WO2007143892A1

WO2007143892A1 - A method for optimizing power of the oadm ring network multiplexing segment and a system thereof

Info

Publication number: WO2007143892A1
Application number: PCT/CN2006/003788
Authority: WO
Inventors: Hongyü ZHANG; Xiaoqiang Wei; Jiaying Wang
Original assignee: Zte Corporation
Priority date: 2006-06-12
Filing date: 2006-12-30
Publication date: 2007-12-21
Also published as: CN1866797A; CN100505591C

Abstract

A method for optimizing power of the OADM ring network multiplexing segment and a system thereof, each network element in the system comprises a VOA and an OA connected to the upstream optical multiplexing segment and an OA connected to the downstream optical multiplexing segment, wherein each network element is connected to a control apparatus, the method comprises: monitoring the input and output power of each network element, calculating the gain attenuation sum of each optical multiplexing segment and the total gain attenuation sum of the ring network; determining whether the ring network status satisfy the restriction, if no, determining the OA and VOA to be adjusted and the adjust amount thereof, based on the difference between the gain attenuation sum of each optical multiplexing segment and the total gain attenuation sum of the ring network and the respective restriction thereof, and based on the adjust range of the OA and VOA corresponding to the downstream node of the optical multiplexing segment, so as to make the total gain attenuation sum of the ring network satisfy the restriction; sending and executing the OA and VOA to be adjusted and the adjust amount thereof, so as to optimize the ring network. The invention could prohibit the OSNR degradation and power degradation of the ring network, and avoid the ring network self-excitation as well.

Description

TECHNICAL FIELD The present invention relates to a WDM optical transmission device in the field of communications, and in particular, to a multiplex section of an OADM (optical add/drop multiplexer) ring network. Power optimization methods and systems. BACKGROUND OF THE INVENTION In a WDM system for urban optical transport network applications, OADM equipment is widely used to form an OADM ring network. The gain and loss of the OADM ring network includes the loss of the OADM device within the node, the gain of the upstream node OA (optical amplifier), the fiber line loss, and the gain of the downstream node OA. Among them, the loss of the OADM device in the gain compensation node of the upstream node OA, the loss of the OADM device is stable, so the OA gain of the upstream node OA can be adjusted to compensate the loss of the OADM device during device debugging, and no change needs to be considered in the operation of the device. Thus, in the operation of the equipment, the variation of the gain and loss of the ring network is mainly determined by the variation of the fiber line damage and the gain of the downstream node OA. When the condition of the optical fiber line changes (aging, temperature, etc.), the line loss will have a deviation value, and the gain of the ring network may be greater than the loss or less than the loss. When the loop gain and loss ratio is too small, the OSNR (Optical Signal-to-Noise Ratio) and optical power of the ring network will deteriorate. In the limit case, the system will generate bit errors. In the OADM ring network, there is a wavelength of protection, an idle wavelength, or an inconsistency between the bandwidth of the OADM device and the center wavelength, causing a part of the wavelength leakage (such as the bandwidth of the band-stop filter and the band-pass filter, the inconsistency of the center wavelength, and the band rejection filter). At the lower end of the band, outside the bandwidth of the band-stop filter, but the wavelength that is still within the bandwidth of the band-pass filter will leak). These wavelengths are directly connected at various points of the ring network, and loops are formed by OADM devices, optical amplifiers, and fiber transmission links. When the total gain of the loop is greater than the total loss, the noise of the optical amplifier is continuously amplified in the network, which may form itself. The oscillation will seriously affect the network work. In the OADM ring network shown in Figure 1, a wavelength that is directly through at each point will form a loop in the ring network. If the total gain formed by the optical amplifier is greater than the total loss inside the fiber line and the OADM node, the network may be generated. Self-excited. Therefore, in the OADM ring network, when the optical line conditions change (aging, temperature, etc.), the power of the OADM ring optical multiplex section (OMS) must be controlled to control the gain and loss of the ring network within an appropriate range. At present, there are methods and devices for avoiding self-excitation of the OADM ring network separately, and there is also a power element optimization method at the network element level established on the link, but it is not seen that the optical power of the ring network is controlled, and the ring network is suppressed. A method of making the gain and loss of the ring network within a suitable range. SUMMARY OF THE INVENTION The problem to be solved by the present invention is to provide an optical add/drop multiplexer ring network multiplex section power optimization method and system thereof, which can avoid the OSNR and power of the ring network and prevent the ring network from generating self-excitation. In order to solve the above technical problem, the present invention provides a power optimization method for a multiplex section of an optical add/drop multiplexer ring network, which is applied to a corresponding optical amplifier OA at an upstream node of each optical multiplex section, and a corresponding OA and optical attenuator at a downstream node. The VOA system, the method includes the following steps: monitoring the input and output power of the amplifiers in each network element of the ring network, and calculating the gain attenuation of each optical multiplex section and the total gain attenuation of the ring network;

(b) judging the calculated gain attenuation of each optical multiplex section and the total gain attenuation of the ring network and whether it is within the range specified by the ring network constraint, if yes, perform step); otherwise, perform step (c); c) determining the OA and VOA to be adjusted and the adjustment amount according to the gain attenuation of each optical multiplex section and the total gain attenuation of the ring network and the difference between the respective constraints, and the adjustment range of the corresponding OA and VOA of the downstream node of the optical multiplex section , making the total gain of the ring network attenuate and satisfy the constraints;

(d) The OA and VOA to be adjusted and their adjustments are issued to optimize the ring network. Further, the foregoing method may further have the following feature: calculating the gain attenuation of a certain optical multiplex section in the step), subtracting the output optical power of the upstream node corresponding to the OA of the monitored optical multiplex section from the downstream node thereof Corresponding to the input optical power of the OA, plus the gain of the downstream node corresponding to the OA, or the output optical power of the downstream node corresponding to the OA minus the output optical power of the upstream node corresponding to the OA; The attenuation sum is obtained by attenuating and adding the gains of the optical multiplex sections of the ring network. Further, the above method may further have the following characteristics: the requirement of the gain attenuation and Mi for each optical multiplex section in the ring network constraint in the step (b) is: Cl < Mi <0,; The requirements of M are: C2 < M <0; where C1 and C2 are preset constants less than 0, and the total gain attenuation of the ring network and the requirement of M are given priority. Further, the above method may further have the following features: The step (C) further includes the following steps:

(c1) calculating the gain of the optical multiplex section that does not satisfy the constraint and the reachable value that can be reached closest to a set standard value according to the adjustment range of the OA and VOA corresponding to the downstream node of the optical multiplex section;

(c2) adding the gain attenuation and the reachable value of each optical multiplex section to be adjusted and the measured value of the attenuation of each optical multiplex section without adjustment, and comparing with the constraint of the total gain attenuation of the ring network, such as If the condition is met, the reachable value is the final value of the attenuation and adjustment of the corresponding optical multiplex section gain, and step (c4) is performed. If the condition is not met, step (c3) is performed; (c3) each optical multiplex section of the ring network The gain reduction and the reachable value or the detected value are finely adjusted, so that the total gain of the ring network is attenuated and the constraint condition is satisfied, and the value after the fine adjustment is used as the final value of the gain attenuation and adjustment of each optical multiplex section;

(c4) The difference between the current value and the final value of the attenuation of each optical multiplex section gain, that is, the adjustment amount is allocated to the OA and/or VOA of the downstream node, and ends. Further, the above method may further have the following features: The standard value in the step (cl) is selected within a range specified by the optical multiplex section gain attenuation and the constraint condition. Further, the above method may further have the following features: The step (cl) is further divided into the following steps:

(cll) starting with a certain network element, starting from the first optical multiplex section, determining its gain attenuation and whether the constraint is satisfied, and finding the first optical multiplex section that does not satisfy the constraint, Next step;

(cl2) according to the adjustment range of the corresponding OA and VOA of the downstream node of the current optical multiplex section, selecting a standard value from the specified range of the constraint condition, and calculating the gain attenuation of the optical multiplex section and the achievable closest to the standard value Value; (cl3) Determine whether the optical multiplex section gain attenuation and the reachable value of Mi satisfy the constraint: C1

<Mi<0, if yes, execute step (cl7), otherwise execute step (cl4);

(cl4) determining whether the gain attenuation of the optical multiplex section and the reachable value of Mi are greater than zero, and if yes, performing step (cl5); otherwise, performing step (cl6); (cl5) If the upstream optical multiplex section has not been processed, the difference between the value of the constraint specified in the range closest to Mi and the reachable value of the current optical multiplex section Mi is taken as the offset value, and is allocated to the upstream optical multiplex section, and the steps are performed. (cl7);

(cl6) if the downstream optical multiplex section has not been processed, the difference between the value of the constraint specified range closest to Mi minus the current optical multiplex section Mi reachable value is used as the offset value, and is allocated to the downstream optical multiplex section;

(cl7) Determine whether each optical multiplex section of the ring network has been processed. If yes, perform step (c2); otherwise, the following optical multiplex section is the current multiplex section, and perform step (cl8);

(cl8) determining whether the current optical multiplex section is assigned a deviation value, and if so, using the sum of the offset values assigned by the other optical multiplex sections as a standard value, calculating the optical multiplex section gain attenuation and the closest achievable to the standard The reachable value of the value, return to step (cl3), if no deviation value is assigned, execute (cl9);

(cl9) Determine the gain attenuation of the optical multiplex section and whether the constraint is satisfied. If it is satisfied, no adjustment is needed, and step (cl7) is performed; otherwise, the step (cl2) is returned. Further, the foregoing method may further have the following features: when the step (c3) is fine-tuned for the gain-attenuation and the reachable value or the detected value of each optical multiplex section, the reachable value or the detected value is preferentially satisfied. The gain and attenuation of the optical multiplex section with conditions and adjustment room and the direction adjustment to satisfy the total gain attenuation and constraints of the ring network; if the total gain attenuation and constraints of the ring network are not met, the optical multiplex section gain is attenuated and adjusted to Beyond the constraints, or replace the OA and / or VOA. Further, the above method may further have the following features: when the adjustment of the optical multiplex section gain attenuation and the adjustment amount is performed in the step (c4), when the gain attenuation is to be increased, the attenuation of the VOA is preferentially reduced, and then increased. The gain of the large OA; when the gain attenuation is to be reduced, the gain of the OA is preferentially reduced, and the attenuation of the VOA is increased. Further, the above method may further have the following features: In the step (d), when sorting the adjustment amount of the OA and the VOA to be adjusted, the priority of the ring network is preferentially arranged when the first round is sent. Attenuation and the amount of adjustment that tends to satisfy the constraint or can maintain the constraint. If there is still an adjustment amount that has not been issued, the second round will continue to be issued according to the priority principle. Further, the above method may further have the following features: In the step (d), the adjustment amount issued to an OA or VOA does not exceed a set unit step size, and the one-time delivery may not be completed, and the multiple rounds are performed. hair. The optical add/drop multiplexer ring network multiplex section power optimization system provided by the present invention includes an optical multiplexing section Connected network elements, each of which includes a tunable optical attenuator VOA connected to the upstream optical multiplex section, an optical amplifier OA connected to the VOA, and an OA connected to the downstream optical multiplex section, and each network element is Connected to a control device, the control device further includes a monitoring module, a control module, and an execution module, wherein: the monitoring module is connected to the OA in each network element, and is configured to monitor input and output power of each OA, and output to The control module is configured to monitor the input and output power of each OA, calculate the gain attenuation of each optical multiplex section, and the total gain attenuation of the ring network, and determine whether the respective ring network constraints are met. Within the range, if it is not satisfied, the OA to be adjusted is determined according to the gain attenuation of each optical multiplex section and the difference between the total gain attenuation of the ring network and the constraint conditions, and the adjustment range of the OA and VOA corresponding to the downstream nodes of each optical multiplex section. And the VOA and the adjustment amount thereof; the execution module is connected to the OA and the VOA in each network element, and is used for issuing the OA and VOA and the adjustment value determined according to the control module. . Further, the above system may further have the following features: The control module further includes a gain attenuation and calculation unit, an adjustment decision unit, and an adjustment amount calculation unit: a gain attenuation and calculation unit, and a first calculation sub-unit, configured to For each optical multiplex section, calculate the difference between the upstream node's OA output optical power and the downstream node's corresponding OA input optical power, and the downstream node's corresponding OA gain, that is, obtain the gain and attenuation of the optical multiplex section; a second calculating sub-unit, configured to obtain gain and attenuation and summation of each optical multiplex section in the obtained ring network, to obtain a total gain attenuation of the ring network; and an adjustment determining unit, configured to increase the gain of each optical multiplex section of the ring network The attenuation and the total gain attenuation of the ring network are compared with the ring network constraints. If the constraint condition is met, no optimization is needed; if the constraint condition is not met, the trigger adjustment amount calculation unit is processed; the adjustment amount calculation allocation unit includes: a first calculating sub-unit, configured to calculate an adjustment of each optical multiplex section according to a gain attenuation sum, a constraint condition, and an adjustment amount of each optical multiplex section The second calculation sub-unit is configured to add the target values adjusted by the optical multiplex sections, and determine the final value of each optical multiplex section adjustment compared with the constraint condition of the total gain attenuation of the ring network, so that the total ring network is The gain is attenuated and the constraint is satisfied; the allocation subunit is configured to calculate the adjustment value of the final value of each optical multiplex section adjustment and allocate it to the OA and/or VOA corresponding to the downstream node. Further, the above system may further have the following features: The control module further includes an adjustment and sorting unit, configured to preferentially schedule the total gain of the ring network to be attenuated and tend to satisfy the constraint condition or maintain the constraint condition when the first round is sent. The amount of adjustment, if there is still an adjustment amount that has not been issued, and then continues to be issued according to the priority principle in the second round; and the adjustment amount issued to an OA or VOA in each round does not exceed one unit step, one time is issued. If it is not complete, it will be issued in multiple rounds; Further, the above system may further have the following features: the first calculation subunit of the adjustment amount calculation allocation unit is configured to calculate the adjustment range of the corresponding OA and VOA of the downstream node of the optical multiplexing segment, and calculate each of the unsatisfied constraints. The optical multiplex section gain attenuation and the reachable value that can be reached closest to a set standard value selected from the range specified by the optical multiplex section gain attenuation and the constraint, or the standard value is The deviation value of the reachable value and the constraint condition assigned by the upstream or downstream node; the second calculation sub-unit of the adjustment amount calculation allocation unit obtains the final value of the gain attenuation and adjustment of each optical multiplex section as follows: Adjusting the gain attenuation and the reachable value of each optical multiplex section and the detected values of the gain attenuation of each optical multiplex section that are not adjusted, and comparing with the constraint of the total gain attenuation of the ring network, if the condition is satisfied, The reachable value is the final value of the gain attenuation and adjustment of the corresponding optical multiplex section. If the condition is not met, the gain attenuation and reachable value or detection of each optical multiplex section of the ring network The value is fine-tuned so that the total gain of the ring network is attenuated and the constraints are met, and the trimmed value is used as the final value of the gain reduction and adjustment of each optical multiplex section. Further, the above system may also have the following features: The control device is connected to each network element through a network management system or a signaling system. It can be seen from the above that the optical power of the optical multiplexing section of the OADM ring network is optimized according to the optical power of the optical multiplexing section of the OADM ring network, and the optical power of the optical multiplexing section of the ring network is optimized when the line loss changes due to aging or temperature. The control loop gain and loss are within the proper range. Due to the consideration of excessive ring loss and self-excitation, the ring network OSNR and power degradation caused by the increase of line loss are effectively avoided, and the avoidance is effectively avoided. The loss is reduced and the ring network is self-excited. Further, when the adjustment amount is issued, technical measures such as adjustment subdivision and adjustment sequence optimization can be adopted, and the device is gradually optimized to ensure that the device has no error code operation. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of an OADM ring network;

2 is a schematic diagram of an OADM ring network for implementing multiplex section power optimization according to an embodiment of the present invention; 3 is a schematic diagram of an overall process for implementing a power optimization method for a multiplex section of a ring network according to an embodiment of the present invention; FIG. 4 is a schematic flowchart of a method for optimizing gain attenuation and method of each optical multiplex section of a ring network;

Figure 5 is a schematic flow chart of the method for optimizing the adjustment sequence;

6 is a schematic diagram of a four-node OADM ring network implementing multiplex section power optimization. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the technical solution are further described in detail below with reference to the accompanying drawings. FIG. 1 is a schematic diagram of an OADM ring network, and each network element includes a wavelength converter (OUT) and an optical add/drop multiplexer. (OADM) and optical amplifier (OA). In Figure 1, at the wavelengths through which each node is through, when the loop gain is greater than the loss, it will self-excitation in the ring network, which will degrade the transmission performance of the ring network. The wavelengths through which the nodes are directly connected include: the wavelength of the protection, the wavelength of the idle wavelength, or the inconsistency of the bandwidth of the OADM device and the center wavelength, causing a part of the wavelength leakage. 2 is a schematic diagram of an OADM ring network implementing the multiplex power of the OADM ring network of the embodiment, each of which is composed of a wavelength converter (OUT), an optical add/drop multiplexer (OADM), and an optical amplifier (OA). ), a tunable optical attenuator (VOA) and a control unit. In the following, the corresponding OA of the upstream node of the optical multiplex section refers to the OA connected to the optical multiplex section in the upstream node, and the OA corresponding to the downstream node of the optical multiplex section refers to the downstream node connected to the optical multiplex section by a VOA. OA. The control device is connected to each network element through a network management system or a signaling system, and is used to implement power optimization of the OADM ring network multiplex section. The device further includes a monitoring module, a control module, and an execution module. The monitoring module is connected to the OA in each network element, and can be connected through a network management system or a signaling system, and is used for monitoring input and output power of each OA, and outputting to the control module; the control module, the control The module is configured to monitor the input and output power of each OA, calculate the gain attenuation of each optical multiplex section, and the total gain attenuation of the ring network, and determine whether it meets the range specified by the respective ring network constraints, and does not satisfy Determine the OA and VOA to be adjusted and their adjustment amount according to the gain attenuation of each optical multiplex section and the difference between the total gain attenuation of the ring network and the constraint conditions, and the OA and VOA adjustment ranges of the downstream nodes of each optical multiplex section; The method includes: a gain attenuation and a calculation unit, including: a first calculation subunit, configured to calculate, for each optical multiplex section, a difference between an OA output optical power of the upstream node and an OA input optical power of the downstream node, The span loss, plus the gain of the downstream node corresponding to the OA, obtains the gain and attenuation sum of the optical multiplex section; the second calculation sub-unit is used to obtain the gain and attenuation and phase of each optical multiplex section in the obtained ring network. Plus, obtain the total gain attenuation of the ring network. Adjusting the decision unit for comparing the gain attenuation of each optical multiplex section of the ring network and the total gain attenuation of the ring network with the ring network constraint condition, if the constraint condition is met (see below), no optimization is needed; The constraint condition is triggered by the adjustment amount calculation unit; the adjustment amount calculation distribution unit comprises: a first calculation sub-unit, configured to calculate the gain attenuation of each optical multiplexing segment, corresponding constraints, adjustment amount, and other optical multiplexing The deviation value assigned by the segment calculates the target value of each optical multiplex section adjustment. Specifically, in this embodiment, according to the adjustment range of the OA and VOA corresponding to the downstream node of the optical multiplex section, the gain of the optical multiplex section that does not satisfy the constraint condition and the reachable value that can be reached closest to a set standard value are calculated. The standard value is selected from a range specified by the optical multiplex section gain attenuation and the constraint condition, or the standard value is a deviation value of the reachable value and the constraint condition allocated from the upstream or downstream node; the second calculation subunit And adding the target values adjusted by the optical multiplex sections, and determining the final value of each optical multiplex section adjustment compared with the constraint condition of the entire ring network, so that the total gain of the ring network is attenuated and the constraint condition is satisfied. Specifically, in this embodiment, the gain of the optical multiplex section to be adjusted and the reachable value of each optical multiplex section and the detected value of the attenuation of each optical multiplex section are not added, and the constraint of the total gain attenuation of the ring network is For example, if the condition is met, the reachable value is the final value of the attenuation and adjustment of the corresponding optical multiplex section gain. If the condition is not met, the gain or attenuation or the reachable value or the detected value of each optical multiplex section of the ring network is performed. Fine-tuning, so that the total gain of the ring network is attenuated and the constraints are satisfied, and the trimmed value is used as the final value of the gain attenuation and adjustment of each optical multiplex section; and the allocation sub-unit is used to calculate the final value of each optical multiplex section adjustment. The amount is adjusted and assigned to the OA and/or VOA corresponding to the downstream node. The adjustment sorting unit is configured to perform execution in a unit step and a scheduled order, so that the ring network is gradually and gradually optimized; in the first round, the total gain of the ring network is attenuated and tends to satisfy the constraint or can be maintained. The adjustment amount that satisfies the constraint condition, if there is still an adjustment amount that is not issued, and then continues to be issued according to the priority principle in the second round. Moreover, the adjustment amount issued to an OA or VOA in each round does not exceed one unit step, and one time is not completed, and is issued in multiple rounds. The execution module is connected to the OA and the VOA in each network element, and is configured to perform dynamic adjustment according to a certain step according to the OA and VOA, the adjustment value, and the adjustment sequence determined by the control module, so as to achieve the total gain of the ring network. Attenuate and satisfy the constraints, and under this premise, try to make the gain of each optical multiplex section attenuate and satisfy the constraints. As shown in FIG. 3, the overall flow of the OADM ring network multiplex section power optimization method according to the present invention is shown in FIG. The schematic diagram includes the following steps: Step 1: Monitor the state of the ring network, calculate the gain attenuation of each optical multiplex section and the total gain attenuation of the entire ring network; the so-called ring state is the gain attenuation of each optical multiplex section. The total gain of the entire ring is attenuated and expressed. For an optical multiplex section, the output optical power of the OA corresponding to the upstream node is subtracted from the input optical power of the OA corresponding to the downstream node, and the gain of the OA corresponding to the downstream node is obtained, and the gain attenuation of the optical multiplex section is obtained. Then, the gains of the optical multiplex sections are attenuated and added to obtain the total gain attenuation sum of the entire ring network. In other embodiments, the output optical power of the OA corresponding to the OA of the downstream node of the optical multiplex section may be directly subtracted from the output optical power of the OA corresponding to the upstream node to obtain the gain and attenuation of the optical multiplex section. Step 2: Determine whether the state of the ring network satisfies the ring network constraint condition. If yes, continue to perform the ring state monitoring of step 1. If not, perform step 3; and the ring network constraint includes the gain for each optical multiplex section. Attenuation and Mi (i = l, 2, ..., N) requirements: CI < Mi < 0, used to ensure that the gain and attenuation of the ring network match, the OSNR and power of the ring network are not degraded; Total gain attenuation and M requirements: C2 M <0, used to ensure that the gain of the ring network is less than the loss, avoiding self-excitation. Among them, C1 and C2 are preset constants less than 0, which can be based on the ring network. The value of the structure and other factors take precedence. The total gain attenuation and M requirements of the ring network are given priority. The constraints are not limited to the above, and sometimes the gain attenuation of the optical multiplex section can be greater than 0. Step 3, Ring Network Configuration optimization: According to the difference between the state and constraints of the ring network and the adjustment range of the OA and VOA corresponding to the downstream nodes of the optical multiplex section, determine the OA and VOA to be adjusted and their adjustments, and optimize the gain attenuation of the ring optical multiplex section. Meet the ring network constraints; Step 4, Network configuration reset: The OA and VOA to be adjusted and their adjustments are executed in an appropriate step and order, so that the ring network is gradually and smoothly optimized. As shown in Figure 4, the above step 3 is excellent for t-ring optical multiplexing. The process of the segment gain reduction sum further includes the following steps: Step 40: First, start with a certain network element as a starting network element, start processing from the first optical multiplex section (OMA segment), and sequentially determine the gain attenuation and whether the constraint is satisfied. Condition, find the first optical multiplex section that does not satisfy the constraint, and perform the next step; Step 41: The adjustment range of the downstream node of the current optical multiplex section corresponding to the OA and the VOA, and the intermediate value of the constraint condition is a standard value, and the gain attenuation of the optical multiplex section and the reachable value closest to the standard value can be calculated. This embodiment is based on the intermediate value of the constraint condition, in order to have more room for adjustment in subsequent fine adjustment. However, for a specific environment, the present invention can also be calculated based on experience by selecting another value as a standard value in the range specified by the constraint. Step 42: Determine whether the optical multiplex section gain attenuation and the reachable value of Mi satisfy the constraint condition: CK MK 0, if yes, do not assign a deviation value to other optical multiplex sections, and perform step 46. If not, the other light recovery is required. And assigning a deviation value to the segment, performing step 4; step 43, determining whether the gain attenuation of the optical multiplex section and the reachable value of Mi are greater than zero, and if yes, performing step 44, otherwise, proceeding to step 45; step 44; The upstream optical multiplex section has not been processed yet, and the difference between the value of the constraint condition and the value of the current optical multiplex section Mi is subtracted from the value of the current optical multiplex section Mi as the offset value, and is allocated to the upstream optical multiplex section, and step 46 is performed; If the downstream optical multiplex section has not been processed, the constraint is specified in the range closest to

The value of Mi minus the difference between the current optical multiplex section Mi reachable value is assigned as the offset value to the downstream optical multiplex section; for example, assuming that the gain attenuation of an optical multiplex section before adjustment is 1, the optical multiplex section constraint is - 1 Mi < 0, where the point is -0.5, and the adjustment range of the downstream node corresponding to the VOA is 2, then the gain attenuation and the reachable value of the optical multiplex section are -0.5. If the gain attenuation of the optical multiplex section before adjustment is 2, other conditions are unchanged, the gain attenuation of the optical multiplex section and the reachable value is 0, if the gain attenuation of the optical multiplex section before adjustment is 2.5, other If the conditions are unchanged, the gain attenuation of the optical multiplex section is as high as 0.5, and a deviation of -0.5 is required to be allocated to the unprocessed upstream optical multiplex section. If the above multiplex section has been processed, it will be processed again in the week. Step 47: Determine whether the optical multiplex sections of the ring network have been processed. If yes, go to step 49. Otherwise, the following optical multiplex section is the current multiplex section. Step 47 is performed. Step 47: Determine the current optical multiplex section. Whether the offset value is assigned, if any, the sum of the offset values assigned by the other optical multiplex sections is a standard value, and the gain of the optical multiplex section and the reachable value closest to the standard value can be calculated (step 47a) ), return to step 42, if no deviation value is assigned, go to step 48; Step 48: Determine the gain attenuation of the optical multiplex section and whether the constraint condition is met. If yes, no adjustment is needed, and step 46 is performed. Otherwise, return to step 41; step 49, the gain of each optical multiplex section to be adjusted is attenuated and The reachable value is added to the detected value of the gain attenuation of each optical multiplex section that does not need to be adjusted, and the total attenuation of the obtained ring network is judged whether the constraint condition C2 <M<0 is satisfied, and if so, these reachable values are used. Step 51 is performed to determine the final value of the optical multiplex section gain attenuation and adjustment, otherwise, step 50 is performed; Step 50, fine-tuning the gain and the reachable value and the detected value of each optical multiplex section of the ring network, so that the total gain of the ring network is obtained. Attenuate and satisfy the constraint C2 <M<0, and use the value after the week as the final value of the gain attenuation and adjustment of each optical multiplex section; when fine-tuning, first reach those reachable or detected values in the constraint CI < Mi < 0 The gain attenuation of the optical multiplex section within the range and with room for adjustment and the direction adjustment to satisfy the total gain attenuation and constraints of the ring network. For example, the optical multiplex section gain attenuation and the total gain attenuation sum are both -1<M<0, and the total gain attenuation of the ring network calculated before the fine adjustment is +0.5, then the time is adjusted, and the optical multiplex sections are preferentially The gain or the reachable value or the detected value is adjusted within the range specified by the constraint, here is the adjustment to -1, such as the gain attenuation of the two optical multiplex sections and the adjustment from -0.5 to -0.75 to satisfy the ring network. Under the premise of total gain attenuation and constraints, the gain of each optical multiplex section is attenuated and also meets its own constraints. When the conditions of the total gain attenuation are not met, the optical multiplex section gain can be attenuated and adjusted to the outside of the constraint, or the devices OA and VOA can be replaced. Step 51: The difference between the current value and the final value of each optical multiplex section gain attenuation sum, that is, the adjustment amount is allocated to the OA and/or VOA corresponding to the downstream node, and ends. The preferred allocation principle is: when increasing the gain attenuation, the VOA attenuation is preferentially reduced, and the gain of the OA is increased. When the gain attenuation is to be reduced, the gain of the OA is preferentially reduced, and then the VOA is increased. Attenuation. This is more conducive to the performance of the system. In particular, the process of determining the final value of the gain reduction and optimization adjustment of each optical multiplex section of the ring network is only an example. In fact, it does not have to follow a fixed procedure to derive, for example, by taking each optical multiplex section. It is also possible to derive the value of the method to try. Or, at the outset, only the reachable values of the optical multiplex sections that do not satisfy the constraint are calculated, and the offset value is not allocated; then the gain of each optical multiplex section to be adjusted and the reachable value and the optical multiplexing without adjustment are performed. The detected values of the segment gain attenuation sum are added, and compared with the constraint condition C2 <M<0. If the condition is satisfied, it can be no longer adjusted. If it is not satisfied, it is also possible to perform fine adjustment uniformly. In short, as long as the total ring network gain can be reduced Under the premise, the gain reduction of each optical multiplex section and the constraint condition are satisfied as much as possible, and the final result of the adjustment is not unique. In order to prevent the execution module from being improperly delivered or sent too fast, the performance of the ring network is degraded. Therefore, when the ring network configuration reset is performed in the above step 4, the adjustment amount of the OA and VO A to be adjusted is appropriately stepped. The execution is performed in the following steps: Step 61: Select a node of the ring network as the start node; Step 62, find the first optical multiplex section to be adjusted; Step 63 Determining whether the adjustment amount of the current optical multiplex section causes the total gain of the ring network to be attenuated and tends to be constrained or kept within the constraint condition; if yes, step 65 is performed; otherwise, step 64 is performed; for example, the value of the current total attenuation of the ring network is Is 1, and the current optical multiplex section adjustment amount is -0.5, then the adjustment amount causes the total gain of the ring network to attenuate and tend to be constrained. This is to avoid self-excitation or performance degradation of the ring network due to unsatisfied constraints during the adjustment process. Step 64: Find the next optical multiplex section to be adjusted, and return to step 63. Step 65: Arrange the OA or VOA corresponding to the downstream node of the optical multiplex section to be adjusted in order, and adjust the amount on the OA or VOA. The allocation method has been described above. Each round can limit the adjustment amount of one optical multiplex section to a value, which can be called unit step size, to avoid the impact of over-adjustment on the work of the ring network; Step 66 Determining whether the optical multiplex section is the last optical multiplex section to be adjusted, and if yes, performing step 67; otherwise, returning to step 64; Step 67, determining whether the adjustment amount of each optical multiplex section has been scheduled to be completed (including the unarranged one of the rounds) Or only part of the adjustment amount is arranged, and if yes, go to step 69; if no, go to step 68; step 68, go to the next round of adjustments, go back to step 62; step 69, get all the optical multiplex sections The adjustment order of the adjustment amount is executed in this order. In another embodiment, simultaneous delivery in the calculation is also possible. The invention is further illustrated by an example below: Figure 6 shows a ring network with 4, 2, 3, and 4 OADM network elements. The ring network has 4 optical multiplex sections. Between network element 1 and network element 2 is an optical multiplex section, denoted as OMS# l. Between network element 2 and network element 3 is an optical multiplex section, denoted as OMS#2. Between network element 3 and network element 4 is an optical multiplex section, denoted as OMS#3. The network element 4 to the network element 1 is an optical multiplex section, and "3⁄4 is OMS#4. The detected ring network status is as shown in the following table.

Assume that the constraints of the ring network are: -l <Mi<0 and -l <M <0. OMS#2 does not satisfy the constraints of the optical multiplex section, and the total gain attenuation of the ring network is greater than the loss, and there is a possibility of self-excitation. The adjustment range of each VOA is set to 3. According to the method shown in the present invention, the gain and the final value of the OMS#2 gain attenuation are both -0.5, and the gain attenuation and final value of other OMSs are still 0. Adjusted, the resulting total gain attenuation of the ring network is -0.5. When the issuance, because the gain attenuation is required to be reduced, the VOA2 corresponding to the downstream node of the OMS# 2 is adjusted. Assuming that the VOA adjustment step is 0.5, the adjustment amount of the VOA 2 is 2.5 rounds. Of course, it is also possible to set the final value of the OMS #2 gain attenuation to 0, and to adjust the amount 2 of VOA2 in 4 rounds. Under another condition, if the adjustment amount of the VOA is 1.5, the reachable value of OMS#2 is calculated to be 0.5, and the deviation value of -0.5 needs to be assigned to OMS#1, and the final value of the gain attenuation of each segment is In the case, OMS#l is -0.5, the adjustment amount is -0.5; OMS#2 is 0.5, the adjustment amount is -1.5; the others are all zero. According to the distribution method of the adjustment amount by the invention, it can be determined that the adjustment amount of VOA1 is 0.5, and the adjustment amount of VOA2 is 1.5, and when it is issued, the adjustment amount of VOA1 and VOA2 is 0.5 in the first round, second and third rounds. Then release the adjustment amount of VOA2 to 0.5. In summary, the present invention resides in the optical power multiplex layer optical power of the OMS optical multiplex section OMS of the entire OADM ring network, optimizes the optical power of the entire ring optical multiplex section, and takes constraints considering excessive loss and self-excitation. The ring network OSNR and power degradation caused by the line loss reduction is effectively avoided, and the ring network is self-excited due to the loss reduction. At the same time, in the process of executing the module adjustment amount, the adjustment amount is gradually released in a small adjustment step, and the ring network tends to be constrained in the process of issuing, so that the optical power of the ring network is gradually and gradually optimized. Due to the technical measures such as taking into account the constraints of excessive and self-excited loss, the subdivision of adjustments, and the order of adjustment according to whether the adjustment tends to be constrained, the system can be effectively guaranteed to operate without errors in the OADM ring network optimization process. Hey.

Claims

A method for optimizing a multiplex section power of an optical add/drop multiplexer ring network is applicable to a system in which an upstream node of each optical multiplex section has a corresponding optical amplifier OA, and a downstream node has a corresponding OA and an optical attenuator VOA, and the method includes The following steps:

(a) monitoring the input and output power of the amplifiers in each network element of the ring network, and calculating the gain attenuation of each optical multiplex section and the total gain attenuation of the ring network;

(b) judging the calculated gain attenuation of each optical multiplex section and the total gain attenuation of the ring network and whether it is within the range specified by the ring network constraint. If yes, perform step (a), no-be |J, and perform steps ( c ) ;

(c) Determine the OA and VOA to be adjusted and their adjustment according to the gain attenuation of each optical multiplex section and the total gain attenuation of the ring network and the difference between the respective constraints, and the adjustment range of the OA and VOA corresponding to the downstream nodes of the optical multiplex section Quantity, such that the total gain of the ring network is attenuated and the constraints are met;

(d) The OA and VOA to be adjusted and their adjustments are issued and implemented to optimize the ring network. The method according to claim 1, wherein in step (a), the gain attenuation of a certain optical multiplex section is calculated, and the detected output optical power of the upstream node of the optical multiplex section corresponding to the OA is reduced. Go to its downstream node ^ f should be the input optical power of the OA, and then force. The downstream node ^ f should be obtained by the gain of the OA, or by the output optical power of the downstream node corresponding to the OA minus the output optical power of the upstream node corresponding to the OA; the total gain attenuation of the ring network is Optical multiplex section gain attenuation and addition. The method according to claim 1, wherein the requirement of gain attenuation and Mi for each optical multiplex section in the ring network constraint in the step (b) is: Cl < Mi < 0, ; The requirements for attenuation and M are: C2 "M <0; where C1 and C2 are preset constants less than 0, giving priority to the total gain attenuation of the ring network and the requirement of M. The method according to claim 1, wherein said step (c) further comprises the following steps:

( cl ) the adjustment range of the downstream node of the optical multiplex section corresponding to OA and VOA, calculation The optical multiplex section gain attenuation that does not satisfy the constraint condition and the reachable value that can be reached closest to a set standard value;

(c2) adding the gain attenuation and the reachable value of each optical multiplex section to be adjusted and the detected value of the gain attenuation of each optical multiplex section that does not need to be adjusted, and comparing with the constraint of the total gain attenuation of the ring network, if the condition is satisfied Then, the step (c4) is performed according to the reachable value of the corresponding optical multiplex section gain attenuation and adjustment, and if the condition is not satisfied, step (c3) is performed;

(c3) To adjust the gain attenuation and the reachable value or the detected value of each optical multiplex section of the ring network, so that the total gain of the ring network is attenuated and the constraint condition is satisfied, and the value after the fine adjustment is used as the gain attenuation and adjustment of each optical multiplex section. Final value

(c4) The difference between the current value and the final value of the attenuation of each optical multiplex section gain, that is, the adjustment amount is allocated to the OA and/or VOA corresponding to the downstream node, and ends. The method of claim 4 wherein the standard value in said step (cl) is selected from a range specified by optical multiplex section gain attenuation and constraints. The method of claim 4, wherein the step (cl) is further divided into the following steps:

(cl2) according to the adjustment range of the corresponding OA and VOA of the downstream node of the current optical multiplex section, selecting a standard value from the specified range of the constraint condition, and calculating the gain attenuation of the optical multiplex section and the achievable closest to the standard value Value

(cl3) Determine whether the optical multiplex section gain attenuation and Mi reachable value satisfy the constraint condition: Cl<Mi “0, if satisfied, perform 4 steps (cl7), otherwise perform step 4 (cl4);

( cl4 ) determining whether the gain attenuation of the optical multiplex section and the reachable value of Mi are greater than zero, and if yes, performing step (cl5); otherwise, performing step (cl6);

(cl5) If the upstream optical multiplex section has not been processed, the difference between the value of the constraint specified in the range closest to Mi and the reachable value of the current optical multiplex section Mi is taken as the offset value, and is allocated to the upstream optical multiplex section, and the steps are performed. (cl7);

( cl6 ) If the downstream optical multiplex section has not been processed, the difference between the value closest to Mi in the specified range of the constraint is subtracted from the reachable value of the current optical multiplex section Mi as the deviation value, and is assigned to the lower Sighting multiplex section

( cl 7 ) judging whether the optical multiplex sections of the ring network have been processed, and if yes, performing step ( c2 ); otherwise, the following optical multiplex section is the current multiplex section, and the step (cl 8 ) is performed;

( cl 8 ) determining whether the current optical multiplex section is assigned a deviation value, and if so, using the sum of the offset values assigned by the other optical multiplex sections as a standard value, calculating the optical multiplex section gain attenuation and the closest achievable to the optical multiplex section The reachable value of the standard value, return to step (cl3), if no deviation value is assigned, execute ( cl9 );

( cl9 ) Determine the gain attenuation of the optical multiplex section and whether the constraint condition is satisfied. If it is satisfied, no adjustment is needed, and step (cl7) is performed; otherwise, the step (cl2) is returned. The method according to claim 4, wherein, in the step (c3), when the gain or attenuation of each of the optical multiplex sections is fine-tuned, the reachable value or the detected value is preferentially satisfied. The gain attenuation of the optical multiplex section with constraints and adjustment margins and the direction adjustment to satisfy the total gain attenuation and constraints of the ring network; if the total gain attenuation and constraints of the ring network are not met, the optical multiplex section gain is attenuated and adjusted. Beyond the constraints, or replace the OA and / or VOA. The method according to claim 4, wherein, in the step (c4), when the amount of adjustment of the optical multiplex section gain attenuation and the amount of adjustment is performed, when the gain attenuation is to be increased, the attenuation of the VOA is preferentially reduced. Increase the gain of OA again; when you want to reduce the gain attenuation, reduce the gain of OA first, and then increase the attenuation of VOA. The method according to claim 1, wherein in the step (d), when sorting the adjustment amount of the OA and the VOA to be adjusted, the ring network is preferentially arranged when the first round is issued. The total gain is attenuated and the adjustment amount tends to satisfy the constraint or can maintain the constraint. If there is still an adjustment amount that is not issued, then the second priority will continue to be issued according to the priority principle. The method according to claim 1 or 9, wherein in the step (d), the adjustment amount issued to an OA or VOA does not exceed a set unit step size, and the one-time delivery is not completed. Delivered in multiple rounds. An optical add/drop multiplexer ring network multiplex section power optimization system, comprising each network element connected through an optical multiplex section, wherein the dimming of the packet 4 tongue and the upstream optical multiplex section in each network element An attenuator VOA and an optical amplifier OA connected to the VOA, and an OA connected to the downstream optical multiplex section, and each network element is connected to a control device, and the control device further includes The monitoring module, the control module and the execution module, wherein:

The monitoring module is connected to the OA in each network element, and is used for monitoring input and output power of each OA, and outputting to the control module;

The control module is configured to monitor the input and output power of each OA, calculate the gain attenuation of each optical multiplex section, and the total gain attenuation of the ring network, and determine whether the range of the respective ring network constraints is met. When not satisfied, determine the OA and VOA to be adjusted according to the gain attenuation of each optical multiplex section and the difference between the total gain attenuation of the ring network and the constraint conditions, and the adjustment range of the OA and VOA corresponding to the downstream nodes of each optical multiplex section. Adjustment amount

The execution module is connected to the OA and the VOA in each network element, and is used to perform the execution according to the OA and VOA and the adjustment value determined by the control module. The system of claim 1 , wherein the control module further comprises a gain attenuation and calculation unit, an adjustment decision unit, and an adjustment amount calculation unit:

The gain attenuation and calculation unit comprises: a first calculation subunit, configured to calculate, for each optical multiplex section, a difference between an OA output optical power of the upstream node and an OA input optical power of the downstream node, and a downstream node corresponding to the OA The gain, that is, the gain and attenuation sum of the optical multiplex section; the second calculation sub-unit is configured to obtain the gain and attenuation of the optical multiplex sections in the obtained ring network and add them to obtain the total gain attenuation of the ring network;

The adjustment decision unit is configured to compare the gain attenuation of each optical multiplex section of the ring network and the total gain attenuation of the ring network with the ring network constraint condition, and if the constraint condition is met, no optimization is needed; if the constraint condition is not met, Trigger adjustment amount calculation unit processing;

The adjustment amount calculation allocation unit comprises: a first calculation subunit, configured to calculate a reachable value of each optical multiplex section adjustment according to a gain attenuation sum, a constraint condition and an adjustment amount of each optical multiplex section; a second calculation subunit, For adding the target values of each optical multiplex section adjustment, determining the final value of each optical multiplex section adjustment compared with the constraint condition of the total gain attenuation of the ring network, so that the total gain of the ring network is attenuated and the constraint condition is satisfied; a unit, configured to calculate a final value of each optical multiplex section adjustment and allocate the OA and/or VOA to the downstream node. The system according to claim 12, wherein the control module further comprises an adjustment sorting unit, configured to preferentially schedule the total gain of the ring network to be attenuated and tend to satisfy the constraint or remain satisfied when the first round is delivered. The adjustment amount of the constraint condition, if there is still an adjustment amount that is not issued, and then continues to be issued according to the priority principle in the second round; and the adjustment amount issued to an OA or VOA in each round does not exceed one unit step, once If it is not issued, it will be issued in multiple rounds; The system according to claim 12, wherein the first calculation subunit of the adjustment amount calculation allocating unit is configured to calculate each unsatisfied constraint condition according to an adjustment range of the OA and VOA corresponding to the downstream node of the optical multiplex section The optical multiplex section gain attenuation and the reachable value that can be reached closest to a set standard value selected from the range specified by the optical multiplex section gain attenuation and the constraint, or the standard value is The deviation between the reachable value and the constraint condition assigned by the upstream or downstream node;

The adjustment calculation unit calculates the second calculation sub-unit of the distribution unit, and obtains the final value of the gain reduction and adjustment of each optical multiplex section in the following manner: firstly, the gain and attenuation of each optical multiplex section to be adjusted and the need to adjust The attenuation values of the optical multiplex sections and the detected values are added, and compared with the constraint of the total gain attenuation of the ring network, if the condition is satisfied, the reachable value is the final value of the attenuation and adjustment of the corresponding optical multiplex section gain, If the condition is not met, the gain-attenuation and the reachable value or the detected value of each optical multiplex section of the ring network are adjusted, so that the total gain of the ring network is attenuated and the constraint condition is satisfied, and the value of the fine-tuned is used as the gain of each optical multiplex section. The final value of attenuation and adjustment. The system according to claim 11, wherein the control device is connected to each network element through a network management system or a signaling system.