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 http://soe.unn.ac.uk/ocr/ First International Conference on Communications and Electronics HUT - ICCE 2006, 10th-11th Oct. 2006 Hanoi, Vietnam
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
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
Introduction – All-optical network Network transparency All-optical core router Processing, switching and routing in optical domain high throughput Packet format is preserved 1
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
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. 209-216 [2] Z. Ghassemlooy et al., ICTON 2005, Spain, Vol. 2, pp. 50-53 2
(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 packet @1 . All Cs are multiplexed and feed into multiwavelength PPRT. The router is a non-blocking 1M router (up to M input packets at M wavelengths) 3
Router - PPM-HP PPM-HP module 4
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
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
Router - PPM-HP - Clock Extraction CP1 Clk GCP 12 SOA1 12 SOA1 22 22 SMZ-1 SMZ-2 12 in 22 22 12 in 22 22 22 SW SOA2 SW 22 SOA2 CP2 Polarization Beam Splitter (PBS) Polarization Controller (PC) Optical fiber span Amplifier Attenuator Optical delay 6
Router - PPM-HP - Clock Extraction GCP 12 SOA1 12 SOA1 22 22 SMZ-1 SMZ-2 12 in 22 22 12 in 22 22 22 SW SOA2 SW 22 SOA2 Polarization Beam Splitter (PBS) Polarization Controller (PC) Optical fiber span Amplifier Attenuator Optical delay 6
Router - PPM-HP - Clock Extraction Clk GCP 12 SOA1 12 SOA1 22 22 SMZ-1 SMZ-2 12 in 22 22 12 in 22 22 22 SW SOA2 SW 22 SOA2 Polarization Beam Splitter (PBS) Polarization Controller (PC) Optical fiber span Amplifier Attenuator Optical delay 6
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. 64-67 7
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
Router - PPM-HP - Address Conversion (b) (b) (a) 8
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
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. 1053-1061, 2002 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
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
Router - PPM-HP - All-optical Flip-Flop SET (blue) / RESET (red) Q output SOA1 gain (blue) / SOA2 gain (red) ON/OFF Contrast Ratio 11
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
Router - PPM-HP - Wavelength Conversion SOA1 SOA2 CW @ 2 Data packet @ 1 22 @ 2 Ref: Y. Ueno et al., ECOC 2002 12
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
Simulation – 13 Router OP 1 OP 2 OP 3 4-bit 13
Simulation – Parameters 14
Simulation – Input / Clock Extraction Input packets (3 wavelengths) Input spectrum / Extracted clock pulses 14
Simulation – Router Outputs Spectrum at router output 1 15
Simulation – Router Outputs 16
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
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
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
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