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O pen Dy namic S pectum S haring with minimal E nerg Y. Our Odyssey* towards Cognitive Radio. * 1. An extended adventurous voyage or trip. 2. An intellectual or spiritual quest. A range of technologies for a range of requirements. Many technologies share the same spectrum. 22 MHz.
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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.
Many technologies share the same spectrum 22 MHz WLAN ~15dBm 2.4 GHz 1 MHz Bluetooth 0dBm 2.4 GHz 5 MHz 2 MHz Sensors 0dBm 2.4 GHz 2.4 GHz example
Spectrum Sharing Further Classification in 4 Sub Projects 802.15.4 Low load + 802.11 802.15.4 High load + 802.11 PER: 10% Heterogeneous Capabilities Heterogeneous Capabilities Both adapt (symm) Only one adapts (asymm) Odyssey Heterogeneous Policies Heterogeneous Policies SU should Not harm PU PU-SU game Only SU acts SU QoS SU QoS 802.11 Resource Planning With priorities Punishment PU QoS PU QoS Policies/Priorities Spectrum Sharing Heterogeneous networks Time/Space/Frequency Adaptation Capabilites
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
Active observations:Gambling for the best channel • 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 PER: 5% PER: 10% PER: 50%
Multi-armed bandit theory gives us the optimal strategy 802.15.4 searches it’s best channel in ISM band (11-26)
Predicting PU idle time Switching to a channel that will remain idle longer minimizes switching overhead
Improve channel selection with efficient passive scanning Collision with 1 802.11packet AIC 802.15.4 packets Measuring interference power by Nyquist sampling is expensive (ADC cost, large amount of data to transfer) ADC Informationis only in the edges: new sampling method that converts analog signals directly into information
Spatial planningKeep-Out-Region in theory Distance SU from contour F(50,10) Desired/Undesired: 28dB for DTV Required Sensitivity F(50,90) Field Strength Contour size 41dBu
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
Spectrum Sharing Further Classification in 4 Sub Projects 802.15.4 Low load + 802.11 802.15.4 High load + 802.11 PER: 10% Heterogeneous Capabilities Heterogeneous Capabilities Both adapt (symm) Only one adapts (asymm) Odyssey Heterogeneous Policies Heterogeneous Policies SU should Not harm PU PU-SU game Only SU acts SU QoS SU QoS 802.11 Resource Planning With priorities Punishment PU QoS PU QoS Policies/Priorities Spectrum Sharing Heterogeneous networks Time/Space/Frequency Adaptation Capabilites
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
Coexistence approach does not work 802.15.4 is not expected to harm 802.11 because: • 802.15.4 output power is >15dB 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 @ 1Mbps collision because 802.15.4 sensing resolution is coarse
PU identification: which PU present on which channels we can identify different PU’s No presence 802.11 at channel 1 and 6 802.11 at channel 1 802.11 at channel 6 802.15.4
SU QoS depends on PU requirements and sensing performance SU QoS Only SU acts PU QoS Can we build a PU-SU game?
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