John Guttag

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Virtual Radios for Adaptive Application-Specific N
etworking

• John Guttag
• Networks and Mobile Systems Group
• MIT LCS

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Adaptive Wireless Networking

• Goal Better communication (not better networks)
• Customize network on-the-fly
• Application-specific and condition-specific
• Different applications have different
  requirements
• Bandwidth, latency, error rate, security
• In a wireless network channel conditions
• Vary significantly over time
• Can be hard to predict
• Design for the actual case
• Not the worst (or even the average) case
• Oxygen couples applications and communications
• Provides perfect venue for adaptive networking

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Digital Communication
Many-one
One-one

• Only the channel is out of our control

Source
Source Encoder
Channel Encoder
Channel
One-many
One-one
Many-one
Sink
Source Decoder
Channel Decoder
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An Adaptive Wireless Network Interface
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From Physical Radios to Virtual Radios
SpectrumWare Radio
Edisons Radio
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0.0 OutputDataImag 0.0
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index) bsin(TwoPi CenterFreq /
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OutputDataImag ((float)pdata ImagTapk)
...
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Ideal Software Radio
Wideband Antenna
Wideband ADC
Processor and Memory
A/D
D/A
RF Power Amp
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SpectrumWare Virtual Radio
PC
AMPS
TV
Patch Panel
PSpectra Environment
Wideband IF (33MSPS)
Linux
Multiband Frontend
A/D,D/A GuPPI
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A Short Demonstration
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Research Goals

• Explore uses of communication between layers
• Adapt protocol based on transmission channel
• Adapt transmission to needs of protocol
• Explore issues related to mobility
• Configuration of ad hoc networks, security
• Including across multiple networks
• Explore issues related to dynamic resource
  allocation
• Especially energy and spectrum
• Explore application-specific networking at all
  levels
• Waveforms to services

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Some Deliverables

• Development environment for signal processing
• Useful for both software physical layers and
  applications
• Novel algorithms
• Digital communications
• API connecting physical and higher layers
• Coordinated adaptation on a single node
• Mechanisms for coordinating adaptation across
  nodes
• Basically a protocol problem
• Prototype application
• Exploring medical applications with Center for
  Minimally Invasive Therapies at Partners Health
  Care