1 Simulation of High Speed Photonic Networks Professor Z. Ghassemlooy Optical Communications...
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1 Simulation of High Speed Photonic Networks Professor Z. Ghassemlooy Professor Z. Ghassemlooy Optical Communications Research Group Optical Communications Research Group http://soe.unn.ac.uk/ocr/ School of Computing, Engineering and Information School of Computing, Engineering and Information Sciences Sciences University of Northumbria at Newcastle, University of Northumbria at Newcastle, UK UK
1 Simulation of High Speed Photonic Networks Professor Z. Ghassemlooy Optical Communications Research Group School of Computing,
1 Simulation of High Speed Photonic Networks Professor Z.
Ghassemlooy Optical Communications Research Group
http://soe.unn.ac.uk/ocr/ School of Computing, Engineering and
Information Sciences University of Northumbria at Newcastle,
UK
3 Optical Communications 1 st generation optical networks:
packet routing and switching are mainly carried out using
high-speed electronic devices. However, as the transmission rate
continues to increase, electronically processing data potentially
becomes a bottleneck at an intermediate node along the network. 1P
100T 10T 1T 100G 10G 1G 100M 1995 2000 2005 2010 [bit/s] Voice Data
Total Traffic demand forecast (NEC2001) Capacity increase : 2~4
times a year Bit cost decrease : 1/2 time a year Solution:
All-optical processing & switching
Slide 4
Eng. of S/W Pro., India 2009 Ref: Prof. Leonid G. Kazovsky, et
al. Broadband Fiber Access , available online from
http://www.comsoc.org/freetutorials/http://www.comsoc.org/freetutorials/
Slide 5
Eng. of S/W Pro., India 2009 5 All-Optical Packet Switching
Objectives High Bit Rate High Throughput HeaderProcessing!
Slide 6
Eng. of S/W Pro., India 2009 6 Photonic Network - Packet
Routing O/E Processing E/O PatternsOutputs 0000 B (0 D ) OP 1 0001
B (1 D ) OP 2 0010 B (2 D ) OP 1 0011 B (3 D ) OP 1 0100 B (4 D )
OP 2 0101 B (5 D ) OP 1 1110 B (14 D ) OP 2 1111 B (15 D ) OP 1
0100 Matching! H Routing table Electrical domain IC: Large scale,
cheap, memory Speed limitation < 40 Gbit/s Optical domain High
Speed >> 40 Gbit/s Complexity, costly, no memory Optical vs.
Electrical in High-speed Routing All-Optical Processing Integration
Light Frozen? Opt. Capacitors?
Slide 7
Eng. of S/W Pro., India 2009 Photonic Network All-optical
Routing 7 Aim: 1.To optimise the SMZ performance for all-optical
functions. 2.To design a bi-directional SMZ and implement it in the
router to reduce components, time and cost.
Slide 8
Eng. of S/W Pro., India 2009 8 Photonic Network - Packet
Routing Packet header is compared with all entries of a routing
table for checking the matching Robust All-Optical Processing
Exhaustive Correlation N 2 N N 2 N bit-wise AND operations Reduce
routing table entries Minimise number of AND operations Our
solution: Pulse-Position-Modulation based Header Processing PPM-HP
(PPM-HP)
Slide 9
Eng. of S/W Pro., India 2009 9 Photonic Network - Packet
Address Bit duration: T b Slot duration: T s = T b /4 PPM 0 1 2 3 4
5 6 7 8 9 10 11 12 13 14 15 T s No. of slot L = 2 4 TbTb LSB 1 0 0
1 a 3 a 2 a 1 a 0 Add. in Binary One Frame of 4-bit RZ OOK Decimal
value = 9 Location 9 Payload Address Clock Optical Packet
Slide 10
Eng. of S/W Pro., India 2009 10 Photonic Network - Routing
Table Conventional routing table Address patterns Decimal metric
Output ports 000000Port 2 000011Port 1 000102Port 3 000113Port 1
001004Port 3 001015Port 2 001106Port 2 001117Port 1 11102 N -2Port
2 11112 N -1Port 1 2 N entries Entry Positions (Decimal) Actual PPM
frame (length 2 N slots) 11,3,7,,2 N -1 20,5,6,,2 N -2 32,4, PPM 0
1 2 3 4 5 6 7 2 N -1 Pulse-position routing table 1M1M (M = 3
ports) Port 1 Port 2 Port 3
Slide 11
Eng. of S/W Pro., India 2009 11 Clk Matched pulse &1 Entry
1 Entry 2 Entry M CP 1 CP 2 CP M Port 1 Port 2 Port M PPM-HP
All-optical Switch &2 &M&M Clock Extraction Header
Extraction PPM Add. Conversion PPRT OSWC Synchronisation APLClk
APLClk APLClk APLClk PPMA A All-optical Packet-switched Router PPM
Touting Table OSW1 OSW2 OSWM
Slide 12
12 Simulation Software to Model Routers OptiWave (systems,
devices, components) OptiWave (systems, devices, components)
http://www.optiwave.com/ R-Soft (systems & devices) R-Soft
(systems & devices) http://www.rsoftdesign.com/ Photoss (WDM
systems & devices) Photoss (WDM systems & devices)
http://www.lenge.de/english/index.php Virtual Photonic Inc. (VPI)
(systems & devices) Virtual Photonic Inc. (VPI) (systems &
devices) http://www.vpiphotonics.com/......
Slide 13
Simulation Software - Matlab No optical communications tool box
Complex to model optical networks Need strong theory Can be used
with other software packages such as VPI to save modelling and
debugging time Ideal for the end users with a strong mathematical
and programming background 13
Slide 14
14 Simulation Software - VPI Very powerful for optical networks
and optical devices modelling Support C and Matlab Support C and
Matlab Has visual interface (drag and drop) e.g. oscilloscopes etc
Provide extensive simulation examples and manuals Provide extensive
simulation examples and manuals Online discussion forum Online
discussion forum http://forums.vpisystems.com/
Slide 15
15 VPI Simulation Software Laser Source Optical Scope BER
Tester SMZ Eng. of S/W Pro., India 2009 A typical optical
switch
Slide 16
Eng. of S/W Pro., India 2009 Simulation of Devices - SOA
Semiconductor Optical Amplifier Best to use Matlab: Segmentisation
of SOA improves accuracy Not possible with the current VPI 16 L
Injection current (I) Input facet of active region Input signals
Output signals Output facet H w segment 1 segment 2 .. . segment 5
t=0 g t=l/v g t=L/v g Input signal output signal NiNi N(1)
N(5)
Slide 17
17 Total gain with no input Signal output gain corresponding to
the input power at different wavelengths Simulation of Devices SOA
Results
Eng. of S/W Pro., India 2009 VPI SMZ Switch 19 CP1=CP2 Recovery
region
Slide 20
Eng. of S/W Pro., India 2009 VPI SMZ Switch 20 Optical receiver
Data pulse train
Slide 21
AA bar 10 01 VPI Simulation Software Inverter Gate Input
packets Control pulse Output1 Output2 SOA Input (CLK) CP 1 (CLK) CP
2 (A) Output (A bar)
Slide 22
Eng. of S/W Pro., India 2009 Packet Address Correlator To carry
packet routing decision one needs to check (correlated) packet
address with entries of routing table AND gate A B A*B PP packet
address One PPRT entry Matched SOA1 SOA2 in SW A B ABAB
Slide 23
Eng. of S/W Pro., India 2009 PPM-HP Router - Clock Extraction
Clock extraction requirements: Asynchronous and ultrafast response
High on/off contrast ratio of extracted clock Clock, header and
payload: same intensity, polarization and wavelength 4 Clock
Extraction Clk Optical packet
Slide 24
Eng. of S/W Pro., India 2009 PPM-HP Router - Clock Extraction 5
2222 2222 SOA1 SOA2 1212 2222 SMZ-1 2222 in SW 1212 G CP Optical
delay Attenuator Polarization Beam Splitter (PBS) Polarization
Controller (PC) Amplifier Optical fiber span SMZ-2 1212 2222 2222
2222 2222 SW in 1212 SOA1 SOA2 Clk Self-extraction: packet as the
control signal High on/off contrast ratio: two switching-stage
Slide 25
Simulation Clock Extraction 13 2 nd stage Packet in Extracted
clock 1 st stage Crosstalk
Slide 26
Eng. of S/W Pro., India 2009 26 (a) (b) VPI Packet Address
Conversion
Slide 27
1 2 SMZ Switch with a High Contrast Ratio CEM: clock extraction
module low inter-output CR (< 10 dB) Improved CR (> 32
dB)
Slide 28
Eng. of S/W Pro., India 2009 Fibre Delay Line Passive using
Matlab A B C In Out Fibre loop Switch Eye diagram after 200
iterations without regeneration
Slide 29
Eng. of S/W Pro., India 2009 Fibre Delay Line - Active with
Regeneration A B C In Out DSF fibre loop Switch Optical amplifier
Optical regenerator Clock Eye diagram after 200 iterations with
regeneration
Slide 30
Eng. of S/W Pro., India 2009 SMZ - Simulation Parameters
Slide 31
Eng. of S/W Pro., India 2009 VPI PPM Routing Table 31
Slide 32
32 VPI Simulation Software Router
Slide 33
Simulation Results-Time Waveforms (a) input packet at node A
(b) extracted clock at nodes A (c) extracted clock at nodes B FWHM
= 2ps
Slide 34
Routing Table Single PPM RT Multiple PPM RTs Conventional
RT
Slide 35
E 1A E 2A E 3A E 1B E 2B E 3B E 1C E 2C E 3C E 1D E 2D E 3D E A
(24 31)E B (16 23)E C (8 15)E D (0 7) E1E1 E2E2 E3E3 Check MSBs a4
a4 a3 a3 (X=2) a2 a1 a0a2 a1 a0 a 4 a 3 =11 a 4 a 3 a 2 a 1 a 0
(N=5) a 4 a 3 =10 a 4 a 3 =01 a 4 a 3 =00 VPI PPM Multiple Routing
Table
Slide 36
Simulation Results-Multi-hop An optical core network with 32
edge nodes (4 hops)
Slide 37
37 Simulation - Multiple-hop Routing 0 1 2 3 4 5 6 7 8 9 10 11
12 13 14 15 Node/Router 1 Node/Router 2 Node/Router 3 Signal
intensity is varied Noise level is increased B B M B M B: broadcast
M: multicast Node/Router 1 Node/Router 2 Node/Router 3
Slide 38
Eng. of S/W Pro., India 2009 SMZ - Simulation Results
Inter-channel crosstalk Eye diagram
Slide 39
Eng. of S/W Pro., India 2009 Simulation Results Network
Performance Multiple-hop OSNR Predicted & simulated OSNRs
Slide 40
1xM All-optical Packet-switched WDM Router WDM MUX WDM MUX
Input Output 1 Output 2 DEMUXDEMUX WDM MUX e 1 e 2 e M E 1 E 2 E 3
E M PPM-HP 1 PPM-HP 2 PPM-HP L OutputM... PK 1 @ 1 PK 2 @ 2 PK M @
L... PK 3 @ 3 E 1 E 2 E 3 E M E 1 E 2 E 3 E M 1 1 1 2 2 2 L L L PK
1 @ 1 PK 2 @ 2 PK M @ L PK 1 @ 1 PK 2 @ 2 PK M @ L L: The numbers
of input wavelengths M: The numbers of the output ports (In this
simulation L = 2 and M =3)
Slide 41
Simulation Results- Time Waveforms Packets at the inputs of the
WDM router Packets observed at the output 2 of the WDM router
Slide 42
Optical OFDM 42 Orthogonal Frequency Division Multiplexing
(OFDM) Harmonically related narrowband sub-carriers The
sub-carriers spaced by 1/Ts The peak of each sub-carrier coincides
with trough of other sub-carriers Splitting a high-speed data
stream into a number of low-speed streams Different sub-carrier
transmitted simultaneously
Slide 43
Applications of OOFDM Modems Access and local area networks -
Access and local area networks - IMDD modems Future high-capacity
long-haul networks Coherent modems: Combating optical fibers
dispersion and polarization mode dispersion 43
Slide 44
OOFDM Modems - Modelling Matlab: easy to model the OFDM modem
32-QAM modulation 32-QAM detectionm with additive noise 44
Software Modelling VPI is not very flexible when it come to
modelling algorithm, consequently Matlab code can be used as a part
of VPI VPI has visual interface (drag and drop), with the ability
to use test and measurement tools Solid mathematical background is
essential to fully utilise VPI, otherwise it could lead to mis-
understanding and consequently obtaining wrong results 46
Slide 47
47 It All Starts From An Initial Idea Simulation softwares
enables us to develop new ideas & gain some insight before
designing systems System block diagram Simulation layout
Experimental setup
Slide 48
Eng. of S/W Pro., India 2009 48 Conclusions What one should
look for in simulation software packages in photonic switching
network: 1. Easy to learn and use 2. Lower PC hardware
specifications 3. Fast and as realistic as possible 4. Quality
technical support, training and online discussion forums 5.
Updateability 6. Compatibility with other simulation softwares
Slide 49
Special Thanks for Dr. Wai Pang Ng Dr. Hoa Le Minh Dr M F
Chaing A. Shalaby M. A. Jarajreh
Slide 50
Eng. of S/W Pro., India 2009 50 Thank you for your attention !
Any questions?