WP3Optical Switch Node Design and Implementation
Transparent Ring Interconnection Using Multi-wavelength Photonic switches
Second Year Review
Brussels, March 6, 2008
Transparent Ring Interconnection Using Multi-wavelength Photonic switches 2
Outline
• Contributing Partners
• Timeline and Deliverables
• WP3 Activities Task 3.1 – Design of the Switching Node Task 3.2 – Demonstration of Key Elements Task 3.3 – Final Assembly of the Switching Node
• Conclusion and Outlook
Transparent Ring Interconnection Using Multi-wavelength Photonic switches 3
WP3: Partners Involved
Participant ID Person-Months
Partners‘ Individual Contribution
UKA 27 (31)Will coordinate WP3 and work on the node design activities. Responsible for implementation and testing and performance evaluation.
NSN 4Involved in design definitions and manufacturability issues of node design.
Optium 20Will contribute devices for implementation
AIT 18Contributes to node design and performance evalution.
UCC 1.5 (6)Contributes to node design, and send people over to UKA for component integration.
UoE 6Will contribute to design and system requirements.
Transparent Ring Interconnection Using Multi-wavelength Photonic switches 4
WP3: Timeline
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D3.2 Assembly of switch node
Task 3.1 Design of the switching node
Task 3.2 Demonstration of key elements of switching node
Task 3.3 Final assembly of the optical switching node
D3.3 Report on the optical switch node architecture (UKA, AIT)
D3.1 Evaluation of various optical switching node architectures (SIEMENS, UoE, AIT)
D3.4 Report on the switch implementation and performance (UKA, AIT)
M3.1 Outcome of comparison of alternative 2R regeneration (SIEMENS, UoE, AIT)
M3.2 Implementation of the optical regenerator (UKA, ORC, TUB UCC)
M3.3 Implementation of the optical switching node
TODAY
Transparent Ring Interconnection Using Multi-wavelength Photonic switches 5
Task 3.1- Design of the Node
Duration: M1-M3, M12-M15
Evaluation of different node architectures featuring transparency to bit rates and protocols optical switching and add/drop functionality optical monitoring signal 2R regeneration
Timeline
Transparent Ring Interconnection Using Multi-wavelength Photonic switches 6
Task 3.1- Design of the Node
Optical Node Subsystems
1
2
3
Transparent Ring Interconnection Using Multi-wavelength Photonic switches 7
Task 3.1- Design of the Node
Signal Structure
• circuit switched traffic from the point of view of physical routes through the network, carried over a burst mode transport layer
• for an all-optical router buffer stores to accommodate for variations in propagation delay along various routes are not practical
therefore at points of aggregation, retiming is needed to account for jitter, wander and clock frequency drifts
Data block length, taking into account fibre expansion, wavelength drift considering a local clock accuracy of 10e-9 (a compact atomic clock in each node) Leads to a maximum block length in the order of 1ms + guard band of around 1µs with preamble for clock recovery locking
2
Transparent Ring Interconnection Using Multi-wavelength Photonic switches 8
Task 3.1- Design of the Node
OTDM-to-WDM Subsytem: Expected Output signal conditions
Input Value Output Value or Implication
Wander 30 ns p-p > 20 ns guard band
Random Jitter 200 fs rms 400 fs rms
Deterministic Jitter
1 ps p-p 2 ps p-p
Clock Offset 200 kHz 200 kHz
Bit Rate (Gbit/s) 128.1 42.7
Modulation Format
Interleaved RZ RZ
Routing Protocol Any As input
OSNR 40 dB >25 dB
Power per channel
> 0 dBm > -10 dBm
Channel frequencies
193.1 or 193.7 THz192.50, 193.1, 193.7, 194.3 THz
fixed
Transparent Ring Interconnection Using Multi-wavelength Photonic switches 9
An analytical model has been proposed for the performance evaluation of the TRIUMPH MAN
The non-linear reshaping element modifies the statistics of the input Gaussian noise
pdfin
Pin
Pout pdfout
ΔΔss
ΔτΔτ
pdfin
Pin
Pout pdfout
ΔΔss
ΔτΔτ
ΔΔss
ΔτΔτ
dtdss
/
1
g
g
)(22
1222
1
1 NNg
PErfciBERNBER
jitterASE
N
iamp
Amplitude distortions introduce logical errors that accumulate linearly along the cascade
Jitter is not suppressed and its effect is considered only at the final receiver
Task 3.1- Design of the Node
Transparent Ring Interconnection Using Multi-wavelength Photonic switches 10
WB
SMF+DCF
2R G1G2
G3
WB
OTDM to WDM
WDM to OTDM
Pdown
Pin
PoutLMUX : -6dB
-6dB
LWB : -6dB
LF
LC : -3dB
2R
1 2 3 4 5 6 7 8 9 10-16
-14
-12
-10
-8
-6
-4
-2
Cascaded Nodes
log(
BER
)
OSNRin/0.1nm : 28dB g : 0g : 0.2g : 0.4g : 0.6g : 0.8g : 1
Similar performance when the regenerator is either at the input or at the output of the node
Moderate OSNR of 28 dB has been assumed in study
For sufficient low g, 2R regenerator can be cascaded
Task 3.1 - Cascadability of OADM Node
Transparent Ring Interconnection Using Multi-wavelength Photonic switches 11
Task 3.1- Design of the Node
Conclusion
Fulfills all functionalities Design based on proposed node structure Incorporates results from WP2
and WP5 Tunable filters in 130Gbit/s
paths, one can select wavelength channel to be dropped/added
Picked up on Reviewers comment regarding 100GE
Transparent Ring Interconnection Using Multi-wavelength Photonic switches 12
T3.2 – Demonstration of Key Elements
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Task 3.2 Demonstration of key elements of switching node
M3.1 Outcome of comparison of alternative 2R regeneration (UKA, SIEMENS, UoE, AIT)
M3.2 Implementation of the optical regenerator (UKA, ORC, TUB UCC)
D3.3 Report on the optical switch node architecture and initial results on the individual functionalities (UKA, AIT, UoE)
Timeline
Duration: M4 – M24
Demonstration of key elements of the switching node
• Clock signal extraction and multiple channel synchronization
• Grooming functionality such as WDM to OTDM conversion and vice-versa
• Fibre and Quantum Dot (QD) SOA based multi-wavelength regenerators
Work on contingency plan in case of unsuitability of developed technologies
Transparent Ring Interconnection Using Multi-wavelength Photonic switches 13
T3.2 – Demonstration of Key Elements
Joint Experiments among the Consortium Partners in WP3
OTDM-to-WDM
HNLF Regenerator
WDM-to-OTDM
HNLF Regenerator
Equipment Loan
Transparent Ring Interconnection Using Multi-wavelength Photonic switches 14
T3.2 – Demonstration of Key Elements
Error free performance achieved
-36 -34 -32 -30 -28 -26 -24 -22 -2010-11
10-10
10-9
10-8
10-7
10-6
10-5
10-4
10-3
BE
R
Received Optical Power (dBm)
-31-30-29-28-27-26-25-24-23-22-21
0 5 10 15 20 25
Relative Delay (ps)
Re
ce
ive
r S
en
sit
ivit
y (
dB
m)
ADORE Subsystem Testing at UCC in Collaboration with WP5
2
Bit Error Rate Performance
of ADORE with automatic
channel selection for a variety
of different input phase delays
Variation in receiver sensitivity as a
function of phase delay showing two
independent measurements.
Transparent Ring Interconnection Using Multi-wavelength Photonic switches 15
• Optimise SOA-MZIs for pulse width adaptation (i.e. operation with the MLL pulses)
• Optimise ADORE operation
• Full scale experiment
• Expected completion: week commencing 10th March
T3.2 – Demonstration of Key Elements
WDM-to-OTDM Subsystem: Next Steps
Transparent Ring Interconnection Using Multi-wavelength Photonic switches 16
T3.2 – Demonstration of Key Elements
Collaboration between ORC and University of Karlsruhe
OTDM-to-WDM converter subsystem testing at UKA, Nov. 2007
3
WDM1
WDM3
WDM2
Transparent Ring Interconnection Using Multi-wavelength Photonic switches 17
WDM Channels[nm]
1546 1548 1550 1552 1554 1556 1558
Se
nsi
tivity
[dB
m]
-32
-30
-28
-26
WDM Channels vs OTDM1 Other Channels OFF WDM Channels vs OTDM2 Other Channels OFF WDM Channels vs OTDM3 Other Channels OFF WDM Channels vs OTDM1 All Channels ON WDM Channels vs OTDM2 All Channels ON WDM Channels vs OTDM3 All Channels ON
T3.2 – Demonstration of Key Elements
BER Measurements
WDM1: Penalty=3.5dB
WDM2: Penalty=1.7dB
WDM3: Penalty=0.5dB
All-Optical Conversion of a 128.1Gb/s OTDM signal to a 342.7Gb/s WDM signal was experimentally demonstrated.
- Maximum of 3.5dB penalty for WDM1 at a BER of 10-9.
No error floor
Transparent Ring Interconnection Using Multi-wavelength Photonic switches 18
T3.2 – Demonstration of Key Elements
2. OTDM-to-WDM converter implementation by NSN
All-Optical Conversion of a 128.1Gb/s OTDM signal to a 342.7Gb/s WDM signal was experimentally demonstrated.
- No error floor
-Maximum of 2dB penalty for the central channel at a BER of 10-9.
Will shortly be tested at UKA
Transparent Ring Interconnection Using Multi-wavelength Photonic switches 19
1st Solution: (QD-SOAs+ Filter)• Numerical studies have been performed comparing different regenerative schemes based on
QD-SOAs : 1. XGM + saturable absorbers2. XGM + delay interferometer3. Regenerative amplification
• Conclusion : XGM modulation can provide better nonlinear reshaping, but with more increased requirements in terms of gain recovery for the devices.
• Although the theoretical studies have designated the required specifications for the QD-SOA devices, these have not been met yet due to fundamental issues. Although we strive to overcome the corresponding problems during the 3rd year of the project
Activated contingency plan: Regeneration schemes based on bulk SOA (Optium)
T3.2 – Demonstration of Key Elements
M3.1 – Comparison of Alternative 2R Regenerators
2nd Solution : (HNLF )•This is a more mature technology. Multiwavelength regeneration has been shown based on two different approaches. (ORC+AIT)
1
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Results so far:Wavelength conversion at 43 Gbit/s by exploitation of XGM and XPM effects using a pulse reformatting optical filter (PROF)
SOA
Data signalPdata , λdata
CW signalPCW , λCW
50:50
Invertedsignal
BSOFλCW l
RSOF λCW+l
VOAODBPF λCW
50:50 50:50
Convertedsignal
Pulse Reformating Optical Filter (PROF)
Figure 2: Experimental setup for wavelength conversion with pattern effect cancelation. (RSOF: Red-shifted optical filter, BSOF: Blue shifted optical filter, OD: optical delay, VOA: variable optical attenuator, BPF: band pass filter)
Contingency plan – PROF scheme
T3.2 – Demonstration of Key Elements
Transparent Ring Interconnection Using Multi-wavelength Photonic switches 21
Contingency plan – Results (PROF)
Blue shifted (BS)
Nor
mal
ized
Pow
er [d
B]
RSOF
BSOF
Frequency [GHz]
-100 0 100
-40
-20
0
Q 2 = 13.0 dB
Q 2 = 7.9 dB
0
0
Spectr.
Spectr.
Red shifted (RS) -100 0 100
-40
-20
0
50ps/div 10ps/div Q
2 = 8.3 dB
0
Inverted signal
110011010111111110
Combined RS & BS
PROF
Q 2 = 17.8 dB
0Spectr.
-100 0 100
-40
-20
0
BPF
Spectr.
-100 0 100
-40
-20
0
Publication:
Wang, J.; Marculescu, A.; Li, J.; Vorreau, P.; Tzadok, S.; Ezra, S. B.; Tsadka, S.; Freude, W.; Leuthold, J., "Pattern Effect Removal Technique for Semiconductor-Optical-Amplifier-Based Wavelength Conversion“, Photonics Technology Letters, IEEE , vol.19, no.24, pp.1955-1957, Dec.15, 2007
T3.2 – Demonstration of Key Elements
Next step: experiment using PROF scheme for wavelength conversion and regeneration at 130 Gbit/s.
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T3.2 – Demonstration of Key Elements
Dispersion Managed Regenerator – AIT+UKA Joint ExperimentODL AWG
42.7 Gbit/s Tx 33% RZ-OOK
PRBS 231-1
PC DEDFB
DFB
DFB
Chan1
Chan3
Chan2
EDFA
ODL
AWG
Mon1Regenerator
RX Demux
Clock Recovery
VOA
VOA
Rx
HP- EDFA DCF SMFTunableOBPF
x 5 0.56nm
Mon2 Mon3
DUT
Chan2:
1552.52nm
Chan3:
1557.36nm
1
Misaligned bias: deterministic degradation
Chan1: 1547.72nm
Transparent Ring Interconnection Using Multi-wavelength Photonic switches 23
T3.2 – Demonstration of Key Elements
3-Channel Regenerative Capabilities
600 700 800 900 1000 1100 1200 130012
13
14
15
16
17
18
Q̂2
(dB)
Average Total Input Power (mW)
Chan1 3Chan Regen Chan2 3Chan Regen Chan3 3Chan Regen Chan1 B2B Degraded Chan2 B2B Degraded Chan3 B2B Degraded
Transfer functions measuring the output power after the OBPF with an offset of -0.6nm for the three channels
Operating Point
Three copropagating channel regeneration at 43 Gbit/s with 600 GHz spacing
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Comparison with Simulation Results
0 0.25 0.5 0.75 1 1.25 1.50
0.25
0.5
0.75
1
1.25
1.5
Input Power (norm.)
Out
put P
ower
(nor
m.)
g1
g0
T3.2 – Demonstration of Key Elements
The network analytical model has been fitted to the experimental data
At the operating point of the HNLF regenerator, the slope is g : 0.62
Transparent Ring Interconnection Using Multi-wavelength Photonic switches 25
Comparison with Simulation Results
The network analytical model has been fitted to the experimental data
At the operating point of the HNLF regenerator, the slope is g : 0.62
These specifications enable 6 node cascadability if input OSNR >25 dB
Deployment of FEC would relax OSNR margin
Note : pulse reformatting effects are not considered in the analytical approach
-50
-45
-40
-40
-35
-35
-30
-30
-30
-25
-25
-25
-20
-20
-20
-15
-15
-15
-15
-10
-10
-10
OSNR (dB)
g
log10
(BER)
20 22 24 26 28 30
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9Log10(BER) @ 40 Gb/s , 6th node
T3.2 – Demonstration of Key Elements
Transparent Ring Interconnection Using Multi-wavelength Photonic switches 26
T3.2 – Demonstration of Key Elements
Task 3.2 Conclusion
UKA has planned test setups for key element demonstration
Necessary equipment has been evaluated, purchased and tested
Alternative 2R regenerators have been compared, contingency plan is
put in action
Subsystem testing of all the individual node functionalities
carried out
Transparent Ring Interconnection Using Multi-wavelength Photonic switches 27
Task 3.3 - Switch Node Concept
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D3.2 Assembly of switch node
Task 3.3 Final assembly of the optical switching node
D3.4 Report on the switch implementation and performance (UKA, AIT)
M3.3 Implementation of the optical switching node
Timeline
Duration: M25 – M31
Final assembly of the optical switching node will be supported by activities in other WPs challenge: bringing all technologies on common wavelength standard assemble switching node and perform testing at bit-rates between 10 Gbit/s and potentially 130 Gbit/s
Transparent Ring Interconnection Using Multi-wavelength Photonic switches 28
Task 3.3 - Switch Node Implementation
• Layout will undergo changes as project evolves • Continuous traffic only • Node demonstration with burst traffic in network environment at UoE
1
2
3
Transparent Ring Interconnection Using Multi-wavelength Photonic switches 29
WP3
Conclusion and Progress
Different node architectures have been studied based on input from WP2
(T3.1)
Cascadability study carried out based on chosen node architecture (T3.1)
Developed refined node implementation based on results (T3.1)
Necessary equipment has been evaluated, purchased and tested (T3.2)
Subsystem testing of all individual node functionalities has been carried out (T3.2)
Results achieved to be published in the near future
Switch node implementation soon to start (T3.3)!