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Technology for Mobile Broadband
Bill SullivanManaging Director, Mobile Broadband Systems
Carlsbad, CA
Satellite ForumViaSat BackgroundViaSat Background
VSAT Products
AntennaSystems
Consumer Broadband
GovernmentProducts
Satellite ForumViaSat Broadband in the SkyViaSat 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
Satellite Forum
The Satellite Mobile Broadband ProblemThe Satellite Mobile Broadband Problem
Downlink Power Spectrum
-40
-35
-30
-25
-20
-15
-10
-5
0
-20 -15 -10 -5 0 5 10 15 20
Frequency Offset from Carrier Center (Mhz)
Pow
er D
ensi
ty (
dBc)
ComplexTrade-off
SatelliteBandwidth and Power
Waveform Design
Network Management
AntennaSize &
Complexity
Regulatory
Satellite Forum
Key Technologies forSatellite Mobile BroadbandKey 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
Satellite Forum
TDMA/FDMACDMA
Waveform
.5 Degree
CDMA = Mobile at Ku-BandCDMA = Mobile at Ku-Band Standard Ku antennas
have narrow beamwidths
Small antennas needed for mobile systems too wide
CDMA waveform reduces adjacent satellite interference
FDMA/TDMAWaveform
6 Degree
EffectiveCDMASpread
SpectrumWaveform
FDMA/TDMAWaveform
6 Degree
Satellite ForumAntenna SubsystemsAntenna Subsystems
KVH
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
ViaSat’s CDMA waveform & network managementenable these very small antennas
Satellite ForumWaveform DesignWaveform Design
Aggressive forward error correcting codes Turbo, PCCC, SCCC & others
Spread spectrum
Outage mitigation Burst CRMA Expanded interleaving HTTP caching Alternate media routing
Downlink Power Spectrum
-40
-35
-30
-25
-20
-15
-10
-5
0
-20 -15 -10 -5 0 5 10 15 20
Frequency Offset from Carrier Center (Mhz)
Pow
er D
ensi
ty (
dBc)
Satellite ForumPCMA Hub Cancellation
Gateway Downlink View Remote Downlink View
Gateway transmits Uplink signalGateway transmits Uplink signal Gateway cancels its received signalGateway cancels its received signal Subscriber Terminal transmits a return linkSubscriber Terminal transmits a return link
Return link power too low to interfere with Outbound
Return link above residual of cancelled Outbound Uplink
Gateway receives inbound return links from remotesGateway receives inbound return links from remotes
Satellite ForumMobile Broadband Future??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
Satellite ForumSummarySummary
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