CN114499659A - Method for realizing dispersion compensation and setting of automatic detection optical fiber link - Google Patents

Abstract

The invention relates to the technical field of optical fiber communication, and discloses a method for realizing dispersion compensation and setting of an automatic detection optical fiber link, which comprises the following steps: s1, configuring an optical module A and an optical module B, and inserting TDCM line cards A and B; s2, a PRBS signal is transmitted between a PRBS generator of an optical module A and a PRBS detector of an optical module B in a one-way mode through an optical fiber link, when the PRBS signal is transmitted to the optical module B from the optical module A, a bit error rate set is calculated by adjusting a dispersion compensation value of a TDCM line card B, and when the PRBS signal is transmitted to the optical module A from the optical module B, the bit error rate set is calculated by adjusting the dispersion compensation value of the TDCM line card A; and S3, judging the communication quality of the optical signals in different directions according to the error rate set, and selecting the dispersion compensation value of the TDCM line card corresponding to the minimum error rate point as an optimal setting value to realize the dispersion compensation and setting of the automatic detection optical fiber link.

Description

Method for realizing dispersion compensation and setting of automatic detection optical fiber link

Technical Field

The invention relates to the technical field of optical fiber communication, in particular to a method for realizing automatic detection of dispersion compensation and setting of an optical fiber link, which is used for automatically detecting the optimized parameter configuration of dispersion compensation for a DWDM optical communication system needing high-precision optical fiber dispersion compensation. After the parameters are confirmed and the configuration is completed, a method can be provided to realize the real-time dynamic adjustment of the dispersion compensation parameters of the optical fiber link according to the user requirements.

Background

Dense Wavelength Division Multiplexing (DWDM) optical fiber communication technology can combine optical signals with a plurality of wavelengths and transmit the optical signals by using one optical fiber, so that the utilization rate of optical fiber resources is greatly improved. The zero dispersion point of the G.652 type optical fiber used in most of the current optical fiber lines is located near 1310nm of wavelength, and for 1550nm band where DWDM is located, the optical fiber has a large dispersion coefficient (17ps/nm/km), while optical pulse signals are broadened due to dispersion accumulation after optical signals are transmitted in the optical fiber, and intersymbol crosstalk and bit errors are caused when the broadening effect is comparable to the width of the optical pulses. The transmission margin distance limited by the dispersion effect when an optical signal is transmitted in an optical fiber is inversely proportional to the 2 nd power of the optical signal rate, and thus the transmission margin distance caused by dispersion rapidly decreases when the optical signal rate exceeds 10 giga (10 Gbit/s). When the optical signal reaches 100Gbit/s of single wave, the tolerance distance of the incoherent DWDM transmission system is only about 2 kilometers. For the incoherent DWDM system with the speed of more than 10Gbit/s, when the transmission distance is more than the dispersion tolerance distance, dispersion compensation equipment needs to be deployed in an optical fiber line to compensate the optical fiber dispersion in transmission. Dispersion compensation is typically achieved by deploying a dispersion compensating fiber, a fixed dispersion compensating module, and a tunable dispersion compensating module. Currently, when deploying a dispersion compensation device, engineers usually estimate the dispersion compensation value required by the line according to the estimated fiber length on site and the empirical dispersion value of the corresponding fiber type (for example, the dispersion coefficient of the g.652 fiber is 17 ps/nm/km). Typically this estimated dispersion value may have an error of several kilometres from the actual dispersion value of the optical fibre link.

If the dispersion compensation is performed by using a Dispersion Compensation Fiber (DCF) or a fixed Dispersion Compensation Module (DCM), the dispersion value of the optical fiber is usually set to a normal value, such as 10 km, 20 km, 40km, 80 km, etc., to meet the production cost and the practical engineering requirements. That is, the compensation accuracy is about 10 km, and even if 1 km or 2 km of the divided DCF/DCM is used to increase the production and engineering costs, the divided fixed DCF/DCM has no practical application value because the estimated dispersion value itself has an error of several km, and the subscription period is also affected. For DWDM optical signals with single wavelength rate of 25Gbit/s or below, the dispersion compensation precision within 10 kilometers can generally reach the engineering design requirement. However, with the emergence of incoherent DWDM optical transmission devices with higher speed, such as a single-wavelength 100Gbit/s DWDM QSFP28 optical module, the accuracy of dispersion compensation is required to be within 1 km, the adjustment accuracy of dispersion compensation is required to be within 0.5 km, and fixed dispersion compensation cannot be applied. Therefore, in order to solve the problem of how to set dispersion compensation for a single-wavelength 100Gbit/s DWDM QSFP28 optical module and control the accuracy of the dispersion compensation within 1 kilometer, the invention provides a method for realizing dispersion compensation and setting of an automatic detection optical fiber link.

Disclosure of Invention

The invention aims to provide a method for realizing automatic detection of dispersion compensation and setting of an optical fiber link, realizes the function of quickly and accurately detecting the optimal dispersion compensation parameter of the optical fiber link, and has obvious help effects on improving the quality of engineering opening of a high-speed DWDM system and improving the working efficiency.

The invention is realized by the following technical scheme: a method for realizing dispersion compensation and setting of an automatic detection optical fiber link comprises the following steps:

s1, configuring an optical module A and an optical module B, inserting the optical module A into a TDCM line card A, inserting the optical module B into the TDCM line card B, and opening a PRBS generator and a PRBS detector of the optical module when the TDCM line card identifies that the optical module is inserted;

s2, a PRBS signal is transmitted between a PRBS generator of an optical module A and a PRBS detector of an optical module B in a one-way mode through an optical fiber link, when the PRBS signal is transmitted to the optical module B from the optical module A, an error rate set Xn (n is 1,2,3, and is) is calculated by adjusting a dispersion compensation value of a TDCM line card B, and when the PRBS signal is transmitted to the optical module A from the optical module B, an error rate set Yn (n is 1,2,3, and is, and) is calculated by adjusting the dispersion compensation value of the TDCM line card A;

and S3, judging the communication quality of the optical signals in different directions according to the bit error rate set Xn or Yn, and selecting the dispersion compensation value of the TDCM line card corresponding to the minimum bit error rate point as an optimal setting value to realize the dispersion compensation and setting of the automatic detection optical fiber link.

In order to better implement the present invention, step S1 further includes:

after the optical module A is inserted into the TDCM line card A, the TDCM line card A identifies the optical module A, automatically configures the optical module A into a PRBS signal receiving and transmitting working mode, and opens a PRBS generator and a PRBS detector of the optical module A;

and after the optical module B is inserted into the TDCM line card B, the TDCM line card B identifies the optical module B, automatically configures the optical module B into a PRBS signal receiving and transmitting working mode, and turns on a PRBS generator and a PRBS detector of the optical module B.

In order to better implement the present invention, step S1 further includes:

the optical module a and the optical module B are 100G DWDM QSFP28 optical modules.

To better implement the present invention, step S2 further includes, when the PRBS signal is transmitted from optical module a to optical module B:

the optical module A sends the PRBS signal to the optical module B through an optical fiber link, calculates a dispersion compensation value setting range according to the condition of the optical fiber link, adjusts the dispersion compensation value of the TDCM line card B according to step length, and reads back an error rate corresponding to each calculated dispersion compensation value from the optical module B to form an error rate set Xn (n is 1,2,3,,).

To better implement the present invention, step S2 further includes, when the PRBS signal is transmitted from optical module B to optical module a:

the optical module B sends the PRBS signal to the optical module A through an optical fiber link, calculates a dispersion compensation value setting range according to the condition of the optical fiber link, adjusts the dispersion compensation value of the TDCM line card A according to the optical step length, and reads back the error rate corresponding to each calculated dispersion compensation value from the optical module A to form an error rate set Yn (n is 1,2,3,,).

In order to better implement the present invention, further, the method for the TDCM line card to identify the optical module includes:

the optical module A and the TDCM line card A form equipment A;

the optical module B and the TDCM line card B form equipment B;

the TDCM line card recognizes that an optical module is inserted, and sets a specific address of the optical module through an SFF 8636I 2C interface to enable the optical module to work in a PRBS signal working mode;

and accessing a specific address of the optical module through the I2C interface to acquire the current error rate of the received signal of the optical module.

In order to better realize the invention, further, after a DWDM PRBS signal sent by a QSFP28 module of a TDCM line card A is combined with other DWDM service signals through a DWDM wave combining disc, the DWDM PRBS signal is firstly connected to a device B after being transmitted through an optical fiber link;

in the equipment B, DWDM PRBS signals obtain dispersion compensation through a TDCM module of a TDCM line card B, and then are transmitted to a QSFP28 module receiving end of the TDCM line card B in the equipment B after being demodulated through a DWDM demodulation disk;

after receiving the PRBS signal, the QSFP28 module of the TDCM line card B calculates the current error rate.

In order to better implement the present invention, further, the method for calculating the current bit error rate includes: error rate is the number of erroneous data counts/total received data.

In order to better implement the present invention, the method for adjusting the dispersion compensation value of the TDCM line card to obtain the optimal dispersion compensation setting value in step S3 further includes:

and judging the optical signal communication quality corresponding to different dispersion compensation values according to the bit error rate set Xn or Yn, and selecting the dispersion compensation value of the TDCM line card corresponding to the minimum bit error rate point as an optimal setting value.

Compared with the prior art, the invention has the following advantages and beneficial effects:

(1) the invention combines the TDCM module and the PRBS checking function on a TDCM functional line card, realizes the function of rapidly and accurately detecting the optimal dispersion compensation parameter of the optical fiber link by the cooperation of the optical modules, and has obvious help for improving the quality of high-speed DWDM system engineering opening and the working efficiency;

(2) the DWDM optical module used in the invention is a standard optical module, and can be pulled out for reuse in normal service communication only when the optical fiber link is opened and is temporarily used for related dispersion compensation debugging and measuring work, and the dispersion compensation is set. Finally, the method can be completed without any other optical communication equipment or instrument, saves an optical fiber dispersion testing instrument, and is an innovative and efficient implementation method.

(3) The invention also supports the automatic adjustment of the real-time dispersion compensation optimization, and can continuously carry out the real-time dispersion optimization on the line which is sensitive to dispersion.

Drawings

The invention is further described in connection with the following figures and examples, all of which are intended to be open ended and within the scope of the invention.

Fig. 1 is a structural diagram of a linkage relationship between a device a and a device B in a method for implementing dispersion compensation and setting of an automatic detection optical fiber link according to the present invention.

Fig. 2 is an internal structural diagram of an optical module in a method for implementing dispersion compensation and setting of an automatic detection optical fiber link according to the present invention.

Detailed Description

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments, and therefore should not be considered as a limitation to the scope of protection. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

In DWDM transmission systems, it is often necessary to add an optical amplifier (EDFA) to the fiber link to compensate for the insertion loss of the fiber and various optical devices in the fiber link, and for simplicity of illustration, the fiber amplifier is not included in fig. 1. But an optical fiber link with an optical amplifier is also within the scope of the present invention.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "disposed," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Example 1:

a method for implementing dispersion compensation and setting of an automatic detection optical fiber link according to this embodiment, as shown in fig. 1-2, includes the following steps:

s1, configuring an optical module A and an optical module B, inserting the optical module A into a TDCM line card A, inserting the optical module B into the TDCM line card B, and opening a PRBS generator and a PRBS detector of the optical module when the TDCM line card identifies that the optical module is inserted;

s2, a PRBS signal is transmitted between a PRBS generator of an optical module A and a PRBS detector of an optical module B in a one-way mode through an optical fiber link, when the PRBS signal is transmitted to the optical module B from the optical module A, an error rate set Xn (n is 1,2,3, and is) is calculated by adjusting a dispersion compensation value of a TDCM line card B, and when the PRBS signal is transmitted to the optical module A from the optical module B, an error rate set Yn (n is 1,2,3, and is, and) is calculated by adjusting the dispersion compensation value of the TDCM line card A;

and S3, judging the communication quality of the optical signals in different directions according to the bit error rate set Xn or Yn, and selecting the dispersion compensation value of the TDCM line card corresponding to the minimum bit error rate point as an optimal setting value to realize the dispersion compensation and setting of the automatic detection optical fiber link.

In the present embodiment, the function of the optical module is expanded to be used by the optical fiber network signal quality detector. As shown in fig. 2, a PRBS (Pseudo-Random Binary Sequence) signal generation function and a PRBS signal detection function are turned on inside an optical module, and after receiving a PRBS signal, the PRBS signal detection function calculates a corresponding error rate and determines quality of the optical fiber network signal according to the error rate. As shown in the following figure, the PRBS signal generator of the optical module a transmits a PRBS signal to the optical module B through the optical fiber network, and the optical module B receives the PRBS signal and then transmits the PRBS signal to the PRBS detector, thereby calculating a corresponding error rate. Similarly, the PRBS detector of the optical module a receives the PRBS signal sent by the optical module B and calculates the corresponding error rate. The size of the error rate can directly reflect the quality of the communication quality of the optical fiber channel. Normally, the PRBS generator and PRBS detector functions inside the optical module are not switched on. And there is no provision in the SFF protocol that the QSFP28 module must support this function. Therefore, no unified software command interface definition related to the PRBS detection is formulated in the protocol. In the implementation of the invention, the functions of the PRBS generator and the PRBS detector are realized in the optical module, and on the basis of following the SFF-8636 protocol, the related instruction interface for turning on/off the PRBS generator and the PRBS detector and reading the current PRBS error rate is expanded. When the optical module is inserted into the device, the device automatically sends a related instruction when detecting the module, turns on the PRBS generator and the PRBS detector, and reads and retrieves a corresponding error rate from the optical module after adjusting the TDCM setting so as to judge the optical fiber channel communication quality corresponding to the setting.

In particular, when only the communication signals of the device a to the device B exist on the line, the relevant processing of the device B to the device a in the step S2 can be obviously omitted. The handling in this case is also within the scope of protection of the patent.

The invention provides a method for realizing a PRBS working mode by specific configuration of a TDCM line card and a DWDM optical module and a method for acquiring the error rate of the DWDM optical module. In the invention, the TDCM module and the DWDM optical module are linked to automatically detect the optimal dispersion compensation setting and carry out dispersion compensation on the optical fiber line according to the optimal dispersion compensation setting value in real time.

Example 2:

this embodiment is further optimized on the basis of embodiment 1, and step S1 includes:

after the optical module A is inserted into the TDCM line card A, the TDCM line card A identifies the optical module A, automatically configures the optical module A into a PRBS signal receiving and transmitting working mode, and opens a PRBS generator and a PRBS detector of the optical module A;

and after the optical module B is inserted into the TDCM line card B, the TDCM line card B identifies the optical module B, automatically configures the optical module B into a PRBS signal receiving and transmitting working mode, and turns on a PRBS generator and a PRBS detector of the optical module B.

In this embodiment, fig. 1 and fig. 2 are schematic diagrams of paths for transmitting PRBS signals from optical module a to optical module B according to the present invention, because the PRBS signals are transmitted unidirectionally between the PRBS generator of optical module a and the PRBS detector of optical module B through an optical fiber link, and the PRBS signals can be transmitted from optical module a to optical module B or from optical module B to optical module a, the schematic diagrams of the paths for transmitting from optical module B to optical module a are schematic diagrams with conceivable opposite arrow transmission directions, and are not provided here.

It should be emphasized that the TDCM line card B is set to open the PRBS generator of the optical module B to send the PRBS signal to the optical module a through the optical fiber network, after the PRBS detector in the open optical module a receives the PRBS signal transmitted by the optical module B, the dispersion compensation value of the TDCM line card is adjusted, and the error rate Yn (n is 1,2,3, and, B) corresponding to each dispersion compensation value is calculated, and then Xn (n is 1,2,3, and, B) is obtained without being opened at the same time, and finally the communication quality of the optical signal is judged according to the error rate Xn and the error rate Yn, and the dispersion compensation value of the TDCM line card corresponding to the minimum error rate is selected as the optimal setting value. The other parts of this embodiment are the same as those of embodiment 1, and thus are not described again.

Example 3:

the present embodiment is further optimized based on the above embodiment 1 or 2, and in the present embodiment, the optical module a and the optical module B are 100G DWDM QSFP28 optical modules. The QSFP28 optical module is a small-sized packaged optical module designed according to the standard SFF-8024, SFF-8636, SFF-8679 and the like established by SFF Committee. The electrical interface of the QSFP28 optical module system side can simultaneously transmit four paths of signals up to 28Gbaud/s, is widely applied to 40G and 100G Ethernet transmission, and is also widely applied to 5G networks. The optical module is mainly used for completing signal conversion between optical signals and electric signals, one end of the optical module is an electrical interface and is usually connected to a switch or other special communication equipment, and the other end of the optical module is an optical interface and is usually externally connected with an optical fiber network. The QSFP28 optical module in this embodiment is a 100G DWDM QSFP28 optical module that our device can actually support to use at present, this optical module can actually transmit a single-wave 100Gbit/s optical signal, and the device can access the optical module through a software interface defined by the SFF-8636 protocol.

In this embodiment, the dispersion compensation value range is estimated according to the condition of the optical fiber link, and the dispersion compensation value of the TDCM linecard B is adjusted accordingly in a certain step length, for example, 1010ps/nm (specifically, adjustment may be performed according to the required precision). The step size is a common unit of adjustment in the art and will not be described in detail here.

The rest of this embodiment is the same as embodiment 1 or 2, and therefore, the description thereof is omitted.

Example 4:

this embodiment is further optimized on the basis of any of embodiments 1 to 3, and when the PRBS signal is transmitted from the optical module a to the optical module B, the method includes:

the optical module A sends the PRBS signal to the optical module B through an optical fiber link, calculates a dispersion compensation value setting range according to the condition of the optical fiber link, adjusts the dispersion compensation value of the TDCM line card B according to step length, and reads back an error rate corresponding to each calculated dispersion compensation value from the optical module B to form an error rate set Xn (n is 1,2,3,,). And the communication quality of the optical signal can be judged according to the bit error rate set Xn, and the dispersion compensation value of the TDCM line card corresponding to the minimum bit error rate point is selected as an optimal setting value, so that the dispersion compensation and setting of the automatic detection optical fiber link are realized.

In this embodiment, after a DWDM PRBS signal sent by a QSFP28 module of a TDCM line card a is combined with other DWDM service signals by a DWDM combiner, the DWDM PRBS signal is transmitted by an optical fiber link and then is first connected to a device B;

on the equipment B, DWDM PRBS signals obtain dispersion compensation through a TDCM module of a TDCM line card B, and then are transmitted to a QSFP28 receiving end of the TDCM line card B in the equipment B after being demodulated by a DWDM demodulation disk;

after receiving the PRBS signal, a QSFP28 module of the TDCM line card B calculates the current bit error rate.

The TDCM line card of the equipment can adjust the parameter configuration of dispersion compensation through the TDCM module on the line card, so that the following method can be used for quickly judging which dispersion compensation configuration is optimal:

and setting the maximum value and the minimum value of the adjustable dispersion compensation value and the adjustment step length of each step according to the estimated dispersion range.

Within the range of the maximum value and the minimum value of the set adjustable dispersion compensation value, the dispersion compensation value is set in turn by a specified step length, and the PRBS error rate corresponding to each set value is recorded. The dispersion compensation value corresponding to the minimum bit error rate is the optimal setting. After the optimal dispersion compensation value is obtained through the automatic detection function of the dispersion compensation optimization parameters, the optimal dispersion compensation value can be solidified into the configuration of the line card through a command provided by the line card. The dispersion compensation value of the TDCM module is adjusted to within 0.5 kilometer, and after the dispersion compensation optimization parameters are automatically detected, the dispersion compensation accuracy can reach within 1 kilometer, so that the requirement of a single-wavelength 100Gbit/s incoherent DWDM optical signal on dispersion compensation is met.

Usually, a user only needs to perform automatic detection of dispersion compensation optimization parameters once during opening, and the dispersion compensation value is not changed after the current optimal dispersion compensation value is solidified, so that the 100G DWDM QSFP28 module inserted on the line card can be pulled out for transmission of common services, and the use cost of the user is greatly saved. If the engineering design margin of the optical fiber link is tight and sensitive to the requirement of dispersion compensation, continuous tracking and real-time optimization of dispersion compensation configuration are needed, and the TDCM line card also provides a real-time dispersion compensation optimization automatic regulation function. The topological link is the same as that in the figure, and the implementation method is as follows:

step 1, reading a current dispersion compensation value S0 of a TDCM module, defining a detection range R0, wherein the detection step length is P0;

step 2, from the dispersion compensation values S0 to (S0+ R0), taking P0 as a step length, and recording a corresponding error rate after each step is set;

step 3, from the dispersion compensation values S0 to (S0-R0), taking P0 as a step length, and recording a corresponding error rate after each step is set;

step 4, comparing all the error rates in the steps 2 and 3, finding a dispersion compensation value corresponding to the optimal error rate, and updating and setting the dispersion compensation value into the line card in real time;

and 5, delaying the time T0, and executing the step 1.

Other parts of this embodiment are the same as any of embodiments 1 to 3, and thus are not described again.

Example 5:

this embodiment is further optimized on the basis of any one of embodiments 1 to 4, and when the PRBS signal is transmitted from the optical module B to the optical module a, the method includes:

the optical module B sends the PRBS signal to the optical module A through an optical fiber link, calculates a dispersion compensation value setting range according to the condition of the optical fiber link, adjusts the dispersion compensation value of the TDCM line card A according to the optical step length, and reads back the error rate corresponding to each calculated dispersion compensation value from the optical module A to form an error rate set Yn (n is 1,2,3,,). The other parts of this embodiment are the same as those of embodiment 4, and thus are not described again.

Example 6:

this embodiment is further optimized on the basis of any one of the above embodiments 1 to 5,

in this embodiment, device a: TDCM ply-yarn drill and equipment B: QSFP28 notches of a TDCM line card are respectively inserted into a 100G DWDM QSFP28 module which I self developed, and after the line card identifies the module, the module is automatically configured to be in a PRBS signal receiving and transmitting working mode. The configuration method comprises the following steps:

the line card recognizes that the module is inserted, and sets a module specific address through a software interface based on SFF8636 protocol extension so as to enable the module to work in a PRBS mode.

And accessing a module specific address through a software interface based on the SFF8636 protocol extension to obtain the current error rate of the received signal of the module.

Device A: after the DWDM PRBS signal sent by the QSFP28 module of the TDCM line card is combined with other DWDM service signals through a DWDM wave combining disc, the DWDM PRBS signal is firstly connected to equipment B after being transmitted through an optical fiber link. In the device B, DWDM PRBS signals obtain dispersion compensation through a TDCM module of a TDCM line card B, and then are transmitted to a QSFP28 receiving end of the TDCM line card in the device B after being demodulated through a DWDM demodulation disk.

And B, equipment B: after receiving the PRBS signal, the QSFP28 module of the TDCM line card can calculate the current bit error rate, and the value of the bit error rate can directly reflect the quality of the current optical fiber link transmission quality.

Other parts of this embodiment are the same as any of embodiments 1 to 5, and thus are not described again.

Example 7:

in this embodiment, a further optimization is performed on the basis of any one of the foregoing embodiments 1 to 6, and the method for adjusting the TDCM line card to obtain the optimal setting value in step S3 includes:

setting the maximum value and the minimum value of the adjustable dispersion compensation value and the adjustment step length of each step according to the estimated dispersion range;

for example, a 40Km optical fiber line would theoretically have a dispersion compensation value of 40Km x 16.5ps/nm Km x 660ps/nm, so that a maximum value of-700 ps/nm and a minimum value of-600 ps/nm could be set for dispersion compensation. And sequentially setting dispersion compensation values in a specified step length within the range of the maximum value-600 ps/nm and the minimum value-700 ps/nm of the set adjustable dispersion compensation value, and recording the error rate read back from the QSFP28 optical module corresponding to each dispersion compensation setting value, wherein the dispersion compensation value corresponding to the minimum error rate is the optimal setting value. This is because the bit error rate directly reflects the quality of link communication, and different dispersion compensation values are set, which may cause the quality of link communication to change. The smaller the bit error rate value is, the better the link communication quality is, and the better the corresponding dispersion compensation value is.

In this embodiment, the problem of insufficient precision of fixed dispersion compensation can be avoided by using a Tunable Dispersion Compensation Module (TDCM), but an engineer needs to carefully try one by one within a certain parameter range, which is time-consuming and labor-consuming, and because of lack of a very accurate reference value, for example, only whether a switch port has packet loss can be seen, but actually, the switch port may not have packet loss within a certain setting value range, and a specific value is optimal and cannot be determined), and the setting is not an optimal value in many cases.

Other parts of this embodiment are the same as any of embodiments 1 to 6, and thus are not described again.

Example 8:

this embodiment is further optimized on the basis of any one of the embodiments 1 to 7, and the method for calculating the current bit error rate includes: error rate is the number of erroneous data counts/total received data. In this embodiment, after the PRBS signal is received, the error rate in the corresponding direction is calculated. Setting TDCM and modifying dispersion compensation value, if the dispersion compensation value is not changed, the detected error rate will not be changed obviously, and the optimum dispersion compensation value can be found by modifying TDCM dispersion compensation value and inquiring corresponding error rate, and then comparing and looking at which dispersion compensation value is optimum.

Other parts of this embodiment are the same as any of embodiments 1 to 7, and thus are not described again.

Example 9:

in this embodiment, a further optimization is performed on the basis of any one of the foregoing embodiments 1 to 8, and the method for adjusting the dispersion compensation value of the TDCM line card to obtain the optimal dispersion compensation setting value in step S3 includes:

and judging the optical signal communication quality corresponding to different dispersion compensation values according to the bit error rate set Xn or Yn, and selecting the dispersion compensation value of the TDCM line card corresponding to the minimum bit error rate point as an optimal setting value.

In this embodiment, after the optimal dispersion compensation value is obtained through the automatic detection function of the dispersion compensation optimization parameter, the optimal dispersion compensation value is fixed to the line card configuration through a command provided by the line card, so as to realize the dispersion compensation and setting of the automatic detection optical fiber link. As shown in fig. 1, the dispersion compensation optimization parameters are automatically detected: this function is accomplished using the TDCM linecard in the device in conjunction with my self-developed 100G DWDM QSFP28 optical modules. When the 100G DWDM optical module is inserted into other communication equipment with a standard QSFP28 notch, the optical module can work as a standard optical module, but when the optical module is inserted into a TDCM line card of the department, the line card can configure the working mode of the 100G DWDM optical module into a specific PRBS signal mode through a self-defined command, and the specific link topology is shown as follows, wherein the following steps are shown as follows: TDCM line card "to" device B: traffic in the TDCM linecard "direction to illustrate the basic principle of automatic detection of dispersion compensation optimization parameters.

The self-defined command is that on the basis of an SFF-8636 protocol framework, a self-defined access Page (Page) and a corresponding high 128-byte address are expanded inside the QSFP28 optical module, and by sending specified data to a specific Page and address, data interaction between the TDCM board card and the QSFP28 module can be realized, and the expansion functions of modifying the working mode of the optical module, reading error rate information and the like are completed.

Other parts of this embodiment are the same as any of embodiments 1 to 8, and thus are not described again.

It should be noted that what the present invention proposes is that a PRBS signal needs to be transmitted from an optical module a to an optical module B, and also needs to be transmitted from the optical module B to the optical module a, so the optical module a and the optical module B are respectively inserted into a TDCM line card a and a TDCM line card B, and a TDCM line card needs to be used to read back a QSFP28 optical module, but when the PRBS signal only needs to be transmitted from the optical module a to the optical module B in a single direction, the TDCM line card a does not need to read back, and at this time, other devices that achieve the same or better function as the TDCM line card a are also within the protection scope of the present invention.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention in any way, and all simple modifications and equivalent variations of the above embodiments according to the technical spirit of the present invention are included in the scope of the present invention.

Claims (9)

1. A method for realizing dispersion compensation and setting of an automatic detection optical fiber link is characterized by comprising the following steps:

s1, configuring an optical module A and an optical module B, inserting the optical module A into a TDCM line card A, inserting the optical module B into the TDCM line card B, and opening a PRBS generator and a PRBS detector of the optical module when the TDCM line card identifies that the optical module is inserted;

s2, a PRBS signal is transmitted between a PRBS generator of an optical module A and a PRBS detector of an optical module B in a one-way mode through an optical fiber link, when the PRBS signal is transmitted to the optical module B from the optical module A, an error rate set Xn (n is 1,2,3, and is) is calculated by adjusting a dispersion compensation value of a TDCM line card B, and when the PRBS signal is transmitted to the optical module A from the optical module B, an error rate set Yn (n is 1,2,3, and is, and) is calculated by adjusting the dispersion compensation value of the TDCM line card A;

and S3, judging the communication quality of the optical signals in different directions according to the bit error rate set Xn or Yn, and selecting the dispersion compensation value of the TDCM line card corresponding to the minimum bit error rate point as an optimal setting value to realize the dispersion compensation and setting of the automatic detection optical fiber link.

2. The method according to claim 1, wherein the step S1 includes:

after the optical module A is inserted into the TDCM line card A, the TDCM line card A identifies the optical module A, automatically configures the optical module A into a PRBS signal receiving and transmitting working mode, and opens a PRBS generator and a PRBS detector of the optical module A;

and after the optical module B is inserted into the TDCM line card B, the TDCM line card B identifies the optical module B, automatically configures the optical module B into a PRBS signal receiving and transmitting working mode, and turns on a PRBS generator and a PRBS detector of the optical module B.

3. The method according to claim 1, wherein the step S1 further comprises:

the optical module a and the optical module B are 100G DWDM QSFP28 optical modules.

4. The method of claim 1, wherein the step S2 includes when the PRBS signal is transmitted from optical module a to optical module B:

the optical module A sends the PRBS signal to the optical module B through an optical fiber link, calculates a dispersion compensation value setting range according to the condition of the optical fiber link, adjusts the dispersion compensation value of the TDCM line card B according to step length, and reads back an error rate corresponding to each calculated dispersion compensation value from the optical module B to form an error rate set Xn (n is 1,2,3,,).

5. The method of claim 1, wherein the step S2 includes when the PRBS signal is transmitted from optical module B to optical module a:

the optical module B sends the PRBS signal to the optical module A through an optical fiber link, calculates a dispersion compensation value setting range according to the condition of the optical fiber link, adjusts the dispersion compensation value of the TDCM line card A according to the optical step length, and reads back the error rate corresponding to each calculated dispersion compensation value from the optical module A to form an error rate set Yn (n is 1,2,3,,).

6. The method of claim 3, wherein the TDCM linecard identifies the optical module by comprising:

the optical module A and the TDCM line card A form equipment A;

the optical module B and the TDCM line card B form equipment B;

the TDCM line card recognizes that an optical module is inserted, and sets a specific address of the optical module through an SFF 8636I 2C interface to enable the optical module to work in a PRBS signal working mode;

and accessing a specific address of the optical module through the I2C interface to acquire the current error rate of the received signal of the optical module.

7. The method of claim 4 for implementing automatic detection fiber link dispersion compensation and setting, comprising:

DWDM PRBS signals sent by a QSFP28 module of a TDCM line card A are combined with other DWDM service signals through a DWDM wave combining disc and then are transmitted through an optical fiber link and then are firstly connected to equipment B;

on the equipment B, DWDM PRBS signals obtain dispersion compensation through a TDCM module of a TDCM line card B, and then are transmitted to a QSFP28 module receiving end of the TDCM line card B in the equipment B after being demodulated by a DWDM demodulation disk;

after receiving the PRBS signal, a QSFP28 module of the TDCM line card B calculates the current bit error rate.

8. The method of claim 5, wherein the calculating the current bit error rate comprises:

error rate is the number of erroneous data counts/total received data.

9. The method of claim 1, wherein the step S3 of adjusting the dispersion compensation value of the TDCM line card to obtain the optimal dispersion compensation setting value includes:

and judging the optical signal communication quality corresponding to different dispersion compensation values according to the bit error rate set Xn or Yn, and selecting the dispersion compensation value of the TDCM line card corresponding to the minimum bit error rate point as an optimal setting value.

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