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) 17
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) 18
- 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
19
Thermo-Optic Switch - Silica Mach – Zehnder Configuration Input Ii
Heater
Outputs I1 I2
I1 sin 2 ( / 2) Ii Directional coupler 20
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 21
Thermo-Optic Switch - Characteristics Parameters
22
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
15
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: 23
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 24
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 25
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 + + + – 26
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 27
1 2
N X N Cross Connect
N
Optical Cross Connects
28
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. 29
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 30
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 35
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 36
Yamada et al., 1998
retiming
Router & Optical Switch
CHIAROOptIPuter Optical Switch Workshop 37
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.
•
39
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
