ENERGY EFFICIENT ALL-OPTICAL SOA SWITCH FOR THE “GREEN INTERNET”

1. ENERGY EFFICIENT ALL-OPTICAL SOA SWITCH FOR THE “GREEN INTERNET” Yuri Audzevich, Michele Corrà, Giorgio Fontana, Yoram Ofek, Danilo Severina Università degli Studi di Trento, Dipartimento di Ingegneria e Scienza dell’Informazione, via Sommarive 14, POVO, 38100 Trento ITALIA

2. Introduction • The possible commercial success of traditional “all-optical switching” depends on the solution of several difficult challenges: like building • optical buffers, • optical header processors, and • optical systems in general. • When all these problems will be solved, hundreds of Gb/s link speeds will become standard. Unfortunately this is something that might not happen very soon within the current network asynchronous IP switching paradigm. • An alternative switching paradigm has been recently developed that predetermines the routing configuration of network switches according to SCHEDULEDtraffic using “freely available” global time or UTC (coordinated universal time) from a variety of sources on earth and in space[1]. Better than 1us accuracy. • The novel paradigm, called Time Driven Switching (TDS) or Fractional Lambda Switching (FLS), allows the efficient use of all-optical switches RIGHT NOW because it does not require buffers and header processing.

3. A TDS Network (simplified) • Like Circuit Switching (physical-zero latency), • But you only need to OWN the fraction of the circuit where the datagram is TEMPORARILY located. • Precise synchronization is required. • Shown to work, see literature. • Specific hardware: • Time Driven servers • Time Driven switches • Network: • TCP/IP can be adopted • Gb Eth optical can • be adopted

4. UTC second with 80k Time-frames Time Cycle1 Time Cycle0 Time Cycle79 1000 1000 1000 1 2 1 2 1 2 Time-of-Day or UTC 1 beginning of a UTC second 0 beginning of a UTC second Pipeline Forwarding with UTCFactor of 20 Lower Cost / Premium Services • Pipelines are deployed to increase efficiency: • Optimal method - independent of a specific realization • Factory (automotive) / computers (CPU) • Internet Pipeline thanks: GPS/Galileo/multitude of other sources • Time frames as virtual containers for IP packets • Thus, no header processing • Tfaccuracy of 1µs is sufficient

5. Current Networking Test-bed Setuphttp://dit.unitn.it/ip-flow/ GPS/GALILEO O-E: Optical-to-Electrical (analog) E-O: Electrical-to-Optical (analog) Streaming Media Source UTC 1PPS Pipeline Forwarding router UTC 1PPS FPGA GPS TDSAll-opticalSwitch Streaming Media Arbitrary Distance Arbitrary Distance UTC 1PPS 25 km Optical Fiber UTC 1PPS TDS switch TDS switch FPGA GPS FPGA GPS Streaming Media 25 km Optical Fiber E-O O-E E-O O-E

6. GPS FC-APC FC-APC X 8 OUTPUT 1 - 0 dBm 50/50 50/50 SOA FC-APC MONITOR PD3 FC SOA MONITOR PD4 50/50 50/50 SOA FC FC-APC SOA OUTPUT 2 – 0 dBm FC-APC FC-APC FPGA + UBLOX-T GPS POWER AMP For SOA Switch actuation FC-APC FC-APC 90 90 FC-APC INPUT 1 MONITOR PD1 10 10 FC Individual Gain control 90 10 LABview environment MONITOR PD2 90 10 INPUT 2 internet FC-APC PC Typ. Out of 40km transceiver = -4 to +1 dbm - SOA out +3dbm All Optical Switch Design

7. Components ComBlock COM1300 PCMCIA FPGA Xilinx Spartan-3 XC3S400-4 FPGA features 400K system gates including 288Kbit of dual port memory and 16 dedicated 18x18 multipliers. • 32MB SDRAM for use as elastic buffer Ublox LEA-4T GPS Timing Receiver QPhotonics SOA1550

8. Components

9. Complete Optical Switch

10. SOA Controller

11. GPS Timing Panel

12. Operating Parameters Panel

13. Switch Scheduling Panel

14. Eye Pattern Eye pattern of GbEth transmitter->25km fiber->SOA (25%Inom)->25kmfiber->RX Inom = 200 mA

15. Eye Pattern Eye pattern of GbEth transmitter->25km fiber->SOA (35%Inom)->25kmfiber->RX

16. Eye Pattern Eye pattern of GbEth transmitter->25km fiber->SOA (50%Inom)->25kmfiber->RX

17. Energy Efficiency • In our 2x2 switch each output fiber requires an average of 1.2 V*100 mA= 120mW of power for SOA power supply. The requirement can be scaled up for larger switches operating within fractional lambda switching and TDS principles. • 128x128 Banyan switch will require 4x7x64/128=14 SOA per output fiber. To avoid switch blocking the number of SOA simultaneously active per output fiber has to be 7. • At 10 Gb/s this is 7*120/10 mW/Gb/s = 84 mW/Gb/s that clearly is only 8.4 mW/Gb/s if the switch is operated at 100Gb/s. • By comparison high-end traditional switches require abut 20 W/Gb/s per output fiber. • – We have three orders of magnitude lower power!

18. Conclusion & The Future • We described a high performance all-optical switch implementing the fractional lambda switching paradigm with time driven scheduled switching. The switch has been successfully tested with BERT at 1.25 Gb/s and with UDP multimedia streams with Gb Ethernet interfaces. • The switch can scale to very high capacity and provide an energy efficient switching solution for the future green internet. This first combination of TDS with SOA switching is the first small step; much more efforts and funding should be directed towards this new technology for a better characterization of existing hardware and future experimentation on a larger scale, including the important combination of WDM-TDS. INTERNET KeyWORDS: IPFLOW TRENTO