110 likes | 261 Views
Technology for Mobile Broadband. Bill Sullivan Managing Director, Mobile Broadband Systems Carlsbad, CA. ViaSat Background. Government Products. Antenna Systems. Consumer Broadband. VSAT Products. ViaSat Broadband in the Sky. ConneXion by Boeing Airborne transceivers
E N D
Technology for Mobile Broadband Bill Sullivan Managing Director, Mobile Broadband Systems Carlsbad, CA
ViaSat Background Government Products Antenna Systems Consumer Broadband VSAT Products
ViaSat Broadband in the Sky • ConneXion by Boeing • Airborne transceivers • Ground transceivers • SKYLink by ARINC Direct • Airborne integrated terminals including antennas • Complete ground infrastructure • 7 x 24 network ops
The Satellite Mobile Broadband Problem Waveform Design Satellite Bandwidth and Power Complex Trade-off Network Management Antenna Size & Complexity Regulatory
Key Technologies forSatellite Mobile Broadband • CDMA spread spectrum waveforms • THE enabler of mobile broadband on FSS satellites • Innovative antenna apertures • Antenna pointing & tracking • Aggressive error correction codes • Bandwidth recovery techniques • Outage mitigation features • Mobile IP networking
TDMA/FDMA CDMA Waveform Effective CDMA Spread Spectrum Waveform FDMA/TDMA Waveform FDMA/TDMA Waveform .5 Degree 6 Degree 6 Degree CDMA = Mobile at Ku-Band • Standard Ku antennas have narrow beamwidths • Small antennas needed for mobile systems too wide • CDMA waveform reduces adjacent satellite interference
Antenna Subsystems • Antenna aperture • Low profile • Small footprint • Pointing / tracking • Accuracy vs. cost • Smaller antennas can meet regulatory limits with less accuracy • Integrated design is key!! • Waveform • Network management KVH ViaSat’s CDMA waveform & network management enable these very small antennas
Waveform Design • Aggressive forward error correcting codes • Turbo, PCCC, SCCC & others • Spread spectrum • Outage mitigation • Burst CRMA • Expanded interleaving • HTTP caching • Alternate media routing
PCMA Hub Cancellation • Gateway transmits Uplink signal • Gateway cancels its received signal • Subscriber Terminal transmits a return link • Gateway receives inbound return links from remotes Return link above residual of cancelled Outbound Uplink Return link power too low to interfere with Outbound Gateway Downlink View Remote Downlink View
Mobile Broadband Future?? • Smaller & smaller antennas • Innovative system architectures • Other frequency bands? • C-band for non-maritime? • Ka-band?? • Press to reduce cost • Cheaper bandwidth • Cheaper equipment
Summary • Major shift in mobile satellite communications towards true broadband • Mainstay low-rate heritage systems (e.g., Inmarsat) will remain and evolve • New Ku systems moving rapidly to market • ViaSat will remain a key player • Innovative system architectures • Aggressive new products