Engineering and Planning Dwdm

7/31/2019 Engineering and Planning Dwdm

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ENGINEERING AND PLANNINGDWDM



WDM APPLICATIONS

2

22dB

30dB

33dB



Aplicaciones en Tandem

3

Caso: El numero de repetidores llega al maximo, se utiliza un “back-to-back”



Flujo de la Señal

4

+2 ~ -3dBm

-10 ~ -15dBm

L.16-2

-4.0 dBm

-16.5 ~ 12.5 dBm

+18.5 ~ +20.0 dBm

-26.5 ~ -10.0 dBm

+18.5 ~ +20.0 dBm

-10.0 ~ -25.0 dBm-2.0 ~ +3.0 dBm

Rx -28.0 dBm

+7.0 ~ +8.5 dBm



Diseño del Enlace Óptico

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Thz xsmV

f 50048.19236.1557

10) / (548.299792 12

1

1

Thz xsmV

f 0003.19432.1545

10) / (548.299792 12

1

16

GHzTHz x x f f f 1001.0

15

15.1920.194

15

1116



Especificación del Diseño de Sistema

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f

o

P

Ch xPdBm

Re

16log105.18 16 Canales

f

o

P

PdBm

Re

log1046.6 1 Canal



Especificación del Amplificador ILA

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Limitaciones del Sistema de Diseño

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If you deploy wavelengthas much as possible….

If you enlarge section lengthas long as possible….

Reducing output powerlevel to avoid non-lineareffect(FWM, SPM and soon).

Keeping output power levelhigh to improve OSNR.

The detailed information about fiber such as;1) Cable Loss, 2) Zero Dispersion Wavelength, 3) Dispersion Slopeis necessary to determine available channel count and section length.



Formula del Cálculo SNR

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Since “G-1” almost equals to “G”,

SNR can be expressed by following formula,

SNR PIN(SIG) / (NF x df x x h + PIN(ASE))

SNR = POUT(SIG) / POUT(ASE)

POUT(SIG) = PIN(SIG) x GainPOUT(ASE) =NF x (Gain-1) x df x x h + PIN(ASE) x Gain

Noise (ASE) generated inthe amplifier

Noise (ASE) from theprevious amplifier

If calculation result of SNR (Term to Term) is more than 18dB,the System can assure BER less than 10-12.

To keep SNR high is important to improve WDM engineering rule.

SNR is in proportion toPIN(SIG).

NF:Noise FigureV: speed of ighthh: Plank´s Constantdf: Bandwidth(measuring

the NF), 0.1nm(12.5kHz)



Dispersión

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Pulse Form

G.652 Single Mode Fiber 17 ~ 20ps/nm/km @ 1550nm20ps/nm/km x 400km = 8000ps/nm

Allowable Dispersion : 8000ps/nm 2.5G Transponder+/-300ps/nm 10G Transponder



Compensación por Dispersión

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DCF : Dispersion Compensation Fiber-100ps/nm-200ps/nm-300ps/nm-400ps/nm..

-2200ps/nm

Pulse Form

PA O/EDCF2E/O BA DCF1 LALA



Dispersión por el Modo de Polarización PMD (1)

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“Polarization mode dispersion” is a dispersion phenomenon that occurs

when the optical fiber (core) is not a true circle.

da

d

b

da

db

(da = db)

True circle fiber

The transmission speedvaries depending on theplane of polarization.

The receiving pointarrival time varies.

No inconsistencies in thetransmission speed depending onthe polarization mode.(The polarization mode is reduced.)

PMD changes every moment due to external factors (stress, temperaturechanges). However, it relies mostly on the degree of true circle of a fibercable achieved in the manufacturing phase.

Fiber that isnot a true circle

(da db)




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In case of good fiber, there is no such kind of dispersion.Case 1: 0.5ps / km, ave.DGD 10ps ->400km

Case 2: 5ps / km, ave.DGD 10ps ->4km

Good PMD Fiber

Bad PMD Fiber

If exceeding the limitation of DGD, it may add REG in the WDM section.




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STM64: PMD (ps) must be less than 10ps (Terminal to Terminal).STM16: PMD (ps) must be less than 40ps (Terminal to Terminal).

En caso de excederse, penalidades de potencia o B-B deberán deimplementarse.

El valor real del coeficiente PMD puede obtenerse a través de una seriede pruebas de Survey en los enlaces de fibra.

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Engineering and Planning Dwdm