WDM

WDM
DWDM, CWDM
Spektrum Frekwensi
Mengapa WDM
• Tahun 1990 WDM mulai memainkan peran
besar dalam jaringan telekomunikasi.
• Permintaan kapasitas link yang besar dan
terbatasnya instalasi serat optik untuk laju
sinyal optik yang cepat.
• Awalnya bekerja dengan baik pada laju bit
mencapai 2,5 Gb/s (Optical Core 48). Kedepan
kecepatan level multiplexing berikutnya
mencapai 10 Gb/s dengan OC 192.
Optical Network - Issues
• Capacity
2.5 Gb/s
10 Gb/s
40 Gb/s Larger
• Control (switching)
– Electronics
• 10 Gb/s (GaAs, InP) dapat memberikan orde rendah
optical cross connects (16 x 16)
• > 10 Gb/s ??(terutama disipasi daya)
– Optical
• Reconfiguration:
– Statis atau dinamis
5
Sejarah WDM
Teknologi WDM
NTT tahun 2010 tanggal 25 Maret telah mampu mencapai
transmisi 69,1 Tb/s dengan menggunakan WDM 432 kanal kapasitas
171 Gb/s dan untuk long haul panjang serat optik singlemode 240 km.
Wavelength Division Multiplexing (WDM)
WDM = A Capacity Multiplier
Perkembangan teknologi telah didorong oleh kebutuhan bandwidth
Sumber pertumbuhan trafik adalah Internet
Internet diperkirakan masih tumbuh pada 100%/tahun
Jaringan harus tumbuh dalam kapasitas dengan 32x dalam 5 tahun!
.
Klasifikasi WDM
Point-to-Point Wavelength Multiplexing Systems
•
Multiplexing sebanyak ~ 200 panjang gelombang pada serat ("Dense
WDM", atau DWDM)
•
Laju 2.5 and 10 Gb/s; sistem bekerja pada 40 Gb/s
•
Penggelaran jaringan jarak jauh yang significant (largest aggregation of
traffic, long distances)
•
Products yang tersedia dari berbagai produsen (Ciena, Nortel, Lucent,...)
•
Fundamental layer Optic menyediakan transport paket IP
Optical Switches
• Untuk menyediakan switching kecepatan tinggi
• Untuk menghindari kemacetan kecepatan
elektronik
• Interface I / O dan switching fabric di optik
• Switching kontrol dan switching fabric di optik
• Switch bertindak sebagai router dan mengarahkan
kembali sinyal optik dalam arah tertentu.
• Ini menggunakan switch 2x2 sederhana sebagai
building blok
Main feature: Switching time (msecs - to- sub nsecs)
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Optical Switches - Types
 Waveguide
 Electro-optic effect
- Semiconductor optical amplifier
- LiNbO
- InP
 Thermo-optic effect
- SiO2 / Si
- Polymer
 Free Space
- Liquid crystal
- Mechanical / fibre
- Micro-optics (MEM’s)
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- Fast
- Complex
- Maturing
- Lossy
- Slow
- Maturity
- Reliable
- Slow
- Low loss & crosstalk
- Inherently scalable
Optical Switches - Thermo-Optic Effect
• Some materials have strong thermo-optics effect that
could be used to guide light in a waveguide.
• The thermo-optic coefficient is:
– Silica glass
dn/dt = 1 x 10-5 K-1
– Polymer
dn/dt = -1 x 10-5 K-1
• Difference thermo-optic effect results in different switch
design.
+v
Electrodes
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Thermo-Optic Switch - Silica
Mach – Zehnder Configuration
Input Ii
Heater
Outputs
I1
I2
I1
 sin 2 ( / 2)
Ii
Directional coupler
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I2
 cos 2 (  / 2)
Ii
Thermo-Optic Switch - Polymer
Y – Junction Configuration
PH1
I1
Ii
PH2
I2
• If PH1 = PH2 = 0, then I1 = I2 = Ii /2
• If PH1 = Pon & PH2 = 0, then I1 = 0, and I2 = Ii
• If PH1 = 0 & PH2 = Pon, then I1 = Ii, and I2 = 0
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Thermo-Optic Switch - Characteristics
Parameters
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Switch Size
2x2
Si Poly.
8x8
Poly.
16 x 16
Si
Si
No. of S/W
1
1
64
112
256
Insertion Loss (dB)
2
0.6
4
10
18
Crosstalk
22
39
18
17
13
S/W time (ms)
2
1
~3
1.5
~4
S/W power (W)
0.6 0.005
5
4.5
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Mechanical Switches
1st Generation – Mid. 1980’s
•
•
•
•
•
Loss
Speed
Size
Reliability
Applications:
Low (0.2 – 0.3 dB)
slow (msecs)
Large
Has moving part
- Instrumentation
- Telecom (a few)
Size:
Loss:
Crosstalk:
Switching time:
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8X8
3 dB
55 dB
10 msecs
Micro Electro Mechanical Switches
Combines optomechanical structures, microactuators, and micro-optical elements
on the same substrate
Input fibres
 Made using micromachining
 Free-space: polarisation
independent
 Independent of:
– Bit-rate
– Wavelength
– Protocol
 Speed: 1 10 ms
Output fibres
Lens
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Flat mirror
Raised mirror
4 x 4 Cross point
switch
Micro Electro Mechanical Switches
This tiny electronically tiltable mirror
is a building block in devices such
as all-optical cross-connects and new types of
computer data projectors.
I/O Fibers
Reflector
MEMS 2-axis
Tilt Mirrors
Lightwave
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Imaging
Lenses
Micro Electro Mechanical Switches
 Monolithic integration --> Compact, lightweight, scalable
Batch fabrication
--> Low cost
 Share the advantages of optomechanical switches without their
adverse effects
 General Characteristics:
+ Low insertion loss (~ 1 dB)
+ Small crosstalk (< - 60 dB)
+ Passive optical switch (independent of wavelength, bit rate, modulation
+
+
+
–
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format)
No standby power
Rugged
Scalable to large-scale optical crossconnect switches
Moderate speed ( switch time from 100 nsec to 10 msec)
Large Optical Switches - Optical Cross Connects
• Switch sizes > 2 X 2 can be implemented by means of cascading small
switches.
• Used in all network control
• Bit rate at which it functions depends on the applications.
– 2.5 Gb/s are currently available
• Different sizes are available, but not up to thousands (at the moment)
Control
1
2
N
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1
2
N X N Cross Connect
N
Optical Cross Connects
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Optical Switches
Electrical switching and optical
cabling: inputs come
from different clock domains
resulting in a switch that is
generally timing-transparent.
Optical switching and optical cabling, clocking
and synchronization are not significant
issues because the streams are independent.
Inputs come from different clock domains,
so the switch is completely timing-transparent.
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Optical Switches - System Considerations
• For a given switch size N,
– the number of 2x2 switches should be as small as
possible. When the number is large it will result in:
• high cost
• large optical power loss and crosstalk.
• A switch with reduced number of crosspoints in
each configured path, can have a large internal
blocking probability
• In some switching architectures, the internal
blocking probability can be reduced to zero by:
– using a good switching control
– or rearranging the current switch configuration
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Optical Cross-Connects (OXCs)
OXC
Input fibers
with WDM
channels
•
Output fibers
with WDM
channels
OXC switches signals on input {wavelengthi, fiberk} to output {wavelengthm,
fibern}
Optical Cross-Connects (OXCs)
OXC
Input fibers
with WDM
channels
•
•
•
•
•
‘Opaque’: o-e, e-o, electronic switch fabric
‘Transparent’: o-o-o, optical switch fabric
Hybrid, (o-e-o): optical switch fabric, o-e-o
Hybrid: both opaque and transparent fabrics
Tunable lasers + passive waveguide grating
Output fibers
with WDM
channels
Important optical layer capability: reconfigurability
IP
Router
IP
IP
Router Router
IP
Router
OXC - A
OXC - B
OXC - C
IP
Router
OXC - D
Crossconnects are reconfigurable:
Can provide restoration capability
Provide connectivity between any two routers
Smaller routers combined with optical crossconnects
OXC
OXC
OXC
OXC
• Router interconnectivity through OXC’s
• Only terminating traffic goes through routers
• Thru traffic carried on optical ‘bypass’
• Restoration can be done at the optical layer
• Network can handle other types of traffic as well
•But: network has more NE’s, and is more complicated
Optical Gateway Cross-Connect
Performs digital grooming, traditional multiplexing, and routing of lower-speed
circuits in mesh or ring network configurations. Specifically, it brings in lower rate
SONET/SDH layer OC-3/STM-1, OC-12/STM-4 and OC-48/STM-16 rates and
electrical DS-3, STS-1 and STM-1e rates and grooms them into higher rate optical
signals.
Alcatel. 2001
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IP-router with Tb/s throughput can be built with
fast tunable lasers & NxN optical mux
From Input Port
Scheduler
Buffer
Output
T-Tx
40 G mod
40G Rx
T-Tx
40 G mod
40G Rx
T-Tx
40 G mod
40G Rx
T-Tx
40 G mod
40G Rx
Clock
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Yamada et al., 1998
retiming
Router & Optical Switch
CHIAROOptIPuter Optical Switch Workshop
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The Optical Future- Tomorrow's Architecture
•
38
Services are consolidated onto a
single access line at the user site and
fed into a Sonet multi-service
provisioning platform at the carrier’s
POP (point of presence). Several
POPs feed traffic into a terabit switch
capable of handling all traffic—
including IP, ATM and TDM. The
terabit switches sit at the edge of a
three-tier network of optical
switches—local, regional and long
distance-each of which has a mesh
topology. DWDM is used throughout
the network and access lines. Where
fiber is scarce, FDM (frequency
division multiplexing) is used to pack
as much traffic as possible into
wavelengths. Light signals no longer
need regeneration on long distance
routes.
•
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Separate access networks carry
telephony and data into the
carrier’s point of presence. Voice
traffic runs over a TDM (time
division multiplexer) network
running over a Sonet (synchronous
optical network) backbone. IP
traffic is shunted onto an ATM
backbone running over other
Sonet channels. The Sonet
backbone comprises three tiers of
rings at the local, regional and
national level, interconnected by
add-drop multiplexers and crossconnects. DWDM (dense wave
division multiplexing) is in use in
the regional and national rings,
but not the local rings. Light
signals need regenerating on long
distance routes.
Pengertian DWDM
Definisi
Teknologi DWDM
Perkembangan DWDM
Perangkat DWDM
Perangkat DWDM
Alternatif Pemenuhan Kapasitas
Pemilihan DWDM
Keunggulan DWDM
DWDM 40 Kanal