Transcript energy efficient all-optical soa switch for the “green internet”

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 alloptical switches RIGHT NOW because it does not require buffers
and header processing.
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.
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C7
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10
…
90
C2
C6
Specific hardware:
1) Time Driven servers
2) Time Driven switches
C5
C3
C1
C4
Network:
1) TCP/IP can be adopted
2) Gb Eth optical can
be adopted
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10
…
90
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10
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90
Pipeline Forwarding with UTC
Factor 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
– Tf accuracy of 1µs is sufficient
UTC second
with Time
80k Time-frames
Time
Cycle0
Tf
12
Cycle
T1f
Tf
1000 1 2
1000
Time
Cycle 79
Tf
Tf
12
1000
Time-of-Day or UTC
0
1
beginning
of a UTC second
beginning
of a UTC second
Current Networking Test-bed Setup
http://dit.unitn.it/ip-flow/
GPS/GALILEO
Streaming Media
Source
Pipeline
Forwarding
router
O-E: Optical-to-Electrical (analog)
UTC
1PPS
E-O: Electrical-to-Optical (analog)
UTC
1PPS
FPGA
GPS
TDS
All-optical
Switch
Arbitrary
Distance
Arbitrary
Distance
UTC
1PPS
GPS
E-O
TDS switch
UTC
1PPS
25 km
Optical
Fiber
FPGA
O-E
Streaming
Media
25 km
Optical
Fiber
GPS
FPGA
E-O
O-E
TDS switch
Streaming
Media
All Optical Switch Design
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
FC-APC
FC-APC
FC-APC
FC-APC
OUTPUT 2 – 0 dBm
FC-APC
90
FPGA
POWER AMP
For
SOA Switch
actuation
90
+
UBLOX-T GPS
INPUT 1
MONITOR PD1
10
10
FC
Individual
Gain control
90
10
MONITOR PD2
90
LABview
environment
10
INPUT 2
internet
FC-APC
Typ. Out of 40km transceiver = -4 to +1 dbm
-
SOA out +3dbm
PC
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
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