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xWDM?

, , OSNR

(EDFA), , FEC

PMD, FWM, SPM, XPM

DWDM-

/ /

: OADM / ROADM


Wavelength Division Multiplexing

WDM-

TX

TX

TX

TX

RX

RX

RX

RX

WDM


, , :

850 , 1310 , 1550 , 1625

-

850 1310 1550 1625

l

C =x l

: l()

: ()


ITU-T

()

() 1528.77 1578.23

0.4

1552.52

193.1

196.2 190.1

50

= = () =

O E S C L U l()

12

60

13

60

14

60

15

30

15

65

16

25

16

75


DWDM CWDM

Dense WDM Coarse WDM

Long Haul, Metro Metro

88- 8-

l 0.4 20

3000 80

1528 1562 1270 1610


()

()

,


Bit Error Ratio (BER)

BER

, BER, BER

BER

DWDM- BER=1012


=

2-3

, ,

,

(BER)


-

= -2

= -28

=

-2 -28

= 26

-2 (-28) = 26


(Core) ,

(Cladding) .

(Coating)

250

:

125

8


n2

n1

n2

n1

(1)

(MMF):

50 62,5

(SMF):

8

WDM-


SMF (NDSF) G.652

>90%

DSF G.653

NZDSF G.655 -20

-15

-10

-5

0

5

10

15

20

25

1350 1390 1430 1470 1510 1550 1590 1630

DS NZDS+ NZDS- SMF

(

/

*

)

()

(2)


1310

OK 1550

OK DWDM ( )

CWDM (>8 )

Extended Band

(G.652.C)

OK 1310

1550

DWDM (C + L Bands)

NZDSF

(G.655)

OK 1310

1550

DWDM (C-Band)

DSF

(G.653)

1310

OK 1550

OK DWDM ( )

SMF

(G.652)

(3)


, , .

()

OSNR

OSNR


(/)

(CD)

()

/ (OSNR)

800 900 1000 1100 1200 1300 1400 1500 1600

Wavelength (nm)

0.2

0.5

2.0

Loss (dB/km)

L-b

an

d:1

565

1625n

m

C-b

an

d:1

5301565n

m

S-b

an

d:1

4601530n

m

800 900 1000 1100 1200 1300 1400 1500 1600

Wavelength (nm)

0.2

0.5

2.0

Loss (dB/km)

L-b

an

d:1

565

1625n

m

C-b

an

d:1

5301565n

m

S-b

an

d:1

4601530n

m

Time Slot

10Gb/s

2.5Gb/s Fiber

Fiber

Time Slot

10Gb/s

2.5Gb/s Fiber

Fiber

S+N

N

S+N

N


()

()

()


:

850 nm

1310 nm

1550 nm


800 900 1000 1100 1200 1300 1400 1500 1600

OH-

()

0.2 dB/Km

0.5 dB/Km

(

/

)

S-band:14601530

L-band:15651625

C-band:15301565

Hydroxyl ion absorption is the absorption in optical fibers of electromagnetic waves,

due to the presence of trapped hydroxyl ions remaining from water as a contaminant.


(Microbends)

(Macrobends)

/


T T

P P

:

() = 10log10 (P /P)

: (/) = 10log10 (P/P)/L

: P () = 10log10(P / 1 )

P P

L ()


P P

P/P

: Gain = 10log10 P/P

: P/P = 2; Gain = 10log10 2 = 3

: Gain = 17 , P/P = 1017/10

= 50


EDFA-

Erbium Doped Fiber Amplifiers (EDFA)

:

C-band: 1530 1565 L-band: 1605 1625

30

+27 , 500


980- 1480-

WDM

EDFA-

,

, 980 1480


980

~1u

1550

Energy = h*

+ =

1550

EDFA-

, . ,

Energy = h*


Bit 1 Bit 2 Bit 1 Bit 2 Bit 1 Bit 2 Bit 1 Bit 2 Bit 1 Bit 2

, , (ISI),

/ (/*)


(DCF)

O-E-O


, (D>0), ,

(D


(DCF), ,

(2)


[/*]

[/]

(3)


/ OSNR (1)

OSNR,

OSNR ()

OSNR

()

()

OSNR = -----------------


/ OSNR (2)

EDFA-. C (ASE)

, OSNR

OSNR O-E-O

OSNR,

EDFA

(OSNR) (OSNR)

NF

Pin

(OSNR)out = 1

1 + h*f*B*NF

(OSNR)in Pin


/

G.709 Forwarding Error Correction (FEC)


/ G.709 Forwarding Error Correction (1)

G.709 Forwarding Error Correction (FEC)

FEC ,

38

25

40

80

1 7 8 14

15

16

17

38

24

1

2

3

4

OPU k Payload

OP

Uk O

H

OPUk Optical Channel Payload Unit

ODUk

ODUk Optical Channel Data Unit

Client Signal

Mapped in

OPUk Payload

Client Signal

OTUk

FEC

OTUk OH

OTUk Optical Channel Transport Unit

Alignm

Alignment

k Indicatesthe Order:

1 2.5G

2 10G

3 40G



, , ,

1011 1

1000 1

1001 1

0100 1

1100 0

1011 1

1000 1

1011 1

0100 1

1100 0

1 =

0 =



FEC OSNR

G.709 FEC OSNR 6.2 (BER 10-15)

FEC OSNR 8.4

4 5 6 7 8 9 10 11 12 13 14 15

BE

R

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

OSNR ()

EFEC = 8.4 dB

FEC = 6.2 dB


/ (1) 20-

,

,


/ (2)

100

~48

,

0 10 20 30 40 50 60 70 80 90 100

()

DWDM

DWDM


0

5

25

30

2.5G

0

28

1600 /

OSNR 21

SMF-28

120

0.25


0

20

25

9

+5

EDFA

9

+5

11

6

2.5G

0

28

1600 /

OSNR 21

SMF-28

120

0.25


EDFA

9

+5

11

6

2.5G

0

28

1600 /

OSNR 21

SMF-28

120

0.25

16.7 /*

0 /

334 /

1670 /

2004 /


DCF

1950 /

10

+0 334 /

20 1670 /

9 dBm

+ 5 0 /

25 2004 /

35 54 /

EDFA

9

+5

11

6

2.5G

0

28

1600 /

OSNR 21

SMF-28

120

0.25

16.7 /*


+0 334 /

20 1670 /

9

25 2004 /

15 54 /

EDFA 2

35

15

20

6

OSNR

16.9 dB

+ 5 0 /

OSNR

DCF

1950 /

10

2.5G

0

28

1600 /

OSNR 21

SMF-28

120

0.25

16.7 /*

OSNR

35 54 /


+0 334 /

20 1670 /

9

25 2004 /

15 54 /

EDFA 2

35

15

20

6

OSNR

16.9 dB

+ 5 0 /

OSNR

DCF

1950 /

10

2.5G

0

28

1600 /

OSNR 21

SMF-28

120

0.25

16.7 /*

RAMAN

5

0

OSNR

21.9 dB


+0 334 /

20 1670 /

9

25 2004 /

15 54 /

EDFA 2

35

15

20

6

OSNR

16.9 dB

+ 5 0 /

OSNR FEC

DCF

1950 /

10

2.5G

0

28

1600 /

OSNR (E-FEC) 12

SMF-28

120

0.25

16.7 /*


(PMD)

(FWM)

- (SPM, XPM)

Wavelength (nm)

-5

-10

-15

-20

-25

-30

-35

-40

1542 1543 1544 1545 1546 1547 1548

Po

wer

(dB

m)

Wavelength (nm)

-5

-10

-15

-20

-25

-30

-35

-40

1542 1543 1544 1545 1546 1547 1548

Wavelength (nm)

-5

-10

-15

-20

-25

-30

-35

-40

1542 1543 1544 1545 1546 1547 1548

Po

wer

(dB

m)

nx

nyEx

Ey

Pulse As it Enters the Fiber

Spreaded Pulse As

it Leaves the Fiber

nx

nyEx

Ey

Pulse As it Enters the Fiber

Spreaded Pulse As

it Leaves the Fiber

Power SP

M D

isto

rtio

n

Power SP

M D

isto

rtio

n


nx

ny

X Y. - , . .

PMD , CD

PMD (10 / )

Ex

Ey


, ,

(FWM)

l1 l2 l3

f113 f112

f123

f213

f223 f132

f312

f221 f332

f321

f231

f331

Input Power = +4 dBm/ch 5

10

15

20

25

30

35

40

()

1542 1543 1544 1545 1546 1547 1548

(

)

: CD


(SPM)

, , . , .

SPM + Dispersion < 0 SPM + Dispersion > 0


- (XPM)

XPM

,

XPM , ,

XPM

XPM

XPM c XPM


2.5 /

FEC


DWDM-

,

,

- (OADM)

OADM (R-OADM)

, ,


O-E-O

850, 1310, 1550 15xx.xx

Tx

Rx

G.709

DWDM-

ITU-T


ITU-T

O-E-O

850, 1310, 1550 nm 15xx.xx

Tx

Rx

G.709

DWDM-


1

2

3

N

N

1

2

3

N

DWDM-

1, 2, .N

DWDM-


1 drop

1Ch OADM

1 add

DWDM- -

Rx Tx


ROADM

West

ROADM

East

R-OADM

Line

West Line

East

Add/Drop

West Add/Drop

East

R-OADM ( /) /

, R-OADM 2- , /

DWDM- OADM (R-OADM)


l3

80/20

80/20

l1 l3

(Pass-through/Add/Block)

DWDM

DWDM

l1

drop block block drop

drop block block drop

Add

Pass

Add

Pass

Pass

Pass

Add

Add

(Pass-through/Add/Block)

l1 l3

DWDM- R-OADM

l1

l1

l3

l1

l3

l3


2-Degree R-OADM (R-OADM 2- )

/

Multi-Degree R-OADM (R-OADM )

/

(Mesh)

RO

AD

M

(West)

RO

AD

M

(East)

PP-MESH

ROADM

(Side B)

DWDM- 2-Degree Multi-Degree R-OADM


A

B

C

D PP-MESH-4 WXC

MUX

DMX

B

P

WX

C

MU

X

DM

X

B

P

WXC

MUX

DMX

P

B

WX

C

MU

X

DM

X

P

B

DWDM- 4-Degree R-OADM


DWDM- 4-Degree Broadcast & Select

WXC

MUX

DMX

B

P

A

B

C

D PP-MESH-4

1D 2D 3D 4D 80D ...

1A 2A 3A 4A 80A ...

1C 2C 3C 4C 80C ...

1 2 3 4 80 ...


DWDM- 8-Degree R-OADM

A

B

C

D

E

F

G

H

8-Degree

Patch Panel WXC

MUX

DMX

B

P

WX

C

MU

X

DM

X

B

P

WXC

MUX

DMX

P

B

WX

C

MU

X

DM

X

P

B


. West, .

DCU

AMP-C

AMP-C

ROADM

AMP-C

DCU

AMP-C

ROADM

West East

Directional DWDM

DCU

AMP-C

AMP-C

ROADM

AMP-C

DCU

AMP-C

West East

Omni-Directional DWDM

DWDM- Omni-Directional R-OADM


DCU

AMP-C

AMP-C

ROADM

AMP-C

DCU

AMP-C

ROADM

West East

Color-Specific DWDM

DCU

AMP-C

AMP-C

ROADM

AMP-C

DCU

AMP-C

West East

Colorless DWDM

DCU

AMP-C

AMP-C

ROADM

AMP-C

DCU

AMP-C

West East

Omni-Directional & Colorless

DWDM- Colorless R-OADM

, . 1 1, 2 2

Colorless

, Colorless/Omni-Directional

, DWDM-


(EDFA)

(VOA)

(DCM/DCU)

DWDM- EDFA, VOA, DCU


VOA

EDFA

DCM

VOA

EDFA

EDFA

VOA

EDFA

DCU

VOA

OSC OSC

OSC OSC

DWDM-


EDFA Terminal Terminal OADM

(Linear)

Hub

OADM

EDFA

(Open Ring)

EDFA

(Ring)

Amplified OADM

OADM

ROADM

Multidegree

ROADMs

(Mesh)

ROADM

DWDM