add of the signal light (step ST44).
- the individual channel optical switch function unit 54 is set to Through, the signal light demultiplexed by the demultiplexing function unit 53 is transmitted to the individual channel light level equalizing unit 55 as it is.
- the individual channel optical switch function unit 54 is set to Drop, the signal light demultiplexed by the demultiplexing function unit 53 is transmitted to the signal receiving unit 4 via the connection optical cord 14.
- the individual channel optical switch function unit 54 is set to Add, the signal light received from the signal transmission unit 3 via the connection optical cord 13 is transmitted to the individual channel light level equalization unit 55.
- the individual channel optical level equalization unit 55 automatically sets the optical level of the signal light received from the individual channel optical switch function unit 54 so as to match the target optical level determined by the wavelength division multiplexing transmission system. Adjust (step ST45). The signal light whose light level is adjusted by the individual channel light level equalizing unit 55 is transmitted to the multiplexing function unit 56.
- the multiplexing function unit 56 wavelength-multiplexes again the signal light received from the plurality of individual channel light level equalization units 55 (step ST46).
- the wavelength multiplexed light wavelength-multiplexed by the multiplexing function unit 56 is sent to the transmission light amplifying unit 6 through the connection optical cord 12.
- the transmission light amplification function unit 61 of the transmission light amplification unit 6 optically amplifies the wavelength multiplexed light received from the optical multiplexing / demultiplexing unit 5 according to the control by the amplification unit control circuit 62, and transmits it downstream via the transmission path 102.
- the data is sent to the node device (step ST47).
- FIG. 5 is a flowchart showing an abnormality determination operation of the node device 1 according to the first embodiment of the present invention.
- the abnormality determination operation of the node device 1 is as follows. First, the output level detection circuit 24 sets the total optical level of the wavelength multiplexed light that is optically branched by the optical branching coupler 23 (the output of the received light amplifying unit 2). Level) is detected (step ST51). The light level detection result (Prx_out) by the output level detection circuit 24 is transmitted to the determination circuit 25.
- the determination circuit 25 confirms whether or not the output level of the received light amplification function unit 22 is appropriate from the light level detection result (Prx_out) by the output level detection circuit 24 (step ST52). For example, when the received light amplification function unit 22 is shut down to stop the emission of the excitation LD, the received light amplification function unit 22 cannot perform optical amplification, and the output level decreases. When the output level is low, the detection accuracy of the light level by the output level detection circuit 24 and the input level detection circuit 52 is deteriorated, and the loss cannot be correctly checked.
- step ST52 when the determination circuit 25 determines that the output level of the reception light amplification function unit 22 is not appropriate (the reception light amplification function unit 22 is in the output stop state), the abnormality detection count i is then set to 0. Set to. Thereafter, the sequence returns to step ST51.
- the input level detection circuit 52 when the determination circuit 25 determines that the output level of the received light amplification function unit 22 is appropriate in step ST52, the input level detection circuit 52 then wavelength-multiplexes the light branched by the optical branching coupler 51. The total light level of light (the input level of the optical multiplexing / demultiplexing unit 5) is detected (step ST53). The light level detection result (Padm_in) by the output level detection circuit 24 is transmitted to the determination circuit 25.
- the determination circuit 25 compares the light level detection result (Prx_out) by the output level detection circuit 24 with the light level detection result (Padm_in) by the input level detection circuit 52 to thereby compare the light by the connection light cord 11.
- the level loss amount (L) is calculated and compared with a preset abnormality detection threshold ( ⁇ ) (step ST54).
- the abnormality detection threshold ( ⁇ ) is set between the difference between the normal output level when the maximum number of wavelengths is input to the transmission light amplification function unit 61 and the maximum saturation output level, and when the connection optical cord 11 is normal. Connector loss (actual value of about 0.2 to 0.4 dB at both ends) and monitor errors of the output level detection circuit 24 and the input level detection circuit 52 are determined.
- step ST54 the determination circuit 25 determines that the loss is normal when the loss amount (L) is less than the abnormality detection threshold ( ⁇ ), and sets the abnormality detection count i to zero. Thereafter, the sequence returns to step ST51.
- step ST54 the determination circuit 25 determines that there is an abnormal loss when the loss amount (L) is equal to or greater than the abnormality detection threshold ( ⁇ ), and increments the abnormality detection count i (step ST55).
- the determination circuit 25 determines whether the abnormal loss has been detected N times continuously by determining whether the abnormality detection count i is a preset threshold value N (step ST56). In this step ST56, when the determination circuit 25 determines that the abnormal loss has not been detected continuously N times, the sequence returns to step ST51. On the other hand, if it is determined in step ST56 that the abnormal loss has been detected N times in succession, the determination circuit 25 finally determines that the loss amount (L) of the optical level by the connected optical cord 11 is in an abnormal state. (Step ST57). Thereafter, the determination circuit 25 notifies the attenuation unit control circuit 26 to that effect, and increases the light attenuation amount of the variable optical attenuation unit 21.
- FIG. 6 is a diagram showing an optical level diagram in the node device 1 according to Embodiment 1 of the present invention.
- a solid line indicates a normal light level diagram per wavelength
- a dotted line indicates an abnormal light level diagram when excessive loss occurs in the connection optical cord 11.
- the optical attenuation amount of the variable optical attenuation unit 21 when the attenuation unit control circuit 26 is in the fixed loss mode is set in advance so that the output level of the individual channel optical level equalization unit 55 is lower than the shutdown detection threshold (Pd). Keep it.
- the VOA control circuit unit 554 can change to the fixed loss mode, and the optical attenuation amount of the variable optical attenuation unit 551 can be increased.
- FIG. 7 is a flowchart showing a normality determining operation of the node device 1 according to the first embodiment of the present invention.
- the normal determination operation of the node device 1 shown in FIG. 7 is obtained by changing the abnormality detection count i of the abnormality determination operation shown in FIG. 5 to the normal detection count j and changing the operation after step ST54.
- steps ST74 operations after step ST74 will be described.
- step ST74 the determination circuit 25 compares the optical level detection result (Prx_out) by the output level detection circuit 24 with the optical level detection result (Padm_in) by the input level detection circuit 52, thereby connecting the optical connection code 11
- the light level loss amount (L) is calculated and compared with a preset abnormality detection threshold ( ⁇ ) (step ST74).
- step ST74 the determination circuit 25 determines that there is an abnormal loss when the light level loss amount (L) is larger than the abnormality detection threshold ( ⁇ ), and sets the normal detection count j to zero. Thereafter, the sequence returns to step ST71.
- step ST74 the determination circuit 25 determines that there is a normal loss when the loss amount (L) of the light level is less than the abnormality detection threshold ( ⁇ ), and increments the normal detection count j (step).
- step ST76 determines whether the normal loss is continuously detected M times by determining whether the normal detection count j is the preset threshold value M (step ST76).
- step ST76 when the determination circuit 25 determines that the normal loss has not been detected M times continuously, the sequence returns to step ST71.
- step ST76 when the determination circuit 25 determines that the normal loss has been detected M times continuously, the determination circuit 25 finally determines that the loss amount (L) of the optical level by the connected optical cord 11 is in the normal state.
- Step ST77 the determination circuit 25 notifies the fact and returns the light attenuation amount of the variable light attenuation unit 21 to the normal value.
- the transition time constant is made sufficiently slower than the response speed of the individual channel light level equalization unit 55 to suppress the transient response of the output level of the individual channel light level equalization unit 55, and at this output level. Can be prevented.
- the variable optical attenuation is achieved. Since the optical attenuation amount of the unit 21 is increased, even when an abnormality occurs in the connection optical cord 11 in the node apparatus 1 during system maintenance, the signal light whose light level has increased rapidly is generated. Since transmission to the transmission light amplifying unit 6 can be suppressed, gain saturation can be avoided, signal quality of the Add wavelength can be ensured, and an inexpensive and highly reliable system can be constructed.
- FIG. FIG. 8 is a diagram showing a configuration of the node device 1 according to Embodiment 2 of the present invention.
- the node device 1 according to the second embodiment shown in FIG. 8 has the same configuration as that of the node device 1 according to the first embodiment shown in FIG. 1, but the processing contents of the determination circuit 25 and the amplification unit control circuit 27 are different. . Only different points will be described below.
- the abnormality determination operation and the normality determination operation of the node device 1 according to the second embodiment are the same as the abnormality determination operation and the normality determination operation of the node device 1 according to the first embodiment shown in FIGS. Description is omitted.
- the determination circuit 25 determines that the optical level loss amount (L) is in an abnormal state, the determination circuit 25 notifies the amplification unit control circuit 27 to that effect (abnormality determination notification), and the received light amplification function unit 22 Reduce the amount of light amplification.
- the determination circuit 25 determines that the loss amount (L) of the optical level has returned to the normal state, the determination circuit 25 notifies the amplification unit control circuit 27 to that effect (normal determination notification), and the received light amplification function The optical amplification amount of the unit 22 is returned to the normal value.
- the amplification unit control circuit 27 When receiving the abnormality determination notification from the determination circuit 25, the amplification unit control circuit 27 performs APC control to decrease the optical amplification amount of the reception light amplification function unit 22, and receives the normal determination notification from the determination circuit 25.
- the AGC control is performed to control the ratio (gain) of the total input level and the total output level of the received light amplification function unit 22 to be constant, thereby returning the optical amplification amount to the normal value.
- FIG. 9 is a diagram showing an optical level diagram in the node device 1 according to Embodiment 2 of the present invention.
- the solid line indicates the normal optical level diagram per wavelength
- the dotted line indicates the optical level diagram in the node device 1 at the time of abnormality when excessive loss occurs in the connection optical cord 11.
- the optical amplification amount of the received light amplification unit 22 when the amplification unit control circuit 27 performs APC control is set in advance so that the output level of the individual channel light level equalization unit 55 is lower than the shutdown detection threshold (Pd). Set it.
- the VOA control circuit unit 554 can change to the fixed loss mode, and the optical attenuation amount of the variable optical attenuation unit 551 can be increased.
- the second embodiment when the loss amount is calculated from the input / output level difference of the connection optical cord 11 and it is determined that excessive loss has occurred in the connection optical cord 11, the received light amplification is performed. Since the optical amplification amount of the unit 22 is reduced, the same effect as in the first embodiment can be obtained, and the signal quality of the Add wavelength can be improved even when a failure of the connection optical cord 11 occurs and during maintenance work. A system that does not affect the system can be realized.
- the optical amplification amount of the reception optical amplifier 22 is reduced.
- the optical attenuation amount of the variable optical attenuation unit 21 may be increased, and the optical amplification amount of the reception optical amplification amount 22 may be decreased.
- FIG. FIG. 10 is a diagram showing a node device 1 according to Embodiment 3 of the present invention
- FIG. 11 is a diagram for explaining the control state transition of the VOA control circuit unit according to Embodiment 3 of the present invention.
- the node device 1 according to the third embodiment illustrated in FIG. 10 is obtained by deleting the determination circuit 25 of the node device 1 according to the first embodiment illustrated in FIG. 1 and adding a determination circuit (determination unit) 57.
- Other configurations are the same, and the same reference numerals are given and the description thereof is omitted.
- the abnormality determination operation and the normality determination operation of the node device 1 according to the third embodiment are performed by the determination circuit 25 in the abnormality determination operation and the normality determination operation of the node device 1 according to the first embodiment illustrated in FIGS. Since the processing is the same except that the determination circuit 57 performs the processing, the description thereof is omitted.
- the determination circuit 57 compares the light level detection result (Prx_out) by the output level detection circuit 24 with the light level detection result (Padm_in) by the input level detection circuit 52, thereby comparing the light level by the connection light cord 11.
- a loss amount (L Prx_out ⁇ Padm_in) is calculated to determine whether this loss amount (L) is in an abnormal state.
- the determination circuit 57 determines that the loss amount (L) is in an abnormal state, the determination circuit 57 notifies the individual channel light level equalization unit 55 to which the signal light of the Thorough wavelength is input (abnormality determination notification). ) To increase the optical attenuation amount of the variable optical attenuation unit 551.
- the determination circuit 57 determines that the loss amount (L) is in an abnormal state, the light level detection result (Prx_out) by the output level detection circuit 24 and the light level detection result (Padm_in) by the input level detection circuit 52. ) With respect to each other, the loss amount (L) of the optical level due to the connection optical cord 11 is calculated, and it is determined whether the loss amount (L) has returned to the normal state.
- the determination circuit 57 determines that the loss amount (L) has returned to the normal state, the determination circuit 57 notifies the individual channel light level equalization unit 55 to which the signal light of the Thorough wavelength is input (normal determination). Notification) to return the optical attenuation amount of the variable attenuation unit 551 to the normal value.
- the VOA control circuit unit 554 when the individual channel optical switch function unit 54 in the previous stage is set to Through and the abnormality determination notification is received from the determination circuit 57, the VOA control circuit unit 554, as shown in FIG. Operates in fixed loss mode. In the second fixed loss mode, the VOA control circuit unit 554 increases the optical attenuation amount of the variable optical attenuation unit 551 according to the system.
- the VOA control circuit unit 554 changes from the second fixed loss mode to the fixed loss mode. Transition to.
- the individual channel optical switch function unit 54 in the previous stage transitions to Add setting or Drop setting other than Through setting, it transits to the fixed loss mode.
- FIG. 12 is a diagram showing an optical level diagram in the node device 1 according to Embodiment 3 of the present invention.
- a solid line indicates a normal light level diagram per wavelength
- a dotted line indicates an abnormal light level diagram when excessive loss occurs in the connection optical cord 11.
- the VOA control circuit unit 554 is shifted to the second fixed loss mode to increase the optical attenuation amount of the variable optical attenuation unit 551. it can.
- the loss amount is calculated from the input / output level difference of the connection optical cord 11, it is determined that an excessive loss has occurred in the connection optical cord 11, and the individual channel light is determined.
- the functional unit 54 is set to Through, the optical attenuation amount of the variable optical attenuating unit 551 is increased, and the optical multiplexing / demultiplexing unit 5 is demultiplexed and configured to optically attenuate only the transmitted signal light.
- the same effects as those of the first embodiment can be obtained, and a system that does not affect the signal quality of the Add wavelength can be realized even when a failure of the connection optical cord 11 occurs or during maintenance work.
- FIG. FIG. 13 is a diagram showing a configuration of the node device 1 according to Embodiment 4 of the present invention.
- the node device 1 according to the fourth embodiment illustrated in FIG. 13 changes the optical branching coupler 23 of the node device 1 according to the first embodiment illustrated in FIG. Part) 29, and the determination circuit 25 is changed to a determination circuit (determination part) 30.
- Other configurations are the same, and the same reference numerals are given and description thereof is omitted.
- the optical branching coupler 28 optically branches the wavelength multiplexed light optically amplified by the reception light amplification function unit 22 and optically branches the reflected light from the output connector end face of the reception light amplification unit 2.
- One of the wavelength multiplexed lights branched by the optical branching coupler 23 is transmitted to the optical multiplexing / demultiplexing unit 5 via the connection optical cord 11, and the other wavelength multiplexed light is transmitted to the output level detection circuit 24 to be reflected light. Is transmitted to the reflection level detection circuit 29.
- the reflection level detection circuit 29 periodically detects and observes the total light level (absolute value) of the reflected light branched by the light branching coupler 23.
- the light level detection result (Prx_ref) by the reflection level detection circuit 29 is transmitted to the determination circuit 30.
- the determination circuit 30 determines that the connection optical cord 11 is in a semi-extraction state or a complete extraction state, and performs the attenuation unit control circuit 26 and the amplification. This is notified to the unit control circuit 27 (abnormality determination notification), the optical attenuation amount of the variable optical attenuation unit 21 is increased, and the optical amplification amount of the received optical amplification function unit 22 is decreased.
- the determination circuit 30 determines the light level detection result (Prx_out) by the output level detection circuit 24 and the light level by the reflection level detection circuit 29. By making a relative comparison with the detection result (Prx_ref), the return loss (D) is calculated, and it is determined whether the connection optical cord 11 is in the inserted state.
- the determination circuit 30 determines that the connection optical cord 11 is in the inserted state, and sends the determination to the attenuation unit control circuit 26 and the amplification unit control circuit 27. This is notified (normal determination notification), and the optical attenuation amount of the variable optical attenuating unit 21 and the optical amplification amount of the received optical amplification function unit 22 are returned to normal values.
- the abnormality determination operation and normality determination operation of the node device 1 according to the fourth embodiment are the same as the input level detection circuit in the abnormality determination operation and normality determination operation of the node device 1 according to the first embodiment shown in FIGS.
- the processing by 52 is replaced by the processing by the reflection level detection circuit 29, and the determination circuit 30 performs the processing by the determination circuit 25, and the connection state of the connection optical cord 11 is determined by the reflection attenuation amount (D) instead of the loss amount (L).
- D reflection attenuation amount
- L loss amount
- the optical level of the input level detection circuit 52 of the optical multiplexing / demultiplexing unit 5 may be fed back to control the variable optical attenuating unit 21 and the received optical amplifying function unit 22 of the received optical amplifying unit 2. If a failure occurs in the connection optical cord 11 in such a state, there is a possibility that high-energy optical power is output from the reception optical amplifier 2. Therefore, when the detected light level falls below a preset threshold value, the input level detection circuit 52 notifies the determination circuit 30 to that effect (input level decrease notification). The determination circuit 30 that has received this input level lowering notification determines that a failure has occurred in the connection optical cord 11 and notifies the attenuation unit control circuit 26 and the amplification unit control circuit 27 to that effect. The output level is managed so as not to unnecessarily increase the output level.
- FIG. 14 is a diagram showing an optical level diagram in the node device 1 according to Embodiment 4 of the present invention.
- a solid line indicates a normal light level diagram per wavelength
- a dotted line indicates an abnormal light level diagram when excessive loss occurs in the connection optical cord 11.
- the optical attenuation amount of the variable optical attenuation unit 21 when the attenuation unit control circuit 26 is in the fixed loss mode and the optical amplification amount of the reception optical amplification unit 22 when the amplification unit control circuit 27 performs APC control are individually described.
- the output level of the channel light level equalizer 55 is set in advance so as to be lower than the shutdown detection threshold (Pd). As shown in FIG.
- the optical attenuation amount of the variable optical attenuating unit 21 is increased, and the optical amplification amount of the received optical amplifying function unit 22 is decreased.
- the output level of the light level equalizing unit 55 can be made to be lower than the shutdown detection threshold (Pd). Therefore, the VOA control circuit unit 554 can change to the fixed loss mode, and the optical attenuation amount of the variable optical attenuation unit 551 can be increased.
- the fourth embodiment when the return loss is calculated based on the light level of the reflected light at the output connector end face, and it is determined that an excessive loss has occurred in the connection light cord 11, Since the optical attenuation amount of the variable optical attenuating unit 21 is increased and the optical amplification amount of the received optical amplifying unit 22 is decreased, the same effect as in the first embodiment can be obtained, and the connection optical cord 11 It is possible to realize a system that does not affect the signal quality of the Add wavelength even when a failure occurs or during maintenance work.
- FIG. 15 is a diagram showing the configuration of the node device 1 according to the fifth embodiment of the present invention.
- the node device 1 according to the fifth embodiment illustrated in FIG. 15 is different from the node device 1 according to the fourth embodiment illustrated in FIG. 13 in that an intermediate optical amplification function unit (optical amplification unit) 31, an optical branching coupler 32, and an output level detection circuit.
- (Output level detection unit) 33, reflection level detection circuit (reflection level detection unit) 34, first determination circuit (determination unit) 35, and amplification unit control circuit (control unit) 36 are added, and determination circuit 30 is subjected to second determination.
- the circuit (determination unit) 37 is changed, and a dispersion compensation unit (DCF: Dispersion Compensation Fiber) 7 is further added.
- DCF Dispersion Compensation Fiber
- the dispersion compensator 7 receives the wavelength multiplexed light from the optical branching coupler 28 as light through the connection optical cord 15, and the residual dispersion in the transmission path between the received light amplification functional unit 22 and the intermediate optical amplification functional unit 31. Is to compensate.
- the wavelength multiplexed light whose residual dispersion has been compensated for by the dispersion compensation unit 7 is transmitted to the intermediate optical amplification function unit 31 as light through the connection optical cord 16.
- the intermediate optical amplification function unit 31 optically amplifies the wavelength multiplexed light received from the dispersion compensation unit 7 according to the control by the amplification unit control circuit 36, and compensates for the optical level loss due to the passive DCF of the dispersion compensation unit 7. It is.
- the wavelength multiplexed light optically amplified by the intermediate optical amplification function unit 31 is transmitted to the optical branching coupler 32.
- the optical branching coupler 32 optically branches the wavelength multiplexed light optically amplified by the intermediate optical amplification function unit 31 and optically branches the reflected light from the output connector end face of the reception light amplification unit 2.
- One of the wavelength multiplexed lights branched by the optical branching coupler 32 is transmitted to the optical multiplexing / demultiplexing unit 5 as light through the connection optical cord 11, and the other wavelength multiplexed light is transmitted to the output level detection circuit 33.
- the reflected light is transmitted to the reflection level detection circuit 34.
- the output level detection circuit 33 periodically detects and observes the total optical level (absolute value) of the wavelength division multiplexed light that has been optically branched by the optical branching coupler 32.
- the light level detection result (Prx_out) by the output level detection circuit 33 is transmitted to the first determination circuit 35.
- the reflection level detection circuit 34 periodically detects and observes the total light level (absolute value) of the reflected light branched by the light branching coupler 32.
- the light level detection result (Prx_ref) by the reflection level detection circuit 34 is transmitted to the first determination circuit 35.
- the return loss (D) exceeds a preset threshold value
- the first determination circuit 35 determines that the connection optical cord 11 is in a semi-extraction state or a complete extraction state, and the amplification unit control circuit 36. To that effect (abnormality determination notification), the amount of light amplification of the received light amplification function unit 31 is reduced.
- the first determination circuit 35 also performs abnormality determination notification to the second determination circuit 37.
- the first determination circuit 35 determines that the connection light cord 11 is in the semi-extraction state or the complete extraction state, and then detects the light level detection result (Prx_out) by the output level detection circuit 33 and the light by the reflection level detection circuit 34. By comparing the level detection result (Prx_ref) with a relative comparison, the return loss (D) is calculated, and it is determined whether the connection optical cord 11 is in the inserted state.
- the return loss (D) is equal to or less than a preset threshold value
- the first determination circuit 35 determines that the connection optical cord 11 is in the inserted state, and notifies the amplification unit control circuit 36 to that effect. (Notification of normality determination) and the optical amplification amount of the reception optical amplification function unit 31 is returned to the normal value.
- the amplification unit control circuit 36 When receiving the abnormality determination notification from the first determination circuit 35, the amplification unit control circuit 36 performs APC control to decrease the optical amplification amount of the received light amplification function unit 31, and from the first determination circuit 35, the normal determination notification Is received, AGC control is performed to control the ratio (gain) of the total input level and the total output level of the received light amplification function unit 31 to be constant, and the optical amplification amount is returned to the normal value.
- the reflection attenuation amount (D) exceeds a preset threshold value
- the second determination circuit 37 determines that the connection optical cord 15 (16) is in a half-extraction state or a complete extraction state, and the attenuation unit.
- the second determination circuit 37 Even when the second determination circuit 37 receives the abnormality determination notification from the first determination circuit 35, the second determination circuit 37 notifies the attenuation unit control circuit 26 and the amplification unit control circuit 27 to that effect (abnormality determination notification), and is variable.
- the optical attenuation amount of the optical attenuation unit 21 is increased, and the optical amplification amount of the reception light amplification function unit 22 is decreased.
- the second determination circuit 37 determines that the connection light cord 15 is in the half-extraction state or the complete extraction state, and then detects the light level detection result (Prx_out) by the output level detection circuit 24 and the light from the reflection level detection circuit 29. By comparing the level detection result (Prx_ref) with the relative value, the return loss (D) is calculated, and it is determined whether the connection optical cord 15 (16) is in the inserted state.
- the second determination circuit 37 determines that the connection optical cord 15 (16) is in the inserted state when the reflection attenuation amount (D) is equal to or less than a preset threshold, and the attenuation unit control circuit 26 and the amplification unit This is notified to the unit control circuit 27 (normal determination notification), and the optical attenuation amount of the variable optical attenuation unit 21 and the optical amplification amount of the reception optical amplification function unit 22 are returned to normal values.
- the received light amplifying unit 2 is divided into the former-stage optical amplifying unit including the variable optical attenuating unit 21 and the received-light amplifying function unit 22 and the subsequent-stage including the intermediate light amplifying function unit 31.
- the dispersion compensator 7 is provided between the front-stage optical amplifier and the rear-stage optical amplifier divided into the optical amplifiers, the return loss between the connection optical cords 11 and the connection optical cords 15 and 16
- the optical amplification amount of the reception optical amplifier 31 is decreased, and excess loss has occurred in the connection cord 15 (16).
- the optical attenuation amount of the variable optical attenuating unit 21 is increased and the optical amplification amount of the received light amplifying unit 22 is decreased, the same effect as in the fourth embodiment can be obtained. , Maintenance work when failure of connecting optical cord 11, 15, 16 occurs In can also be realized the system do not affect the signal quality of the Add wavelength.
- the node device suppresses the steep and large level fluctuation accompanying the gain saturation of the optical amplifier when a failure occurs in the node device during system maintenance, and affects the signal quality.
- an output level detection unit that detects the optical level of the wavelength multiplexed light in the previous stage of the optical code
- an input level detection unit that detects the optical level of the wavelength multiplexed light in the subsequent stage of the optical code, Since it is configured to include a determination unit that performs an abnormality determination of the optical level loss amount and a control unit that controls the light attenuation amount of the light attenuation unit, even when an abnormality occurs in the connection optical cord in the node device
- An inexpensive and highly reliable wavelength multiplexing transmission system can be constructed without affecting the signal quality of service wavelengths that are not subject to failure.
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Abstract
Description
そのため、トータルパワーが送信光増幅器に対して過入力状態になると、送信光増幅器では利得飽和が発生し、各波長の利得を一定に保つことができなくなり、短波側光出力レベル(Add波長の信号光の光レベル)の利得が著しく低下する現象が発生する。
実施の形態1.
図1はこの発明の実施の形態1に係るノード装置1の構成を示す図である。なお、波長多重伝送システムは、複数のノード装置1が伝送路を介して接続されるものである。
ノード装置1は、図1に示すように、受信光増幅部2、複数の信号送信部(TX)3、複数の信号受信部(RX)4、光合分波部5および送信光増幅部6から構成される。
信号受信部4は、光合分波部5により分波された対応する信号光を接続光コード14を介して光のまま受信するものである。
なお、パッケージ間通信は、通信の正当性を確認するためのパリティチェックやCRCエラーチェック機能を保有しているものとする。
個別チャンネル光レベル等化部55は、図2に示すように、可変光減衰部(VOA)551、光分岐カプラ552、光レベル検出部553およびVOA制御回路部(制御部)554から構成される。
なお、シャットダウン復帰閾値(Pr)は、個別チャンネル光スイッチ機能部54から通常運用時の最小光レベルが入力された場合に、可変光減衰部551の固定損失で光減衰した光レベルとなるように設定されている。また、シャットダウン検出閾値(Pd)は、ALC制御モードの際の光レベル低下を検出し、通常運用を行うことができなくなる光レベルとなるように設定される。
ノード装置1の主動作は、図4に示すように、まず、受信光増幅部2の可変光減衰部21は、減衰部制御回路26による制御に従い、伝送路101を介して上流のノード装置から受信した波長多重光を光減衰する(ステップST41)。この可変光減衰部21により光減衰された波長多重光は受信光増幅機能部22に送信される。
ノード装置1の異常判定動作は、図5に示すように、まず、出力レベル検出回路24は、光分岐カプラ23により光分岐された波長多重光のトータルの光レベル(受信光増幅部2の出力レベル)を検出する(ステップST51)。この出力レベル検出回路24による光レベルの検出結果(Prx_out)は判定回路25に送信される。
このステップST56において、判定回路25が異常損失を連続してN回検出していないと判定した場合には、シーケンスはステップST51に戻る。
一方、ステップST56において、判定回路25は、異常損失を連続してN回検出したと判定した場合には、接続光コード11による光レベルの損失量(L)が異常状態であると最終判定する(ステップST57)。その後、判定回路25は、その旨を減衰部制御回路26に通知して、可変光減衰部21の光減衰量を増加させる。
図6に示すように、接続光コード11で過剰損失が発生した場合、可変光減衰部21の光減衰量を増大させることによって、個別チャンネル光レベル等化部55の出力レベルがシャットダウン検出閾値(Pd)を下回るようにすることができる。そのため、VOA制御回路部554が固定損失モードに遷移して、可変光減衰部551の光減衰量を増加させることができる。
図7に示すノード装置1の正常判定動作は、図5に示す異常判定動作の異常検出カウントiを正常検出カウントjに変更して、ステップST54以降の動作を変更したものである。以下、ステップST74以降の動作について説明を行う。
このステップST76において、判定回路25は、正常損失を連続してM回検出していないと判定した場合には、シーケンスはステップST71に戻る。
一方、ステップST76において、判定回路25は、正常損失を連続してM回検出したと判定した場合には、接続光コード11による光レベルの損失量(L)が正常状態であると最終判定する(ステップST77)。次いで、判定回路25は、その旨を通知して、可変光減衰部21の光減衰量を通常値に戻す。
図8はこの発明の実施の形態2に係るノード装置1の構成を示す図である。図8に示す実施の形態2に係るノード装置1は、図1に示す実施の形態1に係るノード装置1の構成と同様であるが、判定回路25および増幅部制御回路27の処理内容が異なる。以下、異なる点についてのみ説明する。
なお、実施の形態2に係るノード装置1の異常判定動作および正常判定動作は、図5,7に示す実施の形態1に係るノード装置1の異常判定動作および正常判定動作と同様であるためその説明を省略する。
図9に示すように、接続光コード11で過剰損失が発生した場合、受信光増幅部22の光増幅量を減少させることによって、個別チャンネル光レベル等化部55の出力レベルがシャットダウン検出閾値(Pd)を下回るようにすることができる。そのため、VOA制御回路部554が固定損失モードに遷移して、可変光減衰部551の光減衰量を増加させることができる。
図10はこの発明の実施の形態3に係るノード装置1を示す図であり、図11はこの発明の実施の形態3におけるVOA制御回路部の制御状態遷移を説明する図である。図10に示す実施の形態3に係るノード装置1は、図1に示す実施の形態1に係るノード装置1の判定回路25を削除し、判定回路(判定部)57を追加したものである。その他の構成は同様であり同一の符号を付してその説明を省略する。
なお、実施の形態3に係るノード装置1の異常判定動作および正常判定動作は、図5,7に示す実施の形態1に係るノード装置1の異常判定動作および正常判定動作において、判定回路25による処理を判定回路57が行う点以外は同様であるためその説明を省略する。
図12に示すように、接続光コード11で過剰損失が発生した場合、VOA制御回路部554を第2の固定損失モードに遷移して、可変光減衰部551の光減衰量を増加させることができる。
図13はこの発明の実施の形態4に係るノード装置1の構成を示す図である。図13に示す実施の形態4に係るノード装置1は、図1に示す実施の形態1に係るノード装置1の光分岐カプラ23を光分岐カプラ28に変更し、反射レベル検出回路(反射レベル検出部)29を追加し、判定回路25を判定回路(判定部)30に変更したものである。その他の構成は同様であり、同一の符号を付してその説明を省略する。
図14に示すように、接続光コード11で過剰損失が発生した場合、可変光減衰部21の光減衰量を増大させ、受信光増幅機能部22の光増幅量を減少させることによって、個別チャンネル光レベル等化部55の出力レベルがシャットダウン検出閾値(Pd)を下回るようにすることができる。そのため、VOA制御回路部554が固定損失モードに遷移して、可変光減衰部551の光減衰量を増加させることができる。
図15はこの発明の実施の形態5に係るノード装置1の構成を示す図である。図15に示す実施の形態5に係るノード装置1は、図13に示す実施の形態4に係るノード装置1に中間光増幅機能部(光増幅部)31、光分岐カプラ32、出力レベル検出回路(出力レベル検出部)33、反射レベル検出回路(反射レベル検出部)34、第1判定回路(判定部)35、増幅部制御回路(制御部)36を追加し、判定回路30を第2判定回路(判定部)37に変更し、さらに、分散補償部(DCF:Dispersion Compensation Fiber)7を追加したものである。
Claims (5)
- 受信した波長多重光を光減衰する光減衰部と、光コードを介して前記光減衰部から受信した波長多重光を光合分波する光合分波部とを備えたノード装置において、
前記光コードの前段で波長多重光の光レベルを検出する出力レベル検出部と、
前記光コードの後段で波長多重光の光レベルを検出する入力レベル検出部と、
前記出力レベル検出部により検出された光レベルと、前記入力レベル検出部により検出された光レベルとに基づいて、前記光コードによる光レベルの損失量の異常判定を行う判定部と、
前記判定部による異常判定結果に基づいて、前記光減衰部の光減衰量を制御する制御部と
を備えたことを特徴とするノード装置。 - 前記光減衰部から受信した波長多重光を光増幅して前記光コードを介して前記光合分波部に送信する光増幅部をさらに備え、
前記制御部は、前記判定部による異常判定結果に基づき、前記光増幅部の光増幅量および/または前記光減衰部の光減衰量を制御する
ことを特徴とする請求項1記載のノード装置。 - 受信した波長多重光を光増幅する光増幅部と、光コードを介して前記光増幅部から受信した波長多重光を光合分波する光合分波部とを備えたノード装置において、
前記光コードの前段で波長多重光の光レベルを検出する出力レベル検出部と、
前記光コードの後段で波長多重光の光レベルを検出する入力レベル検出部と、
前記出力レベル検出部により検出された光レベルと、前記入力レベル検出部により検出された光レベルとに基づいて、前記光コードによる光レベルの損失量の異常判定を行う判定部と、
前記判定部による異常判定結果に基づいて、前記光合分波部により分波され透過する信号光を光減衰させる制御部と
を備えたことを特徴とするノード装置。 - 受信した波長多重光を光減衰する光減衰部と、光コードを介して前記光減衰部から受信した波長多重光を光合分波する光合分波部とを備えたノード装置において、
前記光コードの前段で波長多重光の光レベルを検出する出力レベル検出部と、
前記光コードの前段で前記光コードが接続される出力コネクタからの反射光レベルを検出する反射レベル検出部と、
前記出力レベル検出部により検出された光レベルと前記反射レベル検出部により検出された反射光レベルとに基づいて、前記光コードの接続状態の異常判定を行う判定部と、
前記判定部による異常判定結果に基づいて、前記光減衰部の光減衰量を制御する制御部と
を備えたことを特徴とするノード装置。 - 前記光減衰部から受信した波長多重光を光増幅して前記光コードを介して前記光合分波部に送信する光増幅部をさらに備え、
前記制御部は、前記判定部による異常判定結果に基づき、前記光増幅部の光増幅量および/または前記光減衰部の光減衰量を制御する
ことを特徴とする請求項4記載のノード装置。
Priority Applications (4)
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EP11771758.7A EP2562946A4 (en) | 2010-04-22 | 2011-04-20 | Node device |
US13/521,354 US8948588B2 (en) | 2010-04-22 | 2011-04-20 | Node equipment |
JP2012511553A JP5420068B2 (ja) | 2010-04-22 | 2011-04-20 | ノード装置 |
CN201180020274.1A CN102845000B (zh) | 2010-04-22 | 2011-04-20 | 节点装置 |
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US (1) | US8948588B2 (ja) |
EP (1) | EP2562946A4 (ja) |
JP (1) | JP5420068B2 (ja) |
CN (1) | CN102845000B (ja) |
WO (1) | WO2011132417A1 (ja) |
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US9667312B2 (en) * | 2015-01-13 | 2017-05-30 | Hughes Network Systems, Llc | Radio based automatic level control for linear radio calibration |
US10447420B2 (en) * | 2016-06-03 | 2019-10-15 | Infinera Corporation | Method and system for signaling defects in a network element with optical fabric |
US10608773B2 (en) * | 2016-09-13 | 2020-03-31 | Telefonaktiebolaget Lm Ericsson (Publ) | Optical transceiver and method of controlling optical powers of optical channels |
CN110808793B (zh) * | 2018-08-02 | 2022-04-15 | 中兴通讯股份有限公司 | 监控信道控制方法、设备及可读存储介质 |
CN112887029B (zh) * | 2019-11-29 | 2022-08-26 | 华为技术有限公司 | 光放大器、光信号的处理方法及存储介质 |
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JP4710357B2 (ja) * | 2005-03-09 | 2011-06-29 | 日本電気株式会社 | 光増幅装置及びその動作制御方法並びにプログラム |
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US20120321300A1 (en) | 2012-12-20 |
EP2562946A1 (en) | 2013-02-27 |
EP2562946A4 (en) | 2017-06-28 |
CN102845000A (zh) | 2012-12-26 |
JP5420068B2 (ja) | 2014-02-19 |
JPWO2011132417A1 (ja) | 2013-07-18 |
US8948588B2 (en) | 2015-02-03 |
CN102845000B (zh) | 2015-06-17 |
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