wifi signal emitter identification
DESCRIPTION
Using the GNURadio and USRP to analyze 802.11 traffic.TRANSCRIPT
802.11 Signal Emitter Identification
2007
Joel Kenny
A Double Edged Sword
• Security Enhancement– Transparent Identification– Difficult to Circumvent
• Implications for Privacy– Less of it
The ConstellationQuadrature
In-Phase
Phase Error
Fig. 2: Change in Magnitude
Fig. 3: Change in Phase
Magnitude Error
Signal Emitter Identification
• Define Features of Transmissions
• Measure Captured Transmissions
• Use a Database to Profile Transmitters
IQ O
ffset
Phase Error
Fig. 4: IQ Offset vs. Phase Error
GNU Radio PlatformComputer Running GNU Radio
USRP
usrp_src Blocks
USB
MoreBlocks
usrp_sink
SignalSink
SignalSource
Fig. 5: Photograph of the Universal Software Radio Peripheral
802.11 Signal CaptureComputer Running GNU Radio
USRP
usrp_src DemodulationChain
USB
802.11Packets
BasebandSignal
Timestamp
Fig. 5: Photograph of the Universal Software Radio Peripheral
Best Metrics
• Phase Error
• Magnitude Error
• IQ Offset
• Frequency Error
Results / Work In Progress
• Preliminary Success with GNU Radio
Future Research
• Development of New Metrics
• Multiple USRPs
• Research on Channel Characteristics