1. Simulation of All-optical Packet Routing employing PPM-based Header Processing in Photonic Packet Switched Core Network
H. Le Minh, Z. Ghassemlooy and Wai Pang Ng
Optical Communications Research Group
Northumbria University, UK
First International Conference on Communications and Electronics
HUT - ICCE 2006, 10th-11th Oct Hanoi, Vietnam

2. Contents Introduction PPM-Header Processing Overview
Operation principle
Clock extraction
PPM address conversion
PPM header correlation
All-optical flip-flop
Wavelength conversion
Simulation Results
Summary

3. Contents Introduction PPM-Header Processing Overview
Operation Principle
Clock Extraction
PPM Address Conversion
PPM Header Correlation
All-optical Flip-Flop
Wavelength Conversion
Simulation results
Summary

4. Introduction – All-optical network
Network transparency  All-optical core router
Processing, switching and routing in optical domain  high throughput
Packet format is preserved 1

5. Contents Introduction PPM-Header Processing Overview
Operation Principle
Clock Extraction
PPM Address Conversion
PPM Header Correlation
All-optical Flip-Flop
Wavelength Conversion
Simulation results
Summary

6. Convert to pulse-position routing table?
OP 1
OP 2
OP 3
4-bit i
1001B = 9D
Convert to pulse-position routing table
Ref: [1] Z. Ghassemlooy et al., NOC 2005, UK, pp
[2] Z. Ghassemlooy et al., ICTON 2005, Spain, Vol. 2, pp 2

7. (up to M input packets at M wavelengths)
Router Operation
Principle
Implementation
OP 1
OP 2
OP 3
4-bit
C1, is the recovered clock from the incoming . All Cs are multiplexed and feed into multiwavelength PPRT.
The router is a non-blocking
1M router
(up to M input packets at M wavelengths) 3

8. Router - PPM-HP
PPM-HP module 4

9. Contents Introduction PPM-Header Processing Overview
Operation Principle
Clock Extraction
PPM Address Conversion
PPM Header Correlation
All-optical Flip-Flop
Wavelength Conversion
Simulation results
Summary

10. Router - PPM-HP - Clock Extraction
Clk
Clock, header and payload:- have the same intensity, polarization and wavelength
Clock extraction requirements:
Asynchronous and ultrafast response
High on/off contrast ratio of extracted clock 5

11. Router - PPM-HP - Clock Extraction
CP1
Clk
GCP
12
SOA1
12
SOA1
22 
22
SMZ-1
SMZ-2
12
in
22
22
12
in
22
22
22
SW
SOA2
SW
22
SOA2
CP2
Polarization Beam Splitter (PBS)
Polarization Controller (PC)
Optical fiber span
Amplifier
Attenuator
Optical delay 6

12. Router - PPM-HP - Clock Extraction
GCP
12
SOA1
12
SOA1
22 
22
SMZ-1
SMZ-2
12
in
22
22
12
in
22
22
22
SW
SOA2
SW
22
SOA2
Polarization Beam Splitter (PBS)
Polarization Controller (PC)
Optical fiber span
Amplifier
Attenuator
Optical delay 6

13. Router - PPM-HP - Clock Extraction
Clk
GCP
12
SOA1
12
SOA1
22 
22
SMZ-1
SMZ-2
12
in
22
22
12
in
22
22
22
SW
SOA2
SW
22
SOA2
Polarization Beam Splitter (PBS)
Polarization Controller (PC)
Optical fiber span
Amplifier
Attenuator
Optical delay 6

14. Router - PPM-HP - Clock Extraction
Input packets
Extracted clock pulse by single SMZ. The residual signal intensities are high, but eventually fading due to SOA gain is saturated with the stream of high-powered control pulses
Extracted clock pulse by two-inline SMZs. The residual signals are suppressed  improving the on/off contrast ratio
(b)
(c)
Ref: Z. Ghassemlooy et al., ICTON 2006, UK, Vol. 4, pp 7

15. Contents Introduction PPM-Header Processing Overview
Operation Principle
Clock Extraction
PPM Address Conversion
PPM Header Correlation
All-optical Flip-Flop
Wavelength Conversion
Simulation results
Summary

16. Router - PPM-HP - Address Conversion
(b)
(b)
(a) 8

17. Contents Introduction PPM-Header Processing Overview
Operation Principle
Clock Extraction
PPM Address Conversion
PPM Header Correlation
All-optical Flip-Flop
Wavelength Conversion
Simulation results
Summary

18. Router - PPM-HP - Header Correlation
Matched
xPPM(t)
E2(t)
SMZ-based AND gate: only one bit-wise operation!
SOA gain recovery is no longer an issue, since it is saturated only once for header recognition
Ref: R. P. Schreieck et al., IEEE Quantum Elec., Vol. 38, pp , 2002 9

19. Contents Introduction PPM-Header Processing Overview
Operation Principle
Clock Extraction
PPM Address Conversion
PPM Header Correlation
All-optical Flip-Flop
Wavelength Conversion
Simulation results
Summary

20. Router - PPM-HP - All-optical Flip-Flop
Operate at < nanoseconds responses
Multiple SET/RESET pulses for compensating the actual loop delay (~ hundreds
of picoseconds) and for speeding up the transient ON/OFF states of Q output 10

21. Router - PPM-HP - All-optical Flip-Flop
SET (blue) / RESET (red)
Q output
SOA1 gain (blue) / SOA2 gain (red)
ON/OFF Contrast Ratio 11

22. Contents Introduction PPM-Header Processing Overview
Operation Principle
Clock Extraction
PPM Address Conversion
PPM Header Correlation
All-optical Flip-Flop
Wavelength Conversion
Simulation results
Summary

23. Router - PPM-HP - Wavelength Conversion
SOA1
SOA2 2
Data packet
@ 1
22
@ 2
Ref: Y. Ueno et al., ECOC 2002 12

24. Contents Introduction PPM-Header Processing Overview
Operation Principle
Clock Extraction
PPM Address Conversion
PPM Header Correlation
All-optical Flip-Flop
Wavelength Conversion
Simulation results
Summary

25. Simulation – 13 Router
OP 1
OP 2
OP 3
4-bit 13

26. Simulation – Parameters14

27. Simulation – Input / Clock Extraction
Input packets (3 wavelengths)
Input spectrum / Extracted clock pulses 14

28. Simulation – Router Outputs
Spectrum at router output 1 15

29. Simulation – Router Outputs16

30. Simulation – Multiple-hop OSNR
1- Multiple-hop OSNR due to accumulated ASE
2- Predicted & simulated OSNRs
Ref:
Z. Ghassemlooy et al., IEEE 49th GLOBECOM 2006, USA, (accepted) 17

31. Contents Introduction PPM-Header Processing Overview
Operation Principle
Clock Extraction
PPM Address Conversion
PPM Header Correlation
All-optical Flip-Flop
Wavelength Conversion
Simulation results
Summary

32. Summary PPM-HP Further investigation
Provides ultrafast header processing
Reduces the number of routing table entries
Avoids the SOA recovery time during header correlation
Operates in a large BW as employing SOA
Supports multiple transmitting modes (uni/multi/broadcasting)
Offers add/drop edge node scalability
Further investigation
ASE noise sources
Timing jitter and pulse dispersion effects on PPM-HP
Effective wavelength conversion
IP-based optical transparent network 18

33. Thank you