CN117713925A - OSNR dynamic optimization system of data center interconnection network - Google Patents

Abstract

The invention discloses an OSNR dynamic optimization system of a data center interconnection network, which can dynamically test and evaluate the actual optical power attenuation condition and can determine the optical fiber span attenuation through real measurement; and link OSNR can be improved. And adding an optical performance monitor OPM or an optical channel monitor OCM at the optical amplification node of each interconnection link of the existing data center to monitor the optical power in the optical fiber or the optical attack rate of each wavelength in real time, thereby rapidly evaluating the condition of the link OSNR.

Description

OSNR dynamic optimization system of data center interconnection network

Technical Field

The invention relates to the technical field of data transmission, in particular to an OSNR dynamic optimization system of a data center interconnection network.

Background

With the rise of applications such as artificial intelligence and source universe, the flow among data centers is obviously increased, and the transmission rate and the distance are gradually increased. By means of the high-order modulation, a higher transmission bandwidth can be realized, but at the same time, the requirement on the transmission quality of the link is higher. The main criterion for the transmission link is the optical signal to noise ratio (OSNR), which is calculated as signal power/noise power. Since the optical signal is transmitted in the optical fiber with a certain attenuation, an optical amplifier needs to be added, and a certain amount of noise is introduced into the optical amplifier while the optical signal is gained. Because in an actual transmission link, the OSNR is difficult to accurately measure, and meanwhile, factors influencing the OSNR are also many, the OSNR is currently evaluated mainly by adopting a model calculation mode, and it is difficult to accurately determine and optimize the transmission link OSNR.

At present, as shown in fig. 1, a traditional data interconnection network model has a plurality of optical fiber spans from a transmitting end to a receiving end, and optical gain is carried out among each optical fiber span through amplifiers such as EDFAs. Noise is introduced while the optical gain is simultaneously increased. In the conventional calculation mode, it will be assumed that the ATT is damaged by the span insertion _i ＝L _i X alpha + margin, where L _i For the span fiber length, α is the fiber attenuation coefficient. The default optical amplifier in general calculation will uniformly compensate the insertion loss of the optical fiber, and the gain of each amplifier is gain _i ＝ATT _i . The noise density of each amplifier is: s is S _ASE,T ＝∑ _i nhv(gain _i -1)×gain _i+1 ×ATT _i+1 Where n is the spontaneous emissivity of the amplifier. Osnr=2×b×s at final system Rx _ASE,T /P _sig Wherein B is the optical bandwidth of the optical filter, P _sig Is the signal light power.

The existing OSNR calculation method mainly has the following problems:

1. the optical power attenuation caused by the optical fiber line is calculated according to theoretical values, and the problem that the health degree of the optical fiber is reduced after long-time operation due to the complex construction environment in an actual link cannot be accurately estimated;

2. the optimal solution of the link OSNR can not be achieved by directly setting the gain of the optical amplifier according to the span insertion loss, and misjudgment of the link communication quality is easy to cause;

3. for multi-span systems, each span distance varies greatly, and it is difficult to quickly obtain an optimal link gain scheme by calculation.

Disclosure of Invention

Aiming at the problems, the invention provides an OSNR dynamic optimization system of a data center interconnection network, which can dynamically test and evaluate the actual optical power attenuation condition and can determine the optical fiber span attenuation through real measurement; and link OSNR can be improved.

An OSNR dynamic optimization system for a data center interconnection network, characterized in that:

and adding an optical performance monitor OPM or an optical channel monitor OCM at the optical amplification node of each interconnection link of the existing data center to monitor the optical power in the optical fiber or the optical attack rate of each wavelength in real time so as to rapidly evaluate the condition of the link OSNR.

It is further characterized by:

for a WDM transmission system, a WSS is placed at an optical amplifying node, and power correction is carried out on the wavelength with the excessively high gain, so that the optical power balance of the system is ensured.

It is further characterized in that:

based on the accurately detected span power measurement, the link OSNR condition can be rapidly estimated, and the steps are as follows:

s1, injecting test light at a link starting point Tx, and recording the light power as P ₀ ；

S2, sequentially recording the optical power value P detected by each node OPM/OCM _i Each span optical power decays to P _ai ＝P _i -P _i-1 ；

S3, enabling the initial gain of the optical amplifiers of all nodes to be equal to the optical power attenuation of the span, and calculating initial OSNR ₀ 。

A set of random simulation method is arranged in the system, and the system OSNR is improved by finely correcting the gain of the optical amplifier every time and judging whether the modification is selected or not, so that the optical fiber communication quality is improved, and the method comprises the following steps:

s4, randomly selecting 2 optical amplifiers, and respectively adjusting the gain +0.1dB/-0.1dB. Computing link OSNR after gain adjustment _k ；

S5, setting an analog reference index EK, if the OSNR after each random adjustment _k >OSNR _k-1 If the OSNR is considered to be effective, the present adjustment is _k ≤OSNR _k-1 Then making a determination, e.g. EK.ltoreq.OSNR _k /OSNR _k-1 If EK > OSNR, then the adjustment is considered to be effective _k /OSNR _k-1 Then consider the current adjustmentInvalidating, discarding the adjustment, and restoring the last adjustment setting of the link;

and S6, repeating the steps S4 and S5 repeatedly, and confirming the final link setting if the OSNR is not changed after a plurality of times of adjustment.

After the invention is adopted, the data center interconnection link is improved by the existing optical device in the market, so that the actual optical power attenuation condition can be dynamically tested and evaluated; the optical fiber span attenuation can be determined through real measurement, and a mode of the attenuation coefficient plus margin of the traditional distance is not adopted, so that the real state of the system is better met; the gain of the amplifier is simulated by adopting an algorithm, a better setting scheme can be obtained quickly in a short time, and the OSNR of the link is improved.

Drawings

FIG. 1 is a conventional data center Internet relay method model;

FIG. 2 is a block diagram of a data center interconnect link with span optical power detection capability in accordance with the present invention;

FIG. 3 is a flow chart of a calculation and simulation process applicable to the system of the present invention;

FIG. 4 is a data center interconnect link with span optical power detection and optical power equalization capability for a WDM transmission system;

FIG. 5 is a graph of optical power versus data center interconnect links according to the present invention;

fig. 6 is a graph of gain versus optical amplifier nodes in an interconnect link of a data center according to the present invention.

Detailed Description

An OSNR dynamic optimization system for a data center interconnection network, see fig. 2-4:

an Optical Performance Monitor (OPM) or an Optical Channel Monitor (OCM) is added at the existing optical amplification node of each data center interconnection link to monitor the optical power in the optical fiber or the optical attack rate of each wavelength in real time, so as to rapidly evaluate the link OSNR condition.

For a WDM transmission system, a WSS can be placed at an optical amplification node to perform power correction on the wavelength with an excessively high gain, so that the system optical power balance (see fig. 4) is ensured, and the specific wavelength is attenuated by analyzing the difference of different light attacks in an optical fiber and performing overall optical power balance by a Wavelength Selective Switch (WSS).

Based on the accurately detected span power measurement, the link OSNR condition is rapidly evaluated, and the accurate link span optical power attenuation is rapidly obtained for accurately regulating and controlling the span optical amplifier gain, and the method comprises the following steps:

s1, injecting test light at a link starting point Tx, and recording the light power as P ₀ ；

S2, sequentially recording the optical power value P detected by each node OPM/OCM _i Each span optical power decays to P _ai ＝P _i -P _i-1 ；

S3, enabling the initial gain of the optical amplifiers of all nodes to be equal to the optical power attenuation of the span, and calculating initial OSNR ₀ 。

A set of random simulation method is arranged in the system, the system OSNR is improved by finely correcting the gain of the optical amplifier every time and judging whether the modification is selected, so that the optical fiber communication quality is improved, the attenuation of different spans of the whole link is analyzed, and an optimal optical amplifier gain setting scheme is obtained through algorithm calculation, so that the continuous reading OSNR is optimal, and the method comprises the following steps:

s4, randomly selecting 2 optical amplifiers, and respectively adjusting the gain +0.1dB/-0.1dB. Computing link OSNR after gain adjustment _k ；

S5, setting an analog reference index EK, if the OSNR after each random adjustment _k >OSNR _k-1 If the OSNR is considered to be effective, the present adjustment is _k ≤OSNR _k-1 Then making a determination, e.g. EK.ltoreq.OSNR _k /OSNR _k-1 If EK > OSNR, then the adjustment is considered to be effective _k /OSNR _k-1 Considering that the adjustment is invalid, discarding the adjustment, and restoring the last adjustment setting of the link;

and S6, repeating the steps S4 and S5 repeatedly, and confirming the final link setting if the OSNR is not changed after a plurality of times of adjustment.

In a specific embodiment, in a certain scenario, the interconnection distance between two data centers is about 650km, the optical power curve measured and evaluated in the conventional OSNR evaluation manner of the data center is shown by the dashed line in fig. 5, and the gain of the optical amplifier is shown by the dashed line in fig. 6. After adopting the system of the invention, after carrying out certain simulation, the amplifier is regulated to a certain degree (solid line in fig. 6), the optical power of the whole link is optimized, and under the condition that the input and output optical power is unchanged, the OSNR of the whole link is optimized by 4.64dB.

The beneficial effects are as follows: (1) The data center interconnection link is improved through the existing optical devices in the market, so that the actual optical power attenuation condition can be dynamically tested and evaluated; (2) Determining the attenuation of the optical fiber span through real measurement, and not adopting the mode of the attenuation coefficient plus margin of the traditional distance to better meet the real state of the system; (3) The gain of the amplifier is simulated by adopting an algorithm, a better setting scheme can be obtained quickly in a short time, and the OSNR of the link is improved; (4) For WDM system, WSS is configured to perform optical power equalization, so as to further improve transmission quality.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present disclosure describes embodiments, not every embodiment is provided with a separate embodiment, and that this description is provided for clarity only, and that the disclosure is not limited to the embodiments described in detail below, and that the embodiments described in the examples may be combined as appropriate to form other embodiments that will be apparent to those skilled in the art.

Claims (4)

1. An OSNR dynamic optimization system for a data center interconnection network, characterized in that:

and adding an optical performance monitor OPM or an optical channel monitor OCM at the optical amplification node of each interconnection link of the existing data center to monitor the optical power in the optical fiber or the optical attack rate of each wavelength in real time and rapidly evaluate the OSNR condition of the link.

2. An OSNR dynamic optimization system for a data center internetwork according to claim 1, wherein: for a WDM transmission system, a WSS is placed at an optical amplifying node, and power correction is carried out on the wavelength with the excessively high gain, so that the optical power balance of the system is ensured.

3. An OSNR dynamic optimization system for data center internetworks according to claim 1 or 2, characterized in that the link OSNR situation can be evaluated quickly based on accurately detected span power measurements, the steps of which are as follows:

s1, injecting test light at a link starting point Tx, and recording the light power as P ₀ ；

S2, sequentially recording the optical power value P detected by each node OPM/OCM _i Each span optical power decays to P _ai ＝P _i -P _i-1 ；

S3, enabling the initial gain of the optical amplifiers of all nodes to be equal to the optical power attenuation of the span, and calculating initial OSNR ₀ 。

4. A dynamic OSNR optimizing system for an interconnection network of a data center according to claim 3, wherein a set of random simulation methods is provided in the system, and the OSNR of the system is improved by finely modifying the gain of the optical amplifier each time and by determining whether to use the modification, thereby improving the quality of optical fiber communication, comprising the steps of:

s4, randomly selecting 2 optical amplifiers, and respectively adjusting the gain +0.1dB/-0.1dB. Computing link OSNR after gain adjustment _k ；

S5, setting an analog reference index EK, if the OSNR after each random adjustment _k >OSNR _k-1 If the OSNR is considered to be effective, the present adjustment is _k ≤OSNR _k-1 Then making a determination, e.g. EK.ltoreq.OSNR _k /OSNR _k-1 If EK > OSNR, then the adjustment is considered to be effective _k /OSNR _k-1 Considering that the adjustment is invalid, discarding the adjustment, and restoring the last adjustment setting of the link;

and S6, repeating the steps S4 and S5 repeatedly, and confirming the final link setting if the OSNR is not changed after a plurality of times of adjustment.