Green Photonics in Switching - University of Melbourne
21
Green Photonics in Switching : Rod Tucker Centre for Energy-Efficient Telecommunications University of Melbourne
Transcript of Green Photonics in Switching - University of Melbourne
Green Photonics in Switching:
Rod TuckerCentre for Energy-Efficient TelecommunicationsUniversity of Melbourne
2
Po
we
r C
on
su
mp
tio
n (
W)
Year
40% p.a. Data growth
10% p.a. Growth in user numbers
Power Consumption of the Global Internet
2010 2015 2020
109
1011
1010
1012
Global electricity supply
1013
Power Consumption of Internet
(Including servers)
1.5 billion users
Source: Tucker 2012
Fixed access only
3
Inside the Network
Ethernet
Switch
OLTSplitter
Metro/Edge NetworkCore Network
Edge Routers
FTTP
FiberCore Router
Content Distribution Network
Storage
Server
Server
Storage
Fiber
Access Network
DSL
DSLAMCu
OLT
ONU
Cabinet
FTTN
DSLAM
Cu
Broadband Network Gateways
Hot
spots
PON
Data Center
4
Data Centers and Content Servers
Racksof Servers
Aggregation Switches
Load-Balancing Switches
Border Routers
RacktopSwitches
80% of traffic stays in data center
5% of traffic to other data centers
15% of traffic to users
5
Energy Consumption of Switches
Year
Source: O. Tamm et al. 2010
2005 2007 2009 2011 2013 2015 2017 20190
2
4
6
8
10
12
14
16
18
20
Ene
rgy
per
Bit
(n
J) Router
Packet switch
SDH Cross-connect
OTN Cross-connect
6
Equipment Energy Consumption Trends
1
10
100
1000
10000
1985 1990 1995 2000 2005 2010 2015
nan
o-J
ou
les
pe
r b
it
Year
Router Energy Efficiency
Cisco AGS
Wellfleet BCN
Cisco GSR 12000
Cisco GSR 12000b
Avici TSR
Cisco CRS 1
Cisco CRS-3
ALU7750
Actual improvement
may be declining
Linear fit gives ~25% improvement pa
Source: Nielsen, ECOC 2011
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Power Consumption of the Global Internet
Year
15% p.a. technology improvement
Po
we
r C
on
su
mp
tio
n (
W)
109
1011
1010
108
1012
20102015
2020
Access (PON)
Global electricity supply (3% p.a.)
TotalTotal (2010 Technology)
8
Network Energy per User Bit
Year
Energ
y p
er
User
bit (m
J)
1.0
100
0.1
10
0.01
2010 2015 2020
Total
PON
Core and Metro
Switches/Routers
Optical Transport
0.1
1
10
100
Ave
rag
e A
cce
ss R
ate
(M
b/s
)
9
Gap Between Theory and Practice
10-6
10-9
10-10
10-8
10-11
10-7
10-5
10-12
Current
Trends
Lower
Bounds
x 104
Year2010 2015 2020 2025
Netw
ork
Energ
y p
er
Bit (
J)
Transport
Switches
Transport
Access
Source: Tucker, JSTQE 2011
10-4
Global Network
10
Gap Between Theory and Practice
Source: Tucker, JSTQE 2011
Management
and control,
interconnects,
power supplies,
etc.Subsystem
ETotal
Key
Function
Overheads
Eoverheads
Loss,
Inefficiencies
Emin
minfunction
function
EE
Laser efficiency,
interconnects,
system penalties,
system margins,
etc
2 410 10min
Total
E
E
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How can Photonics Green the Internet?
• Optical bypass in the core network
– IP/OTN/WDM, IP/Ethernet, etc.
– GMPLS
• Agile optical switching in data centers and content servers
– Switching layer energy consumption
– Crosstalk and Scalability
– Some examples
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WDM LinkWDM Link
WDM
OXC
(Short Reach)
(Long Reach)
TDM
IP
~ 5 nJ/bit
~ 1 nJ/bit
<< 1 nJ/bit
Optical Bypass and GMPLS
< 1 nJ/bit
< 0.1 nJ/bit
GM
PL
SC
on
tro
ller
13
Energy savings ~ 40 - 50% can be achieved by ASON-enabled network compared to legacy IP/WDM network.
Fibre
EDFA
Core Router
WDM
TDM
IP
WDM
TDM
IP
WDM
TDM
IP
WDM
TDM
IP
WDM
TDM
IP
Core
WDM
TDM
IP
WDM
TDM
IP
IP
IP
IP
Optical Bypass in the Core
14
20
25
30
35
40
45
50
55
0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5
Po
wer
Savin
g (
%)
Mean Utilisation
Legacy
IP/SDH/WDM
IP/SDH/WDM
(GMPLS)
IP/WDM
(GMPLS)
WDM
LinksWDM
Links
IP
Patch
panel
Legacy IP/WDM
Co
ntr
ol
Elem
ent
WDM
LinksWDM
Links
IP
WDM
OXC
WDM
OXCWDM
LinksWDM
Links
IP
TDM Co
ntr
ol
Elem
ent
Patch
panelWDM
LinksWDM
Links
IP
TDM
Reference:
NSFNET 14 nodes, 21 links network, 100 wavelengths
Feng et al., OFC 2011
Optical Bypass and GMPLS
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Optical Networking in Data Centers
Servers
Optical Switch
(~1000 ports)
Border Router
RacktopSwitches
Controller
• Fast (< 10 ns)• Low crosstalk• Low power
10 – 100 Gb/s
Some Options:• Phased-array switches• SOA-based gate arrays• AWG-based switches • Micro-ring resonators
Optical
Device
Device
control
energy, Ec
Device supply power, PsupplySwitch
Energy Consumption in Optical Switch
Controller
Interface (R/C)
Interconnect
(optical/electrical)
Driversupply controllerbit c
data data
P RE E
B B
1
N
1
N
Key factors:• Loss-compensation amps • Interconnects• Drivers• Interface energy
dataB
controllerR
Analog/Digital
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4 x 104 SOA gates1000
1
3-dB Coupler
1
2
3
2
20
Crosstalk
Signal ERER> 43dB
1
1000
1
2
1000
1
2
1
1000
1:1000
splitter
1000:1
combiner
1000 splitters
1:1000
splitter
1000:1
combiner
106 SOA gates 1000 combiners
1000
1000
1000
Crosstalk
Signal ERER> 60 dB
Driver Gate
Control
Input Output
PSOA
~1SOA
driver
PW
SOA Gate ArraysBenes SOA Gate Array
Broadcast and Select SOA Gate Array
1SOA
driver
PW
30SIR dB
18
50 x 100
AWG
1,000
TWCs
20
AWGs 2,000
Interconnects
10
AWGs
200 x 200
AWG100 x 50
AWG
1,000
FWCs2,000
TWCs2,000
TWCs
1
1000
2
Driver Wavelength
Control
Input Output
TWCP
FWCP
tuneP
tune
driver
P
TWC
~ 1000 analog control lines
1
1000
12
1000
1
1000
1 x 1000
switch
~ 1000 control lines
1 x 1000
switch
1000 x 1
switch
1000 x 1
switch
12
1000
1
2
1000
12
1000
> 1
06 c
on
tro
l lin
es2
1000
Crosstalk
Signal ERER> 30 dB
Phased-Array and AWG SwitchesSpanke Phased-Array Switch
AWG Array
T. Tanemura and Y. Nakano, IEICE, 2008. (Also Workshop 1)
1
1000
Energy dominated by large numbers of analog control lines
Andrea Bianco Workshop 1
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Lee et al., IEEE Photonics Society Annual meeting, 2010
Andrea Bianco, Workshop 1
1000
1
100
2
FWCs
1
2
Dilated crosspointsControl lines
Resonance
thermal
controllers
CMOS driver
Dilated Benes Ring Resonator Switch
> 40 dB
• Crosstalk vs. loss trade-off• > 40 dB loss for 1000 x 1000 switch
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Optical Switch Technologies Compared
• 1000x1000
• No controllers
• No buffering
Bit Rate per Port (Gb/s)10 100
Energ
y p
er
Bit (
J)
AWG (3 kW)
10-7
10-8
10-9
10-10
10-11
Total power
consumption
of switch
600 W
Phased-Array Spanke
Electrical Interconnect (2 MW)
Optical Interconnect
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Conclusions
• Switching and routing is becoming a major contributor to energy consumption in the network
• GMPLS combined with optical bypass can offer modest improvements in network energy consumption
• Opportunities for Green Optical Switching in data centres
– Control and interconnect energies may dominate
– System-level analysis is necessary
– 50 Ω
