Dwdm Intro e4e5

7/29/2019 Dwdm Intro e4e5

1/33

INTRODUCTION

TO DWDM


2/33

9/19/2013 2

FIBRE EXHAUST

2.5- Gbit/s

2.5- Gbit/s

2.5- Gbit/s

2.5- Gbit/s

transmitter

2.5-Gbit/s2.5 Gbit/s

2.5 Gbit/s

reciever

LAY NEW FIBRE AND PUT NEW SYSTEMS


3/33

9/19/2013 3

FIBRE EXHAUST

2.5- Gbit/s

2.5- Gbit/s

2.5- Gbit/s

2.5- Gbit/s

transmitter

2.5-Gbit/s

2.5 Gbit/s

2.5 Gbit/s

reciever

INSTAL HIGHER BITRATE TDM

EXPENSIVE, NEW FIBRE NEEDED

10-Gbit/s 10-Gbit/s10-Gbit/s

transmitter regenerator reciever


4/33

9/19/2013 4

FIBRE EXHAUST

DEPLOY DWDM

2.5-Gbitt/s

transmitter

M

U

X

D

E

M

U

X

10-Gbit/s 10-Gbit/s10-Gbit/s

transmitter regenerator reciever

2.5- Gbit/s

2.5- Gbit/s

2.5- Gbit/s

2.5- Gbit/s

2.5- Gbit/s

transmitter

2.5-Gbit/s

2.5 Gbit/s

2.5 Gbit/s

reciever

2.5- Gbit/sreciever

2

1

3

4

2

1

3

4

2.5- Gbit/sreciever

2.5- Gbit/sreciever

2.5- Gbit/sreciever

2.5-Gbitt/stransmitter

2.5-Gbitt/s

transmitter

2.5-Gbitt/s

transmitter


5/33

5

DWDM History

Early WDM (late 80s)

Two widely separated wavelengths (1310, 1550nm)

Second generation WDM (early 90s)

Two to eight channels in 1550 nm window

400+ GHz spacing

DWDM systems (mid 90s)

16 to 40 channels in 1550 nm window

100 to 200 GHz spacing

Next generation DWDM systems

64 to 160 channels in 1550 nm window

50 and 25 GHz spacing


6/33

9/19/2013 6

Overview

Now in use:

C-band1525~1565nm

In research :

L-band 1570~1620nm

S-band 1400nm

In Future, the

communication window1280~1625nm


7/33

9/19/2013 7

ACHIEVING HIGHER BANDWIDTH

THREE POSSIBLE SOLUTIONS

Install new fibre

Invest in new TDMTechnologies to

Achieve higher

Bandwidth.

Deploy DWDM

Expensive

ExpensiveRequire new

Type fibre

Economical


8/33

9/19/2013 8

JUST LIKE WIDENING OF ROAD USING AVAILABE LAND TO MEET INCREASED TRAFFIC


9/33

9/19/2013 9

DWDM BASICS

SINGLE FIBRE

SDH OPTICAL SIGNALS

NEW REQUIREMENTS:


10/33

9/19/2013 10

BLOCK SCHEMATIC

Tx RxMUX DEMUX

OFAWD

M

W

D

M

2.

.

.

.

1

16

TRANSPONDERS

OPTICAL

SIGNALS.

STM-1

STM-4

STM-16

ATM

IP


11/33

9/19/2013 11

Wayside Optical Add/Drop Multiplexer

TM TMWDM

MUX

WDM

DEMU

X2

15

16

1

1-4 5-8

O

A

O

A


12/33

9/19/2013 12

Optical Add/Drop

Multiplexing

1 12 2 2 2

Configurable

OADM :1 or2

1 12 2 2 2

1 1

fixed OADM:

2

OADM : Optical Add/Drop Multiplexer

Terminal Equipt Terminal EquiptIn-Line Amplifier


13/33

9/19/2013 13

DIFFERENCES FROM OLD SYSTEM

REGs

FIBRES REQUIREMENT

LASERS TYPES OF COMPONENTS

CAPACITY

FIBRE TRANSMISSION BEHAVIOUR


14/33

9/19/2013 14

ADVANTAGES OF DWDM


15/33

9/19/2013 15

Transparency Can carry multiple protocols on same fiber

Monitoring can be aware of multiple protocols

Wavelength spacing 50GHz, 100GHz, 200GHz

Defines how many and which wavelengths can be used

Wavelength capacity Example: 1.25Gb/s, 2.5Gb/s, 10Gb/s

Characteristics of a WDM Network

Wavelength Characteristics


16/33

9/19/2013 16

Why Optical (DWDM) Networking?

Fibre Exhaust : Unlimited bandwidth on a fibre pair

Bit Rate Transparency

Format/Protocol Transparency : IP, ATM etc. Efficient use and rearrangement of embedded optical

capacity as per demand.

Minimal Capital Expenditure : Capacity Expansions

Demand


17/33

9/19/2013 17

Economics of WDM

Saving of regeneration costs:

one optical amplifier for many channels regeneration

cost per channel drastically reduced Saving of fibres/fibre shortage

Cost effective compared to laying new fibres

Introduction of a new network layer:

additional planning possibilities by passing of traffic

on nodes reduces node costs


18/33

9/19/2013 18

OPTICAL NETWORK ELEMENTS

TP

TP OA

ODEM

UX

OMUX

OADM OXC


19/33

9/19/2013 19

TRANSPONDER / TRANSLATOR /

WAVELENGTH CONVERTOR

O/E E/OElectricalREGENERATION

OPTIONAL

REGENERATOR


20/33

9/19/2013 20

Transponders

Converts broadband optical signals to a specific wavelength viaoptical to electrical to optical conversion (O-E-O)

Used when Optical LTE (Line Termination Equipment) does nothave tight tolerance ITU optics

Performs 2R or 3R regeneration function

Receive Transponders perform reverse function

Low Cost

IR/SR Optics

Wavelengths

Converted

1

From OpticalOLTE To DWDM MuxOEO

OEO

OEO

2

n


21/33

9/19/2013 21

Optical Amplifier

Advantages:

Design simplicity &high reliability.

Fewer components and economical.

Very low noise level.

Ability to amplify multiple wavelength signals in the operating

band.

No interchannel interference .

Careful design can remove the dispersion

problems also.

E bi D d Fib


22/33

EDF Amplifier Charactertics

1. Highly Efficient

2. High gain

3. Low Noise figure.

4. Low Cost

Erbium Doped Fiber

Amplifier (EDFA)


23/33

9/19/2013 23

Erbium Doped Fiber Amplifier

Simple device consisting of four parts:

Erbium-doped fiber An optical pump

A coupler

An isolator to cut off backpropagating noise

Isolator Coupler IsolatorCoupler

Erbium-Doped

Fiber (1050m)

Pump

Laser

Pump

Laser


24/33

9/19/2013 24

NMS FOR DWDM SYSTEMS

NMS IN CONVENTIONAL SDH SYSTEMS:

DCC: TIME SLOTS

DWDMNO TIME SLOTS

WAVELENGTH SLOTS

ONE WAVELENGTH IS DEDICATED FOR N.M.S.

OPTICAL SUPERVISORY CHANNEL

OSC needs to be accessed at all points in the network


25/33

9/19/2013 25

Optical Supervisory Channel - OSC

OSC mainly carries orderwire and network

management information.

signals at 1510 nm or 1625 nm

2.048 Mb/s


26/33

9/19/2013 26

Optical Supervisory Channel

(OSC)

Line Terminal Equipment In-line Amplifier

Tx 1

Tx 2

Tx 3

Tx 4

Tx 5

Tx 6

Tx 7

Tx 8

D

ATAIN

1

2

3

4

5

6

7

8

Rx

Rx

Rx

Rx

Rx

Rx

Rx

Rx

1

2

3

4

5

6

7

8

Line Terminal Equipment

+ supervisory

Tx sup

System Control

Processor

Rx Tx

OSC

Network Management Network Management

System Control

Processor

Rx sup


27/33

9/19/2013 27

OPTICAL BANDS

EXTENSIVE USE OF WAVELENGTHS

DIFFERENT VENDORS:INTEROPERABILITY ISSUES

NEED FOR STANDARD WAVELENGTH VALUES

ITU Classification of bands

Standard values : ITU Grid

Center frequency: 193.10THz (1552.52 nm)

Standard spacings of 200, 100, 50 GHz for different applications


28/33

9/19/2013 28

ITU-T BAND ALLOCATION

Optical

Supervisory

channel

1500 1520 1530 1542 1547 1560 1620

RED

BAND

C BAND L BAND

BLUE

BAND

CBAND PRODUCTS ARE COMMERCIALLY AVAILABLE.ERBIUM DOPED FIBRE AMPLIFIERS SUITABLE FOR

C BAND.

GAIN IN RED BAND FLATTEST FOR EDFA. SOME MANUFACTURERS PROVIDE 16 CHANNELS IN

RED BAND ONLY. OTHERS USE BOTH RED

& BLUE BANDS.

ITU T G 692 Frequency Grid


29/33

9/19/2013 29

Nominal

Central

(THz)

Central

(nm)

Nominal

Central

(THz)

Central

(nm)

Nominal

Central

(THz)

Central

(nm)

196.1 1528.77 194.7 1539.77 193.3 1550.92

196.0 1529.55 194.6 1540.56 193.2 1551.72

195.9 1530.33 194.5 1541.35 193.1 1552.52

195.8 1531.12 194.4 1542.14 193.0 1553.33

195.7 1531.90 194.3 1542.92 192.9 1554.13

195.6 1532.68 194.2 1543.73 192.8 1554.94

195.5 1533.47 194.1 1544.53 192.7 1555.75

195.4 1534.25 194.0 1545.32 192.6 1556.55

195.3 1535.04 193.9 1546.12 192.5 1557.36

195.2 1535.82 193.8 1546.92 192.4 1558.17

195.1 1536.61 193.7 1547.72 192.3 1558.98

195.0 1537.40 193.6 1548.51 192.2 1559.79

194.9 1538.19 193.5 1549.32 192.1 1560.61

194.8 1539.77 193.4 1550.12

ITUT G.692 Frequency Grid


30/33

9/19/2013 30

LIMITATIONS

THE MAXIMUM DISTANCE IS 640 km, MADE OF 8 SPANS OF 80km The assumptions are:

* Fibre attenuation, including splice loss is 0.28 db/km

* Span loss of 22 db. (0.28 *80km =22.40 )

* Total dispersion is less than 12800 ps/nm.

* For G.652 fiber/ cable is DISPERSION 17/20 ps/nm-km

* For 640 Km dispersion= 12800ps/nm


31/33

9/19/2013 31

Metropolitan Area Network

Unlimited Bandwidth, bit rate and format

transparencyEfficient Bandwidth use and Management

New Applications with DWDM


32/33

9/19/2013 32

Wavelength LeasingNetwork Customers are beginning to demand

high capacity Network Transport that affords

high reliability and security, as well as

segmentations from the providers Network

A spare Wavelength (Leased ) is used to

provide clear-channel transport to a customer

The Customers Bandwidth requirements arecleanly separated from the providers core

Network Needs.

New Applications with DWDM


33/33

9/19/2013 33

Thank You

Date post:	14-Apr-2018
Category:	Documents
Upload:	khanduja2
View:	226 times
Download:	0 times

Dwdm Intro e4e5

Documents