communications research innovation across … communications research innovation across commercial...
TRANSCRIPT
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Communications Research Innovation Across
Commercial and Military Boundaries—
Optical Communications
27 October 2015
Bryan Robinson MIT Lincoln Laboratory
This work is sponsored by National Aeronautics and Space Administration under Air Force Contract #FA8721-05-C-0002. Opinions, interpretations, recommendations and conclusions are those of the authors and are not necessarily endorsed by the United States Government.
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Free Space Optical Communications The Promise • Extremely narrow beams with small
apertures
– Low SWaP terminals
– Enhanced security
– Requires precision pointing
• Unlimited, unregulated spectrum
– No spectrum congestion
– High data rates
– High power efficiency
– Requires high bandwidth electronic and optical processing
• Also challenges associated with developing efficient transmitters and receivers, propagation through the atmosphere…
10-cm Optical
Terminal
Lower cost, higher value missions
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Free Space Optical Communications The Challenge • Extremely narrow beams with small
apertures
– Low SWaP terminals
– Enhanced security
– Requires precision pointing
• Unlimited, unregulated spectrum
– No spectrum congestion
– High data rates
– High power efficiency
– Requires high bandwidth electronic and optical processing
• Also challenges associated with developing efficient transmitters and receivers, propagation through the atmosphere…
10-cm Optical
Terminal
Lower cost, higher value missions
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Free Space Optical Communications Demonstrations
2004 2006 2008 2010 2012 2014 2015+ 2002 < 2002
SILEX (ESA) 50 Mbps LEO-GEO
2001
LCE (Japan) GEO-Ground
1995
GEOLITE (MITLL) GEO-Ground
2001
ALEX (MITLL) Air-GEO
2002
OICETS (Japan) LEO-GEO 50 Mbps
LEO-Ground 2005
LOLA (France) 50 Mbps
2006
NFIRE/TerraSar (ESA/FRG/MDA)
LEO-LEO 5.6 Gbps 2008
FOCAL (SAF/MITLL) Air-Ground 2.5 Gbps
2009
FALCON (AFRL) Air-Ground 2.5 Gbps
2010
FOENEX (DARPA) Air-Air 10 Gbps
Air-Ground 2012
LLCD (NASA/MITLL) Moon-Ground 622 Mbps
2013
OPALS (NASA/JPL) 2014
Alphasat (ESA) GEO-LEO 1.8 Gbps 2013-14
SOTA (Japan) 2014
OSIRIS (DLR) 2015
EDRS/Sentinal (ESA) 2015
Adapted from D.M. Boroson, “Laser Communications,” ICSSC 2014 Colloquium.
HY-2 (China) LEO-Ground, 504 Mbps
LCRD (NASA) 2018
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Free Space Optical Communications Demonstrations
2004 2006 2008 2010 2012 2014 2015+ 2002 < 2002
SILEX (ESA) 50 Mbps LEO-GEO
2001
LCE (Japan) GEO-Ground
1995
GEOLITE (MITLL) GEO-Ground
2001
ALEX (MITLL) Air-GEO
2002
OICETS (Japan) LEO-GEO 50 Mbps
LEO-Ground 2005
LOLA (France) 50 Mbps
2006
NFIRE/TerraSar (ESA/FRG/MDA)
LEO-LEO 5.6 Gbps 2008
FOCAL (SAF/MITLL) Air-Ground 2.5 Gbps
2009
FALCON (AFRL) Air-Ground 2.5 Gbps
2010
FOENEX (DARPA) Air-Air 10 Gbps
Air-Ground 2012
LLCD (NASA/MITLL) Moon-Ground 622 Mbps
2013
OPALS (NASA/JPL) 2014
Alphasat (ESA) GEO-LEO 1.8 Gbps 2013-14
SOTA (Japan) 2014
OSIRIS (DLR) 2015
EDRS/Sentinal (ESA) 2015
Adapted from D.M. Boroson, “Laser Communications,” ICSSC 2014 Colloquium.
HY-2 (China) LEO-Ground, 504 Mbps
LCRD (NASA) 2017
Operational
Lasercom has been successfully
demonstrated in a wide range of
applications.
All major engineering challenges have
been solved.
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Nature of Demonstrations to Date
• Government funded
• Some pathfinder demonstrations by Government labs
• Some Government-directed industry development
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BSR 8/19/14 DO - 7
Lunar Laser Communication Demonstration NASA’s First Lasercom Demonstration (2013-2014)
Tech demo on NASA’s Lunar Atmosphere and Dust Environment Explorer (LADEE) • Longest lasercom link ever
• Error-free comm through the atmosphere
• 622 Mbps downlink from moon
• 20 Mbps uplink to moon
Ground Terminal
Space Terminal
• System and terminals
designed, assembled, tested
and operated by MITLL
(FFRDC) for NASA
• Subsystems built from COTS
components (1.55 µm fiber
telecom components for
transceiver)
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Lasercom Technology Transition
Multi-Rate DPSK Modem
Optical Module
(based on LLCD design)
Optical
Subassembly
Laboratory Hardware &
IP Development
Inertially Stable
Platform
Gimbal
and Latch
Solar Window
Assembly
Pointing
Processor
NASA Laser Communication Relay
Demo (LCRD)
Technology Transition
to Industry
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• Optical LEO-GEO relay with Ka-band downlink
• Optical terminals developed by industry (TESAT) with funding from DLR/ESA
– Utilizes industry components (1 µm) with commitments to maintaining processes for space applications
• First LEO-LEO intersatellite optical links demonstrated in 2008 (TerraSAR-NFIRE)
• First LEO-GEO intersatellite optical links demonstrated in October 2014 (Sentinal 1A-Alphasat)
• Many more LEO and GEO terminals in progress…
European Data Relay System (EDRS)
Image Source: http://www.esa.int/spaceinimages/Images/2012/05/Das_LCT-Terminal_von_Tesat_Spacecom
Image Source: http://www.esa.int/spaceinimages/Images/2014/06/European_Data_Relay_System_EDRS
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Technology Exchange between Free-Space Optical
Communications and Fiber Telecom Industry
• In general, FSO development has lead in the adoption of techniques for increasing the power efficiency of optical comm systems – Power efficient modulation (DPSK, BPSK, PPM, …)
– Forward error correction
• Telecom industry has lead in component development and integration – Large volumes
– Widely adopted industry standards (e.g. Telcordia) provide high-reliability components and systems
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Evolution of Fiber Telecom Transceiver Technolgy
Space community can leverage the billions of dollars spent in the Telecom fiber industry
10G OOK telecom fiber line card for 1550 nm
40G MSA optical transceiver module for 1550 nm
Timeline 2000 2010 2015
100G coherent CFP2 optical transceiver
module for 1550 nm
Reduced SWAP and increase in performance
Potential path for low cost space based operational systems
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• International standards for free space optical communications are being developed by the CCSDS
– High data rate (near Earth)
– Low photon flux (deep space)
– Low complexity
• Present emphasis in standards process is on interoperability of costly shared assets
– Ground terminals for deep space
– Optical relays near Earth
Free Space Lasercom Standards Development
“The maturity of onboard space terminals that are already realized (e.g., for Earth relay inter-satellite links) or are in preparation as demonstrations (e.g., for Moon-to-Earth links through the Earth atmosphere) now requires that economical ground segment solutions be identified for potential future operational implementations.”
– IOAG Optical Link Study Group Final Report (2012)
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Commercial Global Internet Initiatives
– UAV-based internet connectivity
– Optical interconnects between drones
• Project Loon (Google)
– Balloon-based internet connectivity
– Interest in lasercom inferred from recent patent applications and recruiting efforts
• SpaceX/Google
– “[Elon Musk] has discussed using optical-laser technology in his satellites, according to a person familiar with the matter.” (WSJ, 1/19/15)
• OneWeb
– Developing network of satellites for world-wide communications services
• …
Image Source: oneweb.world
Image Source: www.google.com/loon:
Image Source: newsroom.fb.com:
Large scale commercial ventures may have
significant impact in developing
affordable optical communications link
technology
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• Lasercom has been successfully demonstrated for a wide range of applications
– Major engineering challenges have been addressed in a variety of ways
• Making the transition from prototype/pathfinder demonstrations to operational systems has been challenging
• Developing clear roadmaps for Government use of lasercom technology and adopting standards may help to stimulate industry development of supporting technologies
• Recent commercial initiatives may lead to reduced costs for future lasercom systems
Summary Comments
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COTS Active and Passive
Components, Sub-Systems and Systems
• Use of COTS sub-systems can
potentially reduce mission costs
• Need to follow the evolution of the
Telecom market
4.7”
5.0”
2” 1”
4” 1”
Components
Sub-systems
Systems
WDM Photo-detector Modulator Laser
Transceiver EDFA
Networking