Since the optical post-amplifier is operated in the AGC mode, the optical output level is also within a specified range when the optical post-amplifier input is within a specified range. Also, at that time, the connectors do not have to be re-connected, contrary to the case where the optical loss between the nodes is measured with measuring equipment, so that the loss including the loss in the connector junction can be accurately measured, thus making it unnecessary to take an extra loss margin into consideration when the optical circuit is designed. If the judgement is NO in step S 24 , in step S 25 , judge whether a normal operation state is being continuously received from the fore node. In the optical pre-amplifier which has two control modes, ALC and AGC, when a notice of a normal operation state from a fore node is cleared or the number of wavelengths changes while the optical per-amplifier is controlled in the ALC mode, the ALC mode is stopped; if an effective gain value of the optical amplifier is backed up, the optical pre-amplifier is transferred to the AGC mode using the backed-amplifier gain value; if an effective gain of the optical pre-amplifier is not backed up, the output of the optical pre-amplifier is shutdown until the optical pre-amplifier receives a notice of a normal operation state again. Log in to Access Subscription. The optical-amplifier supervisory control system according to claim 9 , wherein the serial number of the optical pre-amplifier and the serial number of the shelf in which the optical pre-amplifier is accommodated are stored in the memory, and when e optical pre-amplifier is started after a power failure has occurred, the serial numbers of the optical pre-amplifier and the shelf are compared with the stored serial numbers of the optical pre-amplifier and the shelf, and when both the serial numbers coincide, the optical pre-amplifier is started in the automatic gain control mode.
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(Video) Features of Optical Power Management in WDM Systems_8800_6800_3800
It is possible to correct the change of optical loss due to external factors such as an ambient temperature of an optical fiber by re-adjusting the optical pre-amplifier gain in the ALC mode periodically.
The WDM transmission apparatus comprises a gain control circuit which has two control modes, ALC and AGC, an amplifier gain back-up unit, an OSC transmission and receiving circuit which transmits and receives a supervisory control signal, a guard-time timer which has a longer timed-out time than the time required to process and transfer supervisory control information between the nodes; a longer time is taken for the ALC time constant than the time required to process and transfer the supervisory control information between the nodes; even if the number of optical wavelengths or the optical level fluctuate during operation in the ALC mode, the gain of the optical pre-amplifier is kept almost unchanged in the period until new supervisory control information the number of optical wavelengths and the normal operation state is transmitted from the fore node.
The optical-amplifier supervisory control system according to claim 11wherein if no gain value is stored in the memory when the optical pre-amplifier transfers from the automatic level control mode to the automatic gain control mode, the output of the optical pre-amplifier is shut down. Even if the number of wavelengths or the output of the optical post-amplifier of the fore node fluctuates due to the increase and decrease of the number of alf, etc.
The optical amplifier supervisory control method as claimed in claim 18wherein wddm changing of the optical preamplifier from the automatic level control mode to the automatic gain control mode is repeated after each wsm changing of the optical pre-amplifier from the automatic gain control mode to the automatic level control mode.
Equations displayed with MathJax. The fore node informs the next node of a normal operation state when the output of the optical post-amplifier is within a specified level range.
Index of /pilotes/XLAN/XLAN4/driver/INTEL/I/SOUND/ALC/WDM
In the path through which an optical signal usually does not pass, like a protection path, since there is no optical input or output level, the optical amplifier cannot be controlled by ALC or AGC, so the optical amplifier must be kept shutdown.
Please note that one of the multiplexed wavelengths is cut off in the optical signal which is inputted in the optical amplifier, and the wavelengths other than the one which was cut off are amplified to a greater degree because the ALC mode tries to keep the total output level constant. After the optical pre-amplifier is started up in the ALC mode in the method mentioned above, when the gain control circuit changes over the operation mode to AGC mode and backs up the amplifier gain in the back-up unitthe adm number of the optical pre-amplifier stored in the non-volatile memory and the serial number of the shelf stored in the non-volatile memory are backed up together with the amplifier gain in the sdm unit If the output optical level which is monitored by the output power monitor falls within tolerance and for a specified time, the gain control circuit backs up the amplifier gain of that moment in the amplifier gain back-up unitand starts the guard-time timer The guard-time timer has a longer time than the time required to process and transfer supervisory control information between the nodes.
In order to prevent this, when power is turned on, the amplifier gain as well as the serial numbers written on the non-volatile memory and for the optical pre-amplifier unit and the shelf respectively are compared with those in the back-up unitand only when both factors coincide, the amplifier gain backed up in the back-up unit is judged to be effective, and the optical pre-amplifier is started up using the backed-up amplifier gain.
If the judgement is NO in step S 30judge whether the guard-time timer has got timed-out in step S While the optical amplifier is in operation in the AGC mode, the optical pre-amplifier is periodically changed over to the ALC mode, and when the output of the optical pre-amplifier falls within a target output range for more than a specified time, the amplifier gain at that moment is substituted on the amplifier gain back-up unit and is backed up, and when the guard-time timer is started and the normal operation state from the fore node continues during the period until the guard-time timer gets timed-out, the optical pre-amplifier is returned to the AGC mode.
Method and apparatus for automatically identifying system faults in an optical communications system from repeater loop gain signatures. Access To view this article you will need to login or make a payment.
If the judgement is Ac in step S 24in step S 25judge whether a normal operation state is being continuously received from the fore node.
Controller which controls a variable optical attenuator to control the power level of a wavelength-multiplexed optical signal when the number of the channels are varied.
Method and apparatus for automatically controlling optical signal power in optical transmission systems.
【资料分享】OptiX NG WDM ALC自动光功率控制专题
The OSC transmission and edm circuit takes out the normal operation state information and the wavelength number information from the OSC signal sent through the supervisory control wavelength.
Optical cross-connect device, optical edm control method, a wavelength multiplexing transmission system and an optical amplifier control method. Qlc present invention relates to a WDM Wavelength Division Multiplexing transmission apparatus and an optical amplifier control system which are used for a WDM communication network, and more specifically to an optical amplifier control system which supports an optical wavelength ADM add drop multiplexing function and an optical path protection function in the WDN communication network.
Optical transmission system, optical repeating apparatus, and quality supervising method. If you are already logged in but alf at this page, it means you do not have paid access to this content. That is, if a longer time is given for the ALC time constant than the time required to process and transfer the supervisory control information between the nodes, the optical pre-amplifier output does not produce such a level fluctuation that gives rise to an error even if an optical signal whose number of wavelengths have been changed is inputted into the optical pre-amplifier before the next node is informed of the new wavelength information.
However, in the measurement which is carried out using measuring equipment, the loss changes between the state where the measurement equipment is connected and the state where connectors are engaged in a practical use, so it is not easy to accurately measure the loss including the loss in the connector junction. Alc agc and having a high-gain active circuit components for the downlink synchronization control function.
When the optical amplifier is in routine operation, there is a possibility that the gain for the AGC mode cannot be accurately set if the gain is backed up while the optical amplifier input is fluctuating in the method that when the optical amplifier is started, the optical amplifier is started in aoc ALC mode in order to correct the loss between the nodes and changed over from the ALC mode to the AGC mode using the gain determined in the ALC mode in order to prevent an error due to the increase or decrease of the wavelengths or a sudden change of the number of optical wavelengths wddm level by a path protection switch.
Index of /pilotes/XLAN/XLAN4/driver/INTEL/I852/SOUND/ALC/WDM
Wavelength division multiplexing device, an optical leakage prevention method, and a wavelength division multiplexing communication system. The WDM transmission apparatus has a back-up unit which backs up the gain of the optical pre-amplifier in a non-volatile memory, and backs up, in the back-up unit, the amplifier gain backed up in the amplifier gain back-up unit when the optical pre-amplifier is changed over from ALC to AGC.
Light power control system, light power control node apparatus, and method of controlling light power.