CN1288869C - A WDM optical transmission system with automatic link gain adjustment and method thereof - Google Patents
A WDM optical transmission system with automatic link gain adjustment and method thereof Download PDFInfo
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- CN1288869C CN1288869C CN 200410102768 CN200410102768A CN1288869C CN 1288869 C CN1288869 C CN 1288869C CN 200410102768 CN200410102768 CN 200410102768 CN 200410102768 A CN200410102768 A CN 200410102768A CN 1288869 C CN1288869 C CN 1288869C
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Abstract
The present invention relates to a wavelength division multiplexing optical transmission system which can automatically regulate link gains and a method which is used for automatically regulating link gains and is used by the system. The present invention detects the receiving optical power of the wavelength of an optical supervisory channel at a downstream station with a given span section, the difference of the transmitting optical power of an upstream station and the receiving optical power of the downstream station is used for calculating the loss of the optical fiber route, the optical power attenuation value of an electric adjustable optical attenuator of the downstream station of the span section is regulated by the route loss quantity, and the route loss is matched with the gain of an optical amplification repeater. The link power and the gain control of the dense wavelength division multiplexing optical transmission system can reach automatic, quick, exact and stable technical requirements by the method of the present invention.
Description
Technical field
The present invention relates to the link gain Automatic adjustment method that the self-regulating Wave division multiplexing optical transmission system of a kind of link gain and this system use, the light that the present invention is used in particular in light dense wave division multipurpose (DWDM) transmission system transmits link Gain Automatic adjusting of single spanning distance section and full link gain automatic adjustment technology, makes that optical amplification repeater section and overall optical transmit link in the dwdm system can carry out adjusting automatically in real time of link gain automatically effectively.
Background technology
In existing wave division multiplexing transmission system design, the gain of erbium-doped fiber amplifier (EDFA) is mainly determined by pump power, pumping wavelength, Er-doped fiber length, after in case Er-doped fiber length, pumping wavelength, power are determined, the gain of image intensifer changes just not too easy, has only by the power of adjusting pump light source to adjust gain among a small circle.For can be in dwdm system optical amplification repeater section optical channel number when changing, keep the received optical power of each optical wavelength of system receiving terminal constant and guarantee the Optical Signal To Noise Ratio requirement that touches the mark, the method that generally adopts the gain to EDFA in the relay station to lock at present.The method is to detect the total optical power of input main channel, and makes the Output optical power of pump light source change along with the change of input main channel total optical power.Because the luminous power in the optical fiber is directly proportional with channel quantity, so when increasing with the number of channel as if input optical power, the Output optical power of pump light source is also along with increase, thereby total Output optical power of EDFA is also increased, and simultaneously the luminous power of single wavelength channel remained unchanged.The gain locking technology that Here it is dwdm system generally adopts at present.Because the gain of EDFA generally is changeless, even the EDFA of some type gain can be adjusted in right amount, still be subjected to the restriction of other technical indicator, the scope that its Gain Adjustable is put in order is very little.And in the dwdm system engineering of reality is used, the cable length of each fiber spans is inequality, considers that for the maintainability of system the gain of image intensifer can not arbitrarily be provided with simultaneously, must design by stepping, have interchangeability between the alternate device so that guarantee.On the other hand in order to keep the rich amount of certain system gain to system, the gain of general image intensifer is always disposed higherly than actual track loss, but the rich amount of these gains in link in the image intensifers at different levels must be sponged by Variable Optical Attenuator again when circuit is normal, otherwise can influence the adaptation function that the channel increase and decrease is regulated, flatness that also can deterioration EDFA gain spectral, when serious even can cause the nonlinear effect that is harmful to, influence the normal operation of system.As time passes, the welding point that optical cable is aging, amplifier gain decline, optical cable fracture cause such as increases at factor, and line loss is increased in system's running.Therefore, dwdm system needs can non-interrupting service, need not manual intervention, just can discharge the rich amount of unnecessary system gain automatically, change so that adapt to the loss of circuit, guarantee that thus the Optical Signal To Noise Ratio of system transmissions and system's received optical power are constant, finally guarantee the transmission quality of system.
At present, conventional fiber spans relay station in the dwdm system generally adopts electric light modulation attenuator (EVOA) and erbium-doped fiber amplifier (EDFA) to constitute the image intensifer of Gain Adjustable, increase and decrease by electric adjustable attenuator attenuation adapts to the variation that light transmits link load, it is suitable to make that line loss adds the gain of the pad value sum of adjustable attenuator and EDFA, make interior line loss of fiber spans and gain amplifier in a basic balance, guarantee the Optical Signal To Noise Ratio of system receiving terminal on the one hand, control the input optical power of image intensifers at different levels and the incident optical power of optical fiber on the other hand, this helps the balanced and inhibition nonlinear interaction that generation is disturbed to transmission performance of channel gain of control system.
For solving automatic gain adjusting in the fiber spans, proposed to measure the interior main optical path power calculation link attenuation of fiber spans and regulated the method that gains in the optical amplification repeater station, for example also proposed the Chinese patent application disclosed method of denomination of invention in the past for " a kind of light-repeating ship equipment and automatic gain control method thereof that is used for optical transmission system " by the applicant.
But the above-mentioned Gain Automatic control method that formerly proposes adopts the power of main optical path is measured, thereby calculates the fiber spans link attenuation.Yet, because the variable power of main optical path is subjected to the influence of following various factors, all relay station equipment parameter changes, the optical cable in the top n fiber spans of the variation of the light source number of channel, our station amplifier is aging, auto light power reduces factors such as (APR) process, our station power supply.Therefore the key light power that these multiple factors mixed in together all can make our station receive changes, and is interfered easily by detecting the method that main optical path transmitting-receiving optical power difference calculates the fiber spans link attenuation.In addition, when the next stop transmitted power compares with station, back received power, because the time-delay that processes such as power detection, line coding decoding, transmission delay cause, accomplish not too easily to send " synchronously " of sampling, that is to say that the transmission/received optical power that compares does not collect at " synchronization " probably with the received optical power value.Because the influence of above-mentioned factor, may make that the adjustment of EVOA is very frequent on the one hand, cause in the whole system that the light amplification relay station interferes with each other on the relay stations at different levels, also increased the burden that the treatment facility logarithm value is carried out computing in the burden of Optical Supervisory Channel through-put power numerical value and the relay station.Owing to be not easy to accomplish on the time to detect transmission/received optical power at " synchronization ", this all has the potential hazard that causes the EVOA mistuning is put in order, mistake is controlled on the other hand.
Summary of the invention
The object of the invention provides the link gain Automatic adjustment method of self-regulating wavelength-division multiplex system of a kind of link gain and the use of this system, this method is applicable in the dense wavelength division multiplexing system carries out the automated power gain-adjusted to the fiber spans relay station, thereby overcomes the problem that method had that prior art is carried out the automatic gain adjusting by the measurement to main optical path.
The know-why of the inventive method is as follows:
The present invention adopts electric adjustable optical attenuator (EVOA) and as the erbium-doped fiber amplifier (EDFA) of power amplifier in relay stations at different levels, stable with each wavelength light output power signal in the main channel that keeps our station output by setting fixing power amplifier gain and regulating the attenuation of EVOA in the station according to the lightguide cable link attenuation.
The attenuation α of the one section fibre circuit L in this relay station image intensifer front is monitored in employing on the optical amplification repeater station of cascade
L, according to this Line Attenuation amount α
LThe insertion attenuation of the variation control EVOA of value.And the overall attenuation α between two image intensifers of adjacent two relay stations
∑1510nm wavelength multiplexer by last station is inserted loss α
M, the optical cable towpath inserts loss α in the fiber spans
L, our station 1510nm wavelength demultiplexer inserts loss α
DAddition forms.In order to simplify, the insertion loss of light wire jumper between Optical Distribution Frame and the image intensifer in each is stood, the Insertion Loss of all flexible jumpers and fixed connector etc. all counts line loss α
LIn.Circuit luminous power overall attenuation then:
α
∑＝α
M+α
L+α
D (1)
In formula (1), α
M, α
DAll be changeless, α
LValue only is subjected to lightguide cable link length, optical cable to be subjected to stress and the deformation that causes or the influence of factors such as stretching, temperature and fused fiber splice quality, and is not subjected to optical channel to count the influence of increase and decrease.Therefore as if complete attenuation value α according to this fiber spans
∑Value is controlled the interference that EVOA attenuation in the image intensifer then is not subjected to the optical channel increase and decrease fully.
Method of the present invention utilizes the power attenuation of Optical Supervisory Channel wavelength to replace the power attenuation of employed key light channel in the art methods, makes α
LIt is easily simple more that the measurement of value becomes.Because the transmitting power of each Optical Supervisory Channel is consistent basically, and remain unchanged at system's run duration.Need only the received optical power that detects Optical Supervisory Channel (OSC) at the N+1 relay station of overall optical transmission system like this, just be easy to calculate Line Attenuation α between (N)-relay station and the N+1 relay station
LValue.Suppose that N station OSC transmitting optical power is Pt, N+1 station OSC received optical power is Pr, then Line Attenuation α
LValue is:
α
∑＝Pt-Pr (2)
At system's run duration, usually Pt is a constant, as long as just can be easy to calculate Line Attenuation so measure Pr, the benefit of this method of measurement is that the transmitting-receiving power samples need not " synchronously " and carries out, and can not produce the phase mutual interference between grade optical amplification repeater station before and after on the other hand.
The guiding theory that this method solves the Gain Automatic adjustment of circuit is two principal element branches that influence DWDM circuit luminous power processing of coming, and promptly uses circuit luminous power complete attenuation α
∑Control EVOA, make the gain G of N+1 station image intensifer
EdfaApproximate front one section fibre circuit complete attenuation α
∑Pad value α with EVOA
AttSum promptly has following relational expression:
G
edfa＝α
∑+α
att (3)
Make overall line attenuation and gain reach balance.Like this each optical amplification repeater station just can adapt to automatically that the length variations, optical fiber of each optical cable fiber spans is aging, ambient temperature, optical cable deformation and the Line Attenuation amount that causes changes.
Because the increase and decrease of number of wavelengths can not cause overall line attenuation α in the main channel
∑The change of value, thus when dense wavelength division multiplexing system increase or the minimizing main channel in during operation wavelength quantity, lightguide cable link attenuation α
∑Remain unchanged.So on the one hand EVOA can not responded to operation wavelength quantity increase and decrease in the main channel, the light signal gross power of the input EDFA that causes for the increase and decrease of number of wavelengths in the key light channel changes on the other hand, the gain locking function that EDFA had can make also increase and decrease simultaneously of Output optical power according to the luminous power increase and decrease of input, thereby makes the gain G of EDFA
EdfaRemain unchanged, realize that the luminous power of variant wavelength channel in the power amplifier output port remains unchanged, if EDFA and EVOA are put together as an optical amplification repeater station, then this relay station is again the optical amplification repeater station of a Gain Adjustable.
And can adopt the method that adds modifying factor to be proofreaied and correct for the error of decay of key light channel lines and Optical Supervisory Channel Line Attenuation.Because in the dwdm system of reality, Insertion Loss during by wave multiplexer and channel-splitting filter of service wavelength and Optical Supervisory Channel wavelength is also inconsistent, causes detected circuit total losses α
∑Produce error.Therefore also need to increase a calibrator quantity α
AdjustCalibrated.
In a word, the link gain Automatic adjustment method that is used for Wave division multiplexing optical transmission system of the present invention, basic principle just is: receive the power difference by sending out of measuring light monitoring and controlling channels, come this section of perception circuit actual power dissipation, the actual track power loss is adjusted the gain configuration of this fiber spans circuit in view of the above.Method of the present invention in force, automatically handle link power and the change in gain that optical channel increases and decreases or these two kinds of different causes of fibre circuit attenuation change cause exactly with the light amplification relay station, embodiment is: normally transmit at the OSC channel under the condition of network management information, the power loss of utilizing the 1510nm wavelength light signal of its emission to come the measuring optical fiber circuit simultaneously, according to the optical power attenuation amount that this line loss is regulated EVOA, adapt to the increase and decrease of optical channel number with the gain locking function of EDFA.Method of the present invention is made adjustment EDFA and EVOA respectively independently to optical channel increase and decrease and fibre circuit attenuation change, do not disturb mutually.The method of the circuit optical power change that two kinds of different factors of this separate processes cause can make the link power of DWDM optical transmission system and gain controlling reach automatic, quick, accurate, stable specification requirement.
A kind of link gain of the present invention is regulated Wave division multiplexing optical transmission system automatically, forms by upstream relay stations and downstream relay station,
Station, upstream OSC sending part branch comprises:
Optical Supervisory Channel wavelength emission machine and optical wavelength multiplexing device, wherein
Optical Supervisory Channel wavelength emission machine produces Optical Supervisory Channel wavelength light signal and is transferred to the optical wavelength multiplexing device,
The optical wavelength multiplexing device is transferred on the lightguide cable link after with a plurality of main channel wavelength light signals and Optical Supervisory Channel wavelength light signal multiplexing;
The receiving unit of downstream relay station OSC comprises:
Optical wavelength demodulation multiplexer, beam split power coupler, Optical Supervisory Channel wavelength power detector, the mechanical, electrical adjustable optical attenuator drive circuit of monolithic, electric adjustable light power attenuator, power amplifier, wherein the processing of 1 pair of OSC receiving optical signals of embodiment is as follows:
The optical wavelength demodulation multiplexer will be decomposed into a plurality of main channel wavelength light signals and Optical Supervisory Channel wavelength light signal from the light signal of lightguide cable link, and a plurality of main channel wavelength light signals are transferred to electric adjustable optical attenuator, simultaneously Optical Supervisory Channel wavelength light signal is transferred to Optical Supervisory Channel wavelength power detector by the beam split power coupler
Optical Supervisory Channel wavelength power detector detects the magnitude of power of Optical Supervisory Channel wavelength light signal and is transferred to single-chip microcomputer,
Single-chip microcomputer earlier calculates the Optical Supervisory Channel wavelength light signal power numerical value that our station receives with Optical Supervisory Channel wavelength light signal power numerical value according to the splitting ratio of beam split power coupler, then predetermined station, upstream Optical Supervisory Channel wavelength light output power signal numerical value is received Optical Supervisory Channel wavelength light signal power numerical value subtraction calculations with the our station that calculates and go out the lightguide cable link complete attenuation, the attenuation that the power amplifier yield value in the downstream stations and the lightguide cable link complete attenuation subtraction calculations that calculates are gone out electric adjustable optical attenuator is transferred to electric adjustable optical attenuator drive circuit again
Electricity adjustable optical attenuator drive circuit drives electric adjustable optical attenuator according to the attenuation of calculating, and makes the gain of our station power amplifier equal lightguide cable link attenuation and electric adjustable optical attenuator attenuation sum,
Optical line amplifier (EDFA) is used for a plurality of main channel wavelength light signals are amplified back output.
Above-mentioned link gain of the present invention is regulated Wave division multiplexing optical transmission system automatically, it is characterized in that downstream stations has also comprised a light preamplifier, this light preamplifier is between optical wavelength demodulation multiplexer and electric adjustable optical attenuator, be used for before a plurality of main channel wavelength light signals that the optical wavelength demodulation multiplexer decomposites enter electric adjustable optical attenuator, a plurality of main channel wavelength light signals being amplified.This moment, the light amplifier gain at this station comprised light preamplifier and power amplifier sum, and is identical with aforesaid technical scheme to the control method of EVOA.
Another kind of link gain of the present invention is regulated Wave division multiplexing optical transmission system automatically, is made up of upstream relay stations and downstream relay station:
Upstream relay stations comprises Optical Supervisory Channel wavelength emission machine and optical wavelength multiplexing device, wherein
Optical Supervisory Channel wavelength emission machine produces Optical Supervisory Channel wavelength light signal and is transferred to the optical wavelength multiplexing device,
The optical wavelength multiplexing device is transferred on the lightguide cable link after with a plurality of main channel wavelength light signals and Optical Supervisory Channel wavelength light signal multiplexing;
Downstream relay station comprises optical wavelength demodulation multiplexer, beam split power coupler, Optical Supervisory Channel wavelength power detector, the mechanical, electrical adjustable optical attenuator drive circuit of monolithic, electric adjustable light power attenuator, power amplifier, wherein
The electricity adjustable optical attenuator will be transferred to the optical wavelength demodulation multiplexer after the signal attenuation from lightguide cable link,
The optical wavelength demodulation multiplexer will be decomposed into a plurality of main channel wavelength light signals and Optical Supervisory Channel wavelength light signal from the light signal after the electric adjustable optical attenuator decay, and a plurality of main channel wavelength light signals are transferred to power amplifier, simultaneously Optical Supervisory Channel wavelength light signal is transferred to Optical Supervisory Channel wavelength power detector by the beam split power coupler
Optical Supervisory Channel wavelength power detector detects the magnitude of power of Optical Supervisory Channel wavelength light signal and is transferred to single-chip microcomputer,
Single-chip microcomputer calculates the light monitoring and controlling channels wavelength optical signal power numerical value that our station receives with light monitoring and controlling channels wavelength optical signal power numerical value according to the splitting ratio of light splitting power coupler and in conjunction with the attenuation of electric adjustable optical attenuator earlier; Then predetermined station, upstream light monitoring and controlling channels wavelength light output power signal numerical value being gone out the cable line road with the our station received light monitoring and controlling channels wavelength optical signal power numerical value subtraction calculations that calculates always decays; The attenuation that the subtraction calculations that again power amplifier gain value in the downstream stations and the optical cable circuit that calculates always decayed goes out electric adjustable optical attenuator is transferred to electric adjustable optical attenuator drive circuit
Electricity adjustable optical attenuator drive circuit drives electric adjustable optical attenuator according to the attenuation of calculating, and makes the gain of downstream stations power amplifier equal lightguide cable link attenuation and electric adjustable optical attenuator attenuation sum.
Optical line amplifier is used for a plurality of main channel wavelength light signals are amplified back output.
A kind of link gain Automatic adjustment method that is used for Wave division multiplexing optical transmission system of the present invention comprises step: determine station, upstream Optical Supervisory Channel wavelength light output power signal numerical value; Measure downstream stations and receive Optical Supervisory Channel wavelength light signal power numerical value; Two magnitude of power subtraction calculations are gone out the attenuation of lightguide cable link; Calculate the attenuation that electric adjustable optical attenuator should be provided with in the downstream stations according to gain of downstream stations power amplifier and lightguide cable link attenuation; The attenuation that should be provided with according to the electric adjustable optical attenuator of calculate drives electric adjustable optical attenuator, makes the gain of the interior power amplifier in station equal lightguide cable link attenuation and electric adjustable optical attenuator attenuation sum.
The above-mentioned link gain Automatic adjustment method that is used for Wave division multiplexing optical transmission system of the present invention, it is characterized in that: station, upstream Optical Supervisory Channel wavelength light output power signal numerical value is predefined fixed numbers, and is stored in the single-chip microcomputer memory of downstream stations.
The above-mentioned link gain Automatic adjustment method that is used for Wave division multiplexing optical transmission system of the present invention is characterized in that: station, upstream Optical Supervisory Channel wavelength light output power signal numerical value is transferred to the single-chip microcomputer of downstream stations for can change numerical value by Optical Supervisory Channel.
The above-mentioned link gain Automatic adjustment method that is used for Wave division multiplexing optical transmission system of the present invention, it is characterized in that: during electric adjustable optical attenuator should be provided with in calculating downstream stations attenuation, insertion loss when considering main channel wavelength light signal and Optical Supervisory Channel wavelength light signal through optical wavelength multiplexing device and optical wavelength demodulation multiplexer is inconsistent, leading in cable Line Attenuation calibrator quantity in calculating.
The above-mentioned link gain Automatic adjustment method that is used for Wave division multiplexing optical transmission system of the present invention, it is characterized in that: during electric adjustable optical attenuator should be provided with in calculating downstream stations attenuation, consider the situation that increases light preamplifier in the downstream stations, in calculating, introduce the light preamplifier gain.
The above-mentioned link gain Automatic adjustment method that is used for Wave division multiplexing optical transmission system of the present invention is characterized in that: it is the light signal of 1510 nano wave lengths that Optical Supervisory Channel adopts wavelength.
The above-mentioned link gain Automatic adjustment method that is used for Wave division multiplexing optical transmission system of the present invention, it is characterized in that: when detecting Optical Supervisory Channel wavelength light signal power numerical value in the downstream stations and be zero, be judged as Optical Supervisory Channel wavelength light signal interruption, the automatic adjusting of the link gain of the attenuation of the interior electric adjustable optical attenuator in locking station, and time-out at this moment recovered until Optical Supervisory Channel wavelength light signal.
The beneficial effect that link gain of the present invention is regulated Wave division multiplexing optical transmission system and the gain adjusting method therefore that uses automatically is: the cascade optical amplification repeater link of employing the inventive method can identification channel increase and decrease and line loss variation, automatically adjust the EVOA pad value, can not produce and disturb EDFA gain locking function, sudden change or gradual change to line loss made accurately, suitably adjusted, the performance of keeping system is constant substantially, thereby guarantees that system normally moves.
Description of drawings
Fig. 1 is the first example structure schematic diagram that link gain of the present invention is regulated Wave division multiplexing optical transmission system automatically;
Fig. 2 is the second example structure schematic diagram that link gain of the present invention is regulated Wave division multiplexing optical transmission system automatically;
Fig. 3 is the 3rd example structure schematic diagram that link gain of the present invention is regulated Wave division multiplexing optical transmission system automatically.
Embodiment
The invention will be further described below in conjunction with drawings and Examples.In specific implementation process of the present invention, station, upstream (N station) the OSC radiating portion has a kind of execution mode, and the OSC Return Reception Dept. branch of downstream stations (N+1 station) is that three kinds of execution modes are arranged.Fig. 1, Fig. 2 and Figure 3 shows that three specific embodiments of system of the present invention, for convenience of explanation, the system of actual two fine transmitted in both directions of using only expresses a direction of transfer in the drawings.Simultaneously for the station, upstream, promptly the optical amplification repeater station theory diagram at N station also only marks the transmission part among the figure, for illustrative simplicity light is transmitted other vitals in the link simultaneously, component omission such as raman optical amplifier, Dynamic Gain Equalizer (DGE) parts, dispersion compensation module for example, above-mentioned omission does not hinder the description of operation principle of the present invention and explanation.In actual applications, the composition of upstream and downstream relay station is identical, but for convenience, only the draw Return Reception Dept. branch of OSC (Optical Supervisory Channel) of the transmission part of only drawing OSC (Optical Supervisory Channel) at Figure of description middle and upper reaches station, downstream stations.Each letter sign is described as follows in Fig. 1,2,3:
A: as the erbium-doped fiber amplifier (EDFA) of power amplifier and light preamplifier use
B: beam split power coupler
C:1510nm wavelength light power detector
D:1510nm optical wavelength demodulation multiplexer
E: Optical Supervisory Channel 1510nm wavelength optical transmitter
F: lightguide cable link
G: Optical Supervisory Channel 1510nm wavelength light receiver
H: embedded single-chip microcomputer
The I:EVOA Drive and Control Circuit
M:1510nm optical wavelength multiplexing device
S: electric adjustable light power attenuator (EVOA)
Fig. 1 is N fiber spans connection diagram in the Wave division multiplexing optical transmission system link of the present invention, and the station, upstream represent and N+1 stands and represents downstream stations in N station among Fig. 1.Among Fig. 1, in downstream stations N+1 station, be to punish out a part of luminous power, be used for detecting the received optical power of Optical Supervisory Channel wavelength 1510nm, and the transmitting optical power of N station 1510nm wavelength fixed at beam split power coupler B.Therefore as long as known the received optical power of 1510nm wavelength at the N+1 station, just can calculate the optical fiber attenuation value of fiber spans between N station and the N+1 station, the optical fiber attenuation value is by factor decisions such as lightguide cable link length and optical cable and optical fibres wear out.Use EDFA as power amplifier among Fig. 1.
It is as follows among Fig. 1 EVOA to be carried out control method: at first, 1510nm wavelength light power detector C at the N+1 station detects the 1510nm wavelength light power of being punished out by beam split power coupler B, calculates the luminous power Pr of the 1510nm wavelength signals of our station actual reception then according to the beam split ratio of beam split power coupler.1510nm transmitting optical power Pt at the N station is changeless, because the transmitting optical power at each station can accomplish to have reasonable consistency, can adopt and import in advance or import by webmaster.Also can utilize Optical Supervisory Channel that PT is sent to the N+1 station from the N station.The computer H at N+1 station just can calculate the complete attenuation of lightguide cable link like this:
α
∑＝Pt-Pr (4)
Single-chip microcomputer H is easy to by formula in standing:
α
att＝G
edfa-α
∑ (5)
Calculate the attenuation that EVOA should be provided with.Drive the EVOA control circuit, make the insertion decay adjust to the attenuation that formula (5) calculates, can make the Line Attenuation of this fiber spans and amplifier gain reach balance.
Owing to formula (5) develops via formula (3), when consider main channel wavelength light signal and Optical Supervisory Channel wavelength light signal in the station, upstream in optical wavelength multiplexing device and the downstream stations insertion loss of optical wavelength demodulation multiplexer inconsistent, need when calculating our station EVOA attenuation, count calibration value α
Adjust, so formula (5) further is revised as formula (6):
α
att＝G
edfa-α
∑-α
adjust (6)
The EVOA attenuation that adopts formula (6) to be calculated can remedy main channel and Optical Supervisory Channel inserts the lightguide cable link attenuated error of the inconsistent generation of loss.
Fig. 2 is a kind of improvement technical scheme to the embodiment of the invention shown in Figure 1.Increased light preamplifier in the relay station of Fig. 2, this light preamplifier is placed between optical wavelength demodulation multiplexer and the power amplifier.In embodiment illustrated in fig. 2, link gain Automatic adjustment method and embodiment illustrated in fig. 1 basic identical, difference only is should consider the gain values of light preamplifier when calculating the EVOA attenuation, promptly the power amplifier gain values should be EVOA light preamplifier gain before and EVOA power amplifier gain sum afterwards in the relay station that is adopted in the calculating.
Fig. 3 is another embodiment of the self-regulating optical transmission system of link gain of the present invention.Its functional structure of the embodiment of Fig. 3 is slightly different with the embodiment of Fig. 1, Fig. 2, is embodied in the EVOA device and is placed on before the 1510nm wavelength demultiplexer.But the OSC Return Reception Dept. divides the composition of each functional block and Fig. 1, Fig. 2 embodiment basic identical among Fig. 3.Embodiment illustrated in fig. 3 and Fig. 1, main difference embodiment illustrated in fig. 2 are that EVOA is arranged on before the optical wavelength demodulation multiplexer in the relay station of Fig. 3.Among Fig. 3, the Optical Supervisory Channel wavelength power detector C at N+1 station successively monitors the 1510nm wavelength light power that receives, because 1510nm wavelength light signal has also passed through the decay of electric adjustable optical attenuator S, when therefore calculating the Optical Supervisory Channel magnitude of power Pr of downstream stations N+1 station and lightguide cable link tie point place actual reception, should count the attenuation of light splitting coupler B and electric adjustable optical attenuator S, all the other calculate and regulate identical with system shown in Figure 1 with the EVOA attenuation.
When Wave division multiplexing optical transmission system of the present invention enters optical power attenuation (APR) process, should make EVOA enter lock-out state, promptly keep current attenuation.In case the lightguide cable link reparation, after system withdrawed from the APR process, EVOA unlocked to get final product, and power and gain management function can be recovered normal execution.
Claims (9)
1. a link gain is regulated Wave division multiplexing optical transmission system automatically, is made up of upstream relay stations and downstream relay station: upstream relay stations comprises Optical Supervisory Channel wavelength emission machine and optical wavelength multiplexing device, wherein
Optical Supervisory Channel wavelength emission machine produces Optical Supervisory Channel wavelength light signal and is transferred to the optical wavelength multiplexing device,
The optical wavelength multiplexing device is transferred on the lightguide cable link after with a plurality of main channel wavelength light signals and Optical Supervisory Channel wavelength light signal multiplexing;
Downstream relay station comprises optical wavelength demodulation multiplexer, beam split power coupler, Optical Supervisory Channel wavelength power detector, the mechanical, electrical adjustable optical attenuator drive circuit of monolithic, electric adjustable light power attenuator, power amplifier, wherein
The optical wavelength demodulation multiplexer will be decomposed into a plurality of main channel wavelength light signals and Optical Supervisory Channel wavelength light signal from the light signal of lightguide cable link, and a plurality of main channel wavelength light signals are transferred to electric adjustable optical attenuator, simultaneously Optical Supervisory Channel wavelength light signal is transferred to Optical Supervisory Channel wavelength power detector by the beam split power coupler
Optical Supervisory Channel wavelength power detector detects the magnitude of power of Optical Supervisory Channel wavelength light signal and is transferred to single-chip microcomputer, single-chip microcomputer earlier calculates the Optical Supervisory Channel wavelength light signal power numerical value that our station receives with Optical Supervisory Channel wavelength light signal power numerical value according to the splitting ratio of beam split power coupler, then predetermined station, upstream Optical Supervisory Channel wavelength light output power signal numerical value is received Optical Supervisory Channel wavelength light signal power numerical value subtraction calculations with the our station that calculates and go out the lightguide cable link complete attenuation, the attenuation that the power amplifier yield value in the downstream stations and the lightguide cable link complete attenuation subtraction calculations that calculates are gone out electric adjustable optical attenuator is transferred to electric adjustable optical attenuator drive circuit again
Electricity adjustable optical attenuator drive circuit drives electric adjustable optical attenuator according to the attenuation of calculating, and makes the gain of our station power amplifier equal lightguide cable link attenuation and electric adjustable optical attenuator attenuation sum,
Power amplifier is used for a plurality of main channel wavelength light signals are amplified back output.
2. regulate Wave division multiplexing optical transmission system automatically according to the link gain of claim 1, it is characterized in that downstream stations has also comprised a light preamplifier, this light preamplifier is between optical wavelength demodulation multiplexer and electric adjustable optical attenuator, be used for before a plurality of main channel wavelength light signals that the optical wavelength demodulation multiplexer decomposites enter electric adjustable optical attenuator, a plurality of main channel wavelength light signals being amplified;
Described single-chip microcomputer calculates the light monitoring and controlling channels wavelength optical signal power numerical value that our station receives with light monitoring and controlling channels wavelength optical signal power numerical value according to the splitting ratio of light splitting power coupler earlier; The light monitoring and controlling channels wavelength optical signal power numerical value subtraction calculations that then predetermined station, upstream light monitoring and controlling channels wavelength light output power signal numerical value and our station is received goes out the cable line road and always decays, and the attenuation that the subtraction calculations that again power amplifier gain value in the downstream stations and light preamplifier gain value sum and the optical cable circuit that calculates always decayed goes out electric adjustable optical attenuator is transferred to electric adjustable optical attenuator drive circuit.
3. a link gain is regulated Wave division multiplexing optical transmission system automatically, is made up of upstream relay stations and downstream relay station:
Upstream relay stations comprises Optical Supervisory Channel wavelength emission machine and optical wavelength multiplexing device, wherein
Optical Supervisory Channel wavelength emission machine produces Optical Supervisory Channel wavelength light signal and is transferred to the optical wavelength multiplexing device,
The optical wavelength multiplexing device is transferred on the lightguide cable link after with a plurality of main channel wavelength light signals and Optical Supervisory Channel wavelength light signal multiplexing;
Downstream relay station comprises optical wavelength demodulation multiplexer, beam split power coupler, Optical Supervisory Channel wavelength power detector, the mechanical, electrical adjustable optical attenuator drive circuit of monolithic, electric adjustable light power attenuator, power amplifier, wherein
The electricity adjustable optical attenuator will be transferred to the optical wavelength demodulation multiplexer after the signal attenuation from lightguide cable link,
The optical wavelength demodulation multiplexer will be decomposed into a plurality of main channel wavelength light signals and Optical Supervisory Channel wavelength light signal from the light signal after the electric adjustable optical attenuator decay, and a plurality of main channel wavelength light signals are transferred to power amplifier, simultaneously Optical Supervisory Channel wavelength light signal is transferred to Optical Supervisory Channel wavelength power detector by the beam split power coupler
Optical Supervisory Channel wavelength power detector detects the magnitude of power of Optical Supervisory Channel wavelength light signal and is transferred to single-chip microcomputer, single-chip microcomputer earlier calculates the Optical Supervisory Channel wavelength light signal power numerical value that our station receives with Optical Supervisory Channel wavelength light signal power numerical value according to the splitting ratio of beam split power coupler and in conjunction with the attenuation of electric adjustable optical attenuator, then predetermined station, upstream Optical Supervisory Channel wavelength light output power signal numerical value is received Optical Supervisory Channel wavelength light signal power numerical value subtraction calculations with the our station that calculates and go out the lightguide cable link complete attenuation, the attenuation that the power amplifier yield value in the downstream stations and the lightguide cable link complete attenuation subtraction calculations that calculates are gone out electric adjustable optical attenuator is transferred to electric adjustable optical attenuator drive circuit again
Electricity adjustable optical attenuator drive circuit drives electric adjustable optical attenuator according to the attenuation of calculating, and makes the gain of downstream stations power amplifier equal lightguide cable link attenuation and electric adjustable optical attenuator attenuation sum,
Power amplifier is used for a plurality of main channel wavelength light signals are amplified back output.
4. link gain Automatic adjustment method that is used for Wave division multiplexing optical transmission system comprises step:
Determine station, upstream Optical Supervisory Channel wavelength light output power signal numerical value;
Measure downstream stations and receive Optical Supervisory Channel wavelength light signal power numerical value;
Two magnitude of power subtraction calculations are gone out the attenuation of lightguide cable link;
Calculate the attenuation that electric adjustable optical attenuator should be provided with in the downstream stations according to gain of downstream stations power amplifier and lightguide cable link attenuation;
The attenuation that should be provided with according to the electric adjustable optical attenuator of calculate drives electric adjustable optical attenuator, makes the gain of the interior power amplifier in station equal lightguide cable link attenuation and electric adjustable optical attenuator attenuation sum.
5. according to the link gain Automatic adjustment method that is used for Wave division multiplexing optical transmission system of claim 4, it is characterized in that:
Station, upstream Optical Supervisory Channel wavelength light output power signal numerical value is predefined fixed numbers, and is stored in the single-chip microcomputer memory of downstream stations.
6. according to the link gain Automatic adjustment method that is used for Wave division multiplexing optical transmission system of claim 4, it is characterized in that:
Station, upstream Optical Supervisory Channel wavelength light output power signal numerical value is transferred to the single-chip microcomputer of downstream stations for can change numerical value by Optical Supervisory Channel.
7. according to the link gain Automatic adjustment method that is used for Wave division multiplexing optical transmission system of claim 4, it is characterized in that:
During electric adjustable optical attenuator should be provided with in calculating downstream stations attenuation, insertion loss when considering main channel wavelength light signal and Optical Supervisory Channel wavelength light signal through optical wavelength multiplexing device and optical wavelength demodulation multiplexer is inconsistent, leading in cable Line Attenuation calibrator quantity in calculating.
8. according to the link gain Automatic adjustment method that is used for Wave division multiplexing optical transmission system of claim 4, it is characterized in that:
It is the light signal of 1510 nano wave lengths that Optical Supervisory Channel adopts wavelength.
9. according to the link gain Automatic adjustment method that is used for Wave division multiplexing optical transmission system of one of claim 4 to 8, it is characterized in that:
When detecting Optical Supervisory Channel wavelength light signal power numerical value in the downstream stations and be zero, be judged as Optical Supervisory Channel wavelength light signal interruption, the automatic adjusting of the link gain of the attenuation of the interior electric adjustable optical attenuator in locking station, and time-out at this moment recovered until Optical Supervisory Channel wavelength light signal.
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| CN 200410102768 CN1288869C (en) | 2004-12-29 | 2004-12-29 | A WDM optical transmission system with automatic link gain adjustment and method thereof |
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| CN 200410102768 CN1288869C (en) | 2004-12-29 | 2004-12-29 | A WDM optical transmission system with automatic link gain adjustment and method thereof |
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| CN101656589B (en) * | 2008-08-21 | 2013-04-17 | 华为技术有限公司 | Method and device for optimizing DWDM network channel |
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| CN111416663A (en) * | 2020-04-27 | 2020-07-14 | 中国电子科技集团公司第三十四研究所 | High-performance radio frequency optical transmission link structure |
| CN114205047A (en) * | 2021-12-10 | 2022-03-18 | 中国电信股份有限公司 | Automatic configuration method and device for optical multiplexing section |
| CN116647276A (en) * | 2022-02-16 | 2023-08-25 | 中兴通讯股份有限公司 | Channel power control method, control equipment and storage medium of optical network |
| CN114745048B (en) * | 2022-04-14 | 2023-10-31 | 中国电信股份有限公司 | Service implementation method and device, computer readable storage medium and electronic equipment |
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