KR100673381B1 - Method for planning an optical network by using a computer - Google Patents

Abstract

The present invention relates to a method for designing an optical communication network using a computer, in which a database is formed using a computer to design a network using the database. The optical path information provided by conventional database tools is far from managing a high speed / large time division multiplexing (TDM) and wave length division multiplexing (WDM) system. The optical fiber information was not used to design the network dynamically, but could only retrieve partial information of the optical fiber circuit. According to the present invention, the optical path line information and the optical path characteristic information are databased for each section, and a network design support tool is implemented in a graphic user environment shape to input a section to design a network and system information to be installed. Then, the OSNR of the optical signal, the penalties due to the polarization mode dispersion, the reflection loss, the loss spectrum, and the elements limited by the nonlinear characteristics are calculated to design the schematic network. Therefore, it is easy to know the information of the schematic optical line, so that it is easy to analyze the problem of the optical line and plan the replacement of the optical line.

Description

TECHNICAL FOR PLANNING AN OPTICAL NETWORK BY USING A COMPUTER}

1 is a block diagram showing an embodiment of a computer for implementing the optical communication network design method using a computer according to the present invention,

Figure 2 is a flow chart showing step by step an embodiment of an optical communication network design method using a computer according to the present invention.

<Description of the code | symbol about the principal part of drawing>

10: main body 12: main board

14: hard disk drive 16: floppy disk drive

18: CD-ROM drive 20: graphics card

22: monitor 24: keyboard

26: mouse

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a network plan method using a computer, and more particularly, to a method of designing a network using a database by converting characteristic information of optical paths into a database using a computer. .

As the network type of the network operator becomes complicated and the requirements of the optical path are diversified, the network design for the optical transmission system becomes more difficult, and huge waste of time and economics is expected.

"Truman", a database tool according to the prior art, shows the current status of the optical transmission system installation and information on the optical paths for each route.

However, the optical path information provided by such a conventional database tool is insufficient to manage the ultra-fast / large time-division multiplexing (TDM) and wave-length division multiplexing (WDM) systems. The optical fiber information was not used to design the network dynamically, but could only retrieve partial information of the optical fiber circuit.

The present invention has been made to solve the above-mentioned drawbacks of the prior art, and the characteristics information of the existing optical fiberized database using a computer to use the characteristics information of the database when introducing a high-speed / large-capacity DWDM and time division multiplexing system To provide an optical communication network design method using a computer for easily designing a network.

According to an aspect of the present invention, there is provided a network design system in which a database of characteristic information of an existing optical path is formed using a computer: a first step of inputting an optical transmission system standard and optical transmission network type information to be designed; ; A second step of calculating a limit range of each node by using the optical fiber characteristic information of the database corresponding to the input optical transmission system standard and optical transmission network type information to be designed; A third step of designing a schematic network by dividing an acceptable line and an unacceptable line according to the result of the limited range calculation; A fourth step of determining whether to select the unacceptable line; A fifth step of displaying information related to the unacceptable line when the unacceptable line is selected as a result of the determination in the fourth step; A sixth step of judging whether to select an acceptable line if the unacceptable line is not selected as a result of the fourth step; And a seventh step of displaying information related to the acceptable line when selecting the acceptable line as a result of the determination in the sixth step.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram showing an embodiment of a computer for implementing an optical communication network design method using a computer according to the present invention, a monitor 22, a keyboard 24, and a main body 10; A mouse 26 is connected and configured. The main body 10 includes a main board 12, a hard disk drive (HDD) 14, a floppy disk drive (FDD) 16, a CD-ROM drive (Compact Disk). A read only memory drive 18, and a graphics card 20.                     

In the figure, the user selectively uses the floppy disk drive 16, the CD-ROM drive 18, and the keyboard 24 to store the characteristic information of the existing optical paths on the hard disk drive 14 to store the database. Make up.

Thereafter, the user drives the optical transmission network design application installed in the hard disk drive 14 using the keyboard 24 and the mouse 26 so that the optical transmission network design application accesses a database. Design the desired optical transmission network.

The monitor 22 receives an image signal through the graphic card 20 to display a series of images according to the driving of the optical transmission network design application so that the user can view them.

2 is a flow chart showing step by step an embodiment of an optical communication network design method using a computer according to the present invention.

First, the user executes an optical transmission network design application installed in the hard disk drive 14, and then inputs an optical transmission system standard and optical transmission network type information to be designed by an input device such as a keyboard 24. (Step 30). Optical transmission system specification and optical transmission network form information includes line width of light source, number of channels of light source, output power and noise index per channel, reception sensitivity of optical receiver, transmission speed of light source, gain of optical amplifier, noise index of optical amplifier , Color dispersion compensation module characteristics, forward error correction (FEC) gain, network type and transfer scheme, and end-to-end node designation.                     

The optical transmission network design application uses the optical fiber characteristic information of the database corresponding to the input optical transmission system standard and optical transmission network type information to be designed, for example, to limit the range of each node, for example, an optical to signal noise ratio (OSNR) of an optical signal. ) And the penalties due to polarization mode dispersion, elements limited by nonlinear characteristics, and the like (step 32). The limit range of the node includes the signal-to-noise ratio, surplus color dispersion and polarization mode dispersion, and non-linear related factors. The optical fiber characteristic information includes the polarization mode variance for each section, the loss spectrum for each wavelength, the color dispersion and the color dispersion slope for each section, the connector reflection for each section, the line reflection for each section, the manufacturing year for each section, the distance between nodes, and the light for each section. Contains the track type.

Polarization mode dispersion is most affected by the defects in the path itself and by tension or bending during laying, conditions in the burial area after being laid and seasonal external environmental changes. The polarization mode variances and constants of the detailed items in the optical fiber characteristic database are provided as values for each node, and the total polarization mode variance is obtained by square-rooting the sum of squared polarization mode variances of nodes in the end-to-end. For example, in the optical transmission system with STM-16 class with transmission speed of 2.5 Gb / s and STM-64 class with transmission speed of 10 Gb / s, the total polarization mode dispersion limit is 40ps and 10ps for 400km transmission, respectively. Restrict. If out of this range, the process returns to the optical fiber characteristic database in step 32 to find another line number and repeats the calculation.

The loss spectrum has emerged as an important optical quality parameter with multichannelization through wavelength division multiplexing. Until now, C-bands (1530-1560nm) are used, but the optical path characteristics of L-bands (1570-1600nm) should be taken into consideration to increase capacity. With the development of optical fiber manufacturing technology, currently supplied optical fiber beams have low loss and wide flat band characteristics, but when they are laid, fusion splicing is performed every 1.5 to 2 km. Therefore, more than 40 connection points occur when the distance is 80 km. This may be fatal to the loss spectrum of the L-band, and the loss difference between 1570 nm and 1600 nm may be greater than 0.05 dB / km depending on the interval. This causes a loss difference of more than 4dB per wavelength in the case of 80km transmission, which is beyond the gain flatness of the current optical amplifier, and thus may shorten the transmission distance of the system or generate a channel that cannot be received because the reception sensitivity of each wavelength is not satisfied. . In the database, the loss spectrum is databased by the loss-by-wave loss value, which enables calculation by wavelength when performing the signal-to-noise ratio calculation in the amplifier. In addition, if the loss difference is within 5dB within the available wavelengths and any channel does not meet the amplifier input power level, it returns to the database and selects another line number to repeat the calculation.

Color dispersion is applied to optical transmission system using STM-64 level signal as a dependent signal, and the database type can be divided and displayed by node in end-to-end. The total color variance in end-to-end is calculated by wavelength, which is calculated by adding the color variance of each node. Color variance compensation is processed at the intermediate node and automatically calculates it based on the amount of variance in the light beam between the previous node and the next node, and the value (the amount of variance compensation at each node) is known from the plotted result.                     

Connector reflection characteristics affect the transmission quality if the dependent signal is STM-16 or higher. In general, the connector guarantees more than 40dB of reflectance. However, in some cases, the connector can be more than 20dB. The inclusion of any one of these connectors in the transmission system has a significant impact on the transmission quality. The database of connector reflections is the reflection value across the patch cord connecting the optical fiber distributor (OFD) of each node located within the end-to-end and the line amplifier, expressed in dB.

Each of the above mentioned transmission limit characteristics is calculated at the same time, and in the form of a logical sum, if any one element is limited, it returns to the optical fiber characteristic database and selects another line number and repeats the calculation. The values in the fiber characteristic database can be updated periodically by each measuring instrument linked to the track, or the user can manually update the database. Critical nodes also provide access to any other regional node database.

The optical transmission network design application classifies the acceptable line and the unacceptable line according to the result of the limited range calculation, and designs a schematic network to display on the monitor 22 through the graphic card 20 (step 34). The acceptable line and the unacceptable line are divided into solid lines and broken lines, respectively.

The optical transmission network design application determines whether the user selects an unacceptable line using the mouse 26 (step 36).

As a result of the determination in step 36, the optical transmission network design application displays information related to the unacceptable line through the monitor 22 (step 38) when the user selects an unacceptable line. The information related to the unacceptable line includes a node-by-node light quality limiting element, line number and manufacturer, and year of manufacture.

As a result of the determination in step 36, the optical transmission network design application determines whether the user selects an acceptable line if the user does not select an unacceptable line (step 40).

As a result of the determination in step 40, when the user selects an acceptable line, information related to the acceptable line is displayed on the monitor 22 (step 42). Information related to the acceptable line includes an optical amplifier installation node, operational and protective lines, optical transmission system margin, line number and manufacturer, and year of manufacture indication.

As a result of the determination in step 40, if the user does not select an acceptable line, step 34 is continued.

As described above, the present invention inputs the section to design the network and the system information to be installed by implementing the network design support tool into a graphic user environment by databaseting the optical line line information and the optical line characteristic information for each section. do. Then, the OSNR of the optical signal, the penalties due to the polarization mode dispersion, the reflection loss, the loss spectrum, and the elements limited by the nonlinear characteristics are calculated to design the schematic network. Therefore, it is easy to know the information of the schematic optical line, so that it is easy to analyze the problem of the optical line and plan the replacement of the optical line.

Claims (7)

In the network design system where the characteristic information of the existing optical path is databased using a computer: (a) a first step of inputting optical transmission system standard and optical transmission network shape information to be designed; (b) a limit range of each node using the optical fiber characteristic information of the database in response to the input optical transmission system standard and optical transmission network type information to be designed; the limit range of each node is a signal-to-noise ratio, polarization A second step of calculating mode variance and non-linear related factors; And (c) a third step of designing a schematic network by dividing an acceptable line and an unacceptable line according to the result of the limited range calculation; Optical network design method using a computer comprising a. The method of claim 1, After step (c), A fourth step of determining whether to select the unacceptable line; A fifth step of displaying information related to the unacceptable line when the unacceptable line is selected as a result of the determination in the fourth step; A sixth step of judging whether to select an acceptable line if the unacceptable line is not selected as a result of the fourth step; And And a seventh step of displaying information related to the acceptable line when selecting an acceptable line as a result of the determination in the sixth step. The method according to claim 1 or 2, The optical transmission system standard and optical transmission network form information includes the line width of the light source, the number of channels of the light source, the output power and noise index per channel, the reception sensitivity of the optical receiver, the transmission speed of the light source, the gain of the optical amplifier, and the noise of the optical amplifier. A method for designing a computer-based optical communication network, including an index, color dispersion compensation module characteristics, forward error correction (FEC) gain, network type and switching scheme, and end-to-end node designation. The method according to claim 1 or 2, The optical fiber characteristic information includes polarization mode dispersion by section, loss spectrum by wavelength by section, color dispersion and color dispersion slope by section, connector reflection by section, line reflection by section, and manufacturing year by section, distance between nodes, and section An optical communication network design method using a computer comprising an optical line type. The method according to claim 1 or 2, The acceptable line and the unacceptable line are each divided into a solid line and a broken line, the optical communication network design method using a computer. The method according to claim 1 or 2, And the information related to the unacceptable line includes a node-by-node optical quality limiting element, a line number and a manufacturing company, and a manufacturing year indication. The method according to claim 1 or 2, The information related to the acceptable line includes an optical amplifier installation node, an operation and protection line, an optical transmission system margin, a line number and a manufacturing company, and a manufacturing year indication.

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