Communications Research Innovation Across Commercial and Military Boundaries Optical Communications

Transcription

1 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 #FA C Opinions, interpretations, recommendations and conclusions are those of the authors and are not necessarily endorsed by the United States Government. 1

2 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 2 Lower cost, higher value missions

3 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 3 Lower cost, higher value missions

4 Free Space Optical Communications Demonstrations < 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 FOCAL (SAF/MITLL) Air-Ground 2.5 Gbps 2009 FALCON (AFRL) Air-Ground 2.5 Gbps 2010 HY-2 (China) LEO-Ground, 504 Mbps LLCD (NASA/MITLL) Moon-Ground 622 Mbps 2013 OPALS (NASA/JPL) 2014 Alphasat (ESA) GEO-LEO 1.8 Gbps OSIRIS (DLR) 2015 EDRS/Sentinal (ESA) 2015 SILEX (ESA) 50 Mbps LEO-GEO 2001 NFIRE/TerraSar (ESA/FRG/MDA) LEO-LEO 5.6 Gbps 2008 Adapted from D.M. Boroson, Laser Communications, ICSSC 2014 Colloquium. FOENEX (DARPA) Air-Air 10 Gbps Air-Ground 2012 SOTA (Japan) 2014 LCRD (NASA)

5 Free Space Optical Communications Demonstrations < 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 LLCD (NASA/MITLL) Moon-Ground 622 Mbps 2013 Lasercom has FOCAL been (SAF/MITLL) successfully Air-Ground 2.5 Gbps demonstrated in a wide range of 2009 applications. OPALS (NASA/JPL) 2014 All major engineering FALCON challenges (AFRL) have Air-Ground 2.5 Gbps been solved HY-2 (China) LEO-Ground, 504 Mbps Alphasat (ESA) GEO-LEO 1.8 Gbps OSIRIS (DLR) 2015 EDRS/Sentinal (ESA) 2015 SILEX (ESA) 50 Mbps LEO-GEO 2001 NFIRE/TerraSar (ESA/FRG/MDA) LEO-LEO 5.6 Gbps 2008 Adapted from D.M. Boroson, Laser Communications, ICSSC 2014 Colloquium. FOENEX (DARPA) Air-Air 10 Gbps Air-Ground 2012 SOTA (Japan) 2014 LCRD (NASA) 2017 Operational 5

6 Nature of Demonstrations to Date Government funded Some pathfinder demonstrations by Government labs Some Government-directed industry development 6

7 Lunar Laser Communication Demonstration NASA s First Lasercom Demonstration ( ) 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 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) 7 Space Terminal BSR 8/19/14 DO - 7

8 Lasercom Technology Transition NASA Laser Communication Relay Demo (LCRD) Laboratory Hardware & IP Development Optical Module (based on LLCD design) Pointing Processor Multi-Rate DPSK Modem Technology Transition to Industry Optical Subassembly Inertially Stable Platform Gimbal and Latch Solar Window Assembly 8

9 European Data Relay System (EDRS) Optical LEO-GEO relay with Kaband 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 Image Source: 9 Image Source:

10 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 10

11 Evolution of Fiber Telecom Transceiver Technolgy 10G OOK telecom fiber line card for 1550 nm 40G MSA optical transceiver module for 1550 nm Reduced SWAP and increase in performance 100G coherent CFP2 optical transceiver module for 1550 nm Timeline Space community can leverage the billions of dollars spent in the Telecom fiber industry 11 Potential path for low cost space based operational systems

12 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) 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 12

13 Commercial Global Internet Initiatives Facebook 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: newsroom.fb.com: Image Source: Large scale commercial ventures may have significant impact in developing affordable optical communications link technology Image Source: oneweb.world 13

14 Summary Comments 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 14

15 COTS Active and Passive Components, Sub-Systems and Systems Systems Use of COTS sub-systems can potentially reduce mission costs Need to follow the evolution of the Telecom market Networking Transceiver Sub-systems 5.0 EDFA 4.7 WDM 2 Components Photo-detector Modulator Laser