wp3 optical switch node design and implementation transparent ring interconnection using...

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


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.


WP3: Timeline

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02

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


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



Optical Node Subsystems

1

2

3



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



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


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



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



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


T3.2 – Demonstration of Key Elements

01

36

35

34

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31

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02

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



Joint Experiments among the Consortium Partners in WP3

OTDM-to-WDM

HNLF Regenerator

WDM-to-OTDM

HNLF Regenerator

Equipment Loan



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.


• 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


WDM-to-OTDM Subsystem: Next Steps



Collaboration between ORC and University of Karlsruhe

OTDM-to-WDM converter subsystem testing at UKA, Nov. 2007

3

WDM1

WDM3

WDM2


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


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



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


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)


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


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



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


Next step: experiment using PROF scheme for wavelength conversion and regeneration at 130 Gbit/s.



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



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


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


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


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




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


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


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


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)!

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