DWDMDENSE WAVELENGTH

DIVISION MULTIPLEXING

DEFINITION - DWDM

DENSE WAVELENGTH DIVISION MULTIPLEXING IS A FIBER- OPTIC TRANSMISSION TECHNIQUE WHICH

ALLOWS NUMBER OF OPTICAL SIGNALS, EACH HAVING ITS OWN

OPTICAL WAVELENGTH, TO BE TRANSMITTED ALONG THE SAME

FIBER.

EVOLUTION OF WDM

1980’s

1990’s

1996

2 Channel Wide band WDM

2 - 4 Channel 3nm -5nm spacing

16+ Channels0.8nm spacing

WHY DWDM ?

• Increase Network Capacity

• Working on Existing Fiber Infrastructure

• Low Initial Cost

• Easy Upgradability

COMPONENTS

• MULTIPLEXERS

• DEMULTIPLEXERS

• EDFA (Erbium Doped Fiber Amplifier)

• OADM (Optical Add-Drop Multiplexer)

16 ChannelsSimultaneous flow of 16 Channels in a single Fiber

Multiplexing of Channels

Multiplexer

DWDM NETWORK SYSTEM

TerminalTerminal TerminalTerminal

EDFAEDFA EDFAEDFA

OADMOADM

CHANNEL CAPACITY : 2.5 Gb/s x 16 Channels = 40 Gb/s

STM4 / STM16STM4 / STM16

12

16

12

16

UPGRADATION OF 2.5 Gb/s TO 10 Gb/s

Upgradation is very expensive; As “NZDSF” is 50 times “SMF”. Upgradation is very expensive; As “NZDSF” is 50 times “SMF”.

UPGRADATIONUPGRADATION

TDM STM 16TDM STM 16

TDM STM 64TDM STM 64

Single Mode Fiber (SMF)Single Mode Fiber (SMF)

Non Zero Dispersion Shifted Fiber (NZDSF)Non Zero Dispersion Shifted Fiber (NZDSF)

UPGRADATION OF 2.5 Gb/s TO 10 + Gb/s

UPGRADATIONUPGRADATION

TDM STM 16TDM STM 16

DWDMDWDM

Single Mode Fiber (SMF)Single Mode Fiber (SMF)

Single Mode Fiber (SMF)Single Mode Fiber (SMF)

UPGRADATION IS POSSIBLE ON EXISTING FIBERUPGRADATION IS POSSIBLE ON EXISTING FIBER

ADVANTAGES OF DWDM OVER TDM

• Easier upgradability on existing Fiber Infrastructure.

• Less effect of Dispersion

• More Capacity - 40 Gb/s

• Cost effective solution

• Migration Path to 100Gb/s

APPLICATIONS

• Long Distance Transmission - Point to Point and Ring Topology.

• Flexibility to lease Capacity to users.

• Quick increase in Capacity on existing Fiber Network.

TRANSPONDER

• TRANSPONDERS ARE WAVELENGTH TRANSLATORS

Tx TRPNon-WDMWavelength

ITU WDMWavelength

INTEGRATED DWDM SYSTEM

TERMINAL TERMINAL

16 X 2.5 Gb/s

STM-16

STAND ALONE DWDM SYSTEM

STM - 1

PDH

STM - 4

STM - 16

SONET

ATM

CATV

16 X 2.5 Gb/s

DEMUXMUX

TRP

TRP

TRP

TRP

TRP

TRP

TRP

TRP

TRP TRANSPONDER

EXPRESS TRAFFICEXPRESS TRAFFIC

APPLICATIONS : ADD/DROP CONFIGURATION

LOCAL TRAFFICLOCAL TRAFFIC

OADMOADM

TERMINALTERMINAL TERMINALTERMINAL

EDFA EDFA

OADM

STM4 / STM16

12

16

12

16

APPLICATIONS

OADM

OADMOADM

OADMOADMRING TOPOLOGY

LINEAR TOPOLOGY

DWDM NETWORK MANAGEMENT SYSTEM

TERMINAL

EDFA EDFAOADM

12

16

12

16FIBER CIRCUITS DROPPED & ADDED

NETWORK MANAGEMENT UNIT

TERMINAL

Network Element

Network Element Management

Network Management

Service

Business

LO

CA

L C

RA

FT

EL

EM

EN

T M

AN

AG

ER

NE

TW

OR

K M

AN

AG

EM

EN

TNetwork Management System

The ITU Standardized TMN model:

TMN: Telecommunication Management Network

Security

Accounting

Fault

Configuration

Perform

ance