Open Dynamic Spectum Sharing with minimal EnergY

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Open Dynamic Spectum Sharing with minimal EnergY

• Our Odyssey towards
• Cognitive Radio

1. An extended adventurous voyage or trip. 2.
An intellectual or spiritual quest.
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A range of technologiesfor a range of
requirements
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Many technologies share the same spectrum
2.4 GHz example
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Spectrum Sharing Further Classification in 4 Sub
Projects
Policies/Priorities
Spectrum Sharing Heterogeneous networks
Time/Space/Frequency
Adaptation Capabilites
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Capturing context or spectrum information is
costly

• Active observations try out a configuration
• trade-off between
• exploitation
• and
• exploration
• Passive observations
• Require extra hardware or introduce delay
• Energy costly

Required BW
Channel Sequence
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Active observationsGambling for the best channel
PER 5
PER 10
PER 50

• Just send packets and learn the best performing
  channel
• No (wrong) model, no (false) assumptions, perfect
  adaptation to any situation
• If you do not have to obey a policy rule

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Multi-armed bandit theory gives us the optimal
strategy
802.15.4 searches its best channel in ISM band
(11-26)
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Predicting PU idle time
Switching to a channel that will remain idle
longer minimizes switching overhead
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Improve channel selection with efficient passive
scanning

• Measuring interference power by Nyquist sampling
  is expensive (ADC cost, large amount of data to
  transfer)

ADC
Information is only in the edges new sampling
method that converts analog signals directly
into information
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What is the best multichannel MAC design?
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Spatial planningKeep-Out-Region in theory
F(50,90)
Field Strength
Contour size
41dBu
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Pathloss trend in reality
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Resulting Spatial Reuse much improved
SU QoS
Only SU acts
PU QoS
Proposed a run-time technique to predict and
flood pathloss trends and coverage
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SU sensing requirements as function of SU density
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Spectrum Sharing Further Classification in 4 Sub
Projects
Policies/Priorities
Spectrum Sharing Heterogeneous networks
Time/Space/Frequency
Adaptation Capabilites
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Are there scenarios where both 802.15.4 and
802.11 want to adapt

• 802.15.4 harms 802.11 in measurements

802.15.4 on then 802.11 throughput down
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Coexistence approach does not work

• 802.15.4 is not expected to harm 802.11 because
• 802.15.4 output power is gt15dB lower than 802.11
• 802.15.4 does a listen-before-send

802.15.4 packet train paused for 802.11
transmission 802.15.4 detects 802.11
802.11 packet _at_ 1Mbps
collision because 802.15.4 sensing resolution is
coarse
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PU identification which PU present on which
channels
we can identify different PUs
No presence
802.11 at channel 1 and 6
802.11 at channel 1
802.11 at channel 6
802.15.4
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SU QoS depends on PU requirements and sensing
performance
SU QoS
Only SU acts
PU QoS

• Can we build a PU-SU game?

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Open Dynamic Spectrum Sharing with minimal Energy

• Contibutors
• UC Berkeley
• Maryam,Youwei, Ian, Carl, Mehdi, Nikhil, Wilson
• IMEC
• Michael
• TU Delft
• Przemek
• VTT
• Marko
• Stanford University
• Ali, Bart