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All-optical Packet Router Employing PPM Header Processing. Prof. Z. Ghassemlooy Optical Communications Research Group http://soe.unn.ac.uk/ocr/ School of Computing, Engineering and Information Sciences Northumbria University Newcastle, UK. Presentation Outline. Introduction
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All-optical Packet Router Employing PPM Header Processing Prof. Z. Ghassemlooy Optical Communications Research Group http://soe.unn.ac.uk/ocr/ School of Computing, Engineering and Information Sciences Northumbria University Newcastle, UK
Presentation Outline • Introduction • Original Contributions and Research Outcomes • Future Work Z Ghassemlooy
CEIS - Research Groups Northumbria Communications Research Laboratories Advanced Signal Processing Network Security Non-Linear Control Microwave and Microwave Holography + Active Antenna Optical Communications Research Group (OCRG) Z Ghassemlooy
OCRG –People • Staff • Prof. Z Ghassemlooy • J Allen • Dr R Binns • Dr K Busawon • Dr W. P. Ng • Visiting Academics • Prof. V Ahmadi, Univ. Of TarbiateModaress , Tehran, Iran • Dr M. H. Aly, 2Arab Academy for Scie. and Tech. and Maritime Transport, Egypt • Prof. J.P. Barbot, France • Prof. I. Darwazeh, Univ. College London • Prof. H. Döring, HochschuleMittweida Univ. of Applied Scie. (Germany) • Prof. E. Leitgeb, Graz Univ. of Techn. (Austria) • PhD Students: M. Amiri, A. Chaman-Motlagh, M. F. Chiang, M. A. Jarajreh, R. Kharel, S. Y Lebbe, W. Loedhammacakra, Q. Lu, V. Nwanafio, E. K. Ogah, W. O. Popoola, S. Rajbhandari, A. Shalaby, X. Tang • MSc: A Burton, D Bell, G Aggarwal, M Ljaz, O Anozie, W Leong , S Satkunam Z Ghassemlooy 4 WBU, India 2009
[bit/s] 1P 100T 10T 1T 100G 10G 1G 100M Traffic demand forecast (NEC–2001) Capacity increase : 2~4 times a year Bit cost decrease : 1/2 time a year Total Data Voice 1995 2000 2005 2010 Optical Communications • 1st 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. • Solution: All-optical processing & switching Z Ghassemlooy
Photonics - Applications • Photonics in communications: expanding and scaling Metropolitan Home access Long-Haul Board -> Inter-Chip -> Intra-Chip • Photonics: diffusing into other application sectors Health(“bio-photonics”) Environment sensing Security imaging Z Ghassemlooy
Networks Topology – An Overview Z Ghassemlooy
O-E-O Router Architecture http://www.cisco.com/en/US/products/ps5763/index.html • Up to 92 Tbit/s • Optical inputs but electronic switching • Very large power consumption Dr N. Calabretta (TU/e, Holland) Z Ghassemlooy
Parallel electronic switch Why Photonic Technology 622 Mb/s -> 160 Gb/s 160 Gb/s -> 622 Mb/s Elect. Mux Elect. DeMux DeMux 1 1 Receivers Modulators Mux Clock recovery lasers All-optical Demultiplexer Photonic switch Multiplexer • High speed and parallel all-optical processing of the packets. • Photonic integration potentially allows a reduction of volume, power consumption, scalability, latency and costs. Dr N. Calabretta (TU/e, Holland)
Header Processing! All-optical Packet Switching • Objectives • High Bit Rate • High Throughput Z Ghassemlooy
All-optical Cross-connect node • Functionality 1 x N packet switch • All-optical label recognition • Low latency • Scalable photonic integration • All-optical label rewriting • Optical routing • Low power penalty Node cascadability multiplexer demultiplexer 1 1 2 2 N N 1 x N packet switches Buffering and synchronisation Target: routing and label rewriting in a single device Z Ghassemlooy
Research Road Maps Z Ghassemlooy
O/E Processing E/O Packet Routing –Header Processing 1. Optical vs. Electrical in High-speed Routing H Routing table 0100 Matching! Optical domain Electrical domain High Speed >> 40 Gbit/s IC: Large scale, cheap, memory Complexity, costly, no memory Speed limitation < 40 Gbit/s Integration Light “Frozen”? “Opt. Capacitors”? All-Optical Processing Z Ghassemlooy
2. Address Correlation Packet header is compared with all entries of a routing table for checking the matching Packet Routing –Header Processing N2N bit-wise AND operations Robust All-Optical Processing Our solution: Pulse-Position-Modulation based Header Processing (PPM-HP) Minimise number of AND operations Reduce routing table entries Z Ghassemlooy
One Frame Tf = 4Tb Tb LSB Binary 1 0 0 1 1001 One Frame Tf = 24Ts 9 Ts PPM 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Packet Routing –Header Processing 3. What is Pulse Position Modulation? Tb – bit duration, Ts – slot duration Z Ghassemlooy
Port 1 1M Port 2 (M = 3 ports) Port 3 … 0 1 2 3 4 5 6 7 2N-1 … 0 1 2 3 4 5 6 7 2N-1 … 0 1 2 3 4 5 6 7 2N-1 Packet Routing –Header Processing 4. Pulse Position Routing Table (PPRT) Conventional routing table 2N entries PPM Pulse-position routing table Z Ghassemlooy
PL PL PL PL A A A A Clk Clk Clk Clk PPMA … Matched pulse Clk A Packet Routing –Header Processing All-optical Switch 5. PPM-HP Router Port 1 OSW1 Port 2 … OSW2 … Port M OSWM Header Extraction PPM Add. Conversion CP 1 CP 2 PPRT CP M OSWC &1 Entry 1 … Clock Extraction OSWC Entry 2 &2 Synchronization … … … Entry M OSWC &M PPM-HP Z Ghassemlooy
MEMS*(Lucent Tech.) Bubbles*(Agilent) Packet Routing –Optical Switches Cat.1 Large scale (> 1616) Slow response (s-ms) Non-optically controlled Cat.2 Small scale (22) Fast response (fs-ps) Full-optically controlled SMZ*(Japan) • Crosstalk TOAD*(Princeton) • Contrast * Sources: Internet articles & websites Z Ghassemlooy
90 90 0 0 0 90 90 0 90 90 Terahertz Optical Asymmetric Demultiplexer (TOAD) –Operation (1) • Introduced by P. Prucnal (1993) • Nonlinearity: Semiconductor Optical • Amplifier (SOA) • Low control pulse (CP) power • High inter-channel crosstalk • Asymmetrical switching window profile • Synchronisation 0 Non-switching 180 Z Ghassemlooy
+180 90 90 +180 0 0 90 0 90 +180 0 +180 90 90 0 0 90 90 +180 180+ 180 180 TOAD -Operation (2) • Introduced by P. Prucnal (1993) • Semiconductor Optical Amplifier • induces nonlinearity • Low control pulse energy • High inter-channel crosstalk • Asymmetrical switching window • profile Switching Z Ghassemlooy
OFDL - 1 CP1 SOA1 UA E ( 0 ) Input UA LA = p + p E E ( ) E ( ) 2 , in out , 1 out out UA p E ( ) signal out UA C E ( 0 ) Port 1 2 1 T T delay delay C Port 2 3 C C 1 4 p LA E ( / 2 ) 2 LA p E ( / 2 ) CP2 = + p UA p LA ( 3 / 2 ) ( / 2 ) E E E out SOA2 , 2 out out out LA p E ( / 2 ) 1 , in OFDL - 2 PBS – Polarization beam splitter OFDL – Optical fibre delay line Control pulses (CP1 & CP2) are applied No control pulse is applied Symmetric Mach-Zehnder (SMZ) Z Ghassemlooy
+180 +180 +180 +180 +180 +180 +180 +180 0 0 90 90 0 0 90 0 0 0 0 90 90 90 180 90 180 90 180 90 90 90 180 90 Symmetric Mach-Zehnder (SMZ) +180 +180 +180 +180 Switching window (SW) gain: SW width:Delay interval between two control pulses TSW Z Ghassemlooy
Data pulse train Optical receiver VPI – SMZ Switch Z Ghassemlooy
Clk Clock Extraction PPM-HP Router - Clock Extraction Optical packet Clock, header and payload: sameintensity, polarization andwavelength • Clock extraction requirements: • Asynchronous and ultrafast response • High on/off contrast ratio of extracted clock Z Ghassemlooy
CP1 Clk GCP 12 12 SOA1 SOA1 22 22 SMZ-2 SMZ-1 12 12 22 22 22 22 in in 22 22 SOA2 SOA2 SW SW CP2 Optical fiber span Amplifier Attenuator Optical delay Polarization Beam Splitter (PBS) Polarization Controller (PC) Packet Routing –Clock Extraction Z Ghassemlooy
GCP 12 12 SOA1 SOA1 22 22 SMZ-2 SMZ-1 12 12 22 22 22 22 in in 22 22 SOA2 SOA2 SW SW Optical fiber span Amplifier Attenuator Optical delay Polarization Beam Splitter (PBS) Polarization Controller (PC) Packet Routing –Clock Extraction Z Ghassemlooy
Simulation –Clock Extraction 1st stage Packet in Crosstalk Extracted clock 2nd stage Z Ghassemlooy
On / off contrast ratio against the timing offset of PPM header Packet Routing –PPM-HP Address Conversion Z Ghassemlooy
A AB SOA1 B in SOA2 SW … … Packet Routing –PPM-HP Header Correlation • 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 A PP packet address AND gate A*B One PPRT entry B Ref:R. P. Schreieck et al.,IEEEQuantum Elec., Vol. 38, pp. 1053-1061, 2002 Z Ghassemlooy
Simulation Results - AND operation Z Ghassemlooy
low inter-output CR (< 10 dB) Improved CR (> 32 dB) 12 SMZ Switch with a High Contrast Ratio CEM: clock extraction module Z Ghassemlooy
Packet Routing –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 Z Ghassemlooy
Data packet @ 1 Data packet @ 2 SOA1 CW @ 2 22 22 SOA2 Packet Routing –PPM-HP Wavelength Conversion Z Ghassemlooy
Packet Routing –PPM-HP Demultoplexer • SMZI • Compact size (integrated) • Ultrafast response (~ps) • Low energy (<pJ) • Flexible controlling schemes: Wavelengths, Orthogonal polarizations, Propagation directions • Multiple-channel demultiplexing • Each channel demultiplexing requires one SMZ Z Ghassemlooy
Packet Routing –PPM-HP Chained Demultiplexer Z Ghassemlooy
Fibre loop B In Out C A Switch Eye diagram after 200 iterations without regeneration Fibre Delay Line – Passive Z Ghassemlooy
Optical amplifier DSF fibre loop B In Out C A Switch Clock Optical regenerator Eye diagram after 200 iterations with regeneration Fibre Delay Line – Passive Z Ghassemlooy
VPI –PPMRouting Table Z Ghassemlooy
Simulation Results – Node Performance 0 1 1 1 0 Packet with address 01110 PPM-converted address PPRT entry 1 Synchronized matching pulse Z Ghassemlooy
VPI Simulation Software – Router Z Ghassemlooy
Packet Routing –Multiple Routing Table Conventional RT Single PPRT Multiple PPRTs Z Ghassemlooy
a4 a3a2 a1 a0 1 0 x x x PL PL PL PL PL A A A A A Clk Clk Clk Clk Clk PPMA Matched pulse Matched pulse Clk a3 a3 a4 … a2a1a0 Packet Routing –Multiple Routing Table All-optical Switch Port 1 OSW1 Port 2 … OSW2 … Port M OSWM Header Extraction PPM Add. Conversion CP 1 CP 2 Multiple PPRT CP M OSWC … &1 Entry 1 Clock Extraction Entry 2 OSWC &2 Synchronisation … … … Entry M OSWC &M Group A SW3 Group B Multicast transmission SW4 Multiple PPRT Generator Group C SW3 Group D Z Ghassemlooy
Multi-hop Router An optical core network with 32 edge nodes (4 hops) Z Ghassemlooy
Node/Router 2 B M Node/Router 3 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 B B M Simulation -Multiple-hop Routing Node/Router 1 B: broadcast M: multicast • Signal intensity is varied • Noise level is increased Z Ghassemlooy
Simulation Results – Network Performance Multiple-hop OSNR Predicted & simulated OSNRs
l PK @ 1 1 l PK @ 2 2 l PK @ 3 3 ... l PK @ M M l l PK PK @ @ 1 1 1 1 l l l 1 1 1 l l l 2 2 2 l l PK PK @ @ l l l 2 2 2 2 M M M l l PK PK @ @ M M M M Packet Routing –PPM-HP WDM Router … PPM - H P 1 WDM … MUX Output 1 … e 1 E E E E M 1 2 3 WDM PPM - H P 2 … … MUX Output 2 ... … WDM e DEMUX Input 2 … E E E E M 1 2 3 … WDM … PPM - H P M MUX … Output M … e M E E E E M 1 2 3 All-optical packet-switched WDM router Z Ghassemlooy
Simulation Results - Time Waveforms Packets at the inputs of the WDM router Packets observed at the output 2 of the WDM router
Future Work MIMO WDM Router • SIMO WDM Router Will PPM-HP help for a contention solution? (FIFO) • PPM-HP Further PPRT downsizing? Address subsets Multiple PPRTs Router complexity? PPM-Address • Experimental Test-bed: 4-SMZ Router Z Ghassemlooy
Final Comments • PPM-HP • 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 Z Ghassemlooy