energy efficient all-optical soa switch for the “green internet” yuri audzevich, michele corrà,...
TRANSCRIPT
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
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 SCHEDULED traffic 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.
A TDS Network (simplified)
0 10 … 90
0 10 … 90
0 10 … 90
1C
4C
3C
2C
5C 6C
7C
8C 9C
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:
1) Time Driven servers2) Time Driven switches
Network:
1) TCP/IP can be adopted2) Gb Eth optical can
be adopted
• 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
– Tf accuracy of 1µs is sufficient
Pipeline Forwarding with UTC Factor of 20 Lower Cost / Premium Services
1 2 1000
TimeCycle0
1 2 1000
TimeCycle1
1 2 1000
TimeCycle 79
UTC secondwith 80k Time-frames
Time-of-Day or UTC 0beginning of a UTC second
1beginning of a UTC second
fTfTfTfT fT
Current Networking Test-bed Setuphttp://dit.unitn.it/ip-flow/
TDS switch TDS switch
Streaming Media Source Pipeline
Forwarding
router
25 km Optical Fiber
GPS/GALILEO
Streaming Media
UTC1PPS
UTC1PPS
O-EE-O
O-E: Optical-to-Electrical (analog)
E-O: Electrical-to-Optical (analog)
ArbitraryDistance Arbitrary
Distance
Streaming Media
E-OO-E
25 km Optical
Fiber
TDSAll-opticalSwitch
FPGAGPS
FPGAGPSFPGAGPS
UTC1PPS
UTC1PPS
SOA
SOA
SOA
SOA
OUTPUT 1 - 0 dBm
OUTPUT 2 – 0 dBm
MONITOR PD3
MONITOR PD1
FPGA
+
UBLOX-T GPS
POWER AMPForSOA Switchactuation
GPS
LABviewenvironment
IndividualGain control
internet
INPUT 1
INPUT 2
PC
MONITOR PD4
MONITOR PD2
90
90
90
90
10
10
10
10
50/50 50/50
50/50
FC-APC
FC
FC-APC
FC-APC FC-APC
FC-APC FC-APC
FC-APC FC-APC X 8
FC-APC
FC-APC
FC
FC
50/50
Typ. Out of 40km transceiver = -4 to +1 dbm - SOA out +3dbm
All Optical Switch Design
Components
QPhotonics SOA1550
ComBlock COM1300 PCMCIA FPGA
Ublox LEA-4T GPS Timing Receiver
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
Components
Complete Optical Switch
SOA Controller
GPS Timing Panel
Operating Parameters Panel
Switch Scheduling Panel
Eye Pattern
Eye pattern of GbEth transmitter->25km fiber->SOA (25%Inom)->25kmfiber->RX
Inom = 200 mA
Eye Pattern
Eye pattern of GbEth transmitter->25km fiber->SOA (35%Inom)->25kmfiber->RX
Eye Pattern
Eye pattern of GbEth transmitter->25km fiber->SOA (50%Inom)->25kmfiber->RX
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!
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