Dwdm Ppt Industrial Seminar
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Transcript of Dwdm Ppt Industrial Seminar
DENSE WAVELENGTH DIVISION MULTIPLEXING
(DWDM)
BYBY
AKASH BHARTI
EC-09
0901431007
AKASH BHARTI
EC-09
0901431007
11
Introduction Configurations of DWDM Systems Components of DWDM DWDM Design Considerations Summary
22
Dense wavelength division multiplexing (DWDM) is a fiber-optic transmission technique that employs multiple light wavelengths to transmit in parallel through a single fiber.
TM16TM
16TM16TM
16
WD
M
TM16TM16TM16TM16
WD
M
STM-16
STM-16
STM-16
STM-16
4 * STM-16 = 10 Gb/s
TM16
TM16TM
16
WD
M
TM16
TM16TM16
STM-16
STM-16
STM-16
8 * STM-16 = 20 Gb/sILA
8 * STM-16 = 20 Gb/s WD
M
TM16
TM16TM
16
WD
M
TM16
TM16TM16
STM-16
STM-16
STM-16
32 * STM-16 = 80 Gb/s
OAD
32 * STM-16 = 80 Gb/s
WD
M
8
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2
1
8
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2
1
32
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2
1
32
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2
1
4 Ch p-2-p system 4 Ch p-2-p system
8 Ch range extended by OA 8 Ch range extended by OA
32 Ch system with 80Gbps capacity and OAD feature32 Ch system with 80Gbps capacity and OAD feature
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• STM-1 frame
AU-n pointers
RSOH
MSOH
1 2 9 10 11 270
1
4
9
STM-1 PAYLOADPOH
125µs
C-4
VC-4AU-4
Early WDM (late 80s)Two widely separated wavelengths (1310, 1550nm)
“Second generation” WDM (early 90s)Two to eight channels in 1550 nm window400+ GHz spacing
DWDM systems (mid 90s)16 to 40 channels in 1550 nm window100 to 200 GHz spacing
Next generation DWDM systems64 to 160 channels in 1550 nm window50 and 25 GHz spacing 66
TTimeime DDivisionivision MMultiplexingultiplexing(TDM)(TDM)
SDH is the standardized TDM based hierarchial model where the following transmission rates are defined:STM-1: 155 Mbps STM-4: 622 MbpsSTM-16: 2.5 GbpsSTM-64: 10 GbpsSTM-256: 40 Gbps
number of wavelength channels number of wavelength channels > 16> 16
DDenseense WDMWDM DWDMDWDM
SoSocombining many wavelength onto a combining many wavelength onto a
single fiber using:single fiber using:
WWavelengthavelength DDivisionivision MMultiplexingultiplexing(WDM)(WDM)
Why WDM?
• Capacity upgrade- using existing fiber networks (without adding new fibers).
• Transparency- DWDM optical channels can carry any transmission format, supporting TDM (SDH/SONET) different asynchronous formats, ATM, Gigabit
Ethernet, ESCON, etc.
• Low initial cost- Set up with minimum configuration
• Wavelength routing and switching- Wavelength is used as another dimension to time and space.
99
WDM – Features
• Fully utilizes fiber bandwidth resource
• Super-long-transmission distances (EDFA technology) • Support hybrid of transmission
formats• Easy upgrade/expansion• Saving fiber resources (more
‘s)• Utilizing TDM technology(SDH)• Forming full Optical networks
(OADM & OXC)
1010
WDM (Wavelength Division Multiplexing) Used two wavelengths ; one in 1310 nm window and other in 1550 nm
window, in the initial wavelength division multiplexing case.
Coarse WDM (CWDM) The CWDM technology refers to the WDM technology with large interval
(usually greater than 20 nm) between adjacent wavelengths. Usually, its wavelength quantity is 4 or 8 (16 at most). It uses 1270nm-1610 nm windows.
Dense WDM (DWDM) DWDM spaces the wavelengths more closely. Therefore, DWDM has a
greater overall capacity. DWDM common spacing may be 200, 100, 50,
or 25 GHz with a channel count reaching upto 160 channels at distances
of several thousand kilometers, with amplification and regeneration
along such a route.
Types of WDM System
1111
Two Variants of DWDM:
Long Haul DWDM
Basically P2P system for Long-Haul application.
Metro DWDM (Short Haul)
For Metro area application. Can be configure into a ring network complete with protection mechanism.
Variants of DWDM System
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Short-haul Solutions
• Low cost Tx transponders or SDH integrated transmitters
• Low loss Mux/Demux
D2 TRP
D2 TRP
.
.
.
.
.
.
.
.
AUX-alarms
MUX
DEMUX100 km100 km
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• The value proposition is very different from the long haul Rapid-service provisioning Protocol/bit-rate transparency
• Metro DWDM is an emerging market for next generation
DWDM equipment
Long-haul Systems
• Longhaul Tx transponders or integrated transmitters
• Booster and preamp allows low cost mux/demux
• Remote management (OSC). Optical layer performance supervision may be included
OSC
NetworkManagement
OSCNetworkManagement
OSC
D10 TRP
D10 TRP
.
.
.
.
.
.
.
.
Rx TRP
Rx TRP
. . . . . . . . .
640km640km
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Optical Multiplexer
Optical De-multiplexer
Optical Add/Drop Multiplexer(OADM)
Transponder
1
2
3
1
2
3
15xx
1
2
3
1...n
1...n
1515
Optical Amplifier(EDFA)
Optical AttenuatorVariable Optical Attenuator
Dispersion Compensator (DCM / DCU)
1616
n
MU
X
Transponder at Transmit side
n
DE
MU
X
EDFAEDFA
OADM
DWDM Network Elements
Transponder at Receive side
•A transponder-convert a wavelength to another wavelength •The wavelength converted be used by the DWDM system
Optical Add-Drop Multiplexer (OADM)Optical Add-Drop Multiplexer (OADM)
1717
A transponder is basically a module that can convert a wavelength to another wavelength which can be used by the DWDM system. It also
does the 3R or 2R function.
Transmit Transponder• emits one specific wavelength • perform 3Rs• Relatively high cost
Receive Transponder• accept any wavelength• perform 2Rs (generally)• Relatively lower cost
3R/2R
The 3RsRegeneration ReshapingRetiming
Transponder
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“Simple” device consisting of four parts: Erbium-doped fiber - unstable Erbium ions release energy Two optical pumps (1480/980nm) to stimulate erbium atoms
to release stored energy at 1550nm. A coupler to combines signal light and pump light An isolator to suppress reflections for stable working
Isolator Coupler IsolatorCoupler
Erbium-DopedFiber (10–50m)
PumpLaserPumpLaser
PumpLaserPumpLaser
1919
Pump Laser(980/1480 nm)
Optical Add-Drop Multiplexer (OADM)
1
23
n
Single
Fiber
1
23
n
Dropped s
Multi- in
Single
Fiber
Multi- out
Adding s
Demultiplexer
Local ports
Multiplexer
4
4
Transponder
• Similar to SDH ADM,except only optical wavelength are added and dropped with no O-E conversion.
• Allow adding and dropping of channels at station.
2020
Spectrally broad Uses LED with mirrors Unstable center/peak wavelength Low cost, used at client end of
TRP
cPower
Power c
DWDM Laser Distributed Feedback (DFB)
Non DWDM Laser Fabry Perot
• Dominant single laser line(50khz)
• Stable wavelength
• Higher power, used in DWDM
2121
Transmission Challenges Unidirectional vs. Bidirectional Protection
2222
Attenuation: Reduction of power level with distance
Dispersion and nonlinear effects: Erodes clarity with distance and speed
• Noise and Jitter: Leading to a blurred image(Jitter: Random shift in correct timing of a bit)(Jitter: Random shift in correct timing of a bit)
2323
DWDM systems can be implemented in two different ways
Bi -directional
Fiber
Uni -directional
Fiber
Fiber
• Uni-directional:
wavelengths for one direction travel within one fiber
two fibers needed for
full-duplex system
• Bi-directional:
a group of wavelengths for each direction
single fiber operation for full-duplex system
2424
Uni-directional 32 channels system
32
32
Full band
Full band
ChannelSpacing100 GHz
16
16
Blue-band
Red-band
ChannelSpacing100 GHz
16
16
• Bi-directional 32 channels system
32 chfull
duplex
16 chfull
duplex
2525
Network survivability => ability of a network to› continue to provide a service even after a
failure occurrence within the network
Failures in networks are bound to happen› Fiber cuts or breaks› Node failure e.g. total power failure› Wavelength channel outage e.g. faulty
transmitter› Human error e.g. incorrect configuration or
wrong unit
DWDM provides hundreds of Gbps of scalable transmission capacity today
Better use of existing fiber bandwidth
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Allows fast expansion of capacity on existing routes
‒ 32Channels@ 10Gbit/s‒ 320 Gbit/s on a single fiber pairAllows multiple clients to be carried directly
and in parallel on the same fiber Saves time & cost of laying new fibers System upgrade can maximize existing investment protectionHigh reliability and flexibility of networkingCompatible all-optical exchange
Application codesMax number of spans
Max Bit rate e.g STM-16
Fibre types; 2: G652, Standard SM
Fibre 3: G653 Dispersion shifted
fibre 5:G655 Dispersion
Flattened fibre
n W X - y, zNumber of
optical channels L (Long Haul) = 22dB span
or V (Very Long Haul) = 33dB span
e.g. 32 L 4 -16,2= 32 channels, 22dB span att., 4 spans, STM-
16, Standard Fibre
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